United Slates
f nvironmantal Protection
Agency
Effluent Guidelines Division
WH-552
Washington DC 20460
EPA 440/1-83/091
June 1983
Development
Document for
Effluent Limitations
Guidelines and
Standards for the
Metal Finishing
Point Source Category
-------
DEVELOPMENT DOCUMENT
for
EFFLUENT LIMITATIONS GUIDELINES
NEW SOURCE PERFORMANCE STANDARDS
for the
METAL FINISHING
POINT SOURCE CATEGORY
William D. Ruckelshaus
Administrator
Steven Schatzow
Director, Office of Water Regulations and Standards
Jeffery Denit
Director. Effluent Guidelines Division
Edward Stigall, P.E.
Chief, Inorganic Chemicals Branch
Richard Kinch
Project Officer
June 1983
Effluent Guidelines Division
Office of Water Regulations and Standards
U.S. Environmental Protection Agency
Washington, D.C. 20406
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TABLE OF CONTENTS
TITLE PAGE
I. CONCLUSIONS I-I
II. RECOMMENDATIONS II-1
III. INTRODUCTION III-l
LEGAL AUTHORITY III-l
GUIDELINE DEVELOPMENT SUMMARY II1-3
Sources of Industry Data II1-4
Utilization of Industry Data 111-15
INDUSTRY DESCRIPTION II1-16
Unit Operations Descriptions 111-21
IV. INDUSTRY CATEGORIZATION IV-1
INTRODUCTION IV-1
CATEGORIZATION BASIS IV-1
EFFLUENT LIMITATION BASE IV-7
V. WASTE CHARACTERIZATION V-l
INTRODUCTION V-l
WATER USAGE IN THE METAL FINISHING CATEGORY V-l
Water Usage by Operations V-3
Water Usage by Waste Type V-8
WASTE CHARACTERISTICS FROM METAL
FINISHING UNIT OPERATIONS V-15
Electroplating V-15
Electroless Plating V-31
in
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TABLE OF CONTENTS (CONT)
TITLE PAGE
Anodizing V-31
Coating V-37
Etching V-38
Cleaning V-41
Machining V-43
Grinding V-43
Polishing V-44
Barrel Finishing V-44
Burnishing V-44
Impact Deformation. Pressure
Deformation, and Shearing V-44
Heat Treating V-45
Thermal Cutting V-46
Welding. Brazing. Soldering,
Flame Spraying V-46
Other Abrasive Jet Machining V-46
Electrical Discharge Machining V-46
Electrochemical Machining V-46
Laminating V-47
Hot Dip Coating V-47
Salt Bath Descaling V-47
Solvent Degreasing V-47
Paint Stripping V-48
Painting, Electropainting,
Electrostatic Painting V-48
Testing V-49
Mechanical Plating V-49
Printed Circuit Board Manufacturing V-49
CHARACTERISTICS OF WASTE TYPE STREAMS V-50
Total Plant Raw Waste Discharged
To End-of-Pipe Treatment V-57
Common Metals Waste Type V-59
Precious Metals Waste Type V-59
Complexed Metals Waste Type V-59
Cyanide Waste Type V-59
Hexavalent Chromium Waste Type V-59
Oily Waste Type V-63
Toxic Organics Waste Type V-63
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TABLE OF CONTENTS (CONT)
TITLE PAGE
VI. SELECTION OF POLLUTANT PARAMETERS VI-1
INTRODUCTION VI-1
SELECTION RATIONALE VI-1
Toxic Organic Pollutants VI-1
Non-Toxic Metals VI-2
Other Pollutants VI-3
POLLUTANT PARAMETERS SELECTED VI-3
VII. CONTROL AND TREATMENT TECHNOLOGY VII-1
INTRODUCTION VII-1
APPLICABILITY OF TREATMENT TECHNOLOGIES VII-4
TREATMENT OF COMMON METALS WASTES VI1-8
Introduction VI1-8
Treatment of Common Metal Wastes -
Option 1 VI1-8
Hydroxide Precipitation VII-10
Sedimentation VI1-12
Common Metals Waste Treatment
System Operation - Option 1 vil-17
Common Metals Waste Treatment
System Performance - Option 1 VI1-20
Treatment of Common Metals Wastes -
Option 2 VI1-48
Granular Bed Filtration VII-48
Diatomaceous Earth Filtration VI1-53
Common Metals Waste Treatment
System Operation - Option 2 VI1-55
Treatment of Common Metals Wastes -
Option 3 VI1-72
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TABLE OF CONTENTS (CONT)
TITLE PAGE
Cadmium Background Level VI1-73
Evaporation VI1-76
Ion Exchange VI1-80
Alternative Treatment Methods for
for Common Metals Removal VI1-86
Peat Adsorption VI1-86
Insoluble Starch Xanthate VII-88
Sulfide Precipitation VII-89
Flotation VII-93
Membrane Filtration VII-98
TREATMENT OF PRECIOUS METAL WASTES -
SINGLE OPTION VII-100
Introduction VII-100
Treatment Techniques VII-100
Option 1 Common Metals System VII-100
Evaporation VII-100
Ion Exchange VI1-102
Electrolytic Recovery VI1-102
TREATMENT OF COMPLEXED METAL WASTES VII-104
Introduction VII-104
TREATMENT TECHNIQUES VI1-112
High pH Precipitation/Sedimentation VI1-112
Chemical Reduction - Precipitation/
Sedimentation VI1-113
Membrane Filtration VI1-113
Ferrous Sulfate (FeSO4>
Precipitation/Sedimentation VII-114
Ion Exchange VI1-114
TREATMENT OF HEXAVALENT CHROMIUM WASTES
SINGLE OPTIOM VII-115
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TABLE OF CONTENTS (CONT)
TITLE PAGE
Introduction VII-115
Recommended Hexavalent Chromium
Treatment Techniques VII-115
Chemical Chromium Reduction VII-115
Alternative Hexavalent Chromium
Treatment Techniques VI1-120
Electrochemical Chromium Reduction VI1-120
Electrochemical Chromium
Regeneration VII-123
Evaporation VII-124
Ion Exchange VII-124
TREATMENT OF CYANIDE WASTES - SINGLE OPTION VI1-126
Introduction VII-126
Recommended Treatment Techniques VII-126
Oxidation by Chlorination VII-126
Alternative Cyanide Treatment Techniques VI1-144
Oxidation by Ozonation VI1-144
Oxidation by Ozonation with UV
Radiation VII-148
Oxidation by Hydrogen Peroxide VII-150
Electrochemical Cyanide Oxidation VII-151
Chemical Precipitation (Ferrous Sulfate) VII-153
Evaporation VII-153
TREATMENT OF OILY WASTES VI1-155
Introduction VII-155
Treatment of Oily Wastes for
Combined Wastewater VI1-156
Combined Wastewater Performance for
Oils - Option 1 Common Metals System VII-156
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TABLE OF CONTENTS (CONT)
TITLE PAGS
Combined Wastewater Performance for
Oils - Option 2 Common Metals System VI1-159
Treatment of Segregated Oily Wastes VI1-161
Segregated Oil Waste Treatment
System - Option 1 VI1-162
Emulsion Breaking VII-162
Skimming VII-167
Segregated Oily Waste Treatment
System Performance for Oils -
Option 1 VII-169
Segregated Oily Wastes Treatment
System - Alternative to
Option 1 VII-172
Ultrafiltration VII-172
Segregated Oily Waste Treatment
System Performance
Alternative to Option 1 VI1-177
Segregated Oily Waste Treatment
System - Polishing Techniques VI1-178
Reverse Osmosis VI1-178
Additional Oily Waste Treatment
Technologies VII-180
Coalescing VII-180
Flotation VII-183
Centrifugation VII-185
Integrated Adsorption VII-186
Thermal Emulsion Breaking VI1-187
CONTROL AND TREATMENT OF TOXIC ORGANICS VI1-190
Introduction VII-190
Waste Solvent Control Options VII-190
Waste Solvent Segregation VII-190
Contract Hauling VII-190
Cleaning Alternatives to
Solvent Degreasing VII-191
Vlll
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TABLE OF CONTENTS (CONT)
TITLE PAGE
Treatment of Toxic Organics for
Combined Wastewater VI1-197
Treatment of Toxic Organics in
Segregated Oily Waste VII-205
Additional Treatment Methods for
Toxic Organics Removal VII-208
Carbon Adsorption VII-209
Reverse Osmosis VII-217
Resin Adsorption VII-218
Ozonation VII-219
Chemical Oxidation VII-220
Aerobic Decomposition VII-221
TREATMENT OF SLUDGES VII-229
Introduction VII-229
Treatment Techniques VI1-230
Gravity Sludge Thickening VII-230
Pressure Filtration VII-232
Vacuum Filtration VII-235
Centrifugation VII-238
Sludge Bed Drying VII-241
Sludge Disposal VII-243
IN-PROCESS CONTROL TECHNOLOGY VI1-245
Introduction VII-245
Control Techniques VII-245
Flow Reduction Through Efficient
Rinsing VII-245
Process Bath Conservation VII-251
Oily Waste Segregation VII-253
Process Bath Segregation VII-254
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TABLE OF CONTENTS (CONT)
TITLE PAGE
Process Modification VII-254
Cutting Fluid Cleaning VII-255
Integrated Waste Treatment VI1-257
Good Housekeeping VII-257
STATISTICAL ANALYSIS VI1-260
Introduction VII-260
Data VII-260
Statistical Calculations VII-260
Daily Variability VII-260
Monthly Average Variability VI1-261
Long Term Averages VI1-262
Effluent Limits VII-262
VIII. COST OF WASTEWATER CONTROL AND TREATMENT VIII-1
INTRODUCTION VIII-1
COST ESTIMATION METHODOLOGY VIII-1
Cost Estimation Input Data VII1-2
System Cost Computation VII1-4
Treatment Component Models VII1-7
Cost Factors and Adjustments VII1-9
Subsidiary Costs VIII-10
COST ESTIMATES FOR INDIVIDUAL TREATMENT
TECHNOLOGIES VII1-13
Cyanide Oxidation VII1-14
Chromium Reduction VII1-19
x
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TABLE OP CONTENTS (CONT)
TITLE PAGE
Chemical Precipitation and Settling VIII-24
Chemical Emulsion Breaking ¥111-30
Holding Tanks VII1-33
Multimedia Filtration VIII-36
Ultrafiltration VIII-36
Carbon Adsorption VIII-42
Sludge Drying Beds VII1-46
Vacuum Filtration VII1-51
Countercurrent Rinsing VIII-51
Contract Removal VII1-58
RCRA COST ANALYSIS VI11-62
TREATMENT SYSTEM COST ESTIMATES VII1-63
System Cost Estimates (Option 1) VI11-64
System Cost Estimates (Option 2) VI11-80
System Cost Estimates (Option 3) VIII-80
Use of Cost Estimation Results VIII-80
IN-PROCESS FLOW REDUCTIONS VII1-105
ECONOMIC IMPACT ANALYSIS OF SYSTEM
COST ESTIMATES VI11-105
ENERGY AND NON-WATER QUALITY ASPECTS VI11-106
Energy Aspects VII1-106
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TABLE OF CONTENTS (CONT)
TITLE PAGE
Non-Water Quality Aspects VII1-106
IX. BEST PRACTICABLE CONTROL TECHNOLOGY
CURRENTLY AVAILABLE IX-1
INTRODUCTION IX-1
IDENTIFICATION OF BPT IX-1
RATIONALE FOR THE SELECTION OF BPT IX-4
BPT LIMITATIONS IX-5
PRESENT COMPLIANCE WITH BPT IX-6
BENEFITS OF BPT IMPLEMENTATION IX-7
X. BEST AVAILABLE TECHNOLOGY ECONOMICALLY
ACHIEVABLE X-l
INTRODUCTION X-l
IDENTIFICATION OF BAT X-l
RATIONALE FOR SELECTION OF BAT X-3
BAT LIMITATIONS X-3
PRESENT COMPLIANCE WITH BAT X-4
BENEFITS OF BAT IMPLEMENTATION X-4
XI. NEW SOURCE PERFORMANCE STANDARDS XI-1
INTRODUCTION XI-1
IDENTIFICATION OF NSPS XI-1
RATIONALE FOR SELECTION OF NSPS TECHNOLOGY XI-3
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TABLE OF CONTENTS (CONT)
TITLE PAGE
NSPS LIMITATIONS XI-3
PRESENT COMPLIANCE WITH NSPS XI-4
BENEFITS OF NSPS IMPLEMENTATION XI-5
XII. PRETR1ATMENT STANDARDS XII-1
INTRODUCTION XII-1
IDENTIFICATION OF PRETREATMENT TECHNOLOGY XII-1
RATIONALE FOR SELECTION OF PRETREATMENT
TECHNOLOGY XII-1
PRETREATMENT STANDARDS XII-2
PRESENT COMPLIANCE WITH PRETREATMENT
STANDARDS XII-2
BENEFITS OF IMPLEMENTATION XI1-2
XIII. INNOVATIVE TECHNOLOGY XIII-1
INTRODUCTION XIII-1
INNOVATIVE TECHNOLOGY CANDIDATES XII1-2
Electrodialysis XIII-3
Advanced Electrodialysis XII1-7
Water Reducing Controls for
Electroplaters XIII-10
XIV. ACKNOWLEDGEMENT XIV-1
XV. REFERENCES XV-1
XVI. GLOSSARY XVI-1
APPENDIX A A-l
Exhibit l~ Statistical Analysis of Cadmium A-l
(except new sources). Chromium.
Copper, Lead, Nickel, Silver, Zinc.
Cyanide. TSS. and Oil and Grease
Exhibit 2- Analysis of Total Toxic Organics A-15
(TTO) Data
Exhibit 3- Analysis of New Source Cadmium A-41
Data
x±±i
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LIST OF FIGURES
NUMBER TITLE
3-1 Metal Finishing Process Application 111-20
4-1 Waste Treatment Schematic IV-3
5-1 Flow Distribution Within the
Metal Finishing Category V-7
5-2 Waste Treatment Schematic V-51
7-1 Waste Treatment Schematic VI1-2
7-2 Treatment of Common Metals
Wastes - Option 1 VII-9
7-3 Precipitation and Sedimentation VII-11
7-4 Solubilities of Metal Hydroxides
as a Function of pH VII-13
7-5 Representative Types of Sedimentation VI1-14
7-6 Treatment Scheme - Option 1 VI1-21
7-7 Clarifier TSS Distribution VII-22
7-8 Waste Treatment Scheme - Option 2 VI1-49
7-9 Granular Bed Filtration Example VII-51
7-10 Effluent TSS Concentrations vs. Raw
Waste Concentrations - Option 2 VI1-58
7-11 Effluent Cadmium Concentrations vs. Raw
Waste Concentrations - Option 2 VII-59
7-12 Effluent Chromium Concentrations vs. Raw
Waste Concentrations - Option 2 VI1-60
XIV
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LIST OF FIGURES (Continued)
NUMBER TITLE PAGE
7-13 Effluent Copper Concentrations vs. Raw
Waste Concentrations - Option 2 VI1-61
7-14 Effluent Lead Concentrations vs. Raw
Waste Concentrations - Option 2 VI1-62
7-15 Effluent Nickel Concentrations vs. Raw
Waste Concentrations - Option 2 VI1-63
7-16 Effluent Zinc Concentrations vs. Raw
Waste Concentrations - Option 2 VI1-64
7-17 Cadmium Raw Waste Concentration
Distribution VII-75
7-18 Types of Evaporation Equipment VI1-77
7-19 Ion Exchange with Regeneration VII-81
7-20 Comparative Solubilities of Metal
Sulfides as a Function of pH VI1-90
7-21 Dissolved Air Flotation VII-94
7-22 Observed Evaporation System at
Plant ID 06090 VII-103
7-23 Hexavalent Chromium Reduction with
Sulfur Dioxide VII-117
7-24 Effluent Hexavalent Chromium
Concentrations vs. Raw Waste
Concentrations VII-118
7-25 Treatment of Cyanide Waste by
Alkaline Chlorination VII-127
7-26 Typical Ozonation Plant for
Waste Treatment VI1-145
7-27 UV/Ozonation VII-149
xv
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LIST OF FIGURES (Continued)
NUMBER TITLE PAGE
7-28 Effluent Oil and Grease Concentrations
vs. Raw Waste Concentrations - Option 2
Common Metals Data Base VI1-160
7-29 Treatment of Segregated Oily Wastes -
Option 1 ¥11-163
7-30 Typical Emulsion Breaking/Slimming
System ¥11-164
7-31 Segregated Oil and Grease Effluent
Performance - Option 1 ¥11-170
7-32 Treatment of Segregated Oily Wastes
Alternative to Option 1 ¥11-173
7-33 Simplified Ultrafiltration Flow
Schematic ¥11-174
7-34 Treatment of Segregated Oil Wastes
Polishing Techniques ¥11-179
7-35 Coalescing Gravity Separator ¥11-181
7-36 Typical Dissolved Air Flotation System ¥11-184
7-36a Thermal Emulsion Breaker ¥11-188
7-37 Alkaline Wash Oil Separator ¥11-195
7-38 Percentile Distribution of TTP in
Effluent from Option 1 Plants ¥11-203
7-39 Percentile Distribution of TTO in Raw
Waste in Metal Finishing Wastewaters ¥11-204
7-40 Activated Carbon Adsorption Column ¥11-211
7-41 Schematic Diagram of a Conventional
Activated Sludge System ¥11-222
XVI
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LIST OF FIGURES (Continued)
NUMBER TITLE PAGE
7-42 Schematic Cross Section of a Trickling
Filter VII-223
7-43 Schematic Diagram of a Single-stage
Trickling Filter VII-225
7-44 Mechanical Gravity Thickening VII-231
7-45 Pressure Filtration ¥11-233
7-46 Vacuum Filtration VII-236
7-47 Centrifugation VII-239
8-1 Cost Estimation Program VIII-5
8-2 Simple Waste Treatment System VIII-6
8-3 Cyanide Oxidation Investment Costs VII1-15
8-4 Annual OSM Costs vs. Flow Rate for
Cyanide Oxidation VII1-18
8-5 Annual Energy Costs vs. Flow Rate for
Cyanide Oxidation VII1-20
8-6 Chromium Reduction Investment Costs VII1-22
8-7 Annual O&M Costs vs. Flow Rate for
Chromium Reduction VI11-23
8-8 Chemical Precipitation and
Clarification Investment Costs VIII-26
8-9 Chemical Precipitation and Settling
Annual Operation and Maintenance
Labor Requirements VI11-28
8-10 Annual O&M Costs vs. Flow Rate for
Clarifier VIII-29
xvi i
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LIST OF FIGURES (Continued)
NUMBER TITLE PAGE
8-11 Emulsion Breaking Investment Costs VII1-32
8-12 Annual O&M Costs vs. Flow Rate for
Chemical Emulsion Breaking VIII-34
8-13 Annual Energy Costs vs. Flow Rate for
Chemical Emulsion Breaking VIII-35
8-14 Holding Tank Investment Costs VIII-37
8-15 Annual Energy Costs vs. Flow for
Holding Tanks VIII-38
8-16 Labor Requirements vs. Flow for
Sludge Holding Tanks VIII-39
8-17 Multimedia Filtration Investment Costs VII1-40
8-18 Annual O&M Costs vs. Flow Rate for
Multimedia Filtration VIII-41
8-19 Ultrafiltration Investment Costs VII1-43
8-20 Annual O&M Costs vs. Flow Rate for
Ultrafiltration VIII-44
8-21 Annual Energy Costs vs. Flow Rate for
Ultrafiltration VIII-45
8-22 Carbon Adsorption Investment Costs VII1-47
8-23 Annual O&M Costs vs. Flow Rate for
Carbon Adsorption VIII-48
8-24 Annual Energy Costs vs. Flow Rate for
Carbon Adsorption VIII-49
8-25 Sludge Drying Beds Investment Costs VIII-50
8-26 Annual O&M Costs vs. Flow Rate for
Sludge Beds VIII-52
xv 1.11
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LIST OF FIGURES (Continued)
NUMBER TITLE PAGE
8-27 Vacuum Filtration Investment Costs VII1-53
8-28 Annual O&M Costs vs. Flow Rate Cor
Vacuum Filtration VII1-54
8-29 Annual Energy Costs vs. Flow Rate for
Vacuum Filtration VIII-55
8-30 Submerged Tube Evaporation (Double
Effect) Investment Costs VIII-59
8-31 Annual O&M Costs vs. Flow Rate for
Submerged Tube Evaporation VII1-60
8-32 Annual Energy Costs vs. Flow Rate for
Submerged Tube Evaporation VII1-61
8-33 Option 1 System VIII-62
8-34 Option 1 Treatment System for
Segregated Oily Waste Streams VIII-67
8-35 Total Investment Cost vs. Flow Rate for
Option 1 Treatment System. Case 1 VIII-68
8-36 Total Annual Costs vs. Flow Rate for
Option I. Treatment System, Case 1 VI11-69
8-37 Total Investment Cost vs. Flow Rate for
Option 1 Treatment System, Case 2 VII1-70
8-38 Total Annual Costs vs. Flow Rate for
Option 1 Treatment System. Case 2 VIII-71
8-39 Total Investment Costs vs. Flow Rate for
Option 1 Treatment System. Case 3 VII1-72
8-40 Total Annual Costs vs. Flow Rate for
Option 1 Treatment System, Case 3 VI11-73
8-41 Total Investment Costs vs. Flow Rate for
Option 1 Treatment System. Case 4 VIII-74
XXX
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LIST OF FIGURES (Continued)
NUMBER TITLE PAGE
8-42 Total Annual Costs vs. Flow Rate for
Option 1 Treatment System. Case 4 VIII-75
8-43 Total Investment Costs vs. Flow Rate for
Option 1 Treatment System, Case 5 VIII-76
8-44 Total Annual Costs vs. Flow Rate for
Option 1 Treatment System. Case 5 VII1-77
8-45 Total Investment Costs vs. Flow Rate for
Option 1 Treatment System. Case 6 VII1-78
8-46 Total Annual Costs vs. Flow Rate for
Option 1 Treatment System. Case 6 VIII-79
8-47 Option 2 System VII1-83
8-48 Total Investment Costs vs. Flow Rate for
Option 2 Treatment System. Case 1 VII1-84
8-49 Total Annual Costs vs. Flow Rate for
Option 2 Treatment System. Case 1 VII1-85
8-50 Total Investment Costs vs. Flow Rate for
Option 2 Treatment System. Case 2 VII1-86
8-51 Total Annual Costs vs. Flow Rate for
Option 2 Treatment System, Case 2 VII1-87
8-52 Total Investment Costs vs. Flow Rate for
Option 2 Treatment System. Case 3 VIII-88
8-53 Total Annual Costs vs. Flow Rate for
Option 2 Treatment System. Case 3 VIII-89
8-54 Total Investment Costs vs. Flow Rate for
Option 2 Treatment System. Case 4 VII1-90
8-55 Total Annual Costs vs. Flow Rate for
Option 2 Treatment System. Case 4 VII1-91
8-56 Total Investment Costs vs. Flow Rate for
Option 2 Treatment System. Case 5 VIII-92
xx
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LIST OF FIGURES (Continued)
NUMBER TITLE PAGE
8-57 Total Annual Costs vs. Flow Rate for
Option 2 Treatment System. Case 5 VII1-93
8-58 Option 3 System VIII-94
8-59 Total Investment Costs vs. Flow Rate for
Option 3 Treatment System. Case 1 VII1-95
8-60 Total Annual Costs vs. Flow Rate for
Option 3 Treatment System. Case 1 VII1-96
8-61 Total Investment Costs vs. Flow Rate for
Option 3 Treatment System. Case 2 VII1-97
8-62 Total Annual Costs vs. Flow Rate for
Option 3 Treatment System. Case 2 VII1-98
8-63 Total Investment Costs vs. Flow Rate for
Option 3 Treatment System. Case 3 VIII-99
8-64 Total Annual Costs vs. Flow Rate for
Option 3 Treatment System. Case 3 VIII-100
8-65 Total Investment Costs vs. Flow Rate for
Option 3 Treatment System. Case 4 VIII-101
8-66 Total Annual Costs vs. Flow Rate for
Option 3 Treatment System. Case 4 VII1-102
8-67 Total Investment Costs vs. Flow Rate for
Option 3 Treatment System. Case 5 VIII-103
8-68 Total Annual Costs vs. Flow Rate for
Option 3 Treatment System. Case 5 VIII-104
9-1 BPT System IX-2
10-1 BAT System X-2
11-1 NSPS System XI-2
xxi
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LIST OF FIGURES (Continued)
NUMBER TITLE PAGE
13-1 Simple Electrodialysis Cell XIH-4
13-2 Mechanism of the Electrodialytic
Process XIII-6
13-3 Electrodialysis Recovery System XIII-8
13-4 Electrodialysis Cell XIII-9
XXIX
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LIST OF TABLES
NUMBER TITLE PAGE
2-1 BPT Limitations II-2
2-2 BAT Limitations II-2
2-3 PSES Limitations II-3
2-4 PSNS Limitations II-3
2-5 NSPS Limitations II-4
3-1 Metal Finishing Category Unit Operations III-6
3-2 Sampling Parameters III-ll
3-3 Industries Within the Metal
Finishing Category 111-17
4-1 Metal Finishing Category Raw Waste
Classifications IV-2
4-2 Waste Characteristics Distribution IV-4
5-1 Water Usage by Metal Finishing
Operations V-4
5-2 Determination of Zero Discharge
Operations V-5
5-3 Determination of Zero Discharge
Operations (DCP Data Bases) V-6
5-4 Common Metals Stream Contribution V-9
5-5 Precious Metals Stream Contribution V-10
5-6 Complexed Metals Stream Contribution V-ll
5-7 Hexavalent Chromium Stream
Contribution V-12
XXlll
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LIST OF TABLES (Continued)
NUMBER TITLE PAGE
5-8 Cyanide Bearing Stream Contribution V-13
5-9 Segregated Oily Wastewater
Contribution V-14
5-10 Pollutant Parameter Questionnaire
DCP Responses V-16
5-11 Source Identification for KTBP
(Known to be Present) Pollutant
Parameters V-22
5-12 Waste Characteristic Distribution V-26
5-13 Constituents of Plating Baths V-28
5-14 Constituents of Electroless
Plating Baths V-32
5-15 Constituents of Immersion Plating Baths V-34
5-16 Constituents of Process Baths Used
in Etching V-39
5-17 Minimum Detectable Limits V-53
5-18 Pollutants Found in Total Plant
Raw Waste Discharged to End-of-Pipe
Treatment V-58
5-19 Pollutant Concentrations Found in
the Common Metals Raw Waste Stream V-60
5-20 Pollutant Concentrations Found in
the Precious Metals Raw Waste Stream V-61
5-21 Pollutant Concentrations Found in
the Complexed Metals Raw Waste Stream V-61
5-22 Pollutant Concentrations Found in
the Cyanide Waste Stream V-62
XXIV
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LIST OF TABLES (Continued)
NUMBER TITLE PAGE
5-23 Pollutant Concentrations Found in
the Hexavalent Chromium Raw Waste
Stream V-62
5-24 Pollutant Concentrations Found in
the Oily Raw Waste Stream V-64
5-25 Oily Waste Characterization V-65
5-26 1974 Degreasing Solvent Consumption V-66
5-27 Summary of DCP Solvent Degreasing Data V-68
5-28 Total Toxic Organics (TTO) Concentrations
in Metal Finishing Raw Waste V-70
5-29 TTO Concentrations in Raw Waste from
Electroplating Lines V-72
5-30 TTO Concentrations in Raw Waste from
Electroless Plating Line Rinses V-74
5-31 TTO Concentrations in Raw Waste from
Precious Metals Electroplating
Line Rinses V-78
5-32 TTO Concentration in Raw Waste from
Anodizing Line Rinses V-79
5-33 TTO Concentration in Raw Waste from
Coating Line Rinses V-80
5-34 TTO Concentration in Raw Waste from
Etching and Bright Dipping Rinses V-82
5-25 TTO Concentrations in Raw Waste from
Cleaning Operations V-84
5-36 TTO Concentrations in Raw Waste from
Machining. Grinding. Barrel! Finishing,
Burnishing, and Sheading Operations V-85
xxv
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LIST OF TABLES (Continued)
NUMBER TITLE PAGE
5-37 TTO Concentrations in Raw Waste from
Heat Treating Operations and Quench
Baths V-86
5-38 TTO Concentrations in Raw Waste from
Soldering, Welding, and Brazing
Operations V-87
5-39 TTO Concentrations in Raw Waste from
Paint Stripping and Salt Bath
Descaling V-88
5-40 TTO Concentrations in Raw Waste from
Painting Operations V-89
5-41 TTO Concentrations in Raw Waste from
Solvent Degreasing Condensates V-92
5-42 TTO Concentrations in Raw Waste from
Testing and Assembly Operations V-93
5-43 TTO Concentrations in Treated Oily
Wastestreams V-94
5-44 TTO Concentrations in Raw Waste from
Segregated Chromium Streams V-101
5-45 TTO Concentrations in Raw Waste from
Segregated Cyanide Streams V-103
5-46 TTO Concentrations in Raw Waste from
Air Scrubbers V-104
5-47 TTO Concentrations in Non-Metal
Finishing Operations V-105
6-1 Pollutant Parameters Selected
for Regulation VI-4
7-1 Index and Specific Application of
Treatment Technologies VII-5
7-2 Applicability of Treatment Technologies
to Raw Waste Types VI1-7
7-3 Metal Finishing Plants with Option 1
Treatment Systems for Common Metals VI1-18
xx vi
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LIST OF TABLES (Continued)
NUMBER TITLE PAGE
7-4 Metal Finishing Category Performance
Data for Cadmium VI1-26
7-5 Metal Finishing Category Performance
Data for Chromium (Total) VI1-27
7-6 Metal Finishing Category Performance
Data for Copper VI1-28
7-7 Metal Finishing Category Performance
Data for Lead VII-30
7-8 Metal Finishing Category Performance
Data for Nickel VII-32
7-9 Metal Finishing Category Performance
Data for Zinc VII-34
7-10 Metal Finishing Category Performance
Data for TSS VI1-35
7-11 Treatment of Common Metals - Visited
Plants Summary of option 1 Mean
Effluent Concentration VII-37
7-12 Effluent TSS Self-Monitoring Performance
Data for Plants with Option 1 Systems VI1-39
7-13 Effluent Cadmium Self-Monitoring
Performance Data for Plants with
Option 1 Systems VI1-40
7-14 Effluent Chromium Self-Monitoring
Performance Data for Plants with
Option 1 Systems VI1-41
7-15 Effluent Copper Self-Monitoring
Performance Data for Plants with
Option 1 Systems VI1-42
7-16 Effluent Lead Self-Monitoring
Performance Data for Plants with
Option 1 Systems VI1-43
XXV XI
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LIST OF TABLES (Continued)
NUMBER TITLE PAGE
7-17 Effluent Nickel Self-Monitoring
Performance Data for Plants with
Option 1 Systems VII-44
7-18 Effluent Zinc Self-Mpnitoring
Performance Data for Plants with
Option 1 Systems VII-45
7-19 Summary of Option 1 Daily Maximum
and 10-Day Average Variability
Factors VII-46
7-20 Summary of Option 1 Daily Maximum
and 10-Day Average Factors VII-46
7-21 Percentage of the MFC Data Base
Below the Effluent Concentration
Limitations for Option 1 VII-47
7-22 Metal Finishing Plants with Option 2
Treatment Systems for Common Metals VI1-56
7-23 Treatment of Common Metals Visited
Plant Option 2 Mean Effluent
Concentrations VII-65
7-24 Effluent TSS Self-Monitoring
Performance Data for Plants with
Option 2 Systems VI1-67
7-25 Effluent Cadmium Self-Monitoring
Performance Data for Plants with
Option 2 Systems VI1-67
7-26 Effluent Chromium Self-Monitoring
Performance Data for Plants with
Option 2 Systems VI1-67
7-27 Effluent Copper Self-Monitoring
Performance Data for Plants with
Option 2 Systems VII-68
XXVI11
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LIST OF TABLES (Continued)
NUMBER TITLE PAGE
7-28 Effluent Lead Self-Monitoring
Performance Data for Plants with
Option 2 Systems VI1-68
7-29 Effluent Nickel Self-Monitoring
Performance Data for Plants with
Option 2 Systems VI1-68
7-30 Effluent Zinc Self-Monitoring
Performance Data for Plants with
Option 2 Systems VII-68
7-31 Summary of Option 2 Daily Maximum
and 10-Day Average Variability
Factors VII-69
7-32 Option 2 Common Metal Performance
Levels VI1-70
7-33 Percentage of the MFC Data Base
Below the Daily Maximum
Concentrations for Option 2 VII-70
7-34 Option 1 and Option 2 Mean Concentration
Comparison VII-71
7-3S Option 1 and Option 2 Performance
Comparison VII-71
7-36 Performance Data for Cadmium Metal
Finishing Category VII-74
7-37 Metal Finishing Plants Employing
Evaporation VII-80
7-38 Typical Ion Exchange Performance Data VI1-84
7-39 Metal Finishing Plants Employing
Ion Exchange VI1-85
7-40 Sampling Data from Sulfide Precipita-
tion/Sedimentation Systems VII-92
7-41 Foam Flotation Performance VI1-97
XXIX
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LIST OF TABLES (Continued)
NUMBER TITLE PAGE
7-42 Metal Finishing Plants Employing
Flotation VII-97
7-43 Membrane Filter Performance (mg/1) VII-99
7-44 Metal Finishing Category Performance
Data for Silver Visited Option 1 Plants VII-101
7-45 Ion Exchange Performance VI1-102
7-46 Common Complexing Agents VI1-105
7-47 Complexing Agents Used in the
Visited Plant Data Base VII-105
7-48 Pollutant Concentrations (mg/1) for
Sampled Data from Plants with Complexed
Metal Wastes Employing Precipitation/
Clarification VII-108
7-49 Pollutant Concentrations (mg/1) for
Sampled Data from Plants with Complexed
Metal Wastes Employing Precipitation/
Clarification/Filtration VII-111
7-50 Effluent Hexavalent Chromium Self-
Monitoring Performance Data for
Plants with Option 1 Systems VI1-119
7-51 Metal Finishing Plants Employing
Chemical Chromium Reduction VI1-121
7-52 Amenable Cyanide Data Base VII-130
7-53 Data Used for Amenable Cyanide
Performance VII-133
7-54 Plants Deleted from Cyanide Data
Base due to Poor Performance VII-135
7-55 Data Used for Total Cyanide
Performance VII-136
XXX
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LIST OF TABLES (Continued)
NUMBER TITLE PAGE
7-56 Plant Data Deleted from Total
Cyanide Data Base VII-138
7-57 Effluent Total and Amenable Cyanide Self-
Monitoring Performance Data for
Plants with Option 1 Systems VII-141
7-58 Adjusted Effluent Total and Amenable
Cyanide Self-Monitoring Data ¥11-142
7-59 Metal Finishing Plants Employing
Cyanide Oxidation VII-143
7-60 Oily Waste Removal System Options VI1-155
7-61 Metal Finishing Category Performance
Data for Oil and Grease VII-157
7-62 Oil and Grease Effluent Self-
Monitoring Performance Data
Combined Wastewater - Common
Metals Option 1 VII-158
7-63 Oil and Grease Limitation Summary
Combined Wastewater - Common Metals
Option 1 VII-159
7-64 Oil and Grease Performance Summary
Combined Wastewater - Common Metals
Option 2 VII-159
7-65 Metal Finishing Plants Employing
Emulsion Breaking VII-166
7-66 Skimming Performance Data for
Oil and Grease (mg/1) VII-168
7-67 Metal Finishing Plants Employing
Skimming VII-168
XXXI
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LIST OF TABLES (Continued)
NUMBER TITLE PAGE
7-68 Effluent Oil and Grease Self-
Monitoring Performance Data
Segregated Oily Wastewater -
Option 1 VII-171
7-69 Metal Finishing Plants Employing
Ultrafiltration VII-176
7-70 Ultrafiltration Performance Data
for Oil and Grease Removal VII-177
7-71 Reverse Osmosis Performance (mg/1) VTI-178
7-72 Cleaning Approaches VTI-192
7-73 Cleaning Process Relative Ranking
(Lowest Number is Best) VII-193
7-74 Metal Finishing Category Performance
Data for TTO. Option 1 VII-199
7-75 Metal Finishing Category Performance
for TTO, Option 2 VI1-201
7-76 Metal Finishing Category Performance
for TTO, Other Than Option 1 or 2 VI1-202
7-77 Solubility of Toxic Organic Parameters VI1-206
7-78 TTO Performance Data (mg/1) for
Option 1 Segregated Oil Waste VII-207
7-79 TTO Performance Data (mg/1) for
Ultrafiltration VII-207
7-80 Treatability Rating of Priority
Pollutants Utilizing Carbon
Adsorption VII-214
7-81 Classes of Organic Compounds
Adsorbed on Carbon VII-215
XXXll
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LIST OF TABLES (Continued)
NUMBER TITLE PAGE
7-82 Performance of Carbon Adsorption
at Plant 38040 (mg/1) VII-216
7-83 Metal Finishing Plants Employing
Carbon Adsorption VII-216
7-84 TTO Performance Data (mg/1)
for Reverse Osmosis VI1-217
7-85 Ozone Requirements for Phenol
Oxidation VII-220
7-86 Maintenance Techniques for Aerobic
Decomposition VII-224
7-87 Activated Sludge Removal of Some
Priority Organic Compounds VII-226
7-88 Proposed BAT Effluent Limitations
for the Organic Chemicals Industry VII-227
7-89 Metal Finishing Plants Employing
Aerobic Decomposition VII-228
7-90 Comparison of Wastewater at Plant
ID 23061 Before and After Pumping
of Settling Tank VII-229
7-91 Metal Finishing Plants Employing
Gravity/Sludge Thickening VII-232
7-92 Metal Finishing Plants Employing
Pressure Filtration VII-235
7-93 Metal Finishing Plants Employing
Vacuum Filtration VII-238
7-94 Metal Finishing Plants Employing
Centrifugation VII-241
7-95 Metal Finishing Plants Employing
Sludge Drying Beds VI1-244
XXXI11
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LIST OP TABLES (Continued)
NUMBER TITLE PAGE
7-96 Theoretical Rinse Water Flows Required
to Maintain a 1,000 to 1
Concentration Reduction VII-248
7-97 Comparison of Rinse Type Flow Rates
for Sampled Plants VII-248
8-1 Cost Program Pollutant Parameters VIII-3
8-2 Treatment Technology Subroutines VIII-8
8-3 Wastewater Sampling Frequency VII1-12
8-4 Index to Technology Costs VIII-14
8-5 Lime Additions for Lime
Precipitation VIII-30
8-6 Countercurrent Rinse (For Other
Than Recovery of Evaporative
Plating Loss) VIII-56
8-7 Countercurrent Rinse Used for
Recovery of Evaporative
Plating Loss VIII-57
8-8 Flow Split Cases for Options 1,
2. and 3 VIII-63
8-9 Option 1 Costs VIII-65
8-10 Option 2 Costs VIII-81
8-11 Option 3 Costs VIII-82
8-12 Non-Water Quality Aspects of
Wastewater Treatment VII1-107
8-13 Non-Water Quality Aspects of
Sludge and Solids Handling VIII-108
9-1 BPT Effluent Limitations
Concentration (mg/1) IX-5
XXXIV
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LIST OF TABLES (Continued)
NUMBER TITLE PAGE
9-2 Percentage of the MFC Data Base
Below the BPT Limitations IX-8
9-3 BPT Self-Monitoring Data Compliance
Summary Data Points < BPT
Daily Maximum Limitations/
Total Data Points IX-9
9-4 BPT Self-Monitoring Data Compliance
Summary Data Points < BPT
Daily Maximum Limitations IX-10
9-5 Single Option - Self-Monitoring Data
Compliance Summary Data Points < BPT
Limitations/Total Data Points IX-11
9-6 Single Option - Self-Monitoring Data
Compliance Summary Percent of Data Points
< BPT Limitations IX-12
9-7 BPT Self-Monitoring Data Compliance
Summary 10-Day Averages < BPT Monthly
Maximum Average Limitations/Total
Number of 10-Day Averages IX-13
9-8 BPT Self-Monitoring Data Compliance
Summary Percent of 10-Day Averages
< BPT Monthly Maximum Average
Limitations IX-14
9-9 Single Option - Self-Monitoring Data
Compliance Summary 10-Day Averages
< BPT Monthly Maximum Average
Limitations/Total Number of 10-Day
Averages IX-15
9-10 Single Option - Self-Monitoring Data
Compliance Summary 10-Day Averages
< BPT Monthly Maximum Average
Limitations IX-16
9-11 BPT Treatment Benefit Summary IX-17
10-1 BAT Effluent Limitations X-3
XXXV
-------
LIST OF TABLES (Continued)
NUMBER TITLE PAGE
11-1 NSPS Effluent Limitations XI-4
11-2 NSPS Treatment Benefit Summary
Concentration Reduction (mg/1) XI-5
12-1 PSES Limitations XII-3
12-2 PSNS Limitations XII-3
12-3 Pretreatment Benefit Summary XI1-4
13-1 Index to Innovative Technology XII1-2
Candidates Described in Section VII
XXXV1
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SECTION I
CONCLUSIONS
In order to establish uniformly applicable effluent limitations
and standards, groupings can be established within each
industrial category based on certain criteria. These criteria
include raw waste characteristics, manufacturing processes, raw
materials used, product type and/or production volume, size and
age of facility, number of employees, water usage, and individual
plant characteristics.
After consideration of these factors as applied to the metal
finishing industry, it was concluded that a single metal
finishing subcategory could be established. Thus, all process
wastewaters in the Metal Finishing Category are amenable to
treatment by a single system. One set of discharge limitations
and standards results from the use of a single waste treatment
technology system.
Effluent limitations and standards are expressed in concentration
units (mg/1) without accompanying production based units. Basing
limitations and standards on production based units was rejected
after numerous attempts failed to find production related factors
which could be correlated in a statistically reliable manner with
wastewater flow. This lack of correlation is understandable in
light of the number and complexity of metal finishing
manufacturing operations.
-------
SECTION II
RECOMMENDATIONS
On the basis of the toxic pollutant analysis and the evaluation
of applicable technologies for discharge control and treatment,
it is recommended that effluent limitation guidelines, new source
performance standards and pretreatment standards for new and
existing sources be promulgated for the Metal Finishing Point
Source Category.
Tables 2-1 through 2-5 summarize the regulations for Best
Practicable Control Technology Currently Available (BPT), Best
Available Technology Economically Achievable (BAT), Pretreatment
Standards for Existing Sources (PSES). Pretreatment Standards for
New Sources (PSNS) and New Source Performance Standards (NSPS).
BCT limitations for this industry were proposed on October 29,
1982 (47 FR 49176). They were accompanied by a proposed method-
ology for the general development of BCT limitations. BCT limits
for this industry will be promulgated with, or soon after the
promulgation of the final methodology for BCT development. At
that time EPA will respond to relevant comments filed in either
that rulemaking or in this one.
Il-l
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TABLE 2-1
BPT LIMITATIONS
Pollutant or
Pollutant Parameter
Cadmium
Chromium, total
Copper
Lead
Nickel
Silver
Zinc
Cyanide, total
TTO
Oil and Grease
TSS
pH
Daily
Maximum
0,69
2.77
3.38
0.69
3.98
0.43
2.61
1.20
2.13
52
60
Within the range of 6.0 to 9.0
Alternative to total cyanide:
Cyanide, amenable to chlorination
0.86
Maximum Monthly
Average
0.26
1.71
2.07
0.43
2.38
0.24
1.48
0.65
26
31
0.32
TABLE 2-2
BAT LIMITATIONS
Pollutant or Daily
Pollutant Parameter Maximum
Cadmium 0.69
Chromium, total 2.77
Copper 3.38
Lead 0.69
Nickel 3.98
Silver 0.43
Zinc 2.61
Cyanide, total 1.20
TTO 2.13
Alternative to total cyanide:
Cyanide, amenable to chlorination 0.86
Maximum Monthly
Average
0.26
1.71
2.07
0.43
2.38
0.24
1.48
0.65
0.32
II-2
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TABLE 2-3
PS1S LIMITATIONS
Pollutant or
Pollutant Parameter
Cadmium
Chromium
Copper
Lead
Nickel
Silver
Zinc
Cyanide,
TTO
TTO
total
total
(interim)
(final)
Daily
Maximum
0.69
2.77
3.38
0.69
3.98
0.43
2.61
1.20
4.57
2.13
Alternative to total cyanide:
Cyanide, amenable to chlorination
Maximum Monthly
Average
0.26
1.71
2.07
0.43
2.38
0,24
1.48
0.65
0.86
0.32
TABLE 2-4
PSNS LIMITATIONS
Pollutant or Daily
Pol1utant Par ame t er Maximum
Cadmium 0,11
Chromium, total 2.77
Copper 3.38
Lead 0.69
Nickel 3.98
Silver 0.43
Zinc 2.61
Cyanide, total 1.20
TTO 2.13
Alternative to total cyanide:
Cyanide, amenable to chlorination 0.86
Maximum Monthly
Average
O.07
1.71
2.07
0.43
2.38
0.24
1.48
0.65
0.32
II-3
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TABLE 2-5
NSPS LIMITATIONS
Pollutant or Daily Maximum Monthly
Po[Ilutant Parameter Maximum Average
Cadmium 0.11 0.07
Chcomium. total 2.77 1.71
Copper 3.38 2.07
Lead 0.69 0.43
Nickel 3.98 2,38
Silver 0.43 0.24
Zinc 2.61 1.48
Cyanide, total 1.20 0.65
TTO 2.13
Oil and Grease 52 26
TSS 60 31
pH Within the range of 6.0 to 9.0
Alternative to total cyanide:
Cyanide, amenable to chlorination 0.86 0.32
II-4
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SECTION III
INTRODUCTION
LEGAL AUTHORITY
This document is written under authority of Sections 301,
304, 306, 307, 308, and 501 of the Clean Water Act (the Federal
Water Pollution Control Act Amendments of 1972, 33 USC 1251 et
seg., as amended by the Clean Water Act of 1977, P.L. 95-217T"
(the "Act"). The document is also in response to the Settlement
Agreement in Natural Resources Defense Council, Inc. et al
v. Train, 8 ERG 2120 (D.D.C 1976), modified March 9, 1979.
The Federal Water Pollution Control Act Amendments of 1972
established a comprehensive program to "restore and maintain the
chemical, physical, and biological integrity of the Nation's
waters," Section 101(a). By July 1, 1977, existing industrial
dischargers were required to achieve "effluent limitations
requiring the application of the best practicable control technology
currently available" ("BPT"), Section 301(b)(1)(A); and by July 1,
1983, these dischargers were required to achieve "effluent limita-
tions requiring the application of the best available technology
economically achievable ... which will result in reasonable
further progress toward the national goal of eliminating the
discharge of all pollutants" ("BAT"), Section 301 (b)(2)(A). New
industrial direct dischargers were required to comply with Section
306 new source performance standards ("NSPS"), based on best
available demonstrated technology, and new and existing dischargers
to publicly owned treatment works ("POTWs") were subject to
pretreatment standards under Sections 307(b) and (c) of the Act.
While the requirements for direct dischargers were to be incor-
porated into National Pollutant Discharge Elimination System
(NPDES) permits issued under Section 402 of the Act, pretreatment
standards were made enforceable directly against dischargers to
POTWs (indirect dischargers).
Although section 402 (a)(l) of the 1972 Act authorized the setting
of requirements for direct dischargers on a case-by-case basis,
Congress intended that, for the most part, control requirements
would be based on regulations promulgated by the Administrator of
the EPA. Section 304(b) of the Act required the Administrator to
promulgate regulations providing guidelines for effluent limita-
tions setting forth the degree of effluent reduction attainable
through the application of BPT and BAT. Moreover, Sections 304(c)
and 306 of the Act required promulgation of regulations for NSPS,
and Sections 304(f), 307(b), and 307(c) required promulgation
of regulations for pretreatment standards.
III-l
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In addition to these regulations for designated industry categories,
Section 307(a) of the Act required the Administrator to promulgate
effluent standards applicable to all dischargers of toxic pollu-
tants. Finally, Section 501(a) of the Act authorized the
Administrator to prescribe any additional regulations "necessary
to carry out his functions" under the Act.
The EPA was unable to promulgate many of these regulations by
the dates contained in the Act. In 1976, EPA was sued by several
environmental groups, and in settlement of this lawsuit EPA and the
plaintiffs executed a "Settlement Agreement" which was approved by
the Court. This Agreement required EPA to develop a program and
adhere to a schedule for promulgating for 21 major industries BAT
effluent limitations guidelines, pretreatment standards, and new
source performance standards for 65 "priority" pollutants and classes
of pollutants. See Natural Resources Defense Council, Inc. et al
v. Train, 8 ERG 2120 (D.D.C. 1976), modified March 9, 1979.
On December 27, 1977, the President signed into law the Clean Water
Act of 1977. Although this law makes several important changes in
the Federal water pollution control program, its most significant
feature is its incorporation into the Act of several of the basic
elements of the Settlement Agreement program for toxic pollution
control. Sections 301(b)(2)(A) and 301(b)(2)(C) of the Act now
require the achievement by July 1, 1984 of effluent limitations
requiring application of BAT for "toxic" pollutants, including the
65 "priority" pollutants and classes of pollutants which Congress
declared "toxic" under Section 307(a) of the Act. Likewise, EPA's
programs for new source performance standards and pretreatment
standards are now aimed principally at toxic pollutant controls.
Moreover, to strengthen the toxics control program, Section 304(e)
of the Act authorizes the Administrator to prescribe "best
management practices" ("BMPs") to prevent the release of toxic
and hazardous pollutants from plant site runoff, spillage or
leaks, sludge or waste disposal, and drainage from raw material
storage associated with, or ancillary to, the manufacturing or
treatment process.
In keeping with its emphasis on toxic pollutants, the Clean Water
Act of 1977 also revises the control program for non-toxic pollutants,
Instead of BAT for "conventional" pollutants identified under
Section 304(a)(4) (including biochemical oxygen demand, suspended
solids, fecal coliform and pH), the new Section 301(b)(2)(F)
requires achievement by July 1, 1984, of "effluent limitations
requiring the application of the best conventional pollutant
control technology" ("BCT"). The factors considered in assessing
BCT for an industry include the costs of attaining a reduction
in effluents and the effluent reduction benefits derived compared
to the costs and effluent reduction benefits from the discharge
of publicly owned treatment works (Section 304(b)(4)(B)). For
III-2
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non-toxic, nonconventional pollutants, Sections 301(b)(2)(A) and
(b)(2)(F) require achievement of BAT effluent limitations within
three years after their establishment or July 1, 1984, whichever
is later, but not later than July 1, 1987.
GUIDELINE DEVELOPMENT SUMMARY
The Metal Finishing Category (MFC) encompasses 46 unit operations
involved in the machining, fabrication and finishing of products
primarily associated with SIC groups 34 through 39. The effluent
guidelines for the Metal Finishing Category were developed from
data obtained from previous EPA studies, literature searches,
plant surveys and evaluations, and long term self-monitoring data
supplied by industry. Initially, all existing information from
EPA records and data from literature searches were collected.
This information was then compiled in a format that summarized
the individual plant descriptions for the following information:
manufacturing unit operations performed, water usage, process
water discharges, wastewater treatment practices, and wastewater
constituents.
In addition to providing a quantitative description of the Metal
Finishing Category, this existing information was used to
determine if the wastewater characteristics of the industry as a
whole were uniform and thus amenable to one set of discharge
standards. The discharge characteristics of all plants in the
existing data base were not uniform; however, the discharge from
these plants was amenable to the application of a common end-of-
pipe treatment technology. Therefore, the entire Metal Finishing
Category is represented by a single subcategory and is subject to
one set of effluent discharge limitations. Seven classifications
of raw waste are present and were studied to establish treatment
requirements. These seven waste types are:
Common Metals . Cyanide
Precious Metals . Oils
Complexed Metals . Toxic Organics
Hexavalent Chromium
To supplement existing data, data collection portfolios (DCP's)
under the authority of Section 308 of the Federal Water Pollution
Control Act as amended were transmitted by the EPA to a large
number of manufacturing facilities in the Metal Finishing
Category. In addition to the existing data base and the plant
supplied information (via the completed DCP's), a sampling
program was conducted at selected plant locations. The sampling
program was used to establish the sources and quantities of
pollutant parameters in the raw process wastewater and the
treated effluent. The sites visited were chosen on the basis of
either the specific manufacturing operations performed or the
particular waste treatment technology employed. Historical
effluent information in the form of long term self
III-3
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monitoring data, was requested by the EPA and was responded to by nearly
100 plants. All of the data collected were analyzed to correlate the
pollutants generated with the manufacturing processes performed by
each facility.
In addition to evaluating pollutant constituents and discharge
rates, the full range of control and treatment technologies
within the Metal Finishing Category was identified and examined.
This was done considering the pollutants to be treated and their
chemical, physical, and biological characteristics. Special
attention was paid to in-process technology such as the recovery
and reuse of process solutions, the recycle of process water, and
the reduction of water use.
This information was then evaluated in order to determine the
levels of technology appropriate as bases for effluent limitations
for existing sources after July 1, 1977, ("Best Practicable
Control Technology Currently Available") and after July 1, 1984
("Best Available Technology Economically Achievable"). Levels
of technology appropriate for direct discharge and pretreatment
of wastewater to POTW's from both new and existing sources were
also identified as were the demonstrated control technology,
processes, operating methods, or other alternatives. Various
factors were considered in the evaluation of these technologies.
These factors included demonstrated effluent performance of
treatment technologies, the total cost of application of the
technology in relation to the pollution reduction benefits to
be achieved, the production processes employed, the engineering
aspects of the application of various types of control techniques
and process changes, and non-water quality environmental impact
(including energy requirements).
SOURCES OF INDUSTRY DATA
Data for the Metal Finishing Category were gathered from literature
surveys, previous studies of the industry by the EPA, inquiries to
professional contacts, seminar and meeting attendance, the survey
and evaluation of manufacturing facilities, and long term self-
monitoring data provided by industry.
Literature Study
Published literature in the form of books, periodicals, reports,
papers, and promotional materials was examined. These sources
are listed in Section XV. The material researched included
manufacturing processes, recycling/reclamation techniques,
pollutant characteristics, waste treatment technologies, and
cost data.
III-4
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Previous EP& Studies
Previous EPA studies that contributed technical information
to the Metal Finishing Category study were:
Machinery & Mechanical Products Manufacturing
Category
Electroplating Category
Electroless Plating & Printed Circuit Board
Manufacturing Segments of the Electroplating
Category
Printing & Publishing Category
Mechanical & Electrical Products Category
Copper & Copper Alloy Manufacturing Category
Aluminum & Aluminum Alloy Manufacturing Category
Iron & Steel Manufacturing Category
These EPA studies provided information on the process raw wastes
generated by each of the metal finishing operations listed in
Table 3-1 and the treatment utilized by industry to control the
pollutants in these wastes. Information from the Machinery and
Mechanical Products Manufacturing study was used specifically to
identify plants with segregated wastes for particular manufac-
turing unit operations and with treatment technology to control
these wastes. Applicable plants were selected for sampling to
establish waste characteristics and performance of existing
wastewater treatment components and systems. Plant data from
earlier studies of electroplating, electroless plating, and
printed circuit board manufacturing were examined and incorpor-
ated into the current Metal Finishing data base. Data from the
Printing and Publishing Category study were examined with the
intent of including lithography and metallic plate making in the
Metal Finishing Category. Plant data files from the Mechanical
and Electrical Products study were incorporated directly into the
Metal Finishing data base. Selected data from the copper, alumi-
num, and iron and steel studies were used to determine character-
istics of oily raw waste streams and to determine performance of
oily waste treatment technologies. Most of the preceding infor-
mation was obtained directly from EPA files or EPA contractors
rather than from published reports.
III-5
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TABLE 3-1
METAL FINISHING CATEGORY UNIT OPERATIONS
UNIT OPERATIONS
1. Electroplating
2. Electroless Plating
3. Anodizing
4. Conversion Coating
5. Etching (Chemical Milling)
6. Cleaning
7. Machining
8. Grinding
9. Polishing
10. Tumbling (Barrel Finishing)
11. Burnishing
12. Impact Deformation
13. Pressure Deformation
14. Shearing
15. Heat Treating
16. Thermal Cutting
17. Welding
18. Brazing
19. Soldering
20. Flame Spraying
21. Sand Blasting
22. Other Abrasive Jet Machining
23. Electric Discharge Machining
24. Electrochemical Machining
25. Electron Beam Machining
26. Laser Beam Machining
27. Plasma Arc Machining
28. Ultrasonic Machining
29. Sintering
30. Laminating
31. Hot Dip Coating
32. Sputtering
33. Vapor Plating
34. Thermal Infusion
35. Salt Bath Descaling
36. Solvent Degreasing
37. Paint Stripping
38. Painting
39. Electrostatic Painting
40. Electropainting
41. Vacuum Metalizing
42. Assembly
43. Calibration
44. Testing
45. Mechanical Plating
46. Printed Circuit Board Manufacturing
III-6
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Professional Contacts
All Federal EPA regions and several state environmental agencies
were contacted to obtain permit and monitoring data on plants
that performed metal finishing processes.
Numerous suppliers and manufacturers for the metal finishing
industry were contacted to collect information regarding the
use and properties of materials/ constituents of process
chemicals, waste treatment equipment, waste contract haulers,
and possible applications of process modifications to minimize
the generation of pollutants.
Seminars and Meetings
An Advanced Wastewater Treatment Seminar provided methods for
accurately estimating waste treatment costs. The American Electro-
platers Society Intensive Training Course in Electroplating and
Surface Finishing was taken. The Eastern Plant Engineering Con-
ference on lubricant management, conservation, recycling, and
disposal was also attended.
In addition, jointly sponsored EPA/American Electroplaters'
Society conferences on Advanced Pollution Control for the
Metal Finishing Industry were attended. At these conferences
various papers on metal finishing technology and waste treatment
were presented by the industry and the EPA. A meeting of the
Continuous Coil Anodizing Association was also attended. The
EPA sponsored an informational meeting with the Association of
Home Appliance Manufacturers, the Electrical Industries of
America, the Motor Vehicles Manufacturers Association of the
United States, the National Association of Manufacturers, and
the National Electrical Manufacturers Association.
Plant Survey and Evaluation
The collection of data pertaining to facilities in the metal
finishing industry was accomplished via two primary mechanisms.
The EPA conducted a survey wherein data collection portfolios
(DCPs) in questionnaire form were mailed to production facili-
ties. Also, a plant visit and sampling program was implemented
to accumulate the specific data necessary for each waste charac-
teristic subcategory.
Data Collection Portfolios - Data collection portfolios of three
types were sent to various industries within the Metal Finishing
Category. The first DCP was utilized during the Machinery and
Mechanical Products Industries Study. Data were obtained from
339 production facilities that were selected from a group of 1,422
III-7
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plants originally contacted by telephone. Requested information
included general plant data, principal raw materials consumed,
specific production processes employed, composition of effluent
streams and wastewater treatment in use.
The second DCP, used during the M&EP study was sent to 900 facilities
that were randomly selected from approximately 160,000 manufacturers
listed in recent Dun & Bradstreet data. This DCP requested informa-
tion pertinent to general plant characteristics, unit operations
performed (including quantity, frequency, and method of liquid dis-
posal), data related specifically to plating type operations,
wastewater treatment facilities, and the contract hauling of wastes.
A total of 365 useful responses resulted from the mailing of this
questionnaire.
The third DCP was used during the Electroplating study. It was
mailed to 1883 companies believed to operate plating facilities.
This mailing list was randomly selected from among the approxi-
mately 13,000 facilities that perform plating in the United
States. There were approximately 1190 usable responses (from
419 companies) to this questionnaire mailing. This survey re-
quested information regarding general plant characteristics, pro-
duction history, manufacturing processes, process and waste treat-
ment, wastewater characteristics, treatment costs, and economic
analysis data.
Plant Sampling Visits - During the study of the metal finishing
industry, a total of 322 manufacturing facilities were visited.
The criteria used to select plants for sampling visits were:
1. A large percentage of the plant's effluent discharge should
result from the manufacturing processes listed in Table 3-1.
2. The physical layout of plant plumbing should facilitate
.sampling of the wastewater type under study.
3. The plant must have waste treatment and control
technology in place.
4. The mix of plants visited should contain dischargers to
both surface waters and publicly owned treatment works
(POTW).
111-8
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5. The selected plants should provide a representative
geographical distribution to avoid a data base that
concentrates on a unique geographical condition.
The plant visits consisted of two major activities: collection
of all pertinent technical information related to both the
manufacturing processes and the treatment techniques and collec-
tion of wastewater samples. The technical data gathering effort
entailed completion of the applicable data collection portfolio
and obtaining information in the following specific areas:
1. Rinsing operations and their effect on water use and waste
characteristics.
2. Water conservation techniques, both practiced and planned.
3. Overall performance of the waste treatment system and
future plans or changes anticipated.
4. Current regulations under which the plant is
operating and any difficulties in meeting them.
5. Process modifications which significantly alter the
characteristics of the wastewater generated.
6. Particular pollutant parameters which plant personnel
believe will be found in the waste stream.
7. Any problem or situation peculiar to the plant being
visited.
The object of plant sampling was to determine by analysis which
pollutants were present in the plant wastewater for each sub-
category. The wastewater collection at the visited plants con-
sisted of a composite sampling program performed over a two or
three day period. Prior to the sampling visit, all available
data pertaining to manufacturing processes and waste treatment
were reviewed. Representative sample points were selected for
the raw wastewater entering the treatment systems and for the
final treated effluents. Finally a detailed sampling plan
showing the selected sample points and the overall sampling
procedure was prepared, reviewed, and approved by the EPA.
III-9
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Composite samples (24 hour composites) were taken at each
sample point. The plants which were sampled were divided
into two sample analysis groups. Within each analysis group
the samples were subjected to various levels of analysis
depending on the stability of the parameters to be analyzed.
These analysis groups and the various levels of analysis
within were:
1. On-site analysis/ local laboratory analysis, Chicago EPA
laboratory analysis, GC/MS laboratory analysis, and
central laboratory analysis.
2. On-site analysis, local laboratory analysis, EPA contracted
laboratory metals analysis and EPA contracted laboratory
organics analysis.
In the first analysis group, on-site analysis performed by the
sampler at the facility determined flow rate, pH, and temperature.
Several liters of water from each sample point were delivered to
a laboratory in the locality of the subject plant and analyzed
for total cyanide, cyanide amenable to chlorination, TSS, oil
and grease, and phenols. This analysis was performed by local
laboratories within a 24 hour period after the composite sample
was prepared. Two liters of water from each sample point were
sent to an EPA laboratory where screening analysis was run to
establish metals present in the samples. Water samples
from each point were also sent to a laboratory with GC/MS capa-
bilities to determine organics that were present. The remainder
of the wastewater was shipped to a central laboratory where
analysis was performed to verify the levels of metals, organics,
and total dissolved solids as appropriate. For some sampling
visits the Chicago EPA laboratory and the GC/MS laboratory were
eliminated. Analysis for certain special parameters such as
palladium and rhodium was performed only if the facility being
sampled utilized such materials in their process lines. Samples
from electroless plating plants were also analyzed for the
complexing agents which were being used by the plants. In
addition to this sampling and analysis, special grab samples
were collected from certain plants to obtain data related to
specific unit operations, process variations, or rinsing opera-
tions. In the second analysis group, the on-site analysis
remained the same as in the first group. The local laboratory
analyzed for total cyanide, oil and grease, ammonia nitrogen,
TOC, TSS, BOD, and phenols. These were analyzed within 24 hours
after the composite or grab composite sample was prepared. Two
liters of water were sent to an EPA contracted laboratory to
perform analysis to determine metals present in the water samples.
Additional water was sent to a second EPA contracted laboratory
for analysis to determine organics present in the wastewater.
The acquisition, preservation, and analysis of the water samples
were performed in accordance with methods set forth in 40 CFR Part
136. Sampling parameters are presented in Table 3-2.
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Table 3-2
SAMPLING PARAMETERS
Toxic Pollutants
1 acenaphthene
2 acrolein
3 acrylonitrile
4 benzene
5 benzidine
6 carbon tetrachloride (tetrachlororaethane)
7 chlorobenzene
8 1,2,4-trichlorobenzene
9 hexachlorobenzene
10 1,2-dichloroethane
11 1,1,1-trichloroethane
12 hexachloroethane
13 1,1-dichloroethane
14 1,1,2-trichloroethane
15 1,1,2,2-tetrachloroethane
16 chloroethane
18 bis(2-chloroethyl) ether
19 2-chloroethyl vinyl ether (mixed)
20 2~chloronaphthalene
21 2,4,6-trichlorophenol
22 parachlorometa cresol
23 chloroform (trichloromethane)
24 2-chlorophenol
25 1,2-dichlorobenzene
26 1,3-dichlorobenzene
27 1,4-dichlorobenzene
28 3,3'-dichlorobenzidine
29 1,1-dichloroethylene
30 1,2-trans-dichloroethylene
31 2,4-dichlorophenol
32 1,2-dichloropropane
33 1,2-dichloropropylene (1,3-dichloropropene)
34 2,4-dimethylphenol
35 2,4-dinitrotoluene
36 2,6-dinitrotoluene
37 1,2-diphenylhydrazine
38 ethylbenzene
39 fluoranthene
40 4-chlorophenyl phenyl ether
41 4-bromophenyl phenyl ether
42 bis(2-chloroisopropyl) ether
43 bis(2-chloroethoxy) methane
44 methylene chloride (dichloromethane)
45 methyl chloride (chloromethane)
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Table 3-2 (CONT.)
SAMPLING PARAMETERS
46 methyl bromide (bromomethane)
47 bromoform (tribromomethane)
48 dichlorobromomethane
51 chlorodibromomethane
52 hexachlorobutadiene
53 hexachlorocyclopentadiene
54 isophorone
55 naphthalene
56 nitrobenzene
57 2-nitrophenol
58 4-nitrophenol
59 2,4-dinitrophenol
60 4,6-dinitro-o-cresol
61 N-nitrosodimethylamine
62 N-nitrosodiphenylamine
63 N-nitrosodi-n-propylamine
64 pentachlorophenol
65 phenol
66 bis(2-ethylhexyl) phthalate
67 butyl benzyl phthalate
68 di-n-butyl phthalate
69 di-n-octyl phthalate
70 diethyl phthalate
71 dimethyl phthalate
72 1,2-benzanthraeene (benzo(a)anthracene)
73 benzo (a) pyrene (3,4-benzo-pyrene)
74 3,4-benzofluoranthene (benzo(b)fluoranthene)
75 11,12-benzofluoranthene (benzo(k)fluoranthene)
76 chrysene
77 acenaphthylene
78 anthracene
79 lf12-benzoperylene (benzo(ghi)-perylene)
80 fluorene
81 phenanthrene
82 1,2,5,6-dibenzanthracene (dibenzo (a,h) anthracene)
83 indeno (1,2,3-cd) pyrene (2,3-o-phenylene pyrene)
84 pyrene
85 tetrachloroethylene
86 toluene
87 trichloroethylene
88 vinyl chloride (chloroethylene)
89 aldrin
90 dieldrin
91 chlordane (technical mixture and metabolites)
92 4,4'-DDT
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Table 3-2 (CONT.)
SAMPLING PARAMETERS
93 4,4'-DDE (p,p'-DDX)
94 4,4'-DDD (p,p'-TDE)
95 alpha-endosulfan
96 beta-endosulfan
97 endosulfan sulfate
98 endrin
99 endrin aldehyde
100 heptachlor
101 heptachlor epoxide
102 alpha-BHC (BHC=hexachlorocyclohexane)
103 beta-BHC
104 gamma-BHC (lindane)
105 delta-BHC
106 PCB-1242 (Aroclor 1242)
107 PCB-1254 (Aroclor 1254)
108 PCB-1221 (Aroclor 1221)
109 PCB-1232 (Aroclor 1232)
110 PCB-1248 (Aroclor 1248)
111' PCB-1260 (Aroclor 1260)
112 PCB-1016 (Aroclor 1016)
113 toxaphene
114 antimony
115 arsenic
116 asbestos
117 beryllium
118 cadmium
119 chromium, total and hexavalent
120 copper
121 cyanide, total & amenable to chlorination
122 lead
123 mercury
124 nickel
125 selenium
126 silver
127 thallium
128 zinc
129 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)
Conventional Pollutants
oil & grease
TSS
pH
111-13
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Table 3-2 (CONT.)
SAMPLING PARAMETERS
Nonconventional Pollutants
gold
fluoride
phosphorus
aluminum
barium
iridium
magnesium
molybdenum
osmium
palladium
platinum
rhodium
ruthenium
sodium
tin
titanium
vanadium
yttrium
total phenols
bis (chloromethyl) ether
trichlorofluoromethane
dichlorodifluoromethane
Other Parameters
flow
temperature
111-14
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Long-Term Self-Monitoring Data - During the study of the metal
finishing industry, a request for long-term self-monitoring
data was sent to various industries within the Metal Finishing
Category. More than 50 plants responded with a full year of
daily data that had been analyzed by an approved EPA method.
The criteria used to select plants from whom data were requested
were:
1. The plant was believed to monitor, via analysis,
their effluent.
2. The plant was known to discharge wastewater that
contained cadmium, chromium, copper, lead, nickel,
silver, zinc, cyanide, or oils at levels that re-
quired treatment.
3. The plant had combinations of the following waste
treatment control technologies in-place:
a. Hydroxide precipitation and sedimentation
b. Precipitation/sedimentation followed by fil-
tration
c. Emulsion breaking/oil separation for oily wastes
d. Cyanide destruction
e. Hexavalent chromium reduction
4. A large percentage of the wastewater discharge re-
sulted from the manufacturing processes listed in
Table 3-1.
5. The mix of plants contained discharges to both sur-
face waters and publicly owned treatment works (POTW).
6. The selected plants covered a wide geographical dis-
tribution to avoid any geographical uniqueness.
Post Proposal Data - After publication of the proposed regulation,
industry and control authorities submitted data as part of the
comments. The data were not included in the derivation of the final
limits. The reasons for exclusion were: inadequate treatment, i.e.,
high TSS; technology different from regulatory basis; and incomplete
information. However, all the data were examined and a comparison
made between the submitted data and the effluent limits. Where
reasonable evidence was presented, modifications were made to the
analysis of the data to address the comment.
UTILIZATION OF INDUSTRY DATA
Data collected from the previously described sources are used through-
out this report in the development of a basis for limitations. Sub-
categorization was not deemed necessary because all wastes were amen-
able to the same treatment scheme. However, seven distinct types of
II1-15
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process raw wastes were found to occur in the Metal Finishing Category.
These seven process raw waste types are: common metals, precious metals,
complexed metals, hexavalent chromium, cyanide, oils, and solvents.
The water usage and raw waste characteristics for each raw waste type,
presented in Section V, were obtained from the analysis of raw waste-
water samples taken from the process wastes discharged by the manufac-
turing unit operations. Selection of the pollutant parameters for
control (Section VI) was made from these plant sampling results.
This selection required that two criteria be met: first, the
pollutant nature of the parameter must be significant; and second,
it must be discharged at a significant concentration level.
Based on the amount and types of pollutants requiring control,
applicable treatment technologies were studied and are discussed
in Section VII of this document. Wastewater treatment technolo-
gies utilized by the Metal Finishing Category plants and observed
during plant visits were used to identify applicable treatment
technologies. All performance data presented are for existing
treatment installations. Both in-process control and end-of-pipe
wastewater treatment were studied and are included in the discus-
sion. Actual sampling data are used in Section VII to define
treatment system performance and for the presentation of actual
achievable effluent concentration levels for various treatment
options. The cost of treatment (for both individual technolo-
gies and systems) based on literature surveys, on-site surveys,
and data from equipment manufacturers is contained in Section
VIII of this document. The guidelines and limitations for the
Best Practicable Control Technology Currently Available (BPT) are
presented in Section IX. Section X contains the guidelines and
limitations for the Best Available Technology Economically
Achievable (BAT). New Source Performance Standards (NSPS) are
presented in Section XI. Pretreatment guidelines and limita-
tions are discussed in Section XII. Innovative technologies and
the provisions for their use in the regulations are detailed in
Section XIII.
INDUSTRY DESCRIPTION
The Metal Finishing Category is defined by manufacturing processes.
The industries covered by the Metal Finishing Category are generally
included in Standard Industrial Classification (SIC) Major
Groups 34 through 39 and are those that perform some combination
of the 46 manufacturing unit operations listed in Table 3-1. The
specific industries covered by these Major Groups are listed in
Table 3-3. Industries listed in Table 3-3 which are not exclu-
sively in the Metal Finishing Category include porcelain enamel-
ing, coil coating, batteries manufacturing, electrical and elec-
tronic components, photographic equipment and supplies, iron and
steel, aluminum and aluminum alloys, copper and copper alloys,
and shipbuilding. For example, all of the industries listed
under Major Group 36 are covered under both the Electrical and
Electronics Component Category and the Metal Finishing Category.
The Electrical and Electronic Components Category covers
processes unique to electronics, and the Metal Finishing Category
covers the remaining processes used to manufacture the products
in Major Group 36.
111-16
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TABLE 3-JJ
INDUSTRIES WITHIN THE METAL FINISHING CATEGORY
Major Group 34 Fabricated Metal Products, Except Machinery and Transportation Equipment
341 Metal Cans and Shipping Containers.
342 Cutlery, Hand Tools, and General Hardware.
343 Heating Equipment (except Electric and Warm Air, Plumbing Fixtures).
344 Fabricated Structural Metal Products.
345 Screw Machine Products, and Bolts, Nuts, Screws, Rivets and Washers.
346 Metal Forgings and Stampings.
347 Coating, Engraving and Allied Services.
348 Ordnance and Accessories, except Vehicles and Guided Missiles.
349 Miscellaneous Fabricated Metal Products.
Major Group 35 Machinery, Except Electrical
351 Engines and Turbines.
352 Farm and Garden Machinery and Equipment.
353 Construction, Mining and Materials Handling Machinery and Equipment.
M 354 Metalworking Machinery and Equipment.
M 355 Special Industry Machinery, except Metalworking Machinery.
V 356 General Industrial Machinery and Equipment.
^J 357 Office, Computing, and Accounting Machines.
358 Refrigeration and Service Industry Machinery.
359 Miscellaneous Machinery, except Electrical.
Major Group 36 Electrical and Electronic Machinery, Equipment and Supplies
361 Electric Transmission and Distribution Equipment.
362 Electrical Industrial Apparatus.
363 Household Appliances.
364 Electric Lighting and Wiring Equipment.
365 Radio and Television Receiving Equipment, except Communication Types.
366 Communication Equipment.
367 Electronic Components and Accessories.
369 Miscellaneous Electrical Machinery, Equipment, and Supplies.
Major Group 37 Transportation Equipment
371 Motor Vehicles and Motor Vehicle Equipment.
372 Aircraft and Parts.
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TABLE 3-3 (Cont.)
Major Group 37 Transportation Equipment (Cont.)
373 Ship and Boat Building and Repairing.
374 Railroad Equipment.
375 Motorcycles, Bicycles, and Parts.
376 Guided Missiles and Space Vehicles and Parts.
379 Miscellaneous Transportation Equipment.
Major Group 38 Measuring, Analyzing and Controlling Instruments; Photographic, Medical and
Optical Goods; Watches and Clocks
381 Engineering, Laboratory, Scientific, and Research Instruments and Associated Equipment.
382 Measuring and Controlling Instruments.
383 Optical Instruments and Lenses.
384 Surgical, Medical, and Dental Instruments and Supplies.
385 Opthalmic Goods.
H 386 Photographic Equipment and Supplies
*? 387 Watches, Clocks, Clockwork Operated Devices, and Parts.
00
Major Group 39 Miscellaneous Manufacturing Industries
391 Jewelry, Silverware, and Plated Ware.
393 Musical Instruments.
394 Dolls.
395 Pens, Pencils, and Other Office and Artists' Materials.
396 Costume Jewelry, Costume Novelties, Buttons and Miscellaneous Notions, Except
Precious Metal.
399 Miscellaneous Manufacturing Industries.
-------
Based upon industry journal mailing lists, there are approximately
13,500 manufacturing facilities in the United States which are covered
by the Metal Finishing Category. These plants are engaged in the
manufacturing of a variety of products that are constructed
primarily by using metals. The operations performed (Table
3-1) usually begin with materials in the form of raw stock
(rods, bars, sheet, castings, forgings, etc.) and can progress
to the most sophisticated surface finishing operations. These
facilities vary greatly in size, age, number of employees and
number and type of operations performed. They range from
very small job shops with less than 10 employees to large
facilities employing thousands of production workers. Because of
the differences in size and processes, production facilities are
custom-tailored to the specific needs of each individual plant.
Figure 3-1 illustrates the variation in number of unit operations
that can be performed depending upon the complexity of the product.
The possible variations of unit operations within the Metal Finishing
Category are extensive. The unit operations (and their sequence)
presented in Figure 3-1 are not actual plants but are representa-
tive of possible manufacturers within the Metal Finishing Category.
Some complex products could require the use of nearly all 45 unit
operations, while a simple product might require only a single
operation.
Many different raw materials are used by the plants in the
Metal Finishing Category. Basis materials are almost exclusive-
ly metals which range from common copper and steel to extreme-
ly expensive high grade alloys and precious metals. The
solutions utilized in the various unit operations can contain
acids, bases, cyanide, metals, complexing agents, organic
additives, oils and detergents. All of these raw materials can
potentially enter wastewater streams during the production sequence.
Water usage within the Metal Finishing Category, the processes that
utilize water and the quantities of process wastewater generated by
metal finishing are presented in Section V. Plating and cleaning
operations are typically the biggest water users. While the
majority of metal finishing operations use water, some of them are
completely dry. The type of rinsing utilized can have a marked
effect on water usage as can the flow rates within the particular
rinse types. Product quality requirements often dictate the
amount of rinsing needed for specific parts. Parts requiring exten-
sive surface preparation will generally necessitate the use of larger
amounts of water.
111-19
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OQMMJBX PfiQBJCT
H
H
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I
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•»- Ship
SIMPLE PRODUCT
Raw
Stock
Machining
Ship
FIGURE 3-1
METAL FINISHING PROCESS APPLICATION
-------
UNIT OPERATIONS DESCRIPTIONS
This subsection describes each of the 46 individual unit opera-
tions that are included in the Metal Finishing Category.
1. Electroplating is the production of a thin surface
coating .of one metal upon another by electrodeposition.
This surface coating is applied to provide corrosion
protection, wear or erosion resistance, anti-frictional
characteristics, or for decorative purposes. The electro-
plating of common metals includes the processes in which
ferrous or nonferrous basis material is electroplated with
copper, nickel, chromium, brass, bronze, zinc, tin, lead,
cadmium, iron, aluminum or combinations thereof. Precious
metals electroplating includes the processes in which a
ferrous or nonferrous basis material is plated with gold,
silver, palladium, platinum, rhodium, indium, ruthenium,
iridium, osmium, or combinations thereof.
In electroplating, metal ions in either acid, alkaline or
neutral solutions are reduced on cathodic surfaces. The
cathodic surfaces are the workpieces being plated. The
metal ions in solution are usually replenished by the
dissolution of metal from anodes or small pieces con-
tained in inert wire or metal baskets. Replenishment
with metal salts is also practiced, especially for
chromium plating. In this case, an inert material must
be selected for the anodes. Hundreds of different
electroplating solutions have been adopted commercially
but only two or three types are utilized widely for a
particular metal or alloy. For example, cyanide
solutions are popular for copper, zinc, brass, cadmium,
silver, and gold. However, non-cyanide alkaline solu-
tions containing pyrophosphate have come into use
recently for zinc and copper. Zinc, copper, tin and
nickel are plated with acid sulfate solutions, especially
for plating relatively simple shapes. Cadmium and zinc
are sometimes electroplated from neutral or slightly aci-
dic chloride solutions. The most common methods of plating
are in barrels, on racks, and continuously from a spool or
coil.
2. Electroless Plating is a chemical reduction process which
depends upon the catalytic reduction of a metallic ion
in an aqueous solution containing a reducing agent and
the subsequent deposition of metal without the use of
external electrical energy. It has found widespread use
in industry due to several unique advantages over con-
ventional electroplating. Electroless plating provides a
111-21
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uniform plating thickness on all areas of the part
regardless of the configuration or geometry of the part.
An electroless plate on a properly prepared surface is
dense and virtually non-porous. Copper and nickel
electroless plating are the most common. The basic
ingredients in an electroless plating solution are:
1. A source of metal, usually a salt.
2. A reducer to reduce the metal to its base state.
3. A complexing agent to hold the metal in solution
(so the metal will not plate out indiscriminately)
4. Various buffers and other chemicals designed to
maintain bath stability and increase bath life.
Electroless plating is an autocatalytic process where
catalysis is promoted from one of the products of a
chemical reaction. The chemistry of electroless plating
is best demonstrated by examining electroless
nickel plating. The source of nickel is a salt such as
nickel chloride or nickel sulfate, and the reducer is
sodium hypophosphite. There are several complexing
agents can be used, the most common ones being citric
and glycolic acid. Hypophosphite anions in the presence
of water are dehydrogenated by the solid catalytic
surface provided by nickel to form acid orthophosphite
anions. Active hydrogen atoms are bonded on the catalyst
forming a hydride. Nickel ions are reduced to metallic
nickel by the active hydrogen atoms which are in turn
oxidized to hydrogen ions. Simultaneously, a portion
of the hypophosphite anions are reduced by the active
hydrogen and adsorbed on the catalytic surface producing
elemental phosphorus, water and hydroxyl ions. Elemental
phosphorus is bonded to or dissolved in the nickel making
the reaction irreversible. At the same time hypophosphite
anions are catalytically oxidized to acid orthophosphite
anions, evolving gaseous hydrogen. The basic plating
reactions proceed as follows:
The nickel salt is ionized in water
NiSO4 = Ni+2 + SO4~2
There is then a reduction-oxidation reaction
with nickel and sodium hypophosphite.
Ni+2 + SO ~2 + 2NaH0P00 + 2 HOO =
4 ^ ^ ^
The sodium hypophosphite also reacts in the
following manner:
PO0 + Hn = 2P + 2NaOH + 2H0O
111-22
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&s can be seen in the equations above, both nickel and
phosphorus are produced, and the actual metal deposited
is a nickel-phosphorus alloy. The phosphorus content can
be varied to produce different characteristics in the
nickel plate.
When electroless plating is done on a plastic basis material,
catalyst application and acceleration steps are necessary as
surface preparation operations« These steps are considered
part of the electroless plating unit operation.
Immersion plating is a chemical plating process in which a
thin metal deposit is obtained by chemical displacement of
the basis metal. Unlike electroless plating, it is not an
autocatalytic process. In immersion plating, a metal will
displace from solution any other metal that is below it in
the electromotive series of elements.
The lower (more noble) metal will be deposited from solution
while the more active metal (higher in the series)
will be dissolved. A common example of immersion plating
is the deposition of copper on steel from an acid copper
solution. Because of the similarity of the wastes pro-
duced and the materials involved, immersion plating is
considered part of the electroless plating unit operation.
Anodizing is an electrolytic oxidation process which con-
verts the surface of the metal to an insoluble oxide.
These oxide coatings provide corrosion protection, decora-
tive surfaces, a base for painting and other coating pro-
cesses, and special electrical and mechanical properties.
Aluminum is the most frequently anodized material, while
some magnesium and limited amounts of zinc and titanium
are also treated.
Although the majority of anodizing is carried out by
immersion of racked parts in tanks, continuous anodizing
is done on large coils of aluminum in a manner similar to
continuous electroplating. For aluminum parts, the for-
mation of the oxide occurs when the parts are made anodic
in dilute sulfuric acid or dilute chromic acid solutions.
The oxide layer begins formation at the extreme outer sur-
face, and as the reaction proceeds, the oxide grows into the
metal. The last formed oxide, known as the boundary layer,
is located at the interface between the base metal and the
oxide. The boundary is extremely thin and nonporous. The
sulfuric acid process is typically used for all parts fab-
ricated from aluminum alloys except for parts subject to
stress or containing recesses in which the sulfuric acid
solution may be retained and attack the aluminum. Chromic
acid anodic coatings are more protective than sulfuric acid
coatings and have a relatively thick boundary layer. For
these reasons, a chromic acid bath is used if a complete
rinsing of the part cannot be achieved.
111-23
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Coating - This manufacturing operation includes
chromating, phosphating, metal coloring and passivating.
These coatings are applied to previously deposited
metal or basis material for increased corrosion protection,
lubricity, preparation of the surface for additional
coatings or formulation of a special surface appearance.
In chromating, a portion of the base metal is converted to
one of the components of the protective film formed by the
coating solution. This occurs by reaction with aqueous
solutions containing hexavalent chromium and active organic
or inorganic compounds. Chromate coatings are most frequent-
ly applied to zinc, cadmium, aluminum, magnesium, copper,
brass, bronze and silver. Most of the coatings are applied
by chemical immersion although a spray or brush treatment
can be used. Changes in the solutions can impart a wide
range of colors to the coatings from colorless to irides-
cent yellow, brass, brown, and olive drab. Additional
coloring of the coatings can be achieved by dipping the
parts in organic dye baths to produce red, green, blue,
and other colors.
Phosphate coatings are used to provide a good base for
paints and other organic coatings, to condition the sur-
faces for cold forming operations by providing a base for
drawing compounds and lubricants, and to impart corrosion
resistance to the metal surface by the coating itself or
by providing a suitable base for rust-preventative oils or
waxes. Phosphate conversion coatings are formed by the
immersion of iron, steel, or zinc plated steel in a dilute
solution of phosphoric acid plus other reagents. The
method of applying the phosphate coating is dependent upon
the size and shape of the part to be coated. Small parts
are coated in barrels immersed in the phosphating solution.
Large parts, such as steel sheet and strip, are spray coated
or continuously passed through the phosphating solution.
Supplemental oil or wax coatings are usually applied after
phosphating unless the part is to be painted.
Metal coloring by chemical conversion methods produces a
large group of decorative finishes. This operation covers
only chemical methods of coloring in which the metal surface
is converted into an oxide or similar metallic compound.
The most common colored finishes are used on copper, steel,
zinc, and cadmium.
Application of the color to the cleaned basis metal involves
only a brief immersion in a dilute aqueous solution. The
colored films produced on the metal surface are extremely
thin and delicate. Consequently, they lack resistance to
handling and the atmosphere. A clear lacquer is often used
to protect the colored metal surface. A large quantity of
copper and brass is colored to yield a wide variety of
shades and colors. Shades of black, brown, gray, green and
patina can be obtained on copper and brass by use of appro-
priate coloring solutions. The most widely-used colors for
111-24
-------
ferrous metals are based on oxides which yield black, brown,
or blue colors. A number of colors can be developed on zinc
depending on the length of immersion in the coloring solu-
tion. Yellow, bronze, dark green, black and brown colors
can be produced on cadmium. Silver, tin, and aluminum are
also colored commercially. Silver is given a gray color by
immersion in a polysulfide solution such as ammonium
polysulfide. Tin can be darkened to produce an antique
finish of pewter by immersion in a solution of nitric acid
and copper sulfate.
Passivation refers to forming a protective film on metals,
particularly stainless steel and copper, by immersion in
an acid solution. Stainless steel is passivated in order
to dissolve any imbedded iron particles and to form a thin
oxide film on the surface of the metal. Typical solutions
for passivating stainless steel include nitric acid and
nitric acid with sodium dichromate. Copper is passivated
with a solution of ammonium sulfate and copper sulfate
forming a blue-green patina on the surface of the metal.
5. Etching and Chemical Milling - These processes are used to
produce specific design configurations and tolerances or
surface appearances on parts (or metal-clad plastic in the
case of printed circuit boards)'by controlled dissolution
with chemical reagents or etchants. Included in this classi-
fication are the processes of chemical milling, chemical etch-
ing and bright dipping. Chemical etching is the same process
as chemical milling except the rates and depths of metal
removal are usually much greater in chemical milling. Typical
solutions for chemical milling and etching include ferric
chloride, nitric acid, ammonium persulfate, chromic acid,
cupric chloride, hydrochloric acid and combinations of these
reagents. Bright dipping is a specialized form of etching
and is used to remove oxide and tarnish from ferrous and
nonferrous materials and is frequently performed just prior
to anodizing. Bright dipping can produce a range of surface
appearances from bright clean to brilliant depending on the
surface smoothness desired for the finished part. Bright
dipping solutions usually involve mixtures of two or more
of sulfuric, chromic, phosphoric, nitric and hydrochloric
acids. Also included in this unit operation is the
stripping of metallic coatings.
6. Cleaning involves the removal of oil, grease and dirt from
the surface of the basis material using water with or
without a detergent or other dispersing agent. Alkaline
cleaning (both electrolytic and non-electrolytic) and acid
cleaning are both included.
111-25
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Alkaline cleaning is used to remove oily dirt or solid
soils from workpieces. The detergent nature of the
cleaning solution provides most of the cleaing action
with agitation of the solution and movement of the
workpiece being of secondary importance. Alkaline
cleaners are classified into three types: soak, spray,
and electrolytic. Soak cleaners are used on easily
removed soil. This type of cleaner is less efficient
than spray or electrolytic cleaners. Spray cleaners
combine the detergent properties of the solution with
the impact force of the spray which mechanically
loosens the soil. Electrolytic cleaning produces the
cleanest surface available from conventional methods of
alkaline cleaning. The effectiveness of this method
results from the strong agitation of the solution by
gas evolution and oxidation-reduction reactions that
occur during electrolysis. Also, certain dirt parti-
cles become electrically charged and are repelled from
the surface. Direct current (cathodic) cleaning uses
the workpiece as the cathode, while for reverse current
(anodic) cleaning the workpiece is the anode. In
periodic reverse current cleaning, the current is
periodically reversed from direct current to reverse
current. Periodic reverse cleaning gives improved smut
removal, accelerated cleaning and a more active surface
for any subsequent surface finishing operation.
Acid cleaning is a process in which a solution of an
inorganic (mineral) acid, organic acid, or an acid
salt, in combination with a wetting agent or detergent,
is employed to remove oil, dirt, or"oxide from metal
surfaces. Acid cleaning is done with various acid
concentrations can be referred to as pickling, acid
dipping, descaling, or desmutting. The solution may or
may not be heated and can be an immersion or spray
operation. Agitation is normally required with soaking,
and spray is usually used with complex shapes. An acid
dip operation may also follow alkaline cleaning prior
to plating. Phosphoric acid mixtures are also in
common use to remove oils and light rust while leaving
a phosphate coating that provides a paint base or
temporary resistance to rusting. Strong acid solutions
are used to remove rust and scale prior to surface
finishing.
7. Machining is the general process of removing stock from
a workpiece by forcing a cutting tool through the
workpiece, removing a chip of basis material. Machining
operations such as turning, milling, drilling, boring,
tapping, planing, broaching, sawing and cutoff, shaving,
threading, reaming, shaping, slotting, hobbing, filing,
and chamfering are included in this definition.
111-26
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8. Grinding is the process of removing stock from a workpiece
by the use of a tool consisting of abrasive grains held by
a rigid or semirigid binder. The tool is usually in the
form of a disk (the basic shape of grinding wheels), but
may also be in the form of a cylinder, ring, cup, stick,
strip, or belt. The most commonly used abrasives are
aluminum oxide, silicon carbide, and diamond. The processes
included in this unit operation are sanding (or cleaning to
remove rough edges or excess material), surface finishing,
and separating (as in cut-off or slicing operations).
9. Polishing is an abrading operation used to remove or smooth
out surface defects (scratches, pits, tool marks, etc.)
that adversely affect the appearance or function of a part.
Polishing is usually performed with either a belt or wheel
to which an abrasive such as aluminum oxide or silicone
carbide is bonded. Both wheels and belts are flexible and
will conform to irregular or rounded areas where necessary.
The operation usually referred to as buffing is included in
the polishing operation.
10. Barrel Finishing or tumbling is a controlled method of
processing parts to remove burrs, scale, flash, and oxides
as well as to improve surface finish. Widely used as a
finishing operation for many parts, it obtains a uniformity
of surface finish not possible by hand finishing. For
large quantities of small parts it is generally the most
economical method of cleaning and surface conditioning.
Parts to be finished are placed in a rotating barrel or
vibrating unit with an abrasive media, water or oil, and
usually some chemical compound to assist in the operation.
As the barrel rotates slowly, the upper layer of the work
is given a sliding movement toward the lower side of the
barrel, causing the abrading or polishing action to occur.
The same results may also be accomplished in a vibrating
unit, in which the entire contents of the container are
in constant motion.
11. Burnishing is the process of finish sizing or smooth
finishing a workpiece (previously machined or ground) by
displacement, rather than removal, of minute surface
irregularities. It is accomplished with a smooth point
or line-contact and fixed or rotating tools.
111-27
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12. Impact Deformation is the process of applying an impact
torce to a workpiece such that the workpiece is permanently
deformed or shaped. Impact deformation operations include
shot peening, peening, forging, high energy forming,
heading, and stamping.
13. Pressure Deformation is the process of applying force (at
a slower rate than an impact force) to permanently deform
or shape a workpiece. Pressure deformation includes
operations such as rolling, drawing, bending, embossing,
coining, swaging, sizing, extruding, squeezing, spinning,
seaming, staking, piercing, necking, reducing, forming,
crimping, coiling, twisting, winding, flaring or weaving.
14. Shearing is the process of severing or cutting a
workpiece by forcing a sharp edge or opposed sharp edges
into the workpiece stressing the material to the point of
shear failure and separation.
15. Heat Treating is the modification of the physical properties
of a workpiece through the application of controlled heating
and cooling cycles. Such operations as tempering, carburi-
zing, cyaniding, nitriding, annealing, normalizing, austen-
izing, quenching, austempering, siliconizing, martempering,
and malleabilizing are included in this definition.
16. Thermal Cutting is the process of cutting, slotting or
piercing a workpiece using an oxyacetylene oxygen lance
or electric arc cutting tool.
17. Welding is the process of joining two or more pieces of
material by applying heat, pressure or both, with or with-
out filler material, to produce a localized union through
fusion or recrystallization across the interface. Included
in this process are gas welding, resistance welding, arc
welding, cold welding, electron beam welding, and laser
beam welding.
18. Brazing is the process of joining metals by flowing a thin,
capillary thickness layer of nonferrous filler metal into
the space between them. Bonding results from the intimate
contact produced by the dissolution of a small amount of
base metal in the molten filler metal, without fusion of the
base metal. The term brazing is used where the temperature
exceeds 425°C (800°F).
19. Soldering is the process of joining metals by flowing a
thin (capillary thickness) layer of nonferrous filler metal
into the. space between them. Bonding results from the in-
timate contact produced by the dissolution of a small amount
111-28
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of base metal in the molten filler metal, without fusion
of the base metal. The term soldering is used where the
temperature range falls below 425°C (800°F).
20. Flame Spraying is the process of applying a metallic coating
to a workpiece using finely powdered fragments of wire,
together with suitable fluxes, are projected through a cone
of flame onto the workpiece.
21. Sand Blasting is the process of removing stock, including
surface films, from a workpiece by the use of abrasive
grains pneumatically impinged against the workpiece. The
abrasive grains used include sand, metal shot, slag, silica,
pumice, or natural materials such as walnut shells.
22. Abrasive Jet Machining is a mechanical process for
cutting hard brittle materials. It is similar to sand
blasting but uses much finer abrasives carried at high
velocities (500-3000 fps) by a liquid or gas stream. Uses
include frosting glass, removing metal oxides, de-
burring, and drilling and cutting thin sections of metal.
23. Electrical Discharge Machining is a process which
can remove metal with good dimensional control from any
metal. It cannot be used for machining glass, ceramics,
or other nonconducting materials. The machining action
is caused by the formation of an electrical spark between
an electrode, shaped to the required contour, and the
workpiece. Since the cutting tool has no contact with
the workpiece, it can be made from a soft, easily worked
material such as brass. The tool works in conjunction with
a fluid such as mineral oil or kerosene, which is fed to
the work under pressure. The function of this coolant is
to serve as a dielectric, to wash away particles of eroded
metal from the workpiece or tool, and to maintain a uniform
resistance to flow of current.
Electrical discharge machining is also known as spark
machining or electronic erosion. The operation was de-
veloped primarily for machining carbides, hard nonferrous
alloys, and other hard-to-machine materials.
24. Electrochemical Machining is a process based on the
same principles usedin electroplating except the workpiece
is the anode and the tool is the cathode. Electrolyte is
pumped between the electrodes and a potential applied with
the result that metal is rapidly removed.
In this process, electrode accuracy is important since
the surface finish of the electrode tool will be reproduced
in the surface of the workpiece. While copper is frequently
111-29
-------
used as the electrode, brass, graphite, and copper-tungsten
are also used. The tool must be an electrical conductor,
easy to machine, corrosion resistant, and able to conduct
the quantity of current needed. Although there is no
standard electrolyte, sodium chloride is more generally
used than others.
25. Electron Beam Machining is a thermoelectric process.
In electron beam machining, heat is generated by high
velocity electrons impinging on part of the workpiece. At
the point where the energy of the electrons is
focused, it is transformed into sufficient thermal
energy to vaporize the material locally. The process is
generally carried out in a vacuum. While the metal-removal
rate of electron beam machining is approximately 0.01
milligrams per second, the tool is accurate and is
especially adapted for micro-machining. There is no heat
affected zone or pressure on the workpiece and extremely
close tolerances can be maintained. The process results
in X-ray emission which requires that the work area
be shielded to absorb radiation. At present the
process is used for drilling holes as small as 0.0508
mm (0.002 in.) in any known material, cutting slots,
shaping small parts, and machining sapphire jewel bearings.
26. Laser Beam Machining is the process whereby a highly
focused monochromatic collimated beam of light is used to
remove material at the point of impingement on a workpiece.
Laser beam machining is a thermoelectric process, and material
removal is largely accomplished by evaporation although some
material is removed in the liquid state at high velocity.
Since the metal removal rate is very small, they are used
for such jobs as drilling microscopic holes in carbides
or diamond wire drawing dies and for removing metal in
the balancing of high-speed rotating machinery.
Lasers can vaporize any known material. They have small
heat affected zones and work easily with nonmetallic hard
materials.
27. Plasma Arc Machining is the process of material removal or
shaping of a workpiece by a high velocity jet of high
temperature ionized gas. A gas (nitrogen, argon, or
hydrogen) is passed through an electric arc causing it to
become ionzied and raised to temperatures in excess of
16,649°C (30,000°F). The relatively narrow plasma jet melts
and displaces the workpiece material in its path. Because
plasma machining does not depend on a chemical reaction
IH-30
-------
between the gas and the work material and because plasma
temperatures are extremely high, the process can be used
on almost any metal, including those that are resistant to
oxygen-fuel gas cutting. The method is of commercial im-
portance mainly for profile cutting of stainless steel and
aluminum alloys.
28. Ultrasonic Machining is a mechanical process designed to
effectively machine hard, brittle materials. It removes
material by the use of abrasive grains which are carried in
a liquid between the tool and the work and which bombard
the work surface at high velocity. This action gradually
chips away minute particles of material in a pattern
controlled by the tool shape and contour. A transducer
causes an attached tool to oscillate linearly at a
frequency of 20,000 to 30,000 times per second at an
amplitude of 0.0254 to 0.127 mm (0.001 to 0.005 in). The
tool motion is produced by being part of a sound wave energy
transmission line which causes the tool material to change
its normal length by contraction and expansion. The tool
holder is threaded to the transducer and oscillates linearly
at ultrasonic frequencies, thus driving the grit particles
into the workpiece. The cutting particles, boron carbide
and similar materials, are of a 280-mesh size or finer,
depending upon the accuracy and the finish desired. Opera-
tions that can be performed include drilling, tapping, coin-
ing, and the making of openings in all types of dies.
Ultrasonic machining is used principally for machining
materials such as carbides, tool steels, ceramics, glass,
gem stones, and synthetic crystals.
29. Sintering is the process of forming a mechanical part from
a powdered metal by fusing the particles together under
pressure and heat. The temperature is maintained below
the melting point of the basis metal.
30. Laminating is the process of adhesive bonding layers of
metal, plastic, or wood to form a part.
31. Hot Dip Coating is the process of coating a metallic
workpiece with another metal by immersion in a molten bath
to provide a protective film. Galvanizing (hot dip zinc)
is the most common hot dip coating.
32. Sputtering is the process of covering a metallic or non-
metallic workpiece with thin films of metal. The surface
to be coated is bombarded with positive ions in a gas
discharge tube, which is evacuated to a low pressure.
111-31
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33. Vapor Plating is the process of decomposition of a metal or
compound upon a heated surface by reduction or decomposition
of a volatile compound at a temperature below the melting
point of either the deposit or the basis materi'al.
34. Thermal Infusion is the process of applying a fused zinc,
cadmium, or other metal coating to a ferrous workpiece by
imbuing the surface of the workpiece with metal powder or
dust in the presence of heat.
35. Salt Bath Descaling is the process of removing surface
oxides or scale from a workpiece by immersion of the
workpiece in a molten salt bath or a hot salt solution.
Molten salt baths are used in a salt bath - water quench -
acid dip sequence to clean hard-to-remove oxides from
stainless steels and other corrosion-resistant alloys.
The work is immersed in the molten salt (temperatures range
from 400 - 540 degrees C), quenched with water, and then
dipped in acid. Oxidizing, reducing, and electrolytic
baths are available, and the particular type needed is
dependent on the oxide to be removed.
36. Solvent Degreasing is a process for removing oils and grease
from the surfaces of a workpiece by the use of organic
solvents, such as aliphatic petroleums (eg-kerosene, naptha),
aromatics (eg-benzene, toluene), oxygenated hydrocarbons
(eg-ketones, alcohol, ether), halogenated hydrocarbons
(eg-l,l,l-trichloroethane, trichloroethylene, methylene
chloride), and combinations of these classes of solvents.
Solvent cleaning can be accomplished by either the liquid or
vapor phase. Solvent vapor degreasing is normally quicker
than solvent liquid degreasing. However, ultrasonic vibra-
tion is sometimes used with liquid solvent so as to
decrease the required immersion time with complex shapes.
Solvent cleaning is often used as a precleaning operation
such as prior to the alkaline cleaning that precedes plating,
as a final cleaning of precision parts, or as a surface pre-
paration for some painting operations.
Emulsion cleaning is a type of solvent degreasing that uses
common organic solvents (eg-kerosene, mineral oil, glycols,
and benzene) dispersed in an aqueous medium with the aid of
an emulsifying agent. Depending on the solvent used, clean-
ing is done at temperatures from room temperature to 82°C
(180°F). This operation uses less chemical than solvent
degreasing because of the lower solvent concentration
employed. The process is used for rapid superficial clean-
ing and is usually performed as emulsion spray cleaning.
111-32
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37. Paint Stripping is the process of removing an organic coating
from a workpiece. The stripping of such coatings is usually
performed with caustic, acid, solvent, or molten salt.
38. Painting is the process of applying an organic coating
to a workpiece. The application of coatings such as paint,
varnish, lacquer, shellac, and plastics by processes such
as spraying, dipping, brushing, roll coating, lithographing,
and wiping are included. Spray painting is by far the most
common and can be used with nearly all varieties of paint.
The paint can be sprayed manually or automatically, hot
or cold, and it may be atomized with or without compressed
air to force the paint through an orifice. Other processes
included under this unit operation are printing, silk
screening and stenciling.
39. Electrostatic Painting is the application of electrosta-
tically charged paint particles to an oppositely charged
workpiece followed by thermal fusing of the paint particles
to form a cohesive paint film. Usually the paint is applied
in spray form and may be applied manually or automatically,
hot or cold, and with or without compressed air atomization.
Both waterborne and solvent-borne coatings can be sprayed
electrostatically.
40. Electrepainting is the process of coating a workpiece by
either making it anodic or cathodic in a bath that is
generally an aqueous emulsion of the coating material. The
electrodeposition bath contains stabilized resin, dispersed
pigment, surfactants, and sometimes organic solvents in water,
Electropainting is used primarily for primer coats because
it gives a fairly thick, highly uniform, corrosion resistant
coating in relatively little time.
41. Vacuum Metalizing is the process of coating a workpiece
with metal by flash heating metal vapor in a high-vacuum
chamber containing the workpiece. The vapor condenses on
all exposed surfaces.
i
42. Assembly is the fitting together of previously manufactured
parts or components into a complete machine, unit of a
machine, or structure.
43. Calibration is the application of thermal, electrical, or
mechanical energy to set or establish reference points
for a component or complete assembly.
44. Testing is the application of thermal, electrical, or
mechanical energy to determine the suitability or function-
ality of a component or complete assembly.
111-33
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45. Mechanical Plating is the process of depositing metal coatings
on a workpiece via the use of a tumbling barrel, metal powder.
and usually glass beads for the impaction media. The operation
is subject to the same cleaning and rinsing operations that are
applied before and after the electroplating operation.
46. Printed Circuit Board Manufacturing involves the formation of
a circuit pattern of conductive metal (usually copper) on
nonconductive board materials such as plastic or glass.
There are five basic steps involved in the manufacture of
printed circuit boards: cleaning and surface preparation,
catalyst and electroless plating, pattern printing and masking,
electroplating, and etching.
After the initial cutting, drilling and sanding of the boards.
the board surface is prepared for plating electroless copper.
This surface preparation involves an etchback (removal of
built-up plastic around holes) and an acid and alkaline
cleaning to remove grime, oils, and fingerprints. The board is
then etched and rinsed. Following etching, the catalyst is
applied, and rinsing operations following catalyst
application. The entire board is then electroless copper
plated and rinsed.
Following electroless copper plating, a plating resist is
applied in non-circuit areas. Following application of a
resist, a series of electroplates are applied. First the
circuit is copper plated. A solder electroplate is applied
next followed by a rinse. For copper removal in non-circuit
areas, an etch step is next. After the etch operation, a
variety of tab plating processes can be utilized depending on
the board design requirements. These include nickel
electroplating, gold electroplating, rhodium electroplating.
and tin immersion plating.
There are presently three main production methods for printed
circuit boards: additive, semi-additive, and subtractive. The
additive method uses pre-sensitized. unclad material as the
starting board; the semi-additive method uses unclad.
unsensitized material as the starting board; and the
subtractive method begins with copper clad, unsensitized
material.
111-34
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SECTION IV
INDUSTRY CATEGORIZATION
INTRODUCTION
The primary purpose of industry categorization is to establish
groupings within the Metal Finishing Category (MFC) such that
each group (subcategory) has a uniform set of effluent limita-
tions. This requires that the elements of each group be cap-
able of using similar treatment technologies to achieve the
effluent limitations. Thus, the same wastewater treatment and
control technology is applicable within a subcategory and a uni-
form treated effluent results from the application of a specific
treatment and control technology. This section presents the sub-
categorization established for the Metal Finishing Category and
explains the selection rationale.
Proper industry subcategorization defines groups within an
industrial category whose wastewater discharges can be controlled
by the same concentration or mass based limitations. The
subsections which follow deal with these considerations as
they apply to the Metal Finishing Category.
CATEGORIZATION BASIS
The following aspects of the Metal Finishing Category were
considered for the bases of establishing subcategories:
1. Raw waste characteristics
2. Manufacturing processes
3. Raw materials (basis and process)
4. Product type or production volume
5. Size and age of facility
6. Number of employees
7. Water usage
8. Individual plant characteristics
After examination of the potential categorization bases, a single
metal finishing subcategory was established. All process waste-
waters in the Metal Finishing Category are amenable to treat-
ment by a single system and one set of discharge standards
results from the application of a single waste treatment
technology.
Seven distinct types of raw wastes are present in metal finishing
wastewaters. These raw wastes can be divided into two constituents,
namely: inorganic and organic wastes. These can then be further
subdivided into the specific types of waste that occur in each of
the two major areas and are identified in Table 4-1.
IV-1
-------
TABLE 4-1
METAL FINISHING CATEGORY RAW WASTE CLASSIFICATIONS
MAJOR SUBDIVISION
INORGANIC WASTES
ORGANIC WASTES
RAW WASTE TYPE
1.
2.
3.
4.
5.
6.
7.
Common metals
Precious metals
Complexed metals
Chromium (hexavalent)
Cyanide
Oils
Toxic organics
Figure 4-1 presents the waste treatment requirement for the Metal
Finishing Category and illustrates the effect of raw waste type
upon the treatment technology requirements. All of the process raw
wastes resulting from each of the 46 individual unit operations,
previously defined and described in Section III, are encompassed by
one or more of the raw waste types. Table 4-2 presents a tabulation
of the manufacturing unit operations and the types of the raw waste
that they have the potential to generate. Thus a direct relationship
exists between the treatment system requirements and the unit opera-
tions performed at a manufacturing facility. Subsequent sections of
this document further describe the specifics of the relationship be-
tween the unit operations performed, the wastes they produce, and
the various levels of treatment technology and systems applicable
to guideline limitations.
The following paragraphs discuss other approaches that were con-
sidered as bases for further subdividing the metal finishing sub-
category and the rationale for further subdivision being unneces-
sary.
Manufacturing Processes
The manufacturing processes employed by the Metal Finishing Cate-
gory are fully represented by the 46 unit operations that were
defined in Section III. Unit operation subdivision would be
overly complex as a subcategorization basis due to the number of
combinations of processes that exists in this category. In addition,
subdivision on the basis of each of the unit operations is not unique
since many operations generate the same waste constituents. Unit
operations with similar waste characteristics could be combined to
form individual subcategories and thus effectively provide a cate-
gorization based upon waste characteristics. However, as explained
IV-2
-------
Haste Treatment
(If Applicable)
Treated
Effluent
Manufacturing Facility
Raw Haste Sources
charge
'stem
Fluent \
| . ,___„„_!
nt 1 Oily Waste • | Chromium j
e) ! Removal ' I Reduction j
| J I |
i
Cannon
Metals
1
j Cyanide 2
j *
| Destruction j
| |
Toxic
Organics
•
j Complexed J I Precious •
Metals ! j Metals j
! Removal j j Recovery J
si
•H
f
Without Cyanide
*
^ —
Raw Waste
. (Common Metals)
I
Haul*
sd Or
jf Reclaimed
"~ ~" 1
I
1
I
I—
Metals ~|
Removal j
Hauled Or
Reclaimed
Treated
Effluent
Final Treated
Effluent
Normal Route
Optional Route
Notes Discharge frcm precious metals recovery may be
hauled in alternative ways, depending on the
recovery method in use.
FIGURE 4-1
WASTE TREATMENT SCHEMATIC
-------
TABLE 4-2
WASTE CHARACTERISTIC DISTRIBUTION
^""^^^^ WASTE
^""•••-CHARACTERISTICS
UNIT ^^---^
OPERATION ' ^"---^^^
1. Electroplating
2. Electroless Plating
3. Anodizing
4. Conversion Coating
5. Etching (Chem. Milling)
6; Cleaning
7. Machining
8. Grinding
9. Polishing
10. Tumbling
11. Burnishing
12. Impact Deformation
13. Pressure Deformation
14. Shearing
15. Heat Treating
16. Thermal Cutting
17. Welding
18. Brazing
19. Soldering
20. Flame Spraying
21. Sand Blasting
22. Other Abr. Jet Machining
23. Elec. Discharge Machining
24. Electrochemical Machining
25. Electron Beam Machining
26. Laser Beam Machining
27. Plasma Arc Machining
28. Ultrasonic Machining
INORGANICS
Common Precious Complexed Chromium
Metals Metals Metals (Hexavalent)
XX X
XXX
X X
XX X
XX X X
XX X X
X
X
X X
X X
XX
X
X
X
X
X
X
X
X X
X
X
X
X
X
X
X
X
X
ORGANICS
Toxic
Cyanide Oils Organics
X
X
X
XXX
X
X
X
X X
X X
X
X
X
XXX
X
X
XXX
-------
TABLE 4-2
WASTE CHARACTERISTIC DISTRIBUTION
(com.)
WASTE
CHARACTERISTICS
UNIT
OPERATION
INORGANICS
Connron Precious Conplexed Chromium
Metals Metals Metals (Hexavalent)
ORGANICS
Toxic
Cyanide Oils Qrganics
29. Sintering x
30. Laminating x
31. Hot Dip Coating x
32. Sputtering x
33. Vapor Plating x
34. Thermal Infusion x
35. Salt Bath Descaling x
36. Solvent Degreasing x
37. Paint Stripping x
38. Painting x
39. Electrostatic Painting x
40, Electrcpainting x
41. Vacuum Metalizing x
42. Assembly x
43. Calibration x
44. Testing x
45. Mechanical Plating x
46. Printed Circuit Board x
Manufacturing
x
X
X
X
X
X
X
X
X
X
X
X
IF
«n>
X
X
-------
previously, a direct correlation exists between the unit
operations performed and treatment technology needed via
the selected metal finishing subcategorization. Therefore,
manufacturing process variations are inherently accounted
for by their waste characteristics and no further subdivision on the
basis of manufacturing process is required.
Haw Materials
There is a wide variation in basis materials, process materials,
and process chemicals used within this industry and all wastes are
a direct result of this material usage. Subcategorization
on the basis of raw material usage would not result in industry
subgroups whose wastes are amenable to treatment by different
systems.
Product Type or Production Volume
The products manufactured by the Metal Finishing Category cover
virtually the entire spectrum of metallic goods. There are
specific differences in manufacturing operations and many vari-
eties of raw and process materials are used throughout the cate-
gory. However, wastewaters resulting from the manufacture of many
different products have the same waste treatment requirements and
this is accounted for by the single metal finishing subcategory.
The production volume influences the mass of pollutants discharged
but does not alter the waste constituents. Therefore, the quantity
of work processed is not appropriate as a basis for subcategoriza-
tion.
Size and Age of Facility
The nature of the manufacturing processes for the Metal Finishing
Category is the same in all facilities regardless of their size.
Size is an insufficient criterion for further subdivision since the
waste characteristics of a plant depend on the raw materials and
the unit operations employed. Size, however, is an important
consideration in determining the mass of pollutants dis-
charged.
The relative age of plants is important but is not a suitable basis
for subdividing the metal finishing subcategory because it does not
consider those items which affect the effluent discharged. The age
of a plant has no bearing on the resulting waste characteristics or
the required waste treatment.
Number of Employees
The number of employees is not an appropriate basis for subdivision
since identical manufacturing operations can be performed manu-
al V- 6
-------
ally or by automatic machinery. For example, a specific operation
might be accomplished manually by several machine operators for a
particular production level or, if automated, it might reguire only
one operator to produce an equivalent production output. In both
cases, the resulting waste characteristics are identical if all
other factors are the same.
Water Usage
Variations in water usage will not alter the identity of waste-
water constituents but may affect their concentrations in the
waste stream. These variations are due mainly to the different
rinsing operations employed (i.e. single stage rinsing, series
rinsing, countercurrent rinsing, etc). Since wastewater treat-
ment systems are designed to remove groups of pollutants (having
similar physical or chemical properties), subcategorization
on the basis of water usage would not be appropriate.
Individual Plant Characteristics
Individual plant characteristics, including geographical loca-
tion, do not provide a proper basis for subcategorization
because they do not affect the process wastewater charac-
teristics of the plant.
Summary of Categorization Bases
For this study, a single metal finishing subcategory which includes
seven types of raw waste was established. The primary division of
waste characteristics is the grouping of wastes into inorganic and
organic compounds. These two groups are then subdivided into four
inorganic and three organic raw waste types. The seven raw
waste types encompass the pollutants contained in the wastewaters
generated by all combinations of unit operations, raw materials,
and process materials and chemicals employed in the Metal
Finishing Category.
EFFLUENT LIMITATION BASE
In addition to determining the necessity for subdividing the
Metal Finishing Category, subcategorization also involves the
selection of a parameter on which to base limitations.
IV-7
-------
Since pollutants are measured in terras of their concentration
(mg/1)r concentration itself is the obvious primary considera-
tion for quantification of the limitations. Utilization of
concentration has the following advantages:
1. Concentration is a directly measurable parameter
using fundamental sampling and analysis techniques.
2. Industry, via its self-monitoring data, has the
opportunity to rapidly recognize and respond to
deviations from a given set of limitations.
3. Application of pertinent treatment and control
systems to either new or existing manufacturing
facilities is straightforward because these systems
are designed to provide reduction to specific effluent
concentration levels for specific pollutants.
A production related parameter for this industry, such as a
combination of the product surface area and the number of
particular wastewater producing operations performed, can be
used in conjunction with the concentration and process flow
rate to provide mass discharge limitations (e.g. limitation
in terms of mg/operation-sg.m. for electroplating operations).
Based on previous electroplating studies, the application
of this type of parameter to quantify limitations has proven
to be difficult to understand, implement, and enforce. Several
specific problems associated with the use of a production re-
lated parameter for the Metal Finishing Category are:
1. Differences in part configuration are not
accounted for by merely using a surface
area basis such as was used in the past for
electroplating.
2. It is often difficult to determine the pro-
duction level. For example, the overall
area of barrel plated items such as miscel-
laneous jewelry varies constantly throughout
a normal production day. To determine pro-
duction (surface area plated) requires measure-
ment of each individual part.
IV-8
-------
3. Mass based limitations are difficult to implement
if either the production sequence or processed
parts are constantly changing, as is especially
the case for job shops.
4. It is often difficult to establish what constitutes
a single wastewater producing operation since
operations may be dry or wet and the sequence of
performing operations is subject to variation.
The use of concentration alone as the limitation criterion allows
direct measurement and analysis of the treated effluent to verify
compliance with the regulations. Thus concentration is selec-
ted as the limitations basis for the Metal Finishing Category.
IV-9
-------
SECTION V
WASTE CHARACTERIZATION
INTRODUCTION
This section presents the water uses, identifies the waste
constituents, and quantifies the pollutant parameters that
originate in the Metal finishing Category. Published literature.
data collection portfolio responses, and actual sampling data were
reviewed in order to obtain data for this section. In general.
quantitative raw waste information was not included in the data
collection portfolios. When such information was included, it was
fragmented, incomplete and nearly impossible to correlate.
Therefore, the raw waste data presented are derived from an
analysis of samples taken at visited plants, downstream of the
manufacturing sources, and prior to waste treatment. All
parameters analyzed were measured as total rather than dissolved
and are expressed in terms of milligrams per liter (mg/l).
This section is organized in the following manner. First is a
discussion of water usage within the Metal Finishing Category.
This is followed by a discussion of waste characteristics for each
of the forty-six unit operations. Finally, .there is a description
of the parameters found in the total plant process wastewaters
discharged prior to end-of-pipe treatment, and a description of
the parameters found in each of the seven waste types that were
outlined in Section IV:
o Common metals
o Precious metals
o Complexed metals
o Hexavalent chromium
o Cyanide
o Oils
o Toxic organics
WATER USAGE IN THE METAL FINISHING CATEGORY
Water is used for rinsing workpieces. washing away spills, air
scrubbing, process fluid replenishment, cooling and lubrication.
washing of equipment and workpieces, quenching, spray booths, and
assembly and testing. Descriptions of these uses follow.
Rinsing
A large proportion of the water usage in the Metal Finishing
Category is for rinsing. This water is used to remove the film
(fluids and solids) that is deposited on the surfaces of the
workpieces during the preceding process. As a result of this
v-i
-------
rinsing, the water becomes contaminated with the constituents of
the film. Rinsing can be used in some capacity after virtually
all of the unit operations covered by the Metal Finishing Cate-
gory and is considered to be an integral part of the unit operation
that it follows.
Spills and Air Scrubbing
Water is used for washing away floor spills and for scrubbing of
ventilation exhaust air. In both cases these wastewaters are
contaminated with constituents of process materials and dirt.
Process Fluid Replenishment
As process fluids (e.g. - cleaning solutions, plating solutions,
paint formulations, etc.) become exhausted or spent, new solu-
tions have to be made up, with water a major constituent of these
solutions. When a fluid is used at high temperature, water must
be added periodically to make up for evaporative losses. Exhaus-
ted or spent process solutions to be dumped are either collected
in sumps for batch processing or are slowly metered into dis-
charged rinse water prior to treatment.
Cooling and Lubrication
Coolants and lubricants in the form of free oils, emulsified oils,
and grease are required by many metal removal operations. The
films and residues from these fluids are removed during cleaning,
washing, or rinsing operations and these constituents contaminate
other fluids. In addition, spent fluids in the sumps represent a
further waste contribution that is processed either batchwise
(segregated) or is discharged to other waste streams.
Water from Auxiliary Operations
Auxiliary operations such as stripping of plating or painting racks
are essential to plant operations; waters used in these operations
do become contaminated and require treatment.
Washing
Water used for washing workpieces or for washing equipment such as
filters, pumps and tanks picks up residues of concentrated process
solutions, salts, or oils and is routed to an appropriate wastewater
stream for treatment.
Quenching
Workpieces which have undergone an operation involving intense heat
such as heat treating, welding, or hot dip coating are frequently
quenched or cooled in aqueous solutions to achieve the desired pro-
V-2
-------
perties or to facilitate subsequent handling of the part. These
solutions become contaminated and require treatment.
/
Spray Booths
Plants which employ spray painting processes use spray booths in
order to capture oversprayed paint in a particular medium. Many
of these booths use water curtains to capture the paint
overspray. The paint is directed against a flowing stream of
water, which scrubs the air so that paint and solvents are not
exhausted to the outside atmosphere. The paint collected in the
water is removed by skimming or by use of an ultrafilter and the
water is reused in the curtain. This water will periodically be
dumped.
Testing and Calibration
Many types of testing such as leak, pressure, and performance
testing, make use of large quantities of water that become con-
taminated.
WATER USAGE BY OPERATIONS
Table 5-1 is a listing of the unit operations covered in the
Metal Finishing Category and shows the operations that tend to
utilize water. The table is broken down according to degree of
water use: significant water usage, minimal water usage and zero
discharge. The operations found to have zero discharge were
determined by an analysis of visited plants in the Metal
Finishing Category data base; the data are shown in Table 5-2.
The data shown include total number of occurrences of each unit
operation, number of zero discharges and the percentage of the
total occurrence with zero discharge. The unit operations which
tend to have zero discharge are electron beam machining, laser
beam machining, plasma arc machining, ultrasonic machining,
sintering, sputtering, vapor plating, thermal infusion, vacuum
metalizing and calibration. Table 5-3 shows the zero discharge
data from the DCP data bases for comparison. While an operation
may tend to be zero discharge, associated preparatory operations,
i.e., cleaning, may have discharges.
Figures 5-1 a and 5-1b display the ranges of flows which may be
found within the Metal Finishing Category. This figure is based
on flow information obtained from visited plants and the majority
of the plants fall within a flow range of zero to 100,000 gallons
per day, which is expanded in the figure.
