600284152
FIELD MANUAL
PERFORMANCE EVALUATION AND TROUBLESHOOTING
AT
METAL-FINISHING
WASTEWATER TREATMENT FACILITIES
by
T. N. Sargent, P.E.
G. C. Patrick, P.E.
E. H. Snider, Ph.D., P.E.
Engineering-Science, Inc.
Atlanta, Georgia 30329
EPA Contract No. 68-03-3040
Project Officer
Thomas J. Powers
Industrial Pollution Control Division
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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FIELD MANUAL
PERFORMANCE EVALUATION AND TROUBLESHOOTING
AT
METAL-FINISHING
WASTEWATER TREATMENT FACILITIES
by
T. N. Sargent, P.E.
G. C. Patrick, P.E.
E. H. Snider, Ph.D., P.E.
Engineering-Science, Inc.
Atlanta, Georgia 30329
EPA Contract No. 68-03-3040
Project Officer
Thomas J. Powers
Industrial Pollution Control Division
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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PREFACE
For the first time, an operating and troubleshooting manual has
been put together to assist plant operators and managers of wastewater
treatment plants for the metal finishing industry. This performance
evaluation and troubleshooting guide has been reviewed by true experts
of plating wastewater treatment - the plant operators. Without their
day to day insight into operational and maintenance problems, the ini-
tial field manual effort would not have been possible.
A more detailed development of this guide is destined for the
future. Only by widespread use and evaluation can this manual be re-
vised and upgraded to reflect the current and future trends of complex
treatment and control technology systems required for the metal finish-
ing industry. It is hoped that this field manual will guide plant
operators in achieving consistently higher performance levels.
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CONTENTS
Abstract iv
Figures v
Tables vi
Abbreviations and Symbols vii
1 . Introduction 1
Purpose and Scope of Manual 1
Manual Format 1
2. Literature Review 3
Analysis of Permit Violations 3
Operation and Maintenance Specifics 4
3. Problem Assessment and Recommendations for
Improving Permit Compliance 8
Conventional Wastewater Treatment 8
Problem Assessment 1 0
Recommendations for Improving Permit Compliance 14
Resource Recovery 1 6
4. Equalization 19
Introduction 19
Theory of Operation 19
Description of Equipment 21
Operational Procedures 25
Typical Performance Values 29
Troubleshooting Guide 29
5. Oil Removal ' 29
Introduction 32
Theory of Operation 33
Description of Equipment 35
Operational Procedures 42
Typical Performance Values - 51
Troubleshooting Guide 52
6. Cyanide Oxidation 57
Introduction 57
Theory of Operation 57
Description of Equipment 62
Operational Procedures 64
Typical Performance Values 70
Troubleshooting Guide ' 70
7. Chromium Reduction 74
Introduction 74
Theory of Operation 74
Description of Equipment 75
Operational Procedure 77
Typical Performance Values 85
Troubleshooting Guide 85
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Contents (cont.)
8. pH Control 88
Introduction 88
Theory of Operation 88
Description of Equipment 91
Operational Procedures 98
Typical Performance Values 109
Troubleshooting Guide 109
9. Metal Precipitation 113
Introduction 11 3
Theory of Operation 113
Description of Equipment 11 5
Operational Procedures 118
Typical Performance Values 128
Troubleshooting Guide 1 32
10. Flocculation 135
Introduction 135
Theory of Operation 135
Description of Equipment 136
Operational Procedures 137
Typical Performance Values 144
Troubleshooting Guide 144
11. Sedimentation 147
Introduction 147
Theory of Operation 147
Description of Equipment 148
Operational Procedures 149
Typical Performance Values 159
Troubleshooting Guide 159
12. Filtration 163
Introduction 163
Theory of Operation 163
Description of Equipment 164
Operational Procedures 167
Typical Performance Values 171
Troubleshooting Guide 171
13. Gravity Thickening 179
Introduction 179
Theory of Operation 1 79
Description of Equipment 183
Operational Procedures 1 85
Typical Performance Values 191
Troubleshooting Guide 1 91
14. Belt Filter Presses 196
Introduction 196
Theory of Operation 196
Description of Equipment 1 97
Operational Procedures 197
Typical Performance Values 204
Troubleshooting Guide 204
ii
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Contents (cont,)
15. Vacuum Filtration 207
Introduction 207
Theory of Operation 207
Description of Equipment 208
Operational Procedures 214
Typical Performance Values 221
Troubleshooting Guide 222
16. Pressure Filtration for Dewatering 229
Introduction 229
Theory of Operation 229
Description of Equipment 231
Operational Procedures 235
Typical Performance Values 241
Troubleshooting Guide • 241
17. Centrifugation 245
Introduction 245
Theory of Operation 245
Description of Equipment 246
Operational Procedures 252
Typical Performance Values 262
Troubleshooting Guide 263
References 271
Appendix A - Computer Literature Search 273
Appendix B - Regulations Affecting the Metal Finishing 381
Industry
Appendix C - Metric-English Units Conversion 410
111
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ABSTRACT
This manual provides a technical field guide or reference document
for use in improving the performance of facilities for the treatment of
metal finishing wastes. The main purpose of the manual is to provide a
troubleshooting guide for identifying problems, analyzing problems, and
solving problems.
The manual describes general procedures for evaluating the perfor-
mance of treatment processes and equipment commonly used in metal fin-
ishing waste treatment. The procedures also cover other items related
to the effective operation of treatment facilities.
The methodology used to evaluate compliance problems and develop
Operation and Maintenance (O&M) specifics are described in a review of
the literature, followed by an assessment of the causes of permit vio-
lations and the recommended measures for) improving compliance.
The unit processes described in this manual are those commonly used
in the treatment of metal finishing wastes. They are the following:
equalization, oil removal, cyanide oxidation, chromium reduction, pH
control, metal precipitation, flocculation, sedimentation, filtration,
gravity thickening, belt filter presses, vacuum filtration, pressure
filtration for dewatering, and centrifugation. For each of these unit
processes, the manual contains information on theory of operation, de-
scription of equipment, operational procedures, typical performance
values, and a troubleshooting guide.
IV
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FIGURES
Number Page
1 Electroplating Industry Conventional Wastewater Treatment 9
2 Methods of Equalization 22
3 API Separator 37
4 Line Diagrams of Principal DAF Process Variations 39
5 Destruction Time Required for Cyanate Vs pH 59
6 Distribution of HOCL and OCL 61
7 Two-Stage Cyanide Destruction 63
8 Hexavalent Chromium Reduction with Sulfur Dioxide 76
9 Relationship Between Hexavalent Chromium, pH, and
Retention Time for Sulfur Dioxide 81
10 Relationship Between ORP, Sodium Bisulfite Required, and pH 83
11 A Sample Titration Curve 90
12 Feedback Mode of pH Control 93
13 Feedforward Mode of pH Control 94
14 Feedback-Feedforward Mode of pH Control 96
15 Lead Solubility for a Typical Wastewater 114
16 Lead Solubility as a Function of Carbonate Concentration 116
17 Metal Concentration Versus Treatment Process 117
18 Metal Concentration After Treatment Process 119
19 Metal Concentration Versus Treatment Process 122
20 Solubility of Selected Heavy Metal Hydroxides 124
21 Theoretical Solubilities of Metal Hydroxides and Sulfides
as a Function of pH 1 26
22 Wastewater Treatment Processes for Removing Heavy Metals 127
23 Effect of Gravity Thickening upon Solids Concentration 180
24 Effect of Time on Sludge Compaction 182
25 Liquid Zones in a Continuously Operated Thickener 184
26 A Simple Belt Filter Press 198
27 Operating Zones of a Vacuum Filter 210
28 Typical Equipment Layout of Rotary Vacuum Filter System 213
29 Cutaway View of a Filter Press 232
30 Side View of a Filter Press 233
31 Cross Section of Concurrent Flow Solid-Bowl Centrifuge 247
32 Schematic Diagram of a Basket Centrifuge 249
33 Disc Type Centrifuge 251
v
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TABLES
Number Page
1 Equalization Troubleshooting Guide 30
2 Oil Removal Process Monitoring Requirements 43
3 Oil Removal Troubleshooting Guide 53
4 Cyanide Oxidation Process Monitoring Requirements 65
5 Horsepower Requirements for Medium Agitation 69
6 Cyanide Oxidation Troubleshooting Guide 71
7 Chromium Reduction Process Monitoring Requirements 78
8 Chromium Reduction Troubleshooting Guide 86
9 pH Adjustment Troubleshooting Guide 110
10 Metal Precipitation Process Monitoring Requirements 121
11 Metal Precipitation Troubleshooting Guide 133
12 Flocculation Process Monitoring Requirements 138
13 Flocculation Troubleshooting Guide 145
14 Sedimentation Process Monitoring Requirements 151
15 Sedimentation Troubleshooting Guide 160
16 Filtration Process Monitoring Requirements 169
17 Filtration Troubleshooting Guide 172
18 Gravity Thickening Process Monitoring Requirements 187
19 Gravity Thickening Troubleshooting Guide 192
20 Belt Filter Presses Process Monitoring Requirements 200
21 Belt Filter Press Troubleshooting Guide 205
22 Vacuum Filtration Process Monitoring Requirements 216
23 Typical Performance Values for Vacuum Filtration Dewatering 223
24 Vacuum Filtration Troubleshooting Guide 224
25 Pressure Filtration for Dewatering Process Monitoring
Requirements 238
26 Pressure Filtration for Dewatering Troubleshooting Guide 242
27 Centrifugation Process Monitoring Requirements 254
28 Summary of Operational Variables Affecting Centrifuge
Performance 257
29 Typical Performance Values for Centrifugal Thickening
and Dewatering 264
30 Centrifugation Troubleshooting Guide 265
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LIST OF ABBREVIATIONS AND SYMBOLS
Abbreviations
A:S
API
DAF
HRT
IAF
ORP
PI
PID
SOR
SS
SVR
TSS
Air to Solids Ratio
American Petroleum Institute
Dissolved Air Flotation
Hydraulic Retention Time
Induced Air Flotation
Oxidation-Reduction Potential
Proportional Plus Integral
Proportional-Integral-Derivative
Surface Overflow Rate
Suspended Solids Concentration
Sludge Volume Ratio
Total Suspended Solids Concentration
Symbols
C - Concentration
C - Effluent TSS Concentration
C - Influent TSS Concentration
C. - Influent TSS Concentration to Clarifier
C - Sludge TSS Concentration
J\
MVG - Mean Velocity Gradient for Flocculation
M - Dynamic Viscosity
P - Power Input for Flocculation
PD - Polymer Dosage
q - Polymer Flowrate
Q - Flowrate of Wastewater
Qe - Effluent Flowrate
Q - Influent Flowrate
Q.^ - Influent Flowrate to Clarifier
Q_ - Sludge Removal Flowrate
SL - Solids Loading
V - Volume
vii
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SECTION 1
INTRODUCTION
PURPOSE AND SCOPE OF MANUAL
The purpose of this manual is to provide a technical field guide or
reference document for use in improving the performance of facilities
for the treatment of metal finishing wastes. The main purpose of the
manual is to provide a troubleshooting guide for the following: 1 )
identifying problems, 2) analyzing problems, and 3) solving problems.
Plant personnel responsible for waste treatment processes and
achieving permit compliance must be knowledgeable about not only the
problem areas, but also with electroplating and related metal finishing
concepts and in-plant process modifications and changes as they relate
to1 the waste treatment processes. This manual describes general proce-
dures for evaluating the performance of treatment processes and equip-
ment commonly used in metal finishing waste treatment. The procedures
also cover other items related to the effective operation of treatment
facilities. Troubleshooting guides, operating strategies, and process
monitoring material are discussed in detail for each unit process com-
monly used in metal finishing waste treatment.
MANUAL FORMAT
It is assumed that the manual user has a general understanding of
treatment facilities and their operation. The style, language, and for-
mat of the manual are directed to the level and technical knowledge of a
technician with some experience with in-plant operation, design, inspec-
tion, or performance evaluation.
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The manual is organized into the following major sections:
Section 1 INTRODUCTION. The purpose, scope, and format of the
manual are described in this section.
Section 2 LITERATURE REVIEW. The methodology used to evaluate
compliance problems and develop OSM specifics are
described in this section.
Section 3 PROBLEM ASSESSMENT AND RECOMMENDATIONS FOR IMPROVING
PERMIT COMPLIANCE. The causes of permit violations and
the recommended measures for improving compliance are
described in this section.
Sections 4 through 17. UNIT PROCESS EVALUATION AND TROUBLESHOOTING
INFORMATION. For each unit process commonly used in the
treatment of metal finishing wastes, this section con-
tains the following information:
o Introduction
o Theory of Operation
o Description of Equipment
o Operational Procedures
o Typical Performance Values
o Troubleshooting Guide
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SECTION 2
LITERATURE REVIEW
A literature review was conducted utilizing technical publications,
government reports and documents, and a computerized literature search
(see Appendix A). The literature search also included equipment manu-
facturers' information, data provided by professional organizations, and
communications with personnel who were familiar with the treatment and
disposal of metal finishing wastes. The objectives of the literature
review were to collect data which would aid in identifying the major
causes of permit violation, and to collect information which could be
used to develop OSM specifics on the treatment and disposal of metal
finishing wastes. Furthermore, by qualifying this data and information,
methods and techniques for improving compliance of facilities could be
developed.
ANALYSIS OF PERMIT VIOLATIONS
An analysis of permit violations was conducted to understand the
problems associated with treatment of metal finishing wastes. The
troubleshooting manual was then prepared to address the problems. An
analysis of permit violations was performed utilizing the Quarterly
Noncompliance Report published by the Office of Water of the United
States Environmental Protection Agency. The report listed the major
industries that were out of compliance and the parameters that were out
of compliance. The violations in the Noncompliance Report were listed
by SIC code. The SIC numbers used for identifying industries with metal
wastes were 3471 (electroplating), 3631, 3632, 3633, 3639, 3714, 3721,
and 3731 .
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The report cited thirty-four industries that were out of compliance
from the third quarter of 1979 to the second quarter 1982. The ten
parameters which were most frequently out of compliance between 1979 and
1982 for metal waste treatment are listed below:
Number of Permit
Violation
Parameter Occurrences
Nickel 17
Cyanide 16
Chromium 15
pH 12
Copper 11
Phenol 8
TSS 7
Cadmium 6
Zinc 6
Lead 4
This field manual addresses all the parameters listed above except
phenol. Treatment for removal of phenol was not included in this manual
because it is not specifically regulated in the effluent guidelines for
the electroplating industry. Treatment practices for control of the
other nine parameters as well as oil and grease are included in the
manual.
OPERATION AND MAINTENANCE SPECIFICS
Operation and Maintenance (O&M) specifics for the treatment of
metal finishing wastes were obtained from a search of technical publica-
tions, a computerized literature search, and contacts with equipment
manufacturers and operators. The information collected from these
sources was then interpreted and compiled. This field manual was dev-
eloped from information obtained from these sources.
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Computerized Literature Search
A computerized literature search was performed using DIALOG™ Infor-
mation Service of Lockheed Corporation. The computerized literature
review was conducted in three steps. The first step was to locate the
abstracts from the various data base files. The second step was to
search the abstracts for the appropriate publications and documents.
The final step was to review the publications.
The first step was initiated by selecting, the keywords or series of
keywords used to describe OSM specifics for metal finishing waste treat-
ment. A series of keywords coupled by the words "and" or "or" is often
used to select the desired abstract. A question mark in a keyword
indicates that the identity of a letter is unknown and the computer is
to identify all references including the letters which precede the
question mark. For example, the keyword "chrom?" will cause the com-
puter to search records labeled chrome, chromium, chromate, etc. The
series of keywords selected are listed below:
1. NPDES or Permit and (Violation or Exceed) and Metal
2. Wastewater and Operation? and Maintenance
3. Operation and Maintenance and Metal?
4. Metal? and Precipitate? and Wastewater?
5. Cyanide? and (Oxidation or Removal or Treatment) and Wastewater
6. Chrom? and (Reduction or Removal or Treatment) and Wastewater
The keywords were then used to search the thirty-seven data files
in Lockheed's DIALINDEX1". The search of the data files revealed the
number of abstracts which contained the keywords. The information was
used to ensure that the keyword series was restrictive enough without
being overly restrictive. The two files which contained the most ab-
stracts applicable to this project were the Metals Index (File 32) and
the Pollution Abstracts Index (File 41). The Metals Index contained 99
abstracts which could be identified by the six series of keywords
described above. The Pollution Abstracts contained 445 abstracts.
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The second step in the computerized literature search was to review
the abstracts identified by the keywords. The abstracts reviewed for
both the metals data file and the pollution data file are presented in
Appendix A. These abstracts were reviewed to see which publications
were most applicable to the project.
The final step in the literature search was to review and evaluate
the articles chosen from the abstract search and to incorporate this
information into the O&M manual. Much of the information was used to
review current treatment practices and to develop O&M specifics for the
troubleshooting manual* These articles were only referenced when they
contained specific information such as surface loading rates or mixing
horsepower.
Technical Publications
The review of literature included technical publications which were
not included in the computerized data base or those publications which
were more easily obtained by a manual literature search. The former
category contained articles that were published generally before 1970
and many reference books. The search of articles before 1970 was per-
formed by reviewing annual indexes from publications such as Proceedings
of the Purdue University Industrial Waste Conference, Journal Water
Pollution Control Federation, and Water and Waste Engineering.
Sources from which information and data on metal finishing waste
treatment could be easily obtained were the U.S. Environmental Protec-
tion Agency (EPA), the Water Pollution Control Federation (WPCF), the
American Electroplating Society (AES), and reference books. More than
40 EPA publications relating to metal finishing wastes were reviewed. A
series of seven EPA Technology Transfer documents provided much general
information about metal-finishing waste treatment. /2'3'4'5'6'7^
Twelve AES project reports were also reviewed. Numerous reference books
on treatment of metal wastes were also identified and reviewed. This
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review not only included books written for treatment of metal finishing
wastes but also materials which described pH control, sedimentation, and
sludge dewatering.
Equipment Manufacturers
Several manufacturers of equipment for metal finishing wastes were
contacted. Information obtained from manufacturers' representatives
was used to characterize and describe the different types of equipment,
to develop O&M specifics, and to determine performance data. This
information on field operations and maintenance was referenced when
used.
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SECTION 3
PROBLEM ASSESSMENT AND RECOMMENDATIONS
FOR IMPROVING PERMIT COMPLIANCE
CONVENTIONAL WASTEWATER TREATMENT
Conventional wastewater treatment in the electroplating industry
consists of the following unit processes (see Figure 1):
o Chromium reduction (if needed) of segregated chromium waste
streams to reduce the chromium from its hexavalent form to the
trivalent state, which then can be precipitated as chromium
hydroxide by alkali neutralization,
o Cyanide oxidation (if needed) of segregated cyanide-bearing
waste streams to oxidize the toxic cyanides to harmless carbon
and nitrogen compounds,
o Neutralization of the combined metal-bearing wastewaters,
acid/alkali wastewaters, strong chemical dumps, and the effluent
from the cyanide and chromium treatment systems to adjust the pH
within acceptable discharge limits and to precipitate the dis-
solved heavy metals as metal hydroxides,
o Clarification, in which flocculating/coagulating chemicals are
added to promote the initial settling of the precipitated metal
hydroxides,
o Gravity thickening over extended time to increase solids content
of sludge before disposal.
These unit processes provide effective, reliable treatment for many
electroplating waste streams. That is not to say, however, that such
treatment is suitable for all applications or that the "normal" design
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Chrom*
Solid WUM
CYANIDE
OXIDATION
S - lulfomtor
C » cflionnarar
P > ondnion rMucnon oounfMl
Figure 1. Electroplating industry conventional
wastewater treatment.
SOURCE: USEPA ENVIRONMENTAL REGULATIONS AND TECHNOLOGY; THE
ELECTROPLATING INDUSTRY, EPA 625/10-dO-OOt, AUGUST 1980, P. 13.
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parameters (retention time, reagent dosage, and so forth) will provide
effective pollutant removal from every individual plater's wastewater
discharge.
Many of the items covered in this manual have their basis in a
conventional wastewater treatment system such as the one described in
the preceding.
PROBLEM ASSESSMENT
A plant assessment is the initial step in a pollution control pro-
gram. A plant assessment involves a thorough analysis of the operations
of a metal finishing plant that relate to pollutant sources and water
use. The information generated during a plant assessment is used in
evaluating the application of in-plant changes for reducing chemical
loss and water use.
A plant assessment includes the following steps: 1) inspection of
the plating room layout, 2) review of plant operating practices, 3)
examination of process water use, 4) performance of sampling and labora-
tory analysis to characterize waste streams and to determine dragout
rates, and 5) identification of the frequency, volume, and character-
istics of batch dumps.
Laboratory analyses of wastewater samples are performed using
standard EPA-approved techniques. Throughout this manual, various
analytical parameters and their concentrations are discussed. For all
tests the analytical methodology presented in the EPA document "Methods
(8)
for Chemical Analysis of Water and Wastes" or "Standard Methods for
(9)
the Examination of Water and Wastewater" should be followed.
The successful operation and maintenance (O&M) of a waste treatment
plant requires consistent performance that exceeds regulatory compliance
levels. Failure to meet these compliance levels can result in costly
disposal alternatives, fines, damage to the environment, and adverse
10
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public reaction. If a treatment facility fails to meet compliance
standards, the problem usually falls under one of the following causes:
1) Shock loadings (hydraulic or contaminants) to the waste
treatment plant,
2) Poor understanding of O&M procedures,
3) Poor process control,
4) Equipment failure, and
5) Treatment plant design inadequacies.
The potential effect of good OSM on each of the five categories of
non-compliance reasons is discussed below. If a plant finds itself in
non-compliance it should determine which categories of causes are appli-
cable and take appropriate action to see if improved OSM could be effec-
tive in improving its performance.
Shock Loadings
Shock loadings of flow or contaminants frequently cause treatment
process upsets which can result in non-compliance. Sources of these
shock loadings can be either spills or releases from production batch
operations or cleaning operations. Their impact on the treatment pro-
cess can be mitigated by installing sufficient equalization. Their
impact can also often be controlled by changes in operating procedures
in the production facility or in the treatment plant. Of foremost im-
portance is communication between production and waste-treatment person-
nel. If waste-treatment personnel are notified of potential shock loads
in sufficient time, mitigating action often can be taken, such as
diverting the shock load to sidestream equalization to temporarily
bypass sensitive 'processes, or manually modifying process operating
parameters to adjust for the shock loading.
Modification of production procedures with respect to spill control
and operating procedures for batch processes and cleaning operations can
reduce the magnitude of shock loadings in several ways. Wastes from
batch or cleaning operations can be released slowly or during times of
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low flow. Spills can be cleaned up using dry chemicals and not be hosed
down the drain. Chemical handling procedures can be modified to reduce
the likelihood of spills and chemicals can be stored in diked areas to
contain spills that do occur.
In all cases implementation of the above procedures requires good
training of all personnel in proper operating procedures to control
shock loading. Part of this training must include making production
personnel aware that their procedures impact waste treatment. This
factor is becoming increasingly important as some facilities have had to
curtail production in order to achieve discharge compliance levels.
Treatment plant personnel also must be trained in the proper operating
procedures to mitigate the impact of a shock load. This action may be
diverting flow to sidestream equalization, bypassing an oil water separ-
ator while a non-oily hydraulic shock load is occurring, notifying
production to stop or slow an excessive discharge, or other appropriate
procedures.
Poor Understanding of OSM Procedures
A good understanding of OSM procedures is essential to operate
successfully a facility for the treatment of metal finishing wastes. An
operator who is well versed in the proper OSM procedures can usually
operate the treatment facility to meet permit compliance even though one
or more of the above causes of permit violation exists at the treatment
facility. This manual was developed to assist operators in implementing
the proper O&M procedures at the treatment facility. While no manual
can be general enough for all plants and yet specific enough for one
plant, the intention of this manual is to aid in the understanding of
the cause/effect relationship for several treatment processes. Once an
operator has developed a cause/effect relationship for the control vari-
ables at the treatment facility, then specific adjustments and/or set-
points can be established. A successful OSM program will be attained
when the operator can identify a potential problem, understand the cause
of the problem and what effect it will have on compliance, and then ad-
just the control variables so as to mitigate the problem.
12
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Poor Process Control
One of the most common causes of continuous poor. performance and
frequent non-compliance is poor process control. Poor process control
results in the treatment plant not achieving its full capacity and
efficiency. When the full or design efficiency is not achieved, the
blame is put frequently on poor design, but it must be remembered that
the design is based upon the assumption of good process control which
may or may not be occurring. Good process control can only be achieved
by well trained operators who know and understand their equipment and
the impact of all operating variables under their control. This in-
cludes understanding the interaction between operating variables and the
trade-offs often involved. As an example, increasing the belt tension
in a belt filter press can result in a drier cake but will also result
in more solids in the filtrate and a shorter belt life. However, the
solids in the filtrate might adversely affect the performance of other
treatment processes such as an oil coalescer.
Process control through good operations is particularly important
in the metal finishing industry where several waste treatment processes
require critical control of operating variables to achieve good treat-
ment performance. Examples include pH control for metal precipitation,
and pH and oxidaton-reduction potential (ORP) control for chromium
reduction and cyanide oxidation. A relatively slight change in these
operating variables can result in significant degradation in perfor-
mance, non-compliance, and in the case of cyanide reduction, the poten-
tial for release of toxic gases.
Equipment Failure
Equipment failure can readily cause a treatment plant to fail to
meet regulatory compliance levels. The impact of the equipment failure
can be minimal when repairs are implemented quickly or the impact may be
major with parts and repairs taking days to obtain and install. It is
therefore essential to minimize equipment failure and downtime. This
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minimization of downtime can be achieved partially by a sufficient parts
inventory and overdesign; it also requires good operation and mainte-
nance of existing treatment plant equipment. Mechanical equipment has a
set of design operating conditions and any time these conditions are
exceeded, premature equipment failure can occur. Treatment plant per-
sonnel should be aware of these design conditions and integrate them
with plant operating procedures to insure that mechanical equipment is
not unduly stressed. It should be noted that this stress does not
always come from mechanical forces. Improper pH levels can corrode
equipment and excessively high temperatures can cause materials of
construction to fail. Once equipment failure has occurred, prompt
repair of equipment by well trained maintenance personnel is essential
to minimize the impact and prevent recurrence.
Good operations and maintenance can also prevent equipment failure
by a regular and orderly inspection of equipment for wear or other early
signs of equipment failure such as vibration. A good preventive main-
tenance program is another essential facet of preventing premature
equipment failure.
Treatment Plant Design Inadequacies
No amount of good operations and maintenance can make a poorly or
improperly designed treatment plant achieve consistent compliance with
regulatory standards; conversely, poor operations and maintenance can
make even the best designed treatment plant fall into noncompliance.
Before any major design modifications are implemented, the potential for
treatment plant performance improvement through improved OSM should be
investigated thoroughly.
RECOMMENDATIONS FOR IMPROVING PERMIT COMPLIANCE
The level of pollutants that may be discharged to publicly owned
treatment works (POTW) is regulated by the USEPA. Specifically, the
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level of pollutants dischargable by a plant falling within the electro-
plating and metal finishing point source categories is limited by regu-
lations issued in the Federal Register on July 15, 1983. A copy of
these regulations is included as Appendix B of this manual.
Improving the level of permit compliance for treatment of metal
finishing wastes is a two-step process. The first step is to identify
the problem and the second step is to take the necessary corrective
actions. Permit compliance problems generally will fall into the fol-
lowing four categories: 1) design, 2) operation, 3) administration, and
4) maintenance.
As mentioned elsewhere in this report, the importance of proper
design cannot be overstated. Each unit process along with the inte-
grated waste treatment system must be designed with numerous factors
accounted for. A system which is improperly designed will seldom be a
system which can be operated well. Improvement of permit compliance by
improving design is a long-term process; near-term improvements are
seldom attainable through design changes.
A well-designed system may not perform as expected because of im-
proper operating procedures. A number of instances of improper opera-
tion have existed; improvement of operation is a direct function of the
operators' familiarity with correct OSM procedures. It is the goal of
this publication to provide adequate OfiM procedures and troubleshooting
guides to produce improved levels of permit compliance in metal finish-
ing waste treatment plants.
Administration also affects permit compliance, although often in an
indirect manner. Such items as staff supervision, motivation, funding,
and planning affect the operation of a facility, which in turn affects
all aspects of the treatment plant.
Finally, maintenance affects permit compliance directly. In num-
erous instances throughout the descriptions which follow, routine in-
spection and maintenance are cited as the chief deterrents to operating
15
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problems, and hence to permit violations. A competent, well-trained
maintenance group is indispensable in the smooth and successful opera-
tion of a treatment plant.
Although the tendency is to categorize permit compliance problems
as belonging strictly to one of the four areas discussed above, in fact
most problems have aspects of two or more areas. A plant which hopes to
improve its permit compliance must strive to achieve improvement in all
four areas.
RESOURCE RECOVERY
Pollution control legislation has affected industry by increasing
the economic penalty associated with inefficient use of raw materials.
In the plating industry, for example, loss of a raw material in the
wastewater can result in three distinct cost items: replacement of the
material, removal of the material from the wastewater before discharge,
and disposal of the residue. Similar cost items exist for process
water: replacement of water (no longer inexpensive to purchase) used in
processing, processing the water in the wastewater treatment system, and
processing the water by the treatment plant after discharge into a sewer
system.
In response to the incrased cost of raw material losses, plating
shops are modifying their processes to reduce these losses as well as
water consumption. Recent years also have seen the cost-effective
application of various separation processes that reclaim plating chemi-
cals from rinse waters, enabling both the raw material and the water to
be reused.
The impact of resource recovery and pollutant load reduction
modifications on waste treatment and solid waste disposal costs must be
measured if these modifications are to be evaluated. Cost of sophisti-
cated treatment necessary for electroplating wastewater and of residue
disposal often provides a significant economic incentive for resource
recovery.
16
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Modifications for reducing the pollutant or wastewater loading on a
treatment facility range from using flow restrictors to eliminate excess
dilution in rinse tanks to installing recovery units, such as reverse
osmosis and evaporation, to separating plating chemicals from rinse
water for recycle to the plating bath. Actions that can minimize waste-
water volume include the following:
o Implementing rigorous housekeeping practices to locate and
repair water leaks quickly,
o Employing multiple counterflow rinse tanks to reduce rinse water
use substantially,
o Employing spray rinses to minimize rinse water use,
o Using conductivity cells to avoid excess dilution in the rinse
tanks,
o Installing flow regulators to minimize water use,
o Reusing contaminated rinse water and treated wastewater where
feasible.
Steps to minimize pollutant loading include:
o Implementing a rigorous housekeeping program to locate and
repair leaks around process baths, replacing faulty insulation
on plating racks to prevent excessive solution drag-out, instal-
ling^drip trays where needed, and so forth,
o Using spray rinses or air knives to minimize solution drag-out
from plating baths,
o Recycling rinse water to plating bath to compensate for surface
evaporation losses,
o Using spent process solutions as wastewater treatment reagents
(acid and alkaline cleaning baths are obvious examples),
o Using minimum process bath chemical concentrations,
o Installing recovery processes to reclaim plating chemicals from
rinse waters for recycle to the plating bath,
o Using process bath purification to control the level of impur-
• ities and prolong the bath's service life.
17
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Closed-loop chemical recovery from a rinse stream can often provide the solution to
treat. Applying a closed-loop recovery system to a plating operation
eliminates the need to treat the rinse water normally associated with
that step.
In the case of rinse streams requiring pretreatment (for example,
cyanide or chromium) or rinses containing pollutants not effectively
removed by conventional end-of-pipe technology (for example, some types
of complexed metals), installing a closed-loop system to recycle the
rinse may reduce the investment needed to comply with the effluent
quality limitations.
18
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SECTION 4
EQUALIZATION
INTRODUCTION
One of the most frequently encountered problems in metal finishing
wastewater treatment is process upsets related to intermittent high
flowrates and highly variable contaminant levels. Batch discharge of
high strength plating solutions and plating wastes often can cause large
fluctuations in flowrates, pH, metals concentrations, cyanide concentra-
tion, and other critical contaminant levels. These fluctuations are
often so severe that process upset and subsequent permit violations can
occur before the system is able to compensate. For this reason, waste-
water equalization often is implemented to control the extreme fluc-
tuations in flow and contaminant concentrations. Likewise, whenever
treatment process upsets occur, especially on a periodic basis, proper
equalization should be one of the first operating conditions to be
checked.
THEORY OF OPERATION
Wastewater equalization can accomplish three basic tasks. The
first is hydraulic or flow equalization which dampens hydraulic surges
to downstream treatment processes. Flow equalization can only be accom-
plished by placing some type of variable liquid volume storage tank in
the wastewater flow path upstream of sensitive process equipment. The
liquid is stored in the variable volume tank during high flow periods
and then is released during low flow periods. Therefore, the hydraulic
equalization power is directly related to the utilized variable volume
of the tank.
19
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The second equalization task is contaminant or concentration equal-
ization. Contaminant equalization is accomplished by mixing low and
high contaminant concentration wastewater, which results in an average
concentration with dampened fluctuation. As with flow equalization,
some type of storage must be provided which stores highly (or slightly)
contaminated flow until such time as the contaminant concentration
cycles to the other extreme. Contaminant equalization can be accom-
plished by placing in the flow path a storage tank and mixer with suffi-
cient volume to mix the low and high concentration wastes or by collec-
ting only the high concentration wastes in a storage tank and bleeding
them back during periods of low contaminant concentration. The latter
system has the disadvantage that the contaminant concentration must be
monitored continuously and rapid action taken based on instantaneous
contaminant concentration.
The third equalization task, an offshoot of the earlier discussed
two, is to allow means to control the load that reaches the process
within limits set by the operator. This is accomplished by positioning
the outlet line near the bottom of the equalization basin and providing
valving that allows the operator the option of increasing or decreasing
flows to his process from the equalization basin. The operator would
have the option of lowering flow during period of high concentrations
and raising flows during periods of low concentrations and could control
the load to the process to limits desired. This system has the disad-
vantage that it requires more analytical work than the other two systems
and requires a larger equalization tank that will allow the operator to
vary the tank level and has the advantage that it will reduce the possi-
bility of organic shock and allows much finer control of the process.
Mixing is an integral part of all equalization techniques. Flow
equalization requires mixing to keep suspended material in suspension.
Without it, solids will accumulate in the storage tank thereby reducing
the effective volume of the tank. Contaminant equalization requires
mixing to blend the low and high strength wastes together. Typically,
the mixers are vertical shafts with turbines or marine propellers. If
20
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tanks are deep, draft tubes are installed or multiple impellers are
placed on elongated shafts. Horsepower requirements for equalization
mixing typically run between 0.02 and 0.04 horsepower/1000 gallons if
*
gritty material is not present in the waste. If, however, gritty
material is present, horsepower requirements for mixing can exceed 2.5
horsepower/1000 gallons. In all cases, if mixing is occurring in cir-
cular tanks, then baffles must be installed on the sidewalls.
DESCRIPTION OF EQUIPMENT
Wastewater equalization can be accomplished by a number of dif-
ferent methods. Some equalization occurs in sewer lines. Pollution
control equipment also has some surge capacity available to dampen out
fluctuations. However,' due to the nature of the variations in the metal
finishing industries, these methods provide little if any effective
equalization. Several typical equalization methods other than inherent
system equalization are described below.
Batch Processing
Equalization by batch processing involves storage and batch pro-
cessing of the wastewater in the same tank. To accommodate continuous
systems, multiple reactors are operated in parallel. When one reactor
is full, the flow is switched to another reactor while the wastewater in
the first reactor is being treated. Reactor storage capacity must be
sufficient to handle the maximum volume of wastewater that could be
generated during the time it takes to treat the wastewater and empty
wastewater from the other reactor (see Figure 2(a)). Alternatively, the
*This and the following sections present information in a mix of English
Engineering and metric units. This mix of units occurs because, al-
though metric units are now preferred for data reporting, many of the
quantities are reported still almost exclusively in English units, and
"rules of thumb" have been cast in these units. A table of metric-
English conversions is provided with this report as Appendix C.
21
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(a) Batch Processing
(b) Continuous Processing from Batch Storage
Ws toragri——EXJ-
(c) Side-Stream Equalization
•^Storage
(d) Flow-Through Equalization
Figure 2. Methods of equalization.
SOURCE: EPA REPORT NUMBER 600/2-91-148
22
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system can be operated in batch mode with one tank when the system is
used to treat wastewater flows from batch type plating operations. This
technique is employed often when specialized treatment is required for
intermittent waste flow.
The batch processing procedure is a very effective equalization
technique since wastewater in the treatment reactor is consistent for
each treatment cycle. The system, however, requires that either the
flow must be intermittent with sufficient time for wastewater treatment
to occur between flows, or multiple reactors must be provided. The
latter is usually prohibitively expensive. Therefore, this process is
found primarily on small intermittent flows from batch metal finishing
operations whose wastewater requires specialized treatment, such as
plating solutions which contain high concentrations of cyanide, or
chromium.
Continuous Processing from Batch Storage
Continuous processing from batch storage usually involves two
storage tanks operating on a fill-and-draw cycle. While one tank is
being filled, the other tank is being discharged to a waste treatment
facility (see Figure 2(b)). 'This procedure is unlike batch processing,
in which the equalization and waste treatment steps occur in the same
vessel. Using this technique the waste treatment facility receives a
waste stream with uniform characteristics while processing the contents
of an individual tank. The stream characteristics, however, often vary
significantly from tank to tank.
This equalization technique requires either automated influent and
effluent valves controlled by level indicators in the batch equalization
tanks, or intensive operator supervision. The equalization tanks must
be sized such that the volume from at least one flow cycle or contami-
nant concentration cycle can be collected in one tank. If contaminant
equalization is desired, the tanks must also be mixed. This system is
best suited for relatively small flows and/or rapidly varying (cycling)
flows that will permit reasonably sized tanks. Its primary deficiency
23
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is that some degree of automation or labor is required to operate it.
Also, the step change in reactor feed characteristics that occurs when
the flow is switched from one storage tank to another can be a disadvan-
tage unless the operator keeps his knowledge of tank concentrations
updated often.
Side-Stream Equalization
The side-stream equalization method involves the collection and
storage of flow or contaminant concentration surges that result from
scheduled dumping operations in the production plant. The surge is
diverted to a storage vessel for subsequent processing during slack
periods. This procedure is sometimes used to store an alkali waste in a
plant for future combining with a waste stream that is normally acidic.
The collected alkali could be dispensed into the normally acidic waste
stream to reduce consumption and cost of neutralizing reagents. The
reverse is often practiced to acidify hexavalent chromium wastes prior
to reduction (see Figure 2(c)).
Side-stream equalization for contaminant surges is usually imple-
mented by manually opening diversion valves or directly pumping to the
storage tank. The major problem with the system is that either advanced
knowledge of the event must be available or online monitoring equipment
must be installed. With the possible exception of monitors for flow,
conductivity, and pH, on line monitoring is very difficult and expensive
to implement and maintain. Probably the best implementation of this
type of equalization is as a spill collection tank which can be used to
collect and hold spills if and when waste treatment personnel are noti-
fied of the spill fast enough to implement the system.
If only flow equalization is required, side-stream equalization can
be very effective. It can be implemented either using flow meters
connected to pumps and control valves or by a passive system of weirs
that diverts excessive flow to a storage tank. The stored water can
then be pumped back into the system during low flow. The major advan-
tage of the system is that it requires minimal storage volume and is
24
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reliable and relatively simple to implement. The major disadvantage is
that it provides little contaminant equalization.
Flow-Through Equalization
The system of flow-through equalization dampens and greatly reduces
flow and concentration variations, but does not eliminate them. Typi-
cally the system operates on a continuous basis and requires a large
tank, mixers, tank baffles, and effluent control devices such as weirs,
orifices, control valves, or pumps (see Figure 2(d)). For flow equali-
zation, the tank must be designed to fluctuate in volume in response to
influent flow rates. For contaminant equalization, the tank must be
large enough to hold the volume which corresponds to the discharge cycle
of high or low concentration wastes. The more cycles the tank can hold,
the better the equalization achieved. The mixers for contaminant equa-
lization must be sufficient to keep the tank completely mixed and all
suspended solids in suspension. If the tank is round, baffles must be
installed along the side walls to assure good mixing. The effluent
control devices selected will depend on the objective of the equaliza-
tion. For contaminant equalization, broad crested weirs are frequently
used. For simple and reliable flow and contaminant equalization, narrow
weirs, proportional weirs, or orifices are used. Pumps or flow control
valves are used for maximum flow equalization.
The major advantage of a flow-through equalization system is its sim-
plicity of operation and the continuous nature of its discharge. Flow
and contaminant concentration changes do occur, but very gradually. This
gradual change usually provides downstream processes such as pH adjust-
ment with adequate time to respond. The major disadvantage of the
system is the large tank size generally required.
OPERATIONAL PROCEDURES
The objective of equalization is to limit fluctuations in waste-
water flow and/or contaminant concentration to levels that will not
adversely affect downstream treatment processes. Equalization can occur
25
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on a continuous basis such as in a flow-through system or can be initi-
ated upon demand as with side stream equalization.
Process Monitoring and Operational Criteria
Equalization monitoring takes two forms. First, with the exception
of a continuous flow-through system, the wastewater must be continuously
monitored for flow and/or contaminant concentration. Monitoring is
required to indicate when flow should be diverted to side stream equali-
zation or to determine the fill and draw cycles in batch equalization.
Monitoring can be accomplished using either automated on-line equipment
or by periodic measurements by the operator. The former is subject to
breakdown and the latter is subject to slow response that may completely
miss flow or contaminant surges. Therefore, it is necessary to imple-
ment both monitoring techniques whenever possible.
It is also essential that a form of monitoring be conducted by
production personnel. Whenever production personnel anticipate gener-
ating an abnormal flow or contaminant surge, the production personnel
must notify waste treatment prior to the event and indicate the time,
magnitude, and duration of the the abnormal waste flow. Similarly, if a
spill or accidental release of a large quantity of contaminants or water
is detected in the production area, then production personnel must
notify wastewater treatment personnel immediately. This information is
a critical part of wastewater monitoring and is absolutely essential for
effective operation of equalization equipment.
The second part of wastewater equalization monitoring is a periodic
program to evaluate the effectiveness of the equalization process. As a
minimum, this evaluation should occur monthly with batch systems or
after any downstream equipment experiences operational problems which
could be attributed to poor equalization. To be effective, the monitor-
ing must be set up in a rigorous test program in which influent and
effluent flow and contaminant concentrations are measured simultaneous-
ly. The frequency of sample collection during the test programs and the
26
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duration of the program will depend upon the rate of flow and contamina-
tion variability. Typically, these variations follow some pattern and
exhibit times of peak and minimum flow and contaminant concentration.
To be effective, the monitoring program must collect sufficient grab
samples to detect these variations, usually sampling every hour for 24
to 48 hours. In some cases, however, where the variations occur rapid-
ly, more samples will be required. If possible, the days for equaliza-
tion monitoring should be selected such that the maximum variation in
flow and contaminants that has been experienced under normal operating
conditions is occurring.
Upon completion of the test, the influent and effluent flow and
contaminant concentration should be compared graphically by plotting
influent and effluent parameters versus time on the same graph. The
peak effluent values should be substantially less than the peak influent
values and within the design operating values for downstream equipment.
The maximum rate of change for effluent contaminant concentration must
also be evaluated when the contaminant concentration can affect chemical
feed rates in downstream equipment. Too rapid a change can result in
poor performance of equipment such as pH controllers.
Process Control Strategies
For the most part, the operator has little control over the equal-
ization process. For continuous flow-through equalization, control can
be exercised by adjusting the pumping rate or orifice openings. For
batch equalization processes, little control can be exercised over the
equalization process, except for the fill-and-draw cycle which is
usually dictated by flow patterns. Side-stream equalization, however,
is directly controllable by operators by either adjusting set points on
automatic monitoring equipment or by manually diverting the flow based
on test results or information from production personnel. Rigid cri-
teria for initiating side stream equalization can not be developed;
however, the following facts should be evaluated:
27
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o Sensitivity of downstream equipment to the surge.
o Potential for violating permit conditions if a treatment process
upset occurs.
o Reserve capacity in side stream equalization tank for a second
more severe surge.
o Likelihood of another event requiring side stream equalization
prior to release of current equalization volume.
o Compatability of liquid currently in equalization tank with
current waste stream (i.e., a current acidic wastestream should
not be diverted to side stream equalization if a cyanide waste
is currently stored there. Hydrogen cyanide gas could be pro-
duced ).
In addition to the monitoring of process operating variables speci-
fic to side stream equalization, several general operating and mainte-
nance procedures should be performed routinely on all equalization
equipment. These include the following:
o Equalization tanks should be checked monthly for accumulation of
solids on the bottom of the tank. When the solids accumulation
significantly reduces tank volume, the tank must be cleaned.
o Equalization tanks should be checked weekly for accumulation of
floating material. If the floating material interferes with
weirs, pump intakes, level indicators, or mixers it must be
removed.
o Tanks, baffles, mixers, and pipes should be inspected annually
for condition of materials of construction. Corroded or worn
parts should be repaired or replaced.
o Monitoring programs to evaluate the performance of equalization
should be conducted approximately twice per year or after a
treatment process upset that could be linked to inadequate
equalization.
o Flow meters, level indicators, and on-line monitors should be
calibrated annually or at the manufacturer's specified interval,
whichever is less.
28
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o All pumps, mixers, and automated valves should be included in a
regular preventive maintenance program.
TYPICAL PERFORMANCE VALUES
Almost any desired level of equalization can be achieved by varying
the size and type of equalization equipment. Therefore, performance
criteria must be established for individual facilities based on the
sensitivity of downstream treatment processes.
TROUBLESHOOTING GUIDE
A troubleshooting guide for operation of the equalization tanks or
basin is presented in Table 1 . Two major operating problems are con-
sidered; these are inadequate contaminant equalization and inadequate
flow equalization. For each problem, several probable causes, checks
and monitors, and corrective actions are given.
29
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TABLE 1
EQUALIZATION TROUBLESHOOTING GUIDE
OJ
O
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM: 1. Contaminant equalization inadequate.
la. Broken or worn mixer
impeller.
1b. Inadequate basin volume
caused by solids de-
posits on the bottom
of tank.
1c. Missing mixing baf-
fles on circular tank.
Id. Improperly located
mixer.
1e. Inadequate basin
size.
If. Inadequate mixing
horsepoweri
Check condition of mixer
impeller.
Check for solids accumula-
tions by draining tank or
checking tank side wall depth
with a pole or similar device.
Check for condition of
baffles on outer wall of
circular tanks.
Check location of mixers;
stationary mixers may not
have the proper impeller
submergence and mixers in
deep tanks may be missing
draft tubes or multiple
impellers. Submerged mixers
too close to the surface may
vortex and lose efficiency.
Conduct monitoring pro-
gram to determine if basin
is large enough to contain
wastewater flow between
low and high flow and/or
contaminant cycles.
(Note: for good equali-
zation more than one cycle
volume may be required).
Check mixing horsepower;
check for solids deposition
in equalization tank.
Broken or worn impellers
can dramatically reduce
the efficiency of mixing.
Reduced basin volume
limits storage capabil-
ities and hence equali-
zation capacity.
Baffles must be present
to break circular flow
patterns which do not
contribute to mixing.
The efficiency of a mixer
can be dramatically
affected by. improper
placement.
Inadequate basin volume
limits storage capacity
and hence equalization
capacity.
Mixing is directly related
to input horsepower.
Replace if worn.
- Clean tank and remove solids.
Repair or replace damaged or
missing baffles.
Move and adjust as required.
Reference manufacturer's
recommendations and design
speci fications.
Modify or add tank volume as
required.
Add mixing horsepower as
required. Reference
manufacturer's recommen-
dations. Typical values range
between O.02 and 0.04 hp/1000
gallons. If gritty material
is present, much larger mixing
horsepower will be required.
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TABLE 1
(Continued)
EQUALIZATION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 2: Flow equalization inadequate.
2a. Flow meters or level
indicators that con-
trol tank discharge
are improperly set or
calibrated.
2b. Improper choice of ef-
fluent control device.
2c. Leaks around effluent
control devices.
2d. Inadequate storage
volume.
Check for proper setting
and date of last calibra-
tion.
Check type of effluent con-
trol device.
Check for erosion and wear
around effluent weirs and
orifice plates.
Monitor tank level during
operation.
These devices, when
incorporated into the
system, directly control
the flow to and from the
equalization basin.
Effluent control devices
determine the degree of
control that can be
exercised on effluen flow.
Pumps can provide best
equalization followed by
valves, orifices, propor-
tional weirs, and narrow
rectangular weirs.
The amount of flow equal-
ization is directly
proportional to the
changes in tank volume.
Also, in most equalization
techniques, as the water
level approaches the top of
the tank, the effluent flow
is dramatically increased
to prevent overfilling.
Calibrate and adjust as
required. Reference
manufacturers calibration
procedure and design speci-
fications for proper setting.
Modify discharge device as
required.
Repair or replace as required.
Modify tank design or effluent
control devices as required.
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SECTION 5
OIL REMOVAL
INTRODUCTION
The sources of oil found in metal wastewater are from cooling
operations, cleaning operations, and lubrication. Oil is typically
present in wastewater in three forms: free oils, emulsified oils, and
soluble oils. Free oils in wastewater are those which rise to the
surface of the wastewater due to buoyant forces in a short quiescent
period. Emulsified oil is oil dispersed in the wastewater as small
droplets which can range in size from 0.1 to 100 microns. Soluble oil
is discussed in the next paragraph. A wide variety of oil removal pro-
cesses is available for removing the free and emulsified forms of oil.
The processes include skimming, coalescing, emulsion breaking, flota-
tion, centrifugation, ultrafiltration, reverse osmosis, carbon adsorp-
tion, and biological oxidation. The most widely used and conventional
treatment processes in the metal finishing industry are gravity separa-
tion and skimming, coalescing, emulsion breaking, and flotation. The
other processes are not widely utilized at this time and, therefore, are
not covered in this manual.
Soluble oils are those organic oils which are dissolved in the
wastewater. Soluble oils are generally the lighter, more polar fraction
of an oil mixture. Soluble oils are not removable by the techniques
described in the preceding and in this chapter. Techniques such as
gravity separation, flotation, and emulsion breaking result in removal
of free and emulsified oil, but soluble oils remain dissolved in the
wastewater. Soluble oils are, in general, biodegradable, so that the
32
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most successful treatment for removal of soluble oils is often biode-
gradation in a biological wastewater treatment system.
Along with the topic of oil removal, the subject of total toxic
organics (TTO) must be addressed. The materials which make up the TTO
are listed in Appendix B; they are typically degreasing solvents used in
the cleaning of metal parts. The waste solvents will contain oils, and
will exist as free, emulsified, and soluble oils in the wastewater. The
concentration of TTO in metal finishing wastewaters can be greatly
reduced by proper handling and disposal of solvents and other organics,
•especially by segregation of these wastes for contract disposal or
reclamation for recycle.
Control and management practices for waste solvents and other
components which make up the TTO should be devised to follow resource
recovery guidelines. Specifically, development of segregation facili-
ties for these materials should be implemented, and disposal should be
by a reputable contractor. The potential for reclamation of the organ-
ics should be explored; if reclamation is not feasible then disposal
must be performed by a reportable disposal contractor. The importance
of proper disposal for materials containing the compounds on the TTO
list must be emphasized. Those materials are known to exhibit signifi-
cant toxicity; severe environmental and human health problems can result
from their improper handling or disposal.
THEORY OF OPERATION
The theory of operation for the equipment used to remove free and
emulsified oil from wastewater is discussed below.
Gravity Separator
Separator design is based on the specific gravity difference be-
tween the dispersed oil globules and the wastewater. The lighter oil
globules rise to the wastewater surface and are removed. The oil rise
rate is described by Stokes' Law which states the rise rate is directly
33
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proportional to the difference in the weight of the oil globule and the
wastewater it displaces.
Emulsion Breaking
Emulsified oil is dispersed in wastewater as small droplets. These
droplets can range in size from 0.1 to 100 microns. With pure oil and
pure water, an oil emulsion is highly unstable since both phases quickly
separate and assume a shape having the minimum interfacial area. With
oily wastewater, however, an oil emulsion is often formed which is much
more stable due to emulsifiers which alter the oil-wastewater interface.
Three common emulsifiers are electrical charge, chemical action,
and mechanical assistance. Electrical charge emulsifiers establish a
repulsive electrical field at the oil-wastewater interface. This type
of emulsifier is normally a negligible cause of stability except for
those wastewaters that have a low salt content or dilute oil concentra-
tions . Chemical emulsifiers are materials such as soaps or detergents
which cause chemical reactions at the oil-wastewater interface. Mech-
anical emulsifiers are finely divided colloids such as silt, clay, or
metal fines which attach to the oil or are coated by the oil.
Emulsion stability is affected by droplet size, emulsion age, and
wastewater viscosity. Smaller droplets are typically more stable.
Emulsions generally become more stable with age because the emulsifier
is transported to the oil through the wastewater by diffusion. A
higher wastewater viscosity generally results in a more stable emulsion
since there is more resistance to the movement of small droplets thus
reducing the possibility of coalescence.
Coalescing Separator
Coalescing separators work in a similar manner to gravity separ-
ators with skimmers except that coalescing separators remove smaller and
less bouyant particles. The basic principle of coalescing involves the
preferential wetting of a coalescing medium by oil droplets which accu-
mulate on the medium, and then rise to the surface of the solution. The
34
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most important requirements for coalescing media are wettability for
oil, large surface area, and contact Between the oil particles and the
coalescing medium.
Air Flotation
In a flotation process, fine gas bubbles are introduced into the
wastewater. These gas bubbles attach to oil globules resulting in an
aggregate with a specific gravity much less than that of the surrounding
wastewater. The attachment of the fine, micron size air bubbles to the
oil globules occurs by several mechanisms. The first mechanism is the
adhesion of an air bubble to the oil globule by precipitation or by the
collision of the air bubble with the oil globule. The second mechanism
is the trapping of the rising air bubble under an oil globule floe
structure. The third mechanism is the adsorption of the air babble by
an oil globule floe. The rise rate of the aggregate is described by
Stokes1 Law which states that the rate of rise is directly proportional
to the difference in weight of the aggregate and the wastewater it
displaces. The quantity of gas which can be dissolved in the wastewater
is described by Henry's Law, which states that for gases of low solubil-
ity the gas mass dissolved in water is directly proportional to its
partial pressure.
DESCRIPTION OP EQUIPMENT
Gravity Separators and Skimmers
Gravity separators normally remove free oil and little or no emul-
sified or soluble oil. The separators are used as primary treatment
processes and are particularly applicable for the separation of large
quantities of free oil.
Gravity separators range from lagoons with oil retention booms and
oil removal devices to tanks with automatic oil skimmers. The American
Petroleum Institute (API) has developed design criteria for gravity oil
35
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separators. Separators based on these design principles are the most
common type of oil separator and are referred to as API separators.
A line diagram of an API separator is presented in Figure 3. The
separator includes a trash rack, a forebay with oil skimmer and baffle,
an inlet diffusion device, and oil separation channels each with a
scraper and oil skimmer. The trash rack removes sticks, rags, stones,
and other debris. The forebay distributes the influent. The oil which
rises to the surface in the forebay is retained by the baffle and re-
moved by the skimmer. The inlet diffusion baffle reduces flow turbu-
lence and distributes the flow equally over the channel cross sectional
area. The free oil rises in the channels, is collected with the
scraper, and is removed with the skimmer.
A variation of the gravity separator called the parallel plate
separator is also commonly used. It consists of a gravity separator
with parallel plates installed in the tank to assure laminar flow condi-
tions. The small distance between the plates also reduces the distance
the oil globule must rise, which in turn results in a decrease in the
required actual surface overflow rate and detention time.
Emulsion Breaking
Chemical emulsion breaking can be accomplished as either a batch
process or a continuous process. The emulsion breaking process
resembles gravity separation except that concurrent chemical treatment
occurs to break up the emulsified oil. The mixture of emulsified oils
and water is initially treated by the addition of chemicals to the
wastewater. A means of agitation (either mechanical 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 re-
maining wastewater by a skimming or decanting process. The skimming
process can be accomplished by any of the many types of mechanical
surface skimmers that are presently in use. Decanting methods include
36
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Adjustable
weir
Influent
Figure 3.
S Judge pipe-
Sludge hopper -
API separator.
37
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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 allows the separated oils to be
drawn off the top or allows the wastewater to be drawn off the bottom
until oil appears in the wastewater line. With any of these arrange-
ments, the oil is usually diverted to storage tanks for further proces-
sing or hauling by a licensed contractor.
Coalescing
Coalescing also resembles gravity separation, except that the tank
is filled with various configurations of coalescing media. The coales-
cing media can be plates, fibrous media, reticulated polyurethane foams,
or loose media so long as they provide a tortuous path for the waste-
water. Most media are installed in the form of relatively small dia-
meter cartridges of a standard size, stacked in a parallel position.
Orientation may be vertical or horizontal; however, horizontal designs
can be more difficult to service since the entire separator vessel must
first be drained.
Air Flotation
A variety of flotation methods are commonly used for oil-wastewater
separation. The fundamental difference between these methods is the
mechanism by which the air is introduced into the wastewater. The two
most common methods are the dissolved air flotation (DAF) process and
the induced air flotation (IAF) process.
Many variations of the DAF process are used. Three principal
variations are full, partial, and recycle operation. Simplified line
diagrams of the three principal DAF process variations are presented in
Figure 4. These variations differ in the portion of the wastestream
which is pressurized and saturated with gas. The full pressurization
operation treats the entire influent wastestream. The partial operation
treats a portion of the influent wastestream. The recycle operation
38
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COMPRESSED
AIR
INFLUENT
PRESSURIZATION
SYSTEM
A-TOTAL PRESSURIZATION
INFLUENT
PRESSURIZATION *
SYSTEM I
COMPRESSED
AIR
B- PARTIAL PRESSURIZATTON
INFLUENT
COMPRESSED
PRESSURIZATION
SYSTEM
FLOTATION
TANK
FLOTATBN
TANK
FLOTATION
TANK
EFFLUENT
OIL DISCHARGE
SLUDGE DISCHARGE
EFFLUENT
OIL DISCHARGE
SLUDGE DISCHARGE
EFRUENT
OIL DISCHARGE
SLUDGE DISCHARGE
C- RECYCLE PRESSURIZATION -
Figure 4. Line diagrams of principal OAF process variations.
39
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treats a portion of the effluent wastestream. A typical recycle system
includes a compressed air source, an aeration tank, a feed pump, and a
flotation tank. The compressed air is dissolved into the return waste-
water at an elevated pressure and stored in the aeration tank. The
pressurized wastewater is subsequently mixed with the main wastestream
and released to atmospheric pressure in the flotation tank where the
dissolved air is released from solution as fine air bubbles, approxi-
mately 30 to 120 microns in diameter. The gas bubbles attach to the oil
globules and the aggregate rises to surface and is collected.
The induced air flotation process consists of a multicelled tank,
froth launders, a recycle pump, and static air inductors or aspirators.
The flow through the cells is in series. The wastewater enters the
first cell where air is introduced through the action of an aspirator.
The aspirator utilizes recycle process effluent. The air is released in
the cell in the form of air bubbles approximately 1000 microns in dia-
meter, somewhat coarser than those in a DAF process. The air bubbles
attach to the oil globules and the aggregate rises to the surface and is
collected. The remaining wastewater flows through a baffle into the
subsequent cells and ultimately out of the system. Alternate IAF sep-
arators use different methods to induce air into the wastewater. One
system forces air under pressure into the liquid-. Another common system
induces air into the wastewater through high speed mixers.
DAF separators commonly include a chemical feed system to introduce
coagulant aids such as polymers and metal salts, including ferric chlo-
ride, alum, and lime. IAF separators almost without exception include a
chemical feed system. The chemicals are introduced at a variety of
points in the system. Some systems include a separate rapid mix and
flocculation chamber.
Skimming Devices
Skimming devices to remove floating oil are an integral part of API
gravity, parallel plate, and coalescing separators. Four common
40
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skimming devices are the rotary drum, the rotatable slotted pipe, the
floating weir, and the belt (or rope) type.
With the rotary drum device, a horizontal drum approximately 0.3 to
0.6 meters (1 to 2 feet) in diameter is partially submerged in the
wastestream. Skimming is accomplished as the drum rotates with the
flow, picking up a thin oil film which is later scraped off the drum and
removed. The depth of submergence is not critical as long as the drum
is in contact with the oil layer. A submergence depth of approximately
3 cm (1 inch) is typical. The rotational speed is typically 0.15 to
0.45 m/sec (0.5 to 1.5 ft/sec), but the optimum speed depends upon the
amount of oil to be removed and oil viscosity. The device typically
results in a recovered oil that is low in water content.
With the rotatable slot device, a horizontal slotted pipe is sub-
merged in the wastestream with the slots normally above the surface.
Skimming is accomplished by rotating the pipe such that the slots are
submerged, allowing the oil to flow into the pipe and to be removed.
This device can result in a recovered oil that may be low or high in
water content depending on the amount of care exercised in submerging
the slot and adjusting it during the skimming operation.
t-
With a floating weir device, a floating device suspends a horizon-
tal weir in the wastewater channel. The device is weighted such that
the weir crest is just above the water surface but below the oil
surface. This positioning results in the oil flowing continuously into
the weir channel. The recovered oil exits the channel to a discharge
point via a flexible hose. The device typically results in a recovered
oil high in water content.
With the belt (or rope) device an endless belt is pulled through
the wastewater. Skimming is accomplished as floating oils adhere to the
belt. After passing through the wastewater, the belt continues on a
device located above the liquid level where the recovered oil is
squeezed or scraped from the belt and removed. The oil viscosity
41
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and attraction to the belt material affects the belt speed and perform-
ance. Baffles are commonly used to direct the floating oil to the belt.
Belts are typically 0.3 to 0.6 meters (1 to 2 feet) in width. The
device typically results in a recovered oil with low water content.
OPERATIONAL PROCEDURES
The objective of oil removal is to reduce free, emulsified, and
soluble oil to a level that is acceptable for discharge. This often
requires multiple steps that first remove free oil and then emulsified
oil by emulsion breaking or air flotation.
Process Monitoring
The performance criterion for evaluating oil removal equipment is
effluent total oil concentration., While this parameter provides the
overall performance of the system, several other parameters must be
measured and incorporated into a regular monitoring program to success-
fully and consistently operate an oil removal system. These parameters
are listed in Table 2.
Of the parameters listed in Table 2, flow should be monitored
continuously. Total influent and effluent oil along with pH, suspended
solids, and temperature should be measured at regular intervals as
specified or after any oil violation or process upset caused by exces-
sive oil. Sampling may be either composite or grab with grab sampling
normally preferred for oil measurements. Samples always should be col-
lected in areas of sufficiently high turbulence to entrain free oil.
Influent and effluent oils also should be analyzed for free, emulsified,
and soluble oil fractions on a monthly basis or after poor performance
of oil removal equipment is noted or suspected. More frequent analyses
will be required if a plant upset or permit violation is suspected.
Determination of oil content of water is a critical procedure.
Procedures for sample collection, storage, and analysis should be per-
formed in strict accordance with established standards. Quality
42
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TABLE 2
OIL REMOVAL
PROCESS MONITORING REQUIREMENTS
Parameter
Frequency
Comment
1 . Plow
2. Influent total oil
3. Influent free, soluble,
or emulsified oil
4. Effluent total oil
5. Effluent free, soluble,
or emulsified oil
6. Suspended solids
7. Waste oil volume
8. Waste sludge volume
9. Temperature
10. pH
11 . Oil volume collected
Continuously
Weekly
Monthly
Weekly
Monthly
Weekly
Weekly
Daily
Continuously
or per shift
Continuously
or per shift
Daily
To determine overflow
rate and hydraulic
retention time (HRT).
To determine mass
loading of oil.
To determine mass
loading for a partic-
ular form of oil.
To determine perfor-
mance and determine
loading to downstream
processes.
To determine perfor-
mance of the system.
To determine quantity
of oil to be disposed.
To determine quantity
of sludge to be
disposed.
Temperature will affect
oil removal perfor-
mance .
pH will affect oil
removal performance.
To determine mass
balance for oil.
43
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assurance including duplicate analyses and blanks is indispensable. If
a violation of permit conditions is detected, sample collection, stor-
age, and analysis procedures should be investigated as part of an
assessment of the plant program.
The analysis of samples for total oil content should be conducted
according to one of the procedures given in the current edition of
(9)
"Standard Methods for the Examination of Water and Wastewater".
While other techniques are commonly used, they may not be accepted by
local regulatory agencies. "Standard Methods", however, does not pro-
vide a technique for differentiating between free, emusified, and
soluble oil. This differentiation is particularly important when evalu-
ating equipment that is effective in removing one oil classification,
but not another. As an example, a gravity separator may appear to be
malfunctioning because it is removing only a small fraction of the total
oil. If the majority of the oil is free oil, this will be the case.
If, however, the majority of the oil is soluble or emulsified oil, the
gravity separator may be doing an excellent job removing the free oil
that it was designed to remove. A procedure for determining the free,
soluble, and emulsified fractions of oils is provided below.
Free Oil—
Place a measured amount of the raw wastewater in a separatory
funnel. Shake the sample vigorously and let stand quiescently for
approximately two hours. Draw off a portion of the subnatant and de-
termine its oil concentration. The oil measured is the emulsified and
soluble fraction. The difference between the total oil concentration
and that measured is the free oil concentration of the wastewater
sample.
Soluble Oil-
Place a measured amount of the raw wastewater in a separatory
funnel and acidify with 10 ml/1 of concentrated hydrochloric acid.
Next, add 200 g/1 sodium chloride and 5 g/1 diatomaceous earth. Shake
vigorously and let stand quiescently for a minimum of eight hours.
Filter .the mixture through a wet filter paper and measure the oil
44
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concentration of the filtrate. The oil concentration measured is the
soluble fraction of the wastewater sample.
Emulsified Oil—
The difference between the oil concentration of the emulsified and
soluble fraction measured in the Free Oil determination and the oil
concentration of the soluble fraction measured in the Soluble Oil deter-
mination is the emulsified oil concentration of the wastewater sample.
Example Calculations
Several example calculations are provided below for calculating
operating parameters essential to operation of an oil removal system.
Hydraulic Retention Time (HRT)—
HRT is the average length of time wastewater spends in a process
tank. Since the removal of oil does not occur instantaneously, it is
essential that the wastewater spend a minimum time in the oil separator.
The HRT calculation is:
VOL
where VOL is the liquid capacity of the tank and FLOW is the flow to the
separator. Note that the VOL and FLOW must be expressed in similar
units such as cubic meters or gallons. As an example, if an oil water
separator had a volume of 10,000 m3 and the flow to the tank was 2500 m3
per hour the calculation would be:
2500 m
hr
Surface Overflow Rate —
Surface overflow rate is the process flow rate divided by the
active surface of the area of a clarifier or oil water separator. The
45
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result is usually expressed as gallons per square foot per minute and
represents the loading on the treatment process with respect to its
surface area. The loading can also be expressed as a velocity by con-
verting gallons to cubic meters. This parameter is usually expressed as
meters/minute and is used primarily for circular clarifiers and air
flotation devices where it represents the average vertical velocity of
the water from the submerged center feed well to the surface overflow
weirs.
The surface overflow rate is calculated as follows:
SURFACE OVERFLOW RATE = FL°W
SURFACE AREA
where surface area is the quiesant area of the oil separator excluding
influent and effluent weirs and baffles, and flow includes any recycle
flow. As an example, if a 10-foot diameter dissolved air flotation oil
water separator with a 3-foot diameter center feed well had a flow rate
of 80 GPM and a recycle flow rate of 40%, the calculation would be:
80 + (0.4 X 80)
2
SURFACE OVERFLOW RATE = 2 2 =1.6 Gal/ft /min
Air to Solids Ratios (A:S)—
The air to solids ratio is used in conjuction with the air flota-
tion process and represents the ratio of the mass of applied air to the
mass of oil. This ratio is calculated as follows:
A-S ratio - 8,990 SCFM
A.s ratio - OIL CONC x FLOW
where OIL CONC is oil concentration in milligrams per liter (mg/L), FLOW
is wastewater flow in gallons per minute (gpm), and SCFM is air flow in
standard cubic feet per minute (scfm).
As an example the air requirement for a dissolved air flotation
tank with an influent oil concentration of 60 mg/L, a flow rate of 50
GPM, and an A:S ratio of 0.03 would be calculated as follows:
46
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o,
Process Control Strategies
Gravity Separation & Skimmers—
Gravity separators typically offer minimal opportunity for operator
control. Periodically, the tank must be checked for solids deposits on
the bottom of the tank or on the parallel plates if a plate separator is
used. Similarly, if any influent and effluent weirs are used they must
be periodically checked for trash and debris accumulations which might
impede even flow distribution. The weirs must also be checked to assure
they are level and to maintain proper liquid depth. The latter is
extremely important when slotted pipes are used to remove the collected
oil.
The hydraulic retention time and surface overflow rate should also
be calculated and compared to equipment design values. Flow to an oil
water separator is usually not controllable, but the calculations can
indicate if the system is overloaded or requires more equalization.
Similarly the temperature and suspended solids should be monitored.
Cold temperatures can reduce the rise velocity of oil globules by as
much as 50% and high suspended solids can lead to rapid solids accu-
mulation in the tank.
The oil removing or skimming equipment should be checked daily for
proper operation and depth of floating oil blanket. Excessive blanket
depth, i.e., more than a few inches for most equipment, can rapidly lead
to a system failure. Rotary drum and belt skimming devices should be
checked at least weekly for drum or belt surface integrity, scraper
blade integrity, and tension against drums. Rotating slot skimming
devices should be checked as often as required to keep oil blanket
depths within safe operating ranges. Care must be taken in operating
the slots to prevent excessive water entrainment. The slots must also
be checked periodically for levelness and accumulation of trash or
debris. Floating weirs must be checked daily to make sure trash is not
47
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collecting on the weirs and to make sure the weirs are free floating and
properly balanced. Periodically, the flexible hose must be checked for
integrity.
Coalescers—
The operation of coalescers is essentially the same as that for
gravity separators. The frequency of inspection for solids accumulation
and plugging of the coalescers must, however, be on at least a monthly
basis.
Emulsion Breaking—
Chemical addition is not a separate unit process for oil-water
separation. Rather, it is used prior to or in conjunction with other
separation processes. Chemical addition is first used to break or
demulsify emulsified oils in the wastewater. The treatment is usually
directed toward destabilizing the dispersed oil droplets or chemically
binding or destroying any emulsifying agents present.
As previously stated, chemical demulsifying processes include
acidification, coagulation, salting out, and demulgation with organic
cleaving agents. Acids generally cleave emulsions more effectively than
do coagulant salts, but are more expensive. In addition, the resultant
wastewater must be neutralized after separation. Coagulation with
aluminum or iron salts may be effective and is commonly used. However,
the resultant hydroxide sludges may be voluminous and are difficult to
dewater. Coagulation with polymer may be effective and is sometimes
used. The resultant sludge quantities are smaller than those for metal
salts but are sometimes more difficult to dewater. The salting out of
an emulsifier may be achieved with the addition of large quantities of
an inorganic salt, thereby increasing the dissolved solids content of
the wastewater. Organic demulgators may be extremely effective demul-
sifying agents but are generally very expensive and specialized. Demul-
gators are normally considered only if they are found to be effective in
extremely low concentration due to cost and, in many cases, their toxi-
city at higher concentrations.
48
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The effectiveness of chemical pretreatment is normally determined
with bench scale jar testing. A representative wastewater sample is
split into several aliquots. Each aliquot is reacted with a different
quantity of the chemical under consideration. After each addition, the
aliquots may be flash mixed, flocculated, and quiescently settled and
then examined to note any reaction and emulsion breaking and the rate
and effectiveness of separation.
One typical procedure for jar tests is that suggested by the
Tretolite Division of Petrolite Corporation, in their Industrial Bench
Testing Procedures Manual. The procedure is as follows.
1. Secure appropriate sample for testing.
2. Fill one liter beakers to either 500 or 1000 ml mark. Test
volume is dependent on volume of sample available and volume
required for water quality analysis.
3. Place beakers on paddle mixer and begin mixing at maximum
speed.
4. Dose beakers with appropriate chemical(s) and appropriate
volumes.
5. Mix on high speed for 1 minute.
6. When chemical additions and 1 minute rapid mix intervals are
complete, reduce stirrer speed to slow mix for 1 minute mini-
mum. (Note: Mix times can be varied to more closely duplicate
full scale system).
7. Turn mixer off and remove beakers for settling. Settling time
is dependent on system and rate of contaminant removal (10-30
minutes should prove adequate).
8. Wipe paddles clean with a paper towel or rag in preparation for
the next test.
9. Repeat steps 2-8 until the desired treatment program has been
thoroughly investigated.
10. After the chosen settling time has elapsed, sample beakers for
appropriate water quality analysis.
49
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The j ar test procedure is useful for determining the optimum pH for
separation, the most effective coagulant and coagulant aid, the optimum
chemical dosage and order of chemical addition, the required rapid and
slow mix times, the required settling, and the estimated separation
effectiveness.
The pretreatment chemicals may be added directly to a process line
or may require separate rapid mix and flocculation chambers. The opera-
tion of these chambers is discussed elsewhere in this document under
"Chemical Addition Equipment" and "pH Control".
Air Flotation
Air flotation, as compared to gravity separation, has several con-
trol mechanisms that are directly under the control of the operator.
These include the system pressure, recycle rate, air to solids ratio,
and chemical addition rate. The operator also has some control of
surface overflow rate and hydraulic residence time. Typically increas-
ing the system operating pressure and air to solids ratio will improve
performance. However, care should be taken in increasing these because
past a certain air to solids ratio very little improvement is obtained
and a considerable amount of energy is expended. As the air to solids
ratio is increased it may also be necessary to increase the recycle rate
in order to provide sufficient water for air to initially dissolve.
However, the increase in recycle rates will increase the surface over-
flow rate, a situation which can lead to performance degradation if the
overflow rate exceeds the system design specifications.
The DAF pocess is typically operated with a 40 to 60 psig pressure,
20 to 50 percent recycle, 1 to 4 gpm/sq ft surface overflow rate, 1 to 2
minute aeration tank detention time, 0.01 to 0.06 air to solids ratio
and 20 to 40 minute flotation tank detention time. Typically with the
DAF process, compressed air is used as the feed gas because it is rela-
tively inexpensive. However, inert gases are sometimes used instead.
.For example, nitrogen gas is used to minimize corrosion by keeping iron
in solution. The choice of gas can depend also upon the nature of the
50
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wastewater and any regulations concerning off-gas removal. The volume
of froth layer produced in the DAF process is approximately equal to 0.2
to 2.5 per cent of the influent waste flow.
IAF separators typically use a recycle flow rate of 100 to 400
percent with 5 to 10 minute detention time and result in a froth pro-
duction rate equal to 1 to 15 percent of the influent flow rate.
When operating air flotation units, pressure gauges and flowmeters
should be checked daily for proper readings and calibrated on at least a
yearly basis. In addition, any weirs should be checked monthly for
trash or debris accumulation and levelness. If scraper arms are used to
skim the float, they should be checked monthly for proper submergence,
usually around 1 /2 to 3/4 inches when water level is at the base of the
weirs. They must also be checked for scraper blade integrity and proper
seal when crossing the sludge hopper.
TYPICAL PERFORMANCE VALUES
The performance of oil removal'equipment is extremely dependent
upon the distribution of oil between the free, emulsified, and soluble
forms. Gravity oil separators typically have produced an effluent with
a total oil concentration between 50 and 100 mg/L. However, gravity
separators with an emulsion breaking pretreatment step give typical
performance ranges from less than detectable to 40 mg/L of effluent oil.
Coalescers should provide slightly better performance than gravity
separators. Limited information regarding their performance indicates
that an effluent of 1 to 50 mg/L of oil can be achieved (includes units
with and without emulsion breaking).
DAF and IAF separators typically produce effluents of equal qual-
ity. A flotation separator, preceded by a gravity or parallel plate
separator, typically produces an effluent with an oil concentration less
than 20 mg/L. When used without pretreatment, the flotation separator
can produce an effluent with an oil concentration of 25 to 100 mg/L.
51
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TROUBLESHOOTING GUIDE
A guide for troubleshooting the oil removal process is presented in
Table 3. Six problem areas are noted; all the problem areas deal with
either excessive oil in the aqueous effluent or excessive water in the
collected oil phase. In many cases a detailed analysis of the oil
emulsion breaking treatment will be required, to correct the problem.
Careful sampling, jar test evaluations, and oil analyses are required to
define the problem and investigate corrective actions.
52
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TABLE 3
OIL REMOVAL TROUBLESHOOTING GUIDE
Ln
OJ
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 1: Gravity separator has high effluent oil concentration.
1a. Flowrate too high.
Ib. Emulsified and/or
soluble oil present.
1c. Short circuiting of
tank occurring.
Id. Separator tank
filled with solids.
le. Excessive floating
oil blanket in
separator tank.
If. Change in influent
characterization.
Check peak and average flow
rate, hydraulic retention
time (HRT), and surface over-
flow rate and compare manu-
facturer's recommendation and
design criteria.
Monitor/ the free, emulsified,
and soluble oil concentration
entering and leaving the
separator.
Check influent and effluent
weirs and baffles for
plugged, broken, or missing
units. Check weirs for
for levelness.
Drain tank and inspect or
rod with a pole to detect
the presence of solids or
sludges on the bottom of
the tank.
Monitor effluent for free
oil and visually
inspect for floating oil
in effluent.
Check viscosity, temperature,
and density of oil-water
solution and collected oil.
Compare to original design
conditions and manufacturer's
recommendations.
Separators are designed
to achieve quiescent
conditions in the oil-
water separation zone.
Excessive flow promotes
turbulence.
Gravity separator is
effective for free
oil only.
When short circuiting
occurs the oil does not
have time to separate
from the water.
As the solids collect in
the tank the HRT is
decreased and the oil does
not have sufficient time to
separate from the water.
If floating oil layer
becomes too deep it can
extend down to treated
water effluent port.
If process changes result
in changes in the density
and viscosity of the oil
and water, the design
requirement for gravity
separators can change.
Decrease flow rate; add
more oil-water separator
capacity) increase equaliz-
ation if peak flow is
excessive.
Trouble shoot Step 6;
install emulsion breaking
equipment if not present;
control sources of soluble
oil.
Clean, repair, replace, or
adjust as needed.
Clean and remove all solids
and sludges.
Adjust oil skimming devices
as required.
Modify separator design as
required.
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TABLE 3
(Continued)
OIL REMOVAL TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 2: Gravity separator has a very high water content in collected oil.
2a. Holes or cracks in
collection slots.
2b. Poor operation of oil
collection slot or
tilted floating weir
which allows water
to enter.
2c. Floating weir has
improper ballast result-
ing in weir floating
too low in water.
2d. Slot oil collectors are
located too near the oil
water interface.
Inspect and monitor for water
flow when oil is not being
removed.
Monitor operation of collec-
tion slot, inspect floating
weir for levelness and presence
of trash in weirs.
Check distance between
bottom of weir and oil-water
interface.
Check distance between slot
and oil water interface during
nonskiroming operation.
Treated water can contam-
inate collected oil.
Treated water can contam-
inate collected oil.
If water too close to the
bottom of the weir, wave
action caused by wind or
hydraulic surges can cause
water to enter the weir.
If water too close to the
bottom of the slot, wave
action caused by wind or
hydraulic surges can
cause water to enter the
slot.
- Repair as required.
Adjust equipment or instruct
operators as required.
Clear weir to remove heavy
deposits! adjust weir as
specified by manufacturer.
Adjust as required (may
require adjusting of an
effluent weir opposed to
adjusting slot).
OPERATING PROBLEM 3: Coalescer has high effluent oil concentration.
3a. Coalescers clogged or
broken.
3b. pH of oil-water solu-
tion different from
design or normal
operating condition.
3c. See Step 2.
Drain tank and inspect.
Monitor pH.
See "Troubleshooting
Gravity Separators"
For proper performance
oil must come in contact
with coalescing plates
and proper velocities
must be maintained.
pH can affect surface
properties of oil
droplets and their
ability to coalesce.
See "Troubleshooting
Gravity Separators"
Clean and repair as required.
Adjust pH to design or normal
operating conditions.
- See Step 2.
-------
TABLF 3
(Continued)
OIL REMOVAL TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHFCK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 4: Air flotation unit has high effluent oil concentration.
4a. Inadequate dissolved
air being supplied.
4b. Inadequate recycle
flow.
4c. Inadequate delivery
pressure.
4d. Inadequate hydraulic
retention time (HRT).
4e. Excessive surface
overflow rate.
4f. Short circuiting of
DAF occurring.
4g. Skimmer not removing
solids fast enough.
4h. Improper chemical
addition (where
applicable).
- Monitor oil concentration!
monitor air flow; determine
air:solids (oil) ratio.
Check recycle flow rate.
Check delivery pressure and
check calibration of pressure
gauge.
Monitor flow ratei check tank
for accumulation of solids;
calculate HRT.
Monitor flow rate and
calculate surface overflow
rate.
Check effluent weirs for
plugging and levelness.
Check influent baffles.
Inspect skimmers for
broken scapers, proper
submergence in the water,
poor seal along the edges
or sludge hopper,- check
speed.
Check chemical feed pumps
for proper operation,
setting, and calibration.
Insufficient air being
supplied to float the
mass of oil present.
Recycle flow is often
essential to provide
enough water to dissolve
the required air.
Insufficient pressure
can result in the air not
dissolving in the water.
Short HFT's do not allow
sufficient time for solids
to separate.
Large overflow rates can
carry solids out of the
tank and break foam..
Short circuiting can
result in inadequate
detention times.
Air flotation foam breaks
with time and can cause
reentrainment of oil
particles.
Inadequate chemical
conditioning can result
in significantly reduced
performance of air
flotation equipment.
Adjust as required; typical
range is 0.01 to O.06 pounds
of air per pound of oil.
Adjust as required; see design
and manufacturer's recommen-
dations. Typical values range
from 20 to 50% recycle.
Adjust as required; see design
and manufacturer's recommen-
dations. Typical values range
from 40 to 60 psig.
Decrease flow rate; trouble-
shoot "Equalization"; clean
tank. Typical values are 20
to 40 minutes.
Decrease flow rate; trouble-
shoot "Equalization". Typical
values are 1 to 4 gpm/sq ft.
Clean and adjust weirs as
required.
Repair and replace damaged
scapers as required.
Adjust submergence and rota-
tional speed as required.
Clean, repair, and adjust as
required.
-------
TABLF 3
{Continued)
OIL REMOVAL TROUELFSHOOTIHG GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
Perform jar test to
optimize type dosage and
pH of chemical conditioning
agent. The nature of the
waste may have changed.
If polymer is being used
check initial dilution and
placement of polymer addition.
Inadequate chemical
conditioning can result
in significantly reduced
performance of air
flotation equipment.
Proper mixing of polymer
and waste essential.
Polymers must be initially
diluted to 0.1 to 0.5% for
proper mixing to occur.
Polymer can be sheared by
injecting it upstream of
a centrifugal pump.
Adjust chmical addition
equipment as required.
Adjust initial polymer
dilution procedures as
required. Change polymer
addition point to assure
adequate mixing prior to
downstream release in air
flotation tank. Move addi-
tion point of centrifugal
pump.
Ul
cr>
OPERATING PROBLEM 5: Float from air flotation unit contains excessive water.
5a. Leak in float
collection hopper.
Check hopper with skimmer
arm turned off. If water
enters hopper, leak is pres-
ent in hopper or top of
hopper located below
water surface.
Water contaminating
concentrated oil.
- Repair or adjust as required.
OPERATING PROBLEM 6: Emulsion breaking is not converting all emulsified oil to free oil.
6a. Poor mixing between
oil and chemicals.
Check mixing equipment for
worn mixers, missing
baffles, and adequate horse-
power (See Table 1).
Proper mixing of condi-
tioning agent and waste
water is essential for
conditioning agents to be
effective.
Repair and replace as
necessary.
6b. Improper conditioning
agent or dosage.
6c. Fluctuating or
improper pH.
Perform jar test to determine
optimum conditioning agent,
dosage, and pH.
See "pH Troubleshooting
Guide."
Waste characteristics
determine optimum
conditioning agent,
dosage, and pH.
Most emulsion breaking
breaking techniques are
pH-sensi ti ve.
Adjust chemical addition
equipment as required.
See "pH Troubleshooting
Guide."
-------
SECTION 6
CYANIDE OXIDATION
INTRODUCTION
Cyanide (CN~) is used in the metal finishing industry to keep metal
ions (zinc, copper, etc.) in the electroplating solutions from precipi-
tating. Cyanide is typically added as sodium cyanide (NaCN) or hydro-
cyanic acid (HCN). Added either way, the cyanide ion is both highly
toxic and soluble. Furthermore, if the pH of cyanide containing waste
drops below 7, hydrogen cyanide gas (HCN) which is extremely poisonous
will be evolved.
THEORY OF OPERATION
The most frequently employed method for treating cyanide waste is
cyanide destruction by chlorination. Other oxidants such as ozone are
used also. During the oxidation process, cyanide may be either par-
tially oxidized to a less toxic form, cyanate (CNO~), or completely
oxidized to carbon dioxide (CO_) and nitrogen (N_). This corresponds to
what is commonly referred to as "one-stage" and "two-stage" treatment
respectively. Both stages can be accomplished using various forms of
chlorine including chlorine gas dissolved in water, sodium hypochlorite
(NaOCl), or calcium hypochlorite (Ca(OCl)_). Acid hydrolysis is also
used for destroying cyanate.
Chlorine Oxidation
The first stage of the cyanide destruction is chlorine oxidation of
cyanide to cyanate. The equation for this reaction is:
57
-------
Cl + NaCN + 2NaOH > NaCNO + 2NaCl + H20
This reaction has an intermediate step that first converts chlorine
gas to the hypochlorite ion (OCL ) which then reacts with the cyanide.
Because the oxidation reaction depends upon the presence of the hypo-
chlorite ion, it is necessary to perform this reaction at a pH greater
than 8.5. This requires that caustic (NaOH) be added to ensure that a
pH greater than 8.5 is maintained at all times, and to maintain it
during the reaction which consumes two caustic molecules for each cya-
nide ion oxidized. If the pH is allowed to decrease below 7.0, the
reaction will stop and the highly toxic gas, cyanogen chloride, will be
evolved. The overall reaction of cyanide to cyanate is both time and pH
dependent. At a pH of 10.0 or higher, oxidation of cyanide to.cyanate
is accomplished rapidly and completely if oxidation periods of 30 to 120
. „ . . (13)
minutes are maintained.
The second stage of the cyanide destruction process is chlorine
oxidation of cyanate to nitrogen and carbon dioxide which is then con-
verted to bicarbonate and carbonate ions. This reaction depends upon
the presence of hypochlorous acid (HOC1) for an oxidant, as opposed to
one stage oxidation which requires the hypochlorite ion. Therefore the
pH must be less than 8.5, normally in the range 8.0 to 8.5. The rela-
tionship between the cyanate oxidation reaction, pH, and required
detention time is displayed in Figure 5. However, for actual plant
operations a detention time of 60 minut
chemical formula for cyanate oxidation is:
operations a detention time of 60 minutes is recommended. The
3C1 + 6NaOH + 2NaCNO ^=± 2 NaHCO + N + 6NaCl + 2H O
As previously stated, the chlorine required for cyanide oxidation
can be added to the system in several forms including chlorine gas,
sodium hypochlorite solution, and calcium hypochlorite solution. Chlo-
rine gas is quite soluble in water and when dissolved in water, chlorine
hydrolyzes rapidly to form hypochlorous acid (HOC1) and/or hypochlorite
ion (OC1 ) depending upon the pH. The effect of pH on the distribution
58
-------
RETENTION TIME REQUIRED FOR CYANATE DESTRUCTION
01
10
o
CD
O
CO
O
o
o
00
•
o
un
ID
XJ
I
CO
b
p
b
-------
of hypochlorous acid and hypochlorite ion in water at two different
temperatures is shown in Figure 6. When dissolved in caustic and water
(pH>8.5), chlorine will form the hypochlorite ion (OC1 ). The dissolu-
tion reaction for the hypochlorite ion is
Cl + 2N3OH > 2Na+ + OC1~ + Cl~ + H20.
It can be seen from the equation that one molecule (or one kilogram
mole) of chlorine gas will require two molecules (or two kilogram moles)
of caustic and will yield one molecule (or one kilogram mole) of hypo-
chlorite ion (OC1 ). The ratio of chlorine gas to caustic is important
because caustic and chlorine are generally added at a controlled ratio.
Note that we generally add materials to be reacted by weight (kg or Ib),
although reactions occur by the molecule or mole basis. The mass in
kilograms divided by the molecular weight gives the number of kilogram
moles.
The main advantage of using chlorine gas is that the chemical cost
is the lowest of the three oxidizing agents. However, there is a great
disadvantage because chlorine gas is difficult to handle and is toxic.
Therefore, the choice of using chlorine gas becomes a trade-off between
materials handling-safety and cost.
h
Sodium hypochlorite (NaOCL) requires no preparation and can be used
directly as an oxidizing agent. The main advantage in using sodium
hypochlorite is that it is relatively easy and safe to handle and use.
The use of calcium hypochlorite [Ca(OCl)2] requires that, for best
results, it be dissolved into solution before introduction into the
oxidizing reaction. When calcium hypochlorite is not dissolved in water
first, increased quantities of sludge will be produced.
Acid Hydrolysis
A second method for destruction of cyanate is acid hydrolysis.
Acid hydrolysis is accomplished by lowering the pH to a value of 2 or 3
by adding sulfuric acid. Five minutes reaction time is required to
destroy the cyanates. Two disadvantages of this procedure are that
60
-------
Figure 6.
90
100
10 11
Distribution of HOCL and OCL.
SOURCE: SAWYER, ON. AND MeCARTY. PJ_; CHEMISTRY FOR SANITARY ENGINEERS.
MCGRAW-HILL BOOK COMPANY, laer, p. 347.
61
-------
the pH must be lowered to 2 to 3 with acid; then after hydrolysis, the
pH has to be raised again to pH 6 to 9 for discharge. This requires
significant volumes of neutralizing agents (both acid and caustic) which
increases the total dissolved solids of the wastewater. Furthermore, if
incomplete destruction of cyanides occurs in the first stage for any
reason, hydrogen cyanide gas will be released when the acid is applied.
DESCRIPTION OF EQUIPMENT
Typical equipment for cyanide treatment consists of reaction ves-
sels, mixers, pH controllers, and chlorinators. These can be operated
in a batch or continuous flow mode. Either mode can be used to achieve
single stage cyanide oxidation (the conversion of cyanide to cyanate) or
two stage oxidation (the conversion of cyanide to CO, and N ). A
£ £
typical system for a continuous two-stage oxidation unit is shown in
Figure 7. It includes two reaction vessels, two automatic pH control-
lers, two mixers, and a chlorinator with dual control"circuits to con-v
trol independently the chlorine dose for each reaction vessel based on
reactor oxidation reduction potential (see Section 7, Chromium Reduc-
tion), when only single-stage cyanide reaction is required, the second
reaction vessel is deleted from the system. The advantage of single-
stage operation is reduced chemical and capital costs as compared to
two-stage operation. The disadvantage of single stage oxidation of
cyanide to cyanates is that cyanates are somewhat toxic. However, they
are much less toxic than cyanides, but in some areas discharge of
cyanates may not be allowed.
Batch cyanide oxidation equipment basically resembles the single-
stage continuous equipment except that it is operated in a batch mode.
This mode of operation requires either an intermittent flow or multiple
tanks. In either case, increased operator involvement is required to
fill and draw the tanks and to readjust the pH controller between the
first and second stage when two-stage oxidation is practiced. For these
reasons, batch treatment is seldom practiced when average flows exceed
15 GPM.
62
-------
CTi
RAW WA9TE
CAUSTIC
SODA
PH r—j J
CONTROLLER! l~
D
OO
REACTION TANK
lal Stage
Figure 7.
WATER CONTAINING CVANATE
CHLORINE
~\
CHLORINATOn
CAUSTIC SODA
D
_n pH
—II CONTROLLER
I
t
TREATED
- WASTE
REACTION TANK
2nd Stage
Two-stage cyanide destruction.
-------
OPERATIONAL PROCEDURES
To control the operation of the cyanide destruction process, the
operator should conduct the necessary process monitoring, perform any
control calculations needed, and understand the process control strate-
gies.
Process Monitoring
The main performance criterion used to evaluate the cyanide reduc-
tion process is the reactor effluent concentration of cyanide in one
stage oxidation or the second reactor effluent concentration of cyanide
and cyanate in two stage oxidation. While these parameters provide the
overall performance, many other parameters should be measured and incor-
porated into a regular monitoring program to successfully and consis-
tently operate a cyanide reduction process. These parameters are listed
in Table 4. For continuous treatment systems, flow, pH, and oxidation
reduction potential (ORP) are normally recorded on a continuous basis.
The probes for these units should be calibrated weekly with daily cali-
bration preferable. The cyanide in the process influent and the cyanide
and free chlorine in each reactor vessel effluent should be measured
daily using a composite sample for cyanide and a grab sample for chlo-
rine. These measurements are required to verify adequate treatment and
to establish a working relationship between free chlorine, ORP, and
cyanide destruction. The effluent temperature and suspended solids
should also be measured on a daily basis to provide an understanding of
how these parameters affect efficiency of destruction.
In addition to the above standard, monthly or quarterly analyses of
the treatment plant influent for interfering agents should be performed.
These agents either cause an excessive use of chlorine or form cyanide
complexes that cannot be oxidized by chlorine. These agents include
cuprous, nickelous, ferrous, and ferric ions. The presence of cuprous
ion in cyanide wastes produces an apparent interference to the destruc-
tion of cyanides. The cuprous ion exerts a chlorine demand of 0.56 Ibs
of available Cl. per Ib of cuprous copper present. Therefore, at least
64
-------
TABLE 4
CYANIDE REMOVAL
PROCESS MONITORING REQUIREMENTS
Parameter
Frequency
Comment
1. Reactor Temperature
2. Flow
3. Influent Cyanide
Concentration
4. Effluent Cyanide
Concentration
5. Effluent Cyanate
Concentration
6. Chlorine
Concentration
7. Reactor pH
8. Reactor ORP
9. Effluent Suspended
Solids Concentration
10.Reactor Sludge
Volume
Daily
Continuously
Daily
Daily
Daily
Daily
Continuously
Continuously
Daily
Daily
To measure temperature.
To determine HRT and to
adjust chemical dosages.
To determine destruc-
tion efficiency.
To measure any residual.
To determine loading to
downstream processes.
To measure excess
chlorine.
To control caustic
addition.
To control chlorine
addition.
To determine loading
to downstream processes.
To determine treatment
chemical requirements and
mixing effectiveness.
65
-------
an additional 0.56 Ibs of available Cl has to be used in the oxidation
of cyanides to account for this chlorine demand.
The above discussion of cuprous ions also holds true for nickelous
ion which exerts 2.24 Ibs of available chlorine demand per Ib of nicke-
lous ion. This 2.24 Ibs/lb represents an excess of 3.7 times the
theoretical amount required for the oxidation of nickelous ion to nicke-
lic ion. This excess has been found experimentally to be necessary to
eliminate the nickelous interference.
Ferrous and ferric ions present in wastewaters that contain cyanide
can react with chlorine to form a complex that is only slightly oxidiz-
able by cyanide.
Example Calculations
Hydraulic residence time (HRT) represents the average length of
time wastewater spends in the chemical reaction tank assuming complete
mixing of the reactor. Since the oxidation of cyanide is not an in-
stantaneous reaction, it is essential that the wastewater remain in the
reaction tank for at least the minimum recommended HRT.
The HRT calculation is:
FLOW
where:
VOL = the volume of liquid in the tank
FLOW = the flow to the reactor.
Note that VOL and FLOW must be expressed in similar units such as cubic
meters or gallons. As an example, if a cyanide oxidation vessel had a
volume of 6000 gallons and the flow to the tank was 8000 gallons/hour
the calculation would be:
6000 GAL 0
-------
Process Control Strategies
The principal operating strategies for process control of both one
and two stage cyanide oxidation are pH, ORP (which controls the chlorine
addition), mixing, and HRT. Of these variables the operator has ready
control of pH and ORP. The HRT, while having a major impact on the
process, is established by the wastewater flow rate and the reactor
design, and therefore the operator has little control for continuous-
flow systems. However, for batch systems the operator has control of
the HRT.
For first stage oxidation, the ORP should be maintained between 350
and 400 mV( for a pH between 9.5 and 10. Typically, this will result
in nearly complete . oxidation of cyanide in 30 to 120 minutes. In
general, increasing ORP will decrease the required reaction time (HRT).
Similarly, increasing pH to a value of 10 will decrease required reac-
tion time (HRT). Above a pH of 10, no improvement in performance is
achieved. Therefore, operating at a pH above 10 will only result in
increased caustic consumption and a high strength wastewater that must
be neutralized.
For two stage treatment the first stage is operated as described
above. However, the second stage is typically operated at a pH between
8 and 8.5 and the ORP is maintained at approximately 600 mV. Increasing
the ORP will decrease the reaction time (HRT) but unlike first stage
oxidation as the pH is decreased reaction time (HRT) is also decreased.
In practice, however, the pH is seldom allowed to decrease below 8.0 for
two reasons. First, if incomplete oxidation of cyanides occurred in the
first stage for any reason, extremely toxic hydrogen cyanide gas could
be released when the pH is dropped to 7 or below. Secondly, if the pH
were to drop to 5 or below, nitrogen trichloride, an explosive compound,
could be produced.
In addition to the above parameters several other items should be
checked by the operator on a routine basis. These include reactor
mixing, reactor bottom for solids deposition, the reactor effluent for
67
-------
suspended solids, solids production, temperature, and the condition of
chemical feed equipment.
Mixing is important for four major reasons. Firstly, good mixing
is essential to assure good contact between cyanide and the oxidizing
agent, chlorine. Secondly, good mixing is required to minimize short
circuiting which can cause the actual HRT to be much shorter than the
calculated HRT. Thirdly, if inadequate mixing is present in the first
stage oxidation, cyanide precipitates which resist oxidation can form.
Lastly, inadequate mixing can result in solids settling out in the
reaction vessel, thereby reducing its effective volume and HRT.
To assure good mixing the operator should periodically inspect the
basin. The operator should also check influent and effluent structures
for integrity. The influent and effluent structures should be located
at opposite ends of the reaction vessel. Circular tanks should also be
equipped with mixing baffles along the side walls. The operator either
should occasionally drain the tank or rod the side walls to make sure
solids are not being deposited in the tank. The operator also should
inspect the mixer. The impeller should be checked for proper submer-
gence and wear. The mixer should also be checked for proper horsepower
(see Table 5) especially if poor mixing occurs and no other cause can be
found.
The reactor water temperature also should .be periodically checked.
While wastewater temperature cannot usually be controlled it can affect
reaction rates and general performance of the system. By monitoring
temperature, variations in performance can sometimes be understood.
Similarly, suspended solids concentrations should be monitored. A
significant increase in solids across a first stage reactor can indicate
inadequate mixing and can result in cyanides being carried through as
precipitates.
68
-------
TABLE 5
HORSEPOWER REQUIREMENTS FOR MEDIUM AGITATION
(Source: Shinskey, F. G.: pH and plon Control in Process and
Waste Streams, John Wiley and Sons, Inc., New York, NY 1973,
p. 161).
Vessel Volume
(gal) Horsepower Hp/1000 gal
100 0.27 2.7
1000 2.3 2.3
10,000 12 1.2
100,000 ' 80 0.8
69
-------
TYPICAL PERFORMANCE VALUES
The oxidation of cyanide by chlorine can achieve efficiencies of
99% or greater with respect to cyanides not complexed with iron (ferrous
and ferric ions), giving effluent cyanide concentrations for cyanide not
complexed with iron typically ranging from non-detectable to 10 ppb.
For total cyanide, the concentrations typically run from non-detectable
to 1 00 ppb.
TROUBLESHOOTING GUIDE
\
A troubleshooting guide for operation of the cyanide oxidation pro-
cess is presented in Table 6. The operating problem areas are threefold
— high cyanide in effluents, high cyanates in effluents, and solids
accumulation in the reactors. The high cyanide-cyanates problems
usually involve chemical phenomena or equalization; the problem of
solids accumulation is primarily physical in nature and is resolved by
adequate reactor mixing.
70
-------
TABLF 6
CYANIDE OXIDATION TROUBLESHOOTING GUIDF
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM Is High cyanide in the effluent.
la. Improper or
fluctuating reactor
PH.
See "pH Control Trouble-
shooting Guide."
Cyanide oxidation is
pH sensitive. pH
levels less than 9
dramatically reduce
the reaction rate.
See "pH Control Trouble-
shooting Guide."
1b. Inadequate equali-
zation.
See "Equalization Trouble-
shooting Guide."
Flow surges can
cause erratic per-
formance of pH con-
trol equipment and
wash the cyanide
through the treat-
ment process before
it has had time to
react.
See "Equalization Trouble-
shooting Guide."
Ic. Improper or
fluctuating
ORP.
Check ORP set point.
Check calibration and
condition of ORP probe.
Check chemical feed
equipment for proper
operation.
Low chlorine dos-
ages can prevent
the destruction of
cyanides (ORP should
be between +350 to -t
400 mV in first stage
destruction).
Clean, calibrate, and
adjust chlorine addition
equipment and ORP
controller as required.
Id. Inadequate mixing.
1e. Inadequate resi-
dence time.
Check condition of mixer
impeller.
Check all mixing baffles
including influent,
effluent, and sidewall
baffles on circular tanks.
Check motor RPM and
horsepower. (See Table 5).
Check reaction vessel
for solids accumula-
tion.
Monitor reactor flow
and calculate HRT.
Inadequate mixing
can result in for-
mation of solids
containing cyanide
which resist cyanide
destruction. It can
also result in reactor
short circuiting, poor
pH control, and poor
contact between
chlorine and cyanides.
Accumulation of
solids in the re-
action vessel and
excessive flow can
reduce hydraulic
residence ti'me, thus
leaving inadequate
time for the reaction
to oc-cur.
Repair and adjust
as required.
Clean reactor.
Reduce flow.
-------
TABLE 6
(Continued)
CYANIDE OXIDATION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
If. Significant quan-
tities of ferrous or
ferric ions present.
Monitor wastewater for
presence of iron ions.
Iron cyanide com-
plexes are formed in
presence of ferrous
and cyanide ions.
They are very stable
and resistant to
most treatment
techniques.
Identify source of
ferrous and ferric ion
and eliminate .
OPERATING PROBLEM 2: High cyanates in the effluent.
2a. Improper or
fluctuating
reactor pH.
See "pH Control Trouble-
shooting Guide."
Cyanate oxidation is
pH sensitive. pH
levels between 8.0 and
8.5 should be main-
tained.
See "pH Control Trouble-
shooting Guide."
2b. Inadequate equali-
zation.
See "Equalization Trouble-
shooting Guide."
Elow surges can
cause erratic per-
formance of pH con-
trol equipment and
wash the cyanate
through the treat-
ment process before
it has had time to
react.
See "Equalization Trouble-
shooting Guide."
2c.
Improper or
fluctuating
ORP.
2d. Inadequate mixing.
Check ORP set point.
Check calibration and
condition of ORP probe.
Check chemical feed
equipment for proper
operation.
Check condition of mixer
impeller.
Check all mixing baffles
including influent,
effluent, and sidewall
baffles on circular tanks.
Check motor RPM and
horsepower. (See Table 5)
Low chlorine do-
sages can prevent
the destruction of
cyanides (ORP should
be around +600 mV
for second stage
cyanide destruction).
Inadequate mixing
can result in
reactor short
circuiting, poor
pH control, and
poor contact between
chlorine and cyanates.
Clean, calibrate, and
adjust chlorine addition
equipment and ORP
controller as required.
Repair and adjust
as required.
-------
TABLE 6
(Continued)
CYANIDE OXIDATION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
2e. Inadequate resi-
dence time.
Check reaction vessel
for solids accumula-
tion.
Monitor reactor flow
and calculate HRT.
Accumulation of
solids in the re-
action vessel and
excessive flow can
reduce hydraulic
residence time, thus
inadequate time for
the reaction to occur.
Clean reactor;
reduce flow.
OPERATING PROBLEM 3: Solids accumulate in reactors.
3a. Inadequate mix-
ing.
3b. Grit or metal fil-
ings present in
wastewater.
Check condition of
mixers, mixer horse-
power, RPM of mixers
if variable speed
mixers are used and
condition of side wall
baffles if circular
tanks are used.
Inspect solids in tanks
to determine their na-
ture.
Inadequate mixing
can result in the
formation of pre-
cipitatants that
contain cyanides.
Precipitated cya-
nides resist oxi-
dation.
Gritty solids such
as metal filings
cannot be kept in
suspension unless
very high mixing
horsepower is pro-
vided.
Repair and replace
equipment as required.
Install grit chamber or
similar grit collection
system upstream of the
process.
-------
SECTION 7
CHROMIUM REDUCTION
INTRODUCTION
Chromium is used in the metal finishing industry as a corrosion
_2
inhibitor either in the chromate form, CrO, ion, or as the dichromate
_2 4
form, Cr 0_ ion. As either ion, chromium exists with a valence of +6
(hexavalent). At this valence chromium is both toxic and soluble.
Reduction of chromium from the +6 valence state to the +3 valence state
and subsequent precipitation of the trivalent chromium is the most
common method of chromium removal from wastewater. Other methods in-
clude ion exchange and carbon adsorption.
THEORY OF OPERATION
Reduction is a chemical reaction in which one or more electrons are
transferred to the chemical being reduced (e.g., +6 chromium) from the
chemical initiating the transfer (i.e., reducing agent). There are
several reducing agents that can be used to supply electrons to the
hexavalent chromium to reduce it to trivalent chromium. These reagents
include metallic iron, ferrous sulfate, sulfur dioxide, and various
forms of sulfites such as sodium sulfite, sodium bisulfite, and sodium
metabisulfite. The chemical reactions for chromium reduction by the
•a J
most commonly used reagents are shown below.
Sulfur Dioxide:
Na2Cr2°7 + 3S°2 + H2S°4 > Cr2(S04}3 + Na2S°4 + H2°
74
-------
Sodium Sulfite:
Sodium Bisulfite:
Na2Cr2°7 + 3NaHS03 + 2'5 H2S°4 - > Cr2(S°4)3
Sodium Metabisulfite
H2S°4
The choice of reducing agent depends on the overall process options
and localized cost conditions. Sodium metabisulfite offers stability
and dry chemical feed capabilities as advantages over the use of bisul-
fite. A disadvantage of using sulfur dioxide is the potentially hazard-
ous situation that exists when sulfur dioxide is stored and handled.
Advantages of sulfur dioxide include ease of automatic control and its
lower chemical cost. Ferrous sulfate reduction has been reported to
have the advantage of effectiveness which is independent of pH. How-
ever, it has also been pointed out that ferrous sulfate produces four
times the quantities of sludge produced through the use of sulfur
dioxide or bisulfite.
DESCRIPTION OF EQUIPMENT
Chromium reduction can be achieved in either the batch or con-
tinuous-flow mode. Both modes require a reaction vessel, mixer, pH
controller, ORP controller, and chemical addition equipment (See Figure
8). Batch systems are usually limited to small flows and are operated
manually by employees who monitor the pH and ORP and add chemicals as
required. The advantages of batch treatment are that the level of
hexavalent chromium discharge and complexity of automation are both low.
Continuous-flow systems, however, must have automated chemical feed
systems that are capable of maintaining proper pH and ORP. The advan-
tage of continuous-flow treatment is that the manpower needs are low.
75
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SULFUHIC AGIO
SULFUR DIOXIDE
pH CONTROLLER
RAW WASTE
(HEXAVALENT CHROMI
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ORP CONTROLLER
(TRIVALENT CHROMIUM)
REACTION TANK
Figure 8.
Hexavalent chromium reduction with sulfur dioxide.
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OPERATIONAL PROCEDURE
The objective of chromium reduction is to 'convert hexavalent chrom-
ium to trivalent chromium. This procedure .is crucial because hexavalent
chromium is highly toxic to aquatic organisms and is a known carcinogen.
It is also very soluble in water in its hexavalent state and is very
difficult to remove without first converting it -to the trivalent state.
Trivalent chromium is less toxic than hexavalent chromium and can be re-
moved readily from wastewater by standard chemical precipitation between
pH levels of 7 and 9.
To control the operation of hexavalent chromium reduction proces-
ses, the operator should conduct the necessary process monitoring,
perform any control calculations needed, and understand the process
control strategies or variables.
Process Monitoring
The major parameter used to assess the efficiency of chromium
reduction processes is the concentration of hexavalent chromium
(chromium +6). The main performance parameters used to monitor the
operation of the chromium (+6) reduction process are the flow and the
concentration of hexavalent chromium in the reactor effluent. While
these parameters provide the overall performance, many other parameters
must be measured and incorporated into a regular monitoring program to
successfully and consistently operate a chromium reduction process. The
parameters which should be monitored for chromium reduction are listed
in Table 7.
For continuous-flow treatment, flow, pH, temperature, and ORP are
normally recorded whenever the process is in operation. Effluent triva-
lent chromium and hexavalent chromium concentrations are typically
measured using 24 hr composite samples. The remaining analyses should
be performed on a regular but less frequent basis, typically weekly.
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TABLE 7
CHROMIUM REDUCTION
PROCESS MONITORING REQUIREMENTS
Parameter
Frequency
Comment
1. Reactor Temperature
2. Flow
3. Influent Hexavalent
Chromium
4. Effluent Hexavalent
Chromium
5. Effluent Trivalent
Chromium
6. Reactor pH
7. Reactor ORP
Continuously
Continuously
Weekly
Daily
Daily
Continuously
Continuously
To understand changes in
reaction rate.for
CrT+67 to Cr+3.
To determine HRT and to
adjust chemical dosages.
To determine removal
efficiency.
To determine-any
residual Cr
To determine loading to
downstream treatment.
To control acid addition.
To control sulfite
addition.
78
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Example Calculations
Several example calculations are provided below for calculating
operating parameters essential to operation of a chromium reduction
process.
Hydraulic Residence Time (HRT) is the average length of time waste-
water spends in the chemical reaction tank.' Since the reduction of
chromium is not an instantaneous reaction, it is essential that the
wastewater spend a minimum time in the reaction tank. The HRT calcu-
lation is:
mT = FLOW
where
VOL = the volume of liquid in the tank and
FLOW = the flow to the reactor.
Note that VOL and FLOW must be expressed in similar units such as cubic
meters or gallons. As an example if a chromium reduction tank had a
volume of 5000 gallons and the flow to the tank was 2500 gallons/hour
the calculation would be:
?-
,„,„, 5000 gal „ ,_
HRT = „_,._ y , = 2 hr
2500 gal
hr
Process Control Strategies
The primary operating strategies which control the performance of a
chromium reduction process are the reducing agent used, the reactor HRT,
and the reactor pH and ORP. The selection of reducing agent is typi-
cally made during the design of the facility, and the HRT is a function
of the reaction volume and wastewater flow, both of which are usually
beyond the control of the operator. This leaves pH and ORP as the
primary process control variables over which the operator has control.