V-3
-------
Table 5-1
WATER USAGE BY METAL FINISHING OPERATIONS
Unit
Operation
1. Electroplating
2. Electroless Plating
3. Anodizing
4. Conversion Coating
5. Etching (Chemical Milling)
6. Cleaning
7. Machining
8. Grinding
9. Polishing
10. Tumbling (Barrel Finishing)
11. Burnishing
12. Impact Deformation
13. Pressure Deformation
14. Shearing
15. Heat Treating
16. Thermal Cutting
17. Welding
18. Brazing
19. Soldering
20. Flame Spraying
21. Sand Blasting
22. Other Abr. Jet Machining
23. Elec. Discharge Machining
24. Electrochemical Machining
25. Electron Beam Machining
26. Laser Beam Machining
27. Plasma Arc Machining
28. Ultrasonic Machining
29. Sintering
30. Laminating
31. Hot Dip Coating
32. Sputtering
33. Vapor Plating
34. Thermal Infusion
35. Salt Bath Descaling
36. Solvent Degreasing
37. Paint Stripping
38. Painting
39. Electrostatic Painting
40. Electropainting
41. Vacuum Metalizing
42. Assembly
43. Calibration
44. Testing
45. Mechanical Plating
46. Printed Circuit Board Manufacturing
Major
Water
Usage
x
x
x
x
X
X
X
X
Minimal
Water
Usage
Zero
Discharge
x
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
V-4
-------
TABLE 5-2
DETERMINATION OP ZERO DISCHARGE OPERATIONS
Unit Operation
1. Electroplating
2. Electroless Plating
3. Anodizing
4. Conversion Coating
5. Etching & Chemical Milling
6. Cleaning
7.. Machining
. 8. Grinding
9. Polishing
10. Tumbling (Barrel Finishing)
11. Burnishing
12. Impact Deformation
13. Pressure Deformation
14. Shearing
15. Heat Treating
16. Thermal Cutting
17. Welding
18. Brazing
19. Soldering
20. Flame Spraying
21. Sand Blasting
22. Other Abrasive Jet Machining
23. Electrical Discharge Machining
24, Electrochemical Machining
25. Electron Beam Machining
26. laser Beam Machining
27. Plasma Arc Machining
28. Ultrasonic Machining
29. Sintering
30. Laminating
31. Hot Dip Coating
32. Sputtering
33. Vapor Plating
34. Thermal Infusion
35. Salt Bath Descaling
**36. Solvent Degreasing
37. Paint Stripping
38. Painting
39. Electrostatic Painting
40. Electropainting
41. Vacuum Metalizing
42. Assembly
43. Calibration
44. Testing
***45. Mechanical Plating
These data are from a 41 plant sampled data base. All other
data are from a separate 99 plant sampled data base.
**ttot included in the 99 plant data base. Other data indicate
that this operation consistently generates wastewater.
***Not included in survey at time of plant visits.
Number of
Occurences
32
9
12
11
8
41
60
62
42
53
16
20
39
37
37
18
52
28
38
5
20
20
12
9
6
5
4
2
4
11
4
2
3
3
13
50
18
15
15
7
61
24
70
Number of
Zero
Dischargers
0
0
0
0
0
0
8
31
30
20
10
18
34
33
17
17
46
25
33
3
18
18
9
3
6
5
4
2
4
10
3
2
3
3
2
3
0
0
0
7
57
24
40
.5
.0
,2
.2
Percentage of
Zero
Dischargers
0.0
0.0
0.0
0.0
0.0
0.0
13.3
50.0
71.4
37.8
62,
90.
87.
89.
45.9
94.4
88.5
89.3
86.8
60.0
90.0
90.0
75.0
33.3
100.0
100.0
100.0
100.0
100.0
91.0
75.0
100.0
100.0
100.0
15.4
0.0
6.0
0,0
0.0
0.0
100.0
93.4
100.0
57.0
V-5
-------
TABLE 5-3
DETERMINATION OF ZERO DISCHARGE OPERATIONS
(DCP DATA BASES)
* 1.
* 2.
* 3.
* 4.
* 5.
* 6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
* 45.
Uiit Operation
Electroplating
Electroles's Plating
Anodizing
Conversion Coating
Etching & Chemical Milling
Cleaning
Machining
Grinding
Polishing
Tumbling (Barrel Finishing)
Burnishing
Impact Deformation
Pressure Deformation
Shearing
Heat Treating
Thermal Cutting
Welding
Brazing
Soldering
Flame Spraying
Sand Blasting
Other Abrasive Jet Machining
Electrical Discharge Machining
Electrochemical Machining
Electron Beam Machining
Laser Beam Machining
Plasma Arc Machining
Ultrasonic Machining
Sintering
Laminating
Hot Dip Coating .
Sputtering
Vapor Plating
Thermal Infusion
Salt Bath Descaling
Solvent Degreasing
Paint Stripping
Painting
Electrostatic Painting
Electropainting
Vacuum Metalizing
Assembly
Calibration
Testing
Mechanical Plating
Number of
Occurences
1100
207
233
490
177
1221
241
204
80
41
11
36
48
96
38
32
162
75
87
7
44
8
12
3
0
1
4
2
3
17
7
1
0
0
2
77
16
97
9
2
2
167
46
93
2
Number of
Zero
Dischargers
0
0
0
0
0
0
200
166
79
15
8
35
46
95
29
30
158
75
82
7
44
7
9
1
0
1
4
0
3
16
3
1
0
0
1
28
8
84
9
2
2
165
45
82
0
Percentage of
Zero
Dischargers
0.0
0.0
0.0
0.0
0.0
0.0
83.0
81.5
98.8
36.6
72.7
97.2
95.8
98.9
76.3
93.7-
97.5
100.0
94.2
100.0
100.0
87.5
75.0
34.0
—
100.0
100.0
100.0
100.0
94.1
42.8
100.0
—
-
50.0
36.4
50.0
86.6
100.0
100.0
100.0
98.8
97.8
88.0
0.0
These data are from a 1221 plant DCP data base.
are from a separate 365 plant DCP data base.
All other data
V-6
-------
DISCHARGE RATE.
FIGURE 5-la
o
DISCHARGE RATE, MGD
FIGURE 5-lb
FIGURE 5-1
FLOW DISTRIBUTION WITHIN THE
METAL FINISHING CATEGORY
V-7
-------
WATER USAGE BY WASTE TYPE
Tables 5-4 through 5-9 present data on the contribution of the
various types of waste streams toward the total flow of a plant.
For each visited plant where flows of discrete types of waste
streams could be measured, the tables present total wastewater
flow, waste type stream flow and percentage contribution of the
waste type stream flow.
Table 5-4 shows flow data for those visited plants which had
common metals waste streams measured prior to mixing with other
pretreated wastewaters. The average contribution of these streams
to the total wastewater flow is 67.6% (range of 1.4-100%). All
of the plants visited and sampled had a waste stream requiring
common metals treatment.
Table 5-5 contains flow data for those plants with precious
metals wastewater. Of the plants in the data set used for these
tables, 6.3% of them had production processes which generated
precious metals wastewater. The typical precious metals waste-
water flow contribution is 20.1%.
Table 5-6 presents flow data for those plants with segregated
complexed metals waste streams. Although additional plants have
processes which generate complex metal wastes, their wastes are
not segregated. The average contribution of the complexed metal
streams at those plants listed in the table is 11.9%, and 13.9%
of the plants in the data set used for these tables have com-
plexed metal streams.
Table 5-7 presents the flow contribution of hexavalent chromium
wastewater streams. Of the plants in the data set used for these
tables, 24.1% have segregated hexavalent chromium waste streams.
The average flow contribution of these waste streams to the total
wastewater stream is 23.4%. Of the plants having hexavalent
chromium streams, 100% segregate those streams for treatment.
Table 5-8 presents flow data on cyanide bearing waste streams. As
shown on the table, at those plants with cyanide wastes, the
average contribution of the cyanide bearing stream toward the
total wastewater generated is 14.6% (range: 1.4-29.6%). Of the
plants in the data set used for these tables, 13.9% have segre-
gated cyanide bearing wastes.
Table 5-9 presents data for the flow of segregated oily waste-
water. Segregated oily wastewater is defined as oil waste col-
lected from machine sumps and process tanks that is kept segre-
gated from other wastewaters until it has been treated by an oily
waste removal system. The plants identified in Table 5-9 , which
make up 12.9% of the plants in the data set used for these tables,
are known to segregate their oily wastes. The average contribu-
tion of their oily wastes to this total wastewater flow is 6.4%,
with a range of nearly zero to 31.7%.
V-8
-------
TABLE 5-4
CCMMON METALS STREAM CONTRIBUTION
Common Metals
Stream Flow (gpd)
16,590
56,987
37,680
18,000
145,800
93,600
53,280
304,800
8,269
24,280
165,000
3,200
3,600
272,400
152,912
83,536
252,822
50,400
719,248
80,827
5,280
255,672
151,264
6,421
599,232
65,067
1,600
55,600
400
46,080
303
1,320
6,241
5,000
76,320
9,080
210,880
54,800
96
Total Process
Water Discharge (gpd)
16,590
77,995
59,136
50,400
183,816
194,320
244,080
304,800
8,269
42,780
825,000
3,200
4,880
272,400
186,712
83,536
593,280
723,432
5,352,000
95,634
5,280
292,080
829,192
8,117
603,786
89,840
13,360
82,576
400
50,400
21,842
1,320
6,819
14,750
76,320
103,522
217,280
74,320
96
Percent Of
Total Flow
100.0
73.1
63.7
35.7
79.3
48.2
21.8
100.0
100.0
56.8
20.0
100.0
73.8
100.0
81.9
100.0
42.6
7.0
13.4
84.5
100.0
87.5
18.2
79.1
99.2
72.4
12.0
67.3
100.0
91.4
1.4
100.0
91.5
33.9
100.0
8.8
97.1
73.7
100.0
Plant ID
1003
2032
2033
2062
4069
4071
6091
6110
6679
6960
7001
8006
8007
9052
11103
11108
12061
12065
12075
15608
17050
17061
18538
19068
20022
20083
21003
21066
25010
27046
30054
33028
36048
38052
40060
40063
41051
44062
46025
Average common metals stream contribution = 67.6%
V-9
-------
TABLE 5-5
PRECIOUS METALS STREAM CONTRIBUTION
Precious Metals Total Process Percent Of
Plant ID Stream Flow (gpd) Water Discharge (gpd) Total Flow
02033
06090
21003
30054
36623
12,720
2,400
4,080
5,406
77,040
59,136
171,600
13,360
21,908
364,560
21.5
2.8
30.5
24.7
21.1
Average precious metals stream contribution = 20.1%
V-10
-------
TABLE 5-6
COMPLEXED METALS STREAM CONTRIBUTION
Complexed Metals Total Process Percent Of
Plant ID Stream Flow (gpd) Water Discharge (gpd) Total Flow
02032
02033
04069
04071
06097
12065
15608
17061
20083
34051
36048
6,080
7,667
20,016
100,720
5,232
17,280
10,768
10,320
11,773
960
131
77,995
59,136
183,816
194,320
61,424
723,432
95,634
292,080
89,840
14,400
6,819
7.8
13.0
10.9
51.8
8.5
2.4
11.3
3.5
13.1
6.7
1.9
Average complexed metals stream contribution = 11.9%
V-ll
-------
TABLE 5-7
CHROMIUM STREAM CONTRIBUTION
Hexavalent Chromiun Tptal Process Percent Of
Plant ID Stream Flow (gpd) Water Discharge (gpd) Ibtal Flow
06072 9,480 51,720 18.3
06091 106,560 244,080 43.7
06960 10,175 42,780 23.8
12075 147,480 5,384,072 2.7
18538 172,016 829,192 20.7
20082 91,609 129,859 70.5
20083 5,187 89,840 5.8
21066 14,528 82,576 17.6
30050 7,308 564,000 1.3
30054 1,680 21,908 7.7
30074 25,920 43,392 47.2
31050 600 4,600 13.0
33024 2,952 34,896 8.5
35061 70,000 785,000 8.9
38052 9,750 14,750 66.1
40061 48,600 59,400 81.8
40062 2,160 571,680 0.4
44050 11,040 113,760 9.7
44062 15,752 74,320 21.2
Average hexavalent chromium stream contribution = 23.4%
V-12
-------
TABLE 5-8
CYANIDE BEARING STREAM CONTRIBUTION
Cyanide Bearing Total Process Percent Of
Plant ID Stream Flow (gpd) Water Discharge (gpd) Total Flow
02033 17,496 59,136 29.6
06072 3,280 51,720 6.3
06090 2,400 171,600 1.4
11103 21,704 186,712 11.6
19050 3,480 25,264 13.8
20083 3,960 89,840 4.4
21066 12,448 82,576 15.1
30022 11,520 48,960 23.5
33024 5,256 26,688 15.1
35061 150,000 785,000 19.1
36623 77,040 364,560 21.1
Average cyanide stream contribution = 14.6%
V-13
-------
TABLE 5-9
SEGREGATED OILY WASTEWATER CONTRIBUTION
Plant ID
01058
03043
04892
06019
11477
12078
13042
13324
14062
15010
15055
19462
20005
20103
23041
28699
30012
30166
30516
30698
31031
33050
33692
38040
Segregated
Oily Waste
Discharge (gpd)
125,000
2,081
33,600
30,800
21,600
15,300
60,000
14,400
14,362
13,000
30,000
2,200
174,990
11,100
3,090
190,280
4,845
249
31,700
2,500
286
2,558
68,000
693
Total Plant
Discharge (gpd)
2,590,000
118,650
285,200
1,810,000
1,090,000
1,064,900
223,400
144,900
609,700
1,100,000
600,000
250,000
1,500,000
150,000
900,000
600,000
312,440
11,250
20,000,000
20,000
2,160,000
320,000
500,000
117,000
Percent Of
Total Flow
4.83
1.75
11.8
1.70
1.98
1.44
26.9
9.94
2.36
1.18
5.00
0.88
11.7
7.42
0.34
31.7
1.55
2.21
0.16
12.5
0.01
0.80
13.6
0.59
Average segregated oily waste contribution =6.4%
V-14
-------
WASTE CHARACTERISTICS FROM METAL FINISHING UNIT OPERATIONS
The waste constituents most commonly found in wastewaters gener-
ated by the forty-six metal finishing unit operations are des-
cribed in the following subsections. Information from 1/048
data collection portfolios on the presence of priority pollutants
in metal finishing wastewaters are summarized in Tables 5-10 and
5-11. Table 5-10 shows the number and type of responses given
for each of the 129 pollutant parameters. (KTBP is known to be
present, BTBP is believed to be present, BTBA is believed to be
absent, and KTBA is known to be absent.) Table 5-11 indicates
reported sources of the pollutants known to be present. Table
5-12 summarizes the waste characteristic distribution for the 46
unit operations. Operations which have been designated as
generally zero dischargers are omitted from this discussion.
Included in each of the unit operation presentations is a listing
of each waste type to which the particular operation's wastewater
could contribute.
ELECTROPLATING
Electroplating baths contain metal salts, acids, alkalies, and
various bath control compounds. All of these materials contri-
bute to the wastewater stream either through part dragout, batch
dump, or floor spill. Electroplating baths can contain copper,
nickel, silver, gold, zinc, cadmium, palladium, platinum, chrom-
ium, lead, iron and tin. In addition to these metals, common
cationic components of plating baths are ammonia, sodium and
potassium. Anions likely to be present are chromate, borate,
cyanide, carbonate, fluoride, fluoborate, phosphates, chloride,
nitrate, sulfate, sulfide, sulfamate and tartrate.
Many plating solutions contain metallic, metallo-organic and
organic additives to induce grain refining, leveling of the
plating surface and deposit brightening. Arsenic, cobalt,
molybdenum and selenium are used in this way, as are saccharin
and various aldehydes. These additives are generally present
in a bath at concentrations of less than one percent by volume
or weight. Table 5-13 presents a selection of plating baths
and their major constituents. The processes covered under the
electroplating unit operation and the type of wastewater are
listed below:
Common metals - Electroplating of aluminum, brass,
bronze, cadmium, acid copper, fluo-
borate copper and copper pyrophos-
phate, iron, lead, nickel, solder,
tin and zinc.
Precious metals - Electroplating of gold, silver,
rhodium, palladium, platinum,
indium, ruthenium, iridium, and
osmium.
Cyanide wastes - Cyanide plating of copper, cadmium,
zinc, brass, gold, silver, indium,
and irridium.
Hexavalent chromium wastes - chromium plating.
V-15
-------
Table 5-10
POLLUTANT PARAMETER QUESTIONNAIRE
DCP RESPONSES
Pollutant Parameter
001 Acenaphthene
002 Acrolein
003 Acrylonitrile
004 Benzene
005 Benzidine
006 Carbon tetrachloride
(tetrachloromethane)
007 Chlorobenzene
008 1,2,4-trichlorobenzene
009 Hexachlorobenzene
010 1,2-dichloroethane
Oil 1,1,1-trichloroethane
012 Hexachloroethane
013 1,1-dichloroethane
014 1,1,2-trichloroethane
015 1,1,2,2-tetrachloroethane
016 Chloroethane
017 Bis(chloromethyl) ether
018 Bis(2~chloroethyl) ether
019 2-chloroethyl vinyl ether (mixed)
020 2-chloronaphthalene
021 2,4,6-trichlorophenol
022 Parachlorometa cresol
023 Chloroform (trichloromethane)
Number of
Responses
1011
1011
1013
1014
1011
1012
1010
1010
1010
1011
1020
1010
1010
1010
1010
1010
1010
1009
) 1009
1009
1008
1009
1009
KTBP
0
0
2
9
1
3
1
0
0
2
53
0
1
5
0
9
0
0
1
0
1
0
7
BTBP
2
1
12
16
5
10
8
9
4
11
77
7
8
17
12
14
I
1
1
3
4
4
13
BTBA
762
760
755
734
746
737
751
749
756 .
752
666
752
758
742
746
744
756
755
756
758
754
756
743
KTBA
221
224
218
229
233
236
224
226
224
220
198
225
217
220
226
217
227
227
225
222
222
223
221
V-1S
-------
Table 5-10 (Continued)
jllutant Parameter
24 2-chlorophenol
25 1,2-dichlorobenzene
26 1,3-dichlorobenzene
27 1,4-dichlorobenzene
28 3,3-dichlorobenzidine
29 1,1-dichloroethylene
30 Ir2~trans-dichloroethylene
*
31 2,4-dichlorophenol
32 1,2-dichloropropane
33 1,2-dichloropropylene
(1,3-dichloropropene)
34 2 ,4-dimethylphenol
35 2,4-dinitrotoluene
>36 2,6-dinitrotoluene
i37 1,2-diphenylhydrazine
i38 Ethylbenzene
139 Fluoranthene
•40 4-chlorophenyl phenyl ether
)41 4-bromophenyl phenyl ether
342 Bis(2-chloroisopropyl) ether
)43 Bis(2-chloroethoxy) methane
544 Methylene chloride
(dichloromethane)
)45 Methyl chloride (chloromethane)
)46 Methyl bromide (bromomethane)
Number of
Responses
1008
1009
1009
1009
1009
1010
1010
1009
1010
1010
1008
1008
1008
1008
1010
1006
1007
1010
1009
1010
1015
1011
1012
KTBP
1
1
0
1
0
2
1
0
1
0
0
0
0
1
.. ' 3
0
0
0
0
0
38
5
2
BTBP
3
2
2
3
1
2
2
4
1
1
. 3
1
1
1
, . 5
2
2
2
2
4
49
11
1
BTBA
760
756
758
756
755
763
760
757
756
760
757
759
759
758
758
758
755
755
756
755
695
747
759
KTBA
218
223
223
223
227
217
221
222
226
223
222
222
222
222
218
221
225
225
225
225
206
223
224
V-17
-------
Table 5-10 (Continued)
Pollutant Parameter
047 Bromoform (tribromomethane)
048 Dichlorobromomethane
050 Dichlorodifluoromethane
051 Chiorodibromomethane
052 Hexachlorobutadiene
053 Hexachlorocyclopentadiene
054 Isophorone
055 Naphthalene
056 Nitrobenzene
057 2-nitrophenol
058 4-nitrophenol
059 2,4-dinitrophenol
060 4,6-dinitro-o-cresol
061 N-nitrosodimethylamine
062 N-nitrosodiphenylamine
063 N-nitrosodi-n-propylamine
064 Pentachlorophenol
065 Phenol
066 Bis(2-ethylhexyl) phthalate
067 Butyl benzyl phthalate
068 Di-n-butyl phthalate
069 Di-n-octyl phthalate
070 Diethyl phthalate
Number of
Responses
1014
1014
1014
1014
1014
1012
1012
1015
1015
1013
1013
1013
1012
1012
1014
1014
1012
1020
1014
1014
1014
1013
1012
KTBP
0
1
4
1
0
0
1
2
0
0
0
0
0
0
0
0
0
71
2
2
2
1
2
BTBP
2
2
15
1
2
1
9
14
9
2
2
2
1
1
1
2
8
40
4
4
4
4
2
BTBA
759
758
748
759
761
760
755
748
755
758
758
757
759
762
762
759
754
677
760
759
758
758
759
i
KTBA
227
227f
221!
227
j
225
225'
221'
22 5
225
227
227
228
226
224
224
227
224:
206
222
223
223
224
223
V-18
-------
Table 5-10 (Continued)
jllutant Parameter
'1 Dimethyl phthalate
?2 1,2-benzanthracene
(benzo(a)anthracene)
?3 Benzo(a)pyrene
{3,4-benzo-pyrene)
74 3,4-benzofluoranthene
(benzo(b)fluoranthene)
75 11,12-benzofluoranthene
(benzo(k)fluoranthene)
76 Chrysene
77 Acenaphthylene
78 Anthracene
79 1,12-benzoperylene
(benzo(gh i)-perylene)
BO Fluorene
81 Phenanthrene
82
83
1,2,5,6-dibenzanthracene
(d ibenzo(a,h)anthracene)
Indeno(l,2,3~cd) pyrene
(2,3-o-phenylene pyrene)
84 Pyrene
85 Tetrachloroethylene
86 Toluene
87 Trichloroethylene
88 Vinyl chloride (chloroethylene}
89 Aldrin
Number of
Responses
1014
1014
1014
1014
1014
1014
1014
1012
1012
1011
1010
1009
1009
1009
1008
1016
1011
1009
1010
KTBP
2
1
0
0
0
0
0
0
0
1
0
1
0
1
8
37
27
4
0
BTBP
2
2
2
1
1
1
1
2
1
1
1
1
1
3
19
69
71
8
3
BTBA
759
759
757
759
759
760
759
756
759
760
759
755
755
756
740
694
683
757
752
KTBA
225
226
229
228
228
227
228
227
226
223
224
225
227
223
215
190
204
214
229
V-19
-------
Table 5-10 (Continued)
Number of
Pollutant Parameter Responses
090
091
092
093
094
095
096
097
098
099
100
101
102
103
104
105
106
107
108
109
110
111
Dieldrin
Chlordane (technical mixture
and metabolites)
4,4-DDT
4,4-DDE (p,p-DDX)
4,4-DDD (p,p-TDE)
Alpha-endosulfan
Beta-endosulf an
Endosulfan sulfate
Endrin
Endrin aldehyde
Heptachlor
Heptachlor epoxide
(BHC-hexachlorocyclohexane )
Alpha-BHC
Beta-BHC
Gamma-BHC
Delta-BHC
PCB-1242 (Aroclor 1242)
PCB-1254 (Aroclor 1254)
PCB-1221 (Aroclor 1221)
PCB-1232 (Aroclor 1232)
PCB-1248 (Aroclor 1248)
PCB-1260 (Aroclor 1260)
1008
1008
1008
1008
1008
1008
1008
1008
1008
1008
1008
1008
1008
1008
1008
1009
1010
1009
1009
1009
1008
1006
KTBP
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
6
3
1
2
2
3
BTBP
2
2
2
3
3
2
2
2
2
2
3
2
2
2
2
4
10
6
4
4
5
6
BTBA
753
756
749
751
755
756
756
758
751
756
754
755
753
753
750
750
731
736
744
745
741
733
KTBA
227
224
231
228
224
224
224
222
229
224
225
225
227
227
230
229
237
238
234
232
234
238
V-20
-------
TABLE 5-10 (Continued)
>llutant Parameter
.2 PCB-1016 (Aroclor 1016)
i3 Toxaphene
14 Antimony
L5 Arsenic
16 Asbestos
L7 Beryllium
18 Cadmium
L9 Chromium
20 Copper
21 Cyanide
22 Lead
23 Mercury
24 Nickel
25 Selenium
26 Silver
27 Thallium
28 Zinc
29 2,3,7,8-tetrachlorodibenzo-
p-dioxin (TCDD)
Number of
Responses
990
990
990
996
987
986
1012
1048
1038
1032
1017
1002
1039
990
1007
990
1032
KTBP
1
0
33
39
10
33
272
633
577
457
280
88
531
37
185
25
520
BTBP
5
3
37
18
22
37
56
96
105
86
84
25
110
28
54
13
74
BTBA
729
737
696
689
713
685
479
219
248
330
477
630
276
686
562
702
304
KTBA
231
226
200
226
218
208
179
74
82
133
150
233
98
215
182
227
112
990
733
224
TBP - Known to be present
TBP - Believed to be present
TBA - Known to be absent
TBA - Believed to be absent
V-21
-------
TABLE 5-11
SOURCE IDENTIFICATION FOR KTBP (KNOWN TO BE PRESENT!
POLLUTANT PARAMETERS
Pollutant Parameter
003 Acrylonitrile
004 Benzene
005 Benzidine
006 Carbon tetrachloride
007 Chlorobenzene
010 1,2-Dichloroethane
Oil 1,1,1-Trichloroethane
013 1,1-Dichloroethane
014 1,1,2-Trichloroethane
016 Chloroethane
019 2-Chloroethyl vinyl
ether
021 2,4,6-Trichlorophenol
023 Chloroform
024 2-Chlorophenol
025 1,2-Dichlorobenzene
027 1,4-Dichlorobenzene
029 1,1-Dichloroethylene
030 1,2-trans-Dichloro-
ethylene
KTBP
Responses Sources of Pollutant Parameters
2 ABS components manufactured
9 Fuel component; solvent; raw
material; contaminant in toluene;
water supply
1 Solvent and cleaner
3 Water supply
1 Spray booth wall coating
2 Photoresist developer; water supply
53 Degreaser; photoresist developer;
cleaner; hand washing operations;
plating; maintenance solvent;
milling; water supply
1 Plant lab facilities; cleaning
5 Degreaser; cleaning; plant lab
facilities
9 Raw material; degreaser; wash tanks;
floor cleaner; solvent cleaning
1 Water supply
1 Unknown (detected by sample analysis!
7 Raw material; degreaser; nickel
brightener constituent; water supply
1 Water supply
1 Gum solvent
1 Unknown (detected by sample analysis)
2 Water supply
1 Water supply
V-22
-------
TABLE 5-11 (Continued)
Pollutant Parameter
KTBP
Responses Sources of Pollutant Parameters
032 1,2-Dichloropropane
037 1,2-Diphenylhydrazine
038 Ethylbenzene
044 Methylene chloride
045 Methyl chloride
1
1
3
38
5
046 Methyl bromide 2
048 Dichlorobromomethane 1
050 Dichlorodifluoromethane 4
051 Chlorodibromomethane 1
054 Isophorone 1
055 Naphthalene 2
065 Phenol 71
Water supply
Coolant biocide
Fuel constituent
Paint stripper; photoresist
stripper; cleaner; plastic;
injection molding and extrusion;
etch resist stripper; solvent;
painting; electroplating; rubber
primer
Raw material; cleaner; paint
stripper
Constituent of chrome plating bath
Water supply
Refrigerant; anodizing bath coolant;
water supply
Water supply
White paint
Painting
Lubricating oils; post metal fin-
ishing operations; paper and molding
compounds; photoresist stripper
coolant; creosote floor blocks; iron
phosphatizing; etch resist stripper;
adhesives; gasoline; paint stripper;
painting; washers; hydraulic oils;
wire insulation stripping; rinsing;
plating; emulsion breaker; varnish;
coolant biocide; spindle oil; DTE
oil; spray paint; adhesives;
electropainting; integrated circuit
lab; paint; conformal coating; cast
iron making (coke); paint gun
cleaner; cleaners tin plating
additive; phosphate esters; phenolic
resins; water supply
V-23
-------
TABLE 5-11 (Continued)
Pollutant Parameter
066 Bis (2-ethylhexyi;
phthalate
KTBP
Responses
2
067 Butylbenzyl phthalate
068 Di-n-butyl phthalate
069 Di-n-octyl phthalate
070 Diethyl phthalate
071 Dimethyl phthalate
072 1,2-Benzanthrancene
080 Fluorene
082 1,2,5,6-Dibenzanthracene
084 Pyrene
085 Tetrachloroethylene
!6 Toluene
087 Trichloroethylene
088 Vinyl chloride
106 PCB-1242
1
2
37
27
Sources of Pollutant Parameters
Sealants; paints; adhesives; water
supply
Sealants,
supply
Sealants,
supply
Sealants,
Sealants,
supply
Sealants,
supply
paints,
paints,
paints,
paints,
adhesives; water
adhesives; water
adhesives
adhesives,
water
paints; adhesives; water
Water supply
Unknown (detected by sample analysis)
Unknown (detected by sample analysis)
Unknown (detected by sample analysis)
Degreaser; photoresist stripper;
ceramic tinning; electroplating;
cleaner; solvent recovery; water
supply
Painting; paint thinner; varnish
thinner; paint booth cleanup; thin
ner for printed circuit protective
coating; cleaning solvent; adhesive;
water supply
Degreaser; paint thinner; photo-
resist developer; electroplating
operations; lab solvent; machine
solvent; electrical contact cleaner;
welding tip cleaner; water supply
Plastic molding; sealers; adhesives;
coating for manufactured parts; water
supply
Lighting fixtures; power correction
units; transformers; previous usage
hydraulic fluid; water supply
V-24
-------
TABLE 5-11 (Continued)
Pollutant Parameter
107 PCB-1254
108
109
PCB-1221
PCB-1232
110 PCB-1248
111 PCB-1260
112 PCB-1016
116 Asbestos compounds
KTBP
Responses
3
1
2
3
1
10
Sources of Pollutant Parameters
Process capacitors; previous usage;
water supply
Process capacitors; water supply
Lighting fixtures; power correction
units; transformers; process
capacitors; water supply
Lighting fixtures; power correction
units; transformers; process
capacitors; water supply
Process capacitors; previous usage;
water supply
Water supply
Aluminum dip braze; pipe covering;
brakeband operations; furnace seals;
sealer compound; plaster molds;
nickel electroplating bath filter;
water supply
V-25
-------
TABLE 5-12
CHAMCTERISTIC DISTRIBUTION
f
Ch
^~~"\^ WASTE
UNIT ^"^""\^
OPERATION ^"^"-^
1. Electroplating
2. Electroless Plating
3. .Anodizing
4. Conversion Coating
5. Etching {Chem. Milling)
6. Cleaning
7. Machining
8. Grinding
9. Polishing
10. Tumbling
11. Burnishing
12. Impact Deformation
13. Pressure Deformation
14. Shearing
15. Heat Treating
16. Thermal Cutting
17. Welding
18. Brazing
19. Soldering
20. Flame Spraying
21. Sand Blasting
22. Other Abr. Jet Machining
23. Elec. Discharge Mach.
24. Electrochemical Mach.
25. Electron Beam Mach.
26. Laser Beam Mach.
27. Plasma Arc Mach.
28. Ultrasonic Machining
INORGANICS ORGA1
Common Precious Complexed Chromium
Metals Matals Matals (Hexavalent) Cyanide Oi
XX XX
XX XX
X X
XX XX
XX XX X
XX XX X
X
X
X X
X XX
XX X
X
X
X
X X
X
X
X
X X
X
X
X
X
X X
KflCS
Toxic zero
Is Organics Discharge
X X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
TABLE 5-12 Cont.
WASTE CHARACTERISTIC DISTRIBUTION
I
hJ
"^^^^^ WASTE
^"•••^CHARACTERISTICS
UNIT ^^-\^
OPERATION ^^\^^
29. Sintering
30. Laminating
31. Hot Dip Coating
32. Sputtering
33. Vapor Plating
34. Thermal Infustion
35. Salt Bath Descaling
36. Solvent Degreasing
37. Paint Stripping
38. Painting
39. Electrostatic Painting
40. Electroplating
41. Vacuum Metalizing
42. Assembly
43. Calibration
44. Testing
45. Mechanical Plating
46. Printed Circuit Board
Manufacturing
INORGANICS ORGA1
Common Precious Complexed Chromium
Metals Metals Metals (Hexavalent) Cyanide Oi.
X
X
X X
X X
X X
X
X X
X
X X
X
X X
X X
vies
Toxic Zero
Ls Organics Discharge
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
TABLE 5-13
CONSTITUENTS OF PLATING BATHS
Electroplating Bath
Brass & Bronze:
Cadmium Cyanide:
Cadmium Fluoborate:
Copper Cyanide:
Copper Pluoborate:
Acid Copper Sulfate:
Copper Pyrophosphate:
Fluoride Modified
Copper Cyanide:
Chromium:
Chromium with
Fluoride Catalyst:
Gold Cyanide:
Compos i t ion
Copper cyanide
Zinc cyanide
Sodium cyanide
Sodium carbonate
Ammonia
Rochelle salt
Cadmium cyanide
Cadmium oxide
Sodium cyanide
Sodium hydroxide
Cadmium fluoborate
Fluoboric acid
Boric acid
Ammonium fluoborate
Licorice
Copper cyanide
Sodium cyanide
Sodium carbonate
Sodium hydroxide
Rochelle salt
Copper fluoborate
Fluoboric acid
Copper sulfate
Sulfuric acid
Copper pyrophosphate
Potassium hydroxide
Ammonia
Copper cyanide
Potassium cyanide
Potassium fluoride
Chromic acid
Sulfuric acid
Chromic acid
Sulfate
Fluoride
Metallic gold
Potassium cyanide
Sodium phosphate
V-28
-------
TABLE 5-13 (Con't)
CONSTITUENTS OF PLATING BATHS
Electroplating Bath
Iron j
Lead Fluoborate:
Lead-Tin:
Nickel (Watts):
Nickel-Acid Fluoride:
Black Nickel:
Composition
Ferrous sulfate
Ferrous chloride
Ferrous fluoborate
Calcium chloride
Ammonium chloride
Sodium chloride
Boric acid
Lead fluoborate
Fluoboric acid
Boric acid
Gelatin or glue
Hydroqu inone
Lead fluoborate
Tin fluoborate
Boric acid
Fluoboric acid
Glue
Hydroqu inone
Nickel sulfate
Nickel chloride
Nickel fluoborate
Boric acid
Nickel sulfate
Nickel chloride
Nickel sulfamate
Boric acid
Phosphoric acid
Phosphorous acid
"Stress-reducing agents"
Hydrofluoric acid
Nickel carbonate
Citric acid
Sodium lauryl sulfate
(wetting agent)
Nickel ammonium sulfate
Nickel sulfate
Zinc sulfate
Ammonium sulfate
Sodium thiocyanate
V-29
-------
TABLE 5-13 (Con't)
CONSTITUENTS OF PLATING BATHS
Electroplating Bath
Silver:
Acid Tin;
Stannate Tin:
Tin-Copper Alloy:
Tin-Nickel Alloy:
Tin-Zinc Alloy:
Acid line:
Zinc Cyanide:
V-30
Compos it ion
Silver cyanide
Potassium cyanide or
Sodium cyanide
Potassium carbonate or
Sodium carbonate
Potassium hydroxide
Potassium nitrate
Carbon disulfide
Tin fluoborate
Fluoboric acid
Boric acid
Stannous sulfate
Sulfuric acid
Cresol sulfonic acid
Beta naphthol
Gelatin
Sodium stannate
Sodium hydroxide
Sodium acetate
Hydrogen peroxide
Copper cyanide
Potassium stannate
Potassium cyanide
Potassium hydroxide
Rochelle salt
Stannous chloride
Nickel chloride
Ammonium fluoride
Ammonium bifluoride
Sodium fluoride
Hydrochloric acid
Potassium stannate
Zinc cyanide
Potassium cyanide
Potassium hydroxide
Zinc sulfate
Ammonium chloride
Aluminum sulfate or
Sodium acetate
Glucose or
Licorice
Zinc oxide
Sodium cyanide
Sodium hydroxide
Zinc cyanide
-------
ELECTROLESS PLATING
Electroless plating (autocatalytic) is most often used on printed
circuit boards, as a base plate for plating on plastics, and as
a protective coating on metal parts. Copper and nickel are the
metals most often plated autocatalytically, although iron, cobalt,
gold, palladium, and arsenic can also be plated in this manner.
The components of several electroless plating baths are listed in
Table 5-14. The principle components are the metal being deposited,
a reducing agent such as sodium hypophosphite or formaldehyde, and
various complexing (or chelating) agents such as Rochelle salt,
EDTA, or sodium citrate. Bath constituents enter the waste stream
by way of dragout or batch dumping of the process bath.
Immersion plating, which is categorized with electroless plating,
generates waste by basis material dissolution and process solution
dragout. Table 5-15 lists the different immersion plating solu-
tions as well as the base material upon which each can be deposited.
Immersion plating baths are usually simple formulations of metal
salts, alkalies and complexing agents. The complexing agents are
typically cyanide or ammonia and are used to raise the deposition
potential of the metal. Because of the displacement action in-
volved in the immersion plating operation, more basis material ends
up in the waste stream than the metal being deposited. Electroless
plating wastewaters are contributed to the discrete process wastes
by the following operations:
Precious metals - Electroless gold, electroless silver,
electroless palladium, immersion gold,
immersion palladium, immersion platinum,
immersion rhodium, immersion silver.
Complexed metals - All electroless plating operations, all
immersion plating operations.
Cyanide - Electroless gold, electroless arsenic, electroless
silver, immersion brass, immersion silver, immersion
tin.
ANODIZING
The wastewaters generated by anodizing contain the basis material
being anodized (aluminum or magnesium) as well as the constituents
of the processing baths. Anodizing is done using solutions of
either chromic or sulfuric acid. In addition, it is common to
dye or color anodized coatings. A number of these dyes contain
chromium (which will be found in wastewaters when the dyes are
used) and other metals. Nickel acetate is widely used to seal
anodic coatings and is therefore another potential pollutant
associated with anodizing. Other complexes and metals originating
from dyes, coloring solutions and sealers could possibly be found
in anodizing wastewaters.
V-31
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TABLE 5-14
CONSTITUENTS OF ELECTROLESS PLATING BATHS
Process
Electroless Nickel:
Electroless Copper:
Electroless Cobalt-Nickel:
Electroless Gold:
Electroless Gold over Cu, Nir Kovar:
Composition
Nickel chloride
Sod ium glycollate
Sodium hypophosphite
or
Nickel carbonate
Hydrofluoric acid
Citric acid
Ammonium acid fluoride
Sodium hypophosphate
Ammonium hydroxide
Copper nitrate
Sodium bicarbonate
Rochelle salt
Sodium hydroxide
Formaldehyde
or
Copper sulfate
Sodium carbonate
Rochelle salt
Versene-T
Sodium hydroxide
Formaldehyde
Cobalt chloride
Nickel chloride
Rochelle salt
Ammonium chloride
Sodium hypophosphite
Potassium gold cyanide
Ammonium chloride
Sodium citrate
Sodium hypophosphite
Potassium gold cyanide
Citric acid
Monopotassium acid phthalate
Tungstic acid
Sodium hydroxide
NrN diethylglycine (Na salt)
V-32
-------
TABLE 5-14 (CONTINUED)
Process
Electroless Iron:
Electroless Palladium;
Electroless Arsenic:
Electroless Chromium (acidic):
Electroless Chromium (alkaline)
Electroless Cobalt:
Electroless Silver:
Composition
Ferrous sulfate
Rochelle salt
Sodium hypophosphite
Tetramine palladium chloride
Disodium EDTA
Ammonium hydroxide
Hydrazine
Zinc sulfate
Arsenic trioxide
Sodium citrate
Sodium cyanide
Sodium hydroxide
Ammonium hydroxide
Sodium hypophosphite
Chromic bromide
Chromic chloride
Potassium oxalate
Sodium acetate
Sodium hypophosphite
Chromic bromide
Chromic iodide
Sodium oxalate
Sodium citrate
Sodium hypophosphite
Cobalt chloride
Sodium citrate
Ammonium chloride
Sodium hypophosphite
Silver cyanide
Sodium cyanide
Sodium hydroxide
Dimethylamine borane
Thiourea
V-33
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TABLE 5-15
CONSTITUENTS OP IMMERSION PLATING BATHS
Process
Immersion Plating -
Copper on Steel:
Copper on Zinc:
Gold on Copper Alloys
Gold on Iron & Steel:
Lead on Copper Alloys
and on Zinc:
Lead on Steel:
Nickel on Aluminum;
Nickel on Copper
Alloys:
Nickel on Steels
Nickel on Zinc:
Palladium on Copper
Alloys:
Platinum on Copper
Alloys:
Rhodium on Copper
Alloys j
Composition
Copper sulfate
Sulfuric acid
Copper sulfate
Tartaric acid
Ammonia
Potassium gold cyanide
Sodium cyanide
Sodium carbonate
Denatured alcohol
Gold chloride
Lead monoxide
Sodium cyanide
Sodium hydroxide
Lead nitrate
Sodium cyanide
Sodium hydroxide
Nickel sulfate
Ammonium chloride
Nickel sulfate
Nickel ammonium sulfate
Sodium thiosulfate
Nickel chloride
Boric acid
Nickel sulfate
Sodium chloride
Sodium carbonate
Palladium chloride
Hydrochloric acid
Ammonia (sealant)
Platinum chloride
Hydrochloric acid
Rhodium chloride
Hydrochloric acid
V-34
-------
TABLE 5-15 (Continued)
Process
Immersion Plating -
Arsenic on Aluminum;
Arsenic on Copper
Alloys:
Arsenic on Steels
Brass on Aluminum:
Brass on Steel:
Cadmium on Aluminum;
Cadmium on Copper
Alloys;
Cadmium on Steel:
Copper on Aluminum;
Ruthenium on Copper
Alloys:
Silver on Copper
Alloys;
Composition
White aresenic
Sodium carbonate
White arsenic
Ferric chloride
Muriatic acid
White arsenic
Muriatic acid
Zinc oxide
Sodium hydroxide
Copper cyanide
Sodium cyanide
Lead carbonate
Stannous sulfate
Copper sulfate
Sulfuric acid
Cadmium sulfate
Hydrofluoric acid
Cadmium oxide
Sodium cyanide
Cadmium oxide
Sodium hydroxide
Copper sulfate
Ammonia
Potassium cyanide
Copper sulfate
Hydrofluoric acid
Copper sulfate
Ethylene diamine
Ruthenium chloride
Hydrochloric acid
Silver cyanide
Sodium cyanide
Silver nitrate
Ammonia
Sodium thiosulfate
¥-35
-------
TABLE 5-15 (Continued)
Process
Immersion Plating -
Silver on Zincs
Tin on Aluminum:
Tin on Copper Alloys
Tin on Steel:
Tin on Zinc:
Composition
Silver cyanide
Potassium
Sodium stannate
Tin chloride
Sodium cyanide
Sodium hydroxide
Stannous sulfate
Sulfuric acid
Cream of tartar
Tin chloride
Tin chloride
V-36
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Wastewaters are generated by the following anodizing operations:
Common metals - Sulfuric acid anodizing, phosphoric acid
anodizing, oxalic acid anodizing, dyeing,
nickel acetate sealing.
Cyanide - Ferrocyanide pigment impregnation
Hexavalent chromium - Chromic acid anodizing, dichromate
sealing.
COATING
Several types of conversion coating operations such as phosphating,
chromating, coloring, and passivating contribute pollutants to raw
waste streams. These pollutants may enter the waste stream through
rinsing after coating operations and batch dumping of process baths,
Coating process baths usually contain metal salts, acids, bases,
and dissolved basis materials and various additives.
The phosphates of zinc, iron, manganese, nickel, and calcium are
most often used for phosphate coatings. Strontium and cadmium
phosphates are used in some baths, and the elements aluminum,
chromium, fluorine, boron, and silicon are also common bath
constituents. Phosphoric acid is used as the solvent in
phosphating solutions.
Coloring can be done with a large variety of solutions. Several
metals may be contributed to the waste stream by coloring opera-
tions, among them copper, nickel, lead, iron, zinc and arsenic.
Passivation can be done in a nitric acid solution (for stainless
steel) or a caustic solution (for copper). In both cases,
dissolved basis materials enter the wastewater.
There are a number of conversion coating processes which utilize
chromium-containing solutions. These include chromating, black
oxidizing and sealing rinses. Chromating baths are usually
proprietary solutions which contain concentrated chromic acid
and active organic or inorganic compounds (even cyanide in some
instances). Both hexavalent and trivalent chromium will be
found in chromate conversion coating baths and in the rinses
associated with them. Black oxidizing is done in solutions
containing dichromate while sealing rinses used extensively
following phosphating are usually made up of very dilute chromic
acid. Any of these conversion coating operations will also
contribute small amounts of basis material to their respective
wastewater streams.
The wastewater contribution of conversion coating operations is
as follows:
Common metals - Phosphating, nitric acid or caustic
passivation, coloring.
V-37
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Precious metals - Chromating of silver
Cyanide - Some Chromating processes
Hexavalent chromium - Chromating/ dichromate passivation,
chromic acid sealing of phosphate
coatings.
ETCHING
Wastewater is produced in this unit operation by etching, chemical
milling, bright dipping and related operations. As demonstrated
by the list of etching solutions in Table 5-16, the majority of
etching solutions are acidic while sodium hydroxide is used quite
frequently as a caustic etch on aluminum. The constituents in
the waste stream produced by etching operations are predominatly
dissolved basis materials. Among the basis materials commonly
etched are stainless steel, aluminum and copper. In addition to
these materials, metals such as zinc and cadmium may appear in
the waste stream due to bright dipping of these metals.
Certain etching baths contain concentrated chromic acid and are
usually employed prior to plating steps. Chromic acid etches
are used extensively on plastics prior to electroless plating of
copper or nickel. These etching solutions and their associated
rinses can contain hexavalent and trivalent chromium, small
amounts of organic compounds (when used for etching plastics)
and metals which originate in the basis material being etched.
Chromic acid (in conjunction with other acids) is also used for
the bright dipping of copper and copper alloys as well as zinc
and cadmium plated parts.
An increasing number of etching solutions incorporate ammonia
compounds. Ammonium hydroxide and ammonium chloride are the
most common constituents of these baths. The ammonia contributed
by these compounds acts as a metal-complexing agent in solution.
Dumps of these baths or discharge of rinses following ammoniacal
etches will therefore contain complexed wastes. These etchants
are most widely used in the manufacture of printed circuit
boards and their associated discharges can include complexed
copper as well as various organic compounds (from the epoxy
board and from etch resist formulations).'
Cyanides are not generally used as constituents in etching
baths. However, at least one bright dipping solution (for silver)
does contain a mixture of sodium cyanide and hydrogen peroxide.
The use of this particular bath will yield wastewater containing
the above-mentioned constituents as well as silver.
V-38
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TABLE 5-16
CONSTITUENTS OF PROCESS BATHS USED IN ETCHING
Process
Chemical Etching -
Ferric chloride
solns:
Ammonium persulfate
solns:
Cupric chloride
solns:
Chromic-sulfuric
acid solns:
Chemical
Milling -
For various metals:
For aluminum:
Electrochemical Milling -
on steel, cobalt,
copper, chromi um:
for tungsten &
molybdenum alloys
Composition
Ferric chloride
Hydrochloric acid
Base material
Ammonium persulfate
Mercuric chloride
Sulfuric acid
Ammonium chloride
Sodium chloride
Copper
Base material
Cupric chloride
Hydrochloric acid
Sodium chloride
Ammonium chloride
Base material
Chromic acid
Sodium sulfate
Sulfuric acid
Copper
Base material
Nitric acid
Chromic acid
Hydrochloric acid
Base metal
Sodium hydroxide
Sodium chloride
Sodium nitrate
Base metal
Sodium hydroxide
Sodium chloride
Base metal
V-39
-------
TABLE 5-16(Continued)
Process
Bright Dip -
for Copper:
for Aluminum:
also for Nickel
for Zinc and
Cadmiums
for Silver:
Composition
Nitric acid
Acetic acid
Phosphoric acid
Hydrochloric acid
Phosphoric acid
Nitric acid
Glacial acetic acid
Phosphoric acid
Sulfuric acid
Nitric acid
Phosphoric acid
Nitric acid
Titanium chloride
Chromium acid
Sulfuric acid
Sodium cyanide
Hydrogen peroxide
V-40
-------
Etching operations contribute wastewater to the various waste
types in the following manner:
Common metals - Etching, bright dipping and chemical milling
of common metals basis materials with
solutions such as ferric chloride, cupric
chloride, nitric acid, hydrochloric acid,
phosphic acid, sulfuric acid, hydrofluoric
acid; stripping of common metal platings.
Precious metals - Any etching or bright dipping of precious
metals; stripping of precious metal platings,
Complexed metals - Etching with ammoniated solutions such as
ammonium hydroxide and ammonium chloride.
Cyanide - Certain bright dipping operations; cyanide
stripping operations,,
Hexavalent chromium - Etching, bright dipping, or chemical
milling with solutions containing
chromic acid; stripping with chromic
acid or stripping of chromium platings.
CLEANING ;
Cleaning operations are used throughout the Metal Finishing Category
and provide the bulk of the wastewater generated by the industry.
The purpose of cleaning is to remove the bulk of all of the soils
(oils and dirt) prior to phosphating, electroplating, painting,
pre and post penetrant inspection, burnishing and polishing, or
after any other operation that produces an oil bearing part.
Cleaning is often a necessary antecedent for several of the met^al
finishing operations. This cleaning does not include solvent
cleaning which in itself is a separate unit operation.
Alkaline cleaning solutions usually contain one or more of the
following chemicals: sodium hydroxide, sodium carbonate, sodium
metasilicate, sodium phosphate (di- or trisodium), sodium silicate,
sodium tetraphosphate, and a wetting agent. The specific content
of cleaners varies with the type of soil being removed. For
example, compositions for cleaning steel are more alkaline and
active than those for cleaning brass, zinc die castings, and
aluminum. Wastewaters from cleaning operations contain not only
the chemicals found in the alkaline cleaners but also soaps from
the saponification of greases left on the surface by polishing
and buffing operations. Some oils and greases are not saponified
but are, nevertheless, emulsified. The raw wastes from cleaning
show up in rinse waters, spills and dumps of concentrated solutions.
V-41
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The concentrations of dissolved basis metals in rinses following
alkaline cleaning are usually small relative to acid dip rinses.
Organic chelating agents are utilized in some alkaline cleaning
solutions in order to help soften the water. Hardness constituents
such as calcium and magnesium salts are chelated as inert soluble
complexes. This facilitates their removal from the surface of
a part and prevents the formation of insoluble scums (from
calcium and magnesium soaps). Therefore, some alkaline cleaning
baths and their subsequent rinses contain complexed metals,
phosphates in various forms and organic compounds including oils
and greases.
Solutions for pickling or acid cleaning usually contain one or
more of the following: hydrochloric acid (most common), sulfuric
acid, nitric acid, chromic acid, fluoboric acid, and phosphoric
acid. The solution compositions vary according to the nature of
the basis metals and the type of tarnish or scale to be removed.
These acid solutions accumulate appreciable amounts of metal as
a result of dissolution of metal from workpieces or uncoated areas
of plating racks that are recycled repeatedly through cleaning,
acid treating, and electroplating baths.
As a result, the baths usually have a relatively short life, and
when they are dumped and replaced, large amounts of chemicals must
be treated or reclaimed. These chemicals also enter the waste
stream by way of dragout from the acid solutions into rinse waters.
The amount of waste contributed by acid cleaners and alkaline
cleaners varies appreciably from one facility to another depending
on the substrate material, the formulation of the solution used
for cleaning or activating the material, the solution temperature,
the cycle time, and other factors. The initial condition of the
substrate material affects the amount of waste generated during
treatment prior to finishing. A dense, scale-free copper alloy
part can be easily prepared for finishing by using a mild hydro-
chloric acid solution that dissolves little or no copper, whereas
products with a heavy scale require stronger and hotter solutions
and longer treating periods for ensuring the complete removal of
any oxide prior to finishing.
Electrocleaners are basically heavy duty alkaline types that are
employed with an electrical current. They are designed both for
soil removal and metal activation. A dilute mineral acid dip
usually follows the final cleaners to neutralize the alkaline film
on the metal surface.
Emulsion cleaning removes soils from the surface of metals by
the use of common organic solvents (e.g. kerosene, mineral oil,
glycols, and benzene) dispersed in an aqueous medium with the
V-42
-------
aid of an emulsifying agent. Parts which have been emulsion
cleaned are not normally rinsed following the cleaning operation.
Wastes come from leaks and flo6r spills" and can contain removed
soils plus any of the cleaner constituents listed above.
Phosphates are used in some cleaners and function as water
softeners, rinsing aids, soil suspending agents, and detergency
boosters. Common cleaners include trisodium phosphate, sodium
tripolyphosphate, tetrasodium and tetrapotassium pyrophosphates,
and "glassy" phosphates such as sodium hexametaphosphate.
Diphase cleaning involves two immiscible liquid phases. One phase
consists of water plus water soluble wetting agents, and may also
include inorganic salts and emulsified oil. The other phase
usually is a layer of some suitable organic solvent or solvents.
In general, cleaning baths and their associated rinses can
contain oils, greases, grit, base metals, complexing agents,"
cyanides, acids, alkalies and miscellaneous additives. Cleaning
operations contribute to the raw waste types in the
following way:
Common metals - Most acid and alkaline cleaning operations.
Precious metals - Cleaning operations done on a precious
metal basis material.
Complexed metals - Cleaning operations done with heavily
chelated alkaline cleaners.
Hexavalent chromium - Cleaning done with chromated cleaners.
Cyanide - Cleaning done with cyanide cleaners.
Oily Waste - Cleaning of very oily parts.
Toxic organics - Solvent wiping, emulsion cleaning, vapor
degreasing.
MACHINING
Machining operations performed in the Metal Finishing Category
incorporate the use of natural and synthetic oils for cooling
and lubrication. Spills and leakage onto floor areas may be
washed away with water and contribute oil/water emulsions to
wastewater streams. Chip removal techniques produce large amounts
of metal solids and clinging oils. Chip storage areas may include
oil recovery facilities if the production level warrants them. If
properly contained, these oily wastes will not normally enter
wastewater streams. Any wastewaters which are generated belong
to the common metals and oily waste types.
GRINDING
Natural and synthetic oils are used in many grinding operations.
Soluble oil emulsions and other fluids are used for cooling and
lubrication, in a similar manner to that for machining. Some
V-43
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of these fluids are highly chlorinated and sulfochlorinated water
soluble oils that contain wetting agents and rust inhibitors.
Grinding system sumps contain ground metallic dust (or swarf)
which is an oily sludge requiring periodic removal. This sludge
does not mix with wastewater; however, grinding area spills and
leaks may be washed into wastewater streams. They can contain
any of the oily and additive constituents mentioned above. These
wastes could contribute to the common metals, oily waste and
solvent waste types.
POLISHING
The wastes generated include polishing and buffing compounds,
greases, metallic soaps, wafers, mineral oils, and dispersing
agents. Greases with stearic acid addition, hydrogenated
glycerides, and petroleum waxes are also used in these opera-
tions. Abrasives and fine metal particles accumulate and must be
periodically removed. Area cleaning and washdown can produce
wastes that enter wastewater streams. They would belong to the
common metals and oily waste types.
BARREL FINISHING
Abrasives, cleaners, soaps, anti-rust agents, emulsified oils,
and water are used in barrel finishing (tumbling) operations.
Caustic and alkaline cleaners are also used. Chemical solutions
used in barrel finishing include maleic acid, tartaric acid,
citric acid, sodium cyanide and sodium dichromate. Wastes from
tumbling consist of dilute oils, process chemicals, fine clays,
scale, and abrasive grit. Wastewater is generated by rinsing of
parts following the finishing operation and by periodic dumping
of process solutions. Contributions to the common metals, hexa-
valent chromium, cyanide and oily waste types could be made by
this operation, depending upon the chemicaljsolutions employed.
BURNISHING
Lubricants and soap solutions are used to cool tools used in
burnishing operations. Because burnishing provides a smoother
surface, light spindle oil or rich soluble oil is usually used.
Wastes may come from spills, leaks, process solution dumps and
post-finish rinsing. The wastes could contribute to the common
metals, precious metals and oily waste types depending upon the
basis material finished. In addition, sodium cyanide (NaCN) may
be used as a wetting agent and rust inhibitor (for steel), contri-
buting to cyanide wastes from this operation.
IMPACT DEFORMATION, PRESSURE DEFORMATION, AND SHEARING
Natural and synthetic oils, light greases, and pigmented lubricants
V-44
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are used in deformation and shearing operations. Pigmented
lubricants include: whiting, lithapone, mica, zinc oxide,
molybdenum disulfide, bentonite, flour, graphite, white lead, and
soap-like materials. The presses commonly used for these opera-
tions incorporate hydraulic lines and incur fluid leakage that
contributes oily waste. Spills and leaks in work areas may be
cleaned with water and combined with other wastewater streams.
Wastes from these operations would belong to the common metals
and oily waste types.
HEAT TREATING
Quenching oils are of three general types: Conventional, fast,
and water/oil emulsions (10-90% oil). A conventional oil con-
tains no additives that will alter cooling characteristics.
Fast quenching oils are blends which may contain specially de-
veloped proprietary additives such as nickel-zinc dithiophosphate,
The wastes generated will contain the solution constituents as
well as various scales, oxides and oils. Wastewater is generated
through rinses, bath discharges (including batch dumps), spills
and leaks. Included among the solutions used are:
Brine solutions (used in quenching) which can contribute
sodium chloride, calcium chloride, sodium hydroxide,
sodium carbonate, hydrochloric acid and sulfuric acid to
waste streams.
Water and water-based solutions (for quenching and rinsing)
which may contain dissolved salts, soaps, alcohols, oils,
emulsifiers, slimes and algae.
Cyaniding (liquid carburizing and carbonitriding) solutions
for heat treating containing sodium cyanide, inert salts
(sodium carbonate and sodium chloride), detergents, rust
preventatives, carbon, alkali carbonate, nitrogen, carbon
monoxide, carbon dioxide, cyanide, cyanate and oils (from
subsequent quenching).
High temperature baths containing sodium cyanide, potassium
chloride, sodium chloride, sodium carbonate, calcium and
strontium chlorides, manganese dioxide, boron oxide, sodium
fluoride and silicon carbide.
Unalloyed molten lead used for heat treating steel.
Most heat treating operations contribute wastewater to the common
metals or oily wastes subcategory. Cyaniding operations contri-
bute wastewaters to the cyanide waste type and the oily waste
type.
V-45
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THERMAL CUTTING
Water may be used for rinsing or cooling of parts and equip-
ment following this operation. Wastewaters produced would
contribute to the common metals and oily waste types.
WELDING, BRAZING, SOLDERING, FLAME SPRAYING
These operations are normally not wastewater producers.
However, each of them can be followed by quenching, cooling
or annealing in a solution of water or emulsified oils.
When this is done, wastes produced can belong to the common
metals waste type.
OTHER ABRASIVE JET MACHINING
Abrasive slurries in alkaline or emulsified oil solutions
and abrasives in air, nitrogen, or CO2 are used. Aluminum
oxide, silicon carbide, dolomite, calcium magnesium carbonate,
sodium bicarbonate and glass beads are common abrasives used in
this operation. Wastewater can be produced through solution
dumps, spills, leaks or washdowns of work areas and contributes
to the common metals and oily waste types.
ELECTRICAL DISCHARGE MACHINING
Dielectric fluids are used in this operation. Common fluids
include: hydrocarbon-petroleum oils, kerosene, silicone
oils, deionized water, polar liquids, and; aqueous ethylene
glycol solutions. Rinsing of machined parts and work area
cleanups can generate wastewaters which also contain base
materials. These wastewaters contribute to the common
metals and oily waste types.
ELECTROCHEMICAL MACHINING
In addition to standard chemical formulations, inorganic and
organic solvents are sometimes used as electrolytes for
electrochemical machining. Solvents used include water,
ammonia, hydrocyanic acid, sulfur dioxide, acetone, benzene,
ethanol, diethyl ether, methanol and pyridine. Any of the
constituents listed as well as the basis material being
machined can enter waste streams via rinse discharges, bath
dumps and floor spills. Generated wastes can belong to the
common metals, cyanide, and solvent waste types depending
upon the solvent used.
V-46
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LAMINATING
Water is not often used by this operation. However, occasional
rinsing or cooling may occur in conjunction with laminating. The
waste generated could contribute to the common metals and oily
waste types.
HOT DIP COATING
Hot dipping involves the immersion of metal parts in molten
metal. The molten metal coats the part and an alloy is formed at
the interface of the two metals. Water is used for rinses fol-
lowing precleaning and sometimes for quenching after coating.
Aluminum, zinc, lead and tin are the metals most commonly used.
Hot zinc coating (galvanizing) is probably used more extensively
than any others. Galvanizing (as well as the other coatings) is
done mainly for corrosion protection; in a few instances, hot dip
coatings are also used for decorative purposes. Most hot dip
coatings require fluxing. In galvanizing, a zinc ammonium
chloride flux is normally used prior to the actual coating step.
These wastewaters can contribute to the common metals waste type.
SALT BATH DESCALING
These baths contain molten salts, caustic soda, sodium hydride
and chemical additives. They are designed to remove rust, scale
and resolidified glass. These contaminants (and a small amount
of base material and oils) enter wastewater streams through
rinsing, spills, leaks, batch dumps of process solutions and
improper handling of sludge produced by the process. Wastewaters
produced by salt bath descaling contribute to the common metals
and oily waste types.
SOLVENT DECREASING
Solvent degreasing uses organic solvents such as aliphatic
petroleums (eg-kerosene, naptha), aromatics (eg-benzene, toluene),
oxygenated hydrocarbons (eg-ketones, alcohol, ether), halogenated
hydrocarbons (1,1,1-trichloroethane, trichloroethylene, methylene
chloride), and combinations of these classes of solvents. The
degreasing equipment, sumps, and stills contain spent solvents
and sludges along with removed oils, greases, and metallic par-
ticles. These pollutants can enter wastewater streams and con-
tribute to the toxic organic waste type.
V-47
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PAINT STRIPPING
The stripping of paint films from rejected parts, hooks, hangers,
masks, and other conveyor equipment is included in this opera-
tion. All the stripping wastes can contain any of the constitu-
ents of the paint being removed, as well as a small amount of the
basis material beneath the paint and the constituents of the
stripping solution. Stripping solutions may contain caustic
soda, wetting agents, detergents, emulsifiers, foam soaps,
alcohol, amines, ammonia or solvents. Solvents used include
chlorinated solvents (such as methylene chloride) and highly
polar solvents (such as acetone, methyl ethyl ketone, benzene and
toluene). Other solvents employed in paint stripping operations
include carbon tetrachloride, trichloroethylene, and orthodi-
chlorobenzene. Wastes are primarily generated by rinsing and can
also contain small amounts of emulsified oils. Spills, leaks,
and solution dumps can also contribute to wastewater streams.
Wastes produced belong to the common metals and oily waste
types.
PAINTING, ELECTROPAINTING, ELECTROSTATIC PAINTING
The sources of wastewater associated with industrial painting
processes include scrubbing water dumps, discharge of ultrafilter
permeate and discharge of rinse waters. Scrubbing (water cur-
tain) discharges vary widely in frequency of occurrence, from
once a week up to once every six to twelve months. A dump
schedule of once a month is not unusual for painters using water
curtains. These wastewater dumps may contain any of the common
paint ingredients (which often involve common metals) such as
solvents, pigments, resins and other additives. Dumps are
usually necessitated by buildups in the water of dissolved salts,
odor-causing anaerobic bacteria, and suspended solids that clog
the water curtain nozzles.
Ultrafiltration is used in connection with electropainting to
concentrate paint solids. The permeate contains pollutants from
the spent bath. However, the ultrafilter permeate is commonly
used as a water source for rinses immediately following the
electrodeposition process, and the ultrafilter concentrate is
returned to the painting bath. A final deionized water rinse is
used in electrodeposition painting, and the rinse water is
eventually discharged to a waste stream. This wastewater will
contain pollutants present in the paint bath.
V-48
-------
In the dip coating process, wastewaters containing paint pig-
ments and solvents are generated by selective spray rinsing
following the paint bath. Electrodeposition rinses generate
wastewaters and are described above. Rinses following auto-
deposition are normally discharged to'^waste streams and commonly
contain chromium in addition to paint constituents. Wastewaters
from these unit operations can contribute to the common metals,
hexavalent chromium and solvent waste types.
TESTING
Fuels, lubricating oils, and hydraulic fluids are commonly used
in non-destructive performance testing for many products such as
engines, valves, controls, and pressure vessels. Oily penetrants
are used in dye-penetrant inspection and testing operations.
Common penetrants include water, kerosene, ethylene glycol,
neutral oil, SAE 10W or SAE 40W oils, water-washable penetrants,
color-contrast penetrants, and emulsifiers. Leak testing, final
washing (automobiles, etc.) and test area washdowns enter waste
streams and may contain oils and fluids used at testing stations
as well as heavy metal contamination derived from the component
being tested. These wasitewaters contribute to the common rnetals
and oily waste types.
MECHANICAL PLATING
Cadmium, zinc, and tin, singly or in combination, may be applied
by mechanical plating. The parts are first precleaned by any of
the conventional methods such as solvent degreasing or alkaline
washing. They are then plated in a rotating, rubber lined barrel
containing an acid solution, inert impact media, and the metal to
be plated in powder form. The plated parts are rinsed and some-
times go through a chromating step before drying. Thus, the
plating solution and rinse water contain common metals, while
rinse water from the chromating step contains mainly hexavalent
chromium.
PRINTED CIRCUIT BOARD MANUFACTURING
Wastewater is produced in the manufacturing of printed circuit
boards from the following processes:
1. Surface preparation - The rinses following scrubbing.
alkaline cleaning, acid cleaning, etchback. catalyst
application and activation.
2. Electroless plating - Rinses following the electroless
plating step.
3. Pattern plating - Rinse following acid cleaning, alkaline
cleaning, copper plating, and solder plating.
4. Etching - Rinses following etching and solder brightening,
V-49
-------
5. Tab plating - Rinses following solder stripping,
scrubbing, acid cleaning, and nickel, gold, or other
plating operations.
6. Immersion plating - Rinses following acid cleaning and
immersion tin plating.
Additionally, water may be used for subsidiary purposes such as
rinsing away spills, air scrubbing water, equipment washing, and
dumping spent process solutions.
The principal constituents of the waste streams from the printed
board industry are suspended solids, copper, fluorides,
phosphorus, tin. palladium, and chelating agents. Low pH values
are characteristic of the wastes because of the acid cleaning and
surface pretreatment necessary. The suspended solids are
comprised primarily of metals from plating and etching oprations
and dirt which is removed during the cleaning processes prior to
plating. The large amount of copper present in the waste stream
comes from the electroless copper plating as well as copper
electroplating and etching operations. Fluorides are primarily
the result of cleaning and surface treatment processes utilizing
hydrofluoric and fluorboric acids. Phosphorus results from the
large amount of cleaning that is performed on the boards. Tin
results from operations involving catalyst application and solder
electroplating, and palladium is a waste constituent from catalyst
application. The chelating agents present are primarily from the
electroless plating operations, although others may have been
added by the cleaning, immersion plating, and gold plating
operations.
CHARACTERISTICS OF WASTE TYPE STREAMS
The waste effluent schematic in Figure 5-2 is applicable to raw
waste streams generated by operations within the Metal Finishing
Category. In this scheme, oily waste, hexavalent chromium waste,
cyanide waste, and precious metals waste are treated prior to
combining with other plant wastewaters (i.e., common metals waste)
for end-of-pipe treatment. Complexed metals waste are segregated
and treated separately and toxic organics waste are hauled or
reclaimed. In some cases a waste stream will contain pollutants
belonging to more than one waste type. When this occurs, it is
expected that the waste stream will receive the appropriate
specialized treatment prior to joining other streams and receiving
treatment for metals removal. For example, a waste stream from a
copper cyanide electroplating operation must receive treatment for
cyanide destruction before passing on to metals removal.
V-50
-------
f
en
M
Raw
f f
Raw Waste Discharge
(Treatment System
Influent) , i
I j I
Waste Treatment ! oilv Waste j Chromium j
(If Applicable) I Removal ! Reduction j
Treated
Effluent
i
Raw Wast
End-of-P
j Ket
! Rent
Final
Eff]
anufactur
Waste So
i i
Cannon
Metals
j Cyar
{ Destru
L
ing Facility
urces
i i
'
"I
ide i
i
ction 1
— __._]
s
£
i
!
i
i
Compl
Met
Rene
-------
Oil-bearing streams containing common metals1 must pass through oil
removal before going to metals removal. Selection of pollutant
parameters for regulation is covered in Section VI. Specific
details of appropriate waste treatment techniques are discussed in
Section VII.
In order to characterize the waste streams for each waste type.
raw waste data were gathered from the sampling visits. Discrete
samples of raw wastes were taken for each waste type and analysis
was done as explained previously in this section.
The minimum detectable limits for the priority pollutants, the
conventional pollutants TSS and Oil and Grease, and selected
non-conventional pollutants as published by :EPA in March 1979 and
December 1979 are presented in Table 5-17.
Individual laboratories can vary in their detection limits for
various parameters and can often achieve lower detection limits
than the ones presented in Table 5-17. Laboratories under
contract to EPA for pollutant analysis for this program reported
detection limits that were generally at or below the minimum
detectable limits. The results of the analyses from sample visits
are presented in this section.
The raw waste characteristics of the total plant raw waste
discharged to end-of-pipe treatment and the individual waste types
- common metals, precious metals, complexed metals, cyanide.
hexavalent chromium, oily, and toxic organics wastes - are
discussed in this section, and the sample visit data are
presented. The data tables include the following terms:
o Minimum concentrations found in the analysis of each
appropriate waste stream.
o Maximum concentrations found in the analysis of each
appropriate waste stream.
'*b Mean concentrations calculated from the results of the
analysis of each appropriate waste stream.
o Median concentrations selected by ranking appropriate
waste stream concentration values.
o ft of pts represents the number of streams used in the
preceding computations.
o tt of zeros is the number of times that a parameter was
not detected. Zeros were used in the generation of
statistics for the minimum, mean, median, and flow
proportioned average concentrations.
o Flow Proportioned Mean Concentrations obtained by
multiplying concentration times flow rate for each plant.
summing these products, and dividing by the sum of the
flow rates.
V-52
-------
TABLE 5-17
MINIMUM DETECTABLE LIMITS*
PARAMETER
MINIMUM
DETECTABLE
LIMIT mq/».
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
Acenaphthene
Acrolein
Acrylonitrile
Benzene
Benzidine
Carbon Tetrachloride (Tetrachloromethane)
Chlorobenzene
1. 2. 4 -Tri Chlorobenzene
Hexa Chlorobenzene
1 . 2-Dichlorethane
1. 1. 1-Trichloroethane
Hexachloroe thane
1. 1-Dichloroethane
1. 1.2-Trichloroethane
1.1.2. 2-Tetrachloroethane
Chloroethane
Bis (2-chloroethyl) ether
2-Chloroethyl Vinyl Ether (Mixed)
2-Chloronaphthalene
2.4. 6-Trichlorophenol
p-Chloro-m-cresol
Chloroform (Trichloromethane)
2-Chlorophenol
1. 2 -Di Chlorobenzene
1. 3-Dichlorobenzene
1. 4-Dichlorobenzene
3.3' -Dichlorobenzidine
1. 1-Dichloroethylene
1. 2-trans-Dichloroethylene
2 , 4-Dichlorophenol
1. 2-Dichloropropane
1. 3-Dichloropropylene(l, 3-Dichloropropene)
2.4-Dimethyl Phenol
2 . 4-Dinitrotoluene
2 . 6-Dinitrotoluene
1.2-Diphenylhydrazine
0.01
0.1
0.1
0.005
0.04
0.005
0.005
0.01
0.01
0.001
0.005
0.01
0.005
0.005
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.005
0.01
0.01
0.01
0.01
0.02
0.005
0.005
0.01
0.01
0.005
0.01
0.02
0.02
0.02
References: USEPA Environmental Monitoring and Support
Laboratory. Methods for Chemical Analysis of Water and Wastes,
March 1979; and USEPA Guidelines Establishing Test Procedures
for the Analysis of Pollutants. Proposed Regulations. Federal
Register Vol. 44. No. 233. Monday. December 3. 1979.
V-53
-------
TABLE 5-17 (Continued)
MINIMUM DETECTABLE LIMITS*
PARAMETER
MINIMUM
DETECTABLE
LIMIT ma/8.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
Ethylbenzene
Fluoranthene
4-Chlorophenyl Phenyl Ether
4-Broraophenyl Phenyl Ether
Bis(2-chloroisopropyl)ether
Bis (2-chloroethoxy)methane
Methylene Chloride(Dichlorome thane)
Methyl Chloride(Chloromethane)
Methyl Bromide (Bromomethane)
Bromoforra (Tribromomethane)
Dichlorobromome thane
Chlorodibromome thane
Hexachlorobutadiene
Hexachlorocyclopentadiene
Isophorone
Naphthalene
Nitrobenzene
2-Nitrophenol
4-Nitrophenol
2 . 4-Dinitrophenol
4. 6-Dinitro-o-cresol
N-Nitrosodimethylamine
N-Nitrosodiphenylamine
N-Nitrosodi-n-propylamine
Pentachlorophenol
Phenol
Bis(2-ethylhexyl) Phthalate
Butyl Benzyl Phthalate
Di-n-butyl Phthalate
Di-n-octyl Phthalate
Diethyl Phthalate
Dimethyl Phthalate
1. 2-Benzanthracene [Benzo(a)anthracene]
Benzo(a)Pyrene (3.4-Benzopyrene)
0.005
0.01
0.01
0.01
0.02
0.02
0.005
0.01
0.01
0.01
0.005
0.005
0.01
0.01
0.01
0.01
0.01
0.02
0.05
0.05
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.02
References: USEPA Environmental Monitoring and Support
Laboratory. Methods for Chemical Analysis of Water and Wastes
March 1979; and USEPA Guidelines Establishing Test Procedures
for the Analysis of Pollutants. Proposed Regulations. Federal
Register Vol. 44. No. 233. Monday. December 3. 1979.
V-54
-------
TABLE 5-17 (Continued)
MINIMUM DETECTABLE LIMITS*
PARAMETER
MINIMUM
DETECTABLE
LIMIT ma/ft.
74. 3,4-Benzofluoranthene [Benzo(b)fluoranthene]
75, 11,12-Benzofluoranthene [Benzo(k)fluoranthene]
76. Chrysene
77. Acenaphthylene
78. Anthracene
79, 1.12-Benzoperylene [Benzo(ghi)perylene]
80. Fluorene
81. Phenanthrene
82. 1,2.5,6-Dibenzathracene [Dibenzo(a,h)anthraeene]
83. Indeno(1.2,3-cd)pyrene (2,3-0-Phenylenepyrene)
84. Pyrene
85, Tetracaloroethylene
86. Toluene
87. Trichloroethylene
88. Vinyl Chloride (Chloroethylene)
89. Aldrin
90. Dieldrin
91. Chlordane (Technical Mixture and Metabolites)
92. 4,4'-DDT
93. 4,4'-DDE(P,P'-DDX)
94. 4.4'-DDD(P,P'-TDE)
95. Alpha-Endosulfan
96. Beta-Endosulfan
97. Endosulfan Sulfate
98, Endrin
99. Endrin Aldehyde
100. Heptachlor
101. Heptachlor Epoxide(BHC-Hexachlorocyclohexane)
102. Alpha-BBC
103. Beta-BHC
104. Gamma-BHC(Lindane)
105. Delta-BHC (PCB-Polychlorinated Biphenyls)
106, PCB-1242 (Aroclor 1242)
107. PCB-1254 (Aroclor 1254)
108. PCB-1221 (Aroclor 1221)
109. PCB-1232 (Aroclor 1232)
110. PCB-1248 (Aroclor 1248)
0.02
0.02
0.02
0.01
0.01
0.02
0.01
0.01
0.02
0.02
0.01
0.005
0.005
0.005
0.01
0.005 vg/8,
0.005 vg/i
0.05 vg/1
0.01
0.005
0.01
0.005 yf/5t
O.OO5 vg/%
0.01 yg/St
0.005 vg/51
0.01 vg/8,
0.005 Wg/St
0.005 wg/8,
o.oos
0.005
0.005 pg/8.
0.005
0.05
0.10 vg/i
0.10 wg/fi,
0.10 yg/8.
0.10 pg/9.
References: USEPA Environmental Monitoring and Support
Laboratory. Methods for Chemical Analysis of Water and Wastes,
March 1979; and USEPA Guidelines Establishing Test Procedures
for the Analysis of Pollutants, Proposed Regulations. Federal
Register Vol. 44, No. 233. Monday, December 3, 1979.
V-55
-------
TABLE 5-17 (Continued)
MINIMUM DETECTABLE LIMITS*
PARAMETER
MINIMUM
DETECTABLE
LIMIT mq/il
111.
112.
113.
114.
115.
116.
117.
118.
119.
120.
121.
122.
123.
124.
125.
126.
127.
128.
129.
PCB-1260 (Aroclor 1260)
PCB-1016 (Aroclor 1016)
Toxaphene
Antimony
Arsenic
Asbestos
Beryllium
Cadmium
Chromium
Copper
Cyanide
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
2.3.7. 8-Tetrachlorodibenzo-p-dioxin(TCDD)
Iron
Gold
Iridium
Osmium
Palladium
Platinum
Rhodium
Ruthenium
Tin
Hexavalent Chromium
Phosphorus (total)
Fluoride
Cyanide Amenable to Chlorination
Total Phenols
TSS
Oil and Grease
0.20 vg/S,
0.05 vg/S,
0.05 vg/S,
0.2
0.002
0.005
0.005
0.05
0.02
0.02-0.005
0.1
6.0002
0.04
0.002
0.01
0.1
0.005
0.005 vg/S,
0.03
0.1
3.0
0.3
0.1
0.2
0.05
0.2
0.8
0.001
0.01
0.1
0.005
0.005
10.0
5.0 to 0.2
References: USEPA Environmental Monitoring and Support
Laboratory. Methods for Chemical Analysis of Water and Wastes,
March 1979; and USEPA Guidelines Establishing Test Procedures
for the Analysis of Pollutants. Proposed Regulations. Federal
Register Vol. 44, No. 233. Monday, December 3. 1979.
V-56
-------
TOTAL PLANT RAW WASTE DISCHARGED TO END-OF-PIPE TREATMENT
Analysis of data the from sampled plants representing the raw
waste stream discharged prior to end-of-pipe treatment is pre-
sented in Table 5-18. The major constituents of metal finishing
raw waste discharged to end-of-pipe treatment are toxic metals
contributed primarily from the common metals waste stream and the
chromium waste stream after reduction. Cyanide, precious metals,
and oil and grease appear as minor constituents in the raw waste
to end-of-pipe treatment because (as shown in Figure 5-2) these
streams, like chromium, are combined with the common metals waste
after segregated treatment. The concentrations of these
constituents in the individual raw waste streams prior to initial
treatment, however, are significant.
V-57
-------
TABLE 5-18
POLLUTANTS FOUND IN TOTAL PLANT EAW WASTE
DISCHARGED TO END-OF-PIPE TREATMENT
Flow Proportioned
PARAMETER Mean Concentration
114. Antimony 0.009
115. Arsenic 0.008
117. Beryllium 0.001
118. Cadmium 0.283
119. Chromium 27.46
Chromium, Hexavalent 0.931
120. Copper 12.63
121. Cyanide 1.856
Cyanide. Amenable to Chlorination 1.168
122. Lead 0.331
123. Mercury 0.001
124. Nickel 15.47
125. Selenium 0.001
126. Silver 0.023
127. Thallium 0.009
128. Zinc 12.47
Oil and Grease 391.60
Total Suspended Solids 539.09
V-58
-------
COMMON METALS WASTE TYPE
Table 5-19 shows the concentrations of metals in common metals raw
waste streams from sampled plants. The major constituents in
common metals waste are parameters which originate in process
solutions such as from plating or galvanizing and enter the
wastewater by dragout to rinses. These include cadmium, chromium,
copper, cyanide, lead, nickel, zinc, and tin, and these pollutants
appear in common metals waste streams in widely varying
concentrations.
PRECIOUS METALS WASTE TYPE
Table 5-20 shows the concentrations of silver, gold, palladium.
and rhodium found in precious metals raw waste streams. All of
the precious metals shown are used in Metal Finishing Category
operations. The major constituents are silver and gold, which are
much more commonly used than palladium and rhodium. Because of
their high cost, metal finishers generally attempt to recover
these metals from wastewaters.
COMPLEXED METALS WASTE TYPE
The concentrations of toxic metals found in complexed metals raw
waste streams are presented in Table 5-21. Complexed metals may
occur in a number of unit operations but come primarily from
electroless and immersion plating. The most commonly used metals
in these operations are copper, nickel and tin. Wastewaters
containing complexing agents must be segregated and treated
independently of other wastes in order to prevent further
complexing of free metals in the other streams.
CYANIDE WASTE TYPE
The cyanide concentrations found in cyanide raw waste streams are
shown in Table 5-22. Streams with high cyanide concentrations
normally originate in electroplating and heat treating processes.
Other unit operations can also contribute cyanide wastes.
Cyanide-bearing waste streams should be segregated and treated
before being combined witli other raw waste streams.
HEXAVALENT CHROMIUM WASTE TYPE
Concentrations of hexavalent chromium from metal finishing raw
wastes are shown in Table 5-23. Hexavalent chromium enters
V-59
-------
Toxic Pollutant
TABLE 5-19
POLLUTANT CONCENTRATIONS FOUND IN THE
COMMON METALS RAW WASTE STREAM
(Average Daily Values (mg/liter)
Minimum
Maximum
Mean
Median
t Zeros
f Points
Plow Proportioned
Mean Concentratio
114
115
117
118
119
120
121
122
123
124
125
126
127
^ 128
f
o\
o
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Cyanide
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Aluminum
Barium
Boron
Calcium
Cobalt
Fluorides
Iron
Magnesium
Manganese
Molybdenum
Phosphorus
Sodium
Tin
Titanium
Vanadium
Yttrium
Oil and Grease
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
1.67
25.0
0.0
0.0
0.0
5.6
0.059
0.0
0.0
16.7
0.0
0.0
0.0
0.0
4.70
0
0
0
21
35
500
2370
42
0
415
0
0
0
16,500
200
0
4
76
0
36
13,100
31
0
0
76
310
14
4
0
0
802,000
.430
.064
.044
.5
.4
*
»
.3
.400
,
.060
.080
.062
*
.017
.0
.2
.023
.1
B
.1
.500
.300
.7
,
.7
.30
.216
.020
*
0.007
0.005
0.008
0.613
2.10
14.2
42.1
1.25
0.005
19.4
0.007
0.006
0.008
312.
27.4
0.032
31.4
51.4
0.007
4.31
500.
16.1
0.233
0.102
7.72
151.
1.04
0.493
0.066
0.010
40,700.
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
3
52
0
0
2
13
0
0
3
138
0
0
0
0
6,060
.0
.0
.005
.001
.105
.175
.016
.053
.0
.078
.005
.0
.003
.393
.27
.029
.76
.2
.0
.876
.44
.8
.085
.018
.06
,
.0
.006
.023
.010
*
84
75
4
48
16
3
29
35
67
20
5
59
5
1
2
1
0
0
4
9
1
0
0
1
1
0
60
4
1
1
0
106
105
27
119
116
119
99
122
109
111
26
103
26
122
16
4
3
4
7
99
102
4
7
6
98
4
98
9
4
4
37
0
0
0
1
1
0
0
0
4
0
0
0
41
85
0
3
58
0
6
84
17
0
0
8
211
3
0
0
0
11,600
.0007
.015
.016
.070
.39
.84
.834
.738
.001
.16
.003
.001
.003
.3
.6
.031
.13
.5
.010
.15
.7
.4
.337
.109
.00
,
.35
.046
.069
.010
.
-------
Otoxic Bpllutant
126 Silver
Gold
Palladium
Rhodium
ninimun
TABLE 5-20
POLLUTANT CONCENTRATIONS FOUND IN THE
PRECIOUS METALS RAW WASTE STREAM
Average Daily Values (rag/liter)
Maximum fean Median 12
0.0
0.0
0.0
0.0
600.
42.7
0.120
0.220
69.0
9.27
0.023
0.018
0.243
0.560
0.0
0.0
3
6
10
11
IPoints
15
15
13
12
Flow Proportioned
Msan Comentra.'H on _
8.09
6.11
0.003
0.005
f
Toxic Pollutant
118 Cadmium
120 Copper
122 Lead
124 Nickel
128 Zinc
Minimum
TABLE 5-21
POLLUTANT eOONTRATIONS FOUND IN THE
COMPLEXED METALS RAW WASTE STREAM
Average Daily Values (mg/Liter)
Maximun Wean Median
0.0
0.0
0.0
0.0
0.023
3.65
62.6
3.61 .
294.
17.6
0.247
10.3
0.372
22.5
3.05
0.0
5.90
0.0
0.550
0.210
f Zeros
22
3
21
6
0
Flow Proportioned
I Points tfeanConcentration
31 0.173
31 9.68
31 0.240
31 18.8
31 2.52
-------
f
crt
to
Toxic Pollutant
121 Cyanide, total
Cyanide, Amen, to Chlor.
TABLE 5-22
POLLOTRNT COCEWERA.TICNS FOCM) IN THE
CXANIDE RAH WASTE STREAM
Average E&ily Values (mg/liter)
Minimum Haxintun Maan
0.045
0.0
1680.
1560.
298.
266.
^Median
77.4
7.63
I Zeros
0
1
Flow Proportioned
I Baints Maan Concentration
23 96.3
22 86,8
Toxic Pollutant
Chromium, Bexavalent
TMtE 5-23
POLLUTANT CONCENTRATICNS FOUND IN THE
~KSXAVKL£m CHROMIUM RAW WASTE STREAM
Average Daily Values (ing/liter)
MiniiiiiiB Maximum Mean
0.005 12900. 377.
Flow Proportioned
i Points Mean Concentration
46 54.6
-------
wastewaters as a result of many unit operations and can be very
concentrated. Hexavalent chromium is highly toxic and should be
segregated and treated before combining with other raw waste
streams.
OILY WASTE TYPE
Table 5-24 shows the concentrations of oil and grease in oily
waste streams from sampled plants. Oily waste in the metal
finishing industry consists of free oils, emulsified or water
soluble oils and greases in a concentrated or dilute form. The
relationship between the unit operations and type of oily waste
generated (concentrated or dilute) is illustrated in Table 5-25.
Applicable treatment of oily waste streams can vary dependent upon
the concentration levels of the waste. Concentrated oily wastes
typically include machining oils and process coolants and
lubricants. Concentrated oily wastes are generally characterized
by very high concentrations of oil and grease and should be
segregated for oil removal prior to combining with other plant
wastewaters for treatment. Dilute oily wastes include wastes from
cleaning operations. The concentrations of oil and grease in
these waste streams is generally much lower than that of segre-
gated oily wastes and these streams typically do not receive
segregated treatment before combining with other process waste-
waters .
TOXIC ORQANICS WASTE TYPE
Toxic organics raw wastes are generated in the Metal Finishing
Category primarily by the dumping of spent solvents from
degreasing equipment (including its sumps, water traps, and
stills). These solvents are predominately comprised of compounds
that are classified by the EPA as toxic pollutants. Table 5-26,
extracted from the literature, illustrates specific solvents
employed and shows their annual consumption for 1974. Spent
solvents should be segregated, hauled for disposal or reclamation.
or reclaimed on site. These and other sources of toxic organics
enter various metal finishing wastewaters.
Table 5-26 shows that in 1974 this degreasing solvent consumption
amounted to 1600 million pounds/yr (6.4 million Ib/day) and is
expected to be in the order of 23-00 million pounds/yr (9.3
million Ib/day) by 1985. Literature indicates that nearly 100%
of all solvents consumed reach the atmosphere, either by direct
evaporation from degreasing equipment or by evaporation
subsequent to improper disposal. (Reference: Organic Solvent
Cleaning - Background Information for Proposed Standards; USEPA;
EPA-450/278-045; May 1979). In addition, the same reference
estimates that approximately 75% of the incidence of solvent
degreasing occurs in the metal finishing and related industries.
Since degreasing solvents are predominantly concentrated priority
pollutants that are discharged to the environment from a single
unit operation, solvent degreasing, the reduction
of this source will significantly improve the environment.
V-63
-------
TABLE 5-24
POLLUTANT CONCENTRATIONS FOUND IN THE
OILY RAW WASTE STREAM
Flow
Average Daily Values (mg/lL) Proportioned
Toxic No. No. Mean
Pollutant Minimum Maximum Mean Median Zeros Points Concentration
Oil & Grease 4.7 802,000 40,700 6,060 0 37 11,600
¥-64
-------
TABLE 5-25
OILY WASTE CHARACTERIZATION
Unit Operation Character ofOily Waste Generated
Concentrated Dilute
Cleaning x
Machining x x
Grinding x x
Polishing x
-" Tumbling (Barrel Finishing) . x
Burnishing x
Impact Deformation x
Pressure Deformation x
Shearing x
Heat Treating x x
Welding x
Brazing x
Soldering x
Flame Spraying x
Other Abrasive Jet Machining x
Electrical Discharge Machining x
Salt Bath Descaling x
Solvent Degreasing x
Paint Stripping x
Assembly x
Testing x x
V-65
-------
TABLE 5-26
1974 DECREASING SOLVENT CONSUMPTION
Solvent Consumption (Millions of Pounds/Yr).
Solvent Type Cold Vapor All
Cleaning Degreasing Degreasing
Halogenated;
Trichloroethylene 55 282 337
1,1,1-trichloroethane 180 176 356
Perchloroethylene 29 90 119
Methylene Chloride 51 16 67
Trichlorotrifluoroethane 22 44 66
337 608 945
Aliphatics;
(Kerosenes, Napthas) 489 0 489
Aromatics;
Benzene 15 0 15
Toluene 31 0 31
Xylene 27 0 27
Cyclohexane 2 02
Heavy Aromatics 27 0 27
TU2 ff TO~Z
Oxygenated;
Ketones
Acetone 22 0 22
Methyl Ethyl Ketone 18 0 18
Alcohols
Butyl 11 0 11
Ethers 13 0 13
__. _ -—j
Total Solvents: 992 608 1600
V-66
-------
The primary source of data for this report was 365 Data
Collection Portfolios (DCP's) produced from a random survey of
900 manufacturers having Standard Industrial Classification (SIC)
Codes between 3400 and 3999. These cover the manufacturing of:
Fabricated Metal Products, Machinery, Electrical and Electronics
Machinery, Transportation Equipment, Measuring Instruments, and
Miscellaneous Products. The requested information concerning
manufacturing unit operations and waste treatment methods
provided solvent degreasing unit operation data including waste
solvent consumption quantities and frequencies of
disposition . Additional or missing data were
obtained by telephone survey. Since the manufacturers were
selected at random, the survey data was considered representative
of the entire population of manufacturers within those SIC Codes.
A summary of the DCP data is presented in Table 5-27. These data
show that 24% of the respondents perform the solvent degreasing
operation, and that 73% of these have their waste solvents
contract hauled while 27% discharge their waste directly to the
environment. Based upon a mean discharge rate of 49.4 Ib/day (as
shown in Table 5-27) and a population of 13,470 metal finishing
plants, approximately 43,000 Ib/day of solvent are discharged
directly to the environment.
13,470 (metal finishing plants)
x 24% (percent of plants which do solvent degreasing)
3,233 (number of plants performing solvent degreasing)
x 27% (percent of degreasing operations discharging to
environment)
873 (number of degreasing operations discharging to environment)
x 49.4 (mean spent solvent discharge rate (Ib/day)
43,126 spent solvent discharged to environment (Ib/day)
In addition, approximately 3,300,000 Ib/day are contract hauled.
3,233 (number of plants doing solvent degreasing)
x73% (percent of plants whose solvent wastes are contract hauled)
2,360 (number of plants whose solvents are contract hauled)
x 118.7 mean amount of solvents hauled (Ib/day)
280,143 Total spent solvents hauled (Ib/day)
The total solvent consumption based upon estimates in the
literature is 4.8 million Ib/day.
In addition to the DCP information, plant visits provided data
that identified the particular solvents used by relatively large
manufacturing facilities. These data show that 43 of the 84
manufacturers visited (51%) performed solvent degreasing.
Although the quantity, frequency, and disposal data are
incomplete, 93% of the manufacturers who reported a disposal
method either used contract hauling or reclaimed their waste
solvents. Comparing this with the random survey data (73%
reporting contract haulers) indicates that larger manufacturers
may be more likely to haul or reclaim their spent solvents.
V-67
-------
TABLE 5-27
SUMMARY OF DCP SOLVENT DECREASING DATA
DCP's Issued
DCP Respondents
DCP Respondents Performing Solvent Degreasing
DCP Respondents with Supportive Plant Visit
Data
DCP Respondents Contacted via Telecon
Degreasers - Waste Solvent Disposal Specified
Degreasers - Waste Solvent Disposal Unspecified
Degreasers That Have Waste Solvent Contract Hauled
Maximum hauled
Minimum hauled
Mean
Degreasers Discharging to Sewer or Surface
Maximum discharged
Minimum discharged
Mean
900
365
88 (24%)
14
28
74
14
54 (73%)
960 Ibs/day
0.4 Ibs/day
118.7 Ibs/day
20 (27%)
399 Ibs/day
0.5 Ibs/day
49.4 Ibs/day
V-68
-------
The results of the analysis for total toxic organics (TTO) in the
raw waste from sampled plants is presented in Table 5-28. Data on
TTO concentrations in various operations and waste streams at
sampled plants are presented in Tables 5-29 through 5-47.
¥-69
-------
TABLE 5-28
TOTAL TOXIC ORGANICS (TTO) CONCENTRATIONS
IN METAL FINISHING RAtf tfRSTE
Raw Waste ffo
Concentration
(mq/g,)
Plant ID
Raw Waste TTO
Concentration
Plant ID
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NR
NA
NR
NR
NR
NR
NR
NA
NA
0
0.002
0.003
0.003
0.005
0.006
6019
6091-15-0
6091-15-1
6091-15-2
12061-14-0
12065-14-1
12065-15-2
12065-15-4
13042-21-1
17050-14-0
19068-14-0
19069-15-0
19069-15-1
19069-15-2
20005-21-0
27046-15-2
34050-15-0
34050-15-1
34050-15-2
36048-15-0/1
36048-15-2/3
36048-15-4/5
38040-23-0
38040-23-1
38217-23-0
9025-15-0
20083-15-0/1
20083-15-2/3
20083-15-4/5
11108-15-1
12061-15-0
0.006
0^.007
0.007
0.008
0.008
0.009
0,.009
0.009
0;.009
0.009
0.010
0^010
0.011
o:.on
0,011
0.012
0.012
0.012
0.013
0.014
0.014
0.014
0.017
0.019
0.020
0.020
0.021
0.022
0.023
0.028
0.028
12061-15-2
11108-15-2
20022-15-2
40060-15-0
20022-15-1
18538-15-5
40060-15-1
6110-15-1
6110-15-2
9052-15-0
11103-15-2/3
6110-15-0
2033-15-4/5
11108-15-0
21066-15-1
18538-15-3
21066-15-0
9052-15-2
11103-15-4
21066-15-3
21003-15-2
41051-15-0
15608-15-2
15608-15-0
20022-15-0
41051-15-1
12075-15-2/3
4069-15-0/1
41051-15-2
12075-15-0/1
2033-15-0/1
NA = Total raw waste TTO not available; total effluent TTO presented in
Section VII.
V-70
-------
TABLE 5-28 (Continued)
TOTAL TOXIC ORGANICS (TTO) CONCENTRATIONS
IN METAL FINISHING RAW WASTE
Raw Waste fTO
Concentration
Plant ID
Raw Waste TTO
Concentration
(mq/g.)
Plant ID
0.030
0,030
0.031
0.034
0.036
0.038
0.040
0.040
0.042
0.043
0.059
0.064
0.084
0.091
0.095
0.097
0.097
0.098
0.099
0.104
0.107
0.109
0.110
0.111
,113
,120
,130
,133
0.140
0.141
0,
0,
0,
0,
2033-15-2/3
12061-15-1
2032-15-2
21003-15-0
17061-15-1
15608-15-1
9052-15-1
21003-15-1
12075-15-4/5
4071-15-0
6960-15-4/5
18538-14-0
11103-15-0
34051-15-0
34051-15-1
6090-14-0
38051-15-2
44062-15-0
38052-15-0
6960-15-0/1
44062-15-2
2032-15-5
44062-15-1
34051-15-2
4069-15-2/3
19068-15-1
4071-15-3
4071-15-1
30165-21-0
17061-15-3
0.178
0.192
0.200
0.202
0.204
0.224
0.251
0.259
0.283
0.285
0.289
0.326
0.364
0.400
0.426
0.473
0.477
0.486
0.769
0.888
.083
.09
.161
.287
.619
.938
.005
8.466
12.866
13.50
1,
1,
1,
1,
1,
1,
2,
4069-15-4
38052-15-1
38052-15-2
19068-15-2
6960-15-2/3
38051-15-0
9025-15-1
38051-15-1
4282-21-0
36178-21-0
9025-15-2
36178-21-1
30054-15-0
27046-15-1
27046-15-0
6019
17050-15-1
6090-15-1
30054-15-1
17061-14-1
17050-15-0
33692-23-0
2032-15-0
30054-15-2
28699-21-0
20103-21-0
36178-21-2
6090-15-2
20103-21-1
33692-23-1
V-71
-------
TABLE 5-29
TTO CONCENTRATIONS IN RAW WASTE FROM ELECTROPLATING LINES
TTO Concentration
Plant ID Description
21051-15-0 Wastes from nickel and zinc
plating lines
21051-15-1 wastes from nickel and zinc
plating lines (after copper
reduction)
12075-15-0 Rinses from tin plating lines
12075-15-2 Rinses from tin plating lines
12075-15-4 Rinses from tin plating lines
12075-15-0 Rinses from tin plating lines
12075-15-2 Rinses from tin plating lines
12075-15-4 Rinses from tin plating lines
18538-15-3 Acid/Alkali rinses from nickel
and zinc electroplating
18538-15-5 Acid/Alkali rinses from nickel
and zinc electroplating
2033-15-0 Acid rinses from nickel plating
2033-15-2 Acid rinses from nickel plating
2033-15-4 Acid rinses from nickel plating
12065-15-1 Parts strip & rack strip rinses
on common metals plating line
12065-15-2 Parts strip & rack strip rinses
on common metals plating line
12065-15-4 Parts strip & rack strip rinses
on common metals plating line
19069-15-0 Rinses from common metals
plating (after partial treat-
ment of wastewater)
% Total Flow
43
86
8.86
7.1
10.5
.9
.6
.4
69.4
63.8
53.77
53.77
53.77
54
(mq/a)
.625
.396
.013
.006
.008
.01
.020
0
.010
.010
.011
.015
.014
.026
54
54
42
.016
.035
.282
V-72
-------
TABLE 5-29 (Continued)
TTO CONCENTRATIONS IN RAW WASTE FROM ELECTROPLATING LINES
Plant ID Description
19069-15-1 Rinses from common metals
plating (after partial treat-
ment of wastewater)
19069-15-2 Rinses from common metals
plating (after partial treat-
ment of wastewater)
21066-15-4 Alkaline rinse from common
metals plating
15193-21-0 Sodium nitrate from common
metals plating
12061-15-0 Rinse water from zinc plating
12061-15-1 Rinse water from zinc plating
12061-15-2 Rinse water from zinc plating
12061-15-0 Rinse water from copper plating
12061-15-1 Rinse water from copper plating
12061-15-2 Rinse water from copper plating
6960-15-0 Acid/Alkaline rinses on common
metals electroplating lines
6960-15-2 Acid/Alkaline rinses on common
metals electroplating lines
6960-15-4 Acid/Alkaline rinses on common
metals electroplating lines
6960-15-0 Zinc chloride plating rinse
6960-15-2 Zinc chloride plating rinse
6960-15-4 Zinc chloride plating rinse
6960-15-0 Cadmium plating rinse
6960-15-2 Cadmium plating rinse
6960-15-4 Cadmium plating rinse
% Total Plow
42
100
NA
NA
23
23
TTO Concentration
(mg/U
.313
.011
.041
1.025
21.8
20.9
22.8
17.9
16.6
17.3
23
.006
.007
.004
.003
.004
.003
.084
.253
.030
7
7
7
8
8
8
.135
.003
.004
.028
.107
.042
V-73
-------
TABLE 5-30
fTO CONCENTRATIONS IK RAW WASTE FROM ELECTROLESS PLATING LINE RINSES
Plant ID
Description
% Total Flow
TTO Concentration
(mg/it)
20083-15-0 Neutralization rinses on
electfoless plating line
30083-15-2 Neutralization rinses on
electroless plating line
20083-15-4 Neutralization rinses on
electroless plating line
20083-15-0 Rinses following catalyst application
20083-15-2 Rinses following catalyst application
20083-15-4 Rinses following catalyst application
20083-15-0 Rinses after accelerator step
20083-15-2 Rinses after accelerator step
20083-15-4 Rinses after accelerator step
20083-15-0 Electroless nickel plating rinse
20083-15-2 Electroless nickel plating rinse
20083-15-4 Electroless nickel plating rinse
20083-15-0 Electroless copper plating rinses
to copper seeder
20083-15-2 Electroless copper plating rinses
to copper seeder
20083-15-4 Electroless copper plating rinses
to copper seeder
20083-15-0 Electroless copper plating rinses
not directed to copper seeder
20083-15-2 Electroless copper plating rinses
not directed to copper seeder
20083-15-4 Electroless copper plating rinses
not directed to copper seeder
9
9
9
ion 6
ion 6
ion 6
9
9
9
9
9
9
4,6
NA
4.5
1.5
1.5
NA
.001
.002
.002
.003
.003
.003
.003
.002
.002
.002
.004
.002
.003
.003
.004
.001
.009
.003
V-74
-------
TABLE 5-30 (Continued)
TTO CONCENTRATIONS IN RAW WASTE FROM ELECTROLBSS PLATING LINE RINSES
TTO Concentration
Plant ID Description % Total Flow (mq/t)
34051-15-0 Electroless nickel plating line 6.0 .084
rinse water
36048-15-0 Alkaline rinse on electroless 1 .040
plating line
36048-15-2 Alkaline rinse on electroless 1 .279
plating line
36048-15-4 Alkaline rinse on electroless 1 .233
plating line
36048-15-0 Acid rinse on electroless plating line 4 .022
36048-15-2 Acid rinse on electroless plating line 4 .011
36048-15-4 Acid rinse on electroless plating line 4 .172
36048-15-0 Descaling rinse on electroless 2 .064
plating line
36048-15-2 Descaling rinse on electroless 2 .053
plating line
36048-15-4 Descaling rinse on electroless 2 .063
plating line
36048-15-0 Activator rinse on electroless 1 .087
plating line
36048-15-2 Activator rinse on electroless 1 .136
plating line
36048-15-4 Activator rinse on electroless 1 .148
plating line
36048-15-0 Rinse after electroless nickel plating 3 .261
operation
36048-15-2 Rinse after electroless nickel plating 3.5 .169
operation
36048-15-4 Rinse after electroless nickel plating 3.5 .228
operation
V-75
-------
TABLE 5-30 (Continued)
TTO CONCENTRATIONS IN RAW WASTE FROM ELECTROLESS PLATING LINE RINSES
TTO Concentration
Plant ID Description % Total Plow (mg/t)
2033-15-0 Acid wastes from electroless plating 19.2 .010
line
2033-15-2 Acid wastes from electroless plating 19.2 .007
line
2033-15-4 Acid wastes from electroless plating 19.2 .013
line
2033-15-0 Rinse water from precious metal 5.05 .035
electroless plating
2033-15-2 Rinse water from precious metal 5.05 .023
electroless plating
2033-15-4 Rinse water from precious metal 5.05 .014
electroless plating
12065-15-1 Acid dip neutralizer rinse on 6 .014
electroless plating line
12065-15-2 Acid dip neutralizer rinse on 6 .013
electroless plating line
12065-15-4 Acid dip neutralizer rinse on 6 .055
electroless plating line
12065-15-1 Catalyst rinse from electroless 7 .016
plating (plastic)
12065-15-2 Catalyst rinse from electroless 7 .030
plating (plastic)
12065-15-4 Catalyst rinse from electroless 7 .014
plating (plastic)
12065-15-1 Accelerator rinse from plastic 8 .023
electroless plating line
12065-15-2 Accelerator rinse from plastic 8 .012
electroless plating line
12065-15-4 Accelerator rinse from plastic 8 .014
electroless plating line
V-76
-------
fABLE 5-30 (Continued)
HO CONCENTRATIONS IN RAW WASTE FROM ELECTSOLESS PLATING LINE RINSES
Plant ID
Description
12065-15-1 Rinse following electroless
nickel plating
12065-15-2 Rinse following electroless
nickel plating
12065-15-4 Einse following electroless
nickel plating
4069-15-0 Rinse from electroless copper line
4069-15-2 Rinse from electroless copper line
% Total Plow
7
.3
.3
TTO Concentration
(mg/ft)
.024
.022
.005
.102
.059
V-77
-------
TABLE 5-31
TTO CONCENTRATIONS IN RAW WASTE
FROM PRECIOUS METALS ELECTROPLATING LINE RINSES
TTO Concentration
Plant ID Description
6090-14-0 Silver-bearing raw waste
19069-15-0 Rinses from precious metals
plating line
19069-15-1 Rinses from precious metals
plating line
2033-15-0 DI rinses from silver electroplating
2033-15-2 DI rinses from silver electroplating
2033-15-4 DI rinses from silver electroplating
2033-15-0 Rinses from precious metals
electroless plating
2033-15-2 Rinses from precious metals
electroless plating
2033-15-4 Rinses from precious metals
electroless plating
2033-15-0 Rinses from precious metals
electroless & electroplating
2033-15-2 Rinses from precious metals
electroless & electroplating
2033-15-4 Rinses from precious metals
electroless & electroplating
30054-15-0 Rinses from gold plating
30054-15-1 Rinses from gold plating
30054-15-2 Rinses from gold plating
% Total Plow
0
58
58
.ng 9.2
.ng 9.2
.ng 9.2
5.05
5.05
5.05
19.2
19.2
19.2
19
20
16
(mq/l)
.054
.401
.280
.035
.007
.006
.035
.023
.014
.056
.038
.025
.007
2.53
.961
V-78
-------
TABLE 5-32
TTO CONCENTRATION IN RAW WASTE PROM ANODIZING LINE RINSES
Concentration
Plant IP Description
20022-15-2 Dye rinses (from anodizing plant)
17050-14-0 Raw wastes from anodizing line
40060-15-1 Alkaline cleaning rinse on
anodizing line
9052-15-0 Anodizing line rinses
9052-15-1 Anodizing line rinses
9052-15-2 Anodizing line rinses
41051-15-0 Anodizing rinse water
41051-15-1 Anodizing rinse water
41051-15-2 Anodizing rinse water
% Total Flow
3
82
16
55
55
55
72
72
72
.004
.465
.021
.009
.061
.009
.013
.018
.027
V-79
-------
TABLE 5-33
TTO CONCENTRATIONS IN RAW WASTE FEOM COATING LINE EIMSES
TfO Concentration
Plant ID
6091-15-1
34051-15-0
38051-15-0
38051-15-1
38051-15-2
12075-15-0
12075-15-2
12075-15-4
18538-15-3
18538-15-3
18538-14-0
18538-15-5
18538-15-1
18538-15-5
11103-15-1
11103-15-3
11103-15-4
11103-15-3
Description % Total Flow (mq/il)
Chromating rinse
Conversion coating rinse
Conversion coating rinses
Conversion coating rinses
conversion coating rinses
Electrogalvanizing line rinses
Blectrogalvanizing line rinses
Electrogalvanizing line rinses
Appearance phosphating line rinses
Non-appearance phosphating line rinses
Composite of phosphating line rinses
composite of phosphating line rinses
Phosphating rinse
Phosphating rinse
Rinse water from 1st rinse tank after
black oxidizing process tank
Rinse water from 1st rinse tank after
light zinc phosphating process tank
Rinse water from 1st rinse tank after
zinc phosphating (auto barrel)
Chromic acid sealer tank on zinc
11
5
78.4
78.4
78.4
1.2
1.3
1.3
8.4
6.4
11.7
16.7
NA
NA
7.7
2.5
2.5
1.0
.174
.124
.243
.306
.084
.010
.009
.013
.009
.009
.031
.007
.064
.007
.006
.003
.004
.007
36178
phosphating line
Composite of phosphating line wastes
NA
24.2
V-80
-------
TABLE 5-33(Continued)
TTO CONCENTRATIONS IN RAW WASTE PROM COATING LINE RINSES
TTO Concentration
Plant ID
11103-15-0
11103-15-2
11103-15-3
Iil03-15-0
11103-15-2
11103-15-3
6960-15-2
6960-15-4
6960-15-0
6960-15-2
6960-15-4
6960-15-0
6960-15-2
6960-15-4
44062-15-0
44062-15-1
44062-15-2
44062-15-0
44062-15-1
44062-15-2
Description
Conversion coating rinses
Conversion coating rinses
Conversion coating rinses
Conversion coating rinses
bypassing treatment
Conversion coating rinses
bypassing treatment
Conversion coating rinses
bypassing treatment
Phosphating line cleaning rinse
Phosphating line cleaning rinse
Acid pickle rinse on phosphating line
Acid pickle rinse on phosphating line
Acid pickle rinse on phosphating line
Zinc phosphating rinse
Zinc phosphating rinse
Zinc phosphating rinse
Conversion coating line (Alodine 404) 16
rinse water
Conversion coating line (Alodine 404) 16
rinse water
Conversion coating line (Alodine 404) 16
rinse water
% Total Plow
21
18
18
38
33
33
8
8
.ine 8
.ine 8
.ine 8
8
8
8
104) 16
(roq/fc)
.312
.003
.006
.022
.018
.021
.896
.192
.148
.031
.017
.088
.058
.049
.130
Conversion coating (Alodine 401)
rinse water
Conversion coating (Alodine 401)
rinse water
Conversion coating (Alodine 401)
rinse water
20
20
20
.281
.067
.189
.082
.123
V-81
-------
TABLE 5-34
TTO CONCENTRATIOMS IN RAW WASfE PROM ETCHING AND BRIGHT DIPPING RINSES
TfO Concentration
Plant ID
6091-15-0
6091-15-1
6091-15-2
20083-15-0
20083-15-2
20083-15-4
14062-21-0
36048-15-0
36048-15-4
2032-15-0
2032-15-2
2032-15-5
34050-15-0
34050-15-1
34050-15-2
4069-15-0
4069-15-2
4069-15-4
4282-21-0
9052-15-0
9052-15-1
9052-15-2
Description
Small parts caustic etch rinse
small parts caustic etch rinse
Small parts caustic etch rinse
Chromic acid etch rinse
Chromic acid etch rinse
Chromic acid etch rinse
Chemical milling rinse
Etching rinses
Etching rinses
Alkaline etching rinses
Alkaline etching rinses
Alkaline etching rinses
Bright dip wastes
Bright dip wastes
Bright dip wastes
strip resist and etching rinses
Strip resist and etching rinses
Strip resist and etching rinses
Rinses from chromic acid etching
Etching rinses
Etching rinses
Etching rinses
% Total Flow
22
22
22
6
6
6
27
36.5
40
9
9
8
18.9
21.1
21.1
10.6
10.6
10.6
9.5
45
45
45
-------
TABLE 5-34 (Continued)
TTO CONCENTRATIONS IN RAW WASTE PROM ETCHING AND BRIGHT DIPPING RINSES
Plant ID Description
19068-15-1 Etching rinses
19068-15-2 Etching rinses
30054-15-0 Bright dip etching rinses
38052-15-0 Bright dip chromic etching rinses
38052-15-1 Bright dip chromic etching rinses
38052-15-2 Bright dip chromic etching rinses
41051-15-0 Etching rinse waters
41051-15-1 Etching rinse waters
41051-15-2 Etching rinse waters
% Total Plow
65
62
5
66
66
66
24
24
24
TTO Concentration
(ma/it)
.078
.298
.608
.081
.207
.248
.016
.022
.010
V-83
-------
TABLE 5-35
fTO CONCENTRATIONS IN RAW WASTE FROM CLEANING OPERATIONS
Plant IP
33617
30082
30082
30165-21-0
30165-21-0
44062-15-0
44062-15-1
44062-15-2
44062-15-0
44062-15-1
44062-15-2
Description
small parts wash
Rinse following detergent wash of
filled and sealed capacitors
%Total Flow
NA
.7
Detergent washing of capacitors .002
Acid cleaning rinse 3
Acid cleanlng-muric acid concentrate .01
Acid cleaning rinse 34
Acid cleaning rinse 34
Acid cleaning rinse 34
Precleaning rinse water 30
Precleanlng rinse water 30
Precleaning rinse water 30
TTO Concentration
(mg/ft)
14.5
.092
.86
.06
.10
.062
.083
.117
.060
.068
.106
V-84
-------
TABLE 5-36
TTO CONCENTRATIONS IN RAW VASTS FROM MACHINING, GRINDING,
BARBEL FINISHING, BURNISHING, AND SHEARING OPERATIONS
TTO Concentration
Plant ID
15193-21-0
15193-21-1
30012-21-1
30012-21-1
3043-21-1
31031-10-2
31031-10-3
30166
30166
30166
30166
38217-23-0
38217-23-1
30054-15-1
30054-15-2
3043-21-0
Description
Barrel finishing rinse
Barrel finishing rinse
Non-soluble machining oils
Water-soluble machining oils
Barrel finishing rinses
Raw waste oils from tumbling
Raw waste oils from grinding
Raw oily wastes from machining,
grinding, burnishing
Raw oily wastes from machining,
grinding, burnishing
Raw oily wastes after centrifuge
Ravi oily wastes after centrifuge
Machine coolants and oils, after
skimmer
Machine coolants and oils, after
skimmer
Burnishing rinses
Burnishing rinses
Tube shearing
% Total Flow
16.7
16.7
NA
NA
.07
.2
.2
NA
NA
NA
NA
88
96
13
17
0
(mq/l)
NA
.031
.242
4.91
1.83
.080
.133
2.27
9.93
1.77
1.41
1.58
4.13
.019
.018
1,761
V-85
-------
TABLE 5-37
ffO CONCENTRATIONS IN 1AW WASTE
PROM HEAT TREATING OPERATIONS AND QUENCH BATHS
TTO Concentration
Plant ID
15193-21-0
15193-21-1
20005-21-0
20103-21-0
20103-21-1
14062-21-0
36047-23-0
36119-23-0
30012-21-1
30012-21-1
30012-21-1
4282-21-0
Description % Total Flow
Hardening quench runoff
Hardening quench runoff
In-line heat treating
Heat treat water and coolant quench
Heat treat water and coolant quench
Heat treating quench tank oils
Heat treating raw wastewater
Heat treating quench raw wastewater
Alkaline bath in heat treating line
Dilute alkaline bath in heat treating
line
Immunol bath In heat treating line
Heat treatment quench water
1.7
1.7
0
<.01
<.01
6.0
NA
NA
NA
NA
NA
0.4
(mq/fc)
1.70
.211
.020
.084
.660
.050
.100
.402
.130
.130
1.67
.319
V-86
-------
fABLE 5-38
TTO CONCENTRATION IN WASfE FROM
SOLDERING, WELDING, AND BRAZING OPERATIONS
PlantJljP Description
36048-15-0 Acid rinse on cleaning and solder
dip line
36048-15-3 Acid rinse on cleaning and solder
dip line
36048-15-5 Acid rinse on cleaning and solder
dip line
36048-15-0 Rinses on solder wash line
36048-15-3 Rinses on solder wash line
36048-15-5 Rinses on solder wash line
36048-15-0 Solder plate line rinses
18699-21-0 Solder body rinse water
20170-21-0 Seam welder - roller mill collant
3043-21-0 Curling/seam welding wastes
30165-21-0 Solder quench/water soluble oils
% Total Flow
21.5
23.5
23.5
8
9
9
8
.2
NA
12.0
0
TTO Concentration
(mg/fc)
.019
.046
.047
.075
.172
.163
.109
2.63
10.7
.656
1,043
V-87
-------
TABLE 5-39
TTO CONCENTRATIONS IN RAW WASTE
FROM PAINT STRIPPING AND SALT BATH DESCALING
TTO
Plant ID Description
15193-21-1 Paint strip rinse (ethylene glycol
and NaOH)
20103-21-0 Paint stripper concentrate
20103-21-0 Paint stripper rinse
28699-21-0 Caustic paint strip rinse
28699-21-0 Kolene paint strip rinse
28699-21-0 Caustic paint strip concentrate
14062-21-0 Paint stripping rinse
12078-1 Caustic rinse from paint stripping
3043-21-0 Strip rinse
3043-21-0 Paint strip
4892-21-0 Salt bath descaling rinse
15193-21-0 Salt bath descaling concentrate
15193-21-0 Salt bath descaling rinse
20103-21-0 Kolene salt bath descaling rinse
20103-21-1 Kolene salt bath descaling rinse
33617-3 Kolene rinse
20005-21-0 Kolene rinse
4282-21-0 Kolene paint stripping rinse water
4282-21-0 Kolene salt bath descaling rinse
4282-21-0 Chromic acid and methylene chloride
paint stripping rinse
% Total Flow
Concentration
(mg/U
4.2
.02
<.01
NA
NA
NA
1.5
NA
8.0
0
.20
0
2.5
2.4
2.4
NA
NA
47
31.6
2 9.5
.428
2.20
.402
.140
,104
12.8
2.00
1.61
.318
.543
.107
.502
.397
.060
.002
.245
.120
.214
.460
.215
V-88
-------
TABLE 5-40
TTO CONCENTRATIONS IN RAW WASTE FROM PAINTING OPERATIONS
TTO Concentration
Plant IP Description
4892-21-0 DI rinse from BDP
4892-21-0 influent to water curtain of
water-based paint booth
4892-21-0 Discharge from solvent-based
paint booth
20005-21-0 In-line process L-4 paint booth
20005-21-0 in-line SDP
20005-21-0 Final coat spray booth
20005-21-0 in-process V-8 paint booth
20103-21-0 Paint booth
28699-21-1 Prime spray booth
28699-21-1 Topcoat spray
28699-21-1 Truck prime
28699-21-1 Truck topcoat
28699-21-1 Electrodeposition rinse
28699-21-1 Electrodeposition permeate
30165-21-0 Paint booth water curtain
18538-14-1 Ultrafilter permeate from paint booth
12078-1 Paint booth - plastic parts
12078-2 Paint booth - plastic parts
12078-1 Paint booth
12078-2 Paint booth
12078-1 Prime base coat, paint booth
% Total Flow (mq/8,)
18
.02
.3
.03
.07
.2
.08
.4
NA
NA
MA
MA
.02
.02
0
Oth NA
NA
NA
NA
NA
NA
.744
.078
1.42
.784
1.43
3.58
1.62
1.03
2.13
5.95
1.06
3.25
.903
1.93
2.73
.935
.728
.096
.605
.105
.769
V-89
-------
TABLE 5-40 (Continued)
TTO CONCENTRATIONS IN RAW WASTE FROM PAINTING OPERATIONS
TTO Concentration
Plant ID
12078-2
12078-1
12078-2
12078-1
15055-21-1
15055-21-1
15055-21-2
15055-21-2
15055-21-2
30012-21-1
33617-2
33617-1
3043-21-1
13042-21-1
20170-21-0
20170-21-1
20170-21-0
20170-21-1
36178-21-0
36178-21-1
36178-21-2
36178-21-0
Description
Prime base coat, paint booth
Lacquer, paint booth
Lacquer, paint booth
Urethane paint booth
EDP/DI rinse
Paint booth - wheels
Paint booth - body enamel
Paint booth - truck tutone
Paint booth - wheels
Paint booth water curtain
Painting line (2 booths)
Anodic EDP wastes after UF
(UF perneate)
Paint booth
Paint booth
High solids paint booth
High solids paint booth
Powder paint booth
Powder paint booth
Paint booth, hood color
Paint booth, hood color
Paint booth, hood color
Paint booth, heavy chassis
% Total Flow
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
.1
2.1
NA
NA
NA
NA
NA
NA
NA
NA
(mq/l)
.477
4.21
1.11
5.44
.112
.225
.065
.439
.059
1.82
2.69
.370
1.50
8.72
6.40
2.09
.375
.303
3.36
.649
2.16
4.46
V-90
-------
TABLE 5-40 (Continued)
TTO CONCENTRATIONS IN EAV WASTE FROM PAINTING OPERATIONS
Plant IP Description
36178-21-1 Paint booth, heavy chassis
36178-21-2 Paint booth, heavy chassis
36178-21-0 Paint booth, small parts
36178-21-1 Paint booth, small parts
36178-21-2 Paint booth, small parts
36178-21-0 Paint booth, cab prime
36178-21-1 Paint booth, cab prime
36178-21-2 Paint booth, cab prime
% Total Flow
NA
NA
NA
NA
NA
NA
NA
NA
TTO Concentration
1.62
.255
1.49
.065
.370
7.11
2.99
3.85
V-91
-------
TABLE 5-41
TIO CONCENTRATIONS IN RAM WASTE FEOM SOLVENT DEGEEASING CONDENSATES
TTO Concentration
Plant ID Description % Total Plow (mg/St)
15193-21-0 Solvent degreaslng condensate .8 .555
(water layer)
15193-21-1 Solvent degreasing condensate .8 NA
(water layer)
30012-21-1 condensate from carbon column NA 1.85
on degreaser
30166 Evaporator condensate NA .233
V-92
-------
TABLE 5-42
TTO CONCENTRATIONS IN RAW WASTE FROM TESTING AND ASSEMBLY OPERATONS
TTO Concentration
Plant IP
20005-21-0
20103-21-0
30166
30166
30166
33617
30165-21-0
6019-21-0
6019-21-0
6019-21-0
6019-21-1
6019-21-1
4282-21-0
Description %_
Engine test water
Engine test cooling water
Engine test wash water
Engine test oily waste
Magna Flux wash
Wash testing
Leak testing (heating core element
and radiator)
Zyglo spray rinses
Countercurrent rinse tank on Zyglo
spray line
Countercurrent rinse tank on Zyglo
spray line
Zyglo emulslfler rinses
Zyglo emulsifier rinses
Zyglo rinse
Total Flow
0
5
NA
NA
NA
NA
.6
2.8
.1
.1
2.8
2.8
2
(mq/8.)
.422
.090
.024
.525
.071
.422
.060
.031
2.48
.236
.031
3.11
.484
V-93
-------
TABLE 5-43
TTO CONCENTRATIONS IN TREATED OILY WASTESTREAMS
Plant ID Description
13041-22-0 Raw waste oils (spent
oils)
12095-22-0 Raw waste oils
12095-22-1 Raw waste oils
12095-22-2 Raw waste oils
28125-22-0 Raw oily waste from can
wash rinses
28125-22-1 Raw oily waste from can
wash rinses
40836-22-0 Raw oily waste
41097-22-0 Oily waste from lubricant
spills
41097-22-1 Oily waste from lubricant
spills
41097-22-2 Oily waste from lubricant
spills
40070-22-0 Raw oily waste (die cast
cooling water)
40070-22-1 Raw oily waste (die cast
cooling water)
40070-22-2 Raw oily waste (die cast
cooling water)
41097-22-0 Oily waste from 1st stage
wash overflows
41097-22-1 Oily waste from 1st stage
wash overflows
41097-22-2 oily waste from 1st stage
wash overflows
13324-21-0 Raw oily wastes
(wash water)
% Total Plow
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
TTO Concentration
(ma/U
3.0
6.14
3.15
6.50
.558
.292
21.5
.111
.200
2.14
.538
.858
.853
.039
.015
.020
2.40
V-94
-------
TABLE 5-43 (Continued)
TTO CONCENTRATIONS IN TREATED OILX WASTESTREAMS
TTO Concentration
Plant ID Description % Total Plow (mq/St)
41115-22-0 Raw oily wastes NA 1.14
(car rinses)
41115-22-0 Raw oily wastes HA 3.31
(car rinses)
41115-22-0 Raw oily wastes NA 1.19
(car rinses)
1058-22-0 Ravr oily waste (spent 4.83 15.0
mineral and emulsified oil)
1058-22-1 Raw oily waste (spent 4.83 110
mineral and emulsified oil)
1058-22-2 Raw oily waste (spent 4.83 6.42
mineral and emulsified oil)
13324-22-0 Raw oily wastes (wash 9.94 2.40
water)
19462-23-1 Oily wastestream after NA 1,921
screen and filter
30698-21-0 Concentrated oily waste NA 7.90
tank (prior to treatment)
6019-21-0 Soluble cutting oils - 1.1 24.4
influent totreatment
30012-21-0 Water soluble machining 1.55 4.91
oils
30516-23-0 Raw oily waste (coolants 0.16 58.1
and machining oils)
33617-22-0 Waste machine oil NA 49.8
30698-21-0 Oily waste from drawing, NA .289
welding, and shearing
33692-23-0 Raw oily waste from NA 1.09
machining, grinding,
barrel finishing
V-95
-------
TABLE 5-43 (Continued)
TTO CONCBNfRATIONS IN TREATED OILY'WRSTESTRBAMS
TTO Concentration
Plant ID
33617-22-1
3043-21-0
20170-21-0
30166-21-0
30166-21-0
31031-10-3
15193-21-0
15193-21-1
15193-21-1
20103-21-1
20103-21-0
20103-21-0
38217-23-0
38217-23-1
33692-23-1
Description
Waste oil
Tube shearing
Seam welder - roller
mill coolant
Raw oily waste from
machining, grinding, burning
Engine test oily waste
Raw waste oils from
grinding
Oily waste holding tank
Machining oils
Salt bath descaling
concentrate
Heat treatment coolant
quench
Oily waste after cooker
Heat treatment coolant
quench
Machine coolants and
oils, after skimmer
Machine coolants and
oils, after skimmer
Raw oily waste
% Total Flow
NA
1.75
NA
2.21
2.21
0.2
3.6
NA
0
7.42
7.42
7.42
88
96
NA
(mq/!t)
4219
1761
10.7,
9.93
.525
.133
802
7.83
.502
.659
2.33
.084
1.58
4.13
13.5
V-96
-------
TABL1 5-43 (Continued)
TTO CONCENTRAfIONS IN TREATED OILS WASTBSTREAMS
Plant ID
13041-22-0
13041-22-0
13041-22-0
13041-22-0
13041-22-0
13041-22-0
12095-22-0
12095-22-0
12095-22-0
28125-22-1
28125-22-0
28125-22-1
28125-22-0
28125-22-1
30516-23-0
30516-23-1
40070-22-0
40070-22-0
40070-22-0
Description %Total Plow
Oily wastestream after emulsion breaking NA
Oily wastestream after emulsion breaking NA
Oily wastestream after emulsion breaking NA
Oily wastestream after emulsion breaking NA
and UP
Oily wastestream after emulsion breaking NA
and UP
Oily wastestream after emulsion breaking NA
and UP
Oily wastestream after emulsion NA
breaking and clarification
Oily wastestream after emulsion NA
breaking and clarification
Oily wastestream after emulsion NA
breaking and clarification
Oily wastestream after oil skimmer NA
Oily wastestream after clarification NA
Oily wastestream after clarification NA
Oily wastestream after filtration NA
Oily wastestream after filtration NA
Oily wastestream (ultrafilter permeate) NA
Oily wastestream (ultrafilter permeate) NA
Oily wastestream after oil skimmer NA
Oily wastestream after oil skimmer NA
Oily wastestream after oil skimmer NA
TTO Concentration
(mq/5t)
1,037
14.3
4.84
14.8
13.0
30.8
.996
.800
.480
.767
.707
1.08
.635
.390
4.54
5.51
.763
.395
3.24
V-97
-------
TABLE 5-43 (Continued)
TTO CONCENTRATIONS IN TREATED OILY WASTESTREAMS
TTO Concentration
Plant ID
40836-22-0
41097-22-0
41097-22-1
41097-22-2
41097-22-1
41115-22-0
41115-22-0
41115-22-0
1058-22-0
1058-22-0
1058-22-0
1058-22-0
1058-22-1
1058-22-1
1058-22-2
1058-22-2
13324-21-0
Description % Total Flow
i
Oily wastestream after emulsion breaking
Oily wastestream after emulsion
breaking and DAP
Oily wastestream after emulsion
breaking and DAF
Oily wastestream after emulsion
breaking and DAF
Oily wastestream after emulsion
breaking, DAF, and vacuum filter
Oily wastestream after oil skimmer
Oily wastestream after oil skimmer
Oily wastestream after oil skimmer
Oily wastestream prior to emulsion
breaking
Oily wastestream after emulsion breaking
Oily wastestream prior to polishing
pond
Oily wastestream after polishing pond
Oily wastestream prior to polishing
pond
Oily wastestream after polishing pond
Oily wastestream prior to polishing
pond
Oily wastestream after polishing pond ,
Oily wastestream after oil/water
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
(mq/t)
8.62
.045
.125
.560
23.0
.655
1.64
.905
2.77
1.43
.364
.323
1.34
.278
.308
3.79
12.0
separator
13324-21-0 Oily wastestream after ultrafiltration
and oil/water separator
NA
1.48
V-98
-------
TABLE 5-43 (Continued)
TTO CONCENTRATIONS IN TREATED OILY WASTESTREAMS
TTO Concentration
Plant ID
19462-23-1
19462-23-1
19462-23-1
30698-21-0
31032-15-0
31032-15-1
31032-15-2
31032-15-0
31032-15-1
31032-15-2
33692-23-0
33692-23-0
33692-23-0
33692-23-1
33692-23-1
33692-23-1
Oily
Oily
Oily
Oily
tank
Description
wastestream after
wastestreara
wastestream
wastestream
Rav; waste (rinses
Raw waste (rinses
Raw waste (rinses
Oily
Oily
Oily
Oily
Oily
Oily
tank
Oily
Oily
Oily
wastestream
wastestream
wastestream
wastestream
wastestream
wastestream
wastestream
wastestream
wastestream
after
after
after
from
from
from
after
after
after
after
after
after
after
after
after
% Total
screen and filter
centrifuge
ultrafiltration
batch treatment
FET and PCB)
FET and PCB)
FET and PCB)
OF, RO
UP, RO
UP, RO
clarifier
DAP
final settling
clarifier
DAP
final settling
Flow
NA
NA
NA
MA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
(HW/l)
1.92
1.42
.234
.133
.016
.007
.004
.011
,006
.010
.928
1.19
.823
.720
.795
.433
tank
38040-23-0 Treated oily wastes (API settler, NA
bag filter, cartridge filter, P.O.,
and carbon filter)
38040-23-1 Treated oily wastes (API settler, NA
bag filter, cartridge filter, P.O.,
and carbon filter)
6019-21-0 Effluent from treatment tank 1.1
.288
.377
9.31
V-99
-------
TABLE 5-43 (Continued)
fTO CONCENTRATIONS IN TREATED OILY MASTESTREAMS
TfO Concentration
Plant ID Description % Total Flow (mg/Sl)
14062-21-0 Soluble oils after centrifuge .9 21.9
15193-21-0 Permeate from OP on soluble oils 2.75 80.8
15193-21-1 Permeate from UP on soluble oils 2.2 4.61
V-100
-------
TABLE 5-44
TTO CONCENTRATIONS IN RAW WASTE FROM SEGREGATED CHROMIUM STREAMS
TTO Concentration
Plant ID
4071-15-0
4071-15-1
4071-15-3
34050-15-0
34050-15-1
34050-15-2
38051-15-0
38051-15-1
38051-15-2
12075-15-0
12075-15-3
12075-15-5
18538-15-3
18538-15-5
11103-15-0
Description %
Chromium waste from PCB manufacture
Chromium waste from PCB manufacture
Chromium waste from PCB manufacture
Chromium plating line rinse water
Chromium plating line rinse water
Chromium plat ing- 4ine rinse water
Chromium-bearing wastes
Chromium-bearing wastes
Chromium-bearing wastes
Chromium-plating line rinses
Chromium- plating line rinses
Chromium-plating line rinses
Chromium-bearing wastes
Chromium-bearing wastes
Acidic and chromic wastes from
Total Flow
.7
.01
.01
NA
NA
NA
20.3
20.3
20.3
4.5
2.8
.8
36.2
30.6
23
(mq/l)
.104
.190
.036
.337
.281
.120
.151
.078
.147
.006
.014
.008
.006
.016
.014
electroplating
11103-15-2 Acidic and chromic wastes from
electroplating
11103-15-4 Acidic and chromic wastes from
electroplating
21066-15-0 Chromic wastes from electroplating
21066-15-1 chromic wastes from electroplating
21066-15-3 Chromic wastes from electroplating
6960-15-0 Mild acid rinse and chromic rinse
25
25
.004
.015
1
1
1
15
.010
.015
.010
.053
V-101
-------
TABLE 5-44 (Continued)
TTO CONCENTRATIONS IN RAW WASTE FROM SEGREGATED CHROMIUM STREAMS
TTO Concentration
Plant ID Description % Total Plow (mg/8.)
6960-15-2 Mild acid rinse and chromic rinse 15 .102
6960-15-4 Mild acid rinse and chromic rinse 15 .008
19068-15-1 Chromate rinses and chromic 35 .199
acid rinses
19068-15-2 Chromate rinses and chromic 38 .046
acid rinses
V-102
-------
TABLE 5-45
TTO CONCENTRATIONS IN RAW WASTE FROM SEGREGATED CYANIDE STREAMS
TTO Concentration
Plant ID Description % Total Flow (mq/8,)
11103-15-0 cyanide wastes from electroplating 11 .012
lines
11103-15-2 Cyanide wastes from electroplating 18 .010
lines
11103-15-4 Cyanide wastes from electroplating 18 .005
lines
21066-15-0 Cyanide wastes from electroplating NA .015
lines
21066-15-1 Cyanide wastes from electroplating NA .018
lines
21066-15-3 Cyanide wastes from electroplating NA .009
lines
V-103
-------
TABLE 5-46
TTO CONCENTRATIONS IN RAW WASTE PROM AIR SCRUBBERS
% Total Flow
10
Plant IB Description
4069-15-0 Air scrubber discharge from all
wet operations of PCB manufacture
(stripping, etching, sensitizing,
multilayer operations)
4069-15-2 Air scrubber discharge from all 10
wet operations of PCB manufacture
(stripping, etching, sensitizing,
multilayer operations)
4069-15-4 Air scrubber discharge from all 10
wet operations of PCB manufacture
(stripping, etching, sensitizing,
multilayer operations)
2033-15-0 Wet scrubber wastewater
2033-15-2 Wet scrubber wastewater
2033-15-4 Wet scrubber wastewater
11103-15-0 Conversion coating air scrubber
11103-15-0 Electroplating air scrubber
18538-15-1 Phosphating condensate (similar to ,
air scrubber discharge) collected from
both phosphating lines process tanks.
18538-15-5 Phosphating condensate (similar to NA
air scrubber discharge) collected from
both phosphating lines process tanks.
20022-15-0 Air scrubber discharge from anodizing 3
operations
20022-15-1 Air scrubber discharge from anodizing 4
operations
20022-15-1 Air scrubber discharge from anodizing; 3
operations ,
33617-4 Kolene air scrubber blowdown NA
TTO Concentration
(ma/ft)
.017
.053
.032
NA
HA
NA
3
2
NA
.007
.012
.019
.008
.007
.003
.003
.009
.009
.004
.221
V-104
-------
f ABLE 5-47
fTO CONCENTRATIONS IN NOH-MEfAL FINISHING OPBRAfIONS
Plant ID
18538-14-0
33617-7
13042-21-1
6097-15-0
6097-15-1
6097-15-2
6097-15-0
6097-15-1
6097-15-2
Description
Composite of rinses on procelain
enemaling pickle line
%TotalFlow
NA
Plastics processing effluent NA
Metal impregnation rinse tank overflow NA
70.5
Rlnsewater from grinding and
polishing of plate glass
Rinsewater from grinding and
polishing of plate glass
Rinsewater from grinding and
polishing of plate glass
Rinsewater from beveling and
grinding of lens
Rinsewater from beveling and
grinding of lens
Rinsewater from beveling and
grinding of lens
68.5
70.5
7.9
8.7
6.0
TTO Concentration
Uw/t)
.015
2.69
.043
.032
.015
.181
.406
.100
.259
V-105
-------
SECTION VI
SELECTION OF POLLUTANT PARAMETERS
INTRODUCTION
This section presents the pollutant parameters selected for
limitation in the Metal Finishing Category. These parameters were
chosen from the pollutant parameters identified in Section V from:
o Laboratory analysis results of samples taken during
screening and verification visits.
o Responses received from the data collection portfolios
containing pollutant parameter questionnaires.
o Technical information and data received from chemical
suppliers, equipment manufacturers, and previous studies.
Following are an explanation of the rationale for selection and
exclusion of individual pollutant parameters and a presentation of
the parameters selected for each waste type.
SELECTION RATIONALE
The selection of pollutant parameters for regulation was based
both on sampling analysis data and information received in the
data collection portfolios. The sampling analysis data and a
summary of the data collection portfolios are presented in Section
V.
The parameters available for selection were grouped into four
categories: toxic organic pollutants, toxic inorganic pollutants.
non-toxic metals, and other pollutants. The selection of
parameters from each of these groups is discussed below.
TOXIC ORGANIC POLLUTANTS
The toxic organic pollutants are listed in Table 3-2. During the
analysis of the wastewater samples, it was found that a variety of
toxic organics could be present in both common metals and oily
waste streams. It was also found that the types of toxic organics
detected varied from plant to plant. Because this large variety
of toxic organics is present in the Metal Finishing Category and
because of the difficulty involved with regulating such a large
number of pollutants, a total toxic organics (TTO) heading has
been established which covers all the toxic organic pollutants.
VI-1
-------
It was recognized that some of the toxic organics should rarely be
present in metal finishing wastewaters. For example, parameters
either were not detected through sampling or were found upon rare
occasion in low concentrations. There is no known reason why
pesticide type parameters should be present within the wastewater
streams generated by the Metal Finishing Category. However, the
availability of the certification procedure eliminates the need to
monitor for pollutants not likely to be present and focuses the
identification of toxic organics even for,those rarely used.
Total toxic organics are present in the tptal raw waste of sampled
plants in concentrations ranging from zero to 13.5 mg/8, as shown
in Table 5-28. TTO concentrations in the wastewater from various
metal finishing operations is presented in Tables 5-29 through
5-47 in Section V.
Cyanide, which is commonly used within the Metal Finishing
Category (as evidenced by the 298 mg/& mean concentration of
total cyanide in the cyanide raw waste stream), was an obvious
selection as a pollutant parameter.
Of the toxic metals, cadmium, chromium, copper, lead, nickel.
silver, and zinc were found at significant concentration levels in
the raw waste. Table 5-16 shows the concentrations of toxic
metals that were found in the raw waste discharged to end-of-pipe
treatment. Consequently, cadmium, chromium, copper, lead, nickel.
silver, and zinc have been selected as pollutant parameters to be
regulated. Other toxic metals and asbestos were not regulated
because they either were present only in insignificant
concentrations, or present only at a small number of sources and
effectively controlled by regulating other parameters.
NON-TOXIC METALS
The non-toxic metals group contains those metals which were
analyzed but were not listed among the 126 toxic pollutants.
Table 5-18 presents the non-toxic metals, and their flow
proportioned mean concentrations in the total metal finishing raw
waste. Because of the priority given to the control of toxic
pollutants, these non-toxic metals were not regulated. These
parameters would have to be found at high concentrations with high
frequency to be selected for regulations.
VI-2
-------
OTHER POLLUTANTS
There are other pollutant parameters which are normally controlled
to maintain water quality. Total suspended solids (TSS) is a
traditional pollutant parameter which can serve to control the
discharge of harmful pollutants. Oil and grease is a traditional
pollutant parameter which can cause odor and taste problems with
water and kill aquatic organisms. As evidenced by its mean
concentration in the oily wastes raw waste stream (40,700 mg/St),
oil and grease is a significant pollutant parameter in the Metal
Finishing Category.
POLLUTANT PARAMETERS SELECTED
Table 6-1 presents the pollutant parameters selected for
regulation for the Metal Finishing Category.
Vl-3
-------
TABLE 6-1
POLLUTANT PARAMETERS SELECTED FOR REGULATION
Cadmium
Chromium, total
Copper
Lead
Nickel
Silver
Zinc
Cyanide, total (alternative - cyanide, amenable)
Total Suspended Solids
Oil and Grease
Total Toxic Organics
pH
VI-4
-------
SECTION VII
CONTROL AND TREATMENT TECHNOLOGY
INTRODUCTION
This section describes the treatment techniques currently used
or available to remove or recover wastewater pollutants nor-
mally generated by the Metal Finishing Category. Included is
a discussion of individual wastewater treatment technologies
and in-plant control and treatment technologies. Pertinent
treatment and control technology is discussed specifically for
each of the seven types of raw waste that are present. The
technologies presented are applicable to the metal finishing
industry for both direct and indirect dischargers and reflect
the entire metal finishing data base.
The raw wastes for the Metal Finishing Category were initially
subdivided into two constituent types, inorganic and organic
wastes. These were then further subdivided into the specific
types of waste that occur in each of these two major areas and
grouped into the following seven waste types:
MAJOR SUBDIVISION
INORGANIC
WASTES
ORGANIC
WASTES
WASTE TYPE
1.
2.
3.
4.
5.
6.
7.
Common Metals
Precious Metals
Complexed Metals
Hexavalent Chromium
Cyanide
Oils
Toxic Organics
Treatment for each of these seven waste types is shown schemat-
ically in Figure 7-1. This schematic illustrates the types of
treatment that are needed for wastes of each type. The spe-
cific treatment required for these .wastes is as follows:
WASTE TYPE
PRIMARY
TREATMENT
FINAL
TREATMENT
Common Metals
Precious Metals
Complexed Metals
Hexavalent Chromium
Cyanide
Oils
Toxic Organics
Precious Metals Recovery
Chromium Reduction
Cyanide Destruction
Oily Waste Removal
Metals Removal
Optional (depend-
ing on other wastes
present)
Complexed Metals
Removal
Metals Removal
Metals Removal
Metals Removal
Haul or Reclaim
VII-1
-------
I
to
Raw Waste Dis
Manufacturing Facility
Raw Waste Sources
i
charge
(Treatment System
Influent)
Waste Treatment
(If Applicable)
Treated
Effluent
Oily Waste !
Removal !
J
t
<
r " i
Chromium j
Reduction j
^^
.
i
Conmon
Hetals
! Metala
-»___^
l
Cyanide j
Destruction |
L 1
1
i
\
Toxic
Organics
Cotplexed j Precious .
Metals ! Metals
Removal j Recovery
5 a
£
Without Cyanide
I
L
-«
Raw Waste
(Common Metals)
— 1
•
•«
• Removal J
1
Treated
Effluent
m
1
1
1
1
_- - -J
1
I
I
I
|
I
1
1
t
Hauled Or
Reclaimed
Hauled Or
Reclaimed
Final Treated
Effluent
Normal Route
Optional Route
Note: Discharge from precious metals recovery may be
hauled in alternative ways, depending on the
recovery method in use.
FIGURE 7-1
-------
The wastewater stream segregation shown in Figure 7-1 is
current common practice in the Metal Finishing Category, as
discussed in Section IV. This stream segregation allows the
recovery of precious metals, the reduction of hexavalent
chromium to trivalent chromium, the destruction of cyanide,
and the removal/ recovery of oils prior to the removal of the
common metals that are also present in these streams. Segrega-
tion of these streams reduces the flow rate of wastewater to
be treated in each component and accordingly reduces the cost
of this primary treatment. The complexed metals wastewaters
require segregated treatment to preclude the complexing of
other metal wastes in the treatment system.
This section is divided into subsections with the following
headings: Applicability of Treatment Technologies, Treatment
of Common Metals Wastes, Treatment of Precious Metals Wastes,
Treatment of Complexed Metals Wastes, Treatment of Hexavalent
Chromium Wastes, Treatment of Cyanide Wastes, Treatment of
Oily Wastes, Treatment of Toxic Organics, Treatment of Sludges,
In-Process Control Technology, and Statistical Analysis. The
Applicability of Treatment Technologies Subsection defines specific
applications of individual treatment technologies and references
the location of their respective descriptions within this
section.
The subsections that discuss treatment present three specific
levels of treatment options for common metals. The organization
of each of these subsections is such that the Option 1 system
is described, the particular treatment components that are applic-
able to the first level option (Option 1) for common metals
are described, and their performance is presented. Then,
the Option 1 performance level is presented. The information
relative to Options 2 and 3 is developed and discussed in a
similar manner. The subsections that discuss treatment for
other waste types present only a single option because only one
level of treatment is clearly superior based on performance and
demonstration status. Several alternatives to the Option 1 system
are presented for the oily waste streams.
The In-Process Control Technology Subsection discusses tech-
niques for process water usage reduction, alternative proc-
esses, integrated water treatment, and good housekeeping.
VII-3
-------
APPLICABILITY OF TREATMENT TECHNOLOGIES
This subsection identifies the component technologies that are
applicable for the treatment of raw wastes that are generated
by industries that perform the metal finishing operations des-
cribed in Section III. Table 7-1 lists the component tech-
nologies, shows their specific application to the Metal Fin-
ishing Category, and indicates the page on which each is
described. Table 7-2 illustrates the applicability of each
technology to each of the waste types.
Each treatment component is functionally described and dis-
cussions are presented of the application, performance, and
the demonstration status of each component. In some instances
the technique described has been demonstrated in another industry
to successfully remove a particular waste constituent. Wherever
the waste characteristics are similar to that for a Metal
Finishing Category wastewater type, performance data have been
shown to better illustrate the capabilities of the treatment
techniques being described.
VII-4
-------
Technology
Aerobic Decom-
position
Carbon Adsorption
Centrifugation
Chemical Reduction
Chemical Reduction-
Precipitation/
Sedimentation
Coalescing
Diatomaceous Earth
Filtration
Electrochemical
Oxidation
Electrochemical
Reduction
Electrochemical
Regeneration
TABLE 7-1
INDEX AND SPECIFIC APPLICATION OF
TREATMENT TECHNOLOGIES
Application or Potential Application
to Metal Finishing Page
Oil breakdown and organics removal VII-221
Removal of trace metals and organics VII-209
Sludge dewatering, oil removal VII-185, 238
Treatment of chromic acid and chromates VII-115
Removal of Complexed Metals VII-113
Oil removal VII-180
Metal hydroxides and suspended solids VII-53
removal
Destruction of free cyanide and cyanates VII-151
Reduction of chromium from metal finishing VII-120
and cooling tower blowdowns
Conversion of trivalent chromium to hexa- VII-123
valent valence
Electrolytic
Recovery
Emulsion Breaking
Evaporation
Ferrous Sulfate
(FeSO.)-Preoi-
pitatIon/Sedi-
mentation
Flotation
Granular Bed Fil-
tration
Gravity Sludge
Thickening
Recovery of precious and common metals VII-102
Breakdown of emulsified oil mixtures VII—162
Concentration and recovery of process VII-76, 100
chemicals 124, 153
Removal of complexed metals and cyanides VII-114, 153
Suspended solids and oil removal VII-93, 183
Solids polishing of settling tank VII-48
effluent
Dewatering of clarifier underflow VII-230
VII-5
-------
Technology
High pH Precipi-
tation/Sed imenta-
tion
Hydroxide Precipi-
tation
Insoluble Starch
Xanthate
Integrated
Adsorption
Ion Exchange
TABLE 7-1 (Cont.)
INDEX AND SPECIFIC APPLICATION OF
TREATMENT TECHNOLOGIES
Application or Potential Application
to Metal Finishing .
Removal of complexed metals
Dissolved metals removal
Dissolved metals removal
Emulsified oils and paints removal
Recovery or removal of dissolved metals
Membrane Filtra-
tion
Oxidation by
Chlorine
Oxidation by Hy-
drogen Peroxide
Oxidation by Ozone
Oxidation by Ozone
w/UV Radiation
Peat Adsorption
Pressure Filtra-
tion
Resin Adsorption
Reverse Osmosis
Sedimentation
Skimming
Sludge Bed Drying
Sulfide Precipita-
tion
Ultrafiltration
Dissolved metals and suspended solids
removal
Destruction of cyanides and cyanates
Cyanide destruction and metals removal
Destruction of cyanides and cyanates
Destruction of cyanides and cyanates
Dissolved metals removal
Sludge dewatering or suspended solids
removal
Removal of organics
Removal of dissolved salts'for water
reuse
Suspended solids and metals removal
Free oil removal
Sludge dewatering
Dissolved metals removal
Oil and suspended solids removal and
paint purification
Vacuum Filtration Sludge dewatering
Page
VII-112
VII-8
•VII-88
VII-186
VI1-80, 102
114, 124
VII-98, 113
VII-126
VII-150
VI1-144, 219
Vll-148
VII-86
VII-232
VII-218
VII-178, 217
VII-10
VII-167
VII-246
VII-89, 153
VII-241
VII-235
VII-6
-------
Technology
Common
Metals
Aerobic Decomposition
Carbon Adsorption x
Centri fugation
Chemical Reduction
Coalescing
Diatomaceous Earth x
Filtration
Electrochemical Oxidation
Electrochemical Reduction
Electrochemical Regeneration
Electrodialysis
Electrolytic Recovery x
Emulsion Breaking
Evaporation x
Flotation x
Granular Bed Filtration x
Gravity Sludge Thickening
High pH Precipitation
< Hydroxide Precipitation x
j Insoluble Starch Xanthate x
Ion Exchange x
Membrane Filtration x
Oxidation by Chlorine
Oxidation by Hydrogen Peroxide
Oxidation by Ozone
Oxidation by' Ozone with
UV Radiation
Peat Adsorption x
Pressure Filtration x
Resin Adsorption
Reverse Osmosis x
Sedimentation x
Skimming
Sludge Bed Drying
Sulfide Precipitation x
Ultrafiltration x
Vacuum Filtration
TABLE 7-2
APPLICABILITY OF TREATMENT TECHNOLOGIES TO
RAW WASTE TYPES
Precious Complexed Chromium Cyanide Oily
Metals Metals Bearing Bearing Wastes
x
XX X
X
X
X
X
X
X
Toxic
Organics Sludge
In-Process
x.
x
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
TREATMENT OF COMMON METALS WASTES
INTRODUCTION
Common metals wastes can be generated in the Metal Finishing
Category by the unit operations that have previously been
described. The methods used to treat these wastes are
discussed in this section and fall into two groupings -
recovery techniques and solids removal techniques. Recovery
techniques are treatment methods used for the purpose of
recovering or regenerating process constituents which would
otherwise be lost in the wastewater or discarded. Included in
this group are evaporation, ion exchange, electrolytic recov-
ery, electrodialysis, and reverse osmosis. Solids removal
techniques are employed to remove metals and other pollutants
from process wastewaters to make these waters suitable for
reuse or discharge. These methods include hydroxide and
sulfide precipitation, sedimentation, diatomaceous earth
filtration, membrane filtration, granular bed filtration,
sedimentation, peat adsorption, insoluble starch xanthate
treatment, and flotation. '•
This subsection presents the treatment systems that are appli-
cable to common metals removal for treatment Options 1, 2, and
3; describes the treatment techniques applicable to each
option; and defines the effluent performance levels for each
of those options. Option 1 common metals removal incorporates
hydroxide precipitation and sedimentation. Option 2 for
common metals removal consists of the addition of filtration
devices to the Option 1 system. The Option 3 treatment system
for common metals wastes consists of the Option 1 end-of-pipe
treatment system with the addition of in-plant controls for
cadmium. Alternative treatment techniques that can be applied
to provide Option 1, 2, or 3 system performance are described
following the Option 3 discussion.
TREATMENT OF COMMON METAL WASTES - OPTION 1
The Option 1 system for the treatment of common metals wastes
consists of hydroxide precipitation followed by sedimentation,
as is shown in Figure 7-2. This system accomplishes the end-
of-pipe metals removal from all common metals bearing waste-
water streams that are present at a facility. The recovery of
precious metals, the reduction of hexavalent chromium, the
removal of oily wastes, and the destruction of cyanide must be
accomplished prior to common metals removal, as was shown in
Figure 7-1.
Cyanide bearing wastes must undergo oxidation to destroy the
cyanide in the wastewater. Cyanide, as well as being a highly
toxic pollutant, will complex metals such as copper, cadmium,
and zinc and prevent efficient removal of these metals in the
VII-8
-------
Common Metals
Wastewater
Chemical
Addition
I
Hydroxide
Precipitation
Sedimentation
Sludge
I
Effluent Water
FIGURE 7-2
TREATMENT OP COMMON METALS WASTES - OPTION 1
VII-9
-------
solids removal device. Similarly, complexed metal wastes must
be kept segregated and treated separately to avoid complexing
metals in the primary solids removal device. Complexed metal
wastes should be treated in a separate solids removal device
such as a membrane filter or a high pH clarifier. The spe-
cific techniques for the treatment of all other waste types, a
description of the three levels of treatment options for each
waste type and the performance for all levels of these options
are presented in subsequent subsections. ;
The treatment techniques incorporated in the Option 1 common
metals waste treatment system include pH adjustment, hydroxide
precipitation, flocculation, and sedimentation. Sedimentation
may be carried out with equipment such as1 clarifiers, tube
settlers, settling tanks, and sedimentation lagoons, or it
may be replaced by various filtration devices preceded by
hydroxide precipitation. The following paragraphs describe the
hydroxide precipitation and sedimentation, techniques that are
employed for the Option-1 common metals treatment system.
Hydroxide Precipitation
i • • • • • • •
Dissolved heavy metal ions are often chemically precipitated
as hydroxides so that they may be removed by physical means
such as sedimentation, filtration, or centrifugation. Rea-
gents commonly used to effect this precipitation include
alkaline compounds such as lime and sodium hydroxide. Calcium
hydroxide precipitates trivalent chromium and other metals as
metal hydroxides and precipitates phosphates as insoluble
calcium phosphate. These treatment chemicals may be added to
a flash mixer or rapid mix tank, or directly to the sedimenta-
tion device. Because metal hydroxides tend to be colloidal in
nature, coagulating agents may also be added to facilitate
settling. Figure 7-3 illustrates typical chemical precipita-
tion equipment as well as the associated sedimentation device.
After the solids have been removed, final pH adjustment may be
required to reduce the high pH created by the alkaline treat-
ment chemicals. '
Application
Hydroxide precipitation is used in metal finishing for precip-
itation of dissolved metals and phosphates. It can be uti-
lized in conjunction with a solids removal device such as a
clarifier or filter for removal of metal ions such as iron,
lead, tin, copper, zinc, cadmium, aluminum, mercury, manga-
nese, cobalt, antimony, arsenic, beryllium, and trivalent
chromium. The process is also applicableito any substance
that can be transformed into an insoluble;form like soaps,
phosphates, fluorides, and a variety of others.
Hydroxide precipitation has proven to be an effective tech-
nique for removing many pollutants from industrial wastewater.
VII-10
-------
Rapid Sedimentation
and
Continuous Gravity Drainage
Inlet
Wastewater
Tube Settling Flocculator
Drive
Chemicals
Collection
Trouqh
>'<-< i
Effluent
Rapid
Mix Tank
Flocculator Tube
Settler
Sludge
Sludge Siphon
Sludge Collector
FIGURE 7-3
PRECIPITATION AND SEDIMENTATION
VII-11
-------
Hydroxide precipitation operates at ambient conditions and is
well suited to automatic control. Lime is usually added as
a slurry when used in hydroxide precipitation. The slurry must
be kept well mixed and the addition lines periodically
checked to prevent blocking, which results from a buildup of
solids. The use of hydroxide precipitation does produce large
quantities of sludge requiring disposal following precipitation
and settling. The use of treatment chemicals requires caution be-
cause of the potentially hazardous situation involved with the
storage and handling of those chemicals. Recovery of the
precipitated species is sometimes difficult because of the
homogeneous nature of most hydroxide sludges (where no single
metal hydroxide is present in high concentrations) and because
of the difficulty in smelting which results from the interfer-
ence of calcium compounds.
Performance
The performance of hydroxide precipitation depends on several
variables. The most important factors affecting precipitation
effectiveness are:
1. Addition of sufficient excess anions to drive the
precipitation reaction to completion.
2. Maintenance of an alkaline pH throughout the precip-
itation reaction and subsequent settling. (Figure
7-4 details the solubilities of various metal hydrox-
ides as a function of pH).
3. Effective removal of precipitated solids (see
appropriate solids removal technologies).
Demonstration Status
Hydroxide precipitation of metals is a classic waste treatment
technology used in most industrial waste treatment systems.
As noted earlier, sedimentation to remove precipitates is dis-
cussed separately; however, both techniques have been illus-
trated in Figure 7-3.
Sedimentation
Sedimentation is a process which removes solid particles from
a liquid waste stream by gravitational settling. The operation
is effected by reducing the velocity of the feed stream in a
large volume tank or lagoon so that gravitational settling can
occur. Figure 7-5 shows two typical sedimentation devices.
VII-12
-------
100
4J
•H *~-
M r1
•H \
xi J?
3 e
>H *
o
en
0.0001
0.01
0.001
10
11
12
pH
FIGURE 7-4
SOLUBILITIES OF METAL HYDROXIDES AS A FUNCTION OP pH
VII-13
-------
Sadirrwntatlon Basin
Inlet Zone
Inlet Liquid
Baffles To Maintain
"Quiescent Conditions
Outlet Zone
Settled Particles Collected
And Periodically Removed
Circular Ctarifier
~*—-i-. * Se\tlint| Partiele«TrajSct
-------
For the Option 1 system, sedimentation is preceded by hydrox-
ide precipitation which converts dissolved metallic pollutants
to solid forms and coagulates suspended precipitates into
larger, faster settling particles. Wastewater is fed into a
high volume tank or lagoon where it loses velocity and the
suspended solids are allowed to settle. High retention times
are generally required. (The plants in the data base used
retention times ranging from 1 to 48 hours). Accumulated
sludge can be collected and removed either periodically or
continuously and either manually or mechanically.
Inorganic coagulants or polyelectrolytic flocculants are added
to enhance coagulation. Common inorganic coagulants include
sodium sulfate, sodium aluminate, ferrous or ferric sulfate,
and ferric chloride. Organic polyelectrolytes vary in struc-
ture, but all usually form larger floccules than coagulants
used alone.
The use of a clarifier for sedimentation reduces space require-
ments, reduces retention time, and increases solids removal
efficiency. Conventional clarifiers generally consist of a
circular or rectangular tank with a mechanical sludge col-
lecting device or with a sloping funnel-shaped bottom designed
for sludge collection. In advanced clarifiers, inclined
plates, slanted tubes, or a lamellar network may be included
within the clarifier tank in order to increase the effective
settling area. A more recently developed "clarifier" utilizes
centrifugal force rather than gravity to effect the separation
of solids from a liquid. The precipitates are forced outward
and accumulate against an outer wall, where they can later be
collected. A fraction of the sludge stream is often recir-
culated to the clarifier inlet, promoting formation of a
denser sludge.
Application
Sedimentation is used in metal finishing to remove precip-
itated metals, phosphates, and suspended solids. Because most
metal ion pollutants are easily converted to solid metal
hydroxide precipitates, sedimentation is of particular use in
industries associated with metal finishing and in other indus-
tries with high concentrations of metal ions in their wastes.
In addition to heavy metals, suitably precipitated materials
effectively removed by sedimentation/clarification include
aluminum, manganese, cobalt, arsenic, antimony, beryllium,
molybdenum, fluoride, and phosphate.
The major advantage of simple sedimentation is the simplicity
of the process itself - the gravitational settling of solid
particulate waste in a holding tank or lagoon. The major
disadvantage of sedimentation involves the long retention
times necessary to achieve complete settling, especially if
the specific gravity of the suspended matter is close to that
of water.
VII-15
-------
A clarifier is more effective in removing slow settling sus-
pended matter in a shorter time and in less space than a
simple sedimentation system. Also, effluent quality is often
better from a clarifier. The cost of installing and main-
taining a clarifier is, however, substantially greater than
the costs associated with sedimentation lagoons.
Inclined plate, slant tube, and lamellar clarifiers have even
higher removal efficiencies than conventional clarifiers, and
greater capacities per unit area are possible. Installed
costs for these advanced clarification systems are claimed to
be one half the cost of conventional systems of similar capac-
ity.
Performance j
A properly operating sedimentation system is capable of effi-
cient removal of suspended solids, precipitated metal hydrox-
ides, and other impurities from wastewater. The performance
of the process depends on a variety of factors, including the
effective charge on the suspended particles (adjustments can
be made in the type and dosage of flocculant or coagulant) and
the types of chemicals used in prior treatment. It has been
found that the site of flocculant or coagulant addition may
significantly influence the effectiveness of sedimentation.
If the flocculant is subjected to too much mixing before
entering the settling device, the agglomerated complexes may
be broken up and the settling effectiveness diminished. At
the same time, the flocculant must have sufficient mixing in
order for effective set-up and settling to occur. Most plant
personnel select the line or trough leading into the clarifier
as the most efficient site for flocculant addition. The
performance of sedimentation is a function of the retention
time, particle size and density, and the;surface area of the
sedimentation catchment.
Sampling visit data from plant 40063, a porcelain enameling
facility that performs metal finishing operations, exemplify
efficient operation of a chemical precipitation/settling system.
The following table presents sampling data from this system,
which consists of the addition of lime and caustic soda for
pH adjustment and hydroxide precipitation, polyelectrolyte
flocculant addition, and clarification. Samples were taken
of the raw waste influent to the system and of the clarifier
effluent. Flow through the system is approximately 18,900 LPH
(5000 GPH). Concentrations are given in mg/1. The effluent pH
shown in the table reflects readjustment with sulfuric acid after
solids removal. Parameters which were not detected are
listed as ND.
VII-16
-------
POLLUTANT CONCENTRATIONS (mg/1)
PLANT ID 40063
pH Range
TSS
Al
Co
Cu
Fe
Mn
Ni
Se
Ti
Zn
Day
Inf.
9.2-9.6
4390
37., 3
3.92
0.65
137
175
6.86
28,6
143
18.5
1
Eff .
8.3-9.8
9.0
0.35
ND
0.003
0.49
0.12
ND
ND
ND
0.027
Day
Inf.
9.2
3595
38.1
4.65
0.63
110
205
5.84
30.2
125
16.2
2
Eff.
7.6-8.1
13
0.35
ND
0.003
0.57
0.012
ND
ND
ND
0.044
Inf.
9.6
2805
29.9
4.37
0.72
208
245
5.63
27.4
115
17.0
Day 3
Eff.
7.8-8.2
13
0.35
ND
0.003
0.58
0.12
ND
ND
ND
0.01
Effluent TSS levels were below 15 mg/1 on each day, despite raw
waste TSS concentrations in excess of 2800 mg/1. Effluent pH was
maintained at approximately 8 or above, lime addition was suffi-
cient to precipitate most of the dissolved metal ions, and the
flocculant addition and clarifier retention served to effec-
tively remove the precipitated solids.
Demonstration Status
Sedimentation in conjunction with hydroxide precipitation (the
Option 1 system) represents the typical method of solids
removal and is employed extensively in industrial waste treat-
ment. The advanced clarifiers are just beginning to appear in
significant numbers in commercial applications, while the
centrifugal force "clarifier" has yet to be used commercially.
Sedimentation preceded by hydroxide precipitation is used in
154 plants in the Metal Finishing data base that are listed in
Table 7-3.
Common Metals Waste Treatment System Operation - Option _!
When operated properly, the Option 1 system is a highly reli-
able method for removing dissolved heavy metals from waste-
water, although proper system monitoring, control, and prelim-
inary treatment to remove interfering substances are required.
Effective operation depends upon attention to proper chemical
addition, raw waste load variations, routine maintenance, and
solids removal. Control of chemical addition is required to
VII-17
-------
TABLE 7-3
METAL FINISHING PLANTS WITH OPTION 1 TREATMENT SYSTEMS
FOR COMMON METALS
HYDROXIDE PRECIPITATION WITH SEDIMENTATION
01003
01067
02032
02037
03049
04065
04069
04071
04105
04132
04148
04174
04211
04216
04273
05020
05021
06002
06006
06035
06037
06051
06053
06065
06073
06074
06075
06077
06079
06083
06084
06086
06087
06090
06103
06107
06110
06116
06124
06731
07001
09026
10020
11008
11098
11113
11118
11477
12002
12014
12033
12061
12071
12074
12076
12078
12087
12102
12256
12709
13042
14060
15010
15058
15070
16544
17030
17061
19050
19063
19067
19068
19098
20005
20017
20022
20070
20073
20077
20078
20079
20080
20082
20083
20086
20102
20104
20106
20116
20120
20156
20158
20160
20161
20162
20175
20249
20255
20291
20708
21078
22735
23041
23061
23062
23076
27044
28125
30022
30050
30087
30090
30150
30151
30153
31020
31037
33024
33043
33050
33065
33074
33092
33113
33120
33172
33184
33186
33199
33293
33692
34036
34037
36040
36041
36062
36112
36176
36623
38031
38050
38223
40062
40079
43052
44036
44037
44045
44050
44062
44150
45741
46036
47035
VII-18
-------
maintain the appropriate pH for precipitation of the metals
present and to promote coagulation of the metals precipitated.
When fluctuating levels of raw waste loading occur, constant
monitoring of the system flow and pH is needed to provide
chemical addition at the proper rate. Other raw waste types
such as hexavalent chromium or cyanide must be appropriately
treated before entering the Option 1 system. Specifically,
hexavalent chromium will not be removed by the Option 1
system, and cyanide will interfere with the Option 1 system's
ability to remove dissolved metals. The necessary preliminary
treatment for hexavalent chromium and cyanide is discussed in
detail later in Section VII.
An important factor in successful Option 1 system operation is
the handling of changes in raw waste load. This is equally
true for small batch systems and for large continuous systems.
Most system failures, i.e. excessive discharges of pollutants,
are the result of inadequate response to raw waste loading
changes. Both hydraulic overloading and pollutant shock loads
can be avoided by the segregation and bleed-in of concentrated
batch dumps. When these practices are not employed, success-
ful operation requires careful monitoring and quick response
by the system operator. Appropriate action by the operator in
the event of an upset usually involves adjusting chemical feed
rate, changing residence time, recycling of treated wastewater,
or shutdown for maintenance.
VII-19
-------
The major maintenance requirements involve the periodic inspec-
tion and adjustment of monitoring devices, chemical mixing and
feeding equipment, feed and sludge pumps, and clarifier mixing
and drive components. Removal of accumulated sludge is neces-
sary for efficient operation of precipitation/sedimentation
systems. Solids which precipitate must be continually removed
and properly disposed. Proper disposal practices are
discussed later in this section under Treatment of Sludges.
Common Metals Waste Treatment System Performance - Option 1^
Although the performance of many Option 1 treatment systems (as
shown in Figure 7-6 with sources of wastes) is excellent, others
exhibit inferior performance. The major causes of poor per-
formance are low pH (resulting in incomplete metals precipitation)
and poor sedimentation, evidenced by high suspended solids in
the effluent. In analyzing the data to determine expected per-
formance, poorly performing plants were excluded from the data base
Plants with low effluent concentrations due to dilution, low in-
fluent concentration, or similar factors were also excluded.
The performance for the Option 1 treatment system was estab-
lished from a combination of visited plant sampling data and
long term self-monitoring data that were submitted by industry.
The following subsection describes the procedure used to
establish Option 1 treatment system performance for the vis-
ited plant data set.
Visited Plant Performance
To establish the treatment system performance characteristics/
plants employing Option 1 treatment that were visited were
selected from the Metal Finishing Category data base. The
files for these plants were then examined to ensure that only
properly operating facilities were included in the performance
data base by establishing criteria to eliminate the data for
improperly operating systems. The criteria for eliminating
improperly operating treatment systems were as follows:
1. Data with an effluent TSS level greater than 50 mg/1 were
deleted. This represents a level of TSS above which no
well-operated treatment plant should be discharging.
Figure 7-7 shows effluent TSS concentrations vs. per-
centile distribution. As is shown in the graph there is
an abrupt increase in slope (approximately 5.8:1) at the
50 mg/1 level. Deleting data above this concentration
still includes nearly seventy percent of the data base.
The following presentation of TSS and metals concentra-
tions for plants 20073 and 20083 shows that a low level
of TSS is indicative of low effluent metal concentrations.
VI1-20
-------
Sludge-
NJ
Complexed
Metals
Wastes
t
Solids
Removal
t
Discharge
o
Chromium Common Precious
Bearing Cyanide Metals Metals
Wastes Wastes Wastes Wastes
t t t
Hexa\
Chrc
Redui
ntinn 1
'alent Cyanide
mium Oxidation
stion
i ' (
1
Precious
Metals
Recovery
— — — —
i
I Precipitation
Oily
Wastes
t
Oily Waste
Removal
Recovered
*- Metals
>
1
I
1
1
C
f
F
f
"oxic
)rganics
V
(aul or
leclaim
Sedimentation
Sludge
Discharge
FIGURE 7-6
TREAIMENT SCHEME
OPTION 1
-------
180
160
140
\
o*
4J
C
0)
3
^
MJ
U-l
[J
120
100
< CO
2 -o
o
C/)
•a
0)
•a
c
IV
ni
4J
O
80
60
40
20
5lCg>
10
20
30
40 '<0
'i.Mit i I o Distf LbuL ion
I-'IGUKK 7-7
KI I:K 'i':;:; IHSTKU'.UTIOU
(.0
70
-------
POLLUTANT CONCENTRATIONS (mg/1)
Plant ID 20073
TSS
Cu
Ni
Cr
2.
Avg,
TSS
Cr
Zn
Day 1
Day 2
Day 3
Inf,
Eff.
Inf.
Eff,
Inf.
Eff,
702.
64., 6
53.8
162.
11.
.812
.448
1.47
712.
97.1
52.5
175.
14.
.875
.478
1.89
124.
91.2
89.7
220.
33.
1.37
1.12
2.85
POLLUTANT CONCENTRATIONS (mg/1)
Plant ID 20083
Day 1
Day 2
Day 3
Day 4
Inf.
Eff.
Inf.
Eff.
Inf.
Eff.
Inf.
Eff.
TSS
Cu
Ni
24.0
56.2
103
145
2.75
6.13
18.0
57.7
153
23.0
0.38
0.91
15.0
39.3
82.8
27.0
0.21
0.77
10.0
50.0
87.1
97.0
2.44
4.75
Plants with alkaline precipitation systems that operated at
an average effluent pH of less than 7.0 were deleted. An
alkaline precipitation system will not work properly in
this pH range, as is illustrated by the following data from
plant 21066.
POLLUTANT CONCENTRATIONS (mg/1)
Plant ID 21066
Day 1
Day 2
Inf.
Eff.
effluent pH
*Not Available
NA*
48.0
5.36
114
5.4
448
3.74
150
Inf.
NA*
61.0
8.99
111
Eff.
5.1
371
1.28
140
Proper control of pH is absolutely essential for favorable
performance of precipitation/sedimentation technologies.
This is illustrated by results obtained from a sampling
visit to manufacturing plant 47432 (not a metal finishing
plant) as shown by the following data (concentrations are
in mg/1) :
VII-23
-------
POLLUTANT CONCENTRATIONS (mg/1)
Plant ID 47432
!
Day 1 Day 2 : Day 3
In Out In_ Out ^ri Out
pH Range 2.4-3.4 8.5-8.7 1.0-3.0 5.0-6.0 2.0-5.0 6.5-8.1
TSS 39 8 16 19 16 7
Copper 312 0.22 120 5.12 j 107 0.66
I .....
Zinc 250 0.31 32.5 25 j" 43.8 0.66
Lead 0.16 0.03 0.16 0.04 \ 0.15 0.04
Nickel 42.8 0.78 33.8 0.53 I 36.6 0.46
This plant utilizes lime precipitation and pH adjustment
followed by flocculant addition and sedimentation.
Samples were taken before and after the system. On day
two effluent pH was allowed to range below 7 for the
entire day and the effluent metals control was less
effective than on days one and three. In general, better
results will be obtained in chemical precipitation sys-
tems when pH is maintained consistently at a level be-
tween 8.5 and 9.5. It can be clearly seen that the best
results were produced on day one when the effluent pH was
kept within the recommended range for the entire day.
3. Plants that had complexing agents (unoxidized cyanide
or nonsegregated wastes from electroless;plating)
present were deleted.
4. Plants which had effluent flows significantly greater than
the corresponding raw waste flows were deleted. The in-
crease in flows was assumed to be dilution by other waste-
waters.
5. Pollutant parameters which had an effluent concentration
greater than the raw waste concentration were deleted.
6. Plants that experienced difficulties in system operation
during the sampling period were excluded. These difficulties
included a few hours operation at very low pH (approximately 4.0),
observed operator error,an inoperative chemical feed system,
improper chemical usage, improperly maintained equipment,
high flow slugs during the sampling period, and excessive
surface water intrusion (heavy rains).
The following procedure was followed for each metal pollutant parameter
(except for TSS which is created during precipitation) in order to elimi-
nate spurious background metal readings. The mean effluent concentration
of each parameter was calculated and when a raw waste concentration was
less than the mean effluent concentration for that parameter, the cor-
responding effluent reading was deleted from the data set. The mean was
recalculated using points not removed and the iprocess
VII-24 !
-------
was repeated in an iterative loop. The deletion of these points
prevents the calculation of unrealistically low mean effluent
concentrations from the waste treatment systems due to low raw
waste pollutant loadings.
Option 1 performance data from visited plants are presented in
Tables 7-4 through 7-10 for cadmium, chromium, copper, lead,
nickel, zinc, and total suspended solids. The mean effluent
concentrations for these parameters are summarized in Table 7-11.
VII-25
-------
TftBLE 7-4 i
METRL FINISHING CATEGORY PERFORMANCE DATA FOR CADMIUM
OPTION 1
Data
Point
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
Raw Waste
Concentration
(mg/g.)
0.012
0.012
0.012
0.013
0.013
0.013
0.015
0.017
0.019
0.021
0.021
0.022
0.022
0.024
0.030
0.032
0.033
0.037
0.037
0.042
0.042
0.053
0.068
0.077
0.084
0.087
0.113
0.250
0.925
1.00
1.88
Effluent
Concentration
(mq/8,)
0.006
0.006
0.006
0.005
|0.005
;0.010
:0.008
iO.006
"0.007
0.010
0.018
:0.013
0.019
0.005
0.014
0.005
0.011
'0.005
0.005
,0.006
0.006
0.009
0.017
b.005
0.027
0.024
0.028
0.008
0.012
,0.015
0.018
Plant ID
20083-1-5
20083-1-6
19063-1-2
6083-1-2
19063-1-3
15070-1-1
6731-1-1
6731-1-2
6731-1-3
6074-1-1
31020-1-1
6087-1-3
27044-1-0
20080-1-1
6087-1-1
4065-8-1
6074-1-1
20073-1-1
20073-1-2
36041-1-2
36041-1-3
36041-1-1
21003-15-2
33024-6-0
21003-15-0
21003-15-1
6051-6-0
15070-1-2
20086-1-1
20086-1-3
20086-1-2
Mean
Concentration
0.162 (n=31)
0.011 (n=31)
VII-26
-------
TABLE 7-5
METAL FIMISHIMG CATEGORY PERFORMANCE DATA FOB CHROMIUM (TOTAL)
Data
Point
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
OPTION 1
Raw Waste
Concentration
(mq/i)
0.65
1.09
1.20
1.30
1.31
1.51
1.56
1.60
1.70
2.00
2.43
4.34
7.00
12.2
12.2
14.0
21.6
24.7
25.0
25.3
28.6
29.4
32.2
58.2
69.3
70.3
76.7
85.3
98.0
104.
116.
117.
117.
142.
162.
175.
190.
393.
Effluent
Concentration
(mq/l)
0.052
0.128
1.12
0.013
0.014
0.150
0.255
0.120
1.16
0.040
0.070
0.039
0.020
0.556
0.611
0.250
0.005
0.333
0.333
0.533
0.667
0.733
0.0
0.833
1.06
0.833
1.64
0.143
0.333
0.714
0.018
0.400
0.500
0.195
1.47
1.89
2.36
2.14
Plant ID
6087-1-3
6731-1-2
15010-12-3
19068-15-1
4069-8-1
44062-15-0
6051-6-0
44062-15-1
15010-12-2
11477-22-2
33024-6-0
44062-15-2
11477-22-1
6083-1-2
36041-1-2
33065-9-1
19068-14-0
36040-1-1
36041-1-3
36040-1-1
36041-1-1
36040-1-1
19068-15-2
20086-1-2
20086-1-3
20086-1-1
20078-1-7
6074-1-1
6074-1-1
6074-1-1
31020-1-1
20078-1-2
20078-1-3
20080-1-1
20073-1-1
20073-1-2
40062-8-0
40062-8-0
Mean
Concentration
58.6 (n=38)
0.572 (n=38)
VII-27
-------
TABLE 7-6
METAL FINISHING CATEGORY PERFORMANCE DATA FOR COPPER
OPTION 1 .
Raw Waste Effluent
Data Concentration Concentration
Point (mq/9.) (mq/8,) Plant ID
1. 0.88 0.006 19068-14-0
2. 0.94 0.258 6731-1-2
3. 0.95 0.13 21003-15-2
4. 1.00 0.044 6074-1-1
5. 1.30 0.029 12061-15-2
6. 1.39 0.060 36040-1-1
7. 1.63 0.016 19068-15-2
8. 1.65 0.588 6731-1-3
9. 1.78 0;028 19068-15-1
10. 1.90 0.038 12061-15-0
11. 2.62 1.30 5020-1-6
12. 2.86 1.85 5020-1-4
13. 3.29 0.780 4071-25-3
14. 4.35 0.727 4069-8-1
15. 4.55 0.380 4065-8-1
16. 6.21 0.076 36040-1-1
17. 6.42 0.898 4065-8-1
18. 7.53 0.444 36041-1-2
19. 7.67 O.'l65 5020-1-3
20. 7.69 0.247 20078-1-3
21. 7.69 0.307 20078-1-2
22. 7.79 0.157 27044-1-0
23. 8.16 0.400 20078-1-7
24. 8.31 0.372 20078-1-4
25. 8.44 0.776 4069-8-1
26. 9.56 1.06 36041-1-3
27. 10.2 0.071 36040-1-1
28. 11.0 0.160 33024-6-0
29. 14.7 2.20 19063-1-2
30. 14.9 4.47 19063-1-1
31. 16.1 3.53 19063-1-3
32. 19.5 0.900 5020-1-5
33. 26.5 1.89 36041-1-1
34. 47.5 1.62 40062-8-0
35. 47.8 0.212 20083-1-5
(Continued) j
VII-28
-------
TABLE 7-6 (Continued)
METAL FINISHING CATEGORY PERFORMANCE DATA FOR COPPER
OPTION 1
Data
Point
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
Raw Waste
Concentration
49.3
51.5
52.5
57.7
64.6
80.0
84.6
91.7
95.8
96.9
97,1
108.
Effluent
Concentration
(rng/ft)
1.94
0.163
1.69
0.375
0.812
2.63
0.547
0.500
1.06
0.533
0.875
1.00
Plant ID
6087-1-1
20083-1-6
40062-8-0
20083-1-3
20073-1-1
6087-1-3
20086-1-2
20086-1-1
20086-1-3
33065-9-1
20073-1-2
31020-1-1
Mean
Concentration
26.7 (n=47)
0.815 (n=47)
VII-29
-------
TABLE 7-7
METAL FINISHING CATEGORY PERFORMANCE DATA FOR LEAD
OPTION 1
Data
Point
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
Raw Waste
Concentration
(mg/il)
0.052
0.054
0.064
0.067
0.071
0.072
0.072
0.075
0.084
0.102
0.103
0.125
0.136
0.136
0.144
0.145
0.154
0.160
0.164
0.168
0.174
0.182
0.212
0.218
0.226
0.233
0.270
0.364
0.394
0.474
0.567
0.600
0.800
0.909
1.000
Effluent
Concentration
(mq/ft)
0.048
0.033
0.025
0.013
0.0
0.044
0.048
0.010
0.025
0.025
0.077
0.050
0.032
0.040
0.032
0.038
0.044
0.036
0.040
0.032
0.0 !
0.044
0.036
0.044
0.025
0.0
0.160
0.067
0.021
0.043
0.0
0.036
0.068
0.073
0.064
Plant ID
15070-1-3
36040-1-1
20078-1-3
6731-1-3
19068-15-1
15070-1-1
15070-1-2
20080-1-1
20078-1-2
20078-1-4
4065-8-1
20083-1-3
36041-1-2
20078-1-7
20083-1-6
20073-1-1
20086-1-3
20086-1-1
20086-1-2
20083-1-5
19068-15-2
6074-1-1
36041-1-3
6074-1-1
20073-1-2
36623-15-2
4071-15-3
27044-1-0
33065-9-1
40062-8-0
36623-15-0
40062-8-0
31020-1-1
15010-12-2
36041-1-1
(Continued)
VTI-30
-------
TABLE 7-7 (Continued)
METAL FINISHING CATEGORY PERFORMANCE DATA FOR LEAD
OPTION 1
Data
Point
36.
37.
38.
39.
40.
41.
42.
43.
44.
Raw Waste
Concentration
(rng/t)
1,
1,
1,
2.
.000
.000
,120
.500
2.540
6.928
6.930
8.362
9.701
Effluent
Concentration
(mq/U
0.085
0.133
0.065
0.160
0.0
0.165
0.0
0.098
0.143
Plant ID
6087-1-1
15010-12-3
6087-1-3
6083-1-2
12061-15-2
19063-1-1
12061-15-0
19063-1-2
19063-1-3
Mean
Concentration
1.11 (n=44)
0.0505 (n=44)
VII-.31
-------
TABLE 7-8
METAL FINISHING CATEGORY PERFORMANCE DATAFOR NICKEL
OPTION 1
Raw Vaste Effluent
Data Concentration Concentration
Point (mq/a.) (mq/St) Plant ID
1. 1.07 0.076 19063-1-1
2. 1.44 1.11 6731-1-1
3. 1.48 0.150 21003-15-1
4. 1.69 0.060 19063-1-2
5. 2.14 0.342 4069-8-1
6. 2.22 1.00 6731-1-2
7. 2.23 0.190 19063-1-3
8. 2.57 0.044 36041-1-2
9. 3.20 0.726 27044-1-0
10. 3.24 0.700 36623-15-2
11. 3.87 0.122 4069-8-1
12. 3.89 1.89 6731-1-3
13. 4.49 0.571 36041-1-3
14. 5.00 0.320 36041-1-1
15. 5.42 1.20 36623-15-0
16. 5.60 0.414 5020-1-6
17. 5.80 1.03 36623-15-1
18. 6.80 0.414 5020-1-5
19. 7.31 0.759 5020-1-4
20. 8.56 0.0; 19068-15-2
21. 9.33 2.27 6083-1-2
22. 11.8 0.294 5020-1-3
23. 27.5 0.120 31020-1-1
24. 33.9 0.536 20086-1-2
25. 36.7 0.464 20086-1-3
26. 42.9 0.786 20086-1-1
27. 50.0 7.30 6087-1-1
28. 52.5 0.478 20073-1-2
29. 53.8 0.448 20073-1-1
30. 73.0 6.39 6087-1-3
31. 76.9 0.381 20078-1-7
32. 78.7 0.106 20078-1-3
33. 78.7 0.427 20078-1-4
34. 80.6 1.84 40062-8-0
35. 85.3 0.144 20078-1-2
(Continued)
VII-32
-------
TABLE 7-8 (Continued)
MlfftL FINISHING CATEGORY PERFORMANCE DATA FOR NICKEL
OPTION 1
Data
Point
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
Mean
Concentration
Raw Vaste
Concent ratIon
(mq/St)
1
94.3
94.4
97.
108.
108
111.
128.
142.
153.
167.
effluent
Concentration
46.1 (n=45)
0.600
1.52
0.808
0.778
1.78
0.462
0.571
1.56
0.907
0.304
0.942 (n=45)
Plant ID
6074-1-1
40062-8-0
20083-1-5
36040-1-1
36040-1-1
20083-1-6
6074-1-1
36040-1-1
20083-1-3
6074-1-1
VII-33
-------
TABLE 7-9
METAL FINISHING CATEGORY PERFORMANCE DATA FOR ZINC
OPTION 1
Data
Point
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
Mean
Concentration
Raw Waste
Concentration
(mcr/H)
0.63
0.73
0.81
0.87
0.92
1.08
1.13
1.25
1.36
1.71
1.75
3.71
4.11
4.67
4.89
4.89
5.07
9.91
11.2
13.4
14.3
17.5
18.7
18.8
19.2
42.6
48.5
59.4
100.
103.
121.
169.
171.
175.
33.9 (n=34)
Effluent
Concentration
(mg/il)
0.028
0.024
0.060
0.013
0.123
i 0.020
0.016
0.193
0.105
i 0.070
: o.oio
i 0.166
0.040
' 0.029
0.033
; 0.083
I 0.304
0.889
i 1.00
0.139
\ 0.430
! 1.12
! 0.765
! 0.018
i .0.889
' 3.00
0.308
, 0.375
, 3.12
i 1.33
1.09
0.765
I 1.12
. 1.00
! 0.549 (n=34)
Plant ID
36623-15-1
36040-1-1
19068-14-0
36040-1-1
15010-12-2
19068-15-1
36040-1-1
15010-12-3
20073-1-1
20073-1-2
19068-15-2
6083-1-2
20078-1-7
20078-1-2
20078-1-3
20078-1-4
6731-1-1
6731-1-2
6087-1-1
36041-1-2
36041-1-3
6087-1-3
36041-1-1
31020-1-1
6731-1-3
15070-1-3
33065-9-1
20080-1-1
15070-1-2
15070-1-1
33024-6-0
20086-1-1
20086-1-2
20086-1-3
VII-34
-------
TABLE 7-10
HETRL FINISHING CATEGORY PERFORMANCE DRTftPOR.TJLS
Data
Point
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
OPTION 1
Saw Waste
Concentration
(mg/8.)
Effluent
Concentration
1,
1,
2,
3,
3,
3,
3.
4,
6.
7.
9.
9,
0.0
0.000
.000
.200
.000
.000
.000
.290
.610
.000
.000
.000
.000
.000
10.00
10.00
10.00
14.35
15.00
16.00
16.00
16.00
16.04
16.38
17.00
18.000
21.000
23.000
23.000
26.000
33.000
38.000
42.518
44.606
45.000
46.510
55.268
59.000
66.000
67.000
0.0
12.000
24.000
0.700
38.000
.000
.000
.400
.900
6.
7
2
2.
34.00
5,
6,
000
000
24.00
32.00
5.000
15.000
11.500
21.00
8.000
9.
9,
.000
.000
37.00
17.00
22.00
1.000
34.000
14.000
4.000
27.000
5.000
32.000
16.000
28.487
15.000
8.0000
48.000
4.000
27.000
11.000
4.000
Plant ID
21003-15-0
21003-15-2
33074-1-3
36623-15-2
20078-1-7
20083-1-6
27044-1-0
36623-15-1
36623-15-0
5020-1-4
21003-15-1
6731-1-1
5020-1-5
20078-1-3
20080-1-1
5020-1-6
19051-6-0
19068-15-1
6101-12-1
6101-12-1
20083-1-5
20078-1-4
19068-15-2
19068-14-0
6731-1-2
20083-1-3
20078-1-2
6731-1-3
40062-8-0
5020-1-3
40062-8-0
4065-8-1
19063-1-1
4069-8-1
36040-1-1
4071-15-3
4069-8-1
4065-8-1
36040-1-1
23061-8-1
(Continued)
VII-35
-------
TABLE 7-10 (Continued)
METAL.FINISHING CATEGORY PBRFORMftNCB DRTft FOR TSS
OPTION 1
Data
Point
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
Raw Waste
Concentration
(mq/it)
74.000
78.000
80.000
88.666
117.58
119.00
131.00
139.13
162.00
174.04
180.00
182.28
194.00
201.00
215.00
259.50
344.00
392.00
472.00
504.00
524.00
652.00
672.00
702.00
712.00
812.00
904.00
920.00
1032.0
1036.0
1100.0
2060.0
2425.0
2466.8
3103.8
4410.0
8340.0
9970.0
Effluent
Concentration
32.000
5.000
19.000
13.238
14.000
3,
9.
7.
.000
.000
.9498
10.900
23.000
42.000
13.000
14.;000
15.000
12.000
42.000
44.000
34.000
22.!000
25.000
10.000
5JOOO
0.0
11.000
14.000
.000
.000
12.000
16.000
32.000
.000
,1000
17.000
25.000
22.000
21.000
26.000
46.000
7.
21,
1,
0,
Plant ID
15010-12-2
12061-15-2
14001-12-1
19063-1-2
44062-15-1
11477-22-0
6051-6-0
19063-1-3
33692-23-1
44062-15-2
15010-12-3
44062-15-0
36040-1-1
23061-8-2
11477-22-2
33024-6-0
6087-1-1
6087-1-3
6083 1-2
15070-1-3
36041-1-2
36041-1-3
12061-15-0
20073-1-1
20073-1-2
12061-15-1
15070-1-2
15070-1-1
31020-1-1
36041-1-1
11477-22-1
33065-9-1
20086-1-1
20086-1-2
20086-1-3
6074-1-1
6074-1-1
6074-1-1
Mean
Concentration
599.558 (n=78)
16.836 {n=78>
VII-36
-------
TABLE 7-11
TREATMENT OF COMMON METALS - VISITED PLANTS
SUMMARY OF OPTION 1 MEAN EFFLUENT CONCENTRATIONS
Parameter
Mean Concentration (mq/St)
Cadmium
Chromium. Total
Copper
Lead
Nickel
Zinc
Total Suspended Solids
0.011
0.572
0.815
0.051
0.942
0.549
16.8
VII-37
-------
Long Term Self-Monitoring Data Performance
Long term self-monitoring data were submitted by a number of
plants with Option 1 treatment systems. The total data points
per parameter ranged from 485 for cadmium to 3552 for chromium.
The mean concentrations, daily maximum variability factors, and
10-day variability factors were determined statistically
for these data and are summarized in Tables 7-12 through 7-18.
These tables also show overall values for each pollutant, speci-
fically the total number of points, the mean value for all
points, and the median of the variability factors listed in the
table. :
Overall Performance
The overall Option 1 system performance is based on mean
concentrations calculated from the visited plant data multi-
plied by variability factors calculated from the historical
performance data. For cadmium and lead, the weighted mean Option
1 self-monitoring concentrations rather than the mean visit concen-
trations are used because of the relatively low raw waste con-
centrations of the visit data. The statistical procedures used
to establish the Option 1 system performance are discussed in
Statistical Analysis at the end of this section.
VIl-38
-------
TABLE 7-12
EFFLUENT TSS SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 1 SYSTEMS
Mean Effluent
Number Concentration
Plant ID OF Points (mg/St)
VariabilityFactor
13.85
10.08
11.49
4.71
7.86
8.41
11.64
21.38
12.52
0.40
3.88
4.29
8.88
4.19
14.05
6.84
4.58
3.58
3.50
15.22
OVERALL 1777(Total) 9.02(Mean) 3.59(Median) 1.85(Median)
1067
3049
6002
6035
6051
6053
6087
6103
6107
6111
11008
11477
19063
20080
20116
22735
30050
30090
44045
47025
149
49
18
12
13
12
12
13
10
3
140
69
9
269
243
27
292
51
50
336
Daily
3.41
7.49
3.58
5.33
3.50
4.57
5.01
2.52
3.54
13.21
2.63
3.39
7.18
3.61
2.80
2.80
4.42
4.82
3.42
4.45
10-Dav
1.85
2.55
1.24
1.54
1.76
3.27
1.76
1.24
—
—
1.99
1.36
—
2.24
1.48
2.00
2.13
1.82
1.85
2.25
VII-39
-------
TABLE 7-13
EFFLUENT CADMIUM SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 1 SYSTEMS
Mean Effluent
Number Concentration Variability Factor
Plant ID OF Points (mq/il) Daily 10-Day
1067 222 0.13 3.08 2.04
6002 6 0.05 7.48
6035 9 0.01
6051 13 0.04 -- 1.14
11008 185 0.12 3.14 2.01
47025 50 0.21 7.49 8.54
OVERALL 485(Total) 0.13(Mean) 5.31(Median) 2.02(Median)
VII-40
-------
TABLE 7-14
EFFLUENT TOTAL CHROMIUM SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 1 SYSTEMS
Variability Factor
Mean Effluent
Number Concentration
Plant ID OF Points (mcr/n
0.17
0.03
0.74
0.18
0.27
0.14
0.02
0.10
0.12
0.09
0.20
0.16
0.29
0.60
0.21
0.15
0.40
0.01
O.04
0.24
0.01
0.06
0.06
OVERALL 3552(Total) 0.19(Mean) 4.85(Median) 2.98(Median)
1067
5020
6002
6035
6051
6053
6087
6107
6111
11008
17030
19063
20080
20082
20116
22735
23076
30050
30090
36040
44150
45741
47025
230
228
6
12
13
12
12
10
3
185
344
238
269
253
243
35
242
289
49
224
42
358
255
Daily
3 . 07
—
13.66
7.52
3.97
8.72
5.58
5.57
5.97
6.84
3.51
4.58
5.20
2.76
4.64
4.79
3.80
4.90
1.67
—
4.47
5.57
10-Dav
2.27
10.52
—
1.89
1.78
3.02
«. _
4.08
5.56
4.80
2.63
3.70
1.65
1.39
4.41
3.07
2.12
1.30
37.26
2.98
2.81
VII-41
-------
TABLE 7-15
EFFLUENT COPPER SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 1 SYSTEMS
Plant ID
Number
OF Points
1067
5020
6002
6051
6087
6107
11008
12002
19063
20082
20116
23076
30050
30090
30165
33050
34037
44045
44150
230
232
6
13
12
10
185
59
231
253
243
241
292
259
66
112
123
49
127
Mean Effluent
Concentration
(nrn/9.)
0.09
0.24
0.14
0.12
1.38
2.36
0.06
0.08
0.64
1.38
O.10
0.74
0.10
0.18
1.47
0.07
1.40
0.16
0.43
Variability Factor
Daily
4.07
4.56
5.10
3.19
3.56
3.87
5.87
3.65
4.55
4.02
4.15
9.29
2.30
2.39
2.43
5.06
5.92
4.62
10-Dav
2.81
2.54
—
1,77
2.58
—
5.72
2.24
2.51
3.37
3.07
6.90
1.62
1.62
2.08
2.21
4.08
1.72
5.70
7.25
OVERALL
2744(Total) 0.46(Mean) 4.15(Median) 2.54(Median)
VII-42
-------
TABLE 7-16
EFFLUENT LEAD SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 1 SYSTEMS
Plant ID
5020
19063
30165
44045
OVERALL
Number
OF Points
229
238
65
49
Mean Effluent
Concentration
(rng/it)
0.242
0.10
0.45
0.14
Variability.Factor
Daily 10-Day
4.50
3.15
2.66
3.89
2.11
3.18
1.93
2.26
581(Total) 0.20(Mean) 3.52(Median) 2.19(Median)
VIl-43
-------
TABLE 7-17
EFFLUENT NICKEL SELF-MOWITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 1 SYSTEMS
Va r i ab i 1 i ty Fa c t or
Mean Effluent
Number Concentration
Plant ID OF Points (roq/it)
0.21
0.40
0.09
0.06
0.04
0.66
0.44
0.07
0.32
0.67
0.50
0.03
0.25
0.32
0.32
V* » JL & — — ^ m. *m> ^ ^
OVERALL 1804(Total) 0.39(Mean) 4.22(Median) 2. 52(Median)
1067
5020
6002
6035
6051
6087
11008
19063
20082
20116
23076
30050
33092
36040
44045
44150
230
231
6
9
13
12
185
10
253
243
241
75
27
178
49
42
Daily :
4.05
4.48
4.72
5.37
6.55
—
2.79
2.90
3.72
2.26
6.38
3.78
4.38
1.73
10.13
10-Day
2.39
2.54
—
—
6.12
6.30
1.62
—
2.77
1.31
4.29
2.37
2.51
1.27
2.66
VII-44
-------
TABLE 7-18
EFFLUENT ZINC SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 1 SYSTEMS
Mean Effluent
Number Concentration
Plant ID OF Points (mq/B.)
Variability Factor
0.61
0.15
0.13
1.50
0.26
0.24
0.41
0.32
1.26
0.07
0.02
OVERALL 1216(Total) 0.41(Mean) 4.75(Median) 2.70(Median)
1067
6002
6051
6107
11008
12002
20080
20082
30165
33050
44150
230
6
13
10
184
31
269
250
S6
115
42
Daily
3.52
8.86
7,24
5.20
3.93
14.16
2.22
4.07
4.34
5.15
_ -
10-Day
1.96
—
1.42
—
2.26
11.35
1.41
2.70
3.50
3.07
4.62
VII-45
-------
Table 7-19 summarizes the daily and 10-day variability factors
calculated from the long term data and shown earlier in Tables
7-12 through 7-18.
TABLE 7-19
SUMMARY OF OPTION 1 DAILY MAXIMUM AND 10-DAY AVERAGE
VARIABILITY FACTORS
Pollutant
Total suspended solids
Cadmium
Chromium, total
Copper
Lead
Nickel
Zinc
Variability Factor
Daily Max. 10-Day Average
3.59
5.31
4.85
4.15
3.52
4.22
4.75
1.85
2.02
2.98
2.54
2.19
2.52
2.70
Table 7-20 presents the daily and monthly maximum average
effluent limitations for common metals Option 1. These
limitations were obtained by multiplying the visited plant mean
concentrations of Table 7-11 by the respective variability
factors shown in Table 7-19 (except for cadmium and lead, where
the mean from the long term self-monitoring concentrations were
used in place of the visited mean effluent concentrations).
TABLE 7-20
SUMMARY OF OPTION 1 DAILY MAXIMUM AND 10-DAY AVERAGE
Pollutant
Total suspended solids
Cadmium
Chromium, total
Copper
Lead
Nickel
Zinc
Daily Max.
60
0.69
2.77
3.38
0.69
3.98
2.61
Monthly
Maximum Average
31
' 0.26
1.71
2.07
0.43
2.38
1.48
Long Term
Average
17
0.13
0.57
0.82
0.19
0.94
0.55
VII-46
-------
Table 7-21 summarizes the percent compliance for the EPA sampled
plant data presented previously in Tables 7-4 to 7-10 and for the
Option 1 plants submitting long term data.
TABLE 7-21
PERCENTAGE OF THE MFC DATA BASE BELOW THE
EFFLUENT CONCENT1ATION LIMITATIONS FOR OPTION 1
EPA Sampled Self-Monitoring Self-Monitoring
Plants Data Data
Pollutant Daily Maximum Daily Maximum 10-dayAverage
Total Suspended 100.0 99.8 100.0
Solids
Cadmium 100.0 98.8 97.8
Chromium, total 100.0 99.7 99.7
Copper 95.7 98.5 96.7
Lead 100.0 95.9 92.7
Nickel 95.6 99.9 100.0
Zinc 94.1 99.2 95.8
VTI-47
-------
TREATMENT OF COMMON METALS WASTES - OPTION 2
The Option 2 treatment system for common metals wastes is
pictured schematically in Figure 7-8. As shown in the figure,
the system is identical to the Option 1 common metals treatment
system with the addition of a filtration device after the primary
solids removal step. The purpose of this filtration unit is to
"polish" the effluent, that is, to remove suspended solids
such as metal hydroxides which did not settle out in the
clarifier. The filter also acts as a safeguard against pollu-
tant discharge if an upset should occur in the sedimentation
device. Filtration techniques that are applicable for Option
2 systems include granular bed filtration and diatomaceous
earth filtration.
Granular Bed Filtration
Filtration is basic to water treatment technology, and experi-
ence with the process dates back to the 1800's. Filtration
occurs in nature as the surface ground waters are purified by
sand. Silica sand, anthracite coal, and garnet are common
filter media used in water treatment plants. These are usually
supported by gravel. The media may be used singly or in
combination. The multi-media filters may be arranged to
maintain relatively distinct layers by virtue of balancing the
forces of gravity, flow and buoyancy on the individual parti-
cles. This is accomplished by selecting appropriate filter
flow rates (gpm/sq ft), media grain size, and density.
Granular bed filters may be classified in terms of filtration
rate, filter media, flow pattern, or method of pressurization.
Traditional rate classifications are slow sand, rapid sand,
and high rate mixed media. In the slow sand filter, flux or
hydraulic loading is relatively low, and removal of collected
solids to clean the filter is therefore relatively infrequent.
The filter is often cleaned by scraping off the inlet face
(top) of the sand bed. In the higher rate filters, cleaning
is frequent and is accomplished by a periodic backwash, opposite
to the direction of normal flow.
A filter may use a single medium such as sand or diatomaceous
earth, but dual and mixed (multiple) media filters allow
higher flow rates and efficiencies. The dual media filter
usually consists of a fine bed of sand under a coarser bed of
anthracite coal. The coarse coal removes most of the influent
solids, while the fine sand performs a polishing function. At
the end of the backwash, the fine sand settles to the bottom
because it is denser than the coal, and the filter is ready
for normal operation. The mixed media filter operates on the
same principle, with the finer, denser media at the bottom and
the coarser, less dense media at the top.: The usual arrange-
ment is garnet at the bottom (outlet end) of the bed, sand in
the middle, and anthracite coal at the top. Some mixing of
these layers occurs and is, in fact, desirable.
VII-48
-------
Complexed Chromium
Common Precious
Metals Bearing Cyanide
Wastes Wastes Wastes
* * i
.,, , Solids Hexavalent
Sludge-*H
1 Removal Chromium
I
Cyanide
Oxidation
i Reduction
Sludge-* Filtration
1 r-
H Discharge
V
Sludge -
*•
Metals Metals
Wastes Wastes
i
Pr
f
•n-
K€
t
i
Precipitation
1
Sedimentation
t
Sludge -^-
Filtration
t
•ecious Recovered
letals 1-^- Metals
jcovery
1
1
I
1
1 Option 2 System
1
1
1
1
OUy Wastes
1
^
OUy
Wastes
Removed
Toxic
Organic
r
Haux o]
Reclaii
Discharge
FIGURE 7-8
WASTE TREATMENT SCHEME
OPTION 2
-------
The flow pattern is usually top-to-bottom, but other patterns
are sometimes used. Upflow filters are sometimes used, and in
a horizontal filter the flow is horizontal. In a biflow
filter, the influent enters both the top and the bottom and
exits laterally. The advantage of an upflow filter is that
with an upflow backwash the particles of a single filter
medium are distributed and maintained in the desired coarse-to-
fine (bottom-to-top) arrangement. The disadvantage is that the
bed tends to become fluidized, which ruins filtration effi-
ciency. The biflow design is an attempt to overcome this
problem.
The usual granular bed filter operates by gravity flow.
However, pressure filters are also used. Pressure filters
permit higher solids loadings before cleaning and are advan-
tageous when the filter effluent must be pressurized for
further downstream treatment. In addition, pressure filter
systems are often less costly for low to moderate flow rates.
Figure 7-9 depicts a granular bed filter. It is a high rate,
dual media, gravity downflow filter, with self-stored"backwash.
Both filtrate and backwash are piped around the bed in an
arrangement that permits upflow of the backwash, with the
stored filtrate serving as backwash. Addition of the indi-
cated coagulant and polyelectrolyte usually results in a
substantial improvement in filter performance.
Auxiliary filter cleaning is sometimes employed in the upper
few inches of filter beds. This is conventionally referred to
as surface wash and is accomplished by water jets just below
the surface of the expanded bed during the backwash cycle.
These jets enhance the scouring action in the bed by increasing
the agitation.-
An important feature for successful filtration and backwashing
is the underdrain. This is the support structure for the bed.
The underdrain provides an area for collection of the filtered
water without clogging from either the filtered solids or the
media grains. In addition, the underdrain prevents loss of
the media with the water, and during the backwash cycle it
provides even flow distribution over the bed. Failure to
dissipate the velocity head during the filter or backwash
cycle will result in bed upset and the need for major repairs.
Several standard approaches are employed for filter underdrains.
The simplest one consists of a parallel porous pipe imbedded
under a layer of coarse gravel and manifolded to a header pipe
for effluent removal. Other approaches to the underdrain
system are known as the Leopold and Wheeler filter bottoms.
Both of these incorporate false concrete bottoms with specific
porosity configurations to provide drainage and velocity head
dissipation.
VII-50
-------
INFLUENT
EFFLUENTjH
COMPARTMENT \ MEDIA
C COLLECTION CHAMBER
DRAIN
FIGURE 7-9
GRANULAR BED FILTRATION EXAMPLE
VII-51
-------
Filter system operation may be manual or automatic. The
filter backwash cycle may be on a timed basis, a pressure drop
basis with a terminal value which triggers backwash, or a
solids carryover basis from turbidity monitoring of the outlet
stream. All of these schemes have been successfully used.
Application
Granular bed filters are used in metal finishing to remove
residual solids from clarifier effluent. Filters in wastewater
treatment plants are often employed for polishing following
sedimentation or other similar operations. Granular bed
filtration thus has potential application to nearly all indus-
trial plants. Chemical additives which enhance the upstream
treatment equipment may or may not be compatible with or
enhance the filtration process. It should be borne in mind
that in the overall treatment system, effectiveness and effi-
ciency are the objectives, not the performance of any single
unit. The volumetric fluxes for various types of filters are
as follows:
Slow Sand 2.04 - 5.30 1/min/sq m
Rapid Sand 40.74 - 51.48 1/min/sq m
High Rate Mixed Media 81.48 - 122.22 1/min/sq m
The principal advantages of granular bed filtration are its
low initial and operating costs and reduced land requirements
over other methods to achieve the same level of solids removal.
However, the filter may require pretreatment if the solids
level is high (from 100 to 150 mg/1). Operator training is
fairly high due to controls and periodic backwashing, and
backwash must be stored and dewatered to be disposed of
economically.
The recent improvements in filter technology have significantly
improved filtration reliability. Control systems, improved
designs, and good operating procedures have made filtration a
highly reliable method of water treatment. Deep bed filters
may be operated with either manual or automatic backwash. In
either case, they must be periodically inspected for media
attrition, partial plugging, and leakage. Where backwashing
is not used, collected solids must be removed by shoveling,
and filter media must be at least partially replaced. Filter
backwash is generally recycled within the wastewater treatment
system, so that the solids ultimately appear in the clarifier
sludge stream for subsequent dewatering. Alternatively, the
backwash stream may be dewatered directly or, if there is no
backwash, the collected solids may be suitably disposed. In
either of these situations there is a solids disposal problem
similar to that of clarifiers.
VII-52
-------
Performance
Suspended solids are commonly removed from wastewater streams
by filtering through a deep 0.3-0.9 ra (1-3 feet) granular
filter bed. The porous bed formed by the granular media can be
designed to remove practically all suspended particles. Even
colloidal suspensions (roughly 1 to 100 microns) are adsorbed
on the surface of the media grains as they pass in close
proximity in the narrow bed passages.
Properly operating filters following some pretreatment to
reduce suspended solids should produce water averaging 12.8 mg/1
TSS. Pretreatment with inorganic or polymeric coagulants can
improve poor performance.
Demonstration Status
Deep bed filters are in common use in municipal treatment
plants. Their use in polishing industrial clarifier effluent
is increasing, and the technology is proven and conventional.
Diatomaceous Earth Filtration
Diatomaceous earth filtration, combined with precipitation and
sedimentation, is a solids separation device which can further
enhance suspended solids removal. The diatomaceous earth
filter is used to remove metal hydroxides and other solids
from the wastewater and provides an effluent of high quality.
A diatomaceous earth filter is comprised of a filter element,
a filter housing and associated pumping equipment. The filter
element consists of multiple leaf screens which are coated
with diatomaceous earth. The size of the filter is a function
of flow rate and desired operating time between filter
cleanings.
Normal operation of the system involves pumping a mixture of
diatomaceous earth and water through the screen leaves. This
deposits the diatomaceous earth filter media on the screens
and prepares them for treatment of the wastewater. Once the
screens are completely coated, the pH adjusted wastewater can
be pumped through the filter. The metal hydroxides and other
suspended solids are removed from the effluent in the diatomace-
ous earth filter. The buildup of solids in the filter increases
the pressure drop across the filter. At a certain pressure/
the wastewater is stopped, the filter is cleaned and the cycle
is repeated.
Application
The principal advantage of using a diatomaceous earth filter
is its increased removal of suspended solids and precipitates.
One additional advantage is that sludge removed from the
filter is much drier than that removed from a clarifier (approxi-
mately 50% solids). This high solids content can significantly
reduce the cost of hauling and landfill.
VII-53
-------
The major disadvantage to the use of a filter system is an
increase in operation and maintenance costs.
Performance
Three of the plants that were visited and sampled were operat-
ing diatomaceous earth filters. The analytical results of
samples taken before and after the filters are displayed
below. All of these plants were using filters in place of
sedimentation, and both influent and effluent concentrations
are therefore relatively high. However, the data do illustrate
that removal of solids by these filters is very substantial.
POLLUTANT CONCENTRATION (mg/1)
Plant ID 09026
Day 1
Day 2
Day 3
Parameter
TSS
Cu
Ni
Cr, Total
Zn
Cd
Sn
Pb
Input To
Filter
548.
52.4
.299
.078
22.4
.011
.086
.062
Filter
Effluent
11.
2.25
.116
.008
3.06
.012
.086
.036
Input To
Filter
544.
63.8
.341
.086
27.6
.010
.086
.062
Filter
Effluent
: 15.
4.17
.102
.010
.706
.009
.086
.040
POLLUTANT CONCENTRATION (mg/1)
Plant ID 36041
Day 1
Input To
Parameter Filter
Day 2
Input To
Filter
450.
63.8
.377
.086
30.6
.011
.086
.065
Day 3
TSS
Cu
Ni
Cr, Total
Zn
Cd
Sn
Pb
1036,
26.5
5.00
28.6
18.7
.053
1.77
1.00
Filter
Effluent
32.0
1.89
.320
.667
.765
.009
.171
.064
Input To
Filter
524.
7.53
2.57
12.2
13.4
.042
2.00
.136
Filter
Effluent
10.0
.444
.044
.611
.139
.006
^.143
.032
Input To
Filter
652.
9.56
4.49
25.0
14.3
.042
1.58
.212
Filter
Effluent
67.
2.2
.107
.012
.882
.011
.086
.051
Filter
Effluent
5.00
1.06
.571
.333
.430
.006
.114
.036
VTI-54
-------
POLLUTANT CONCENTRATION (mg/1)
Plant ID 38217
Parameter
TSS
Cu
Ni
Cr,
Zn
Cd
Sn
Pb
Total
Input To
Filter
575.
.158
.253
.022
1.92
.006
.028
.058
Filter
Effluent
30.0
.261
.195
.037
3.79
.011
.034
.154
Input To
Filter
620.
.325
.255
.060
5.20
.019
.054
.150
Filter
E f fluent
90.0
.085
.159
.020
2.31
.010
.003
.032
Demonstration Status
Filters with similar operational characteristics to those
described above are in common use throughout the metal finish-
ing industry.
Common Metals Waste Treatment System Operation - Option _2
The entire Option 1 system operation discussion applies equally
to Option 2. In addition, the use of a polishing filter
necessitates further precautions. Close monitoring is needed
to prevent both hydraulic overloading and solids overloading.
Either form of overloading may result in pollutant bypassing
in a barrier filter (through element breakage or pressure
relief) or pollutant reentrainment in a depth filter. Many
types of filters must be shut down for solids removal. Waste-
water flow must not be bypassed during this period. Bypassing
can be obviated by use of a holding tank or by installation of
dual filters in parallel arrangment. A further consideration
concerns disposable elements for filters that use them.
Because of the contained toxic metals, these elements must be
treated as hazardous waste and should not be placed in the
plant trash,
The following table (Table 7-22) presents a listing of 37 plants
from the metal finishing data base which have an Option 2 common
metals treatment system. These include both sampled plants, DCP
plants, and plants which supplied long term self -monitoring data
VII-55
-------
TABLE 7-22
METAL FINISHING PLANTS WITH OPTION 2 TREATMENT SYSTEMS
FOR COMMON METALS
03043 19069 31033
04140 20483 31044
04151 27042 33110
06062 28115 36048
06131 28121 ' 36082
11096 28699 36102
11125 30159 38223
11182 30165 40047
12075 30507 44150
12077 30519 45041
13031 30927
13033 31021
15193 31022
Common Metals Waste Treatment System Performance - Option 2^
Performance of a properly operating Option 2 treatment system
(shown in Figure 7-8 with its sources of wastes) is demon-
strated by low effluent levels of total suspended solids
(TSS). Effective removal of heavy metals depends on maintain-
ing the system pH at the level needed to form metal hydroxides.
Generally, a pH range of 8.5 to 9.5 is considered most effec-
tive for settling and filtration of precipitated hydroxides in
mixed metal finishing wastes.
The performance for the Option 2 treatment system was estab-
lished from a combination of visited plant sampling data and
long term self-monitoring data that were submitted by industry.
The following subsection describes the procedure used to
establish Option 2 treatment system performance for the visited
plant data set.
Visited Plant Performance
To establish the treatment system performance characteristics,
plants employing Option 2 treatment that were visited were
selected from the Metal Finishing Category data base. The
files for these plants were then examined to ensure that only
properly operating facilities were included in the performance
data base by establishing criteria to eliminate the data for
improperly operating systems. The criteria for eliminating
improperly operating treatment systems were as follows:
1. Data with an effluent TSS level greater than 50 mg/1 were
deleted. This represents a level of TSS above which no
well-operated treatment plant should be discharging.
VII-56
-------
2. Plants with alkaline precipitation systems that operated
at an average effluent pH of less than 7.0 were deleted.
An alkaline precipitation system will not work properly
in this pH range.
3. Plants that had complexing agents (unoxidized cyanide or
nonsegregated wastes from electroless plating) present
were deleted.
4. Plants which had effluent flows significantly greater
than the corresponding raw waste flows were deleted.
The increase in flows was assumed to be dilution by
other wastewaters.
5. Pollutant parameters that had an effluent concentration
greater than the raw waste concentration were deleted.
6. Plants that experienced difficulties in system operation
during the sampling period were excluded.
The following procedure was followed for each metal pollutant
parameter (except TSS which is created during precipitation)
in order to eliminate spurious background metal readings. The mean
effluent concentration of each parameter was calculated, and when a
raw waste concentration was less than the mean effluent concentration
for that parameter, the corresponding effluent reading was deleted
from the data set. The mean was recalculated using points not removed
and the process was repeated in an iterative loop. The
deletion of these points prevents the calculation of unrealistically
low mean effluent concentrations from the waste treatment systems
due to low raw waste pollutant loadings.
Plots of raw waste concentration to the precipitation step vs.
effluent concentration from the filter were generated for
total suspended solids, cadmium, total chromium, copper, lead,
nickel, and zinc. These plots are shown in Figure 7-10 through
7-16. The mean effluent concentrations for these parameters were
then computed and are summarized in Table 7-23.
VII-57
-------
Solids Effluent (mq/1)
Ul A J* tJ
K) O CO O
Suspended
K)
*.
-H
| 16^
s-
0-
—
- •••
c
(
D
-
it:
e
y
»
IX
inum Total
.
O
0
e
A 1
Suspen
m
D
O
Q
led £
oli<
O
I
Is
>
1.0
10 100
Total Suspended Solids Raw Waste (mg/1)
10CO
FIGURE 7-10
EFFLUENT TSS CONCENTRATIONS vs RAW WASTE CONCENTRATIONS
OPTION 2
-------
V
en
VD
E
*""*
•e 020-
Ol
UJ
M
E
3 016 -
E
73
(0
U
m 9
. UJ-z
nns _
.004
.001
> (
i (
i
0
0
0
o e
.01
0.
Cadmium Raw Waste (r.c/i)
Daily Maximum Concentration - 0.54 mg/1
FIGURE 7-11
EFFLUENT CADMIUM CONCENTRATIONS vs RAW WASTE CONCENTRATIONS
OPTION 2
-------
H
cr\
o
1 2-
r* i o-
Hi
e
•H
c
3
1-1 0 8-
«•*
&
s
s
e
0
^ 0 6-
u
r-l
HJ
0
^
04-
n 5-
0.
1.0
»
03
C
e
o
-
D
(E
10
a
o
100 10
Total Chromium Raw Waste {rr.g/15
Daily Maximum Concentration - 1.60 mg/1
FIGURE 7-12
EFFLUENT CHROMIUM CONCENTRATIONS vs RAW WASTE CONCENTRATIONS
OPTION 2
-------
V
1.50-
1.25-
N.
E
^ 1.00-
c
0
3
rH
U
£ 0.75-^
a
o
u
0.50-
0.25-
OJ
<
, 0
1
e
0
e
D
<
i
0
<
Dail;
O
i
(
r Maxir
3
)
tun C
3pp<
(9
kj*
0.1
1.0 10
Copper Raw Waste (mg/1)
100
Daily Maximum Concentration - 1.75mg/l
FIGURE 7-13
EFFLUENT COPPER CONCENTRATIONS vs RAW WASTE CONCENTRATIONS
OPTION 2
-------
V
. OS-
c
o
's .06-
.04-
O
C.I
0.2
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Lead Raw Waste (mg/1)
Daily Maximum Concentration - 0.48 mg/1
FIGURE 7-14
EFFLUENT LEAD CONCENTRATIONS vs RAW WASTE CONCENTRATIONS
OPTION 2
-------
u>
J.. /D-
•
1.50-
1.25-
i-i
\
CT
~ 1.00-
jj
c
o
D
W
U-l
t:
^ 0.75-
o
u
z
0.50-
0.25-
0-
0
1
(
1
\
° 0
0
o
m
o
9
10
Daily
°g
texiirum Nickel
100 1C
Nickel Raw Waste (mg/1)
FIGURE 7-15
EFFLUENT NICKEL CONCENTRATIONS vs RAW WASTE CONCENTRATIONS
OPTION 2
-------
H
V
(Ti
1 ")-
i n.
»-K •
•-H
.E 0 8-
C
0)
3
Vu
Vu
M 0 6-
u
c
•H
N
0 4 -
07-
0 -
0.1
C
1
0
o <0
_
o
0
01
c
1
o
<
)
o
Da
o
o
Lly Ma:
:imu!T
Zii
c
10 1C
Zinc Raw Waste (mg/1)
FIGURE 7-16
EFFLUENT ZINC CONCENTRATIONS vs RAW WASTE CONCENTRATIONS
OPTION 2
-------
TABLE 7-23
TREATMENT OP COMMON METALS
VISITED PLANT OPTION 2 MEAN EFFLUENT CONCENTRATIONS
Parameter mg/1
Total Suspended Solids 12.8
Cadmium .014
Chromium, Total .319
Copper .367
Lead .031
Nickel .459
Zinc .247
VII-65
-------
Long Term Self-Monitoring Data Performance
Long term self-monitoring data were submitted by a number of
plants with Option 2 treatment systems. However, the quantity of
data submitted, relative to the data available for Option 1, was
considered to be statistically inferior for the calculation of
Option 2 variability factors. In addition, the variability for
plants with Option 2 generally fell within the range of the
Option 1 results. Therefore, the previously determined Option 1
variability factors were used in calculating Option 2 effluent
performance. Tables 7-24 through 7-30 present overall values
for each pollutant, the total number of available points, and the
mean value for all points. i
Overall Performance
The overall Option 2 system performance is based on mean effluent
concentrations calculated from visited plant data shown in Table
7-23 (except for cadmium and lead, where the mean from the self-
monitoring data were used) multiplied by variability factors
calculated from long term self-monitoring data taken at Option 1
plants. The statistical procedures used to establish Option 2
system performance are discussed in Statistical Analysis at the
end of this section.
VII-66
-------
TABLE 7-24
EFFLUENT TSS SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 2 SYSTEMS
Number Mean Effluent
Plant ID Of Points Concentration (mq/jlj
03043 94 10.07
15193 12 13.58
20483 357 5.90
38223 234 5.74
OVERALL 697 (TOTAL) 6.54 (MEAN)
TABLE 7-25
EFFLUENT CADMIUM SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 2 SYSTEMS
Number Mean Effluent
Plant ID Of Points Concentration (mq/|J
38223 234 0.08
TABLE 7-26
EFFLUENT CHROMIUM SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 2 SYSTEMS
Number Mean Effluent
Plant ID Of Points Concentration (mq/jtj
03043 91 0.60
15193 12 0.11
31021 86 0.25
38223 234 0.06
OVERALL 423 (TOTAL) 0.22 (MEAN)
VII-67
-------
TABLE 7-27
EFFLUENT COPPER SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 2 SYSTEMS
Plant ID
1112B
15193
31021
OVERALL
Number
Of Points
29
12
121
Mean Effluent
Concentration (mq/il)
1.11
0.06
1.44
225 (TOTAL)
1.32 (MEAN)
TABLE 7-28
EFFLUENT LEAD SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 2 SYSTEMS
Plant ID
38223
Number
Of Points
234
Mean Effluent
Concentration (mq/8.)
0.04
TABLE 7-29
EFFLUENT NICKEL SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 2 SYSTEMS
Plant ID
03043
11125
15193
31021
OVERALL
Number
Of Points
91
29
12
120
Mean Effluent
Concentration (mg/g.)
0,42
1.75
0.27
0.93
252 (TOTAL)
0.81 (MEAN)
Plant ID
03043
15193
31021
38223
OVERALL
TABLE 7-30
EFFLUENT ZINC SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 2 SYSTEMS
Number
O£ Points
91
12
121
234
Mean Effluent
Concentration (roq/st)
0.35
0.14
0.77
0.11
252 (TOTAL)
0.81 (MEAN)
VII-68
-------
Table 7-31 summarizes the daily and 10-day variability factors
used in determining Option 2 effluent limitations. These vari-
ability factors are a repeat of the Option 1 variability factors
presented previously in Table 7-19.
TABLE 7-31
SUMMARY OF OPTION 2 DAILY MAXIMUM AND 10-DAY AVERAGE
VARIABILITY FACTORS
Pollutant
Total suspended solids
Cadmium
Chromium, total
Copper
Lead
Nickel
Zinc
Variability Factor
Daily Max. 10-Day Average
3.59
5.31
4.85
4.15
3.52
4.22
4.75
1,
2,
2,
,85
,02
,98
2.54
2.19
2.52
2.70
VII-69
-------
Table 7-32 presents the daily maximum, 10-day average, and long
term average effluent performance for common metals Option 2.
Performance was obtained by multiplying the visited plant mean
concentrations of Table 7-23 by the respective variability
factors shown in Table 7-31 (except for cadmium and lead, where
the weighted mean Option 2 self-monitoring data concentrations
were used in place of the visited plant mean effluent
concentrations). The allowable daily effluent concentrations for
each of the parameters have been shown on Figures 7-10 through
7-16.
TABLE 7-32
OPTION 2 COMMON METAL PERFORMANCE LEVELS
Long Term
Pollutant Daily Max. 10-Day Average Average
Total suspended solids 46 24 12,8
Cadmium 0.42 0.16 0.08
Chromium, total 1.55 0.95 0.32
Copper 1.52 0.93 0.37
Lead 0.14 0.09 0.04
Nickel 1.94 1.16 0.46
Zinc 1.13 0.67 0.25
Table 7-33 summarizes the percentage of the metal finishing data
base below the Option 2 daily maximum concentration limitation
for the EPA sampled plants.
TABLE 7-33
PERCENTAGE OF THE MFC DATA BASE BELOW THE DAILY
MAXIMUM CONCENTRATIONS FOR OPTION 2
Pollutant EPA Sampled Plants
Da11y Max imum
Total suspended solids 100.0
Cadmium 100.0
Chromium, total 100.0
Copper 100.0
Lead 100.0
Nickel 100.0
Zinc 94.1
VII-70
-------
Summary tables are provided to show a direct comparison of the
mean, daily maximum, and 10-day average concentrations for
Options 1 and 2. Table 7-34 presents a comparison of the mean
concentrations and Table 7-35 lists the daily maximum and maximum
monthly average concentrations for each.
TABLE 7-34
OPTION 1 AND OPTION 2 MEAN CONCENTRATION COMPARISON
Pollutant
Total suspended solids
Cadmium
Chromium, total
Copper
Lead
Nickel
Zinc
CONCENTRATION (mg/8.)
Option 1 Option 2
16.8
0.19
0.572
0.815
0.20
0.942
0.549
12.8
0.08
0.319
0.367
0.04
0.459
0.247
Pollutant
TABLE 7-35
OPTION 1 AND OPTION 2 PERFORMANCE COMPARISON
CONCENTRATION (mg/8.)
Option 1 Option 2
Maximum
Daily Max. Monthly Ave.
Maximum
Daily Max. Monthly Ave
Total Suspended
Solids
Cadmium
Chromium, total
Copper
Lead
Nickel
Zinc
60
0.69
2.77
3.38
0.69
3.98
2.61
31
46
24
0.26
1.71
2.07
0.43
2.38
1.48
0.42
1.55
1.52
0.14
1.94
1.17
0.16
0.95
0.93
0.09
1.16
0.67
V1I-71
-------
TREATMENT OF COMMON METALS WASTES - OPTION 3
The Option 3 treatment system for metal wastes consists of the
Option 1 end-of-pipe treatment system plus the addition of in-
plant controls for cadmium. In-plant controls could include
evaporative recovery, ion exchange, and recovery rinses. The
purpose of these in-plant controls is to nearly eliminate
cadmium from the raw waste stream. These additional controls
will also minimize the chance of discharging this highly toxic
metal due to treatment system failure.
Vli-72
-------
The performance of the Option 3 treatment system, applied to
cadmium plating rinse, acid stripping of cadmium plated parts,and
chromating of cadmium plated parts, will be identical to the
Option 1 treatment system with the exception that only background
concentration levels of cadmium should be discharged. In order
to establish background concentration levels for cadmium all
available sampled data were studied to identify data points from
plants that apply the metal. The objective was to segregate the
data base into two distinct data sets: one data set for plants
that apply cadmium, and one data set for plants in which cadmium
is not applied. The data set for plants that do not apply
cadmium is representative of background metal concentration
levels.
Cadmium Background Level
Table 7-36 presents the data set for plants that do not apply
cadmium which was used to establish a background level for
cadmium. A percentile distribution of these data are presented
in Figure 7-17. While the average of the data is 0.013 mg/2.,
the Agency has conservatively used the average of the two highest
plants not plating cadmium - plants 36041 and 33024. These
plants were determined to be statistically different from the
other facilities. The resultant daily maximum is higher than all
values measured. Furthermore, a new source plant which
eliminates the discharge from the cadmium sources should be more
than adequately able to meet the background level which was
determined using raw waste values. New source performance
standards are based on the in-plant cadmium controls plus
precipitation/clarification. (Examination of the EPA sampled
data for precipitation/clarification of cadmium in Table 7-4
showed an average of 0.011 mg/S.). A summary of the statistics
used in deriving the new source cadmium limits is presented below.
Mean Background Concentration 0.058 mg/Sl
Daily Variability Factor 1.54 mg/8.
10-Day Variability Factor 0.89 mg/8.
Daily Maximum Background 0.114 mg/8.
Concentration
Maximum Monthly Average 0.066 mg/8.
Background Concentration
The daily maximum and maximum monthly average background
concentrations for cadmium detailed in the previous paragraphs
are defined as the Option 3 effluent limitations for cadmium.
A review of the various data bases available did not identify any
plants that had in-process treatment technologies specifically
for the control of three cadmium sources mentioned above. This
does not mean that extensive in-process treatment technologies
for control of cadmium effluents are not in use within the metal
finishing industrial segment; it simply means that no plants were
identified which controlled all three sources based upon the
available information.
VII-73
-------
TABLE 7-36
PERFORMANCE DATA FOR CADMIUM METAL FINISHING CAfEGOEY
OPTION 3
Plant ID
Raw Waste
Concentration
(mcr/St)
1.
2.
3.
4.
5.
6,
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
6101-12-1
6101-12-1
19068-14-0
11477-22-1
11477-22-2
15010-12-2
15010-12-3
4065-8-1
4069-8-1
4069-8-1
5020-1-4
5020-1-5
5020-1-6
19051-6-0
20078-1-2
20078-1-3
20078-1-4
20078-1-7
36040-1-1
36040-1-1
36040-1-1
31021-1-2
31021-1-3
20083-1-3
33692-23-1
31021-1-1
33070-1-1
5020-1-3
33065-9-1
33070-1-3
.001
.002
.002
.002
.002
.004
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.006
.006
.006
.007
.007
.007
.008
Plant ID
Raw Waste
Concentration
31.
32,
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
40062-8-0
40062-8-0
33065-9-1
15070-1-3
19063-1-1
31022-1-2
19063-1-2
20083-1-5
20083-1-6
31022-1-0
33073-1-1
33073-1-3
6083-1-2
15070-1-1
19063-1-3
15070-1-2
33073-1-2
6731-1-1
6731-1-2
6074-1-1
6731-1-3
6074-1-1
31020-1-1
27044-1-0
20080-1-1
4065-8-1
6074-1-1
36041-1-2
36041-1-3
36041-1-1
33024-6-0
.008
.008
.009
.009
.011
.011
.012
.012
.012
.013
.013
.013
.013
.013
.013
.014
.015
.015
.017
.019
.019
.021
.021
.022
.024
.032
.033
.042
.042
.053
.095
Mean
Concentrat ion
0.0131 (n=61)
VII-74
-------
H
(Jl
U.IU
n nn
3
e>
o 0.06
P
cc
01
0
o QQ4
£
3
S
a
o
00?
n
v * * * •
,••••*'
* * '
. * *
» * *
•
.. •
• *
*
f
*
• *
» «
10
20
30
40 50 60
PERCENTILE DISTRIBUTION
70
80
90
100
FIGURE 7-17. CADMIUM RAW WASTE CONCENTRATION DISTRIBUTION
-------
'She following paragraphs detail common metals treatment techniques
that are applicable to Option 3: Evaporation and Ion Exchange.
Evaporation
Evaporation is a concentration process. Wa!ter is evaporated
from a solution, increasing the concentration of solute in the
remaining solution. If the resulting water vapor is condensed
back to a liquid, the evaporation-condensation process is
called distillation. However, to be consistent with industry
terminology, evaporation is used in this report to describe
both processes. Both atmospheric and vacuum evaporation are
commonly used in industry today. Specific evaporation tech-
niques are shown in Figure 7-18 and discussed below.
Atmospheric evaporation could be accomplished simply by boiling
the liquid. However, to aid evaporation, heated liquid is
sprayed on an evaporation surface, and air ,is blown over the
surface and subsequently released to the atmosphere. Thus,
evaporation occurs by humidification of the, air stream, similar
to a drying process. Equipment for carrying, out atmospheric
evaporation is quite similar for most applications. The major
element is generally a packed column with an accumulator
bottom. Accumulated wastewater is pumped from the base of the
column, through a heat exchanger, and back into the top of the
column, where it is sprayed into the packing. At the same
time, air drawn upward through the packing by a fan is heated
as it contacts the hot liquid. The liquid partially vaporizes
and humidifies the air stream. The fan then blows the hot,
humid air to the outside atmosphere. A scrubber is often
unnecessary because the packed column itself acts as a scrubber.
Another form of atmospheric evaporation combines evaporative
recovery of plating chemicals with plating tank fume control.
A third form of atmospheric evaporation also works on the air
humidification principle/ but the evaporated rinse water is
recovered for reuse by condensation. These air humidification
techniques operate well below the boiling point of water and
can utilize waste process heat to supply the energy required.
In vacuum evaporation, the evaporation pressure is lowered to
cause the liquid to boil at reduced temperature. All of the
water vapor is condensed and, to maintain the vacuum condition,
noncondenslble gases (air in particular) are removed by a
VII-76
-------
PACKCD TOWER
EVAPORATOR
CONDKNSATE-
WASTEWATER-
CONCEHTRATE-
.EXHAUST
COUUBNSER
WATER VAPOR
1IKAT
EXCHANGER
STEAM
COMPENSATE
*-CONCENTRATE
ATMOSPHERIC EVAPORATOR
VACUUM LINE
VACUUM
PUMP
.\\\\ \ \. \ \ \.Y
COOLING
WATER
-STEAM
STEAM
COHOEHSATE
STEAM
BASTE
WATER
FERD
EVAPORATOR
STEAM
STEAM
CONDENSATE
WASTEWATER
HOT VAPOR
VAPOR-LIQUID eFp,nRrr,o
MIXTURE SEPARMOR
ZL
«-;'OHCEHTRATF,
CLIMBING FILM EVAPORATOR
VAPOR
STEAM
COMDENPATF,
CONCENTRATE
CONDEIIRER
COHDENSATB
COHOENSATE
COOMHT
WA^BR
VACUUM PUMP
ACCUHUf.ATOn
CON!)RNf3ATF,
-»- FOR
CONCRHTRATR FOR RRUSE
E EVAPORATOR
FIGURE 7-18
TYPES OF EmPOFATION EQUIPMEOT
EVAPORATOR
-------
vacuum pump. Vacuum evaporation may be either single or
double effect. In double effect evaporation, two evaporators
are used, and the water vapor from the first evaporator (which
may be heated by steam) is used to supply heat to the second
evaporator. As it supplies heat, the water vapor from the
first evaporator condenses. Approximately equal quantities of
wastewater are evaporated in each unit; thus, the double
effect system evaporates twice the amount of water that a
single effect system does, at nearly the same cost in energy
but with added capital cost and complexity. The double effect
technique is thermodynamically possible because the second
evaporator is maintained at lower pressure (higher vacuum)
and/ therefore, lower evaporation temperature. Another means
of increasing energy efficiency is vapor recompression (thermal
or mechanical), which enables heat to be transferred from the
condensing water vapor to the evaporating wastewater. Vacuum
evaporation equipment may be classified as submerged tube or
climbing film evaporation units.
In the most commonly used submerged tube evaporator, the
heating and condensing coil are contained in a single vessel
to reduce capital cost. The vacuum in the vessel is maintained
by an eductor-type pump, which creates the required vacuum by
the flow of the condenser cooling water through a venturi.
Wastewater accumulates in the bottom of the vessel, and it is
evaporated by means of submerged steam coils. The resulting
water vapor condenses as it contacts the condensing coils in
the top of the vessel. The condensate then drips off the
condensing coils into a collection trough that carries it out
of: the vessel. Concentrate is removed from the bottom of the
vessel. The major elements of the climbing film evaporator
are the evaporator, separator, condenser, and vacuum pump.
Wastewater is "drawn" into the system by the vacuum so that a
constant liquid level is maintained in the separator. Liquid
enters the steam-jacketed evaporator tubes, and part of it
evaporates so that a mixture of vapor and liquid enters the
separator. The design of the separator is such that the
liquid is continuously circulated from the separator to the
evaporator. The vapor entering the separator flows out through
a mesh entrainment separator to the condenser, where it is
condensed as it flows down through the condenser tubes. The
condensate, along with any entrained air, is pumped out of the
bottom of the condenser by a liquid ring vacuum pump. The
liquid seal provided by the condensate keeps the vacuum in the
system from being broken.
Application
Evaporation is used in the Metal Finishing Category for recov-
ery of a variety of metals, bath concentrates, and rinse
waters. Both atmospheric and vacuum evaporation are used in
metal finishing plants, mainly for the concentration and
recovery of plating solutions. Many of these evaporators also
recover water for rinsing. Evaporation has also been applied
VII-78
-------
to recovery of phosphate metal cleaning solutions. There is
no fundamental limitation on the applicability of evaporation.
Recent changes in construction materials used for climbing
film evaporators enable them to process a wide variety of
wastewaters (including cyanide-bearing solutions), as do the
other types of evaporators described in this report.
Advantages of the evaporation process are that it permits
recovery of a wide variety of process chemicals, and it is
often applicable to removal and/or concentration of compounds
which cannot be accomplished by any other means. The major
disadvantage is that the evaporation process consumes relatively
large amounts of energy for the evaporation of water. However,
the recovery of waste heat from many industrial processes
(e.g., diesel generators, incinerators, boilers and furnaces)
should be considered as a source of this heat for a totally
integrated evaporation system. For some applications, pretreat-
ment may be required to remove solids and/or bacteria which
tend to cause fouling in the condenser or evaporator. The
buildup of scale on the evaporator surfaces reduces the heat
transfer efficiency and may present a maintenance problem or
increased operating cost. However, it has been demonstrated
that fouling of the heat transfer surfaces can be avoided or
minimized for certain dissolved solids by maintaining a seed
slurry which provides preferential sites for precipitate
deposition. In addition, low temperature differences in the
evaporator will eliminate nucleate boiling and supersaturation
effects. Steam distillable impurities in the process stream
are carried over with the product water and must be handled by
pre or post treatment.
Performance
In theory, evaporation should yield a concentrate and a deion-
ized condensate. Actually, carry-over has resulted in condensate
metal concentrations as high as 10 mg/1, although the usual
level is less, than 3 mg/1, pure enough for most final rinses.
The condensate may also contain organic brighteners and anti-
foaming agents. These can be removed with an activated carbon
bed, if necessary. Samples from one metal finishing plant
showed 1,900 mg/1 zinc in the feed, 4,570 mg/1 in the concen-
trate, and 0.4 mg/1 in the condensate. Another plant had 416
mg/1 copper in the feed and 21,800 mg/1 in the concentrate.
Chromium analysis for that plant indicated 5,060 mg/1 in the
feed and 27,500 mg/1 in the concentrate. Evaporators are
available in a range of capacities, typically from 15 to 75
gph, and may be used in parallel arrangements for processing
of higher flow rates.
Demonstration Status
Evaporation is a fully developed, commercially available
wastewater treatment system. It is used extensively to recover
plating chemicals, and a pilot scale unit has been used in
connection with phosphate washing of aluminum coil.
VII-79
-------
Evaporation has been used in 39 of the visited plants
in the present data base and these are identified in the
following table (Table 7-37).
TABLE 7-37
METAL FINISHING PLANTS EMPLOYING EVAPORATION
04266 12065 33033
04276 12075 33065
04284 . 13031 33112
06009 19069 34050
06037 20064 36062
06050 20069 36084
06072 20073 36162
06075 20147 38050
06087 20160 38052
06088 20162 40062
06090 23071 40836
06679 28075 43003
08060 30096 61001
i
Ion Exchange
Ion exchange is a process in which ions, held by electrostatic
forces to charged functional groups on the surface of the ion
exchange resin, are exchanged for ions of similar charge from
the solution in which the resin is immersed. This is classified
as a sorption process because the exchange occurs on the
surface of the resin, and the exchanging ion must undergo a
phase transfer from solution phase to solid phase. Thus,
ionic contaminants in a waste stream can be exchanged for the
harmless ions of the resin.
Although the precise technique may vary slightly according to
the application involved, a generalized process description
follows. The wastewater stream being treated passes through a
filter to remove any suspended solids, then flows through a cation
exchanger which contains the ion exchange resin. Here, metallic
impurities such as copper, iron, and trivalent chromium are
retained. The stream then passes through the anion exchanger
and its associated resin. Hexavalent chromium, for example,
is retained in this stage. If one pass does not reduce the
contaminant levels sufficiently, the stream may then enter
another series of exchangers. Many ion exchange systems are
equipped with more than one set of exchangers for this reason.
The other major portion of the ion exchange process concerns
the regeneration of the resin, which now holds those impurities
retained from the waste stream. An ion exchange unit with
in-place regeneration is shown in Figure 7-19. Metal ions such
as nickel are removed by an acidic cation exchange resin, which
is regenerated with hydrochloric or sulfuric acid, replacing the
metal ion with one or more hydrogen ions. Anions such as dichro-
mate are removed by a basic anion exchange
VII-80
-------
WASTE WATER CONTAINING
DISSOLVED METALS
OR OTHER IONS
OIVERTER VALVE
REGENERANT TO REUSE,
TREATMENT, OR DISPOSAL
REGENERANT
SOLUTION
DIVERTER VALVE
METAL—FREE WATER
FOR REUSE OR DISCHARGE
FIGURE 7-19
ION EXCHANGE WITH REGENERATION
VII-81
-------
resin, which is regenerated with sodium hydroxide, replacing
the anion with one or more hydroxyl ions. The three principal
methods employed by industry for regenerating the spent resin
are:
A) Replacement Service - A replacement service replaces the
spent resin with regenerated resin, and regenerates the
spent resin at its own facility. The service then has the
problem of treating and disposing of the spent regenerant.
B) In-Place Regeneration - Some establishments may find it
less expensive to do their own regeneration. The spent
resin column is shut down for perhaps an hour, and the spent
resin is regenerated. This results in one or more waste
streams which must be treated in an appropriate manner.
Regeneration is performed only as the resins require it.
C) Cyclic Regeneration - In this process, the regeneration
of the spent resins takes place in alternating cycles with
the ion removal process. A regeneration frequency of
twice an hour is typical. This very short cycle time
permits operation with a very small quantity of resin and
with fairly concentrated solutions, resulting in a very
compact system. Again, this process varies according to
application, but the regeneration cycle generally begins
with caustic being pumped through the anion exchanger,
carrying out hexavalent chromium, for example, as sodium
dichromate. The sodium dichromate stream then passes through
a cation exchanger, converting the sodium dichromate to
chromic acid. After concentration by evaporation or other
means, the chromic acid can be returned to the process line.
Meanwhile, the cation exchanger is regenerated with sulfuric
acid, resulting in a waste acid stream containing the metallic
impurities removed earlier. Flushing the exchangers with
water completes the cycle. Thus, the wastewater is purified
and, in this example, chromic acid is recovered. The ion
exchangers, with newly regenerated resin, then enter the ion
removal cycle again.
Application
Many metal finishing facilities utilize ion exchange to concen-
trate and purify their plating baths.
The list of pollutants for which the ion exchange system has
proven effective includes aluminum, arsenic, cadmium, chromium
(hexavalent and trivalent), copper, cyanide, gold, iron, lead,
manganese, nickel, selenium, silver, tin, zinc, and more.
Thus, it can be applied to a wide variety of industrial concerns.
Because of the heavy concentrations of metals in their wastewater,
the metal finishing industries utilize ion exchange in several
ways. As an end-of-pipe treatment, ion exchange is certainly
feasible, but its greatest value is in (recovery applications.
It is commonly used, however, as an integrated treatment to
VII-82
-------
recover rinse water and process chemicals. In addition to
metal finishing, ion exchange is finding applications in the
photography industry for bath purification, in battery manufac-
turing for heavy metal removal, in the chemical industry, the
food industry, the nuclear industry, the pharmaceutical industry,
the textile industry, and others. It could also be used in
the copper and copper alloys industry for recovery of copper
from pickle rinses. Also, many industrial and non-industrial
concerns utilize ion exchange for reducing the salt concentra-
tions in their incoming water.
Ion exchange is a versatile technology applicable to a great
many situations. This flexibility, along with its compact
nature and performance, make ion exchange a very effective
method of waste water treatment. However, the resins in these
systems can prove to be a limiting factor. The thermal limits
of the anion resins, generally placed in the vicinity of 60° C,
could prevent its use in certain situations. Similarly,
nitric acid, chromic acid, and hydrogen peroxide can all
damage the resins as will iron, manganese, and copper when
present with sufficient concentrations of dissolved oxygen.
Removal of a particular trace contaminant may be uneconomical
because of the presence of other ionic species that are prefer-
entially removed. The regeneration of the resins presents its
own problems. The cost of the regenerative chemicals can be
high. In addition, the waste streams originating from the
regeneration process are extremely high in pollutant concentra-
tions, although low in volume. These must be further processed
for proper disposal.
Performance
Ion exchange is highly efficient at recovering metal finishing
chemicals. Recovery of chromium, nickel, phosphate solution,
and sulfuric acid from anodizing is in commercial use. A
chromic acid recovery efficiency of 99.5% has been demonstrated.
Typical data for purification of rinse water in electroplating
and printed circuit board plants are shown in Table 7-38.
VIl-83
-------
TABLE 7-38
TYPICAL ION EXCHANGE PERFORMANCE DATA
Parameter
All Values mg/1
Zinc (Zn)
Cadmium (Cd) 3
El ec t ropla t i ng Plant
Prior To Aft er
Purifi- Purifi-
cation cation
Printed Circuit Board Plant
Prior To
Purifi-
cation
After
Purifi-
cation
Chr om i urn ( Cr -
Chromium (Cr
Copper (Cu)
Iron (Fe)
Nickel (Ni)
Silver (Ag)
Tin (Sn)
Cyanide (CN)
Manganese (Mn)
Aluminum (Al)
Sulfate (SO4)
Lead (Pb}
Gold (Au)
)
14.8
5.7
3.1
7.1
4.5
7.4
6.2
1.5
1.7
9.8
4.4
5.6
0.40
0.00
0.01
0.01
0.09
0.01
0.00
0.00
0.00
0.04
0.00
0.20
43.0
mm t
1.60
9.10
1.10
3.40
210.00
1.70
2.30
0.10
0.01
0.01
0.10
0.09
2.00
0.01
0.10
Plant ID 11065, which was visited and sampled> employs an ion
exchange unit to remove metals from rinsewater. The results
of the sampling are displayed below:
POLLUTANT CONCENTRATION (mg/1}
Plant ID 11065
Day 1
Input To Effluent From
Ion Exchange Ion Exchange
Parameter
TSS
Cu
Ni
Cr, Total
Cd
Sn
Pb
6.0
52.080
.095
.043
.005
.06
.010
4.0
.118
.003
.051
.005
.06
.011
Day 2
Input To
Ion Exchange
1.0
189.3
.017
.026
.005
.06
.010
Output From
Ion Exchangi
1.0
.20
.003
.006
.005
.06
.010
VH-84
-------
Demonstration Status
All of the applications mentioned in this document are available
for commercial use. The research and development in ion
exchange is focusing on improving the quality and efficiency
of the resins, rather than new applications. Work is also
being done on a continuous regeneration process whereby the
resins are contained on a fluid-transfusible belt. The belt
passes through a compartmented tank with ion exchange, washing,
and regeneration sections. The resins are therefore continually
used and regenerated. No such system, however, has been
reported to be beyond the pilot stage.