79
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Operator control of the chromium reduction process is usually exer-
cised by first adjusting the pH of the reactor based on the HRT. The
relationship between the reactor HRT and the required pH for chromium
reduction using sulfur dioxide is given in Figure 9. It is important
to understand the significance of Figure 9. From Figure 9 it can be
seen that' for a 20-minute retention time, a pH of 3.0 or less is
required to achieve complete reduction of chromium. If the retention
time of the system were to decrease from 20 minutes to 10 minutes be-
cause of an increase in the flowrate, complete reduction of chromium
could still be achieved by decreasing the operating pH from 3.0 to 2.5
or less. However, if the pH remained at 3.0, incomplete chromium re-
duction would occur. From Figure 9 it can. be observed that if the
retention time is 50 minutes, a pH of 4.0 or less is sufficient.
The remaining primary control parameter is ORP. ORP is a measure
of the preponderance of easily oxidizable or reduceable substances in a
wastewater sample. The importance to the operator is knowing whether
there is large quantity of reducing substances that may have an immedi-
ate and very high demand for oxygen. Sulfide and sulfite are examples
of such substances. This measurement, although not specific, is instan-
(14)
taneous. The oxidation-reduction potential is measured in a gal-
vanic cell consisting of a reference electrode (e.g., calomel) and an
indicating electrode of a highly noble metal (e.g., platinum or gold).
The calomel electrode is the cathode and the inert platinum or gold
electrode is the anode. The anode is made of a highly noble metal so
that the potential for its oxidation is less than that of any oxidizable
solution components. The anode thus is a site of the oxidation of
solution constituents but ideally is not affected itself.
Oxidation-reduction potential measurements in natural waters and
wastewaters are difficult to interpret. The only potentials that will
register in the ORP cell are those from species that can react at the
indicator electrode surface - these are called electroactive species.
In natural waters only a few reactions proceed at the electrode surface.
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0.1
Figure 9.
0.5 125 10 20 5,0
RETENTION IN MINUTES
Relationship between hexavalent chromium, pH,
and retention time for sulfur dioxide.
SOURCE: PATTERSON. J.W.. TECHNOLOGY AND ECONOMICS OF INDUSTRIAL POLLUTION ABATEMENT,
IIEQ NO. 76/22. ILLINOIS INST. FOR ENV. QUAU 1978.
81
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All the important redox reactions involved in the nitrogen cycle,
the sulfur cycle, and the carbon cycle are not completed at the indi-
cator electrode in an ORP cell. At best, too, the voltage reading
produced by an ORP cell is a reflection of many reactions - it is a
"mixed potential" and its value is difficult if not impossible to inter-
pret in any fundamental chemical terms. Moreover, when an ORP electrode
combination is immersed in a water the voltage reading will vary with
time, usually falling from the initial reading obtained. This behavior
is due to the general process of polarization and of "poisoning" of the
indicator electrode surface by the accumulation of oxidation products on
the surface of the electrode.
Despite all of these limitations ORP measurements have been used
widely in metal finishing treatment systems where, if they are treated
as indices or "black box measurements" rather than fundamental indi-
cators of a specific chemical environment, they can be of qualitative
use.(15>
The ORP of a chromium reduction reactor is controlled by the amount
of reducing agent added. The ORP set point for the chromium reduction
is somewhat dependent upon the pH and the ions present in solution. An
ORP value of +300 mv at a pH of 2.3 will normally be satisfactory for
chromium (+6) reduction. The relationship between pH and ORP for sodium
bisulfite is presented in Figure 10. If inadequate chromium reduction
occurs under these circumstances the operator should try decreasing the
pH and/or increasing the ORP operating level.
Several other factors affect the operation of the chromium reduc-
tion process to a lesser extent and should be checked any time poor
performance or excessive chemical use is encountered. Among these fac-
tors are mixing, temperature, and mass loading. Rapid and good mixing
of the wastewater, acid, and reducing agent is important to ensure
efficient use of chemicals. Overfeeding of chemicals is usually re-
quired if mixing is inadequate. Furthermore, solids can settle out in
the reaction tank if mixing is inadequate, a situation which reduces the
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300
600
fe
O
^ 400
2
o
a.
«
| 200
oc
pH 1
oH 2
0 1.0 . 2.0
Relative Quantity of NaHSQ, Added/Required per Time
Figure 10. Relationship between ORP,
sodium bisulfite required, and pH.
SOURCE: 3HW8KY, F.O; pH AND p«ON CONTROL IN PROCESS AND WASTE STREAMS.
JOHN WILEY AND SONS, INC, MEW YORK. MY., 1973. PL 118.
83
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effective volume of the tank which in turn reduces the HRT. When the
HRT is decreased, lower operating pH levels and hence increased chemical
usage are required.
To ensure that good mixing is maintained several items must be
checked periodically by the operator. Among the items are the
following:
o Check mixer impeller for wear and proper location with respect
to the drive shaft and the tank.
o Check baffles for wear and proper placement. All circular tanks
should have baffles along the outer vertical wall and most other
tank walls should have some form of influent or effluent baffle
to prevent short circuiting.
o Check tank bottom to determine if solids are accumulating. This
is usually accomplished either by draining the tank or by
rodding the sides to determine water depth versus tank depth.
o Check mixer horsepower. Typical mixer horsepower ratings are
given in Table 5.
The effect of temperature on the performance of chromium reduction
sometimes can be very significant. Temperature primarily affects reac-
tion rates and, to a lesser extent, mixing. The operator has little
control over temperature, but periodically monitoring the temperature
may enhance understanding of slightly poorer performance during periods
of cold weather. If large temperature swings occur it may be necessary
to decrease reactor pH- or increase ORP levels. It also should be noted
that temperature changes can have dramatic effects on instrument cali-
bration. Any time significant temperature changes occur, pH and ORP
meters should be recalibrated.
Significant increases in the mass loading of chromium to a treat-
ment process can result in temporary upsets and increased chemical
usage. Hexavalent chromium loading in the reactor effluent also direct-
ly relates to the plant discharge of chromium which often is expressed
84
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as a mass per time (i.e., Ib/day or kg/day). For these reasons the
influent and effluent loadings should be calculated periodically to gain
insight into process performance.
TYPICAL PERFORMANCE VALUES
Hexavalent chromium concentrations in the effluent from chromium
reduction processes range from 0.009 to 0.045 mg/L. Most values, how-
ever, are less than 0.02 mg/L in a well-operated system.
TROUBLESHOOTING GUIDE
A troubleshooting guide for the chromium reduction process is
presented.in Table 8. The major operational problem in chromium reduc-
tion processes is incomplete reduction of hexavalent chromium which
results in a significant concentration of Cr in the reactor effluent.
The causes of incomplete reduction may be physical (short-circuiting,
sampling and analysis errors, etc.) or chemical (incorrect pH, ORP,
etc.).
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TABLE 8
CHROMIUM REDUCTION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 1: Cr concentration too high.
DO
la. Sampling or
analytical error.
1b. Retention time too
short to complete Cr
destruction.
1c. Shortcircuiting in
reaction vessel.
1d. Improper pH.
Check collection proce-
dure with operator and
check with lab to ensure
proper reporting of
results.
Calculate retention time
versus time shown in
retention time/pH graph
(see Figure 9).
Inspect mixing regime of
tank. Look for dead spots,
sludge accumulation, and
inlet and outlet short-
circuiting.
Check desired pfi setting
of meter versus reten-
tion time.
Check calibration of
pH meter.
Check operation of acid
addition equipment (pumps,
valves, and storage tank).
Error could be with
data. -
Retention time may be
insufficient for com-
plete chromium
destruction.
Shortcircuiting will
decrease the effective
retention time.
Setpoint pH may be too
high for given retention.
Meter may be out of ,
calibration.
Correct as necessary.
- Failure to achieve desired
pH could be caused by
insufficient acid, inop-
erable pumps or valves,
or malfunction in control
system.
Recalculate new concentration
and make sure bexavalent
chromium is to be measured,
not total chromium.
Increase retention time by de-
creasing the flowrate; or de-
crease pH.
Shortcircuiting may be reduced
by installing baffles, in-
creasing pumping action of
mixer, or installing inlet and
outlet baffles.
Select lower setpoint pH.
Recalibrate.
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TABLE 8
(Continued)
CHROMIUM REDUCTION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
1e. Improper ORP.
Check desired ORP
setting.
Check calibration of
ORP meter.
Check location of probe.
Check operation of
chemical addition system.
CO
-J
If. Hydraulic surges
to reaction vessel.
Monitor flow rate over
time and check plant
production personnel.
Settings range
from +200 mV to
+400 mV with an
average of +300 mV.
Meter reading may
not represent actual
ORP reading.
If probe is not
located at effluent,
then probe is not
reading effluent ORP.
Failure to achieve
desired ORP could be
caused by insuffi-
cient chemical
supply, inoperable
pumps or valves, or
malfunction in
control system.
Evaluate whether
flow rates reduce
retention time
such that complete
chromium reduction
is not accomplished.
Establish new setpoint
ORP.
Recalibrate meter.
Locate probe at
effluent.
Correct as necessary.
Equalize flow by
decreasing rate of
chromium waste
discharge from
process tanks.
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SECTION 8
pH CONTROL
INTRODUCTION
Control of pH is a fundamental process for virtually every metal
finishing wastewater treatment system. It is the crux of wastewater
metal precipitation that pH be maintained within a narrow range to
achieve optimum metal removal. Close pH control is required also for
chromium reduction, cyanide oxidation, and possibly for emulsion break-
ing of oils. Furthermore, it may be required to post-neutralize the
treated wastewater to assure that the discharge is within regulatory
limits. Because of the number of treatment processes that require pH
adjustment, a metal finishing wastewater treatment system may contain
several pH control steps, and may include pH control within selected
plant processing units.
THEORY OF OPERATION
The parameter pH is a measure of the hydrogen ion (H ) concentra-
tion in a water or wastewater solution. It is calculated as the nega-
tive logarithm (base 10) of the hydrogen ion concentration, which means
that for each drop in pH of one unit a tenfold increase in the H ion
concentration takes place. This means that when the hydrogen ion con-
centration increases, the pH decreases and the water becomes more
"acidic." Likewise, when the hydrogen ion concentration decreases, the
pH increases and the waste becomes more "basic" or "alkaline." When the
pH is 7 the waste is neither acidic or basic and is considered neutral.
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The adjustment of pH requires that, to lower the pH of the waste-
water, some chemicals which release H+ ions must be dissolved in the
water. The most common chemicals used in waste treatment are sulfuric
acid (H SO ), hydrochloric acid (HC1), and nitric acid (HNC>3). Simi-
larly, to raise the pH, some chemical that reacts with the H ion from
solution must be added. The most common chemicals for raising pH are
caustic (NaOH), lime (CaOH), and soda ash (Na CO ) . The lime and caus-
- +
tic work by releasing a hydroxide ion (OH ) which reacts with an H ion
to form water, H.O. The soda ash works by reacting with one H ion to
form the bicarbonate ion (HCO~) or with two H ions to form H20 + CO^.
Whenever pH levels are changed, the concept of buffering must be
discussed. Buffering is the resistance of a solution to pH changes.
This resistance is typically low at pH levels close to 7 and very high
for pH levels less than 4 or greater than 10. The resistance, however,
is very dependent on the chemicals present in the wastewater.
The best way to determine buffering is with a titration curve. A
titration curve is generated by taking a sample of wastewater and grad-
ually adding the acid or base and recording the pH after a small amount
of the reagent is added and well mixed. An example titration curve is
plotted in Figure 11. It is constructed by plotting the volume of
pH-adjusting chemical added versus the pH of the waste sample after
mixing with the adjusting chemical. In the example displayed in Figure
11, it can be seen that the first 40 ml of the caustic (NaOH) solutio'n
raised the pH from approximately 1 to 2. The next 20 ml of the caustic
solution, however, raised the pH to approximately 11.5. In terms of
buffering the first segment of the curve is referred to as highly buf-
fered. A large quantity of caustic solution was required to make a
small change in pH. The second segment is referred to as poorly
buffered. Only a small addition of caustic solution was required to
make a large change in pH.
The practical effects of buffering on pH adjustment will be dis-
cussed in later sections of this chapter, but from this example it is
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Figure 11.
40 50 60 70 30
CAUSTIC (NaOH), MILLJUTERS
NORMALITY =0.10 N
A sample titration curve.
90
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easy to see that a pH of 2 could easily be maintained. A pH of 7, how-
ever, is difficult to maintain because a very small addition of caustic
solution can make a very significant change in pH.
DESCRIPTION OF EQUIPMENT
The pH adjustment process typically consists of a reaction tank,
mixer, pH control system, and reagent feed system. The pH adjustment
process may either be a batch or a continuous flow system. In a batch
system, wastewater is added to the reaction tank; then chemical reagents
are added to adjust the pH; and finally the solution is discharged to
the subsequent treatment units. Control of the steps in the batch pH
adjustment process can either be automatic or manual.
In continuous flow systems, wastewater is continuously entering the
reaction vessel. The flowrate can either be constant, if equalization
is provided, or variable. Often pH adjustment is accomplished in more
than one reaction vessel. This is especially true when the set
point is located on a poorly buffered segment of the titration curve.
The first tank will adjust the pH close to the set point using a rela-
tively large chemical feed system. The second tank will then use a
small metering pump to fine tune and adjust the pH to the set point
level. Alternately, a single tank can be used in conjunction with a low
and high rate chemical feed system. When the deviation between the set
point and the actual pH is large, the high rate system is used. When
the difference is small, the low rate system is used to fine tune the
adjustment. This system is primarily used for batch operations.
Automatic control of chemical reagent addition is mandatory for
continuous systems. There are various methods for providing control of
the pH adjustment process. These methods include feedback, feedforward,
and feedforward-feedback control techniques and several types of control
signal generators. The method best suited for a particular application
is dependent upon characteristics of the waste, hydraulic retention time
of the reaction vessel, mixing, reaction lags, and other factors.
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The common pH control techniques employed today are the feedback,
feedforward, and feedforward-feedback control concepts. Feedback con-
trol bases the chemical feed rate on the difference or error between the
set point pH and the measured pH. Thus, a feedback system solves the pH
control problem by trial and error. An example of a feedback control
system is shown in Figure 12. The major advantage of this system is
that, because it operates by trial and error, the system does not need
to know the flow and pH of the influent. It is also relatively insen-
sitive to changes in the titration curve. A disadvantage to feedback
control is its susceptibility to oscillatory response, which results
from an inherent time lag in the response. This time lag is referred to
as "dead" time and is the time required to deliver the chemicals to the
wastewater, mix the chemical with the wastewater, and for the appropri-
ate chemical reactions to occur. This time lag means that after a
controller initiates a control action, it does not see the results of
that action until the "dead" time has elapsed. If the control action
were excessive because of poor buffering, a rapid change in flowrate, or
excessive "dead" time, the set point can be overshoot before the con-
troller realizes it. It can then overreact to the overshoot and the pH
can begin to oscillate around the set point. This oscillation can
result in unacceptable performance and/or excessive chemical use.
A feedforward control system does not experience the oscillation
problem associated with feedback control. A feedforward system operates
by measuring the flow and pH of the wastewater before it reaches the pH
adjustment tank. It takes this information and computes the necessary
chemical addition based on titration information that has been pro-
grammed into the controller. A schematic of a feedforward system is
shown in Figure 13. The primary advantage of the system is that it is
not susceptible to the problems encountered by feedback control. The
system, however, is dependent upon having the ability to predict the
buffering of the incoming wastewater. This means that the system can
only be used on wastewater streams which have buffering capacity and
titration curves that do not vary with time. This is usually a severe
restraint when controlling pH. The system is also susceptible to
gradual drifts in effluent pH because of cumulative controller error
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INFLUENT
WASTEWATER
Figure 12.
REAGENT
P~[pH CONTROLLER
EFFLUENT
WASTEWATER
Feedback mode of pH control.
93
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REAGENT
pH CONTROLLER I
, ^-<$
I
PH
TRANSMITTER
INFLUENT
WASTEWATER
FLOW
TRANSMIT
ER
EFFLUENT
WASTEWATER
Figure 13.
Feedforward mode of pH control.
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which the controller has no way of detecting because it does not sense
the pH of the wastewater after adjustment.
The most common utilization of feedforward control is in conjuction
with feedback control. This is referred to as feedback-feedforward
control. This configuration is shown in Figure 14. The intent is that
the feedforward counteracts most of the problems caused by rapid changes
in buffering and flowrate and the feedback provides residual control and
setpoint tracking. The advantage of this configuration over feedforward
control is better pH control for variable strength and buffering of the
influent waste. The above control systems can incorporate several
different types of control signal generators that are responsible for
directly controlling chemical addition equipment. These include on-off
signal controllers, proportional signal controllers, integral signal
controllers, differential signal controllers, and programmed signal
controllers. These controllers can be used individually or, as is more
often the case, in combination. A brief desciption of the controllers
and their applicability is provided below.
On-off Controllers
On-off controllers simply generate control signals that turn chemi-
cal feed equipment on and off based upon the reactor pH. This type of
controller is typically slow and unable to achieve fine pH control. Use
of on-off controllers is normally confined to batch operation where
speed is not critical, and to multiple stage continuous systems where
on-off control is used in the first stage which is designed for gross pH
adjustment, not set point tracking.
Proportional Controllers
Proportional controllers generate control signals proportional to
the difference between the set point pH and the actual pH (error). This
means that as the error grows the chemical addition increases to compen-
sate. This technique is quick and effective for linear regions of a
titration curve. However, it does have one drawback in continuous flow
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PH
CONTROLLER
r~
PH
TRANSMITTER
INFLUENT
WASTEWATER
FLOW
TRANSMITTER
REAGENT
M
-SL
PH
-*-EFFLUENT
WASTEWATER
Figure 14.
Feedback-feedforward mode of pH control.
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systems; namely, the controller is continuously approaching the desired
pH but does not reach it before some of the wastewater flows through the
reactor. The reactor pH is always different from the desired pH. This
fact means that the set point pH will have to be offset to compensate
for this difference. The offset will vary with chemical demand and
should be set based on average wastewater conditions. The offset can
only be set by trial and error. This system is very suitable for batch
operations which do not experience the offset problem and for continuous
flow systems with a relatively consistent wastewater which will allow
establishment of an effective offset.
Integral Controllers
Integral control signal generators (reset controllers) are used in
conjunction with proportional controllers to eliminate the offset prob-
lem. This is accomplished by generating a control signal that is pro-
portional to the time since the pH was last at the set point. This
signal is added to the proportional error signal. As the proportional
signal drifts away from the set point for the reasons described in the
previous discussion, the integrator generates a progressively larger
control signal until the pH is forced back to the set point. Once the
set point is reached, the integral signal drops back to zero and the
whole process begins again. This type of controller is useful when
close pH control is required and where the waste flow is not consistent
either in volume or buffering capacities. Integral control is never
used in conjunction with batch operations.
Derivative Controllers
Derivative control signal generators are used primarily when the pH
must pass through a region of low buffer intensity as indicated in a
titration curve by a line segment with a very large slope. The deri-
vative controller generates a signal proportional to the rate of change
of pH with respect to time. As an example, if the pH is constant the
proportional signal is zero. If the pH is rapidly diverging from the
set point, a large control signal is generated to correct the pH. If
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the pH is rapidly approaching the set point, a large negative control
signal is generated to slow the approach to the set point. Once gen-
erated, the derivative signal is added to the error signal and the
integral signal (if present).
The derivative control technique is often used in conjunction with
proportional control for batch neutralization when the set point is in a
poorly buffered location on the titration curve. It is also used in
conjunction with proportional and integral control (a PID device) for
continuous flow.systems when the pH must pass through a poorly buffered
range on the titration curve. Care must be exercised when using deriva-
tive control for continuous systems. If the derivative control is made
too sensitive, the system may oscillate between high and low pH because
of the lag or dead time in the system.
Programmable Controllers
Programmable controllers are sophisticated controllers that gen-
erate control signals based on a logic sequence that is programmed into
the controller. For example, the controller can check the reactor pH
and choose an appropriate proportional gain depending upon whether the
system is operating in a high or low buffer region. Similarly, an
integral and proportional response rate could be selected also. There
is virtually no limit to the complexity and diversity of control strate-
gies that can be built into these systems. Therefore, it is necessary
that the process design manual and manufacturer's literature be refer-
enced to understand individual programmable controllers.
OPERATIONAL PROCEDURES
The operational objective of pH adjustment is to control the addi-
tion of acidic and basic chemicals to the wastewater such that a desired
pH can be achieved and maintained in the wastewater. This objective
should be accomplished with the use of minimal amounts of chemicals in
an effort to keep costs down and effluent total dissolved solids from
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becoming too high. The latter is especially true when several pH ad-
justment steps are performed on the wastewater prior to discharge.
Process Monitoring
Process monitoring of the pH adjustment process should consist of
continuously monitoring and recording effluent pH from the pH control
process. This information is essential to assure that the pH is being
maintained within the critical limits required for metal precipitation,
cyanide oxidation, chromium reduction, or other pH-sensitive treatment
processes. Flow and influent pH must also be measured on a continuous
basis for feedforward control, and as frequently as practical for feed-
back' control where such information can be used to understand deviations
in the effluent pH. Additionally, reactor temperature should be
measured periodically or when poor pH adjustment occurs. Temperature
can change the speed at which pH adjustment chemicals react and can
affect the calibration of pH monitoring equipment. All pH probes should
be calibrated daily with fresh buffer solutions and flow meters monthly.
Calibration of pH meters involves the use of standards of at least two
pH values; standards of pH 4.0, 7.0, and 10.0 are recommended.
In addition to the standard tests just described, titration curves
should be prepared for the influent wastewater for each pH adjustment
process. These curves should be prepared from both composite and grab
samples using the same chemicals that will be used in the actual pH
adjustment. The frequency for preparing these curves will vary greatly
from one pH adjustment process to another depending primarily on the
variability of the waste. As a minimum, a sufficient number of titra-
tion curves should be prepared to define the normal characteristics of
the wastewater and then at least on a quarterly basis to assure that the
wastewater is not gradually changing its characteristics. Whenever poor
pH adjustment or process changes occur, new titration curves should be
prepared and compared to the historical titration curves. If the curves
differ significantly, the upset was probably caused by the non-charac-
teristic waste. If the change represents a permanent change in the
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characteristics of the wastewater, the pH controllers will probably need
readjustment.
Process Control Strategies
The four primary operating variables which enable the operator to
control the pH adjustment process are pH controller adjustments, treat-
ment chemicals, equalization, and mixing.
pH Controller Adjustments—
As previously discussed, pH controllers use 9 variety of control
strategies to generate control signals. The common adjustments that can
be made to the controllers will be described below. The applicable
manufacturer's literature and any available design manuals should be
referenced for specific systems when available. This is particularly
important when manufacturers use. terminology different from that used in
this manual. It. should be stated also that the adjustment procedures
presented here are simplified. Whenever possible, fully-trained control
and instrumentation personnel should be used to perform comprehensive
adjustment procedures.
t-
On-Off Control—On-off control has two primary adjustments; they
are the set points for turning chemical feed equipment on and off.
These set points should bracket the desired pH such that when the pH
starts to move away from the desired pH the chemical feed pumps are
turned on. Then, when the pH passes the desired pH in the reverse
direction, they are turned off. The set points, of course, have to be
selected such that the pH is maintained within acceptable limits. They
also must be adjusted such that the set point for turning the equipment
off is not too close to the set point for turning the equipment on. If
the two set points are too close, the equipment will cycle on and off at
an excessive rate. This can cause mechanical equipment to wear and
sometimes can cause electrical equipment to overheat. The set point for
turning on the equipment is usually controlled by adjusting the "set
point" setting while the set point for turning off the equipment is
-------
controlled by the "dead band" setting. The "dead band" setting can be
preset by the manufacturer (internal) or can be field adjusted
(external).
Proportional Control—The primary control adjustments on a propor-
tional controller are the set point and the gain adjustment. The gain
adjustment determines the magnitude of the control signal relative to
the pH error (actual minus set point pH). That is, as the gain is
increased the magnitude of the control signal relative to the error is
increased. The gain should typically be set as high as possible without
sending the system into oscillation. Oscillation can occur when the
gain is too high and either flow, pH, or buffering capacity of the
wastestream changes. The controller detects the change and responds
with a corrective signal. The effects of the corrective signal are not
sensed by the controller, however, for a period equivalent to the system
dead time. Hence, the system can over-respond when the gain is too high
and can cause the pH to pass the set point in the other direction. This
condition is not in itself bad, unless the pH enters an unacceptable
range or continues oscillating for an extended period of time. If
either .condition occurs, the gain should be decreased. If natural
oscillations are not present at the time of adjustment, they can be
generated by adding directly a small quantity of base to a pH reduction
unit or acid to a unit designed to increase pH. The acid or base should
be added such that it does not cause more than a 1 or 2 pH unit change
in the process effluent. It should be noted that some manufacturers use
a "proportional band" control instead of a gain control. This control
functions identically to a gain control except in reverse. Increasing
the proportional band decreases the gain.
The set point for proportional only controllers may have to be set
at a pH value slightly different from the desired pH value. This is for
the reason discussed under "Description of Equipment". The offset will
be strictly a matter of trial and error. Typically as the gain is
increased the offset can be decreased. Likewise, as buffering intensity
1 m
-------
increases the offset must be increased. In highly variable flow sys-
tems, there may be no need for an offset because of the frequent swings
in pH which will negate the advantage of an offset.
Proportional Plus Integral Control (PI Control)—The function of
the integral mode is to eliminate the need for proportional offset. If
too much integral action is used, the result will be an oscillation of
the measurement as the controller drives the valve from one extreme to
the other. If too little integral action is used, the measurement will
return to the set point too slowly. The integral action adjustment
controls how rapidly the integral control signal changes as a function
of time. Among the various controllers manufactured, the integral
action adjustment is calibrated in one of two ways—either in minutes
per repeat, or the number of repeats per minute. For controllers
measuring integral action in minutes per repeat, the smaller the inte-
gral number, the greater the action of the integral mode. On control-
lers that measure integral action in repeats per minute, the adjustment
indicates how many repeats of the proportional action are generated by
the integral mode 'in one minute. Thus, for these controllers, the
higher the integral number, the greater the integral action. The proper
amount of integral action depends upon the system dead time. The longer
the system dead time, the less the integral action must be.
A simple way of adjusting the integral action is to set it to its
minimum action position and adjust the proportional gain to its optimum
position as described in the previous section. Then the system is
allowed to come to steady state. Achievement of steady state may re-
quire some waiting if proper equalization is not practiced upstream and
the system continuously fluctuates about the set point. When steady
state is reached, a very slow pattern of pH gradually increasing to the
set point and then moving away in the same direction should be evident.
The integral action adjustment should then be increased gradually. The
pattern should occur at an increasing rate with the pH deviations from
the set point becoming less and less. if too much integral action is
applied, the pH will start fluctuating significantly to both sides of
the set point. It must be remembered when performing the adjustment
-------
that if the integral adjustment is in minutes per repeat, the integral
action increases with decreased settings on the adjustment. Conversely,
for adjustments marked in repeats per minute, the larger the setting,
the larger the integral action.
The above procedure is usually satisfactory for field adjustments
when the manufacturer's recommended procedures are not available or when
qualified instrumentation and control personnel are not present. When
the manufacturer's procedures or qualified personnel are available, they
should be utilized.
Proportional-Integra1-Derivative (PIP Control)—The derivative
mode opposes the rapid changes in pH that often occur when the pH ad-
justment procedure enters a poorly buffered section of a titration
curve. The derivative response adjustment is measured typically in
minutes. The higher the reading on the adjustment control, the more
derivative action present. Too much derivative action causes excessive
response of the controller and cycling in the measurement. Too little
derivative action has no significant effect. As with the integral
control, the system dead time is fundamental with respect to the maximum
allowable derivative response. If the derivative response exceeds the
system dead time, the system will become unstable and will oscillate.
A field method for adjusting the gain when manufacturer's recom-
mended procedures 'or qualified instrumentation personnel are not. avail-
able is provided below:
1. Set the integral to maximum time (minimum integral action).
2. Set the derivative to minimum time (minimum derivative action).
3. Adjust the gain to an optimum setting as before, except that a
slight cycle should remain in the measurement.
4. Increase the derivative time until the cycle stops.
5. Increase the gain until the cycle starts again.
6. Repeat Steps 4 and 5 until further increases in the derivative
time fail to stop the cycle.
" 7. Decrease the gain to stop the cycle.
103
-------
8. Set the integral time equal to derivative time. NOTE: If the
integral time is expressed as beats per minute, the time inte-
gral control should be set to (I/derivative setting).
pH Adjustment Chemicals—
The operator often has some control over the chemicals used for pH
adjustment. Factors which should be considered in selecting a suitable
chemical for a wastewater pH adjustment process include speed of reac-
tion, buffering qualities-, product solubility, reagent cost, and availa-
bility. A discussion of some common neutralizing agents follows.
Lime Materials—Lime is a term used to designate calcined or burned
limestone (quicklime or CaO) and its hydrated derivative [hydrated lime
or Ca(OH)-]. The two basic types of limestone used are high calcium and
dolomitic. High calcium limestones consist chiefly of calcium carbonate
with a small amount of magnesium carbonate. Dolomitic limestones ,con-
tain nearly equal molar quantities of calcium and magnesium carbonate.
Typical impurities present in the limestone in amounts of less than five
percent include silica, iron, and alumina.
The reactivity of limestones differs with physical characteristics
(e.g., size and shape) and chemical composition. As a rule, high cal-
cium limestones are more reactive than dolomitic limestones; however,
pronnounced physical characteristics may produce exceptions to the rule.
Theoretically, dolomitic limestone has greater basicity, but actual or
available basicity depends upon the conditions of application. Pul-
verized limestone is a stable noncorrosive product that is amenable to
dry- feeding. It is available in bulk or in 36-kg (80-lb) bags. Various
mechanical conveyors are suitable for unloading the bulk material.
Quicklime - Quicklime has an affinity for carbon dioxide and
water. Under normal handling or storage conditions, quicklime will
air-slake, that is, absorb moisture and carbon dioxide from the atmos-
phere, causing physical swelling and a marked loss of chemical activity.
Consequently, quicklime must be stored in moisture-proof area's that are
-------
free from carbon dioxide. Because of this potential loss of effective-
ness, quicklime is usually consumed within a few weeks after manufac-
ture.
Quicklime is available in various forms, ranging from 20-cm (8-in)
lumps to pulverized, and is supplied in bulk or in 36-kg (80-lb) bags.
Dust from pulverized quicklime can irritate eyes and skin. Although it
can be fed dry, for optimal efficiency it is slaked (hydrated) and
slurried before use under conditions that will yield maximal reactivity.
Improper slaking will adversely affect reactivity. Slaking usually is
carried out at temperatures of 82° to 99° C (180° to 210°P). The
slaking reaction may reach completion in 10 minutes with highly reactive
limes or in more than 30 minutes for limes of lower reactivity.
Following slaking, the lime putty usually is slurried with water to
a concentration of 10 to 35 percent (based on dry solids) for feeding
purposes. Because the slurry is subject to deterioration from carbona-
tion during storage, it is customary to use it soon after it is made.
The applicability of lime,.to specific situations may be expected to
vary significantly from supplier to supplier. Testing under actual or
simulated process conditions is the only sound basis for determination
of relative applicability; empirical basicity tests normally are of
value only when the application is analagous to the test.
Hydrated Lime—Hydrated lime is suitable for dry feeding or for
slurrying. Dust from hydrated lime, a fine powder, can cause eye and
skin irritation. The storage characteristics of dry hydrated lime are
superior to quicklime, but, as with any strong alkali, carbonation can
cause deterioration. Hydrated lime is supplied in bulk or in 23-kg
(50-lb) bags. Bulk unloading is usually accomplished by pneumatic
conveyor.
Sodium Hydroxide—Sodium hydroxide (caustic soda) is a highly
reactive alkali that is marketed in solid or solution form. The solu-
tion form is the most convenient for handling because burn hazards to
-------
personnel are minimized. The solid form is hygroscopic, and both the
solid and the solution are subject to deterioration from carbonation
during prolonged storage. Solid and liquid sodium hydroxide are sup-
plied in drums, but only the liquid fora is available in bulk (tank car
or truck). Heated tanks should be used for storage of 50-percent solu-
tion in situations where the ambient temperature is likely to fall below
12°C (54°F).
Sulfuric Acid—Sulfuric acid is a highly reactive acid that is
supplied in liquid form, usually in concentrations of 98 percent. The
concentrated acid is strongly hygroscopic and presents a burn hazard to
personnel. Dilute solutions are highly corrosive to iron and steel,
whereas concentrated solutions (>93 percent) are not corrosive to iron
and steel. A maximum freezing point of 8°C (46°F) is exhibited at a
concentration of 85 percent. Depending on the concentration, freezing
protection may be required during storage and transport. Sulfuric acid
is shipped in carboys, barrels, tank cars, or trucks.
Equalization-
Equalization is essential to successful pH adjustment particularly
when the set point pH is in a poorly buffered region of the titration
curve. The importance of equalization can best be understood by exam-
ining the "dead" time concept. If the pH, flow, or buffer capacity of
the wastewater stream changes significantly in a time frame shorter than
the dead time of the control system, proper pH control cannot be
achieved. Similarly, as the rate of change approaches the dead time pH
control becomes more difficult and more sophisticated controllers that
incorporate integral and derivative action are required.
Whenever poor pH control occurs, the operator should conduct a
monitoring program immediately to determine the variability of the
influent to the pH adjustment step and to determine if the poor per-
formance coincides with the variability in the influent. If it does,
the operator should troubleshoot the equalization process. As a general
rule, increased equalization makes pH control easier.
106
-------
Mixing—
Adequate mixing is essential for good pH adjustment for three
closely related reasons. First, mixing is required to blend pH adjust-
ment chemicals with the wastewater. Second, mixing decreases reactor
dead time by dispersing the chemicals rapidly throughout the reactor.
Lastly, it provides equalization and homogeneity throughout the reactor.
The latter is important because the feedback pH control probe will
respond to the non-homogeneous contents of the reactor just as readily
as to fluctuations in the influent characteristics.
To acheive good mixing, the minimum horsepower requirements pre-
sented in Table 5 should be provided for mixing. The influent and
effluent devices should also be located at opposite sides of the reac-
tion tank, ideally with one at the top of the tank and one at the
bottom. If circular tanks are used, side wall mixing baffles must be
provided. The tank must also be checked periodically for solids depo-
sition in the bottom of the tank which can adversely affect mixing and
decrease the hydraulic residence time of the system. Similarly, the
mixer impeller should be checked for wear or breakage.
Proper location of the chemical feed and the feedback pH probe is
f-
also essential and should be verified by the operator. The chemicals
either should be added directly at the point of inflow to the system or
directly into the mixing vortex. Care should be exercised in the latter
case to assure that the chemicals will not corrode the impeller or
impeller shaft. The pH probe for feedback control should be located in
the outflow of the reactor just outside the reactor. This provides the
most representative sample for process control.
Influent and pH-adjusting reagent should enter at the same point
premixed for best results. The direction of inflow should oppose the
(16)
direction of agitation for most effective backmixing.
The exit should be diametrically opposite to the point of entry, to
minimize short-circuiting. Otherwise a significant part of the influent
107
-------
could pass by the vessel without treatment, and uncontrollable varia-
tions in effluent quality could result. If the influent enters at the
bottom on one side, effluent should leave at the top from the other
side, and vice versa.
In neutralization of industrial wastes, many streams with widely
differing properties are usually combined for treatment in a single
vessel. Often both acid and basic reagents are required when the in-
fluent pH may be on either side of 7. In these instances, reagent can
be saved by providing a retention vessel upstream of the neutralization
tank. This smoothing vessel should have enough residence time to accom-
(16)
modate the largest expected transient influent variations.
Properly locating the point of measurement is as important as
locating the vessel exit, and is, in fact, tied to it. A representative
measurement of effluent quality is essential and so electrodes should be
placed in the effluent stream. However, they should not be placed out
of the mixed zone. Dynamic response is also important, so every effort
should be made to maintain a reasonable flow past the electrodes. One
tries to avoid the use of stilling wells or other protective devices
which restrict flow, and to avoid locations where flow is variable.
Submersible electrode assemblies will always be more responsive
than flow-through assemblies since they -are directly inserted within the
process stream. Plow-through assemblies were designed for pressurized
service with a sample withdrawn continuously for measurement. Although
desirable for easy maintenance, the additional delay caused by the
(16)
sample line impedes control action.
Submersible electrodes are used primarily in open vessels. They
should extend only slightly below the surface of the liquid to minimize
the possibility of leakage. Occasionally, however, deeper submergence
is necessary. The .assemblies may be air-purged to protect against
leakage even under severe conditions.
108
-------
Flow-through electrode assemblies are required for pressurized
service, or whenever a sample must be treated prior to measurement.
Sample lines should be as short as practical and velocity high to mini-
mize dead time. High velocity also helps keep the electrodes clean,
although excessive velocity can cause erosion and even cleavage of the
electrodes. A velocity of 2 ft/sec past the electrodes is probably as
(16)
high as tolerable for long life.
TYPICAL PERFORMANCE VALUES
With adequate equalization, the proper selection of control strate-
gies, and the proper adjustment of all control equipment, the wastewater
exiting a pH adjustment step should be controllable within +_ 0.25 pH
uni ts.
TROUBLESHOOTING GUIDE
A guide for troubleshooting the pH adjustment process is presented
in Table 9. The pH parameter is one of the first indicators of poten-
tial treatment plant upset conditions. Problem areas include, in addi-
tion to shock loads, pH instability related to controller settings or
breakdown, chemical feed and mixing equipment failure, and chemical
system used.
-------
TABLF 9
pH ADJUSTMENT TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM ): Oscillating or'unstable pll. Previous performance satisfactory.
1a. Shock loading of flow
or pH,
1b. Buffer intensity
of wastewater
changed.
Ic. pH probe failure.
Id. Poor mixing.
1e. Chemical feed
equipment failure.
Check influent flow and pH
for abnormal levels or
fluctuations.
Prepare new titration
curve and compare to
previous curves. Check
to see if chemical feed
system at maximum capa-
city.
Check condition of probe
and all electrical connec-
tions. Clean and calibrate
probe. Check condition of
electrolyte fluid in probe
if probe uses it.
Check mixer, mixer impeller,
all baffles, and the tank
for solids deposition.
Check feed equipment for
smooth operation, leaks,
and any blockage in the
chemical delivery path.
Check calibration of all
chemical metering systems.
pll controllers are opti-
mized for specific flow,
pH, and buffer intensity
conditions. Changes in
these parameters can
cause controller In-
stability.
Decreases in buffer in-
tensity can cause con-
trollers to oscillate.
Large increases in buf-
fer intensity may cause
chemical demand to ex-
ceed the chemical feed
system capacity.
Dirty probes respond
slowly and irregularly.
Routine maintenance of
probes is essential.
Poor mixing can cause
short circuiting and
poor chemical disper-
sion.
If the pH adjustment
chemical is not properly
delivered to the reactor,
no pli adjustment can
occur.
Prevent influent pH and flow
in variations either through
increased equalization or
changes in operating proce-
dures. Tune controller to
make it less sensitive to
fluctuations.
Increase equalization) read-
just controller to reflect new
conditions) modify chemical
addition equipment if its
capacity is exceeded. If
buffer intensity decreased,
consider using chemical that
provides buffering such as
soda ash.
Clean, calibrate, repair, and
adjust as required.
Repair as required. Clean
tank.
Repair and adjust as required.
-------
TABLE 9
(Continued)
ADJUSTMENT TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
If. Defective chemicals.
Ig. Controller break-
down.
Check chemical feed con-
tainers for chemical con-
tent, chemical strength,
and formation of solid lumps
when dry chemicals are used.
Check all other possible
causes.
Improper or defective
chemicals can adversely
affect pli adjustment.
Improper chemical con-
centration can be placed
in feed tanks by accident
or ignorance.
Controllers can break
down, especially from
lightning or other elec-
trical surges.
Replace defective chemicals.
Call qualified repairman.
OPERATING PROBLEMS 2: Slow controller response.
2a. Improper setting
on proportional
gain control.
2b. Dirty pH probe.
2c. Excessive "dead"
time.
2d. Slow reacting
chemical.
Check gain setting and date
of last adjustment.
Check condition of probe.
Check mixingi check feed-
back probe location
and type.
Check type and form of
chemicals.
Lime reacts slowly.
Low gain will cause slug-
gish response.
Dirty probes will re-
spond slowly, particu-
larly if oily material
present in wastewater.
Increasing mixing will
decrease dead time.
Probe should be located
in reactor outflow just
outside of reactor.
Probes that insert
directly into outflow
are quickest.
Liquids react faster
than solids or slurries.
Adjust controller proportional
gain.
Clean probe.
Increase mixing; move probe;
use probe that is inserted
directly into outflow.
Change chemicals.
OPERATING PROBLEM 3: pH offset.
3a. Controller is
proportional
only and Che plJ
set point has nut
boen offset.
Check type and set point
of controller.
Proportional only con-
trollers require that
the set point pit be
slightly offset from
desired pii.
Adjust by trial and error.
-------
TABLE 9
(Continued)
pH ADJUSTMENT TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
3b. Controller is
proportional-
integral type
and integral ac-
tion setting is
too low.
3c. Chemical feed
system inade-
quate.
Check type and integral
control setting.
Check chemical feed system
for proper operation and
delivery rate.
Integral control does
away with the offset
requirement of propor-
tional controllers if
adjusted properly.
Chemical feed system may
be unable to deliver
chemicals at a suffi-
cient rate to adjust pH.
Adjust as required.
Modify feed system; use more
concentrated chemicals;
decrease wastewater flow.
OPERATING PROBLEM 4: pH oscillates around set point.
4a. Improper control-
ler adjustment.
4b. System "dead"
time too long.
Check type controller and
date of last adjustment.
Check mixing, type of
chemicals used, and
location of feedback
control.
Improper adjustment of
proportional, integral,
or derivative control
can cause oscillation.
Excessive dead time
limits a controller's
ability to respond to
pH changes. If rapid
changes occur, the sys-
tem will oscillate about
set point.
Adjust as required.
Improve mlxingi use liquid
chemicals that react quicker,-
place pH probe directly in
outflow just outside of tank.
Use proportional-integral-
derivative controller] use
chemicals with inherent
buffering capacty such as
soda ash.
-------
SECTION 9
METAL PRECIPITATION
INTRODUCTION
Precipitation is a treatment technique which is commonly used to
remove the following metals from wastewater: cadmium, trivalent
chromium, copper, lead, nickel, and zinc. Precipitation is the process
of adjusting the pH of a wastewater to the minimum solubility of the
metal or metals. The insoluble metal precipitate which is formed can
then be easily removed from the wastewater by sedimentation and/or
filtration. Soluble metals are very stable in solution and will not
settle out even at long detention times.
THEORY OF OPERATION
t-
f-
Precipitation of metals from solution involves adjusting the pH to
the point of minimum solubility. An example of the solubility of a
metal (lead) versus the pH of the wastewater is presented by the curve
in Figure 15. The optimum treatment for a wastewater with character-
istics shown in Figure 15 would be to adjust the pH of the wastewater to
9.0 and then- separate the insoluble precipitate from solution by clari-
fication or filtration. Removing 100 percent of the insoluble precipi-
tate or floe would result in an effluent lead concentration of 0.20
mg/L. If the pH of the wastewater were adjusted to 7.5, then the efflu-
ent lead concentration would be 0.8 mg/L for 100 percent removal of the
insoluble precipitate.
Heavy metals can exist in either the particulate form or the solu-
ble or dissolved form. The particulate metal concentration represents
-------
LEAD SOLUBILITY (mg/l)
31
(O*
c
-1
•
o
0
a
o
c"
V
1 *
o
•o
JT
oo
•
o
CO
9
O
o
•
o
ro
•
o
I I I I I 11II
I I I I M|
T I I I
-------
the difference between the total metal concentration and the soluble
metal concentration. At each pH value, the soluble metal concentration
can be determined theoretically from pH solubility diagrams or experi-
mentally by analyzing for the dissolved metal concentration. The dis-
solved metal concentration of a solution can be measured by filtering
the sample with a 0.45 micron filter and then analyzing the filtrate for
the metal concentration. Analyses of aqueous solutions for metal con-
centration is performed using an atomic absorption spectrophotometer
(AAS), an instrument which measures the radiant energy absorbed as the
sample passes through a flame. Procedures for the analysis of most
common metals by AAS are contained in reference 8.
The soluble metal concentration of a sample should not be based on
theoretical considerations because of the effect that other ions have on
the solubility of a metal. An example of the effect that carbonate has
on lead solubility can be observed in Figure 16. This figure shows that
the lead solubility at a pH of 9.0 for carbonate concentrations of 16,
50, and 10,000 mg/L as CaCO, is 0.07, 0.35 and 2.5 mg/L, respectively.
Other metals can be similarly affected by ions in solution. Because of
this effect, the optimum pH value should be based on test data rather
than theoretical values.
DESCRIPTION OF EQUIPMENT
The processes generally used in metal precipitation include pH ad-.
justment, sedimentation, and sometimes filtration. The functions of pH
adjustment and sedimentation processes must not be confused. The pH
adjustment step simply converts a metal from the soluble (ionic) form to
the insoluble (hydroxide precipitated) form. However, the total concen-
tration of the metal in the wastestream does not change during this
process. The sedimentation process removes particulate metal from the
wastestream. However, the sedimentation process does not decrease the
soluble metal concentration.
The relationship between soluble and total metal concentration and
the treatment processes involved is presented in Figure 17. Reading
115
-------
10
09
I
UJ
o
o
o
Q
HI
1.0
0.1
0.01
Figure 16.
5.0 6.0
,000 mg/l
CaC03
* 16 mg/l
CaCOg
7.0 3.0 9.0 10.0 11.0 12.0
PH
Lead solubility as a function of
carbonate concentration.
SOURCE: PATTERSON, 4.W, SCALA, 0-L, AND ALLEN, HL&; HEAVY METAL
TREATMENT BY CARBONATE PRECIPITATION, PflOC. 30th INO.
WASTE CONF, PURDUE UNIV.. 1975.
-------
METAL CONCENTRATION
T|
ID'
c
^
0>
_t
-J
PH
ADJUSTMEt
BEFORE
3 N> .*•. O B O
3 _ b b b b b
'
1
«
«*
&
o
o
3
C
0)
e
o>
33
o m
>a
H
5
V
^B
^^
0
o
CD
0
•
F ^
>s
= 33
O
1
—p
••••
g ?
I I
o c
f *
s ?
-------
from left to right on Figure 17, it can be seen that the pH adjustment
step changes the relative proportions of soluble and insoluble metal
content, but does not in itself reduce the total metal concentration.
However, clarification in general removes the majority of the particu-
late matter, and filtration removes even more, while leaving the soluble
metal concentration unchanged. Because the optimum pH value for preci-
pitation of a metal may occur at a pH greater than that allowed by
regulatory authorities, post pH adjustment or final neutralization is
sometimes necessary. The effect of final pH adjustment will be to
change the concentration of the particulate and soluble metal concentra-
tion. Either form may increase or decrease depending upon the metal
solubility, and the initial pH and final pH to the post pH adjustment
process. However, the total concentration of the metal will not change
during the process. The two possible effects that final neutralization
can have on soluble and particulate metal concentration are shown in
Figure 18. From Figure 18 as with Figure 17, it is apparent that
changes in pH will change the concentration of the forms of the metal
but will not increase or decrease the total metal concentration.
Changes in the pH of wastewater can occur as the result of acid or
alkali addition such as in the final neutralization basin. However,
changes in .the pH of a wastewater can also bccur because of introduction
of CO into the wastewater, especially for poorly buffered waters. In-
troduction of CO- into the water can occur slowly in a tank open to the
atmosphere or more rapidly by aeration or turbulence.
OPERATIONAL PROCEDURES
The objective of precipitation is to cause the metal ion to form an
insoluble precipitate which can be removed by separation techniques such
as sedimentation or filtration. To control the metal precipitation pro-
cess, the operator should perform the necessary process monitoring and
should apply the necessary control strategies to the system variables.
118
-------
3 1.0
o
2 0.5
LU
O
U
< 0.0
2222222
Particuiate
Soluble
CASE NO. 1
NOTE: Soluble (natal in-
creased becausa final
neutralization adjusted
pH away from optimum
pH solubility value.
AFTER
CLARIFICATION
AFTER
FILTRATION
AFTER
FINAL
NEUTRAUZATION
METAL CONCENTRATION (mg
P P r*
b in b
-
B
CASE NO. 2
NOTE: Soluble metal con-
centration decreased because
AFTER AFTER AFTER
CLARIFICATION FILTRATION FINAL
NEUTRALIZATION
Figure 13,
Metal concentration after treatment process.
1 1 Q
-------
Process Monitoring
Since precipitation involves a number of processes such as pH ad-
justment, sedimentation, and filtration, process monitoring will involve
all these processes. The main parameters involved in monitoring each of
the processes are total and dissolved metal, pH, and total suspended
solids. The regular or continuous monitoring requirements are summar-
ized in Table 10.
pH Adjustment —
The influent total metal concentration, effluent soluble metal con-
centration, and reactor pH should be monitored. Ions such as carbonates
or phosphates may be analyzed to determine if these ions have an effect
on metal solubility.
Sedimentation ~
The effluent total and soluble metal concentration should be
measured in order to determine the particulate metal concentration that
is not removed by sedimentation. Influent and effluent suspended solids
should be measured to determine the amount of sludge that must be re-
moved. A correlation may exist between effluent suspended solids and
j-
effluent total metal concentration.
Filtration —
Since filtration is typically the last treatment process employed,
effluent total metal concentration will indicate permit compliance. The
influent and effluent particulate metal concentration should be deter-
mined to evaluate filter performance. Influent suspended solids should
be measured to allow control of the filtration process.
The key to successfully operating a metal precipitation system is
understanding the relationship between the particulate and soluble metal
concentration and the treatment processes. An example of the difference
between particulate and soluble metal concentration and how it affects
permit compliance is shown in Figure 19. Case No. 1 presents data for a
1 on
-------
TABLE 10
METALS PRECIPITATION
PROCESS MONITORING REQUIREMENTS
Process
Paranatar
?reqnancy
Reason for Monitoring
1. pH Adjustment
I. Sedimentation
or Filtration
Flow
Influent Total M«tal
Concentration.
Affluent Soluble Metal
Concentration.
Seactor pfi
Flow
Influent: TSS
Effluent TSS
Influent TSS-effluant
TSS (Mass Loadings)
Effluent Soluble and
Total Metal
Concentration
Continuously To ad-just dosages for faedforvard
control.
Daily To determine mass loading.
Daily To evaluate performance.
Continuously To adjust reagent dosages and for
(Calibrate evaluating natal solubility.
daily)
Daily To evaluate effect of hydraulic
loading on metal precipitate
renewal.
Daily To determine influent mass loading
of TSS.
Daily To determine TSS removal perisr-
manca and to establish correlation
beewaan oetal concentration £ TSS.
Daily To d*tanu.i)« mass loading of
sludge to be reroved.
Daily To determine particulate iretal
concentration in effluent and
particulate metal removal perror-
manca of separation device.
121
-------
0>
(O
METAL CONCENTRATION (mfl/l)
METAL CONCENTRATION (mg/l)
*• t
g
p
o
01
b
p
b
METAL CONCENTRATION
p
b
pi
b
p
b
i
p
b
P
in
o
o
5
TJ
n
c^
ei
o
-------
treatment system which has good operation of pH adjustment and sedimen-
tation. Case No. 2 presents a system which has poor operation of the pH
adjustment process. This is evidenced by a high soluble metal concen-
tration. Soluble metal can be measured by filtering a sample immedi-
ately after collection. Care must be taken that the pH does not change.
A discussion of the variables which affect the solubility of each metal
are presented in the PERFORMANCE portion of this Section.
The third case, Case No. 3, presents a treatment system which has
good operation of the pH adjustment system but poor operation of the
sedimentation process. Poor sedimentation performance will be indicated
by high effluent suspended solids concentration and high particulate
metal concentration. Particulate metal concentration is the difference
between total and soluble metal concentration. The causes and remedies
for troubleshooting the sedimentation process are presented in the
section on sedimentation. The operator should not attempt to correct
the sedimentation problem by installing a filtration unit because the
unit will foul with solids. Most filtration systems should be installed
for wastewaters that are low in suspended solids.
Process Control Strategies
The control strategies associated with operating a metal precipi-
tation system involve the chemical reagent used in pH neutralization and
the operating pH. Other operating variables associated with operating
the unit processes (pH adjustment, flocculation, clarification, and
filtration) are listed and discussed for each unit process.
Hydroxide Precipitation—
The most common anion used to precipitate metals from wastewater is
hydroxide. Hydroxide is generally added to the wastewater as calcium
hydroxide (lime) but sometimes added as sodium hydroxide (caustic). The
primary advantage for using lime'is that a good settling precipitate is
usually formed. The advantage for using caustic is less sludge genera-
tion. The solubility of metal hydroxides is presented in Figure 20.
-------
1.0 —-
OJ
0.1
o
^ 0.01
0,001
I Chromium
I 1
6 7 3 9 10 11 12
SOLUTION pH
Figure 20. SolubiNty of selected heavy metal hydroxides.
SOURCE: U3EPA, SULF1OE PRECIPITATION OF HEAVY METAL3, SPA-600/2-30-139, JUNE, 1960, p. 104.
-------
Because of the different pH ranges for minimum solubility of various
metals, staged precipitation is sometimes needed.
Staged precipitation is a series of two or three units of pH ad-
justment process with each followed by a separation process such as
sedimentation and/or filtration. An example of the necessity of staged
precipitation is for a wastewater which requires removal of both nickel
and trivalent chromium. The first stage would consist of pH adjustment
to a pH of 8.5 followed by sedimentation and, possibly, filtration. The
second stage would consist of pH adjustment of the wastewater from 8.5
to 10.5 followed by sedimentation and/or filtration.
Sulfide Precipitation--
Sulfide precipitation of heavy metals is gaining acceptance because
most metal sulfides are even less soluble than metal hydroxides at alka-
line pH values. Therefore, lower effluent metal concentrations can be
accomplished through the use of sulfide rather than hydroxide. As with
hydroxide precipitation, the solubilities of metal sulfides are pH de-
pendent. The pH dependence for various metal hydroxides are presented
in Figure 21. Figure 21 also shows the metal solubilities of metal
sulfides. Sulfide can be added as hydrogen sulfide, sodium sulfide, or
ferrous sulfide. if the sulfide is added as a water-soluble compound
(e.g., H2S or NaS), the process is referred to as soluble sulfide pre-
cipitation (SSP). If the sulfide is added as a slightly soluble salt
(ferrous sulfide), the process is called insoluble sulfide precipitation
(ISP). Figure 22 shows typical precipitation processes for hydroxide
(4)
precipitation, SSP, and ISP.
In addition to achieving extremely low solubilities for metal
sulfides, the sulfide process has the ability to remove chromates and
dichromates without preliminary reduction of the chromium to the triva-
lent state. Furthermore, the sulfide process will precipitate metals
complexed with certain complexing agents. Iron sulfide has been demon-
strated more effective for metal precipitation when chelating agents
125
-------
10
10
10
1CT1
o
«
2 10
Q
O 10"
I*-
(T
o
10 r
23 4 5 6.7 3 9 10 11 12 13
PH
Rgure 21. Theoretical solubilities of metal hydroxides
and suit ides versus pH.
30URC& 3COTT, M.&; SUL^SX (TW- A N«W PKOCESS THCMMOtOOY FOB flBMOVAL OP HEAVY
MFTAL3 F1WM WASTE 3TJWAM* PUHOU8 32nd INOUSTmAL WASTS CONnERKNCt. 1977, 9. 423,
-------
(a)
C»OHI,
a. Hydroxide Precipitation
C4OHI, N«HS
Clarification
b. Soluble Suifida Precipitation
HSttum
c. Insoluble Sulflde Precipitation
Clarification
Rgure 22. Waatawatar traatmant processes
for removing haavy metals,
SOURCE: EPA REPORT NO. EPA 62678-60-003.