Ion exchange is used in 63 plants in the present data base and
these are identified in Table 7-39.
TABLE 7-39
METAL FINISHING PLANTS EMPLOYING ION EXCHANGE
02033
02034
02037
04145
04221
04223
04236
04263
04541
04676
04690
05050
06103
06679
08073
09025
11065
12065
12075
12080
13040
17030
17050
17061
18538
19081
19120
20017
20075
20120
20162
20483
21059
21065
21066
21075
23065
25033
27046
28111
28121
30153
30967
31032
31050
31070
33130
33172
33186
33187
36087
36623
37060
38036
38039
40048
40061
41086
41089
44062
46035
61001
62032
VII-85
-------
ALTERNATIVE TREATMENT METHODS FOR COMMON METALS REMOVAL
In addition to the treatment methods described under Options
1, 2, and 3? there are several other alternative treatment
technologies applicable for the treatment of common metals
wastes. These technologies may be used in conjunction with or
in place of the Option 1, 2, or 3 system components. The
following paragraphs describe these technologies:
peat adsorption, insoluble starch xanthate> sulfide precipitation,
flotation, and membrane filtration.
Peat Adsorption
Peat moss is a rather complex material with lignin and
cellulose as major constituents. These constituents,
particularly lignin, bear polar functional groups, such as
alcohols, aldehydes, ketones, acids, phenolic hydroxides and
ethers, that can be involved in chemical bonding. Because of
the polar nature of this material, its adsorption of dissolved
solids such as transition metals and polar organic molecules
is quite high. These properties have led to the use of peat
as an agent for the purification of industrial wastewater.
Peat adsorption is a "polishing" process which can achieve
very low effluent concentrations for several pollutants. If
the concentrations of pollutants are above, 10 mg/1, then peat
adsorption must be preceded by pH adjustment and settling.
The wastewater is then pumped into a large metal chamber
(a kier) which contains a layer of peat through which the
waste stream passes. The water flows to a second kier for
further adsorption. The wastewater is then ready for
discharge. This system may be automated or manually operated.
VU-86
-------
Application
Peat adsorption can be used in metal finishing plants for
removal of residual dissolved metals from clarifier effluent.
Peat moss may be used to treat wastewaters containing heavy
metals such as mercury, cadmium, zinc, copper, iron, nickel,
chromium, and lead, as well as organic matter such as oil,
detergents, and dyes. Peat adsorption could be used in metal
finishing industries, coil coating plants, porcelain
enameling, battery manufacturing plants, copper products
manufacturing facilities, photographic plants, textile
manufacturing, newsprint production facilities, and other
industries. Peat adsorption is currently used commercially at
a textile plant, a newsprint facility, and a metal reclamation
operation.
Performance
The following table contains performance figures obtained from
pilot plant studies. Peat adsorption was preceded by pH
adjustment for precipitation and by clarification.
Pollutant Before Treatment (mg/1) After Treatment (mg/1)
Pb 20.0 0.025
Sb 2.5 0.9
Cu 250.0 0.24
Zn 1.5 0.25
Ni 2.5 0.07
Cr b 35,000.0 <0.04
CN 36.0 0.7
Hg >1.0 0.02
Ag >1.0 0.05
In addition, pilot plant studies have shown that complexed metal
wastes, as well as the complexing agents themselves, are removed
by contact with peat moss. Therefore, peat adsorption could be
applied to printed circuit board manufacturing, which uses com-
plexing agents extensively.
Demonstration Status
Only three commercial adsorption systems are currently in use
in the United States. These are at a textile manufacturer, a
newsprint facility, and a metal reclamation firm.
No data have been reported showing the use of peat adsorption in
any metal finishing plants. Its only commercial applications are
as stated above.
VII-87
-------
Insoluble Starch Xanthate
Insoluble starch xanthate (ISX) is essentially an ion exchange
medium used to remove dissolved heavy metals from wastewater.
ISX is formed by reacting commercial cross-linked starch with
sodium hydroxide and carbon disulfide. Magnesium sulfate is
also added as a stabilizer and to improve sludge settling.
ISX acts as a cationic ion exchange material removing the
heavy metal ions and replacing them with sodium and magnesium.
The starch has good settling characteristics/ good filtering
characteristics, and is well suited for use as a filter
precoat. ISX can be added as a slurry for continuous
treatment operations/ in solid form for batch treatments and
as a precoat to a filter. The ISX process is effective for
removal of all uncomplexed metals, including hexavalent
chromium/ and also some complexed metals such as the
copper-ammonia complex. The removal of hexavalent chromium is
brought about by lowering the pH to below 3 and subsequent
raising of it above 7. The hexavalent chromium is reduced by
the ISX at the acid pH and is removed at the alkaline pH as
chromium starch xanthate or chromic hydroxide.
Presently/ ISX is being used in two metal finishing establish-
ments. One of the plants utilizes the ISX process as a
polishing filter and claims to reduce Ievt2ls of metals in the
effluent of their clarifier from 1 mg/1 to .020 mg/1. The
other plant (ID 27046)/ which was visited and sampled, uses
the ISX process to recycle rinse waters on their cleaning line
and nickel/ copper, and solder plating lines. The results of
the sampling are listed below.
Solder Line
Cu
Pb
Sn
Zn
Ni
Pe
Input
To
Filter
.42
.56
2.0
.092
Output
From
Filter
.41
.53
1.5
.083
Nickel Line
Input Output
To From
Filter Filter
.24
.047
552.
.24
.040
547.
Cleaning Line
Input Output
To From
Filter Filter
.43
.167
.38
.39
.126
.26
As shown by the data, the ISX was not removing a high
percentage of metal. Its main purpose was to keep
contaminants from building up to a point where the water would
not be reusable.
VII-88
-------
Sulfide Precipitation
Application
Hydrogen sulfide or soluble sulfide salts such as sodium sul-
fide are used to precipitate many heavy metal sulfides. Since
most metal sulfides are even less soluble than metal
hydroxides at alkaline pH levels, greater heavy metal removal
can be accomplished through the use of sulfide rather than
hydroxide as a chemical precipitant prior to sedimentation.
The solubilities of metallic sulfides are pH dependent and are
shown in Figure 7-20.
Of particular interest is the ability at a pH of 8 to 9 of the
ferrous sulfide process to precipitate hexavalent chromium
(Cr ) without prior reduction to the trivalent state as is
required in the hydroxide process, although the chromium is
still precipitated as the hydroxide. When ferrous sulfide is
used as the precipitant, iron and sulfide act as reducing
agents for the hexavalent chromium.
2FeS + 7H2O = 2Fe(OH)3 + 2Cr(OH)3 + 2S
20H
In this case the sludge produced consists mainly of ferric
hydroxides and chromic hydroxides. Some excess hydroxyl ions
are produced in this process, possibly requiring a downward
re-adjustment of pH to between 8-9 prior to discharge of the
treated effluent.
In addition to the advantages listed above, the process will preci-
pitate metals complexed with most complexing agents. However, care
must be taken to maintain the pH of the solution above
approximately 8 in order to prevent the generation of toxic
hydrogen sulfide gas. For this reason ventilation of the
treatment tanks may be a necessary precaution in some instal-
lations. The use of ferrrous sulfide virtually eliminates the
problem of hydrogen sulfide evolution, however. As with
hydroxide precipitation, excess sulfide must be present to
drive the precipitation reaction to completion. Since sulfide
itself is toxic, sulfide addition must be carefully controlled
to maximize heavy metals precipitation with a minimum of
excess sulfide to avoid the necessity of posttreatment. At
very high excess sulfide levels and high pH, soluble
mercury-sulfide compounds may also be formed. Where excess
sulfide is present, aeration of the effluent stream can aid in
oxidizing residual sulfide to the less harmful sodium sulfate
(Na2SO.). The cost of sulfide precipitants is high in
comparison with hydroxide precipitating agents, and disposal
of metallic sulfide sludges may pose problems. With improper
VII-89
-------
10
10
10
-I
3 »o"4
g 10*
O
to
Q
0 JO'7
c
o
u
-U
I ID'8
o
10
-10
10
-it
10
-12
10
-13
T I I T
I 1 I
CoS
2 3 4 5 6 7 8 9 10 II 12 13
pH
Note;. Plotted data for metal sulfides based on experimental data listed
in Seidell's solubilities.
FIGURE 7-20
COMPARATIVE SOLUBILITIES OF METAL SULFIDES
AS A FUNCTION OF pH
VII-90
-------
handling or disposal of sulfide precipitates, hydrogen sulfide may
be released to the atmosphere creating a potential toxic hazard,
toxic metals may be leached out into surface waters, and sulfide
might oxidize to sulfate and release dilute sulfuric acid to surface
waters. An essential element in effective sulfide precipitation
is the removal of precipitated solids from the wastewater to a site
where reoxidation and leaching are not likely to occur.
Performance
Data from sampling at Plant 27045 show the effectiveness of
sulfide precipitation on unreduced hexavalent chromium as well
as total chromium. Mean concentrations for the only metals
present in the aluminum anodizing operation were as follows:
Parameter Influent mg/1 Effluent mg/1
Chromium, hex. 11.5 Undetectable
Chromium, total 18.4 Undetectable
Aluminum 4.18 0.112
One report (Treatment of Metal Finishing Wastes by Sulfide
Precipitation, EPA-600/2-75-049, U.S. Environmental Protection
Agency, 1977} concluded that (with no complexing agents
present) the following effluent quality can be achieved:
Parameter E £ fluent mg/1
Cadmium 0.01
Copper 0.01
Zinc 0.01
Nickel 0.05
Chromium, Total 0.05
Sampling data from three other industrial plants using sulfide
precipitation are presented in Table 7-40. Concentrations are
given in rag/1.
VII-91
-------
TABLE 7-40
SAMPLING DATA FROM SULFIDE
PRECIPITATION/SEDIMENTATION SYSTEMS
Data Source
Treatment
Reference 1
Reference 2
Lime, FeS?, Poly- Lime, FeS^r Poly-
Electrolyte, Electrolyte,
Settle, Filter
Settle, Filter
Reference 3
NaOH, Ferric
Chloride, Na_S,
Clarify (1 scage
PH, c 5
Cr
Cr, T
Cu
Fe
Ni
Zn
Reference:
1. Treatment
Raw
.0-6.8
25.6
32.3
-
.52
-
39.5
of Metal
Eff.
8-9
< . 01
<.04
-
.10
-
<.07
Finishing
Raw
7.7
.022
2.4
—
108
.68
33.9
3 Wastes b
Eff.
7.38
<.020
<.l
-
0.6
< . 1
<.l
y Sulfide
Raw
27
11.4
18.3
.029
-
-
.060
Precipitat
Eff.
6.4
<.005
<.005
.003
-
-
.009
ion,
EPA Grant No. S804648010.
2. Industrial Finishing, Vo. 35, No. 11, Nov. 1979, p. 40 (Raw
waste sample taken after chemical addition).
3. Visit Plant 27045. Concentrations are two day averages.
VXi-92
-------
In all cases except iron, effluent concentrations are below
0.1 mg/1 and in many cases below 0.01 mg/1 for the three
plants studied.
Sampling data from several chlorine/caustic inorganic
chemicals manufacturing plants using sulfide precipitation
reveal effluent mercury concentrations varying between 0.009
and 0.03 mg/1 (Calspan Report No. ND-5782-M-72). As can be
seen in Figure 7-20, the solubilities of PbS and Ag^S are
lower at alkaline pH levels than either the corresponding hy-
droxides or other sulfide compounds. This implies that removal
performance for lead and silver sulfides should be comparable to
or better than shown for the metals listed in Table 7-38. Bench
scale tests conducted on several types of metal finishing waste-
water (Centec Corp; EPA Contract 68-03-2672) indicate that
metals removal to levels of less than 0.05 mg/1 and in some cases
less than 0.01 mg/1 are common in systems using sulfide precipi-
tation followed by clarification. Some of the bench scale data,
particularly in the case of lead, do not support such low effluent
concentrations. However, no suspended solids data were
provided in these studies. TSS removal is a reliable
indicator of precipitation/sedimentation system performance.
Lack of this data makes it difficult to fully evaluate the
bench tests, and insufficient solids removal can result in
high metals concentrations. Lead is consistently removed to
very low levels (less than 0.02 mg/1) in systems using
hydroxide precipitation and sedimentation. Therefore one
would expect even lower effluent concentrations of lead
resulting from properly operating sulfide precipitation
systems due to the lower solubility of the lead sulfide
compound.
Demonstration Status
Full scale commercial sulfide precipitation units are in
operation at numerous installations, including several plants
in the Metal Finishing Category.
Flotation
Flotation is the process of causing particles such as metal
hydroxides or oil to float to the surface of a tank where they
can be concentrated and removed. This is accomplished by
releasing gas bubbles which attach to the solid particles,
increasing their buoyancy and causing them to float. In
principle, this process is the opposite of sedimentation.
Figure 7-21 shows one type of flotation system. Flotation
processes that are applicable to oil removal are discussed in
the subsection entitled "Treatment of Oily Wastes and
Organics".
VII-93
-------
OILY WATER
INFLUENT
WATER
DISCHARGE
OVERFLOW
SHUTOFF
VALVE
AIR IN
BACK PRESS
VALVE
TO SLUDGE
TANK "*
EXCESS
AIR OUT
LEVEL
CONTROLLER
FIGURE 7-21
DISOLVED AIR FLOTATION
VII-94
-------
Flotation is used primarily in the treatment of wastewater
containing large quantities of industrial wastes that carry
heavy loads of finely divided suspended solids. Solids having
specific gravity only slightly greater than 1.0, which would
require abnormally long sedimentation times may be removed in
much less time by flotation.
This process may be performed in several ways: foam,
dispersed air, dissolved air, gravity, and vacuum flotation
are the most commonly used techniques. Chemical additives are
often used to enhance the performance of the flotation
process.
The principal difference between types of flotation is the
method of generation of the minute gas bubbles, usually air,
in a suspension of water and small particles. Addition of
chemicals to improve the efficiency may be employed with any
of the basic methods. The following paragraphs describe the
different flotation techniques and the method of bubble
generation for each process.
Foam flotation is based on the utilization of differences in
the physiochemical properties of various particles. Wetta-
bility and surface properties affect the particles' ability to
attach themselves to gas bubbles in an aqueous medium. In
froth flotation, air is blown through the solution containing
flotation reagents. The particles with water repellant
surfaces stick to air bubbles as they rise and are brought to
the surface. A mineralized froth layer with mineral particles
attached to air bubbles is formed. Particles of other
minerals which are readily wetted by water do not stick to air
bubbles and remain in suspension.
In dispersed air flotation, gas bubbles are generated by
introducing the air by means of mechanical agitation with
impellers or by forcing air through porous media.
In dissolved air flotation, bubbles are produced as a result
of the release of air from a supersaturated solution under
relatively high pressure. There are two types of contact
between the gas bubbles and particles. The first type is
predominant in the flotation of flocculated materials and
involves the entrapment of rising gas bubbles in the floccu-
lated particles as they increase in size. The bond between
the bubble and particle is one of physical capture only. The
second type of contact is one of adhesion. Adhesion results
from the intermolecular attraction exerted at the interface
between the solid particle and gaseous bubble.
The vacuum flotation process consists of saturating the
wastewater with air either 1) directly in an aeration tank, or
2) by permitting air to enter on the suction of a wastewater
pump. A partial vacuum is applied, which causes the dissolved
air to come out of solution as minute bubbles. The bubbles
VII-95
-------
attach to solid particles and rise to the surface to form a
scum blanket, which is normally removed by a skimming
mechanism. Grit and other heavy solids that settle to the
bottom are generally raked to a central sludge pump for
removal. A typical vacuum flotation unit consists of a
covered cylindrical tank in which a partial vacuum is main-
tained. The tank is equipped with scum and sludge removal
mechanisms. The floating material is continuously swept to
the tank periphery, automatically discharged into a scum
trough, and removed from the unit by a pump also under partial
vacuum. Auxiliary equipment includes an aeration tank for
saturating the wastewater with air, a tank with a short
retention time for removal of large bubbles, vacuum pumps, and
sludge and scum pumps. i
I • • •• • •
Application i
Flotation applies to most situations requiring separation of
suspended materials. It is most advantageous for oils and for
suspended solids of low specific gravity or small particle
size.
Some advantages of the flotation process are the high levels
of solids separation achieved in many applications, the
relatively low energy requirements, and the air Elow
adjustment capability to meet the requirements of treating
different waste types. Limitations of flotation are that it
often requires addition of chemicals to enhance process
performance, and it generates large quantities of solid waste.
Performance
Performance of a flotation unit was measured at Plant 33692,
with results as follows:
Parameter Influent mg/1 Effluent mg/1
Oil & Grease 412 ; 108
TSS 416 210
TOG 3000 132
BOD 130 78
I
For oil removal by a variety of flotation units one literature
source (Chemical Engineering Deskbook - Environmental
Engineering, October 17, 1977, p. 52, McGraw-Hill) indicates
effluents of 10 to 15 mg/1 for influents of 61 to 100 mg/1,
effluents of 15 to 62 mg/1 for influents of 105 to 360 mg/1,
and effluent of 60 to 128 mg/1 for influents of 580 to 1930
mg/1. For suspended solids removal, another source (Process
Design Manual for Suspended Solids Removal, January, 1975,
U.S. Environmental Protection Agency) indicates an effluent of
70 mg/1 for an influent of 2000 mg/1 at one pilot plant, and
an effluent of 12 to 20 mg/1 for an influent of 94 to 152 mg/1
at another pilot plant.
Vli-96
-------
Bench scale experiments have shown foam flotation to be very
effective in removing precipitated copper, lead, arsenic,
zinc, and fluoride. The following table (Table 7-41) shows
the results. A sodium lauryl sulfate (NLS) surfactant and a
flocculant were used in each case, and pollutant concentrations
were between 10 and 500 mg/1.
TABLE 7-41
FOAM FLOTATION PERFORMANCE
Residual
Optimum Concentration,
Pollutant Reagent pH mg/1
Copper Fe(OH).,-NLS 7.0 0.1
Lead Fe(OH)^-NLS 6.5 0.1
Arsenate Fe(OH)^-NLS 4-5 0.1
Zinc A1(OH)^-NLS 8.0-8.5 0.2
Note: NLS is sodium lauryl sulfate
The primary variables for flotation design are pressure,
feed solids concentration, and retention period. The effluent
suspended solids decrease and the concentration of solids in
the float increases with increasing retention period. When
the flotation process is used primarily for clarification, a
retention period of 20 to 30 minutes is adequate for separation
and concentration.
Demonstration Status
Flotation is a fully developed process and is readily available
for the treatment of a wide variety of industrial waste
streams. It is used in 25 plants in the present data base
and these are identified in Table 7-42.
TABLE 7-42
METAL FINISHING PLANTS EMPLOYING FLOTATION
01063 20165 33120
11704 20247 33127
12076 20254 33180
12080 30150 33692
12091 31051 38031
14062 30153 41097
15058 30516 41151
20106 31067
20157 31068
VII-97
-------
Membrane Filtration '.
Membrane filtration is a technique for removing precipitated
heavy metals from a wastewater stream. It must therefore be
preceded by those treatment techniques which will properly
prepare the wastewater for solids removal.' Typically, a
membrane filtration unit is preceded by cyanide and chromium
pretreatment as well as pH adjustment for precipitation of the
metals. These steps are followed by addition of a proprietary
chemical reagent which causes the metal precipitate to be
non-gelatinous, easily dewatered, and highly stable. The
resulting mixture of pretreated wastewater is continuously
recirculated through a filter module and back into a
recirculation tank. The filter module contains tubular
membranes. While the reagent-metal precipitates mixture IMo^s
through the inside of the tubes, the water and any dissolved
salts permeate the membrane. The permeate, essentially free
of precipitate, is alkaline, non-corrosive, and may be safely
discharged to sewer or stream. When the recirculating slurry
reaches a concentration of 10 to 15 percent solids, it is
pumped out of the system as sludge. •
Application
Membrane filtration can be used in metal finishing in addition
to sedimentation to remove precipitated metals and phosphates.
Membrane filtration systems are being used in a number of
industrial applications, particularly in the metal finishing
industry and have also been used for heavy metals removal in
the paper industry. They have potential application in coil
coating, porcelain enameling, battery, and copper and copper
alloy plants.
A major advantage of the membrane filtration system is that
installation can utilise most of the conventional end-of-pipe
system that may already be in place. Also, the sludge is
highly stable in an alkaline state. Removal efficiencies are
excellent, even tfith sudden variation of pollutant input
rates. However, the effectiveness of the membrane filtration
system can be limited by clogging of the filters. Because a
change in the pH of the waste stream greatly intensifies the
clogging problem, the pH must be carefully monitored and
controlled. Clogging can force the shutdown of the system and
may interfere with production. i
The membrane filters must be regularly monitored, and cleaned
or replaced as necessary. Depending on the composition of the
waste stream and its flow rate, cleaning of the filters may be
required quite often. Flushing with hydrochloric acid for
6-24 hours will usually suffice. In addition, the routine
maintenance of pumps, valves, and other plumbing is required.
When the recirculating reagent-precipitate slurry reaches 10
to 15 percent solids, it is pumped out of the system. It can
VII-98
-------
then be disposed of directly or it can undergo a dewatering
process. The sludge's leaching characteristics are such that
the state of South Carolina has approved the sludge for
landfill, provided that an alkaline condition be maintained.
Tests carried out by the state indicate that even at the
slightly acidic pH of 6.5, leachate from a sludge containing
2600 mg/1 of copper and 250 mg/1 of zinc contained only 0.9
mg/1 of copper and 0.1 rag/1 of zinc.
Performance
The permeate is guaranteed by one manufacturer to contain less
than the effluent concentrations shown in the following table,
regardless of the influent concentrations. These claims have
been largely substantiated by the analysis of water samples at
various plants including those shown for comparison in Table
7-43.
TABLE 7-43
MEMBRANE FILTER PERFORMANCE (rag/1)
Parameter
Guarantee Plant #19066
Raw
Treated
Plant #31022
Raw
Treated
Aluminum
Chromium, hexavalent
Chromium, total
Copper
Iron
Lead
Cyanide
Nickel
Zinc
TSS
0.5
0.03
0.02
0.1
0.1
0.05
0.02
0.1
0.1
0.46
4.13
18.8
288
.652
<.005
9.56
2.09
632
0.01
0.018
0.043
0.3
0.01
<.005
.017
.046
0.1
5.25
98.4
8.00
21.1
0.288
<.005
194.
5.00
13.0
<.005
.057
.222
.263
0.01
<.005
.352
.051
8.0
Demonstration Status
There are approximately twenty membrane filtration systems
presently in use by the metal finishing and other industries.
Bench scale and pilot studies are being run in an attempt to
expand the list of pollutants for which this system is known
to be effective.
Membrane filtration is used in 7 plants in the present data
base: Plant ID's 02032, 04690, 15193, 19066, 31022, 34050, and
37042.
VII-99
-------
TREATMENT OF PRECIOUS METAL WASTES - SINGLE;OPTION
INTRODUCTION
This subsection describes the treatment for precious metal wastes
which includes Option 1 common metals treatmentplus precious
metals recovery. Silver removal performance data for Option 1
common metals treatment systems and describes the techniques that
are commonly used for the removal/recovery of precious metals
from waste streams.
Precious metal wastes are produced in the Metal Finishing
Category by electroplating of precious metals and subsequent
finishing operations performed on the precipus metals. Included
among the precious metals are gold, silver,'rhodium, palladium,
platinum, osmium, ruthenium, iridium, and indium. Precious
metal wastes can be treated using the same treatment alterna-
tives as those described for treatment of common metal wastes.
However, due to the intrinsic value of precious metals, every
effort should be made to recover them. The treatment alterna-
tives recommended for precious metal wastes are the recovery
techniques: evaporation, ion exchange and electrolytic recovery.
TREATMENT TECHNIQUES :
Option 1_ Common Metals System
" i
Included in the common metals Option 1 treatment system (precipi-
tation/sedimentation) data base are a total of 21 sampled
occurrences of silver. Performance data for properly operated
Option 1 common metals treatment systems from visited plants and
from plants submitting long term self-monitoring data are presented
in Table 7-44. The pertinent effluent limitation data for silver
are summarized as follows:
Mean Silver Effluent Concentration 0.096 mg/8,
Variability Factors (Daily/10-Day) 4.48/2.54* mg/4
Daily Maximum Effluent Concentration 0.43 mg/8,
Maximum Monthly Average Effluent 0.24 mg/8,
Concentration
* Median common metals variability factor was used because
of insufficient silver data.
The percent compliance for the silver effluent concentrations are
100 percent for EPA sampled. 70.6 percent for the self-monitoring
data daily maximum and 100 percent for the self-monitoring data
10-day averages. The lower percent compliance for the
self-monitoring daily maximum can be attributed to Plant 11125
which does not segregate precious metals wastes for recovery
prior to precipitation/clarification.
Evaporation
Evaporation is used to recover precious metals by boiling off
the water portion of a precious metal solution. This process
is described under the "Treatment of Common:Metal Wastes"
heading. Solutions such as silver cyanide plating baths are
now being recovered through the use of evaporation, the silver
VII-100
-------
TABLE 7-44
METAL FINISHING CATEGORY
PERFORMANCE DATA FOR SILVER
VISITED OPTION 1 PMNTS
Data Point
1.
2.
3.
4.
5.
Raw Waste
Concentration
(mg/t)
o.nso
0.1780
0.2100
0.2700
0.2900
Effluent
Concentration
(rM/St)
0.1670
0.1190
0.0610
0.0640
0.0690
Plant IP
6087-1-1
6087-1-3
21003-15-2
21003-15-0
21003-15-1
Mean
Concentration
0.2252 (n=5)
0.0960 (n=5)
Effluent Silver Self-Monitoring Performance Data
for Plants with Option 1 Systems
Plant ID
6087
11125
No. of
Points
12
5
Concentration (mg/£)
0.04
1.66
Overall
17
0.52
VII-101
-------
cyanide portion either being returned to the process tank or
held aside for subsequent sale. Figure 7-22 displays the
system which was observed at Plant ID 06090. Plant personnel
reported that the recovery of silver solutions paid back the
capital cost of the evaporation equipment after six months.
Ion Exchange
Ion exchange, which was described in detail under the "Treatment
of Common Metal Wastes" heading, is commonly used in the
recovery of precious metals, particularly gold. This recovery
process can be used in an on-line or end-of-pipe capacity.
Analyses of samples taken before and after ion exchange at
photoprocessing plants (from Guidance Document for the Control
of Water Pollution in the: Photographic Processing Industry.
EPA 440/1-81/082-9 April 1981) yielded the data shown in Table
7-45:
TABLE 7-45
ION EXCHANGE PERFORMANCE
1
Silver Concentration (mg/1)
Plant Influent Effluent
06208 2.0 ! 0.14
09061 (Unit 1) 0.74 0.04
09061 (Unit 2) 0.60 0.10
i .
Many plants have ion exchange units hooked up to rinses immedi-
ately following precious metal plating operations to recover
the metal and return the rinse water to the rinse tank. If a
company does precious metal work on a large scale, it may
segregate its precious metal wastes and run them through a
series of ion exchangers prior to sending the water to waste
treatment. In any case, the resins from the ion exchange
units are saved and the precious metal recovered, normally by
burning off the resin.
Electrolytic Recovery
Although electrolytic recovery was covered under the "Treatment
of Common Metal Wastes" heading, it is particularly applicable
to the recovery of precious metals. This is because the more
valuable precious metals offer a faster payback on the equipment
and energy costs. As explained earlier, equipment normally
consists of a dragout rinse located after the precious metal
plating step and an off line electrolytic recovery tank with
pumps and piping connecting the two. The dragout rinse solu-
tion is recirculated between the tanks while the precious
metal is plated out in the electrolytic recovery tank. An
electrolytic recovery system at a photoprocessing plant (Plant
ID 4550; Guidance Document for the Control of Water Pollution in
the: Photographic Processing Industry. EPA 440/1-81/082-9
April 1981) was able to reduce silver concentrations from 476
mg/1 to 21 mg/1.
VII-102
-------
Parts Flow
H
H
O
w
Surface
Preparation
Cone
~
:en
Silver
Cyanide
Plating
trate J
i
Submerged
Tube
Evaporator
-»*-
*
(
2 Stage
Countercurrent
Rinse
1
i
1
1
i i
I
- J
-ondensate
FIGURE 7-22
OBSERVED EVAPORATION SYSTEM AT PLANT ID 06090
-------
TABLE 7-46
COMMON CCMPLEXING AGENTS
Anononia
ATtmonium Chloride
Ammonium Hydroxide
Ammonium Bifluoride
Acetylaeetone
Citric Acid
Chromotropic Acid (DNS)
Cyanide*
DTPA
Dipyridyl
Disulfopyrocatechol (PDS)
Dimethylglyoxime
Disalicylaldehyde 1,2-prqpylenedi imine
Dimereaptopropanol (BAL)
Dithizone
Diethyl Dithiophosphoric Acid
Ethylenediaminetetraacetic Acid (EDTA)
Ethylenebis (hydroxyphenylglycine) (EHPG)
Ethylened iamine
Ethylenediaminetetra(methylenephosphoric
Acid) (EOTPO)
Glyceric Acid
Glycolic Acid
Gluconic £cid
Hydroxyethylethylenediaminetriacetic Ac id
(HEDTA)
Hydroxyethylidenediphosphonic Acid (HEDP)
HEDEft
lactic Acid
Malic Acid
Monosodiura Phosphate
Nitrilotriacetic Acid (NTA)
N-Dihydroxyethylglyc ine
Nitrilotrimethylenephosphonic Acid (ISfTPO,
O-phenanthroline
Qxine, 8-Hydroxyquinoline (Q)
Qxinesulphonic Acid
Ehthalocyanine
Ebtassium Ethyl Xanthate
Phosphoric Acid
Balyethyleneimine (PEI)
RxLyroethacryloylacetone
Rjly (p-vinylbenzyliminodiacetic Acid)
Itochelle Salts
Sodium GLuconate
Sodium Pyrophosphate
Succinic Acid
Sodium Iripolyphosphate
Sulphosalicylic Acid (SSA)
Salicylaldehyde
Salicylaldoxime
Sodium Hydroxyacetate
Sodium Citrate
Sodium Fluoride
Sodium Malate
Sodium Amino Acetate
l^rtaric Acid
Trisodium Phosphate (TSP)
N-fiEydroxyethylethylenediamine
ATMP)
Trifluoroacetylacetone
Thenoyltrif1uoroacetone
Triethylenetetramine
Triaminotriethylamine
Triethanolamine (TEA)
Tetraphenylporphin
Tbluene Dithiol
Thioglycolic Acid
Ihiourea
(TTA)
* Treatment of cyanide vestes are specifically discussed within Section VII.
VII-105
-------
TABLE 7-46
COMMON CCMPLEXING AGENTS
Anononia
ATtmonium Chloride
Ammonium Hydroxide
Ammonium Bifluoride
Acetylaeetone
Citric Acid
Chromotropic Acid (DNS)
Cyanide*
DTPA
Dipyridyl
Disulfopyrocatechol (PDS)
Dimethylglyoxime
Disalicylaldehyde 1,2-prqpylenedi imine
Dimereaptopropanol (BAL)
Dithizone
Diethyl Dithiophosphoric Acid
Ethylenediaminetetraacetic Acid (EDTA)
Ethylenebis (hydroxyphenylglycine) (EHPG)
Ethylened iamine
Ethylenediaminetetra(methylenephosphoric
Acid) (EOTPO)
Glyceric Acid
Glycolic Acid
Gluconic £cid
Hydroxyethylethylenediaminetriacetic Ac id
(HEDTA)
Hydroxyethylidenediphosphonic Acid (HEDP)
HEDEft
lactic Acid
Malic Acid
Monosodiura Phosphate
Nitrilotriacetic Acid (NTA)
N-Dihydroxyethylglyc ine
Nitrilotrimethylenephosphonic Acid (ISfTPO,
O-phenanthroline
Qxine, 8-Hydroxyquinoline (Q)
Qxinesulphonic Acid
Ehthalocyanine
Ebtassium Ethyl Xanthate
Phosphoric Acid
Balyethyleneimine (PEI)
RxLyroethacryloylacetone
Rjly (p-vinylbenzyliminodiacetic Acid)
Itochelle Salts
Sodium GLuconate
Sodium Pyrophosphate
Succinic Acid
Sodium Iripolyphosphate
Sulphosalicylic Acid (SSA)
Salicylaldehyde
Salicylaldoxime
Sodium Hydroxyacetate
Sodium Citrate
Sodium Fluoride
Sodium Malate
Sodium Amino Acetate
l^rtaric Acid
Trisodium Phosphate (TSP)
N-fiEydroxyethylethylenediamine
ATMP)
Trifluoroacetylacetone
Thenoyltrif1uoroacetone
Triethylenetetramine
Triaminotriethylamine
Triethanolamine (TEA)
Tetraphenylporphin
Tbluene Dithiol
Thioglycolic Acid
Ihiourea
(TTA)
* Treatment of cyanide vestes are specifically discussed within Section VII.
VII-105
-------
TABLE 7-47
COMPLEXING AGENTS USED IN THE VISITED PLANT DATA BASE
Ammonia Lactic Acid
Ammonium Bifluoride Malic Acid
Ammonium Chloride Monosodium Phosphate
Ammonium Hydroxide NTA
Citric Acid Phosphoric Acid
DTPA Rochelle Salts
EDTA Sodium Gluconate
Gluconic Acid Sodium Pyrophosphate
Glyceric Acid Succinic Acid
Glycolic Acid Tartaric Acid
HEDDA Trisodium Phosphate
HEDTA Uspecified Chelating Agents
VII-106
-------
wastes for separate treatment. This plant has significantly
lower levels of chromium, copper, and total cyanide than plant
20083 which does not segregate and separately treat their
complexed metals waste. Segregation of complexes metals
wastestreams appears to be necessary to achieve compliance.
Table 7-48 and 7-49 also summarize the percentage of the metal
finishing visited plant data base (that use complexing agents)
that are in compliance within the daily maximum limitation
concentration for the sampled plants that employ either Option 1
or Option 2 common metals waste treatment.
VTI-107
-------
RWWS WITH 0MWUBH3D
TABLE 7-48
COHCfWmATIONS (mg/1) FOR SAHPIJa) Wl'A FHCH
MASKS EMPUJnNG PK!OPITATrON/aARIF.IOmOM
PLANT ID
02032
02033
04069
04071
04077
05020
Cc
Cu
Hi
Fc
H
o
00
05021
06036
06074
06091
09025
2.640
3,140
0.164
0.024
0.025
0.007
0.007
0.005
0.333
0.143
0.714
0.180
0.770
0.360
0.068
0.050
3.07
3.07
3.30
0.776
0.300
0.150
0.150
1.620
0.860
0.780
5-680
4.170
0.206
1.470
0.165
12.70
4.23
5.87
5.060
0..400.
O.U6
7.850
2.780
2.100
0.08 0.049
2.30 0.034
2.70 0.075
1.840
1.300
0.122
0.120
0.140
0.041
0.0 1.700
0.200 1.460
0.160 2.000
24.50
21.00
0.400
0.300
0.294
0.150
0.160
0.065
0.807
0.013
o.oon
2.440
1.110
2.440
0.006
4.154
0.304
0.600
0.571
1.790
1.930
1.320
0.040
0.081
45.00
37.90
0,0012 0.045
0.0012 0.007-
0.0012 0.005
0.0012 0.055
0.0012 0.020
0.0012 0.020
0.215
3.41
1.24
1.25
3.400
0.923
5.170
,450
,650
8.150
0.390
0.190
•ras
40
100
98
650
5
4
30
2
2
02
98
48
50
162
58
234
5
21
75
10
44
18
JO
44
20
21
6
17
46
21
2fi
175
20
5L5
12
0.04
0.04
0,4
0.2
0.01
0,50
0.03
0.53B
0.44U
0.0
0,0
0.0
6.3
0.26
0.005
0.003
0.005
0.005
0.005
0.005
0.131
0.01)')
0.005
0.119
0.000
0.005
O.OOfl
0.005
0.024
0.021
0.012
0.0
0.060
0.0
0.005
o.oor>
-------
TABLE 7-48 (Continued)
POU.UTANT CONCENTRATIONS (mg/j.) TOR SAMPLED i.wm FROM
PLANTS WTO! CCWLEXFD METAL WASTES EMPLOYING rRBCIPrrATtON/OAI?IFICAlTCM
V
H
O
PLANT ID Cd
21003 0.027
0.024
0.017
27044
30050
31032
35061 0.050
36623
TOTAL rwt'A
roiNrs 4
DATA POINTS
IN CCMPLI-
ANCB 4
% POTNl'S IN
COMPLIANCE 100.0
TOfAL FWl'A
POINTS WITH
T,';s AND CN
LIMITATIONS* 4
DATA TO IMS
IN COMPU-
ANCi'1. 4
Cr
0.035
0.035
0.035
0.024
0.200
0.029
0.0
0.0
54
37
68.5
35
27
Co
0.160
0.140
0.130
0.157
4.000
1.810
39.61
0.400
0.290
0.200
1.100
0.220
0.180
0. 210
75
62
82.7
52
47
Fb Ni Acj ?,n Fe
0.2.JO 0.064 0.070 0.610
0.150 0.069 0.050 0.610
O.J70 0.061 0.040 0.390
0.726
3.280
0.744
0.022 0.312 0.098
0.0 O.J60
0.0 0.120
0.0 0.460
0.700
0.0 1.200 0.0 0.039
0.0 1.030 0.0 0.028
0.0 0.700 0.014 0.025
14 80 14 24 27
11 66 14 18 25
78.6 82.5 100.0 75.0 92.6
10 54 13 21 24
9 50 13 17 23
TSS
0.0
5.0
12.0
7.0
96.7
57.0
0.1
11.8
5.0
26.0
2.9
2.4
0.7
— T
0.0
0.0
0.0
0. J20
2.790
2.050
0.006
0.425
0.450
0.790
0.090
0.0)0
0.020
0.033
I',1; IN
COWMANCR 100.0
77.1
90.4
90.0 92.6
100.0
80.9
95.8
* Data points associated with TSS > 61.0 nrj/1 or CH, >_ 1.30 rag/1 have been deleted.
-------
TABI,E 7-18 (Continued)
rofiWAOT OCNCEOTRATICNS (mj/l) FW SWIPfJ^O IJVFA PIOI
wrm coMPtExro rs^im, wares wumrn
rc.wr ID
noes
12061
12065
15608
20064
20073
Od
Cr
H
M
O
20083
1.273
0.455
0.030
0,029
20085
0.250
0.500
0.720
0.760
0.300
0.200
5.000
1.470
1.890
3. 690
3. 190
2.050
40.50
4.810
13.80
3.150
4.050
15.80
18.30
2.55
18.70
9.J10
2.070
5.040
80.00
2.040
128.0
3.360
2.840
1.950
6.380
1.580
2.980
2.100
0.110
0.100
0.068
0.910
0.728
3.670
0.812
0.875
2.440
1.260
1..370
2.750
0. 375
0. 210
0.212
0.163
2.440
2. 170
1.000
2.100
1.920
6. 170
1.440
9.220
1.960
16. 00
0.206
0..1R8
0.132
Jb
0.017
0.011
0.0
0.0
JSL
1SS 04
0.017
0.023
9.230
9.230
11.20
6.46
2.386
3.216
2.250
0.448
0.478
1.300
1.120
1.120
G.I 30
0.907
0.767
0.808
0.462
4.750
5.510
0.2 JO
5.990
3.500
1.030
2.600
30.70
0.150
38.50
1.330
1.330
0.667
26.00 0.290
26.00 1.000
1.040 2.210
1.140 2.530
0.790 1.550
0.500 1.240
5.220 1.240
5.680 1.5BO
1.380 0.820
15
8
0
5
23
23
2f».4
23.2
15.6
23.5
10.3
108
26.0
43.0
11.0
14.0
44.0
3«.0
33.0
145
34.0
27.0
9.0
6.0
97
110
9.0
130
51.0
3.0
24.0
490
2.0
710
29.0
32.0
21.0
0.120
0.005
0.005
0.006
1.858
0.327
0.0
0.014
0.090
0.005
0.005
0.038
0.024
0.060
0.030
0.020
0.370
0.090
0.540
0.030
0.005
0.005
0.005
0.005
0.005
0. 170
135.0
0.0
1.5
1J4
53
0.0
68
o. no
0.007
0.000
0.013
-------
TABLE 7-49
POLLUTANT CONCENTRATIONS (mg/1) FOR SAMPLED CftTA FROM
PLANTS Ifini COMPLEXED flETAL WASTES EMPLOYING PllTCIPITATIOtl/CLARIFTGWJ.ON/P.rLTJWl'ION
PLANT 10 CM £r _Cu Jfo Mi _Ag |ii F
005
I'JO
040
090
046
005
(HO
3
60.0
9
100.0
5
100.0
7
70.0
3
100.0
3
100.0
TOTAL
POIMI'S WITH
TSS AMD CN
LIMITATIONS* 05738337
DATA POIMTS
IN COMPLI-
ANCE NA 37353 37
% POINTS IN
COMPLIANCE NA 60.0 100.0 100.0 62.5 100.0 100.0 100.0
* Data points associated with TSS >^ 42.9 mg/1 or CN,_ >^ 1,30 mg/1 have been deleted.
-------
A comparison (reference Tables 7-48 and 7-28) of the percent
of plants that have complexed metals and;meet Option 1
compliance compared to the percent of plants that do not
have complexed metals and meet Option 1 compliance limitations
reveals that the complexed wastes are frequently more difficult
to treat. A similar comparison (reference Table 7-49 and 7-33
of the Option 2 compliance results does not necessarily
reveal the same conclusion. However, the size of the Option
2 complexed metal data base is much smaller than its Option
1 counterpart, which may influence the results of the comparison.
Based upon the Option 1 comparison results, segregated
treatment of the complexed metal wastes is recommended.
TREATMENT TECHNIQUES
i .. ...
High pH Precipitation/Sedimentation j
The wastewater treatment alternative of hydroxide precipitation
was described in great detail under the heading "Treatment
of Common Metal Wastes". High pH precipitation is a type of
chemical precipitation which is particularly applicable to
complexed metal wastes. The process involves adding chemicals
to the waste solution which bring about a drastic increase
in pH, thereby prompting a shift in the complex disassociation
equilibrium to produce uncomplexed metal ions which then can
be precipitated by available hydroxide ions.
The treatment of solutions of complexed copper with calcium
hydroxide, calcium oxide (lime), calcium chloride, or calcium
sulfate at a pH of 11.6 - 12.5 will effectively remove
copper from the solution as a copper hydroxide. Flocculation
of the copper hydroxide with an anionic polyelectrolyte
accelerates the settling of sludge. This process works well
with both concentrated baths and dilute rinse baths.
The process equipment required for a high pH system includes
holding and treatment tanks if the operation is conducted on
a batch basis. Also needed are pumps to transfer the wastewater
and a settling tank to concentrate the precipitate.
Although results of lab tests have shown that the process is
applicable to removing copper from complexed copper solutions
with calcium ions at a high pH, the effectiveness of treatment
is determined by the structure of the complexing agent in
the solution. The presence of carboxyl groups within the
complexing agent (ligand) increases copper removal in this
procedure. Complexing agents containing no carboxyl group
and only hydroxyl groups show no copper removal. Electroless
nickel solutions were also prepared under laboratory conditions
and the results show the calcium treatment at a high pH to
be effective. The high pH precipitation process is presently
in the laboratory stage of development and has been useful
in the precipitation of the metals in certain copper and
nickel complexes.
VII-112 I
i . . •• . ...;, ii:.iv j,
-------
Chemical Reduction - Precipitation/Sedimentation
This process involves adding chemicals to lower the pH of the
waste stream (to breakup the various metal complexes) followed by
the addition of a reducing agent to reduce the metals to an oxida-
tion state which permits precipitation of the metals. Following
reduction of the metals, additional chemicals are used to
increase the pH of the waste solution, forming metallic
precipitates which are allowed to settle out of solution.
Electroless copper wastes and solder brightener wastes generated
by printed circuit board manufacturers are treated in the following
manner: initially the pH of the waste stream is lowered to
approximately 4.0 using a dilute sulfuric acid solution in
order to break the various metallic complexes. Sodium hydrosul-
fite is then added to reduce the metals to their lowest oxidation
state. Following reduction, lime is added to raise the pH
of the waste solution to approximately 9.0 and precipitate
the metals out of solution. Sedimentation is then employed
to remove the precipitated metals from the waste stream.
Chemical reduction of complexed metal wastes followed by chemical
precipitation and sedimentation is employed at two metal finishing
plants. These are plants 17061 and 19063. Each of these plants
employ the chemical reduction precipitation/sedimentation
technique for the treatment of copper, tin and lead.
Membrane Filtration
Membrane filtration is a treatment method whose primary use is
as an alternative to sedimentation for solids removal. A
description of this treatment process, its application and
performance, advantages and limitations, operational factors
and demonstration status are detailed in the "Treatment ©f
Common Metal Wastes" segment. This process has also proven to
be effective for treatment of complexed metal wastes.
Tests carried out by a printed circuit board manufacturer show
that this system is also effective in the presence of strong
chelating agents such as EDTA, but continuous addition of the
chemical reagent is required. Also, laboratory bench scale
and pilot studies have been conducted on the following waste
streams:
A. Tin and lead waste containing thiourea-copper complexes
were tested on a pilot unit for over 200 hours with
no flux deterioration with tin, lead, and copper all
less than 0.1 mg/1 in the product water.
B. Cupro-"ammonia complex rinse from alkaline etching
was treated in the pilot unit for 400 hours with no flux
deterioration and with copper in the effluent less
than 0.1 mg/1.
VII-113
-------
Based on this laboratory pilot study, a 1 gpm pilot
test was run in a printed circuit board manufacturing
facility. Over a 200 hour period, the flux was always
in excess of 1.1 gpm. The effluent copper was consis-
tently below 0.5 mg/1 and usually at 0.1 mg/1, even
with a varying concentration of ;copper in the feed.
C. Preliminary runs of electroless copper rinse waters have
yielded product water in the range of 0.1 mg/1 copper.
Ferrous Sulfate (FeSO.) - Precipitation/Sedimentation
Sulfide preciptation is capable of achieving low metal solu-
bilities is spite of the presence of certain complexing and chela-
ting agents. The use of complexing agents such as phosphates,
tartrates/ EDTA and ammonia (which are common in cleaning and
plating formulations) can have an adverse effect upon metal re-
moval efficiencies when hydroxide precipitation is used. Modifi-
cation of the hydroxide precipitation process can improve system
performance in the removal of complexed heavy metals from the
waste stream.
Improved performance is attained by the dissolution of a posi-
tively charged ion such as Fe into the waste stream followed
by precipitation of the metals. The ferrous sulfate (FeSO4)
technique uses this principle.
Ion Exchange
Ion exchange is applicable to the treatment of certain metal
complexes. This waste treatment technology has been discussed
under Treatment of Common Metals Wastes within Section VII of the
document.
VII-114
-------
TREATMENT OF HEXAVALENT CHROMIUM WASTES - SINGLE OPTION
INTRODUCTION
This subsection describes the treatment system option for
hexavalent chromium bearing wastewater, presents effluent per-
formance, and discusses alternative treatment techniques.
Hexavalent chromium bearing wastewaters are produced in the
Metal Finishing Category in several ways:
- Chromium electroplating
- Chromate conversion coatings
- Etching with chromic acid
- Metal finishing operations carried out on chromium
as a basis material
The selected treatment option involves the reduction of hexava-
lent chromium to trivalent chromium. The reduced chromium can
then be removed with a conventional precipitation-solids
removal system.
RECOMMENDED HEXAVALENT CHROMIUM TREATMENT TECHNIQUE
Chemical Chromium Reduction
Reduction is a chemical reaction in which electrons are trans-
ferred to the chemical being reduced from the chemical initiat-
ing the transfer (the reducing agent). Sulfur dioxide, sodium
bisulfite, sodium metabisulf ite, and ferrous sulfate form
strong reducing agents in aqueous solution and are, therefore,
useful in industrial waste treatment facilities for the reduc-
tion of hexavalent chromium to the trivalent form. The reduc-
tion enables the trivalent chromium to be separated from
solution in conjunction with other metallic salts by alkaline
precipitation. Gaseous sulfur dioxide is a widely used reducing
agent and provides a good example of the chemical reduction
process. Reduction using other reagents is chemically similar.
The reactions involved may be illustrated as follows:
3 S02 + 3 H2O = 3 H2S03
The above reaction is favored by low pH. A pH of 2 to 3 is
normal for situations requiring complete reduction. At pH
levels above 5, the reduction rate is slow. Oxidizing agents
such as dissolved oxygen and ferric iron interfere with the
reduction process by consuming the reducing agent.
A typical treatment consists of two hours retention in an
equalization tank followed by 45 minutes retention in each of
two reaction tanks connected in series. Each reaction tank
has an electronic recorder-controller device to control process
VII-115
-------
conditions with respect to pH and oxidation reduction potential
(ORP). Gaseous sulfur dioxide is metered to the reaction
tanks to maintain the ORP within the range of 250 to 300
millivolts. Sulfuric acid is added to maintain a pH level of
from 1.8 to 2.0. Each of the reaction tanks is equipped with
a propeller agitator designed to provide approximately one
turnover per minute. Following reduction of the hexavalent
chromium, the waste is combined with other waste streams for
final adjustment to an appropriate alkaline pH to remove
chromium and other metals by precipitation and sedimentation.
Figure 7-23 shows a continuous chromium reduction system.
!
Application
Chromium reduction is used in metal finishing for treating
chromium bearing waste streams, including chromium plating
baths, chromating baths and rinses. The main application of
chemical reduction to the treatment of wastewater is in the
reduction of hexavalent chromium to trivalent chromium. Rinse
waters and cooling tower blowdown are two major sources of
chromium in waste streams. A study of an operational waste
treatment facility chemically reducing hexavalent chromium has
shown that a 99.7% reduction efficiency is easily achieved.
Final concentrations of 0.05 mg/1 are readaly attained, and
concentrations down to 0.01 mg/1 are documented in the litera-
ture.
The major advantage of chemical reduction of hexavalent chromium
is that it is a fully proven technology based on years of
experience. Operation at ambient conditions results in minimal
energy consumption, and the process, especially when using
sulfur dioxide, is well suited to automatic control. Further-
more, the equipment is readily obtainable from many suppliers,
and operation is straightforward.
One limitation of chemical reduction of hexavalent chromium is
that for high concentrations of chromium, the cost of treatment
chemicals may be correspondingly high. When this situation
occurs, other treatment techniques are likely to be more
economical. Chemical interference by oxidizing agents is
possible in the treatment of mixed wastes, and the treatment
itself may introduce pollutants if not properly controlled.
Storage and handling of sulfur dioxide is somewhat hazardous.
Performance
The hexavalent chromium performance data base for visited
plants is presented in Figure 7-24. These data are for metal
finishing plants that use chemical reduction of hexavalent
chromium.
Self-monitor ing performance data for plants treating hexavalent
chromium by chemical reduction are shown in Table 7-47. This
table shows the number of data points for each plant, the
VII-116
-------
SULFURIC SULFUR
ACID DIOXIDE
PH CONTROLLER
RAW WASTE
(HEXAVALENT CHROMIUM)
"1
I
oo
-i
ORP CONTROLLER
(TRIVALENT CHROMIUM)
REACTION TANK
FIGURE 7-23
HEXAVALENT CHROMIUM REDUCTION WITH SULFUR DIOXIDE
VTI-117
-------
H
00
D-
E
C
0)
3
r-l
U-i
U-l
ta
e
D
o
X
u
.u
C
a)
.175-
.ISO-
.125-
.100-
.075-
.050'
.oas-
Mean Concentration
.1
1 10
Hexavalent Chromium Raw Waste (mq/1)
100
Daily Maximm Concentration - 0,180 mg/1
FIGURE 7-24
EFFLl-ENT HEXAVALENT CHROMIL^ CONCENTRATIONS vs RAW WASTE CONCENTRATIONS
-------
corresponding mean concentrations, and the calculated variability
factors. Also shown are the total number of points, the overall
mean concentration, and the median variability factors.
TABLE 7-50
EFFLUENT HEXAVALENT CHROMIUM SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 1 SYSTEMS
Plant ID
Number
Of Points
Mean Effluent
Concentration
(mg/U
Variability
Daily
Factor
10-Dav
1067
3043
6051
11008
17030
19063
20080
20116
30090
31021
47025
OVERALL
230
94
13
185
282
237
269
243
260
35
339
0.048
0.009
0.020
0.034
0.025
0.011
0.014
0.017
0.010
0.096
0.015
3.01
8.46
6.19
2.37
2.52
,88
,06
,04
2
5
5
5.07
2.61
28.08
1.95
6.37
6.59
2.12
1.99
.96
.50
3.05
3.25
1,
3
2187(Total) 6.022(Mean) 5.04(Median) 3.05(Median)
The visited plant mean performance and the self-monitoring data
variability factors were used to establish the following daily
and maximum monthly performance values for hexavalent chromium:
Mean effluent hexavalent chromium
Daily variability factor
10-Day variability factor
Daily maximum effluent concentration
Maximum monthly average effluent
concentration
0.032 mg/9.
5.04 mg/9,
3.05 mg/9.
0.16 mg/9.
0.10 mg/9.
The percentages of hexavalent chromium effluent concentrations
that are less than the daily maximum concentration limitation are
100.0 percent for the EPA sampled data base used to develop the
limits.
VII-119
-------
Demonstration Status
The reduction of chromium waste by sulfur dioxide or sodium
bisulfite is a classic process and is used by numerous plants
employing chromium compounds in metal finishing and non-contact
cooling operations.
Chemical chromium reduction is used in 343 plants in the
present data base and these are identified in Table 7-51,
ALTERNATIVE HEXAVALENT CHROMIUM TREATMENT TECHNIQUES
The following treatments are recovery techniques which can
also be applied to waste streams containing hexavalent chromium.
They include electrochemical chromium reduction, electrochemical
chromium regeneration, evaporation and ion exchange.
Electrochemical Chromium Reduction
This process has been developed to aid the 'removal of chromium
from metal finishing and cooling tower blowdown wastewaters.
It involves an electrochemical reaction in which consumable
iron electrodes in the presence of an electrical current
generate ferrous ions which react with chromate ions in solution.
The reaction produces chromic hydroxides and ferric hydroxides
that can be removed in a settling pond or clarifier without
the need for further chemical addition. The process has also
been shown effective in removing zinc and other heavy metals.
The metallic hydroxides formed are gelatinous and highly
adsorptive. They can therefore coprecipitate other species
which might be present in a wastewater solution.
In addition to the electrochemical unit, the only equipment
required is a pump and a clarifier or pond for settling. As
long as the pH of the entering waste stream is between 7.0 and
8.0, no pH adjustment is necessary.
Application
Although the process was developed for removal of chromium and
zinc from cooling tower discharge, electrochemical chromium
reduction can also be applied to the treatment of metal finishing
wastewaters such as chromating baths and rinses. Coil coating
and porcelain enameling plants are other potential applications.
According to manufacturers, the electrochemical reduction
process performs best on low concentration, high volume waste-
water streams. Conventional chemical reduction is probably
more economical in treating more concentrated effluents.
VII-120
-------
TABLE 7-51
METAL FINISHING PLANTS EMPLOYING CHEMICAL CHROMIUM REDUCTION
01007
01067
01068
02037
02038
03043
04033
04069
04100
04114
04146
04151
04175
04199
04214
04216
04219
04221
04222
04261
04276
04277
04281
20077
20078
20079
20080
20081
20082
20083
20084
20085
20086
20087
20094
20104
20109
20112
20115
20116
20120
20121
20123
20136
20143
20145
20149
20150
20152
04282
04284
04690
04719
05033
05035
05050
06002
06006
06035
06050
06051
06052
06053
06062
06072
06073
06074
06076
06077
06078
06079
06083
20157
20158
21060
20172
20241
21003
21051
21059
21062
21066
21074
21078
22028
22031
22735
23039
23048
23056
23059
23061
23066
23070
23076
23337
25001
25030
06084
06085
06086
06087
06088
06090
06091
06094
06096
06112
06113
06115
06117
06118
06124
06129
06148
06156
06358
06360
06381
06679
06371
25031
25033
25034
25037
27042
28081
28082
28094
28096
28109
30009
30011
30050
30054
33058
30064
30074
30087
30090
30096
30097
30101
30111
30121
30127
30148
06960
07001
08004
08008
08061
08072
08074
08081
09025
09040
09041
09046
09061
11008
11065
11096
11113
11121
11127
11129
11139
11140
11156
30153
30155
30157
30162
30507
30967
31020
31021
31022
31035
31037
31040
31054
31050
31069
31071
33024
33033
33043
33070
33071
33073
33074
33107
33112
33113
11165
11173
11174
11184
11477
11704
12005
12010
12014
12065
12068
12071
12074
12075
12078
12080
12081
12084
12087
12090
12100
12102
12105
33116
33126
33129
33133
33137
33150
33172
33183
33184
33195
33197
33199
33281
33293
33852
34037
34039
34041
34042
34050
35040
35061
36001
36036
36040
36041
13031
13033
13034
13039
13040
14060
14062
15010
15036
15042
15044
15047
15048
15057
15070
15193
15194
16032
16033
16035
16544
17030
17032
36082
36083
36090
36091
36102
36112
36113
36130
36149
36154
36155
36151
36161
36162
36166
36177
36179
36937
37063
38031
38035
38051
38052
38222
38223
40047
17033
17050
18050
18532
18538
19051
19063
19066
19067
19068
19084
19090
19091
19104
20001
20005
20010
20017
20064
20069
20070
20073
20076
40048
40061
40062
41092
41869
43003
44037
44040
44042
44044
44050
44062
44148
44150
45035
45041
45045
46031
47005
47025
47059
47068
47074
47412
62032
62052
VII-121
-------
An advantage of the electrochemical chromium reduction process
is that no pH adjustment chemicals are required with incoming
pH values between 7 and 8. Retention time is unimportant when
the pH is held within this range and the process is continuous
and automatic. However, it is not efficient for effluents
with high chromium concentrations/ and species which consume
hydroxide ions interfere with the precipitation of the ferric
and ferrous hydroxides.
The system normally requires about thirty,minutes of operator
time per day. Since the iron electrodes are consumable they
need to be replaced periodically. Sedimentation is part of
the process and there is consequently a demand for sludge
processing and removal. The precipitation of ferric and
chromic hydroxides generates waste sludge which must even-
tually be dewatered and properly disposed. No appreciable
amounts of sludge are allowed to settle in the actual electro-
chemical process tank.
Performance
The process is capable of removing hexavalent chromium from
wastewater to less than 0.05 mg/1 with input chromium concentra-
tions up to at least 20 mg/1. Performance for one plant is as
follows:
Pollutant Influent Effluent
Hexavalent Chromium 10 mg/1 0^05 mg/1
Zinc 3 0.1
i
Laboratory tests have also shown that the process is capable
of removing metals other than chromium to the following levels
(inlet concentrations not available):
Metal Concentration (mg/1)
Zinc 0.1
Nickel 2,1
Copper Oi2
Silver 0.5
Tin <5
Retention time is unimportant since the reaction is instantane-
ous at pH values between 7.0 and 8.0, but subsequent sedimenta-
tion is needed to remove the precipitate formed in the reaction.
VEI-122
-------
Demonstration Status
There are more than 50 electrochemical reduction systems in
operation in a variety of industries, mostly in organic and
inorganic chemicals plants. Five are presently in service at
plants in the metal finishing industry. The process has
potential for applications in the photographic industry since
it has been shown to successfully remove silver from waste-
waters. Electrochemical chromium reduction is used in 2
plants in the present data base: 34051 and 42030.
Electrochemical Chromium Regeneration
Chromic acid baths must be continually discarded and replen-
ished to prevent buildup of trivalent chromium. An electro-
chemical system employing a lead anode and nickel cathode has
been developed to recover chromium by converting the trivalent
form to the hexavalent form. In this process, trivalent chromium
is electro-oxidized to hexavalent chromium at the lead anode
while hydrogen is released at the nickel cathode. This process
is similar to the electrodialytic chromium oxidation process,
but no membrane is used to separate concentrate from dilute
solution. The reaction is carried out at 68°C, a cell voltage
of 4.5 volts, and an anode-to-cathode area ratio of 30:1. The
same process can also be used to recover chromium from chromic
oxide sludges precipitated by conventional chemical chromium
waste treatment. The sludges are dissolved in 200 g/1 chromic
acid and electro-oxidized under slightly different operating
conditions than those previously described.
Application
Electrochemical chromium regeneration can be used in metal
finishing to prolong the life of chromium plating and chromat-
ing baths. Chromic acid baths are used for electroplating,
anodizing, etching, chromating and sealing. The electro-oxida-
tion process has been commercially applied to regeneration of
a plastic etchant. In this particular installation, chromic
acid dragged out of the etching bath into the first stage of a
countercurrent rinse is concentrated by evaporation and returned
to the etching bath. This closed loop system tends to cause a
rapid buildup of trivalent chromium. However, when the etchant
is recirculated through an electrochemical regeneration unit,
the trivalent chromium is oxidized to the hexavalent form.
The process has also been applied to regeneration of a chromic
acid sealing bath in the coil coating industry.
Some advantages of the electrochemical chromium regeneration
process are its relatively low energy consumption, its opera-
tion at normal bath temperature, eliminating need for heating
or cooling, its ability for recovering and reusing valuable
process chemicals, and elimination of sludges generated by
conventional chromium treatment processes. Some limitations
of chromium electrooxidation are low current efficiencies for
VII-123
-------
baths with less than 5.0 g/1 trivalent chromium, need for
control of impurities which can interfere with the process,
and dependence on electrical energy for oxidation to take
place.
Performance
The current efficiency for this process is 80 percent at
concentrations above 5 g/1. If a trivalent chromium concen-
tration of less than 5 g/1 were treated, research has shown
that the current efficiency would drop.
Demonstration Status '
One automobile plant (Plant ID 12078) is using the system
experimentally to regenerate a chromic acid etching solution.
In addition, one coil coater (Plant ID 01054) is using it on a
full scale basis to regenerate a chromic acid sealing bath.
t
Evaporation !
Evaporation, which is explained in detail in the "Treatment of
Common Metal Wastes" has found applicability in the treatment
of chromium bearing wastes, especially the rinse waters after
chromium plating. The rinse waters following the finishing
operation (normally a countercurrent rinse of at least three
stages) are sent to an evaporator. Here the chromium bearing
solution is broken down into water and process solution (pre-
dominantly chromic acid). The water is returned to the last
(cleanest) stage of the countercurrent rinse and the process
solution may be returned to the process tank or put aside for
sale to a scavenger. Plant 33065 has a similar arrangement on
their chromium plating line. The data presented below represent
the raw waste stream going to evaporation and the concentrate
stream being returned to plating.
Input To
Parameter Evaporator (mg/1) Concentrate
Chromium, Total 5060 27,500
Chromium, Hex 4770 16,700
TSS <.l 400
pH 1.6 1.4
Ion Exchange
Ion exchange is another possible method for recovering and
regenerating chromic acid solution. As explained under the
VII-124
-------
"Treatment of Common Metal Wastes" segment, anions such as
chromates or dichromates can be removed from rinse waters with
an anion exchange resin. In order to regenerate the resin,
caustic is pumped through the anion exchanger, carrying out
sodium dichromate. The sodium dichromate stream is passed
through a cation exchanger, converting the sodium dichromate
to chromic acid. After some means of concentration such as
evaporation, the chromic acid can be returned to the process
bath.
VII-125
-------
TREATMENT OF CYANIDE WASTES - SINGLE OPTION
INTRODUCTION
This subsection describes the technique recommended for cyanide
treatment/ discusses the mean cyanide concentrations found,
identifies the recommended daily maximum and monthly maximum
average concentrations for cyanide and presents alternative
treatments for the destruction of cyanide.
The following paragraphs describe the chlorine oxidation
technique recommended for the treatment of cyanide bearing
wastes. '
RECOMMENDED TREATMENT TECHNIQUE
Oxidation By Chlorination
Cyanides are introduced as metal salts for plating and conver-
sion coating or are active components in plating and cleaning
baths. Cyanide is generally destroyed by oxidation.
Chlorine is used primarily as an oxidizing agent in industrial
waste treatment to destroy cyanide. Chlorine can be used in
the elemental or hypochlorite form. This classic procedure
can be illustrated by the following two step chemical reaction:
1. C12 + NaCN + 2NaOH = NaCNO + 2NaC;l + H2O
2. 3C12 + 6NaOH + 2NaCNO = 2NaHCO3 +: N2 + 6NaCl + 2H2O
The reaction presented as equation(2) for the oxidation of
cyanate is the final step in the oxidation of cyanide. A
complete system for the alkaline chlorinatibn of cyanide is
shown in Figure 7-25. ,
The cyanide waste flow is treated by the alkaline chlorination
process for oxidation of cyanides to carbon dioxide and nitrogen,
The equipment often consists of an equalization tank followed
by two reaction tanks, although the reaction can be carried
out in a single tank. Each tank has an electronic recorder-
controller to maintain required conditions with respect to pH
and oxidation-reduction potential (ORP). In the first reaction
tank, conditions are adjusted to oxidize cyanides to cyanates.
To effect the reaction, chlorine is metered to the reaction
tank as required to maintain the ORP in the range of 350 to
400 millivolts, and 50% aqueous caustic soda is added to
maintain a pH range of 9.5 to 10. In the second reaction
tank, conditions are maintained to oxidize cyanate to carbon
dioxide and nitrogen. The desirable ORP and pH for this
reaction are 600 millivolts and a pH of 8.0^. Each of the
reaction tanks is equipped with a propeller agitator designed
to provide approximately one turnover per minute. Treatment
by the batch process is accomplished by using two tanks, one
VII-126
-------
RAW WASTE
CAUSTIC
SODA
PH
CONTHOUL.KW
H
KJ
oo
CAUSTIC
SODA
00
CONTHOLLEH
,THEATEO
WASTE
REACTION TANK
CHLORINATOR
REACTION TANK
FIGURE 7-25
TREATMENT OF CYANIDE WASTE BY ALKALINE CHLORINATION
-------
for collection of waste over a specified time period, and one
tank for the treatment of an accumulated batch. If dumps of
concentrated wastes are frequent, another tank may be required
to equalize the flow to the treatment tank. When the holding
tank is full, the liquid is transferred to the reaction tank
for treatment. After treatment, the supernatant is discharged
and the sludges are collected for removal and ultimate disposal.
Application
The oxidation of cyanide waste by chlorine is a classic process
and is found in most plants using cyanide. This process is
capable of achieving efficiencies of 99 percent or greater and
effluent levels that are nondetectable. Chlorine has also
been used to oxidize phenols, but use of chlorine dioxide for
this purpose is much preferred because formation of toxic
chlorophenols is avoided.
Some advantages of chlorine oxidation for handling process
effluents are operation at ambient temperature, suitability
for automatic control, and low cost. Some disadvantages of
chlorine oxidation for treatment of process effluents are that
toxic, volatile intermediate reaction products must be con-
trolled by careful pH adjustment, chemical interference is
possible in the treatment of mixed wastes, and a potentially
hazardous situation exists when chlorine gas is stored and
handled. ;
Performance j
Performance for cyanide oxidation was determined by evaluating
the amenable cyanide effluent data from visited plants. Amenable
cyanide was evaluated because treatment for cyanide is almost ex-
clusively performed by alkaline chlorination. This form of
treatment focuses upon oxidizing the cyanide which is amenable
to chlorination.
Amenable cyanide data from visited plants are listed in Table 7-52,
The table has the following four columns:
i
1. ID Number - The identification number of the visited plant.
Duplicate numbers indicate different sampling days at the
same plant. ;
2. Effluent Concentration - The measured concentration of the
final effluent after treatment. At this point, cyanide
wastes are mixed with other wastewaters.
3. Dilution Factor - This number represents the amount of
dilution of the cyanide raw waste stream by other raw
waste streams and is determined by dividing the total
effluent stream flow by the cyanide stream flow.
4. Adjusted Cyanide Effluent Concentration - These concentra-
tions are calculated by multiplying the effluent cyanide
concentrations by the dilution factor applicable in each
individual case.
Vn-128
-------
The data contained in Table 7-52 were arranged in the following
manner:
1. For each plant data set (CN,.) the concentrations
were listed in decending oraer.
2. The plant data sets were listed in ascending order
using the first value in each plant data set as the
basis for ordering (the first value in each plant
data set represents the highest concentration).
Ordering the data in this fashion facilitates identification of
poorly operated treatment systems. As illustrated in the table.
a break occurs between plant 20080 and 04045. The highest con-
centration at plant 20080 is 0.416 mg/4 and at plant 04045 the
highest concentration is 2.2 rag/I. Since alkaline chlorination
is capable of reducing amenable cyanide concentrations to levels
approximating zero, plants listed after plant 20080 exhibit poor
control and excessive effluent concentrations. These plants have
been deleted from the data base used to determine performance for
cyanide oxidation.
Table 7-53 presents amenable cyanide data after deletions to
remove plants with poorly operated treatment systems. The entire
plant data set (both CN^ and CN-j-) was deleted if any cyanide
amenable concentration for that plant exceeded the breakpoint
between 0.416 mg/4 and 2.2 mg/4. Plants which were deleted
from both the amenable and total cyanide data bases are listed in
Table 7-54.
Total cyanide data (after deleting the plants listed in Table
7-54) are presented in Table 7-55. These data correspond to the
amenable cyanide data remaining in the data base from which
performance is determined. In Table 7-55 two data points. 105.0
mg/4 and 5.69 mg/8, were deleted from the calculation of the
mean effluent concentration for total cyanide. The 105.0 mg/8.
was deleted because it was a high outlier although the
corresponding cyanide amenable value did not indicate a high
level. The 5.69 mg/4 was deleted as a high outlier and because
there was no corresponding cyanide amenable value. Plant data
sets which wei:e deleted from the total cyanide data base are
listed in Table 7-56.
The edited data sets (presented in Tables 7-53 and 7-55) were
used to determine performance for cyanide oxidation. The adjusted
mean effluent concentrations from the edited data base are presented
below.
Adjusted Mean
Parameter Effluent Concentration (mg/&)
Cyanide, Total 0.18
Cyanide, Amenable 0.06
VII-129
-------
TABLE 7-52
AMENABLE CYANIDE DATA BASE
CN-EFFLUENT DILUTION ADJUSTED CN.
PLfiNT ID CX3NCENTRHTION (mg/1) FACTOR OTSOMTRATION (mg/1)
12065 0 10.0 0
21051 0 1.0 0
0 1.0 0
0 1.0 0
38051 0 19.9 0
06075 0.005 5.0 0,025
0.005 4.8 0.024
36623 0.005 5.1 0.025
0.005 4.9 0.024
0.005 4.3 0.021
19050 0.005 6.2 0.031
20079 0.005 7.9 0.039
0.005 6.2 0.031
0.005 6.1 0.030
0.005 5.6 0.028
0.005 5.0 0.025
0.005 4.8 0.024
05021 0.005 8.0 0.04
0.005 4.8 0.024
0.005 4.8 0.024
20078 0.01 6.6 0.066
0.005 7.4 0.037
0.005 7.0 0.035
0.005 6.9 0.034
0.005 5.7 0.029
0.005 5.6 0.028
15070 0.02 3.4 0.068
0.005 2.8 0.014
0.005 2.5 0.012
33073 0.027 5.5 0.147
0.008 5.1 0.041
09026 0.06 2.6 0.156
0.01 2.4 0.024
0.005 3.8 0.021
VII-130
-------
TABLE 7-52(CON"T)
AMENABLE CYANIDE DATA BASE
CN-EFFLUENT DILUTION ADJUSTED CN
PLANT ID CONCENTRATIOSI (mg/1) FACTOR CONCENTRATIQS1 (mg/1)
31021 0.05 3.2 0.16
0.05 3.2 0.16
0.05 3.0 0.150
33024 0.04 5.1 0.204
20080 0.104 4.0 0.416
0.005 5.8 0.029
0.005 4.5 0.023
0.005 4.5 0.023 ,
0.005 4.5 0.023
04045 2.2 1.0 2.2
1.0 1.0 1.1
0.25 1.0 0.25
06089 1.14 3.5 3.99
0.285 3.0 0.855
0.163 2.9 0.478
36041 0.4 10.4 4.16
0.1 11.5 1.15
0.1 10.1 1.01
06381 0.751 6.5 4.88
0.089 8.7 0.733
0.096 6.3 0.609
06085 1.08 5.0 5.4
0.56 4.8 2.69
0.06 5.4 0.323
20082 3.0 1.8 5.4
1.08 2.1 2.23
0.945 2.0 1.88
0.625 2.1 1.32
0.056 2.0 0.147
0.034 2.0 0.064
06084 1.97 3.6 7.19
VII-131
-------
TABLE 7-52(CQN'T)
CYANIDE DATA
HANT ID
20081
11103
02033
20077
06090
20086
06037
21066
CN-EFFLUENT DILUTION
CONCENTRATION (mg/1) FACTOR
0.49 15.6
0.348 16.3
0.075 17.6
0.017 17.7
0.005 15.9
0.005 14.4
3.37 3.0
2.91 2.4
4.2 2.6
3.0 5.9
2.1 7.8
0.78 9.7
0.1 6.5
0.005 9.7
0.005 7.1
5.27 4.3
5.25 4.5
0.36 4.5
0.005 4.5
11.6 6.4
0.408 6.4
0.122 6.4
11.75 7.4
6.57 10.2
8.83 4.7
ADJUSTED CN
(mg/1)
7.
5,
1.
.64
,68
,32
0.3
0.079
0.072
10.0
6.98
11.1
17.7
16.4
7.58
0.65
0.049
0.036
22.5
23.6
1.62
0.023
73.7
2.59
0.775
86.9
66.9
41.5
VH-132
-------
TABLE 7-53
DATA USED FOR AMENABLE CYANIDE PERFORMANCE
CNAEFFLUENT DILUTION ADJUSTED CM*
PLANT ID CONCENTRATION (mg/1) FACTOR CO^EMERATroN (mg/1)
12065 0 10.0 0
21051 0 1.0 0
0 1.0 0
0 1.0 0
38051 0 19.9 0
06075 0.005 5.0 0,025
0.005 4.8 0.024
36623 0.005 5.1 0.025
0.005 4.9 0.024
0.005 4.3 0.021
19050 0.005 6.2 0.031
20079 0.005 7.9 0.039
0.005 6.2 0.031
0.005 6.1 0.030
0.005 5.6 0.028
0.005 5.0 0.025
0.005 4.8 0.024
05021 0.005 8.0 0.04
0.005 4.8 0.024
0.005 4.8 0.024
20078 0.01 6.6 0.066
0.005 7.4 0.037
0.005 7.0 0.035
0.005 6.9 0.034
0.005 5.7 0.029
0.005 5.6 0.028
15070 0.02 3.4 0.068
0.005 2.8 0.014
0.005 2.5 0.012
33073 0.027 5.5 0.147
0.008 5.1 0.041
09026 0.06 2.6 0.156
0.01 2.4 0.024
0.005 3.8 0.021
VII-133
-------
TABLE 7-53(CON'T)
DATA. USED TOR AMENABLE CMNIDE PERFORMANCE
CN.EFFLUEWT DILUTION
PLANT ID CONCENTRATION (ntg/1) FACTOR
31021 0.05 3.2
0.05 3.2
0.05 3.0
33024 0.04 5.1
20080 0.104 4.0
0,005 5.8
0.005 4.5
0.005 4.5
0.005 4.5
ADJUSTED CKL
CONCENTRATION (mg/1)
0.16
0.16
0.150
0.204
0.416
0.029
0.023
0.023
0.023
VII-134
-------
TABLE 7-54
PLANTS FROM CYANIDE E&TA BASE
DUE TO POOR PERFORMANCE
04045
06089
36041
06381
06085
20082
06084
20081
11103
02033
20077
06090
20086
06037
21066
VII-135
-------
TABLE 7-55
E&TA USED FDR TOTAL CYANIDE PERFORMANCE
PLANT ID
12065
21051
38051
06075
36623
19050
20079
05021
20078
20080
CNT EFFLUENT DILUTION
CCACENTRATION (mg/1) FACTOR
0.014 10
0 1.0
0 1.0
0 1.0
0 19.9
0.005 4.8
0.005 5.0
0.014 4.8
0.01 4.3
0.02 4.9
0.033 5.1
0.005 6.2
0.005 4.8
0.005 6.1
0.005 6.2
0.005 7.9
0.02 5.6
21.0 5.0
0.005 4.8
0.005 4.8
0.007 8.0
0.005 5.6
0.005 5.7
0.005 7.0
0.005 7.4
0.01 6.9
0.04 6.6
0.005 4.5
0.005 4.5
0.005 4.5
0.005 5.8
0.1 4.1
0.111 4.0
1.23 4.6
ADJUSTED CN
CONCENTRATION (mg/1)
0.14
0
0
0
0
0.024
0.025
0.067
0.043
0.098
0.167
0.031
0.024
0.031
0.031
0.039
0.112
105.*
0.024
0.024
0.056
0.028
0.029
0.035
0.037
0.069
0.266
0.023
0.023
0.023
0.029
0.41
0.444
5.69*
* Not used in calculation of mean effluent concentration.
VII-136
-------
TABLE 7-55(OON'T)
DATA USED FOR TCHM,
CYANIDE PERFORMANCE
CISL, EFFLUENT DILUTION
PLANT ID OafcENTRATION (mg/1) FACTOR
15070 0.02 2.5
0.03 3.4
0.29 2.8
33073 0.013 5.5
0.129 5.1
0.254 5.5
09026 0.03 2.4
0.02 3.8
0.08 2.6
ADJUSTED CISL,
31021
33024
0.16
0.16
0.35
0.04
3.2
3.2
3.1
5.1
(mg/1)
0.05
0.102
0.818
0.071
0.66
1.39
0.072
0.076
0.208
0.512
0.512
1.1
0.204
VJI-137
-------
TABLE 7-56
PLSNT DATA DELETED FROM TOTAL CYANIDE DATA BASE
QL, EFFLUENT DILUTION ADJUSTED C1SL,
PL&NT ID CofcENTRATION (mg/1) FACTOR CONCENTRATION (mg/1)
02033 10.0 2.6 26.0
04045 6.4 1.0 6.4
8.7 1.0 8.7
15.2 1.0 15.2
06037 0.53 6.3 3.37
0.591 6.3 3.75
12.6 6.4 80.6,
06084 0.027 2.9 0.078
0.435 4.3 1.86
2.8 3.6 10.2
06085 0.96 4.8 4.61
0.92 5.4 4.95
1.8 5.0 9.0
06089 0.285 2.9 0.835
0.428 3.0 1.28
2.42 3.5 8.47
06090 2.81 4.3 12.1
6.73 4.3 28.7
10.8 4.3 46.1
06381 0.089 8.7 0.773
0.25 6.3 1.58
0.981 6.5 6.38
11103 10.0 2.4 24.0
9.37 3.0 28.1
20077 0.005 7.1 0.036
1.5 9.7 14.6
2.5 6.5 16.2
3.0 5.9 17.7
2.5 7.8 19.5
2.4 9.7 23.3
VXI-138
-------
TABLE 7-56(CON"T)
PLANT C&TA DELETED FROM TOTAL CYANIDE DATA
PLANT ID
20081
20082
20086
21066
36041
CM EFFLUENT DILUTION
CONCENTRATION (mg/1) FACTOR
0.035 17.7
0.023 14.4
0.068 15.9
0.911 17.6
1.16 16.3
3.82 15.6
0.034 2.0
0.635 2.1
0.722 2.0
0.945 2.0
3.09 1.8
3.31 2.1
0.73 4.5
1.13 4.5
5.25 4.5
16.38 4.7
12.15 10.2
20.65 7.4
0.25 11.5
0.4 10.1
0.6 10.4
ADJUSTED CN
CONCENTRATION (mg/1)
0.618
0.331
1.08
16.0
19.0
59.6
0.068
1,
1,
1.
5,
34
47
88
63
6.85
3.28
5.08
23.6
76.9
123.9
152.8
2.87
4.04
6.24
VII-139
-------
Self-monitoring data for total cyanide and amenable cyanide are
shown in Table 7-57. For each plant, this table shows the number
of data points, the mean effluent concentration, and the
calculated variability factors plus the total number of points.
the overall mean effluent concentration, and the median
variability factors.
CNT CNA
Mean Effluent Concentration (mg/8.) 0.18 0.06
Variability Factors (Daily/10-day) 6.68/3.61 14.31/5.31
Daily Maximum Concentration (mg/a) ' 1.20 0.86
Maximum Monthly Average Concentration (mg/a) 0.65 0.32
The percent of plants with cyanide levels below the cyanide daily
maximum effluent concentration limitations;are as follows:
EPA Sampled Plants Self-Monitoring Self-Monitoring
Parameter Daily Maximum Data Daily Max. Data IP-Day Ave.
Cyanide. Total 97.8 79.2 62.9
Cyanide. Amenable 100.0 92.8 78
The percent compliance for the self-monitoring data for the
cyanide total daily maximum and for the cyanide total and cyanide
amenable 10-day averages is relatively low compared to the EPA
samples plants. When examining the EPA sampled data, the Agency
excluded numerous plants that had high cyanide levels after
correcting for dilution. Apparently many plants are relying on
dilution of treated cyanide wastes rather than performing
alkaline chlorination to its capability. Self-monitoring data
are insufficient to examine the adequacy of the treatment system
because both cyanide amenable and cyanide total results are
generally not available for the same plants. Two plants have
both cyanide amenable and cyanide total values; however, the
cyanide amenable results are indicative of inadequate treatment.
This appears to indicate that there is a need for additional
control of cyanide by many of the plants that submitted
self-monitoring data. This is illustrated in Table 7-58 which
shows the adjusted mean and maximum concentrations for cyanide
total and cyanide amenable for plants with self- monitoring data
for which dilution factors were available. !
Demonstration Status
The oxidation of cyanide wastes by chlorine is a widely used
process in plants using cyanide in cleaning and plating baths.
There has been recent attention to developing chlorine dioxide
generators and bromine chloride generators. A problem that
has been encountered is that the generators produce not only
the bromine chloride and chlorine dioxide gas, but chlorine
gas is also formed simultaneously. Both of these gases are
extremely unstable, corrosive, and have low vapor pressure,
which results in handling difficulties. These generators are
in the development stages and as advances are made in their
design, they may become competitive with chlorine.
Oxidation by chlorine is used in 206 plants in the present
data base, and these are identified in Table 7-59.
VTI-140
-------
TABLE 7-57
EFFLUENT TOTAL CYANIDE SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 1 SYSTEMS
Plant ID
Number
OF Points
1067
3043
6051
6107
11008
11125
15193
20080
20082
31021
36082
44045
47025
230
89
13
10
179
54
12
268
246
119
121
50
138
Mean Effluent
Concentration
(nig/ft)
0.041
0.154
0.07
2.20
0.09
1.21
0.053
0.001
0.132
0.533
0.043
0.008
0.057
Var lability. Factor
Daily 10-Day
1.92
10.02
25.01
6.10
3.64
3.23
7.25
11.16
4.23
7.92
1.46
4.75
4.15
1.35
3.68
3.55
7.67
3.33
7.68
2.57
OVERALL
1529(Total) 0.156(Mean) 6.68(Median) 3.61(Median)
EFFLUENT AMENABLE CYANIDE SELF-MONITORING PERFORMANCE DATA
FOR PLANTS WITH OPTION 1 SYSTEMS
Plant ID
31021
38223
47025
Mean Effluent
Number Concentration
OF Points (mq/l)
28
235
243
0.196
0.0004
0.007
Variability Factor
Daily
14.32
1 O 1
3
5
5
Day
.18
.31
.77
OVERALL
529(Total) 0.016(Mean) 14.31(Median) 5.31(Median)
VH-141
-------
TABLE 7-58
ADJUSTED EFFLUENT TOTAL CYANIDE SELF-MONITORING DATA
Plant ID
3043
11008
11125
15193
20080
2O082
31021
36082
44045
47025
Number
OF Points
89
179
54
12
268
246
119
121
50
138
Adjusted
CN,T Mean
Concentration
(mq/it)
0.57
0.35
10.11
1.75
0.01
0.66
1.48
0.21
0.83
2.26
Adjusted
CN,T Maximum
Daily Concentration
; (rag/in
LIMITATION COMPARISON
0.18 (EPA Sample
Data Mean)
3.11
8.40
33.32
5.33
0.46
7.0
15.29
5.0
15.0
12.32
1.20 (Daily Max.)
ADJUSTED EFFLUENT AMENABLE CYANIDE SELF-MONITORING DATA
Plant ID
31021
38223
47025
Number
OFPoints
28
235
243
Adjusted
CN,T Mean
Concentration
(mq/a.)
0.54
0.06
0.28
LIMITATION COMPARISON
Adjusted
CN,T Maximum
Daily Concentration
(mq/g.)
3.89
1.43
6.80
0.06 (EPA Sample
Data Mean)
0.86 (Daily Max.)
VII-142
-------
TABLE 7-59
METAL FINISHING PLANTS EMPLOYING CYANIDE OXIDATION
007
067
068
033
037
240
042
043
045
076
114
178
199
124
227
236
263
277
279
182
021
05029
05033
06002
06006
06037
06050
06051
06052
06053
06002
06072
06073
06075
06079
06078
06079
06081
06084
06085
06087
06089
06090
06094
06101
06107
06111
06113
06115
06119
06120
06122
06124
06129
06141
06146
06147
06152
06358
06360
06381
06679
08004
08008
08074
09026
09060
10020
11008
11096
11098
11103
11125
11118
11174
11177
11184
12005
12065
12078
12087
12709
13033
13034
13039
13040
15042
15045
15047
15048
15070
15193
16033
16035
18050
18055
18534
19050
19051
19063
19069
19084
19090
19099
19102
19104
20001
20005
20017
20073
20077
20078
20079
20080
20081
20082
20084
20086
20087
20158
20162
20172
20243
20708
21003
21062
21066
21074
21078
22028
22656
23039
23059
23061
23074
23076
23337
25001
25030
25031
27044
27046
28082
28105
30011
30022
30090
30096
30097
30109
30111
30162
30967
31021
31037
31040
31047
31070
33024
33043
33065
33070
33071
33073
33113
33120
33137
33146
33184
33187
33275
34041
34042
35061
35963
36036
36040
36041
36082
36083
36084
36090
36091
36102
36112
36113
36151
36154
36156
36623
37042
38031
38038
38051
38223
40037
40047
41116
42830
43052
44037
44040
44045
45035
47005
47025
VII-143
-------
ALTERNATIVE CYANIDE TREATMENT TECHNIQUES
Alternative treatment techniques for the destruction of cyanide
include oxidation by ozone, ozone with ultraviolet radiation
(oxyphotolysis), hydrogen peroxide and electrolytic oxidation.
These techniques are presented in the following paragraphs.
Oxidation By Ozonation
Ozone may be produced by several methods, but the silent
electrical discharge method is predominant in the field. The
silent electrical discharge process produces ozone by passing
oxygen or air between electrodes separated by an insulating
material. The electrodes are usually stainless steel or
aluminum. The dielectric or insulating material is usually
glass. The gap or air space between electrodes or dielectrics
must be uniform and is usually on the order of 0.100 to 0.125
inches. The voltage applied is 20,000 volts or more, and a
single phase current is applied to the high tension electrode.
Ozone is approximately ten times more soluble than oxygen on a
weight basis in water, although the amount that can be effi-
ciently dissolved is still slight. Ozone's solubility is
proportional to its partial pressure and also depends on the
total pressure on the system. It should be noted, however,
that it is the oxidizable contaminant in the water that deter-
mines the quantity of ozone needed to oxidize the contaminants
present. A complete ozonation system is represented in Figure
7-26.
Thorough distribution of ozone in the water under treatment is
extremely important for high efficiency of the process. There
are four methods of mixing ozone with water; these are: (1)
diffusers, (2) negative or positive pressure injection, (3) packed
columns whereby ozone-containing air or oxygen is distributed
throughout the water, and (4) atomizing the aqueous solution into
a gaseous atmosphere containing ozone.
Application
Ozonation has been applied commercially for oxidation of
cyanides, phenolic chemicals, and organo-metal complexes. It
is used commercially with good results to treat photoprocessing
wastewaters. Divalent iron hexacyanato complexes (spent bleach)
are oxidized to the trivalent form with ozone and reused for
bleaching purposes. Ozone is used to oxidize cyanides in other
industrial wastewaters and to oxidize phenols and dyes to a
variety of colorless, nontoxic products.
VII-144
-------
CONTROUS
OZONE
GENERATOR
DRY AIR
RAW WASTE.
0
OZONE
REACTION
TANK
•M-
t
TREATED
FIGURE 7-26
TYPICAL OZONATION PLANT FOR WASTE TREATMENT
VII-145
-------
Oxidation of cyanide to cyanate is illustrated below:
CN"1 + 03 = CNO"1 + 02 i
Continued exposure to ozone will convert the cyanate formed to
carbon dioxide and ammonia if the reaction is allowed to
proceed; however, this is not economically practical, and
cyanate can be economically decomposed by biological oxidation
at neutral pH.
Ozone oxidation of cyanide to cyanate requires 1.8 to 2.0
pounds of ozone per pound of CN and complete oxidation requires
4.6 to 5.0 pounds of ozone per pound of CN . Zinc, copper,
and nickel cyanides are easily destroyed to a nondetectable
level, but cobalt cyanide is resistant to ozone treatment.
The first commercial plant using ozone in the treatment of
cyanide waste was installed by a manufacturer of aircraft.
This plant is capable of generating 54.4 Kg (120 pounds) of
ozone per day. The concentration of ozone used in the treatment
is approximately 20 mg/1. In this process the cyanate is
hydrolyzed to C02 and NH^. The final effluent from this
process passes into a lagoon. Because of ^n increase in waste
flow the original installation has been expanded to produce
162.3 Kg (360 pounds) of ozone per day.
!
Some advantages of ozone oxidation for handling process effluents
are that it is well suited to automatic control, on-site,
generation eliminates treatment chemical procurement and
storage problems, reaction products are not chlorinated organics,
and no dissolved solids are added in the treatment step.
Ozone in the presence of ultraviolet radiation or other pro-
moters such as hydrogen peroxide and ultrasound shows promise
of reducing reaction time and improving ozone utilization.
Some limitations of the process are high capital expense, possible
chemical interference in the treatment of imixed wastes, and
an energy requirement of 15 to 22 kwh per kilogram of ozone
generated. Cyanide is not economically oxidized beyond the
cyanate form.
i
Performance
An electroplating plant (ID 30022) that serves the electronics
industry plates gold, silver, copper, and nickel. Ozone was
selected for treatment of cyanide bearing waste, and the
results were as follows:
A. Optimum operating conditions were determined to be 1 to
1.5 moles of ozone/mole CN at a pH of 9.0-9.5 in the
ozone contactor.
B. It was established that ozone dosage is the most criti-
cal operating parameter, with 1.0 to 1.5 moles Oo/mole
CN found to be optimum at low CN concentrations [20 mg/1)
and 1.8 to 2.8 moles 0.,/mole CN at levels greater than
40 mg/1.
VII-146
-------
Cost data based on plant experience were obtained.
Treatment operating cost was $1.43/100 gallons of
influent cyanide bearing waste water and $1.03/1000
gallons total waste water. Total capital costs were
$66,613 for this installation but are estimated at
$51,200 for an optimized, non-research installation.
The results of three days of sampling are shown below:
PLANT ID 30022 (mg/1)
Day 1 Day 2 Day 3
Parameter
Cyanide, Total
Cyanide, Amenable
Demonstration Status
In
1.4
1.4
Out
.113
.110
In
.30
.30
Out
.039
.039
In
Out
2.4 .096
2.389 .096
Ozone is useful for application to cyanide destruction. There
are at least two units presently in operation in the country
(Plant ID's 14062 and 30022), and additional units are planned.
There are numerous orders for industrial ozonation cyanide
treatment systems pending.
Ozone is useful in the destruction of wastewaters containing
phenolic materials, and there are several installations in
operation in the United States.
Research and development activities within the photographic
industry have established that ozone is capable of treating
some compounds that are produced as waste products. Solutions
of key ingredients in photographic products were composed and
treated with ozone under laboratory conditions to determine
the treatability of these solutions. It was found that some
of these solutions were oxidized almost completely by ozona-
tion and some were oxidized that were difficult to treat by
conventional methods. Ozone breaks down certain developer
components that biodegrade slowly, including color developing
agents, pheniodone, and hydroxylamine sulfate. Developing
agents, thiocyanate ions, and formate ions degrade more com-
pletely with ozone than when exposed to biological degradation.
Thiosulfate, sulfite, formalin, benzyl alcohol, hydroquinone,
maleic acid, and ethylene glycol can be degraded to a more or
less equal degree with either biological treatment or ozone.
Silver thiosulfate complexes were also treated with ozone
resulting in significant recovery of the silver present in
solution. Ozone for regeneration of iron cyanide photoprocessing
bleach and treatment of thiosulfate, hydroquinone, and other
chemicals is currently being utilized by the photoprocessing
industry. There are 40 to 50 installations of this nature
in use at the present time.
VII-147
-------
O_xid_at.jLpn By Ozonation With UV Rad i at ion -
One of the modifications of the ozonation process is the
simultaneous application of ultraviolet light and ozone for
the treatment of wastewater, including treatment of halo-
genated organics. The combined action of these two forms
produces reactions by photolysis, photosensitization, hydroxyla-
tionr oxygenation and oxidation. The process is unique because
several reactions and reaction species are active simultaneously.
Ozonation is facilitated by ultraviolet absorption because
both the ozone and the reactant molecules are raised to a
higher energy state so that they react more rapidly. The energy
and reaction intermediates created by the introduction of
both ultraviolet radiation and ozone greatly reduce the amount
of ozone required compared with a system that utilizes ozone
alone to achieve the same level of treament. Figure 7-27 shows
a three-stage UV/ozone system.
A typical process configuration employs three single stage
reactors. Each reactor is a closed system which is illuminated
with ultraviolet lamps placed in the reactors, and the ozone
gas is sparged into the solution from the bottom of the tank.
The ozone dosage rate requires 2.6 pounds of ozone per pound
of chlorinated aromatic. The ultraviolet power is on the
order of five watts of useful ultravioletjlight per gallon of
reactor volume. Operation of the system is at ambient tempera-
ture and the residence time per reaction stage is about 24
minutes. Thorough mixing is necessary and the requirement for
this particular system is 20 horsepower per 1000 gallons of
reactor volume in quadrant baffled reaction stages. A system
to treat mixed cyanides requires pretreatment that involves
chemical coagulation, sedimentation, clarification, equalization,
and pH adjustment. Pretreatment is followed by a single stage
reactor, where constituents with low refractory indices are
oxidized. This may be followed by a second, multi-stage reactor
which handles constituents with higher refractory indices.
Staging in this manner reduces the ultimate reactor volume
required for efficient treatment.
Application
The ozonation/UV radiation process was developed primarily for
cyanide treatment in the metal finishing and color photo-
processing areas, and it has been successfully applied to
mixed cyanides and organics from organic chemicals manufactur-
ing processes. The process is particularly useful for treatment
of complexed cyanides such as ferricyanide, copper cyanide and
nickel cyanide, which are resistant to ozone alone, but readily
oxidized by ozone with UV radiation.
VII-148
-------
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c
3
H|
1
a.
I
c
:
GAS
TEMPERATURE
CONTROL
PH MONITORING
TEMPERATURE
CONTROL
PH MONITORING
TEMPERATURE
CONTROL
PH MONITORING
OZONE
OZONE
GENERATOR
FIGURE 7-27
UV/OZONATION
VII-149
-------
Performance
For mixed metal cyanide wastes, consistent'reduction in total
cyanide concentration to less than 0.1 mg/1 is claimed.
Metals are converted to oxides, and halogenated organics are
destroyed. TOC and COD concentrations are reduced to less
than 1 mg/1.
Demonstration Status
A full scale unit to treat metal complexed cyanides has been
installed in Oklahoma, while a large American chemical company
in France has installed an on-line unit for the treatment of
cyanides and organics and a similar design is scheduled for
installation by the same company in the United States. There
are also two other units known to be in service, one for
treating mixed cyanides and the other for treatment of copper
cyanide.
Oxidation By Hydrogen Peroxide '
The hydrogen peroxide oxidation treatment process treats both
the cyanide and metals in cyanide wastewaters containing zinc
or cadmium. In this process, cyanide rinse waters are heated
to 49-54°C (120-130°) to break the cyanide complex, and the pH
is adjusted to 10.5-11.8. Formalin (37% formaldehyde) is
added/ while the tank is vigorously agitated. After 2-5
minutes/ a proprietary formulation (41% hydrogen peroxide
with a catalyst and additives) is likewise added. After an
hour of mixing, the reaction is complete. The cyanide is
converted to cyanate and the metals are precipitated as
oxides or hydroxides. The metals are then removed from
solution by either settling or filtration.:
The chemical reactions which- take place are as follows:
CN + HCHO + H2O = HOCH2CN +,'OH~
The hydrogen peroxide converts cyanide to cyanate in a single
step:
CN + H2O2 = NCO + H2o
The formaldehyde also acts as a reducer, combining with the
cyanide ions:
Zn(CN)4~2 + 4 HCHO + 4H2O = 4 HOCH2CN + 4 OH~ + Zn+2
The metals subsequently react with the hydroxyl ions formed
and precipitate as hydroxides or oxides:
Zn+2 + 2 OH" = ZnO + H2o
The main pieces of equipment required for this process are two
holding tanks. These tanks must be equipped with heaters and
VII-150
-------
air spargers or mechanical stirrers. These tanks may be used
in a batch or continuous fashion with one tank being used for
treatment while the other is being filled. A settling tank or
a filter is needed to concentrate the precipitate.
Application
The hydrogen peroxide oxidation process is applicable to
cyanide bearing wastewaters, especially those from cyanide
zinc and cyanide cadmium electroplating. The process has been
used on photographic wastes to recover silver and oxidize
toxic compounds such as cyanides, phenols and "hypo" (sodium
thiosulfate pentahydrate). Additions of hydrogen peroxide are
made regularly at a large wastewater treatment plant to control
odors and minimize pipe corrosion by oxidizing hydrogen sulfide.
Chemical costs are similar to those for alkaline chlorination
and lower than those for treatment with hypochlorite, and all
free cyanide reacts and is completely oxidized to the less
toxic cyanate state. In addition, metals precipitate and
settle quickly, and they are recoverable in many instances.
However, the process requires energy expenditures to heat the
wastewater prior to treatment. Furthermore, the addition of
formaldehyde results in treated wastewater having relatively
high BOD values. Although cyanates are much less toxic than
cyanide, there is not complete acceptance of the harmlessness
of cyanates.
Performance
In terms of waste reduction performance, this process is
capable of reducing the cyanide level to less than 0.1 mg/1
and the zinc or cadmium to less than 1.0 mg/1.
Demonstration Status
This treatment process was introduced in 1971 and is being
used in several facilities.
Peroxide oxidation is used in three plants in the present data
base: 08061, 21058, and 30009.
Electrochemica1 Cyanide Oxidation
Electrochemical cyanide oxidation is used to reduce free
cyanide and cyanate levels in industrial wastewaters. In this
process, wastewater is accumulated in a storage tank and then
pumped to a reactor where an applied DC potential oxidizes the
cyanide to nitrogen, carbon dioxide and trace amounts of
ammonia. The gases generated are vented to the atmosphere.
The oxidation reaction is accomplished if concentrations are
not greater than 1000 mg/1. If reaction time is critical, the
process can be accelerated by augmenting the system with a
chemical (hypoehlorite) treatment as long as the cyanide
VEI-151
-------
concentration level is less than 200 mg/1. The process equip-
ment consists of a reactor, a power supply, a storage tank and
a pump.
Another electrochemical oxidation system employs a low voltage
anode with a metallic oxide coating. Upon application of an
electrical potential several oxidation reactions occur at the
anode. These reactions include the oxidation of chloride (from
common salt) to chlorine or hypochlorite and the formation of
ozone, as well as direct oxidation at the anode. Although
untested on cyanide-bearing wastewaters, this system shows
good potential in that area.
Application
The electrochemical cyanide oxidation system has been used
commercially only for heat treating applications; however, it
should be equally appropriate for other cyanide bearing wastes.
Its application for plating and photographic process wastewaters
is still in the development stage. The process can also be
applied to the electrochemical oxidation of nitrite to nitrate.
Electrochemical cyanide oxidation has the advantage of low
operating costs with moderate capital investment, relative to
alternative processes. There is no requirement for chemicals,
thereby eliminating both their storage and control, and there
is no need to dilute or pretreat the wastewater as the process
is most efficient at high cyanide concentration levels.
However, the process is less efficient than chemical destruc-
tion at cyanide concentrations less than 100 mg/1, and it is
relatively slow when not accelerated by addition of treatment
chemicals. Moreover, it will not work well in the presence of
sulfates.
Performance
Performance has been demonstrated on a commercial scale and
shown to result in a reduction in the cyanide concentration
level from 3500 mg/1 to less than 1.0 mg/1 in 160 hours. The
process emits no noticeable odor with adequate ventilation.
Demonstration Status
There is currently a unit in operation which is handling the
cyanide bearing wastewater generated by a heat treating opera-
tion. The manufacturer claims that there is a potential for
future use of the process in both the electroplating and
photographic industries. However, despite a variety of experi-
mental programs, industry has not been enthusiastic about the
electrolytic approach to cyanide oxidation.
Electrochemical cyanide oxidation is used at plants 04224,
18534, 19002, and 30080.
VII-152
-------
Chemical Precipitation
Chemical precipitation is a classic waste treatment process
for metals removal as described under the "Treatment of Common
Metal Wastes" heading. The precipitation of cyanide can be
accomplished by treatment with ferrous sulfate. This preci-
pitates the cyanide as a ferrocyanide, which can be removed in
a subsequent sedimentation step. Waste streams with a total
cyanide content of 2 mg/1 or above have an expected waste
reduction of 1.5 to 2 orders of magnitude. These expectations
are substantiated by the following results from plant 01057:
CONCENTRATION OF TOTAL CYANIDE (mg/1)
Raw Waste Final Effluent
2.57 0.024
2.42 0.015
3.28 0.032
Evaporation
Evaporation is another recovery alternative applicable to
cyanide process baths such as copper cyanide, zinc cyanide,
and cadmium cyanide and was described in detail for common
metals removal.
VEI-153
-------
TREATMENT OF OILY W&STSS
INTRODUCTION
This section presents the Option 1 treatment systems that are
applicable to the treatment of oily wastes; describes the
treatment techniques for Option 1 and its alternatives; and
defines the effluent concentration levels for those options. Oily
wastes include process coolants and lubricants, wastes from
cleaning operations directly following many other unit operations,
wastes from painting processes, and machinery lubricants. Oily
wastes generally are of three types: free oils, emulsified or
water soluble oils, and greases. Techniques commonly employed in
the Metal Finishing Category to remove oil include skimming,
coalescing, emulsion breaking, flotation, centrifugation.
ultrafiltration. reverse osmosis, and removal by contractor
hauling. Oil removal techniques may also afford additional
removal of toxic organics, and the applicability and performance
of these techniques for toxic organics is discussed under
"Treatment of Toxic Organics."
Table 7-60 presents oily waste removal system options for free
oils, combined wastewater, and segregated oily waste. The Option
1 oily waste treatment system incorporates the emulsion breaking
process followed by surface skimming (gravity separation is
adequate if only free oils are present). Ultrafiltration may be
employed as an alternative to the Option i; system. Polishing
systems for Option 1 and its alternative a|re presented in the
text. These may be added to further improve effluent quality.
Because emulsified oils, or processes that emulsify oils, are used
extensively in the Metal Finishing Category, the exclusive
occurrence of free oils is nearly nonexistent. Combined
wastewater (e.g., -oils in common metals wastewaters} should
contain only oils that are introduced from rinsing or cleaning
operations, inadvertent spills, or equipment leakage. As a result
of this, these wastewaters contain low oil concentrations but have
high flow rates. Because treatment system costs are proportional
to the quantity of waste oil, segregation of oily waste is
economically preferable. Segregated oily waste is that collected
from tanks and sumps throughout a manufacturing facility for
separate waste treatment or recovery.
VH-154
-------
TABLE 7-60
OILY WASTE REMOVAL SYSTEM OPTIONS
U1
>v WASTE
>v CHARACTERISTICS
TREATMENT OPTION\.
PC
TE
ALTER!
T<
OPTI!
OPTION
1
JATIVE
3
DN 1
)LISHING
CHNIQUES
FREE OILS
Combined
or
Segregated
Haste
Gravity
Separator
I i
COMBINED WASTEWATER SEGREGATED OILY WASTE
Mixture of free oils, grease, and emulsified oils
Wastewater from rinsing or „ ,, . . , , . .
, . _,. .7, Collection from tanks and
cleaning overflow, spills,
and leakage suips
Low oil concentration, High oil concentration,
high flow rate low flow rate
Emulsion Breaking with Skimming
Ultxafiltration
Option 1 (or Alternative) Followed by Carbon Adsorption or Reverse Osmosis
-------
Oily waste performance data and limitations are presented herein
for both combined wastewater and segregated oily wastes. The
combined wastewater concentrations are applicable to the oils
present in common metals wastewaters and concentration limitations
are stated for both the Option 1 and Option 2 common metals
treatment systems. A single option and an alternative are
presented for the treatment of segregated oily wastes.
TREATMENT OF OILY WASTES FOR COMBINED WASTEWATER
The following paragraphs present the oily waste performance data
for combined wastewater in the common metals wastewater data base,
identify the mean concentrations established for oil and grease,
define the concentration limitations, and compare these
limitations with the sampled data base and the self-monitoring
data base for the Option 1 and Option 2 common metals treatment
systems.
COMBINED WASTEWATER PERFORMANCE FOR OILS - OPTION 1
COMMON METALS SYSTEM \
Table 7-61 presents the oil and grease performance data for the
Option 1 common metals treatment system data base for properly
opreating systems. From these data a mean effluent concentration
of 11.8 mg/8. was established for oil and grease in combined
wastewater for the Option 1 common metals treatment system.
An iterative procedure was used in the calculation of the
mean effluent concentration for oil and grease to prevent
the calculation of an unrealistically low mean effluent
concentration due to low raw waste pollutant loadings. The
mean effluent concentration for oil and grease was calculated;
when a raw waste concentration was less than the mean effluent
concentration, the corresponding effluent value was deleted from
the data set. The mean was recalculated using points not removed
initially, and the process repeated in an iterative loop. This
same iterative procedure was used for the toxic metals.
The variability factors for oil and grease in combined wastewater
for the Option 1 common metals treatment system were established
from long term self-monitoring data. The specific data set used
is tabulated in Table 7-62.
VII-156
-------
TABLE 7-61
METAL FINISHING CATEGORY PERFORMANCE DATA FOR OIL AND GREASE
OPTION 1
Data
Point
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
Raw Waste
Concentration
(mg/il)
12.200
14.200
16.111
16.200
16.644
16.900
18.000
22.804
23.000
23.600
28.000
29.444
34.000
36.312
40.350
41.000
43.000
46.000
51.600
54.000
66.000
67.600
72.000
90.393
137.15
195.93
224.11
418.00
1291.0
2650.0
Effluent
Concentration
(mg/U
9.800
11.200
000
000
000
11.700
2.0000
18.150
11.000
12.600
19.300
1.
6.
.0000
.0000
9.6385
23.015
1.0000
24.000
5.
1.
7.
.0000
.600
.0000
14.000
9.600
10.000
23.378
12.000
25.000
16.000
10.200
23.200
31.200
Plant ID
6101-12-1
6731-1-3
20086-1-2
19051-6-0
20086-1-3
6051-6-0
21003-15-0
33024-6-0
15010-12-2
6101-12-1
6083-1-2
20086-1-1
36041-1-1
19063-1-1
19063- 1-3
36041-1-3
15010-12-3
36041-1-2
36040-1-1
11477-22-2
11477-22-0
6074-1-1
11477-22-1
19063-1-2
44062-15-1
44062-15-0
44062-15-2
6074-1-1
6074-1-1
33692-23-1
Mean
Concentration
193.185 (n=30)
11.819 (n=30)
VII-157
-------
TABLE 7-62
OIL AND GREASE EFFLUENT SELF-MONITORING PERFORMANCE DATA
COMBINED WASTEWATER - COMMON METALS OPTION 1
Variability Factor
Mean Effluent
Number Concentration
Plant ID OF Points (mq/g.)
1.80
1.75
10.80
2,57
1.95
4.51
4.73
1.24
4.88
1.46
3.83
3.48
OVERALL 893(Total) 2.79(Mean) 4.36(Median) 2.18(Median)
3049
6051
6107
11477
12002
20080
22735
30050
30079
30090
30165
45741
49
13
2
66
55
269
45
287
12
45
20
48
Daily
I
5.71
6.22
33.38
2.73
5.98
6.70
3.01
7.71
1.38
2.53
1.63
3.00
10-Day
2.58
3.09
—
1.82
2.65
2.68
" "" r.§6
2.40
1.41
1.97
—
1.42
VH-158
-------
In a manner consistent with the development of limitations for
other parameters in common metals wastewaters, the median
variability factor values are used to establish the limitations
presented in Table 7-63.
TABLE 7-63
OIL AND GREASE LIMITATION SUMMARY
COMBINED WASTEWATEH - COMMON METALS OPTION 1
Mean Effluent Concentration 11.8 mg/8.
Daily Variability Factor 4.36 mg/8,
10-Day variability factor 2.18 mg/8.
Daily Maximum Concentration 52 mg/8.
Monthly Maximum Average Concentration 26 mg/8.
The percentage of oil and grease effluent concentrations that are
less than the daily maximum concentration limitation are 100
percent for the EPA sampled data set used to establish mean
effluent concentration, 100 percent for the self-monitoring data
set daily values and 100 percent for the self-monitoring data set
monthly averages.
COMBINED WASTEWATER PERFORMANCE FOR OILS - OPTION 2
COMMON METALS SYSTEM
Figure 7-28 presents the oil and grease performance data for the
Option 2 common metals treatment system data base. From these
data, excluding the outlier at an effluent concentration of 56
rag/ft, which exceeds the Option 1 daily maximum concentration
limitation, the mean effluent oil and grease concentration was
established to be 7.1 mg/8,.
The variability factors for oil and grease is combined wastewater
for the Option 2 common metals treatment system are those used
for oil and grease in the Option 1 common metals treatment
system. Insufficient data are presently available to separately
establish these factors for the Option 2 treatment system.
Applying the Option 1 variability factors to the Option 2 oil and
grease mean effluent concentration results in the performance
presented in Table 7-64.
TABLE 7-64
OIL AND GREASE PERFORMANCE SUMMARY
COMBINED WASTEWATER - COMMON METALS OPTION 2
Mean Effluent Concentration 7.1 mg/S.
Daily Variability Factor 4.36 mg/S.
10-Day variability factor 2.18 mg/S.
Daily Maximum Concentration 31.0 mg/S.
Monthly Maximum Average Concentration 15.5 mg/8.
VII-159
-------
V
so-
•
~
W
<0
u ;
•o
c
f-1
•H
01 fi -
8.
n .
*
0
0
C
0
Daily Maximum Oil And Grease
— A
10
100
Oil And Grease Raw Waste (mg/1)
1000
FIGURE 7-28
EFFLUENT OIL AND GREASE CONCENTRATIONS vs RAW WASTE CONCENTRATIONS
OPTION 2 COMMON METALS DATA BASE
(Combined Wastewater)
-------
The percentage of combined wastewater oil and grease effluent
concentrations that are less than the Option 2 daily maximum
concentration limitation is 96.7 percent for the EPA sampled
data base used in calculating the mean effluent concentration.
TREATMENT OF SEGREGATED OILY WASTES
Treatment of oily wastes can be carried out most efficiently
if oils are segregated from other wastes and treated separ-
ately. Segregated oily wastes originate in the manufacturing
areas, are collected in holding tanks and sumps, and can have
oil and grease concentrations as high as 400,000 mg/1. Combined
oily wastes are those generated from washing or rinsing of
oily parts, spills, and leakages and generally have lower oil
and grease concentrations than segregated oily wastes by
several orders of magnitude. Furthermore, oily wastes in
combined wastewater streams, such as common metals waste-
waters, require larger and thus more costly treatment systems
for oils removal than do segregated oily wastewaters because
the combined wastewaters have significantly greater flow
rates. Performance limitations for combined wastewater oils
and total priority organics are presented in the preceding
subsection.
Treatment of segregated oily wastes consists of separation of
the oily wastes from the water. This separation can require
several different steps depending on the character of the oily
wastes involved. If the oils are all of a free or floating
variety, physical means such as decantation or the use of a
gravity oil separator should be used to remove the oils. If
the oily wastes are emulsified, techniques such as emulsion breaking
or dissolved air flotation with the addition of chemicals are
necessary to accomplish removal of the oils. Once the oil-water
emulsion is broken, the oily waste is physically separated from the
water by decantation or skimming. (Ultrafiltration is an alternative
to emulsion breaking).
After the oil-water separation has been accomplished the water
is sent to the precipitation/sedimentation unit described under
the "Treatment of Common Metals Wastes" heading for removal of
metals.
VII-161
-------
SEGREGATED OILY WASTE TREATMENT SYSTEM - OPTION 1
The Option 1 system for the treatment of segregated oily
wastewater consists of emulsion breaking followed by skimming,
as is illustrated in Figure 7-29. The emulsion breaking is
effected by the addition of chemicals (such as alum or
polymers) to accomplish coagulation and flocculation of the
oily wastes. These floating oily wastes are then removed via
skimming to complete the Option 1 level of treatment.
Treatment alternatives to the Option 1 system that are
presently employed in the metal finishing industry include
ultrafiltration, dissolved air flotation, coalescing gravity sepa-
rators, thermal emulsion breaking and the use of centrifu-
gation. These alternative techniques, as well as contractor
hauling, are described in the subsection entitled "Additional
Oily Waste Treatment Techniques."
The Option 1 treatment system is employed extensively within
the metal finishing data base for treatment of segregated oily
waste. However, because of the increasing price of oil, metal
finishing plants are tending toward the use of treatment
techniques such as ultrafiltration, reverse osmosis, or
centrifugation for the recovery and direct reuse of oils.
The following paragraphs describe the emulsion breaking and
skimming tecniques that are applicable to the removal of oily
wastes for Option 1.
Emulsion Breaking
Emulsion breaking is a process by which emulsified oils are
removed from oil/water mixtures. Emulsified oils are commonly
used as coolants, lubricants, and antioxidants for many of the
unit operations performed in the Metal Finishing Category.
Methods of emulsion breaking include a variety of chemical
processes, thermal processes, and combinations of the two
processes. These techniques are discussed in the following
paragraphs.
Chemical emulsion breaking can be accomplished either as a
batch process or a continuous process. A typical system
(with skimming incorporated) is illustrated in Figure 7-30.
The mixture of emulsified oils and water is initially treated
by the addition of chemicals to the wastewater. A means of
agitation (either mechnical or by increasing the turbulence
of the wastewater stream) is provided to ensure that the chemical
added and the emulsified oils are adequately mixed to break
the oil/water emulsion bond. Finally the oily residue (commonly
called scum) that results rises to the surface and is separated
from the remaining wastewater by a skimming or decanting process.
The skimming process can be accomplished by any of the many types
VII-162
-------
Oily Wastes
Segregated
Oily Wastewater
I
Emulsion
Breaking
Skimming
To Metals/Solids Removal,
or Discharge as Applicable
FIGURE 7-29
TREATMENT OF SEGREGATED OILY WASTES
OPTION 1
¥11-163
-------
Chemical Addition
Emulsified Oils
1
H
*»
Mixing Tank
Skimmer
Oils
Combination Flotation
tod
Settlinq Tank
Treated Wastewater
Sludge
.FIGURE 7-30
TYPICAL EMULSION BREAKING/SKIMMING SYSTEM
-------
of mechanical surface skimmers that are presently in use.
Decanting methods include removal of the oily surface residue
via a technique such as controlled tank overflow or by
removal of the demulsified wastewater from the bottom of the
tank. Decanting can be accomplished with a series of tap-off
lines at various levels which allow the separated oils to be
drawn off the top or the wastewater to be drawn off the bottom
until oil appears in the wastewater line. With any of these
arrangements, the oil is usually diverted to storage tanks
for further processing or hauling by a licensed contractor.
Chemical emulsion breaking can be accomplished by a large
variety of chemicals which include acids, salts, or polymers.
These chemicals are sometimes used separately, but often are
required in combination to break the various emulsions that
are common in the wastewater. Acids are used to lov/er the pH
to 3 or 4 and can cleave the ion bond between the oil and
water, but can be very expensive unless acid rich wastewaters,
such as pickling wastes, can be used. Acids are more commonly
employed in oil recovery systems than in oily waste removal
systems. Iron or aluminum salts such as iiecrous sulfate,
ferric chloride, or aluminum sulfate are more commonly used
because they are less expensive. These salts combine with the
wastewater to form acids which in turn lower the pH and break
the oil/water bond (and 'nave the additional benefit that these
salts aid in agglomeration of the oil droplets), but the use
of these salts produces more sludge because of the addition of
iron or aluminum. Polymers, such as polyamines or polyacryl-
ates and their copolymers, have been demonstrated to be effec-
tive emulsion breakers and generate less sludge than do metal
salts. The Option 1 tredba^ni: system costing, presented in
Section VIII, is based upon the use of aluminum sulfate plus a
quantity of polymer as the emulsion breaking chemicals.
After chemical addition, the mixture is agitated to ensure
complete control: of the emulsified oils with the ^emulsifying
agent. With the addition of the proper amount of chemical and
thorough agitation, emulsions of 5% to 10% oil can be reduced
to approximately 0.01% remaining emulsified oil. The third
step in the emulsion breaking process is to allow sufficient
time for the oil/water mixture to separate. Differences in
specific gravity will permit the oil to rise to the surface in
approximately two hoars. Heat can be added to decrease the
separation ti.iae. Afitec separation, the normal procedure
involves skimming or decanting the oil from the tank.
VII-165
-------
Emulsion breaking technology can be applied to the treatment
of emulsified oil/water mixtures in the Metal Finishing
Category wherever it is necessary to separate oils, fats,
soaps, etc. from wastewaters. Certain machining coolant emul-
sion cannot be chemically or thermally broken and must be treated
by ultrafiltration.
The main advantage of the chemical emulsion breaking process
is the high percentage of oil removal possible with this
system. For proper and economical application of this
process, the oily wastes (oil/water mixture) should be
segregated from other wastewaters either by storage in a
holding tank prior to treatment or be fed directly into the
oily waste removal system from major collection points.
Further, if a significant quantity of free oils are present,
it is economically advantageous to precede the emulsion break-
ing with a gravity separator. Chemical and energy costs can
be high, especially if heat is used to accelerate the process.
Chemical emulsion breaking can be highly reliable if adequate
analysis is performed prior to the selection of chemicals and
proper operator training is provided to ensure that the estab-
lished procedures are followed. ;
For chemical emulsion breaking, routine maintenance is required
on pumps, motors, and valves as well as periodic cleaning of
the treatment tank to remove any sediment which may accumulate
in the tank. The use of acid or acidic conditions Will require
a lined tank, and the lining should be checked periodically.
Emulsion breaking generates sludge which requires proper
disposal.
Performance
The performance attainable by a chemical emulsion breaking
process is dependent on addition of the proper amount of
de-emulsifying agent, good mixing agitation and sufficient
retention time for complete emulsion breaking. Since there
are several types of emulsified oils, a detailed study should
be conducted to determine the most effective treatment techniques
and chemicals for particular application.
Demonstration Status
Emulsion breaking is a common technique used in industry, is a
proven method of effectively treating emulsified wastes, and is in
use at 29 plants in the present data base. These plants are
identified in Table 7-65. '
TABLE 7-65 ;
METAL FINISHING PLANTS EMPLOYING EMULSION BREAKING
i
01058 11477 12095 20173 30153 36074
01063 12075 13041 20247 33050 38040
03041 12076 20103 20249 i 33120 40836
06679 12080 20158 20254 33127 46713
11129 12091 20159 30135 33179
VII-166
-------
Skimming
Skimming is used to remove floating wastes and normally takes
place in a tank designed to allow the debris (with a specific
gravity less then water) to rise and remain on the surface.
Skimming devices are therefore suited to the removal of oily
wastes from raw waste streams after demulsification. Common
skimming mechanisms include the rotating drum type, which
picks up oil from the surface of £he water as it rotates. A
knife edge scrapes oil from the drum and collects it in a
trough for disposal or reuse. The water portion is then
allowed to flow under the rotating drum. Occasionally, an
underflow baffle is installed after the drum; this has the ad-
vantage of retaining any floating oil which escapes the drum
skimmer. The belt type skimmer is pulled vertically through
the water, collecting oil from the surface which is again
scraped off and collected in a tank. System design and
operational controls are important in drum and belt type
skimmers in order to ensure uniform flow through the system
and avoid oil bypassing the skimmer mechanism.
Gravity separators, such as the API type, utilize overflow
and underflow baffles to skim a floating oil layer from the
surface of the wastewater. An overflow-underflow baffle
allows a small amount of wastewater (the oil portion) to
flow over into a trough for disposition or reuse while the
majority of the water flows underneath the baffle. This is
followed by an overflow baffle, which is set at a height
relative to the first baffle such that only the oil bearing
portion will flow over the first baffle during normal plant
operation. An inlet diffusion device, such as a vertical
slit baffle, aids in creating a uniform flow through the
system and increasing oil removal efficiency.
Application
Oil skimming is used in the Metal Finishing Category to remove
oily wastes from many different process wastewater streams.
Skimming is applicable to any waste stream containing pollutants
which float to the surface. Skimming is used in conjunction
with emulsion breaking, dissolved air flotation, clarifiers,
and other sedimentation devices.
API or other gravity-type separators are more suitable for use
where the amount of surface oil flowing through the system is
consistently significant as with free oils. Drum, belt, or
rotary type skimmers are applicable to waste streams which
carry smaller amounts of floating oily waste and where surges
of floating oil are not a problem. The use of a gravity separator
system preceding emulsion breaking is a very effective method
of removing free oil constituents from oily waste streams.
Skimming as a pretreatment is effective in removing naturally
floating waste materials, such as free oils, and improves the
performance of subsequent downstream treatments. Many
pollutants, particularly dispersed or emulsified oil, will not
float "naturally" but require additional treatments. Therefore,
skimming alone will not remove all the pollutants capable of
being removed by more sophisticated technologies.
VII-167
-------
Because of its simplicity, skimming is a Very reliable technique.
however, a mechanical skimming mecahnism requires periodic
lubrication, adjustment, and replacement of worn parts.
The collected layer of debris (scum) must be disposed of in an
approved manner. Because relatively large quantities of water are
present in the collected wastes, direct combustion or incineration
is not always possible.
Performance
The performance attainable by skimming is dependent on proper
mechanical operation of the skimmer and on the separation rate of
the oil/water mixture which is affected by such factors as the
size and specific gravity of the oil globules. Examples of
performance of skimmer systems for oil and grease are presented in
Table 7-66.
TABLE 7-66
SKIMMING PERFORMANCE DATA FOE OIL AND GREASE (mg/1)
Plant ID
6058-14-0
6058-15-5
6058-14-0
11477
Oil and Grease
Influent (rag A)
395.538
53,800
19,4
61
Oil and Grease
Influent (met/1)
13.3
16
8.3
14 ;
Type of
Skimmer
API
API
Belt
Belt
Demonstration Status
Skimming is a common operation utilized extensively in industrial
waste treatment systems and is used by 94 plants in the metal
finishing data base. These are identified in Table 7-67.
TABLE 7-67
METAL FINISHING PLANTS EMPLOYING SKIMMING
01063
04233
04892
06041
06051
06058
06062
06084
06086
06116
06679
07001
09047
09181
11113
12080
12091
13324
14001
14062
15010
15033
16032
17030
18091
18538
19106
20001
20064
20075
20471
20483
20708
22031
23075
25031
25339
28075
28115
28116
28125
30050
30079
30135
30150
33178
33179
33292
35001
36074
36102
36131
36155
36623
38040
38050
38217
40070
41084
41115
VII-168
-------
TABLE 7-67 (Continued)
METAL FINISHING PLANTS EMPLOYING SKIMMING
11129 20106 30151 44062
11137 20157 30153 46025
11152 20158 30516 46032
11477 21059 31040 46713
12007 20165 31067 47025
12033 20173 33024 47048
12042 20177 33050 47049
12075 20249 33120 6019
12076 20254 33127 20103
Segregated Oily Waste Treatment System Performance for Oils -
Option _1
Figure 7-31 presents the Option 1 system performance data base
for segregated oily waste treatment systems that were sampled.
From these data a mean effluent concentration of 23.8 mg/1 was
established for oil and grease in the Option 1 segregated oily
waste treatment system. Long term self-monitoring data means
are presented in Table 7-68.
Oil and grease performance for segregated oily wastewater was
calculated for Option 1 using the mean effluent concentration from
EPA sampled plants and the Option 1 combined oily waste
variability factors. Performance is summarized below:
OIL AND GREASE PERFORMANCE SUMMARY
SEGREGATED OILY WASTE - OPTION 1
Mean Effluent Concentration 23.8 mg/8,
Daily Variability Factor 4.36 mg/8,
10-Day Variability Factor 2.18 mg/8,
Daily Maximum Concentration 104 mg/8,
Monthly Maximum Average Concentration 52 mg/8,
VII-169
-------
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ration
i
^
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O
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io3
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O
«
io4 io5 K
Segregated Raw Oil & Grease Concentration (mg/1)
FIGURE 7-31
SEGREGATED OIL & GREASE EFFLUENT PERFORMANCE
OPTION 1
-------
TABLE 7-68
EFFLUENT OIL AND GREASE SELF-MOWITORING PERFORMANCE DATA
SEGREGATED OILY WASTEWATER - OPTION 1
Plant
ID
06116
12076
13042
20158
20254
20698
33692
OVERALL
Number
of Points
100
25
142
35
10
186
55
533 (Total)
Mean Effluent
Concentra11on {mg/ P)
287.4
23.4
52.8
8.3
104.8
9.2
26.2
74.70 (Mean)
VH-171
-------
SEGREGATED OILY WASTES TREATMENT SYSTEM - ALTERNATIVE TO
OPTION 1
The alternative treatment system for segregated oily wastes is
illustrated in Figure 7-32. The system consists of an ultra-
filtration unit. The ultrafilter's purpose is to reclaim oils
from wastewater which is to be ultimately discharged.
The ultrafiltration unit removes quantities of oil and toxic
organics as well as removing metals and other solids.
Ultrafiltration
Ultrafiltration (UF) is a process using semipermeable
polymeric membranes to separate emulsified or colloidal
materials dissolved or suspended in a liquid phase by pressuriz-
ing the liquid so that it permeates the membrane. The membrane
of an ultrafilter forms a molecular screen which separates
molecular particles based on their differences in size, shape,
and chemical structure. The membrane permits passage of
solvents and lower molecular weight solutes while barring
dissolved or dispersed molecules above a predetermined size.
At present, an ultrafilter is capable of removing materials
with molecular weights in the range of 1,000 to 100,000.
In the ultrafiltration process, the feed solution is pumped
through a tubular membrane unit. Water and some low molecular
weight materials pass through the membrane under the applied
pressure of .767 kg/cm (10 to 100 psig). Emulsified oil
droplets and suspended particles are retained, concentrated,
and removed continuously. In contrast to ordinary filtration,
retained materials are washed off the membrane filter rather
than held by the filter. Figure 7-33 illustrates the ultra-
filtration process.
The pore structure of the membrane acts as a filter, passing
small particles, such as salts, while blocking larger
emulsified and suspended matter. The pores of ultrafiltration
membranes are much smaller than the blocked particles. There-
fore, these particles cannot clog the membrane structure.
Clogging of the membrane by particles near the minimum removal
size can be minimized by proper selection of the membrane to
suit the wastewater to be treated.
Once a membrane is chosen that provides maximum attainable
removal of the desired particles, the next most important
design criterion is the membrane capacity. Here the term flux
is used. Flux is the volume of water passed through the
membrane area per unit time. The standard units are cu
m/day/sq m (gpd/sq ft). The typical flux is 4.2 to 844 cu
m/day/sq m (5 to 1000 gph/sq ft). Both membrane equipment and
operating costs increase with the membrane area required. It
is, therefore, desirable to maximize flux.
VII-172
-------
Segregated
Oily Wastes
Oily Wastes
1
Ultraf iltration
To Metals/Solids Removal,
or Discharge as Applicable
FIGURE 7-32
TREATMENT OP SEGREGATED OILY WASTES
ALTERNATIVE TO OPTION 1
VII-173
-------
ULTRAFILTRATION
\
MACROMOLECULES
*
P=10-50 PSI •.
MEMBRANE
WATER SALTS
•MEMBRANE
PERMEATE
* • !• • • I •/ ' L
.. . f •..•.•{/••• '4
_^ *__•_« •__ A •
°* * ~
FEED * * *
o •• ° • °*
-'Q • * * •<
• * * * O • • • * n '
. CONCENTRATE
• o «o • o
O OIL PARTICLES • DISSOLVED SALTS AND LOW-
MOLECULAR-WEIGHT ORGANICS
FIGURE 7-33
SIMPLIFIED ULTRAFILTRATION FLOW SCHEMATIC
VII-174
-------
Membrane flux is normally dependent on operating pressure,
temperature, fluid velocity, solids concentration (both total
dissolved solids and total suspended solids), membrane permea-
bility, membrane thickness, and fluid viscosity. Membrane
flux is also affected by the surface tension of the solution
being processed. With a fixed geometry, membrane flux will
increase as the fluid velocity is increased in the system.
This increase in fluid velocity win require greater capacity
and more horsepower. Less membrane area i.<3, therefore,
required per unit of effluent to be treated with higher fluid
velocities; membrane replacement and initial capital costs
decrease. Opposing these cost decreases is the increase in
power and its resultant cost, and the fact that these operating
conditions may decrease membrane life, resulting in higher
maintenance costs,
Application
Ultrafiltration is employed in metal finishing plants for the
separation of oils, toxic organics, and residual solids. The
major applications of ultrafiltration in the metal finishing
industries have been to electropainting wastes and oily waste-
waters. Successful commercial use has been proven for the
removal of emulsified oils from wastewater and Eor (recovery of
rinse water and detergent solutions in phosphate washers.
Recovery operations are common because of the increasing value
of oils, but ultrafiltration is used for end-of-pipe treatment
in industrial plants.
Ultrafiltration is a proven technique for the removal of oily
or paint contaminated wastes from the process waste streams.
This permits reuse of both the permeate and concentrate. With
segregated oily wastes, the concentrate is essentially the
recovered oils and application of ultrafiltration for this
purpose is increasing. Ultrafiltration of the waste from
electropainting (electrocoating) provides an excellent example
of this process. Car manufacturers and many other U.S.
companies use electropainting for priming purposes. In this
application, the ultrafiltration unit splits the electro-
painting rinse water circulating through the unit into a
permeate stream and paint concentrate stream. The permeate is
reused for rinsing, and the concentrate is returned to the
electropainting bath.
Bleeding a small amount of the ultrafiltrate, which contains
low suspended solids and generally two or three percent of
organic solids, to the waste system enables ionic contaminants
to be removed from the paint itself. Situations where tanks
of 150,000 to 190,000 liters (40,000 to 50,000 gallons) of
paint were periodically dumped because of contamination have
now been eliminated by using ultrafiltration, thus reducing
effluent problems arising from this dumping process.
VII-175
-------
The permeate or effluent from the ultrafiltration unit is
normally of a quality that can be reused in industrial applica-
tions or discharged directly.
Ultraf iltration is sometimes an attraetivie alternative to
chemical treatment because of lower capital equipment,
installation, and operating costs with a very high oil removal
efficiency. Little, if any, pretreatment is required and
because of its compact equipment, it utilizes only a small
amount of floor space.
A limitation of ultrafiltration for treatment of process
effluents is its narrow temperature range (18°C to 70°C) for
satisfactory operation. Membrane life is decreased with
higher temperatures, but flux increases at elevated temperatures.
Therefore, surface area requirements are a function of temperature
and become a tradeoff between initial costs and replacement
costs for the membrane. In addition, ultrafiltration is limited
in its ability to handle strong oxidizing agents, some solvents,
and other organic compounds which can cause dissolution of the
membrane.
The reliability of an ultrafiltration system is dependent on
the application of proper filtration to incoming waste streams
to prevent membrane damage. The tubular membrane configuration
does not require prefiltration. A limited amount of regular
maintenance is required for the pumping system. In addition,
membranes must be periodically changed.
Ultrafiltration is used primarily for recovery of solids and
liquids. It therefore eliminates solid waste problems when
the solids (e.g., paint solids) can be recycled to the process.
Otherwise, the stream containing solids must be treated by
additional end-of-pipe equipment.
Demonstration Status
The ultrafiltration process is well developed and is commercially
available for the treatment of wastewater' or the recovery of
certain liquid and solid constituents. Ultrafiltration is
used at 20 plants in the present Metal Finishing Category data
base and these are identified in Table 7-69.
TABLE 7-69
METAL FINISHING PLANTS EMPLOYING ULTRAFILTRATION
06062 25010
06071 30100
06102 30516
12065 31022
12074 31032
13041 33092
13324 33617
15193 36074
19462 38217
23076 44048
VII-176
-------
Segregated Oilv Waste Treatment System Performance - Alternative
to Option 1
The raw waste and effluent concentrations of oil and grease for
streams entering into and discharged from ultrafiltration systems
in the data base are displayed in Table 7-70. The performance
(removal efficiency) of these ultrafiltration systems is tabulated
for oil removal. Removal performance was calculated by computing
the percentage of oil removal at each plant using ultrafiltration
and then finding the mean of the individual performances. The
removal performance was calculated by the following formula:
Removal Efficiency = (raw waste - effluent)100
raw waste
TABLE 7-70
ULTRAFILTRATION PERFORMANCE DATA FOR OIL & GREASE REMOVAL
Plant Oil & Grease Concentration (mg/8,) Removal
ID In Out Efficiencv(%)
13041-22-0 95.0 22.0 76.8
13041-22-1 1.540. 52.0 96.6
13041-22-2 38.180. 267. 99.3
13324-21-0 31.000. 21.4 99.9
15193-21-0 1.380. 39.0 97.2
Mean Removal Efficiency 94.0%
VTI-177
-------
SEGREGATED OILY WASTE TREATMENT SYSTEM - POLISHING TECHNIQUES
The Option 1 treatment system for oil and grease removal from
segregated oily wastes with the addition of polishing techniques
is illustrated in Figure 7-34. As shown, the system is comprised
of the components that make up the Option 1 oily waste treatment
system (or its alternative) with the addition of a final polishing
component. A reverse osmosis unit has been identified as a
possible polishing technique because it will remove additional
oils not removed by the Option 1 system. In the case of reverse
osmosis heavy loadings of oil will render the unit ineffective
because oil can plug the membrane of a reverse osmosis system. As
with the Option 1 system, the effluent from the polishing waste
treatment components is directed to the solids removal components
of the metal waste treatment system, to reuse or discharge as
applicable.
The following paragraphs describe a reverse osmosis technique
applicable for the treatment of segregated oily wastes for
polishing.
Reverse Osmosis
Reverse osmosis, which is explained in detail in Section
XIII, "Innovative Treatment Technologies", is the process of
applying a pressure to a concentrated solution and forcing a
permeate through a semipermeable membrane into a dilute solution.
This principle has found use in treating oily wastes. In terms of
oily wastewater, reverse osmosis is used primarily as a polishing
mechanism to remove oils and metals that are still remaining
after treatment such as emulsion breaking or ultrafiltration.
Examples of reverse osmosis performance are shown in Table 7-71.
TABLE 7-71
REVERSE OSMOSIS PERFORMANCE (mg/1)
30166 38040 38040
Day 1 Day 2
Parameter Influent Effluent Influent Effluent Influent Effluent
Oil&Grease 117. 8.5 10.6 4.1 129. 41.
TOC 371. 78. 139. 94. 116. 108.
BOD 183. 60. 60. 58. 27. 53.
TSS 9.6 1.2 37. 14. 13. 1.0
Iron - - 1.91 .182 1.94 .22
VH-178
-------
Segregated
Oily Wastes
Oily Wastes-
I
Option 1
Emulsion Breaking
And
Skimming
(or Ultrafiltration
Alternative)
Oily Wastes-
Reverse Osmosis
or
Carbon Adsorption
T
To Metals/Solids Removal,
or Discharge as Applicable
FIGURE 7-34
TREATMENT OF SEGREGATED OILY WASTES
POLISHING TECHNIQUES
VTI-179
-------
ADDITIONAL OILY WASTE TREATMENT TECHNOLOGIES
In addition to the treatment methods presented there are several
other alternative technologies that are applicable for the
treatment of oily wastewater. The following paragraphs describe
these technologies: coalescing, flotation, centrifugation,
integrated adsorption, and thermal emulsion breaking.
Coalescing
The,basic principle of coalescing involves the preferential
wetting of a coalescing medium by oil droplets which accumulate
on the medium, and. then rise to the surface of the solution.
The most important requirements for coalescing media are
wettability for oil and large surface area.
I
Coalescing stages may be integrated with a wide variety of
gravity oil separation devices, and some systems may incor-
porate several coalescing stages. In general, the provision
of preliminary oil skimming treatment is desirable to avoid
overloading the coalescer. One commercially marketed system
for oily waste treatment (See Figure 7-35) combines coalescing
with gravity separation. In this unit, the oily waste enters
the separator where the large droplets immediately move to the
top surface of the separator because of the specific gravity
differential. The smaller droplets enter the corrugated plate
area where laminar flow produces coalescing of the oil droplets.
The oil droplets deposit on the surface of the plates and
stream upward through weep holes in the plates to the surface,
where adjustable skimmers remove the oil. Heavy solids are
deposited in the entrance chamber before the oily wastewater
enters the plate area.
VII-180
-------
V
I-1
00
INFLUENT
OIL-WATER
MIXTURE
OIL SKIMMER
OIL OUTLET
DRAIN
INLET WEIR
OIL
SEPARATED OIL SKIMMER
OIL DAM
s
\
COALESCING
PLATE ASSEMBLY
OUTLET
WEIR
CLEAN
WATER
EFFLUENT
DRAIN
FIGURE 7-35
COALESCING GRAVITY SEPARATOR
-------
Application
Coalescing is used in the Metal Finishing Category for treatment
of oily wastes. It allows removal of oil droplets too finely
dispersed for conventional gravity separation/skimming technology.
It can also significantly reduce the residence times (and
therefore separator volumes) required to achieve separation of
oil from some' wastes. Because of their simplicity, coalescing
oil separators provide generally high reliability and low
capital and operating costs. Coalescing is not generally
effective in removing soluble or chemically stabilized emulsi-
fied oils. To avoid plugging, coalescers must be protected by
pretreatment from very high concentrations of free oil and
grease and suspended solids. Frequent replacement of prefliters
may be necessary when raw waste oil concentrations are high.
Coalescing is inherently highly reliable because there are no
moving parts, and the coalescing substrate is inert in the
process and therefore not subject to frequent regeneration or
replacement requirements. Large loads or inadequate prior
treatment, however, may result in plugging or bypassing of
coalescing . 'Maintenance requirements are generally limited
to replacement of the coalescing medium on an intrequent basis.
No appreciable solid waste is generated by this process, but
when coalescing occurs in a gravity separator, the normal
solids accumulation is experienced.
Performance
The analysis results of samples taken before and after a
coalescing gravity separator at Plant ID 38217 are shown below
(Concentrations are in mg/1).
Plant ID 38217 (mg/1)
Day 1 Day 2
Parameter Raw Effluent Raw Effluent
Oil & Grease 8320. 490. 4240. 619.
TOC 923. 1050. - 535.
BOD 2830. 2950. 1980. 1530.
TSS 637. 575. 1610. 620.
Demonstration Status
I
Coalescing has been fully demonstrated in the Metal Finishing
Category and in other industries that generate oily wastewater,
Coalescers are used at 3 facilities in the present data base;
Plant ID'S 14001, 20173, and 38217.
VII-182
-------
Flotation
Flotation, as was explained in the "Treatment of Common Metals
Wastes" section, is the process of causing particles such as
oil or metal hydroxides to float to the surface of a tank
where they can be concentrated and removed. This is brought
about by releasing gas bubbles which attach themselves to the
particles, increasing their buoyancy, causing them to rise to
the surface and float. Flotation units are commonly used in
industrial operations to remove free and emulsified oils and
grease. For these applications in the Metal Finishing Category,
the flotation technique commonly referred to as dissolved air
flotation (DAF) is employed. Dissolved air flotation utilizes
the emulsion breaking techniques that were previously discussed
and in addition uses the bubbles of dissolved air to assist in
the agglomeration of the oily droplets and to provide increased
buoyancy for raising the oily droplets to the surface. A
typical dissolved air flotation system is shown in Figure
7-36.
Application
The use of dissolved air for oily waste flotation subsequent
to emulsion breaking can provide better performance in shorter
retention times (and therefore smaller flotation tanks) than
with emulsion breaking without flotation. A small reduction
in the quantity of chemical for emulsion breaking is also
possible. Dissolved air flotation units have been used success-
fully, in conjunction with further subsequent processes, to
reclaim oils for direct reuse and/or use as power plant fuels
in the Metal Finishing Category.
Performance
The performance of a flotation system depends upon having
sufficient air bubbles present to float essentially all of the
suspended solids. An insufficient quantity of air will result
in only partial flotation of the solids, and excessive air
will yield no improvement. The performance of a flotation
unit in terms of effluent quality and solids concentration in
the float can be related to an air/ solids ratio. The shape
of the curve obtained will vary with the nature of the solids
in the feed.
VTI-183
-------
V
M
Chemical
Addition
Oil To
Disposal
Sludge Line (If Req'd)
1
Pressure
Regulator
Pressure
Tank
Air Supply
Flotation
Tank
Effluent
cycle II Jf
* — y !
Optional
'Source
t_
Recycl
Centrifugal Pump
FIGURE 7-36
TYPICAL DISSOLVED AIR FLOTATION SYSTEM
-------
The results of sampling done at Plant ID 33692 are presented
below (Concentrations are in mg/1).
Plant ID 33692 (mg/1)
Day 1 Day 2
Parameter Influent Effluent. Influent Effluent
Oil & Grease 412. 108. 65.8 28.9
TOG 3000. 132. 98. 86.
BOD 130. 78. 31. 24.
TSS 416. 210. 166. 103.
Demonstration Status
Flotation is used in 25 facilities in the present data base
and these are identified in Table 7-42.
Centrifugation
Centrifugation is the process of applying a centrifugal force
to cause the separation of materials. This force is many
times the force of gravity so it allows for solids separation
in a much shorter time than that required by settling. When a
suspension is centrifuged, the components of the solution with
the greatest specific gravity accumulate at the farthest
distance from the axis of the centrifuge and those with the
least specific gravity are located nearest the axis. So when
oily wastes containing suspended solids are centrifuged, the
solids portion collects at the outside of the centrifuge, the
oil forms the innermost layer, and the water portion is sand-
wiched in between. The different layers that are formed can
VII-185
-------
then be collected separately. Centrifuges are currently avail-
able that have been specifically designed to separate either
oil/water mixtures or oil/solids/water mixtures. Centrifugation
equipment is in use as a pretreatment technique to separate
oil/water mixtures prior to further wastewater treatment.
The performance of the centrifuge at plant ID 19462, which
employs centrifugation to lower the oil concentration of the
wastewater prior to further oil removal by ultrafiltration,
was established by sampling the influent and effluent streams.
The results are presented below (Concentrations are in mg/1).
Plant JED 19462 (mg/1) !
Day 1 Day 2
Parameter _In Out In Out
Oil and Grease 373,280 3402 14,639 1102
TSS 6866 1266 8938 1154
A detailed discussion on the various types of centrifuges is
presented under the heading "Treatment of Sludges".
Centrifugation is used on oily wastes by 5 plants in the
present data base: Plant ID'S 06019, 11184, 14062, 19462, and
30166.
Integrated Adsorption
Application
The integrated adsorption process is designed for disposal oE
materials in dilute aqueous emulsion, such as oils and paints.
The active agent is any of several aluminum silicate-based
formulations in powder form. This material is added to the
wastewater, and the mixture is agitated for six minutes.
During this period, the powder adsorbs the emulsified materials.
Next, the solid material is allowed to settle for two minutes,
and the water phase is then decanted through a disposable belt
filter, leaving any unsettled solids on the filter. Finally,
the sludge phase is ejected on the disposable belt filter,
where it is partially dewatered. Both the belt and the material
retained on it feed into a disposal container. The filtered
water is collected for reuse or discharge.
The integrated adsorption process is available as a commercial
system. Equipment consists of a reagent feed hopper, an
associated automatic feed device, a wastewater feed pump, a
reaction vessel, a high-speed turbine mixer, a disposable
belt, a band filter, a clean water pump, a clean water tank,
and associated controls.
VII-186
-------
The integrated adsorption system does not add anything to the
processed water, the pH and salinity of which are unaffected..
The system is designed for automatic operation, and the sludge
is leach-resistant because of the strong bonding of the adsorbed
materials. The system obviates the need for other chemical
treatment or physical separation, but it does entail both
capital and operating expense.
Performance
The integrated adsorption system consistently removes greater
than 99 percent of the paints, detergents, and emulsified oils
in the feed stream. The sludge is 20 to 40 percent solids,
and is strongly resistant to leaching.
Demonstration Status
The system is employed for treating paint booth water and
emulsified oils by a leading European auto maker, among others.
There are more than 100 units presently in service.
Thermal Emulsion Breaking
Thermal emulsion breaking is usually a continuous process. In
most cases, however, these systems are operated intermittently,
due to the batch dump nature of most emulsified oily wastes.
The emulsified raw waste is collected in a holding tank until
sufficient volume has accumulated to warrant operating the
thermal emulsion breaking system. One such system is an
evaporation-distillation-decantation apparatus which separates
the spent emulsion into distilled water, oil and other floating
particles, and sludge (See Figure 7-36a) . Initially, the raw
waste flows from the holding tank into the main conveyorized
chamber. Warm dry air is passed over a large revolving drum
which is partially submerged in the emulsion. Some water
evaporates from the surface of the drum and is carried upward
through a filter and a condensing unit. The condensed water
is discharged and can be reused as process makeup, while the
air is reheated and returned to the evaporation stage. As the
concentration of water in the main conveyorized chamber decreases,
oil concentration increases and some gravity separation occurs.
The oils and other emulsified wastes which separate flow over
a weir into a decanting chamber. A rotating drum skimmer
picks up oil from the surface of this chamber and discharges
it for possible reprocessing or contractor removal. Mean-
while, oily water is being drawn from the bottom of the decant-
ing chamber, reheated, and sent back into the main conveyorized
chamber. This aids in increasing the concentration of oil in
the main chamber and the amount of oil which floats to the
top. Solids which settle out in the main chamber are removed
by a conveyor belt. This conveyor, called a flight scraper,
moves slowly so as not to disturb the settling action. As
with the use of acids for chemical emulsion breaking, thermal
emulsion breaking is more commonly used for oil recovery than
for oily waste removal.
VII-187
-------
REHEATING
COIL
MAKE UP TO
OPERATING
EMULSION SYSTEM
AIR
RECIRCULATION
FAN
CONDENSING
UNIT
MAIN CONVEYOR I ZED
FROM SPENT
EMULSION TANK
OIL
DISCHARGE
TRANSFER
PUMP
FIGURE 7-36a
THERMAL EMULSION BREAKER
VII-188
-------
Application
Emulsion breaking technology can be applied to the treatment
of emulsified oil/water mixtures in the Metal Finishing Category
wherever it is necessary to separate oils, fats, soaps, etc.
from wastewaters.
Advantages of thermal emulsion breaking include an extremely
high percentage of oil removal, the separation of floating oil
from settleable sludge, and the production of distilled water
which is available for process re-use. In addition, no chemical
additives are required and the operation is fully automatic,
factors which reduce operating costs and maintenance require-
ments. Disadvantages of this system are the cost of heat to
run the small boiler and the necessary installation of a large
storage tank. Thermal emulsion breaking models are currently
available to handle loads of 150, 300, and 600 gallons per
day.
Performance
The performance level using thermal emulsion breaking is
dependent primarily on the characteristics of the raw waste
and proper maintenance and functioning of the system components.
Some emulsions may contain volatile compounds which could.
escape with the distilled water. In systems where the water
is recycled back to process, however, this problem is essentially
eliminated. Experience in at least two plants has shown that
trace organics or other contaminants found in the effluent
will not adversely affect the lubricants when this water is
recycled back to process emulsions.
Demonstration Status
Thermal emulsion breaking is known to be in regular use in at
least two plants (ID 04086 and 15030) manufacturing copper wire.
The process is equally applicable to oil-water emulsions used
in metal finishing plants.
VII-189
-------
CONTROL AND TREATMENT OF TOXIC ORGAN!CS
INTRODUCTION
This section presents information on the control and treatment of
toxic ocganics from spent solvents; in total plant process
wastewaters; and in segregated oily waste streams. This section is
organized as follows: (1) waste solvent control options; (2) treat-
ment of toxic organics for combined wastewater; and (3) treatment of
toxic organics in segregated oily wastestreams. In addition.
alternative treatment methods for toxic organics control are
presented.
WASTE SOLVENT CONTROL OPTIONS
The primary control technology for toxic organics is not to dump
concentrated toxic organics directly into waste streams or to
combine concentrated toxic organics with any waste that will enter
the waste treatment system. The major source of toxic organics in
metal finishing wastewaters are waste solvents from degreasing
operations that have been dumped into the waste stream. The
solution to controlling toxic organics in the wastewaters, there-
fore, is to segregate concentrated toxic organics wastes for
contract hauling or reclamation. Additionally, alternative
techniques for solvent degreasing may be employed to reduce or
eliminate the quantity of waste solvent generated. The following
paragraphs discuss the segregation of waste solvents, contract
hauling of waste solvents, and cleaning alternatives that can be
substituted for solvent degreasing.
Waste Solvent Segregation
Spent degreasing solvents should be segregated from other
process fluids to maximize the value of the solvents, to
preclude the contamination of other segregated wastes (such as
oily wastes)/ and to prevent the discharge ;of priority pollu-
tants to any wastewaters. This segregation can be accomplished
by providing and identifying the necessary storage container(s),
establishing clear disposal procedures, training personnel in
the use of these techniques, and checking periodically to
ensure that proper segregation is occuring. Segregated waste
solvents are appropriate for on-site solvent recovery or can
be contract hauled for disposal or reclamation.
Contract Hauling
The DCP data identified several waste solvent haulers most of
whom haul solvent in addition to their primary business of
haulinq waste oils. The value of waste solvents seems to be
VII--190
-------
sufficient to make waste solvent hauling a viable business.
Telephone interviews indicate that the number of solvent
haulers is increasing and that their operations are becoming
more sophisticated because of the increased value of waste
solvent. In addition, a number of chemical suppliers include
waste hauling costs in their new solvent price. Some of the
larger solvent refiners make credit arrangements with their
clientele; for example it was reported that one supplier
returns 50 gallons of refined solvent for every 100 gallons
hauled.
Cleaning Alternatives to Solvent Degreasing
The substitution for solvent degreasing of cleaning techniques
that use no solvents or use lesser amounts of solvents would
eliminate or reduce the quantity of toxic organics that are
found in wastewaters. Alternative cleaning methods for the
removal of oils and grease include wiping, immersion, and
spray (both liquid and vapor phase) techniques using water,
alkaline or acid mixtures, and solvent emulsions. Various
methods of agitation, including ultrasonic and electrolytic
are helpful wherever they are applicable. Table 7-72 presents
a generalized matrix of these cleaning approaches, each of
which has the capability for cleaning oily metal parts.
Fundamentally, the factors required to remove oil and clean
the metal surfaces of a part are:
1. A fluid to transport the cleaning agent to and the
soil particles away from the surface to be cleaned.
2. A chemical in which oily residues are soluble.
3. Heat (temperatures above 150°F) to lower the
viscosity of the oil and enhance the activity
of the chemical agent.
4. A scrubbing or wiping mechanism to physically
remove the cleaner and soil.
In the metal finishing industry, the factors that dictate the
cleaning needs include:
1. Production volume
2. Product size
3. Product material (eg-ferrous, non-ferrous)
4. Product shape and complexity (eg-blind holes, internal
corners)
5. Degree of cleanliness required (eg-surface purity)
6. Surface preparation required (eg-dry, oil film,
oxide/scale'removal, oxidation resistance)
Obviously, a single cleaning approach is not practicable for
all of these diverse product and manufacturing requirements.
The task of identifying feasible cleaning alternatives to
solvent degreasing then becomes one of identifying areas which
have similar cleaning requirements so that substitution for
solvent degreasing is practicable. Typical areas that are
VII-191
-------
TABLE 7-72
CLEANING APPROACHES
CLEANING METHOD
SORBENT WATER
CLEANING AGENT
ALKALINE ACID EMULSION SOLVENT
WIPING
A. Dry
B. Wfet
IMMERSION
A. Cold
X
X
1. without agitation
2. with agitation
B. Hot
1. without agitiation
2. with agitation
SPRAY
A. Liquid
1. Cold
2. Hot
B. Vapor
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
VII-192
-------
imenable to cleaning techniques other than solvent degreasing
ire:
1. Low to medium volume production levels where cleaning
cycle time does not impact the cost of production
2. Non-ferrous products
3. Simple product shapes
4. Small parts (adaptable to automated processes)
5. Oily film residue not objectionable
6. No exacting surface finishing required.
kll of the previously described cleaning methods are applicable
:o some of these cleaning needs. For comparative purposes,
:hese cleaning processes have been ranked on the relative
>asis of cost, quality of cleaniness, and significant environ-
\ental effects. This relative ranking is presented in Table
'-73 for the five general cleaning methods. The bases for the
criteria used for relative ranking are defined as follows;
1. Cost - include equipment, facilities, chemicals,
heat, power, maintenance, operation (rinsing and
drying where applicble) and wastewater treatment.
2. Cleanliness Quality - surface purity.
3. Pollution - environmental effects of the process.
4. Energy - thermal and electrical energy requirement.
CLEANING METHOD
TABLE 7-73
CLEANING PROCESS RELATIVE RANKING
(LOWEST NUMBER IS BEST)
CLEANINESS ENVIRONMENTAL •
COST QUALITY POLLUTION ENERGY COMBINED
MEAN
OVERALL
RANKING
Solvent Degreasing
Emulsion Cleaning
Alkaline Cleaning
Acid Cleaning
Hot Water/Steam
Cleaning
1
3
2
4
5
3
4
2
1
5
5
4
2
3
1
1
2
3
4
5
3
3
2.5
3.5
3
2.
3.
2.
3
4
5
25
25
VTI-193
-------
Alkaline cleaning is the most feasible substitute for solvent
degreasing. This selection is based in part on the fact that
the combined alkaline cleaning environmental ranking and the
mean overall ranking are lowest. Further, data derived from
existing cleaning processes, shows that alkaline cleaning is
only 14% less cost effective than vapor degreasing. It is
believed that further development of alkaline cleaners and the
associated equipment should make its cost effectiveness equiva-
lent to or better than that for solvent degreasing. The major
advantage of alkaline cleaning over solvent degreasing is the
elimination or reduction in the amount of priority pollutants
being discharged. A major disadvantage connected with alkaline
cleaning is the energy consumption. Another disadvantage is
the fact that the process itself tends to dilute the oils
removed and discharges these diluted oils as well as the
cleaning additive, whereas in solvent degreasing, the oils are
contractor hauled along with the spent solvent and not dis-
charged. However, at least one firm produces a close-loop
alkaline cleaning system oil separator that is illustrated in
Figure 7-37.
This system provides in-process removal of oils and metals
wastes which extends the useful alkaline cleaner life and
significantly reduces treatment requirements because the spent
cleaning solution is normally contract hauled. Only the
alkaline solution dragout to a subsequent rinsing operation
produces a waste that requires treatment. Best described as a
continous-batch oil separator, the system has dual compartments
holding caustic wash solution, each equipped with an oil
skimmer and separated by a waste tank. Piping leads from each
compartment to a series of washers and back to a pump. Auto-
mated valves control flow from the pump to one of the compart-
ments. One compartment continuously supplies caustic solution
to a group of washers as the other stands for 24 hours, allowing
heavy materials to settle to the bottom as sludge and permitting
the oils to float to the surface. There, :surface oils are
skimmed off, drained into the waste tank, and periodically
drawn off for reclamation or reuse. While one wash solution
in the first compartment is undergoing treatment, the clean
solution in the other compartment is circulated to the washers.
Four plants have these systems in operation and one installation
has been in use since June 1975. At this facility they report
zero discharge (via contract hauling the spent cleaning solu-
tion) and the reclamation of 25,000 gallons of oil annually
from a cleaning operation prior to heat treatment. The specific
advantages of applying this type of in-process oil/metal
treatment are as follows:
1. The concentrated discharges of spent alkaline cleaning
baths are eliminated by contract hauling the reduced
volume of spent cleaner.
VII-194
-------
H
VO
in
Make up
water
Collection
sump
Lift
pump
fteussabla
alkaline
cleaning wale'
FIGURE 7-37
ALKALINE WASH OIL SEPARATOR
-------
2. Energy requirements are lowered:because of water
conservation.
3. Water and air pollution resulting from alkaline
cleaning are less than for the solvent degreasing
operation.
4. Oil reclamation is accomplished.
5. Lower cleaning costs are available through the con-
servation of cleaning agent and heat; less frequent
waste haulingi the use of cold cleaners; and lowered
treatment requirements.
¥11-196
-------
TREATMENT OF TOXIC ORGANICS FOR COMBINED WASTEWATER
Toxic organics that enter the plant process wastewater from
various sources such as rinses and paint booth water curtains are
usually present at lower concentrations than toxic organics in
waste solvents or in concentrated oily wastes.
The applicable treatment technologies for toxic organics removal
from combined wastewater are the common metals treatment
technologies. To the extent that these technologies, evaluated
by the Agency for control of metals and cyanides, also remove
toxic organics. the TTO limit should reflect the discharge from
plants with these technologies.
The limitations for TTO are based on total plant wastewater data
for EPA sampled plants. EPA sampled plants cover three
technology groupings: Option 1 (precipitation/clarification).
Option 2 (precipitation/clarification/filtration), and other than
Option 1 or Option 2 plants. These data are presented in Tables
7-74 through 7-76. Option 1 plant data were used to derive the
end-of-pipe TTO limits. The raw waste TTO limits were derived
using the total plant raw waste data from all three groupings.
The TTO data were evaluated on the basis of processes, products.
type of work, pre- and post-process water quality characteristics
to investigate combinations of plants that generate larger
amounts of TTO than other groups. The data were classified into
groups, namely plants that perform painting, solvent degreasing.
painting and solvent degreasing; plants with total raw waste oil
and grease concentrations above and below 100 mg/£; and plants
with TTO concentrations in the supply water of above and below
0.1 mg/5t. In addition, the Agency examined job shops.
captives, printed circuit board manufacturers, and automotive
plants. (This classification analysis is presented in detail in
Exhibit 2 at the back of the development document.)
The results of this analysis showed that plants that have both
paint and solvent degreasing operations discharge the highest TTO
concentrations of any other process sector of the metal finishing
industry. The painting and solvent degreasing plants were used
to establish an overall mean. The daily variability factor was
derived using the data from plants involved in painting or
degreasing. Long term self-monitoring for TTO were not available
for the industry (primarily because plants typically had not been
required to monitor for organics in the past). Considering the
high cost of TTO monitoring, no 10-day variability factors or
monthly maximum averages were developed for TTO. The results of
the statistical calculations of the TTO daily maximum limitations
are summarized below:
VII-197
-------
TTO EFFLUENT LIMITATIONS -;OPTION 1
Mean TTO effluent concentration 0.434 mg/i
Daily variability factor 4.91 mg/8.
Daily maximum effluent concentration 2.13 mg/8,
TTO HAW WASTE LIMITATIONS
Mean TTO effluent concentration 1.08 mg/8.
Daily variability factor 4.23 mg/8.
Daily maximum raw waste concentration 4.57 mg/8.
Percentile distribution graphs for TTO Option 1 effluent data and
for TTO total raw waste data are presented in Figures 7-38 and
7-39. respectively. As is evident from these graphs, compliance
with the TTO effluent limits and with the TTO raw waste limits is
100 percent when data, which are considered indicative of
improper disposal of toxic organics. are excluded.
VXl-198
-------
TABLE 7-74
METAL FINISHING CATEGORY PERFORMANCE DATA FOR TTO
OPTION 1
Data
Point
1.
2.
3.
4.
5. •
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
Raw Waste
Concentration
(mq/8.)
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
0
0.002
0.003
0.003
0.006
0.006
0.007
0.008
0.009
0.009
0.009
0.010
0.012
0.014
0.014
0.017
0.019
0.020
0.020
0.022
0.023
0.030
0.031
0.034
0.036
0.038
0.040
0.040
0.043
0.059
0.091
Effluent
Concentration
(mg/it)
0.019
0.001
0.019
0.037
0.025
0.430
0.007
0.007
0.020
0.007
0.485
0
0.004
0.004
0.007
0.005
0.008
0.009
0.016
0.005
0.006
0.010
0.006
0.007
0.008
0.013
0.015
0.004
0.008
0.024
0.254
0.012
0.014
0.207
0.002
0.020
0.013
0.002
0.035
0.032
0.038
NA
Plant ID
6091-15-0
6091-15-1
6091-15-2
12061-14-0
19068-14-0
20005-21-0
27046-15-2
34050-15-0
34050-15-1
34050-15-2
6019
9025-15-0
20083-15-0/1
20083-15-2/3
20083-15-4/5
12061-15-0
12061-15-2
20022-15-2
20022-15-1
6110-15-1
6110-15-2
9052-15-0
6110-15-0
9052-15-2
21003-15-2
41051-15-0
15608-15-2
15608-15-0
20022-15-0
41051-15-1
4069-15-0/1
41051-15-2
12061-15-1
2032-15-2
21003-15-0
17061-15-1
15608-15-1
9052-15-1
21003-15-1
4071-15-0
6960-15-4/5
34051-15-0
(Continued)
VII-199
-------
TABLE 7-74 (continued)
METRL FINISHING CATEGORY PERFORMANCE DMR FOR TTO
OPTION 1 i
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
80.
81.
Raw Waste
Concentration
(met/it)
0.095
0.097
0.097
0.098
0.099
0.104
0.107
0.109
0.110
0.111
0.113
0.120
0.130
0.133
0.140
0.141
0.178
0.192
0.200
0,202
0.204
0.224
0.251
0.259
0.283
0.289
0.364
0.400
0.426
0.473
0.486
0.769
0.888
1.161
1.287
1.619
1.938
8.466
12.866
Effluent
Concentration
(mg/8.)
0.016
0.203
0.003
0.228
0.180
0.056
0.081
0.081
0.122
0.007
0.131
'0.017
0.093
0.040
0.130
0.034
0.322
0.012
0.109
0.016
0.144
0.007
0.008
0.005
NA
18.005
0.067
0.002
0.012
0.483
0.052
0.140
0.699
0.082
0.109
0.643
0.181
37.355
NA
Plant ID
34051-15-1
6090-14-0
38051-15-2
44062-15-0
38052-15-0
6960-15-0/1
44062-15-2
2032-15-5
44062-15-1
34051-15-2
4069-15-2/3
19068-15-1
4071-15-3
4071-15-1
30165-21-0
17061-15-3
4069-15-4
38052-15-1
38052-15-2
19068-15-2
6960-15-2/3
38051-15-0
9025-15-1
38051-15-1
4282-21-0
9025-15-2
30054-15-0
27046-15-1
27046-15-0
6019
6090-15-1
30054-15-1
17061-14-1
2032-15-0
30054-15-2
28699-21-0
20103-21-0
6090-15-2
20103-21-1
VH-200
-------
TABLE 7-75
METAL FINISHING CATEGORY PERFORMANCE DATA FOR TTO
OPTION 2
Raw Waste Effluent
Data Concentration Concentration
Point (mq/fi.) (mq/H) Plant ID
1. NA 0.400 17050-14-0
2. NA 0.415 36048-15-0/1
3. NA 0.103 36048-15-2/3
4. NA 0.091 36048-15-4/5
5. 0.012 0.056 18538-15-3
6. 0.021 0.010 12075-15-2/3
7. 0.028 0.043 12075-15-0/1
8. 0.042 0.007 12075-15-4/5
9. 0.064 0.030 18538-14-0
10. 0.477 0.037 17050-15-1
11. 1.083 0.003 17050-15-0
VII-201
-------
TABLE 7-76
METAL FINISHING CATEGORY PERFORMANCE DATA FOR TTO
OTHER THAN OPTION 1 or 2
Raw Waste
Concentration
Effluent
Concentration
(mqA)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
10.
21.
22.
23.
24.
25.
26.
27.
28.
29.
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
0.005
0.007
0.008
0.009
0,010
0.011
0.011
0.011
0.012
0.013
0.014
0.028
0.030
0.084
0.285
0.326
.09
.005
2,
o:.
1.
2.
13.50
52
.189
0|.153
0.165
0.005
0.007
0.007
0.288
0,377
0.673
0^006
0.001
old 12"
0;012
0.009
0.014
0.005
0.009
No Data
0.009
0.011
0.014
0.010
0.011
0.257
0.140
0.823
0.120
0.433
Plant ID
12065-14-1
12065-15-2
12065-15-4
13042-21-1
19069-15-0
19069-15-1
19069-15-2
38040-23-0
38040-23-1
38217-23-0
11108-15-1
11108-15-2
40060-15-0
40060-15-1
11103-15-2/3
2033-15-4/5
11108-15-0
21066-15-1
21066-15-0
11103-15-4
21066-15-3
2033-15-0/1
2033-15-2/3
11103-15-0
36178-21-0
36178-21-1
33692-23-0
36178-21-2
33692-23-1
VII-202
-------
<
_J
O-
o
EC
=>
m
31X01 1V101
VII-203
-------
to
o
en
CO
u
5
<
a
oc
o
u
12
10
OU-
••••••••
10
20
30
40 50 60
PERCENTILE DISTRIBUTION
70
80
90
100
FIGURE 7-39. PERCENTILE DISTRIBUTION OF TTO IN RAW WASTE
IN METAL FINISHING WASTEWATERS
-------
TREATMENT OF TOXIC ORGANICS IN SEGREGATED OILY WASTE
Toxic organics can be removed from wastewater streams during
treatment for oil and grease because of their solubility in
hydrocarbons as shown in Table 7-77. Segregated oily wastes
treatment of concentrated oily wastestreams will effectively remove
oil and grease, which will result in removal of toxic organics.
However, as stated previously, preventing toxic organics from
entering the wastewater stream can be the most effective control.
The technologies applicable to removing TTO in segregated oily waste
streams include Option 1 for segregated oily wastes (emulsion
breaking and skimming or ultrafiltration). A detailed description
plus information on the applicability and demonstration status of
these technologies is presented in "Treatment of Oily Waste."
TTO performance data for Option 1 and ultrafiltration are presented
in this section in Tables 7-78 and 7-79.
VTI-205
-------
TABLE 7-77
SOLUBILITY OP TOXIC ORGANIC PARAMETERS
Parameter
001 Acenaphthene
006 Carbon Tetrachloride
010 1,2-dichloroethane
Oil 1,1,1-trichloroethane
013 1,1-dichloroethane
021 2,4,6-trichlorophenol
022 Paraehlorometa Cresol
029 1,1-dichloroethylene
030 1,2-trans-diehloroethylene
034 2,4-dimethyl Phenol
038 Ethylbenzene
039 Fluoranthene
044 Methylene Chloride
045 Methyl Chloride
054 isophorone
055 Naphthalene
059 2,4-dinitrophenol
060 4,6-dinitro-o-cresol
062 N-nitrosodiphenylamine
064 Pentachlorophenol
065 Phenol
066 Bis(2-ethylhexyl)phthalate
067 butyl Benzyl Phthalate
068 Di-n-butyl Phthalate
070 Diethyl Phthalate
077 Acenaphthylene
078 Anthracene
081 Phenanthrene
085 Tetrachloroethylene
086 Toluene
087 Trichloroethylene
Water
Solubility in
Hydrocarbons
Insoluble
Very Slightly
Very Slightly
Insoluble
Very Slightly
Slightly "'
Soluble
Slightly
Slightly
Soluble
Soluble
Insoluble
Slightly
Slightly
Slightly
Insoluble
Slightly
Slightly
Insoluble
Slightly
Soluble
Insoluble
Insoluble
Insoluble
Insoluble
Insoluble
Insoluble
Insoluble
Insoluble
Slightly
Insoluble
Soluble
Infinitely
Very to Infinitely
Soluble
Soluble
Soluble
Very to Infinitely
Soluble
Soluble
Soluble
Soluble to Infiniti
Soluble
Soluble
Soluble
Soluble
Soluble
Very Soluble
Infinitely
Soluble
Soluble
Infinitely
Soluble
Soluble
Soluble
Soluble
Very Soluble
Soluble
Soluble
Soluble
Infinitely
Infinitely
vii-206
-------
Plant ID
1058-22-0
12095-22-0
12095-22-1
12095-22-2
20103-21-0
28125-22-1
40836-22-0
TABLE 7-78
TTO PERFORMANCE DATA (mg/S,) FOR
OPTION 1 SEGREGATED OILY WASTE
Influent Effluent
2.77 1.43
6.14 0.996
3.15 0.800
6.50 0.480
1.94 1.86
0.767 1.076
21.5 8.6
TABLE 7-79
TTO PERFORMANCE DATA (Hig/a) FOR ULTRAFILTRATION
Plant ID Influent Effluent
15193-21-0
30166-21-0
13041-22-0
13041-22-1
13041-22-2
13324-21-0
802.05
9.93
1037.5
14.3
4.84
12.02
80.83
1.41
14.82
13.0
30.8
1.48
VII-207
-------
ADDITIONAL TREATMENT METHODS FOR TOXIC ORGANICS REMOVAL
Additional treatment technologies applicable for the treatment of
TTO include carbon adsorption and reverse osmosis (polishing
techniques) and resin adsorption, ozonation, chemical oxidation,
and aerobic decomposition. These technologies are described in
detail in this subsection.
VH-208
-------
Carbon Adsorption
Carbon adsorption in industrial wastewater treatment involves
passing the wastewater through a chamber containing activated
carbon. The use of activated carbon has been proven to be
applicable for removal of dissolved organics from water and
wastewater. In fact, it is one of the most efficient organic
removal processes available. This process is reversible, thus
allowing activated carbon to be regenerated and reused by the
application of heat and steam.
The term activated carbon applies to any amorphous form of
carbon that has been specially treated to give high adsorption
capacities. Typical raw materials include coal, wood, coconut
shells, petroleum base residues and char from sewage sludge
pyrolysis. A carefully controlled process of dehydration,
carbonization, and oxidation yields a product which is called
activated carbon. This material has a high capacity for
adsorption, 500-1500 square meters/gram, resulting from a
large number of internal pores. Pore sizes generally range
from 10-100 angstroms in radius.
Activated carbon removes organic contaminants from water by
the process of adsorption, or the attraction and accumulation
of one substance on the surface of another. Activated carbon
has a preference for organic compounds and, because of this
selectivity, is particularly effective in removing organic
compounds from aqueous solutions.
Some important but general rules based on considerations
relating to carbon adsorption capacity are:
Higher surface area will give a greater adsorption capacity,
Larger pore sizes will give a greater adsorption capacity
for large molecules.
Adsorptivity increases as the solubility of the solute
decreases. For hydrocarbons, adsorption increases with
molecular weight.
Adsorption capacity will decrease with increasing
temperature.
For solutes with ionizable groups, maximum adsorption
will be achieved at a pH corresponding to the minimum
ionization.
The rate of adsorption is also an important consideration.
For example, while capacity is increased with the adsorption
of higher molecular weight hydrocarbons, the rate of adsorp-
tion is decreased. Similarly, while temperature increases will
decrease the capacity, they may increase the rate of removal
of solute from solution.
VH-209
-------
Carbon adsorption requires pretreatment to remove excess
suspended solids, oils, and greases. Suspended solids in the
influent should be less than 50 ppm to minimize backwash
requirements; a downflow carbon bed can handle much higher
levels (up to 2000 ppm), but frequent backwashing is required.
Backwashing more than two or three times a day is not desirable;
at 50 ppm suspended solids, one backwash will suffice. Oil
and grease should be less than about 10 ppm. A high level of
dissolved inorganic material in the effluent may cause problems
with thermal carbon reactivation (i.e., scaling and loss of
activity) unless appropriate preventive steps are taken; such
steps might include pH control, softening, or the use of an
acid waste on the carbon prior to reactivation.
Activated carbon is available in both powdered and granular
form. The equipment necessary for a granular activated carbon
adsorption treatment system consists of the following: a
preliminary clarification or filtration unit to remove the
bulk of suspended solids; two or three adsorption columns
packed with activated carbon similar to the one shown in
Figure 7-40; a holding tank located between the adsorbers; and
liquid transfer pumps. Unless a reactivation service is
utilized, a furnace and associated quench tanks, spent carbon
tank, and reactivated carbon tank are necessary for reactiva-
tion.
Powdered carbon is less expensive per unit ^weight than granular
carbon and may have slightly higher adsorption capacity but it
does have some drawbacks. For example, it is more difficult
to regenerate; it is more difficult to handle (settling characteris-
tics may be poor); and larger amounts may be required than for
granular systems in order to obtain good contact. One innova-
tive powdered carbon system uses wet oxidation for regeneration
instead of fluidized bed incineration. This technique has
been applied mainly to municipal treatment but can be used in
industrial systems.
The necessary equipment for a two stage powdered carbon unit
is as follows: four flash mixers, two sedimentation units,
two surge tanks, one polyelectrolyte feed tank, one dual media
filter, one filter for dewatering spent carbon, one carbon
wetting tank, and a furnace for regeneration of spent carbon.
Thermal regeneration, which destroys adsorbates, is economical
if carbon usage is above roughly 454 kg/day (1000 Ibs/day).
Reactivation is carried out in a multiple hearth furnace or a
rotary kiln at temperatures from 870°C to 988°C. Required resi-
dence times are of the order of 30 minutes. With proper
control, the carbon may be returned to its original activity;
carbon losses will be in the range of 4-9% and must be made up
with fresh carbon. Chemical regneration may be used if only
one solute is present which can dissolve off the carbon. This
allows material recovery. Disposal of the carbon may be required
if use is less than approximately 454 kg/day (1000 Ibs/day)
and/or a hazardous component makes regeneration dangerous.
VII-210
-------
FLANGE
WASTE WATER
INFLUENT
DISTR IBUTOR
WASH WATER
BACKWASH
BACK WASH
REPLACEMENT CARBON
SURFACE WASH
MANIFOLD
CARBON REMOVAL PORT
TREATED WATER
SUPPORT PLATE
FIGURE 7-40
ACTIVATED CARBON ADSORPTION COLUMN
VII-211
-------
A new type of carbonaceous adsorbent is made by pyrolizing ion
exchange resins. These spherical adsorbents appear to have
the best characteristics of adsorbent resins and activated
carbon. They have a greater physical strength, attrition
resistance, and regeneration flexibility than either activated
carbon or polymeric resins. One type is particularly suited
for halogenated organics and has greater capacity than selected
carbons for compounds such as 2-chloroethyl ether, bromodichloro-
methane, chloroform, and dieldrin. Another type (based on a
different polymeric resin) is best suited for removing aromatics
and unsaturated hydrocarbons. A third type has a particularly
mg/1) for phenol and other relatively polar organic molecules.
These adsorbents are commercially available but have not yet
been proven in large scale operation.
Application
The principle liquid-phase applications of activated carbon
adsorption include sugar decolorization; municipal water
purification; purifications of fats, oils, foods, beverages
and Pharmaceuticals; and industrial/municipal wastewater
treatment. Potentially, it is almost universally applicable
because trace organics are found in the wastewater of almost
every industrial plant.
The major benefits of carbon treatment include applicability
to a wide variety of organics, with high removal efficiency.
Inorganics such as cyanide, chromium, and mercury are also
removed effectively. Variations in concentration and flow rate
are well tolerated. The system is compact, and recovery of
adsorbed materials is sometimes practical. However, destruc-
tion of adsorbed compounds often occurs during thermal regenera-
tion. If carbon cannot be thermally desorbed, it must be
disposed of along with any adsorbed pollutants. When thermal
regeneration is utilized, capital and operating costs are
relatively high. Cost surveys show that thermal regeneration
is generally economical when carbon usage exceeds about 454
kg/day (1,000/lbday). Carbon cannot remove low molecular
weight or highly soluble organics. It also has a low tolerance
for suspended solids, which must be removed to at least 50 ppm
in the influent water.
This system should be very reliable assuming upstream protec-
tion and proper operation and maintenance procedures. It
requires periodic regeneration or replacement of spent carbon
and is dependent upon raw waste load and process efficiency.
Solid waste from this process is contaminated activated
carbon that requires disposal. If the carbon undergoes regenera-
tion, the solid waste problem is reduced because of much less
frequent replacement.
VII-212
-------
Performance
Carbon adsorption, when applied to well-treated secondary
effluent, is capable of reducing COD to less than 10 mg/1 and
BOD to under 2 mg/1. Removal efficiencies may be in the range
of 30% to 90% and vary with flow variations and different bed
loadings. Carbon loadings in tertiary treatment plants fall
within the range of 0.25 to 0.87 kg of COD removed per kg of
carbon, and if the columns are operated downflow, over 90%
suspended solids reduction may be achieved.
Quite frequently, segregated industrial waste streams are
treated with activated carbon. The contaminants removed
include BOD, TOC, phenol, color, cresol, polyesters, polynitro-
phenol, toluene, p-nitrophenol, p-chlorobenzene, chlorophenols,
insecticides, cyanides and other chemicals, mostly organic.
The flows being treated are generally small in comparison with
tertiary systems (less than 75,700 liters/day (20,000 gpd)).
Thermal reactivation of the carbon does not become common
until flows are above 227,100 liters/day (60,000 gpd). Some
installations reactivate their carbon chemically and the
adsorbate is recovered. Recoverable adsorbates are known to
include phenol, acetic acid, p-nitrophenol, p-chlorobenzene,
p-cresol, and ethylene diamine. Carbon loadings approach one
kg COD removal per kg carbon in installations where the adsorbates
are easily adsorbed and present in relatively high concentra-
tions. In other cases, where influent concentrations are
lower and where the adsorbates are not readily adsorbed, much
lower loadings will result. For example, it was determined
that brine wastewaters containing 150-750 ppm phenol and
1500-1800 ppm acetic acid could be reduced to about 1 ppm
phenol and 100-200 ppm acetic acid with phenol loadings in the
range of 0.09-0.16 kg per kg and acetic acid loadings in the
range of 0.04-0.06 kg per kg.
From metal finishing, loadings for cyanide removal have been
found to be on the order of 0.01 kg for influ'ent concentrations
around 100 ppm. Loadings for removal of hexavalent chromium
have been shown to be as high as 0.07 kg/kg carbon at 100 ppm
and 0.14 kg/kg carbon at 1000 ppm.
EPA isotherm tests have indicated that activated carbon is
very effective in adsorbing 65 percent of the organic priority
pollutants and reasonably effective for another 22 percent.
Specifically, for the organics of particular interest, activated
carbon was very effective in removing 2,4-dimethylphenol,
fluoranthene, isophorone, naphthalene, all phthalates, and
phenanthrene. It was reasonably effective on 1,1,1-trichloroe-
thane, 1,1-dichloroethane, phenol, and toluene. Table 7-80
summarizes the treatability effectiveness for most of the
organic priority pollutants by activated carbon as compiled by
EPA. Table 7-81 summarizes classes of organic compound together
with examples of organics that are readily adsorbed on carbon.
VII-213
-------
TABLE 7-80
TREATABILnV RATING OF PRIORITY POLLUTANTS UTILIZING CARBCN ADSORPTICN
Priority Pollutant
1. acenaphthere
2. actolein
3. aerylonitrlie
4. benzene
5. benzidine
6. carton tetrachloride
(tetrachlorome thane)
7. chlorobenzene
8. 1,2,4-trichlorobenzere
9. hexachlocobenzene
10. 1,2-dichloroethane
11. 1,1,1-trichloroethane
12. hexachloroethane
13. 1,1-dichloroethane
14. l,l»2-trichloroethane
IS. 1,1,2,2-tetrachloroethane
16. chlorcethane
17. bis(chloeanethyl)ether
18. bis(2-chloroethyl)ether
19. 2-chloroethyl vinyl ether
(mixed)
20. 2-chloronaphthalene
21. 2,4,6-trichlorophenol
22. parachloroneta cresol
23. chloroform (trichloronethane)
24. 2-chlorophenol
25. 1,2-dichlorobenzene
26. 1,3-dichlorobenzene
27. 1,4-dichlorobenzene
28. 3,3'-dichlorobenzidine
29. 1,1-dichloroethylene
30. 1,2-trans-dichloroethylene
31. 2,4-dichlorophenol
32. 1,2-dichloropropane
33. 1,2-dichlorcpropylene
(1,3,-dichloropropene)
34. 2,4-diiDethylphenol
35. 2,4-dinitrotoluene
36. 2,6-dinitrotoluene
37. 1,2-diphenylhydrazine
38. ethylbenzene
39. fluoranthene
40. 4-chlorophenyl phenyl ether
41. 4-bromophenyl phenyl ether
42. bis(2-chloroisopropyl)ether
43. bis(2-chloroethoxy)methane
44. trethylene chloride
(dichloromethane)
45. methyl chloride (chloronethane)
46. methyl bromide (bromomethane)
47. bromoform (tribromomethane)
48. dichlorobromomethane
*Retnoval Rating
H
L
L
M
H
M
H
H
H
M
M
H
M
M
H
L
M
L
H
H
H
L
H
H
H
H
H
L
L
H
M
M
H
H
H
H
M
H
H
H
H
H
L
L
L
H
M
Priority Pollutant
*Renoval Rating
49. trichlorofluoromethane M
50. dichlorodifluoromethane L
51. chlorodibroncnie thane H
52. hexachlorobutadiene H
53. hexachlorocyclopentadiene H
54. isophorone H
55. naphthalene H
56. nitrobenzene H
57. 2-nitrophenol H
58. 4-nitrophenol H
59. 2,4-dinitrophenol H
60. 4,6-dinitro-o-cresol H
61. N-nitrosodimethylamine M
62. N-nitrosodiphenylamine H
63. N-nitrosodi-n-propylamine M
64. pentachlorophenol H
65. phenol M
66. bis(2-ethylhexyl)phthalate H
67. butyl benzyl phthalate H
68. di-n-butyl phthalate H
69. di-n-octyl phthalate H
70. diethyl phthalate H
71. dimethyl phthalate H
72. Ij2-benzanthracene (benzo H
(a)anthracene)
73. bsnzo(a)pyrene (3,4-benzo- H
pyrene)
74. 3,4-benzofluoranthene H
(benzo(b)fluoranthene)
75. 11,12-benzofluoranthene H
(benzo(k)fluoranthene)
76. cnrysene H
77. acenaphthylene H
78. anthracene H
79. 1,12-benzoperylene (benzo H
(ghi)-perylene)
80. fluorene H
81. ptienanthrene H
82. 1,2,5,6-dibenzathracene H
(dibenzo (a,h) anthracene)
83. indeno (1,2,3-cd) pyrene H
(2,3-o-phenylene pyrene)
84. pyrene
85. tetrachloroethylene M
86. toluene M
87. trichloroethylene L
88. vinyl chloride L
(chloroethylene)
106. PCB-1242 (Arochlor 1242) H
107. PCB-1254 (Arochlor 1254) H
108. PCB-1221 (Arochlor 1221) H
109. PCB-1332 (Arochlor 1232) H
110. PCB-1248 (Arochlor 1248) H
111. PCB-1260 (Arochlor 1260) H
112. PCB-1016 (Arochlor 1016) H
* NOTE; Explanation of Removal RAtings
Category H (high removal)
adsorbs at levels >^ 100 mg/g carbon at C, = 10 rog/1
adsorbs at levels _> 100 mg/g carton at CJj < 1.0 rog/1
Category H (moderate removal)
adsorbs at levels >^ 100 mg/g carton at Cf = 10 rog/1
adsorbs at levels £ 100 an/g carbon at C^ < 1.0 mg/1
Category L (low removal)
adsorbs at levels < 100 mg/g carton at C- = 10 rog/1
adsorbs at levels < 10 n»g/g carton at C, < 1.0 mg/1
C, « final concentrations of priority pollutant at equilibrium
VII-214
-------
TABLE 7-81
CLASSES OF OBGANIC COMPOUNDS ADSORBED ON CARBON
Organic Chemical Class
Aromatic Hydrocarbons
Fblynuclear Aromatics
Chlorinated Aromatics
Phenolics
Chlorinated Fhenolics
*High Molecular Weight Aliphatic and
Branch Chain Hydrocarbons
Chlorinated Aliphatic Hydrocarbons
*High Molecular Weight Aliphatic Acids
and Aromatic Acids
*High Molecular Weight Aliphatic'Amines
and Aromatic Amines
*High Molecular Weight Ketones. Esters,
Ethers & Alcohols
Surfactants
Soluble Organic Dyes
Examples of Chemical Class
benzene, toluene, xylene
naphthalene, anthracene
biphenyls
chlorobenzene, polychlorinated
biphenyls, aldrin, endrin,
toxaphene, DDT
phenol, cresol, resorcenol
and polyphenyls
trichlorophenol, pentachloro-
phenol
gasoline, kerosine
1,1,1-Tr ichloroethane, tri-
chloroethylene, carbon tetra-
chloride, perchloroethylene
tar acids, benzoic acid
aniline, toluene diamine
hydrcquinone, polyethylene
glycol
alkyl benzene sulfonates
methylene blue, Indigo carmine
* High Molecular Weight includes compounds in the range of
4 to 20 carbon atoms
VII-215
-------
Samples were taken of influent and effluent streams around the
carbon adsorption unit at Plant ID 38040. ; The results of this
sampling are presented in Table 7-82.
TABLE 7-82 ;
PERFORMANCE OF CARBON ADSORPTION AT PLANT 38040
(mg/1)
Day 1 Day 2
Parameter Influent Effluent Influent Effluent
oil and Grease 4.1 3.3 ! 41.0 2.0
BOD 58.0 * 53.0 8.0
TOC 93.9 87.7 108.0 77.5
TSS 14.0 11.0 1.0 9.0
TTO 1.02 0.29 1.40 0.38
* Lab analysis experienced interference
Demonstration Status
Carbon adsorption systems have been demonstrated to be practical
and economical for the reduction of COD, BOD and related
parameters in secondary municipal and industrial wastewatersz
for the removal of toxic or refractory organics from isolated
industrial wastewaters? for the removal and recovery of certain
organics from wastewaters; and for the removal, at times with
recovery, of selected inorganic chemicals from aqueous wastes.
Carbon adsorption must be considered a viable and economic
process for organic waste streams containing up to 1-5% of
refractory or toxic organicsj its applicability for removal of
inorganics such as metals, although demonstrated in a few
cases, is probably much more limited.
Carbon adsorption is being used in 10 plants in the present
Metal Finishing Category data base. These plants are identified in
Table 7-83.
TABLE 7-83
METAL FINISHING PLANTS EMPLOYING CARBON ADSORPTION
04236 18538
04690 19120
12065 25033
14062 31044
17061 38040
VII-216
-------
Reverse Osmosis
A detailed description of reverse OSMOSIS along with information
on general applicability and demonstration status are presented in
"Treatment of Oily Waste." Reverse osmosis or carbon adsorption
are considered effective polishing techniques for wastewaters
containing toxic organics.
Performance Data
Table 7-84 presents the performance data for TTO for reverse
osmosis.
TABLE 7-84
TTO PERFORMANCE DATA (mg/1) FOR REVERSE OSMOSIS
Plant ID Influent Effluent
38040-23-0 4.301 1.018
38040-23-1 0.887 1.401
30166-21-0 1.413 0.774
VII-217
-------
Resin... Adsorption
Adsorption of trace organics on synthetic resins is similar to
adsorption on activated carbon. The basic materials are different
and the means of regeneration are different. A potential
advantage is that resins are more easily tailored for removal of
specific pollutants.
The resins are generally microporous styrene-divinylbenzenes,
acrylic esters, or phenol-formaldehydes. Each type may be
produced in a range of densities, void volumes, bulk densities,
surface areas, and pore sizes. The formaldehyde resins are
granular, and the others are in the form of beads.
Adsorptive resins are in limited commercial use for removal of
priority and other organics. There are existing operations for
removal of phenols in two plants (one in Indiana and the other at
a coal liquefaction plant in West Virginia), for removal of fats
at a food processing plant, and for removal of organic dyes at
several plants. Pilot plant operations have been designed for
removal of trinitrotoluene, 2,4-dinitrotoluene, cyclomethylene-
trinitramine, cyclotetramethylenetetranitramine, Endrin, other
pesticides, laboratory carcinogens (unspecified), 2,4-dichloro-
phenol, ethylene dichloride, and vinyl chloride. In a non-
industrial application, organic carbon removal efficiency
decreased from 58 percent to 40 percent during a through-put of
5,000 bed volumes, with an input concentration of about 6 mg/l.
Regeneration of the resins is done chemically, while regeneration
of activated carbon is thermal. The chemical may be an inorganic
acid, base, or salt, or an organic solvent such as acetone.
VH-218
-------
Ozonation
Ozone is effective in the treatment of phenols. It is about
twice as powerful as hydrogen peroxide and is not as selective;
thus it oxidizes a wider range of material. For low concentra-
tion phenolic wastes, the usual practice is to oxidize the
phenolic compound to intermediate organic compounds that are
toxic but readily biodegrdable. For this application, ozone
requirements are in the range of 1.5 to 2.5 parts of ozone per
part of phenol. As the concentration decreases, the relative
amount of ozone needed increases. If other material with COD
is present, the ozone requirement will be still greater. When
pH values of 11.5 to 11.8 are maintained, this range appears
to result in selective or preferential oxidation of phenol
over other substances.
For concentrated or intermediate level phenolic wastes chemical
oxidation by ozone may not be economical as a primary treatment
system; however, it is useful as a polishing process following
a biological system. In treating phenolic refinery wastes,
ozone is used as tertiary treatment to produce final effluents
as low as 3 ug/1 phenol.
Several manufacturers have begun using ozone for the treatment
of phenolic industrial wastewaters. They are listed and
briefly described below:
A. An oil refinery in Canada treats waste effluent of
1,514,000 liters/day (400,000 gallons/day) with the
phenol concentration averaging 50 mg/1.
Pretreatment consists of pre-aeration and a biologi-
cal trickling filter. Ozonation is the final treat-
ment step and utilization is 86 kg/day (190 pounds/
day). This treatment results in an effluent of less
than 0.012 mg/1 residual phenol.
B. A manufacturer of a thermoplastic resin in New York
treats a phenolic effluent by biological oxidation.
Further treatment was necessary to meet state stan-
dards. The effluent had a high COD of about 1500
mg/1 which competed with the phenol for ozone;
therefore a large ozone dosage level, 300 ppm, was
required to reach the desired phenol effluent con-
centration. At a flow rate of 946,250 liters/day
(0.25 MGD), a total of 283.5 kg (625 pounds) of
ozone was required daily. The air feed generating
equipment represents a capital investment of $220,000
and requires daily operating expenditures of $98.43
including electrical costs of 1.5^/kwh. Concurrent
with phenol removal, 30 percent of the color, 29
percent of the turbidity and 17 percent of the COD
were removed.
VTI-219
-------
C. Study of various coke plant wastes shows that various
ozone requirements are necessary to oxidize the phenol.
The results are displayed in Table 7-85. The great
variation in the ozone-to-phenol ratios of samples
from different sources illustrates the differences
in the composition of the wastes;.
TABLE 7-85
OZONE REQUIREMENTS FOR PHENOL OXIDATION
Source
Coke Plant
it n
ii it
H H
n it
it n
it it
it H
Chemical "
Refinery
A
B
C
D
E
F
G
H
A*
A
Initial
Phenols
mg/1
Ozone
Demand
mg/1
2500
1200
1700
950
550
900
1000
700
400
11,000
Ozone/
Phenol
ratio
2.0
1.5
5.2
6.8
4.3
8.8
20
18
1.4
18.0
Residual
Phenols
1.2
0.6
1.0
1.0
0.2
0.0
0.4
0.1
0.3
2.5
*This plant effluent contained 2,4-dichlorophenol and the
results are expressed as such.
There are 40 to 50 commercial installations utilizing ozone
for bleach regeneration and photoprocessing wastewater treatment.
Ozone is also effective in treating wastewaters containing
other organics and organo-metal complexes. In organo-metal
complexes the metals can be released and then precipitated.
One kilogram of COD should consume three kilograms of ozone
and yield two kilograms of molecular oxygen.
Chemical Oxidation
Chemical oxidation can be effective in destroying some of the
priority organic compounds. Oxidation can be accomplished
by ozone, by ozone with ultraviolet radiation, by hydrogen
peroxide, and possibly by electrolytic oxidation. Oxidation
by chlorine is more likely to generate priority organics than
to destroy them.
VII-22"0
-------
These oxidation techniques are used industrially primarily for
cyanide destruction. They are therefore discussed in detail
under the general heading of "Treatment of Cyanide Wastes",
earlier in this section. Where information is available/
these discussions include consideration of ability to destroy
priority organics.
Aerobic Decomposition
Aerobic decomposition is the biochemically actuated decomposi-
tion or digestion of organic materials in the presence of
oxygen. The chemical agents effecting the decomposition are
microorganism secretions termed enzymes. The principal products
in a properly controlled aerobic decomposition are carbon
dioxide and water. Aerobic decomposition is used mainly in the
treatment of organic chemicals and lubricants used in the film
industry and such other industries that use organic lubricants.
As a waste treatment aid, aerobic decomposition plays an
important role in the following organic waste treatment
processes:
1. Activated Sludge Process
2. Trickling Filter Process
3. Aerated Lagoon
The activated sludge process consists of the aeration of a
biodegradable waste for a sufficient time to allow the formation
of a large mass of settleable solids. These settleable solids
are masses of living microorganisms and are termed activated
sludge.
A schematic diagram of the basic process is shown as Figure
7-41. The wastes enter the aeration tank after being mixed
with return sludge. The microorganisms from the returned
sludge aerobically stabilize the organic mixture which then
flows to a sedimentation tank. Sedimentation allows the
activated sludge to flocculate and to settle out, producing a
clear effluent of low organic content. A portion of the waste
sludge is returned to the aeration tank, thereby•repeating the
process. Excess sludge is discharged from the process for
further treatment or disposal.
The trickling filter is basically a bed of stones or other
suitable material covered with slime over which organic wastes
slowly flow. A schematic cross section of a trickling filter
is shown as Figure 7-42. As wastewater passes through the
filter, it diffuses into the slimes where aerobic and anaerobic
decomposition occurs. After primary sedimentation, the waste-
water is introduced onto the filter by a rotary distributor so
designed that the wastes are discharged at a uniform volume
per unit of filter surface. The waste flows by gravity over
the filter bed into an underdrain system. The liquid is collected
into a main effluent channel which flows to a final sedimenta-
tion tank. A schematic diagram of a single stage trickling
VTI-221
-------
SETTLED
WASTES
AERATION
RETURN SLUDGE
SECONDARY
SEDIMEN-
TATION
EFFLUENT
WASTE EXCESS
SLUDGE
FIGURE 7-41
SCHEMATIC DIAGRAM OF A CONVENTIONAL ACTIVATED SLUDGE SYSTEM
VTI-222
-------
I Rotary distributor
///\\\
//\ \\
II ^ \
///\\\
C?
Stone media
6-10' depth
.>.* ..;-y / f %:>^Jt'
Vitrified clay underdrains
Reinforced concrete floor
FIGURE 7-42
SCHEMATIC CROSS SECTION OF A TRICKLING FILTER
VII-223
-------
filter is shown as Figure 7-43.
An aerated lagoon is a large shallow pond to which raw waste
is added at one end or in the center and the treated effluent
discharged at the other end. Aeration is accomplished by
mechanical aerators or diffusers in the wastewater. Aerobic
decomposition is one of the factors involved in degradation of
the organic matter and is carried out by bacteria in a manner
similar to activated sludge. It is necessary to periodically
dredge the oxidation pond in order to maintain the proper
ecological balance.
Application
Aerobic decomposition can be applied to the treatment of oily
wastes from the Metal Finishing Category.
Advantages of aerobic decomposition include 1) low BOD concentra-
tions in supernatant liquor, 2) production of an odorless,
humuslike, biologically stable end product with excellent
dewatering characteristics that can be easily disposed, 3)
recovery of more of the basic fertilizer values in the sludge,
and 4) few operational problems and low initial cost. The
major disadvantages of the aerobic decomposition process are
1) high operational cost associated with supplying the required
oxygen, and 2) sensitivity of the bacterial population to
small changes in the characteristics of their environment.
Reliability can be high, assuming adequate temperature, pH,
detention time, and oxygen content control. Prior treatment
to eliminate substances toxic to the microorganisms affecting
decomposition may be necessary. (In some cases, adaptation
will increase the tolerance level of the microorganisms for
toxic substances).
Maintenance of the three main waste treatment techniques
employing aerobic decomposition is detailed in the following
Table 7-86.
TABLE 7-86
Maintenance Techniques for Aerobic Decomposition
Process Maintenance
Activated Sludge Periodic removal of excess sludge and skimming
of scum layer. ;
Trickling Filter Periodic application of insecticides to reduce
the insect population and periodic chlorination
to reduce excess bacterial population.
Aerated Lagoon Periodic dredging to remove excess sludge, and
periodic aeration to maintain the pond's aero-
bic character.
VII-224
-------
RAW
SEWAGE
PRIMARY
SEDIMENTA
TION
SECONDARY
SEDIMENTA
TION
FIGURE 7-43
SCHEMATIC DIAGRAM OF A SINGLE-STAGE TRICKLING FILTER
VII-225
-------
Performance
Aerobic decomposition is very effective for1organic constituents
that are readily biodegradeable. The toxic organics. however.
represent a range of biodegradability. Performance of a pilot
scale activated sludge system is reported in "Removal of Organic
Constituents in a Coal Gasification Process Wastewater by
Activated Sludge Treatment." Argonne National La;oratory. 1979.
In this system, phenol was reduced from 250 mg/8, to an
undetectable level, naphthalene was reduced from 0.405 to
0.009 mg/8,. and ethylbenzene at 0.015 mg/8, concentration was
not reduced.
Another source of information on organics (Handbook of Environ-
mental Data on Organic Chemicals. Verschueren. 1977) indicates
treatability for a number of priority organics. These data are
summarized in Table 7-87. i
An additional source of toxic organics performance information are
the BAT limitations for the organic chemicals industry developed
using data from plants using biological treatment. These limits.
proposed by EPA in March 21. 1983. are presented in Table 7-88.
The activated sludge process also reduces concentrations of toxic
metals, by agglomeration of precipitates and by adsorption of
dissolved metals. However, effectiveness ;is highly variable and
unpredictable.
TABLE 7-87 |
ACTIVATED SLUDGE REMOVAL OF SOME PRIORITY ORGANIC COMPOUNDS
Influent Concentration Reported Removal
Compound (mg/8.) [ Efficiency. Percent
Benzene 500 33
1,2-Dichloroethane 200 45
11 " 400 30
" " 1000 9
2.4-Dimethylphenol 94.5
Ethylbenzene 500 27
" " 50-100 8
Phenol 500 33
VII-226
-------
TABLE 7-88
PROPOSED BAT EFFLUENT LIMITATIONS FOR THE ORGANIC CHEMICALS INDUSTRY
BAT Effluent Limitations.. (mg/t)
Average of
Daily Values for
Maximum 4 Consecutive
Toxic Organic For Any 1 Pay Mo n i t o r i nq Pays
2.4.6~trichlorophenol 175 100
2-chlorophenol 75 50
2,4-dichlorophenol 200 100
2,4-dimethylphenol 50
2-nitrophenol 100 75
4-nitrophenol 500 325
2.4-dinitrophenol 150 100
pentachlorophenol 100 50
phenol 50
acenaphthene 50
1,2.4-trichlorobenzene 225 125
1,2-dichlorobenzene 250 125
isophorone 50
bis(2-ethylhexyl) phthalate 350 150
di-n-butyl phthalate 300 150
diethyl phthalate 275 125
dimethyl phthalate 375 175
acenaphthylene 50 —
fluorene 50
phenanthrene 50
benzene 125 75
carbon tetrachloride 50
1,2-dichloroethane 150 100
1,1,1-trichloroethane 50
1.1-dichloroethane 225 125
1,1.2-trichloroethane 75 50
chloroethane 50
chloroform 75 50
1,1-dichloroethylene 125 75
ethylbenzene 275 150
methylene chloride 50
methyl chloride 50
methyl bromide 50
dichlorobromomethane 50
toluene 225 125
trichloroethylene 75 50
VII-227
-------
Demonstration Status
Aerobic digestion is a widely used unit process to reduce organic
content of wastewaters. It is currently employed at 14 of the
plants in the data base. These plants are identified in Table
7-89.
TABLE 7-89
METAL FINISHING PLANTS EMPLOYING AEROBIC DECOMPOSITION
05050 11560 23041 33263
06067 11179 30927 44050
08172 13031 31050
11050 14062 33050
VII-228
-------
TREATMENT OF SLUDGES
INTRODUCTION
Sludges are created by waste treatment alternatives which
remove solids from wastewater. Removal of sludges from the
treatment system as soon as possible in the treatment process
minimizes returning pollutants to the waste stream through
re-solubilization. One plant visited during this program (ID#
23061) utilized a settling tank in their treatment system that
required periodic cleaning. Such cleaning had not been done
for some time, and analysis of both their raw and treated
wastes showed little difference. The accumulation of sludge
apparently decreased the effective residence time to a point
where the sedimentation process was unsuccessful. Subsequent
pumping out of this settling tank resulted in an improved
effluent (Reference Table 7-90) .
Once removed from the primary effluent stream, waste sludges
must be disposed of properly. If landfills are used for
sludge disposal, the landfill must be designed to prevent
material from leaching back into the water supply. Mixing of
waste sludges which might form soluble compounds should be
prevented. If sludge is disposed of by incineration, the
burning must be carefully controlled to prevent air pollution.
A licensed scavenger may be substituted for plant personnel to
oversee disposal of the removed sludge.
TABLE 7-90
COMPARISON OF WASTEWATER AT PLANT ID 23061
BEFORE AND AFTER PUMPING OF SETTLING TANK
Parameter
Concentration (mg/1)
Before Sludge Removal
Concentration (mg/1)
After Sludge Removal
Total Raw Treated
Waste Effluent
Cyanide, Amen, to
Chlorination 0.007 0.001
Cyanide, Total 0.025 0.035
Phosphorus 2.413 2.675
Silver 0.001 0.001
Gold 0.007 0.010
Cadmium 0.001 0.006
Chromium, Hexavalent 0.005 0.105
Chromium, Total 0.023 0.394
Copper 0.028 0.500
Iron 0.885 3.667
Fluoride 0.16 0.62
Nickel 0.971 1.445
Lead 0.023 0.034
Tin 0.025 0.040
Zinc 0.057 0.185
Total Suspended Solids 17.0 36.00
Total Raw
Waste
0.005
0.005
14.35
0.002
,005
,005
,005
,010
127
883
,94
378
,007
,121
,040
0.
0,
0,
0,
0.
2.
0,
0.
0,
0.
0,
67.00
Treated
Effluent
0.005
0.005
13.89
0.003
0.005
0.002
0.005
0.006
0.034
1.718
0.520
0.312
0.014
0.134
0.034
4.00
VII-229
-------
TREATMENT TECHNIQUES
Sludges can typically vary between one and five percent solids.
The sludge should be dewatered to lessen space requirements if
sludges are landfilled on the plant site and to decrease shipping
costs if sludges are hauled away by a contractor. Applicable sludge
dewatering techniques include gravity sludge thickening,
pressure filtration, vacuum filtration, centrifugation and
sludge bed drying. These techniques are discussed in the
following subsections.
Gravity Sludge Thickening
In the gravity thickening process, dilute sludge is fed from a
primary settling tank or clarifier to a thickening tank.
Rakes stir the sludge gently to densify the sludge and to push
it to a central collection well. The supernatant is returned
to the primary settling tank. The thickened sludge that
collects on the bottom of the tank is pumped to dewatering
equipment or hauled away. Figure 7-44 shows the construction
of a gravity thickener. !
Application
Thickeners are generally used in facilities where the sludge
is to be further dewatered by a compact mechanical device such
as a vacuum filter or centrifuge. Doubling the solids content
in the thickener substantially reduces capital and operating
cost of the subsequent dewatering device and also reduces cost
for hauling. The process is potentially applicable to almost
any industrial plant.
The principal advantage of a gravity sludge thickening process
is that it facilitates further sludge dewatering. Other
advantages are high reliability and minimum maintenance require-
ments. Limitations of the sludge thickening process are its
sensitivity to the flow rate through the thickener and the
sludge removal rate. These rates must be low enough not to
disturb the thickened sludge. i
Reliability is high assuming proper design ;and operation. A
gravity thickener is designed on the basis of square feet per
pound of solids per day, entering and leaving the unit.
Thickener area requirements are also expressed in terms of
mass loading, grams of solids per square meter per day (pounds
per square foot per day).
Twice a year, a thickener must be shut down for lubrication of
the drive mechanisms. Occasionally, water must be pumped back
through the system in order to clear sludge pipes. Thickened
sludge from a gravity thickening process will usually require
further dewatering prior to disposal, incineration, or drying.
The clear effluent may be recirculated in part, or it may be
subjected to further treatment prior to discharge.
VII-230
-------
-0—-i
^THICKENING;
-TANK:
SLUDGE PUMP
CD
OVERFLOW
RECYCLED
THROUGH
PLANT
FIGURE 7-44
MECHANICAL GRAVITY THICKENING
VII-231
-------
Performance
Organic sludges from sedimentation units of one to two percent
solids concentration can usually be gravity thickened to six
to ten percent; chemical sludges can be thickened to four to
six percent.
Demonstration Status
Gravity sludge thickeners are used throughout industry to
reduce water content to a level where the sludge may be effi-
ciently handled. Further dewatering is usually practiced to
minimize costs of hauling the sludge to approved landfill
areas.
Sludge thickening is used in 78 plants in Ithe present data
base. These are identified in Table 7-91.i
TABLE 7-91
METAL FINISHING PLANTS EMPLOYING GRAVITY/SLUDGE THICKENING
03043
04069
04071
04263
04719
04981
05021
05035
06052
08004
11156
11177
11182
11704
12033
12074
12075
12078
12091
12100
Pressure Filtration
12102
12709
13031
13040
14061
15042
15044
17061
18050
18091
19063
20005
20010
20064
20073
20075
20078
20082
20085
20116
20120
20157
20165
20248
20291
21078
23062
23337
25001
27044
28082
28115
30079
30087
30090
30151
30153
30927
30967
33065
33070
33113
33120
36085
36090
36091
36092
36112
36130
36180
36623
40061
40063
41151
43003
43052
44044
62032
Pressure filtration is achieved by pumping the liquid through
a filter material which is impenetrable to the solid phase.
The positive pressure exerted by the feed pumps or other
mechanical means provides the pressure differential which is
the principal driving force. Figure 7-45 represents the
operation of one type of pressure filter.
A typical pressure filtration unit consists of a number of
plates or trays which are held rigidly in a frame to ensure
alignment and are pressed together between a fixed, end and a
VII-232
-------
PERFORATED
BACKING PLATE
FABRIC
FILTER MEDIUM
SOLID
RECTANGULAR
END PLATE
INLET
SLUDGE
FABRIC
FILTER MEDIUM
ENTRAPPED SOLIDS
PLATES AND FRAMES ARE PRESSED
TOGETHER DURING FILTRATION
CYCLE
RECTANGULAR
METAL PLATE
FILTERED LIQUID OUTLET
RECTANGULAR FRAME
FIGURE 7-45
PRESSURE FILTRATION
VT.I-233
-------
traveling end. On the surface of each plate is mounted a
filter made of cloth or a synthetic fiber. The sludge is
pumped into the unit and passes through feed holes in the
trays along the length of the press until the cavities or
chambers between the trays are completely filled. The solids
in the sludge are then entrapped, and a cake begins to form on
the surface of the filter material. The water passes through
the fibers, and the solids are retained. ,
At the bottom of the trays are drainage ports. The filtrate
is collected and discharged to a common drain. As the filter
medium becomes coated with sludge, the flow of filtrate through
the filter drops sharply, indicating that the capacity of the
filter has been exhausted. The unit must then be cleaned of
the sludge. After the cleaning or replacement of the filter
media, the unit is again ready for operation.
Application \
Because dewatering is such a common operation in treatment
systems, pressure filtration is a technique which can be found
in many industry applications concerned with removing solids
from their waste stream.
The pressures which may be applied to a sludge for removal of
water by filter presses that are currently;available range
from 5 to 13 atmospheres. Pressure filtration may also reduce
the amount of chemical pretreatment required. The sludge,
retained in the form of the filter cake, has a higher percent-
age of solids than either a centrifuge or vacuum filter yield.
Thus, the sludge can be easily accommodated by materials
handling systems.
Two disadvantages associated with pressure filtration in the
past have been the short life of the filter cloths and lack of
automation. New synthetic fibers have largely offset the
first of these problems. Also, units with automatic feeding
and pressing cycles are now available. I
Assuming proper pretreatment, design, and control, pressure
filtration is a highly dependable system. Maintenance consists
of periodic cleaning or replacement of the filter media,
drainage grids, drainage piping, filter pans, and other parts
of the system. If the removal of the sludge cake is not
automated, additional time is required for this operation.
Because it is generally drier than other types of sludges, the
filter sludge cake can be handled with relative ease. Disposal
of the accumulated sludge may be accomplished by any of the
accepted procedures.
Performance \
In a typical pressure filter, chemically preconditioned sludge
detained in the unit for one to three hours under pressures
VTI-234
-------
varying from 5 to 13 atmospheres exhibited final moisture
content between 50 and 75 percent.
Demonstration Status
Pressure filtration is a commonly used technology that is
currently utilized in a great many commercial applications.
Pressure filtration is used in 66 plants in the present data
base and these are identified in Table 7-92.
TABLE 7-92
METAL FINISHING PLANTS EMPLOYING PRESSURE FILTRATION
01002 12074 31033
01003 13031 31035
10007 14060 31068
03043 19066 31070
04069 19083 33110
04146 20022 33113
04276 20070 33148
04284 20083 33172
05050 20115 33195
06050 20255 33293
06077 20483 34050
06107 23039 35041
06153 23076 36102
06960 27042 36176
08060 27044 38223
09046 27045 40047
11096 28043 41051
11103 28121 41068
11115 30087 42030
12005 30927 44044
12065 30967 47025
12071 31021 47074
Vacuum Filtration
In wastewater treatment plants, sludge dewatering by vacuum
filtration is an operation that is generally accomplished on
cylindrical drum filters. These drums have a filter medium
which may be cloth made of natural or synthetic fibers, coil
springs, or a wire-mesh fabric. The drum is suspended above
and dips into a vat of sludge. As the drum rotates slowly,
part of its circumference is subject to an internal vacuum
that draws sludge to the filter medium. Water is drawn through
the porous filter cake to a discharge port, and the dewatered
sludge, loosened by compressed air, is scraped from the filter
mesh. Because the dewatering of sludge on vacuum filters is
relativley expensive per kilogram of water removed, the liquid
sludge is frequently thickened prior to processing. A vacuum
filter is shown in Figure 7-46.
VII-235
-------
FABRIC OR WIRE
FILTER MEDIA
STRETCHED OVER
REVOLVING DRUM
DIRECTION OF ROTATION
ROLLER
SOLIDS SCRAPED
OFF FILTER MEDIA
SOLIDS COLLECTION
HOPPER
V
INLET LIQUID
TO BE
FILTERED
TROUGH
FILTERED LIQUID
FIGURE 7-46
VACUUM FILTRATION
VII-236
-------
Application
Vacuum filters are frequently used both in municipal treatment
plants and in a wide variety of industries for dewatering
sludge. They are most commonly used in larger facilities,
which have a thickener to double the solids content of clari-
fier sludge before vacuum filtering.
Although the initial cost and area requirement of the vacuum
filtration system are higher than those of a centrifuge, the
operating cost is lower, and no special provisions for sound
and vibration protection need be made. The dewatered sludge
from this process is in the form of a moist cake and can be
conveniently handled.
Vacuum filter systems have been proven reliable at many indus-
trial and municipal facilities. At present, the largest
municipal installation is at the West Southwest wastewater
treatment plant of Chicago, Illinois, where 96 large filters
were installed in 1925, functioned approximately 25 years, and
then were replaced with larger units. Original vacuum filters
at Minneapolis-St. Paul, Minnesota now have over 28 years of
continuous service, and Chicago has some units with similar or
greater service life.
Maintenance consists of the cleaning or replacement of the
filter media, drainage grids, drainage piping, filter pans,
and other parts of the equipment. Experience in a number of
vacuum filter plants indicates that maintenance consumes
approximately 5 to 15 percent of the total time. If carbonate
buildup or other problems are unusually severe, maintenance
time may be as high as 20 percent. If intermittent operation
is to be employed, the filter equipment should be drained and
washed each time it is taken out of service and an allowance
for wash time should be made in the selection of sludge filter-
ing schedules.
Vacuum filters generate a solid cake. All of the metals
extracted from the plant wastewater are concentrated in the
filter cake as hydroxides, oxides, sulfides, or other salts.
These metals are subject to leaching into ground water, espe-
cially under acid conditions.
Performance
The function of vacuum filtration is to reduce the water
content of sludge, so that the proportion of solids increases
from about 5 percent to about 30 percent.
Demonstration Status
Vacuum filtration has been widely used for many years. It is
a fully proven, conventional technology for sludge dewatering.
VII-237
-------
Vacuum filtration is used in 67 plants in the present data
base and these are identified in Table 7-93.
TABLE 7-93
METAL FINISHING PLANTS EMPLOYING VACUUM FILTRATION
02062
03041
03042
06037
06074
06087
06088
06152
09052
09060
11182
11704
12002
12014
12042
12075
12078
12091
12709
15058
15070
16544
17030
18050
19084
19090
20005
20010
20073
20077
20080
20100
20161
20175
20248
20249
20291
21078
28115
30079
30090
30153
30927
31044
31047
33092
33110
33120
33124
33195
33263
34036
36040
36092
36113
36130
36623
38217
40037
40063
40067
40079
41097
41151
42030
43003
44036
Centrifugation
Centrifugation is the application of centrifugal force to
separate solids and liquids in a liquid/solid mixture or to
effect concentration of the solids. The application of cen-
trifugal force is effective because of the density differen-
tial normally found between the insoluble solids and the
liquid in which they are contained. As a waste treatment
procedure/ Centrifugation is applied to dewatering of sludges.
One type of centrifuge is shown in Figure 7-47.
i
There are three common types of centrifuges: the disc/ basket,
and conveyor type. All three operate by removing solids under
the influence of centrifugal force. The fundamental difference
between the three types is the method by which solids are
collected and discharged. |
In the disc centrifuge, the sludge feed is distributed between
narrow channels that are present as spaces between stacked
conical discs. Suspended particles are collected and dis-
charged continuously through small orifices in the bowl wall.
The clarified effluent is discharged through an overflow weir.
VTI-238
-------
CONVEYOR DRIVE . DRYING _
ZONE
LIQUID
OUTLET
CYCLOGEAR
IMPELLER
FIGURE 7-47
CENTRIFUGATION
VH-239
-------
A second type of centrifuge which is useful in dewatering
sludges is the basket centrifuge. In this type of centrifuge,
sludge feed is introduced at the bottom of the basket, and
solids collect at the bowl wall while clarified effluent
overflows the lip ring at the top. Since the basket cen-
trifuge does not have provision for continuous discharge of
collected cake, operation requires interruption of the feed
for cake discharge for a minute or two in a 10 to 30 minute
overall cycle.
The third type of centrifuge commonly used in sludge dewater-
ing is the conveyor type. Sludge is fed through a stationary
feed pipe into a rotating bowl in which the solids are settled
out against the bowl wall by centrifugal force. From the bowl
wall, they are moved by a screw to the end of the machine, at
which point they are discharged. The liquid effluent is
discharged through ports after passing the length of the bowl.
Application
Virtually all of those industrial waste treatment systems
producing sludge can utilize centrifugation to dewater it.
Centrifugation is currently being used by a wide range of
industrial concerns.
Sludge dewatering centrifuges have minimal; space requirements
and show a high degree of effluent clarification. The opera-
tion is simple/ clean, and relatively inexpensive. The area
required for a centrifuge system installation is less than
that required for a filter system or sludge drying bed of
equal capacity, and the initial cost is lower.
Centrifuges have a high power cost that partially offsets the
low initial cost. Special consideration must also be given to
providing sturdy foundations and soundproofing because of the
vibration and noise that result from centrifuge operation.
Adequate electrical power must also be provided since large
motors are required. The major difficulty, encountered in the
operation of centrifuges has been the disposal of the concen-
trate which is relatively high in suspended, non-settling
solids.
Reliability is high, assuming proper control of factors such
as sludge feed, consistency, and temperature. Pretreatment
such as grit removal and coagulant addition may be necessary.
Pretreatment requirements will vary depending on the composi-
tion of the sludge and on the type of centrifuge employed.
Maintenance consists of periodic lubrication, cleaning, and
inspection. The frequency and degree of inspection required
varies depending on the type of sludge solids being dewatered
and the maintenance service conditions. If the sludge is
abrasive, it is recommended that the first inspection of the
rotating assembly be made after approximately 1,000 hours of
VII-240
-------
operation. If the sludge is not abrasive or corrosive, then
the initial inspection might be delayed. Centrifuges not
equipped with a continuous sludge discharge system require
periodic shutdowns for manual sludge cake removal.
Performance
The performance of sludge dewatering by centrifugation depends
on the feed rate, the rotational velocity of the drum, and the
sludge composition and concentration. Assuming proper design
and operation, the solids content of the sludge can be increased
to 20-35 percent.
Demonstration Status
Centrifugation is currently used in a great many commercial
applications to dewater sludge. Work is underway to improve
the efficiency, increase the capacity, and lower the costs
associated with centrifugation.
Centrifugation is used in 55 plants in the present data base
and these are identified in Table 7-94.
TABLE 7-94
METAL FINISHING PLANTS EMPLOYING CENTRIPUGATION
02032
04151
04153
06006
06071
06075
06086
06148
11050
11125
11127
12005
12033
12061
12075
12077
14062
15044
17050
19067
19068
19104
19107
19462
20070
20079
20106
20140
20149
20241
20708
21062
21065
21074
23048
27044
30097
30111
30155
30927
31022
33'024
33071
34051
36091
36937
38052
41086
41116
41629
41869
44040
44150
45041
47041
Sludge Bed Drying
As a waste treatment procedure, sludge bed drying is employed
to reduce the water content of a variety of sludges to the
point where they are amenable to mechanical collection and
removal. These beds usually consist of 15.24 to 45.72 cm (6
to 18 inches) of sand over a 30.48 cm (12 inch) deep gravel
drain system made up of 3.175 to 6.35 mm (1/8 to 1/4 inch)
graded gravel overlying drain tiles.
VII-241
-------
Drying beds are usually divided into sectional areas approxi-
mately 7.62 meters (25 feet) wide x 30.48 to 60.96 meters (100
to 200 feet) long. The partitions may be earth embankments,
but more often are made of planks and supporting grooved
posts. \
To apply liquid sludge to the sand bed, a closed conduit or a
pressure pipeline with valved outlets at each sand bed section
is often employed. Another method of application is by means
of an open channel with appropriately placed side openings
which are controlled by slide gates. With either type of
delivery system, a concrete splash slab should be provided to
receive the falling sludge and prevent erosion of the sand
surface.
Where it is necessary to dewater sludge continuously throughout
the year regardless of the weather, sludge beds may be covered
with a fiberglass reinforced plastic roof. Covered drying
beds permit a greater volume of sludge drying per year in most
climates because of the protection afforded from rain or snow
and because of more efficient control of temperature. Depend-
ing on the climate, a combination of open and enclosed beds
will provide maximum utilization of the sljjdge bed drying
facilities.
Application
Sludge drying beds are a common means of dewatering sludge
from clarifiers and thickeners. They are widely used both in
municipal and industrial treatment facilities.
The main advantage of sand drying beds over other types of
sludge dewatering is the relatively low cost of construction,
operation, and maintenance. Its disadvantages are the large
area of land required and long drying times that depend, to a
great extent, on climate and weather.
Maintenance consists of periodic removal of the dried sludge.
Sand removed from the drying bed with the sludge must be
replaced and the sand layer resurfaced. The resurfacing of
sludge beds is the major expense item in sludge bed mainte-
nance, but there are other areas which may require attention.
Underdrains occasionally become clogged and have to be cleaned.
Valves or sludge gates that control the flow of sludge to the
beds must be kept watertight. Provision for drainage of lines
in winter should be made to prevent damage from freezing. The
partitions between beds should be tight so that sludge will
not flow from one compartment to another. The outer walls or
banks around the beds should also be watertight.
The full sludge drying bed must either be abandoned or the
collected solids must be removed. These solids contain what-
ever metals or other materials were settled in the clarifier.
Metals will be present as hydroxides, oxides, sulfides, or
VII-242
-------
other salts. They have the potential for leaching and contami-
nating ground water, whatever the location of the semidried
solids. Thus an abandoned bed should include provision for
runoff control and leachate monitoring.
Performance
Dewatering of sludge on sand beds occurs by two mechanisms:
filtration of water through the bed and evaporation of water
as a result of radiation and convection. Filtration is gener-
ally complete in one to two days and may result in solids
concentrations as high as 15 to 20 percent. The rate of
filtration depends on the drainability of the sludge.
The rate of air drying of sludge is related to temperature,
relative humidity, and air velocity. Evaporation will proceed
at a constant rate to a critical moisture content, then at a
falling rate to an equilibrium moisture content. The average
evaporation rate for a sludge is about 75 percent of that from
a free water surface.
Demonstration Status
Sludge beds have been in common use in both municipal and
industrial facilities for many years. However, protection of
ground water from contamination is not always adequate.
Sludge bed drying is used in 77 plants in the present data
base and these are identified in Table 7-95.
Sludge Disposal
There are several methods of disposal of sludges from indus-
trial wastewater treatment. The two most common techniques
are landfilling by the company on its own property and removal
by licensed contractor to an outside landfill or reclamation
point. Other disposal techniques proposed for industrial
waste sludges include chemical containment, encapsulation,
fixation, and thermal conversion. All of these techniques
require landfilling, but they reduce the probability of
groundwater contamination.
The chemical containment approach has been demonstrated commer-
cially. The heavy metal sludge is placed in pits lined with
powdered limestone. This keeps the pit-soil interface at an
alkaline pH, reducing the solubility of metals at the interface
to a very low value. This minimizes heavy metal leaching,
even by acid rainfall.
Encapsulation consists of two approaches. One is to seal the
sludge in a heavy concrete container. The other is to coat
the material with a nondegradable, waterproof polymer.
VII-243
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TABLE 7-95
METAL FINISHING PLANTS EMPLOYING SLUDGE DRYING BEDS
01067
01068
04076
04262
05050
06002
06035
06051
06067
06073
06076
06081
06083
06084
06091
06094
06101
06113
06117
06119
06124
06128
06138
06360
08061
08072
09025
09047
11008
11113
11152
11173
12075
13041
14061
14062
15048
17061
18050
19050
20003
20064
20082
20085
20247
21003
22735
23'039
23070
23072
25001
30009
30031
30'064
30519
31032
31050
31067
33024
33047
33050
33179
33184
33200
33287
36001
36082
36083
36592
38039
40062
40075
40079
40836
41068
45035
47412
VTI-244
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IN-PROCESS CONTROL TECHNOLOGY
INTRODUCTION
This section presents flow guidance and process controls in
the form of available methods and practices which can help
reduce the water usage and pollution discharge at metal finish-
ing facilities.
CONTROL TECHNIQUES
The in-process control techniques described below include
techniques for:
Flow reduction through efficient rinsing
Process bath conservation
Waste oil segregation
. Process bath segregation
Process modification
Cutting fluid cleaning
Integrated waste treatment
Good housekeeping
These techniques deal with reducing water usage and with
efficient handling of process wastes. All of the areas of
in-process control are presented in the following sections.
Flow Reduction Through Efficient Rinsing
Reductions in the amount of water used in metal finishing can
be realized through installation and use of efficient rinse
techniques. Cost savings associated with water use reduction
result from lower cost for rinse water and reduced chemical
costs for wastewater treatment. An added benefit is that the
waste treatment efficiency is also improved. It is estimated
that rinse steps may consume over 90 percent of the water used
by a typical metal finishing facility. Consequently, the
greatest water use reductions can be anticipated to come from
modifications of rinse techniques.
Rinsing is essentially a dilution step which reduces the
concentration of contaminants on the work piece. The design
of rinse systems for minimum water use depends on the maximum
level of contamination allowed to remain on the work piece
(without reducing acceptable product quality or causing poison-
ing of a subsequent bath) as well as on the efficiency or
effectiveness of each rinse stage.
A rinse system should be considered efficient if the dissolved
solids concentration is reduced just to the point where no
noticeable effects occur either as a quality problem or as
excessive drag-in to the next process step. Operation of a
rinse tank or tanks which achieve a 10,000 to 1 reduction in
concentration where only a 1,000 to 1 reduction is required
VII-245
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represents inefficient use of water. Operating rinse tanks at
or near their maximum acceptable level of contamination provides
the most efficient and economical form of rinsing. Insufficient
operation manifests itself in higher operating costs not only
from the purchase cost of water, but also from the treatment
of it.
Dragout Control
Since the purpose of rinsing is to remove process solution
dragout from the surface of the workpiece, the best way to
reduce the amount of rinsing required is to reduce the dragout.
A reduction in dragout results in a reduction of waste that
has to be treated. Dragout is a function of several factors
including workpiece geometry, viscosity and surface tension of
the process solution, withdrawal and drainage time and racking.
These factors affecting dragout are described below.
Geometry of the Part - This partly determines the amount of
dragout contributed by a part and is one of the principal
determinants for the type of rinsing arrangement selected. A
flat sheet with holes is well suited for an impact spray rinse
rather than an immersion rinse, but for parts with cups or
recesses such as a jet fuel control, a spray rinse is totally
ineffective.
Kinematic Viscosity of the Process Solution - The kinematic
viscosity is an important factor in determining process bath
dragout. The effect of increasing kinematic viscosity is that
it increases the dragout volume in the withdrawal phase and
decreases the rate of draining during the drainage phase. It
is advantageous to decrease the dragout and increase the
drainage rate. Consequently, the process solution kinematic
viscosity should be as low as possible. Increasing the tempera-
ture of the solution decreases its viscosity, thereby reducing
the volume of process solution going to the: rinse tank. Care
must be exercised in increasing bath temperature, particularly
with electroless plating baths, because the rate of bath
decomposition may increase significantly with temperature
increases.
Surface Tension of the Process Solution - Surface tension is a
major factor that controls the removal of dragout during the
drainage phase. To remove a liquid film from a solid surface,
the gravitation force must overcome the adhesive force between
the liquid and the surface. The amount of work required to
remove the film is a function of the surface tension of the
liquid and the contact angle. Lowering the surface tension
reduces the amount of work required to remove the liquid and
reduces the edge effect (the bead of liquid adhering to the
edges of the part). Surface tension is reduced by increasing
the temperature of the process solution or more effectively,
by use of a wetting agent.
VII-246
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Time of Withdrawal and Drainage - The withdrawal velocity of a
part from a solution has an effect similar to that of kinematic
viscosity. Increasing the velocity or decreasing the time of
withdrawal increases the volume of solution that is retained
by the part. Since time is directly related to production
rate, it is more advantageous to reduce the dragout volume
initially adhering to the part rather than attempt to drain a
large volume from the part.
Racking - Proper racking of parts is the most effective way to
reduce dragout. Parts should be arranged so that no cup-like
recesses are formed, the longest dimension should be horizon-
tal, the major surface vertical, and each part should drain
freely without dripping onto another part. The racks them-
selves should be periodically inspected to insure the integ-
rity of the rack coating. Loose coatings can contribute
significantly to dragout. Physical or geometrical design of
racks is of primary concern for the control of dragout both
from the racks and the parts themselves. Dragout from the
rack itself can be minimized by designing it to drain freely
such that no pockets of process solution can be retained.
Rinsing Techniques
The different types of rinsing commonly used within the metal
finishing industry are described below.
Single Running Rinse - This arrangement requires a large
volume of water to effect a large degree of contaminant removal,
Although in widespread use, single running rinse tanks should
be modified or replaced by a more effective rinsing arrangement
to reduce water use.
Countercurrent Rinse - The countercurrent rinse provides for
the most efficient water usage and thus, where possible, the
countercurrent rinse should be used. There is only one fresh
water feed for the entire set of tanks, and it is introduced
in the last tank of the arrangement. The overflow from each
tank becomes the feed for the tank preceding it. Thus, the
concentration of dissolved salts decreases rapidly from the
first to the last tank.
In a situation requiring a 1,000 to 1 concentration reduction,
the addition of a second rinse tank (with a countercurrent
flow arrangement) will reduce the theoretical water demand by
97 percent.
Series Rinse - The major advantage of the series rinse over
the countercurrent system is that the tanks of the series can
be individually heated or level controlled since each has a
separate feed. Each tank reaches its own equilibrium condi-
tion? the first rinse having the highest concentration, and
the last rinse having the lowest concentration. This system
uses water more efficiently than the single running rinse, and
VH-247
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the concentration of dissolved salts decreases in each succes-
sive tank.
Spray Rinse - Spray rinsing is considered the most efficient
ortne various rinse techniques in continuous dilution rinsing.
The main concern encountered in use of this mode is the effi-
ciency of the spray (i.e./ the volume of water contacting the
part and removing contamination compared to the volume of
water discharged). Spray rinsing is well suited for flat
sheets. The impact of the spray also provides an effective
mechanism for removing dragout from recesses With a large
width to depth ratio.
Dead/ Still/ or Reclaim Rinses - This form of rinsing is
particularly applicable for initial rinsing after metal plating
because the dead rinse allows for easier recovery of the metal
and lower water usage. The rinse water can often be periodi-
cally transferred to the plating tank that precedes it. The
dead rinse is followed by spray or other running rinses.
Effect on Water Use - The use of different rinse types will
result in wide variations in water use. Table 7-96 shows the
theoretical flow arrangements for several different rinse
types to maintain a 1,000 to 1 reduction in concentration.
Table 7-97 shows the mean flows (1/m ) found: at sampled
plants for three rinse water-intensive operations.
TABLE 7-96
THEORETICAL RINSE WATER FLOWS REQUIRED TO MAINTAIN A
1,000 TO 1 CONCENTRATION REDUCTION
Type of Rinse Single Series Countercurrent
Number of Rinses 1 2 3 23
Required Flow (gpm) 10 0.61 0.27 0.31 0.1
TABLE 7-97
COMPARISON OF RINSE TYPE FLOW RATES FOR SAMPLED PLANTS
2
Rinse Type and Mean Flow (1/m )
Single 2 Stage 2 Stage 3 Stage
Operation Stage Series Countercurrent Countercurrent
Alkaline Cleaning 1504. 235.6 i67-36 28.76
Nickel Electroplate 322.9 88.96 26.54 7.44
Zinc Electroplate 236.8 33.78 21.79 7.84
VII-248
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Rinsing Systems
By combining different rinse techniques, a plant can greatly
reduce water consumption and in some cases form a closed loop
rinsing arrangement. Some examples of primary rinse types and
specialized rinsing arrangements applicable to metal finishing
are discussed below.
Closing The Loop With A Countercurrent Rinse - This particular
arrangement is well suited for use "with heated process baths.
The overflow from the countercurrent rinse becomes the evapora-
tive makeup for the process bath. By installing the proper
number of countercurrent tanks, the fresh feed rate for a
given dilution ratio is sized to equal the bath's evaporative
rate. This arrangement is easily controlled by using liquid
level controllers in both the process bath and rinse tank, a
pump to transfer rinse solution to the process bath, and a
solenoid valve on the fresh feed line for the rinse tanks.
Plant ID's 06037, 06072, and 20064 use this arrangement.
Closing The Loop With Spray Followed By Countercurrent Rinse -
The spray followed by countercurreYft FTnseHf ~weT 1 suite~d fo"r
flat sheets and parts without complex geometry. The spray is
mounted over the process bath, and the work is fogged before
moving to the countercurrent rinse. A major advantage of this
arrangement is that the spray reduces concentration of the
dragout on the part, returning the removed portion to the
process tank. This provides for evaporative makeup of the
process bath and a lower water usage and/or a smaller number
of tanks necessary for the countercurrent rinse. Plant ID
40062 utilizes this rinse technique.
Closing The Loop With Countercurrent Rinsing Followed By Spray
Rinsing - The countercurrent "foITowed by spray rinsing approach
can be used when a very clean workpiece (and, therefore, final
rinse) is required. The spray is mounted above the last
countercurrent rinse. Depending on the evaporation rate of;
the process solution, the evaporative makeup can come from the
first countercurrent tank.
Closing The Loop With Dead Rinse Followed By Countercurrent -
The dead rinse followed by countercurrent IFTnse arrangement is
particularly useful with parts of a complex geometry. Evapora-
tive losses from the original solution tank can be made up
from the dead rinse tank and the required flow for the counter-
current system can be greatly reduced. The following plants
VII-249
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make use of this rinsing arrangement: 04045, 06036, 06072,
06081, 06088, 20064, 20073, 20080, 21003, 21651, 30022, 31022,
33065, 33070, 33073, 36041, 41069, 61001. j
Closing The Loop With Recirculatory Spray - When the geometry
of the work permits, the recirculating spray offers an improved
alternative to the dead rinse. Operating with a captive
supply of rinse solution, the solution is sprayed onto the
work. The advantage of this system is that the impact of the
spray is used to remove dragout, particularly for work with
holes in it. The basic equations for concentration buildup
hold but are modified by the removal efficiency of the spray.
The required flow rate of the spray is dependent on the
geometry of the parts, the production rate,and the solution
evaporation rate. Plant ID's 15608 and 27046 have this
rinsing system.
Rinse Water Control
Another method of conserving water through^efficient rinsing
is by controlling the flow of the feed water entering the
rinse tanks. Some flow control methods are listed below.
Conductivity Controllers - Conductivity controllers provide
for efficient use and good control of the rinse process. This
controller utilizes a conductivity cell to measure the conduc-
tance of the solution which, for an electrolyte, is dependent
upon the ionic concentration. The conductivity cell is tied
to a controller which will open or close a solenoid on the
makeup line. As the rinse becomes more contaminated, its
conductance increases until the set point of the controller is
reached, causing the solenoid to open and allowing makeup to
enter. Makeup will continue until the conductance drops below
the set point. The advantage of this method of control is
that water is flowing only when required. A major manufacturer
of conductivity controllers supplied to plants in the Metal
Finishing Category claims that water usage can be reduced by
as much as 50-85% when the controllers are used.
Liquid Level Controllers - These controllers find their great-
est use on closed loop rinsing systems. A typical arrangement
uses a liquid level sensor in both the process solution tank
and in the first rinse tank, and a solenoid on the rinse tank
makeup water line. When the process solution evaporates
to below the level of the level controller, the pump is acti-
vated, and solution is transferred from the first tank to the
process tank. The pump will remain active until the process
tank level controller is satisfied. As the liquid level of
the rinse tank drops due to the pumpout, the rinse tank con-
troller will open the solenoid allowing fresh feed to enter.
Manually Operated Valves - Manually operated valves are suscep-
tible to misuse and should, therefore, be installed in conjunc-
tion only with other devices. Orifices should be installed in
VTI-250
-------
addition to the valve to limit the flow rate of rinse water.
For rinse stations that require manual movement of work and
require control of the rinse (possibly due to low utilization),
dead man valves should be installed in addition to the orifice
to limit the flow rate of rinse water. They should be located
so as to discourage jamming them open,,
Orifices or Flow Restrictors - These devices are usually
installed for nmse tanks that have a constant production
rate. The newer restrictors can maintain a constant flow even
if the water supply pressure fluctuates. Orifices are not as
efficient as conductivity or liquid level controllers, but are
far superior to manual valves.
Process Bath Conservation
There are a number of techniques that are utilized to recover
or reuse process solutions in the Metal Finishing Category.
The costs and reduced availability of certain process solutions
have encouraged finishers to recognize process solutions as a
valuable resource rather than a disposal problem. Some examples
of chemical recovery and reuse are: reprocessing of oil,
reclamation of oil, recycling of oil, reuse of spent etchants,
recovery of metal from spent process baths, regeneration of
etchants and dragout recovery. These techniques are described
below.
Oil Recovery
Reprocessing of Oil - Reprocessing consists of contaminant
removal by physical separation, filtering, centrifuging, or
magnetic separation, as previously discussed. Reprocessing
also includes the preparation of waste oils for burning as a
fuel supplement.
Reclamation of Oil - Oil reclamation combines the elements of
reprocessing along with mechanical or chemical steps. Reclama-
tion is used to remove solids and water, fuel or solvents, and
degradation products such as acid. Two common processes are
flash distillation and chemical adsorption. The addition of
heat with a partial vacuum and filtration are employed to
remove degradation products in used oil.
Reclamation is used with synthethic fluids or highly refined
mineral oils. Reclamation systems are available for either
fixed or portable operation, and outside reclamation services
are available.
Recycling of Oil - Recycling is the most comprehensive treatment,
The waste oil is prefiltered to remove most of the solids,
solvents/ fuel, and water, leaving essentially base oil and
additives. Removing the additives leaves a high quality
basestock. The basestock is then formulated with conventional
additives and can be used in the same application as the
VTI-251
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virgin basestock. Re-refining provides the best economics
when large volumes of waste oil are available. Re-refiners
may accept industrial oil wastes when a large source or many
smaller sources of waste oils are available for collection in
a region. '
Other Recovery Operations
Reuse of Spent Etchant - If a facility maintains both an
additive and a conventional subtractive line for the manufac-
turing of printed boards, a two-fold incentive exists for
reuse of spent copper etchant. The copper etchant used in a
conventional subtractive process is normally dumped when the
copper concentration reaches approximately 45,000 mg/1.
However, by removing the iron and chromium from the etchant,
it can become an inexpensive source of copper for the additive
plating baths. This technique can be extended to recover the
copper bearing waters from copper etchant rinse tanks as well
as from the etch tank and is practiced at Plant ID 11065.
Some concentrating devices, such as vacuum distillation, may
be required to reduce the volume of the rinse.
Recovery of Metal from Spent Plating Baths - Spent plating
baths contain a significant percentage of metal in solution.
Recovery can be effected by electrolizing the solution at low
voltage or by decomposing a hot bath with seed nuclei. The
resultant material, while pure, can be refined or sold to
recover some of its original value. The advantage of this
type of treatment is that a large percentage of the metal is
recovered and does not require treatment. This type of metal
recovery is performed by Plant ID'S 17061 and 11065.
Regeneration of Etchants - Regeneration of etchants from a
copper etchant solution can be achieved by partially dumping
the bath and then adding fresh make-up acid and water. If
this is done, the etchant life can be extended indefinitely.
Another method practiced for the regeneration of etchants used
in the electroless plating of plastics is fto oxidize the
trivalent chromium back to the active hexavalent chromium.
The oxidization is done by an electrolytic cell. Plant 20064
regenerates its preplate etchants in this manner. Use of this
method reduces the amount of material requiring waste treatment,
Reclamation of Paint Powders - A plant which uses powder
coating does not need water wash spray booths to catch over-
spray. The oversprayed particles can be collected with a
vacuum arrangement in a dry booth, filtered, and reused on the
production line.
Dragout Recovery - If the overflow water from a rinse tank can
be reusecfT it does not have to be treated, and additional
water does not have to be purchased. One approach currently
in use is to replace the evaporative losses from the process
bath with overflow from the rinse station.1 This way a large
VII-252
-------
percentage of process solution normally lost by dragout can be
returned and reused.
The usefulness of this method depends on the rate of evapora-
tion from the process tank. The evaporation from a bath is a
function of its temperature, surface area, and ventillation
rate, while the overflow rate is dependent on the dilution
ratio, the geometry of the part, and the dragout rates. If
the rinse is noncritical, i.e., where the part is going to
another finishing operation, closing the loop (returning rinse
overflow to the process tank) can be accomplished with far
fewer rinse tanks than a critical rinse (following the last
process operation). For example, if a particular line is
always used to plate base metals only, and afterwards the work
always goes to another process, then this permits a lower flow
rate with consequently higher buildup of pollutants in the
rinse. Under these conditions, an external concentrator, such
as an evaporator, is not required, and the rinse overflow can
be used directly for process bath makeup. The reverse is
often true with the rinse following the final finishing step.
The flow rate in this instance may be high enough that it
exceeds the bath evaporation rate and some form of concen-
trator is required.
When using any rinse arrangement for makeup of evaporative
losses from a process solution, the quality of the rinse water
must be known and carefully monitored. Naturally occurring
dissolved solids such as calcium and magnesium salts can
slowly build up and cause the process to go out of control.
Even using softened water can cause process control problems.
For this reason, deionized water is often used as a feed for
rinsing arrangements which will be used for evaporative makeup
of process solutions.
Oily Waste Segregation
Many different types (or compounds) of oils and related fluids
are common in oily wastes and include cutting oils, fluids,
lubricants, greases, solvents, and hydraulic fluids. Segrega-
tion of these oily wastes from other wastewaters reduces the
expense of both the wastewater treatment and the oil recovery
process by minimizing the quantity and number of constituents
involved. In addition, segregated oily wastes are appropriate
for hauling to disposal/reclamation by a contractor in lieu of
on-site treatment. Additional segregation of oily wastes by
type or compound can further reduce treatment or hauling
costs. Some oils have high reclaimer values and are more
desirable if they are not contaminated by other oils.
Properly segregated spent oils containing common base oils and
additives will retain much more of their original value and
can be efficiently processed. Spent oils, properly segregated,
can be reprocessed in-house or sold to an outside contractor.
Some plants purchase reprocessed oils which results in substan-
tial savings.
VI1-253
-------
The true value of oils and cutting fluids should be realized
during its entire use cycle, from purchase ,to disposal and
reuse. This is particularly true during used oil collection
and storage. i
Process Bath Segregation
Process baths which are to be sent to waste treatment rather
than being shipped out should be segregated from one another.
The purpose of this is the same as for segregating raw waste
streams. Mixing together of process solutions may form com-
pounds which are very difficult to treat or create unneces-
sarily larger volumes of water requiring specialized treatment
such as chromium reduction or cyanide oxidation.
Process Modification
Process modifications can reduce the amount of water required
for rinsing or reduce the load of certain pollutants on a
waste treatment facility. For example, a rinse step can be
eliminated in electroless plating by using a combined sensiti-
zation and activation solution followed by a rinse in place of
a process sequence of sensitization-rinse-activation-rinse.
Another potential process modification would be to change from
a high concentration plating bath to one with a lower concen-
tration. Parts plated in the lower concentration bath require
less rinsing (a dilution operation) and, thus, decrease the
water usage relative to high concentration baths.
There are also constantly increasing numbers of substitute
bath solutions and plating processes becoming commercially
available. A number of these are listed below:
Non-chromic acid pickling solutions j
Non-cyanide zinc and copper plating j
Non-aqueous plating processes !
Trivalent chromium plating
Etch recovery and recirculating systems
Non-chromium decorative plating
Substitutions for cadmium where applicable
Phosphate-free and biodegradable cleaners
These options have been formulated in an effort to reduce the
level of critical pollutants generated.
For plants which are currently using spraying as their painting
application method, there are several alternative methods of
application which could reduce the amount of wastewater gene-
rated by the painting operation. Among these methods are
electrostatic spraying, powder coating, flow coating and dip
coating. Electrostatic spraying has a smaller percent of
overspray so less paint enters into the wastewater stream.
Powder coating, flow coating and dip coating generate no
wastewater and the powders or paints used can be recycled.
VII-254
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The selection of an application method is highly dependent
upon the geometry of the part being painted so not all of the
methods mentioned above will work for a specific work piece.
A plant which has a painting operation and employs water wash
spray booths to capture overspray may reduce its pollutant
generation by modifications to the spray booths. One possi-
bility is switching over to dry filter booths or oil wash
booths. Neither of these produces any wastewater. Another
alternative is improving the existing booths by adding auto-
matic screening or electrostatic treatment. Both of these
features continuously remove paint solids from the water and
allow for less frequent dumps of the booth water, thereby
reducing wastewater generation.
Another process modification applicable to metal finishing
plants is the replacement of solvent degreasing, where possi-
ble, with an alternative cleaning method such as alkaline
cleaning. Typical areas that are amenable to cleaning tech-
niques other than solvent degreasing are:
1. Low to medium volume production levels when cleaning
cycle time does not impact the cost of production.
2. Non-ferrous products.
3. Simple product shapes
4. Small parts (adaptable to automated processes)
5. Situations where an oily film residue is not
objectionable.
6. Situations where no exacting surface finishing
is required.
Cutting Fluid Cleaning
Essential to efficient machining operations is a clean and effi-
cient cutting fluid cleaning system. An efficient cleaning
system allows for recycling and reuse of oils. In maintaining
clean fluid, the operation, the metal, and the fluid must be
considered. Settling and skimming is only efficient when large
volumes of fluid and long retention times are available. When
fine particles or micro-debris are involved, the cleaning or
maintenance of a cutting fluid also depends on whether it is a
straight oil or an aqueous emulsion. Many operations and
metals will produce coarse debris while brittle metals produce
fine debris requiring a more sophisticated type of treatment.