127
-------
such as EDTA or Rochelle Salt are present. These tests were per-
formed for copper, cadmium, chromium (III), nickel, and zinc precipita-
tion. One disadvantage of the sulfide process is the evolution of toxic
hydrogen sulfide gas for certain sulfide reagents if the pH should
decrease below 8.0. However, the usage of iron sulfide virtually elim-
inates the possibility of evolution of hydrogen sulfide. Another dis-
advantage of the process is that high levels of excess sulfide sometimes
must be oxidized to sulfate before discharge.
A key to good operation of the sulfide precipitation is applying
the correct amount of sulfide. As with any precipitation reaction,
excess reactant {sulfide) must be present to drive the precipitation
reaction to completion. However, because sulfide is toxic, sulfide
addition must be carefully controlled with only a minimum of excess
sulfide used. High levels of unreacted sulfide will require post-
treatment such as aeration to oxidize sulfide to sulfate.
TYPICAL PERFORMANCE VALUES
Typical performance values for removal of metals commonly present
in plating and finishing wastes are discussed in the following. Also
discussed are the effects that various compunds or ions may have upon
the shape of the pH-soliability curve.
Chromium
A pH range of 8 to 9 is recommended to achieve the minimum solubil-
ity of trivalent chromium. However, this range is very dependent upon
the concentration of anions in solution, particularly carbonates and
(18)
phosphates. Thomas and Theis have demonstrated that a bicarbonate
alkalinity and pyrophosphate at concentrations as low as 250 mg/L as
CaC03 and 30 mg/L as P, respectively, together cause appreciable com-
plexation and may make alternatives other than lime impractical. Thomas
and Theis showed that if causti.c was used for pH adjustment of a waste-
water containing pyrophosphate and carbonates not only would the pH
range of minimum solubility be altered, but the supernatant chromium
-------
concentrations would be greater than 1 .0 mg/L. They recommended that
lime should be substituted for caustic soda. The use of lime will cause
precipitation and removal of most of the carbonate and pyrophosphate
species from solution while providing doubly charged counter ions to aid
in coagulation of the negatively charged Cr(OH), colloid which exists at
pH values above 8. An alternative to substitution of lime for caustic
for solutions which contain chromium (III), carbonates, and pyrophos-
phates is to segregate the Cr(VI) was.tes from waste rinses which contain
carbonates and phosphates. The advantage for this alternative is that
the caustic sludge volume is much lower than the lime sludge volume.
Copper
The presence of anions can affect the solubility of copper. The pH
range of minimum solubility for copper hydroxide without the presence of
interferences is 7.5 to 11.0. The soluble copper concentration at this
level is approximately 0.03 mg/L. However, the presence of carbonates
(19)
can increase the soluble copper concentration. Patterson showed
that the soluble copper concentration for a solution with a carbonate
species concentration of 500 mg/L as CaCO, was 4.5 mg/L at a pH of 7.5,
0.25 mg/L at a concentration of 8.5, and 0.09 mg/L at a concentration of
9.5. Therefore the presence of bicarbonate at a concentration of 500
mg/L as CaCO, will increase the copper solubility concentration 15-fold
at a pH of 7.5.
The operator can reduce the effect of carbonate by several methods.
One solution is to reduce or eliminate the concentration of carbonates.
An alternative is to use lime and operate at a pH of 10.0 or higher so
as to form the insoluble calcium carbonate precipitate.
Lead
The pH range of minimum solubility for lead is 8.5 to 9.5 for lead
hydroxide precipitation as seen in Figure 16. Patterson^ noted that
the effect of carbonate on lead solubility is a complex function of car-
bonate concentration. Furthermore, he reported that at a treatment pH
129
-------
near 9.0, increased carbonate will increase lead solubility while the
reverse pattern will occur at a pH near 6. Bicarbonate concentrations
as low as 25 mg/L as CaCO will result in a soluble lead concentration
of 4.1 mg/L at a pH of 9.3.
Carbonate can be introduced into the system in many ways. One
source of carbonate is municipal water supplies. Municipal water sup-
plies in the West, Southcentral, and Midwest regions of the United
States have alkalinities greater than 100 mg/L as CaCO.. A second
source- of carbonate is the atmosphere. Depending upon the equilibrium
position (pH and concentration), aqueous solutions not in equilibrium
may either evolve or take up carbon dioxide. The equilibrium bicarbo-
nate concentration at a pH of 8.0 is 25 mg/L as CaCO,. The third source
of carbonate is carbonate salts used in plating solutions. Examples of
these include sodium carbonate, potassium carbonate, and nickel carbo-
nate. The dosages of these salts in solution can be extremely high
(e.g., 50,000 mg/L).
The problem of excess carbonate or bicarbonate concentrations can
be solved by reducing or eliminating the carbonate concentration by con-
trolling the source or by adding lime to the wastewater and precipita-
ting calcium carbonate. Calcium carbonate precipitation forms a heavier
floe which aids in the settling of the lighter lead hydroxide floe.
Mercury
Sulfide precipitation for mercury removal is commonly used.
Patterson reported that sulfide precipitation will achieve 994-
percent removal for high initial mercury levels, but the minimum ef-
fluent mercury concentration that is achievable with precipitation
followed with filtration or activated carbon appears to be 10-20 g/L.
Best results for sulfide precipitation are obtained at pH values less
than 9.0. Patterson listed three drawbacks of sulfide precipita-
tion. These are the formation of soluble mercury sulfide complexes at
-------
high levels of excess sulfide, the difficulty of monitoring excess
sulfide levels, and the problem of toxic sulfide residual in the treated
effluent.
Nickel
The theoretical solubility curve for precipitation of nickel as
nickel hydroxide was presented in Figure 20. A study conducted by
Patterson has shown that experimental results for nickel hydroxide pre-
cipitation will be similar to the theoretical results. However, the
actual solubility curve for carbonate precipitation will probably be
greater than the theoretical carbonate solubility. This anomaly occurs
because the kinetics of precipitation for nickel carbonate are very slow
and the precipitate will not form within typical treatment plant deten-
tion times.
Zinc
The theoretical solubility for zinc hydroxide precipitation is
presented in Figure 20. This solubility curve is for a wastewater which
}-
is low in carbonate alkalinity. The effect of carbonate either present
in the wastewater or induced by the uptake of atmospheric C0_ is to
/ **s\ \ *
lower zinc solubility with increased carbonate levels. * This effect
is especially significant at a pH value less than 9.0 where the presence
of carbonate alkalinity can significantly enhance the zinc precipitation
process.
Other Metals
Metals other than those discussed in the preceding can be removed
from metal finishing wastewates by precipitation. For example, silver
may be recovered as the sulfide, although silver hydroxide is relatively
soluble. Aluminum may be removed by precipitation as the hydroxide
or by phosphate precipitation at pH 5. In point of fact, metal
finishing wastewaters may be treated for phosphate removal by addition
of aluminum salts and precipitation of A1PO4<
-------
TROUBLESHOOTING GUIDE
The troubleshooting guide for the metal precipitation process is
presented in Table 11. The problem areas in the metal precipitation
process involve too high a concentration of soluble metal in the
effluent (which often traces to inadequate pH adjustment or control) and
too high a concentration of particulate metal in the effluent (which
usually traces to the solids separation system). In the case of sulfide
precipitation processes, sulfide odors may arise due to improper concen-
trations of the sulfide salt or too short a reaction time.
13-2
-------
TABLE tl
METAL PRECIPITATION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OB MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 1: Total metal concentration In final discharge is too high.
la. Soluble metal concen-
tration in discharge
is too high.
1b. Soluble metal concen-
tration in pH adjust-
ment discharge is too
high.
Compare soluble metal
concentration for pH
adjustment process to
soluble concentration
for plant discharge.
Check operating
problems for the pH
adjustment process.
Check operating pH of
pH adjustment process.
Analyze pH adjustment
discharge for high
concentration of ions.
Shifts in pH of wastewater
from pH adjustment to final
discharge will affect metal
solubility.
The problems listed for pli
adjustment (see Table 9)
can result in soluble metal
concentration that is too
high.
The operating pH may not
be at optimum pH for
precipitation.
Ions, especially phosphates
and carbonates, can alter
solubility of metal ions.
If soluble metal concentra-
tion of pll adjustment process
is low and within permit, then
operation of pH adjustment is
acceptable, and cause of
problem is solids separation.
See Probable Cause (c).
If soluble metal concentration
of pH adjustment process is
high and out-of-spec, then see
Probable Cause (b).
Perform corrective action as
identified in Table 9.
Review or develop pH-
solubility diagram for
metal. Changing the oper-
ating pH of the system can
affect precipitation of other
metals.
Coprecipitate ions in treat-
ment process with lime or
other precipitation reagents;
eliminate ions that cause
problem from wastewater.
OPERATING PROBLEM 2: Particulate metal concentration in final discharge is too high.
2a. Floe carryover.
Poor operation of floc-
culatiori system.
Poor performance of
sedimentation system.
Operation of flocculation
system must enhance
sedimentation.
Sedimentation units should
remove most of insoluble
precipitate formed in pll
adjustment process.
Perform corrective action in
Table 13.
Perform corrective action in
Table IS.
-------
TABLE 11
(Continued)
METAL PRECIPITATION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OB MONITOR
REASON
CORRECTIVE ACTION
Poor performance of
filtration system
(if provided).
Shifts in pH of the
wastewater from ptl
adjustment process to
final discharge.
filtration units should
polish the discharge fron>
sedimentation system.
Shifts in pH of the waste-
water (especially across
the post neutralization
tank) from the pH adjust-
ment to final discharge
will affect metal solu-
bility and, hence, parti-
culate metal concentra-
tion.
Perform corrective action in
Table 17.
If changes in pH occur, then
analyze soluble metal concen-
tration for pH adjustment
discharge and final discharge.
Refer to Probable Cause la.
OPERATING PROBLEM 3: Sulfide odor in effluent.
3a. Too high a concentra-
tion of sulfide salt
used.
Sulfide application
rate.
Too high a concentration
or too short reaction
time will cause sulfide
odors.
Modify sulfide precipitation
procedures. Decrease sulfide
application rate.
-------
SECTION 10
FLOCCULATION
INTRODUCTION
Flocculation is the process whereby particles are gently agitated
to enhance particle agglomeration. The purpose of flocculation is to
increase the size of the floe because larger floe particles settle
faster than smaller floe particles. The flocculation process generally
follows the pH adjustment process which generates the flocculant par-
ticles and precedes the sedimentation or filtration process which
removes the flocculant particles from the wastewater. Flocculation of
particles can be accomplished in tanks, basins, or in pipes. Polymers,
which are used extensively to enhance the particle agglomeration for
metal finishing wastewaters, are typically added in the flocculation
tank or basin.
THEORY OF OPERATION
The key to flocculation is to promote particle contact and agglome-
ration without providing excess agitation that will shear the floe into
smaller particles. Agitation should be carefully monitored and control-
led so that the floe particles will not be sheared. The amount of
agitation in a flocculation tank can be determined by calculating the
mean velocity gradient. The mean velocity gradient is a function of the
power input, the basin volume, and viscosity of the water.
In addition to depending upon proper agitation, particle contact
and agglomeration will also depend upon the size of the particles and
135
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their charge in solution. Coagulants are added because they destabilize
the particles in solution by altering the charge of the particles and
bridging small particles into masses or floes. Generally the larger the
size of the floe, the faster the particles will settle. Both inorganic
metal salts and organic polymers are used to aid in particle settling.
Some of the inorganic chemicals used are aluminum sulfate (alum), ferric
chloride, ferrous sulfate, and lime.
Determination of the best coagulant for a given system should be
based upon jar tests and scale-up factors. Jar tests are a series of
bench scale tests which can be employed to simulate chemical addition,
floccuation, and clarification. A "gang stirrer" is commonly used to
perform four to six jar tests at one time. Each jar test is subjected
to one different condition from the prior test, such as polymer dosage.
when performing a jar test, the operating condition of the test should
simulate the conditions in the field. The conditions of the full-scale
flocculation/clarification system which should be duplicated by the jar
test include similar dilutions of the concentrated polymer, similar HRT,
and similar mixing intensity of the flocculation/clarification system.
The procedure for jar testing for emulsion breaking presented in Section
5, Oil Removal, are applicable with only minor modification to coagula-
tion processes.
Chemical coagulants are used extensively in the trea'tment of metal
finihsing wastes. However, the type and dosage of the coagulant com-
monly are not optimized. This failure to optimize the system can cause
increased chemical cost and/or poor performance. The operator should
perform a series of jar tests to determine the optimum dosage whenever
the wastewater characteristics change. Every six to twelve months, the
operator should evaluate different coagulants in order to select the
most cost-effective coagulant.
DESCRIPTION OF EQUIPMENT
Plocculation of particles is promoted by gently stirring the waste-
water. There are several methods which range from simple, inexpensive
136
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devices to large pieces of equipment for flocculation. Three types of
flocculation equipment commonly used are in-line mixers, reactor-clari-
fiers, and flocculation basins. In-line or static mixers are simple
devices mounted in the pipe. A bypass which will allow for the in-line
mixer to be taken out of service should also be provided.
Flocculation can be an integral part of a clarifier (reactor-
clarifiers). This system is accomplished by providing an inlet well
with a mechanical mixer. Variable speed mixers allow the operator
flexibility in controlling the mixing intensity.
Flocculation basins are used for systems which require long mixing
periods or for systems in which it is necessary to vary the mixing in-
tensity within the basin. Long mixing periods are desired for slow re-
acting reagents such as limestone. Flocculation in the tank is usually
provided by mechanical mixers but can be provided by either stationary
baffles or diffused air.
OPERATIONAL PROCEDURES
To control the operation of the flocculation process, the operator
should conduct the necessary process monitoring, perform any control
calculations needed, and understand the process control strategies or
variables.
Process Monitoring
The primary parameters which should be monitored to control the
flocculation .process are power input and polymer dosage. Other para-
meters which should be measured for the polymer system include optimum
dosage (e.g., by jar testing), polymer type, and polymer feed concen-
tration. These monitoring requirements are shown in Table 12.
In addition to heeding these requirements, the operator should
inspect the flocculation system regularly. The operator should inspect
137
-------
TABLE 12
FLOCCULATION
PROCESS MONITORING REQUIREMENTS
Parameter
Frequency
Comment
1 . Polymer Dosage
2. Polymer Jar Tests
3. Polymer Type
Regularly
Daily
Occasionally
Polymer Feed
Concentration
Flocculation
Horsepower
For each
batch
Occasionally
Dosage should be deter-
mined at least hourly.
Jar tests should be per-
formed daily to determine
optimum dosage.
Jar tests should be
performed occasionally to
select best polymer when
process problems dictate.
Concentration should be
calculated and must not
exceed manufacturer's
recommendations.
Velocity gradient should
be calculated occasionally
so that correct power is
applied.
138
-------
mixing baffles and look for hydraulic short-circuiting, torn impellers,
or solids accumulation. Any deficiencies should be corrected immedi-
ately.
Example Calculations
Example calculations are shown below for determining the mean
velocity gradient and the polymer dosage.
Mean Velocity Gradient —
The mean velocity gradient MVG is a function of the mixing inten-
sity or mixing horsepower. The mathematical formula for MVG is as
follows:
where MVG = mean velocity gradient (sec )
P = power input (Hp)
m = dynamic viscosity (Ib-sec/ft )
V = flocculation volume (ft )
Consider a flocculation system with the following characteristics:
Horsepower = 12 Hp, Viscosity = 2.05 x 10~ Ib-sec/ft , and Volume =
75,000 ft3.
MVG = ( 12 * 55° ) 1/2
2.05 x 10~ x 75,000
MVG = 66/sec
Polymer Dosage ~
The polymer dosage can be determined from the following formula:
q x c x 106
6000 x Q X 1U
139
-------
where: PD = polymer dosage (ppm)
q = polymer flowrate (gal/hr)
C = polymer concentration in solution feed (%)
Q = wastewater flowrate (gpm)
Consider the following example: Polymer flowrate = 2.0 gal/hr, Polymer
concentration = 0.5%, and Wastewater flowrate = 1.0 gpm. The polymer
dosage will be
2.0 gal/hr x 0.5 6
PD = a—' x 10
6000 x 10
=16.7 ppm
Process Control Strategies
The two primary adjustments controlling the flocculation process
are mixing intensity and polymer addition. The operator should deter-
mine the optimum set points for these adjustments based on the settling
ability of the flocculant particles.
Mixing Intensity—
The operator should control the mixing intensity such that the de-
sired level of agitation between metal particles and polymer is
achieved. The correct amount of agitation will result in particles that
settle rapidly and do not require high dosages of polymer. Under-agita-
tion between particles and polymer will result in the formation of very
small floe particles that do not settle readily. Onder-agitation of the
flocculation process may be caused by not providing sufficient power or
not allowing enough time for particle/polymer contact.
The power input to a flocculation basin should be controlled to ob-
tain a mean velocity gradient between 20 and 75 sec ~ for a 15 to 30
minute detention time. High velocity gradients should be used for
shorter detention times and low velocity gradients should be used for
140
-------
longer detention times. Polymers should be added to the inlet or
further upsetream of the floculation basin to achieve maximum contact.
Under-agitation for in-line mixers is a result of not providing
sufficient head loss through the mixer. The minimum pressure drop for
most in-line mixers should be approximately one foot of head for a fluid
velocity between 1 and 2 feet per second (fps). For most systems, a
four or six element in-line mixer will be adequate. Lower element
mixers should be used for systems where there are changes in the direc-
tion of flow from the mixer to the settling device.
Over-agitation of the wastewater may shear the floe into smaller
particles which also will not settle. Too much agitation may be caused
by operating the flocculation paddles at too high a speed or by using a
centrifugal pump to pump flocculated wastewater. Also over-agitation
may be caused by high velocities in the pipe or the inlet to the clari-
fier.
„ , ,^.4.- (24,35,26,27)
Polymer Addition—
Polymers used as coagulants in wastewater treatment can be either
synthetic or natural. They are composed of many small compounds (mono-
mers), which can be identical to each other, or of different materials.
Polymers are chains of monomers whose number is varied by reaction to
produce polymers with different molecular weights; those used in waste-
water treatment normally range from 100,000 to 1,000,000. Their prime
function is to act as a "coagulant aid," a term applied to chemicals
such as lime that are added to wastewater, in addition to conventional
coagulants, to improve colloidal destabilization and flocculation.
The term "polyelectrolyte" is used to describe chemicals of charged
groups in the form of a polymer. The polyelectrolytes are further
classified according to the type of charge they will have in solution,
as follows:
141
-------
Anionic Polyelectrolytes-negative charges
Cationic Polyelectrolytes-positive charges
Nonionic Polymers (Nonionic Polyelectrolytes)-neutral charges
The variety of monomers available as buildling materials for poly-
mers is endless, meaning that there is a large assortment of polyelec-
trolytes available for use in coagulation.
Polymers can be purchased dry or in liquid form. They are easily
handled at the plant site and are generally nonhazardous. The usual
protection from dust is required, and the storage facilities for the dry
powders must be moisture-free. The materials of construction for stor-
age and handling equipment are normally stainless steel 316 and
plastics; selection is made on the basis of the polyelectrolyte chosen.
The coagulation mechanisms of polyelectrolytes are associated with
charge reduction of the colloids, which results in adsorption or enmesh-
ment of the individual particles to form a settleable mass. Due to the
size of the polymeric compound, the polymers can attach themselves to
the surfaces of the suspension at one or more sites. The excess part of
the polymer chain extends into the solution and adsorbs onto other
particles. The size of the floe being formed is generally restricted by
the strength of the attractive forces between the particles and those
between the solids and the stream.
Polyelectrolytes are used extensively in coagulation processes
because of their versatility, range of properties, handling ease, and
effect on coagulation rates. Generally, cationic polyelectrolytes are
used alone or as aids to other coagulants in forming metallic salts.
Anionic polymers are used as coagulant aids in colloidal destabilization
where negative charges are required to bridge the positvely charged
colloids. Nonionic polyelectrolytes are added to increase colloid
concentration, thereby aiding floe formation, and to increase floe size
by attaching themselves to agglomerated colloids.
142
-------
Polyelectrolytes will:
o Increase the size and stability of the floes;
o Decrease dosages of conventional chemical coagulants, such as
alum;
o Decrease floe formation;
o Extend the effective range of coagulant dosage;
o Extend range of pH over which conventional coagulants are effec-
tive; and
o Increase suspended-solids removal efficiencies.
In actual plant use, liquid polymers are usually diluted
to approximately a 1% solution (vol/vol). This is done by adding one
part (by volume) of polymer to 100 parts (by volume) of water. Dry
polymers are usually diluted to approximately a 0.1% solution, (wt/wt).
This is done by adding one part of dry polymer (by weight) to 1000 parts
of water (by weight). An example of a 1 % solution of liquid polymer is
to add one gallon raw polymer to 100 gallons of water. To prepare the
same solution for a jar test one adds one milliliter of liquid polymer
to 100 milliliters of water. An example of a 0.1 % solution of dry
polymer would be to add .834 Ibs of polymer to 100 gallons of water (834
Ibs). To prepare a 0.1% solution for a jar test one adds one gram of
polymer to one liter of water (1000 grams). Polymer solutions in excess
of these concentrations may be difficult to mix or to pump.
Polymers vary widely as far as their shelf life is concerned and
mixed polymers often lose their effectiveness in as short a time as one
day. It is recommended that only enough polymer to last for one day's
run time be mixed. The method used to add polymer to water and mixing
times used are critical. A recommended procedure is to fill the mixing
tank to about 3/4 of desired level and start mixers and add polymer very
slowly. After all the polymer is added, the tank is filled to the
desired level and mixed for a minimum of 30 minutes. Mixing times vary
widely for different polymers so one is advised to check with the poly-
mer manufacturer for detailed information.
143
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Different polymers are often not compatible. If polymers being
used are changed, all lines and pumps should be thoroughly flushed out,
as should mix tanks and day tanks, before the new polymer is added.
Polymers should be protected from extreme changes in weather and so
should be stored inside.
Handling, storage, and feed-flow control facilities are as impor-
tant as proper selection of coagulants and determination of the
coagulant dosage. The wrong coagulant dosage can adversely affect the
settling and flocculation rates of suspended solids by causing the
colloidal suspension to restabilize. Low coagulant flow rates have
similar effects.
A data sheet should be completed when performing jar tests. The
data sheet contains the various parameters and observations which are
important when performing a jar test.
TYPICAL PERFORMANCE VALUES
The performance of the flocculation process can be measured by how
s •
well the flocculant particles settle or are filtered. A well operated
flocculation process will generally require low dosages of coagulants
and will produce low concentrations of suspended solids in the effluent.
TROUBLESHOOTING GUIDE
The troubleshooting guide for the flocculation process is presented
in Table 13. The chief problem of the flocculation process is poor
settling floe, which may be caused by under-agitation, overagitation, or
improper polymer use. Improper polymer use may include the use of an
ineffective polymer or the improper application of an otherwise effec-
tive polymer.
144
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TABLE 13
FLOCCULATION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 1: Poor settling floe.
la. Underagitation
(Tanks or Basins)
Ib, Underagitation
(In-line mixing)
1c. Overagitation
(Tanks or Basins)
Calculate mixing intensity
of basin or tank.
Check tank baffles and
mixer impeller.
Calculate theoretical
detention time of basin
or tank.
Observe basin for short-
circuiting.
- Check operation of inline
mixers.
Determine number of changes
in.direction of flow due to
number of elements for
in-line mixer plus number
of bends in piping.
- Calculate mixing intensity
in basin or tank.
- Determine impeller speed or
RPM.
- Look for excessive shear
forces acting on flocculant
particles.
Inadequate power will not
provide correct particle/
polymer contact.
Horn or broken baffles
and impeller will cause
Underagitation.
Sufficient detention time
required for particle/
polymer contact.
Short-circuiting due to
accumulation of solids or
improper placement of inlet
and outlet structures nay
reduce detention time.
Worn or torn elements may
reduce mixing capactly.
Four to six or more
changes in direction of
flow (velocity = 1 to 2
Ips) are recommended
minimum.
Excessive power input may
shear flocculant particles.
Excessive impeller speed
may shear flocculant
particles.
Excessive shear can be
caused by centrifugal
pumps or very high pipe
veloci ties.
Increase horsepower.
Repair baffles and impeller
as needed.
Increase detention time
by reducing flowrate at
the equalization basin
(if possible).
Remove solids or relocate
inlet and outlet structures
if possible.
Repair/replace as necessary.
Add more in-line mixing by
adding more changes in
direction of flow (Add
in-line mixer or bends in
piping.)
Reduce horsepower.
Contact agitator manufacturer
to determine correct impeller
speed for particular
application.
Peduce shear forces by
replacing centrifugal pumps
with positive displacement
pumps or replace pipe with
larger diameter pipe.
-------
TABLE 13
(Continued)
FLOCCULATION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
Id. Incorrect Polymer
Addition
CTi
Observe location of polymer
addition.
Determine concentration
and shelf life of polymer
solution.
Perform jar tests to
determine optimum polymer
dosage.
Perform jar tests to
determine optimum
coagulant type.
Improper location of
polymer addition will not
provide sufficient time for
polymer/particle contact.
Incorrect polymer solution
concentration or too long
a solution storage time
can reduce effect of
polymer addition.
Compare dosage determined
from jar tests to dosage
of full-scale system.
Optimum coagulant will
depend upon jar test re-
sults, cost, and applica-
bility to full scale system.
Relocate polymer addition
location.
Make-up new polymer solution
at correct concentration or
be sure storage time of pre-
pared solution is short.
Adjust polymer solution flow-
rate to achieve optimum
dosage.
Select new coagulant.
-------
SECTION 11
SEDIMENTATION
INTRODUCTION
Particles or suspended solids which are generated in pH adjustment
and flocculation processes can usually be separated effectively from the
wastewater by gravity separation or sedimentation. Since the settling
characteristics of flocculant particles will vary with the system, the
operation of a sedimentation unit should be based on an understanding of
the theory of the sedimentation process and the variables which affect
its efficiency.
THEORY OF OPERATION
Settling basins handling wastewater must separate a variety of
types of materials in the clarification zone. These materials vary from
discrete particles at relatively low concentrations to suspensions of
highly flocculent solids at elevated concentrations levels. For pur-
poses of discussion these materials are divided into three general
, (22)
classes:
1. Class I materials;
(a) discrete particles,
(b) settling rate independent of concentration, and
(c) settling rate equal to overflow rate.
2. Class II materials;
(a) particle growth,
(b) overflow rate and detention time critical, and
(c) rate of particle growth important.
147
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3. Class III materials?
(a) high suspended solids concentration,
(b) settling rate is a function of the concentration, and
(c) detention time and solids loading important.
Sedimentation of Class I suspensions is at a constant rate through-
out the sedimentation basin and is, therefore, independent of depth.
These are discrete particles which will not flocculate, for example,
grit particles.
Sedimentation for Class II type suspensions occurs when larger
particles settle at faster rates than smaller particles and overtake the
smaller particles in their descent. If the particles have characteris-
tics which might cause agglomeration, then growth of the finer particles
to larger ones will occur. The greater the tank depth, the greater is
the opportunity for contact among particles. Therefore, removal of sus-
pended solids will be dependent upon basin depth as well as properties
of the particles and fluid. The growth of individual particles enhances
removal rates because larger particles create a reduced surface-area-to-
mass ratio and thus the drag forces opposing subsidence are reduced.
Polymer addition is normally required to improve particle agglomeration.
Class III suspensions are characterized by relatively high concen-
trations of material. The material may be flocculent, but not necessar-
ily so. "Hindered settling" is the term generally used to describe
Class III solids separation. An example of this type of separation is
found in activated sludge settling. Design of settling basins for Class
III suspensions must consider hydraulic as well as mass surface area
i ^- <22)
loading.
DESCRIPTION OF EQUIPMENT
The equipment used in gravity sedimentation includes clarifiers,
parallel plate or tube settlers, and lagoons. The function of this
equipment is to provide quiescent conditions to permit the heavier-than-
water particles to settle.
148
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There are many types of gravity clarifiers in service today. Con-
ventional clarifiers vary in complexity but generally consist of a cir-
cular or rectangular tank with a mechanical sludge collecting device or
with a sloping funnel-shaped bottom designed for sludge collection.
Reactor clarifiers combine flocculation and sedimentation in one unit.
Parallel or tube settlers utilize a series of inclined settling
plates in close proximity to each other. The inclined plate concept
provides the effective surface area of each plate as projected onto the
horizontal surface. This arrangement provides a higher effective sur-
face area for a given horizontal surface. Since settling of metal
finishing suspended solids is a function of the effective surface area,
increasing this area by adding inclined plates allows the horizontal
surface to be reduced. Therefore, the total horizontal surface area
required for parallel or tube settlers will always be less than that for
conventional gravity clarifiers.
Lagoons are also used for gravity settling. The advantage of a
lagoon is that very little maintenance is required other than periodic
sludge removal. However, appropriate disposal of the sludge is re-
quired; recent solid waste regulations can make effective lagoon opera-
tion an expensive procedure.
OPERATIONAL PROCEDURES
To control the operation of the sedimentation process, the operator
should conduct the necessary process monitoring, perform any control
calculations needed, and understand the process control strategies or
variables. The operator also should understand how the design of the
sedimentation equipment will affect treatment performance.
Process Monitoring
The performance criterion for evaluating sedimentation equipment is
effluent total suspended solids concentration. While this parameter
assesses the overall performance of the system, several other parameters
149
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must be measured and incorporated into a regular monitoring program to
operate a sedimentation system successfully and•consistently. The para-
meters of importance are listed in Table 14.
The influent or effluent wastewater flowrate must be monitored to
determine the solids loading and the hydraulic loading to the clarifier.
If either the solids loading or the hydraulic loading to the clarifier
is greater than the design value, then the performance of the process
may decline significantly. Example calculations for determining the
solids loading and the hydraulic loading (surface overflow rate) are
discussed in the following section.
The influent TSS concentration should be measured to determine the
influent solids loading and the effluent TSS concentration should be
measured to determine removal performance. In addition to these analy-
ses, the sludge depth and sludge suspended solids concentration should
be measured so that a mass balance for suspended solids around the
sedimentation basin can be determined. A mass balance is important for
estimating sludge wasting rates and for adjusting the timer which con-
trols operation of the sludge wasting pumps. It is essential that the
samples collected for the mass balance analyses be flow proportional.
Example Calculations
Several computations should be made by the operator to measure the
performance of a sedimentation unit. These calculations are surface
overflow rate, solids loading rate, and mass balance. These calcula-
tions can be made with minimal effort and are helpful to the operator in
avoiding and anticipating problems.
Surface Overflow Rate—•
The surface overflow rate of a sedimentation unit is defined as the
flowrate divided by the effective surface area.
Surface Overflow Rate (GPD/Ft2) Flowrate (GPP)
Effective Surface Area (Ft )
150
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TABLE 14
SEDIMENTATION
PROCESS MONITORING REQUIREMENTS
Parameter
Frequency
Comment
1 . Wastewater Flow
2. Influent and Effluent
TSS
3. Sludge Level
4. Sludge Solids
Concentration
5. Temperature
6. pH
Continuously
Daily
Daily
Daily
Occasionally
Occasionally
To determine surface
overflow rate and TSS
loading.
To measure efficiency and
TSS loading.
To determine volume of
sludge that must be
disposed.
To determine solids
loading to disposal
equipment.
Temperature can affect
performance.
pH affects the
coagulation ability of
many polymers and
inorganic coagulants.
151
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When calculating the surface overflow rate, only the effective surface
area should be included in the calculation. The effective surface area
is the area in which settling occurs and does not include inlet or
outlet zones or dead space. Furthermore, the effective surface area for
tube settlers or parallel plate separators should include the sum of the
surface area of the plates projected on the horizontal surface.
The following calculation is offered as a guide for determining
surface overflow rate.
Given: Flow = 126,000 gallons per day
No. of Tanks = 2
Area of each Tank = 100 ft
Surface Overflow Rate (SOR) is calculated as
SOR (GPD/Ft2) = ^fluent (GPD) ^
Total Tank Area (Ft )
126,000 GPD
2
2 x 100 Ft
= 630 GPD/Ft2
Solids Loading-—•
Even though the settling basin design may meet the hydraulic load-
ing criterion, it is still possible for overloading to occur on a solids
basis. Solids overloading occurs when the solids loading to the clari-
fier exceeds the ability of the clarifier to transport solids to the
bottom of the basin. The maximum solids loading for a settling basin
generally will be a function of sidewater depth, overflow rate, and
feedwell sizing.
Solids loading is determined by the following equation:
Q x C x 8.34
SL= si
152
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where
2
SL = Solids loading (Ibs/day/ft )
Q = Influent flowrate (mgd)
C = Influent suspended solids concentration (mg/L)
2
SA = Effective surface area (ft )
Material Balance—
A suspended solids mass balance should be calculated around the
sedimentation process to detemine if sufficient solids are being
removed. The amount of sludge that should be removed from the sedi-
mentation tank is the difference between the amount of solids entering
the clarifier and the amount of solids leaving the clarifier.
This is shown mathematically as:
Mass to remove = Influent Mass - Effluent Mass
2RCR
where Q. = Influent Flow Rate to Clarifier (gpm)
Q = Effluent -Flow Rate from Clarifier (gpm)
Q = Sludge Removal Flow Rate (gpm)
C. = Influent Wastewater TSS concentration (mg/L)
C = Effluent Wastewater TSS concentration (mg/L)
C,, = Sludge TSS concentration (mg/L)
Also, a mass balance on flow gives the fact that flow out is equal
to flow in minus the sludge removal rate, or Q = Q. - Q .
G i R
Since Q ~ Q. for systems where the influent flowrate is much greater
than the sludge removal flowrate,
153
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or
- C
An example problem which determines the sludge removal rate is:
Given: Influent TSS concentration = 550 mg/L
Effluent TSS concentration = 30 mg/L
Sludge removal TSS concentration = 20,000 mg/L
Plant Flow Rate = 90 gpm
Find: Sludge Removal Flow Rate
. - ce)
_ 90 gal/min (550 mg/L - 30 mg/L)
R 20,000 mg/L
Q = 2.3 gal/min
The amount of sludge to be removed will be a function of the sludge
concentration (C_.) and the sludge removal flow rate (O_). The greater
R K
the sludge concentration is, the lower the sludge removal rate will be.
Conversely, the lower the solids concentration is, the greater the
sludge removal rate will be. The concentration of the sludge will
change with changes in influent loading (Q. and C.), effluent quality
(C ), and sludge removal rates. The operator should find the sludge
e
removal flow rate which will not hydraulically overload the downstream
dewatering units and which is high enough such that the sludge does not
remain in the clarifier sedimentation tank for periods longer than a few
hours. Allowing sludge to remain in the clarifier for long periods may
cause the sludge to become cementous. Excess sludge in a clarifier
increases the torque on the clarifier. High torque in the clarifier
will actuate the torque limit switch which will turn off the clarifier
rakes.
154
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Process Control Strategies
Based on the monitoring data collected and the values calculated
for surface overflow rate, solids loading, or mass (material) balance,
the operator can adjust several variables of clarifier operation to meet
permit requirements. The important variables in the operation of a
sedimentation basin are sludge wasting, hydraulic loading, and chemical
addition.
Sludge Wasting—
The sludge wasting rate or sludge removal volume should be adjusted
so that sludge does not accumulate in the clarifier. The operator
should adjust the sludge wasting rate so that the mass of sludge removed
is equal to the difference between the influent mass of suspended solids
and the effluent mass of suspended solids. An example of this calcula-
tion is presented in the "Material Balance" section discussed previous-
ly. The two types of sedimentation systems in which solids overloading
are most likely to occur are parallel plate or tube separators and
sludge recirculation systems. Solids overloading can occur in tube
settlers due to plugging of the tubes. If this happens frequently, the
operator should backwash the tube settlers more often in order to elimi-
nate plugging.
Solids overloading can also be caused by not wasting enough sludge
from the clarification system. This condition usually occurs in systems
that employ sludge recirculation, but can occur if sludge is allowed to
build up in the clarifier. The operator should calculate solids loading
from the equation presented above. If the solids loading exceeds the
maximum value, the operator should waste sludge from the clarifier or
should decrease the flowrate temporarily.
Hydraulic Loading Capacity—
In addition to adjusting the flow rate to control the solids load-
ing to the sedimentation unit, the operator should control the flow rate
to the sedimentation process so as not to exceed its hydraulic loading
capacity, if possible. The hydraulic loading of a sedimentation basin
155
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is generally determined by the surface overflow rate calculation (see
preceding discussion). The maximum hydraulic capacity of a sedimenta-
tion unit or clarifier will be dependent upon the type of clarifier, the
settling characteristics of the particles, and the chemical coagulants
used.
2
Surface overflow rates of 600 to 2880 gpd/ft are recommended for
calcium carbonate precipitate. Lower rates (600-1800 gpd/ft ) are
(21 )
recommended for aluminum and iron floe . Generally higher overflow
rates are used for lime precipitation because of favorable settling
characteristics. Lower overflow rates are employed for small systems
and for systems which use caustic or soda ash for pH adjustment. The
hydraulic loading capacity for a particular clarifier should be based on
a relationship between flow rate and effluent suspended solids that has
been calculated from actual operating data. If the operator determines
that flows in excess of a given flow rate will cause treatment problems,
then the operator should take steps necessary to reduce the flow rate.
The most practical way to control the flow rate is with a variable
level equalization tank or surge tank. However, peak flow rates can be
minimized by scheduling tank washdowns and clean-ups during periods of
low hydraulic loading.
Coagulant Addition—
The operator can control the settling rate of particles by adjust-
ing the coagulant or polymer addition system. The polymer addition
variables which can affect settling are polymer type and dosage, point
of injection, and flocculation. The operator should refer to the
troubleshooting table for flocculation (see Table 13) for adjusting the
polymer addition system.
Design Characteristics
The performance of sedimentation equipment will depend upon operat-
ing variables such as influent flow, sludge wasting, and polymer
156
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addition, but will also depend upon factors beyond the control of the
operator. These factors can be a function of either the wastewater
characteristics or the design of the system. Generally, proper sedi-
mentation of the wastewater will result in suspended solids concentra-
tions of less than 50 mg/L.
The factors which are associated with the design of a sedimentation
basin are discussed below.
Flow Variations—
Flow variations can be caused by extremes in instantaneous flows or
by a constant speed pump cycling on and off. High instantanous flows
can be reduced with equalization, elimination of storm water inflow/in-
filtration, or reduction of the rate at which high volume wastes are
discharged.
Cycling on and off of a constant speed pump can cause pulsating
turbulence in the clarification zone and can damage the pump and motor.
A number of solutions are available to correct this problem. Part of
the discharge from the pump can be recycled back to the pump sump or the
pump can be throttled with a valve. Other solutions include replacing
the constant speed pump with a variable speed pump and adding a smaller
capacity constant speed pump.
Inlet Design™
The Manual of Practice for Wastewater Treatment Plant Design
reports that next to the importance of proper sizing of a settling tank
is proper inlet design. The inlet to a sedimentation basin must be an
effective arrangement to achieve horizontal and vertical distribution of
the flow across the entire cross-sectional flow-through area. The inlet
design must also dissipate the inlet energy. The maximum inlet velocity
to the center inlet well should not exceed 3 fps and the outflow veloc-
(22)
ity should not exceed 15 feet per minute.
In order to dissipate energy readily, clarifier inlets are normally
equipped with baffles or small ports. Inlet ports should be sized for
157
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velocities in the range of 15 to 30 fpm. Baffles should extend from a
point several inches below the water surface to a point 6-12 inches
below the inlet point.
Density Currents—
Short-circuiting can occur in sedimentation basins if the incoming
flow has a higher temperature or density than the mass of liquid in the
basin. This condition is usually evidenced by violent rolling of masses
of liquid with entrained solids to the surface. Short-circuiting can
occur when the temperature suddenly increases 1 to 2°C with light floc-
(22)
culant-type solids.
Temperature increases can be especially significant during start-
ups. Control over density currents is achieved by limiting the tempera-
ture change to 1-2°C over a period of at least an hour. One method for
eliminating temperature gradients in the sedimentation basin is to
recycle the clarifier underflow back to the treatment processes.
Outlet Design—
The overflow or effluent takeoff weir should be designed and opera-
ted such that the clarifier liquid can be removed from the basin without
causing localized high velocity up-drafts. These updrafts cause previ-
ously settled solids to be carried over the weir. For this reason most
sedimentation basins have a sidewater depth between 8 and 12 feet.
In order to eliminate short circuiting caused by localized velocity
up-drafts, a multiplicity of weirs is recommended. The Ten States
•ds s
(23)
2
Standards suggested a limit of 15,000 gpd/ft for secondary settling
basins.
Tank Depth—
The depth of a tank will affect performance by affecting particle
contact. Since settling of flocculant particles is affected by tank
depth, a greater tank depth will produce higher removal efficiencies.
158
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TYPICAL PERFORMANCE VALUES
Sedimentation of flocculant particles from metal finishing waste-
water treatment should result in suspended solids concentrations less
than 50 mg/L.
TROUBLESHOOTING GUIDE
The troubleshooting table for the sedimentation process is pre-
sented in Table 15. Several types of problems are addressed; these
include high sludge blanket, high solids concentration in the effluent,
flow short-circuiting, mechanical torque problems in the equipment,
deflocculation in the clarifier, and high metals concentration in the
effluent. Many of the potential solutions involve correction of mech-
anical problems.
159
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TABLE )5
SEDIMENTATION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 1: Sludge blanket overflow weirs.
la. sludge blanket
too high.
Depth of sludge blanket.
Operation of sludge pump.
Sludge not being removed
at fast enough rate.
Increase removal rate of
sludge from clarifier.
OPERATING PROBLEM 2: Sludge blanket too high. Sludge removal pumps operating properly.
2a. Defective scraper
blades on bottom
sludge scrapers.
Bottom sludge scraper
blade.
Scraper blade out of
adjustment or broken.
Sludge not being moved
to clarifier hopper.
Drain clarifier and adjust
or repair scraper blade.
CTi
O
OPERATING PROBLEM 3: Excessive torque on rake mechanism.
3a. Sludge blanket
too high. Sludge
concentration
too high.
Depth of blanket and
sludge concentration.
Thick sludge can cause
torque overload.
Increase removal rate of
sludge. Blanket depth will
have to be decreased rapidly
to prevent damage to
clarifier.
3b. Foreign object in
clarifier.
3c. Bottom sludge scraper
out of adjustment.
Bottom of clarifier
for foreign objects.
Bottom scraper arm
adjustment.
Foreign object can wedge
scraper and cause torque.
Scraper blades touching
bottom causing torque
overload.
Drain clarifier and
remove object.
Drain clarifier and readjust
bottom scaper arm and/or
blades.
3d. Top skimmer out of
adjustment.
Top skimmer.
3e. Mechanical problems.
- Gear box, bearings,
motor.
Skimmer could be rub-
bing side walls of
clarifier or could
have dropped causing
excessive torque as
skimmer passes over
skimmings hopper.
Excessive drag due to
mechanical problems can
cause torque problems.
Adjust blade on end of skimmer
arm.
Adjust baffle of clarifier if
out of round.
Readjust position of top
skimmer.
Replace or repair defective
part.
-------
TAPLF 15
(Continued)
SEDIMENTATION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
CORRECTIVE ACTION
OPERATING PROBLEM 4: High TSS concentration in clarifier effluent.
CTv
4a. Sludge blanket too
high.
4b. Influent flow too
high.
4c. Chemical dosage
wrong.
4d. Sludge hopper on
clarifier for floating
solids plugged.
See Steps 1 and 2.
Flow rate to clarifier.
- Chemical dosage.
Exit lines of sludge
hopper.
- See Steps 1 and 2.
Excessive flow rates
will cause solids
carryover.
- Low or high cheipical
dosage can cause solids
carryover.
Plugged hopper will
cause increased con-
centration of float-r
ing solids. Solids
will overflow weir.
See Steps 1 and 2.
- Reduce flow rate.
Fun jar test.
Readjust dosage.
Unplug hopper.
4e. Poor mixing of waste-
water and chemicals.
4f. Short circuiting of
clarifier flow.
4g. Solids concentration
to clarifier too high.
- Chemical injection point.
Turbine drive on reactor
clarifiers.
Level of clarifier weirs.
Partial blocking of V notch
weirs.
Solids concentration.
Point of entry of
chemicals is critical
to proper mixing.
Drive may be too fast
or too slow.
Uneven weirs causes
short circuiting.
Partial blocking can
cause short circuiting.
Exceeding solids load-
ing rate will cause
solids carryover.
Inject chmicals at proper
point.
Readjust speed of turbine
drive.
Level weirs.
- Clean weirs.
- Decrease solids loading.
OPERATING PROBLEM 5: Short-circuiting of clarifier flows.
5a« Uneven weirs.
5b. Plugged weirs
See Step 4f.
See Step 4f.
- See Step 4f.
- See Step 4f.
See Step 4f.
See Step 4f.
-------
TABLE 15
(Continued)
SEDIMENTATION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
5c. Excessive hydraulic
load.
5d. Temperature difference
between influent flow
and clarifier water.
- Plow rate to clarifier.
Hater temperatures.
High flow rate will
cause short circuiting.
Temperature differences
can cause short circuit-
ing.
Reduce flow rate or place
additional units in service.
Reduce hydraulic load.
OPERATING PROBLEM 6: Deflocculation in clarifier.
6a. Excessive shear.
Injection point and
agitation.
Excessive mixing or
excessive turbulence can
cause shear.
Reduce mixing or
agitation.
OPERATING PROBLEM 7: High concentration of metals in effluent.
CTi
7a. Improper treatment
prior to sedimentation.
7b. Incorrect polymer
dosage in clarifier.
- pH adjustment and
metal precipitation.
Polymer dosage.
7c, Sludge blanket too high.
7d. Short circuiting of
clarifier flows.
See Steps 1 and 2.
See Step 5.
Improper chemical treat-
ment will cause metals to
remain in solution.
High or low polymer
dosage can allow solids
carryover.
See Steps 1 and 2.
See Step 5.
Correct pH steps. (See pH
Adjustment Troubleshooting
Guide and Metal Precipitation
Troubleshooting Guide.)
Bun jar test and readjust
polymer dosage. See
Flocculatibn Troubleshooting
Guide.
See Steps 1 and 2.
See Step 5.
7e. See Step 4.
See Step 4.
- See Step 4.
- See Step 4.
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SECTION 12
FILTRATION
INTRODUCTION
Filtration is a separation process used to remove suspended solids
generated by precipitation and other suspended solids present in the
wastewater. Generally, filtration is used after clarification to fur-
ther reduce the suspended solids concentration in the final effluent,
thus enabling the treatment system to meet more stringent effluent re-
quirements or to permit the treated wastewater to be recycled. Addi-
tionally, filters are sometimes used in treatment systems in which space
is severely limited as the sole suspended solids removal process.
In the filtration process, wastewater is passed through a bed of
porous material which separates the solids from the wastewater. Depend-
ing upon the nature of the filter, one of two different separation pro-
cesses predominate. In deep granular filters the solids are removed
through an adsorption/disposition process as the wastewater passes
through a deep bed of granular material. In pre-coat and cartridge
filters the solids are removed through a mechanical straining process as
the wastewater passes through a thin layer of filter media.
THEORY OF OPERATION
Filtration involves the passage of water through porous media with
a resulting removal of suspended solids. A number of mechanisms, some
chemical and some physical, are involved in the solids removal process.
The predominant mechanisms are straining^ disposition, and adsorption.
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The dominant mechanism for a given filter depends upon the physical and
chemical characteristics of the wastewater and the filter.
Straining involves removal of particles either at the filter sur-
face or within the interstices of the filter media and is affected by
the filter media and particle size and the filtration rate. For both
precoat filters and cartridge filters, the predominant removal mechanism
is assumed to be straining which occurs at the surface of the filter
media. Although straining also occurs to a limited degree in deep
granular filters, primarily within the interstices of the media, its
importance is generally minimized during design because it leads to
rapid buildup of head loss which limits the length of filter runs.
Disposition and adsorption within the filter bed are the predom-
inant solids removal processes in deep granular filters. Disposition
involves gravitational settling, diffusion, and interception and is
affected by the physical characteristics and size of the media, the
filtration rate, the fluid temperature, and the size and density of the
suspended solids. Adsorption relies upon the attachment of the sus-
pended solids particles to the filter media. The amount of surface
available for adsorption is enormous, roughly 3,000 to 5,000 square feet
per cubic foot of media. Adsorption re»lies upon attachment and is
affected by use of coagulants, the characteristics of the wastewater
(especially particle size), shear strength and driving force, adhesive-
ness of the suspended solids floe, and the characteristics of the filter
media.
DESCRIPTION OF EQUIPMENT
Filtration processes vary in the type of equipment used, the manner
that the driving force is applied to the filter, and the method of
backwashing.
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Types of Filters
The four most common types of filtration equipment used for treat-
ment of metal wastes are granular deep-bed filters, diatomaceous earth
filters, cartridge filters, and pressure filters. Deep bed filters
consist of a basin or tank with an 18 to 30 inch layer of sand or other
fine granular material supported by an underdrain system and operated
under either a gravity head or pressure head. Deep granular filters are
generally applicable for the removal of suspended solids in the 5-50
mg/L range, but can handle suspended solids concentrations up to 1000
mg/L and provide about a 90 percent solids removal.
Pre-coat filters consist of a number of porous septa supportirc a
thin layer of filter media. The filter medium is generally diatomaceous
earth and pre-coat filters generally operate under a pressure head.
Pre-coat filters can handle high suspended solids concentrations pro-
vided solids concentrations remain constant. Precoat filters can pro-
vide up to 98 percent solids removal.
The use of cartridge filters for wastewater treatment is limited to
effluent polishing prior to wastewater recycling. Cartridge filters
consist of cartridges of porous material that are enclosed in a housing
and operated under a pressure head. Cartridge filters are limited to
wastewaters with low suspended solids concentrations, but, depending up-
on the pore size of the filter cartridge, can provide essentially com-
plete removal of suspended solids.
Pressure filters are also generally used for effluent polishing
after clarification. Pressure filters consist of sand media enclosed in
a housing and operated under a pressure head. Pressure filters can be
operated under a constant head or variable head. A variable head is
used often to achieve a constant flowrate.
I 65
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Driving Force
There are three basic filter operating methods, and they differ in
the way that the driving force is applied across the filter. These
methods are referred to as constant-pressure filtration, constant-rate
filtration, and declining rate filtration. For constant-pressure fil-
tration a constant driving force is applied across the filter for the
entire filter run. Because filter resistance is lowest at the start,
the flow rate is at its peak. As solids are captured, filter resistance
increases and the rate of flow decreases. This operating method is
seldom used because a large flow equalization basin is required to deal
with the change in flow during the filter run.
In constant-rate filtration a constant pressure is applied to the
filter, but filter resistance is modulated through control of the flow
rate using a flow control valve. At the start of the filter run the
flow control valve is nearly closed, then as solids accumulate, the flow
control valve is opened to compensate for the increase in filter resis-
tance. While storage capacity is minimized the initial and operating
costs for the rate controller are high and water quality is lower than
with declining rate filtration. The constant rate system is also waste-
ful of available head because excess head is lost in the controller.
Additionally the control valve may set up high frequency surges in the
filter bed.
Declining-rate filtration utilizes a bank of filters to moderate
the effect of increases in filter resistance. As the filters served by
a common header become dirty, the flow through the dirtiest filter drops
rapidly, increasing the driving force so that the other filters can
handle additional flow from the dirtiest filter. This method provides a
more gradual decrease in the rate of flow over the filter cycle and
provides a better effluent quality than with constant rate operation.
As with constant pressure filtration, a large upstream water storage is
needed.
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Backwashing
Once filter resistance exceeds the available driving force the
accumulated solids must be removed from the filter. In cartridge fil-
ters this process requires dismantling of the filter housing and re-
placement of the filter cartridges. For precoat filters the filter
layer is removed from the system by scraping the septa manually or by
washing either directly or by a reverse flow. For deep granular filters
and pressure filters, the media are washed and returned to service.
Backwashing of deep granular filters involves reversing the flow
through the filter at a rate sufficient to expand the filter bed. The
deposited material is then dislodged by hydraulic shearing action of the
water and abrasion of the grains of filter media. Where cleaning is
inadequate, mud balls, masses of filtered solids, develop and over time
will grow and sink deeper into the filter bed, increasing head loss and
decreasing effluent quality. Where backwash rates are inadequate to
thoroughly clean the filter, longer duration backwashes must be used (5
to 10 or at an extreme, 15 minutes) to provide the necessary cleaning.
Air scour is often used to assist in backwashing. Deep bed filters can
either be backwashed continuously or intermittently.
OPERATIONAL PROCEDURES
The objective of wastewater filtration is to achieve a high capture
of suspended solids and to minimize operating and power requirements
without constraining wastewater flow. To achieve this objective, the
operator should know how to perform the necessary calculations, perform
the required process monitoring, and understand the process control
variables or strategies.
Process Monitoring
To maintain the desired level of filtration performance, usually
measured by effluent suspended solids or metal concentration, the opera-
tor should perform the necessary monitoring and understand how the
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various parameters can be used to diagnose problems. The monitoring re-
quired to troubleshoot the filtration process is listed in Table 16.
Included in this table are the frequency of analysis and the reason for
monitoring the parameter.
The operation performance of the filtration process is defined by
the influent and effluent suspended solids, metal concentration or
turbidity, and the filtration rate. As a filter run progresses, the
captured solids increase the filter resistance and thus either increase
the head loss through the bed or decrease the flowrate through the bed.
Decreasing the flowrate through the bed will reduce the filtration
capacity of the bed. By operating at higher system pressures the rate
of flow can be maintained, but with metal hydroxide floes there is
considerable penetration into the filter and breakthrough can occur at
relatively low heads. While run lengths can be shortened to maintain a
higher rate of flow, the effects of downtime and backwashing become
increasingly important. Thus, filter operation focus is on obtaining
the longest possible filter cycle that is consistent with minimal solids
breakthrough, practical system head losses, and acceptable filtration
rates. Floe breakage at higher pressures can be partially compensated
for by use of alum or polyelectrolytes to condition the floe prior to
filtration.
Example Calculations
The calculation used most often to troubleshoot the filtration
process is the filtration rate. The mathematical formula for filtration
rate is
Filtration rate (gpm/ft2) : Flow rate (gpm)
Surface area of filter (ft2)
Consider the following example calculation. Determine the filtra-
tion rate for a system which has two filters and each filter has a
5-foot diameter. The flow rate is 60 gpm.
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TABLE 16
FILTRATION
PROCESS MONITORING REQUIREMENTS
Parameter
Frequency
Comment
1. Influent flow
2. Influent TSS
3. Effluent TSS
Continuously
Weekly
Daily
4. Headloss
5. Filter run time
6. Backwash flowrate
7. Filter aid
(type and dosage)
8. Influent and effluent
metal concentration
Continuously
Each run
Continuously
Daily
Regularly
- To determine filtration
rate.
- To determine mass loading
to filters.
- To troubleshoot low filter
run problem.
- To determine filter
performance.
- To determine whether to
backwash filters.
- To determine when to
backwash filter.
- To identify short run
periods.
- To optimize backwash
flowrate and duration.
- To optimize type and
dosage.
- To determine performance.
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60
Filtration rate =
2 X ( X 52)/4
Filtration rate =1.53 gpm/ft
The recommended filtration rates for granular filters are shown
below.
Type Filtration
Slow Sand 0.050 - 0.130 gpm/ft
2
Rapid Sand 1.00 - 1.26 gpm/ft
High Rate Mixed Media 2.00 - 3.00 gpm/ft
Higher filtration rates can be obtained with cartridge filters or
pressure filters. Generally these filters are limited by a maximum
pressure drop across the filter of 60 psi.
While most systems are designed to operate at the correct filtra-
tion rate, problems can occur when one or more filtration units are out
of service due to backwashing, replacement of media, or broken equip-
ment.
Process Control Strategies
Filter operation is generally automatic and requires limited oper-
ator control. Possible process variables are thus limited to filter run
time, length and duration of backwash, and chemical conditioning.of the
influent wastewater.
Filter Run Time—
The length of the filter run is generally determined by the time
required to reach a predetermined head loss or is set at a predetermined
length of time. Head loss control is the most commonly used because it
minimizes backwashing or filter renewal. Increasing the final head loss
point allows longer filter runs but results in lower filter rates and
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possible solids breakthrough. The head loss point setting is also
limited by the maximum available system pressure.
Length and Duration of Backwash—
Effective cleaning of the filter media in deep granular filters is
very important to successful plant operation. If the bed is not cleaned
well, solids can accumulate, leading to bed cracking and the formation
of .mud balls. Because all filter backwashing water must be returned for
treatment excess backwashing should be avoided. The actual requirements
for backwashing will vary depending upon the nature of the wastewater
and filter aids being used.
Chemical Conditioning of Influent—
Filter performance can be improved by adding filter aids such as
polymer and/or alum. These act to strengthen the floe, control penetra-
tion of the floe into the filter bed, and improve solids capture on
precoat filters. As a result final solids are reduced and allowable
flow rate can be increased.
The amount of filter aid required varies with influent wastewater
characteristics and should be determined through testing. The optimum
dose should be based upon desired filter rate at-the end of the filter
run.
TYPICAL PERFORMANCE VALUES
The performance of the filtration process can be measured by the
suspended solids level of the liquid effluent from the filtration pro-
cess. A well-operated filtration process produces an effluent with
low-suspended solids concentrations; removal efficiences of 90 to 99
percent are common.
TROUBLESHOOTING GUIDE
The guide shown in Table 17 should be used to troubleshoot the fil-
tration process. The table has been divided into three sections to
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TABLE 1 7
FILTRATION TROUBLFSHOOTING GUIDE
{PRESSURE FILTFRS-SAMD )
PROBABLE CRUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 1: High headless through filter bed.
la. Filter clogged
with solids.
Headless through filter.
Duration of filter run.
Solids concentration and
flow rates to filter.
-4
to
High headless will
indicate that solids are
clogging filter and
filter requires back-
washing.
Duration of filter run
as compared to other
filter runs will indi-
cate if other problems
exist.
Solids concentration and
flow rates will indicate
if unusual conditions
exist in plant that will
shorten run time of
filters.
Peroove filter from service
and backwash.
If filter run is high com-
pared to others, then refer
to 3a, 3e, and 3f.
Reduce solids concentration
(see Clarification Trouble-
shooting Guide) or reduce
flow-rate.
OPERATING PROBLEM 2: High headloss through filter just backwashed.
2a. Insufficient backwash
of filter.
Backwash flow rate.
Backwash pump. Check
impeller clearance.
Check for partial
blockage of impeller.
Backwash flow valve.
Plugging in bottom
spargers of filters.
Insufficient rate of back-
wash water will not allow
solids to be removed from
filter.
Defective pump is often
the cause of loss of flow
rate.
Defective flow valve can
cause loss of flow.
Plugged spargers can
restrict backwash flow
into filters.
Increase backwash flow rate
to desired value.
If pump is defective, it
will have to be dismantled
and repaired.
Defective flow control valves
will have to be dismantled
and repaired.
Plugged spargers can some-
times be cleared by pro-
longed backwash!ng. If this
fails, the spargers must be
removed and manually cleaned
or replaced.
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TABLE 17
(Continued)
FILTRATION TROUBLESHOOTING GUIDF
(PRESSURE FILTFRS-SAND)
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
Defective valves in
backwash system.
Instrument air pressure
to backwash control
system.
Suction piping of pumps
or screens inside back-
wash water supply tank.
Defective valves could
restrict backwash flow
into filters.
Insufficient instrument
air pressure to backwash
controls or valves can
limit the operation of
the system.
A blockage of suction
piping or dirty suction
screens can cause a loss
of backwash flow rates.
Check valves for open and
closed position. Valves
that are not functioning
properly will have to be
dismantled and repaired.
Reset individual pressure
regulators to proper
setting.
Backflush suction lines of
pump. Remove and clean
suction screens.
CO
Duration of backwash.
Filter skipping backwash
cycle.
Complete backwash re-
quires specified flow
rate for a specified
period of time.
If filter is completely
automated a defective
circuit can cause the
filter to skip the
backwash cycle.
Increase backwash time.
Defective timers may have
to be replaced.
Visually observe a complete
filter cycle. Have defective
circuits repaired. Backwash
cells manually.
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TABLE 17
(Continued)
FILTRATION TROUBLESHOOTING GUIDE
(GRANULAR DEEP EED FILTERS)
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 1: High headless through filter bed.
la. Filter needs
backwashing.
Headloss through filter.
- High headless will indi-
cate solids accumulating
in filter and filter
requires backwashing.
Remove filter from service
and backwash it.
OPERATING PROBLEM 2: High headloss through a filter just backwashed.
2a. Insufficient backwash
time to thoroughly
clean the filter
media.
2fo. Inoperative surface
wash arm (if
applicable).
2c. Inoperable air
scouring system
(if applicable).
2d. Rapid accumulation
of solids on the
top surface
of the media due to:
i) Inadequate prior
clarification for
sand filters.
ii) Excessive filter
aid dosages in
dual or mixed-
media filters.
Headloss greater than
normal and influent
suspended solids.
Visually inspect surface
wash arm.
Inspect pressure setting
and aeration pattern.
Measure influent TSS
concentration.
Evaluate filter aid
dosage and type.
High initial headloss
(1 - 2 ft) even with low
suspended solids con-
centration will cause
short filter runs.
Surface wash arm must
turn freely.
Pressure setting could
be too high or low and
air ports could be
plugged.
High TSS concentration
will reduce filter run
time.
Filter aid dosage and
type will affect rate
of headloss build-up.
Increase the setting on the
backwash timer to provide
longer backwash period.
Repair suface wash arm.
Adjust pressure to correct
setting.
Unplug air ports.
Improve clarification
performance.
Reduce or eliminate filter
aid dosage.
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TABLF 17
(Continued)
FILTRATION TROUBLESHOOTING GUIDE
(GRANULAR DFEP BED FILTFRS)
PROBABLE CAUSE
CHFCK OP MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 3: Short filter runs.
3a. See Item 2d.
3b. Insufficient filter
backwash.
- See Item 2d.
- Check backwash rate and
duration.
Check air scour or surface
wash (if applicable).
- See Item 2d.
Low backwash or short
backwash duration can
reduce filter runs.
Insufficient air scour or
inoperable air wash can
reduce fiIter runs.
- See Item 2d.
- See Item 2a.
- See Items 2b and 2c.
OPERATING PROBLEM 4: Filter effluent turbidity increases suddenly but filter headless is low.
Ul
4a. Inadequate dosage
of polymers as filter
aid.
4b. Coagulant feed system
malfunction.
4c. Change in influent
characteristics.
Run jar tests.
Check chemical feeders.
Check pH adjustment
and clarification.
Jar tests will indicate
needed dosage of polymer.
Excessive turbidity can
be caused by chemical
feeder malfunction.
Change in pH can change
solubility and increase
turbidity.
Adjust polymer dosage.
Repair feeders.
See pH Adjustment Trouble-
shooting Guide and
Sedimentation Trouble-
shooting Guide.
OPERATING PROBLEM 5: Mud ball formation.
5a. Inadequate backwash
or surface wash.
5b. Media needs replacing.
- Check backwash flowrate and
duration.
- Look for cementaceous
media.
Backwash flowrate and
duration may be too low.
Cementaceous media will
reduce filter run time.
Provide backwash flow rate
up to 20 gpm/sq.ft,, and
maintain proper auxiliary
scour (surface wash).
Replace media.
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TABLE 17
(Continued)
FILTRATION TROUBLESHOOTING GUIDE
(GRANULAR DEEP BED FILTERS)
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 6: Loss of media during backwashing.
6a. Excessive flows used
for backwashing.
6b. Auxiliary scour
excessive.
6c. Air bubbles attach-
ing to anthracite
causing it to float.
- Check backwash rate.
- Check backwash program.
Check for floating
anthracite.
High backwash can cause
solids carryover.
Excessive air scour can
cause solids carryover.
Loss of anthracite can
reduce effectiveness of
filter system.
- Reduce rate of backwash flow.
Cut off the auxiliary scour
2 min. before the end of the
main backwash.
- Reduce air scour.
CTi
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TABLE 17
(Continued)
FILTRATION TROUBLESHOOTING GUIDE
(PRESSURE FILTERS-CARTRIDGE)
PROBABLE CAUSE
OPERATING PROBLEM 1 :
la. Cartridge plugged
with solids.
OPERATING PROBLEM 2:
CHECK OR MONITOR REASON ' CORRECTIVE ACTION
High differential pressure across filter.
- Filter cartridge. - Plugged cartridge. - Replace cartridge.
New cartridge but -solids breaking through. Low differential pressure.
2a. Defective "O" ring
or cartridge seal.
2b. Hole in cartridge.
- Cartridge seal.
- Cartridge.
Solids could be bypassing
cartridge.
Solids passing through
hole.
- Replace seal.
Replace cartridge.
-J
OPERATING PROBLEM 3t Low differential pressure-solids passing through cartridge - no holes in cartridge - seals not defective.
3a. Wrong cartridge.
- Cartridge type.
Particles too small for
cartridge.
Change cartridge type.
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represent the different types of filtration equipment. Each type of
equipment is subject to its own kind of operating problems; most prob-
lems have to do with high head loss, short cycle times, backwashing
problems, or inadequate solids capture.
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SECTION 13
GRAVITY THICKENING
INTRODUCTION
Gravity thickening is a commonly used process for removing water
from sludges generated during wastewater treatment, thereby concentrat-
ing them prior to dewatering or disposal. Sludges are thickened
primarily to decrease the capital and operating costs of subsequent
sludge processing steps by substantially reducing the volume. As shown
in Figure 23, thickening from one to two percent solids concentration,
for example, decreases the sludge volume by fifty percent. Further
concentration to five percent solids reduces the volume to one-fifth of
its original volume.
In plants in which thickening is the final treatment before sludge
disposal, good operation of the gravity thickener can minimize final
disposal costs by reducing the volume of sludge to be disposed. The
degree of thickening can also affect the performance of downstream
processes, particularly dewatering, since the efficiency of process
equipment is often related to the concentration of solids in the feed
sludge.
THEORY OF OPERATION
Gravity thickeners work on the principle that sludge solids are
more dense than water and, under quiescent conditions, will settle and
become concentrated over a period of time. As the sludge settles, it
forms an interface with the clear water above. In a thickener the
solids layer below this interface is referred to as the sludge blanket.
179
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100%T
UJ
§ 50%+
20%-*
Figure 23,
2%
PERCENT SOLIDS
Effect of gravity thickening upon solids concentration,
180
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Thickening, concentration, or compaction takes place in the sludge
blanket as a result of compression caused by the weight of solids above
and by the release of entrapped water. As the sludge becomes more
concentrated, the interface moves downward. With time, the interface
moves more and more slowly since it becomes progressively more difficult
to compact solids and release water entrapped in the sludge. This
process is illustrated in Figure 24.
Sludge is removed by pumping from the bottom of the thickener once
the desired concentration has been achieved. The supernatant, or clear
liquid, is usually sent back to an upstream treatment process since it
is rarely of good enough quality to be discharged directly.
Often it is necessary to add chemical coagulants or settling aids
to the sludge to improve its thickening characteristics and to maintain
a clear supernatant. Polyelectrolytes are most commonly used for con-
ditioning, although chemicals such as lime, alum, and ferric chloride
are also used. The choices of conditioning agent(s) and optimum dosage
rates are made experimentally in jar tests and through operating expe-
rience.
All gravity thickeners operate in one of two ways: either as a
batch process or as a continuous process. In batch thickeners, sludge
is pumped into the thickener and then sufficient time is provided for
settling. Once the desired concentration is achieved, based upon either
the sludge blanket (interface) level or the amount of time elapsed since
batch thickening began, clear water is decanted off the top until only
the sludge blanket remains. The sludge is then pumped to the next
treatment process or to final disposal, making the thickener available
for a new batch of sludge.
Continous thickeners operate much like clarifiers. Sludge enters
at mid-depth, usually in a center well, and is removed by pumping from a
hopper or collection box at the bottom. Sludge removal can be either
continuous or intermittent with sludge pumps operating on a timed cycle.
The latter mode of operation is more common. The supernatant or clear
181
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0
UJ
o
<
u.
(Z
iu
Rgure 24.
TIME (minutes)
Typical curve of effect of time on sludge compaction.
182
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liquid effluent continuously passes over weirs at the top of the thick-
ener. The most basic difference between the two types of thickeners is
in formation and behavior of the sludge blanket.
The concentration of solids within a continuously operated thick-
ener is shown in Figure 25. There are three very distinct zones which
develop in such a thickener. The clear zone on top is composed of
liquid that eventually becomes the effluent or supernatant escaping over
the weirs. This liquid has a very low solids concentration. The next
zone is called the sedimentation zone; it is characterized by a fairly
uniform solids concentration. Below the sedimentation zone is the
thickening or compaction zone, characterized by an increasing solids
concentration to the point of sludge discharge.
The sludge blanket in a continuous thickener is defined as begin-
ning at the top of the sedimentation zone. Looking into an operating
thickener, one can often see the sludge blanket below the clear efflu-
ent. The sludge blanket depth is the main operational control that a
treatment plant operator has over a thickener. The blanket can be
lowered by increasing the underflow sludge pumping rate (or reducing the
cycle time on intermittent pumping systems) and blanket depth can be
increased by decreasing the underflow rate.
DESCRIPTION OF EQUIPMENT
Most gravity thickeners are circular tanks, either concrete or
steel, with sloped bottoms to help in moving the thickened sludge to a
hopper or collection box from which it is removed by pumping. Sludge
pumping is either continuous or on an intermittent cycle, depending upon
the size of the unit. A rotating rake-arm equipped with scrapers is
usually provided to push the sludge toward the center and into the
hopper. Sometimes pickets are attached to the rake arm to gently agi-
tate the thickened sludge and help release water entrapped in the
sludge. _ Sludge enters the clarifier in a localized area that is en-
closed by baffles to help maintain the quiescent conditions required
for thickening. Relatively clear effluent passes over weirs at the top
183
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FEED
EFFLUENT
CLEAR ZONE
SEDIMENTATION ZONE
COMPACTION
ZONE
SOUDS CONCENTRATION
UNDERFLOW
Figure 25. Liquid zones in a continuously operated thickener.
184
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and usually is recycled back to a preceding treatment process. Some
continuous thickeners are rectangular or even square basins, in which
case they generally have moving flights to push sludge toward one end
where it falls into a hopper or collection box and is removed by pump-
ing.
Batch thickeners are similar to continuous thickeners except that
they lack influent baffles and effluent weirs. Since sludge is added
batchwise rather than continuously, influent baffles are not necessary
in batch thickeners. Likewise, effluent weirs are not needed. Batch
thickeners also have sloped bottoms and a rotating arm equipped with
pickets and scrapers to help compact the sludge. The thickened sludge
is pumped directly out of the bottom after the supernatant is decanted.
OPERATIONAL PROCEDURES
The main objective in operating thickeners is to provide the thick-
est possible sludge without upsetting the quality of the supernatant.
This objective usually is accomplished by providing the maximum time
possible for thickening to occur, or in other words, the longest pos-
sible solids residence time. In batch thickeners, one controls the
settling time for each batch, taking into account the number of batches
that must be thickened in a given period of time.
In continuous thickeners, control of the time available for thick-
ening is usually achieved by adjusting the underflow pumping rate or
cycle time to maintain a constant sludge blanket depth. Alternatively,
the underflow rate can be controlled to maintain a constant solids
concentration in the thickened sludge, which indirectly determines the
average solids residence time within the thickener.
Process Monitoring
The main parameter used in evaluating thickener performance is the
solids concentration in the thickened sludge.
185
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Continuous gravity thickeners are usually designed to meet two
conditions - maximum hydraulic overflow rate and a maximum solids load-
ing. The overflow rate is generally expressed as a surface loading rate
with units of gallons per day per square foot of thickener surface area
(gal/ft /day). A maximum overflow rate is established to insure that
adequate residence time is provided for a sludge blanket to form and for
solids separation or clarification to occur. Otherwise, the supernatant
would contain an unacceptably high solids concentration. The maximum
solids loading rate is determined by how well the sludge compacts, and
is established to insure adequate time for solids thickening or compac-
tion to occur in the sludge blanket layer. The solids loading is also
expressed as a surface loading, with units of pounds of solids per
2
square foot of surface per day (Ib/ft /day).
The operation of gravity thickeners is fairly simple, provided the
operator has sufficient data to allow a determination of the cause of
problems when they occur. Even small changes in sludge characteristics,
temperature, pH, flow rates, or other factors can reduce thickener
performance. To determine the cause of a problem, a complete record of
operating data is necessary. With such information, the operator can
compare periods of good and poor thickener performance and easily iden-
tify changes in operating conditions which may be causing poor thicken-
ing. The data which should be monitored routinely are presented in
Table 18.
In addition to the data collected above, several calculated para-
meters can be used to characterize and monitor thickener performance.
Among these are sludge volume ratio, solids loading rate, surface over-
flow rate, and sludge wasting rate.
The sludge volume ratio (SVR) is an estimate of the average solids
residence time or thickening time provided in a continuous thickener.
It is calculated by dividing the sludge blanket volume by the underflow
pumping rate and is usually expressed in units of hours or days.
186
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TABLE 18
GRAVITY THICKENING
PROCESS MONITORING REQUIREMENTS
Parameter
Frequency
Comment
1. Influent suspended solids
concentration (mg/L).
2. Underflow suspended solids
concentration (mg/L).
3. Sludge blanket depth (ft or
meters).
4. Effluent or supernatant
suspended solids concentra-
tion (mg/L).
5. Chemical dosage rate
(ppm or mg/L).
6. Influent flow rate (m /min
or gpd).
7. Underflow pumping rate
(gpm or m /min).
Daily
Daily
Daily
Daily
Daily
Continuously
Daily
To determine solids
loading and removal
efficiency.
To calculate solids
loading to downstream
treatment processes.
To determine whether
sludge is accumulating
in clarifier.
To determine removal
efficiency.
To adjust/optimize
chemical dosage as
necessary.
To calculate solids
loading.
To determine sludge
loading to downstream
treatment processes.
187
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The solids loading rate is the mass of suspended solids applied to
the thickener each day divided by the thickener surface area. It has
2 2
the units of Ib/ft /day or kg/m /day.
The surface overflow rate is the total volume of water passing over
the effluent weirs in a day divided by the thickener surface area. It
is expressed in units of gal/'ft /day or L/m /day.
The sludge wasting rate refers to the mass of suspended solids re-
moved in the underflow each day, expressed on a dry weight basis. It is
calculated by multiplying the average underflow pumping rate by the
underflow suspended solids concentration and has units of Ib/day or
kg/day.
Example Calculations
The following examples show how the various operating parameters
are calculated. Consider a gravity thickener for which the following
data have been collected.
(1) Thickener diameter = 20 feet
(2) Average sludge blanket depth = 8 feet f
(3) Underflow sludge pumping is intermittent. Pumps are on for 20
minutes every half hour and pump at a rate of 15 gallons per
minute.
(4) Influent flow rate = 25 gpm
(5) Influent suspended solids (TSS) concentration = 15,000 mg/L
(6)' Average underflow pumping rate = 5 gpm
(7) Underflow suspended solids concentration = 72,000 mg/L
188
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Sludge Volume Ratio—
Thickener Surface Area = (Diameter/2) (3.14) = 314 square feet
Sludge Blanket Volume = (Thickener Surface Area)(Blanket Depth)
= (314 square feet)(8 feet) = 2,512 cubic feet in blanket
Conversion From Cubic Feet to Gallons = 7.48 gallons/cubic foot
(2,512 cubic feet)(7.48) = 18,792 gallons in blanket
Average Underflow Pumping Rate = (Pumping Rate)(Pumping Time)/
(Cycle Time) = (15 gpm)(10 minutes)/(30 minutes) = 5 gpm
SVR = (Sludge Blanket Volume)/(Average Underflow Pumping Rate)
= (18,792 gallons)/(5 gpm) = 3,758 minutes
(3,758 minutes)(1,440 minutes per day) = 2.61 days
Solids Loading Rate—
2
Thickener Surface Area = (Diameter/2) (3.14) = 314 square feet
Daily Flow = (25 gallons/minute)(1,440 minutes/day) = 36,000 gpd
(36,000 gpd)/(1,000,000) = 0.036 Mgd
Mass of Influent Solids per Day = (Infl. Flow)(Infl. TSSM8.34)
= (0.036 Mgd)(15,000 mg/L)(8.34) = 4,504 Ib solids per day
Solids Loading Rate = (Mass of Influent Solids/Day)/(Thickener
Surface Area) = (4,504 Ibs solids per day)/(314 sq ft)
=14.3 Ib/sq ft/day
Surface Overflow Rate--
Daily Effluent Flow = (Influent Flow Rate)-(Average Underflow
Pumping Rate) = (25 gpm) - (5 gpm) = 20 gpm
(20 gpm)(1,440 minutes per day) = 28,800 gpd
Surface Overflow Rate = (Daily Effluent Flow)/(Thickener Surface
Area) = (28,800 gpd)/(314 square feet) = 92 gal/sq ft/day
Sludge Wasting Rate—
Daily Volume of Sludge Underflow = (5 gpm)(1,440) = 7,200 gpd
(7,200 gpd)/(1,000,000) = 0.0072 Mgd
Sludge Wasting Rate = (Daily Underflow Volume)(Underflow Solids
Concentration)(8.34) = (0.0072 Mgd)(72,000 mg/L)(8.34)
= 4,323 Ib solids per day
189
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For the influent mass of solids = 4,504 Ib/day,
(4,323)/(4,504) x 100 = 96.0 % of solids are in underflow
Process Control Strategies
The simplest type of thickener to operate is a batch thickener
since the only operational control is the amount of time provided before
decanting off the clear liquid. The optimum time must be determined
from operating experience and will depend upon the desired underflow
solids concentration and the total amount of sludge that must be thic-
kened in a given period of time with the available equipment.
In a continuous gravity thickener, the depth of the sludge blanket
(or position of the sludge-liquid interface) is the main process vari-
able used for control. The sludge blanket can be lowered by increasing
the underflow sludge pumping rate (or reducing the cycle time on inter-
mittent pumping systems) and can be raised by decreasing the underflow
rate. Lowering the sludge blanket essentially reduces the average
solids residence time within the thickener and, as is the case in batch
thickeners, this usually results in a lower solids concentration in the
underflow. Increasing the sludge blanket depth results in a longer
solids residence time which usually results in a higher underflow solids
concentration.
One advantage of maintaining a lower sludge blanket is that some
extra sludge storage capacity is provided within the thickener for per-
iods of high sludge loadings or for occasions when downstream equipment
is being serviced or repaired.
Sometimes thickeners are operated to maintain a minimum sludge
volume ratio (SVR). While the SVR is helpful in understanding the
operation of a thickener, its use as an operational control parameter is
limited unless the underflow solids concentration and other factors are
also considered. For example, the SVR could increase while at the same
time the underflow solids concentration drops, if the influent solids
190
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concentration decreases or if a problem occurs with the operation of the
chemical addition system.
Solids loading and solids wasting rates are useful in several ways.
The solids wasted each day should be almost the same as the solids fed
to the thickener. If not, one of three things must be happening.
Either solids are accumulating in the sludge blanket, solids are being
lost from the sludge blanket, or solids are leaving the thickener with
the effluent. On a short-term basis, only the last of these possibil-
ities is really to be avoided, since a high solids concentration in the
supernatant defeats the purpose of thickening and can cause problems in
other treatment processes. Over a longer period of time changes in the
sludge blanket can also cause problems. As discussed earlier, there are
limits to the range in which the sludge blanket can be maintained with-
out reducing underflow solids concentration too much or increasing
solids to the point that underflow pumping becomes difficult.
TYPICAL PERFORMANCE VALUES
Performance of gravity thickeners can vary considerably depending
upon design features such as solids loading and surface overflow rates.
Another factor affecting performance is the nature of the sludge. Metal
hydroxide sludges are lighter and do not thicken as well as lime sludges
that are high in calcium carbonate concentration. A gravity thickener
is designed to achieve about 95 percent solids capture and will produce
a thickened sludge ranging from 4 to 10 percent solids. Sludges much
thicker than 10 percent may be achievable, but are often difficult to
pump and handle. As a minimum, the thickener should about double the
solids concentration of the sludge.
TROUBLESHOOTING GUIDE
The problems which are commonly associated with gravity thickener
operation have been summarized in the form of a troubleshooting guide in
Table 19. Specific details on pumps, sludge rake drives, and other
191
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TABLE 19
GRAVITY THICKENING TROUBLFSHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 1: Thickened sludge is too thin.
la. Underflow pumping
rate is too great.
1b. Surface overflow
rate is too great
in continuous
thickener.
- Blanket depth and pumping
rate.
Check for high solids in
effluent and increased
feed flow rate.
Low blanket indicates
pumping rate is too
high, may be confirmed
if pumping rate has
been increased recently.
Increased overflow rate
results from higher flows
and usually results in
greater solids losses in
the effluent.
Decrease pumping of
thickened sludge to main-
tain a blanket volume
between 1/4 and 1/2 of
total thickener volume.
Reduce flow to thickener
if possible to keep a
maximum surface overflow
rate of 600-800 gpd/ft .
(See also Items 1e and 3a).
V.O
to
1c. Insufficient time
for settling in
batch thickeners.
Id. Short-circuiting
of flow through
thickener.
1e. Improper chemical
dosage or wrong
chemical being
used.
Check the time allowed
for settling against
previous data and
perform batch settling
tests.
Check for high effluent
solids concentrations.
Inspect surface of
clarifier for evidence
of uneven flow and
solids discharge.
Check level of weirs.
Check chemical addition
system for malfunction
and check chemical flow.
To determine if suf-
ficient time is being
provided for settling
and if sludge character-
istics have changed.
Short circuiting reduces
the time available for
settling and results in
higher effluent solids.
Problem may be equipment
malfunction or improper
setting. If neither,
the dosage or chemical
used must be changed.
If necessary and possible,
allow more time per batch
for settling and thickening
to occur.
Level weirs and repair or
adjust influent baffles to
eliminate short circuiting.
Repair, replace, or adjust
equipment if this is the
problem. Otherwise,
perform jar tests to select
new chemical and/or dosage
rates to be used.
If. Sludge collection
or conveying
equipment not
functioning
properly.
Check for non-uniform
blanket and rat-holing
(coning). Check to see
that drive is working
properly. Use probe to
check for broken rake or
pickets.
Sludge may be accumu-
lating elsewhere in
thickener than the
sludge hopper or broken
rakes and pickets may
cause water to be
entrapped in thickened
sludge.
Repair or replace
broken equipment, drain
tank if necessary.
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TABLE J9
(Continued)
GRAVITY THICKENING TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK CR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 2: Torque overload on sludge collection equipment.
Ul
2a. Heavy accumulation
of sludge in bottom
of thickener -
sludge too thick,
2b. Foreign object
jamming equipment.
2ce Mechanical prob-
lems such as
insufficient
lubrication.
Check sludge blanket depth
and underflow solids
concentration.
Inspect all visible parts
for foreign objects.
Probe along front of under-
water collection equipment.
- Check maintenance records,
lubricant reservoirs, and
free movement of parts.
Sludge can get too thick
to move, especially if
blanket is very thick.
To determine the presence
and location of foreign
objects.
Poor maintenance, such as
improper lubrication, can
cause friction that
increases torque.
Agitate sludge in front
of collection equipment
using rod, water jet,
or air.
Remove foreign object.
Use grappling hook, if
possible, for objects
underwater. Drain tank
if necessary.
Correct any problems and
and revise routine
maintenance procedures to
to prevent future problems.
OPERATING PROBLEM 3: Plugging of sludge pumps or pipelines.
3a. Underflow sludge
concentration too
high due to
insufficient
pumping.
- Check blanket level
and underflow solids
concentra tion.
Sludge can become too
thick to pump.
Flush out plugged lines
with water, making sure all
valves are open. If this
doesn't work, try 2a above.
Increase underflow pumping
rate or decrease pump
cycle time to reduce
blanket level and underflow
solids concentration.
OPERATING PROBLEM 4: Poor solids capture.
4a. Overflow rate
too high.
4b. Short circuiting
of flow through
thickener.
- See Item 1b.
- See Item Id.
- See Item 1b.
See Item Id.
— See Item 1b.
- See Item 1d.
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TABLE 19
(Continued)
GRAVITY THICKENING TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
4c. Improper chemical
dosage or wrong
chemical.
4d. Excessively high
sludge blanket
due to insufficient
underflow pumping
rate.
- See Item 1e.
Check blanket level and
underflow pumping rate.
See Item 1e.
A high sludge blanket
can cause carryover of
solids in effluent.
See Item 1e.
Increase underflow
pumping to reduce blanket
level to half or less of
total thickener volume.
OPERATING PROBLEM 5s Changing sludge blanket level at constant underflow pumping rate.
5a. Changing influent
flow rates or
solids loadings.
Influent, effluent, and
underflow rates and solids
concentrations.
- To isolate the causes of
the fluctuations and
determine how rapidly
they occur.
If underflow solids con-
centration and effluent
quality are acceptable, do
nothing. If either is in-
adequate, make adjustments in
underflow rate to achieve an
acceptable average condition
or, if possible, even out
flow rate to thickener.
-------
equipment can be found in the manufacturer's literature. The two pre-
dominant problems considered in Table 19 are inadequate thickening of
the sludge and problems with sludge blanket level.
195
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SECTION 14
BELT FILTER PRESSES
INTRODUCTION
The treatment of metal plating wastewater often generates dilute
sludges during treatment processes such as metal precipitation. These
sludges are difficult to dispose of because of their volume and their
liquid nature. It is therefore advantageous to dewater the sludges.
Dewatering reduces volume and weight of sludges and allows them to be
handled as solids.
A belt filter press is a device for accomplishing sludge dewater-
ing. The process produces a solid cake and a relatively clean water
stream called the filtrate. Often belt filter presses used for dewater-
ing are preceded by a gravity thickener or centrifuge to increase the
solids concentration of the sludge fed to the filter. This combination
helps to maximize the solids content of the cake produced.
THEORY OF OPERATION
Filtration for dewatering is a process whereby solids are separated
from a liquid by passing the liquid through a porous medium on which the
solids remain, eventually building up to form a cake that is removed for
disposal. The formation of a solids cake and the fact that solids are
removed primarily on the surface of the medium rather than throughout
its depth are two distinguishing features that characterize this type of
filtration. Both features are important since the object of dewatering
is to maximize the recovery of solids in a concentrated form.
196
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DESCRIPTION OF EQUIPMENT
The belt filtration process includes three basic operational
stages: chemical conditioning of the feed slurry, gravity drainage to a
nonfluid consistency, and compaction of the previously dewatered sludge.
These stages are shown in the simple belt filter press shown in in
Figure 26. Although present-day belt presses are more complex, they
follow the same principles indicated in Figure 26.
Chemical conditioning is essential for successful and consistent
performance of the belt filter press, as for other dewatering processes.
As shown in Figure 26, a flocculant (usually an organic polymer) is
added to the sludge prior to the sludge being fed to the belt press.
Free water then drains from the conditioned sludge in the gravity drain-
age stage of the press.
Following gravity drainage the sludge enters a contact zone usually
consisting of two belts. The sludge is initially gently pressed between
the two belts and carried passed a series of rollers with generally de-
creasing diameters. This stage subjects the sludge to continuously in-
creasing pressure and shear forces. Progressively, more and more water
is expelled throughout the roller section to the end where the cake is
discharged. A scraper blade is often employed for each belt at the dis-
charge point to remove the cake from the belts.
After scraping the cake from the belts, the belts are subjected to
a spray wash to clean any remaining solids from the belt surface.
Usually treated wastewater is used as a water source. The spray water
is then combined with the filtrate and returned to the influent of the
treatment plant.
OPERATIONAL PROCEDURES
The objective of operating a belt filter press is to concentrate
sludges into a dry cake suitable for disposal. The filter press also
produces a filtrate that must be maintained relatively free of solids.
197
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HORIZONTAL
DRAINAGE
SECTION
ROTARY DRUM
CONDITIONER
FINAL
OSWATERING
SECTION
DIS-
CHARGE
Figure 26.
A simple belt filter press.
198
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Excessive solids in the filtrate will get recycled through the treatment
process and may adversely affect other treatment operations.
Process Monitoring
The primary criteria for evaluating the performance of a belt
filter press are percent solids in the filter cake and the percentage of
total solids entering the filter press that are captured in the cake.
The calculation of these parameters and other parameters necessary for
successfully operating a filter press are listed in Table 20.
The above parameters, with the possible exception of filtrate flow
rate and total dissolved solids concentration, should be measured any
time the belt press is used. Filtrate flow rate and total dissolved
solids concentration may be measured less frequently but still should be
measured approximately monthly. In addition the belt speed and the type
and application rate of chemical conditioner should be recorded.
Example Calculations
Influent Suspended Solids—
Influent suspended solids are often difficult to measure directly
in thick sludges. Therefore this parameter is often calculated by
measuring the total solids in the influent and subtracting the filtrate
total dissolved solids. If possible the filtrate total dissolved solids
sample should be collected prior to the addition of wash water.
Percent Capture--
Percent capture is the percentage of influent solids that are
captured in the cake. Percent capture is calculated as follows:
% Capture = 100 x (1 - Filtrate SS x Filtrate Flow
Influent SS x Influent Flow
An alternate, but less sensitive technique, for calculating percent
capture is available when details about the filtrate are unavailable:
199
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TABLE 20
BELT FILTER PRESS
PROCESS MONITORING REQUIREMENTS
Parameter
Frequency
Comment
1. Influent flow rate
(gpm or L/min).
2. Filtrate flow rate
(gpm or L/min).
3. Influent total solids
concentration (mg/L).
4. Filtrate suspended
solids concentration
(mg/L) .
5. Percent solids in
cake.
6. Net cake production
rate (Ib/hr, kg/hr,
yd /hr, or m /hr).
7. pH
8. Chemical conditioner
type and
concentration.
Con ti nuously
Monthly
Regularly
Monthly
Weekly
Weekly
Continuously
Weekly
To set chemical dosages
and
to set flow rate.
To determine mass (solids)
loading of filtrate.
To set chemical dosage and
to set flow rate.
To determine mass (solids)
loading of filtrate.
- To determine percent
capture.
- To set loading rate.
- High or low pH values can
increase solubility of
particles.
- To set chemical dosage.
200
-------
Wet Cake Production Rate x Percent Cake Solids
% Capture Influent SS x Influent Flow
When using the above equations care must be taken to convert all para-
meters to similar units.
As an example, if a belt filter press received 50 liters/min of
20,000 mg/L sludge and produced 190 kg/hour of 30% cake the percent
capture would be:
190 kg/hr x (1,000,000 mgAg) * (hr/60 min) x 30 QC
% Capture , 20,000 mg/L x 50 1/min' = 95
Conditioning Agent Application Rate—
As previously described, the pretreatment of the sludge with chemi-
cal conditioning agents is essential for good dewatering. Typically,
the conditioning agent is a polymer which is purchased in a dry or
liquid form. The polymer is then diluted with water to a concentration
that typically ranges from 1000 to 5000 mg/L (0.1 to 0.5 percent). The
operator is advised to see manufacturer's recommendations for concentra-
tions. This dilute polymer solution is then applied to the sludge on a
basis of mass of polymer to mass of sludge suspended solids. The appli-
cation rate of conditioner can be calculated as follows:
t Polymer Dosage x Influent Flow x Influent SS
Feed Rate = Polymer Solution Concentration
where polymer dosage is the ratio of the weight of polymer applied per
weight of influent solids and feed rate is the polymer pumping rate.
As an example, suppose a sludge stream containing 20,000 mg/L (2.0
percent) solids is being dewatered using a belt filter press at a rate
of 50 liters per minute. Jar testing has indicated that a polymer
dosage rate of five pounds of polymer per ton of dry solids is the
optimum dosage rate and the manufacturer recommends that the polymer be
diluted and premixed with water to a concentration of 5000 mg/L (0.5%
solution). The polymer feed rate could then be calculated as follows:
5 Ib ton 50 Ib 20,000 mg
ton 2000 Ib min L
Feed Rate = r— =0.5 L/min
mg/L
201
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One must use extreme care to make sure that the proper unit's and
conversion factors are used.
Process Control Strategies
The operator of a belt filter press has several operating variables
that are under his direct control. These variables and their effect on
dewatering are listed below.
Sludge Feed Rate—•
Increasing sludge feed rate will increase machine throughput if the
belt speed is high enough, but will also cause an increase in cake
moisture.
Conditioning Agent—
Proper selection of conditioning agent can dramatically increase
solids capture and percentage of solids in cake. Selection of polymer
is usually made based on jar test results.
Conditioning Agent Application Rate--
As polymer dosages increase, both cake solids and solids capture
increase until an upper limit is reached. If sludge is undercondi-
tioned, improper drainage occurs in the gravity drainage section, and
either extrusion of inadequately drained solids from the compression
section or uncontrolled overflow of sludge from the drainage section may
occur. Most belt presses can be equipped with sensing devices which can
be set to automatically shut off the sludge feed flow in case of under-
conditioning. Both underconditioned and overconditioned sludges can
blind the filter media. In addition, overconditioned sludge drains so
rapidly that solids cannot distribute across the belt. Vanes and dis-
tribution weirs included in the gravity drainage section help alleviate
the problem of distribution of overconditioned sludge across the belt.
Inclusion of a sludge blending tank before the belt press can also
reduce this problem.
202
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Belt Speed—
Increasing belt speed can increase machine throughput but will
typically result in lower cake solids content because both gravity
drainage time and press time are decreased. Conversely, decreasing belt
speed should result in a drier cake.
Belt Tension—
Increasing belt tension will promote a drier cake but solids cap-
ture typically will decrease and belt wear will increase.
Washwater Flow Rate—
An increase in washwater flow and/or pressure can increase cake
solids concentration if the washwater was not adequately cleaning the
belt, but also increases the flow requiring retreatment back to the head
end of the plant. The flow rate required for belt washing is usually 50
to 100 percent of the flow rate of sludge to the machine and the pres-
sure is typically 690 kPa (100 psi) or more. The combined filtrate and
belt washwater flow is normally about 1.5 times the incoming sludge
flow.
Belt Material-
Belts with different porosities are available. Increasing the
porosity will increase the solids content of the cake, but will decrease
the percent capture.
PH—
The pH of the sludge usually has little effect on polymers. The pH
can, however, significantly affect the sludge material. Most sludges
are metal precipitates and changing the pH can resolubilize a signifi-
cant fraction of the sludge. This resolubilization is most likely to
happen if sludges from two separate precipitations at different pH
levels were mixed.
Polymer Addition Point--
It is essential that • the polymer and sludge be properly mixed.
Mixing usually occurs in a small tank prior to the belt filter press.
203
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However, in some systems polymer is injected to the feed pipe to the
filter press. Changing the injection point can significantly change the
effectiveness of the polymer. Typically, increasing the distance be-
tween the injection point and the press will improve performance.
influent Solids Concentration—
In general, a thicker incoming sludge will produce a drier cake.
However, the initial solids concentration is not normally a process
control variable. It is customary, unless special conditions apply, to
deliver as thick a sludge as practical to the belt filtration unit.
TYPICAL PERFORMANCE VALUES
The performance of a properly operated belt filter press will vary
significantly depending primarily upon the material being dewatered.
Metal carbonates, such as those generated during lime precipitation,
dewater easily with cake solids concentration in the range of 35 to 45%
and capture ratios of over 95%. Hydroxide sludges usually do not
dewater as well as carbonates. Typical cake solids concentrations will
be 20 to 30% with capture ratios of 90 to 95%.
TROUBLESHOOTING GUIDE
The troubleshooting guide for the belt filter press process is
presented in Table 21. The major problem in belt filter press operation
is too thin or watery a sludge cake. The corrective methods involve
either mechanical corrections (belt speed, application rate, etc.) or
chemical changes (adjustments to the flocculation process, etc.). The
problem of excessive belt wear is also addressed is Table 21.
204
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TABLE 21
BELT FILTER PRESS
TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 1; Dewatered sludge not thick enough.
la. Sludge application
rate too high.
tb. Belt speed too high.
1c. Incorrect polymer
dose.
Id. Poor polymer-sludge
mixing.
1e. Belt tension Inade-
quate.
- Check sludge pumping rate.
Check belt speed.
Check polymer type, ini-
tial dilution, and flow
rate. Determine polymer
application rate on a
pound polymer to ton of
dry aolida
basis.
Check polymer-sludge
mixing.
- Check belt tension.
Excessive pumping causes
excessively thick cake
that does not have time
to dewater.
Sludge is carried through
belt press before it has
time to dry.
Proper polymer dosage is
essential for effective
dewatering.
Improper mixing of polymer
and sludge can completely
negate the benefits of
polymers.
Insufficient tension
will not force water
out of cake.
Adjust influent sludge
pumping rate.
- Adjust belt speed.
If polymer dose is much
less or much greater than
optimum dose, performance
will decrease. Use jar
test procedure to deter-
mine optimum dose.
Enhance mixing. Change
polymer addition point.
Increase belt tension.
If. Improper belt type.
tg. Insufficient wash
water or pressure.
Check belt type and manu-
facturer's recommendations.
Check belt to see if
it is clean after
washing.
Belt porosity can
directly affect cake
solids content.
A dirty belt can inhibit
the transport of water
through the belt during
dewatering.
Change belt.
Increase water pressure
and/or flow.
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TABLE 21
(Continued)
BELT FILTER PRESS
TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 2: Excessive belt wear.
2a. Improper alignment
of rollers.
2b. Sludge buildup on
bottom of belt or on
rollers causing Im-
proper alignment.
2c. Belt tension too high.
Check tracking of belt to
see If It creeps off to one
side.
Check bottom of belt and
the rollers.
Check belt tension and
automatic tension
adjustment mechanism.
Can cause excessive
pressure on localized
areas.
Can caliee excessive
pressure on localized
areas.
Excessive tension
causes wear.
Adjust alignment of belt.
- Clean belt and rollers.
Adjust tension} repair
tension adjustment
equipment.
to
O
-------
SECTION 15
VACUUM FILTRATION
INTRODUCTION
Vacuum filtration is a process used for dewatering sludges generat-
ed during wastewater treatment. The two products of vacuum filtration
are a relatively clear liquid, the filtrate, and a solids cake which is
suitable for final disposal. Depending upon the type of sludge being
dewatered, vacuum filtration can produce a cake that is typically be-
tween 20 and 30 percent solids. Often, vacuum filters used for dewater-
ing are preceded by a gravity thickener or a centrifuge to increase the
solids concentration of the sludge fed to the filter, a combination
which helps to maximize the solids content of the cake produced.
THEORY OF OPERATION
Filtration for dewatering is a process whereby solids are separated
from a liquid by passing the liquid through a porous medium on which the
solids remain and eventually build up to form a cake that is removed for
disposal. The formation of a solids cake and the fact that. solids are
removed primarily on the surface of the medium rather than throughout
its depth are two distinguishing features that characterize this type of
filtration. Both features are important since the object of dewatering
is to maximize the recovery of solids in a concentrated form.
Two steps are involved in the vacuum filtration process. In the
first, a solids cake is formed when a portion of the water in the sludge
drains through the filter medium leaving a more concentrated but still
very wet sludge layer or cake behind. In the second step, additional
207
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water drains from the solids, resulting in a much drier cake that can be
handled as a solid material and is suitable for disposal. Thus, filtra-
tion to form a dry solids cake works on the same basic priniciple as do
sludge drying beds, which are sometimes used for dewatering of metal
finishing sludges.
The rate at which a solids cake is formed and is dried depends upon
the rate at which water drains through the filter medium. In sludge
drying beds, gravity is the force which causes the water to drain out of
the sludge solids (the importance of evaporation is neglected in this
discussion). To increase the rate at which sludge can be dewatered and
thereby reduce the land area or size of equipment required, vacuum
filters were developed. Such machines apply a suction or vacuum to one
side of the filter medium while liquid sludge is applied to the other.
Water is removed by the force of the pressure differential that develops
across the medium, a pressure differential which is much greater than
the force exerted by gravity.
Many types of vacuum filters and filter media have been developed,
and several have been successfully used for dewatering sludges generated
during treatment of metal finishing wastes. All operate on the same
basic principle, differing primarily in the means by which the sludge is
applied to and the solids cake removed from the medium. Although the
process itself is fairly simple, the complexity of both machine-related
and process- or sludge- related variables makes the operation of vacuum
filters as much of an art as a science. For example, to optimize filter
performance often requires that sludge conditioning with polymers and
other chemicals be used. Although jar tests can be used to select ap-
propriate polymers, finding the best combinations and optimum dosages is
largely a matter of operating experience.
DESCRIPTION OF EQUIPMENT
Almost all of the vacuum filters used in wastewater treatment ap-
plications operate continuously and have as their principal component a
horizontal cylindrical drum which rotates partially submerged in a vat
208
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or tank containing the sludge to be dewatered, as shown in Figure 27.
The drum is divided by partitions or seal strips into multiple compart-
ments or sections each of which is connected by pipe to a rotary valve
within the drum. Bridge blocks in this- valve divide the drum compart-
ments into three zones referred to as the cake formation zone, the cake
drying zone, and the cake discharge zone.
The portion of the drum which is submerged in the sludge vat is the
cake formation zone. Vacuum applied through the rotary valve to this
portion of the drum causes liquid (filtrate) to pass through the medium
with the sludge being retained on its surface in the form of a wet cake.
The sludge vat is usually equipped with a reciprocating agitator to keep
the slurry mixed and solids in suspension. As the drum rotates, each
section or compartment is passed through the cake formation zone and on
to the cake drying zone. Beginning where the rotating drum leaves the
vat of. liquid sludge, the cake drying zone usually represents 40 to 60
percent of the drum surface and ends at the point where the internal
vacuum is shut off by the rotary valve. Here the sludge cake and drum
section enter the cake discharge zone where the cake is removed from the
medium.
A few vacuum filters have a gravity feed system which applies
sludge directly on the top of the drum for cake formation rather than
having the drum pass through a vat of sludge. Otherwise, the operation
of this type of filter is essentially the same as the others.
The cake discharge cycle depends upon the type of filter medium
used. The earliest type developed employs a scraper mechanism and a
pressure blow-back system for cake removal. A positive air pressure is
continuously applied through the rotary valve to the drum segment just
preceding the scraper or "doctor" blade; the air aids in loosening the
dried cake for removal. Often a fine spray is used to clean the medium
after cake removal, with the washings being captured in a trough for
recycle to a preceding treatment process.
209
-------
PICK-UP
OR FORM
Figure 27. Operating zones of a vacuum filter.
210
-------
More recently the belt-type rotary vacuum filters have gained in
popularity since they do not depend upon intimate contact between a
scraper and the rotating drum for effective removal of the solids cake.
Rather, the filter medium forms a continuous belt that leaves the rotat-
ing drum when it enters the cake discharge zone and returns just before
the cake formation zone. This kind of filter is shown in Figure 27.
Three types of media or drum coverings have been used commonly: coil
springs, closely spaced strings, and either woven cloth or metal fabric.
In one type of coil spring, belt-type vacuum filter, two layers of
stainless steel springs wrap around the drum and act as the filter
medium. After leaving the cake drying zone, the coil springs leave the
drum and are separated in such a manner that the sludge cake is lifted
off the lower layer and discharged off the upper layer with the aid of a
positioned tine bar. The two coil spring layers are then washed with a
water spray before returning to the drum just ahead of the cake forma-
tion zone.
A very similar type of filter uses closely spaced strings which are
wrapped around the filter drum and serve as the medium. After leaving
the drum, the strings pass over a series of discharge and return rolls
i-
which frees the cake from the medium. The strings then pass through a
set of aligning combs before returning to the drum.
The other type of rotary vacuum belt filter has a fiber belt made
of woven cloth (either natural or synthetic) or metal. A wide range of
materials has been developed for use as filter media and the selection
of media type and pore size for use with a particular sludge is a crit-
ical variable affecting filter performance. In this type of filter, the
belt (or filter medium) leaves the cake drying zone and passes over a
small diameter discharge roll which facilitates cake removal. Generally
this type of filter has a small diameter curved bar between the point
where the belt leaves the rotating drum and the discharge roll. The
position of this bar can be adjusted so that it pushes against the in-
side of the belt to control belt tension and maintain dimensional sta-
bility. After the cake is discharged, the belt usually is washed with
211
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water sprays from one or both sides before it returns to the drum just
ahead of the cake formation zone.
There are several important auxiliary equipment items which are
part of the vacuum filtration system. These are vacuum pumps, vacuum
receiver, filtrate pump, sludge pump, chemical feed system, sludge
conditioning tank, silencer, and, with some units, blowers. In larger
facilities these auxiliary items are often remote from the filters
themselves and several filters may be served by the same equipment
through common headers. A schematic illustration of a typical system is
presented in Figure 28.
The most important auxiliary item is, of course, the vacuum pump
which provides the negative pressure filtering force. Several types of
vacuum pumps have been used including reciprocating positive displace-
ment types, centrifugal (wet), and rotary or lobe pumps (semi-wet).
Depending on solids content and chemical composition, the filtrate is
sometimes used as seal water on these pumps. A silencer usually is
provided on the discharge of a vacuum pump to reduce the noise produced
during its operation. The "wet" operating pumps must also have provi-
sions for water separation and draining of the seal water. Vacuum pumps
are usually sized to provide between 1 and 2 scfm/sq ft of filter sur-
face area at negative operating pressures of 20 inches of mercury.
Each filter generally is supplied with a vacuum receiver located
between the rotary valve (which distributes the vacuum inside the drum)
and the vacuum pump. The principal purpose of the vacuum receiver is to
separate the air from the filtrate, as well as to serve as a reservoir
for the filtrate pump suction. With dry-type vacuum pumps, a moisture
trap is provided between the vacuum receiver and the pump.
Usually a filtrate pump is provided to carry away the water sepa-
rated in the vacuum receiver. Specially designed centrifugal pumps that
operate at very low net positive suction heads are used for this pur-
pose, since the receiver is often under a negative pressure of about 20
inches of mercury. Check valves generally are provided on the discharge
212
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AM TO ATMOSPHERE
i-l-i 3ILEMCSR
HLTHATI
MJMP
WATOI
\
VACUUM «JMI»
VAT
Figure 28.
Typical equipment layout of
rotary vacuum fitter system.
213
-------
side of these pumps to prevent air from leaking back through the pump
and into the receiver. Sometimes the filtrate pump is omitted when a
barometric leg or gravity discharge is provided on the bottom of the
receiver.
Piston, diaphragm, and progressive cavity pumps are all commonly
used as sludge feed pumps. They are installed so that a constant capa-
city can be maintained at a given setting. Usually a stroke counter or
other totalizing device is provided for flow measurement.
A sludge conditioning tank usually is provided in close proximity
to the vacuum filter from which the conditioned sludge either flows by
gravity or is pumped to the filter. The tank acts as both a mixing
vessel and a flocculation tank. Other aspects of the chemical addition
system are common to other sludge handling systems and are described in
a separate section.
In vacuum filters that have a positive pressure blow-back system to
lift the medium from the filter drum ahead of a scraper or doctor blade,
low capacity lobe type air blowers are used. These are usually sized to
provide about 0.25 scfm/sq ft of filter surface area and operate at
pressures of about 2 psig.
OPERATIONAL PROCEDURES
The main objective of vacuum filter operation is to produce a
sludge cake with a high solids concentration (low moisture content) that
is suitable for final disposal.. In doing so, the filtrate that is pro-
duced must be low in suspended solids so that problems are not created
when it is recycled back to preceding treatment processes. Further,
these two objectives must be met without reducing the filter yield below
a level sufficient to handle the sludge solids generated during waste-
water treatment. Otherwise, solids will accumulate in the system and
will eventually affect other treatment processes. Maintaining an accep-
table filter yield often requires the addition of chemical coagulants
and filter aids. Another process objective is to minimize the operating
214
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costs associated with sludge conditioning. Vacuum filter performance
cannot be maximized with respect to all of these objectives at the same
time, since some of them are conflicting. Therefore, good vacuum filter
operation represents a compromise between these objectives in which
filter performance is optimized for a particular application.
Process Monitoring
The criteria used to evaluate vacuum filter performance are solids
concentration or water content of the cake, efficiency of solids re-
moval, and filter yield. The efficiency of solids removal usually is
expressed as the percent solids recovery (or solids capture) which is
the mass ratio of dry cake solids produced by the filter to the dry
sludge solids fed to the filter over a given period of time. A decrease
in solids recovery means that more solids are passing through the filter
medium. Since this usually results in higher solids concentrations in
the filtrate, the efficiency of filtration is sometimes expressed as a
function of the filtrate solids concentration, although the solids
removed from the cloth by water sprays should also be accounted for.
The filter yield refers to the amount of solids, on a dry weight basis,
removed as part of the solids cake over a given period of time.
In order to evaluate vacuum filter performance and diagnose pro-
blems, a complete record of several operating parameters must be kept.
These are summarized in Table 22.
This information should be recorded routinely, along with machine
operating conditions such as drum speed, drum submergence, vacuum pres-
sure, etc. It is particularly important that any changes in performance
or operating conditions be recorded along with the time that they are
made.
215
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TABLE 22
VACUUM FILTRATION
PROCESS MONITORING REQUIREMENTS
Parameter
Frequency
Comment
1. Feed sludge flowrate Daily
(GPM or L/min).
2. Filtrate flowrate (gpm Weekly
or L/min).
3. Total and suspended Daily
solids concentration
in feed sludge slurry
(mg/L).
4. Total solids concen- Daily
tration in solids cake
(mg/L or percent by
weight).
5. Total and suspended Daily
solids concentration in
filtrate (mg/L).
6. Concentration of chemi- Weekly
cal conditioners added
to sludge (ppm or,
percent).
7. Feed rate for chemical Weekly
conditioners (L/min or
gpm) .
8. Feed sludge temperature Daily
(°F or °C).
9. Feed sludge pH. Daily
10. Wash water flowrate Weekly
(gpm or L/min).
11. Solids concentration in Weekly
wash water (mg/L).
To determine flowrate.
To determine filter
performance.
To determine feed rate
to filter.
To determine solids
removal and filter
efficiency.
To determine solids
loading in filtrate.
To set conditioning
requirements.
To set conditioning
requirements.
Temperature affects
filterability.
High or low pH values
can change solubility
of particles.
To determine volumes
of liquid in mass
balance.
To determine solids
in wash water, solids
removal, and filter
efficiency.
216
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Example Calculations
Example calculations of operating parameters are presented below.
Consider a rotary belt vacuum filter for which the following data have
been collected:
Feed sludge flow rate = 20 gpm
Filtrate flow rate =18 gpm
Feed suspended solids » 40,000 mg/L (4.0 percent)
Filtrate suspended solids = 600 mg/L
Cake solids concentration = 300,000 mg/L (30 percent)
Cloth wash water spray = 6 gpm
Solids concentration in wash water = 4,900 mg/L
The solids feed rate (dry solids fed to the filter per hour) is
calculated as follows:
Solids feed rate = (feed sludge flow rate)(feed suspended solids)
= (20 gpm)(60 min/hr)(3.785 L/gal)(40 g/L)
(kg/103 g)
= 182 kg/h = 400 Ib/hr
The solids removed (dry solids removed per hour) is calculated as
follows:
Solids removal = (feed solids mass)-[(filtrate solids mass)+
(wash water solids mass)]
= 400 Ib/hr - [(18 gpm)(0.6 g/L)+(6 gpm)(4.9 g/L)]
[(3.785 L/gal)(lb/454 g)(60 min/hr)]
=380 Ib/hr
The filter efficiency, expressed as percent solids recovered, is
calculated as follows?