Filtration, centrifuging, or magnetic separation may be necessary,
VII-255
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Straining
Oil or water solutions require straining to ensure pump protec-
tion. Double strainers should be inserted and kept free of
rags, lint, or other clogging elements. Stainless mesh
strainers are recommended for aqueous systems to minimize
corrosion.
Settling
Large sumps or central systems permit settling. Particle size
and retention time are important considerations to ensure
debris or sediment removal. Settling is essential to other
methods of fluid cleaning by helping reduce sediment loads on
filters and centrifuges. !
Baffles above and below the surface of the fluid level will
improve settling and deposition. Tramp oils, scums, and soaps
may be skimmed either continuously or intermittently. Dense
debris and sediment can be removed by drag chains, periodic
sump cleanout, scum gutters, or surface paddles and sweeps.
Centrifuging
As an accelerated settling process, the centrifuge is largely
limited to low solids content removal. It! may be used to
enhance the efficiency of low volume systems and will remove
fine particles.
Magnetic Separators
Magnetic separators are an effective means of removing ferrous
or magnetic metals and are most efficiently used with low
viscosity fluids or aqueous systems.
Filtration
The pore size or opening of a filter medium will determine the
particle size which may be removed. The most common filtering
systems consist of self-advancing rolled fabric. Filtration
may be enhanced by vacuum or negative pressure. Supplemental
coatings on filter media, such as diatomaceous earth, add
depth to barrier filtration.
Flotation
The cleaning of cutting fluids can utilize the aeration process,
which causes fine particles to attach themselves to air bubbles,
producing an efficient flotation system. Floating matter,
foam, and scum are then removed by continuous skimmers or froth
paddles. Flotation by aeration has the advantage of high
solids removal in relation to liquid losses and effectively
conserves coolant. In general, the flotation-type system
works best with emulsifiable coolants, but foam must be con-
VII-256
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trolled. This system cannot be used with water miscible
fluids of high wettability.
Integrated Waste Treatment
Waste treatment can be accomplished in the production area
with constant recycling of the effluent. This process is
generally known as integrated waste treatment. Integrated
waste treatment can be applied to oily wash waters and elec-
troplating rinse waters.
The washing of oily metal parts, rinses following oil quenches,
machine system leaks, and some testing washes or rinses produce
the largest majority of oily wastewater. Steps should be
taken in-plant to segregate cutting fluids, hydraulic oils,
crankcase oil, quench oils, and solvents from these waste
streams.
Closed loop systems are available for removing oils, metal
fines, and other residues from wash water through a combina-
tion of settling and skimming. A typical closed loop system
consists of two compartments holding caustic wash solution,
each equipped with an oil roll skimmer. While one compartment
supplies wash solution to a series of washers, the other
remains dormant, allowing heavy material to settle and oils
float to the surface. The solids are collected as sludge and
the oils are skimmed off. An alternative system would be an
ultrafiltration system which can recycle water back to rinse
and wash make-up stations.
Integrated treatment for plating processes uses a treatment
rinse tank in the process line immediately following a process
tank (plating, chromating, etc). Treatment solution (usually
caustic soda in excess) circulating through the rinse tank
reacts with the dragout to form a precipitate and removes it
to a clarifier. This clarifier is a small reservoir usually
designed to fit near the treatment rinse tank and is an
integral part of water use in the production process. Further
treatment may take place in the clarifier (cyanide oxidation,
chromium reduction) or settling alone may be used to separate
the solids. Sludge is removed near the spillover plate on the
effluent side of the clarifier, and the effluent is returned
to the treatment rinse tank. Consequently, no pollutants are
directly discharged by the waste treatment process. Although
further rinsing of the parts is required to remove treatment
chemicals, this rinse will not contain pollutants from the
original process tank, and no further treatment is needed.
Good Housekeeping
Good housekeeping, proper selection and handling of process
solutions, and proper maintenance of metal finishing equipment
are required to reduce wastewater loads to the treatment
system. Good housekeeping techniques prevent premature or
VII-257
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unnecessary dumps of process solutions and cooling oils.
Examples of good housekeeping are discussed below.
i
Frequent inspection of plating racks for loose
insulation prevents excessive dragout of process
solutions. Also, periodic inspection of the condi-
tion of tank liners and the tanks themselves reduces
the chance of a catastrophic failure which would
overload the treatment system. :
Steps should be taken to prevent the formation of
hard-to-treat wastes. Separation of cyanide wastes
from nickel or iron wastes is advisable to avoid
formation of cyanide complexes. Proper tank linings
in steel tanks prevent the formation of ferrocyanides.
Periodic inspection should be performed on all
auxiliary metal finishing equipment. This includes
inspection of sumps, filters, process piping, and
immersion steam heating coils for leaks. Filter
replacement should be done in curbed areas or in a
manner such that solution retained by the filter is
dumped to the appropriate waste stream.
Chemical storage areas should be isolated from high
hazard fire areas and arranged such that if a fire
or explosion occurs in the storage area, loss of the
stored chemicals due to deluge quantities of water
would not overwhelm the treatment facilities.
To prevent bacterial buildup on machines, sump walls
and circulatory systems should be sterilized at regular
intervals. Centralized cooling systems are self-cleaning
to some extent, but physical and biological cleaning
are required. The physical cleaning entails the
removal of metallic fines, oxidized oil and other
sludge forming matter. Biological cleaning involves
the use of antiseptic agents, detergents and germi-
cides.
Chip removal from machining operations should include
oil recovery and salvage provisions.
. A lubrication program schedule keeps track of leakage
and contamination. By analyzing records of consump-
tion, it is possible to identify high consumption
equipment. Premature drain intervals may indicate
abnormal system contamination which should be corrected.
A general accounting of oils and fluids throughout
their life cycle (purchasing, storage, application,
cleaning and disposal) will lead.to oil and fluid
conservation.
VII-258
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It is important that proper labricants should be
employed in a particular piece of machinery. Marking
each piece of equipment with the product type required
is practiced throughout the industry. This helps
prevent the use of an improper oil and the subsequent
premature dumping of that oil.
Training and educating the operators of production
equipment and waste treatment equipment can prevent
unnecessary waste.
VII-259
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STATISTICAL ANALYSIS
INTRODUCTION
To establish effluent guideline limitations for the Metal Finishing Category,
the available toxic pollutant data were examined statistically to determine
the performance levels that were attained by properly operated metal finishing
treatment systems.
Details regarding the statistical analysis of toxic pollutants are described
in exhibits: total toxic organics in Exhibit 2, new source Cd in Exhibit 3,
and all other pollutants in Exhibit 1. The statistical analysis followed
three approaches with fundamentally similar methodology. Differences in approach
are due mainly to differences in quantity and structure of the data.
DATA
The types of data usable for TTO and new source ICd were similar and are
therefore discussed together. That data consisted of one set of EPA sampling
data resulting from samples taken daily over a 1 to 4 day period. The data
sets were subdivided (the resulting set of data is refered to as a "subgroup")
based on industrial process (for TTO) or statistical,properties (for new source
Cd). For each pollutant the "subgroup" provided all the numerical information
used for the estimation of variability, and a "subset" of the "subgroup" pro-
vided estimation of the long term average.
The limitations on all other pollutants were based on two distinct sets
of sampling data. The first set consists of raw and effluent concentration
data that were collected during EPA conducted sampling visits. Typically,
these data cover a period of 3 days of sampling, although as many as 6 days
were occassionally recorded. The other data consisted of sets of long term
self monitoring effluent data (usually without parallel raw waste data) that
were submitted by plants in the Metal Finishing Category. These self moni-
toring data cover periods of continuous effluent monitoring up to a year, with
much of the data collected on a daily basis. The self monitoring data were
used to estimate variability and the EPA data were used to estimate the long
term average concentration. There are only a few exceptions to the above.
For Cd and Pb self monitoring data were used to estimate the long term average
and variability; EPA sampling data were not used. This was because the EPA
sampled data indicated very low raw waste Pb and Cd levels and it was not
certain that they adequately represented the range of Pb or Cd in actual use.
For Ag no usable self monitoring data were available,so variability was esti-
mated using the variability estimates of other toxic metals.
STATISTICAL CALCULATIONS
DAILY VARIABILITY
For all pollutants a measure of variability (referred to as a variability
factor) is calculated. In all cases the variability factor is the ratio of
the 99th percentile estimated using a lognomal distribution to the arithmetic
mean of the same data that was used to estimate the 99th percentile. Variability
factors are used to account for fluctuations in effluent levels expected in
well operated treatment systems.
VII-260
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Variability factors for TTO and new source Cd, because of the data
similiarities, have been calculated in a similar manner and are described
together. The data were assumed to follow a lognormal distribution by plant
although the new source Cd and TTO data sets have no single plants with data
sets sufficient to test lognormality. This assumption has been found to be
satisfactory for the discharge of other pollutants in this industry as well as
other industries. Although not tested formally, these data do not display
significant departures from lognormality. The 99th percentiles in these cases
were estimated using a pooled within plant variance. The pooled within plant
variance uses only those plants with multiple observations. The 99th percentile
of the "subgroup" is then divided by the arithmetic mean of the entire "subgroup"
to arrive at the variability factor for the pollutant.
The variability factors for all the remaining toxic pollutants have been
calculated in a similar manner and are discused below. Because the self moni-
toring data base contained large within plant data sets, lognormality of the
toxic pollutant data was graphically and statistically verified by plant. In
cases where detection limit observations were present in the data, a generalized
form of the lognormal, known as the delta lognormal distribution was used.
The variability factor used to calculate the limitations was determined by
taking the median of the variability factors for each pollutant. Any datura
reported as below a detection limit was assigned a value of zero. If more
than 50 percent of the data were reported below the detection limit the plant
was not used to estimate variability.
MONTHLY AVERAGE VARIABILITY
The monthly average variability calculations for new source Cd were based
upon the average of ten daily samples. The assumption is made that the distri-
bution of means of small samples of lognormally distributed values are also
lognormally distributed.* This assumption provides the basis for the parameter
estimates used to determine the 10-day (monthly average) 99th percentile estimate.
Details regarding the methodology behind this approach to 10-day 99th percen-
tiles are described in Exhibit 3. The 10-day (monthly average) variability
factor is calculated in an identical manner to the daily variability factor;
the 99th percentile estimate is divided by the arithmetic mean of the same
data used to estimate the 99th percentile. No monthly average limitations
were calculated for TTO.
The monthly average variability calculations for all other toxic
pollutants was also based on the assumption that averages of 10 daily
samples are approximately lognormally distributed. In these cases, however,
with large quantities of self monitoring data, the 10 day average limitations
* This lognormal characteristic of small sample averages from lognormal dis-
tributions has been observed in many industry categories for a wide variety
of pollutants and was used as the basis of four (4) sample monthly average
limitations in Pretreatment Standards for the Electroplating industry.
VII-261
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were based on empiricial distributions of the logs of 10 day averages. That
is, averages of 10 sequential daily values were constructed from each plants'
self monitoring data and fit to a lognormal distribution. The estimated 99th
percentiles of these fitted distributions were then used as the numerator of
the variability factor. The arithmetic mean of the 10 day averages was used
as the denominator. The median plant 10 day average variability factor for
each pollutant was then used to determine 10 day average monthly limitations.
LONG TERM AVERAGES ;
Long term averages were calculated for TTO, and new source Cd in a similar
manner. A "subgroup" was used to estimate variability and a "subset" of the
"subgroup" was used to estimate the long term average. The "subsets" for both
pollutants contained plants that were exceptional either because of the sta-
tistical properties (eg. extremely large average) and/or because of a special
industrial process (eg. painting and solvent degreasing). An arithmetic average
was calculated from the "subset" and was used as the long term average.
The long term averages for all the other toxic pollutants (except Pb and
Cd) were calculated from the EPA sampling data described above. Arithmetic
means of all values for each pollutant were used as the long term average.
The arithmetic averages of the previously described self monitoring data were
used for Cd and Pb.
EFFLUENT LIMITS
The effluent limitations are based on a plant's treatment system being
operated to maintain an average effluent concentrations equal to the long term
averages. The day-to-day concentrations are expected to fluctuate about these
average concentrations.
The variability factors estimated from the long term self monitoring data
account for these fluctuations. Daily and monthly average limitations were
determined by multiplying the appropriate variability factors and averages.
Details of the data and analysis used to determine the limitations are provided
in exhibits attached to this document and supplemental computer printouts and
worksheets contained in the administrative record supporting this rulemaking.
VII-262
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SECTION VIII
COST OF WASTE WATER CONTROL AND TREATMENT
INTRODUCTION • • -
This section presents estimates of the cost of implementation of
wastewater treatment and control options for each of the sub-
categories included in the Metal Finishing Category. These
costs estimates, together with the pollutant reduction perform-
ance for each treatment and control option presented in Section
VII provide a basis for evaluation of the options presented.
The cost estimates also provide the basis for the determination
of the probable economic impact of regulation at different
pollutant discharge levels on the Metal Finishing Category. In
addition, this section addresses non-water quality environmental
impacts of wastewater treatment and control alternatives includ-
ing air pollution, noise pollution, solid wastes, and energy
requirements.
To arrive at the cost estimates presented in this section,
specific wastewater treatment technologies and in-process con-
trol techniques from among those discussed in Section VII were
selected and combined in wastewater treatment and control sys-
tems appropriate for each waste type. The different waste
treatment systems were combined for cost estimation in six
different plant treatment systems corresponding to the most
common types of facilities operating within the Metal Finishing
Category. As described in more detail below, investment and
annual costs for each system were estimated based on wastewater
flows and raw wastewater characteristics for each waste type as
presented in Section V. Cost estimates are also presented for .
individual treatment technologies included in the waste treat-
ment systems.
COST ESTIMATION METHODOLOGY . - ,
Cost estimation is accomplished using a computer program which ..
accepts inputs specifying the treatment system to be estimated,
chemical characteristics of the raw wastewater streams treated, .
flow rates and operating schedules. The program accesses models
for specific treatment components which relate component invest-
ment and operating costs, materials and energy requirements, and
effluent stream characteristics to influent flow rates and
stream characteristics. Component models are exercised sequen-
tially as the components are encountered in the system to deter-
mine chemical characteristics and flow rates at each point.
Component investment and annual costs are also determined and
used in the computation of total system costs. Mass balance
calculations are used to determine the characteristics of com-
bined streams resulting from mixing two or more streams and to
determine the volume of sludges or liquid wastes resulting from
treatment operations such as chemical precipitation and set-
tling, filtration, and oil separation.
VIII-1
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Cost estimates are broken down into several distinct elements in
addition to total investment and annual costs: operation and
maintenance costs, energy costs, depreciation, and annual costs
of capital. The cost estimation program incorporates provisions
for adjustment of all costs to a common dollar base on the basis
of economic indices appropriate to capital equipment and operat-
ing supplies. Labor and electrical power costs are input vari-
ables appropriate to the dollar base year for cost estimates.
These cost breakdown and adjustment factors as well as other
aspects of the cost estimation process are discussed in greater
detail in the following paragraphs.
Cost Estimation Input Data
The wastewater treatment system descriptions input to the com-
puter cost estimation program include both a specification of
the wastewater treatment components included and a definition of
their interconnections. For some components, retention times or
other operating parameters are specified in the input, while for
others, such as reagent mix tanks and clarifiers, these para-
meters are specified within the program based on prevailing
design practice in industrial wastewater treatment. The waste-
water treatment system descriptions may include multiple raw
wastewater stream inputs and multiple treatment trains. For
example, cyanide bearing waste streams are segregated and
treated for cyanide oxidation and chromium bearing wastes are
segregated for chromium reduction prior to subsequent chemical
precipitation treatment with the remaining process wastewater.
The specific treatment systems selected for cost estimation for
each subcategory were based on an examination of raw waste
characteristics, consideration of manufacturing processes, and
an evaluation of available treatment technologies discussed in
Section VII. The rationale for selection of these systems and
their pollutant removal effectiveness are also addressed in
Section VII.
The input data set also includes chemical characteristics for
each raw wastewater stream specified as input to the treatment
systems for which costs are to be estimated. These character-
istics are derived from the raw wastewater sampling data pre-
sented in Section V. The pollutant parameters which are pre-
sently accepted as input by the cost estimation program are
shown in Table 8-1. The values of these parameters are used in
determining materials consumption, sludge volumes, treatment
component sizes, and effluent characteristics. The list of
input parameters is expanded periodically as additonal pollut-
ants are found to be significant in wastewater streams from
industries under study and as additional treatment technology
cost and performance data become available. Within the Metal
Finishing Category, individual waste types commonly encompass a
number of different wastewater streams which are present to
varying degrees at different facilities. The raw wastewater
characteristics shown as input to wastewater treatment represent
VIII-2
-------
a mix of these streams including all significant pollutants
found and will not in general correspond precisely to process
wastewater at any existing facility. The process by which these
raw wastewaters were defined is explained in Section V.
TABLE 8-1
COST PROGRAM POLLUTANT PARAMETERS
Parameter, Units
Flow, MGD
pH, pH units
Turbidity, Jackson Units
Temperature, degrees C
Dissolved oxygen, mg/1
Residual Chlorine, mg/1
Acidity, mg/1 CaCOS
Alkalinity, mg/1 CaC03
Ammonia, mg/1
Biochemical Oxygen Demand mg/1
Color, Chloroplatinate units
Sulfide, mg/1
Cyanides, mg/1
Kjeldahl Nitrogen, mg/1
Phenols, mg/1
Conductance, micromhos/cm
Total Solids, mg/1
Total Suspended Solids, mg/1
Settleable Solids, mg/1
Aluminum, mg/1
Barium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chromium, Total, mg/1
Copper, mg/1
Fluoride, mg/1
Iron, Total, mg/1
Lead, mg/1
Magnesium, mg/1
Molybdenum, mg/1
Total Volatile Solids, mg/1
Parameter, Units
Oil, Grease, mg/1
Hardness, mg/1 CaCOS
Chemical Oxygen Demand, mg/1
Alg ic ides , mg/1
Total Phosphates, mg/1
Polychlorobiphenyls, mg/1
Potassium, mg/1
Silica, mg/1
Sodium, mg/1
Sulfate, mg/1
Sulfite, mg/1
Titanium, mg/1
Zinc, mg/1
Arsenic, mg/1
Boron, mg/1
Iron, Dissolved, mg/1
Mercury, mg/1
Nickel, mg/1
Nitrate, mg/1
Selenium, mg/1
Silver, mg/1
Strontium, mg/1
Surfactants, mg/1
Beryllium, mg/1
Plasticizers, mg/1
Antimony, mg/1
Bromide, mg/1
Cobalt, mg/1
Thallium, mg/1
Tin, mg/1
Chromium, Hexavalent, mg/1
VII1-3
-------
The final input data set comprises raw wastewater flow rates for
each subcategory input stream addressed. Six treatment scenar-
ios corresponding to different types of manufacturing facilities
within the Metal Finishing Category are addressed in the cost
estimates. Each scenario entails a different combination of
individual subcategory wastewater streams. For each, costs are
estimated for five total plant wastewater flow rates spanning
the range of flows generally encountered within the Metal
Finishing Category (1,000 - 10,000,000 I/day). From these data,
graphs have been prepared showing total treatment system invest-
ment costs and total annual costs as a function of flow rate for
each scenario.
In establishing costs for the Metal Finishing Category, the
Agency used the total plant process flow which could include
wastewaters from other categories, e.g., porcelain enameling.
This analysis provides conservative cost estimates for metal
finishing in that other categorical regulations have costed and
examined the impact of pollution control for non-metal finishing waste-
water streams. !
System Cost Computation
A simplified flow chart for the estimation of wastewater
treatment and control costs from the input data described above
is presented in Figure 8-1. In the computation, raw wastewater
characteristics and flow rates are used as input to the model
for the first treatment technology specified, in the system
definition. This model is used to determine the size and cost
of the component, materials and energy consumed in its opera-
tion, and the volume and characteristics of the stream(s) dis-
charged from it. These stream characteristics are then used as
input to the next component(s) encountered in the system defini-
tion. This procedure is continued until the complete system
costs and the volume and characteristics of the final effluent
stream(s) and sludge wastes have been determined. In addition
to treatment components, the system may include mixers in which
two streams are combined, and splitters in which part of a
stream is directed to another destination. These elements are
handled by mass balance calculations and allow cost estimation
for specific treatment of segregated process wastewaters prior
to combination with other process wastewaters for further treat-
ment, and representation of partial recycle of wastewater.
As an example of this computation process, the sequence of cal-
culations involved in the development of cost estimates for the
simple treatment system shown in Figure 8-2 may be described.
Initially, input specifications for the treatment system are
read to set up the sequence of computations. The subroutine
addressing chemical precipitation and clarification is then
accessed. The sizes of the mixing tank and clarification basin
are calculated based on the raw wastewater flow rate to provide
45 minute retention in the mix tank and 4 hour retention with a
33.3 gal/hr/sq ft surface loading in the clarifier. Based on
these sizes, investment and annual costs for labor, supplies for
VIII-4
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SIMPLIFIED LOGIC DIAGRAM
SYSTEM COST ESTIMATION PROGRAM
NON-RECYCLE
SYSTEMS
INPUT
A) RAW WASTE DESCRIPTION
B) SYSTEM DESCRIPTION
C) "DECISION" PARAMETERS
D) COST FACTORS
PROCESS CALCULATIONS
A) PERFORMANCE - POLLUTANT
PARAMETER EFFECTS
B) EQUIPMENT SIZE
C} PROCESS COST
(RECYCLE SYSTEMS)
CONVERGENCE
A) POLLUTANT PARAMETER
TOLERANCE CHECK
(NOT WITHIN
TOLERANCE LIMITS)
(WITHIN TOLERANCE LIMITS)
COST CALCULATIONS
A) SUM INDIVIDUAL PROCESS
COSTS
B) ADD SUBSIDIARY COSTS
C) ADJUST TO DESIRED DOLLAR BASE
OUTPUT
A) STREAM DESCRIPTIONS-
COMPLETE SYSTEM
B) INDIVIDUAL PROCESS SIZE AND
COSTS
C) OVERALL SYSTEM INVESTMENT
AND ANNUAL COSTS
FIGURE 8-1
COST ESTIMATION PROGRAM
VHI-5
-------
CHEMICAL
ADDITION
RAW WASTE
(PLOW, TSS, LEAD,
ZINC, ACIDITY)
^ 1 _
PRECIPITATION
c^>
^ -h_ -YJ-VJ-VJ. -t-inu-rx-OL.
L^^^^ggyse^J
EFFLUENT
SLUDGE
{CONTRACTOR
REMOVED)
FIGURE 8-2
SIMPLE WASTE TREATMENT SYSTEM
VI11-6
-------
the mixing tank and clarifier including mixers, clarifier rakes
and other directly related equipment are determined. Fixed
investment costs are then added to account for sludge pumps,
controls, piping, and reagent feed systems.
Based on the input raw wastewater concentrations and flow rates,
the reagent additions (lime, alum and polyelectrolyte) are
calculated to provide fixed concentrations of alum and poly-
electrolyte and 10% excess lime over that required for stoichio-
metric reaction with the acidity and metals present in the
wastewater stream. Costs are calculated for these materials,
and the suspended solids and flow leaving the mixing tank and
entering the clarifier are increased to reflect the lime solids
added and precipitates formed. These modified stream character-
istics are then used with performance algorithms for the clari-
fier (as discussed in Section VII) to determine concentrations
of each pollutant in the clarifier effluent stream. By mass
balance, the amount of each pollutant in the clarifier sludge
may be determined. The volume of the sludge stream is deter-
mined by the concentration of TSS which is fixed at 4.5% based
on general operating experience, and concentrations of other
pollutants in the sludge stream are determined from their masses
and the volume of the stream.
The subroutine describing vacuum filtration is then called, and
the mass of suspended solids in the clarifier sludge stream is
used to determine the size and investment cost of the vacuum
filtration unit. To determine manhours required for operation,
operating hours for the filter are calculated from the flow rate
and TSS concentration. Maintenance labor requirements are added
as a fixed additional cost.
The sludge flow rate and TSS content are then used to determine
costs of materials and supplies for vacuum filter operation
including iron and alum added as filter aids, and the electrical
power costs for operation. Finally, the vacuum filter perform-
ance algorithms are used to determine the volume and character-
istics of the vacuum filter sludge and filtrate, and the costs
of contract disposal of the sludge are calculated. The recycle
of vacuum filter filtrate to the chemical precipitation and
settling system is not reflected in the calculations due to the
difficulty of iterative solution of such loops and the general
observation that the contributions of such streams to the total
flow and pollutant levels are, in practice, negligibly small.
Allowance for such minor contributions is made in the 20% excess
capacity provided in most components.
The costs determined for all components of the system are summed
and subsidiary costs are added to provide output specifying
total investment and annual costs for the system and annual
costs for capital, depreciation, operation and maintenance, and
energy. Costs for specific system components and the character-
istics of all streams in the system may also be specified as
output from the program.
Treatment Component Models
The cost estimation program presently incorporates subroutines
providing cost and performance calculations for the treatment
VIII-7
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technologies identified in Table 8-2. These subroutines have
been developed over a period of years from the best available
information including on-site observations of treatment system
performance, costs, and construction practices at a large number
of industrial facilities, published data, and information ob-
tained from suppliers of wastewater treatment equipment. The
subroutines are modified and new subroutines added as additional
data allow improvements in models for treatment technologies
presently available, and as additional treatment technologies
are required for the industrial wastewater streams under study.
Specific discussions of each of the treatment component models
used in costing wastewater treatment and control systems for the
Metal Finishing Category is presented later in this section
where cost estimation is addressed, and in Section VII where
performance aspects were developed.
TABLE 8-2
TREATMENT TECHNOLOGY SUBROUTINES
Treatment Process Subroutines
Spray/Fog Rinse
Countercurrent Rinse
Vacuum Filtration
Gravity Thickening
Sludge Drying Beds
Holding Tanks
Centrifugation
Equalization
Contractor Removal
Reverse Osmosis
Landfill
Chemical Reduction of Chromium
Chemical Oxidation of Cyanide
Neutralization
Clarification (Settling
Tank/Tube Settler)
API Oil Skimming
Emulsion Breaking (Chem/Thermal)
Membrane Filtration
Filtration {Diatomaceous Earth)
Ion Exchange - w/Plant Regeneration
Ion Exchange - Service Regeneration
Flash Evaporation
Climbing Film Evaporation
Atmospheric Evaporation
Cyclic Ion Exchange
Post Aeration
Sludge Pumping
Copper Cementation
Sanitary Sewer Discharge Pee
Ultrafiltration
Submerged Tube Evaporation
Flotation/Separation
Wiped Film Evaporation
Trickling Filter
Activated Carbon Adsorption
Nickel Filter
Sulfide Precipitation
Sand Filter
Chromium Regeneration
Pressure Filter
Multimedia Granular Filter
Sump
Codling Tower
Ozonation
Activated Sludge
Coalescing Oil Separator
Non Contact Cooling Basin
Raw Wastewater Pumping
Preliminary Treatment
Preliminary Sedimentation
Aerator - Final Settler
Chlorination
Flotation Thickening
Multiple Hearth Incineration
Aerobic Digestion
VIII-8
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In general terms, cost estimation is provided by mathematical
relationships in each subroutine approximating observed cor-
relations between component costs and the most significant
operational parameters such as water flow rates, retention
times, and pollutant concentrations. In general, flow rate is
the primary determinant of investment costs and of most annual
costs with the exception of material costs. In some cases,
however, as discussed for the vacuum filter, pollutant concen-
trations may also significantly influence costs.
Cost Factors and Adjustments
As previously indicated, costs are adjusted to a common dollar
base and are generally influenced by a number of factors in-
cluding: Cost of Labor, Cost of Energy, Capital Recovery Costs
and Debt-Equity Ratio. These cost adjustments and factors are
discussed below.
Dollar Base - A dollar base of August 1979 was used for all
costs.
Investment Cost Adjustment - Investment costs were adjusted to
the aforementioned dollar base by use of Sewage Treatment Plant
Construction Cost Index. This cost is published monthly by the
EPA Division of Facilities Construction and Operation. The
national average of the Construction Cost Index for August 1979
was 337.8.
Supply Cost Adjustment — Costs of supplies such as chemicals
were related to the dollar base by use of the Producer Price
Index (formerly known as the Wholesale Price Index). This
figure was obtained from the U.S. Department of Labor, Bureau of
Labor Statistics, "Monthly Labor Review". For August 1979 the
"Industrial Commodities" Producer Price Index was 240.3. Pro-
cess supply and replacement costs were included in the estimate
of the total process operating and maintenance cost.
Cost of Labor - To relate the operating and maintenance labor
costs, the hourly wage rate for non-supervisory workers in sani-
tary services was used from the U.S. Department of Labor, Bureau
of Labor Statistics October, 1979, publication, "Employment and
Earnings". For August 1979, this wage rate was $6.71 per hour.
This wage rate was then applied to estimates of operation and
maintenance man-hours within each process to obtain process
direct labor charges. To account for indirect labor charges, 15
percent of the direct labor costs was added to the direct labor
charge to yield estimated total labor costs. Such items as
Social Security, employer contributions to pension or retirement
funds, and employer-paid premiums to various forms of insurance
programs were considered indirect labor costs.
VIII-9
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Cost of Energy - Energy requirements were calculated directly
within each process. Estimated costs were' than determined by
applying an electrical rate of 4.5 cents per kilowatt hour.
This electrical charge was determined by a'ssuming that any
electrical needs of a waste treatment facility or in-process
technology would be satisfied by an existing electrical distri-
bution system, i.e., no new meter would be required. This
eliminated the formation of any new demand, load base for the
electrical charge.
Capital Recovery Costs - Capital recovery costs were divided
into straight line five-year depreciation and cost of capital at
a thirteen percent annual interest rate for a period of five
years. The five year depreciation period was consistent with
the faster write-off (financial life) allowed for these facili-
ties even though the equipment life is in the range of 20 to 25
years.
l
The annual cost of capital was calculated by using the capital
recovery factor approach.
The capital recovery factor is normally used in industry to help
allocate the initial investment and the interest to the total
operating cost of the facility. It is equal to:
where i is the annual interest rate and N is the number of years
over which the capital is to be recovered. The annual capital
recovery was obtained by multiplying the initial investment by
the capital recovery factor. The annual depreciation of the
capital investment was calculated by dividing the initial invest-
ment by the depreciation period N, which was assumed to be five
years. The annual cost of capital was then equal to the annual
capital recovery minus the depreciation.
Debt-Equity Ratio - Limitations on new borrowings assume that
debt may not exceed a set percentage of the shareholders'
equity. This defines the breakdown of the capital investment
between debt and equity charges. However, due to the lack of
information about the financial status of various plants, it was
not feasible to estimate typical shareholders equity to obtain
debt financing limitations. For these reasons, capital cost was
not broken into debt and equity charges. Rather, the annual
cost of capital was calculated via the procedure outlined in the
Capital Recovery Costs section above.
Subsidiary Costs
The waste treatment and control system costs presented in
Figures 8-34 through 8-65 for end-of-pipe and in-process waste-
water control and treatment systems include subsidiary costs
VIII-10
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associated with system construction and operation. These sub-
sidiary costs include:
- administration and laboratory facilities
- garage and shop facilities
*
- line segregation
- yardwork
- piping
- instrumentation
- land
- engineering
- legal, fiscal, and administrative
- interest during construction
contingency
Administrative and laboratory facility treatment investment is
the cost of constructing space for administration and laboratory
functions for the wastewater treatment system. For these cost
computations, it was assumed that there was already an existing
building and space for administration and laboratory functions.
Therefore, there was no investment cost for this item.
For laboratory operations, an analytical fee of $105 (August 1979
dollars) was charged for metals and cyanide and $635 for toxic
organics for each wastewater sample, regardless of whether the
laboratory work was done on or off site. This analytical fee is
typical of the charges experienced by the EPA contractor during
the past several years of sampling programs. The frequency of
wastewater sampling is a function of wastewater discharge flow
and is presented in Table 8-3. This frequency was suggested by the
Water Compliance Division of the USEPA. However, for the economic
impact analysis, the Agency costed 10 samples per month for
metals and cyanide which is consistent with the statistical basis
for the monthly limit.
For industrial waste treatment facilities being costed, no
garage and shop investment cost was included. This cost item
was assumed to be part of the normal plant costs and was not
allocated to the wastewater treatment system.
Line segregation investment costs account for plant modifica-
tions to segregate wastewater streams. The investment costs for
line segregation included placing a trench in the existing plant
floor and installing the lines in this trench. The same trench
was used for all pipes. The pipes were assumed to run from the
center of the floor to a corner. A rate of 2.04 liters per hour
of wastewater discharge per square meter of area (0.05 gallons
per hour per square foot) was used to determine floor and trench
dimensions from wastewater flow rates for use in this cost
VIII-11
-------
estimation process. It was assumed that a transfer pump would
be required for each segregated process line in order to trans-
fer the wastes to the treatment system.
TABLE 8-3
WASTEWATER SAMPLING FREQUENCY
Waste Water Discharge
(liters per day) Sampling Fregency
I "" .' " ' . " "
0 - 37,850 once per month
i
37,850 - 189,250 twice per month
189,250 - 378,500 once per week
378,500 - 946,250 twice per week
i
946,250+ thrice per week
The yardwork investment cost item includes: the cost of general
site clearing, lighting, manholes, tunnels, conduits, and gen-
eral site items outside the structural confines of particular
individual plant components. This cost is typically 9 to 18
percent of the installed components investment costs. For these
cost estimates, an average of 14 percent was utilized. Annual
yardwork operation and maintenance costs are considered a part
of normal plant maintenance and were not included in these cost
estimates.
The piping investment cost item includes the cost of inter-
component piping, valves, and piping required to transfer the
wastes to the waste treatment system. This cost is estimated to
be equal to 20 percent of installed component investment costs.
The instrumentation investment cost item includes the cost of
metering equipment, electrical wiring and cable, treatment
component operational controls, and motor control centers as
required for each of the waste treatment systems described in
Section VII of the document. The instrumentation investment
cost is estimated based upon the requirements of each waste
treatment system. For continuous operations a base cost of $25.000
was used for instrumentation and was adjusted upward by a variable
factor that depended on the complexity of the treatment system.
No new land purchases were required. It was assumed that the
land required for the end-of-pipe treatment system was already
available at the plant.
Engineering costs include both basic and special services.
Basic services include preliminary design reports, detailed
design, and certain office and field engineering services during
VIII-12
-------
construction of projects. Special services include improvement
studies, resident engineering, soils investigations, land sur-
veys, operation and maintenance manuals, and other miscellaneous
services. Engineering cost is a function of process installed
and yardwork investment costs . The engineering cost ranges from
approximately one percent for investment costs of about $1.2 million
to 37 percent for investment costs of about $12,000.
Legal, fiscal and administrative costs relate to planning and
construction of waste water treatment facilities and include
such items as preparation of legal documents, preparation of
construction contracts, acquisition of land, etc. These costs
are a function of process installed, yardwork, engineering, and
land investment costs, ranging between approximately 0.5 and 5.3 percent
of the total of these costs.
Interest cost during construction is the interest cost accrued
on funds from the time payment is made to the contractor to the
end of the construction period. The total of all other project
investment costs (process installed; yardwork; land; engineer-
ing; and legal, fiscal, and administrative) and the applied
interest affect this cost. An interest rate of 13 percent was
used to determine the interest cost for these estimates.
A contingency allowance was included equal to ten percent of the
sum of the cost of individual treatment technologies plus piping,
line segregation, and yard work.
COST ESTIMATES FOR INDIVIDUAL TREATMENT TECHNOLOGIES
Table 8-4 lists those technologies which are incorporated in the
wastewater treatment and control options offered for the metal
finishing category and for which cost estimates have been devel-
oped. These treatment technologies have been selected from
among the larger set of available alternatives discussed in
Section VII on the basis of an evaluation of raw waste character-
istics, typical plant characteristics (e.g. location, production
schedules, product mix, and land availability), and present
treatment practices within the subcategory addressed. Specific
rationale for selection is addressed in Section IX, X XI and
XII. Cost estimates for each technology addressed in this
section include investment costs and annual costs for deprecia-
tion, capital, operation and maintenance, and energy.
Investment - Investment is the capital expenditure required to
bringthe technology into operation. If the installation is a
package contract, the investment is the purchase price of the
installed equipment. Otherwise, it includes the equipment cost,
cost of freight, insurance and taxes, and installation costs.
Total AnnualCost - Total annual cost is the sum of annual costs
for depreciation, capital, operation and maintenance (less
energy), and energy (as a separate function).
Depreciation - Depreciation is an allowance, based on tax
regulations, for the recovery of fixed capital from an
investment to be considered as a non-cash annual expense.
VIII-13
-------
It may be regarded as the decline in value of a capital
asset due to wearout and obsolescence.
Capital - The annual cost of capital is the cost, to the
plant, of obtaining capital expressed as an interest rate.
It is equal to the capital recovery cost (as previously
discussed on cost factors) less depreciation.
Operation and Maintenance - Operation and maintenance cost
is the annual cost of running the wastewater treatment
equipment. It includes labor and materials such as waste
treatment chemicals. As presented in the tables, operation
and maintenance cost does not include energy (power or
fuel) costs because these costs are shown separately.
Energy - The annual cost of energy is shown separately,
although it is commonly included as part of operation and
maintenance cost. Energy cost has been shown separately
because of its importance to the nation's economy and
natural resources.
TABLE 8-4
INDEX TO TECHNOLOGY COSTS
Technology
CN Oxidation
Chromium Reduction
Clarification
Emulsion Breaking
Holding Tanks
Multimedia Filtration
Ultrafiltration
Carbon Adsorption
Sludge Drying Beds
Vacuum Filtration
Contract Removal
Countercurrent Rinse
Evaporation
Cyanide Oxidation
Figure or Table
Figures 8-3 to 8-5
Figures 8-6 : & 8-7
Figures 8-8 to 8-10
Figures 8-11 to 8-13
Figures 8-14 to 8-16
Figures 8-17 & 8-18
Figures 8-19 to 8-21
Figures 8-22 to 8-24
Figures 8-25 & 8-26
Figures 8-27 to 8-29
Tables 8-6 & 8-7
Figures 8-30 to 8-32
In this technology, cyanide is destroyed by reaction with sodium
hypochlorite under alkaline conditions. A complete system for
accomplishing this operation includes reactors, sensors, con-
trols, mixers, and chemical feed equipment. Control of both pH
and chlorine concentration (through oxidation-reduction poten-
tial) is important for effective treatment.
Investment Costs - Investment costs for cyanide oxidation as
shown in Figure 8-3 include reaction tanks, reagent storage,
mixers, sensors and controls necessary for operation. Costs are
estimated for both batch and continuous systems with the oper-
ating mode selected on a least cost basis. Specific costing
assumptions are as follows:
VIII-14
-------
Ul
iu-
oT
r-
0
3,05
I
V)
(t
INVESTMENT COST (DOLLA
0 0
u to
r
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TIT
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^m
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X1
x I
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•
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2 B
i
1
1
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1
1
I
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1
1
1
1
1
£
X*
AT
n
44
±1
SEPARATE
CAUSTIC
STORAGE
TANK
COSTS
INCLUDED
**•
Ch
«s
IE
3
s/
7
SI
1
HIFT
10
100
to-
10*
10 =
FLOW (L/DAY)
FIGURE 8-3
CYANIDE OXIDATION INVESTMENT COSTS
-------
For batch teatment, oxidation is accomplished by the addition of
sodium hypochlorite. Sodium hydroxide and sulfuric acid are
added to maintain the proper pH level. A: manually controlled
feed pump is included for each treatment chemical. Chemical
storage for the limited quantities generally involved in batch
treatment is assumed to be in shipping containers, and no invest-
ment costs for storage facilities are calculated. Reaction tank
costs are based on two fiberglass tanks, each of which is sized
to provide four hours retention based on process flow rates.
Mixers, based on one horsepower per 1000 gallons of reaction
tank volume (0.5 HP minimum) are also provided. Investment
costs also include a transfer pump and a manual instrumentation
set including:
2 pH probes
1 pH probe maintenance kit
1 pH meter
3 ORP probes
1 ORP meter
Installation is included as 60% of the sum of the component
costs. '
For continuous treatment, oxidation is accomplished using chlo-
rine obtained as a gas. Sodium hydroxide .and sulfuric acid are
used for pH control. Investment costs include a chlorination
system and automatically controlled pH control systems for two
treatment tanks (for the two-stage cyanide destruction process).
These systems include: [
pH Control and Instrumentation
2 Pump stands
2 Peed pumps
2 Liquid Level detectors
15 days storage for acid and sodium hydroxide
2 pH probes
2 pH meters
1 pH probe maintenance kit
2 pH controllers
3 ORP probes
2 ORP meters
2 ORP controllers
2 Recorders
Chlor ina t ion Sys tern
Chlorinator
Pressure Reducing valves
Venturi ejector
Diffuser
Piping and fittings
Evaporator
VIII-16
-------
Weighing scale
Gas detector
Emergency vent system
Hoisting equipment
Installation and start-up service
Costs are estimated for fiberglass reaction tanks providing 0.5
hours retention for the first stage of treatment and 1 hour
retention for the second stage. Mixers based on 1 horsepower
per 1000 gallons with a minimum of 1 horsepower are costed for
each tank. Cost estimates also include 2 emergency vent fans, 3
circulation pumps, and 2 transfer pumps.
Operation and Maintenance Costs - Costs for operating and main-
taining cyanide oxidation systems include labor and chemical
expenses. Annual operation and maintenance expenses for batch
and continuous cyanide oxidation systems are shown in Figure 8-4
as a function of waste stream flow rate.
Labor expenses for the batch treatment system are estimated
based on 1.5 hours of labor per batch of waste treated plus 2
hours of maintenance labor per week plus additional labor for
chemical handling based on the amounts of treatment chemicals
consumed. For continuous treatment, maintenance labor is esti-
mated at 4 hours per week, and operating labor at 1 hour per
shift plus an additional 0.5 hours per cylinder (1 ton) of
chlorine consumed.
Chlorine or sodium hypochlorite addition is calculated based on
a 10% excess over stoichiometric requirements calculated from
measured cyanide concentrations plus concentrations of some
metals, (copper, iron, and nickel) which form cyanide complexes.
Sodium hydroxide requirements to maintain pH are calculated
based on the flow and the amount of cyanide being treated, and
sulfuric acid consumption is based on flow and sodium hydroxide
consumption.
Chemical costs have been based on the following unit prices:
$ 600 Per ton of chlorine (August, 1979 price)
$1462 Per ton of sodium hypochlorite (August, 1979 price)
$ 699 Per ton of sodium hydroxide (August, 1979 price)
$ 113 Per ton of sulfuric acid (August, 1979 price)
The assumption has been made that the plants operate 24 hours
per day, 260 days per year. This assumption overestimates the
costs for facilities which operate less than 24 hours per day.
Energy Costs - Motor horsepower requirements for chemical mixing
have been described above. Mixing equipment is assumed to
operate continuously over the operation time of the treatment
system for both the continuous and batch modes. Pump motor
VIII-17
-------
H
H
H
00
10"
0
3 10s
I
in
K
j
j
0
(0
(0
0
o
s
*
0
10"
3
Z
Z
10
CONTINUOUS
BATCH
100
10"
ioa
FLOW (L/DAY)
10*
FIGURE 8-4
ANNUAL O&M COSTS VS. FLOW RATE FOR CYANIDE OXIDATION
-------
horsepower requirements are calculated based on several var-
iables. These include system flow, pump head and system oper-
ating time.
Annual energy expenses for batch and continuous cyanide oxida-
tion systems are shown in Figure 8-5 as a function of waste
stream flow rate. Energy expenses have been estimated based
upon a rate of $Q.045/kilowatt hour of required electricity.
Plant operation was assumed to be for 24 hours/day, 260 days/
year. For continuous treatment, the treatment system operates
during plant operation. Batch treatment operation schedules
vary with flow rate as discussed above.
Chromium Reduction
This technology provides chemical reduction of hexavalent chro-
mium under acidic conditions to allow subsequent removal of the
trivalent form by precipitation as the hydroxide. Treatment may
be provided in either continuous or batch mode; cost estimates
are developed for each. Operating mode for system cost esti-
mates is selected on a least cost basis.
Investment Cost - Cost estimates include all required equipment
for performing this treatment technology including reagent
dosage, reaction tanks, mixers and controls. Different reagents
are provided for batch and continuous treatment resulting in
different system design considerations as discussed below.
For both continuous and batch treatment, sulfuric acid is added
for pH control. The acid is purchased at 93% concentration and
stored in the cylindrical drums in which it is purchased.
For continuous chromium reduction a single chromium reduction
tank is used. Costs are estimated for an above-ground cylin-
drical rubber lined tank with a one hour retention time, and an
excess capacity factor of 1.2. Sulfur dioxide is added to
convert the influent hexavalent chromium to the trivalent form.
The control system for continuous chromium reduction consists
of:
1 immersion pH probe and transmitter
2 immersion ORP probes and transmitter
1 pH monitor and controller
1 ORP monitor and controller
1 sulfonator and associated controls, diffuser,
evaporator, and pressure regulator
1 sulfuric acid pump
2 dilute acid pumps and pump stands
1 transfer pump for sulfur dioxide ejector with
pump stand
1 pH probe maintenance kit
1 pen recorder
2 mixers
VIII-19
-------
H
M
to
O
0
3
I
V)
£
<
_l
_l
0
Q^
in
8
u
>•
o
o:
Id
Z
Id
_l
<
3
Z
-Z-
io
o
10
• CONTINUOUS
BATCH
100
10"
10=
FLOW (L/DAY)
FIGURE 8-5
ANNUAL ENERGY COSTS VS. FLOW RATE FOR CYANIDE OXIDATION
-------
For batch chromium reduction, the dual chromium reduction tanks
are sized as above-ground cylindrical rubber-lined tanks, with a
variable retention time, depending on flow rates. Up to a flow
of 400 I/day to chromium reduction, one batch is treated per 5
days of operation, and treatment tanks are sized to contain 5
days' flow. Above this flow rate, one batch is treated each
day. Sodium bisulfite is added to reduce the hexavalent chro-
mium.
A completely manual system is provided for batch operation.
Subsidiary equipment includes:
2 immersion pH probes
1 pH probe maintenance kit
1 pH meter
3 immersion ORP probes (one stand by)
1 ORP meter
1 sulfuric acid transfer pump and stand
1 sulfuric acid dilution tank
1 sulfuric acid feed pump and stand
1 reduction tank drain transfer pump
Investment costs for batch and continuous treatment systems are
presented in Figure 8-6.
Operation and Maintenance - Costs for operating and maintaining
chromium reduction systems include labor and chemical expenses.
Annual operation and maintenance expenses for batch and continu-
ous chromium reduction systems are shown in Figure 8-7 as a
function of waste stream flow rate.
Labor requirements for batch treatment include 2 hours/week
maintenance, 45 minutes/batch treated and additional labor for
chemical handling depending on the amount of sulfuric acid
consumed. For continuous treatment, labor requirements are 4
hours/week maintenance, 1 hour/day operation and additional
labor for chemical handling depending on the amount of sulfuric
acid consumed.
For the continuous system, sulfur dioxide is added according to
the following:
(Ibs SO /day) - (8.34) (flow to unit-MGD) (1.85xmg/lCr+6+4 x
mg/1 dissolved 02) (1.1 excess capacity factor)
In the batch mode, sodium bisulfite is added in place of sulfur
dioxide according to the following:
(Ibs NaHSO /day) = (8.34)(flow to unit-MGD)(2.74 x mg/lCr+6 +
5.94 x mg/1 dissolved 02)(1.1 excess
capacity factor)
Costs for these labor and chemical requirements are estimated
based on the following:
VIII-21
-------
NJ
10°
0
3«««
I
OT
J
J
0
£
tn
V)
0
u
h
z
UI
U)
u
—-z -----
10-
10
.CONTINUOUS
BATCH
100
10°
FLOW (L/DAY)
10"
10 =
10C
FIGURE 8-6
CHROMIUM REDUCTION INVESTMENT COSTS
-------
I
w
U)
10"
01
rs
0
D
I
V)
a:
0
Q
V)
V)
0
u
0
-l
<
D
Z
Z
105
10"
10"
100
BATCH--
^
10J
10"
10 =
10"
FLOW (L/DAY)
FIGURES-?
ANNUAL O&M COSTS VS. FLOW RATE FOR CHROMIUM REDUCTION
-------
$6.71 per manhour +15% indirect labor charge
$760. per ton of sulfur dioxide
$280. per ton of sodium metabisulfite (1978 dollars)
Energy Costs - The horsepower required for chemical mixing is
estimated based on tank volumes at 1 hp per 1,000 gallons. The
mixers are assumed to operate continuously :over the operation
time of the treatment system. Pump motor horsepower require-
ments are calculated based on system flow, pump head, and oper-
ating time. Energy expenses are estimated based on a rate of
$0.045/kilowatt hour of required electricity.
Chemical Precipitation and Settling
This technology removes dissolved pollutants by the formation of
precipitates by reaction with added lime and subsequent removal
of the precipitated solids by gravity settling in a clarifier.
Several distinct operating modes and construction techniques are
costed to provide least cost treatment over a broad range of
flow rates. Because of their interrelationships and integration
in common equipment in some installations, both the chemical
addition and solids removal equipment are addressed in a single
subroutine. The chemical precipitation/sedimentation subroutine
also incorporates an oil skimming device on the clarifier for
removal of floating oils. '•
Investment Costs - Investment costs are determined for this
technology for both batch and continuous treatment systems using
steel tank or concrete tank construction. jThe system selected
is based upon least cost on an annual basis as discussed previ-
ously in this section of the development document. Continuous
treatment systems include a mix tank for reagent feed addition
(flocculation basin) and a clarification basin with associated
sludge rakes and pumps. Batch treatment systems include only
reaction settling tanks and sludge pumps.
The flocculator included in the continuous chemical precipita-
tion and sedimentation system can be either a steel tank or
concrete tank unit. The concrete unit is based on a 45 minute
retention time, a length to width ratio of'5, a depth of 8 feet,
a wall thickness of 1 foot, and a 20 percent excess capacity
factor. The steel unit size is based on a 45 minute retention
time, and a 20 percent excess capacity factor. Capital costs
for the concrete units include excavation (as required). A
mixer is included in flocculators of both constructions.
The concrete settling tank included in the'continuous chemical
precipitation and clarification system is an in-ground unit
sized for a hydraulic loading of 33.3 gph/square foot, a wall
thickness of 1 foot, and an excess capacity factor of 20 per-
cent. The steel settling tank included in:the continuous chem-
ical precipitation and sedimentation system is a circular above-
VIII-24
-------
ground unit sized for a hydraulic loading of 33.3 gph/square
foot, and an excess capacity factor of 20 percent. The depth of
the circular steel tank is assumed to increase linearly between
six and fifteen feet for tanks with diameters between eight and
twenty-four feet respectively. For tanks greater than twenty-
four feet in diameter, the depth is assumed to be a constant
fifteen feet. An allowance for field fabrication for the larger
volume steel settling tanks is included in the capital cost
estimation.
For batch treatment systems, dual above ground cylindrical steel
tanks sized for an eight hour retention period and a 20 percent
excess capacity factor are employed. The batch treatment system
does not include a flocculation unit.
A fixed cost of $3,349 is included in the clarifier investment cost
estimates for sludge pumps regardless of whether above-ground
steel tanks (in the batch or continuous operation modes) or the
in-ground concrete settling tank are used. This cost covers the
expense of two centrifugal sludge pumps. Fixed costs of $2,346
and $12,902 are included to cover the expense of polymer feed
systems for the batch and continuous operation modes respec-
tively. The $12,902 figure is included regardless of whether
concrete or steel tank construction is employed for the contin-
uous operation mode.
Lime addition for chemical precipitation in the batch mode is
assumed to be performed manually. A variable cost allowance for
lime addition equipment is included in the continuous operation
mode. This cost allowance covers the expense associated with a
lime storage hopper, feeding equipment, slurry formation and
mixing and slurry feed pumps. The cost allowance increases as
clarifier tank size increases.
Figure 8-8 shows a comparison of investment cost curves for
batch and continuous chemical precipitation and sedimentation
systems. The continuous treatment system investment cost
is based on a steel flocculation unit followed by a steel clari-
fication basin. This combination of treatment components was
found to be less expensive than the concrete flocculation
basin, concrete clarification basin combination, or any
combination of steel and concrete flocculation and clarification
units. The batch treatment investment curve is based upon two
above-ground cylindrical steel tank clarifier units. Both the
continuous and batch system investment curves include allowances
for the sludge pump, polymer feed systems, and lime addition
equipment (continuous system only).
All costs presented above include motors, controls, pump stands,
and piping specifically associated with each treatment compo-
nent .
Operation and Maintenance Costs - The operation and maintenance
costs for the clarifier routine include the cost of chemicals
VII1-25
-------
I
NJ
10'
0
3
I
V)
J
0
Q
CONTINUOUS
V)
0
u
1-
u
Sto*
bl
to-
TREATMENT
BATCH
TREATMEN-
MANUAL MIXING
"OF TREATMENT
TANKS
ONE PORTABLE
"MIXER
FIXED MIXERS ON
"BOTH TREATMENT
TANKS
10
100
10"
10 =
10"
FLOW (L/DAY)
FIGURE 8-8
CHEMICAL PRECIPITATION AND CLARIFICATION INVESTMENT COSTS
-------
added (lime, flocculants), and of labor for operation and mainte-
nance. Each of these contributing factors is discussed below.
Figure 8-9 presents the annual manhour requirements for the
continuously operating chemical precipitation and settling
system. For the batch system, maintenance labor is calculated
from the following equation:
Annual manhours for maintenance = 0.75 x (Days of operation per
year)
Operational labor for the batch system is calculated from the
following equation:
Annual manhours for operation = 780 + (1.3) (Ibs of lime added
per day)
Labor expenses have been estimated using a labor rate of $6.71
per manhour plus an additional 15% to cover indirect labor ex-
penses .
Lime is added to the waste solution in order to precipitate
dissolved metals so that the metal may be removed from the waste
stream as settleable particulates. The amount of lime required
for addition is based on equivalent amounts of various pollutant
parameters present in the waste stream entering the unit. The
coefficients used for calculating lime requirements are shown in
Table 8-5.
The cost of lime required has been determined using a rate of:
$44.61 per ton of lime (August, 1979 price)
Figure 8-10 presents annual operation and maintenance cost
curves for the continuous and batch operation modes of the
chemical precipitation and settling system as a function of
waste stream flow rate. The cost curves have been based on the
assumption that the waste treatment system will operate 24 hours
per day, 5 days per week, 260 days per year.
Energy Costs - The energy costs are calculated from the clar-
ifier and sludge pump horsepower requirements.
Continous Mode - The clarifier horsepower requirement is assumed
constant over the hours of operation of the treatment system at
a level of 0.0000265 horsepower per 3.8 I/hour (1 gph) of flow
influent to the clarifier. The sludge pumps are assumed opera-
tional for 5 minutes of each operational hour at a level of
0.00212 horsepower per 3.8 I/hour (1 gph) of sludge stream flow.
Batch Mode - The clarifier horsepower requirement is assumed to
occur for 7.5 minutes per operational hour at the following
level:
VI11-27
-------
800
700
K 600
U
oT
« 500
0
§ 400
m
S 30°
tt
5
o
100
I
I
I
I
50
100
300
350
150 200 <>50
FLOW RATE (1000 L/HR)
FIGURE 8-9
CHEMICAL PRECIPITATION AND SETTLING
ANNUAL OPERATION AND MAINTENANCE LABOR REQUIREMENTS
400
VI11-28
-------
V
Ni
^D
ANNUAL O&M COSTS (DOLLARS - AUG. '79
10°
0
O
0
BATCH=^
.CONTINUOUS
0
U
^
s
*'
100
10
10
I0
10
10y
FLOW (L/DAY)
FIGURE 8-10
ANNUAL O&M COSTS VS. FLOW RATE FOR CLARIFIER
-------
influent flow < 3944 I/hour; 0.0048 hp/gph
influent flow > 3944 I/hour; 0.0096 hp/gph
The power required for the sludge pumps in the batch system is
the same as that required for the sludge pumps in the continuous
system. Energy costs for these requirements are estimated based
on a unit cost of $0.045/kilowatt hour of required electricity.
TABLE 8-5
LIME ADDITIONS FOR LIME PRECIPITATION
Lime Addition
Stream Parameter kg/kg (Ibs/lb)
Aluminum 0.81
Antimony 4.53
Arsenic 1.75
Cadmium 2.84
Chromium 2.73
Cobalt 2.35
Copper 1.38
Iron (Dissolved) 1.28
Lead 2.19
Magnesium 0.205
Manganese 3.50
Mercury 1.48
Nickel 0.42
Selenium 1.45
Silver 3.23
Zinc 1.25
Chemical Emulsion Breaking
Chemical emulsion breaking removes emulsified oil droplets from
suspension through chemical destabilization. Destabilization
allows the oil droplets to agglomerate, rise to the surface of
the separation tank, and be removed from the wastewater by
surface skimming mechanisms. This technology assumes that the
waste oil emulsion is capable of being broken through chemical
addition only, and that addition of heat will not be required.
In this waste treatment system, emulsified oil wastes are mixed
with alum and chemical polymers, then allowed to separate via
gravity separation in a settling tank. Once separation has
occurred, the waste oils can be skimmed from the tank surface
and disposed. The remaining wastewater is either passed on to
further treatment or discharged depending on the waste treatment
system.
Chemical emulsion breaking can be performed in either a continu-
ous or a batch mode. Each operating mode, the equipment asso-
ciated with each mode, and the design and operating assumptions
incorporated are discussed in the following paragraphs.
VIII-30
-------
Investment Costs - The investment costs associated with the
continuous and batch operating modes for chemical emulsion
breaking are shown in Figure 8-11 as a function of waste stream
flow rate. For the continuous operating mode, the cost curve is
based upon the purchase and installation of the following equip-
ment :
2 946 liter (250 gallon) alum dilution tanks
2 Alum dilution tank mixers
2 Variable speed alum feed pumps (with pump
stands and associated automatic control equipment)
2 946 liter (250 gallon) polymer dilution tanks
2 Polymer dilution tank mixers
2 Variable speed polymer feed pumps (with pump
stands and associated automatic control equipment)
1 Steel mixing tank with liner for chemical addition
(sized for 15 minute retention time)
1 Mixing tank mixer (motor horsepowe'r variable with
mixing tank volume)
1 Steel gravity separation tank with liner, weirs,
and baffles (sized for 1 hour retention time)
1 Separation tank surface oil skimming mechanism
1 Skimmed oil transfer pump
1 Waste oil storage tank (steel tank with liner, sized
for 20 day retention)
1 Separation tank effluent transfer pump
For the chemical emulsion breaking unit operated in the batch
mode, the cost curve is based upon the purchase and installation
of the following equipment:
1 946 liter (250 gallon) alum dilution tank
1 Alum dilution tank mixer
1 Alum feed pump with pump stand
1 946 liter (250 gallon) polymer dilution tank
1 Polymer dilution tank mixer
1 Polymer feed pump with pump stand
2 Steel gravity separation tanks with liners
(sized for variable retention depending on least cost
mode)
2 Tank mixers (motor hp variable with separation
tank volume)
1 Separation tank effluent transfer pump
The chemical emulsion breaking system (both batch and continuous
operating modes) have been sized for a 20% excess capacity
factor. Selection of the operating mode is based on a least
cost basis as discussed previously in the Section VIII text.
Operation and Maintenance Costs - The operation and maintenance
costs associated withthe chemical emulsion breaking unit con-
sist of labor and material expenses.
VII1-31
-------
V
CO
0
3
<
l
tfl
0
Q
W
0
U
h
U
2
U)
u
10J
BATCH-
10"
to-
1 BATCH/DAY
2 BATCH/SHIFT
100
10"
10 =
10'
FLOW (L/DAY)
FIGURE 8-11
EMULSION BREAKING INVESTMENT COSTS
-------
Annual labor expenses for both the continuous and batch op-
erating modes for the chemical emulsion breaking unit are shown
in Figure 8-12 as a function of waste stream flow rate. For the
continuous operating mode, labor requirements are based on ':.
estimated manhours required for diluting and mixing the polymer
and alum solutions and operating the unit. General operation
labor has been estimated at 0.75 manhours per 8 hour shift.
General maintenance of the entire system has been estimated at 2
manhours per week.
For the batch operating mode, labor requirements are based on
estimated manhours required for diluting and mixing the polymer
and alum solutions and operating the unit. General operation
labor has been estimated at 0.75 manhours required per batch.
General maintenance of the entire system has been estimated at 1
manhour per week.
Labor expenses have been calculated using a labor rate of $6.71
per manhour plus an additional 15% to cover indirect labor
costs.
Material costs are associated with the alum and polymer chemical
addition requirements. Polymer is added to the wastewater until
a concentration of 150 mg/1 is attained. Alum is added to the
wastewater until a concentration of 25 mg/1 is attained. Chem-
ical costs have been based upon the following unit prices;
$0.38 per kg of alum
$1.55 per kg of polymer , •
The assumption has been made that the unit operates 24 hours per
day, 5 days per week, 52 weeks per year.
Energy Costs - Annual energy expenses for the chemical emulsion
break ing sy s tern (both batch and continuous operating modes)- -are
shown in Figure 8-13 as a function of waste stream flow rate.
These costs are based on operation of the dilution tank mixers,
chemical feed pumps, mixing and separation tank mixers (as
applicable), oil skimmer (as applicable), and solution transfer
pumps (oil and separation tank transfer pumps, as applicable).
Energy expenses have been estimated based upon a rate of $0.045/
kilowatt-hour of required electricity. It has been assumed that
the unit operates 24 hours per day, 5 days per week, 52 weeks
per year.
Hold ing Tanks
Tanks serving a variety of purposes in wastewater treatment and
control systems are fundamentally similar in design and construc-
tion and in cost. They may include equalization tanks, solution
holding tanks, slurry or sludge holding tanks, mixing tanks, and
settling tanks from which sludge is intermittently removed
manually or by sludge pumps. Tanks for all of these purposes"
are addressed in a single cost estimation subroutine with addi-
tional costs for auxilliary equipment such as sludge pumps added
as appropriate.
VIII-33
-------
$
H
V
U)
01
ts
0
3
i
(0
£
0
Q
(0
0
u
s
*
*I04
3
Z
Z
BATCH-
too
103
10"
10 =
106
10'
FLOW (L/DAY)
FIGURE 8-12
ANNUAL O&M COSTS VS. FLOW RATE FOR CHEMICAL EMULSION BREAKING
-------
H
V
OJ
10
0
3
w 10-
K
U)
8
u
o
K
U
Z
U 2
j 102
D
Z
Z
100
CONTINUOUS
BATCH.
/.
10"
10 =
FLOW (L/DAY)
7
10"
10
FIGURE 8-13
ANNUAL ENERGY COSTS VS. FLOW RATE FOR CHEMICAL EMULSION BREAKING
-------
Investment Costs - Costs are estimated for steel tanks. Tank
construction may be specified as input data, or determined on a
least cost basis. Retention time is specified as input data
and, together with stream flow rate, determines tank size.
Investment costs for steel tanks sized for 0.5 days retention
and 20% excess capacity are shown as functions of stream flow
rate in Figure 8-14. These costs include mixers, pumps and
installation.
Operation and Maintenance Costs - For all holding tanks except
sludge holding tanks, operation and maintenance costs are min-
imal in comparison to other system O&M costs. Therefore only
energy costs for pump and mixer operation are determined. These
energy costs are presented in Figure 8-15.
For sludge holding tanks, additional operation and maintenance
labor requirements are reflected in increased O&M costs. The
required manhours used in cost estimation are prsented in Figure
8-16. Labor costs are determined using a labor rate of $6.71
per manhour plus 15% indirect labor charge.
Where tanks are used for settling as in lime precipitation and
clarification batch treatment, additional operation and mainte-
nance costs are calculated as discussed specifically for each
technology.
Multimedia Filtration
This technology provides removal of suspended solids by filtra-
tion through a bed of particles of several distinct size ranges.
As a polishing treatment after chemical precipitation and clar-
ification processes, multimedia filtration provides improved
removal of precipitates and thereby improved removal of the
original dissolved pollutants, '
Investment Costs - The size of the granular bed multimedia
filtration unit is based on 20%_excess flow capacity and a
hydraulic loading of 81.5 Ipm/m . Investment cost is presented
in Figure 8-17 as a function of flow installation.
Operation and Maintenance - The costs shown in Figure 8-18 for
operation and maintenance include contributions of materials,
electricity and labor. These curves result! from correlations
made with data obtained by a major manufacturer. Energy costs
are estimated to be 3% of total O&M.
Ultrafiltration
Ultrafiltration is a separation process involving the use of a
semipermeable polymeric membrane. The porous membrane acts as a
barrier, separating molecular sized particulates from the waste
stream. Membrane permeation by particulates is dependent upon
particulate size, shape and chemical structure. Solvents and
lower molecular weight solutes are typically passed through the
VIII-36
-------
to
u
3 10-
I
m
K
J
J
0
Q
(A
(A
0
U
I-
Z
III
s
H
H
-J
(BASED ON o.s DAY RETENTION-
INCLUDED ARE MIXER & TRANSFER PUMP)
10
to
100
10-
10"
10 =
FLOW (L/DAY)
10°
FIGURE 8-14
HOLDING TANK INVESTMENT COSTS
-------
104
103
too
1
-
- • " -
-
»
*
s*
JS
^r
. . ^
s
f
... . .
/
'
'
_..
>
/
^
>"
s
t
(B
P(
y
f
/
J
/
/
/
t
/
f
/
ASED ON O.S DAY RETENTION -
3WER FOR MIXER AND TRANSFER PUMP
)
30 103 104 105 106 'O7
FLOW (L/DAY)
FIGURE 8-15
ANNUAL ENERGY COSTS VS. FLOW FOR HOLDING TANKS
-------
10"
10J
n
a
D
0
X
z
0
CD
s
M
M
OJ
100
10
100
TOTAL LABOR
i—r—i-
OPERATION
-MAINTENANCE
10J
10"
10s
10s
10'
FLOW (L/DAY)
FIGURE 8-16
LABOR REQUIREMENTS VS. FLOW FOR SLUDGE HOLDING TANKS
-------
I
£>
o
10°
INVESTMENT COST (DOLLARS - AUG, '79)
o o o
W £> Ul
_
s
s
s
/
X
/
/
-
/
s\
s
s
x^
^
^
^
x^
r
-
X
/
x
x
^
s
X
X
PACKfl
S
/
GED
X
UN
X*
IT
/I
1
^
C
X
>rv
I-S
.^
^^
t*r
ITE FABI
- -
^X
*r
RICA
.
xx
no
X
N
"
X
X
X
f
too
10-
to"
10s
FLOW (L/DAY)
FIGURE 8-17
MULTIMEDIA FILTRATION INVESTMENT COSTS
-------
at
IN
0
< 105
I
(0
a:
4
0
a
(0
(0
0
u
2
*
0
j
4
D
Z
Z
103
100
103
105
10'
FLOW (L/DAY)
FIGURE 8-18
ANNUAL O&M COSTS VS. FLOW RATE FOR MULTIMEDIA FILTRATION
-------
membrane, while dissolved or dispersed materials with molecular
weights in the range of 1,000 to 100,000 are removed from solu-
tion.
The ultrafiltration process occurs when a. waste solution is
pumped under a fixed head (10 to 100 psig) through a tubular
membrane unit. Water and low molecular weight materials pass
through the membrane and are recycled, passed on to further
treatment or are discharged. Emulsified oils and larger sized
suspended particulates are blocked by the! membrane and are thus
concentrated in a continuously discharged waste stream. The
concentrated waste solution can then be passed on to further
treatment or disposal. ,
Investment Costs - The investment cost curve for the ultra-
filtration unit has been calculated using information supplied
by leading manufacturers in the industry.! Figure 8-19 presents
investment cost information for ultrafiltration systems as a
function of waste stream flow rate. This cost curve has been
generated based upon purchase and installation of a complete
package ultrafiltration system. This system includes the fol-
lowing equipment:
1 wastewater flow equalization tank
1 wastewater process tank
1 set of ultrafiltration membrane modules (quantity
variable with wastewater flow rate)
1 set of transfer and circulation pumps
1 acid feed system (includes storage and pumps as
required for membrane cleaning)
1 set of process controls and instrumentation
Operation and Maintenance Costs - Annual operation and main-
tenance costs for the ultrafiltration system are shown in Figure
8-20 as a function of waste stream flow rate. This cost curve
includes labor and materials required for system operation. The
operation and maintenance cost curve has been estimated based
upon information supplied by a leading ultrafiltration system
manufacturer. The curve is based on the assumption that the
system operates 24 hours per day, 5 days per week, 52 weeks per
year.
Energy Costs - Annual energy costs for the ultrafiltration
system are shown in Figure 8-21 as a function of waste stream
flow rate. This cost curve has been generated based upon infor-
mation supplied by a leading ultrafiltration system manufac-
turer. The curve is based on the assumption that the system
operates 24 hours per day, 5 days per week, 52 week per year.
Carbon Adsorption
This technology removes organic pollutants and suspended solids
by pore adsorption, surface reactions, and physical filtering by
the carbon grains. It typically follows other types of treat-
VIII-42
-------
s
M
2
U)
10'
o io6
3
-I
-I
0
£
I-
V)
0
U
Z
U
Z
in
ui
10 =
10"
too
10-
10"
10 =
FLOW (L/DAY)
10'
FIGURE 8-19
ULTRAFILTRATION INVESTMENT COSTS
-------
10'
l-l
0
3 ios
I
10
K.
-I
0
Q
(0
(0
0
U
s
*
<
3
Z
Z
10-
Z
X
Z
10'
o
,06 3
_J
_J
o
Q
(0
(0
0
U
I05 J
Z
<
100
10J
10a
10C
10"
107
FLOW (L/DAY)
FIGURE 8-20
ANNUAL O&M COSTS VS. FLOW RATE FOR ULTRAFILTRATION
-------
10"
DOLLARS- AUG. '79
ANNUAL ENERGY COS
0
0
10«
10s
10*
100
10-
10"
10"
10'
FLOW (L/DAY)
FIGURE 8-21
ANNUAL ENERGY COSTS VS. FLOW RATE FOR ULTRAFILTRATION
-------
merit as a means of polishing the effluent. A variety of carbon
adsorption systems exist: upflow, downflow, packed bed, ex-
panding bed, regenerative, and throwaway. Regeneration of
carbon requires an expensive furnace and fuel for regeneration
that are not required for a throwaway system. Large systems may
find that the high cost of replacement carbon makes a regenera-
tive system economically attractive.
Investment Costs - The investment costs presented in Figure 8-22
are for a packed-bed throwaway system as based on the EPA
Technology Transfer Process Design Manual for Carbon Adsorption.
They include a contactor system, a pump station, and initial
carbon. The design assumes a contact time_of 30 minutes, a
hydraulic loading of 1.41 liters/minute/ft (4 gpm/ft ,) and 20%
excess capacity.
Operation and Maintenance Costs - The chief operation and mainte-
nance costs are labor and replacement carbon. The labor hours
required are computed using Figure 8-23 which is taken from an
EPA Technology Transfer. The labor unit cost used is $6.71/hr
plus 15% indirect charges. The replacement carbon cost was
calculated by assuming:
1) One pound of replacement carbon is required
per pound of organics removed.
2) The influent organic concentration (materials
effectively adsorbed) is 0.42 mg/1.
3) Activated carbon costs $2.62/kg. ($1.19 Ib).
Energy Costs - Energy is required for carbon adsorption operated
in the throwaway mode for the operation of pumps. Costs for :
this electrical energy requirement based on a unit cost of
$0.045/kilowatt hour of required electricity are shown as a
function of wastewater flow rate in Figure 8-24.
Sludge Drying Beds
This technology provides for the dewatering of sludge by means
of gravity drainage and natural evaporation. Beds of highly
permeable gravel and sand underlain by drain pipes allow the
water to drain easily from the sludge. This is a non energy-
intensive alternative to sludge dewatering.
Investment Costs - The curve shown in Figure 8-25 illustrates
the correlation used to estimate the cost of sludge drying beds.
The investment cost is a function of both the flow rate to the
beds and the settleable solids concentration in the stream
influent to the sludge beds; however, the effect of solids
concentration is very small in comparison to the dependence on
flow rate. The cost estimates presented include excavation,
fill, drain and feed pipes, and concrete splash boxes.
VIII-46
-------
10'
I
^
-J
o>
IS
I
V)
a:
o
£
in
0
U
1-
z
1U
111
>
z
10'
100
10"
10'
10'
FLOW (L/DAY)
FIGURE 8-22
CARBON ADSORPTION INVESTMENT COSTS
-------
10=
I
4^
CO
0
3
<
in
K
in
0
(J
2
*
0
<
3
Z
Z
10'
100
10 =
10*
10'
FLOW (U/DAY)
FIGURE 8-23
ANNUAL O&M COSTS VS. FLOW RATE FOR CARBON ADSORPTION
-------
10"
ANNUAL ENERGY COSTS (DOLLARS - AUG, '79
o
0
M
lot-
too
iZ
10s
to"
toj
ai
r»
0
3
in
K.
<
j
j
0
0
in
in
0
u
>•
(5
E
Ul
Z
Ul
J
3
Z
Z
10
I0
10
106
I0
FLOW (L/DAY)
FIGURE 8-24
ANNUAL ENERGY COSTS VS. FLOW RATE FOR CARBON ADSORPTION
-------
10°
79
H
r
Ul
o
o
o
X
o
10
100
10
10'
10'
FLOW (L/DAY)
FIGURE 8-25
SLUDGE DRYING BEDS INVESTMENT COSTS
-------
Operation and Maintenance - Operation and maintenance costs for
sludge drying bedsinclude labor and materials. Labor require-
ments include routine operation and maintenance and periodic
removal of sludge from the beds. Material costs include the
replacement of sand and gravel removed with the sludge.
The cost of labor and material required to maintain and operate
the sludge beds is shown as a function of flow rate to the beds
in Figure 8-26.
Vacuum Filtration
Vacuum filtration is widely used to reduce the water content of
high solids streams. In the metal finishing category, this
technology is applied to dewatering sludge from clarifiers,
where the volume of sludge is too large for economical dewater-
ing in sludge drying beds.
Investment Costs - The vacuum filter is sized based on a typical
loading of 14.6 kilograms of influent solids per hour per square
meter of filter area (3 Ibs/ft /hr). The investment costs are
shown as a function of sludge flow rate to the filter in Figure
8-27. The investment costs shown on this curve include installa-
tion costs and correspond to a solids content of 4.5% in the
influent to the filter, typical of the sludge stream from»a
clarifier.
Operation and Maintenance Costs - Annual costs for operation and
maintenance for vacuum filtration include both operation and
maintenance labor and the cost of materials and supplies. These
costs are presented as a function of sludge flow rate to the
filter in Figure 8-28.
The vacuum filtration subroutine calculates operating hours per
year based on flow rate and the total suspended solids concentra-
tion in the influent stream. Maintenance labor for vacuum
filtration is fixed at 24 manhours per year.
The cost of materials and supplies needed for operation and
maintenance includes belts, oil, grease, seals, and chemicals
required to raise the total suspended solids to the vacuum
filter. The amount of chemicals required (iron and alum) is
based on raising the TSS concentration to the filter by 1 mg/1.
Energy Costs - Electrical costs needed to supply power for pumps
and controls are presented in Figure 8-29. The required horse-
power of the pumps is dependent on the influent TSS level. The
costs shown are based on a unit cost of $0.045/kilowatt hour of
required electricity.
Countercurrent Rinsing
This technology is applied in rinsing operations to substan-
tially improve the efficiency of rinse water use and decrease
VI11-51
-------
M
V
171
NJ
,06
1 ANNUAL O&M COSTS (DOLLARS - AUG, '79)
000
_, W fe 01
SLUDGE
HAULED-*
WET
NO DRYING
BEDS
COSTEI
D
H
I
=a
^
•
•
•
*•
— H
*-—
p^-
--
**
'
f
*
^^^
^^^^
x
X
\
/
*
f
/
t
.
s
y
f
/
,
/
/
_
_ _ _. ... .
_
00 103 I04 105 106 107
FLOW (L/DAY)
FIGURE 8-26
ANNUAL O&M COSTS VS. FLOW RATE FOR SLUDGE BEDS
-------
M
V
Ul
OJ
INVESTMENT COST (DOLLARS - AUG. '79)
0000
t> 01 O> SJ
[VACUUM
FILTER
I
NOT COSTED
SLUGE
DISPOSED
-WET
••"••
•^M
••
••
•
^^~~*^
^
^^
*^~
4*
**
+•
^f
*^
*>*
^>
•*
X*
X'
.X-
100
10
10
10
10
10'
FLOW (L/DAY)
FIGURE 8-27
VACUUM FILTRATION INVESTMENT COSTS
-------
ANNUAL O&M COSTS (DOLLARS- AUG, '79)
o o o o
•• u> £• 01 o>
. ...
-^
H
f
SLUDGE
HAULED
WET
VACUUM
NOT
FILTER
COSTED
iii
*•
*•
^
m
^
— —•
*-^"
-
^^
- •-
—
X*
^
x
<•
X
^
'-
J*
X
X
x
,/
x
/
/
X
X
X
/
x'
^
/
-
)0 103 104 JO5 106 JO
FLOW (L/DAY)
FIGURE 8-28
ANNUAL O&M COSTS VS. FLOW RATE FOR VACUUM FILTRATION
-------
10«
01
U1
•
0
a:
u
z
u
_1
<
D
Z
Z
<
o
01
o
SLUDGE
"HAULED
WET
"VACUUM
FILTER
NOT
•COSTED
10J
too
10
10"
10 =
10V
FLOW (L/DAY)
10'
FIGURE 8-29
ANNUAL ENERGY COSTS VS. FLOW RATE FOR VACUUM FILTRATION
-------
the volume of wastewater generated. In countercurrent rinsing
the product is rinsed in several tanks in series. Water flows
counter to the movement of product so that clean water enters
the last rinse tank from which clean product is removed, and
wastewater is discharged from the first rinse tank which re-
ceives the contaminated product to be rinsed. Two different
countercurrent rinsing modes are addressed in costing depending
on whether wastewater is discharged from the rinse or is used as
make-up for evaporative losses from a process bath. The costs
of countercurrent rinsing without using the first stage for
evaporative loss recovery are presented in Table 8-6 as a func-
tion of the number of rinse tanks utilized. Costing assumptions
are:
Investment Costs - Unit cost is based on open top stainless
steel tanks with a depth of 1.22 meters (4 feet), length of 1.22
meters (4 feet), and width of 0.91 meters (3 feet). Investment
cost includes all water and air piping, a blower on each rinse
tank for agitation, and programmed hoist line conversions.
Operation and Maintenance Costs - Operation and maintenance
costsinclude a cost for electricity for the blowers based on a
capacity of 1,219 liters/min./sg. meter of tank surface, area (4
cfm/sq. ft.) at a discharge pressure of 1,538 kg/meter /meter of
tank depth (1 psi/18 in.). Fan efficiency is assumed to be 60
percent. A water charge based on a rinse ratio of 8,180 is also
included. Rinse maintenance charges are assumed to be negli-
gible when compared to normal plating line maintenance and are
ignored.
TABLE 8-6 ;
COUNTERCURRENT RINSE (FOR OTHER THA1N RECOVERY
OF EVAPORATIVE PLATING LOSS)
Number of Rinse Tanks: 3 4j 5
Investment: 10,794 13,8,85 16,978
Annual Costs:
Capital Cost 909 1,170 1,430
Depreciation 2,158 2,777 3,396
Operation & Maintenance
Costs (Excluding Energy
& Power Costs) 27 ;12 8
Energy & Power Costs 511 682 851
Total Annual Costs $3,605 $4,641 $5,685
VIII-56
-------
The costs of countercurrent rinsing with a rinse flow rate
sufficient to replace plating tank evaporative losses are pre-
sented in Table 8-7. The results are tabulated for various
evaporative rates which are equal to the rinse water flow rates,
Costing assumptions are:
TABLE 8-7
COUNTERCURRENT RINSE USED FOR RECOVERY OF
EVAPORATIVE PLATING LOSS
Evaporative Rate
(Liters/Hr): 15.3 24.0 50.8
Investment: $15,430 $12,736 $10,042
Annual Costs:
Capital Costs 1,301 1,074 847
Depreciation 3,086 2,547 2,008
Operation & Maintenance
Costs (Excluding Energy
& Power Costs) 5 7 16
Energy & Power Costs 714 572 428
Total Annual Cost $ 5,105 $ 4,200 $ 3,300
Note: Savings due to recovery of plating solution are not
presented in this table.
Investment Costs - Unit cost is based on a sufficient number of
rinse stages to replace the evaporative loss from a plating bath
at approximately 43 degrees C while also maintaining a rinse
ratio of 8,180.
Investment costs include open top stainless steel tanks with a
depth of 0.91 meters (3 feet), length of 1.22 meters (4 feet),
and width of 1.22 meters (4 feet). All water and air piping, a
blower on each rinse tank for agitation, a liquid level con-
troller, solenoid, and pump are also included in the investment
cost. Operation is assumed to be programmed. Hoist and line
conversion costs are included.
Operation and Maintenance Costs - Operation and maintenance
costs include a cost for electricity for the blowers based on a
capacity of 1.219 liters/min/sq. meter of tank surface area (4
cfm/sq. ft.) at a discharge pressure of 1,538 kg/sq. meter/meter
of tank depth (1 psi/18 in.). A fan efficiency of 60 percent is
assumed. A water charge is also included. Rinse maintenance
charges are assumed to be neglible when compared to normal
plating line maintenance and are ignored.
VIII-57
-------
Submerged Tube Evaporation
In this technology, contaminants present in process wastewater
are concentrated by removing the water as vapor. Evaporation is
accomplished by applying heat, and the evaporated water is
condensed using non-contact cooling water, and reclaimed for
process use. Costs generated in this subroutine are based on
double effect evaporation in which heat contained in vapor from
the first stage (effect) is used to evaporate water from the
second.
Investment Costs - Investment costs for this technology are
estimated based on data supplied by a manufacturer of submerged
tube evaporation equipment. As shown by the plot of costs
versus wastewater flow rate in Figure 8-30, costs were supplied
for units of specified capacities which are available from the
manufacturer. Cost estimates are based on the smallest avail-
able unit which is adequate for the specified wastewater flow
rate. The investment costs shown include the evaporation unit
and purification devices required for the return of the evapora-
tion concentrate to a process bath. Costs for installation of a
non-contact cooling loop are not included. The availability of
this service on-site is assumed.
Operation and Maintenance Costs - Estimates for operation and
maintenance costs are based on manufacturer supplied data.
These costs are shown as a function of wastewater flow rate in
Figure 8-31.
Energy Costs - Energy is required in this technology primarily
to supply the heat of vaporization for the evaporated water.
The use of a double effect evaporator significantly reduces the
total amount of heat consumed per unit of water evaporated.
Energy requirements are based on an evaporative heat of 583
cal/gram of water which is reduced to an effective value of 292
cal/gram in the double effect unit. Fuel consumption is based
on a lower heat value of 10,140 cal/gram with an 85% heat re-
covery efficiency. Energy costs based on these factors are
shown in Figure 8-32 as a function of wastewater flow rate to
the evaporator.
Contract Removal
Sludge, waste oils, and in some cases concentrated waste solu-
tions frequently result from wastewaster treatment processes.
These may be disposed of on-site by incineration, landfill or
reclamation, but are most often removed on a contract basis for
off-site disposal. System cost estimates;presented in this
report are based on contract removal of sludges. In addition,
where only small volumes of concentrated wastewater are pro-
duced, contract-removal or off-site treatment may represent the
most cost effective approach to water pollution abatement.
Estimates of solution contract haul costs are also provided by
VIII-58
-------
I
(Jl
10"
oT
ts
0
3. .5
INVESTMENT COST (DOLLARS - A
o o e
— w t>
0 '00 103
•
r
t—1
__J
104 10s 106
FLOW (L/DAY)
FIGURE 8-30
SUBMERGED TUBE EVAPORATION (DOUBLE EFFECT) INVESTMENT COSTS
-------
10=
V
-------
to
0
3
M
V
-I
J
0
Q
W
OT
0
U
>•
(9
K
U
Z
U o
_. '0-
<
3
Z
z
<
0
O
100
10
104
10
to
to
FUOW (U/DAY)
FIGURE 8-32
ANNUAL ENERGY COSTS VS. FLOW RATE FOR SUBMERGED TUBE EVAPORATION
-------
this subroutine and may be selected in place of on-site treat-
ment on a least-cost basis.
Investment Costs - Investment for contract removal is zero.
Operating Costs - Annual costs are estimated for contract re-
moval of total waste streams of sludge and oil streams as spec-
ified in input data. Sludge and oil removal costs are further
divided into wet and dry haulage depending upon whether or not
upstream sludge dewatering is provided. The use of wet haulage
or of sludge dewatering and dry haulage is based on least cost
as determined by annualized system costs over a ten year period.
Wet haulage costs are always used when the volume of the sludge
stream is less than 100 gallons per day.
Both wet sludge haulage and total waste haulage differ in cost
depending on the chemical composition of the waste removed.
Wastes are classified as cyanide bearing, hexavalent chromium
bearing, or oily and assigned different haulage costs as shown
below. |
Waste Composition Haulage .Cost
>0.05 mg/1 CN- $0.16/liter ($0.60/gallon)
X).l mg/1 Cr+6 $0.18/liter ($0.56/gallon)
Oil & grease-TSS $0.08/liter (0.30/gallon)
All others $0.06/liter (0.24/gallon)
Dry sludge haul costs are estimated at $0.07/liter ($0.27/
gallon).
RCRA COST ANALYSIS
RCRA costs were originally developed for sludge disposal from
electroplating plants using data from 48 surveyed plants and from
contacting haulers. Of the 48 plants surveyed. 38 plants had
their waste hauled to a commercial or municipal site for disposal
while 10 plants disposed of the sludge at company owned sites.
The cost for transport and disposal of these sludges reported by
the plants varied from zero to $2.04 per gallon. Haulers quoted
costs for transport and disposal ranging from $0.06 per gallon to
$2.80 per gallon, dependent on the quantity and type of sludge.
The detailed results of the RCRA analyses are presented in:
"Electroplating RCRA Review - Technical Contractor's Final
Report." and "RCRA Impact Analysis for Sludge Disposal for the
Machinery and Mechanical Products Category." These reports along
with the supporting data are available in the metal finishing
record.
RCRA sludge disposal was recosted to reflect costs for the entire
Metal Finishing Category. RCRA related costs were generated for
39 job shops. 100 captive indirects. and 103 captive directs. For
each plant RCRA related annual costs, initial costs, and capital
costs were developed using the methods and equations presented in
"Guidance for RCRA ISS Costs." Office of Analysis and Evaluation.
December 1980.
VIII-62
-------
TREATMENT SYSTEM COST ESTIMATES
This section presents estimates of the total cost of wastewater
treatment and control systems for metal finishing process waste-
water incorporating the treatment and control components dis-
cussed above. Flows in the Metal Finishing Category vary from
approximately 378 to 3,785,000 liters/day (100 gpd to 1,000,000
gpd). This wide variation in flow rate necessitates the presen-
tation of treatment system total annual cost curves for each
option. Total annual costs have been plotted against flow in
units enabling the determination of cost for any flow rate. All
available flow data from industry data collection portfolios
were used in defining the raw waste flows. Raw waste character-
istics were determined based on sampling data as discussed in
Section V.
Cost curves for each option are presented for six different cases
for Option 1 and five different cases for Options 2 and 3. Each
case corresponds to different types of plants encountered in the
Metal Finishing Category. Cases one and two represent facilities
primarily engaged in electroplating. In case two electroless pla-
ting is performed resulting in the presence of complexed metal
wastes. Cases three and five represent integrated facilities com-
bining electroplating with other metal finishing operations. In
case five electroless plating is practiced. Case four represents
plants performing a variety of metal finishing operations including
heat treating, but without on-site electroplating, while case six
represents plants generating only oily wastewater. The flow splits
for those cases as shown in Table 8-8 are based on the ratios of
the average wastewater flow rates from all subcategories included
in each case. These flow splits are presented to show examples of
a broad range of cases which occur within the Metal Finishing
Category.
TABLE 8-8
FLOW SPLIT CASES FOR OPTIONS 1, 2, AND 3
Case Waste Type Flows (% of total plant flow)
Complexed
Oily Cyanide Chromium Metals Metals
1
2
3 31.5
4 30
5 30 4 9 52.5 4.5
6 100
Five examples of varying total daily waste volumes (gallons per day)
have been presented for each of the six cases in order to provide a
range of estimated system costs. The system costs presented include
component costs as discussed above and subsidiary costs including
VIII-63
Cyanide
7
6
4.5
4
Chromium
13
12.5
9
9
Metals
80
75.5
55
70
52. 5
-------
engineering, line segregation, administration, and interest expenses
during construction. In developing cost estimates for these option
systems, it is assumed that none of the specified treatment and con-
trol measures is in place so that the presented costs represent total
costs for the systems.
Several of these system cost curves show discontinuities. Some
of these result from transitions occurring in specific component
cost subroutines, and others result from changes in system cost
factors. Sludge dewaterina costs are of particular signif-
icance. For flows below 10 I/day sludge dewatering is accom-
plished using sludge drying beds, and cost estimates reflect
this technology. Above this flow sludge dewatering is accom-
plished using a vacuum filter. Since the degree of dewatering
achieved (typically 40% solids from a sludge drying bed and 20%
solids from a vacuum filter) is influenced by this change,
system costs are influenced not only by the dewatering costs
themselves, but also through an effect on the volume of sludge
requiring contract removal. At very high flow rates, the cost
of removing sludge at 20% solids may become substantial, and the
most economical system design would incorporate further dewater-
ing of the vacuum filter product. This refinement, however, has
not been included in these cost estimates.
System Cost Estimates (Option 1)
This section presents the system cost estimates for the Option 1
end-of-pipe treatment systems. The representative flow rates
used in these system cost estimates were determined based upon
actually sampled flows and flow information received in the data
collection portfolios. The complete system block diagram appli-
cable to cases 1-5 is shown in Figure 8-33. Option 1 treatment
for the isolated oily waste stream addressed in case 6 is shown
in Figure 8-34. ;
The costing assumptions for each component .of the Option 1
system were discussed above under Technology Costs and Assump-
tions. In addition to these components, contract sludge removal
was included in all cost estimates. '
Table 8-9 presents costs for each of the six cases discussed
above for various treatment system influent flow rates. The
basic cost elements used in preparing these tables are the same
as those presented for the individual technologies; investment,
annual capital costs, annual depreciation, annual operations and
maintenance cost (less energy cost), energy cost, and total
annual cost. These elements were discussed in detail earlier in
this section.
For the cost computations, a least cost treatment system selec-
tion was performed. This procedure calculated the costs for a
batch treatment system and a continuous treatment system over a
5 year comparison period. Figures 8-35 through 8-46 show the
investment and total annual costs for each case shown in Table
8-9. .'
VIIl-64
-------
I
o>
1/1
Case
Number
Batch
Batch
Batch
Continuous
Continuous
Batch
Batch
Batch
Continuous
Continuous
Batch
Batch
Batch
Continuous
Continuous
Batch
Batch
Batch
Continuous
Continuous
Batch
Batch
Batch
Continuous
Continuous
Batch
Batch
Batch
Batch
Continuous
Flos
gpd
264.
2638.
26380.
263800.
2637999.
264.
2662.
26350.
263600.
2637998.
264.
2660.
26410.
266330.
2638998.
264.
2642.
26420.
264300.
2642999.
264,
2638.
26460.
264600.
2645998.
264.
2640.
26400.
264000.
2640000.
Flow
I/day
1,000
10,000
100,000
1,000,000,
10,000,000,
1,000.
10,000,
100,000
1,000,000
10,000,000
1,000
10,000
100,000
1,000,000
10,000,000
1,000
10,000
100,000
1,000,000
10,000,000
1,000
10,000
100,000
1,000,000,
10,000,000
1,000
10,000
100,000
1,000,000
10,000,000
TABI-E 8-9
Option I Costs
Investment
(Dollars)
129466,937
156768.312
271783.812
658308. 6R7
1389210.00
141021.000
169637.562
295868.875
754696.125
1547783.00
177289.500
207743.000
386569.187
947278.312
2148885.00
76337.000
9845 1 . 000
239445.562
674088.500
1638202.00
144796.750
223017.687
408999.937
1035760.50
2291527.00
48120.527
79619.937
95708, 8] 2
306961.562
1412968.00
Capital Costs
(Dollars)
10916.160
13217.984
22915.613
55505.562
117132.437
11890.398
14303.066
24946.352
63632.437
130502.937
14948.301
17516.000
32593.875
79870.062
181185.187
6436.414
8300.969
20188.953
56836.125
138126.312
12208.711
18803.766
34485.125
87330.375
193212.625
4057.312
6713.219
8069.754
25881.625
119135.750
Depreciation
(Dollars)
25893.387
31353.660
54356.762
131661.687
277842.000
28204.199
33927.512
59173,773
150939.187
309556.562
35457.898
41548.598
77313.812
189455.625
429777.000
15267.398
19690,199
47889.109
134817.687
327640,375
28959.348
44603.535
81799.937
207152.062
458305.375
9624.105
15923.984
19141.762
61392.312
282593.562
Operation S
Maintenance
(Dollars)
12446.344
22896.891
32761.973
182141.437
1433646.00
19893.262
24395.422
395S6.77?
178190.812
1368158.00
14035.863
21761.270
40553.965
268203,125
2172029.00
10597.324
17826,531
31906.484
242074.375
2034457.00
19384.918
28946.770
47390.582
261455.187
2095432.00
3676.566
5396.180
21783.789
10B626.562
818738.375
Energy
(Dollars)
35 . 090
53.571
396.887
5877,852
36224.941
63.154
81.395
271.490
5740.566
34512.113
36.611
61.020
463.474
6650.617
41918.371
31.078
51.313
405.359
4442.797
28883.500
59.162
88.451
479.039
6539.930
40662.414
7.431
26.372
203.722
2637.227
1054-> 426
Tola] Annual
(Dollars)
49290.977
67522.062
110431.187
375186.500
1864844.00
60051.012
72707.375
123978.312
398503.000
1842729.00
64478.672
80886.812'
150925.062
544179.375
2824909.00
32332.2)5
45869.012
100389.812
438170.937.
2529106.00
60612.937
92442.500
164154.625
562477.500
2787612.00
17365.414
28059.754
492:>9.023
198537.687
1231010.00
-------
OILY RAW WASTE RAW WASTE .„,,.. RAW WASTE RAW WASTE RAW WASTE
WITH
RAW WASTE TOXIC ORGANI
p
I
EMULSION
BREAKING
OIL
1 CYANIDE ^J
1
PR EC
<
•inns
METALS
RECOVERY
1
HAU
'
t
CYA
MIDE
OXIDATION
WITHOUT
1
CYANIDE *^
UOR
•fc-
1
CHROMIUM
REDUCTION
COMMON
METALS
r
CHEMICAL
PRECIPITATION
1
r
CLARIFIER
\
TREATED
EFFLUENT
LIME *>.
^ ii LIME "
SLUDGE
\
r I
r
SLUDGE
DEWATERING
SLUDGE
1
1
HAUL OR
RECLAIM
COMPLEXED
METALS
f
CHEMICAL
PRECIPITATION
\
r
CLARIFIER
1
TREATED
EFFLUENT
CONTRACTOR
„,_..„_„-., REMOVAL
OPTION ! SYSTEM
-------
OILY HAW WASTE
EMULSION
BREAKING
SKIMMED OIL
TREATED
EFFLUENT
FIGURE 8-34
OPTION 1 TREATMENT SYSTEM
FOR SEGREGATED OILY WASTE STREAMS
VIII-67
-------
H
M
CTi
00
10'
Ol
fs
0
D
i«o«
0
£
H
in
0
u
H
Z
U
W
u ,
> 10'
Z
H
0
(0'
100
CONTINUOUS
BATCH
10 =
106
to?
FLOW (L/DAY)
FIGURE 8-35
TOTAL INVESTMENT COST VS. FLOW RATE FOR OPTION 1 TREATMENT SYSTEM, CASE 1
-------
10'
0
D
<
I
to
o
£
in
0
u
j
<
D
Z
Z
101
CONTINUOUS
>' J>
0
BATCH
10"
(00
10-
10s
FLOW (L./DAY)
FIGURE 8-36
TOTAL ANNUAL COSTS VS. FLOW RATE FOR OPTION 1 TREATMENT SYSTEM, CASE 1
10'
-------
a
M
V
^J
O
10?
0
3
J
J
0
£
(A
0
u
H
Z
U
S
ui
U
> 10
z
0
10'
too
CONTINUOUS
BATCH
10-
10*
10s
10C
FLOW (L/DAY)
10'
FIGURE 8-37
TOTAL INVESTMENT COST VS. FLOW RATE FOR OPTION 1 TREATMENT SYSTEM, CASE 2
-------
to'
H
-J
0
3
I
V)
V)
V)
0
O
-i
<•
3
Z
Z
h
0
h
10 =
100
CONTINUOUS
BATCH
10'
10"
105
10'
FL.OW (L./DAY)
FIGURE 8-38
TOTAL ANNUAL COSTS VS. FLOW RATE FOR OPTION 1 TREATMENT SYSTEM, CASE 2
-------
10'
M
T
^j
NJ
01
rs
6
3
in io
a:
0
Q
(0
(0
0
U
H
Z
Ul
2
0
10*
100
BATCH
10
10'
10
10'
10
FLOW (L/DAY)
FIGURE :8-39
TOTAL INVESTMENT COSTS VS. FLOW RATE FOR OPTION 1 TREATMENT SYSTEM, CASE 3
-------
s
M
M
OJ
0
3
<
I
U)
tt
U)
U)
0
U
3
Z
z
0
I-
10 =
10"
100
CONTINUOUS
BATCH — — —
/
f
'/I
10
10'
10'
10
FLOW (L/DAY)
FIGURE 8-40
TOTAL ANNUAL COSTS VS. FLOW RATE FOR OPTION 1 TREATMENT SYSTEM, CASE 3
-------
01
ts
0
3
(0
tt
0
£
in
VI
0
o
H
Z
Ul
5
in
Ul
>
z
J
<
0
10s
'CONTINUOUS
BATCH
10"
100
10-
10'
10'
FLOW (L/DAY)
FIGURE 8-41
TOTAL INVESTMENT COST VS. FLOW RATE FOR OPTION I TREATMENT SYSTEM, CASE 4
10
-------
10'
Ol
f.
o
3
<
I
(A
K
10°
J
0
(A
(A
0
U
J
<
3
Z
Z
0
CONTINUOUS
BATCH
10"
100
10'
10'
10'
107
FLOW (L/DAY)
FIGURE 8-42
TOTAL ANNUAL COSTS VS. FLOW RATE FOR OPTION 1 TREATMENT SYSTEM, CASE 4
-------
N
-J
Ch
0
3
j
0
£
tn
0
u
H
Z
Id
2
V)
10s
0
10*
100
CONTINUOUS
BATCH
10"
10=
10'
FLOW {L./DAYJ
FIGURE 8-43
TOTAL INVESTMENT COSTS VS. FLOW RATE FOR OPTION 1 TREATMENT SYSTEM. CASE 5
-------
V
TOTAL ANNUAL COST (DOLLARS - AUG, '79)
o o o c
r ..*. . w o>
CO
NT
ir>
U
0
AT
US
i— ""• """
— —
^
«*— '
^*
.•—
1— •
,
W
^
^
^
^
V
.^ '
» ^^
— •*
^^
-•—
***
—?
^«
•«
!^
^
^
V
»
»
rf
— ^
^^
^^
S>'
^
S
**
x
^
^
X
^
^
^x^
^*iX
^Zr
^
4
\r^
r
/
/
/
/
/
/
s
*
/
/
/
0 103 I04 105 106 10
FLOW (U/DAY)
FIGURE 8-44
TOTAL ANNUAL COST VS. FLOW RATE FOR OPTION 1 TREATMENT SYSTEM, CASE 5
-------
H
3
00
JO'
I
W
K
<
J
0
Q
1-
U)
0
u
1-
z
III
2
1-
V)
u
10=
0
10s
100
CONTINUOUS
BATCH
10"
10 =
10C
10'
FLOW (U/DAY)
FIGURE 8-45
TOTAL INVESTMENT COSTS VS. FLOW RATE FOR OPTION 1 TREATMENT SYSTEM, CASE 6
-------
M
M
10'
0
3
4
I
10
DC
J
J
0
£
W
0
U
J
3
Z
Z
to1
10 =
1-
o
i-
too
CONTINUOUS
BATCH
to-
FLOW (L/DAY)
10 =
10C
FIGURE 8-46
TOTAL ANNUAL COST VS. FLOW RATE FOR OPTION 1 TREATMENT SYSTEM , CASE 6
-------
The investment costs shown assume that the 'treatment system must
be specially constructed and include all subsidiary costs dis-
cussed under the Cost Breakdown Factors segment of this section.
It is also assumed all plants operate 24 hours a day, 5 days per
weekr for 52 weeks per year (260 total days). This assumption
overestimates the costs for facilities which operate less than
24 hours per day.
System Cost Estimates (Option 2)
System cost estimates of the effects of adding a multimedia
filter to the previously discussed end-of-pipe systems were
developed to provide Option 2 Treatment Cost Estimates. A
schematic of the system for cases 1-5 is shown in Figure 8-47.
The cases used are the same as those for Option 1 and are shown
in Table 8-8. The costing assumptions for the multimedia filter
were discussed above under the technology costs and assumptions
subsection.
Several flow rates were used for each case Ito effectively model
a wide spectrum of plant sites. Figures 8-48 through 8-57
present the investment and total annual costs for each case in
Option 2.
Table 8-10 presents Option 2 treatment costs for construction of
the entire end-of-pipe system. These costs would be representa-
tive of expenditures to be expected to attain Option 2 for a
plant with no treatment in place.
System Cost Estimates (Option 3)
The Option 3 system takes the Option 1 system and makes one signi-
ficant change. The one change requires the closed loop operation
(zero discharge) of any processes using cadmium. For cost-
ing purposes, an evaporative system has been used with the
condensate reused for rinsing and the concentrate hauled for
disposal. This may also be accomplished by other means selected
by the individual plants. Closed loop precipitation with reuse
of the treated water and licensed hauling of the sludge, or ion
exchange with reuse of the water and treatment and hauling of
the regenerant solution are two possible options. The schematic
for the complete Option 3 system for cases 1-5 is shown in
Figure 8-58. The investment and total annual cost curves for each
case are shown in Figures 8-59 through 8-68. Table 8-11 presents a
summary of the Option 3 costs. :
Use of Cost Estimation Results
Cost estimates presented in the tables and figures in this
section are representative of costs typically incurred in imple-
menting treatment and control equivalent to the specified op-
tions. They will notr in general, correspond precisely to cost
experience at any individual plant. Specific plant conditions
such as age, location, plant layout, or present production and
treatment practices may yield costs which are either higher or
lower than the presented costs. Because the costs shown are
VIII-80
-------
ee
Case
Humber
1
1
1
1
1
2
2
2
2
2
3
3
3
3
3
4
4
4
4
4
5
5
5
5
5
Batch
Batch
Batch
Continuous
Continuous
Batch
Batch
Batch
Continuous
Continuous
Batch
Batch
Batch
Continuous
Continuous
Batch
Batch
Batch
Continuous
Continuous
Batch
Batch
Batch
Continuous
Continuous
Flow
gpd
264.
2638.
26380.
263800.
2637999.
264.
2662.
26350.
263600.
2637998.
264.
2660.
26410.
266300.
2638998.
264.
2642.
26420.
264300.
2642999.
264.
2638.
26460.
264600,
2645998.
Flew
I/day
1,000.
10,000.
100,000.
1,000,000.
10,000,000.
1,000.
10,000.
100,000.
1,000,000.
10,000,000.
1,000.
10,000.
100,000.
1,000,000.
10,000,000.
1,000.
10,000.
100,000.
1,000,000.
10,000,000.
1,000.
10,000.
100,000.
1,000,000.
10,000,000.
1»BI£ 8-10
Option 2 Costs
Investment
(Dollars)
131895. ?12
166617.362
317501.575
775782.562
1759412.00
143877.062
180996.687
347292.300
897996.562
1999361 .CD
179689,'C-62
222102.1:5
433213.250
1064609.00
2517744.00
73779. ~'?Q
112982.575
286488.000
790898. 575
2006627.00
147632.500
238419.312
460628.062
1174778.00
2753802.00
Capital Costs
(Dollars)
11120.953
1404S.422
26770.312
65410.125
US346.250
12131.211
15260.781
29282.125
75714.625
168577.750
15150.605
18726.656
36526.687
89762.937
212285.625
6642.379
9526.258
24155.402
66684,812
169190.500
12447.863
20102.391
38838.125
99051.750
232189.375
Depreciation
(Dollars)
26379.160
33323.512
63500.375
155156.500
351882.375
28775.410.
36199.336
69458.375
179599.312
399372.187
35937.812
44420.422
86642. -625
212921.750
503548.750
15755.949
22596.574
57297.598
158179.750
401325.375
29526.500
47683.859
92125.562
234955.562
550760.375
Operation S
Maintenance
(Dollars)
18059.805
2466! .469
39294.414
191502.062
1473137.00
31575.918
38055.617
52200.605
193548.937
1413598.00
19417.297
28194.559
47096.309
277545.437
2211218.00
16829.016
24253.570
33450.984
251363.750
2073672.00
31636.180
41643.074
60006.383
276797.875
2140789.00
Energy
(Dollars)
41.582
80.944
512.365
6365.043
33230.355
70.738
112.773
402.604
6294.062
36848.262
43.060
88.314
578.113
7136.859
43957.875
37.520
78.484
519.993
4926.543
30924.371
67.495
118.835
607.457
7081.457
42947.062
Total Annual
(Dollars)
55601.496
72114.312
130077.375
418433.687
2011645.00
72553.187
89628.437
151343.625
455156.937
2018895.00
70548.687
91429.937
170843.625
587366.937
2971009.00
39264.863
56454.887
120423.875
481159.812
2675111.00
73677.937
109548.125
191577.500
617886.625
2966685.00
-------
Case
Number
1
1
1
1
1
2
2
2
2
2
3
3
3
3
3
4
4
4
4
4
5
5
5
5
5
TABLE 8-11
Option 3 Costs
Batch
Batch
Batch
Continuous
Gbntinuous
Batch
Batch
Batch
Continuous
Continuous
Batch
Batch
Batch
Continuous
Continuous
Batch
Batch
Batch
Continuous
Continuous
Batch
Batch
Batch
Continuous
Continuous
Blow
qpd
264.
2476.
24490.
244684.
2446819.
264.
2500.
24686.
246740.
2459499.
264.
2542.
25134.
251046.
2510287.
264.
2566.
25544.
255372.
2553623.
288.
2544.
25252.
252328.
2523349.
Blow
Vday
1,000.
10,000.
100,000.
1,000,000.
10,000,000.
1,000.
10,000.
100,000.
1,000,000.
10,000,000.
1,000.
10,000.
100,000.
1,000,000.
10,000,000.
1,000.
10,000.
100,000.
1,000,000.
10,000,000.
1,000.
10,000.
100,000.
1,000,000.
10,000,000.
Invesfcnent
(Dollars)
192780.875
215883.312
348419.812
715315.000
1472822.00
208C25.375
232406.812
371089.625
812359.375
1634327.00
240344.062
271247.562
460278.000
1005995.31
2223688.00
. 140197.937
165645.187
304231.000
737350.312
1732473.00
255809.187
283810.000
481832.250
1095964.00
2353792.00
Capital Costs
(Dollars)
16254.516
18202.301
29377.250
60312.000
124182.125
17539.859
19595.391
31288.687
68494.250
137799.500
20264.812
22870.301
38808.687
84820.250
187492.875
. 11820.918 ... ...
13966.504
25651.426
62170.000
146075.062
21568.664
23929.562
40625.937
92406.125
198462.500
Depreciation
(Dollars)
38556.172
43176.660
69683.937
143063.000
294564.375
41605.074
46481.359
74217.875
162471.875
326865.375
48068.812
54249.512
92055.562
201199.062
444737.562
28039.586
33129.035
• 60846.199
147470.062
346494.562
51161.836
56762.000 -
96366.437 '
219192.750
470758.375 i
Operation &
Maintenance
(Dollars)
12600.187
16988.187
29551.547
166658.062
1334110.00
20047.117
24332.359
36565.973
163858.187
1276480.00
14189.594
21771.258
37829.395
259804.250
2105460.00
. 10807.941.
17912.301
31900.461
238480.000
1998380.00
21734.387
28998.359
44753.180
254738.937
2029948.00
Energy
(Dollars)
4827.246
4843.324
5002.102
16672.348
107447.812
4855.309
4871.309
5028.004
15326.258
99898.000
4828.766
4851.891
5217.797
15027.391
91024.125
._ 4823,234 .
4843.039
5187.508
11617.648
65666.812
4856.965
4879.828
5100.312
12488.359
72823.687
Total Annual
(Dollars)
72238.062
83210.437
133614.750
386705.375
1660303.00
34047.250
95280.312
147100.500
410150.562
1841042.00
87351.937
103742.937
173911.375
560850.937
2828714.00
55491.680
69850.875
123585.562
459737.687
2556615.00
99321.812
114569.687
: 186845.812
578826.125
2771991.00
-------
OILY RAW WASTE
RAW WASTE
RAW WASTE
RAW WASTE
SKIMMED OILS
PRECIOUS
METALS
RECOVERY
}
•— *
CYANIDE
OXIDATION
WITH!
CYANIDE]
IWITHOUT
1
, CYANIDE ""~
1
CHROMIUM
REDUCTION
COMMON
METALS
r
RAW WASTE TOXIC ORGANlCS
COMPLEXED
METALS
HAUL OR
RECLAIM
LIME-
HAUL OR
RECLAIM
CHEMICAL
PRECIPITATION
FIGURE 8-47
OPTION 2 SYSTEM
CONTRACTOR
REMOVAL
-------
s
H
H
00
o
rs
0
3
<
I
V)
10°
J
J
0
Q
V)
0
U
I-
z
LJ
5
tn
LJ
I
CONTINUOUS
BATCH
10"
100
10"
10 =
10"
FLOW (L/DAY)
FIGURE 8-48
TOTAL INVESTMENT COST VS. FLOW RATE FOR OPTION 2 TREATMENT SYSTEM, CASE 1
-------
10'
0
< 106
I
tn
j
j
0
Q
1-
tn
0
u
j
<
3
Z
< 105
00
Ul
CONTINUOU:
0
BATCH
10'
100
10"
FLOW~IL/DAY)
10=
FIGURE 8-49
TOTAL ANNUAL COSTS VS. FLOW RATE FOR OPTION 2 TREATMENT SYSTEM, CASE 1
-------
H
H
CO
-------
00
-J
10'
10'
I
CO
cn
0
u
D
I ios
10"
CONTINUOUS-
BATCH
100
10-
10"
10 =
10"
FLOW (L/DAY)
FIGURE 8-51
TOTAL ANNUAL COST VS. FLOW RATE FOR OPTION 2 TREATMENT SYSTEM, CASE 2
10'
-------
00
JO'
at
N
0
3
<
8.0
<
J
J
0
£
V)
V)
0
U
H
UI
5
V)
u
10'
BATCH — — — '
100
10"
10s
10"
10'
FLOW (L/DAY)
FIGURE 8-52
TOTAL INVESTMENT COST VS. FLOW RATE FOR OPTION 2 TREATMENT SYSTEM, CASE 3
-------
00
to3
Ol
fs
d
3
J
J
0
£
U)
0
U
J
0
10"
100
CONTINUOUS
BATCH
tOJ
10"
10-
10*
107
FLOW (L/DAY)
FIGURE 8-53
TOTAL ANNUAL COSTS VS. FLOW RATE FOR OPTION 2 TREATMENT SYSTEM, CASE 3
-------
V
VD
O
10'
0
3
-J
0
£
(A
(A
0
U
1-
Z
U
S
in
u _
> to5
0
10'
100
CONTINUOUS
-BATCH
10*
10 =
10°
10'
FLOW (L/DAY)
FIGURE 8-54
TOTAL INVESTMENT COSTS VS. FLOW RATE FOR OPTION 2 TREATMENT SYSTEM, CASE 4
-------
M
T
a>
r»
0
D
<
I
10
10"
J
J
0
£
10
10
0
U
J
D
Z
Z
10 =
1-
0
10"
-BATCH
100
10"
FLOW (U/DAY)
10 =
10*
10'
FIGURE 8-55
TOTAL ANNUAL COSTS VS. FLOW RATE FOR OPTION 2 TREATMENT SYSTEM, CASE 4
-------
H
M
ifl
K
0
Q
f-
w
0
u
H
Z
111
in
u 10s
-H-
0
H
10"
100
CONTINUOUS
BATCH
10
10'
10'
10
FLOW (L/DAY)
FIGURE 8-56
TOTAL INVESTMENT COSTS VS. FLOW RATE FOR OPTION 2 TREATMENT SYSTEM, CASE 5
-------
10'
I
VD
CO
0
3
<
I
in
J
J
0
Q
M
in
0
o
0
1-
10=
too
CONTINUOUS
.BATCH
10*
10 =
10'
to'
FLOW (U/DAY)
FIGURE 8-57
TOTAL ANNUAL COSTS VS. FLOW RATE FOR OPTION 2 TREATMENT SYSTEM, CASE 5
-------
OILY RAW WASTE
SKIMMED OILS
EMULSION
BREAKING
HAUL OR
RECLAIM
RAW WASTE W,TH RAW WASTE RAW WASTE RAW WASTE
I CYANIDE
I
CYANIDE
OXIDATION
i
WITHOUT
CYANIDE
RAW WASTE
CADMIUM
CHROMIUM
REDUCTION
COMMON
METALS
i
RAW WASTE TOXIC ORGANICS
EVAPORATIVE
RECOVERY OR
ION EXCHANGE
COMPUEXED
METALS
Zero
Discharge
HAUL OR
RECLAIM
CHEMICAL
PRECIPITATION
H
H
H
I
•LIME
LIME.
CHEMICAL
PRECIPITATION
TREATED
EFFLUENT
CLARIFIER
CLARIFIER
SLUDGE
SLUDGE
DEWATERING
SLUDGE
TREATED
EFFLUENT
CONTRACTOR
REMOVAL
FIGURE 8-58
OPTION 3 SYSTEM
-------
U1
10
100
10'
FLOW (L/DAY)
FIGURE 8-59
TOTAL INVESTMENT COST VS. FLOW RATE FOR OPTION 3 TREATMENT SYSTEM, CASE 1
-------
I
<£>
CTl
10
100
10
FLOW (L/DAY)
FIGURE 8-60
TOTAL ANNUAL COST VS. FLOW RATE FOR OPTION 3 TREATMENT SYSTEM, CASE 1
-------
10'
H
r
VO
-J
01
Is
0
D
to 10
X
0
£
(A
10
0
U
H
Z
U
s
H
U)
hi
>
Z
0
10'
CONTINUOUS
•BATCH
100
10-
10"
10 =
10C
10'
FLOW (L/DAY)
FIGURE 8-61
TOTAL INVESTMENT COSTS VS. FLOW RATE FOR OPTION 3 TREATMENT SYSTEM, CASE 2
-------
V
\o
CO
100
FLOW (L/DAY)
FIGURE 8-62
TOTAL ANNUAL COSTS VS. FLOW RATE FOR OPTION 3 TREATMENT SYSTEM, CASE 2
-------
10'
M
V
o>
r>
I
in 10"
0
£
V)
V)
0
U
I-
z
u
V)
u
10=
0
10"
100
BATCH
10-
10"
10 =
10'
10'
FLOW (L/DAY)
FIGURE 8-63
TOTAL INVESTMENT COSTS VS. FLOW RATE FOR OPTION 3 TREATMENT SYSTEM, CASE 3
-------
V
o
o
100
FLOW (L/DAY)
FIGURE 8-64
TOTAL ANNUAL COSTS VS. FLOW RATE FOR OPTION 3 TREATMENT SYSTEM, CASE 3
-------
H
r
100
10
FLOW (L/DAY)
FIGURE 8-65
TOTAL INVESTMENT COST VS. FLOW RATE FOR OPTION 3 TREATMENT SYSTEM, CASE 4
-------
M
M
h-1
o
to
100
10
10°
FLOW (L/DAY)
FIGURE 8-66
TOTAL ANNUAL COSTS VS. FLOW RATE FOR OPTION 3 TREATMENT SYSTEM, CASE 4
-------
10'
o
u>
0
D
<
I I0<
tfl
en
<
J
J
0
£
V)
0
U
I-
z
kl
10 =
H
0
H
10'
100
CONTINUOUS
BATCH
10-
10"
10 =
10'
FLOW (L/DAY)
FIGURE 8-67
TOTAL INVESTMENT COSTS VS. FLOW RATE FOR OPTION 3 TREATMENT SYSTEM, CASE 5
-------
V
10
100
FLOW (L/DAY)
FIGURE 8-68
TOTAL ANNUAL COST VS. FLOW RATE FOR OPTION 3 TREATMENT SYSTEM, CASE 5
-------
total system costs and do not assume any treatment in place, it
is probable that most plants will require smaller expenditures
to reach the specified levels of control from their present
status.
The actual costs of installing and operating a system at a
particular plant may be substantially lower than the tabulated
values. Reductions in investment and operating costs are pos-
sible in several areas. Design and installation costs may be
reduced by using plant workers. Equipment costs may be reduced
by using or modifying existing equipment instead of purchasing
all new equipment. Application of an excess capacity factor,
which increases the size of most equipment foundation costs
could be reduced if an existing concrete pad or floor can be
utilized. Equipment size requirements may be reduced as a
result of treatment conditions (for example, shorter retention
time) for particular waste streams. Substantial reduction in
both investment and operating cost may be achieved if a plant
reduces its water use rate below that assumed in costing.
IN-PROCESS FLOW REDUCTIONS
The use of in-process techniques to achieve reductions in waste
flows can result in significantly reduced operating and mainte-
nance costs. Although an additional initial investment will be
required for a countercurrent rinse or other flow reducing
equipment, in roost cases it will be less than the saving due to
downstream treatment components may be sized for smaller flows. This
reduces the initial investment for downstream treatment components
ECONOMIC IMPACT ANALYSIS OF SYSTEM COST ESTIMATES
The individual waste treatment component and system cost estimates
presented in this section of the development document can be ap-
plied to each manufacturing facility in the Metal' Finishing Cate-
gory. The cost estimates can be used to estimate the value of
existing in-place waste treatment components and to estimate the
economic impact of a proposed level of waste treatment upon an
individual manufacturing facility.
In order to establish the economic impact of the various proposed
waste treatment systems upon actual Metal Finishing firms, treat-
ment system cost estimates were developed for one hundred (100)
captive indirect dischargers, one hundred three (103) captive
direct dischargers, and forty (40) job shop direct dischargers.
These firms were determined to be representative of the Metal
Finishing Category and these cost estimates were used to assess
the economic impact of the proposed regulations upon the entire
VI11-105
-------
Metal Finishing Industry. Cost estimates for job shop indirect
dischargers were developed only for the control of total toxic
organics (TTO) because these firms are regulated under the Pre-
treatment Regulations for the Electroplating Point Source Category,
40 CFR Part 413 (Ref. EPA 440/1-79/003, August 1979) .
System cost estimates for the previously described groups of
plants were provided to the Office of Analysis and Evaluation
of the EPA for use in Economic Impact Analysis (EIA) of the
Metal Finishing Category. Option 3 for the !new source cadmium
limitations was recosted to include three sources of cadmium:
cadmium plating rinses, acid stripping of ca'dmium plated parts,
and chromating of cadmium plated parts. The revised costs
were used in the economic impact analysis and the results are
presented in the Metal Finishing record.
ENERGY AND NON-WATER QUALITY ASPECTS j
Energy and non-water quality aspects of the wastewater treatment
technologies described in Section VII are summarized in Tables
8-12 and 8-13. Energy requirements are listed, the impact on
environmental air and noise pollution is notjed, and solid waste
generation characteristics are summarized. The treatment proc-
esses are divided into two groups, wastewater treatment proc-
esses on Table 8-12 and sludge and solids handling processes on
Table 8-13.
Energy Aspects
Energy aspects of the wastewater treatment processes are impor-
tant because of the impact of energy use on our natural re-
sources and on the economy. Electrical power and fuel require-
ments (coal, oil, or gas) are listed in units of kilowatt hours
per ton of dry solids for sludge and solids handling. Specific
energy uses are noted in the "Remarks" column.
Evaporation as applied in Option 3 is an energy intensive tech-
nology for waste treatment. However, its energy consumption is
significantly reduced by the use of double effect evaporation
and by the use of countercurrent rinsing to limit the volume of
wastewater flowing to the evaporator. With the effective imple-
mentation of these techniques the total energy requirements for
evaporation in this category will be small and will probably not
exceed the energy consumed in treating and pumping the volume of
water which would be used in rinsing without these techniques.
Non-Water Quality Aspects
It is important to consider the impact of each treatment process
on air, noise, and radiation pollution of the enviroment to
preclude the development of a more adverse environmental impact.
VIII-106
-------
TA3LE 3-12
NON-WATER QUALITY ASPECTS OF WASTEWATER TREATMENT
PROCESS
Chemical Reduction
Ski-.tiing
Clarification
ENERGY REQUIREMENTS
Power Fuel
kwh kwh
1000 liters
NON-WATER QUALITY IMPACT
1000 liters
1.0
0.01-.3
0.1-3.2
Chemical Precipitation 1.02
Sedimentation
Reverse Osmosis
0.1-3.2
3.0
Energy
Use
Mixing
Skimmer Drive
Sludge Collec-
tor Drive
Flocculation
Paddles
Sludge collector No
Drive
Air
Pollution
Impact
No
No
No
High Pressure
Pump
No
Noise
Pollution Solid
Impact Waste
No
No
No
No
Yes
No .
Yes:
Yes:
Yes'
Yes"
Yes-
Yes"
Solid Waste
Concentration
% Dry Solids
5-50 (oil)
1-10
3-10
1-3
1-40
Ultrafiltration
1.25-3.0
High Pressure
Pump
No
Yes
Yes.