Filter efficiency (%) = Solids removal
Solids feed rate
217
-------
Filter efficiency = (380)/(400) x 100 = 95.0 percent
Process Control Strategies
The operation and performance of a vacuum filter is determined by
several variables that are related either to the machine itself (machine
variables) or to the specific sludge dewatering application (process
variables). Among these are the following:
Machine Variables
Vacuum Pressure
Drum. Speed
Drum Submergence
Filter Medium
Tank Agitation
Spray Water Pressure
Position of Doctor Blades
Process Variables
Sludge Characteristics
Chemical Addition
Solids Concentration
Sludge Feed Rate
Temperature
pH
Machine Variables—
One of the most important machine-related variables is the vacuum
pressure applied during formation and drying of the sludge cake. Within
limits, the filter yield can be increased by increasing the vacuum since
a higher vacuum generally results in greater cake thickness during the
formation process. Practical limits usually are encountered at vacuum
pressures of about 15 inches of mercury, since energy requirements
increase rapidly with higher operating pressures. Further, many waste-
water sludges are highly compressible, though this is not true for all
types of sludge, and under higher vacuums these sludges form an imper-
vious cake that is difficult to dewater. In such a case, increased
vacuum pressures may reduce filter yield.
The drum speed, or the rate at which the filter drum rotates,
affects both cake formation and cake drying operations. As the drum
speed is reduced, the cake has a longer period of time to dewater,
resulting in a drier cake. However, reducing drum speed reduces filter
218
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yield so that less sludge can be dewatered in any given period of time.
Conversely, an increase in the drum speed results in a higher filter
yield since more medium is passed through the cake formation zone during
any given period of time. A wetter cake also results, however, since
the sludge cake spends less time in the cake drying zone.
The degree to which the filter drum is submerged in the sludge vat,
referred to as drum submergence, usually is expressed as a percentage of
the drum circumference or filter medium surface area (the difference
between these is a constant value). Drum submergence normally can be
varied between 15 and 25 percent. An increase in submergence increases
the cake formation area (and therefore cake formation time) but reduces
the area (and time) available for cake drying; this usually results in a
wetter but thicker cake. Decreasing the drum submergence produces a
thinner but drier cake. A minimum submergence must be maintained to
prevent vacuum on the filter from being broken.
Probably the most important machine variable is the filter medium
itself. Selection of a filter medium suitable for use in a particular
application is one of the most critical design considerations since it
can determine the operating and performance limits of the vacuum filter.
Materials which have been used as fabric media include cotton, rayon,
acrylic, polyolefin, polyester, polypropylene, and nylon. Metal wire or
mesh media also have been used, as have stainless steel coil springs.
All of these media can be categorized as open or tight, with open media
having larger size pores through which small solid particles can pass.
Although a tight filter medium will remove a higher percentage of fine
particles, thereby increasing filter efficiency, it can blind or stop up
completely making filtration impossible. Spray washing of the media
after cake discharge helps to prevent the build-up of fine particles
which might otherwise blind the filter media. The characteristics of
the filter medium usually change with use as it becomes worn or partial-
ly blinded with solids. While such changes usually occur gradually, it
can eventually become necessary to replace the medium. Occasionally the
medium type has to be changed, either to improve filter performance or
because the previously used medium is not available. whenever the
219
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filter medium is changed, and particularly when a different type of
medium is used, the operation and performance of the vacuum filter can
be expected to change also; sometimes these changes are significant.
Two machine variables that affect solids removal from the filter
media are the pressure of the water sprays and the position of the
doctor blades. Both are of critical importance and very minor adjust-
ments can result in improved or diminished performance. • Optimization of
water spray pressure and doctor blade position is a matter of operating
experience.
The final machine variable requiring discussion is the degree of
agitation provided in the sludge vat through which the filter drum
rotates. Agitation is required to prevent solids from settling, and
some minimum level needed to meet this objective must be determined from
operating experience. However, too much agitation can result in shear-
ing or break-up of the sludge floe resulting in a lower filter efficien-
cy and higher solids levels in the filtrate.
Process Variables—
The physical and chemical characteristics of the sludge to be de-
watered together represent the single most important process variable
affecting vacuum filtration. Different sludges exhibit dramatically
different dewatering characteristics. Among the factors that determine
filterability are the size, shape, density, and electrical charge of
solid particles, viscosity of the liquid, and compressibility of the
sludge solids. Generally these factors are not directly under the.
operator's control since they result from optimization of upstream
treatment processes.
To compensate for poor filtering characteristics or to increase
cake solids concentration, polymers and other chemicals often are added
to the sludge prior to filtration. These may be required to help in
cake formation and/or cake drying. Polymers and other coagulant aids
promote flocculation, which increases particle size and improves filter
efficiency. Filtering aids such as lime, diatomaceous earth, clay, fly
220
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ash, and other materials can be mixed with the sludge to improve solids
recovery, facilitate good cake formation, and reduce sludge compressi-
bility (which helps in cake drying). Selecting the proper coagulants
and filter aids for a particular application is based upon jar tests,
while optimizing their use is a matter of operating experience. Optimi-
zation of chemical usage is important since chemical cost usually repre-
sents the greatest single operating cost associated with vacuum filtra-
tion.
Another process-related variable is the solids concentration of the
feed sludge. Up to a point, a higher solids concentration in the feed
sludge usually results in a drier cake discharge and a higher filter
yield. Another advantage of higher feed solids levels is that chemical
requirements for sludge conditioning often are reduced. For these rea-
sons, vacuum filters are sometimes preceded by gravity thickeners or
centrifuges that increase the sludge solids concentration. Changes in
the operation of upstream thickeners, centrifuges, or even clarifiers
can improve filter performance if the changes increase the concentration
of solids in the feed sludge. However, there are practical limits as to
how high the feed solids concentration can be, as determined when pump-
ing, mixing, and other problems begin to occur. The maximum solids
concentration usually fed to vacuum filters is from 8 to 10 percent; (
above these numbers cake formation becomes difficult.
TYPICAL PERFORMANCE VALUES
The most important factor affecting the performance of a vacuum
filter is the type of sludge being dewatered. If sodium hydroxide is
used for pH adjustment to precipitate metal hydroxides, a light, slimy,
and relatively difficult to dewater sludge will result. One of the main
problems caused by this type of sludge is that it can blind the filter
medium and form an impermeable cake that dewaters poorly. These pro-
blems usually can be overcome, however, by using proper conditioning
agents, such as polymers and filter aids.
221
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When lime is used for precipitation of metals, the amount of excess
lime determines the dewatering characteristics of the sludge. When very
little or no excess lime is added, most of- the sludge formed will be
metal hydroxides. If considerable excess lime is used, a large amount
of calcium carbonate will be present in the sludge, making it heavier
and more easily dewatered, since calcium carbonate sludges tend to form
much more permeable cakes.
Table 23 gives typical performance values for rotary vacuum filters
applied to both metal hydroxide and lime-carbonate sludges.
TROUBLESHOOTING GUIDE
The problems which are commonly associated with vacuum filter oper-
ations have been summarized in the form of a troubleshooting guide in
Table 24. This is a general guide and some parts of the vacuum filtra-
tion system may have unique operating problems; these are usually ad-
dressed in the manufacturer's literature.
Vacuum filtration is one of the more difficult wastewater treatment
processes to operate, because of the number of variables which affect
performance. Therefore, whether diagnosing operating problems or opti-
mizing filter performance, it is important to change only a single
variable at a time. Otherwise, the cause of a problem (or its solution)
cannot be determined with certainty. It is especially important that
all other variables be held constant when determining optimum dosages
for sludge conditioning.
222
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TABLE 23
TYPICAL PERFORMANCE VALUES FOR VACUUM FILTRATION DEWATERING
Type of
Sludge
Feed Solids Cake Solids
Concentration Concentration
Solids
Recovery
Typical
Conditioning
Chemicals
Metal Hydroxide
- without condi-
tioning 2-6
- with conditioning 4-8
High CaCO
- without condi-
tioning 2-8
- with conditioning 6-10
15-25
20-30
20-30
30-45
Lime ;
85-95 Diatomaceous
Earth
90-95 Anionic
Polymers
Anionic
90-95 Polymers
Diatomaceous
95+ Earth
223
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TABLE 24
VACUUM FILTRATION
TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 1s Thin cake, poor dewatering.
(0
K>
*»
la. Filter media blinding.
Ib. Improper chemical
dosage.
Ic. Inadequate vacuum.
Id. Drum speed too high.
te. Drum submergence too
low.
If. Feed sludge solids
concentration has
decreased.
- Digest media and
check spray washes.
Check chemical
addition system for
malfunction.
Vacuum gauges and
input for leaks or
broken seals.
Drum speed -and
operating records.
Drum submergence and
operating records.
Solids feed rate and
operating records.
To determine if
blinding is occurring
and if it is caused
by insufficient
washing.
If no problems with
equipment, the
optimum dosage may
have changed.
To isolate the
problem.
To determine if a
change has occurred.
To determine if a
change has occurred.
If solids have
decreased, different
operating conditions
may be required.
Adjust spray washes or,
if necessary, shut down
filter and clean media.
Repair or adjust
chemical addition
system or, if neces-
sary, determine new
optimum dosage rates.
Repair or adjust vacuum
system to achieve
desired vacuum.
Reduce drum speed if
necessary.
Increase drum sub-
mergence to get thicker
cake, decrease it to get
drier cake.
Determine if the solids
level can be increased
by changes in upstream
processes. Otherwise,
new operating conditions
will have to be
determined.
OPERATING PROBLEM 2: High solids in filtrate - low efficiency.
2a. Improper chemical
dosage.
- Check chemical
addition system
for malfunction.
If no problems with
equipment, the opti-
mum dosage may have
changed.
Repair or adjust
chemical addition
system or, if necessary,
determine new dosage
rates.
-------
TABLE1 24
(Continued)
VACUUM FILTRATION
TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
2b. Wrong type of media. - Filter leaf tests.
To select better
media.
Change media type.
OPERATING PROBLEM 3: Vacuum pump stops.
3a. Lack of power.
Check to see
if heater tripped.
Motor overload will
trip heater.
Determine cause of
overload. Restart
after cooling period.
3b. Lack of seal water.
Source of seal water.
To insure adequate
flow.
Start seal water flow.
NJ
to
U1
3c. Broken V-belt.
- V-belt.
V-belt may be worn
or broken.
OPERATING PROBLEM 4: Drum stops rotating.
- Replace V-belt.
4a. Lack of power.
Check to see
if heater tripped.
Motor overload will
trip heater.
Determine cause of
overload. Restart after
cooling period.
4b. Drive mechanism
broken.
Check belt, chain,
gear, etc.
To determine what
is broken.
Repair or replace
broken part(s).
OPERATING PROBLEM 5: High vat level.
5a. Feed rate too high.
Feed rate, solids
yield, and operating
records.
To determine if any
changes have occurred.
Lower feed rate
or increase drum speed.
5b. Drum speed too slow.
Drum speed, solid
yield, and operating
records.
To determine if any
changes have occurred.
Increase drum speed or
reduce feed rate.
-------
TABI.F 24
(Continued)
VACUUM FILTRATION
TROUBI.FSHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
PFASON
CORRECTIVE ACTION
K)
to
0%
5c. Improper chemical
dosage - poor cake
formation.
5d. Filtrate pump off
or clogged.
5e. Drain line clogged.
Check chemical
addition equipment
for malfunction.
- Check filtrate pump
and discharge.
Drain line for flow.
If no problems with
equipment, optimum
dosages may have
changed.
If on, it may be
clogged.
Drain line may stop
flow.
Repair or adjust
chemical addition
system and, if
necessary, determine
new dosage rates.
Turn on pump or
unclog it.
Clear drain line.
5f.
5g.
Vacuum pump stopped. - See Item 3.
Seal strips missing. - Drum interior.
See Item 3.
- Loss of vacuum
would prevent
removal of filtrate.
- See Item 3.
Replace seal strips.
OPERATING PROBLEM 6: Low vat level.
6a. Feed rate too low.
6b. Vat drain valve open.
Feed rate, solids
yield, operating
records.
Vat drain valve.
Cake forms faster
than solids applied
to filter.
Open valve can drain
vat.
Increase feed rate
or decrease drum
speed.
Close vat drain valve.
OPERATING PROBLEM 7: Filtrate receiver vibrating.
7a. Filtrate pump is
clogged.
7b. Loose bolts or other
parts.
7c. Check to see if ball
valve in filtrate pump
or suction line is worn.
- Check pump outlet
for flow.
Check gaskets,
inpaction plates,
mounting, etc.
Che'ck ball valve.
Flow indicates
possible clog.
Damage can result.
Worn ball valves can
cause vibrations.
Turn off pump and
clean it.
Tighten loose parts;
replace broken parts.
Replace worn parts.
-------
TABLE 24
(Continued)
VACUUM FILTRATION
TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
7d. Air leaks in suction
line.
7e. Dirty drum face.
If. Seal strips missing.
- Impact line for
leaks.
Check drum face.
- Check drum interior.
Leaks in air line can
cause vibrations.
Uneven vacuum
results in pressure
surges.
Uneven vacuum
results in surges.
Seal leaks.
Clean off drum face with
with hose.
Replace seal strips.
OPERATING PROBLEM 8s High amperage draw by vacuum pump.
N>
to
8a. Filtrate pump clogged.
8b. High vat level.
8c. Cooling water flow
to vacuum pump too
high.
8d. Blinding of media
causing high vacuum
pressure.
8e. Highly compressible
sludge terming
impermeable cake.
Filtrate pump output
for flow.
See Item 6.
Cooling water flow.
Check media and spray
washer.
Cake dryness and
consistency. Check
chemical addition
system.
Vacuum pump drawing
water from receiver.
- See Item 6.
To determine if
media is soiled.
May require addition
of lime or other
filter aid to
improve sludge
characteristics.
- Turn pump off and clean.
See Item 6.
Decrease cooling water
flow.
Adjust spray washer and
clean media, if
necessary.
Adjust chemical
addition rates to
improve cake
characteristics.
OPERATING PROBLEM 9: Scale buildup on equipment.
9a. High dosage of lime.
pH adjustment to deter-
mine if excessive lime
is added.
Nigh lime dosages
or presence of un-
reacted lime may cause
scale.
Fine tune lime
dosage (see pH ad-
justment and metal
precipitation.)
-------
TABLE 24
(Continued)
VACUUM FILTRATION
TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
9b. CaCO is precipitating
out of solution.
Influent calcium con-
centration and calcium
solubility at -operating
pH.
If influent calcium
concentration is
greater than solubil-
ity, then scale will
form.
Fine tune lime
dosage, operate pH
adjustment at dif-
ferent pH or decrease
retention time of sludge
in equipment by washing
thoroughly with muriatic
acid after operation.
K>
00
-------
SECTION 16
PRESSURE FILTRATION FOR DEWATERING
INTRODUCTION
Pressure filtration is a process used for dewatering sludges gen-
erated during wastewater treatment. Pressure filtration results in the
generation of two products: a relatively clear liquid, called the fil-
trate, and a solids cake that is suitable for direct disposal. Compared
to other mechanical dewatering processes, pressure filtration generally
achieves the driest solids cake for any particular sludge. There is a
cost associated with improved performance, however, as pressure filters
are usually more expensive to operate than other types of dewatering
equipment. Generally, but not always, pressure filters used for sludge
dewatering are preceded by a gravity thickener or a centrifuge to in-
crease the solids concentration of the sludge fed to the filter. Since
pressure filters are designed and operated as batch processes, it may be
important to reduce sludge volume by thickening prior to filtration.
THEORY OF OPERATION
The basic principle by which pressure filtration works is the same
as for vacuum filtration: solids are separated from a liquid by passing
the liquid through a porous medium on which the solids remain, eventual-
ly building up to form a cake that is removed for disposal. This pro-
cess is much like what happens when sludge is applied to a sand drying
bed. Water drains from the sludge into the sand leaving behind a con-
centrated solids layer. Given time, the force of gravity will cause
enough water to drain out so that a sludge cake will form which can be
handled and disposed of as a solid. In vacuum filters, a negative
229
-------
pressure differential that is equivalent to about 1000 times that of
sand drying is applied to speed up the drying process. Pressure filters
apply even greater forces to the sludge—up to 20,000 times the pressure
differential of sand drying—which results in an even drier solids cake.
Almost all pressure filters used in sludge dewatering applications
are designed to operate in a batch mode, as opposed to continuous opera-
tion. The usual sequence of events is as follows. First, the sludge
slurry is applied to the filter and a sludge cake is formed on the
filter medium as the filtrate passes through it and is removed. As
additional sludge is pumped into the filter, the cake grows thicker and
the backpressure increases. Eventually a point is reached when the
sludge feed pumps are stopped. This point is based either upon time,
decrease in feedrate, or operating pressures. Depending upon the type
of filter, a cake compression step may follow, in which additional water
is removed from the cake. Any remaining sludge slurry is then drained
from the filter, after which the filter is opened to expose and dis-
charge the solids cake. Once the cake has been removed and the media
cleaned (if necessary), the filter is closed and the next cycle can
begin.
Some filters and some types of sludge require that additional steps
be performed. For example, to prevent blinding of the media, to improve
solids capture, and to allow easy cake removal, it may be necessary to
apply a precoat to the filter media before introducing the sludge.
Precoating is done often when a greasy or sticky sludge, e.g., metal
hydroxide, is being dewatered.
Sludge characteristics can affect dewaterability by pressure fil-
tration just as they affect vacuum filtration. Generally, the much
higher operating pressures compensate for poor sludge characteristics,
although there are exeptions to this rule. Chemical conditioning with
polymers or inorganic chemicals may be necessary to improve the sludge
compressibility (resulting in a drier cake) and achieve a good quality
filtrate. Sludge conditioning may also be necesary to get good cake
release.
230
-------
DESCRIPTION OF EQUIPMENT
As with vacuum filtration, the formation of a solids cake and the
fact that solids are removed primarily on the surface of the filter
medium rather than throughout its depth are two features that distin-
guish pressure filtration for sludge dewatering from other filtration
processes. This distinction is important since pressure filters are
used in other applications, such as in cartridge filters and strainers
used online for the removal of solids from liquid streams. Since such
types of pressure filters are not used in sludge handling and treatment
operations, they will not be discussed in this section of the manual.
Batch pressure filters can be divided into three major groups:
(1) Filter Presses—including plate-and-frame presses and recessed-
plate presses,
(2) Leaf, Plate, and Candle (Tubular) Filters—filters which take
their names from the shape or orientation of the surfaces that
collect the filter cake,
(3) Variable-Volume Filters—in which a cake is formed by pressure
filtration and then compressed to expel the excess water re-
maining in it.
The distinction between these groups is somewhat arbitrary and different
people may consider the same kind of filter to belong in different
groups. These points are not important, however, since all operate on
the same basic principles.
Filter Presses
Filter presses represent the most common type of pressure filters
and consist of numerous plates with corrugated surfaces over which the
filter medium is draped, as shown in Figures 29 and 30. The filter
medium is usually in the form of woven cloth and often is made of syn-
thetic monofilament fiber. The operating pressure is created by pumps
231
-------
FILTER CLOTHS
FIXED END
SLUDGE IN
i-f- '„ •'w. ^ • «*' V* •"
*-. y vV V .--• /* •;
FILTRATE DRAIN HOLES
Figure 29.
Cutaway view of a filter press.
232
-------
to
u>
U)
FIXED END
pddololn
TRAVELLING END
ELECTRIC
CLOSING GEAR
QJoiQlololnlolQ
OPERATING HANDLE,
Q
\
ta
Figure 30.
Side view of a filter press.
-------
which introduce the sludge slurry between layers of the filter medium.
One end of the press is fixed while the other end can be moved to allow
separation of the plates and discharge of the solids cake. There are
two main types of filter presses, the plate and frame press and the
recessed plate press.
In the plate-and-frame press, the plates are separated by hollow
frames which are covered with the filter medium. The alternating plates
and frames are held tightly together during filter operation to form a
continuous unit. Sludge is introduced into the hollow frames and the
solids cake then forms on the filter medium (within the frames). The
filtrate passes through and drains along the corrugations in the plate
from which, depending upon the individual filter, it may drain directly
out the bottom of each plate or may flow through a channel that runs the
length of the press. Sludge feed continues until the frames are full,
as judged by time, decrease in feedrate, or increase in backpressure.
At the end of the batch, the press usually is drained of any remaining
liquid after which it is opened and the plates and frames separated to
release the solids cake.
Another type of filter press is the recessed-plate press. In this
type of press, the plates are shaped so that a hollow space exists
between them in which the solids cake forms. There are no separate
hollow frames between adjacent plates. Sludge enters the press through
ports in the center of the plates. Otherwise, the recessed-plate press
looks and is operated just like the plate and frame press.
Leaf, Plate, and Candle Filters
Pressure filters in this group have a number of hollow filter
elements suspended either vertically or horizontally within a closed
vessel. The shape of these elements is what gives the various types of
filters in this group their names. These filter elements are often
covered with a woven cloth filter medium, although there are some appli-
cations in which the surface of the filter element also serves as the
filter medium. Sludge flows into the vessel under pressure and liquid
234
-------
(filtrate) flows out through the. hollow elements to a common discharge
manifold. In the process, the solids left behind on the filter medium
build up to form a cake which eventually causes the operating pressures
to increase and sludge feedrates to decrease.
At the end of an operating cycle, the vessel is depressurized and
any remaining slurry is drained. The filter is then opened and the
filter elements are removed (usually this process is automatic). The
cake is then removed from the filter elements by one or more of several
methods including vibration, scraping, compressed air blow-back, cen-
trifugal force, and leaf rotation.
Variable-Volume Filters
The third type of pressure filter first forms a solids cake, usual-
ly by pressure filtration, and then compresses it to expel additional
water contained in the wet cake. The purpose is to produce a drier cake
than in conventional filter presses. The variable-volume name refers to
the fact that in these filters the size of the chamber in which the cake
is formed changes during operation by the movement of a diaphragm. In
fact, these filters are often referred to as diaphram filters. The most
common type of variable-volume diaphragm pressure filter somewhat resem-
bles a recessed plate filter press. All of the filters of this type
operate on the same basic principle, although there are numerous varia-
tions in the individual steps of an operating cycle.
OPERATIONAL PROCEDURES
The main objective of using pressure filters for dewatering is to pro-
duce a solids cake for discharge that has a very high solids concen-
tration. High solids concentration is important since the moisture
content of the sludge directly affects hauling and disposal costs—it is
certainly not desirable to pay more for hauling water in the form of a
wet cake, if a drier cake can be achieved. To achieve a high concentra-
tion in the cake, very high operating pressures are required, as is a
tight filter medium (one with very small pore sizes). As a result of
235
-------
these features, filtrate quality is usually not considered to be a
performance limiting factor in pressure filtration. More important is
the filter yield, or mass of solids (dry weight) that can be dewatered
in a given amount of time. An increase in the yield usually requires
that the batch cycle time be decreased, which in turn results in a
wetter cake. Therefore, the objective of pressure filter operation is
to maximize cake solids while still achieving a filter yield that is
sufficient to process all the sludge generated in upstream treatment
processes.
Process Monitoring
Filter press performance is measured by the solids content in the
feed sludge, required chemical conditioning dosages, cake solids con-
tent, total cycle time, solids capture, and the filter yield. Of these,
the last two require some explanation.
Solids capture, also called solids recovery, is the mass ratio of
cake (or thickened sludge) solids to the feed solids for a single batch
run. A low solids capture means that solids are lost in the filtrate
and are not part of the solids discharge. The solids yield (removal)
refers to the amount of solids, on a dry weight basis, that can be re-
moved by a pressure filter during a single batch run. The yield multi-
plied by the number of batches run must equal or exceed the sludge gene-
ration rate if solids are not to accumulate upstream in the treatment
system.
The performance parameters discussed above are all interrelated;
for example, as the feed solids content increases, the required chemical
dosages and total cycle time usually decrease, while the filter yield or
throughput usually increases. As the chemical conditioning dosage is
increased to the optimum level, the cake solids content, solids capture,
and yield all increase, while the cycle time decreases.
236
-------
In order to evaluate pressure filter performance and diagnose
operating problems, a complete record of several operating parameters
must be kept. These are listed in Table 25.
This information should be recorded routinely, preferably for each
batch. It is especially important that changes in pressure settings,
filter cycle time settings, chemical conditioning dosages, etc. be
recorded along with the time (batch number) that they are made. In this
way a useful record of the effects of process variables on performance
will be developed.
Example Calculations
Consider a pressure filter for which the following data have been
collected:
Volume of sludge fed per run = 10,000 gallons
Volume of filtrate produced per run = 9,000 gallons
Peed suspended solids = 40,000 mg/L (4 percent)
Filtrate suspended solids = 6 mg/L
Cake solids concentration = 400,000 mg/L (40 percent)
f-
Sludge feed volume and filtrate volume per run are functions of
cycle time and maximum operating pressures. The solids fed per filter
run (dry weight basis) is calculated as follows:
Solids fed per run = (Volume of sludge fed)(Feed suspended solids)
= (10,000 gallons (3.785 L/gal)(40 g/L)
= 1514 Kg = 3335 Ibs.
The solids lost per filter run is calculated as follows:
Solids lost per run = (Volume of filtrate)(Filtrate suspended
solids)
= (9,000 gallons)(3.785)(0.6g/L)
= 20 Kg = 45 Ibs.
237
-------
TABLE 25
PRESSURE FILTRATION
PROCESS MONITORING REQUIREMENTS
Parameter
Frequency
Comment
1. Batch cycle times (minutes). Per batch
2. Volume of sludge fed per Per batch
batch (gallons or liters).
3. Total and suspended solids Per batch
in feed slurry (mg/L or per-
cent by weight).
4. Feed slurry back-pressure Per batch
(psi).
5. Machine hydraulic pressure Per batch
(psi).
6. Filtrate flowrate (gpm or Weekly
L/min).
7. Filtrate suspended solids Weekly
concentration.
8. Total solids concentration Per batch
of cake (mg/L or percent by
wei ght.)
9. Dosage rate for chemical Per batch
conditions and filter aids
(mg/L, ppm, or percent by
weight)
10.Feed sludge temperature Per batch
o o
( F or C).
11.Feed sludge pH. Per batch
To determine system
performance.
To determine solids
feed rate, solids
capture, and solids
yield.
See Comment 2.
To determine pressure
history during
operation.
To assess system opera-
tion.
To correlate filtrate
solids to solids
capture.
See Comment 6.
To determine percent
capture and solids
yield.
To determine condition-
ing requirements.
Temperature affects
solubility of
particles.
pH affects solubility
of particles.
238
-------
The solids yield for a single run is calculated as follows:
Solids yield = (Solids fed per run) - (Solids lost per run)
= 3335 - 45
= 3,290 Ibs.
The solids capture for a single run is calculated as follows:
Solids capture (percent) = (Solids yield)/(Solids fed per run) x 100
= (3,290/3,335) x 100
= 98.7 %
Process Control Strategies
The operation and performance of pressure filters for sludge dewa-
tering is determined by a relatively small number of variables, compared
to other mechanical dewatering processes. Although control of the
process may be manual, semi-automatic, or fully automatic, the basic
operating cycle and machine related variables are the same.
A typical cycle begins with the closing of the filter, after which
sludge is pumped into the press until it is essentially full of cake.
Sludge pumping then continues with increasing back pressures and de-
creasing sludge flows. The end of the sludge feed step in the filter
cycle is determined when back-pressures reach the designed maximum
(usually 100 psi, but sometimes as much as 220-250 psi). To reach this
point typically takes 20 to 30 minutes. The high back-pressure is then
maintained for a period of usually one to four hours, during which time
additional water is removed from the cake as filtrate. Based upon
either time or filtrate flow rate (which becomes nearly zero), the
filter cycle is ended by relieving the pressure, opening the filter, and
removing the solids cake. The only real variation on this cycle is when
a variable volume filter is used. In this case, the high-pressure
holding time is much less, and it is followed by an additional step in
239
-------
which diaphragms behind the filter media are expanded by high pressure
air or water to force out water and further concentrate solids in the
cake.
Therefore, the only machine variables that are under operator
control are the time settings for each step in the filter cycle and, in
the case of some machines, the operating back-pressures (which are
determined by the sludge feed pumps). Cycle time is usually the main
machine variable affecting filter yield. In rare cases, it may be
necessary to select a different type of filter medium to improve per-
formance, particularly if the sludge cake is not removed easily from the
medium or high filtrate solids concentrations are a problem.
Of the process (non-machine) variables, the most obvious are those
related to the sludge. The sludge characteristics that improve dewater-
ing by vacuum filtration are also advantageous for pressure filtration.
Because of the greater energy involved in pressure filtration, however,
the sludge variables are considered to be less of a factor in dewatering
performance.
However, the variable over which the operator can exercise complete
control is chemical conditioning. The wide range of chemicals used in
pressure filtration also are similar to those for vacuum filtration.
Filter presses usually require a filter aid and/or a precoat material to
reduce blinding and to facilitate release of the cake from the media
during the unloading stage. Incinerator ash or diatomaceous earth are
typical precoat materials that are added just before sludge charging.
Precoat application is a critical step in the batch operating cy-
cle, and manufacturers' recommendations for mixing and applying precoat
must be followed explicitly to achieve good results. A poor precoat can
cause several problems, one of which is high solids in the filtrate.
However, the most important reason for achieving a good precoat is to
insure good solids cake release from the media. Otherwise, it will be
necessary to wash the medium with high pressure water sprays after each
batch to prevent media blinding and maintain performance. This step can
240
-------
be extremely time consuming, in addition to defeating the whole purpose
of filtration by diluting with water the cake solids that remain stuck
on the media.
Other operating procedures include routine water washing of the
filter media to prevent blinding and to maintain filter yield. Occa-
sionally acid washing with dilute muriatic acid is necessary to remove
calcium carbonate scale that forms on the media. It is also occasional-
ly necessary to replace worn media, although this is usually only done
after filter yields drop to the point that water and acid cleaning are
no longer sufficient to maintain acceptable yields.
TYPICAL PERFORMANCE VALUES
Most sludges from metals finishing wastewater treatment dewater
very well in pressure filters, provided proper precoat application and
chemical conditioning are used. Typically, a solids cake from 30 to 50
percent by weight is achieved, with a solids recovery of 95 to 99 per-
cent.
TROUBLESHOOTING GUIDE
t-
The troubleshooting guide for the pressure filtration process is
presented in Table 26. Major problem areas include filter blinding,
improper sludge conditioning, and high cake moisture content. Both
chemical and mechanical methods of solving these problems are con-
sidered.
241
-------
TABLF 26
PRESSURE FILTRATION FOR DEWATFRING
TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM Is Low cake solids concentration (high moisture content in cake).
1a. Filter cycle time too
short.
1b. Improper sludge condi-
tioning.
Operating records to
correlate filtrate
flow and cycle time with
cake moisture content.
Chemical and filter aid
feed systems and mixers.
To determine if optimum
operating conditions
have changed.
To determine if mech-
anical problems exist or
if a dosage change is'
required.
Increase filter cycle time.
Repair any malfunctioning
equipment or change dosage
of either chemicals or filter
aid and re-evaluate filter
performance.
OPERATING PROBLEM 2: Cake discharge is difficult or incomplete.
o
p»
•o
2a. Inadequate precoat on
media.
2b. Improper sludge
conditioning.
Precoat slurry mixing and
pumping system.
See Item 1b.
To determine if a mech-
anical problem exists or
if precoat mix or applica-
tion procedure should be
changed.
- See Item 1b.
Repair any malfunctioning
equipment or change either
precoat mix or application
procedure. Follow manu-
facturers' recommendations
for initial changes.
See Item 1b.
OPERATING PROBLEM 3: Filter cycle time excessively long.
3a. Feed solids concentra-
tion too low.
3b. Improper sludge condi-
tioning.
- Operation of upstream
thickening process. Check
solids feed rate with his-
torical data.
See Item 1b.
Inadequate thickening can
result in an excessive
time to build up solids
cake.
See Item 1b.
- If possible, improve
performance of upstream
thickening operation to
achieve higher feed solids;
otherwise, see Item 3b.
- See Item 1b.
-------
TABLF 26
{Continued)
PRESSURE FILTRATION FOR DEWATERING
TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 4: Frequent media blinding, failure to develop cake on media.
4a. Inadequate precoat on
media.
4b. initial sludge feed
rate too high (where
no precoat is used).
4c. Improper sludge
conditioning.
- See Item 2a.
Feed sludge pumping rates
and correlate with previous
performance.
- See Item Ib.
- See Item 2a.
- To establish whether
lower pumping rates have
previously resulted in
less blinding and better
cake formation.
- See Item 1b.
- See Item 2a.
Keep initial feed rate low to
develop cake slowly; or
consider use of precoat if
problems persist.
- See Item Ib.
f-O
OPERATING PROBLEM 5: Pressures increasing during precoat application.
5a. Filter media becoming
blinded, possibly with
carbonate scale.
5b. Improper sludge con-
ditioning causing media
blinding.
- Filter media.
See Item 1b, Also check for
high moisture content in cake
or increased filter cycle
times.
To establish if blinding
has occurred.
See Item 1b.
Water wash filter media. Acid
wash media to remove carbonate
buildup.
- See Item Ib.
5c. Improper precoat mix
or feed procedure.
See Item 2a. Also check
manufacturer's recommended
procedures for precoat
application.
- See Item 2a.
- See Item 2a.
OPERATING PROBLEM 6: Solids cake sticks to conveying equipment after removal from filter.
6a. Improper sludge condi-
tioning.
- See Item 1b.
- See Item Ib.
See Item Ib. Also may need
to change to more inorganic
chemicals (e.g. lime) or
different filter aid material.
-------
TABLE 26
(Continued)
PRESSURE FILTRATION FOR DEHATERIHG
TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM 7: Failure to form adequate seal between plates.
7a. Plates out of align-
ment.
7c. Foreign object
preventing a good
seal.
- Check alignment.
7b. Inadequate skimming. - Check stay bosses.
Open press and inspect
sealing faces for foreign
objects.
See Probable Cause.
See Probable Cause.
See Probable Cause.
Realign plates.
Adjust skimming of stay
bosses.
Remove foreign object.
iv)
-------
SECTION 17
CENTRIFUGATION
INTRODUCTION
Centrifugation is a process used for concentrating sludges generat-
ed during wastewater treatment. Often, centrifuges are used in place of
gravity thickeners. Centrifuges have also been installed, usually
following a thickener, as dewatering devices. The difference between
thickening and dewatering depends upon the final water content of the
sludge. The product of thickening is still a fluid that can be pumped,
while the product of dewatering is a cake that can be handled as a solid
and is transported by conveyers and dumpsters. Whether a sludge needs
to be thickened only or dewatered prior to disposal depends upon many
factors. Similarly, the objective of centrifugation (whether for thick-
ening or dewatering) will be different from one facility to the next,
although the basic principles and operating procedures are the same.
THEORY OF OPERATION
Centrifugation works on the same principle as gravity settling and
thickening, except that the centrifugal forces which cause the particles
to settle are much greater than the force of gravity. In a clarifier or
thickener, the suspended solids which are more dense than water sink to
the bottom of the tank leaving clear liquid above. In centrifuges, a
rotating bowl acts as a highly effective settling chamber. When sludge
is introduced into the bowl and is thrown against the inside wall, it
forms a pool or layer of liquid. The suspended solids in this pool move.
toward the wall, as a result of their greater density, and leave behind
a layer of clear liquid called the centrate. The centrate then is
245
-------
removed, leaving a thickened sludge or solids cake for further treatment
or disposal. Since the same principle is involved as with other thick-
ening devices, sludges that thicken poorly by gravity are generally more
difficult to thicken and dewater by centrifugation. As is the case in
gravity thickening, both polymers and chemical coagulants often are used
to condition sludges prior to centrifugation.
DESCRIPTION OF EQUIPMENT
The method by which the centrate and solids are separated is the
main difference between the many types of centrifuges used in wastewater
treatment. The basic operating principles are the same for all, how-
ever. Three basic types of centrifuges have been used commonly for
wastewater treatment applications in the metal finishing industry; the
solid bowl decanter, the imperforate basket, and the disk-nozzle centri-
fuge. These will be discussed separately below.
Solid Bowl Decanter
The solid bowl decanter centrifuge, also sometimes called a scroll
or conveyor centrifuge, is the most common type used for dewatering
wastewater sludges. This type of centrifuge operates in a continuous or
flow-through mode and consists of a rotating horizontal cylindrical bowl
containing a screw type conveyor or scroll which also rotates, but at a
slightly lower or higher speed than the bowl, as shown in Figure 31 .
The differential speed between the bowl and the conveyor is used to move
the solids toward one end of the bowl for discharge. The bowl is usu-
ally a cylinder made of mild or stainless steel with a conical section
at one end. The conical section is the discharge end for the sludge and
serves as a dewatering beach or drying deck. Sludge enters the rotating
bowl through a stationary feed pipe extending into the hollow shaft of
the rotating conveyor and is distributed through ports in this hollow
shaft into a pool within the rotating bowl.
There are ,two main types of solid bowl centrifuges. The most com-
mon is the counter-current type in which the solids cake and centrate
246
-------
, OIAIN HtO < CASt _ HOC >OOl
SOtlOS OISCHA«G£
?oits AND >iows
HOC
INISI
OlSC»A«Ct
OIIVCN KtO CONVCTOI 5«ASK
SHCAVt riPC COM»»«tM4Nr
flUNMION
SiAlS
Figure 31.
Cross section of concurrent
flow solid - bowl centrifuge.
247
-------
move toward opposite ends of the bowl for discharge. The centrate is
decanted off the top of the liquid pool through a port or over a weir,
the location of which can be adjusted to change the depth of the liquid
within the bowl. In the other type of centrifuge, the concurrent flow
type (Figure 31), the sludge slurry is introduced at the far end of the
bowl from the dewatering beach and the sludge solids and centrate both
flow in the same direction. The centrate is withdrawn by a skimming
device or return tube located near the junction of the bowl and the
beach. Clarified centrate then flows into channels inside the scroll
hub and returns to the feed end of the machine where it is discharged
over adjustable weir plates through discharge ports built into the bowl
head.
Imperforate Basket Centrifuge
The imperforate basket centrifuge, also known as a knife-discharge
centrifuge, is a semi-continuous feeding and solids discharging unit
that rotates about a vertical axis, as shown in Figure 32. Sludge is
fed into the bottom of the basket and sludge solids form a cake on the
bowl walls as the unit rotates. The centrate is displaced over a baffle
or weir at the top of the unit. Sludge feeding is continued either for
a specific period of time or until the suspended solids in the centrate
reach a predetermined concentration.
After sludge feeding is stopped, the centrifuge slows to about 70
rpm, and a plowing knife moves into position, either automatically or
manually, to cut the sludge away from the walls; the sludge cake then
drops through the open bottom of the basket. After plowing terminates,
the centrifuge begins to accelerate and feed sludge again is introduced.
At no time does the centrifuge actually stop rotating. Many units also
have a skimming step which precedes plowing. A special skimmer nozzle
swings into position to remove the low concentration solids which remain
in the basket near the inside surface of the liquid pool. These are
recycled back to an upstream process along with the centrate.
248
-------
FEED
POLYMER-,
SKIMMINGS
CAKE
CAKE
Figure 32.
Schematic diagram of a basket centrifuge.
249
-------
In smaller facilities, where the volume of sludge to be handled is
less, centrifugation may be strictly a batch operation in which rotation
stops completely after each batch is processed. In this case, operation
is usually not automated and the equipment is somewhat simpler in de-
sign.
Although the cake solids concentration and yield are not as high
for the basket centrifuge as for a solid bowl centrifuge, solids recov-
ery is generally better and often less polymer and other conditioning
chemicals are required. Obviously, the cake solids concentration must
be considered as average solids content, since the solids content is
maximum at the bowl wall and decreases toward the center.
Disk-Nozzle Centrifuge
The disk-nozzle centrifuge is a continuous-flow vertical bowl ma-
chine which contains a number of closely spaced disks against which the
particulate solids settle, as shown in Figure 33. The feed slurry
normally enters through the top although bottom feed is also possible,
and passes down through a feedwell in the center of the rotor. An
impeller within the rotor accelerates and distributes the feed slurry,
filling the rotor interior. The heavier solids settle outward toward
the circumference of the rotor under increasing centrifugal force. The
«
liquid and the lighter particles flow inward through the cone-shaped
disc stack. These lighter solids are settled out on the underside of
the discs, where they agglomerate, slide down the discs, and migrate out
to the nozzle region. The centrifugal action causes the solids to con-
centrate as they settle outward. At the outer rim of the rotor bowl,
the high energy imparted to the fluid forces the concentrated material
through the rotor nozzles.
Often, a portion of the thickened sludge discharge is recycled back
into the concentrating chamber near the base of the rotor to increase
the final concentration in the sludge and to help prevent plugging of
the nozzles. In addition to providing a flushing action, the recycle
also permits the use of larger nozzles which are less likely to plug.
250
-------
SLUDGE
DISCHARGE
Figure 33. Disc type centrifuge.
251
-------
Plugging or clogging of the nozzles or the space between disks (which
are generally separated by only 1 to 2 mm) is the main reason that disk-
nozzle centrifuges have not gained wider acceptance in wastewater treat-
ment. However, for thickening sludges from the treatment of metal
finishing wastes, which contain little or no fibrous or gritty material,
they are gaining acceptance.
OPERATIONAL PROCEDURES
The purpose of centrifugation is to minimize both the water content
of the thickened sludge or solids cake and the solids concentration in
the centrate while maintaining sufficient machine throughput to prevent
a buildup or accumulation of sludge in upstream treatment processes.
Generally, efforts to increase . the solids concentration result in a
centrate of poorer quality, while improving centrate quality usually
reduces the sludge or cake solids concentration. Acceptable limits on
the solids content of the centrate are determined when the recycled
centrate begins to interfere with the operation of other treatment pro-
cesses or fine solids begin to build up to unacceptable levels in the
sludge handling system. Although a high solids concentration and good
centrate quality often can be achieved at the same time, to improve both
may require that the machine throughput or solids yield be reduced and
that the use of chemicals for conditioning be increased. There is a
limit on how much the yield can be reduced, as solids must be removed
for disposal as fast as they are generated or they will build up and
affect the performance of other treatment processes. Similarly, there
are limits on chemical usage since such usage represents a significant
part of the total operating costs associated with centrifugation.
Therefore, good centrifuge operation is a compromise between final
solids concentration, centrate quality, solids loading or yield, and
operating costs.
Process Monitoring
The main criteria used in evaluating centrifuge performance are
concentration of the solids discharge, concentration of solids in the
252
-------
centrate, solids capture or recovery, and solids removal or yield (or
machine throughput). Of these the last two require some explanation.
Solids capture, also called solids recovery, is the mass ratio of
cake (or thickened sludge) solids to the feed solids over equal sampling
periods. A lower solids capture means that a greater fraction of the
feed solids are lost to the centrate and are not part of the solids dis-
charge. For a constant solids feed rate, the result is a higher, concen-
tration of solids in the centrate.
The solids yield (removal) refers to the amount of solids, on a dry
weight basis, that can be removed by the. centrifuge during a given per-
iod of time. As a long term average, the yield must equal or exceed the
solids feed rate if sludge solids are not to accumulate in the treatment
system.
In order to evaluate centrifuge performance and diagnose problems,
a complete record of several operating parameters must be kept. These
are listed in Table 27.
The information listed in Table 27 should be recorded routinely,
along with machine operating conditions such as bowl speed, weir set-
tings or pool depth, sludge recycle rate, etc. It is particularly
important that any changes in performance or operating conditions be
"recorded along with the time that they occur.
Example Calculations
Example calculations of operating parameters are presented below.
Consider a continuous solid bowl centrifuge operation for which the
following data have been collected:
Feed sludge flow rate
Centrate flow rate
Feed suspended solids
Centrate suspended solids
= 40 gpm
= 36 gpm
= 40,000 mg/L (4.0 percent)
= 2,250 mg/L (0.23 percent)
253
-------
TABLE 27
CENTRIFUGATION
PROCESS MONITORING REQUIREMENTS
Parameter
Frequency
Comment
1. Sludge flowrate or volume. Daily
2. Sludge suspended solids Daily
concentration.
3. Dewatered cake suspended Daily
solids concentration.
4. Dewatered cake volume. Daily
5. Centrate flowrate. Weekly
6. Centrate suspended solids Weekly
concentration.
7. pH, Temperature Daily
8. Polymer type and dosage. Weekly
To determine solids
feed rate.
To determine solids
feed rate.
To determine centrifu-
gation dewatering
performance.
To determine volume of
cake to be disposed.
To determine solids
capture.
To determine solids
capture.
To evaluate effects of
pH and temperature.
To determine condition-
ing requirements.
254
-------
Solids cake concentration = 350,000 mg/L (35 percent)
Polymer dosage rate = 2 Ib/ton
Concentration of polymer feed = 1.0 percent
The solids feed rate (dry solids fed to centrifuge per hour) is
calculated as follows:
Solids Feed Rate = (feed sludge flow rate) x (feed suspended solids)
= (40 gpm)(60 min/hr)(3.785 L/gal)x(40 g/L)
= 363 kg/hr = 800 Ib/hr
Solids removed (dry solids per hour) is calculated as follows:
Solids removed = (feed solids mass applied) - (centrate solids mass)
= (800 Ib/hr) - (2.25 g/L)(lb/454g)(36gpm)(3.7854 L/gal)
(60min/hr)
=760 Ib/hr
Solids capture or solids recovery is calculated as follows:
Solids Capture = (760)/(800) x 100 = 94.9 percent
Process Control Strategies
The operation and performance of a centrifuge is determined by a
number of variables that can be related either to the machine itself
(machine variables) or the specific sludge thickening or dewatering
application (process variables). Although these variables differ for
various types of centrifuges, many are of general importance. Among
them are the following.
255-
-------
Machine Variables . Process Variables
Centrifuge Design Sludge Characteristics
Bowl Speed Chemical Addition
Pool Depth Solids Concentration
Conveyor Speed Solids Feed Rate
Tempera ture
PH
Recycle of Sludge
These variables and the effect that these variables have on solids
recovery and cake solids concentration are presented in Table 28.
Machine Variables--
Some of the most important machine variables are fixed by the
centrifuge design and are not under operator control. Among these are
the bowl length to diameter ratio, bowl angle or slope of the dewatering
deck, scroll or conveyor design, flow patterns (concurrent or counter-
current), disk spacing, and nozzle diameter. Although important as
design choices, a detailed discussion of these variables and their
effects on the process will not be presented in this manual.
The rotational speed of the centrifuge is one of the most important
factors affecting performance since centrifugal force speeds up the
sedimentation process. An increase in bowl speed provides more gravity-
settling force, thus providing greater clarification of the centrate and
compaction of the solids. In solid bowl decanters, greater centrifugal
forces also can help to squeeze water out of the sludge on the drainage
deck, thereby producing a drier solids cake. Sometimes, higher bowl
speeds can reduce polymer usage. If these advantages outweigh the
increased power costs, operation at higher speeds can be beneficial.
There are problems with increasing bowl speeds, however. Higher
speeds sometimes result in shearing of the sludge floe. Since smaller
particles settle more slowly, higher bowl speeds can result in a higher
concentration of suspended solids in the centrate. This problem can be
avoided largely in machines where coagulant aids are added internally
256
-------
TABLE 28
SUMMARY OF OPERATIONAL VARIABLES AFFECTING
CENTRIFUGE PERFORMANCE
Effect of increase in variable on
Variable % Solids Recovery Cake Solids Concentration
Machine Variables
Bowl Speed Increase Increase
Pool Depth Increase ' Decrease
Scrolling Speed Decrease Decrease
Process Variables
Feed Rate Decrease Increase
Feed Concentration Decrease Increase
Temperature Increase Increase
Chemical Addition Decrease Increase
*Sludge Recycle Decrease t- Increase
* Disk-nozzle centrifuges only. -
257
-------
into the bowl and flocculation occurs after the solids are up to the
bowl speed. Another problem with higher speeds, especially in solid
bowl centrifuges with a conveyor or scroll, is that tremendous pressures
are set up between the solids and the surfaces of scroll and bowl,
tending to lock these two parts together. Further, with abrasive
sludges, high friction and costly wear result. Some sludges, though not
especially abrasive, have poor sliding characteristics and resist con-
veying. This resistance .can impose high loads on the scroll and on the
gear unit which drives it. Therefore, final adjustment of bowl speed
must be a compromise between degree of clarification, degree of cake
dryness, chemicals used, and costs of maintenance and power. Because of
these and other complicating factors, bowl speed is not normally varied
on most centrifuge models once a centrifuge is installed.
Pool depth affects the performance of both conveyor and basket
centrifuges, while disk-nozzle centrifuges usually are designed to
operate completely filled without a variable pool depth. Settling
theory says that the best clarification (or solids capture) occurs when
liquid depths are shallow, since the solid particles have a shorter
distance to travel to be separated from the liquid. However, experience
has shown there to be a limit to how shallow the pool can be and still
maintain good solids capture. Too shallow a pool results in a high
linear velocity through the centrifuge, a condition which causes turbu-
lence that resuspends settled particles and prevents settling of very
fine particles. In conveyor type centrifuges, the turbulence caused by
the scroll also has more adverse effect on settleability when the pool
depth is shallow. Since the residence time within the centrifuge is
shorter when the pool depth is shallower, less time is available for
flocculation to occur. This also can result in poorer centrate quality.
There are limits to how deep the liquid pool in a centrifuge can
be, however. As settling theory predicts, increasing the depth too much
can also cause a low solids capture and poor centrate quality since the
particles must settle through a greater distance to be removed. There
are also cases in which a shallow pool is desirable. In a solid bowl
conveyor type centrifuge, lowering the pool exposes more of the drainage
258
-------
deck or beach area, and increases the time available for dewatering.
This condition results in a drier solids cake.
With most centrifuges, pool depth is more
speed, but still requires several hours of
fore, other remedies usually are tried first
easily changed than bowl
and down-time. There-
wh|en a problem exists.
labor
In solid bowl decanter centrifuges, the
at a slightly different speed (either faster <
This speed differential can normally be varied
manually while the machine is not running.
ped with an automatic backdrive, making the
ly easy to change. Usually the pool depth is
Conveyor speeds normally are designed or
still provides sufficient conveying capacity
cpnveyor or scroll rotates
r slower) than the bowl.
by adjusting gear ratios
centrifuges are equip-
speed relative-
fixed in such machines.
to the minimum that
Some
differential
adjusted
Increasing the differential between the
speed normally results in a wetter sludge
covery because of increased turbulence and
time. However, the machine throughput or
more sludge can be processed in a given period
differential speed reduces turbulence inside
quality centrate and a drier cake. Differen
reduces the rate of wear on the conveyor
sludges are handled. The main disadvantage
is reduced.
ca.ce
yield
the
blades
is
spe«;d
Operating at too low a differential
solids formed in front of the scroll conveyor
all height such that it infringes on the
condition may result in the skimming of some f:
the cake pile to the centrate, thereby lowering
low differentials, it is even possible to plug
259
bowl speed and the scroll
and poorer solids re-
reduced solids residence
is increased; that is,
of time. A reduction in
pool, yielding a better
:ial speed reduction also
when poorly degritted
that machine throughput
can cause the pile of
iblade to increase in over-
clarjified liquid area. This
ne solids from the top of
solids capture. At very
centrifuge with solids.
-------
Process Variables—
Among the process-related variables, the most basic are those asso-
ciated with the sludge itself. The factors that influence settling and
gravity thickening also affect centrifugation. Among these are particle
size, shape, and density, viscosity of the liquid, and consistency of
the sludge. These variables are generally not under direct control of
the operator, but simply result from optimizing upstream treatment pro-
cesses. In some cases, changes in the operation of an upstream process
can affect the thickening and dewatering properties of the sludge gene-
rated without reducing performance.
Often, polymers or other chemical conditioners can be used to
improve the characteristics of a sludge prior to centrifugation. These
polymers generally work by promoting flocculation of the sludge solids,
thereby increasing solids capture. Usually flocculating agents are
required to achieve an acceptable centrate quality. Although polymers
can sometimes improve the compatability of a sludge, their use in cen-
trifuges generally results in a wetter solids cake. The wetter cake
results because the additional particles that are captured are very fine
and their presence in the solids cake makes it more difficult for the
entrapped water to be released. Jar tests are used to select the best
polymers and to determine approximate dosage levels, after which oper-
ating experience is required to optimize polymer usage. Very small
changes in sludge properties sometimes can require that polymer dosages
be changed and can occasionally even necessitate the use of different
types or combinations of polymers. In addition to wasting money, adding
too much polymer (overdosing) can hurt performance.
The solids concentration in the sludge feed can affect both solids
capture and cake dryness. A higher feed concentration generally results
in lower solids capture and higher concentrations of suspended solids in
the centrate. However, depending upon the concentration range, there
are some sludges which show better clarification at higher solids con-
centrations. The concentration of solids in the feed slurry can also
affect the optimum coagulant dose, and jar tests should be performed
whenever the feed concentration changes significantly. The other effect
260
-------
of higher solids concentrations in the feed is to produce a drier sludge
cake. If a drier cake is an objective of centrifuge operation, changes
in the operation of upstream treatment steps which affect sludge concen-
tration, such as clarification and thickening, can improve centrifuge
performance.
The rate at which sludge is fed to a centrifuge is important. When
the volume of sludge centrifuged during a given period of time is in-
creased, the residence time within the centrifuge is decreased and more
solids are lost in the centrate. However, a higher feed rate sometimes
can result in a drier cake since the additional solids lost in the
centrate are fines which tend to entrap water within the cake. When
centrifugation is not performed on a continuous basis, taking a longer
period of time to centrifuge a batch of sludge can improve performance
and possibly can reduce chemical requirements for coagulation. In
facilities in which centrifugation is a continuously operated process,
the feed rate can only be decreased by increasing the concentration of
the sludge feed.
Recycle of concentrated solids usually is performed only in disk-
nozzle type centrifuges where several functions are served. First,
recycle permits control over the solids residence time in the centrifuge
and helps to optimize operation under equilibrium conditions. If the
feed rate changes, the recycle rate can be changed accordingly to main-
tain the required solids residence time to achieve the desired degree of
solids concentration. Second, the use of recycle helps keep the velo-
cities high through the concentrating section so that the nozzles do not
become plugged. In fact, some centrifuges are designed with larger
nozzles (to prevent plugging) which require that recycle be used in
order to achieve the necessary solids residence times. The third reason
for recycle or for changing the recycle rate is to provide a longer
residence time and thereby achieve even greater concentration of the
sludge solids.
261
-------
Another process variable affecting centrifugation is temperature.
As is the case in gravity settling and thickening, an increase in sludge
temperature reduces the viscosity of the liquid and results in better
centrifuge performance since solid particles settle faster. Although
temperature is not usually a controlled variable, it is of importance if
seasonal changes affect the temperature of the sludge fed to a centri-
fuge. For example, poorer solids capture and a wetter cake can be
expected during winter months when sludge temperatures drop.
Changes in either or machine or process-related variables generally
result in changes in centrifuge performance. Some factors which affect
performance are not subject to change, such as those related to centri-
fuge design or sludge thickening and dewatering characteristics. Of the
variables which can change, some are used in controlling centrifuge
operation while others (such as temperature and feed concentration) may
depend upon the operation of upstream treatment processes. The typical
effects of these variables on performance are summarized in Table 23.
It should be noted that these effects only apply over normal operating
ranges when one variable is changed at a time. Generally predictions
cannot be made as to the effects of changing several variables at once.
TYPICAL PERFORMANCE VALUES
Two factors must be considered when referring to typical perfor-
mance values for centrifugation of sludges generated during treatment of
metals finishing wastewater. First is the type of sludge. If sodium
hydroxide is used for pH adjustment to precipitate metal hydroxides, a
light, slimy, and relatively difficult to dewater sludge will result.
When lime is used, the amount of excess lime determines the dewatering
characteristics of the sludge. When very little or no excess lime is
added, most of the sludge formed will be metal hydroxides. If consider-
able excess lime is used, a large amount of calcium carbonate will be
present in the sludge, making it heavier and more easily dewatered.
The second factor to consider is the objective of centrifugation.
Most often, centrifuges are used for dewatering and are sized to give a
262
-------
high solids concentration cake. Sometimes, however, centrifuges are
intended to function as thickeners prior to final dewatering by another
process. This is especially common when disk-nozzle centrifuges are
used. The product of centrifugal thickening is still a pumpable liquid,
rather than a solids cake.
Table 29 gives some typical applications and performance values for
different types of centifuges applied to both metal hydroxide and lime
carbonate type sludges.
TROUBLESHOOTING GUIDE
The problems which are commonly associated with centrifuge opera-
tions have been summarized in the form of a troubleshooting guide in
Table 30. This is a general guide and some specific types or brands of
centrifuges may be subject to unique operating problems which usually
are covered in the manufacturer's literature.
The most important fact to remember regarding centrifuge operation
is that all of the machine and process variables which have been discus-
sed are interrelated in some way. Therefore, when evaluating the effect
of any one variable, care must be taken to insure that all others remain
unchanged. Otherwise, the cause of a particular problem (or its solu-
tion) cannot be determined with certainty.
263
-------
TABLE 29
TYPICAL PERFORMANCE VALUES FOR CENTRIFUGAL
THICKENING AND DEWATERING
Centrifuge
Type/Sludge
Type
Feed Solids
Concentration
Cake Solids
Concentration
Solids
Recovery
Polymer
Dosage
(Ib.per
dry ton)
Solid Bowl (Scroll)
Metal Hydroxide 0.5-4
High CaCO,
15-45
2-8
80-95
90-99
0-10
20-50
Imperforate Basket
Metal Hydroxide 0.5-4
High CaCO-
10-30
2-8
80-95
90-99
0-5
15-45
*Disk-Nozzle
Metal Hydroxide 0.2-1
High CaCO,
0.5-2
1-5
2-10
85-90
90-95
0-10
0-10
*Generally used only for thickening.
264
-------
TABLE 30
CENTRIFUGATION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
(Centrifuge Type)
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
OPERATING PROBLEM Is Poor centrate quality - 3ow solids recovery.
KJ
CTv
Ul
la. Improper chemical
dosage. (All types)
1b. Feed rate too high.
(All types)
1c. Feed solids
concentration too
high. (All types)
Id. Pool depth setting
wrong.(Solid bowl,
basket)
1e. Improper speed
differential
between bowl and
conveyor.(Solid
bowl)
If. Morn or damaged
conveyor flights.
(Solid bowl)
Chemical addition
system.
Flow data records
and performance.
Check feed solids
against previous
values.
Check weir or ef-
fluent port position
and compare with
operating records.
Differential speed
setting and
operating records.
Excessive build-up
of solids in bowl.
Vibration or unusual
noise; excessive
build-up of solids
in bowl.
Setting may be
wrong or equipment
malfunctioning. If
neither, sludge
characteristics may
have changed.
High flows can
reduce detention
times. Compare
with period of good
operation to see if
this is the case.
Determine if good
operation has been
achieved at the same
high feed solids
concentration.
Generally, poor
solids capture
results from too
shallow a pool
depth, but not
always. Compare
with previous
performance.
Probably too great
a differential
causing turbulence
in liquid pool.
If solids build-up
is great, speed
differential may be
too small.
Puild-up of solids
causes conveyor
entrainment into
centrate discharge.
Repair or reset equip-
ment or perform jar
tests to establish new
polymer dosage.
Reduce flow to centri-
fuge or reduce sludge
recycle.
Dilute sludge feed or
reduce flow rate.
Adjust weir or
port settings.
Adjust differential
speed.
Repair or replace
solids conveyor.
-------
TABLE 30
(Continued)
CENTRIFUGATION TROUBLESHOOTING GUIDF
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
NJ
cn
CTi
Ig. Improper bowl
speed.(All types)
1h. Solids discharge
line or nozzle
plugged*(Disk-nozzle,
Solid bowl)
- Check bowl speed and
operating records.
- Check solids dis-
charge line and
nozzle for foreign
objects and low flow.
Insufficient speed
results in poor
solids capture.
Low sludge discharge
results in poor
solids capture.
2d. Pool depth too
great.(Solid bowl,.
Basket)
2e. Improper bowl speed.
(All types)
2f. Centrate outlet
partially plugged.
(Solid bowl. Disk-
nozzle)
Weir or effluent put
setting.
Check bowl speed and
operating records.
Check outlet for
foreign objects.
Shallower pool
exposes more beach
or drying deck.
Insufficient speed
results in poor
sludge compaction.
Low centrate flow
results in thinner
sludge discharge.
Increase bowl
speed or repair
or replace malfunc-
tioning equipment.
Unplug solids discharge
line or nozzle.
OPERATING PROBLEM 2: Cake
2a.
2b.
2c.
Improper chemical
dosage. (All types)
Feed rate too high.
(All types)
Feed solids
concentration too
low. (All types)
or sludge discharge too wet.
- Chemical addition
system and chemical
flow rate.
Flow and perform-
ance data.
Solids concentra-
tion 'and operating
records .
Setting may be
wrong or equipment
malfunctioning.
High flows reduce
retention tine.
Compare with period
of good operation.
- Higher feed solids
usually give a
drier cake.
Repair equipment
or adjust dosage.
Run jar tests to
determine dosage.
Reduce flow to
centrifuge or
increase sludge
recycle.
- Determine if thick-
ened sludge can be
obtained from
previous treatment
steps.
Adjust weir or put
settings.
Increase speed or
repair/replace
malfunctioning
equipment.
- Clean outlet port.
-------
TABLE 30
(Continued)
CENTRIFUGATION TKOUBLFSHOOTING GUIDE
CTl
PROBABLE CAUSE
OPERATING PROBLEM 3: High torqe
3a. Feed rate too high. -
(All types)
3t>. Feed solids too
high. (All types)
3c. Foreign material in
machine. (All types)
3d. Gear unit mis-
aligned. (All types)
3e. Faulty bearing,
gear. (All types)
OPERATING PROBLEM 4: Excessive
4a . Improper
lubrication.
(All types)
CHECK OR MONITOR REASON CORRECTIVE ACTION
alarm.
Flow records. - Reduce flows.
Solids data records. - Dilute sludge or
reduce flow rate.
Inspect interior. - Remove foreign
material.
Vibration. - Correct alignment.
Inspect gear unit. - Replace faulty parts.
vibration.
Check lubrication - Correct lubrication.
system.
4b. Improper adjust-
ment of vibration
isolators.(All types)
4c. Discharge funnels
may be contacting
centrifuge,(All types)
4d. Portion of conveyor
flights may be
plugged with solids
causing imbalance.
(Solid bowl)
4e. Gear box improperly
aligned.(All types)
4£. Pillow block
bearings damage.
(All types)
Vibration isolators.
- Position of funnels.
Interior of machine.
Gear box alignment.
Inspect bearings.
Adjust isolators.
Reposition slip
joints at funnels.
Flush out centrifuge.
Align gear box.
Replace bearings.
-------
TABLE 30
(Continued)
CENTRIFUGATION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
RFASON
CORRECTIVE ACTION
4g. Bowl out of balance.
(All types)
4h. Pacts not tightly
assembled.
(All types)
4i. Uneven wear of
conveyor.
(Solid bowl)
Inspect conveyor.
Return rotating parts
to manufacturer for
rebalance.
Tighten parts.
Resurface, rebalance.
OPERATING PROBLEM 5: Sudden increase in power consumption.
00
5a. Contact between
bowl and accumulated
solids in centrifuge
case.(All types)
5b. Effluent pipe
plugged.(All types)
Solids plows; look
for polished area
on outer bowl.
Check for free
discharge of solids.
Apply hard surfacing to
to areas with wear.
Clear effluent pipe.
OPERATING PROBLEM 61 Gradual increase in power consumption.
6a. Conveyor blade wear.
(Solid bowl)
- Conveyor condition.
- Pesurface blad^s,
OPERATING PROBLEM 7: Spasmodic, surging solids discharge.
7a, Pool depth too low.
(Solid bowl)
Plate dam position.
- Increase pool depth.
7b. Conveyor helix
rough. (Solid bowl)
7c. Feed pipe (if adjust-
able) too near drain-
age deck.(Solid bowl)
Improper hard
surfacing or corrosion.
Refinish conveyor
blade areas.
Move feed pipe to
effluent end.
-------
TABLE 30
(Continued)
CFNTRIFUGATION TROUBLESHOOTING GUIDE
PROBABLE CAUSE
CHECK OR MONITOR
REASON
CORRECTIVE ACTION
7d. Machine vibration
excessive (Solid bowl.
Disk-nozzle)
- See Item
See Item 4.
OPERATING PROBLEM 8: Centrifuge shuts down (or will not operate).
cn
8a. Blown fuses.
(All types)
8b. Overload relay
tripped.
(All types)
8c. Motor overheated,
thermal protectors
tripped.(All types)
6d. Torque control
tripped.(All types)
8e. Vibration switch
tripped.(All types)
Fuses.
Overload relay.
Thermal protectors.
- See Item 3. Check
torque indicator.
See Item 4.
Overload or weak
fuse. May be
wrong size fuse.
Insufficient ventila-
tion. High air
temperature.
Torque indicator may
be stuck or defective.
Switch may be
defective.
- Replace fuses, flush
machine. If fuse blows
on start-up, mechanical
inspection is required.
- Flush machine, reset
relay. If relay trips
on restart, mechanical
inspection is required.
- Flush machine, reset
thermal protectors.
Check fan on motor.
Replace or repair.
Replace.
-------
REFERENCES
1. USEPA. Environmental Regulations and Technology: The Electro-
plating Industry, EPA 625/10-80-001, 1980. 44 pp.
2. USEPA. Environmental Pollution Control Alternatives: Centralized
Waste Treatment Alternatives for the Electroplating Industry, EPA
625/5-81-017, 1981. 36pp.
3. USEPA. Summary Report: Control and Treatment Technology for the
Metal Finishing Industry, Ion Exchange, EPA 625/8-81-007, 1981. 46
pp.
4. USEPA. Summary Report: Control and Treatment Technology for the
Metal Finishing Industry, Sulfide Precipitation, EPA 625/8-80-003,
1980. 54 pp.
5. USEPA. Summary Report: Control Technology for the Metal Finishing
Industry, Evaporators, EPA 625/8-79-002, 1979. 42 pp.
6. USEPA. Environmental Pollution Control Alternatives: Economics of
Wastewater Treatment Alternatives for the Electroplating Industry,
EPA 625/5-79-016, 1979. 72 pp.
7. USEPA. Summary Report: Control and Treatment Technology for the
Metal Finishing Industry, In-Plant Changes, EPA 625/8-82-008, 1982.
30 pp.
8. USEPA. Methods for Chemical Analysis of Water and Wastes, EPA
600/4-79-020, 1979.
9. American Public Health Association. Standard Methods for the Exam-
ination of Water and Wastewater, 14 ed., American Public Health
Association, Washington, D.C., 1975. 1193 pp.
10. Federal Register, 48(137), 32462-32488 (July 15, 1983).
11. Tretolite Industrial Bench Testing Procedures Manual, Tetrolite
Corporation, St. Louis, MO.
12. Cherry, K. F. Plating Waste Treatment. Ann Arbor Science Publish-
ers, Inc., Ann Arbor, Michigan, 1982. 324 pp.
13. .Patterson, J. w. Technology and Economics of Industrial Pollution
Abatement. IIEQ No. 76/22, Illinois Institute for Environmental
Quality, Chicago, Illinois, 1976. 614 pp.
14. Water Pollution Control Federation. Operation of Wastewater Treat-
ment Plants, Manual of Practice No. 11, Water Pollution Control
Federation, Washington, D.C., 1976.
270
-------
15. Snoeyink, V. L. and D. Jenkins. Water Chemistry, John Wiley and
Sons, Inc., New York, NY, 1980.
16. Shinskey, F. G. pH and plon Control in Process and Waste Streams,
John Wiley and Sons, Inc., New York, NY, 1973.
17. Scott, M. C. Sulfex® - A New Process Technology for Removal of
Heavy Metals from Waste Streams* In: Proceedings of the 32nd
Industrial Waste Conference, Purdue University, Ann Arbor Science
Publishers, Inc., Ann Arbor, Michigan, 1977. pp. 622-629.
18. Thomas, M. J., and T. L. Theis. Effects of Selected Ions on the
Removal of Chrome (III) Hydroxide. Journal Water Pollution Control
Federation, 48(9):2032-2045, 1976.
19. Patterson, J. W. Effect of Carbonate Ion on Precipitation Treat-
ment of Cadmium, Copper, Lead, and Zinc. In: Proceedings of the
36th Industrial Waste Conference, Purdue University, Ann Arbor
Science Publishers Inc., Ann Arbor, Michigan, 1975. pp. 132-150.
20. Patterson, J. W., J. J. Scala, and H. E. Allen. Heavy Metal Treat-
ment by Carbonate Precipitation. In: Proceedings of the 30th
Industrial Waste Conference, Purdue University, Ann Arbor Science
Publishers Inc., Ann Arbor, Michigan, 1975. pp. 132-150.
21. Weber, W. J., Jr. Physiochemical Processes for Water Quality Con-
trol. John Wiley and Sons, Inc., New York, New York, 1972. 640
PP.
22. Water Pollution Control Federation. Wastewater Treatment Plant
Design, Manual of Practice 9, Water Pollution Control Federation,
Washington, D.C., 1977. 560 pp.
23. Great Lakes - Upper Mississippi River Board of State Sanitary
Engineers. Recommended Standards for Sewage Works, Health Educa-
tion Service, Inc., Albany, New York, 1978.
24. Sexsmith, D. R., E. A. Sayinelli, and J. S. Beecher. The Use of
Polymers for Water Treatment. Ind. Water Eng., Dec. 1969, pp.
18-24.
25. The American City and County, Dec. 1976, pp. 45-48.
26. BIF Technical Information, Polyelectrolyte Coagulant Aids and
Flocculants, Dry and Liquid, Handling and Application, April 1971.
27. Adorjan, L. A. Some Aspects of Flocculation. Coal Preparation,
Sept./Oct. 1968, pp. 171-176.
271
-------
(This page left blank intentionally.
272
-------
APPENDIX A
LITERATURE REVIEW
This appendix consists of a computer literature search performed on
the Lockheed Dialog™ system. Two data files were accessed, after a
preliminary scan indicated that they contained the most references for
the applicable keywords. These files were the Metals Index (File 32)
and the Pollution Abstract Index (File 41). A total of 289 references
are contained herein; 47 are from the Metals Index and 247 are from
Pollution Abstract Index.
273
-------
Print 4/5/1-21
DIAIOG File32: METADEX - 66-82/Jun
(Copr. Am. Soc. Metals) (Item
784136 81-58O849
Routes to Metals Recovery From Metal Finishing Sludges.
Mehta. A
Third Conference on Advanced Pollution Control for the Metal
Finishing Industry. Klsslmmee. Fla.. 14-16 Apr. 198O
76-79
Publ Industrlal Environmental Research Laboratory, U.S.
EnvIronmental Protect ion Agency. ClnclnnatI, Ohio 45268,
1981
Language: ENGLISH
Document Type: BOOK
Process wastewaters from the electroplating Industry contain
cyanides and heavy metals that must be treated because of
environmental impact and discharge regulations. One of the
treatment technologies already in wide use and more likely to
be Instalted Is neutralIzatlon and precipitation technology
which destroys the cyanide and removes the heavy metals as
hydroxides. Various ways to recover metals from metal
finish!ng s1udges are dIscussed a 1ong with economIca1
considerations. The concept of a Centralized Waste Treatment
Facility (CWTF) Is presented as an alternate to Individual
metal recovery treatments. Other topics discussed ,are:
pyrometat 1urgleal treatments; hydrometal1urgleal treatments;
commonly used leaching reagents; Ion exchange; solvent
extraction; cementation and electrolysis.7 refs.--G.G.M.
Descr iptors: ElectroplatIng; Sludge disposal; Pol IutIon
aba tement; Copper, Recover Ing; Zinc, Recover Ing
Section Heading. 58 (METALLIC COATING) Journal
Announcement: 811O
784O34 81-57O6O4
Stabilization of Heavy Metal Wastes by the Soil roc Process.
Rousseaux, J M ; Craig Jr. A B
Third Conference on Advanced Pollution Control for Metal
Finishing Industry. Klssfmmee, Fla., 14-fG Apr. 198O
7O-75
Publ• Industrlal Environmental Research Laboratory, U.S.
Env i ronmentat Protect Ion Agency, CInclnnatI, Ohio 45268,
1981
Language: ENGLISH
Document Type: BOOK
The metal finishing Industry generates a variety of waste
materials that are potentially hazardous. I.e. electroplatIng
process resIdues, pIcklIng acIds and wastewater treatment
sludges containing cyanides and heavy metals. Landfill Ing and
ponding are two common methods for disposal of these wastes
but very little precaution Is taken to prevent ground water
contarnlnat Ion. Vanlous f txatIon techniques have been studied
t o chem1ca11y b1nd 1norgan1c res Idues and sIudges; these
Include prec ipt tat Ion, encapsulatIon, asphaltIng, cementatIon
and other similar stabilization processes. An evaluation of
one fIxatIon process. the Sol I roc process, developed by
Cemstobel In Brussels. Belgium. Is discussed. fhe evaluation
was designed to provide experimental data and to establish a
data base for future pilot scale work.--G.G.M.
1 Of 21) User23913 23jun82
Descriptors. Waste disposal; Pollution abatement; Pickling;
Electroplat1ng
Sect Ion Heading: 57 .(FINISHING) Journal Announcement. 811O
7649OI 81-42O522
Process for Recovering Molybdenum and Tungsten From Mining
Wastewater.
Ramirez. E R ; Ramadoral, G
Oravo Corp
Patent: US4219416 .U.S.A . 29 June 1978
Off. Gaz. ,26 Aug. 198O,
Document Type: PATENT
A method for removing heavy metals selected from the group
consisting essentially of Mo, tungsten, Cr and arsenic from
wastewater In their anIonic forms as molybdates, Kingstates,
chromates and arsenates comprises the steps of adding to a
wastewater having a pH of approx 2.O-6.O a trlvalent metal
Ion selected from the group consisting of ferric, Co, Al, Cr
or Re to the wastewater In an amount sufficient to provide
6-2O ppm trIvatent metal cat ions/ppm of total molybdate.
ungs
^luble
heteropoly molybdate, tungstate, chrornate and arsenate salts
within the wastewater; adding a hydroxyl providing base to
raise the pH yet maintain It within the acidic range to form a
gelatinous precipitate; subjecting the wastewater to a dense
zone of microbubbles to form embryo floes from the Insoluble
salts; adding an anlonlc polyelectrolyte polymer flocculant to
the wastewater; and subjecting the wastewater to an additional
dense zone of microbubbles to form from the embryo floes full
floes that are buoyed to the surface.
Descr iptors; Molybdenum. Recover Ing; Tungsten, Recover Ing;
Chromium, Recovering; Solvent extraction; Flocculating
Section Heading: 42 .(EXTRACTION AND SMELTING) Journal
Announcement: 81O5
-------
DIALOG Flle32- MEtADEX - 66-82/Jun (Copr. Am. Soc Metals) (Item 4 of 21) User23913 23junB2
724528 BO-58O612
Removal of Copper. Nickel, Zinc, Cadmium and Cyanide From
Plating Wasteuater by Electroflotatlon.
Poon, C P C
Management and Control of Heavy Metals In the Environment,
London, England, Sept. 1979
572-575
Publ: Commission of the European Communities, Botte
Postale 1OO3, Luxembourg. 1979
Language- ENGLISH
Document Type. BOOK
The use of an electrof lotat Ion process to remove heavy
metals from plating wastewaters was Investigated. Cathodlc
generation of hydroxides raised the pH and reduced the metal
solubility, resulting In metal precipitation which was carried
up to the surface by the rising gas bubbles. Copper, Nl. Zn
and Cd were successfully removed, with the effluents meeting
U S standards. Free oxygen and ozone produced at the afiode
oxidized Nl In solution to form nickel oxides which
precipitated out. Hypochlorlte and Cl gas oxidized cyanide and
liberated heavy metals from the cyanide--metal complexes which
preceded alkaline precipitation. Performance equations were
developed which Indicated the relative significance of the
effect of each operating variable on treatment performance and
suggested how the process could be better modified to treat
plating wastewaters of different character IstIcs.--AA
Descriptors: Electroplating; Flotation; Pollution abatement;
Copper, Recovering; Nickel, Recovering; Zinc, Recovering;
Cadmium. Recovering
Section Heading 58 .(METALLIC COATING) Journal
Announcement: 8O08
724527 8O 5BO61I
Laboratory Scale Treatment of Nickel-Bearing Industrial
Effluent.
Chin. K K ; Tay. J H
Management and Control of Heavy Metals In the Environment.
London, England. Sept. 1979
567-571
Publ. Commission of the European Communities. Bolts
Postale IOO3, Luxembourg. 1979
Language. ENGLISH
Document Type: BOOK
A laboratory scale study was carried out for Nl-bearlng
wastes from the electroplating Industry. The wastewater In
general contained approx 8O mg/1 of Nl . Chemical
precipitation using approx 5 mg/1 of lime or alum resulted
In 8O% removal of the metal. Barium sulflde precipitation
produced excellent settling floes and 1OO3& removal of th metal
at pH > 9. Polymer dosage of up to O.I mg aided the
precipitation process. Ion exchange using amberllte IR-I2O was
able to remove 1OO% of the ions present. Cost for treating 50O
OOO kg/day of this waste, using chemical precipitation
followed by Ion exchange with pH adjustment, was dollars U.S.
O 6fl/m3 water treated.--AA
Descriptors: Nickel plating: Wastes; Pollution abatement
Sec 11on HeadIng:
Announcement: 8OO8
.(METALLIC COATING)
7O3O24 8O-72OO19
Eleventh Mid-Atlantic Industrial Wastes Conference.
Pennsylvania State University. Pa., 15-17 duly 1979
Pp 244. BI/4 x IO3/4 In., Illustrated
Publ: Pennsylvania State University, Philadelphia, Pa.,
1979
Language: ENGLISH
Document Type: BOOK
Contents Include: J.L. FALK. "Water Pollution Abatement
Moore Co."; B.D. GILLEN. "Removal of Dilute Zinc, Manganese,
Lead Concentrations From a Municipal Refuse Quench/Scrubber
Wastewater Effluent Using Chemical Precipitation Techniques";
R.M. Results for Sulflde Treatment of Heavy Metal Wastewaters
Using Generated Ferrous Sulflde"; F.A. DAM1CO and O.F SMITH.
Recoverable Wastes From III--V Compound Semiconductor
Manufacture"; SUdARITTANONTA and J.H. SHERRARD, "Activated
Sludge
Descriptors: Pollution abatement
Section Heading: 72 .{SPECIAL PUBLICATIONS) Journal
Announcement: BOO1
702973 8O-71OO42
Removal of Dilute Zinc, Manganese, Cadmium and Lead
Concentrations From a Municipal Refuse Quench/Scrubber
Uasteuater Effluent Using Chemical Precipitation Techniques.
Gillen. B D
Eleventh Mid-Atlantic Industrial Wastes, Pennsylvania
State University. Pa.. 15-17 July 1979
14-24
Publ: Pennsylvania State University. Philadelphia. Pa..
1979
Language: ENGLISH
Document Type: BOOK
Various sampling programs and bench-scale treatablllty
studies performed on the process water discharge of two
municipal refuse Incinerators are described. The waste water
was characterized for chemical composition and solids
concentration. Effluent metal concentrations were related to
effluent pH and temp. Metal removal In the 90-97% range was
achieved by lime polymer addition. A system for the removal
of metals Is recommended.14 refs.--A.M.G.
Descriptors: Gas scrubbing; Industrial wastes; Effluents;
Zinc. Recovering; Cadmium, Recovering; Manganese. Recovering:
Lead (metal). Recovering 1
Section Heading: 71 .(GENERAL AND NONCLASSIFIED) Journa\
Announcement: BO01 w
-------
DIALOG Flle32: METADEX - 66-B2/Jun (Copr. Am. Soc. Metals) (Item
8 of 21) Usei-23913 23jun82
cn
Philadelphia. Pa..
wastewater treatment
of metal finishing
employs an advanced
7O2779 8O-580O4O
Operating Results for Sulflde Treatment of Heavy Metal
Wastewatens Using In-Process Generated Ferrous Sulflde.
Schlauch. R M
Eleventh Mid-Atlantic Industrial Wastes, Pennsylvania
State University. Pa.. 15-17 duly 1979
38-51
Publ: Pennsylvania State University,
1979
Language: ENGLISH
Document Type: BOOK
The operation and performance of four
Installations for different types
operations are described. Each system
technique for highly effective removal of heavy metals by
reaction with sulflde. A novel method of sulflde
precipitation, using ferrous sulflde, has been shown to be
superior to the conventional hydroxide processes In removing
both dissolved and complexed heavy metals. It also has the
advantage over other sulflde precipitation methods In that It
will maintain a high stolchlometrIc excess of sulflde In the
system to Increase reaction kinetics, but prevents the
unwanted formation and evaluation of toxic hydrogen sulflde
gas.--AA
Descriptors: Copper, Recovering; Iron. Recovering;
Electroless plating; Precipitation; Water pollution; Effluents
: Sulfides
Section Heading: SB .(METALLIC COATING) Journal
Announcement: 80O1
68OO8O 79-72O34O
Advanced Pollution Control for the Metal Finishing Industry.
Klsstmmee. Ma.. 5-7 Feb. 1979
Pp 151, 81/2 x II In.. Illustrated
Publ: U.S. Environmental Protection Agency, Cincinnati,
Ohio 45268. May 1979
Language: ENGLISH
Document Type: BOOK
Contents Include. M E. BROWNING, J. KRALJIC and G.S.
Finishing Sludge Disposal; Economic, Legislative and Technical
for 1979"; C. ROY, "Methods and Technologies for Reducing the
Electroplating Sludges"; P.S. MINOR and R.J. BATSTONE.
Federal Republic of Germany'-s Centralized Waste Treatment
Approach In United States"; F.A. STEWARD and H.H HEINZ.
"Economical Shop Case History"; J A. BIENER, "City of Grand
Rapids. Industrial Waste Control"; A.F. LISANTI and S.O.
Proper Unit Processes for the Treatment of Electroplating
Wastewaters"; PRICE and C. NOVOTNY, "Water Recycling and
Nickel Recovery Exchange"; K.J. McNULTY and J.W. KUBAREWICZ.
"Field Closed-Loop Recovery of Zinc Cyanide Rlnsewater Using
Reverse Osmosis Evaporation"; J.L. EISENMANN, "Membrane
Processes for Metal Electroplating Rinse Water"; M.C. SCOTT.
"An EPA Heavy Metals Removal by Sulflde Precipitation"; C.P.
HUANG and "The Development of an Activated Carbon Process for
the Treatment of Chromium (VI)-ContaInirig Plating Wastewater";
J. SANTO, et "Removal of Heavy Metals From Battery
Manufacturing Wastewaters by Cross-Flow MlcrofI ItratIon";
G.D. McKEE. "Status of Analytical Cyanide"; V.S. KATARI, R.W
GERSTLE and C.H. Degreaser Emissions".
Descriptors: Pollution abatement; Electroplating
Section Heading: 72 .(SPECIAL PUBLICATIONS) Journal
Announcement: 7911
68OO36 79-7IOBO6
Removal of Heavy Metals From Battery Manufacturing
Wastewaters by Hydroperro Cross-Flow Mlcrof11tratlon.
Santo. J
Advanced Pollution Control for the Metal'Finishing Industry,
Klsslmmee. Fla.. 5-7 Feb. 1979
123-ISO
Publ: U.S. Environmental Protection Agency, Cincinnati,
Ohio 45268. May 1979
Language: ENGLISH
Document Type: BOOK
The results of the heavy metals separation tests by the
Hydroperm separation system described are not dependent on
either the fact that the wastewater containing the heavy
metals Is from a battery manufacturing plant or that the
metals were precipitated with lime. Removal by Hydroperm of
various metals In suspended solid (SS) form as a result of
precipitation by chemicals other than lime would still be just
as effective. Thus, the results would appear to have
widespread application throughout the metal finishing
Industry. If either the waste characteristics or the
precipitant were to be changed. It Is clear from past
Hydroperm tests (with Zn, Cu, Cd and NO results similar to
those reported In suspended solids removal would be obtained
by appropriate changes In tube pore-size distribution and
operating conditions. Tube performance In removal of SS Is
substantially Independent the type of metal or
concentratIon.1O refs.--AA
Descriptors: Lead (metal). Recovering; Cadmium, Recovering;
Electric batteries; Water pollution: Filtration; Precipitation
Section Heading: 71 .(GENERAL AND NONCLASSIFIED) Journal
Announcement: 7911
-------
DIALOG Flle32. METADEX - 66-82/Jun (Copr. Am. Soc. Metals) (Item II of 21) User239t3 23jun82
66B264 79-71O324
Ammonia Steam Stripping at Miscellaneous Nonferrous Metals
Plants, Case Histories.
Struzeskl Jr. E J
The 33rd Industrial Waste Conference. Lafayette. Ind..
9-11 May 1978
204-210
Publ: Ann Arbor Science Publishers Inc. P.O. Box 1425. Ann
Arbor. Mich. 481O6. 1979
Language: ENGLISH
Document Type: BOOK
The advantages and disadvantages of various methods for
removal of N from nonferrous metals plants' wastewaters are
described. These are: biological nltrIfIcatIon--dentr1fIcat1o-
n. chemical precipitation, reverse osmosis. Ion exchange,
breakpoint chlorInatIon. evaporation. air stripping and steam
stripping. Four case histories of steam stripping are given;
Ta and rare earths, processing of nuclear fuels and Zr
processing --H.A.D.
Descriptors: Water pollution; Pollution abatement:
Nonferrous metals; Ammonia-, Stripping (distillation)
Section Heading: 71 .(GENERAL AND NONCLASSIFIED) Journal
Announcement: 79O6
£68069 79-58O327
Recovery of Metals From Electroplating Wastes.
Knocke. W R ; Clevenger. T ; Ghosh. M M ; Novak. J T
The 33rd Industrial Waste Conference. Lafayette, Ind.,
9-11 May 1978
415-426
Publ: Ann Arbor Science Publishers Inc., P.O. Box 1425.
Ann Arbor. Mich. 481O6
Language: ENGLISH
Document Type: BOOK
Two alternate methods for I Iquld--1Iquld extraction of
metals from wastewaters were Investigated: direct extraction
of metals and physIco--chemical concentration treatment
followed by IIquld--IIquld extraction. The following topics
are discussed: plating process description, tnsolubllIzatlon/-
precIpltat Ion, sludge dewaterlng. metal hydroxide sludge
characteristics, and IIquld-- IIquld extract Ion.18 refs.--H.A.-
D.
Descriptors: Electroplating; Wastes; Reclamation
Section Heading 58 .(METALLIC COATING) Journal
Announcement 79O6
Document Type: BOOK
Contents Include: J. McVAUGH and W.T. WALL. Jr.. Metals
Wastewater Treatment Effluent Quality Vs. Sludge Treatment";
METRY and M.E. HARRIS. "A New Concept for Treating Leachate
Runoff Waters From a Taconlte Transshipment Facility"; M-H
Wu. and C-P. HUANG. 'Regeneration of Activated Carbon for the
Chromium"; W.E. LINK and J.G. RABOSKY. "Fluoride Ion
Waste-Water Employing Calcium Precipitation and Iron Salt
WARNKE. K G. THOMAS and S.C. CREASON. "Reclaiming Re
erse
ants
Osmosis"; J.A. DRAGO and J.R. BUCHHOLZ. "Removal Contain!
From Aqueous Laboratory Wastes by Chemical Treatm
PROBER. P.B. MELNYK and L.A. MANSFIELD, "Treatment Fu
Effluents to Inhibit Formation of -Iron-Cyanide Comple
HOCKENBURY, J.M. BOWSER and A.W. LOVEN. "Metal Waste
Treatment: a Case History.".
Descriptors: Waste disposal; Pollution abatement
Section Heading: 72 .(SPECIAL PUBLICATIONS) Joi
Announcement: 79O1
652174 79-71OO43
Removal of Heavy Metals From a Fatty Acid Wasteuater With a
Completely Mixed Anaerobic Filter.
Chlan, t K ; DeWalle. F B
Proceedings of the 32nd Industrial Waste Conference,
Lafayette. Ind.. 1O-12 May 1977
92O-928
Publ: Ann Arbor Science Publishers, Inc.. Ann Arbor, Mich.
1978
Language: ENGLISH
Document Type: BOOK
A study showed that a completely mixed anaerobic filter Is
effective In removing heavy metals (Fe, Zn, Cu. Cr. Nl, Pb .and
Cd) from a acidic wastestream. The effectiveness of the
filter Increases with increasing metal concentrations In the
Influent. The metals are precipitated as carbonates and
hydroxides and are removed from the filter as a slurry that
accumulates In the bottom solids ' collection device. The
percentage metal removal decreased while the metal content In
the bottom slurry Increased with decreasing hydraulic
detention time. Analysis of metals at different depths the
filter showed that most of the metals are removed In the lower
SO cm of the filter.12 refs.--AA
Descriptors: Wastes; Filtration: Pollution abatement:
Effluents: Iron; Zinc; Copper
Section Heading: 71 .(GENERAL AND NONCLASSIFIED) Journal
Announcement: 79O1
6522O3 79-72OO1I
Proceedings of the 31st industrial Waste Conference.
Bell. J M
Lafayette. Ind.. 6-8 May 1976
Pp 1164. 6 x 91/4 In., Illustrated
Publ: Ann Arbor Science Publishers, Inc.. P.O. Box 1425,
Ann Arbor. Mich. 48IO6., 1976
Language- ENGLISH
-------
DIALOG FI1e32 METADEX - 66-82/Jun (Copr. Am. Soc Metals) (Item 15 of 21) User23913 23JunB2
OD
652172 79-71OO41
Sulfex- a New Process Technology for Removal of Heavy Metals
From Waste Streams.
Scott, M C
Proceedings of the 32nd Industrial Waste Conference,
Lafayette. Ind.. 1O-12 May 1977
622-629
Publ: Ann Arbor Science Publishers, Inc., Ann Arbor, Mich.
1978
Language: ENGLISH
Document Type. BOOK
The Sulfex process described represents an economical and
feasible approach to sulftde precipitation of heavy metals. As
such It offers the advantages of more complete removal of
metals from waste streams than hydroxide preclpttat ton,
generally at pH ranges which are acceptable discharge. It
removes most chela ted metals from wastewaters and reduces
hexavalent Cr as It precipitates the other heavy metals as
sulfides. It is a new process which has been successfully
piloted on three waste --AA
Descriptors: Sludge; Precipitation; Sulfides; Wastes;
Chrom1urn; Iron
Section Heading: 71 .(GENERAL AND NONCLASSIFIED) Journal
Announcement: 79O1
652153 79-71OO22
Fluoride Ion Removal From Wastewater Employing Calcium
Precipitation and Iron Salt Coagulation.
Link. W E ; Rabosky, J G
Proceed Ings of the 31st Industr1a1 Was te Conference,
Lafayette. Ind.. 6-8 May 1976
485-5OO
Publ: Ann Arbor Science Publishers, Inc., Ann Arbor, M1ch.
1976
Language: ENGLISH
Document Type: BOOK
Fluor1de-laden wastewaters originate from many dlfferent
types of industries. Some metal finishing and electroplating
operat ions produce effluents contaInlng fluorIde. Other
Industr ies which use fluorides are A1, InsectIclde. chemical
and fertilizer. The results of a study in which fluoride ion
was reduced to approx 3.O mg/1 are presented. Laboratory
studies were conducted using both sodium fluoride solutions
and actual plant wastewater from a manufacturing plant. The
process employed required lime for precipitation which was
then followed by coagulation with iron salts. The proposed
method For fluorIde removal ut11ized two dist tnct chemical
additions. In the first, time provided the Ca and hydroxide
necessary. for fluor ide preclpltat Ion and downstream
1 neutralIzatlon of acid wastewaters, respectIvely. Ferrous
sulfate, which was the second chemical to be added, was
necessary for coagulatIon. FluorIde removal effIclencIes of
approx 96 to 98% were achieved using actual plant
wastewaters. These reduct ions were obtained for both the
segregated or concentrated fluoride waste stream and for the
total or blended plant wastewaters. Using the proposed method
of treatment, one series of samples was reduced In fluoride
concentrat Ion from 145 to 3.O rag/1; however, fInal fluor ide
concentrat Ion averaged approx 6-7 mg/1 For- all treated
samples.28 refs.--AA
DescrIptors: Water pollut ion; FluorIdes; PrecIpltat Ion;
CoagulatIon
Section Heading: 71 .(GENERAL AND NONCLASSIFIED) Journal
Announcement: 79OI
652H3 79-71OO12
Heavy Metal Treatment by Carbonate Precipitation.
Patterson, J W ; Scala. J J ; Allen, H E
Proceedings of the 3Oth Industr ial Waste Conference,
Lafayette, Ind., 6-8 May 1975
132-15O
Publ: Ann Arbor Science Publishers. Inc.. Ann Arbor. Mich
1975
Language- ENGLISH
Document Type: BOOK
Varlous treatment methods are employed to remove heavy
metals such as N1. Cd. Pb, Cu and Cr from industrial
wastewaters. Carbonate the heavy metals Zn, Nl, Cd and Pb was
Investigated for three reasons: predicted optimum carbonate
preclpltat Ion treatment occurs at pH values less than those
for optImum hydroxIde treatment; the metal carbonate
precipitate Is reported to be more dense than the hydroxide
precipitate, yielding Improved solids separation and decreased
sludge volume; and carbonate precipitates are reported to have
better filtration characteristics than hydroxide precipitates.
The determination of hydroxide solubility for Zn, Cd and Pb
over a range of approx pH 6-13, the carbonate solubility for
same heavy meta1s over the same pH range. a t se1ec ted
carbonate concentrations are determined and the solubility of
the hydroxide precipitate vs. the carbonate precipitate in
control 1 ing the eolublI Ity of the precfpltated me tal was
assessed --AA
Descriptors: Industr ial wastes; Preclpi tat ion; Solubi11ty;
Zinc, Solubllity; Nickel, Solubll1ty; Cadmium, SolubllIty:
Lead (metal). Solubility
Section Heading: 71 .(GENERAL AND NQNCLASSIFIED) Journal
Announcement: 79Oi
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DIALOG Flle32: METADF.X - 66-B2/Jun (Copr. Am. Soc. Metals) (Item 18 of 21) User23913 23Jun82
652OO2 79-58O025
Cementation Treatment of Copper in Wasteuater.
Patterson. J y ; Jancuk, W a
Proceedings of the 32nd Industrial Waste Conference.
Lafayette. Ind., 1O-I2 May 1977
853-865
Publ: Ann Arbor Science Publishers. Inc.. Ann Arbor, Mich.
1978
Language. ENGLISH
Document Type: BOOK
The cementation treatment process Is employed to a llmlte'd
extent for removal and recovery of Cu In an essentially pure
metallic form. The stolchlometry and kinetics of Cu
cementation, utilizing Fe as the metal were Investigated.
Copper cementation was determined to be a reaction with
respect to the removal of Cu from wastewater and the rate of
cementation Is Independent of the presence of 0. Copper
cementation Is Independent of pH, but at pH > 3 ferric
hydroxide precipitation masks and Interferes with Cu recovery.
Kinetic expressions developed In experiments can be employed
to predict the performance of continuous-flow reactors. The
recovered Cu contains approx 38X moisture, and 95.SX pure Cu
on a dry weight basts.13 refs.--AA
Descriptors: Copper; Cementation; Reclamation; Wastes
Section Heading: 58 .(METALLIC COATING) Journal
Announcement: 79OI
651582 7.9-52OO25
Metal Forging and Processing Wasteuater Treatment: a Case
History.
Hockenbury. M R ; Bower, J M ; Loven. A W
Proceedings of the 31st Industrial Waste Conference.
Lafayette. Ind.. 6-8 May 1976
982-993
Publ: Ann Arbor Science Publishers. Inc.. Ann Arbor. Mich.
1976
Language: ENGLISH
Document Type: BOOK
Wastewater from the forge shop containing suspended solids
and oil and grease can be treated using series gravity
oil/water separation, equalization, coagulation, flocculatlon
and dlssolved-alr flotation. Emulsified oily wastewater Is
treated by chemical coagulation. acid cracking, free oil
removal and gravity settling following pH adjustment. Chemical
rlnsewaters containing heavy metals and fluoride are amenable
to hlgh-pH (to to 11) precipitation of metal hydroxides and
calcium fluoride. followed by coagulation, flocculatlon and
clarification. Secondary pH adjustment, coagulation.
flocculatlon and clarification are necessary for Al removal
due to Its solubility at high pH. Spent acids can continue to
be on a batch basis with lime and caustic as efficient heavy
metal and fluoride precipitation can be accomp 1 I shed. 8
refs.--AA
Descriptors: Forging; Wastes; Aluminum; Pollution abatement
Section Heading: 52 .(WORKING) Journal Announcement: 79O1
63O5I9 78 58O798
Sulflde Vs. Hydroxide Precipitation of Heavy Metals From
Industrial Wasteuater.
Robinson, A K
First Annual Conference on Advanced Pollution Control for
the Metal Finishing Industry tl S EPA. Cincinnati. Ohio. 1978.
59-65.
Language: ENGLISH
Document Type: ARTICLE
Descriptors: Waste disposal; Chromium, Reactions (chemical);
Sulfldes. Reactions (chemical); Precipitation; Electroplating
Section Heading' 58 .(METALLIC COATING) Journal
Announcement: 7812
559847 77-42O2O9
Integrated Recycling of Wastewater by Application of Ion,
Precipitate and UltrafIne-Partlcle Flotation In the Pb-Zn
Concentrator of Kamloka Mine.
Ishlzu. Aklra; Matsul, Nobuo; Nagahama. Tatsuya
World Mining and Metals Technology Vol 2 American Institute
of Mining. Metallurgical and Petroleum Engineers, New York.
1976. 754-776.
Language: ENGLISH
Document Type: ARTICLE
Descriptors: Recycling; Water; Lead (metal). Extraction;
Zinc. Extraction; Flotation; Pollution abatement
Section Heading: 42 .(EXTRACTION AND SMELTING) 'Journal
Announcement: 77O4
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DIALOG Mle32 MET&DEX - 66-82,/dun
(Copr. Am. Soc. Metals) (Item
12) User23913 23JU082
00
o
78G7IO 81-421536
Air. Land or Water: the Dilemma of Coke Plant Waste Water
Disposal. (Retroactive Coverage).
Dunlap. R W ; McMlchae), F C
American Iron and Steel Institute. 83rd General Meeting,
New York, N.Y.. 21 May 1975
Pp 27
Publ: AISl, t5O E. 42nd St.. New York, N.Y. 1OCM7, 1975
Language: ENGLISH
Document T ype; BOOK
Was tewater d1scharges contaIn1ng cyan1de, phenol and
ammonia. e.g. must be treated according to EPA standards.
Eight alternative strategies are discussed, considering levels
of wastewater treatment, recycle or quench water. Choices
between alternatIve strategies are based on the relatIve
values of a numerical Index with cross-media analysts, which
Is basically a weighted mass emissions analysis. Quenching
with coke plant effluents appears to be a preferred practice
for greatest net Improvement of the environment.--J.J.P,
Descriptors: Pollution abatement; Coke ovens; Waste disposal
; Water pol Kit ion; Recycling
Section Heading: 42 .(EXTRACTION AND SMELTING) Journal
Announcement: 81 M
784136 81-5BOB49
Routes to Metals Recovery from Metal Finishing Sludges.
Mehta. A
Third Conference on Advanced Pollution Control for the Metal
Finishing Industry, Klsslmmee, Fla., 14-16 Apr, 198O
76-79
Publ: Industrial Environmental Research Laboratory, U.S.
Environmental Protect ion Agency. Cindnnat i , Ohio 45268.
1981
Language: ENGLISH
Document Type• BOOK
Process wastewaters from the electroplating Industry contain
cyanides and heavy metals that must be treated because of
environmental Impact and discharge regulations. One of the
treatment technologies already In wide use and more Ifkely to
be Installed Is neutralizatIon and preclpltat Ion technology
which destroys the cyanide and removes the heavy metals as
hydroxIdes. Varlous ways to recover metals from metal
f Inish1ng sIudges are dIscussed a1ong with econom1caI
considerations. The concept of a Centralized Waste Treatment
Facility (CWTF1 is presented as an alternate to individual
meta1 recovery treatments. 0 ther topIcs dlscussed are'
pyrometal Kirgteal treatments; hydrometa11urgteal treatments;
common1y used 1each1ng reagen t s; Ion exchange; so1ven t
extraction; cementation and electrolysis 7 refs.--G.G.M.
Descriptors: Electroplating; Sludge disposal; PollutIon
abatement; Copper, Recover Ing; 2Inc, Recover Ing
Section Heading: 58 .
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DIALOG Flle32: METADEX - 66-B2/Jun (Copr. Am. Soc Metals) (Item 4 of 12) User239t3 23Jun82
(O
00
Comroun(ties.
Bolte
MILLS. "Effects of
N.W. GHELBERG and E.
724758 8O-72O283
Management and Control of Heavy Metals In the Environment.
London. England. Sept. 1979
Pp 664, 8 x 113/4 In., Illustrated
Publ: Commission of the European
Postale IOO3, Luxembourg, 1979
Language: ENGLISH
Document Type- BOOK
Contents Include: I. BREMNER and C.F.
Diet on tha Toxlclty of Heavy Metala";
BODQR. "Arsenic Levels In the Environment and In Human Body In
a Copper Metallurgy Plant Area"; M. ABDULLA, S. SVENSSON and
A. NORDEN. "Antagonistic Effect of Zinc In Heavy Metal
Poisoning"; W.H. STRAIN. A.M. VARNES andO.A. HILL. JR.,
"Heavy Metal Contamination of Household Water"; B.2. OIAMANT,
"Environmental Health Impact of Heavy Metals In Wastewater
Sludge Applied to Cropland"; I. SAITO, "Removal of Chromium
(VI) In Aqueous Solutions by Activated Carbons"; K.K. CHIN and
J.H. TAV. "Laboratory Scale Treatment of Nickel-Bear Ing
Industrial Effluent"; C.p C. POON, "Removal of Copper. Nickel.
Zinc. Cadmium and Cyanide From Plating Wastewater by
Electroflotatlon"; N.L. GALE and B.C. WIXSON, "Control of
Heavy Metals In Lead Industry Effluents by Algae and Other
Aquatic Vegetation"; J. HRSAK and M. FUQAS. "Distribution of
Part leu I ate Lead. Zinc and Cadmium Around a Lead Smelter"; K.
SCHWITZGEBEL, R.V. COLLINS and R.T. COLEMAN. "Arsenic
Discharge 'From a Primary Copper Smelter"-; C.L. CHAPPELL and
S.L. WILLETTS. "Isolation of Heavy Metals From the
Environment"; A.N. CLARKE and O.U. WILSON, "The Removal of
Metallo-Cyanlde Complexes by Foam Flotation"; H J. JEBENS.
G.J. MEVERHOFER and D.J. MASTERS. "Removal of Heavy Metals
From Industrial Wastewaters"; F. EL-GOHARY. M.R. LASHEEN and
H I. ABDEL-SHAFV, "Trace Metal Removal From Wastewater Via
Chemical Treatment".
Descriptors: Toxicology; Water pollution; Pollution
abatement
Section Heading: 72 .(SPECIAL PUBLICATIONS) Journal
Announcement: BOOB
U.S. standards. Free oxygen and ozone produced at the anode
oxidized Nl In solution to form nickel oxides which
precipitated out. Hypochlorlte and C1 gas oxidized cyanide and
liberated heavy metals from the cyanide — metal complexes which
preceded alkaline precipitation. Performance equatIons .were
developed which Indicated the relative significance of the
effect of each operating variable on treatment performance and
suggested how the process could be better modified to trea.t
plating wastewaters of different character 1stIcs.--AA
Descriptors: Electroplating: Flotation; Pollution abatement:
Copper, Recovering; Nickel. Recovering: Zinc. Recovering;
Cadmium. Recovering
Section Heading: 58 .(METALLIC COATING) Journal
Announcement: BOOB
724528 8O-58O6I2
Removal of Copper, Nickel, Zinc, Cadmium and Cyanide From
Plating Wastewater by Electroflotatlon.
Poon, C P C
Management and Control of Heavy Metals In the Environment,
London. England. Sept. 1979
572-575
Pub)- Commission of the European Communities. Bolte
Postale IOO3, Luxembourg. 1979
Language. ENGLISH
Document Type: BOOK
The use of an electrof lotat Ion process to remove heavy
metals from plating wastewaters was Investigated. Cathodlc
generation of hydroxides raised the pH and reduced the metal
solubility, resulting In metal precipitation which was carried
up to the surface by the rising gas bubbles. Copper. Nl, In
and Cd were successfully removed, with the effluents meeting
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DIALOG File32: METAOEX - 66-82/Jun (Copr. Am Soc. Metals) (Item 6 of 12) User23913 23JunS2
CD
to
715594 8O-72OIB9
IronmakIng Conference. Vol. 35.
St. Louis. Mo.. 28-31 Mar. 1976
Pp 651. 81/4 x 111/2 In.. Illustrated (retroactive coverage)
Publ: Iron and Steel Society AIME. 345 E. 47th St., New
York. N.V. 1OO17. 1976
Language: ENGLISH
Document Type: BOOK
Contents Include: M. HATANO and M. FUKUDA. "The Effect on
the Blast Furnace Operation"; D.G. WHITE. "An Adaptive Model
Top-Gas Analysis";" O. KONCHAR and R.L. PRIOOY. Iron'; A.
MERTOOGAN and R. LANGHOFF. "Response Time of Composition of
Molten Iron to the Changes In Coke Moisture and Chemical
Composition of Sinter In the Blast Furnace"; T. OCHIAI. H
HOSHIIOE. "Vibration Forming Troughs"; R. SANTELLA. Furnace
Linings"; J.L. PUGH. "Anhydrous Clay Vs. Water-Base VOUNT.
JR., "Anhydrous Taphole Mixes for the Blast Furnace'; "Blast
Furnace Anhydrous Taphole Mixes'; R.E. ROSS, "Blast Taphole
Mixes"; J.A. WILLIAMS and O.A. HOMBERG. "Coke DesulfurIzatIon
and Sulfur Recovery Utilizing the Sulflran Process"; LOWNIE.
JR.. and A.o. HOFFMAN, "A Research Approach to Problems":; O.
GLASSMAN. "LISS CYAM System—an Improved and Cyanide Removal
From Coke-Plant Wastewater': J.G. MANDA. and D F CAIRNS,
"Development of One-Spot Enclosed Coke Pushing N.A. HASENACK,
R.B. VOGEL and F. HOMMINGA, "The and Their Behavior In the
Blast Furnace"; R.F. CNARE and G.M. Recoup System--a New
Method of Heat Recuperation In the Grate-Klin R.P. SOU2A.
"The Production of Pellets In CVRD Using Hydrated Is Growing
Up Fast": W.J. PRIESTNER. "Air Preheater System Stoves"; G.
VICARO and P.M. WECHSELBLATT, "High Furnaces"; E.L. GUNTHER
and H. SCHOPPA. "Panel In the Blast Furnace. Experience With
Stave Coolers on a Blast Hoesch Huttenwerke, AG"; H.U.
BLACKBURN. "Experience With Cooling at the Steel Co. of
Canada's No 4 Blast Furnace"; T.E. "Cooling Hazards In High
Tonnage Carbon Hearths"; C.M. on Blast-Furnace Tuyeres"; M.
YOSHINAGA. M. SANADA and "Industrialization of Briquet Blent
Coking Process": L.G. THOMPSON. "Selection of Coals and Coal
Mixes to Avoid Excessive Pressure"; E.J. OSTROWSKI. "Coal
Quality — Its Effect on the 0. FISCHLEY, "Some Aspects of
Blast Furnace Operation at Poor Quality Coking Coals In the
Coke Plant Mix"; P. SCHROTH ROBINSON. "The Effects of Alkali
Attack on Various Carbon LAMBERT. "Operation of Geneva Works
Blast Furnaces With Burdens"; F. FORES, J. BALLANO. J.
LAVANOERA. M. "Alkalles--Problem or Solution? at Altos Hornos
de VIzcaya SA"; and W.R. CORZILL1US. "Blast Furnace
Operations at Granite High Alkali Bearing Burdens"
R.T.Roberts., "MIOREX Yesterday H.A. KULBERG, "Current Status
of the FIOR de Venezuela Plant G.G.W. THOM and K. WILSON. "New
SL/RN Direct Reduction Mine"; J. CELADA and G.E. McCOMBS,
"HYL Direct LEONARD and S. MACOONALD. "Direct Reduction With
Gas Coal Gasification Process"; R.d. HELFINSTINE. "Charging
a Pilot Coke Oven"; D.A. COOPER, P.J. DE KOKER. I. and A N.
VENTER, "South African Experiences With Preheated Coal J.P.
GRAHAM. "Coal Preheat Ing--Research and Development In the
Kingdom": R.F. DAVIS. JR., "The COALTEK System--PIpelIne
Ovens": W L McHENRY. R.L LAND and A. FERNANDEX, and
Stait-Up of United States Steel's No. 2 Coke Battery at Gary
PRIES and F WACKERBARTH, "Experience Gained During the
Start-Up of the 7.5 Meter Coke Ovens In Fos-sur-Mer, France";
W.C. and J.L. BAYER. "Measurement and Evaluation of Heat
Distribution Ovens"; M. HIGUCHI. M. IIZUKA and Y. TAKASAKI,
"On Operational Control of No, 5 Sinter Machine at Fukuyama
Works, Nippon KK"; P.T. SEATON and F.8. TRAICE. "Development
of a Prediction of Sinter Plant Productivity From Ore
Properties"; H. J. OTTO, "Possibilities of Improvements to
Existing Sinter WILSON and G.K. JEFFERSON, "Operating
Experience of No. Gary Works"; S.E. NANNE. "Operating
Experience on Algoma's No. Furnace"; S. SH1MADA. "Production
of 13.5 Million Tons on Furnace".
Descriptors: Ironmaking; Blast furnaces; Heat recovery
Section Heading: 72 .(SPECIAL PUBLICATIONS) Journal
Announcement: BOOS
714467 8O-42O433
USS CYAM System--an Improved Process for Ammonia and Cyanide
Removal From Coke-Plant Wasteuater. (Retroactive Coverage).
Classman, D
Ironmaking Conference. Vol. 35, St. Louis. Mo.. 28-31
Mar. 1976
121-131
Publ: Iron and Steel Society AIME. 345 E. 47th St . New
York. N.Y. IOO17. 1976
Language: ENGLISH
Document Type: BOOK
Environmental regulatory agencies require the treatment of
coke-plant wastewater for removal of ammonia. cyanide and
phenol before discharge to streams and other utilities, uses
lime and avoids fouling. Wh&n used In conjunction with an
activated-sludge system, 'It provides an Ideal feed that
promotes smooth operation because of the virtual absence of
simple cyanides. These benefits are achieved with capital
costs that are competitive with for conventional free- and
fixed-ammonia stills.--AA
Descriptors: Coking: Water, pollution; Waste disposal;
Purification; Ammonia
Section Heading: 42 .(EXTRACTION AND SMELTING) Journal
Announcement: BOOB
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DIALOG FIIe32 METADEX - 66-B2/dun (Copr. Am. Soc. Metals) (Item B of 12) User23913 23JunB2
K)
00
U)
68OOBO 79-72O34O
Advanced Pollution Control for the Metal Finishing Industry.