Yes"
1-40
i Electrochemical
5 Chromium Reduction
«j
Chemical Oxidation
by Chloride
Chemical Emulsion
Breaking
Deep Bed Filtration
Carbon Adsorption
Throwaway
Evaporation
0.2-0.8
4.4-9.6
.1-3,2
.02-1.0
.08
2,500,000
ReactiEier, Pump No
Mixing
Mixer, Skimmer, No
Sludge Pump
Head, Backwash No
Pumps
Head, Backwash No
Pumps
Evaporation Yes
No
No
Yes"
No
1-3
Yes
No
No
NO
3
Yes
Yes3
Yes3
Yes3
3-50 (oil)
1-3 (TSS)
Variable
Variable
50-100
Countercurrent Rinse
Negligible
No
No
No
-------
TABLE 8~B
N35-KKTER QUALITY AS?EGTS OF SLUDGE AND SOLIDS HANDLING
PHOCESS
EJEBGY RBQUIREMENTS
NOH-KFER QUALITY IHPACT
Sludge
Thickening
Pressure
Filtration
Vacuum
Filter
Power
kwh
ton dry solids
29-930
21
16.7-
66.8
Fuel
kwh
ton dry
—
Energy
solids Ose
Skimmer/
Sludge Rake
Drive
High Pressure
Pumps
Vacuum Pump,
Rotation
Air
filiation
Impact
ita
>fo
So
Noise
Pollution
Impact
No
No
Yes2
Solid
Waste
Yes3
Yes5
Yes5
Solid 'ivaste
Concentration
% Dry Solids
4-27
25-50
12-40
Solid Waste
Disposal
Technique
Debater & Landfill
or Incinerate
Landfill or Incinerate
Landfill or Incinerate
Centrifugation 0.2-
98.5
f Landfill
Lagooning
Sand Bed Drying
Rotation
20-980 Haul, Land- No
fil 1-10
Mile Trio
Yes
Nc
Yes'
Yes"
15-50
N/A
36
35
Removal
Equipment
Removal
"Equipment
No
Mo
No
NO
Yes
c
YesT
3-5
15-40.
Landfill or Incinerate
N/A
Dewater S Landfill
Landfill
1) Depends on volatiles present
2) Not objectionable . ,
3} Wastewater pollutants have been concentrated into a solid for disposal
or further treatment
4) Wastewater pollutants have been concentrated into a liquid for disposal
or further treatment
5} Wastewater pollutants which have been concentrated into a solid have
been further concentrated by dewatering for disposal
-------
In general, none of the liquid handling processes causes air
pollution. Alkaline chlorination for cyanide destruction and
chromium reduction using sulfur dioxide also have potential
atmospheric emissions. With proper design and operation, how-
ever, air pollution impacts are eliminated. Incineration of
sludge or solids can cause significant air pollution which must
be controlled by suitable bag houses, scrubbers, or stack gas
precipitators as well as proper incinerator operation and main-
tenance. Care must be taken to insure that solids collected in
air pollution control do not become a water pollution threat.
None of the wastewater treatment processes causes objectionable
noise and none of the treatment processes has any potential for
radioactive radiation hazards.
The solids waste impact of each sludge dewatering process is
indicated in two columns on Table 8-13. The first column shows
whether effluent solids are to be expected and, if so, the
solids content in qualitative terms. The second column lists
typical values of percent solids of sludge or residue. The
third column indicates the usual method of solids disposal
associated with the process.
The processes for treating the wastewaters from this category
produce considerable volumes of sludges. In order to ensure
long-term protection of the environment from harmful sludge
constituents, all sludges must be disposed of in accordance with
the Resource Conservation and Recovery Act (RCRA).
VIII-109
-------
SECTION IX
BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE
INTRODUCTION
This section describes the best practicable control technology
currently available (BPT) for the treatment of process waste-
waters generated within the Metal Finishing Category. BPT re-
flects existing treatment and control practices at metal finish-
ing plants of various sizes, ages, and manufacturing processes.
The factors considered in defining BPT include the total cost of
application of technology in relation to the effluent reduction
benefits from such application, the age of equipment and facili-
ties involved, the processes employed, non-water quality environ-
mental impact (including energy requirements), and other factors
considered appropriate by the Administrator. In general, the BPT
technology level represents the best existing practices at plants
of various ages, sizes, processes, or other common characteristics.
Where existing practice is uniformly inadequate, BPT may be trans-
ferred from a different subcategory or category. Limitations based
on transfer of technology must be supported by a conclusion that
the technology is, indeed, transferrable and a reasonable predic-
tion that it will be capable of achieving the prescribed effluent
limits (see Tanner1 s Council of America v_._ Train Supra) . BPT fo-
cuses on end-of-pipe treatment rather than process changes or in-
ternal controls, except where such are common industry practice.
IDENTIFICATION OF BPT
Plants in the Metal Finishing Category generate process wastewater
streams of several distinct types. As described in Sections V and
VI, waste streams produced in this category may contain common
metals (e.g., copper, nickel, zinc, etc.), precious metals
(e.g., gold, palladium, silver), cyanide, hexavalent chromium,
oil and grease, and a variety of toxic organic compounds (de-
signated total toxic organics, TTO). Individual process waste-
water streams characteristically contain only some of these pollu-
tants, and metal finishing facilities generally produce several
distinct streams differing in their chemical composition and treat-
ment requirements. These considerations are reflected in pre-
vailing wastewater treatment practices within the category, and
in the identified BPT.
The BPT wastewater treatment system (Option 1 System in Section
VII) for the Metal Finishing Category is illustrated in Figure
9-1. This treatment system provides for the removal of metals
IX-1
-------
i
to
Oily Raw Waste Raw Waste
Raw Waste
Raw Waste
r
Skiimtecl
Oil
1
Emulsion
Breaking
3
1
Cyanide
Oxidation
Common
Metals
!
I
1
Chror
Redu<
Chemical j. .
'recipitation
'
Clari
Tees
Rffl
i
Sludge
_
f Slu
ited Dewat
\
nium
3tion
Complexed
Metals
r
no , ». Chemical
""" Precipitation
i
Slw3ge „
.._.._._..„. Pl-rr
'_
dge '
ering „_
^ Trea
Lfier
i
ted
Raw Waste Toxic Organic
1
Effluent
Contractor
Removal
Hauled or
Reclaimed
FIGURE 9-1
BPT SYSTEM
-------
from all process wastewater streams by chemical precipitation and
clarification, and specific treatment of some waste streams for
the removal of other process wastewater pollutants. Extensive
description of these treatment components is provided in Section
VII. Individual plants in the Metal Finishing Category that do
not produce all of the distinct wastewater types shown need to
install only the system components necessary for the treatment of
those wastewater types existing at the plant to achieve compliance
with BPT.
Where some process waste streams contain complexed metals, BPT
includes the segregation of these wastes and separate treatment
for the precipitation of metals and removal of suspended solids.
Precipitation of metals from these wastes is characteristically
accomplished at a high pH (11.6 - 12.5) to induce dissociation of
the metal complexes. Lime or other calcium compounds are used
to adjust the pH to the high levels required to induce precipita-
tion of the free metals as hydroxides. Sedimentation is then
used in order to allow the resulting suspended solids to settle
out of solution.
Waste streams containing cyanide or hexavalent chromium are also
segregated for treatment in the BPT system. Cyanide bearing
wastes are treated chemically to oxidize the cyanide, and streams
containing hexavalent chromium are subjected to chemical chromium
reduction. After these separate treatment operations are com-
pleted, these waste streams are combined with other process waste-
water for the chemical precipitaion of metals and clarification.
Concentrated oily waste streams are segregated and treated for the
removal of oil and grease prior to treatment for metals removal.
Oils and greases are removed by gravity separation and skimming
of free oils followed by chemical emulsion breaking and subsequent
skimming for the removal of emulsified oils. Some oily waste
streams produced in this category may contain very low concen-
trations of emulsified oils making chemical emulsion breaking
unnecessary, while others may contain low free oil concentrations
obviating the need for skimming prior to emulsion breaking.
Some oily waste streams containing very low concentrations of
dissolved metals may be of a quality suitable for discharge af-
ter oil removal treatment. In these cases, further treatment
for metals removal with other process waste streams would not
be necessary to achieve compliance with BPT.
Following separate stream treatment the effluents are combined and
the metals are removed by precipitation and subsequent clarifica-
tion. Precipitation is accomplished by the addition of lime,
caustic, sodium carbonate, or acid to achieve a favorable pH.
Most metals precipitate as hydroxides although some, such as lead
and silver, preferentially form other compounds (e.g. carbonates
or chlorides). The optimum pH for precipitation is generally in
the range of 8.8-9.3, although it will vary somewhat depending on
the specific waste composition. The use of coagulents or flocculants
to enhance the effectiveness of clarification is also specifically
included in BPT.
IX.-3
-------
In addition to the control of toxic metals, cyanide. TSS, and pH.
BPT regulates toxic organics as Total Toxic Organics. Compliance
with the TTO limit can be achieved by good management practices
(i.e.. not dumping waste solvents into the wastewater). No
additional end- of-pipe technology beyond that required for metals
removal is necessaty.
Alternative technologies are available which are equivalent to
BPT for the removal of the pollutants encountered in the Metal
Finishing Category. Some of these technologies as well as those
discussed above as BPT have been describedindetailin Section
VII of this document. The specific technologies implemented at
each individual plant to achieve compliance with BPT limitations
will depend on economic and operational considerations specific
to the facility.
RATIONALE FOR THE SELECTION OF BPT
The BPT system identified above has been selected on the basis
of: proven effectiveness in treating pollutants present in
metal finishing process wastewaters; present practice within
the category; and non-water quality considerations. All of the
elements of the selected BPT are presently practiced at many plants
within the Metal Finishing Category and have been proven to be
reliable and effective in treating industrial wastewater.
Energy requirements for these technologies are moderate. However,
sludges and waste oils which prove to be hazardous must be handled
and disposed of in accordance with the Resource Conservation and
Recovery Act regulations.
Chemical precipitation is a proven technology which is widely
applied at Metal Finishing Category plants. As is shown in
Section VII, over 100 facilities employing hydroxide precipita-
tion and sedimentation for the removal of metals from process
wastewaters are identified. With appropriate control of pH and
settling conditions, this technology can be effectively applied
to process wastewaters containing any of the metals commonly
encountered in this category. Because this technology has been
applied at many facilities over extended periods of time, its
performance capabilities were established on the basis of a
large body of data from industrial effluents within the Metal Fi-
nishing Category. '..
Chemical chromium reduction is also a proven and widely applied
technology. Over 300 plants in the Metal Finishing Category
which employ this technology were identified. It may be imple-
mented using a variety of equipment, reagents, and operating pro-
cedures, and is readily adaptable to the wide range of flow
rates and hexavalent chromium concentrations encountered in the
Metal Finishing Category. Similar to chemical precipitation,
its pollutant reduction performance capabilities were established
from effluent data from a number of plants within the category.
IX-4
-------
Chemical oxidation of cyanide using chlorine is also a common
wastewater treatment practice within the Metal Finishing Category.
Over 200 plants employing this technology were identified within
the surveyed data base. As a result, considerable data establishing
the reliability and performance of this technology were available
from industrial sites within the Metal Finishing Category.
Treatment of process wastewater for the removal of oils and
greases is common practice in the Metal Finishing Category. A
variety of oil removal techniques are employed as discussed in
Section VII. These correspond to the wide range of waste stream
compositions encountered. The identified BPT provides for the
removal of both free and emulsified oils commonly encountered in
metal finishing wastewaters. Twenty-nine plants in the data base
were identified which employ emulsion breaking technology. The
number of plants employing skimming for the removal of oils and
greases is much larger. Performance capabilities for these
technologies were firmly established on the basis of extensive
long-term practice in treating industrial process wastewater.
The specific technologies identified as BPT are relatively simple
and reliable; however, comparable effluent performance can be
achieved by numerous technical alternatives.
The technical merits, present practice, and demonstrated per-
formance of the BPT technologies are discussed in detail in
Section VII. The costs and non-water quality environmental
aspects of these technologies are presented in Section VIII.
BPT LIMITATIONS
The effluent limitations attainable by application of BPT are
presented in Table 9-1 .
TABLE 9-1
BPT EFFLUENT LIMITATIONS
Concentration (mg/fc)
Pollutant or Daily Maximum Monthly
Pollutant Parameter Maximum Average
Cadmium 0.69 0.26
Chromium, total 2.77 1.71
Copper 3.38 2.07
Lead 0.69 0.43
Nickel 3.98 2.38
Silver 0.43 0.24
Zinc 2.61 1.48
Cyanide, total 1.20 0.65
TTO 2.13
Oil and Grease 52 26
TSS 60 31
pH Within the range of 6.0 to 9.0
Alternative to total cyanide
Cyanide, amenable to chlorination 0.86 0.32
IX-5
-------
These limitations are based on demonstrated performance at metal
finishing plants employing the identified BPT technologies. As
described in Section VII, both on-site sampling and observations,
and long-term effluent monitoring data are reflected in the limi-
tations. They therefore incorporate both plant to plant varia-
tions in raw wastes and treatment practices and the day-to-day
variability of treatment system performance. The effluent con-
centrations shown in Table 9-1 represent levels attainable by a
well run BPT system 99% of the time.
The concentrations shown are all applicable to the treated ef-
fluent prior to any dilution with sanitary wastewater, noncon-
tact cooling water, or other non-process water. The total cyanide
concentration limitation applies to the discharge from cyanide
.oxidation prior to mixture with any other process wastes.
As an alternative the amenable cyanide limit may apply in place
of the total cyanide limit for industrial facilities with
cyanide treatment and upon agreement between a source subject
to those limits and the pollution control authority.
j..~ • -
The derivation of these performance limitations from effluent
data for Metal Finishing Category plants is described in detail
in Section VII. After technical analysis of the effluent data
and supporting information to identify plants with properly
operating treatment systems, the data were screened to ensure
that only effluent data corresponding to raw waste streams which
contained significant levels of each pollutant were used to
establish limitations for that parameter. These data were then
analyzed statistically as described under Statistical Analysis
(reference Section VII) to derive 99th percentile limits on tooth
single day and monthly maximum average effluent concentrations,
PRESENT COMPLIANCE WITH BPT ;
Table 9-2 shows the compliance percentages for the two data bases
evaluated in developing the BPT effluent limitations: (1) the
EPA sampled data base; and (2) the long teem self-monitoring data
base from data submitted by plants in the industry. Compliance
Cor^the self-monitoring data was determined for both daily
maximum values and 10-day average values.
IX-6
-------
Tables 9-3 and 9-10 present a detailed summary of the self-
monitoring data relative to compliance with the daily maximum and
the monthly maximum average limitations for the regulated
parameters. Table 9-3 shows the number of data points in
compliance with the BPT daily maximum limitations and the total
number of data points for each parameter at each plant. Table 9-4
presents the corresponding compliance percentage values. Tables
9-5 and 9-6 present the same information for total cyanide.
amenable cyanide, and silver. Compliance information is presented
in the same format for the maximum monthly averages in Tables 9-7
through 9-10 using 10 days as a basis.
BENEFITS OF BPT IMPLEMENTATION
The estimated environmental benefits of the application of BPT to
all plants in the Metal Finishing Category are summarized in Table
9-11. This table presents estimates of the total mass of the
regulated pollutant parameters in raw wastewaters from all metal
finishing plants and the remaining mass of these pollutants
discharged after application of BPT at all facilities with direct
discharges. The differences between these values are presented as
quantitative estimates of the environmental benefits of
implementing BPT. These benefits may be compared to the costs of
BPT (Option 1) as presented in Section VIII.
IX-7
-------
TABLE 9-2
PERCENTAGE OF THE MFC DATA BASE
BELOW THE BPT LIMITATIONS
Self-Monitoring Self-Monitoring
IPA Sampled Data* Data Data
Pollutant Daily Maximum Daily Maximum 10-Day Average
Cadmium 100.0 98.8 97.8
Chromium 100.0 99.7 99.7
Copper 95.7 98.5 96.7
Lead 100.0 95.9 92.7
Nickel 95.6 99.9 100.0
Silver 100.0 7d,6 100.0
Zinc 94.1 99.2 95.8
Cyanide, total 97.8 79.3 63.4
TTO 100.0
Oil & grease 100.0 100^.0 100.0
TSS 100.0 991.8 100.0
EPA sampled data used to develop limits (ij.e.. Tables 7-4 to 7-10,
7-55, 7-74).
IX-8
-------
X
I
PLANT
1067
3049
5020
6002
6035
6051
6053
6087
6103
6107
11008
11477
12002
17030
19063
20080
20082
20116
22735
23076
30050
30079
30090
30165
33050
33092
34037
36040
44045
44150
45741
47025
TSS
148/149
49/49
12/12
13/13
12/12
12/12
13/13
10/10
140/140
69/69
269/269
243/243
27/27
292/292
51/51
50/50
335/337
TABLE 9-3
BPT SELF-MONITORING DATA COMPLIANCE SUMMARY
DATA POINTS < BPT DAILY MAXIMUM^IMITATIONS/TOTAL DATA POINTS
CADMIUM
228/230
—
6/6
9/9
13/13
—
—
183/185
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
49/51
CHROMIUM
230/230
228/228
—
12/12
13/13
—
10/10
185/185
—
342/344
238/238
269/269
250/253
243/243
35/35
237/242
289/289
49/49
—
—
—
225/225
—
—
358/358
256/256
COPPER
230/230
232/232
—
—
13/13
12/12
8/10
185/185
58/58
—
247/248
—
240/253
243/243
—
231/241
292/292
260/260
65/66
112/112
172/184
—
49/49
124/127
—
—
LEAD
217/229
238/238
54/65
48/49
NICKEL
13/13
185/185
10/10
253/253
243/243
239/241
75/75
33/33
228/228
49/49
ZINC
OIL & GREASE
230/230 230/230
231/231
13/13
9/10
184/184
51/51
269/269
249/250
58/66
115/115
42/42
49/49
13/13
66/66
55/55
269/269
45/45
287/287
12/12
45/45
49/49
OVERALL 1745/1748 488/494
3469/3479 2773/2815 557/581
1789/1791 1220/1230 890/890
— = No data or material not used in metal finishing processes.
-------
TABLE 9-4
BPT SELF-MONITORING DATA COMPLIANCE SUMMARY
PERCENT OP DATA POINTS < BP1 DAILX MAXIMUM LIMITATIONS
H
X
1
H
O
PLANT
1067
3049
5020
6002
6035
6051
6053
6087
6103
6107
11008
11477
12002
17030
19063
20080
20082
20116
22735
23076
30050
30079
30090
30165
33050
33092
34037
36040
44045
44150
45741
47025
OVERALL
TSS
99.3
100.0
—
—
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
~-
—
...
100.0
__
100.0
100.0.
--
100.0
—
,100.0
—
—
—
—
—
100.0
—
99.4
99.8
CADMIUM CHROMIUM
99.1 100.0
100.0
100.0
100.0 100.0
100.0 100.0
- -
...
100.0
98.9 100.0
_.
, -
99.4
100,0
100.0
98.8
100.0
100.0
97.9
100.0
_.
100.0
- -
...
--
100.0
--
.. -
100.0
96.1 100.0
98.8 99.7
COPPER LEAD
100.0
..-
100.0 94.8
-
—
100.0
„_
100.0
...
80.0
100.0
._
100.0
~-
99.6 100.0
—
94.9
100.0
__
95.9
100.0
...
100.0
98.5 83.1
100.0
...
93.5
__
100.0 97.9
97.6
- -
— -—
98.5 95.9
NICKEL
100.0
100.0
—
,_
100.0
—
--
__
.._
100.0
—
_._
100.0
—
100.0
100.0
__
99.2
100.0
—
—
—
_.-
100.0
.„
100.0
100.0
,_
.._
—
99.9
ZINC
100.0
—
—
—
—
100.0
—
--
—
90.0
100.0
—
100.0
—
—
100.0
99.6
—
_._
—
—
—
:
87.9
100.0
--
—
—
.
100.0
__
—
99.2
OIL & GREASE
_.
100.0
__
—
—
100.0
—
--
__
—
—
100.0
100.0
—
— -
100.0
—
—
100.0
--
100.0
100.0
wo. a
—
--
--
—
__
—
—
100.0
—
100.0
— = No data or .material not used In metal finishing processes.
-------
TABLE 9-5
SINGLE OPTION - SELF -MONITOR ING DATA COMPLIANCE SUMMARY
DATA POINTS <. BPT LIMITATIONS/TOTAL DATA POINTS
Plant
1067
3043
6002
6051
6087
6107
11008
11125
15193
20080
2OO82
31021
36082
38223
44045
47025
Cyanide. Total
*
78/89
Cyanide. Amenable
Silver
170/179
0/54
4/12
268/268
2OO/246
86/140
119/121
—
40/50
63/139
12/12
0/5
31/40
234/235
216/243
Overall
1028/1298
481/518
12/17
t Adjusted for dilution.
* Dilution factor not known.
— No data or material not used in metal finishing processes
IX-11
-------
TABLE 9-6
SINGLE OPTION - SELF-MONITORING DATA COMPLIANCE SUMMARY
PERCENT OF DATA POINTS <. BPT LIMITATIONS
Plant Cyanide. Total * Cyanide. Amenablet Silver
1067 *
3043 87.6 --'
6002
6051 *
6087 — — 100.0
6107 *
11008 94.9
11125 0.0 — 0.0
15193 33.3
20080 100.0
20082 81.3
31021 61.4 77.5
36082 98.3
38223 — 99.6
44045 80.0
47025 45.3 88.9
Overall 79.2 92.8 70.5
t Adjusted for dilution.
* Dilution factor not known.
— No data or material not used in metal finishing processes.
IX-12
-------
TABLE 9-1
BPT SELF-MONITORING DATA COMPLIANCE
10-DAY AVERAGES < BPT MONTHLY MAXIMUM AVERAGE LIMITATIONS/TOTAL NUMBER OF 10-DAY AVERAGES
H
X
1
M
U)
PLAMT
1067
3049
5020
6002
6035
6051
6053
6087
6103
6107
11008
11477
12002
17030
19063
20080
20082
20116
22735
23076
30050
30079
30090
30165
33050
33092
34037
36040
44045
44150
45741
47025
OVERALL
TSS
14/14
4/4
—
—
1/1
1/1
1/1
1/1
1/1
1/1
14/14
6/6
—
—
— .
26/26
— --
24/24
2/2
__
29/29
—
5/5
—
—
—
—
5/5
—
. —
33/33
168/168
CADMIUM CHROMIUM
23/23 23/23
—
22/22
—
1/1
1/1 1/1
—
—
—
1/1
18/18 18/18
—
—
34/34
23/23
26/26
24/25
24/24
3/3
24/24
28/28
—
4/4
_._
__
__
—
22/22
—
__
35/35
3/4 25/25
45/46 338/339
COPPER LEAD
23/23
__
23/23 21/22
—
—
1/1
—
1/1
—
0/1
18/18
—
5/5
—
24/24 23/23
22/25
24/24
—
23/24
29/29
—
26/26
6/6 3/6
11/11
—
14/18
—
4/4 4/4
12/12
_..
—
266/275 51/55
NICKEL
23/23
—
23/23
—
—
1/1
—
—
—
—
18/18
—
-..
—
1/1
25/25
24/24
--
24/24
7/7
—
--
—
_._
3/3
—
22/22
4/4
_.
--
--
175/175
ZINC
23/23
— .
—
—
1/1
—
—
—
0/1
18/18
—
5/5
—
26/26
25/25
—
—
—
—
—
__
2/6
11/11
—
—
_._
__
4/4
—
—
115/120
OIL & GRBJ
-
4/4
--
—
—
1/1
—
—
—
—
—
6/6
5/5
—
.._
26/26
__
...
4/4
--
28/28
1/1
4/4
—
__
--
.._
--
—
4/4
. —
83/83
— = No data or material not used in metal finishing processes.
-------
TABLE 9-8
BPT SELF-MONITORING DATA COMPLIANCE SUMMARY
PERCENT OF 10-DAX AVERAGES < BPT MONTHLY MAXIMUM AVERAGE LIMITATIONS
PLANT
1067
3049
5020
6002
6035
6051
6053
6087
6103
6107
11008
11477
12002
17030
19063
20080
20082
20116
22735
23076
30050
30079
30090
30165
33050
33092
34037
36040
44045
44150
45741
47025
OVERALL
TSS
100.0
100.0
—
__
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
__
--
—
100.0;
--
100.0
100.0,
....
100.0
100.0
—
—
—
- .
—
100.0
—
—
100.0
100.0
CADMIUM CHROMIUM
100.0 100.0
100.0
._
100.0
100.0 100.0
--
- -
100.0
100.0 100.0
—
...
100.0
100.0
100.0
96.0
100.0
100.0
100.0
100.0
100. d
. .. . .. _ •
- -
._
100.0
--
100.0
75.0 100.0
97.8 99,7
COPPER LEAD
100.0
--
100.0 95.5
.._
__
100.0
100.0
0.0
100.0
—
100.0
—
100.0 100.0
--
88,0 —
100.0
_._
95.8
100.0
...
100.0" —
100.0 50.0
100.0
. -
77.8
__
100.0 100.0
100.0
__
— —
96.7 92.0
NICKEL
100.0
—
100.0
—
—
100.0
__
--
--
100.0
—
_-
—
100.0
—
100.0
100.0
—
100.0
100.0
—
—
—
__
100.0
—
100.0
100.0
--
—
—
100.0
ZINC
100.0
—
--
__
—
100.0
__
--
—
0.0
100.0
—
100. 0
100.0
100.0
--
— :.
__
:
—
33.3
100.0
—
—
—
__
100.0
—
—
95.8
OIL & GREASE
__
100.0
__
—
—
100.0
—
—
—
—
—
100.0
100.0
—
—
100.0
—
—
100.0
—
100.0
100.0
100.0
—
__
—
—
--
--
—
100.0
—
100.0
— = No data or; material not used in metal finishing processes.
-------
TABLE 9-9
SINGLE OPTION - SELF-MONITORING DATA COMPLIANCE SUMMARY
10-DAY AVERAGES <. BPT MONTHLY MAXIMUM AVERAGE LIMITATIONS/TOTAL
NUMBER OF 10-DAY AVERAGES
Plant Cyanide.Total* Cyanide. Amenable* Silver
1067 *
3043 6/8
6002
6051 *
6087 ~ -- 1/1
6107 *
11008 15/17
11125 0/5
15193 , 0/1
20080 26/26
20082 12/24
31021 4/14 0/3
36082 11/12
38223 -- 22/23
44045 3/4
47025 1/13 17/24
Overall 78/124 39/50 1/1
t Adjusted for dilution.
* Dilution factor not known.
-- No data or material not used in metal finishing processes.
IX-1S
-------
TABLE 9-10
SINGLE OPTION - SELF-MONITORING DATA COMPLIANCE SUMMARY
PERCENT OF 10-DAY AVERAGES <. BPT MONTHLY MAXIMUM AVERAGE LIMITATIONS
Plant Cyanide. Totalt Cyanide! Amenablet Silver
1067 *
u
3043 75.0 ' j~
6002 — -- •->*
6051 * --
6087 — p- 100.0
6107 * -- --
11008 88.2
11125 0.0
15193 0.0
20080 100.0
20082 50.0 ;-- =-
31021 28.6 0.0
36082 91.7 ;—
38223 — 9516 --
44045 75.0
47025 7.7 70.8
i
overall 62.9 78.0 100.0
t Adjusted for dilution.
* Dilution factor not known.
— No data or material not used in metal finishing processes.
IX-16
-------
Pollirbant Parameter
Cadmium
Chromium, Total
Copper
Lead
Nickel
Silver
Zinc
TOXIC METALS TOTALS:
Cyanide, Total
Total Toxic Organics
OVERALL TOTALS:
TABLE 9-11
BPT TREATMENT BENEFIT SUMMARY
Discharge (Metric tons/year)
RawLoading
102
9886
4547
119
557
8
4489
19708
3582
1170
24460
BPT
_Effl_uetrt
3
136
206
14
237
6
110
712
65
30
807
BPT
Benefit
99
9750
4341
105
320
2
4379
18996
3517
1140
23653
IX-17
-------
SECTION X
BEST AVAILABLE TECHNOLOGY
ECONOMICALLY ACHIEVABLE
INTRODUCTION
This section describes the best available technology economically
achievable (BAT) for the treatment and control of process waste-
water generated within the Metal Finishing Category. BAT represents
the best existing economically achievable performance of plants
of various ages, sizes, processes or other shared characteristics.
The Federal Water Pollution Control Act of 1972 required that BAT
represent reasonable further progress (beyond BPT) toward elimina-
ting the discharge of all pollutants. In fact, elimination of
discharge of all pollutants is required if technologically and
economically achievable. The Clean Water Act of 1977 specifically
defined both the conventional and toxic pollutants that must be
regulated (See Section V of this document for identification of
these pollutants) and also established a class of nonconventional
pollutants for regulation.
BAT has been further defined as the very best control and treatment
technology within a subcategory or as superior technology transferred
from other industrial subcategories or categories. This definition
encompasses in-plant process improvements as well as more effective
end-of-pipe treatment.
IDENTIFICATION OF BAT
BAT is the technology defined under Option 1 in Section VII of
this document and is shown in Figure 10—1. For toxic metals,
toxic organics, and cyanide, BAT effluent control is achieved by
the BPT system described in Section IX.
For waste streams containing complexed metals, BAT will be identi-
cal to BPT. This will require the segregation of the complexed
metals waste stream with separate treatment for the precipitation
of metals and removal of suspended solids. Precipitation of
metals from this waste stream can be accomplished by adjusting
the pH of the wastewater to 11.6-12.5 in order to promote dis-
sociation of the metal complexes and subsequent precipitation
of the free metals. Sedimentation is then employed in order
to allow the resulting suspended solids to settle out of solution.
The BAT treatment systems (Option 1 system in Section VII) is
adequate to achieve the BAT effluent limitations presented later
in this section. However, a plant may elect to supplement this
system with other equipment or use an entirely different treat-
ment technique in order to attain the BAT limitations. Alterna-
tive technologies (both end-of-pipe and in-process) are described
in Section VII of this document. In-plant techniques such as
evaporative recovery or reverse osmosis may substantially reduce
the end-of-pipe treatment requirements.
X-J
-------
x
N)
Oily Raw Waste Raw Waste Raw Waste Raw Waste Raw Waste Toxic Organi<
I
Emulsion
Breaking
Skimmed
Oil
I
Cyanide
Oxidation
Cannon
Metals
1
Chromium
Reduction
Ccnplexed
Metals
Chemical
Precipitation
Lime
Hauled or
Reclaimed
Chemical
Precipitation
Clarifier
Sludge Sludge
Treated
Effluent
Sludge
Dewatering
T
I
Treated
Effluent
Contractor
Removal
FIGURE 10-1
BAT SYSTEM
-------
fiATIONALE FOR SELECTION OF BAT
The BAT treatment system identified previously was selected
because it has been proven in metal finishing plants to represent
a well demonstrated, reliable technology which achieves a high
degree of toxic pollutant removal. This is demonstrated by the
Option 1 system performance in Section VII.
Although demonstration of BAT at a single plant is adequate for
its selection, the common metals Option 1 system is identified in
Section VII as presently employed at over 100 known metal
finishing plants. Precipitation, clarification, and filtration.
has been demonstrated to be effective at several plants, although
far less frequently than precipitation/clarification alone.
Although precipitation/clarification/filtration was considered
for BAT, it was not selected as the technology basis because of
the very high incremental aggregate costs.
Compared to BPT. BAT has identical impact on energy requirements
and nonwater quality aspects.
BAT LIMITATIONS
The BAT effluent limitations are presented in Table 10-1.
TABLE 10-1
BAT EFFLUENT LIMITATIONS
Pollutant or Daily Maximum Monthly
Pollutant Parameter Maximum Average
Cadmium 0.69 0.26
Chromium, total 2.77 1.71
Copper 3.38 2.07
Lead 0.69 0.43
Nickel 3.98 2.38
Silver 0.43 0.24
Zinc 2.61 1.48
Cyanide, total 1.20 * 0.65
TTO 2.13
Alternative to total cyanide:
Cyanide, amenable to chlorination 0.86 0.32
As discussed in Section VII, these limitations represent the
effluent concentrations attainable by a properly operating BAT
system 99 percent of the time. The concentrations presented
X-3
-------
in Table 10-1 reflect treated effluent undiluted by sanitary
wastewater. noncontact cooling water, or other nonprocess water.
The total cyanide concentration limitation applies to the
discharge from cyanide oxidation prior to mixture with any other
process wastes. As an alternative to the total cyanide limit.
cyanide amenable limit may apply in place of total cyanide for a
facility with cyanide treatment and contingent on agreement
between the facility and the pollution control authority.
The development of these effluent limitations from performance
measurements of existing BAT systems is described in Section VII.
The statistical rationale used in developing these limitations is
presented at the end of Section VII under the heading of Statis-
tical Analysis.
PRESENT COMPLIANCE WITH BAT
The percent compliance with BAT for the EPA sampled data base and
the long-term self-monitoring data base is the same as for BPT for
the toxic metals and cyanide as presented in Tables 9-2 to 9-10.
BENEFITS OF BAT IMPLEMENTATION
Since the BAT treatment system is identical to the BPT system, no
increased environmental benefit above that derived from BPT
treatment is attained.
X-4
-------
SECTION XI
NEW SOURCE PERFORMANCE STANDARDS
INTRODUCTION
This section describes the new source performance standards
(NSPS) for the treatment and control of process wastewaters
generated within the Metal Finishing Category. NSPS reflects
existing treatment and control practices or demonstrations that
are not necessarily in common practice.
The Federal Water Pollution Control Act of 1972 required that
NSPS represent the best available demonstrated control tech-
nology, processes, and operating methods. Where practicable, no
pollutant discharge at all is to be allowed. Where pollutant
discharge is unavoidable, these standards are to represent the
greatest degree of effluent reduction achievable. They apply
to new sources, which are defined as any building, structure,
facility, or installation that discharges pollutants and for
which construction is started after promulgation of the standards,
IDENTIFCATION OF NSPS
NSPS is the technology defined under Treatment of Common Metals
Wastes - Option 3 in Section VIII of this Development Document.
The NSPS waste treatment system is shown in Figure 11-1. For
common metals, precious metals, oil and grease and cyanide wastes,
NSPS is achieved by the previously described BPT and BAT treat-
ment systems, plus the use of in-process treatment modifications
for controlling the discharge of cadmium. The BPT or BAT waste
treatment systems have been previously described in Sections IX
and X of the document.
The in-process modifications for controlling cadmium consist of
using evaporative recovery or ion exchange on segregated cadmium
bearing waste streams prior to mixing with other common metals
bearing wastewaters for end-of-pipe treatment. These in-process
modifications will reduce cadmium discharges to the background
levels detailed in Section VII of the document.
For complexed metal bearing waste streams, NSPS will be identi-
cal to the BPT and BAT waste systems. This requires segregation
of the complexed metals waste stream with separate treatment for
the precipitation of metals and removal of suspended solids.
Precipitation of metals from this waste stream is accomplished by
pH adjustment of the wastewater to 11.6-12.5 in order to promote
dissociation of the metal complexes and subsequent precipitation
of the free metals. This is followed by sedimentation in order
to allow the resulting suspended solids to settle out of solution.
Xl-1
-------
OILY RAW WASTE
RAW WASTE wtTH RAW WASTE RAW WASTE RAW WASTE
SKIMMED OILS
HAUL OR
RECLAIM
CHROMIUM
REDUCTION
RAW WASTE
CADMIUM!
i
RAW WASTE TOXIC ORGANICS
EVAPORATIVE
RECOVERY OR
ION EXCHANGE
COMPLEXED
METALS
Zero
Discharge
HAUL OR
RECLAIM
CHEMICAL
PRECIPITATION
X
H
I
K!
•LIME
LIME.
CHEMICAL
PRECIPITATION
TREATED
EFFLUENT
CLARIFIER
CLARIFIER
SLUDGE
SLUDGE
DEWATERING
SLUDGE
TREATED
EFFLUENT
CONTRACTOR
REMOVAL
FIGURE 11-1
NSPS SYSTEM
-------
The NSPS treatment system will, with proper operation, achieve
the NSPS effluent limitations presented later in this section.
However, a plant may elect to supplement this system with other
equipment or use an entirely different treatment technique in
order to attain the NSPS limitations. Alternative technologies
(both end-of-pipe and in-process) are described in Section VII of
this document. In-plant treatment modifications such as the use
of evaporated recovery may substantially reduce end-of-pipe
treatment requirements.
RATIONALE FOR SELECTION OF NSPS TECHNOLOGY
The NSPS treatment components identified previously for control
of cadmium were selected because they have been proven in metal
finishing plants to represent reasonable performance improvement
beyond the BPT and BAT levels of treatment. This improvement is
demonstrated by the comparison of Option 1 and Option 3 system
performance for cadmium in Section VII.
Option 3 effluent limitations for cadmium represent background
levels detected in effluents from plants which do not apply this
metal in their production operations. Because the technology
basis eliminated the discharge from cadmium wastewater sources.
this limit is appropriate. In using data indirectly, the Agency
has been conservative in two ways. First, the background levels
used to develop the standards are raw waste concentrations; the
technology basis of precipitation/clarification is expected to
result in further removal. Second, the highest two plants were
used for the derivation of the long term average. The
conservative nature of this procedure can be seen by comparing
the new source average with the EPA sampled discharges of cadmium
from precipitation/clarification. (A detailed explanation of
this approach and the data supporting the reasonableness of
this approach are provided in Section VII.)
When compared to BPT and BAT, NSPS has only minor incremental
impact upon energy requirements and other nonwater quality
aspects.
NSPS LIMITATIONS
The NSPS effluent limitations are presented in Table 11-1.
XI-3
-------
TABLE 11-1
NSPS EFFLUENT LIMITATIONS
Pollutant or
Pollutant Parameter
Cadmium
Chromium, total
Copper
Lead
Nickel
Silver
Zinc
Cyanide, total
TTO
Oil and Grease
TSS
Daily
Maximum
i
0.11
2.77
3.38
0.69
3.98
0.43
2.61
1.20
2.13
52
60
pH
Alternative to total cyanide:
Cyanide, amenable to chlorination
Maximum Monthly
Average
0.07
1.71
2.07
0.43
2.38
0.24
1.48
0.65
Within the range of 6.0 to 9.0
26
31
0.86
0.32
As discussed in Section VII of this document, these limitations
represent the effluent concentrations attainable by a well
operating NSPS system 99 percent of the time. The concentrations
presented in Table 11-1 reflect treated effluent undiluted by
sanitary wastewater. non-contact cooling water, or other non-
process water. The total cyanide concentration limitation applies
to the discharge from in-process modifications (for this
pollutant) prior to mixture with any other process wastes. As an
alternative to the total cyanide limit, a facility with cyanide
treament may apply the cyanide amenable limit in place of the
total cyanide limit upon agreement between the facility and the
pollution control authority. The cadmium limitation applies to
the discharge from in-process modifications (for this pollutant)
prior to mixture with any other process wastes.
The development of the NSPS effluent limitations is described in
Section VII under Common Metals Waste Treatment System Performance
- Option 3. and the statistical rationale is presented at the end
of Section VII under the heading of Statistical Analysis.
PRESENT COMPLIANCE WITH NSPS
The NSPS compliance for all parameters other than cadmium is the
same as that presented in Section IX (for BPT) because the NSPS
limitations for all parameters other than cadmium are identical
tothe BPT limitations. Present compliance with the Option 3
cadmium limitation cannot be determined because data are not
available from metal finishing plants using the specified
technology.
XI-4
-------
BENEFITS OF NSPS IMPLEMENTATION
Table 11-2 shows the estimated benefit of reduced cadmium dis-
charge in terms of concentration reduction that results
from the implementation of the NSPS limitations. An incremental
reduction benefit of 0.19 mg/£ of cadmium would be achieved.
The estimated environmental benefits for all pollutant para-
meters other than cadmium were presented in Section IX (for
BPT) and Section X (for BAT). Quantitative benefits cannot
be determined for NSPS because installation of future facilities
cannot be predicted, and the wastewater flow rates from new
sources cannot be projected.
TABLE 11-2
NSPS TREATMENT BENEFIT SUMMARY
Concentration Reduction (mg/1)
Average Average Average
BPT/BAT NSPS NSPS
Pollutant Parameter Effluent Effluent Reduction
Cadmium 0.13 0.06 0.07
XI-
-------
SECTION XII
PRETREATMENT STANDARDS
INTRODUCTION
This section describes the pretreatment standards for existing
sources (PSES) and the pretreatment standards for new sources
(PSNS) for the treatment of wastewaters generated within the
Metal Finishing Category that are discharged to a publicly owned
treatment works (POTW). These standards are intended to provide
an equivalent degree of toxic metals and toxic organic pollutant
removal as provided by direct discharge limitations.
The Federal Water Pollution Control Act of 1972 stated that the
pretreatment standards shall prevent the discharge to a POTW of
any pollutant that may interfere with, pass through, or otherwise
be incompatible with the POTW. The Clean Water Act of 1977
further stipulated that industrial discharges must not interfere
with use and disposal of municipal sludges. In accordance with
the Clean Water Act, individual POTWs may specify more stringent
standards or (after meeting specified criteria) may relax the
standards presented here.
IDENTIFICATION OF PRETREATMENT TECHNOLOGY
Pretreatment technology for PSES is the same as that defined in
Section X for BAT, and pretreatment technology for PSNS is the same
as that defined in Section XI for NSPS, with the exception that oil
and grease and TSS are not regulated parameters. In addition, the
Agency is allowing 31 months for compliance with the metals, cyanide,
and total toxic organics standards. However, the Agency believes
that toxic organics should not be uncontrolled for this period
and has. therefore, established an interim TTO limit based on
data prior to precipitation/clarification and reflecting proper
management of toxic organics. The interim TTO limit has been
established with a compliance date of June 30, 1984.
RATIONALE FOR SELECTION OF PRETREATMENT TECHNOLOGY
Toxic metals, and toxic organics may pass through a POTW. or they
may contaminate its sludge, or they may interfere with the
treatment process. These pollutants must therefore be controlled
by pretreatment.
XII-1
-------
PRBTREATMENT STANDARDS
Pretreatment standards for existing sources are the same as BAT
(reference Section X) for existing sources' with the exception of
the interim TTO limit. The PSES interim TTO daily maximum
limitation is 4.57 ing/a and applies to the TTO concentration in
the total plant raw wastewater. Pretreatment standards for new
sources are the same as NSPS (reference Section XI) for new
sources, with the exception of control of oil and grease, TSS,
and pH. Table 12-1 quantifies the PSES requirements and Table
12-2 presents the requirements for PSNS. Although specific
control of TSS is not required, it will be effectively controlled
by the need to control metals.
PRESENT COMPLIANCE WITH PRETREAMENT STANDARDS
I.. .
The percent compliance for EPA sampled pljants with the interim
TTO limitation is 100 percent, for plants which appear to properly
manage toxic organic wastes. Compliance with PSES for metals,
cyanide and TTO (final) is the same as that presented in
Section IX for BPT. Compliance with PSNS is discussed in Section
XI for NSPS. '
BENEFITS OF IMPLEMENTATION
Table 12-3 shows for existing sources the estimated benefit of
reduced metals, cyanide, and total toxic organics discharge in
terms of metric tons of pollutant per day that results from the
implementation of the pretreatment limitations. A reduction of
toxic metals (52549 metric tons/year), total cyanide (7699 metric
tons/year), and total toxic organics (4098 metric tons/year) may
be achieved by pretreatment prior to discharge to the municipal
sewer. Benefits derived from implementing new source performance
standards cannot be predicted. However, the impact on cadmium
effluent concentration reduction is presented in Section 11,
Table 11-2.
xn-2
-------
TABLE 12-1
PSES LIMITATIONS
Pollutant or
Pollutant Parameter
Cadmium
Chromium, total
Copper
Lead
Nickel
Silver
Zinc
Cyanide, total
TTO (interim)
TTO (final)
Daily
Maximum
0.69
2.77
3.38
0.69
3.98
0.43
2.61
1.20
4.57
2.13
Alternative to total cyanide:
Cyanide, amenable to chlorination 0.86
Maximum Monthly
Average
0.26
1.71
2.07
0.43
2.38
0.24
1.48
0.65
0.32
TABLE 12-2
PSNS LIMITATIONS
Pollutant or
Pollutant Parameter
Cadmium
Chromium, total
Copper
Lead
Nickel
Silver
Zinc
Cyanide, total
TTO
Daily
Maximum
0.11
2.77
3.38
0.69
3.98
0.43
2.61
1.20
2.13
Alternative to total cyanide:
Cyanide, amenable to chlorination 0.86
Maximum Monthly
Average
0.07
1.71
2.07
0.43
2.38
0.24
1.48
0.65
0.32
XII-3
-------
TABLE 12-3
PRETREATMENT BENEFIT SUMMARY
Discharge (kkg/yr)
Pollutant Parameter
Raw Loading
Pretreatment
Effluent
Pretreatment
Benefit
Cadmium 223
Chromium, Total 21638
Copper 9952
Lead 261
Nickel 12190
Silver 18
Zinc 9826
6
296
451
30
522
14
240
217
21342
9501
231
1 1668
4
9586
TOXIC METALS TOTALS: 54108
1J559
52549
Cyanide, Total
Total Toxic Organics
7841
4164
142
66
7699
4098
OVERALL TOXIC TOTALS:
66113
1767
64346
XII-4
-------
INNOVATIVE TECHNOLOGY
INTRODUCTION
The Clean Water Act of 1977, Public Law 95-217, provides that di-
rect discharging facilities which make use of innovative tech-
nology that results in an effluent reduction greater than that
required by the limitations may have a date of July 1, 1987 for
compliance with the limitations.
Specifically, this compliance date extension is authorized by
Section 47 of the Act and is reproduced herein for reference:
Compliance
date
extension.
Supra.
INNOVATIVE TECHNOLOGY
Sec. 47. Section 301 of the Federal Water Pollution
Control Act is amended by adding at the end thereof
a new subsection as follows:
"(k) In the case of any facility subject to a
permit under section 402 which proposes to comply
with the requirements of subsection (b) (2) (A) of
this section by replacing existing production capa-
city with an innovative production process which
will result in an effluent reduction significantly
greater than that required by the limitation other-
wise applicable to such facility and moves toward
the national goal of eliminating the discharge of
all pollutants, or with the installation of an in-
novative control technique that has a substantial
likelihood for enabling the facility to comply with
the applicable effluent limitation by achieving a
significantly greater effluent reduction than that
required by the applicable effluent limitation and
moves toward the national goal of eliminating the
discharge of all pollutants, or by achieving the
required reduction with an innovative system that
has the potential for significantly lower costs than
the system which have been determined by the Admin-
istrator to be economically achievable, the Admini-
strator (or the State with an approved program un-
der section 402, in consultation with the Admini-
strator) may establish a date for compliance under
subsection (b) (2) (A) of this section no later than
July 1, 1987, if it is also determined that such
innovative system has the potential for industry
wide application".
This section describes pollution control techniques that have the
capability of achieving the significant effluent reduction neces-
sary to qualify as an innovative technology.
XIII-1
-------
INNOVATIVE TECHNOLOGY CANDIDATES
This section presents information on various innovative technologies
available to the industry for use in wastewater treatment and
control. The innovative technologies described in this section may
not be applicable to all metal finishing facilities as the
appropriateness of these technologies is dependent on a number of
factors, including the design and operating characteristics of a
facility. Currently, the appropriateness of these innovative
technologies should be determined on a plant-by-plant basis.
However, the innovative technologies described in this section have
been reported to be effective for wastewater treatment and control
at plants in the metal finishing industry. These technologies, if
properly applied, can qualify as innovative technologies. Included
among these candidate systems are evaporative systems, ion exchange.
electrolytic recovery systems, electrodialysis. reverse osmosis, and
electrochemical chromium regeneration. A discussion of water
reducing controls is also presented in this section.
I
Descriptions of evaporation, ion exchange, electrolytic recovery.
reverse osmosis, and electrochemical chromium regeneration
technologies are provided in Section VII along with information on
application, performance, and demonstration status in the Metal
Finishing industry.
An index to these technologies is provided in Table XIII-1.
Electrodialysis is described below.
TABLE 13-1
INDEX TO INNOVATIVE TECHNOLOGY CANDIDATES DESCRIBED IN SECTION VII
TECHNOLOGY PAGE
Evaporation VII-76. 100. 124. 153
Ion Exchange VII-80. 102. 114. 124
Reverse Osmosis VI1-178
Electrolytic Recovery VII-102
Electrochemical Chromium Regeneration VI1-123
XIII-2
-------
Electrodialysis
Electrodialysis is a process in which dissolved species are
exchanged between two liquids through selective semiperraeable
membranes. An electromotive force causes concentration of the
species from a waste stream, thereby providing purified water.
Water to be treated by electrodialysis is pumped through a stan-
dard cartridge filter and into the membrane stack. The stack
consists of about fifty cell pairs operated in parallel flow.
Each cell pair consists of an anion-selective membrane, a cation-
selective membrane, and membrane spacers. These membranes and a
membrane from the adjacent cell pair define a diluting compart-
ment and a concentrating compartment.
Water to be treated flows through the diluting compartments. As
it does so, the contained ions (e.g. nickel and sulfate) are
drawn toward the electrodes at either end of the stack. Negative
and positive ions are drawn in opposite directions through the
selective membranes on either side of the diluting compartment
into the adjacent concentrating compartments. Water of hydration
goes with them. The ions continue in each direction across the
concentrating compartments but are trapped there because they are
blocked by membranes having a selectivity opposite to the one
they passed through. The net effect is that the water passing
through the diluting compartments is deionized, while a concen-
trate (the ions and their water of hydration) is formed in the
concentrating compartments (the concentrating compartments have
no inlet, only an outlet).
The end (electrode) compartments are different. They are
continously flushed with a common-ion liquid (e.g. sodium
sulfate for nickel sulfate plating solution) to remove oxygen,
hydrogen, and chlorine formed by electrolysis at the
electrodes. These gases are vented from the electrode wash
solution reservoir.
The overall effect is that the total mineral content of the
treated water is reduced to about 1,000 mg/1. Further reduction
in concentration is not efficient and is not practical because
of excessive electrolysis. Thus, electrodialysis functions more
like ion exchange than like reverse osmosis and evaporation.
That is, ions are removed from wastewater rather than concen-
trated. Nqn-ionic constituents such as organic brighteners
remain in the treated water rather than in the concentrate.
Figure 13-1 shows the application of a simple electrodialysis
cell to separate potassium sulfate solution (KjSO.) into its
components. Practical electrodialysis installations contain
from ten to hundreds of compartments between one pair of
electrodes. The application of an electric charge draws the
cations to the cathode and anions to the anode. Industrial
wastewater containing metallic salts enters the center cell,
XIII-3
-------
(CATHODE) —
I
CATION- ANION-
PERMEABLE PERMEABLE
MEMBRANE MEMBRANE
1
I
OH-
K2S04
f°2
(ANODE)
FIGURE 13-1
SIMPLE ELECTRODIALYSIS CELL
XIII-4
-------
and the charge takes the positive ions to the cathode and
negative ions to the anode. The result is a significant
reduction in salt concentration in the center cell with an
increase in solution concentrations in the adjacent cells.
Thus, the water from the center of each of three adjacent
cells is purified and metal ions are concentrated in the
cathode cell, with sulfates, chlorides, etc., concentrated in
the anode cell. At the outlet end of the cell stack, streams
are drawn off from the individual cells either as the purified
water or as concentrate for recovery or for further treatment.
Figure 13-2 illustrates the operation of a seven chamber
conventional electrodialysis cell. In large electrodialysis
installations, two or more stacks are linked in series. The
dilute effluent from the first stage is passed through an
identical second stage, and so forth, with the effluent from
the final stage reaching the desired concentration.
Application
The functional characteristics just described are the key to
potential application. Electrodialysis treated water is not
pure enough for a final rinse. Adding a reverse osmosis unit
would achieve adequately pure water, with the RO concentrate
returning to the ED feed. The standard setup, however, is
recirculation of a dead rinse (following the plating tank)
through the ED unit and back. This maintains a low concentra-
tion (about 1,000 mg/1 of total mineral content) in the dead
rinse, minimizing the flow needed in the following running rinses.
If desired, these running rinses could be counterflowed through
an RO unit, with the concentrate directed to the ED unit.
Present applications include nickel, gold (cyanide and citrate),
silver, and cadmium plating. Any type of plating solution is
potentially recoverable for direct return to the plating tank.
Electrodialysis has been shown to be an effective method for
concentrating rinse waters to a high percentage of bath strength.
Nickel, copper,'cyanide, chromic acid, iron and zinc can be
removed from process wastes by electrodialysis. The natural
evaporation taking place in a plating bath will often be suffi-
cient to allow electrodialysis to be used to close the loop
without the addition of an evaporator.
At the time of the sampling visit, conventional electrodialysis
was being used by plant ID 20064 as a means of concentrating and
recovering chromic acid etch solution. Electrodialysis can be
combined with an existing treatment system for recovery of metals,
or it can be used with other treatment to effect recirculation of
rinse water. Many possibilities exist for electrodialysis and
with recent developments in membrane materials and cathode design
and increased knowledge of their applications, it may become a
major form of treatment for metals.
XIII-5
-------
PURIFIED
WATER
CONCENTRATE
1 CATHODE
i
£f
y^Prt^
~i t
-------
Performance
Little information is available on performance for treatment of
chromic acid; however, information is available on copper cyanide
performance. Copper cyanide rinse water is treated in an electro-
dialysis unit for return of the concentrated chemicals to the
process bath. The copper cyanide chemicals in the rinse water
can be concentrated to slightly more than 70 percent of the bath
strength. For most copper cyanide plating, this concentration
may be sufficient to permit the direct return of all chemicals to
the processing operation. One manufacturer guarantees 94 percent
recovery of dragged-out plating metals. Figure 13-3 shows an
electrodialysis recovery system.
Demonstration Status
Commercial electrodialysis units are manufactured by at least
two major suppliers to the metal finishing industry. At least
20 units have been installed.
Three metal finishing plants in our data base indicate the use
of electrodialysis. These plant ID'S are: 20064, 20069, and
41003.
Advanced Electrodialysis
This particular electrodialysis system is used to oxidize chro-
mium (in spent chromic acid) from a trivalent form to a hexa-
valent form. Its design uses a circular, permeable anode,
separated from the cathode by perfluorosulfonic membrane. The
anode material is a specially designed lead alloy. The cathode
is made from Hastelloy C tubing, which is a nickel alloy. The
cathode is located in the center of the circular, permeable anode
and has a catholyte (10 percent sulfuric acid) which is circulat-
ing through it and surrounds the cathode. This solution is used
as a transfer solution. Figure 13-4 shows the physical construc-
tion of this circular electrodialysis cell.
The etchant is pumped in at the bottom of the unit through the
anode so that it remains in the chamber between the anode and the
perfluorosulfonic membrane. Chromium in the trivalent form is
contained in the etchant and, when a current is passed through
this etchant solution, electrons are stripped from the trivalent
chromium causing oxidation of the trivalent chromium to hexavalent
chromium. The newly stripped electrons migrate through the
perfluorosulfonic membrane into the catholyte solution. Converted
hexavalent chromium is pumped back into the chromium etch tank
for reuse, while at the same time the catholytic solution is
being recirculated. The reaction which occurs at the anode is as
follows:
Cr+3 + 12 H20 + 3e- = CrO4~2 + 8H3O+1 + 6e-
XIII-7
-------
H
H
H
I
OD
DRAG-OUT
DRAG-OUT
ri
| ^~ DRAG-OUT
PARTS
PLATING TANK
RINSE #1
CONCENTRATE
I
r
J
JL
RINSE #2
j FEED Jl
U r
PARTS
, f •« ;. DEIONIZED WATER
| ELECTRODIALYZER STACK f
L_
LFEED „
- 1
_ J
_
r ~
L. _
_ —
I
—T1-J
FEED
DEIONIZED WATER
FIGURE 13-3
ELECTRODIALYSIS RECOVERY SYSTEM
-------
CATHOLYTIC
X
H
H
H
I
SPENT CHROMIC
ACID
CATHODE-
SPLNT
ACID
EN E RATED
OMIC ACID ^
ANODE -
LFONIC
E
1
.f-
5MIc'r~"
I «
14
r«
— »-U
c
r.
n
n
1.4
;i
n
u
•^
Vrf
rk
(
•— INPUT
^1 CAT
x*1 OU1
U
0
a
§
a
a
a
0
a
n
:ATHOLYTIC—
CATHOLYTE
STORAGE
TOP VIEW
SIDE VIEW
FIGURE 13-4
ELECTRODIALYSIS CELL
-------
This reaction is continually taking place as both the etchant and
the catholyte are circulated through the cell.
Application
Electrodialysis of chromium, oxidizing trivalent chromium to
hexavalent chromium, is not a widely practiced,method of waste
treatment as yet. It is, however, a very efficient method for
waste treatment of chromium, and it is used at one company visited
(ID 20064). This electrodialysis cell closes the loop on chromium
so that there is no need to reduce hexavalent chromium. The only
application, current or predicted, for this electrodialysis cell
system is the oxidation of chromium wastes. .
Performance ;
The electrical efficiency of the unit varies with the concentration
of both hexavalent chromium and trivalent chromium. The electro-
chemical efficiency of the unit is generally between 50 to 90
percent, depending on the concentrations. This corresponds to an
energy consumption of 8 to 16 kwh/kg of chromic acid from reduced
chromium. The metal removed efficiency of the electrodialysis
unit is 90 percent for 8 mg/1 of trivalent chromium and 95 percent
for 12 mg/1.
Water Reducing Controls for Electroplaters
To minimize pollution problems, electroplaters have discovered
that relatively simple strategies can effectively be made
operational. First, water can be used more efficiently. Second,
water can be kept clean to begin with and, therefore, will not be
a problem that requires wastewater treatment.
Efficient water use means getting the most rinsing from each
gallon of water. A single rinse tank is the least efficient
means to obtain adequate rinsing because a much larger volume of
water must be used in comparison to counterflow rinsing.
(Counterflow rinsing is an effective flow reduction technique but
it can also be expensive.) Electroplaters have found that using
rinse water two or three times before it is purified or discarded
not only reduces water consumption, but it can actually improve
rinsing and save process chemicals. Moreover,
-------
Multiple Drag-Out Control: Techniques and Effectiveness
By controlling the amount of plating solution that is dragged from
work pieces upon their removal from the process tank, the amount of
contamination in subsequent rinse tanks can be reduced. A dragout
tank, consisting of nothing more than a still rinse, installed immedi-
ately following the plating process will capture some of the
contamination.
The multiple dragout method uses the same number of rinse tanks
as counterflow rinsing. The difference is that instead of a
single dragout tank and several running rinse tanks, several
dragout tanks and a single running rinse tank are used.
Most of the solution dragged from the plating tank is captured in
the first dragout tank. The multiple drag-out tank protect the
running rinse from intense contamination and often allows the
rinsewater to be discharged with little or no treatment because
it already meets the Federal standards. As a result, the
multiple drag-out method greatly reduces the cost the wastewater
treatment. Likewise, because wastewater treatment is minimized
so is sludge generation and sludge management costs.
Periodically, some of the solution from the first tank must be
drained and replaced by the less contaminated solution from the
second drag-out tank. Fresh water is than used to fill the
second tank. The solution drained from the first drag-out tank
can be (1) recycled to the plating process; (2) processed to
recover the metals; or (3) sent to a waste treatment plant.
Multiple drag-out tanks are a simple and efficient means to
reduce drag-out contamination. Two or more drag-out tanks
operated in series assure almost complete control of drag-out
losses.
Reactive Rinsing: Techniques and Effectiveness
Reactive rinsing means reusing or recycling the rinse water. By
flowing rinse water back through the electroplating process and
taking advantage of the chemical reactivity of contaminated
water, water use can be minimized.
As an example, consider a nickel plating process composed of an
alkaline cleaning tank, an acid dip tank, and a plating tank,
with a rinse tank after each process. In a conventional plating
process, water would be individually fed to each rinse tank.
Using reactive rinsing, water fed to the rinse tank following the
planting tank would supply the rinse tank following the acid dip;
the water from this rinse would supply the tank following the
alkaline cleaner.
Reactive rinsing allows a pH neutralization reaction to occur as
the rinse water from the acid dip is fed back to the rinse water
XIII-11
-------
from the alkaline cleaner. The reaction does not harm the
plating process, and actually improves the rinsing effectiveness
following the cleaner. Cleaner solution is greasy and hard to
rinse; however, with acid rinsewater the .alkaline solution is
neutralized and rinses easily. Drag-out contamination may also
be reduced because rinse water from thetank following the
plating tank (i.e., water containing drag-out) is fed back to the
rinse tank preceding the plating tank. Accordingly, the drag-in
to the nickel tank will contain some nickel solution.
This example describes an in-process, counterflow reactive
rinsing technique, other reactive rinsing opportunities are
possible. Depending upon the particular plating process, it may
be possible to feed rinse water forwards. In some instances, it
is be possible to feed rinse water across processes to obtain the
desired reaction. The possibilities for interprocess reuse at
plating shops are great but have been largely unexplored.
XIII-12
-------
SECTION XIV
ACKNOWLEDGMENTS
Mr. Richard Kinch. of the EPA's Effluent Guidelines Division served
as the Project Officer during the preparation of this document and
limitations. Mr. Jeffery Denit. Director. Effluent Guidelines
Division, and Mr. G. Edward Stigall. Chief. Inorganics Chemicals and
Services Branch, offered guidance and suggestions during this
project. Appreciation is extended to Mr. Devereaux Barnes and Mr.
J. Bill Hanson for their previous work on the Electroplating
Pretreatment Regulations which was useful in developing the Metal
Finishing Category Regulations.
The Environmental Protection Agency was aided in the preparation of
this Development Document by Hamilton Standard. Division of United
Technologies Corporation in the collection of data and in the
preparation of the proposed development document and by Versar Inc.
in the analysis of comments, the re-analysis of data, and the
preparation of the final development document. The engineering
activities and field operations of Hamilton Standard were directed
by Mr. Kenneth Dresser. Mr. Jeffrey Wehner. and Mr. Jack Nash
directed the engineering activities, and field operations were under
the direction of Mr. Richard Kearns. Hamilton Standard's effort was
managed by Mr. Daniel Lizdas. Mr. Walter Drake, and Mr. Robert
Blaser. Versar's efforts were directed by Mr. Larry Davies. Program
Manager, and Ms. Gayle Riley. Task Manager. Technical assistance
was provided by Mr. Bill Moran and Ms. Jean Moore.
Significant contributions were made by Mr. Dwight Hlustick. Mr.
Frank Hund. Mr. David Pepson. Mr. John Newbrough, Mr. James Berlow,
and Mr. Walter Hunt of EPA's Effluent Guidelines Division: by Mr.
James Spatarella and Ms. Alexandra Tarnay of EPA's Monitoring and
Data Support Division; by Ms. Kathleen Ehrensberger and Mr. Bruce
Clemens of EPA's Office of Analysis and Evaluation; by Mr. Michael
Dworkin of EPA's Office of General Counsel; and by Eric Auerbach.
Steven Bauks. David Bowker. Charles Hammond. Lewis Hinman. Steven
Klobukowski. Raymond Levesque. Robert Lewis, Lawrence McNamara. Jeff
Newbrough. Joel Parker. James Pietrzak. Donald Smith, and Peter
Williams of Hamilton Standard. Data and information acquisition.
analysis, and processing were performed by Clark Anderson. Michael
Derewianka. Remy Halm. Robert Patulak. and John Vounatso of Hamilton
Standard. Mr. Richard Kotz. Barnes Johnson, and Henry Kahn of EPA's
Office of Analysis and Evaluation provided analytical guidance and
statistical support.
Acknowledgement and appreciation is also given to Glenda Nesby.
Pearl Smith, and Carol Swann of EPA's word processing staff. Mrs.
Lynne McDonnell. Ms. Lori Kucharzyk. and Ms. Kathy Maceyka of
Hamilton Standard, and Mrs. Nan Dewey of Versar.
Finally, appreciation is also extended to those metal finishing
industry associations and plants that participated in the con-
tributed data for the formulation of this document; the companies
that have already installed pollution control equipment: and the
states and regional offices that have addressed pollution control in
the Metal Finishing Industry.
xiv-l
-------
SECTION XV
REFERENCES
XV-1
-------
OIL, SOLVENT, AND CHEMICAL RECOVERY
"Alcoa Employs Ultrafiltration to Recycle 90,000 GPD", news item,
Ind* Water Eng^, Jan/Feb., 1981. :
Allen, Paul, "Reclaiming Four Plating Solutions", Products Finishing,
Aug., 1979.
"A Low-Cost Answer to Oil Recycling?"
Factory Management, January 1977, pp. 32-33.
Easily, William, "Industrial Waste Water Treatment Facility,
Charleston Plant", General Electric, April 5, 1978.
Bech, E.G., Giannini, A.P., and Ramirez, E.R.,
"Electrocoagulation Clarifies Food Wastewater", Reprinted
from Food Technology, Vol. 28, No. 2, 1974, 'pp. 18-22.
Belinke, Robert J., "Central Filtration for Coolants",
American Machinists, December 1976, pp. 86-88.
Bolster, Maurice, "How to Maintain Emulsion .Coolant Systems",
Modern Machine Shop, March 1977, pp. 112-115.
Bowes, H. David, "In-House Solvent Reclamation Eliminates
Quality Problems at Low Cost", Plastics Design & Processing,
May 1978, pp. 20-32.
Chonisby, J. and Kuhn, D., "Practical Oil Reclamation,
Purification", Hydraulics & Pneumatics, April 1976, pp. 71-73.
Chua, John P., "Coolant Filtration Systems",
Plant Engineering, December 23, 1976, pp. 46-51.
"Coolant Failure and How to Prevent It", Sun Coolant
Control Inc., Southfield, Mich.
"Coolant Tripples Tool Life", Modern Machine Shop,
June 1979, pp. 140-141.
Cutting and Grinding Fluids; Selection and Application,
American Society of Tool and Manufacturing Engineers,
Dearborn, Mich., 1967.
Dinius, B., "How to Choose an In-Plant Oil Reclamation System",
Hydraulics and Pneumatics, July 1978, pp. 62-64.
"Economic Impact of the Proposed Illinois Special Waste Hauling
Regulations (R76-10)", Illinois Institute of Environmental
Quality, Project No. 80.089, IIEQ Document No. 77/26,
October 1977.
XV-2
-------
Electrostatic Separation of Solids from Liquids", Filtration &
Separation, March/April 1977, pp. 140-144.
"EPA/AES Conference . . . The Third Time Around: Recovery",
Plating and Surface Finishing, June, 1980.
Ford, Davis L., and Elton, Richard L, , "Removal of Oil and Grease
from Industrial Wastewaters", Chemical Engineering/Deskbook Issue,
October 17, 1977, pp. 49-56.
Gransky, Michael, "The Case for Electrodialysis", Products
Finishing, April 1980.
Hura, LCdr Myron, USN and Mittleman, John,
"High Capacity Oil-Water Separator", Naval Engineers Journal,
December 1977, pp. 55-62.
"Ion Transfer Recovers Chrome", Industrial Finishing, April, 1980.
"IX for Nickel Recovery at Oldsmobile", Products Finishing, May, 1979,
Johnson, Ross E. Jr., Wastewater Treatment and Oil Reclamation
atGeneral Motors, St. Catherines, pp. 345-357.
Kellogg, Jack, "Cutting Oil and Coolant Reclamation Pays Its
Way at Twin Disc".
Kelley, Ralph, "The Use of Cutting Fluids and Their Effect on
Cutting Tools and Grinding Wheels in Solving Production Problems",
Cincinnati Milacron/Products Division.
Kostura, John D., "Recovery and Treatment of Plating and Anodizing
Wastes", Plating and Surface Finishing, Aug., 1980.
Koury, Anthony J., and Gabel, M.K., and Wijenayake, Anton P.,
"Effect of Solid Film Lubricants on Tool Life", Journal of the
American Society of Lubrication Engineers, June 1979, Volume 35,6.,
pp. 315-316, 329-338.
Kremer, Lawrence N. , "Prepaint Final Rinses: Chrome or Chrome-
Free?", Products Finishing, Nov., 1980.
Lewis, Tom A., " Elow to Electrolytically Recovery Metals from
Finishing Operations", Industrial Finishing, April, 1980.
Luthy, Richard G., and Sellech, Robert E., and Galloway, Terry R.,
"Removal of Emulsified Oil with Organic Coagulants 'and Dissolved
Air Flotation", Journal WPCF, February 1978, pp. 331-346.
XV-3
-------
Lutz-Nagey, Robert C., "Detroit Experimenters Reveal New Ways
to Save Cutting Oil", Production Engineering, June 1977, pp. 54-55,
"Making Recycling Work for You Through Proper Process Selection",
ibid, p. 10.
McNutt, J.E. and Swalheim. D.A., "Recovery and Re-use of Chemicals
in Plating Effluents", AES Illustrated Lecture Series,
American Electroplaters Society, Inc., Winter Park, FL, 1975.
McNutt, James. E., "Electroplating Waste Control", Plating and
Surface Finishing, July, 1980.
Miranda, Julio G., "Designing Parallel-Plates Separators",
Chemical Engineering, January 31, 1977. '
"Model Plant for Plastics Painting-Decorating", _Ind us trial
Finishing, Feb., 1980.
"Oil Audit and Reuse Manual for the Industrial Plant", Illinois
Institute of Natural Resources, Project No.'80.085, Document
No. 78/35, November 1978. \
"Oil/Water Splitter Snags Emulsified Oil", Chemical Engineering.
July 18, 1977, p. 77. ~
Parker, Konrad, "Renewal of Spent Electroless Nickel Plating
Baths", Plating and Surface Finishing, March, 1980.
"Plastics Plated at Norris Meet Rigid Specifications", Industrial
Finishing, March, 1981.
"Plating on Plastics Etchants Regenerated", Products Finishing,
May, 1979.
Quanstrom, Richard L., "Central Coolant Systems-Closing the Loop
on Metalworking Fluids", Lubrication Engineering, January 1977,
Volume 33,1, pp. 14-19.
Rasquin, Edgar A. and Lynn, Scott and Hanson, Donald N.,
"Vacuum Steam Stripping of Volatile, Sparingly Soluble Organic
Compounds from Water Streams", Ind. Eng. Chemical Fundam.,
Vol. 17, No. 3, 1978, pp. 170-174.
"Recovery Pays at Sommer Metalcraft", Industrial Finishing, June,
1980. ;
"Recycling Etchant for Printed Circuits", Metal Finishing,
Metals and Plastics Publications Inc., Hackensack,NJ,
March 1972, pp. 42-43.
XV-4
-------
Reininga, O.G. and Wagner, R.H. and Bonewitz,
"Thermopure for Processing Water-Oil Emulsions",
Wire Journal, October 1976, pp. 48-53.
Roberts, David A., "Romicon Ultrafiltration for Waste Oil Re-
clamation", Paper presented to the Water Pollution Control Asso-
ciation of Pennsylvania, June 15, 1977.
"Selection of Lubricants for Drawing and Cleaning", Daniel Brewer,
Ceramic Industry Magazine, June 1978, pp. 34-35.
Seng, W.C. and Kreutzer, G.M., "Resume of Total Operation of
Waste Treatment Facility for Animal and Vegetable Oil Refinery",
Reprinted from the Journal of the American Oil Chemists' Society,
Volume 52, No. 1, 1975, pp. 9A-13A.
Shah, B. and Langdon, W., and Wasan, D., "Regeneration of Fibrous
Bed Coalescers for Oil-Water Separation", Environmental Science
a nd Tec h no logy, Volume 11, No. 2, February 1977, pp. 16~7-170.
"Simple Dragout Recovery Methods", Products Finishing, Oct., 1979.
Sutcliffe, T. and Barber, S.J., "How to Select a Water-Base
Coolant", American Machinist, April 1977.
"System Strips Solvents, Separates Solids Simultaneously",
Chemical Engineering, November 22, 1976, pp. 93-94.
Taylor, J.W., "Evaluation of Filter/Separators and Centrifuges
for Effects on Properties of Steam Turbine Lubricating Oils",
Journal of Testing and Evaluation, Volume 5, No. 5, September 1977,
pp. 401-405.
Teale, James M., "Fast Payout from In-Plant Recovery of Spent
Solvents", Chemical Engineering, January 31, 1977, pp. 98-100.
"The First Step-Reducing Waste Oil Generation", ibid, p. 16.
"Used Oil Recycling in Illinois", Data Book, Illinois Institute
of Natural Resources, Project No. 80.085, Document No. 78/34,
October, 1978.
Vucich, M.G., "Emulsion Control and Oil Recovery on the Lubricating
System of Double-Reduction Mills", Iron and Steel Engineer,
December 1976, pp. 29-38.
Wahl, James R. , and others, "Ultrafiltration for Today's Oily
Wastewaters: A Survey of Current Ultrafiltration Systems", Pro-
ceedings of the 34th Industrial Waste Conference, Purdue University,
May,1979, Ann Arbor Science.
XV-5
-------
"Waste Oil Reclamation", The Works Managers Guide to Working
Fluid Economy, Alfa-Laval NO.I«4u4y4 K^.|
"Waste Oil Recycling - Coming Up a Winner", Fluid and Lubricant
Ideast Volume 2, Issue 3, Summer 1979, p. 8.
Young, James C., "Removal of Grease and Oil by Biological Treatment
Processes", Jl.WPCF, Vol. 51, no. 8, Aug.,il979.
PLATING AND COATING
Adams, F., "Getting the Most Out of Vacuum I Metalizing",
Products Finishing, Gardner Publications, Inc., Cincinnati,
Ohio, November, 1977, pp. 43-51. :
"Alkaline Zinc Bath Solves Low-CD Problems", Prod ucts Finish ing,
Aug., 1980.
Allied Chemical Company and Aluminum Company of America,
"Chromic Acid Anodizing of Aluminum", AES Illustrated
Lecture Series, American Electroplaters Society, Inc.,
Winter Park, FL, 1973. j
Atiroion, Leo, "A program of Conservation, Pollution Abatement",
Plating and Surface Finishing, March, 1980,1
Baker, R. G. et al, "Gold Electroplating Part 2", AES
Illustrated Lecture Series, American Electroplaters Society,
Inc., Winter Park, FL, 1978. :
Bellis, H.E. and Pearlstein, F., "Electroless Plating of Metals",
AES Illustrated Lecture Series, American Electroplaters Society
Inc., Winter Park, FL, 1972.
Blount, Ezra A., "How Guide Recovers Nickel and Chromium",
Products Finishing, Dec., 1980.
Breslou, Barry R., and others, "Hollow Fiber Ultrafiltration
Technology", Ind. Water Eng., Jan./Feb., 1980.
"Cheminator", Chemical Eng ineer ing, McGraw Hill, New York, NY,
September,19 75, p. 26.
"Current Events and Cadmium Plating", Plating and SurfaceFinishing,
July, 1980.
"Developments to Watch", Product Engineering, Morgan-Grampian,
New York, NY, October 1976, p. 5.
XV-6
-------
DiBari, G.A., "Practical Nickel Plating", AES Illustrated
Lecture Series, American Electroplaters Society, Inc., Winter
Park, FL, 1977.
Duva, R., "Gold Electroplating Part 1", AES Illustrated
Lecture Series, American Electroplaters Society, Inc., Winter
Park, FL, 1977.
Electroplating Engineering Handbook, Third Edition, edited
by A.Kenneth Graham, Van Nostrand Reinhold Company, New York,
NY, 1971.
Electroplating - Fundamentals of Surface Finishing, Frederick
ATLowenheim, McGraw-Hill,Inc., New York, NY, 1978.
General Motors Research Laboratories, "Factors Influencing
Plate Distribution", AES Illustrated Lecture Series, American
Electroplaters Society, Inc., Winter Park, FL, 1975.
Halva, C.J. and Rothschild, B.F., "Plating and Finishing of
Printed Wiring/Circuit Boards", AES Illustrated Lecture Series,
American Electroplaters Society, Inc., Winter Park, FL, 1976.
Harrison, Albert, Coil Coater Cuts Effluent Treatment Costs",
Products Finishing, November, 1980.
Hubbell, F.N., "Chemically Deposited Composites - A new Gener-
ation of Electroless Coatings", Plating and Surface Finishing,
American Electroplaters Society, E. Orange, NJ, Vol.~65, Dec.
1978, p. 48.
"Ion Transfer Method Developed for Metal Plating", Industrial
Finishing, Hitchcock Publishing Co., Wheaton, Ohio, April 1979,
p. 95.
Logozzo, Arthur W., "Hard Chromium Plating", AES Illustrated
Lecture Series, American Electroplaters Society, Inc., Winter
Park, FL, 1973.
MacDermid, Inc., "Chromate Conversion Coatings" AES Illus-
trated Lecture Series, American Electroplaters Society, Inc.,
Winter Park, FL, 1970.
Mazzeo, D.A., "Energy Conservation In Plating and Surface
Finishing", Plating and Surface Finishing, American Electroplaters
Society, Inc., Winter Park, FL, July, 1979, pp. 10-12.
M&T Chemical Inc., "Decorative Chromium Plating", AES Illus-
trated Lecture Series, American Electroplaters Society, Inc.,
Winter Park, FL, 1972.
XV-7
-------
Mohler, J.B., "The Art and Science of Rinsing", AES Illustrated
Lecture Series, American Electroplaters Society, Inc., Winter
Park, PL, 1973.
Montgomery, D.C., "The Coloration of Anodic Coatings for
Architectural Applications by Using Organic Dyes", Plating
and Surface Finishing, American Electroplaters Society, IT
Orange, NJ7 Vol. 65, Dec. 78, p. 48.
Ostraw, R. and Kessler, R.B., "A Technical and Economic Com-
parison of Cyanide and Cyanide-Free Zinc Plating", Plating,
American Electroplaters Society, Hackensack, NJ, April 1970.
Pearlstein, P., "Selection and Application of Inorganic Fini-
shes - Part I11, plating and Surface Finishing, American Elec-
troplaters Society, E. Orange,"NJ, Vol. 65, Dec. 1978., p. 32.
Pearlstein, P. et al, "Testing and Evaluation of Deposits",
AES Illutrated Lecture Series, American Electroplaters Society
Inc., Winter Park, PL, 1974.
"Plater Turns Fire Woes into Golden Opportunity", Industrial
Finishing, Nov., 1980.
"Plating Aluminum Busbar", Industri a 1 Finishing, Feb., 1979.
Rajagopal, I., and Rajam, K.S., "A New Addition Agent for
Lead Plating", Metal Finishing, Metals and Plastics Publi-
cation Inc., Hackensack, NJ,December, 1978.
Riley, Thomas C., "Benefits are Bountiful with Elco's Bright
Zinc Process", Ind us tria1 Finish ing, Jan. 1981.
Roberts, Vicki, "A Low-Cyanide Zinc for Champion Spark Plugs",
Products Fin ish ing, Sept., 1979. i
Rose, Betty A., "Bulk Platec Saves with Evaporative Recovery",
Industrial Finishing, Jan. 1979.
Rose, Betty A., "Design for Recovery", Industrial Finishing,
May, 1979.
"Slide into Compliance", Industrial Fir^ishi_ng_, Dec., 1979.
"Tri-Chrome Takes on New Importance to Platers", Industrial
Finishing, Nov., 1980.
XV-8
-------
SURFACE PREPARATION
Axelson, William, "Specialized Cleaning Equipment Supports
Efficient Maintenance", Pit & Quauy, October 1976, pp. 95-98.
Bauks, S.V., and Dresser, K. J. , Cleaning Alternatives to Solvent;
Degreasing, EPA, December 7, 1978.
Jackson, Lloyd, C., "How to Select a Substrate Cleaning Solvent",
Ad he si ves Age, April 1977, p.p. 23-31.
Jackson, Lloyd C., "Removal of Silicone Grease and Oil
Contaminants", Adhesiyes Age, April 1977, pp. 29-32.
Jackson, Lloyd C. , "Solvent Cleaning Process Efficiency",
Adhesives Age, July 1976, pp. 31-34.
Maloney, J.E., "Low Temperature Cleaning", Me ta 1 Finish_ing,
June 1976, pp. 33-35.
Metal Cleaning Fundamentals, Materials and Methods, Oakite
Products, Tnc r,™ F 10646R13-379"!
Metals Hand book, American Society for Metals, 8th Edition, Volume
T~i ^Heat Treating, Cleaning, and Finishing", 1964, pp. 307-314.
Mohler, J.B., "Guidelines for Cleaning Metal Parts", Plant
Engineering, October 2, 1975, pp. 93-95.
Obrzut, John J., "Metal Cleaning Bends with Social Pressures",
Iron Age, February 17, 1974, pp. 41-44.
Taller, R.A. and Koleske, J.V., "Energy Conservation in Metal
Pretreatment and Coating Operations", Metal Finishing,
August 1977, pp. 18-19.
Tonis, Paul G., "Try Steam Cleaning/Phosphatizlng", Products
Finishing, January 1979, pp. 56-57.
SURFACE PREPARATION - ACID CLEANING
Frey, S.S. and Swalheirn, D.A., "Cleaning and Pickling for
Electroplating", AES Illustrated Decture Series, American
Electroplaters Society, Inc., Winter Park, FL, 1970.
MetaIs Handbook, American Society for Metals, 8th edition.
Volume 2, "Heat Treating, Cleaning and Finishing", 1964.
Rodzewich, Edward A., "Theory and Practice of Phosphating",
AES Illustrated Lecture Series, American Electroplaters
Society, Inc., Winter Park, FL, 1974.
Roebuck, A.H., "Safe Chemical Cleaning - The Organic Way",
Chemical Engineering, July 31, 1978, pp. 107-110.
XV-9
-------
SURFACE PREPARATION - ALKALINE CLEANING
Erichson, Paul R. and Throop, William M, , "Alkaline Treatment
System Reduces Pollution Problems", Industrial Wastes, March/
April 1977.
Erichson, Paul R. and Throop, William M., "Improved Washing of
Machined Parts", Production Engineering, March 1977.
Graham, A. Kenneth, Electroplating Engineering Handbook, 1971,
pp. 152-176.
Metals Handbook, American Society for Metals, 8th Edition,
Volume ~2," "Heat Treating, Cleaning and Finishing", 1964,
pp. 317-325. !
SURFACE PREPARATION - EMULSION CLEANING ',
Connolly, James T., "Metal Cleaning with Emulsions - An Update",
Lubrication Engineering, December 1976, pp. 651-654.
Glover, Harry C., "Are Emulsified Solvents Safer Cleaners?",
Production Engineering, July 1978, pp. 41-43.
Me ta1 Ha ndbook, American Society for Metals, 8th Edition,
Volume 2,"Heat Treating, Cleaning and Finishing", 1964,
pp. 326-330.
SURFACE PREPARATION - VAPOR DECREASING
Bauks, S.V. and Dresser, K.J., Solvent DecreasingUnit Operation
Report, EPA, September 17, 1979. i
MetalsHandbook, American Society for Metals, 8th Edition,
Volume2~7"Heat Treating, Cleaning and Finishing", 1964,
pp. 334-340.
"Organic Solvent Cleaning-Background Information for Proposed
Standards", US EPA, EPA-450/2-78-045, May :1979.
Suprenant, K., "Vapor Degreasing or Alkaline Cleaning?",
Products Finishing, March 1979, pp. 67-71.
XV-10
-------
TREATMENT
Barrett, F., "The Electroflotation of Organic Wastes",
Chemistry and Industry, October 16, 1976, pp. 880-882.
Bell, John P., "How to Remove Metals from Plating Rinse Waters",
Products Finishing, Aug., 1979.
Chin, D.T., and Echert, B., "Destruction of Cyanide Wastes
with a Packed-Bed Electrode", Platingand Surface Finishing,
October 1976, pp. 38-41.
DeLatour, Christopher, "Magnetic Separation in Water Pollution
Control", IEEE Transactions on Magnetics, Volume Mag-9, No. 3,
September 1973, p. 314.
"Development Document for Proposed Exisiting Source Pretreat-
ment Standards for the Electroplating Point Source Category",
EPA 440/1-78/085, United States Environmental Protection
Agency, Washington, DC, 1978,
"Economic Analysis of Proposed Pretreatment Standards for
Existing Sources of the Electroplating Point Source Category",
EPA 230/1/78-001, United States Environmental Protection
Agency, Washington, DC, 1977.
"Electrotechnology Volume 1, Wastewater Treatment and Separation
Methods", Cheremisinof£, Paul N., King, John A., Oullette, Robert P.,
Ann Arbor Science Publishers, Inc., Ann Arbor, MI, 1978.
"Emerging Technologies for Treatment of Electroplating
Wastewaters", for presentation by Stinson, M.K., at AICHE
71st Annual Netting, Session 69, Miami Beach, Florida,
November 15, 1978.
Flynn, B.L. Jr., "Wet Air Oxidation of Waste Streams", CEP,
April 1979, pp. 66-69.
Grutsch, James F., "Wastewater Treatment: The Electrical
Connection", Environmental Science and Technology, Volume 12,
No. 9, Sept. 1978, pp."1022-1027.
Grutsch, James F., and Mallatt, R.C., "Optimizing Granular
Media Filtration", GEP, April 1977, pp. 57-66.
"Handbook of Environmental Data on Organic Chemicals", Karel
Verschueren, Van Nostrand Reinhold Company, New York, NY 1977.
Henry, Joseph D, Jr., Lowler, Lee P., and Kuo, C.H. Alex,
"A Solid/Liquid Separation Process Based on Cross Flow and
Electrofiltration", AIChE Journal, Volume 23, No. 6, November
1977, pp. 851-859.
XV-11
-------
Hochenberry, H.R. and Lieser, J.E., Pr a c tic a 1 App lication
of Membrane Techniques of Waste Oil Treatme'nt, presented
at the31st Annual Meetingin PhiladeTphia, Pennsylvania,
May 10-13, 1976, American Society of Lubrication Engineers,
Reprint Number 76-AM-28-2. !
Humenich, Michael J. and Davis, Barry J., "High Rate
Filtration of Refinery Oily Wastewater Emulsions",
Journal WPCF, Agusut 1978, pp. 1953-1964. '
11 In Process Pollution Abatement - Upgrading Metal Finishing
Facilities to Reduce Pollution", EPA Technology Transfer Semi-
mar Publication, Environmental Protection Agency, July 1973.
(*T» . • ' a . :. L .i to «.J H. . .> ."*
Kaiser, Klaus L.E. and Lawrence, John, Polyelectrolytes;
Potential Chloroform Precursors, Environment Canada, Canada
Centre for Inland Waters, BurTington, Ontario, January 25, 1977.
Kitagewa, T. and Nishikawa, Y. and Frankenfeld, J.W. and LlW
IMr«W "Wastewater Treatment by Liquid Membrane Process",
Environmental Science and Technology, Volume 11, No. 6,
June 1977, pp. 602-605.;
Kohn, Philip M., "Photo-Processing Facility Acheives Zero Discharge",
Chem. Eng., Dec. 4, 1978.
Kolm, Henry H., "The Large-Scale Manipulatibn of Small Particles",
IEEE Transactions on Magnetics, Vol. Mag-lli, No. 5, Sept. 1975,
pp. 1567-1569. I
Lancy, L. E., "Metal Finishing Waste Treatment Aims Accomplished
by Process Changes", Chemical Engineering Progress Symposium
Series, Vol. 67, 1971, pp. 439-441.
Lancy, L.E. and Steward, F.A., "Disposal of Metal Finishing
Sludges - The Segregated Landfill Concept",. Plating and Surface
Finishing, American Electroplaters Society, E, Orange, NJ,
Vol. 65, Dec. 1978. p. 14.
i
Lawes, B.C. and Stevens, W.F., "Treatment of Cyanide and
Chromate Rinses", AES Illustrated Lecture Series, American
Electroplaters Society, Inc., Winter Park, PL, 1972.
Lee, Carl, "Huge New Plating Facility Builtj for the Future",
Products Finishing, Nov., 1979.
Lorenzo, George A., and Hendrickson, Thomas N., "Ozone in the
Photoprocessing Industry", Ozone: Science and Engineering, Pergamon
Press, 1979.
i
i
Lowder, L.R., "Modifications Improve Treatment of Plating Room
Wastes", Water and Sewage Works, Plenum Publishing Ocj? , New
York, NY, December, I968. p. 581.
XV-12
-------
Nakayaraa, S,, and others, "Improved Ozonation in Aqueous Systems",
Ozone; Science and Engineering, Pergamon Press, 1979.
"No More Woes for Custom Plater", Indus tria1 Finishing, Jan., 1979.
Novak, Fred, "Destruction of Cyanide Wastewater by Ozonation",
Paper presented at the International Ozone Assn. Conf., Nov., 1979.
Oberteuffer, John A., "High Gradient Magnetic Separation",
IEEE Transaction on Magnetics, Volume Mag-9, No. 3,
September 1973, pp. 303-306.
Okamato, S., "Iron Hydroxide as Magnetic Scavengers",
Institute of Physical and Chemical Research, Waho-shi,
Saitama-hen, 351 Japan.
Oulman, Charles S. and Baumann, Robert E., "Polyelectcolyte
Coatings for Filter Media", Industrial Water Engineering,
May 1971, pp. 22-25.
Pietrzak, J., Unit Operation Discharge Summaryforthe Mechanical
Products Category,. EPA, September 7, 1979.
Pinto, Steven, D., Ultrafiltration for Dewatering of Waste
Emulsified Oils, Lubrication Challenges in Metalworking and
Processing Proceedings, First International Conference, IIT
Research Institute, Chicago, Illinois 60616, USA, June 7-9, 1978.
"Physiochemical Processes for Water Quality Control", Wiley-
Interscience Series, Walter, J. Weber, Jr., John Wiley and Sons
Inc., New York, NY 1972.
"Pollution Control 1978", Products Finishing, Gardner Publica-
tions, Inc., Cincinnati, Ohio,August,1978, pp. 39-41.
Read, H.J., "Principles of Corrosion", AES Illustrated Lecture
Series, American Electroplaters Society, Inc., Winter Park,
PL, 1971.
Rice, Rip G., "Ozone for Industrial Water & Wastewater Treatment",
Paper presented at WWEMA Industrial Pollution Control Conf.,
June, 1980.
Robison, Thomas G., "Chromecraft's New High-Production Plating Line",
Products Finishing, Feb., 1981.
Robinson, G.T., "Powder Coating Replaces Zinc Plating for
Pulleys", Products Finishing, Gardner Publications inc.,
Cincinnati, OH, Feb., 1974, pp. 79-81.
Rose, Betty A., "Managing Water at Helicopter Plant", Industrial
Finishing.
XV-13
-------
Sachs, T.R./ "Diversified Finisher Handles Complex Waste
Treatment Problem", Plating and SurfaceFinishing, American
Electroplaters Society, E. Orange, NJ, Vol. 65, Dec. 1978, p. 36.
"Semiconductor Technique Now to Plate Auto Parts", Machine
Design, Penton Publishing, Cleveland, OH, p. 18.
Shambaugh, Robert T. and Melhyh, Peter B., "Removal of Heavy
Metals via Ozonation", Journal WPCF, Jan. 1978, pp. 113-121.
"Simple Treatment for Spent Electroless Nickel", Products
Finishing, Feb., 1981. i
i ... , ,
Spooner, R.C., "Sulfuric Acid Anodizing of1 Aluminum and Its
Alloys", AES Illustrated Lecture Series, American Electro-
platers Society, Inc., Winter Park, FL, 1969.
Staebler, C.J. and Simpers, B.F., "Corrosion Resistant Coatings
with Low Water Pollution Potential", presented at the EPA/AES
First Annual Conference on Advanced Pollution Control for the
Metal Finishing Industry, Lake Buena Vista, FL, January 17-19, 1978,
Sundaram, T.R. and Santo, J.E., "Removal of Suspended and
Colloidal Solids from Waste Streams by the Use of Cross-Flow
Microfiltration", American Society ofMechanical Engineers,
77-ENAs-Sl.
Swalheim, D.A. et al, "Cyanide Copper Plating", AES Illustrated
Lecture Series, American Electroplaters Society, Inc., Winter
Park, FL, 1969. !
Swalheim, D.A. et al, "Zinc and Cadmium Plating", AES Illustrated
Lecture Series, American Electroplaters Society, Inc., Winter
Park, FL. '
Tang, T.L. Don, "Application of Membrane Technology to Power
Generation Waters", Industrial Water Engineering, Jan./Feb., 1981.
"The Electrochemical Removal of Trace Metals for Metal Wastes
with Simultaneous Cyanide Destruction", for presentation by
H.S.A. Reactors Limited at the First annual EPA/AES Conference
on Advanced Pollution Control for the Metal Finishing Industry,
Dutch Inn, Lake Buena Vista, FL, Jan. 18, 1978.
"Treating Electroless Plating Effluent", Prod uc ts Fin i s h ing,
Aug., 1980.
Tremmel, Robert A., "Decorative Nickel-Iron Coatings11, Plating
and Surface Finishing, Jan., 1981. i
Udylite Corporation, "Bright Acid Sulfate Copper Plating",
AES Illustrated Lecture Society, American Electroplaters Society,
Inc., Winter Park, FL, 1970.
XV-14
-------
Ukawa, Hiroshi, Koboyashi, Kaseimaza, and Iwata, Minoru "Analysis
of Batch Electrokinetic Filtration", Journal of Chemical Engineering
of Japan, Volume 9, No. 5, 1976, pp. 396-401.
Wahl, James R., Hayes, Thomas C., Kleper, Myles H., and Pinto,
Steven D. , Ultrafiltration for Today's Oily Wastewaters;
A Survey of Current Ultrafiltratiqn Systems, presented at the
34th Annual Purdue Industrial Waste Conference, May 8-10, 1979.
Wing, R.E., and others, "Treatment of Complexed Copper Rinsewaters
with Insoluble Starch Xanthate", Plating and Surface Finishing,
Dec., 1978.
"Wooing Detroit with Cheaper Plated Plastic", Busin es s Week,
McGraw-Hill Inc., New York City, NY, May 9, 1977, pp. 44c-44d.
Yost, Kenneth J., and Scarfi, Anthony, "Factors Affecting Copper
Solubility in Electroplating Waste", Journal WPCF, Vol. 51, No. 7,
July, 1979.
Zabban, Walter, and Heluick, Robert, "Cyanide Waste Treatment
Technology - The Old, the New, and the Practical", Plating and
Surface Finishing, Aug., 1980.
XV-15
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SECTION XVI
GLOSSARY
Abrasive Belt Grinding - Roughing and/or finishing a workpiece by
means of a power-driven belt coated with an abrasive, usually
in particle form, which removes material by scratching the
surface.
Abrasive Belt Polishing - Finishing a workpiece with a power-driven
abrasive-coated belt in order to develop a very good finish.
Abrasive Blasting - (Surface treatment and cleaning.) Using dry or
wet abrasive particles under air pressure for short durations
of time to clean a metal surface.
Abrasive Cutoff - Severing a workpiece by means of a thin abrasive
wheel.
Abrasive Jet Machining - Removal of material from a workpiece by a
high-speed stream of abrasive particles carried by gas from a
nozzle.
Abrasive Machining - Used to accomplish heavy stock removal at high
rates by use of a free-cutting grinding wheel.
Acceleration - See Activation.
Acceptance Testing - A test, or series of tests, and inspections
that confirms product functioning in accordance with specified
requirements.
Acetic Acid - (Ethanoic acid, vinegar acid, methanecarboxylic acid)
CH3_COOH. Glacial acetic acid is the pure compound (99.8% min.),
as distinguished from the usual water solutions known as acetic
acid. Vinegar is a dilute acetic acid.
Acid Cleaning - Using any acid for the purpose of cleaning any mater-
ial. Some methods of acid cleaning are pickling and oxidizing.
Acid Dip - An acidic solution for activating the workpiece surface
prior to electroplating in an acidic solution, especially after
the workpiece has been processed in an alkaline solution.
Acidity - The quantitative capacity of aqueous solutions to react
with hydroxyl ions. It is measured by titration with a standard
solution of a base to a specified end point. Usually expressed
as milligrams per liter of calcium carbonate.
XVI-1
-------
Act - Federal Water Pollution Control Act Amendments of 1972.
Activitated Sludge Process - Removes organic matter from sewage by
saturating it with air and biological active sludge.
Activation - The process of treating a substance by heat, radiation
or the presence of another substance so that the first mentioned
substance will undergo chemical or physical change more rapidly
or completely. '.
i • • ••• .....
Additive Circuitry - 1. Full - Circuitry produced by the buildup of
an electroless copper pattern upon an unclad board. 2. Semi -
Circuitry produced by the selective "quick" etch of an electro-
less layer; this copper layer was previously deposited on an
unclad board.
Administrator - Means the Administrator of the United States Environ-
mental Protection Agency.
s
Adsorption - The adhesion of an extremely thin layer of molecules
(as of gas, solids or liquids) to the surface of solid or
liquids with which they are in contact.
Aerobic - Living, active, or occurring only in the presence of oxygen.
Aerobic Biological Oxidation - Any waste treatment process utilizing
organisms in the presence of air or oxygen to reduce the pol-
lution load or oxygen demand of organic substance in water.
Aerobic Digestion - (Sludge Processing) The biochemical decomposition
of organic matter, by organisms living or active only in the
presence of oxygen, which results in thetformation of mineral and
simpler organic compounds. ;
Aging - The change in properties (eg. increase in tensile strength and
hardness) that occurs in certain metals at atmospheric temperature
after heat treatment. :
I
Agitation of Parts - The irregular movement given to parts when they
have been submerged in a plating or rinse solution.
Air Agitation - The agitation of a liquid medium through the use of
air pressure injected into the liquid.
Air Flotation - See Flotation
Air Pollution - The presence in the outdoor (ambient) atmosphere of one
air pollutants or any combination thereof in such quantities and
of such characteristics and duration as to be, or be likely to be,
injurious to public welfare, to the health of human, plant or
animal life, or to property, or as unreasonably to interfere with
the enjoyment of life and property.
XVI-2
-------
Air-Liquid Interface - The boundary layer between the air and the
liquid in which mass transfer is diffusion controlled.
Aldehydes Group - A group of various highly reactive compounds
typified by actaldehyde and characterized by the group CHO,
Algicides - Chemicals for preventing the growth of algae.
Alkaline jC_l_eaning - A process for cleaning basis material where
mineral and animal fats and oils must be removed from the
surface. Solutions at high temperatures containing casutic
soda, soda ash, alkaline silicates and alkaline phosphates
are commonly used,
Alkalinity - The capacity of water to neutralize acids, a property
imparted by the water's content of carbonates, bicarbonates,
hydroxides, and occasionally borates, silicates, and phosphates.
Alloy Steels - Steels with carbon content between 0.1% to 1.1% and
containing elements such as nickel, chromium, molybdenum and
vanadium. (The total of all such alloying elements in these type
steels is usually less than 5%.)
Aluminizing - Forming an aluminum or aluminum alloy coating on a metal
by hot dipping, hot spraying or diffusion.
Amines - A class of organic compounds of nitrogen that may be considered
as derived from ammonia (NIO) by replacing one or more of the
hydrogen atoms by organic radicals, such as CH_3 or C6HJ5, as in
methylamine and aniline. The former is a gas at ordinary tempera-
ture and pressure, but other amines are liquids or solids. All
amines are basic in nature and usually combine readily with hydro-
chloric or other strong acids to form salts.
Anaerobic Biological Treatment - Any waste treatment process utilizing
anaerobic or facultative organisms in the absence of air to
reduce the organic matter in water.
Anaerobic Digestion - The process of allowing sludges to decompose
naturally in heated tanks without a supply of oxygen.
Anaerobic Waste Treatment - (Sludge Processing) Waste stabilization
brought about through the action of microorganisms in the absence
of air or elemental oxygen.
Anhydrous - Containing no water.
Anions - The negatively charged ions in solution, e.g., hydroxyl.
Annealing - A process for preventing brittleness in a metal part.
The process consists of raising the temperature of the metal
to a pre-established level and slowly cooling the steel at a
prescribed rate.
XVI-3
-------
Annual Capital Recovery Cost - Allocates the initial investment and
the interest to the total operating cost. The capital recovery
cost is equal to the initial investment multiplied by the capital
recovery factor.
Anode - The positively charged electrode in an electrochemical process.
i
Anodizing - The production of a protective oxide film on aluminum or
other light metal by passing a high voltage 'electric current
through a bath in which the metal is suspended.
Aquifer - Water bearing stratum.
Ash - The solid residue left after complete combustion.
Assembly - The fitting together of manufactured parts into a complete
machine, structure, or unit of a machine. j
Atmospheric Evaporation - Evaporation at ambient pressure utilizing
a tower filled with packing material. Air is drawn in from
the bottom of the tower and evaporates feed material entering
from the top. There is no recovery of the vapors.
!
Atomic Absorption - Quantitative chemical instrumentation used for the
analysis of elemental constituents.
i
Automatic Plating - 1. Full - Plating in which the workpieces are
automatically conveyed through successive cleaning and plating
tanks. 2. Semi - Plating in which the workpieces are conveyed
automatically through only one plating tank.
Austempering - Heat treating process to obtain greater toughness and
ducticity in certain high-carbon steels. The process is charac-
terized by interrupted quenching and results in the formation of
bainite grain structure.
i
Austenitizing - Heating a steel to a temperature at which the structure
transforms to a solution of one or more elements in face-centered
cubic iron. Usually performed as the essential preliminary of
heat treatment/ in order to get the various alloying elements
into solid solution.
Barrel Finishing - The process of polishing a workpiece using a rotat-
ing or vibrating container and abrasive grains or other polishing
materials to achieve the desired surface appearance.
Barrel Plating - Electroplating of workpieces in barrels (bulk).
Basis Metal or Material - That substance of which the workpieces are
made and that receives the electroplate and 'the treatments in
preparation for plating.
XVI-4
-------
Batch Treatment - A waste treatment method where wastewater is collect-
ed over a period of time and then treated prior to discharge.
Bending - Turning or forcing by a brake press or other device from a
straight or even to a curved or angular condition.
Best Available Technology Economically Achievable (BAT) - Level of
technology applicable to effluent limitations to be achieved
by 1984 for industrial discharges to surface waters as defined
by Section 301(b) (2) (A) of the Act.
Best Practicable Control Technology Currently Available - Level of
technology applicable to effluent limitations to be achieved
for industrial discharges to surface waters as defined by
Section 301 (b) (1) (A) of the Act.
Biochemical Oxygen Demand (BOD) - The amount of oxygen in milligrams
per liter used by microorganisms to consume biodegradable organics
in wastewater under aerobic conditions.
Biodegradability - The susceptibility of a substance to decomposition
by microorganisms; specifically, the rate at which compounds may
be chemically broken down by bacteria and/or natural environmental
factors.
Blanking - Cutting desired shapes out of sheet metal by means of dies.
Slowdown - The minimum discharge of recirculating water for the purpose
of discharging materials contained in the water, the further build-
up of which would cause concentration in amounts exceeding limits
established by best engineering practice.
BODS - The five-day Biochemical Oxygen Demand (BODS) is the quantity
of oxygen used by bacteria in consuming organic matter in a sample
of wastewater over a five-day period. BOD from the standard five-
day test equals about two-thirds of the total BOD. See Biochem-
ical Oxygen Demand.
Bonding - The process of uniting using an adhesive or fusible
ingredient.
Boring - Enlarging a hole by removing metal with a single or occasion-
ally a multiple point cutting tool moving parallel to the axis of
rotation of the work or tool. 1. Single-Point Boring - Cutting
with a single-point tool. 2. Precision Boring - Cutting to
tolerances held within narrow limits. 3. Gun Boring - Cutting
of deep holes. 4. Jig Boring - Cutting of high-precision and
accurate location holes. 5. Groove Boring - Cutting accurate
recesses in hole walls.
XVI-5
-------
Brazing - Joining metals by flowing a thin layer, capillary thickness,
of non-ferrous filler metal into the space between them. Bonding
results from the intimate contact produced by the dissolution of
a small amount of base metal in the molten filler metal, without
fusion of the base metal. The term brazing is used where the
temperature exceeds 425°C(800°F). ,
Bright Dipping - The immersion of all or part of a workpiece in a
media designed to clean or brighten the surface and leave a
protective surface coating on the workpiece.
Brine - An aqueous salt solution.
Broaching - Cutting with a tool which consists of a bar having a
single edge or a series of cutting edges (i.e., teeth) on its
surface. The cutting edges of multiple-tooth, or successive
single-tooth, broaches increase in size and/or change in shape.
The broach cuts in a straight line or axial direction when
relative motion is produced in relation to the workpiece, which
may also be rotating. The entire cut is made in single or
multiple passes over the workpiece to shape the required surface
contour. 1. Pull Broaching - Tool pulled through or over work-
piece. 2. Push Broaching - Tool pushed over or through work-
piece. 3. Chain Broaching - A continuous high production
surface broach. 4. Tunnel Broaching;- Work travels through an
enclosed area containing broach inserts.
Bromine Water - A nonmetallic halogen liquid, normally deep red,
corrosive and toxic, which is used as!an oxidizing agent.
Buffing - An operation to provide a high luster to a surface. The
operation, which is not intended to remove much material,
usually follows polishing. :
Buffing Compounds - Abrasive contained by a liquid or solid binder
composed of fatty acids, grease, or tallow. The binder serves
as lubricant, coolant, and an adhesive of the abrasive to the
buffing wheel.
Burnishing - Finish sizing and smooth finishing of a workpiece
(previously machined or ground) by displacement, rather than
removal, of minute surface irregularities with smooth point or
line-contact, fixed or rotating tools.
Calendering - Process of forming a continuous sheet by squeezing the
material between two or more parallel rolls to impart the desired
finish or to insure uniform thickness*
Calibration - The application of thermal, electrical, or mechanical
energy to set or establish reference points for a part, assem-
bly or complete unit.
XVI-6
-------
Calibration Equipment - Equipment used for calibration of instruments.
Capital Recovery Costs - Allocates the initial investemnt and the inter-
est to the total operating cost. The capital recovery cost is
equal to the initial investment multiplied by the capital recovery
factor.
Capital Recovery Factor - Capital Recover Factor is defined as:
i -f i/(a - 1) where i = interest rate, a = (1 + i) to the power n,
n = interest period in years.
Captive Facility - A facility which owns more than 50 percent (annual
area basis) of the materials undergoing metal finishing.
C a p t i v e Qp_era_t_ip n - A manufacturing operation carried out in a facility
to support subsequent manufacturing, fabrication, or assembly
operations.
Carbides - Usually refers to the general class of pressed and sintered
tungsten carbide cutting tools which contain tungsten carbide plus
smaller amounts of titanium and tantalum carbides along with
cobalt which acts as a binder. (It is also used to describe hard
compounds in steels and cast irons.)
Carbon Adsorption - Activated carbon contained in a vessel and
installed in either a gas or liquid stream to remove organic
contaminates. Carbon is regenerable when subject to steam which
forces contaminant to desorb from media.
Carbon Bed Catalytic Destruction - A non-electrolytic process for the
catalytic oxidation of cyanide wastes using filters filled with
low-temperature coke.
Carbon Steels - Steel which owes its properties chiefly to various
percentage of carbon without substantial amounts of other alloying
elements.
Carbonate - A compound containing the acid radical of carbonic acid
group) .
Carbonit r id i ng - Process for case or core hardening of metals. The
heated metals absorb carbon in a gaseous atmosphere.
Carburizing - (Physical Property Modification) Increasing the carbon
content of a metal by heating v?ith a carburizing medium (which
may be solid, liquid or gas) usually for the purpose of producing
a hardened surface by subsequent quenching.
Carcinogen - Substance which causes cancerous growth.
Case Hardening - A heat treating method by which the surface layer of
alloys is made substantially harder than the interior. (Carburiz
ing and nitriding are common ways of case hardening steels.)
Cast - A state of the substance after solidification of the molten
substance.
XVI -7
-------
Casthquse - The facility which melts metal, holds it in furnaces for
degassing (fluxing) and alloying and then casts the metal into
pigs, ingots, billets, rod, etc.
Casting - The operation of pouring molten metal into a mold.
Catalytic Bath - A bath containing a substance used to accelerate the
rate of chemical reaction. !
Category - Also point source category. A segment of industry for
which a set of effluent limitations has been established.
Cathode - The negatively charged electrode in an electrochemical
process.
Cation - The positively charged ions in a solution.
Caustic - Capable of destroying or eating away by chemical action.
Applies to strong bases and characterized, by the presence of
hydroxyl ions in solution.
Caustic Soda - Sodium hydroxide, NaOH, whose solution in water is
strongly alkaline. I
Cementation - The electrochemical reduction of metal ions by contact
with a metal of higher oxidation potential. It is usually used
for the simultaneous recovery of copper and reduction of
hexavalent chromium with the aid of scrap iron.
!
Centerless Grinding - Grinding the outside or inside of a workpiece
mounted on rollers rather than on centers. The workpiece may be
in the form of a cylinder or the frustrum of a cone.
Central Treatment Facility - Treatment plant which co-treats process
wastewaters from more than one manufacturing operation or co-
treats process wastewaters with non-contact cooling water, or
with non-process wastewaters (e.g., utility blowdown, miscellan-
eous runoff, etc.).
Centrifugation - An oil recovery step employing a centrifuge to remove
water from waste oil.
Centrifuge - A device having a rotating container in which centrifugal
force separates substances of differing densities.
Chelated Compound - A compound in which the metal is contained as an
integral part of a ring structure and is not readily ionized.
XVI-8
-------
Chelating Agent - A coordinate compound in which a central atom
(usually a metal) is joined by covalent bonds to two or more
other molecules or ions (called ligands) so that heterocyclic
rings are formed with the central (metal) atom as part of each
ring. Thus, the compound is suspending the metal in solution.
Chemical Brightening - Process utilizing an addition agent that leads
to the formation of a bright plate or that improves the brightness
of the deposit.
Chemical Deposition - Process used to deposit a metal oxide on a
substrate. The film is formed by hydrolysis of a mixture of
chlorides at the hot surface of the substrate. Careful control
of the water mixture insures that the oxide is formed on the
substrate surface.
Chemical Etching - To dissolve a part of the surface of a metal or
all of the metal laminated to a base.
Chemical Machining - Production of derived shapes and dimensions
through selective or overall removal of metal by controlled
chemical attack or etching.
Chemical Metal Coloring - The production of desired colors on metal
surfaces by appropriate chemical or electrochemical action.
Chemical Milling - Removing large amounts of stock by etching
selected areas of complex workpieces. This process entails
cleaning, masking, etching, and demasking.
Chemical Oxidation - (Including Cyanide) The addition of chemical
agents to wastewater for the purpose of oxidizing pollutant
material.
Chemical Oxygen Demand (COD) - The amount of oxygen in milligrams per
liter to oxidize both organic and oxidizable inorganic compounds.
Chemical Precipitation - A chemical process in which a chemical in
solution reacts with another chemical introduced to that solution
to form a third substance which is partially or mainly insoluble
and, therefore, appears as a solid.
Chemical Recovery Systems - Chemical treatment to remove metal or
other materials from wastewater for later reuse.
Chemical Reduction - A chemical reaction in which one or more electrons
are transferred to the chemical being reduced from the chemical
initiating the transfer (reducing agent).
XVI-9
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Chemical Treatment - Treating contaminated water by chemical means.
Chip Dragout - Cutting fluid or oil adhering 'to metal chips from a
machining operation.
Chlorinated Hydrocarbons - Organic compounds containing chlorine
such as many insecticides.
Chlorination - The application of chlorine to water generally for
purposes of disinfection, but frequently for accomplishing
other biological or chemical results.
Chromate Conversion Coating - Protective coating formed by immersing
metal in an aqueous acidified solution consisting substantially
of chromic acid or water soluble salts of chromic acid together
with various catalysts or activators.
Chromatizing - To treat or impregnate with a chromate (salt of ester
of chromic acid) or dichromate, especially with potassium
dichromate.
Chrome-Pickle Process - Forming a corrosion-resistant oxide film on
the surface of magnesium base metals by immersion in a bath of
an alkaline bichromate.
Clarification - The composite wastewater treatment process consisting
of flash mixing of coagulants, pH adjusting chemicals, and/or
polyelectrolytes, flocculation, and sedimentation.
Clarifier - A unit which provides for settling and removal of solids
from wastewater. \
Cleaning - The removal of soil and dirt (including grit and grease)
from a workpiece using water with or without a detergent or
other dispersing agent.
See Vapor Degreasing
Solvent Cleaning
Contaminant Factor
Acid Cleaning
Emulsion Cleaning
Alkaline Cleaning
Salt Bath Descaling
Pickling
Passivate
Abrasive Blast Cleaning
Sonic and Ultrasonic Cleaning
Closed-Loop Evaporation System - A system used for the recovery of
chemicals and water from a chemical finishing process. An
evaporator concentrates flow from the rinse water holding tank.
The concentrated rinse solution is returned to the bath, and
distilled water is returned to the final rinse tank. The
system is designed for recovering 100 percent of chemicals nor-
mally lost in dragout for reuse in the process.
XVI-10
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Closed Loop Rinsing - The recirculation of rinse water without the
introduction of additional makeup water.
Coagulation - A chemical reaction in which polyvalent ions neutralize
the repulsive charges surrounding colloidal particles.
Coating See Aluminum Coating
Hot Dip Coating
Ceramic Coating
Phosphate Coating
Chromate Conversion Coating
Rust-Preventive Compounds
Porcelain Enameling
COD - See Chemical Oxygen Demand
Cold Drawing - A process of forcing material through dies or other
mandrels to produce wire, rod, tubular and some bars.
Cold Heading - A method of forcing metal to flow cold into enlarged
sections by endwise squeezing. Typical coldheaded parts are
standard screws, bolts under 1 in. diameter and a large variety
of machine parts such as small gears with stems.
Cold Rolling - A process of forcing material through rollers to produce
bars and sheet stock.
Colorimetric - A procedure for establishing the concentration of impur-
itites in water by comparing its color to a set of known color
impurity standards.
Common Metals - Copper, nickel, chromium, zinc, tin, lead, cadmium,
iron, aluminum, or any combination thereof.
Compatible Pollutants - Those pollutants which can be adequately
treated in publicly-owned treatment works without upsetting
the treatment process.
Complexing Agent - A compound that will join with a metal to form
an ion which has a molecular structure consisting of a central
atom (the metal) bonded to other atoms by coordinate covalent
bonds.
Composite Wastewater Sample - A combination of individual samples of
water or wastewater taken at selected intervals, generally hourly
for some specified period, to minimize the effect of the varia-
bility of the individual sample. Individual samples may have
equal volume or may be proportioned to the flow at time of
sampling.
Conductance - See Electrical Conductivity.
XVI-11
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Conductivity Surface - A surface that can transfer heat or electricity.
Conductivity Meter - An instrument which displays a quantitative
indication of conductance.
Contact Water - See Process Wastewater.
Contam ination - Intrusion of undesirable elements.
Continuous Treatment - Treatment of waste streams operating without
interruption as opposed to batch treatment; sometimes referred
to as flow=through treatment.
Contractor Removal - Disposal of oils, spent solutions, or sludge
by a scavenger service. '
Conversion Coating - A coating produced by chemical or electrochemical
treatment of a metallic surface that gives a superficial layer
containing a compound of the metal. For example, chromate coating
on zinc and cadmium, oxide coatings on steel.
Coolant - See Cutting Fluids.
Cooling Water - Water which is used to absorb and transport heat
generated in a process or machinery.
Copper Flash - Quick preliminary deposition of copper for making
surface acceptable for subsequent plating.
Coprecipitation of Metals - Precipitation of a metal with another
metal.
Corrosion Resistant Steels - A term often used to describe the stain-
less steels with high nickel and chromium alloy content.
Cost o£ Capital - Capital recovery costs minus the depreciation.
Cpunterboring - Removal of material to enlarge a hole for part of
its depth with a rotary, pilot guided, end cutting tool having
two or more cutting lips and usually having straight or helical
flutes for the passage of chips and the admission of a cutting
fluid. l
Countercurrent Rinsing - Rinsing of parts in such a manner that the
rinse water is removed from tank to tank counter to the flow of
parts being rinsed.
Countersinking - Beveling or tapering the work material around the
periphery of a hole creating a concentric surface at an angle
less than 90 degrees with the centerline of the hole for the
purpose of chamfering holes or recessing screw and rivet heads.
XVI-12
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Crys tal1i ne So1id - A substance with an ordered structure, such as
a crystal.
Crystallization - 1. Process used to manufacture semiconductors
in the electronics industry. 2. A means of concentrating
pollutants in wastewaters by crystallizing out pure water.
Curcumine or Carmine Method - A standard method of measuring the
concentration of boron (B) within a solution.
Cutting Fluids - Lubricants employed to ease metal and machining
operations, produce surface smoothness and extend tool life
by providing lubricity and cooling. Fluids can be emulsified
oils in water, straight mineral oils when better smoothness
and accuracy are required, or blends of both.
Cyaniding - A process of case hardening an iron-base alloy by the
simultaneous absorption of carbon and nitrogen by heating in a
cyanide salt. Cyaniding is usually followed by quenching to
produce a hard case.
Cyclone Separator - A device which removes entrained solids from gas
streams.
Dead Rinse - A rinse step in which water is not replenished or dis-
charged.
Deburring - Removal of burrs or sharp edges from parts by filing,
grinding or rolling the work in a barrel with abrasives sus-
pended in a suitable medium.
De ep Bed F i 1t rat ion - The common removal of suspended solids from
wastewater streams by filtering through a relatively deep
(0.3-0.9 m) granular bed. The porous bed formed by the granular
media can be designed to remove practically all suspended
particles by physical-chemical effects.
Degassing - (Fluxing) The removal of hydrogen and other impurities
from molten primary aluminum in a casthouse holding furnace by
injecting chlorine gas (often with nitrogen and carbon).
Degradable - That which can be reduced, broken down or chemically
separated.
Demineralization - The removal from water of mineral contaminants
usually present in ionized form. The methods used include ion-
exchange techniques, flash distillation or electrolysis.
XVI-13
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Denitrification (Biological) - The reduction of nitrates to nitrogen
gas by bacteria. ;
i
Deoxidizing - The removal of an oxide film from an alloy such as
aluminum oxide. ,
Depreciation - Decline in value of a capital asset caused either by use
or by obsolescence. '
Descaling - The removal of scale and metallic oxides from the surface
of a metal by mechanical or chemical means. The former includes
the use of steam, scale-breakers and chipping tools, the latter
method includes pickling in acid solutions.
Desmutting - The removal of smut (matter that soils or blackens)
generally by chemical action.
Dewatering - (Sludge Processing) Removing water from sludge.
Diaminobenzidene - A chemical used in the standard method of measuring
the concentrations of selenium in a solution.
!
Dibasic Acid - An acid capable of donating two protons (hydrogen
ions) . ! " "
Dichromate Reflux - A standard method of measuring the chemical
oxygen demand of a solution.
Die Casting - (hot chamber, vacuum, pressure) Casting are produced
by forcing molten metal under pressure into metal mold called
dies. In hot chamber machines, the pressure cylinder is sub-
merged in the molten metal resulting in a minimum of time and
metal cooling during casting. Vacuum feed machines use a
vacuum to draw a measured amount of melt from the molten bath
into the feed chamber. Pressure feed systems use a hydraulic
or pneumatic cylinder to feed molten metal to the die.
Digestion - A standard method of measuring organic nitrogen.
Dipping - Material coating by briefly immersing parts in a molten
bath, solution or suspension.
Direct Labor Costs - Salaries, wages and other direct compensations
earned by the employee.
Discharge of Pollutant(s) - 1. The addition of any pollutant to
navigable waters from any point source. 2. Any addition of any
pollutant to the waters of the continguous zone or the ocean
from any point source, other than from a vessel or other floating
craft. The term "discharge" includes either the discharge of a
single pollutant or the discharge of multiple pollutants.
XVI-14
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Dispersed-air Flotation - Separation of low density contaminants from
water using minute air bubbles attached to individual particles
to provide or increase the buoyancy of the particle. The bubbles
are generated by introducing air through a revolving impeller or
porous media.
Dissolved-air Floatation - Separation of low density contaminants from
water using minute air bubbles attached to individual particles
to provide or increase the buoyancy of the particle. The air is
put into solution under elevated pressure and later released under
atmospheric pressure or put into solution by aeration at atmos-
pheric pressure and then released under a vacuum.
Dissolved Oxygen (DO) - The oxygen dissolved in sewage, water, or other
liquid, usually expressed in milligrams per liter or percent of
saturation. It is the test used in BOD determination.
Distillation - Vaporization of a liquid followed by condensation of
the vapor.
Distillation Refining - A metal with an impurity having a higher vapor
pressure than the base metal can be refined by heating the metal
to the point where the impurity vaporizes.
Distillation-Silver Nitrate Titration - A standard method of measuring
the concentration of cyanides in a solution.
Distillation-SPADNS - A standard method of measuring the concentration
of fluoride in a solution.
Dollar Base - A period in time in which all costs are related. Invest-
ment costs are related by the Sewage Treatment Plant Construction
Cost Index. Supply costs are related by the "Industrial Commod-
ities" Wholesale Price Index.
Drag-in - Water or solution carried into another solution by the work
and the associated handling equipment.
Dragout - The solution that adheres to the objects removed from a bath,
more precisely defined as that solution which is carried past the
edge of the tank.
Dragout Reduction - Minimization of the amount of material (bath or
solution) removed from a process tank by adherring to the part
or its transfer device.
Drainage Phase - Period in which the excess plating solution adhering
to the part or workpiece is allowed to drain off.
XVI-15
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Drawing - Reduction of cross section area and increasing the length
by pulling metal through conical taper dies.
Drawing Compounds - See Wire Forming Lubricants.
Drilling - Hole making with a rotary, end-cutting tool having one or
more cutting lips and one or more helical or straight flutes or
tubes for the ejection of chips and the passage of a cutting
fluid. 1. Center Drilling - Drilling a conical hole in the
end of a workpiece. 2. Core Drilling - Enlarging a hole with
a chamer-edged, multiple-flute drill. 3. Spade Drilling -
Drilling with a flat blade drill tip. 4. Step Drilling - Using
a multiple diameter drill. 5. Gun Drilling - Using special
straight flute drills with a single lipiand cutting fluid at high
pressures for deep hole drilling. 6. Oil Hole or Pressurized
Coolant Drilling - Using a drill with one or more continuous
holes through its body and shank to permit the passage of a
high pressure cutting fluid which emerges at the drill point
and ejects chips.
Drip Station - Empty tank over which parts are allowed to drain
freely to decrease end dragout.
Drip Time - The period during which a part is suspended over baths
in order to allow the excessive dragout to drain off.
Drying Beds - Areas for dewatering of sludge by evaporation and
seepage.
EDTA Titration - EDTA - ethylenediamine tetraacetic acid ( or its
salts). A standard method of measuring the hardness of a
solution.
Effluent - The water and the quantities, rates, and concentrations
of chemical, physical, biological, and other constituents
which are discharged from point sources.
Effluent Limitation - Any restriction (including schedules of compli-
ance) established by a state or the federal EPA on quantites,
rates, and concentrations of chemical, physical, biological,
and other constituents which are discharged from point sources
into naviigable waters, the waters of the contiguous zone, or
the ocean.
Electrical Conductivity - The property which allows an electric current
to flow when a potential difference is applied. It is the re-
ciprocal of the resistance in ohms measured between opposite
faces of a centimeter cube of an aqueous solution at a specified
temperature. It is expressed as micromhos per centimeter at
temperature degrees Celsius.
XVI-16
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Electrical Discharge Machining - Metal removal by a rapid spark dis-
charge between different polarity electrodes, one the workpiece
and the other the tool separated by a gap distance of 0.0005 in.
to 0.035 in. The gap is filled with dielectric fluid and metal
particles which are melted, in part vaporized and expelled from
the gap.
Electrobrightening - A process of reversed electro-deposition which
results in anodic metal taking a high polish.
Electrochemical Machining (ECM) - A machining process whereby the part
.; to be machined is made the anode and a shaped cathode is maintain-
ed in close proximity to the work. Electrolyte is pumped between
the electrodes and a potential applied with the result that metal
is rapidly dissolved from the workpiece in a selective manner and
the shape produced on the workpiece complements that of the
cathode.
Electrocleaning - The process of anodic removal of surface oxides and
scale from a workpiece.
Electrode - Conducting material for passing electric current into or
out of a solution by adding electrons to or taking electrons
from ions in the solution.
Electrodialysis - A treatment process that uses electrical current and
and arrangement of permeable membranes to separate soluble minerals
from water. Often used to desalinate salt or brackish water.
Electroless Plating - Deposition of a metallic coating by a control-
led chemical reduction that is catalyzed by the metal or alloy
being deposited.
Electrolysis - The chemical decomposition by an electric current of
a substance in a dissolved or molten state.
Electrolyte - A liquid, most often a solution, that will conduct an
electric current.
Electrolytic Cell - A unit apparatus in which electrochemical react-
ions are produced by applying electrical energy or which supplies
electrical energy as a result of chemical reactions and which
includes two or more electrodes and one or more electrolytes con-
tained in a suitable vessel.
Electrolytic Decomposition - An electrochemical treatment used for the
oxidation of cyanides. The method is practical and economical
when applied to concentrated solutions such as contaminated baths,
cyanide dips, stripping solutions, and concentrated rinses.
Electrolysis is carried out at a current density of 35 amp/sq.
ft. at the anode and 70 amp/sq. ft. at the cathode. Metal is
deposited at the cathode and can be reclaimed.
XVI-17
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Electrolytic Oxidation - A reaction by an electrolyte in which there
is an increase in valence resulting from a loss of electrons.
Electrolytic Reduction - A reaction in which there is a decrease in
valence resulting from a gain in electrons.
i
i
Electrolytic Refining - The method of producing pure metals by making
the impure metal the anode in an electrolytic cell and depositing
a pure cathode. The impurities either remain undissolved at the
anode or pass into solutions in the electrolyte.
Electrometallurgical Process - The application of electric current to
a metallurgical process either for electrolytic deposition or as
a source of heat.
Electrometric Titration - A standard method of measuring the alkalin-
ity of a solution.
Electron Beam Machining - The process of removing material from a
workpiece by a high velocity focused stream of electrons which
melt and vaporize the workpiece at the point of impingerent.
Electroplating - The production of a thin coating of one metal on a
surface by electrodeposition.
Electropolishing - Electrolytic corrosion process that increases the
percentage of specular reflectance from a metallic surface.
j
Embossing - Raising a design in relief against a surface.
Emulsified Oil and Grease - An oil or grease dispersed in an immis-
cible liquid usually in droplets of larger than colloidal size.
In general suspension of oil or grease within another liquid
(usually water).
Emulsifying Agent - A material that increases the stability of a
dispersion of one liquid in another. i
Emulsion Breaking - Decreasing the stability of dispersion of one
liquid in another.
Emulsion Cleaning - A cleaning process using organic solvents dis-
persed in an aqueous medium with the aid of an emulsifying agent.
End-of-Pipe Treatment - The reduction and/or removal of pollutants by
treatment just prior to actual discharde.
Environmental Protection Agency - the United States Environmental
Protection Agency.
XVI-18
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EPA - See Environmental Protection Agency.
Equalization - (Continuous Flow) - The balancing of flow or pollutant
load using a holding tank for a system that has widely varying
inflow rates.
Equilibrium Concentration - A state at which the concentration of
chemicals in a solution remain in a constant proportion to one
another.
Ester - An organic compound corresponding in structure to a salt in
inorganic chemistry. Esters are considered as derived from the
acids by the exchange of the replaceable hydrogen of the latter
for an organic alkyl radical. Esters are not ionic compounds,
but salts usually are.
Etchant - The material used in the chemical process of removing glass
fibers and epoxy between neighboring conductor layers of a PC
board for a given distance.
Etching - A process where material is removed by chemical action.
Evaporation Ponds - Liquid waste disposal areas that allow the liquid
to vaporize to cool discharge water temperatures or to thicken
sludge.
Excess Capacity Factor - A multiplier on process size to account for
shutdown for cleaning and maintenance.
Extrusion - A material that is forced through a die to form lengths
of rod, tube or special sections.
4-AAP Colorimetric - A standard method of measurement for phenols
in aqueous solutions.
Fermentation - A chemical change to break down biodegradable waste.
The change is induced by a living organism or enzyme, specific-
ally bacteria or microorganisms occurring in unicellular plants
such as yeast, molds, or fungi.
Ferrite - A solid solution in which alpha iron is present.
Ferrous - Relating to or containing iron.
Filtrate - Liquid after passing through a filter.
Filtration - Removal of solid particles from liquid or particles
from air or gas stream by means of a permeable membrane.
Types: Gravity, Pressure, Microstraining, Ultrafiltration,
Reverse Osmosis (Hyperfiltration).
XVI-19
-------
Flameless Atomic Absorption - A method of measuring low concen-
tration values of certain metals in a solution.
f r"> : .; •" . <•' '•'•'•' ...;T •'•." a1:' • •
Flame Hardened - Surface hardened by controlled torch heating
followed by quenching with water or air.
i
Flame Spraying - The process of applying a metallic coating to a
workpiece whereby finely powdered fragments or wire, together
with suitable fluxes, are projected through a cone of flame
onto the workpiece.
Flash Evaporation - Evaporation using steam heated tubes with feed
material under high vacuum. Feed material "flashes off" when
it enters the evaporation chamber.
Flocculation - The process of separating suspended solids from waste-
water by chemical creation of clumps or floes.
Flotation - The process of removing finely .divided particles from
a liquid suspension by attaching gas bubbles to the particles,
increasing their buoyancy, and thus concentrating them at the
surface of the liquid medium.
Fluxing - (Degassing) The removal of oxides and other impurities
from molten primary aluminum in a casthouse holding furnace by
injecting chlorine gas (often with nitrogen and carbon monoxide).
Fog - A type of rinse consisting of a fine spray.
Forming Compounds (Sheet) - Tightly adhering lubricants composed of
fatty oils, fatty acids, soaps, and waxes and designed to resist
the high surface temperatures and pressures the metal would
otherwise experience in forming.
Forming Compounds (Wire) - Tightly adhering lubricants composed of
solids (white lead, talc, graphite, or molybdenum disulfide)
and solible oils for cooling and corrosion protection. Lubri-
cants typically contain sulfur, chlorine, or phsophate additives.
Free Cyanide - 1. True - the actual concentration of cyanide radical
or equivalent alkali cyanide not combined in complex ions with
metals in solutions. 2. Calculated - the concentration of
cyanide or alkali cyanide present in solution in excess of that
calculated as necessary to form a specified complex ion with a
metal or metals present in solution. 3. Analytical - the free
cyanide content of a solution as determined by a specified
analytical method.
Freezing/Crystallization - The solidification of a liquid into
aggregations of regular geometric forms (crystals) accomplished
by subtraction of heat from the liquid. This process can be used
for removal of solids, oils, greases, and heavy metals from
industrial wastewater.
XVI-20
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Galvanizing - The deposition of zinc on the surface of steel for
corrosion protection.
Gas Carburizing - The introduction of carbon into the surface layers
of mill steel by heating in a current of gas high in carbon.
Gas Chr onto tag rophy - Chemical analytical instrumentation generally
used for quantitative organic analysis.
Gas Nitriding - Case hardening metal by heating and diffusing nitro-
gen gas into the surface.
Gas Phase Separation - The process of separating volatile constitu-
ents from water by the application of selective gas permeable
membranes.
Gear Forming - Process for making small gears by rolling the gear
material as it is pressed between hardened gear shaped dies. .
Glass Fiber Filtration - A standard method of measuring total sus-
pended solids.
Good Housekeeping - (In-Plant Technology) Good and proper mainten-
ance minimizing spills and upsets.
GPP - Gallons per day.
Grab Sample - A single sample of wastewater taken without regard
to time or flow.
Gravimetric 103-105C - A standard method of measuring total
solids in aqueous solutions.
Gravimetric 550C - A standard method of measuring total volatile
solids in aqueous solutions.
Gravity Filtration - Settling of heavier and rising of lighter
constituents within a solution.
Gravity Flotation - The separation of water and low density contam-
inants such as oil or grease by reduction of the wastewater
flow velocity and turbulence for a sufficient time to permit
separation due to difference in specific gravity. The floated
material is removed by some skimming technique.
Gray Cast Irons - Alloys primarily of iron, carbon and silicon along
with other alloying elements in which the graphite is in flake
form. (These irons are characterized by low ductility but have
many other properties such as good castability and good damping
capacity.)
XVI-21
-------
Grease - In wastewater, a group of substances including fats, waxes,
free fatty acids, calcium and magnesium soaps, mineral oils,
and certain other nonfatty materials. The type of solvent
and method used for extraction should be stated for quantifi-
cation.
Grease Skimmer - A device for removing floating grease or scum from
the surface of wastewater in a tank.
Grinding - The removal of stock from a workpiece by use of abrasive
grains held by a rigid or semi rigid binder. 1. Surface
Grinding - Producing a flat surface with a rotating grinding
wheel as the workpiece passes under the wheel. 2. Cylindrical
Grinding - Grinding the outside diameters of cylindrical work-
pieces held between centers. 3. Internal Grinding - Grinding
the inside of a rotating workpiece by use of a wheel spindle
which rotates and reciprocates through the length of depth of
the hole being ground.
Grinding Fluids - Water based, straight oil, or synthetic based
lubricants containing mineral oils, soaps, or fatty materials
lubricants serve to cool the part and maintain the abrasiveness
of the grinding wheel face.
i
Hammer Forging - Heating and pounding metal to shape it into the
desired form.
Hardened - Designates condition produced by various heat treatments
such as quench hardening, age hardening and precipitation
hardening.
i
Hardness - A characteristic of water, imparted by salts of calcium,
magnesium and iron such as bicarbonates, carbonates, sulfates,
chlorides and nitrates, that cause curdling of soap, deposition
of scale, damage in some industrial processes and sometimes
objectionable taste. It may be dtermined by a standard labora-
tory procedure or computed from the amounts of calcium and
magnesium as well as iron, aluminum, manganese, barium,
strontium, and zinc and is expressed as equivalent calcium
carbonate.
Heading - (Material forming) Upsetting wire, rod or bar stock in
dies to form parts having some of the cross-sectional area
larger than the original. Examples are bolts, rivets and
screws. !
Heat Resistant Steels - Steel with high resistance to oxidation and
moderate strength at high temperatures above 500 Degrees C.
XVI-22
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Heat Treatment - The modification of the physical properties of a
workpiece through the application of controlled heating and
cooling cycles. Such operations are heat treating, tempering,
carburizing, eyaniding, nitriding, annealing, normalizing,
austenizing, quenching, austempering, siliconizing, martemper-
ing, and malleabilizing are included in this definition.
Heavy Metals - Metals which can be precipitated by hydrogen sulfide
in acid solution, e.g., lead, silver, gold, mercury, bismuth,
copper, nickel, iron, chromium, zinc, cadmium, and tin.
High Energy Forming - Processes where parts are formed at a rapid
rate by using extremely high pressures. Examples: Explosive
forming, Electrohydraulic forming.
High Energy Rate Forging (HERF) - A closed die process where hot or
cold deforming is accomplished by a high velocity ram.
Bobbing - Gear cutting by use of a tool resembling a worm gear in
appearance, having helically-spaced cutting teeth. In a single-
thread hob, the rows of teeth advance exactly one pitch as the
hob makes one revolution. With only one hob, it is possible to
cut interchangeable gears of a given pitch of any number of
teeth within the range of the hobbing machine.
Honing - A finishing operation using fine grit abrasive stones to
produce accurate dimensions and excellent finish.
Hot Compression Molding - (Plastic Processing) A technique of
thermoset molding in which preheated molding compound is closed
and heat and pressure (in the form of a downward moving ram)
are applied until the material has cured.
Hot Pi p Coat ing - The process of coating a metallic workpiece with
another metal by immersion in a molten bath to provide a pro-
tective film.
Hot Rolled - A term used to describe alloys which are rolled at tem-
peratures above the recrystallization temperature. (Many alloys
are hot rolled, and machinability of such alloys may vary because
of differences in cooling conditions from lot to lot.
Hot Stamping - Engraving operation for marking plastics in which roll
leaf is stamped with heated metal dies onto the face of the
plastics. Ink compounds can also be used.
Hot Upset Forging - The diameter is locally increased i.e. to upset
the head of a bolt, the end of the barstock is heated and then
deformed by an axial blow often into a suitably shaped die.
Hyd rof1uor ic Ac id - Hydrogen fluoride in aqueous solution.
XVI-23
-------
Hydrogen Embrittlement - Embrittlement of a metal or alloy caused by
absorption of hydrogen during a pickling, cleaning, or plating
process.
Hydrometallurgical Process - The treatment of ores by wet processes
such as leaching.
!
Hydrophilic - A surface having a strong affinity for water or being
readily wettable.
Hydrophobic - A surface which is non-wettable or not readily wettable,
Hydrostatic Pressure - The force per unit area measured in terms of
the height of a column of water under the influence of gravity.
Immersed Area - Total area wetted by the solution or plated area plus
masked area.
Immersion Plate - A metallic deposit produced by a displacement re-
action in which one metal displaces another from solution, for
example: Fe + Cu(+2) = Cu + Fe(+2)
Impact Deformation - The process of applying impact force to a work-
piece such that the workpiece is permanently deformed or shaped.
Impact deformation operations such as shot peening, peening,
forging, high energy forming, heading, or stamping.
Incineration - (Sludge Disposal) The combustion (by burning) of
organic matter in wastewater sludge after dewatering by
evaporation.
Incompatible Pollutants - Those pollutants which would cause harm to,
adversely affect the performance of, or be inadequately treated
in publicly-owned treatment works.
Independent Operation - Job shop or contract shop in which electro-
plating is done on workpieces owned by the customer.
Indirect Labor Costs - Labor-related costs paid by the employer
other than salaries, wages and other direct compensation such as
social security and insurance.
Induction Hardened - Surface or through hardened using induction
heating followed by quenching with water or air.
Industrial User - Any industry that introduces pollutants into public
sewer systems and whose wastes are treated by a publicly-owned
treatment facility. ;
Industrial Wastes - The liquid wastes from industrial processes, as
distinct from domestic or sanitary wastes.
XVI-24
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Inhibition - The slowing down or stoppage of chemical or biological
reactions by certain compounds or ions.
In-Process Control Technology - The regulation and the conservation
of chemicals and the reduction of water usage throughout the
operations as opposed to end-of-pipe treatment.
Inspection - A checking or testing of something against standards or
specification.
Intake Water - Gross water minus reuse water.
Integrated Chemical Treatment - A waste treatment method in which a
chemical rinse tank is inserted in the plating line between the
process tank and the water rinse tank. The chemical rinse
solution is continuously circulated through the tank and removes
the dragout while reacting chemicals with it.
Integrated Circuit (1C) - 1. A combination of interconnected circuit
elements inseparably associated on or within a continuous sub-
strate. 2. Any electronic device in which both active and
passive elements are contained in a single package. Methods of
making an integrated circuit are by masking process, screening
and chemical deposition.
Intraforming - A method of forming by means of squeezing.
Investment Costs - The capital expenditures required to bring the
treatment or control technology into operation.
Ion Exchange - A reversible chemical reaction between a solid (ion
exchanger) and a fluid (usually a water solution) by means of
which ions may be interchanged from one substance to another.
The superficial physical structure of the solid is not
affected.
Ion Exchange Resins - Synthetic resins containing active groups
(usually sulfonic, carboxylic, phenol, or substituted amino
groups) that give the resin the property of combining with
or exchanging ions between the resin and a solution.
Ion-Flotation Technique - Treatment for electroplating rinse waters
(containing chromium and cyanide) in which ions are separated
from solutions by flotation.
Iridite Dip Process - Dipping process for zinc or zinc-coated objects
that deposits protective film that is a chromium gel, chromium
oxide, or hydrated chromium oxide.
Isolation - Segregation of a waste for separate treatment and/or
disposal.
XVI-25
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Job Shop - A facility which owns not more than 50 percent (annual
area basis) of the materials undergoing metal finishing.
Kiln - (Rotary) A large cylindrical mechanized type of furnace.
Kinematic Viscosity - The viscosity of a fluid divided by its density.
The C.G.S. unit is the stoke (cm2/sec) . '•
Knurling - Impressing a design into a metallic surface, usually by
means of small, hard rollers that carry the corresponding design
on their surfaces.
Lagoon - A man-made pond or lake for holding wastewater for the removal
of suspended solids. Lagoons are also used as retention ponds,
after chemical clarification to polish the effluent and to safe-
guard against upsets in the clarifier; for stabilization of
organic matter by biological oxidation; for storage of sludge;
and for cooling of water.
Laminate - 1. A composite metal, wood or plastic usually in the form
of sheet or bar, composed of two or more layers so bonded that
the composite forms a structural member-. 2. To form a product
of two or more bonded layers.
Landfill - Disposal of inert, insoluble waste solids by dumping at an
approved site and covering with earth.
Lapping - An abrading process to improve surface quality by reducing
roughness, waviness and defects to produce accurate as well as
smooth surfaces.
Laser Beam Machining - Use of a highly focused mono-frequency colli-
mated beam of light to melt or sublime material at the point of
impingement on a workpiece.
Leach Field - A area of ground to which wastewater is discharged.
Not considered an acceptable treatment method for industrial
wastes. I
Leaching - Dissolving out by the action of a percolating liquid,
such as water, seeping through a landfill.
Ligands - The molecules attached to the central atom by coordinate
covalent bonds. !
Liquid/Liquid Extraction - A process of extracting or removing contam-
inant(s) from a liquid by mixing contaminated liquid with another
liquid which is immiscible and which has a higher affinity for
the contaminating substance(s).
Liquid Nitriding - Process of case hardening a metal in a molten
cyanide bath.
XVI-26
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Liquid Phase Refining - A metal with an impurity possessing a lower
melting point is refined by heating the metal to the point of.
melting of the low temperature metal. It is separated by sweat-
ing out.
Machining - The process of removing stock from a workpiece by forcing
a cutting tool through the workpiece removing a chip of basis
material. Machining operations such as turning, milling, drill-
ing, boring, tapping, planing, broaching, sawing and filing, and
chamfering are included in this definition.
Maintenance - The upkeep of property or equipment.
Malleablizing - Process of annealing brittle white cast iron in such
a way that the combined carbon is wholly or partly transformed
to graphitic or temper carbon nodules in a ferritic or pearlitic
microstructure, thus providing a ductile and machinable material.
Manual Plating - Plating in which the workpieces are conveyed manually
through successive cleaning and plating tanks.
Maraged - Describes a series of heat treatments used to treat high
strength steels of complex composition (maraging steels) by
aging of martensite.
Martensite - An acicular or needlelike microstructure that is formed
in quenched steels. (It is very hard and brittle in the quenched
form and, therefore, is usually tempered before being placed into
service. The harder forms of tempered martensite have poorer
machinability.)
Martempering - Quenching an austentized ferrous alloy in a medium at a
temperature in the upper part of the martensite range, or slight-
ly above that range, and holding it in the medium until the
temperature throughout the alloy is substantially uniform.
The alloy is then allowed to cool in air through the martensite
range.
Masking - The application of a substance to a surface for the pre-
vention of plating to said area.
Material Modification - (In-Plant Technology) Altering the substance
from which a part is made.
Mechanical Agitation - The agitation of a liquid medium through the
use of mechanical equipment such as impellers or paddles.
Mechanical Finish - Final operations on a product performed by a
machine or tool. See: Polishing, Buffing, Barrel Finishing,
Shot Peening, Power Brush Finishing.
XVl-27
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Mechanical Plating - Providing a coating wherein fine metal powders
are peened onto the part by tumbling or other means.
Membrane - A thin sheet of synthetic polymer through the apertures
of which small molecules can pass, while larger ones are re-
tained.
!
Membrane Filtration - Filtration at pressures ranging from 50 to 100
psig with the use of membranes or thin films. The membranes
have accurately controlled pore sites and typically low flux
rates.
Metal Ion - An atom or radical that has lost or gained one or more
electrons and has thus acquired an elebtric charge. Positively
charged ions are cations, and those having a negative charge
are anions. An ion often has entirely differnt properties from
the element (atom) from which it was formed.
Metal Oxidation Refining - A refining technique that removes impuri-
ties from the base metal because the impurity oxidizes more
readily than the base. The metal is heated and oxygen supplied.
The impurity upon oxidizing separates by gravity or volatilizes.
Metal Paste Production - Manufacture of metal pastes for use as pig-
ments by mixing metal powders with mineral spirits, fatty acids
and solvents. Grinding and filtration are steps in the process.
Metal Powder Production - Production of metal particles for such uses
as pigments either by milling and grinding of scrap or by atomi-
zation of molten metal.
Metal Spraying - Coating metal objects by spraying molten metal upon
the surface with gas pressure.
I
Microstraining - A process for removing solids from water, which con-
sists of passing the water stream through a microscreen with
the solids being retained on the screen.
Milling - Using a rotary tool with one or more teeth which engage the
workpiece and remove material as the workpiece moves past the
rotating cutter. 1. Face Milling - Milling a surface perpendi-
cular cutting edges remove the bulk of the material while the
face cutting edges provide the finish of the surface being
generated. 2. End Milling - Milling accomplished with a tool
having cutting edges on its cylindrical sufaces as well as on
its end. In end milling - peripheral, the peripheral cutting
edges on the cylindrical surface are used; while in end milling-
slotting, both end and peripheral cutting edges remove metal.
3. Slide and Slot Milling - Milling of the side or slot of a
workpiece using a peripheral cutter. 4. Slab Milling - Milling
of a surface parallel to the axis of a helical, multiple-toothed
cutter mounted on an arbor. 5. Straddle Milling - Peripheral
milling a workpiece on both sides at once using two cutters
spaced as required.
XVI-28
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Ijplecule - Chemical units composed of one or more atoms.
Ptonitoring - The measurement, sometimes continuous, of water quality.
E|ylti-Effeet Evaporator - A series of evaporations and condensations
with the individual units set up in series and the latent heat of
vaporization from one unit used to supply energy for the next.
Rfeiltiple Operation Machinery - Two or more tools are used to perform
simultaneous or consecutive operations.
l|ultiple Subcategory Plant - A plant discharging process wastewater
from more than one manufacturing process subcategory.
t|ational Pollutant Discharge Elimination System (NPDES) - The federal
mechanism for regulating point source discharge by means of
permits.
l|avigable Waters - All navigable waters of the United States; tribu-
taries of navigable waters of the United States; interstate
waters,intrastate lakes, rivers and streams which are utilized
for recreational or other purposes.
I|eutralization - Chemical addition of either acid or base to a solu-
tion such as the pH is adjusted to 7.
E|ew Source - Any building, structure, facility, or installation from
which there is or may be the discharge of pollutants, the con-
struction of which is commenced after the publication of proposed
regulations prescribing a standard of performance under Section
306 of the Act which will be applicable to such source if such
standard is thereafter promulgated in accordance with Section
306 of the Act.
Ijjitriding - A heat treating method in which nitrogen is diffused into
the surface of iron-base alloys. (This is done by heating the
metal at a temperature of about 950 degrees P in contact with
ammonia gas or other suitable nitrogenous materials. The surface,
because of formation of nitrides becomes much harder than the
interior. Depth of the nitrided surface is a function of the
length of time of exposure and can vary from .0005" to .032"
thick. Hardness is generally in the 65 to 70 Re range, and,
therefore, these structures are almost always ground.)
!|itriding Steels - Steels which are selected because they form good
case hardened structures in the nitriding process. ( In these
steels, elements such as aluminum and chromium are important
for producing a good case.)
Nitrification (Biological) - The oxidation of nitrogenous matter into
nitrates by bacteria.
XVI-29
-------
Noble Metals - Metals below hydrogen in the electromotive force series;
includes antimony, copper, rhodium, silver, gold, bismuth.
Noncontact Cooling Water - Water used for cooling which does not come
into direct contact with any raw material, intermediate product,
waste product, or finished product.
Nonferrous - No iron content.
Non-Water Quality Environmental Impact - The ecological impact as a
result of solid/ air, or thermal pollution due to the appli-
cation of various wastewater technologies to achieve the effluent
guidelines limitations. Associated with the non-water quality
aspect is the energy impact of wastewater treatment.
Normalizing - Heat treatment of iron-base alloys above the critical
temperature, followed by cooling in still air. (This is often
done to refine or homogenize the grain structure of castings,
forgings and wrought steel products.)
Notching - Cutting out various shapes from the edge or side of a
sheet, strip, blank or part.
NPDES - See National Pollutant Discharge Elimination System.
Oil Cooker - Open-topped vessel contining a heat source and typically
maintained at 68°C (180°F) for the purpose of driving off excess
water from waste oil.
Operation and Maintenance Costs - The cost of running the wastewater
treatment equipment. This includes labor costs, material and
supply costs, and energy and power costs.
Organic Compound - Any substance that contains the element carbon,
with the exception of carbon dioxide and various carbonates.
ORP Recorders - Oxidation-reduction potential recorders.
Oxidants - Those substances which aid in the formation of oxides.
i
Oxidizable Cyanide - Cyanide amenable to oxidation.
Oxidizing - Combining the material concerned with oxygen.
Paint Stripping - The term "paint stripping" shall mean the process
of removing an organic coating from a workpiece or painting
fixture. The removal of such coatings using processes such
as caustic, acid, solvent and molten salt stripping are included.
XVI-30
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Parameter - A characteristic element of constant factor.
Passivation - The changing of the chemically active surface of a
metal to a much less reactive state by means of an acid dip.
Patina - A blue green oxidation of copper.
Pearlite - A microstituent found in iron-base alloys consisting of
a lamellar (Patelike) composite of ferrite and iron carbide.
(This structure results from the decomposition of austenite
and is very common in cast irons and annealed steels.)
Peening - Mechanical working of metal by hammer blows or shot im-
pingement.
pH - A unit for measuring hydrogen ion concentrations. A pH of 7
indicates a "neutral" water or solution. A pH lower than 7,
a solution is acidic. At pH higher than 7, a solution is
alkaline.
pH Buffer - A substance used to stabilize the acidity or alkalinity
in a solution.
Phenols - A group of aromatic compounds having the hydroxyl group
directly attached to the benzene ring. Phenols can be a con-
taminant in a waste stream from a manufacturing process.
Phosphate Coating - Process of forming a conversion coating on iron
or steel by immersing in a hot solution of manganese, iron or
zinc phosphate. Often used on a metal part prior to painting
or porcelainizing.
Phosphate - Salts or esters of phosphoric acid.
Phosphatizing - Process of forming rust-resistant coating on iron
or steel by immersing in a hot solution of acid manganese,
iron or zinc phosphates.
Photoresists - Thin coatings produced from organic solutions
which when exposed to light of the proper wave length are
chemically changed in their solubility to certain solvents
(developers). This substance is placed over a surface which
is to be protected during processing such as in the etching
of printer circuit boards.
Photosensitive Coating - A chemical layer that is receptive to
the action of radiant energy.
XVI-31
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Pickling - The immersion of all or part of a workpiece in a
corrosive media such as acid to remove scale and related
surface coatings.
Planing - Producing flat surfaces by linear reciprocal motion of
the work and the table to which it is attached relative to
a stationary single-point cutting tool.
Plant Effluent or Discharge After Treatment - The wastewater
discharged from theindustrial plant. In this definition,
any waste treatment device (pond, trickling filter, etc.)
is considered part of the industrial plant.
Plasma Arc Machining - The term "plasma arc machining" shall mean
the process of material removal or shaping of a workpiece
by a high velocity jet of high temperature ionized gas.
Plated Area - Surface upon which an adherent layer of metal is
deposited.
Plating - Forming an adherent layer of metal upon an object.
Point Source - Any discernible, confined, and discrete conveyance
including, but not limited to, any pipe, ditch, channel,
tunnel, conduit, well, discrete fissure, container, rolling
stock, concentrated animal feeding operation, or vessel or
other floating craft from which pollutants are or may be
discharged.
Point Source Category - See Category.
Polishing - The process of removing stock from a workpiece by the
action of loose or loosely held abrasive grains carried to
the workpiece by a flexible support. Usually, the amount of
stock removed in a polishing operation is only incidental to
achieving a desired surface finish or appearance.
Polishing Compounds - Fluid or grease stick lubricants composed
of animal tallows, fatty acids, and waxes. Selection depends
on surface finish desired.
Pollutant - Dredged spoil, solid waste, incinerator residue, sewage,
garbage, sewage sludge, munitions, chemical wastes, biological
materials, radioactive materials, heat, wrecked or discarded
equipment, rock, sand, cellar dirt and industrial, municipal
and agricultural waste discharged intp water. It does not
mean (1) sewage from vessels or (2) water, gas, or other mat-
erial which is injected into a well to facilitate production
of oil or gas, or water derived in association with oil or
gas production and disposed of in a well, if the well, used
either to facilitate production or for disposal purposes, is
XVI-32
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approved by authority of the State in which the well is
located, and if such State determines that such injection
or disposal will not result in degradation of ground or
surface water resources.
Pollutant Parameters - Those constituents of wastewater deter-
minded to be detrimental and, therefore, requiring control.
Pollution - The man-made or man-induced alternation of the
chemical, physical, biological, and radiological integrity
of water.
Polychlorinated Biphenyl (PCS) - A family of chlorinated biphenyls
with unique thermal properties and chemical inertness which
have a wide variety of uses as plasticizers, flame retardants
and insulating fluids. They represent a persistent contam-
inant in waste streams and receiving waters.
Polyelectrolyte - A high polymer substance, either natural or
synthetic, containing ionic constituents? they may be either
cationic or anionic.
Post Curring - Treatment after changing the physical properties
of a material by chemical reaction.
Pouring - (Casting and Molding) Transferring molten metal from
a furnace or a ladle to a mold.
Power Brush Finishing - This is accomplished (wet or dry) using a
wire or nonmetallic-fiber-filled brush used for debarring,
edge blending and surface finishing of metals.
Precious Metals - Gold, silver, iridium, palladium, platinum,
rhodium, ruthenium, indium, osmium, or combination thereof.
Precipitate - The discrete particles of material rejected from a
liquid solution.
Precipitation Hardening Metals - Certain metal compositions which
respond to precipitation hardening or aging treatment.
Pressure Deformation - The process of applying force, (other than
impact force), to permanently deform or shape a workpiece.
Pressure deformation operations may include operations such
as rolling, drawing, bending, embossing, coining, swaging,
sizing, extruding, squeezing, spinning, seaming, piercing,
necking, reducing, forming, crimping, coiling, twisting,
winding, flaring or weaving.
Pressure Filtration - The process of solid/liquid phase separation
effected by passing the more permeable liquid phase through a
mesh which is impenetrable to the solid phase.
XVI-33
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Pretreatment - Treatment of wastewaters from sources before intro-
duction into municipal treatment works.
i
Primary Settling - The first treatment for the removal of settle-
able solids from wastewater which is passed through a treat-
ment works.
Primary Treatment - The first stage in wastewater treatment in
which floating or settleable solids are mechanically removed
by screening and sedimentation.
Printed Circuit Boards - A circuit in which the interconnecting
wires have been replaced by conductive strips printed, etched,
etc., onto an insulating board. Methods of fabrication in-
clude etched circuit, electroplating,' and stamping.
j
Printing - A process whereby a design or pattern in ink or types
of pigments are impressed onto the surface of a part.
Process Modification - (In-Plant Technology) Reduction of water
pollution by basic changes in a manufacturing process.
Process Wastewater - Any water which, duribg manufacturing or
processing,comes into direct contact with or results from
the production or use of any raw material, intermediate
product, finished product, byproduct, or waste product.
Process Water - Water prior to its direct .contact use in a process
or operation. (This water may be any combination of raw water,
service water, or either process wastewater or treatment facil-
ity effluent to be recycled or reused).
Punching - A method of cold extruding, cold heading, hot forging or
stamping in a machine whereby the mating die sections control
the shape or contour of the part.
Pyrolysis - (Sludge Removal) Decomposition of materials by the
application of heat in any oxygen-deficient atmosphere.
Pyrazolone-Colorimetric - A standard method of measuring cyanides
in aqueous solutions.
Quantity GPP - Gallons per day.
Quenching - Rapid cooling of alloys by immersion in water, oil, or
gases after heating.
Racking - The placement of parts on an apparatus for the purpose
of plating.
RackPlating - Electroplating of workpieces on racks.
XVI-34
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Radiography - A nondestructive method of internal examination
in which metal or other objects are exposed to a beam of
x-ray or gamma radiation. Differences in thickness, density
or absorption, caused by internal discontinuities, are
apparent in the shadow image either on a fluorescent screen
or on photographic film placed behind the object.
Raw Water - Plant intake water prior to any treatment or use.
Reaming - An operation in which a previously formed hole is sized
and contoured accurately by using a rotary cutting tool (reamer)
with one or more cutting elements (teeth). The principal sup-
port for the reamer during the cutting action is obtained from
the workpiece. 1. Form Reaming - Reaming to a contour shape.
2. Taper Reaming - Using a special reamer for taper pins. 3.
Hand Reaming - Using a long lead reamer which permits reaming
by hand. 4. Pressure Coolant Reaming (or Gun Reaming) -
Using a multiple-lip, end cutting tool through which coolant is
forced at high pressure to flush chips ahead of the tool or
back through the flutes for finishing of deep holes.
Receiving Waters - .Rivers, lakes, oceans, or other water courses
that receive treated or untreated wastewaters.
Recirculating Spray - A spray rinse in which the drainage is pumped
up to the spray and is continually recirculated.
Recycled Water - Process wastewater or treatment facility effluent
which is recirculated to the same process.
Recycle Lagoon - A pond that collects treated wastewater, most of
which is recycled as process water.
Reduction - A reaction in which there is a decrease in valence
resulting from a gain in electrons.
Redox - A term used to abbreviate a reduction-oxidation reaction.
Residual Chlorine - The amount of chlorine left in the treated
water that is available to oxidize contaminants.
Reverse Osmosis - The application of pressure to the surface of
solution through a semipermeable membrane that is too dense
to permit passage of the solute, leaving behind the dissolved
solids (concentrate).
Reused Water - Process wastewater or treatment facility effluent
which is further used in a different manufacturing process.
Ring Rolling - A metals process in which a doughnut shaped piece of
stock is flattened to the desired ring shape by rolling between
variably spaced rollers. This process produces a seamless ring.
XVI-35
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Rinse - Water for removal of dragout by dipping, spraying,
fogging, etc.
Riveting - Joining of two or more members of a structure by means
of metal rivets, the undeaded end being upset after the rivet
is in place.
Routing - Cutting out and contouring edges of various shapes in a
relatively thin material using a small'diameter rotating
cutter which is operated at fairly high speeds.
Running Rinse - A rinse tank in which water continually flows in
and out.
Rust Prevention Compounds - Coatings used to protect iron and steel
surfaces, against corrosive environment during fabrication,
storage, or use.
Salt - 1. The compound formed when the hydrogen of an acid is
replaced by a metal or its equivalent (e.g., an NH4 radical).
Example: HC1 + NaOH = NaCl + H20
This is typical of the general rule that the reaction of an
acid and a base yields a salt and water. Most salts ionize
in water solution. 2. Common salt, s6dium chloride, occurs
widely in nature, both as deposits left by ancient seas and
in the ocean, where its average concentration is about 3%.
Salt Bath Descaling - Removing the layer of oxides formed on some
metals at elevated temperatures in a salt solution. See:
Reducing, Oxidizing, Electrolytic.
Sand Bed Drying - The process of reducing the water content in a wet
substance by transferring that substance to the surface of a
sand bed and allowing the processes of:drainage through the
sand and evaporation to effect the required water separation.
Sand Blasting - The process of removing stock including surface
films, from a workpiece by the use of abrasive grains
pneumatically impinged against the workpiece.
Sand Filtration - A process of filtering wastewater through sand.
The wastewater is trickled over the bed of sand where air and
bacteria decompose the wastes. The clean water flows out
through drains in the bottom of the bed. The sludge accumulat-
ing at the surface must be removed from the bed periodically.
Sanitary Water - The supply of water used for sewage transport and
the continuation of such effluents to disposal.
Sanitary Sewer - Pipes and conveyances for sewage transport.
Save Rinse - See Dead Rinse.
XVI-36
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Sawing - Using a toothed blade or disc to sever parts or cut
contours. 1. Circular Sawing - Using a circular saw fed
into the work by motion of either the workpiece or the
blade. 2. Power Band Sawing - Using a long, multiple-
tooth continuous band resulting in a uniform cutting
action as the workpiece is fed into the saw. Power Hack
Sawing - Sawing in which a reciprocating saw blade is fed
into the workpiece.
Scale - Oxide and metallic residues.
Screening - Selectively applying a resist material to a surface
to be plated.
Secondary Settling - Effluent from some prior treatment process
flows for the purpose of removing settleable solids.
Secondary Treatment - The second step in most sanitary waste
treatment plants in which bacteria consume the organic
portions of the waste. This removal is accomplished by trick-
ling filters, an activated sludge unit, or other processes.
Sedimentation - The process of subsidence and deposition of suspended
matter carried by water, wastewater, or other liquids by
gravity. It is usually accomplished by reducing the velocity
of the liquid below the point at which it can transport the
suspended material. Also called settling.
Sensitization - The process in which a substance other than the
catalyst is present to facilitate the start of a catalytic
reaction.
Sequestering Agent - An agent (usually a chemical compound) that
"sequesters" or holds a substance in suspension.
Series Rinse - A series of tanks which can be individually heated
or level controlled.
Service Water - Raw water which has been treated preparatory to
its use in a process or operation; i.e., makeup water.
Settleable Solids - That matter in wastewater which will not stay
in suspension during a preselected settling period, such as one
hour, but either settles to the bottom or floats to the top.
Settling Ponds - A large shallow body of water into which indus-
trial wastewaters are discharged. Suspended solids settle
from the wastewaters due to the large retention time of water
in the pond.
XVI-37
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Shaping - Using single point tools fixed to a ram reciprocated in
a linear motion past the work. 1. Form Shaping - Shaping
with a tool ground to provide a specified shape. 2. Contour
Shaping - Shaping of an irregular surface, usually with the
aid of a tracing mechanism. 3. Internal Shaping - Shaping
of internal forms such as keyways and guides.
Shaving - 1. As a finishing operation, the accurate removal of a
thin layer by drawing a cutter in straight line motion across
the work surfaces. 2. Trimming parts like stampings, forgings
and tubes to remove uneven sheared edges or to improve accuracy,
Shearing - The process of severing or cutting of a workpiece by
forcing a sharp edge.or opposed sharp edges into the workpiece
by forcing a sharp edge or opposed sharp edges into the work-
piece stressing the material to the point of sheer failure and
separation.
i
i
Shipping - Transporting. I
Shot Peening - Dry abrasive cleaning of metal surfaces by impacting
the surfaces with high velocity steel shot.
Shredding - (Cutting or Stock Removal) Material cut, torn or broken
up into small parts. .
SIC - Standard Industrial Classification - Defines industries in
accordance with the composition and structure of the economy
and covers the entire field of economic activity.
Silica - (Si(^2_) Dioxide of silicon which occurs in crystalline form
as quartz, cristohalite, tridymite. Used in its pure form for
high-grade refractories and high temperature insulators and in
impure form (i.e. sand) in silica bricks.
Siliconizing - Diffusing silicon into solid metal, usually steel,
at an elevated temperature for the purposes of case hardening
thereby providing a corrosion and wear-resistant surface.
Sintering - The process of forming a mechanical part from a
powdered metal by bonding under pressure and heat but below
the melting point of the basis metal.
Sizing 1. Secondary forming or squeezing operations, required
to square up, set down, flatten or otherwise correct surfaces,
to produce specified dimensions and tolerances. See restriking.
2. Some burnishing, broaching, drawing and shaving operations
are also called sizing. 3. A finishing operation for correct-
ing ovality in tubing. 4. Powder metal. Final pressing of
a sintered compact.
XVI-38
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Skimming - The process of removing floating solid or liquid wastes
from a wastewater stream by means of a special tank and skim-
ming mechanism prior to treatment of the water.
Slaking - The process of reacting lime with water to yield a
hydrated product.
Sludge - Residue produced in a waste treatment process.
Sludge Dewatering - The removal of water from sludge by introducing
the water sludge slurry into a centrifuge. The sludge is
driven outward with the water remaining near the center. The
water is withdrawn and the dewatered sludge is usually land-
filled.
Slurry - A watery suspension of solid materials.
Snagging - Heavy stock removal of superfluous material from a work
piece by using a portable or swing grinder mounted with a
coarse grain abrasive wheel.
Soldering - The process of joining metals by flowing a thin
(capillary thickness) layer of nonferrous filler metal into
the space between them. Bonding results from the intimate
contact produced by the dissolution of a small amount of base
metal in the molten filler metal, without fusion of the base
metal. The term soldering is used where the temperature range
falls below 425°C (800°F).
Solids - (Plant Waste) Residue material that has been completely
dewatered.
Solute - A dissolved substance.
Solution - Homogeneous mixture of two or more components such as a
liquid or a solid in a liquid.
Solution Treated - (Metallurgical) A process by which it is
possible to dissolve micro-constituents by taking certain
alloys to an elevated temperature and then keeping them in
solution after quenching. (Often a solution treatment is
followed by a precipitation or aging treatment to improve
the mechanical properties. Most high temperature alloys which
are solution treated and aged machine better in the solution
treated state just before they are aged.)
Solvent - A liquid used to dissolve materials. In dilute solutions
the component present in large excess is called the solvent
and the dissolved substance is called the solute.
Solvent Cleaning - Removal of oxides, soils, oils, fats, waxes,
greases, etc. by solvents.
XVI-39
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Solvent Degreasing - The removal of oils and grease from a
workpiece using organic solvents or solvent vapors.
Specific Conductance - The property of a solution which allows
an electric current to flow when a potential difference is
applied.
Spectrophotometry - A method of analyzing a wastewater sample by
means of the spectra emitted by its constituents under
exposure to light.
Spray Rinse - A process which utilizes the expulsion of water
through a nozzle as a means of rinsing:.
Spinning - Shaping of seamless hollow cylindrical sheet metal parts
by the combined forces of rotation and pressure.
I
Spotfacing - Using a rotary, hole piloted end facing tool to produce
a flat surface normal to the axis of rotation of the tool on ow
slightly below the workpiece surface.
Sputtering - The process of covering a metallic or non-metallic
workpiece with thin films of metal. The surface to be coated
is bombarded with positive ions in a gas discharge tube,
which is evacuated to a low pressure.
Squeezing - The process of reducing the size of a piece of heated
material so that it is smaller but more compressed than it
was before.
Stainless Steels - Steels which have good or excellent corrosion
resistance. (One of the common grades contains 18% chromium
and 8% nickel. There are three broad classes of stainless
steels - ferritic, austenitic, and martensitic. These various
classes are produced through the use of various alloying
elements in differing quantities.
Staking - Fastening two parts together permanently by recessing
one part within the other and then causing plastic flow at
the joint.
Stamping - A general term covering almost all press operations.
It includes blanking, shearing, hot or cold forming, drawing,
bending and coining.
Stamping Compounds - See Forming Compounds (Sheet).
Standard of Performance - Any restrictions established by the Admin-
istrator pursuant to Section 306 of the Act on quantities,
rates and concentrations of chemical, physical, biological,
and other constituents which are or may be discharged from
new sources into navigable waters, the' waters of the contiguous
zone or the ocean.
XVI-40
-------
Stannous Salt - Tin based compound used in the acceleration process.
Usually stannous chloride.
Utill Rinse - See Dead Rinse.
Storm Water Lake - Reservoir for storage of storm water runoff
collected from plant site; also, auxiliary source of process
water.
Stress Relieved - The heat treatment used to relieve the internal
stresses induced by forming or heat treating operations.
(It consists of heating a part uniformly, followed by cooling
slow enough so as not to reintroduce stresses. To obtain low
stress levels in steels and cast irons, temperatures as high
as 1250 degrees F may be required.)
Strike - A thin coating of metal (usually less than 0.0001 inch in
thickness) to be followed by other coatings.
Stripping - The removal of coatings from metal.
Subcategory or Subpart - A segment of a point source for which
specific effluent limitations have been established.
Submerged Tube Evaporation - Evaporation of feed material using
horizontal steam-heat tubes submerged in solution. Vapors
are driven off and condensed while concentrated solution is
bled off.
Subtractive Circuitry - Circuitry produced by the selective etching
of a previously deposited copper layer.
Substrates - Thin coatings ( as of hardened gelatin) which act as a
support to facilitate the adhesion of a sensitive emulsion.
Surface Tension - A measure of the force opposing the spread of
a thin film of liquid.
Surface Waters - Any visible stream or body of water.
Surfactants - Surface active chemicals which tend to lower the
surface tension between liquids, such as between acid and
water.
Surge - A sudden rise to an excessive value, such as flow, pressure,
temperature.
Swaging - Forming a taper or a reduction on metal products such as
rod and tubing by forging, squeezing or hammering.
Tank - A receptacle for holding transporting or storing liquids.
XVI-41
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Tapping - Producing internal threads with a cylindrical cutting
tool having two or more peripheral cutting elements shaped
to cut threads of the desired size and form. By a combination
of rotary and axial motion, the leading end of the tap cuts
the thread while the tap is supported mainly by the thread it
produces.
i
Tempering - Reheating a quench-hardened or normalized ferrous alloy
to a temperature below the transformation range then cooling
at any rate desired. :
Testing - The application of thermal, electrical, or mechanical
energy to determine the suitability or functionality of a
part, assembly or complete unit.
Thermal Cutting - The term "thermal cutting" shall mean the process
of cutting, slotting or piercing a workpiece using an
oxy-acetylene oxygen lance or electric arc cutting tool.
Th e rm a1 Infus ion - The process of applying a fused zinc, cadmium or
other metal coating to a ferrous workpiece by imbueing the
surface of the workpiece with metal -powder or dust in the
presence of heat.
Thickener - A device or system wherein the solid contents of slurries
or suspensions are increased by gravity settling and mechanical
separation of the phases, or by flotation and mechanical separ-
ation of the phases.
Thickening - (Sludge Dewatering) Thickening or concentration is the
process of removing water from sludge after the initial separ-
ation of the sludge from wastewater. The basic objective of
thickening is to reduce the volume of liquid sludge to be
handled in subsequent sludge disposal processes.
Threading - Producing external threads on a cylindrical surface.
1. Die Threading - A process for cutting external threads
on cylindrical or tapered surfaces by the use of solid or
self-operning dies. 2. Single-Point Threading - Turing
threads on a lathe. 3. Thread Grinding - See definition
under grinding. 4. Thread Milling - A method of cutting
screw threads with a milling cutter.
i
i .
Th reshold Tox ic i ty - Limit upon which a substance becomes toxic or
poisonous to a particular organism.
Through Hole Plating - The plating of the inner surfaces of holes in
a PC board. ;
Titration - 1. A method of measuring acidity of alkalinity. 2. The
determination of a constituent in a known volume of solution by
the measured addition of a solution of known strength for complet-
ion of the reaction as signaled by observation of an end point.
XVI-42
-------
Total Chromium - The sum of chromium in all valences.
Total Cyanide - The total content of cyanide expressed as the
radical CN- or alkali cyanide whether present as simple or
complex ions. The sum of both the combined and free cyanide
content of a plating solution. In analytical terminology,
total cyanide is the sum of cyanide amenable to oxidation
by chlorine and that which is not according to standard
analytical methods.
Total Dissolved Solids (TDS) - The total amount of dissolved solid
materials present in an aqueous solution.
Total Metal - Sum of the metal content in both soluble and insoluble
form.
Total Organic Carbon (TOC) - TOC is a measure of the amount of
carbon in a sample originating from organic matter only. The
test is run by burning the sample and measuring the CC^2
produced.
Total Solids - The sum of dissolved and undissolved constituents
in water or wastewater, usually stated in milligrams per liter.
Total Suspended Solids (TSS) - Solids found in wastewater or in the
stream, which in most cases can be removed by filtration. The
origin of suspended matter may be man-made or of natural
sources, such as silt from erosion.
Total Volatile Solids - Volatile residue present in wastewater.
Tool Steels - Steels used to make cutting tools and dies. (Many of
these steels have considerable quantities of alloying elements
such as chromium, carbon, tungsten, molybdenum and other
elements. These form hard carbides which provide good wearing
qualities but at the same time decrease machinability. Tool
steels in the trade are classified for the most part by their
applications, such as hot work die, cold work die, high speed,
shock resisting, mold and special purpose steels.)
Toxic Pollutants - A pollutant or combination of pollutants including
disease causing agents, which after discharge and upon exposure,
ingestion, inhalation or assimilation into any organism either
directly or indirectly cause death, disease, cancer, genetic
mutations, physiological malfunctions (including malfunctions
in such organisms and their offspring.
Treatment Facility Effluent - Treated process wastewater.
Trepanning - Cutting with a boring tool so designed as to leave
an unmachined core when the operation is completed.
XVI-43
-------
Trickling Filters - A filter consisting of an artificial bed of
coarse material, such as broken stone, clinkers, slate, salts, or
brush over which an effluent is distributed and applied in drops,
films, or spray from troughs, drippers, moving distributors, or
fixed nozzles and through which it trickles to the underdrains
giving opportunity for the formation of zoological slimes which
clarify and oxidize the effluent.
Tumbling - See Barrel Finishing.
Tubidimeter - An instrument for measurement of turbidity in which
a standard suspension is usually used for reference.
Turbidity - 1. A condition in water or wastewater caused by the
presence of suspended matter resulting ; in the scattering and
absorption of light rays. 2. A measure of fine suspended
matter in liquids. 3. An analytical quantity usually report-
ed in arbitrary turbidity units determined by measurements of
light diffraction.
Turning - Generating cylindrical forms by removing metal with a
single-point cutting tool moving parallel to the axis of
rotation of the work. 1. Single-Point Turning - Using a
tool with one cutting edge. 2. Face Turning - Turning a
surface perpendicular to the axis of the workpiece. 3.
Form Turning - Using a tool with a special shape. 4.
Turning Cutoff - Severing the workpiece with a special
lathe tool. 5. Box Tool Turning - Turning the end of
workpiece with one or more cutters mounted in a boxlike
frame, primarily for finish cuts.
Ultrafiltration - A process using semipermeable polymeric membranes
to separate molecular or colloidal materials dissolved or
suspended in a liquid phase when the liquid is under pressure.
Ultrasonic Agitation - The agitation of a liquid medium through
the use of ultrasonic waves.
!
Ultrasonic Cleaning - Immersion cleaning aided by ultrasonic waves
which cause microagitation.
Ultrasonic Machining - Material removal by means of an ultrasonic-
vibrating tool usually working in an abrasive slurry in close
contact with a workpiece or having diamond or carbide cutting
particles on its end.
Unit Operation - A single, discrete process1 as part of an overall
sequence, e.g., precipitation, settlina anfi fi 1 f-r^f-ion.
Vacuum Deposition - Condensation of thin metal coatings on the cool
surface of work in a vacuum.
XVI-44
-------
Vacuum Evaporization - A method of coating articles by melting
and vaporizing the coating material on an electrically
heated conductor in a chamber from which air has been
exhausted. The process is only used to produce a decor-
ative effect. Gold, silver, copper and aluminum have been
used.
Vacuum Filtration - A sludge dewatering process in which sludge
passes over a drum with a filter medium, and a vacuum is
applied to the inside of the drum compartments. As the
drum rotates, sludge accumulates on the filter surface,
and the vacuum removes water.
Vacuum Metalizing - The process of coating a workpiece with
metal by flash heating metal vapor in a high-vacuum
chamber containing the workpiece. The vapor condenses on
all exposed surfaces.
Vapor Blasting - A method of roughing plastic surfaces in prepar-
ation for plating.
Vapor Degreasing - Removal of soil and grease by a boiling liquid
solvent, the vapor being considerably heavier than air. At
least one constituent of the soil must be soluble in the
solvent.
Vapor Plating - Deposition of a metal or compound upon a heated
surface by reduction or decomposition of a volatile compound
at a temperature below the melting points of either the
deposit or the basis material.
Viscosity - The resistance offered by a real fluid to a shear
stress.
Volatile Substances - Material that is readily vaporizable at a
relatively low temperature.
Volumetric Method - A standard method of measuring settleable
solids in an aqueous solution.
Waste Discharged - The amount (usually expressed as weight) of
some residual substance which is suspended or dissolved
in the plant effluent.
Wastewater Constituents - Those materials which are carried by
or dissolved in a water stream for disposal.
XVI-45
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APPENDIX A
EXHIBIT 1
Statistical Analysis of Cadmium (except new sources), Chromium, Copper, Lead,
Nickel, Silver, Zinc, Cyanide, Total Suspended Solids and Oil and Grease
Background
This exhibit provides documentation of the data and methods used to
determine final effluent guidelines limitations for the Metal Fininshing
industry. Limitations are expressed in concentration units (mg/1); production
based limitations were not developed because flow data were fragmentary and
relationships of flow to other indices of production were not reliable. The
Final Regulation for Effluent Limitations, Guidelines, and Standards for the
Metal Finishing Point Source Category specifies daily maximum and 10 day average
limitations for Best Practicable Control Technology Currently Available (BPT),
Best Available Technology Economically Achievable (BAT), Pretreatment Standards
for Existing Sources (PSES) Pretreatment Standards for New Sources (PSNS) and
New Source Performance Standards (NSPS).
Unless mentioned otherwise, limitations for the following pollutants
under each standard are based on the methodology, data, and results presented
in this exhibit. The standards will limit cadmium (Cd), total chromium (Cr^),
copper (Cu), lead (Pb), nickle (Ni), silver (Ag), zinc (Zn), total cyanide
and amenable cyanide (Cn^). Oil and Grease (OG), total suspended solids
(TSS) and pH are regulated only under BPT and NSPS, and are derived in accord
with this exhibit. The development of new source (PSNS and NSPS) Cd limits
are discussed in another exhibit. Guidance limitations for hexavalent chromium
(Cr°+) are also established here. The establishment of limits for TTO standards
are discussed in another exhibit.
Details regarding the technical background and justification for effluent
guidelines for the Metal Finishing Category are discussed in chapter VII of
the "Final Development Document for Effluent Limitations Guidelines and Standards
for the Metal Finishing Point Source Category".
Several appendices are referred to in this exhibit. They include computer
printouts which support the results reported here. These printouts are voluminous
and are not attached physically to this exhibit. They have, however, been
entered into the administrative record supporting the metal finishing rulemaking;
the titles to the Appendices are listed in Table 1.
Data
Two data sets are used for the development of the limitations; a set of
EPA collected and analyzed wastewater data, (refered to as EPA data) and a data
set of the results from self monitoring samples, collected and analyzed by
metal finishing plants as part of their compliance monitoring activities,
(refered to as self monitoring data).
A-l
-------
The EPA data are analytical results of samples collected at metal finishing
plants before and after wastewater treatment. The availability of paired raw
and treated waste data allows assessment of treatment when pollutants are pre-
sent in significant concentrations in the raw waste. Daily samples were generally
taken over a 1 to 3 day period (in some cases, as many as 6 daily samples were
taken at a plant). Total suspended solids (TSS) andjpH were measured and if
the treated waste samples had TSS concentrations greater than 50 mg/1 or pH
less than 7.0, the entire sample was deleted for all pollutants measured.
Plants with complexing, dilution, or poor operation were deleted.* Plants that
were not option 1 (precipitation-clarification) metal finishing plants were
also deleted. Effluent observations which were greater than influent observa-
tions taken on the same day were deleted. Also, effluent observations identified
by an iterative procedure were deleted. The iterative procedure is intended
to remove treated effluent values associated with low pollutant mesurements in
untreated wastewater and is described in Appendix A. The values remaining,
after all the deletions are listed in Appendix A. The treated effluent con-
centrations as listed in Appendix A for all pollutants, except Cd and Pb, are
used to calculate long term average pollutant concentrations in treated waste-
water. Cadmium and Pb means are from the self monitoring data discussed below.
Table 2 lists the pollutants, the number of observations, and the number of
plants used from the EPA sampling data. :
The self monitoring data were obtained from metal finishing plants where
sampling, analysis, and reporting of treated waste waters were conducted by
industry without EPA's direct involvement. Analytical methodology is reported
to have followed acceptable EPA methods. To the extent information was avail-
able, plants were checked for properly constructed and managed Option 1 treatment
systems. Raw waste data were not available for the self monitoring data to
measure treatment when pollutants are present in significant concentrations in
the raw waste; as an alternative the Agency used a pollutant only when there
was an identifiable process source of the pollutant. Self monitoring data
were used for the evaluation of variability, which will be presented in the
following data-analysis section. Table 3 lists the pollutants, the number
of observations and the number of plants chosen from the self monitoring data.
When pollutant concentrations were too low to be quantified they were
reported as below a detection limit (DL). For a particular pollutant-plant
data set, DL's could differ depending on the laboratory, sample dilution, or
methodology. Values reported at below a DL were set equal to zero for the
purpose of estimating variability and central tendency. This was done for the
* The cut-off criteria are: 1) plants that had complexing agents unoxidized
cyanide or nonsegregated wastes; 2) plants which had effluent flow signifi-
cantly greater than the corresponding raw waste flows were deleted; 3) plants
that experienced difficulties in system operation during the sampling period
were excluded. These difficulties include a few hours operation at very
low pH (approximately 4.0), observed operator error, an inoperative chemical
feed system, improper chemical usage, improperly maintained equipment, high
flow slugs during the sampling period, and excessive surface water intrusion
(heavy rains).
A-2
-------
following reasons: the data above the DL were found to generally fit the
lognormal distribution; the assignment of the value zero to DL observations
is recommended for estimation from data sets that are mixtures of DL observa-
tions and observations that fit the lognormal (see Owen and DeRouen, "Estimation
of the Mean for Lognormal Data Containing Zeroes and Left Censored Values,
with Applications to the Measurement of Worker Exposure to Air Contaminents",
Biometrics (1980), V. 36, pp. 707-719). Appendix B is a listing of the self
monitoring data and Appendix C presents summary statistics of the self moni-
toring data.
Analysis
Lognormal Goodness-of-Fit
Lognormality was examined graphically and tested for each pollutant-plant
combination in the self monitoring data base in Appendix B. The distributional
form of each plant-pollutant combination data set is displayed in Appendix D
as empirical frequency histograms of the data, before logarithmic transfor-
mation. A majority of the histograms have the general shape of the lognormal
distribution, i.e., positive skewness and long "tails" to the right. The
larger data sets tend to display the lognormal characteristics more than the
smaller data sets. This is not surprising since the lognormal distribution has
provided a satisfactory fit to effluent data for a wide range of industrial
categories and pollutants. The visual suggestion of lognormality is best
revealed in the larger sets as distributional shapes cannot be identified with
only a few observations.
Three goodness-of-fit tests were performed on the natural logarithms of
the self-monitoring data for each pollutant-plant combination for which suffi-
cient data were available. (Appendix E) If the distribution of the logarithms
of the data are not significantly different from the normal distribution then
the assumption of lognormality is reasonable. The Kolmogorov-Smirnov test
(KS), the Anderson-Darling test (AD) and the D'Agostino test (DA) were applied
to each pollutant-plant data set. These procedures test the null hypothesis
that the distribution of the logs of the observed values follow a normal distri-
bution. The DA test was not performed in some cases because the data did not
meet the minimum sample size required for the test. The three tests together
provide a thorough examination of the distributional form because the KS is a
general test of normality, the AD is sensitive to normality departures in
the tails, and DA is sensitive to normality departures in the higher moments.
Table 4 summarizes the results of the 3 significance tests and indicates that
the pollutant distributions within each plant frequently follow a lognormal
distribution. Appendix F contains time plots of the data which permit visual
inspection of data structure over time.
Daily Variability Factors
A variability factor (VF) for a pollutant-plant combination is defined as
the ratio of the lognormally estimated 99th percentile of the distribution of
within-plant pollutant values to the arithmetic mean of the same values. In
cases where there were DL observations present in the data, a generalized form
of the lognormal disbribution, known as the delta lognormal distribution (DLN)
was used to model the data. The delta lognormal distribution is described in
Chapter 9 of The Lognormal Distribution, by Aitchison and Brown, Cambridge
A-3
-------
University Press, 1963. The DLN is a mixed probability distribution, having
both discrete and continuous portions. The discrete portion models the possi-
bility of observing a DL value while the continuous portion is a lognormal
probability distribution and models the distribution of all values above the
DL.
The 99th percentile for the DLN is
5 ~ exp(y + Vq'cr)
where
q' = (.99 - 6)/(l - 6)
and
6 * probability of observing a DL value
Vq' is the quantile of order q1 of the N(0,l) distribution
Vq' - 2.326 if 6 = 0
The 99th percentile is estimated by using the following estimates of the
DLN parameters in the above formulae:
n where n is the number of DL values and n is the total number of
values
_ ni
x = £ xi/nl where x^ = In y^ for non DL values of y, _
i=l nj is the number 'of non DL values , and x
is the logmean of the non DL values
(x.. -7)/(ni - 1).
The DLN 99th percentile was not estimated if greater than 50% of the
observations for a pollutant-plant data set were DL lvalues. This is because a
large proportion of DL observations can introduce mathematical instabilities
into the estimates and result in extremely exaggerated and unreliable measures
of variability.
For each pollutant-plant combination a DLN 99th percentile was estimated
and divided by the arithmetic mean (AM) from the same pollutant-plant combina-
tion to estimate the daily VF. The median VF of all the plants that had data
on a particular pollutant was then used as the daily VF for that pollutant.
Table 5 presents the median daily VF for each pollutant. Appendix E is a
listing of each pollutant-plant combination and the corresponding goodness-of-
fit results, DLN parameter estimates, 99th percentiles, AMs, and VFs.
A-4
-------
Usable Self monitoring data were not available for silver so the average
median variability factor for CrT, Cu, Pb, Ni, Cd and Zn was used as an
estimate of the Ag VF.
Ten Day Variability Factors
Ten day variability factors were determined on the basis of the assumption
that averages of 10 samples drawn from the distribution of daily values are
approximately lognormally distributed. This characteristic of small sample
averages drawn from underlying distributions that are lognormally distributed has
been observed in effluent data from many different industry categories for a
wide variety of pollutants. This assumption was used as the basis of four
sample average monthly limitations in the effluent guideline regulations for
pretreatment standards for the electroplating industry. The assumption of log-
normality for the 10 day averages was also verified empirically by constructing
averages of sequences of 10 observations in the self monitoring data base and
examining their distributions. The listing of the 10 day average data are in
Appendix G. Summary statistics of the 10 day average are in Appendix H and
the empirical distributions of 10 day averages are listed in Appendix I.
Lognormal goodness-of-fit tests of the ten day average distributions are shown
in Appendix J. In general, the lognormal provides a reasonable fit to the data.
Appendix K presents plots of temporally sequential 10 day average data which
permit visual inspection of data structure over time.
The empirical distributions were used to estimate 10 day VF's using a
methodology identical to the calculation of the daily VFs. That is, the data
were fit to a lognormal distribution and the VF was determined by the ratio of
the estimated 99th percentile to the arithmetic mean. The DLN model was used
in some cases because there were several instances in the self monitoring data
when there are series of ten or more DL values in a row. Table 6 lists the 10
day average variability factors for each pollutant.
Effluent Limitations
The maximum daily and 10 day average effluent limitations were determined
by multiplying the long term average pollutant concentrations and the daily
and 10 day average variability factors, respectively. The long term average
concentration was determined by the arithmetic average of the EPA sample data
for each pollutant with the exception of Cd and Pb. For Cd and Pb the arithmetic
average of the self monitoring data was used. The AMs, daily VFs, 10 day VFs
and resulting limitations are shown in Tables 5 and 6. The VFs shown in Tables
5 and 6 are the median plant VFs of daily and 10 day VFs for each pollutant.
Alternative Methodologies Considered
Effluent limitations for the MF industry were determined on the basis of
median VFs and average effluent concentrations. Given the data on hand, however,
other methods of combining or averaging the results across plants to form
limitations are possible and reasonable alternatives. During the development
of daily maximum limitations for the MF regulation a variety of methodologies
were examined. These exploratory analyses were conducted to examine reasonable
alternatives and ensure that methods used to develop the final limitations
-------
were both appropriate and consistent with methods used previously in the pro-
posed metal finishing regulations. Consideration was also given to identifying
plants whose data exerted excessive influences on the results.
The daily maximum limitations that result from the various alternatives
considered are shown in Tables 7 and 8. Although the results in Tables 7 and
8 include plant 11118, it was discovered that for the pollutants reported for
this plant (Cr-^, Zn, Ni, Cn^, Cu, Pb, Cd), the mean concentration or variability
were excessive relative to the other plants with data for a particular pollutant.
This led to an engineering assessment of the plant|s wastewater treatment
system. Because plant 11118 was not isolating complexing wastewaters that
plant was not operating as an option 1 plant during the time the self monitoring
data were collected. Therefore, plant 11118 is not used in final limitations.
Column II in Table 7 lists the limitations including plant 11118 calculated
using the same methodology used to calculate the final limitations in Table 5
which do not include 11118.
The proposed and final limitations for MF used median plant VFs. During
the examination of other alternatives weighted mean VFs were also considered
and limitations based on these are listed in columns III and V of Table 7.
The median has the convienient interpretation of being the "middle most" value
in a set of data while the weighted mean procedure is an objective way of
combining data from sources providing unequal amounts of observations.
i
The EPA sampling data were also evaluated under various methodologies.
For both proposed and final limitations EPA data were used to establish a
long term average performance level for each pollutant (except Cd and Pb).
The EPA data for each pollutant were summarized as an AM and as a mean estimated
by fitting the data to a lognormal distribution. Each mean was then used in
combination with weighted mean self monitoring VF's and median self monitoring
VFs. These limitations are listed in columns II through V of Table 7. The
EPA data were also used to estimate limitations without the use of self moni-
toring data. These values are shown in column VI of Table 7.
Table 8 shows alternative limitation values based on the self monitoring
data only. In each case the variability factors and means were determined on
the basis of estimates of lognormal means and 99th percentiles calculated by
fitting the data to a lognormal distribution. The estimated lognormal means
are slightly different from the AM of the data but given that the data fit a
lognormal distribution it would be appropriate to use an estimated lognormal
mean. The AM and estimated lognormal mean are both estimates of the mean of
the distribution and thus either could be reasonable. Arithmetic means are,
of course, more easily understood and were used in proposal.
Appendix L details the results of alternative methods for computing 10
Day (average monthly) limitations.
A-6
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TABLE 1
List of Appendices Which Can Be Found in the Administrative Record
Appendix Title
A A Listing of the EPA Data Used for the Long Term
Mean
B A Listing of the Self Monitoring Data Used for
Estimating Variability
C Summary Statistics of the Self Monitoring Data
D Empirical Frequency Histograms of the Self Monitoring
Data
E Listing of Goodness-of-Fit Results, Delta Lognormal
Parameter Estimates, 99th Percentiles, Arithmetic
Means and Variability Factors for Each Pollutant-
Plant Combination in the Self Monitoring Data Base
F Plots Over Time of the Daily Self Monitoring
Pollutant Concentrations for Each Pollutant-Plant
Combination
G A Data Listing of the 10 Day Average Data Derived
from the Self Monitoring Daily Data
H Summary Statistics of the 10 Day Average Self
Monitoring Data
I Empirical Frequency Histograms of the 10 Day
Average Data Derived from the Self Monitoring
Daily Data
J Listing of Goodness-of-Fit Results, Delta Lognormal
Parameter Estimates, 99th Percentiles, Arithmetic
Means, and Variability Factors for Each Pollutant-
Plant Combination in the Derived 10 Day Average
Data Derived from the Self Monitoring Data
K Plots of Temporally Sequential 10 Day Average Data
of the Daily Self Monitoring Pollutant Concentrations
for Each Pollutant-Plant Combination
L Listing of 10 Day Limitations Using Various
Alternative Methodologies.
A-7
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TABLE 2
A Summary of the Pollutants, Number of Plants, and Number of Observations
Used to Establish the EPA Long Term Averages
Pollutant
TSS
OG
Cu
Pb
Ni
Zn
Ag
of Plants
36
16
6
20
5
22
5
20
17
15
15
2
of Observations
78
30
485
38
10
47
620
45
34
45
43
5
Data are from the self monitoring data set.
A-8
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TABLE 3
A Summary of the Pollutants, Number of Plants and Number of Observations
Used from the Self Monitoring Data
Pollutant
# of Plants
# of Observations
TSS
OG
Cd*
CrT*
Gr6+
Cu*
Pb*
Ni*
Zn*
CnT*
CnA
20
12
4
20
9
19
4
14
11
13
1
1777
893
463
3270
1811
2743
581
1750
1216
1198
28
* Plant 11118 is not included in the summary.
A-9
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TABLE 4
A Summary of Normality Tests Applied to the Natural Logarithms of the Daily
Self Monitoring Metal Finishing Data for Each Pollutant-Plant Combination
KS
AD
DA
TSS
OG
Cd
CrT
Cr6+
Cu
Pb
Ni
Zn
CnA
Total
*
20
12
4
9
9
19
4
14
10
10
1
Accept1
20
10
4
9
9
17
4
13
9
10
1
Accept1
100
83
100
100
100
90
100
93
90
100
100
Total
#
20
12
4
9
9
19
4
14
10
10
1
Accept1
12
8
2
4
2
10
2
7
6
3
1
Accept1
60
67
50
44
1
2;2
5-3
50
5p
60
1
30
100
Total
11
8
3
9
8
15
4
10
7
8
1
Accept1
10
6
2
6
2
9
2
6
5
5
1
Accept1
91
75
67
67
25
60
50
60
71
63
100
K-S - Kolmogorov-Smirnov test.
A-D - Anderson Darling test.
D-A - D'Agostino test.
* Fail to reject the null hypothesis that the data are from a lognormal
distribution.
A-10
-------
TABLE 5
Metal Finishing Daily Median Variability Factors, EPA Arithmetic Means, and
the Daily Maximum Limitations for Each Pollutant Parameter
TSS
OG
Cd
Cu
Pb
Ni
Zn
Ag
VF1
3.59
4.36
5.31
4.85
5.04
4.15
3.52
4.22
4.75
6.68
14.31*
4.4?
X2 (tng/1)
16.8
11.8
0.130
0.572
0.032
0.815
0.197
0.942
0.549
0.180
0.060
0.096
DAILY LIMIT3 (mg/1)
60.0
52.0
0.69
2.77
0.16
3.38
0.69
3.98
2.61
1.20
0.86
0.43
* Median plant variability factor calculated for each pollutant-plant combina-
tion by taking the ratio of the estimated delta lognormal 99th percentile to
the arithmetic mean.
2 Arithmetic mean of the EPA sampled data.
3 VF * X = Daily maximum limitation.
* VF based on only one plant with data suitable for estimating variability.
A-ll
-------
TABLE 6
Metal Finishing Ten Day Median Variability Factors, EPA Arithmetic Means,
and the Daily Maximum Limitations for Each Pollutant Parameter
TSS
OG
Cd
CrT
Or**
Cu
Pb
Ni
Zn
CnT
CnA
Ag
VF1
10
1.85
2.18
2.02
2.98
3.05
2.54
2.19
2.53
2.70
3.61
5.31
2.49
X2 (mg/1)
16.8
11.8
0.130
0.572
0.032
0.815
0.197
0.942
0.549
0.180
0.060
0.096
10 Day Limit3 (mg/1)
31.0
26.0
0.26
1.71
0.10
2.07
0.43
2.38
1.48
0.65
0.32
0.24
Median plant 10 day average variability factor calculated for each pollutant-
plant combination by taking the ratio of the delta lognorraal 99th percentile
(with detection limits equal to zero) to the arithmetic mean.
Arithmetic mean of the EPA sampled data.
—
VF,Q * X = 10 day average maximum limitation.
A-12
-------
TABLE 7
Metal Finishing Alternative Daily Maximum Limitations
I
ITSS
1
io&c
1
1
|Cd
1
iCrT
i
1
|Cr6+
1
1
|Cu
1
1
jPb
I
1
iNi
i
1
jZn
i
1
|CnT
|CnA
i
I
PROPOSED
LIMITS
60.1
42.2
1.29**
2.87
0.18
3.72
0.67**
3.51
2.64
1.30
0.54
II
MEDIAN VF
0 EPA X
60.8
51.8
1.41**
2.94
0.16
3.56
0.80**
4.17
2.40
1.29
0.71
III
WEIGHTED VF
0 EPA X
63.3
67.0
0.80**
2.55
0.14
3.89
0.79**
3.83
2.39
1.12
0.71
IV
MEDIAN VF
0 EPA LN MEAN
51.8
39.8
0.07
1.90
*
1.90
0.19
3.20
Oo92
*
*
V
WEIGHTED VF
0 EPA LN MEAN
54.6
51.5
0.04
1.65
*
2.08
0.19
2.94
0.91
*
*
VI
EPA SAMPLING!
DATA ONLY
(LN)
52.1
26.7
0.014
1.11
*
1.35
0.08
2.29
0.62
*
*
I Limits Proposed for Metal Finishing, August, 1982.
II Product of Self Monitoring Data Median Variability Factor (VF) based on
lognormal and EPA MF data arithmetic mean (X).
Ill Product of Self Monitoring Data Weighted Average VF~ and EPA MF data X.
IV Product of Self Monitoring Data Median VF and EPA MF data lognormal mean.
V Product of Self Monitoring Data Weighted Average VF and EPA MF data lognormal
mean.
VI EPA MF data only, lognormal 99th percentile estimate.
* EPA MF data required to estimate lognormal mean not available.
** The arithmetic means of the EPA data were not used for these limitations.
Instead, the arithmetic means of the self monitoring data were used.
A-13
-------
TABLE 8
Metal Finishing Alternative Daily Maximum Limitations
Self Monitoring Data Only
1
ITSS
i
i
IO&G
|Cd
i
I Cr"^
i
jCr&+
1
ICu
1
iPb
iNi
1
|Zn
1
I0"
1°
I
MEDIAN VF °
WTG. LN MEAN
32.9
12.7
1.46
1.02
0.10
1.91
0.78
1.73
1.88
3.51
*
II
WTG. VF °
WTG. LN MEAN
34.7
16.4
0.83
0.88
0.09
2.09
0.77
1.59
1.88
1.30
*
III
MEDIAN VF °
MED. LNiMEAN
28.2
13.2
0.97
0.81
0.09
•
0.92
t
i
0.85
i
i
1.36
1.36
0.75
*
I IV
1
1 WTG. VF °
i MED. LN MEAN
i
t 30.8
I
1 17.0
I
i 0.56
j
1 0.70
I
I
i 0.07
i
i 1.01
1
1 0.84
1
1 1.25
1
t 1.35
j
I 0.65
1
( *
1
I Product of Median plant variability factors based on lognormal and weighted
average of plant estimated lognormal means.
II Product of weighted average of plant lognormal variability factors and
weighted average of plant lognorraal means.
Ill Product of median plant lognormal variability factors and median of plant
lognormal mean.
IV Product of weighted average of plant lognormal variability factors and
median of plant lognormal means.
* Self monitoring data on Cn" suitable for estimation were available from
only one plant with excessive variability. Accordingly, limitation values
were not calculated.
A-14
-------
EXHIBIT 2
Analysis of Total Toxic Organic (TTO) Data
Background
The final effluent guideline regulation for the Metal Finishing (MF)
industry contains limitations on TTO. The purpose of including TTO limitations
is to require MF facilities to practice control of the release of toxic organics,
into process wastewaters. This exhibit documents the data and analysis used
to determine two daily limitations for TTO. The data sources and industrial
sector to which each limitation applies are outlined in Table 1.
Data
Total toxic organic data are presented in Appendix A. Each value is
the sum of all toxic organic compounds found in the sample. In Chapter 6
there is a description of the toxic organic chemicals whose concentrations are
summed to arrive at TTO, when toxic organic chemicals were reported below the
detection limit (DL) the measurement was assigned a value equal to the DL.
This yields TTO concentrations that tend to be slightly higher than actual
concentrations and results in less stringent limitations than would be obtained
by setting DL values equal to zero or some value between zero and the detection
limit. TTO concentrations calculated by setting the DL values equal to zero
(DL = 0) were also calculated; (indicated by "<" in the Table). Although summary
information was examined for TTO concentrations generated using the DL=0
technique, no limitations were developed using these data.
Plants with TTO data were divided into three categories: Option 1 plants,
(plants with precipitation-clarification) Option 2 plants (plants with preci-
pitationclarification plus filtration) and other than Option 1 and Option 2
plants. Option 1 plants were used to estimate end-of-pipe TTO limits.
These data are shown in Table 2; descriptive information regarding the limit
derived from the data is in Table 1, section A. Raw waste TTO limits were
estimated using the raw waste TTO data from all three categories. These
data are shown in Table 3; descriptive information regarding the limit derived
from these data is in Table 1, section B.
The data were also classified on the basis of other characteristics.
This was done to investigate combinations of plants that would be expected, on
the basis of processes, pre- and post-process water quality characteristics,
products, or type of work, to generate larger amounts of TTO than other groups
of plants. The processes were classified into two categories, painting and
solvent degreasing (these two processes were specifically examined because
they have higher TTO concentrations in the raw waste than metals finishers
without these processes). Classifications were also provided for the raw
waste stream, oil and grease (OG) concentration (which is an indicator of
certain processes), and the TTO concentration in the plant's influent water
supply ("supply stream"). The raw waste stream oil and grease data were used
to place plants into groups with concentrations above and below 100 mg/1 OG.
The supply stream TTO data were used to categorize plants into groups with
concentrations above and below 0.1 mg/1 TTO. There were three product
A-15
-------
categories: printed circuit board manufacturing, automotive, and auto
assembly. The type of work also considered, i.e., plants were classified as
job shops or captives. If their work was partially job order or partially
captive, then a percentage of involvement was generally provided. This array
of classifications allows examination of the TTO characteristics of various
components of the Metal Finishing Industry. The number of plants and
observations used for the Option 1, treated effluent based analysis within
each of the above described categories and various combinations are reported
in Table 2. Similar information for the raw waste based analysis of the
Option 1, Option 2, and other than Option 1 or Option 2 plants are reported in
Table 3. The overall EPA metal finishing TTO data base is comprised of 75
observations from 29 plants. There were from 1 to 4 observations per plant.
Analysis
Metal Finishing plants that paint and also solvent degrease (P&SD) discharge
more toxic organic chemicals than any other sector of the metal finishing
industry, with the partial exception of the automobile assembly plants (AA)
(Tables 2 and 3). The P&SD group is the intersection of the painting group and
the solvent degreasing group; i.e. it includes only plants that fit in both
groups. P&SD plants were used to establish an overall mean. The overall mean
specifically includes the AA plants because the AA plants are a subset of the
P&SD plants. The P&SD group represents a more reasonable measure of process
control than the AA plants; because P&SD plants are identifiable by the use of
solvent degreasers and paints which are linked to the process rather than to
the type of product produced. Finally, and significantly, there are more
observations in the P&SD group (N=4 for the end-of-pipe data and N=5 for the
untreated waste data) than in the AA group (N=2). Data based on process and
larger sample sizes give a better measure of appropriate levels.
!
!
The painting or solvent degreasing group (PorSD) is the union of painting
and solvent degreasing plants — it includes plants from either group — and
is used to estimate overall variability. It is appropriate to estimate vari-
ability from the PorSD group because it corresponds with the processes used in
the P&SD group which provided the mean and because there are more observations
in the PorSD group than in the P&SD (Tables 2 and 3). The variability of the
PorSD group is expressed as a variability factor (VF) which is calculated by
dividing the lognormal estimate of the 99th percentile by the arithmetic mean.
Details of the formulae and calculations are presented in Appendix B. Table
4 lists the data used for the treated effluent analysis; Table 5 lists the
data used for the raw waste analysis.
The daily limitations are presented in Table 6. The VF from the PorSD
group is multiplied by the arithmetic mean from the P&SD group to calculate
the daily limitations.
In conclusion, these limitations are rather high as a result of the heavy
consideration given to the painting and/or solvent:degreasing operations at
some MF plants. By comparison, if the entire data set was used, the daily
maximum limitations for the raw waste option 1, option 2, and other than option
1 and option 2 plants would be 0.71 mg/1 TTO and for the treated effluent of
option 1 plants the daily maximum limitation would be 0.19 mg/1 TTO.
A-16
-------
TABLE 1
AN OUTLINE OF EACH TTO LIMITATION (A AND B)
DESCRIBING THE DATA SOURCE AND INDUSTRIAL APPLICATION
A. Limits calculated using TTO concentrations after treatment of toxic metals
with option 1 technology (precipitation—clarification).
a. DATA SOURCE: Treated wastes of option 1 plants.
b. APPLICATION: Applies to Metal Finishing (MF) and Electroplating
Pretreatment (part 413, PSES) plants expected to treat toxic metals
with precipitation-clarification treatment.
B. Limits calculated using TTO concentrations before treatment of waste waters,
a. DATA SOURCE: Raw wastes, prior to treatment from option 1, option 2,
and non option 1 or option 2 plants.
b. APPLICATION: An interim limit for MF that applies prior to complying
with limits in A, above. This is also a limit that applies to part
413, PSES for plants which are not expected to treat toxic metals with
precipitation-clarification technology, namely, those discharging
less than 10,000 gals/day.
A-17
-------
TABLE 2
SUMMARY OF TTO (mg/1) DATA FROM THE TREATED EFFLUENT OF
OPTION 1 METAL FINISHING PLANTS
# of # of
Subset
Solvent Degreasing
Solvent Degreasing
& not Painting
Painting
Painting & not Solvent
Degreasing
Neither Painting nor
Solvent Degreasing
Either painting or
Solvent Degreasing
Painting and Solvent
Degreasing
Printed Circuit
Board Manufactuers
Automobile Assembly
Plants
100% Jobshops
Any Jobshop Work
100% Captive
Any Captive Work
TTO in the water supply
greater than 0.1 mg/1
fTO in the water supply
less than 0.1 mg/1
O&G in the raw waste
greater than 100 mg/1
O&G in the raw waste
less than 100 mg/1
TOTAL
X « arithmetic mean, „ »
Plants
9
5
7
3
17
12
4
4
2
11
14
16
19
3
21
4
22
29
Observations
18
14
10
6
51
24
4
12
2
32
41
38
47
6
52
6
62
75
X
0.209
0.144
0.231
0.095
0.030
0.180
0.434
0.166
0.536
0.046
0.064
0.088
0.095
0.171
0.084
0.231
0.064
0.078
u
-2.257
-2.630
-1.854
-2.593
-4.309
-2.33
-.931
-2.318
-0.643
-3.934
-3.808
-3.646
-3.590
-1.904
-3.796
-1.714
-3.845
-3.694
_OJ1
"'""W ""^•"
1.019
1.019
0.521
0.521
0.850
0.948
—
1.061
—
0.864
0.939
0.783
0.882
0.423
0.909
0.521
0.838
0.875
log mean, o ™ pooled within plant log standard deviation,
P
A-18
-------
TABLE 3
SUMMARY OF TTO (mg/1) DATA FROM THE RAW WASTE OF OPTION 1, OPTION 2, and
OTHER THAN OPTION 1 & OPTION 2 METAL FINISHING PLANTS
Category
Solvent Degreasing
Solvent Degreasing
& not Painting
Painting
Painting & not Solvent
Degreasing
Neither Painting nor
Solvent Degreasing
Either Painting or
Solvent Degreasing
Painting and Solvent
Degreasing
Printed Circuit
Board Manufactuers
Automobile Assembly
Plants
100% Jobshops
Some Jobshop Work
100% Captive
Some Captive Work
TTO in the water supply
greater than 0.1 mg/1
TTO in the water supply
less than 0.1 mg/1
O&G in the raw waste
greater than 100 mg/1
O&G in the raw waste
less than 100 mg/1
TOTAL
X = arithmetic mean p = log mean a = pooled within plant log standard deviation.
P
t of
Plants O1
11
6
10
5
20
16
5
4
2
13
16
21
24
3
27
5
31
45
# of
bservation
23
18
17
12
56
35
5
12
2
36
45
49
58
7
69
9
82
90
s X
0.381
0.186
0.473
0.220
0.112
0.326
1.081
0.249
1.354
0.089
0.124
0.247
0.250
0.431
0.164
0.456
0.165
0.194
ji
-1.965
-2.467
-1.542
-2.172
-3.434
-2.032
-0.156
-2.156
0.284
-3.189
-3.198
-2.734
-2.808
-1.430
-3.1003
-2.022
-2.982
-2.095
0
1.149
1.149
0.658
0.658
0.579
1.012
—
1.378
—
0.608
0.842
0.658
0.848
0.898
0.664
.250
0.778
.752
A-19
-------
TABLE 4
A SUMMARY OF THE DATA USED TO CALCULATE
LIMITS FOR THE TREATED EFFLUENT OF OPTION 1
METAL FINISHING PLANTS
CATEGORY
FLANT
2032
4069
4071
6019
17061
20005
20103
9025
28699
30165
44062
34051
TTO1
ing/1
0.082
0.207
0.081
0.254
0.131
0.322
0.032
0.040
0.093
0.483
0.699
0.020
0,034
0.430
0.181
0.008
0.643
0.130
0.228
0.122
0.081
0.016
0.007
In
TTO P or SD2 P & SD3
-2.501 x
-1.575
-2.513
-1.370 x
-2.033
-1.133
-3,442 x
-3.219
-2.375
-0.728 x x
-0.358 x
-3.912
-3.381
-0.844 x x
-1.709 x x
-4.828 x
-0.442 x x
-2.040 x
-1.478 x
-2.104
-2.513
-4.135 x
-4.962
1 Concentrations of TTO after processing by the treatment facility.
„ i
z Painting or Solvent Degreasing is performed at the plant.
3 Painting and Solvent Degreasing is performed at the plant.
x Indicates category membership.
-------
TABLE 5
A SUMMARY OF THE DATA USED TO CALCULATE LIMITS FOR THE RAW WASTE OF OPTION 1,
OPTION 2, AND OTHER THAN OPTION 1 OR OPTION 2 METAL FINISHING PLANTS
CATEGORY
PLANT
2032
4069
4071
4282
6019
9025
17061
20103
28699
44062
30165
34051
17050
TTO1
mg/1
1.161
0.031
0.109
0.022
0.113
0.178
0.032
0.040
0.093
0.283
0.473
0.000
0.251
0.289
0.888
0.036
0.141
1.938
1.619
0.098
0.110
0.107
0.140
0.091
0.095
0.111
1.083
0.477
In
TTO
0.149
-3.474
-2.216
-3.817
-2.180
-1.726
-3.147
-2.017
-2.040
-1.262
-0.749
-1.382
-1.241
-0.119
-3.324
-1.959
0.662
0.482
-2.323
-2.207
-2.235
-1.966
-2.397
-2.354
-2.198
0.090
-0.740
P or SD2 P & SD3
X
X
X
X X
X X
X
X
X X
X X
X
X
x • " • :-
X
-------
TABLE 5 (CON'D)
A SUMMARY OF THE DATA USED TO CALCULATE LIMITS FOR THE RAW WASTE OF OPTION 1,
OPTION 2, AND OTHER THAN OPTION 1 OR OPTION 2 METAL FINISHING PLANTS
CATEGORY
In
PLANT TTO1 TTO P or SD2 P & SD3
rag/I
18538 0.064 0.030
0.012 0.056
0.009 0.001
2033 0.028 -3.576
0.030 -3.507
0.011 -4.510
33692 1.090 0.086
1 Concentrations of TTO before processing by the treatment facility!
2 Painting or Solvent Degreasing is performed at the plant,
3 Painting and Solvent Degreasing is performed at the plant.
x Indicates category membership.
A-22
-------
TABLE 6
DAILY LIMITATIONS FOR TTO (mg/1) IN THE METAL FINISHING INDUSTRY
Yp or SD2 Y.993 VFp ^ so4 LIMIT5
Raw Waste6 1.081 0.326 1.380 4.23 4.57
Treated Effluents7 0.434 0.180 0.883 2.13
1 Arithmetic mean of plants that paint and solvent degrease.
2 Arithmetic mean of plants that either paint or solvent degrease.
3 Lognoraal estimates of the 99th percentile (Appendix B) from plants that
paint or solvent degrease.
* Variability factor from plants that paint or solvent degrease,
VF = X.99/Xp or SD.
5 Limitation = VFp or SD ' ¥p&SD
6 TTO concentrations from the raw wastewater of option 1, option 2, and
nonoption 1 or 2 metal finishing plants.
' TTO concentrations from the treated wastewater option 1 metal finishing
plants.
A-23
-------
EXHIBIT 2
APPENDIX A
A-24
-------
METAL FINISHING - OPT ION 1 PLANTS FOR TTO DATA BASE
>
Plant
ID
Metal Auto
Job Finishing Solvent Automotive Assembly
Shop Captive PCBH Plant Pegreasing Painting Plant Plant
Supply
Water Water Supply Total Raw
Sampled TTO >0.1 mq/g. O&G >100 mq/jl
10%
90%
2032
4069
4071
4282
4892*
6019
6090
6091
6110
6960
9025
9052
12061
15193*
15608
17061
19068
20005
20022
20083
20103
21003
21051* 40%
27046
28699
30054
30165
34050 / / v
34051 / / / v
38051 / V v
38052 V / v
41051 V /
44062 / / V v
* No total raw waste or total effluent TfO data available.
** Electroplating-captive, wire drawing - job shop - no percentage breakdown supplied
General Cable Corporation (likely captive).
70%
75%
/**
30%
25%
60%
No
-------
Plant ID
2032
4069
4071
4282
4892
6019
6090
6091
6110
6960
9025
9052
12061
15193
15608
17061
19068
20005
20022
20083
20103
21003
21051
27046
28699
30054
30165
38052
41051
44062
34050
34051
38051
Total Raw
/*
/*
/*
/*
METAL FINISHING - OPTION 1 PLANTS
TTO DATA BASE
Total
Effluent
V
v
/*
/*
Example
streams
* Total raw TTO from precision and
accuracy study.
* 14-0 - total raw not available.
* 14-0 - no TTO raw waste data.
* 21-1 - no TTO effluent data.
* 15-2 - no TTO raw waste data.
*15-0 - no TTO effluent data.
-------
fTO DATA SIMOTA1X - METAL FINISHING - OPTION 1 PLANTS
TTO Concentration (mg/8.)
RAW
with <
4282-21-0
0,283
W/O <
2032-15-0
2032-15-2
2032-15-5
4069-15-0/1
4069-15-2/3
4069-15-4
4011-15-0
4071-15-1
4071-15-3
1.161
0.031
0.109
0.022
0.113
0.178
0.043
0.133
0.130
1.158
0.026
0.103
0.014
0.109
0.175
0.035
0.124
0.121
0.283
EFFLUENT
With <
0.082
0.207
0.081
0.254
0.131
0.322
0.032
0.040
0.093
W/O <
0.075
0.202
0.074
0.245
0.121
0.322
0.019
0.032
0.089
NO DATA
6090-14-0
6090-15-1
6090-15-2
6091-15-0
6091-15-1
6091-15-2
6110-15-0
6110-15-1
6110-15-2
6960-15-0/1
6960-15-2/3
6960-15-4/5
9025-15-0
9025-15-1
9025-15-2
0,097
0.486
8.466
— —
0.010
0.009
0.009
0.104
0.204
0.059
0
0.251
0.289
0.093
0.475
8.458
0
0
0
0.099
0.198
0.052
0
0.248
0.285
0.203
0.052
36.355
0.019
0.001
0.019
0.006
0.005
0.006
0.056
0.144
0.038
0
0.008
18.005
0.199
0.043
37.342
0.015
0
0.018
0.001
0
0
0.049
0.142
0.036
0
0
18.0
FOOTNOTE:
— = No total plant wastewater TTO data available.
No Data = No toxic organics data available.
A-27
-------
TfO DAfA SUMMARY - MEfAL FINISHING - OPTION 1 PLANTS
TTO Concentration (mg/SL)
RAW
EFFLUENT
9052-15-0
9052-15-1
9052-15-2
12061-14-0
12061-15-0
12061-15-1
12061-15-2
15608-15-0
15608-15-1
15608-15-2
17061-14-1
17061-15-1
17061-15-3
1 Qrt^HO—. 1 A f\
JL"UOO l*i U
19068-15-1
19068-15-2
With <
0.009
0.040
0.012
—
0.006
0.030
0.006
0.019
0.038
0.017
0.888
0.036
0.141
JNU U
0.120
0.202
W/O <
0
0.034
0.003
—
0.0001
0.030
0.0001
0
0.032
0.0001
0.886
0.031
0.139
A1A
0.119
0.196
With <
0.010
0.002
0.007
1 -
0.037
0.005
0.014
0.008
0.004
0.013
0.015
0.699
0.020
0.034
OnoK
. UZ3
0.017
6.016
W/O <
0
0
0
0.037
0
0
0.0001
0.0001
0
0.0001
0.696
0.012
0.011
OJTlOO
* \J 4tt\J
0.010
0.013
10005-21-0
0.430
0.357
20022-15-0
20022-15-1
20022-15-2
20083-15-0/1
20083-15-2/3
10083-15-4/5
0.020
0.008
0.007
0.002
0.003
0.003
0.0009
0
0
0.0004
0
0.0001
0.008
0.016
6.009
6.004
0.004
0.007
0.0003
0
0
0
0
0.0001
20103-21-0
20103-21-1
21003-15-0
21003-15-1
21003-15-2
1.938
0.034
0.040
0.014
1.868
0.024
0.034
0
. 181
0,002
0.035
6.008
0.061
0.002
0.028
0.007
POOTNOYB:
— = No total plant wastewater TTO data available.
No Data = No toxic organics data available.
A-28
-------
TTO DATA SUMMARY - METAL FINISHING - OPTION 1 PLANTS
(Continued)
TTO Concentration (rng/8,)
RAW
With <
W/O <
EFFLUENT
With <
W/O <
27046-15-0
27046-15-1
27046-15-2
0.426
0.400
0.420
0.398
NO DATA
0.012
0.002
0.007
0
0
0
28699-12-0
1.619
1.619
0.643
0.643
30054-15-0
30054-15-1
30054-15-2
0.364
0.769
1.287
0.354
0.761
1.282
0.067
0.140
0.109
0.060
0.138
0.108
30165-21-0
0.140
0.070
0.130
0.060
34050-15-0
34050-15-1
34050-15-2
34051-15-0
34051-15-1
34051-15-2
38051-15-0
38051-15-1
38051-15-2
38052-15-0
38051-15-1
38052-15-2
41051-15-0
41051-15-1
41051-15-2
44062-15-0
44062-15-1
44062-15-2
6019
6019 (P&A)
—
0.091
0.095
0.111
0.224
0.259
0.097
0.099
0.192
0.200
0.014
0.020
0.023
0.098
0.110
0.107
0.473
—
0.086
0.084
0.110
0.214
0.255
0.094
0.096
0.188
0.199
0.001
0.014
0.018
0.087
0.101
0.097
0.473
0.007
0.020
0.007
0.016
0.007
0.007
0.005
0.003
0.180
0.012
0.109
0.013
0.024
0.012
0.228
0.122
0.081
0.485
0.483
0
0.011
0
0
0
0
0
0
0.173
0
0.101
0
0.018
0
0.227
0.110
0.074
0.485
0.483
FOOTNOTE:
— = No total plant wastewater TTO data available.
No Data = No toxic organics data available.
A-29
-------
METAL FINISHING - OPTION 2 PLANTS FOR TTO DATA BASE
Metal Auto
Plant Job Finishing Solvent Automotive Assembly
ID Shop Captive PCBH Plant Degreasing Painting Plant Plant.
Supply
Water Water Supply Total Raw
Sampled TTO >0.1 rag/it OSG >100.mg/t
1
w
o
12075 / / / /
14062* V / V / /
17050 / / / /
18538 / / / /
31031* /'//./ / /
36048 / / / /
* Ho total raw waste or total effluent TTO data available.
-------
METAL FINISHING - OPTION 2 PLANTS
ffO DATA BASE
I
w
Total
Plant ID Total Raw Effluent
12075 / /
14062
17050 /* /
18538 / V
31031
36048 /
Example
Streams
/
/
/
/
/
*14-0 - no TTO raw waste data.
-------
IfO DATA SUMMARY - METAL FINISHING - OPTION 2 PLANTS
i
TTO Concentration (mg/fi.)
RAW
EFFLUENT
12075-15-0/1
12075-15-2/3
12075-15-4/5
17050-14-0
17050-15-0
17050-15-1
With <
0.028
0.021
0.042
1.083
0.477
¥/O <
0.0003
0.0004
0.020
1.081
0.475
With <
0.043
0.010
0.007
0.400
0.003
0.037
W/O <
0.025
0
0
0.400
0
0.032
18538-14-0
18538-15-3
18538-15-5
36048-15-0/1
36048-15-2/3
36048-15-4/5
0.064
0.012
0.009
0.019
0.004
0
0.030
0.056
0.001
0.415
0.103
0.091
0
0.055
0.413
0.097
0.081
FOOTNOTE;
— = No total plant wastewater TTO data Available.
No Data = No toxic organics data available.
A-32
-------
METAL FINISHING - OTHER THAN OPTION 1 08 2 PLANTS FOR THE TTO DATA BASE
w
w
Plant
ID
2033
3043
11103
11108
12065
13042
19069
20170
21066
30166
31032
33692
36178
38040
38217
40060
Job
Metal
Finishing Solvent
Auto
Autemot ive Assembly
Shop Captive PCBM Plant Degreasing Painting Plant
Plant
Supply
¥ater Water Supply Total law
Sampled TTO >0.1 mg/il O&G >100 mq/jl
NO
NO
-------
HETftL FINISHING - OfHBR THM OPTION 1 OR 2 PLANTS
FOR THE TTO DATA BRSE
Plant ID
2033
3043
11103
11108
12065
21066
20170 :
31032
30166
36178
40060
19069
33692
38040
38217
13042
Total Raw
Total
Effluent
Example
Streams
/*
*15-0 - No TTO effluent data.
-------
fTO DATA SUMMARY - MBTAL FINISHING PLANTS
OTHER THAN OPTION 1 or 2
TTO Concentration (mg/l)
RAW
With <
13042-21-1
38217-23-0
40060-15-0
40060-15-1
.008
.009
W/O <
19069-15-0
19069-15-1
19069-15-2
21066-15-0
21066-15-1
21066-15-3
33692-23-0
33692-23-1
36178-21-0
36178-21-1
36178-21-2
38040-23-0
38040-23-1
—
0.012
0.011
0.014
1.09
13.50
0.285
0.326
2.005
—
--
0
0.001
0.003
1.08
13.49
0.285
0.326
2.005
—
.0001
EFFLUENT
With <
W/O <
2033-15-0/1
2033-15-2/3
2033-15-4/5
11103-15-0
11103-15-2/3
11103-15-4
11108-15-0
11108-15-1
11108-15-2
12065-14-1
12065-15-2
12065-15-4
0.028
0.030
0.011
0.084
0.010
0.013
0.011
0.005
0.007
—
0.012
0.019
0.003
0.069
0.0001
0.0001
0
0.003
0
—
0.014
0.010
0.014
0.011
0.009
0.009
0.005
0.006
0.001
2.52
0.189
0.153
0.011
0.0007
0.013
0.0001
0.0001
0.0001
0
0
0.001
2.52
0.168
0.144
0.165
0.005
0.007
0.007
0.009
0.011
0.823
0.433
0.257
0.140
0.120
0.288
0.377
0.673
0.012
0.012
0.165
0
0
0
NO DATA
0
0
0.763
0.373
0.257
0.140
0.120
0.218
0.327
0.634
0
0
FOOTNOTE;
— - No total plant wastewater TTO data available.
No Data = No toxic organics data available.
A-35
-------
EXHIBIT 2
APPENDIX B
A-36
-------
DEFINITIONS
K
K
ni
total number of plants
number of observations at
plant i
total number of observa-
tions
concentration of TTO in
mg/1, observation j at
plant i; j = 1,..., n^,
•*» ~~ JL f * * * f K.
natural logarithm of TTO
in mg/1
. .
1=1 3=1
mean of the logs
n
2i
i _
i -Xij)/ni-l
within plant variance,
for plant i
K
T (ni-1) a2,
1
pooled within plant
variance
a - / a2
P P
E(Y) = e P + O 2/2
.99 " e
U -I- 2.326
pooled within plant
standard deviation
estimated mean (expected
value) of the distribution
of Y
estimated 99th percentile
» I I
ni
arithmetic mean of all
observations
A-37
-------
METAL FINISHING - TTO
RAW WASTE - OPTION 1, OPTION 2, AND OTHERS
Daily Data
P or SD; N - 35
y = 2.032
02 = 1.024
P
a - 1.012
YP _ -2.032+2.326(1.021)
x.99 ~ e
» e0.322
= 1.380
E(Y) = e-2.032+0.5(1.024)
e-1.520
- 0.219
Y" - 0.326
P&SD:
N - 5
Y = 1.081
A-38
-------
METAL FINISHING - TTO
TREATED EFFLUENT - OPTION 1
Daily Data
P or SD; N =24
y = 2.33
o2 = 0.899
P
o = 0.948
v _ -2.334-2.326(. 948)
I QQ ~ &
*yy . e-.125
= 0.883
E(Y) = e-2.33+.5(.899)
= e-1.88
= 0.153
¥ = 0.180
P&SD;
N =4
Y = 0.434
A-39
-------
EXHIBIT #3
Analysis of New Source Cadmium (Cd) Data
Introduction
This exhibit documents the data and methodology used to determine New
Source Performance Standards i(NSPS) and Pretreatment Standards for New Sources
(PSNS) for the Metal Finishing Industry for Cadmium1 (Cd). The NSPS for Cd
will require treatment of the segregated waste from Cd plating, acid cleaning
of Cd plated parts, and chromating of Cd plated parjts with evaporative recovery
or ion exchange technology. These processes are the major sources of Cd in
the Metal Finishing Industry, but there are no knowb metal finishing plants in
existence that have all components of the treatment1 technology required by
NSPS. Some plants, for example, have evaporative recovery applied to their Cd
plating operation, but not the acid cleaning or chromating which is instead
commingled with other wastes prior to wastewater treatment.
The evaporative recovery and ion exchange technologies are capable of
eliminating the discharge from Cd related processes and thereby reducing con-
centrations of Cd to extremely low levels. In order to estimate treated effluent
Cd concentrations achievable using these technologies, we have examined data
on Cd concentrations in the untreated wastewater from metal finishing plants
that do not plate Cd. It has been found that in the untreated wastes of plants
not involved with Cd plating, measurable quantities of Cd still exist, possibly
from source waters or from the waste water of operations that do not plate Cd
but contain low concentrations of Cd. Therefore, in order to establish NSPS
limits for Cd we have assumed that background concentrations from the raw
waste streams of metal finishing plants not involved with Cd plating are similar
to the Cd concentrations in wastewaters that have been treated according to
NSPS requirements.
Data
The data from plants not involved with Cd plating are listed in Appendix
A and include measurements of Cd (mg/1) in raw (untreated) wastewater. The
sampling and analyses were conducted by EPA. There are a total of 61 measure-
ments from 27 plants. Eight of the 27 plants have single observations. The
data range from 0.005 mg/1 to 0.095 mg/1 Cd.
A-40
-------
Analysis
The data were assumed to follow a lognormal distribution by plant. The
lognormal has been found to provide a satisfactory fit to effluent data for a
wide range of industrial categories and pollutants.* This data base includes
too few values from any given plant to confirm the assumption of lognormality;
however they do not contradict it. Cadmium concentrations have been trans-
formed using the natural logarithm function and are hereafter refered to as
logs. (The symbol "In" means natural logarithm).
Because the data exhibited large plant to plant variation, several methods
of grouping the plants into subsets with statistically homogenous means were
examined. The subsets are based on a statistical partitioning of the data.
They should reflect variation in underlying unidentifiable sources of cadmium.
The purpose of this exercise was to assess the possibility of determining
limitations on the basis of groups of statistically homogenous plant values.
Subsets were chosen based on several statistical comparisons of plant means:
Duncan's multiple range test, Student-Newman-Keuls, Scheffe's, and Tukey's
tests. These tests examine the log means of plants with multiple observations
and place them into groups with nonsignificantly different means. The groups
can overlap, for example, a given plant or several plants can have log means
that are intermediate in size between two groups (a larger mean group and a
smaller mean group). The plants with intermediate log means are not statisti-
cally larger than the small mean group, and not statistically smaller than the
large mean group; therefore, these plants fall in the overlap between the two
groups and it would be reasonable to include them in both or either group(s).
Thus, subset definition, because of the overlap, is somewhat flexible. Five
groupings emerged that were supported by the four mean comparison tests.
These are shown in Appendix B.
The large variation in Cd levels among the 5 groups of plants suggested
that limitations could be based reasonbly on subsets of the plants that were
homogenous statistically. Accordingly, the NSPS Cd limits are based on subsets
of the plants with the largest mean Cd concentrations. The data from these
subsets are shown in Table 1. The plants with the statistically largest mean
are designated as subset 2. Plants in the group with the next largest mean
are included in subset 1 along with the two plants in 2. Although only plants
with multiple observations were included in the multiple comparison tests, plants
with single observations that fell within the group ranges are also listed in
Table 1. The mean used in determining the NSPS Cd limits was taken from subset
2 (the set with the largest mean.) The variance estimate used to determine
variability was taken from subset 1 because this provided a reasonable quantity
of data with which to estimate the variance and an F test showed that the
pooled within plant variance for subset 1 was significantly greater than the
variance for the other subsets combined.
* The methodology used here for fitting the lognormal distribution to effluent
data across plants is discussed in detail in the Final Development Document
for the Porcelain Enameling Industry, EPA 440/1-82/072.
A-41
-------
Table 2 presents several statistics that summarize the entire data set
and statistics based on three methods of partitioning the Cd raw waste
concentration data into subsets.
!
L, ;.. , ': , : ,. .: :
The limits are based upon the variability of subset 1 and the mean of
subset 2. The variability is expressed as a variability factor (VF) and
calculated by dividing the estimated 99th percentile (daily and 10-day 99th
percentile estimates as described in Appendix C) from subset 1 by the arithmetic
mean from subset 1. The mean Cd concentration is obtained from subset 2; the
subset 2 arithmetic mean is then multiplied by the subset 1 variability factors
to arrive at daily maximum and 10-day average maximum limitations (shown in
Table 3). This multiplication, therefore, used both the highest variability
group and the highest mean concentration group, producing a limit that is
larger than would result from reliance on any single group.
In conclusion, it should be noted that the limitations in Table 3 are
large relative to the limitations calculated using the entire data set. If
all 61 observations had been used for the VF and the overall mean, the daily
maximum and 10-day average maximum limitations would be 0.017 and 0.0115 mg/1
of Cd respectively. (see Table 2). This serves to illustrate the effect of
using subsets of plants for the purpose of determining limitations.
A-42
-------
TABLE 1
Subsets of Cd (mg/1) Concentrations that have Higher Values
(Subsets with lower values are presented in Appendix B)
Plant
4065
6074
6083
6731
15070
19063
20080
27044
31020
31022
33024
33073
36041
Raw Cd (mg/1)
0.005
0.032
0.019
0.021
0.033
0.013
0.015
0.017
0.019
0.009
0.013
0.014
0.011
0.012
0.013
0.024
0.022
0.021
0.011
0.013
0.095
0.013
0.013
0.015
0.042
0.042
0.053
In Cd
-5.2983
-3.4420
-3.9633
-3.8632
-3.4112
-4.3428
-4.1997
-4.0745
-3.9633
-4.7105
-4.3428
-4.2687
-4.5099
-4.4228
-4.3428
-3.7297
-3.8167
-3.8632
-4.5099
-4.3428
-2.3539
-4.3428
-4.3428
-4.1997
-3.1701
-3.1701
-2.9375
Subsets
1
1
1
1
1
1
1
1
1
1
1 2
1
1 2
N - 27
A-43
-------
TABLE 2
Estimates for NSPS Cd (mg/1) in
the Metal Finishing Industry
Daily E(Y)
All plants 0.0093
All plants except
plant 33024 0.0089
Subset A Plants 0.0197
Subset B Plants 0.0551
10 Day
All plants
All plants except
plant 33024
Subset A Plants
Subset B Plants
Y.qq Y
0.017 0'.013
0.017 0!.012
0.045 o'.023
0.075 0.075
i • •
Y.qg (10)'
0.012
0.009
0.026
0.061
M
-4.726
-4.765
-3,998
-2.908
JLLO_ _
-4.683"
-4.722
-3.931
-2.900
op
0.2937
0.2937
0.3885
0.1342
_°JLO
0.0947
0.0947
0.1273
0.0424
E(Y) = estimated lognormal mean
^.99 = estimated lognormal 99th percentile
p = estimated log mean
0 = estimated pooled within plant log standard deviation
« estimated 10 day average 99th percentile
- estimated 10 day log mean
~ estimated 10 day log standard deviation
A-44
-------
TABLE 3
A Summary of Values Used to Estimate the NSPS Cd Limitations
YA1 Y_B2 I.993 VFA4 Limit5
Daily 0.023 0.058 0.045 1.96 0.114
10-Day 0.026 1.13 0.066
Arithmetic mean of subset A.
Arithmetic mean of subset B.
Lognormal estimates of 99th percentile, daily and 10-day, based on data from
subset A.
5
Variability Factors from subset A, VF^
Limitation = VFA * ¥fi.
A-45
-------
EXHIBIT 3
APPENDIX A
A-46
-------
Cd DATA BASE
Observation
Number
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
Plant ID
6101-12-1
6101-12-1
19068-14-0
11477-22-1
11477-22-2
15010-12-2
15010-12-3
4065-8-1
4069-8-1
4069-8-1
5020-1-4
5020-1-5
5020-1-6
19051-6-0
20078-1-2
20078-1-3
20078-1-4
20078-1-7
36040-1-1
36040-1-1
36040-1-1
31021-1-2
31021-1-3
20083-1-3
33692-23-1
31021-1-1
33070-1-1
5020-1-3
33065-9-1
33070-1-3
40062-8-0
Raw (mg/1)
.001
.002
.002
.002
.002
.004
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.005
.006
.006
.006
.007
.007
.007
.008
.008
Observation
Number
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
Plant ID
40062-8-0
33065-9-1
15070-1-3
19063-1-1
31022-1-2
19063-1-2
20083-1-5
20082-1-6
31022-1-0
33073-1-1
33073-1-3
6083-1-2
15070-1-1
19063-1-3
15070-1-2
33073-1-2
6731-1-1
6731-1-2
6074-1-1
6731-1-3
6074-1-1
31020-1-1
27044-1-0
20080-1-1
4065-8-1
6074-1-1
36041-1-2
36041-1-3
36041-1-1
33024-6-0
Raw (mg/1)
.008
.009
.009
.011
.011
.012
.012
.012
.013
.013
.013
.013
.013
.013
.014
.015
.015
.017
.019
.019
.021
.021
.022
.024
.032
.033
.042
.042
.053
.095
A-47
-------
EXHIBIT 3
APPENDIX B
A-48
-------
DEPENDENT VARIABLE:
SOURCE
MODEL
ERROR
CORRECTED TOTAL
MODEL F =
R-SQUARE
0.914324
SOURCE
PLANT
SOURCE
PLANT
NEW SOURCE CADMIUM DATA IN MG/L
NATURAL LOGARITHMS OF CADMIUM (MG/L)
GENERAL LINEAR MODELS PROCEDUEE
LNRAWCD NAT LOG OF CONG. FOR NS CD MG/L
DF SUM OP SQUARES MEAN SQUARES
19 30.37781823 1.59883254
33 2.84653212 0.08625885
52 33.22435035
18.54
C.V.
6.1396
DF
19
DF
19
PR > F = 0.0001
ROOT MSB LNRAWCO MEAN
0.29369808 -4.78368585
TYPE I SS F VALUE PR > F
30.37781823 18.54 0.0001
TYPE III SS F VALUE PR > F
30.37781823 18.54 0.0001
A-49
-------
NEW SOURCE CADMIUM DATA IN MG/L .
NATURAL LOGARITHIMS OF CADMIUM (MG/L)
GENERAL LINEAR MODELS PROCEDURE
DUNCAN'S MULTIPLE RANGE TEST FOR VARIABLE: LNRAWCD
NOTE: THIS TEST CONTROLS THE TYPE 1 COMPARISONWISE ERROR RATE, NOT THE
EXPERIMENTWISE ERROR RATE.
ALPHA = 0.05
DR
33
MSE = .0862585
WARNING: CELL SIZES ARE NOT EQUAL.
HARMONIC MEAN OF CELL SIZES =2.5
**MEANS WITH THE SAME LETTER ARE NOT SIGNIFICANTLY DIFFERENT.***
DUNCAN CLUSTERS
C
C
C
C
C
C
C
C
C
C
C
C
C
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
A
B
B
B
B
B
E
E
E
E
E
E
E
E
E
E
E
G
G
G
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
MEAN
-3.0925
-3.7459
-4.0792
-4.2951
-4.3702
-4.4252
-4.4263
-4.4407
-4.6539
-4.5283
-4.8362
-4.8951
-5.2142
-5.2375
-5.2983
-5.2983
-5.2983
-5.4099
-6.2146
-6.5612
A-50
N
3
3
3
3
2
3
2
3 .
3
2
2
2
4
3
4
2
3
2
2
2
PLANT
36041
6074
6731
33073
4065
19063
31022
15070
20083
40062
33065
33070
5020
31021
20078
4069
36040
15010
1147?
6101
GROUPING
1
2
3
4
5
-------
NEW SOURCE CADMIUM DATA IN MG/L
NATURAL LOGARITHIMS OF CADMIUM (MG/L)
GENERAL LINEAR MODELS PROCEDURE
STUDENT-NEWMAN-KEULS TEST FOR VARIABLE: LNRAWCD
NOTE: THIS TEST CONTROLS THE TYPE I EXPERIMENTWISE ERROR RATE UNDER THE COMPLETE
NULL HYPOTHESIS BUT NOT UNDER PARTIAL NULL HYPOTHESES
MSB = .0862585
ALPHA = 0.05 DF = 33
WARNING: CELL SIZES ARE NOT EQUAL.
HARMONIC MEAN OF CELL SIZES =2.5
MEANS WITH THE SAME LETTER ARE NOT SIGNIFICNATLY DIFFERENT.
SNK CLUSTERS
A
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
B
B
B
B
B
B
B
B
B
B
B
B
B
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
-3
-3
-4
-4
-4
-4
-4
-4
-4
-4
-4
-4
— S
— 5
-5
-5
-5
-5
MEAN
.0925
.7459
.0792
.2951
.3702
.4252
.4263
.4407
.6539
.8283
.8362
.8951
.2142
.2375
.2983
.2983
.2983
.4099
N
3
3
3
3
2
3
2
3
3
2
2
2
4
3
4
2
3
2
PLANT GROUPING
36041 1
6074 '.. 2
6731
33073
4065
19063
31022
15070
20083 3
40062
33065
33070 ' . -
5020 4
31021
20078
4069
36040
15010
A-51
-------
NEW SOURCE CADMIUM DATA IN MG/L
NATURAL LOGARITHMS OF CADMIUM (MG/L)
GENERAL LINEAR MODELS PROCEDURE
SNK CLUSTERS
G
G
G
MEAN
-6.2146
-6.5612
N
2
2
PLANT
11471
6101
GROUPING
5
A-52
-------
NEW SOURCE CADMIUM DATA IN MG/L
NATURAL LOGARITHMS OF CADMIUM (MG/L)
GENERAL LINEAR MODELS PROCEDURE
TUKEY'S STUDENTIZED RANGE (HSD) TEST FOR VARIABILE: LNRAWCD
NOTE: THIS TEST CONTROLS THE TYPE I EXPERIMENTWISE ERROR RATE, BUT GENERALLY
HAS A HIGHER TYPE II ERROR RATE THAN REGWQ.
ALPHA = 0.05
DF - 33
MSB = .0862585
CRITICAL VALUE OF STUDENTIZED RANGE = 5.432
MINIMUM SIGNIFICANT DIFFERENCE = 1.009
WARNING: CELL SIZES ARE NOT EQUAL.
HARMONIC MEAN OF CELL SIZES =2.5
MEANS WITH THE SAME LETTER ARE NOT SIGNIFICANTLY DIFFERENT.
TUKEY CLUSTERS
A
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
„
F
F
F
F
F
F
F
F
F
F
F
F
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
A
A
A
A
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
MEAN
-3.0925
-3
-4
-4
-4
-4
-4
-4
-4
-4
_4
-4
^C
-5
-5
-5
-5
-5
.7459
.0792
.2951
.3702
.4252
.4263
.4407
.6539
.8283
.8362
.8951
.2142
.2375
.2983
.2983
.2983
.4099
N
3
3
3
3
2
3
2
3
3
2
2
2
4
3
4
2
3
2
PLANT GROUPING
36041 1
6074 2
6731
33073
4065
19063
31022
15070
20083 3
40062
33065
33070
5020 4
31021
20078
4069
36040
15010
A-53
-------
NEW SOURCE CADMIUM DATA IN MG/L
NATURAL LOGARITHMS OF CADMIUM (MG/L)
GENERAL LINEAR MODELS PROCEDURE
TUKEY CLUSTERS MEAN N| PLANT GROUPING
G -6.2146 2, 11477 5
G ;
G -6.6512 2 6101
A-54
-------
NEW SOURCE CADMIUM DATA IN MG/L
NATURAL LOGARITHIMS OF CADMIUM (MG/L)
GENERAL LINEAR MODELS PROCEDURE
SCHEFFE'S TEST FOR VARIABILE: LNRAWCD
NOTE: THIS TEST CONTROLS THE TYPE I EXPERIMENTWISE ERROR RATE, BUT GENERALLY
HAS A HIGHER TYPE II ERROR RATE THAN REGWF FOR ALL PAIRWISE COMPARISONS.
ALPHA = 0.05
DF = 33
MSB = .0862585
CRITICAL VALUE OF T = 1.38254
MINIMUM SIGNIFICANT DIFFERENCE = 1.58307
WARNING: CELL SIZES ARE NOT EQUAL.
HARMONIC MEAN OF CELL SIZES =2.5
MEANS WITH THE SAME LETTER ARE NOT SIGNIFICANTLY DIFFERENT.
SCHEFFE CLUSTERS
A
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
E
E
E
E
E
E
E
E
E
E
E
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
-3
-3
-4
-4
-4
—4
-4
-4
-4
-4
-4
-4
-5
-5
-5
-5
-5
-5
MEAN
.0925
.7459
.0792
.2951
.3702
.4252
.4263
.4407
.6539
.8283
.8362
.8951
.2142
.2375
.2983
.2983
.2983
.4099
A-55
N
3
3
3
3
2
3
2
3
3
2
2
2
4
3
4
2
3
2
PLANT GROUPING
36041 1
6074 2
6731
33073
4065
19063
31022
15070
20083 3
40062
33065
33070
5020 4
31021
20078
4069
36040
15010
-------
NEW SOURCE CADMIUM DATA IN MG/L
NATURAL LOGARITHIMS OF CADMIUM (MG/L)
GENERAL LINEAR MODELS PROCEDURE
SCHEFFE CLUSTERS
D E
D E
E
MEAN
-6.2146
-6.5612
N
2
2
PLANT
11477
6101
GROUPING
5
A-56
-------
EXHIBIT 3
APPENDIX C
A-57
-------
Definitions
K
K
N
total number of plants
number of observations at
plant i
total number of observa-
tions
concentration of Cd in
mg/1, observation j at
plant i; j—1, ..., n£,
3.— I j * » « j IX
natural logarithm of Cd
observation in mg/1
K
mean of the log
02 , I (n.-i) 0
P i-1
K
within plant variance,
plant i
pooled within plant variance
B(Y) = e
p + 02/2
Y.99 = e
w + 2.3260p
pooled within plant
standard deviation
estimated mean (expected
value) of the distribu-
tion of Y
estimated 99th percentile
of the distribution of Y
K
p (10) = p + a2/2 - (0.5)ln(_ef_2 + 10-1)
P 10 10
arithmetic mean of all
observations
10-day log mean estimate
A-58
-------
Definitions (Con'd)
2
a2(10) = In e + 10-1 10-day log variance estimate
10 10
Y<99(10) = e^10 + ^«^°olu 10-day 99th percentile
estimate
A-59
-------
Metal Finishing - NSPS Cd
All Data
Dail-s
N - 61
V = 4.726
O2n = 0.08626
Op = 0.29370
10 Day
Y . e-4.726+2.326(0.2937)
* y y
a e-4.726+.6832 = e-4.0429
= 0.018
E(Y) - e-4.726+.5(.08626)
» 0.0093
VF - with plant 33024
Overall Mean - with plant 33024
U10 = y + .5( a2 ) - (.5) In e +
n
n-1
n
= -4.726 + ,5(.08626) -
= -4.6874
o2 t
= In e + "-1
.08626
I'O
+ .9
In
,.08626
- -
10
Y.99(10)
.00897
P 9
e 10 + 2'
--
10
10
-4. 6874+2. 326C. 0947)
.0115
= .0947
A-60
-------
Metal Finishing - NSPS Cd
All Data Without Plant 33024
Dail
N = 60
U = -4.765
o2p = 0.08626
ap = .29370
.99
_ -4. 765+2. 326(. 2937)
~
= .017
E(Y) = e~4'765+('5)'08626
= 0.0089
10 Day
= U
= -4.765 + .0387
= -4.7264
a210 = -00897
a10 = .0947
_ -4.7264+2.326(.00897)
.99(10) ~ e
= .0091
VF - without plant 33024
Overall Mean - without plant
33024
n n
A-61
-------
Metal Finishing - NSPS Cd
Using High Effluent Concentration Plants
Subset A
Dail-v
N = 27
U = -3.998
VF - using subset A
Overall Mean - using subset A
= 0.1510
0.3886
10 Day
Y = e-3. 998+2. 326(0. 3886)
= 0.045
E(Y) = e~3. 998+0. 5(. 1510)
= .0198
= P + .5 ( a
n n
= -3.998 + (.5X.1510) - (.5)ln
= -3.9306
a2 = In e'1510 + .9
~~
= .0162
010 = .1273
^-3. 9306+2. 326(. 1273)
,.1510 + .9
10
Y.99(10)
.0264
A-62
-------
Daib
Metal Finishing - NSPS Cd
Using High Effluent Concentration Plants
, Subset B
10-Day
y = -2.908
a2 = 0.0180
0p = 0.1342
v _ -2. 908+2. 326(. 1342)
Y.99 ~ e
= .0746
E(X) = e-2. 908+0. 5(. 0180)
= .0551
X" = .058
.5
VF - using subset B
Overall Mean - using subset B
n-1
.018
= -2.908 + .5C.018) - (.5)ln _f + _9
10 10
10
= -2.900
.018
= In e
10
9
10
10
Y.99(10)
= .0018
= .0424
= e-2.90+2.326(.0424)
= .0610
A-63
------- |