Klsslmmee. Fla.. 5-7 Feb 1979
Pp 151. 81/2 x 11 In.. Illustrated
Publ. U.S. Environmental Protection Agency, Cincinnati,
Ohio 4S268, May 1979
Language: ENGLISH
Document Type: BOOK
Contents Include: M.E. BROWNING. J. KRALJIC and G.S.
Finishing Sludge Disposal; Economic. Legislative and Technical
for 1979"; C. ROY, "Methods and Technologies for Reducing the
Electroplating Sludges"; P.S. MINOR and R.J. BATSTONE,
Federal Republic of Germany's Centralized Waste Treatment
Approach In United States1; F.A. STEWARD and H.H. HEINZ,
"Economical Shop Case History"; d.A. BIENER, "City of Grand
Rapids, Industrial Waste Control"; A.F. LISANTI and S.O.
Proper Unit Processes for the Treatment of Electroplating
Wastewaters"; PRICE andC. NOVOTNY, "Water Recycling and
Nickel Recovery Exchange"; K.d. McNULTY and J.W. KUBAREWICZ,
"Field Closed-Loop Recovery of Zinc Cyanide Rlnsewater Using
Reverse Osmosis Evaporation"; d.L. EISENMANN. "Membrane
Processes for Metal Electroplating Rinse Water"; M.C. SCOTT.
"An EPA Heavy Metals Removal by Sulflde Precipitation"; C.P.
HUANG and "The Development of an Activated Carbon Process for
the Treatment of Chromium (VI)-Containing Plating Wastewater";
d. SANTO, et "Removal of Heavy Metals From Battery
Manufacturing Wastewaters by Cross-Flow Microf11tratIon";
G.D. McKEE, "Status of Analytical Cyanide"; V.S. KATARI, R.W.
GERSTLE and C.H. Degreaser Emissions*.
Descriptors: Pollution abatement; Electroplating
Section Heading: 72 .(SPECIAL PUBLICATIONS) dournal
Announcement: 7911
67986B 79-580679
Selecting the Proper Unit Processes for the Treatment of
Electroplating Wastewaters.
Llsantl. A F ; Megantz, S O
Advanced Pollution Control for the Metal Finishing Industry.
Ktsslmmee. Fla., 5-7 Feb. 1979
64-75
Publ: U.S. Environmental Protection Agency, Cincinnati,
Ohio 45268, May 1979
Language. ENGLISH
Document Type: BOOK
An engineering approach to the selection of unit processes
for the treatment of electroplating Wastewaters Is presented.
The approach consists of rinse water conservation, waste
stream segregation. stream characterization. field
treatablllty studies, laboratory treatablllty studies, system
design, construction and startup. Three electroplating
facilities are described to show differences In these systems
and how to accomodate unique problems with these systems Data
are given on removal of complexed Cu, Nl other metals,
electrolytic reduction of segregated Cr(+6), treatment of
cyanide. effect of polishing- filtration, effect of total
treatment. analysis of effluent, projected concentrations In
chemical O demand waste, removal of soluble and Insoluble oil,
quality of combined treated Wastewaters. destruction of
amenable cyanide, filter press performance and ultraf11tratton
effluent quality of permeate soluble oil.--H.A D.
Descriptors: Electroplating; Water pollution; Pollution
abatement; Effluents; Recovering
Section Heading: 58 .(METALLIC COATING) dournal
Announcement: 7911
67986O 79-58O671
Environmental Pollution Control Alternatives: Economics of
Wastewater Treatment Alternatives for the Electroplating
Industry. (Pamphlet).
Pp 72
Publ: Industrial Environmental Research Laboratory,
Cincinnati, Ohio 45268. dune 1979
Report Number: EPA 625/S-79-O16
Language: ENGLISH
Document Type: REPORT
This report provides a detailed examination of the costs
associated with various water pollution control alternatives
available to the metal finishing Industry. The document also
provides some figures for computing the savings associated
with various good housekeeping practices such as spent bath
reuse and minimization of water usage. The document Is geared
to the plater who may be evaluating control costs for the
first time. However. even those experienced In these matters
will probably benefit from the discussions of housekeeping
practices, various recovery techniques and emerging
technologies.--AA
Descriptors: Electroplating; Cyanides; Recycling; Effluents;
Water pollution; Pollution abatement
Section Heading: 58 .(METALLIC COATING) .Journal
Announcement: 7911
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DIALOG File32. METADEX - 66-82/Jun (Copr. Am. Soc. Metals) (Item II of 12) User239l3 23JunB2
6522O3 79-72OO11
Proceedings of the 31st Industrial Waste Conference.
Bel I, d M
Lafayette. Ind., 6-8 May 1976
Pp 1164. 6 x 91/4 In.. Illustrated
Publ: Ann Arbor Science Publishers. Inc.. P.O. Box 1425.
Ann Arbor. Mich. 481O6.. 1976
Language. ENGLISH
Document Type BOOK
Contents Include: J. McVAUGH and W.T. WALL, Jr.. Metals
Wastewater Treatment Effluent Quality Vs. Sludge Treatment";
METRV and M.E. HARRIS. "A New Concept for Treating Leachate
Runoff Waters From a Taconlte Transshipment Facility"; M-H.
Wu. and C-P. HUANG. "Regeneration of Activated Carbon for the
Chromium"; W.E. LINK and J.G. RABOSKY, "Fluoride Ion
Waste-Water Employing Calcium Precipitation and Iron Salt
WARNKE. K.G. THOMAS and S.C. CREASON. "Reclaiming Reverse
Osmosis"; J.A. DRAGO and J.R. BUCHHOLZ. "Removal Contaminants
From Aqueous Laboratory Wastes by Chemical Treatment";
PROBER, P.B. MELNYK and L.A. MANSFIELD. "Treatment Furnace
Effluents to Inhibit Formation of Iron-Cyanide Complexes";
HOCKENBURY. J.M BOWER and A.W. LOVEN, "Metal Wastewater
Treatment' a Case History".
Descriptors: Waste disposal; Pollution abatement
Section Heading: 72 .(SPECIAL PUBLICATIONS) Journal
Announcement: 79O1
CD
•t^ 652171 79-71OO4O
Industrial Wastewater Ozonatlon.
Hardlsty. D M : Rosen. H M
Proceedings of the 32nd Industrial Waste Conference.
Lafayette. Ind.. 1O-12 May 1977
294-3O2
Publ: Ann Arbor Science Publishers, Inc.. Ann Arbor. Mich
1978
Language ENGLISH
Document Type: BOOK
Ozone generation and application Is an established
technology with numerous applications In Industrial Wastewater
treatment. The key advantage offered by ozone Is Its strong
oxidizing capability and Its clean, add-nothing feature. As
for any Wastewater treatment system. the cost factors require
careful assessment The economics of using O feed vs. air feed
bear on this cost analysis. Treatment of effluents with
materials such as cyanide, phenol, color and COD Is
feasible.1O refs.--AA
Descriptors: Wastes, Oxidation; Ozone: Pollution abatement
Sect ion Heading: 71 .(GENERAL AND NONCLASSIFIED) Journal
Announcement 79O1
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DIALOG F I le.12
METADEX - 66 82/Jun (Copr. Am. Soc. Metals) (Item I of 9) User239l3 23jun82
3162
t-J
co
Cn
75599O 8I-57OO54
Uastewater and Hazardous Solid Waste Disposal In the
Aluminum Products Industry.
Marino, M
Met Finish. .Oct. 198O. 78. (tO). 2t-27. 4O
Language: ENGLISH
Document Type: ARTICLE
Government regulations concerning the disposal of solid and
liquid wastes in the Al industry are discussed. The existing
regulations for waste water discharge were established by the
Federal Water Pollution Control Act Amendments of 1972. The
practical application of these regulations to At product
plants (anodizing, chromating and phosphatlng) is described
and the impact of probable future regulatory changes is
'outlined. Solid waste disposal is regulated by the 1976
Resource Conservation and Recovery Act. The proposed EPA
guidelines for defining hazardous solid wastes are Included.
Recommendations for meeting guidelines and treatment cost
minimization are Included.--G.P.K.
Descriptors: Aluminum base alloys. Coating; Waste disposal;
Pollution abatement; Anodizing; Chromating
Section Heading: 57 (FINISHING) Journal Announcement: 81O2
724758 8O-72O283
Management and Control of Heavy Metals In the Environment.
London. England. Sept. 1979
Pp 66-1. 8 x 113/4 In., Illustrated
Pub): Commission of the European Communities.
Postale 1OO3. Luxembourg, 1979
Language- ENGLISH
Document Type: BOOK
Contents Include: I. BREMNER and C.F.
Diet on the Toxlclty of Heavy Metals";
BODOR, "Arsenic Levels In the Environment and in Human Body in
a Copper Metallurgy Plant Area"; «. ABOULLA. S. SVENSSON and
A. NORDEN, "Antagonistic Effect of Zinc in Heavy Metal
Poisoning"; W.H. STRAIN. A.W. VARNES and 0. A. HILL. JR..
"Heavy Metal Contamination of Household Water"; B.Z. DIAMANT,
"Environmental Health Impact of Heavy Metals In Wastewater
Sludge Applied to Cropland"; I. SAITO, "Removal of Chromium
(VI) In Aqueous Solutions by Activated Carbons"; K.K. CHIN and
J.H. TAV. "Laboratory Scale Treatment of Nickel-Bear Ing
Industrial Effluent"; C.P.C. POON, "Removal of Copper, Nickel,
Zinc, Cadmium and Cyanide From Plating Wastewater by
Electrof lotat ion"; N.L GALE andB.G. WIXSON, "Control of
Heavy Metals In Lead Industry Effluents by Algae and Other
Aquatic Vegetation"; J. HRSAK and M. FUGAS, "Distribution of
Partlculate Lead, Zinc and Cadmium Around a Lead Smelter"; K
SCHWITZGEBEL, R.V. COLLINS and R.T. COLEMAN, "Arsenic
Discharge From a Primary Copper Smelter"; C.L. CHAPPEtL and
S.L. WILLETTS, "Isolation of Heavy Metals From the
Environment"; A.N. CLARKE and D.J. WILSON. "The Removal of
Metallo-Cyanlde Complexes by Foam Flotation"; H.J. JE8ENS,
G.J. MEVERHOFER and D.J MASTERS. "Removal of Heavy Metals
From Industrial Wasteualets", F. EL-GOHARY. M R. LASHEEN and
Bolte
MILLS. "Effects of
N.W. GHEL8ERG and E.
H.I. ABDEL-SHAFV,
Chemical Treatment".
Descriptors: Toxicology;
abatement
Section Heading: 72 .(SPFCIAL PUBLICATIONS)
Announcement: BOOS
Trace Metal Removal From Wastewater Via
Water pollutIon; Pol Hit Ion
Journal
68OO8O 79-72O340
Advanced Pollution Control for the Metal Finishing Industry.
Klsslromee, Fla., 5-7 Feb. 1979
Pp 151. et/2 x It in.. Illustrated
Publ: U.S. Environmental Protection Agency. Cincinnati,
Ohio 45268. May 1979
Language: ENGLISH
Document Type: BOOK
Contents Include: M.E. BROWNING. J. KRALJIC and G.S.
Finishing Sludge Disposal; Economic. Legislative and Technical
for 1979"; C. ROY, "Methods and Technologies for Reducing the
Electroplating Sludges"; P.S. MINOR and R.J. BATSTONE,
Federal Republic of Germany's Centralized Waste Treatment
Approach In United States"; F.A. STEWARD and H.H. HEINZ.
"Economical Shop Case History"; J.A. BIENER, "City of Grand
Rapids. Industrial Waste Control"; A.F. LISANTI and S.O.
Proper Unit Processes for the Treatment of Electroplating
Wastewaters"; PRICE and C. NOVOTNY. "Water Recycling and
Nickel Recovery Exchange*; K.J McNULTY and J.w. KUBAREW1CZ.
"Field Closed-Loop Recovery of Zinc Cyanide Rlnsewater Using
Reverse Osmosis Evaporation"; J.L. EISENMANN. "Membrane
Processes for Metal Electroplating Rinse Water"; M.C. SCOTT.
"An EPA Heavy Metals Removal by Sulflde Precipitation"; C.P.
HUANG and "The Development of an Activated Carbon Process for
the Treatment of Chromium (VI)-Contalnlng Plating Wastewater";
J. SANTO. et "Removal of Heavy Metals From Battery
Manufacturing Wastewaters by Cross-Flow Mlcrof11tratIon" :
G.O. McKEE, "Status of Analytical Cyanide"; V.S. KATARI. R.W.
GERSTLE and C.H. Oegreaser Emissions".
Descriptors: Pollution abatement; Electroplating
Section Heading: 72 .(SPECIAL PUBLICATIONS) Journal
Announcement: 7911
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DIALOG Flle32: METADEX - 66-82/Jun (Copr. Am. Soc Metals) (Item 4 of 9) User 23913 23jur)B2
679872 79-58O6B3
The Development of an Activated Carbon Process for the
Treatment of Chromium (VI(--Containing Plating Wasteuater.
Huang, C P ; Bowers, A R
Advanced Pollution Control for the Metal Finishing Industry,
Kisstmmee, Ma.. 5-7 Feb. 1979
114-122
Publ: U.S. Environmental Protection Agency, Cincinnati,
Ohio 45268. May 1979
Language: ENGLISH
Document Type: BOOK
The recent developments tn the use of activated C for total
Cr removal from plating wastewaters are discussed. The topics
Include Interactions of (VI) with activated C In batch
experiments and packed columns, operation of packed columns,
regeneration of exhausted activated C by thermal, caustic,
combined thermal-caustic and acid methods, and the removal of
Cr (III!. are given for the effects of C bed size, depth.
increasing Cr concentration, number of regeneration cycles and
effect of time and caustic concentration on desorptIon.2O
refs --H.A 0.
Descriptors: Chromium, Recovering; Electroplating; Water
pollution; Activated carbon, Reactions (chemical); Effluents;
Regenerators
Section Heading: 58 .(METALLIC COATING) Journal
Announcement: 7911
Descriptors: Waste disposal; Pollution abatement
Section Heading: 72 .(SPECIAL PUBLICATIONS)
Announcement: 79O6
668O68 79-58O326
Treatment of Zinc Plating and Oil Bearing Washer Wasteuater.
Kreye. W C ; Olver. J W ; Sutton, H C ; V/orch. f R
The 33rd Industrial Waste Conference, Lafayette, Ind .
9-It May 1978
155-164
Publ: Ann Arbor Science Publishers Inc., P.O Box i425.
Ann Arbor. Mich. 481O6. 1979
Language: ENGLISH
Document Type: BOOK
The treatment of Zn and Cr plating and washer wastewaters of
a major manufacturer Is described. Following a survey of the
wastewaters, laboratory testing, treatment system evaluation,
an interim treatment system and pilot testing, a final
treatment system was built. Details and data are given for the
system.--H.A.O.
Descriptors: Zinc plating; Chromium plating; Wastes; Water
pollution; Pollution abatement
Section Heading: 58 .(METALLIC COATING) Journal
Announcement: 79O6
to
00
01
668318 79-72O17O
The 33rd Industrial Waste Conference.
Lafayette. Ind., 9-11 May 1978
Pp IO28. 6x9 In.. Illustrated
Publ: Ann Arbor Science Publishers Inc. P.O. Box 1425. Ann
Arbor. Mich 481O6. 1979
Language. ENGLISH
Document Type: BOOK
The Conference Is under the direction of the Purdue
University Civil Engineering and the Dlv. of Conferences and
Continuation Services, cooperation with the Indiana State
Board of Health. Indiana Stream Control Board. Indiana
Environmental Management Board, Indiana Dept. Natural
Resources. Indiana Section of tha American Water Works Assoc.,
Water Pollution Control Assoc. and Indiana Section of the
American Civil Engineers. Contents Include: M.E. McGUIRE.
D R. FAUSCH. "Pollution Control Through Water Conservation at
a Gray Foundry"; W.C. KREVE, J.W. OLVER. H.C. SUTTON and
Zinc Plating and Oil Bearing Washer Wastewater"; E.O.
"Ammonia Steam Stripping at Miscellaneous Nonferrous Metals
Plants, Histories"; W.M. WINN and E.L MORGAN, "Stream
Ecosystem Municipal Sewage Discharges and Accommodation to
Aluminum Industry Effluents"; W R. KNOCKE, T. CLEVENGER, M.M.
GHOSH of Metals From Electroplating Wastes"; I L. LEE and
R.E. of Oily Machinery Wastes"; D.M. SOBOROFF. J.D. TROVER
One-Step Method for Recycling Waste Chromic Ac Id--SulfurIc
Acid Solutions"; M.C. FISCHER, "Wet Scrubber Water Treatment
in the Steel Industry Using Lamella Gravity Settlers"; J
"Extended Aeration of Coke-Plant Effluents"
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DIALOG Flle32: METADEX - 66-82/Jun (Copr. Am. Soc. Metals) (Item 7 of
9) User23913 23jun82
K)
CO
6522O3 79-72OO1I
Proceedings of the 31st Industrial Waste Conference.
Bell. J M
Lafayette, Ind.. 6-8 May 1976
Pp 1164. 6 x 91/4 In.. Illustrated
Publ: Ann Arbor Science Publishers. Inc., P.O. Box 1425,
Ann Arbor, Mich. 481O6.. 1976
Language: ENGLISH
Document Type: BOOK
Contents Include: J. McVAUGH and W.T. WALL. Jr.. Metals
Wastewater Treatment Effluent Quality Vs. Sludge Treatment";
METRY and M.E. HARRIS. "A New Concept for Treating Leachate
Runoff Waters From a Taconlte Transshipment Facility"; M-H.
Wu. and C-P. HUANG. "Regeneration of Activated Carbon for the
Chromium"; W.E LINK and J.G. RABOSKY. "Fluoride Ion
Waste-Water Employing Calcium Precipitation and Iron Salt
WARNKE, K.G. THOMAS and S.C. CREASON. "Reclaiming Reverse
Osmosis"; J.A. DRAGO and J.R. BUCHHOLZ, "Removal Contaminants
From Aqueous Laboratory Wastes by Chemical Treatment";
PROBER. P.B. MELNYK and L.A MANSFIELD. "Treatment Furnace
Effluents to Inhibit Formation of Iron-Cyanide Complexes";
HOCKENBURY. J.M. BOWER and A.W. LOVEN, "Metal Wastewater
Treatment: a Case History".
Descriptors: Waste disposal; Pollution abatement
Section Heading: 72 .(SPECIAL PUBLICATIONS) Journal
Announcement1 79O1
652172 79-71OO41
Sulfex--a New Process Technology for Removal of Heavy Metals
From Waste Streams.
Scott, M C
Proceedings of the 32nd Industrial Waste Conference.
Lafayette. Ind., 1O-12 May 1977
622-629
Publ: Ann Arbor Science Publishers. Inc.. Ann Arbor, Mich.
1978
Language: ENGLISH
Document Type: BOOK
The Sulfex process described represents an economical and
feasible approach to sulflde precipitation of heavy metals. As
such It offers the advantages of more complete removal of
metals from waste streams than hydroxide precipitation.
generally at pH ranges which are acceptable discharge. It
removes most chelated metals from wastewaters and reduces
hexavalent -Cr as It precipitates the other heavy metals as
sulfldes. It Is a new process which has been successfully
piloted on three waste --AA
Descriptors: Sludge; Precipitation; Sulfldes; Wastes;
Chromium; Iron
Section Heading- 71 (GENERAL AND NONCLASSIFIEO) Journal
Announcement' 79O1
Chromium.
Wu, M-H ; Hsu. D Y ; Huang. C-P
Proceedings of the 31st Industrial Waste Conference.
Lafayette. Ind.. 6-8 May 1976
409-419
Publ: Ann Arbor Science Publishers. Inc., Ann Arbor. Mich.
1976
Language: ENGLISH
Document Type: BOOK
Recent studies have shown that Cr can be effectively removed
by the C adsorption process, but the practical application of
this technique to the treatment of Industrial uastewater
depends not only upon the adsorption capacity but also on the
feasibility of regenerating the spent C. Research was
conducted to study some physical and chemical techniques for
the regeneration of Cr-loaded activated C. The activated C,
Calgon flltrasorb effectively removed hexavelent Cr The
removal efficiency Is governed by pH and the ratio of Cr to C
Among the three regeneration techniques studied--caustIc
desorptlon, thermal activation and a combined caustIc-thermaI
process — the latter gave the best regeneration results.
showing that > 97% of the original removal efficiency was
maintained through three regeneration cycles. To achieve high
adsorption and regeneration efficiencies. It Is recommended
that a relatively low Initial Cr loading (e.g. O CIS g
Cr(VI)/g C) be applied for the adsorption cycle and that the
used C be regenerated at a level of surface occupancy (e.g.
O.O5O g Cr(VI)/g C) well below the max. adsorption capacity. II
refs.--AA
Descriptors: Chromium, Sorptlon; Industrial wastes;
Activated carbon, Sorptlon; Adsorption; Reclamation
Section Heading: 71 .(GENERAL AND NONCLASSIFIEO) Journal
Announcement: 79O1
652152 79-7IOO2I
Regeneration of Activated Carbon for the Adsorption of
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DIALOG Flle4l: Politic-" Abstracts - 7O-82/Apr (Copr. Cambridge Scl Abs) (Item 1 of 98) User239l3 23Jun82
00
en
or DDT In Factory Effluent by Thin-Layer
J.V.
Jawaharlal Nehru Univ.. New Delhi. India
4. NO. 516, pp. 391-395, Publ.Yr:
ENGLISH
82 O2169
Characterization
Chroma t ography
Sharma. S.K.; Dave
Sell. Environ. Scl.
ENVIRON. INT VOL.
I98O
SUMMARY LANGUAGE -
Languages: ENGLISH
Thin- layer chromatography (TLC) Is shown as an effective,
inexpensive, reliable, and less time-consuming technique for
simple and effective monitoring of persistent toxicant- 1 Ike
present In Its manufacturing plant effluent Aqueous untreated
and treated grab and compost effluent samples were collected.
extracted with a solvent and concentrated and chroma tographed
both for qualitative and quantitative analysis for p.p'-DOT
and related compounds. This technique was sucessful and can
form an effective. Inexpensive method to be used by the
developing countries, which have limited financial resources.
Descriptors: chromatography; DDT; effluents; monitoring;
toxicants; pollutant detection; wastewater treatment; cost
benefit analysis
82-O2O9O
Economical and Efficient Phosphorus Control at a
Domestic-Industrial Wastewater Plant
Van Dam. O.
Address Not Stated
J WATER POLLUT. CONTR. FED VOL. 53, NO. 12. pp.
1732-1737. Publ.Yr- 1981
SUMMARY LANGUAGE - ENGLISH
Languages ENGLISH
It Is the purpose of this paper to discuss the special
challenges the merged waste flow posed to design and
subsequent operation of the treatment plant. How concentrated
side streams. such as heat treatment supernatants, must be
considered In overall plant efficiency Is discussed. The
techniques used to control phosphorus at a very low cost are
presented. A summary of several years of plant efficiency and
cost figures accompany the text. The Grand Haven, Mich.,
wastewater plant was designed to best accomodate the domestic
wastewater from Grand Haven and the adjacent village of Spring
Lake, as well as a sizable contribution of wastes from a local
chrome and vegetable tanning operation. Five-year operating
results and cost experience of phosphorus control with the
addition of waste pickle liquor to primary settling tank
Influent followed by activated sludge treatment Is shown.
Descriptors: wastewater treatment plants; economics;
phosphorus; activated sludge process: technology; cost benefit
analysis; chromium; settling basins
Plants
Lue-Hlng. C. ; Lord I, D.T.; Kelada, N.P.
Metro. Sanitary Dlst. Greater Chicago, IL
AlChE Nat. Mtg. Boston, Portland, Chicago I960
IN "WATER - 198O VOL. 77. NO. 2O9. pp 144-ISO,
Publ.Yr: 1981
AICHE. 345 EAST 47 ST.. NEW YORK. NY 1OOI7
SUMMARY LANGUAGE - ENGLISH
Languages: ENGLISH
The U.S. Environmental Protection Agency has Issued a list
of 129 priority pollutants which Include metals. cyanides,
phenols, pesticides and other organlcs. The Metropolitan
Sanitary District of Greater Chicago (MSDGC) which operates
seven treatment plants has regulated heavy metals, phenols and
cyanides for a number of years The heavy metals found In the
Influents Include chromium, copper, zinc. Iron, nickel, and
cadmium. Substantial but variable removals do occur with the
effluents reaching some background level for a specific metal.
These metals are found to concentrate In the treatment plant
sludges. The results of a screening of the occurrence of the
priority organlcs at four of the MSDGC treatment plants showed
relatively few organlcs occurring In detectable quantities.
The concentrations of those found were highly variable but
generally less than 1OO mu g/l In the Influents and less than
2O mu g/1 In the effuents.
Descriptors: pollutants; organic compounds; heavy metals;
effluents; wastewater treatment plants; sludge; cyanides;
phenol; pesticides: contamination
82-O2O74
Fate of Priority Pollutants In Large Municipal Treatment
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DIALOG Ftle4l Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Set Abs) (Item 4 of 98) User23913 23Jun82
NJ
CO
82-O2O13
Water Purification System
Shorn, J.
Sys. Eng.
U.S.
p. 2O34.
Publ.Yr:
& Mfg. Corp.. Stoughton. MA
PAT. OFF. GAZ.
VOL. 10O7, NO. 5,
1981
Pat. No. 1,276, t76
Languages . ENGL I SH
A method of purifying water including. combining at least
17OO ppra of a combining agent with wastewater at a pH of fnom
7.1 to 14 with the molar ratio of satd combining agent to the
impurities In satd wastewater being 1:1 on greater so that a
part tele-water blend Is formed wherein said impur 1 1 les are
bound with said combining agent In particles of size at least
1O angstroms; said combining agent Including inorganic metal
hydro* tde with the metal be Ing selected from the group
consisting essentially of Iron aluminum. tin. copper, zinc,
cadmium nickel . cobal t , s 1 1 icon, bar I urn,
and chrome.
Descr tptors : Pur if 1 cat Ion; Wastewater treatment ;
sizes; Inorganic compounds; pH; Patent;
management ; Particle size
calcium, manganese.
Part Id e
Heavy metals; Water
82-00578
Industrial Waste-Water Reuse by Selective Silica Removal
Matson, J.V.
Houston, TX
U.S. PAT OFF. GAZ VOL. 1OO7. NO. 5, p 2O35. Publ.Yr:
1981
Pat. No. 4.276. 18O
Languages: ENGLISH
A method for maintaining silica content In a rectrculating
cooling water system containing waten conditioning chemicals
selected from the group consisting of sulfates. phosphonates
and chromates below a level at which silica scale formation
occurs without discharging blowdown from the system with
consequentlal el in(mat ion from the system of satd water
cond111on 1ng chem1ca1s on resu111ng po11utIon of the
environment, which include continuously diverting a portion of
the chemically conditioned cooling water from said cooling
system as a side stream.
Descr iptors. Cool ing systems; Industrlal effluents;
Wastewater treatment; Water reuse; Chemicals; Environmental
protec tIon. ActIvated alumina; Patent
At Elmo-Calf tannery a new system for recovering chromium
has been installed. Ear 1ler some process 1tquors were
reclrculated back to the process. But the amount of chromium
In the waste waten was too high. The new system was worked out
through laboratory tests and tests in pilot plant. During the
tests magnesium oxide together with anionic polymers were
used. The fulI scale plant was then constructed for
precipitation with either magnesium oxide or sodium carbonate.
The plant which has been in operation with sodium carbonate as
precipitation agent since 1978 with good results. consists of
batchwise precipitation and settlIng of the wastewater and
thIcken tng and dewa ten t ng and dIsso1vIng the siudge. As
dissolving agent concentrated sulfunlc acid has been used. The
chromium liquor Is then reclrculated to the tanning processes.
DescrIptors: Tanning Industry wastes; Chromium; Sludge
dewaterIng; Polymers; RecyclIng; Wastewater treatment
Identifiers: Elmo Calf tannery
81-O7214
Two Step Removal of Metal Ions From Effluents
Cassella. V.J.; Irani, M.R.
PO Corp., Valley Forge. PA
U.S. PAT. OFF. GAZ VOL. 1OO4. NO. 3.
1981
Pat. No. 4.256,577
Languages: ENGLISH
A process f on reducing the metal
aqueous effluents to less than O.I part
consisting of the sequential steps of: a. Agitating an aqueous
effluent containing up to 150O ppm of a metal Ion selected
from the group cons 1st ing of diva lent manganese, copper .
cadmium, lead. Iron, cobal t . nickel and z tnc and tn ivalent
chromium and Iron; b. Adding an aqueous solut Ion of an
tnonganlc base to adjust the pH of the effluent to a value
between 7.O and 9.O.
Descn iptons : Heavy metal s ; Ef f luents; Ions; Wastewater
treatment; pH; Patent
1131.
Publ.Yr*
on concentration of
per ml 11 Ion (ppm)
82-OO563
RenIng av Kromhattlgt Avloppsvatten och Ateranvandnlng av
Utfallt Krom Vld Elmo-Calf AB, Svenljunga
Emanuelsson. I.; Persson, C E ; Horrdln, S
Scandlaconsult AB. Goteborg
VATTEN VOL. 36. NO. 4, pp. 343-351. Publ.Yr 198O
Languages- ENGLISH
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O1AIOG F11e4l. Pollution Abstract's - 7O~82/Apr (Copr. Cambridge ScI Abs) (Item 8 of 98) User23913 23Jun82
to
^
O
B1-O7183
New Method of Regeneration of An*on Exchangers Used for
Recovering Chromates From Wastewater
Paw 1owsk \ . L. ; K1epacka. B.; 2aIewskI. R.
Oept. Chem. Tech., Inst. Chem., tubI In, Poland
WATER RES VOL 15. NO. 1O, pp. 1153-1*56, Publ.Yr:
1981
Languages• ENGLISH
A new economically attractive method of recovery of water
and chromates from wastewater has been presented. In order to
obtain a high enough concentrated regeneration effuent for
refilling plating bath, high concentrated sodium hydroxide
(45%) was used for regeneration of a weakly based anlon
exchanger bed (Wofat It AO 41). Further Increase of the
concentration of the regeneration effluent was obtained by
recyclIng certain frontal and tat 1 parts of regeneration
effuent to raw wastewater. It permits to recycle only a high
concentrated part of the regeneration effluent to refilling
the platfng bath. The Influence of flow rates, doses of sodium
hydroxide and reclrculatIon ratio on the average concentration
of the regeneration effluent and Ion exchange capacity has
been presented.
Descr Iptors: Ef fluents; Resource management; Wastewater
treatment; Recycling; Flow rates; Chromates; Sodium compounds;
Anton exchangers
81-O7175
Elimination of Toxic Metals From Wastewater by an Integrated
Wastewater Treatment/Water Reclamation
Smith, R.; Wtechers, S.G.
Council Scl. A Indust. Res.
Inst. Water Res.
2. pp. 65-7O.
Publ.Yr:
. Rep.
1981
S.
Nat.
Afr .
WATER SA VOL. 7, NO.
Languages: ENGLISH
The overal 1 effect tveness of a pi tot -scale. Integrated
wastewater treatment/water reclamation plant for the removal
of the eight toxic metals listed In the U.S. Environmental
Protect Ion Agency Nat tonal Inter Im Pr Imary Or Ink Ing Water
Regu 1 a t 1 ons < ar sen I c . bar I um , cadm I urn , chrom 1 urn . 1 ead ,
mercury, selenium and silver) was Investigated. Certain unit
processes In the system were shown to be capable of acting as
additional safety barriers against toxic metal contamination.
The most s Igntf leant processes for toxic metal removal were
dent tr If (cat Ion. chemical mix Ing/clar If teat Ion and act I ve
carbon treatment .
Descr I p tors : Wastewater treatment ; EPA ; Federal regulat Ions;
Toxic metals; Contaminants; Activated carbon
1981
Languages: ENGLISH
The wastewaters from paint stripping and surface treatment
operations on aircraft contain a range of materials Including
phenolIc compounds and chromium. The wastewaters are generated
errat leally and only during part of the paint stripping.
repainting cycle. A Fenton's reagent system employing 10O-2OO
rag.L super(-) super(l) of ferrous Iron and hydrogen peroxide
at a weight ratio of hydrogen peroxide to phenol of 2.5-3.O to
1, has been shown to oxidise phenols and reduce any he>
chromium to trIvalent chromium. Subsequent 1 Ime tr
removed the organic residues, chromium and phosphate
s1udge and produced a supernatant su1table for dIsch
sewers and subsequent biological treatment. The lab
results have been confirmed by pilot plant scale studte
DescrIptors: Wastewater; Phenol compounds; Chromium;
valent
atment
to the
rge to
ratory
Laboratory methods;
trea tment; AIrcraf t
Contain t nant s; Paint strl pp 1 ng; Sur f ace
81-O7129
Mechan t caI Aera 11on Versus
Stabilization Pond Treatment
Iwugo, K.O,
Publ. Health Eng. . Univ. Lagos.
EFFLUENT AND WATER TREAT. J VOL
Publ.Vr: 1981
Languages: ENGLISH
This article presents the
Investigations on the treatment of
Hydrogen Perox1de
21, NO.
results of
molasses-based
pp. 8-18.
laboratory
yeast and
chrome-based tannery wastewaters In waste stabilization ponds.
DescrIptors: Tannery Industry wastes; Wastewater; Ponds;
Laboratory methods; Water treatment
81-O7159
Treatment of Paint-Stripping Wastewaters Which Contain
Phenol and Chromium
Barnes, 0.; O'Hara, M.; Samuel, E ; Waters. D.
Sch. Civil Eng , Unlv NSW. Kensington, Austral
ENVIRON TECH. LETT VOL. 2, NO 2. pp. 85-94. Publ . Vr •
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DIALOG F1te4t: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Set Abs ) (Item 12 of 9B) User23913 23jvjn82
KJ
VO
H
chrome from waste water
hexava lent va 1 ence state.
81-O7O18
Chrome Removal Waste Treatment Process
Cassldy, J.D. ; Stelnbrecher . L.
Amchein Prod., Inc., Ambler, PA
U.S. PAT. OFF. GAZ VOL. 1O05 . NO. 1. p. 256. Publ.Yr.
1981
Pat. No. 4.26O.491
Languages: ENGLISH
In a process for the removal of
wh 1 ch * nc 1 udes chrom 1 urn i n the
wherein the pH of said waste water fa adjusted to below about
5, wherein a reducing agent Is added to said waste water while
Its pH Is below about 5 In an amount sufficient to convert all
of the chromium present In the hexava lent valence state to the
tr 1 valent valence state.
Descr Iptors : Wastewater treatment ; pH; Chromium; Pol lut Ion
control ; Patent
81-O5676
Main Compounds Behavior In Kraft Wastes Cleaning by Acid
Coagulation and Carbon Adsorption
Aguado . J . ; Rodr 1 guez , J . U . ; T 1 J ero . J .
Dept , Qulmlca Indust . , Fac. C lend as
Complu tense, Madr Id, Spain
J. ENVIRON. SCI . HEALTH VOL. A16, NO.
Publ . Vr : 1981
Languages: ENGLISH
A kraf t wastewater cleaning method, cons 1st Ing In acid
coagulation and carbon adsorption 1s studied on a chemical
basis. The results obtained show that acid coagulation mainly
produces a precipitation as well as a partial acldolysls of
1 Ignln compounds; a certain retention of celluloslc compounds
was also noticed. Subsequent carbon adsorption substantlaly
removes carbohydrates and pract leal ly a! I of the remaining
1 Ignln Ic compounds.
Descr Iptors : Paper Industry wastes; Preclpl tat 1 on; Carbon;
Adsorpt Ion; Wastewater treatment; Spectroscopy ; Chroma tography
Qu 1m leas , Unlv .
4, pp. 4O5-418.
said munitions In trace amounts as low as 25 parts per billion
onto a reverse phase, high performance liquid chromatographtc
column; (b) chromatographlcally separating said munitions on
said column by elution with a mobile phase comprising methanol
and water; and, (c) monitoring the absorbance of the resulting
eluant In the ultra-violet region to provide a quantitative
determination of the munitions present In said sample.
PescrIptors: Wastewater treatment; LIquld chromatography;
AbsorptIon; Water samplIng; Pur 1fleatIon; Chemicals; Patent
8I-O5578
Elimination of Toxic Metals From Wastewater by an Integrated
Wastewater Treatment/Water Reclamation System
Smith, R.; Wlechers, S.G.
Nat. Inst. Water Res. Councl1 Scl. Indust. Res., Pretoria,
Rep. S. Afrlea
WATER SA VOL. 7, NO 2. pp. 65-7O, Publ.Yr: 1981
Languages: ENGLISH
The overal1 effectIveness of a pilot-scale. Integrated
wastewater treatment/water reclamatIon plant for the removal
of the eight toxic metals 1tsted In the U.S. Environmental
Protect Ion Agency Natlonal Inter 1m PrImary DrInk Ing Water
ReguIat Ions (arsenIc barlum, cadm1urn, chrom1um, 1ead,
mercury, selenium and silver) was Investigated. Certain unit
processes In the system were shown to be capable of acting as
additional safety barriers against toxic metal contamination.
The most signIf leant processes for toxIc metal remova1 were
denttrIfIcatlon. chemical mlxlng/clarIftcation and active
carbon treatment.
DescrIptors: Wastewater treatment; Potable waters; Heavy
metals; ContamlnatIon; Act Ivated carbon; EPA; Federal
regulat tons; Water reuse
81-O56OO
Quantification of the Munitions, HMX. RDX, and TNT In Waste
Water by Liquid Chromatography
Cattran, D.E.; Stanford, T.B ; Graffeo, A.P.
Dept. Secretary Army. Wash., DC
U.S. PAT OFF. GAZ VOL. IOO3, NO. 4, p. 1557, Publ.Yr:
1981
Pat. No 4.252,537
Languages: ENGLISH
A method for the quantitative detection of alIphatIc
nltroamlne and nltroaromatIc munitions selected from the group
consist Ing of 1.3,5,7-tetrant tro-1,3,5,7-tetraazacyclooctane,
1,3,5~trlnltro~ 1.3.5-trlazacycIohexane, 2,4.6-trInltrotoluene.
comblnatIons thereof, and the degradatIon products thereof. In
liquid samples. which Includes (a) directly Injecting up to
40O mlcrollters of a non-concentrated liquid sample containing
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DIALOG FUe41' Pollution Abstracts - 7O-82/Apr (Copr Cambridge Scl Abs) (Item 16 of 98) User23913 23Jun82
81-O5574
Activated Sludge and Activated Carbon Treatment of a Wood
Preserving Effluent Containing Pentachlorophenol
Quo, P.H.H.; Fowlle. P.J.A.; Cairns, V W.; Jank. B.E.
Wastewater Tech. Ctr.. Environ. Protect. Serv.. Environ.
Can.
Publ.Yr• 19BO
ENVIRONMENTAL PROTECTION SERVICE. ENVIRONMENT CAN.. OTTAWA,
ONT. K1A 1C8, CAN.
ISBN. O-662-1O978-3; Rept. No. EPS 4-WP-8O-2
Languages: ENGLISH
A sIx-month monltoning and wastewater treatment plant
effluent upgrading-program was carried out at AbitIbl-Northern
Wood Preservers Limited. Thunder Bay, Ontario, a plant which
preserves wood with creosote, pentachlorophenol (PCP) and
chromated copper arsenate (CCA). Treatment of the wastewater,
after oil separatIon and flow equalIzatIon by the extended
aeration activated sludge process. gave good removal of most
organ1cs; however, PCP remova1 averaged only 35% and the
ef fluent was toxic to rainbow trout. Treatment of the
activated sludge effluent by carbon adsorption resulted In
effectIve PCP removal and nan-toxic effluents. ActIvated
carbon treatment of wastewater, after oil separation and flow
equalization, gave good removals of organ!cs and PCP.
DescrIptors: Wastewater treatment plant; Effluent; AeratIon;
Activated sludge process; Toxic materials; Contaminants; PCP
compounds
8I-O5377
Heavy Metals In the Ruhr River and Their Budget In the
Catchment Area
Imhoff, K.R.; Koppe, P.; Oietz. F.
Ruhrverband. FRG
lOth Int. Conf Int. Assoc. Water Pollut. Res. (IAWPR)
Toronto. Ont. dun. 23-27, 198O
WATER SCI. & TECH VOL. 13. NO. I. Publ.Yr: 1981
Languages: ENGLISH
Numerous analyses of heavy metals have been evaluated with
respect to origin. concentration, behavior and fate of these
elements In the 4.488 km super(2) large catchment area of the
most Intens1vely used Ruhr RIver. For the ratio of the
dissolved and the total heavy metal concentration In Ruhr
water the foltowing topological progress Ion wlth IncreasIng
dissolved fractIon results: tead< copper< z1nc< nickel<
chrom1um< cadmium. A heavy metal balance has demonstrated that
55% of the heavy metals In the Ruhr River are discharged from
municipal and Industrial waste water treatment plants. 45% are
of geochemlcal orIgln. The municipal treatment plants receive
31% of the heavy metals from domestic and 69% from industrial
waste water. These fIgures represent the average of all
analysed heavy metals. The fraction of the particular elements
varies considerably. For example 9O% of the chromium, 65% of
nickel and cadmium and 5O% of copper and zinc are discharged
by industries. The "population equivalent" of heavy metals was
caleulated from the results of 19 plants receIvlng only
domestic waste water deducting the fraction contained In the
drink Ing water.
DescrIptors: Heavy metals; Rivers; Industr1a1
Wastewater treatment plants; Potable water
Ident Iflers: Ruhr River
effluents;
81-O4O11
Control of pollution In Waters Containing Heavy Metals
Klncannon. D.F.; Bates, M.H.; DeVrles. R.N.
DK St. Univ., Stlllwater, Sch Civil Eng
Publ.Yr. 198O
NTIS. SPRINGFIELD. VA
PB81-124133
Languages: ENGLISH
An integrated set of experiments wre carried out on the fate
of chromium and copper In biological waste water treatment
processes. aqueous environments, and soII systems. A rotatIng
biological contactor and activated sludge were used as the
waste water treatment processes; Still water. Oklahoma area
lake and river water and sediments. as the aqueous
environments; and sandy and red sllty clay soils. as the soil
systems. While It was determined that chromium was removed by
the lake and river sediments but not generally removed by
biological treatment processes or by algae, it was found that
copper was removed by all systems. Removal efficiencies of the
metals were highly dependent upon operating and environmental
conditions. Sediments and soils had strong affinities for
copper, and uptake could be correlated with soil type.
DescrIptors: Wastewater treatment; Act Iva ted sludge process;
Soils: Freshwater environments; Algae; Heavy metals
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DIALOG FI1e41: Pollution Abstracts - 7O-B2/Apr (Copr Cambridge Sci Abs) (Item 19 of 98) User239l3 23junB2
VOL. 13. NO. 2
Publ.Yr: 1981
K)
va
U)
81-O398I
Type A Zeolite In the Activated Sludge Process-II: Heavy
Metal Removal
Carrondo, M.J.T.; Lester. J.N.; Perry. R.
Publ. Health Eng. Lab., Imperial Col).. London. G.B.
d. WATER POLLUT. CONTR. FED. VOL. 53. NO. 3 , pp.
344-351 , Publ.Yr: 1981
Languages: ENGLISH
Pilot plant studies were conducted over a range of type A
zeolite concentrations expected In settled wastewater and at
two degrees of calcium exchange for sodium In the zeolite. Two
hydraulic regimes also were examined. An Identical pilot
plant. operating under conditions Identical to those of the
test unit and to which no zeolite was added. provided a
control. At the high calcium exchange rate, no effect was
detected on heavy metal removal. At the low calcium exchange,
the removals of cadmium, chromium, nickel, and lead were
unaffected. There also seemed to be a slight deterioration In
zinc removal and an equally small Improvement In copper
removal, but the evidence for both was Inconclusive The
general order of decreasing removal observed was Cu > Cr. Zn,
Pb > Cd > N1. Although not studied so Intensively, the removal
of Iron seemed to be unaffected by zeolite.
Descriptors: Activated sludge process; Wastewater treatment;
Heavy metals; Water pollutants; Chemical compounds
Identifiers, zeolite
81-O3936
Activated Carbon Processes for the Treatment of Chromium
(VI(-Containing Industrial Wastewaters
Bowers. A.R.; Huang, C.P.
Environ. Eng. Prog., Dept. Civil Eng., Univ. DE, Newark
loth Int. Conf. Int. Assoc Water Poltut. Res. (IAWPR)
Toronto, Ont. dun. 23-27. 198O
WATER SCI. ft TECH. VOL. 13, NO. I . Publ.Yr: 1981
Languages: ENGLISH
Various operational systems using activated carbon for the
removal of Chromium (VI) from synthetic wasteuaters have been
examined In the laboratory. The Influence of controllable
parameters, such as pH. Cr(VI) concentration. column depth.
and mixing In solution were evaluated for the possibility of
scale-up to an economically feasible treatment system.
Completely-mixed. column, and rotating carbon disk systems
were compared as system design alternatives.
Descriptors: Activated carbon; Wastewater treatment;
Chromium; Heavy metals; Economics; Engineering; Water
pur IfleatIon
WATER SCI. & TECH.
Languages- ENGLISH
Percolation of secondary effluent from oxidation ponds to
the groundwater aquifer, which was studied In a large-scale
field operation, acted as an efficient advanced wastewater
treatment system. The major processes Involved were: slow sand
filtration, biological degradation, nitrification.
denl tr If Icat Ion, chemical precipitation, adsorption and Ion
exchange. Excellent removal was obtained by effluent passage
through the soil -aquifer system for several Important
pollutants. Including: phosphorus, partlculate organic matter,
collform bacteria, cadmium and chromium. Good removal was also
obtained for soluble organlcs (expressed as DOC or filtered
KMnO sub(4) consumption).
Descriptors: Effluent treatment; Oxidation; Groundwa ters ;
Aquifers; Filtration; Blodegradat Ion; Denl trlf Icat Ion;
Nitrification; Adsorption: Ion exchange; Wastewater treatment
81-O3O9O
Hexachlorocyclopentadlene Contamination of a Municipal
Wasteuater Treatment Plant
Komlnsky. JR.: Wtsseman, C.L.; Morse, D.L.
Nat. Inst. Occup. Safety Health, Cincinnati. Oh.
AM. INDUST. HYG. ASSOC. d. VOL. 41. NO. 8 . pp 552-556
Publ.Yr: Aug. 19BO
Languages: ENGLISH
In Mar. 1977 hexachlotocyclopentadlene (HCCPD) and
octachlorocyclopentene (OCCP) entered the Morris Forman
Wastewater Treatment plant In Louisville. Kentucky. Airborne
HCCPD concentrations of a blue haze generated by cleanup
procedures measured 19.2OO ppb. A NIOSH questionnaire sought
Information on type and duration of symptoms. HCCPD and OCCP
were collected on pre-extracted Chromosorb 1O2 (2O/4O mesh)
packed Into a 7 cm long 4 mm ID glass tube and then analyzed
using a gas chromatograph equipped with a flame lonlzatlon
detector. The type of protective equipment used varied with
the conditions of exposure. Usable responses to medical
questionnaires were received from 177 treatment plant
employees.
Descriptors: TOXICOLOGY AND HEALTH
Identifiers: hexachlorocyc1opentadIne contamination of
wastewater treatment plants
81-O3878
Treatment Effects and Pollution Dangers of Secondary
Effluent Percolation to Groundwater
Idelovltch, f. : Mlchall, M.
Sewage Reclam Dept , Tel Aviv. Israel
Tenth Int Conf. IAWPR Toronto, Ont. dun 23-27. 198O
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DIALOG F11e4): Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Sd Abs) (Item 23 of 98) User23913 23Jun82
K)
B1-O2773
Trace Organic Behavior In Soli Columns During Rapid
Infiltration of Secondary Wasteuater
Bouwer, E.J.; McCarty, P.L,; Lance, J.C.
Env iron. Eng, Scl . , Civil Eng. Dept., Stanford. CA
WATER RES. VOt. 15, NO. 1 . pp. 151-159 . Publ.Yr;
1981
Languages: ENGLISH
Secondary treated municipal wastewater from the City of
Phoenix was applled to three laboratory-scale sol 1 columns at
var lous Inf11trat ion rates typical of high-rate land
application systems. and a fourth column was Inundated with
tapwater to serve as a control. Samples of the column Influent
and effluent streams, collected with continuous flow-through
systems to prevent organic volat11IzatIon losses, were
ana ^yzed for organic compounds us 1ng gas chromatography/mass
spectrometer. This study was performed to give a general
IndlcatIon of the behavior of trace organleg In sol I column
systems with an attempt to Indicate the presence of various
removaI processes.
Descriptors: SEWAGE & WASTEWATER TREATMENT; LAND POLLUTION
Identifiers: trace organic behavior In soil columns during
Infiltration of wastewater
81-O2772
Efficiencies of Liquid-Liquid Extraction and XAD-4 and XAD-7
Resfns In Collecting Organic Compounds From a Coke Plant's
Effluent
Schaeffer, Q. J. ; TIgwelI, O.C.; Somant, S.M.; Janardan, K.G.
IL E.P.A. Springfield, IL
BULL. ENVIRON, CONTAM. TOXICOL. VOL. 25. NO. 4 , pp,
569-573 , 'Publ.Yr: Oct. I98O
Languages: ENGLISH
The authors have examined the theoretleal requirements of
composite sampling, the propagation of errors which occur from
samp)ing through tdentIf teat ion, and the eff iclency of
sampling methods using capture-recapture methods. Estimates of
the total number of compounds which might be Identifiable by
gas chroma tograhpy-mass spec trometry, have been made. The
theoretical findings have been translated Into practice by the
development of a multichannel sampler (Tigwell and Schaeffer
198Q) which permits the simultaneous collection of a sample by
up to four methods. The present paper will describe how these
elements Interptayed in a study of a coke plant's waste water.
Descriptors: SEWAGE 8 WASTEWATER TREATMENT
Identifiers: organic compounds extraction from coke plant
effluents
Languages: ENGLISH
Oecationized wastewater Is directed onto weakly base ion
exchanger bed Amber lite IRA 67. The cation exchanger bed is
regenerated by means of 5% H sub(2)SO sub(4). The anfon
exchanger bed Is regenerated with \Q>% NaOH. Some fractions of
the front and tall
Into raw wastevtat
regeneration efflue
that rectrculatIon
regeneration efflue
f the regeneratIon effluent are recycled
r to Increase the concentration of the
t. Using computer analysis it was shown
f about 23% of chromates contained (n the
t Into raw wastewater Increases twice the
concentration of the recovered concentrate of chromates from
about 25g to 47g Cr svjper(+6)/dm super(3).
Descriptors: SEWAGE * WASTEWATER TREATMENT
Identifiers: ion exchange In recycling of plating effluents
81-O27O3
Influence of Sludge Age on Heavy Metal Removal In the
Activated Sludge Process
Sterrltt, R.M.; Lester. J.N.
Publ. Health Eng. Lab . Imperial Coll., London. Engl.
WATER RES. VOL. 15. NO. 1 . pp. 59-65 , Publ.Vr: 1981
Languages. ENGLISH
In a laboratory simulation of the activated sludge process
ten heavy metals were added continuously to the system which
was allowed to equilibrate at six sludge ages between 3 and
16d. Cobalt, manganese and molybdenum removals were poor and
were unaffected by changes In the sludge age The highest
removal efficiencies for the other metals occurred at the I5d
sludge age. Chromium (trlvalent) and cadmium had the highest
removal efficiencies, typically greater than 5Q'J4. The
behaviour of the majority of the metals which were removed to
a significant extent was related to one of the parameters
influenced by sludge age. The metals which were poorly removed
showed little affinity for the activated sludge.
Descriptors: SEWAGE & WASTEWATER TREATMENT
Identifiers: sludge age Influence on heavy metal removal
BI-02759
Ion Exchange In the Recycling of Plating Effluents
Paw I owsk I, L . ; 2a I ewsk 1 . R .
Inst. Chern. Inst, Math Marie Curie-Sklodowsda Univ
EFFLUENT AND WATER TREAT J VOL. 2O. NO. 12
581-58b , Publ Yr. Dec 198O
PP
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DIALOG Filell. Pollution Abstracts - 7O-82/Api (Copr. Cambridge Set Abs) (Item 27 of 98) User23913 23juriB2
81-02692
Comparison of the Characteristics of Soluble Organic
Nitrogen In Untreated and Activated Sludge Treated Wastewaters
Parkin. G.f ; McCarty. P.L.
Pept. Civil Eng.. Drexel Univ., Phlla.. PA
WATER RES. VOL. 15. NO. I , pp. 139-149 . Publ.Vr:
1981
Languages: ENGLISH
Soluble organic materials containing nitrogen (SON) are
present In effluents from activated sludge treatment of
domestic wastewater. but little Is known about the sources and
characteristics of these materials. The characteristics of SON
In untreated wastewaters and activated sludge effluents were
evaluated. Characterization techniques used Included low
mtcroblal seed blodegradabl11 ty . molecular weight distribution
using gel filtration chromatography. removal by activated
carbon and Ion exchange, and analysis for free and combined
am(no acids.
Descriptors: SEWAGE & WASTEWATER TREATMENT
Identifiers: organic nitrogen In untreated and treated
sludge treated wastewater
81-O26BO
Field Disposal of Methyl Parathlon Using Acidified Powdered
Zinc
Butler. L C.; Stalff. D.C.; Davis. J.E.; Sovocool. G.W.
Wenatchee Pesticides Res. Br.. Health Effects Res. Lab.,
U.S. EPA, Wenatchee, Wa.
J. ENVIRON. SCI. HEALTH VOL. BI6, NO. 1 , pp. 49-58 .
Publ Yr: 1981
Languages- ENGLISH
The degradation of methyl parathlon In soil with various
amounts of acidified powdered zinc under field conditions was
studied. Treatment was progressively more effective with
Increasing amounts of zinc Disappearance of parent compound
was followed for 2 1/2 years. The expected conversion product
aminomethyl parathlon and Its N-methyl derivative were formed.
Amlnomethyl parathlon was shown to be Identical to an
authentic standard The other specific positional Isomers were
considered likely, but were not proven by mass spectrometry.
Structure elucidation was made with high resolution mass
spectrometry. using the direct Insertion probe, and with gas
chrotnatography/low resolution mass spectrometry.
Descriptors SEWAGE & WASTEWATER TREATMENT
Identifiers field disposal of methyl parathlon
Illus. 9O refs.
Abs. (Available from NTIS. Springfield, VA 22161)
Languages: ENGLISH
TREATMENT CODES: D .(DESCRIPTIVE) ; I .(INVESTIGATIVE/OBSER-
VATION)
A floe foam flotation pilot plant removed Pb and Zn In
dilute aqueous solution to quite low concentrations. Design
Improvements are presented. The floe foam flotation of Zn Is
readily carried out with aluminum hydroxide (AI(OH)3) and
sodium lauryl sulfate (NLS). Chromium hydroxide Is floated
with NLS, but adsorbing colloid flotation of Cr+3 with ferric
hydroxide (Fe(OH)3) or AI(OH)3 yielded better results. Cobalt
and Nl levels are reduced to =1 mg/L by flotation with A1(OH)3
and NLS. The Mnt2 levels can be reduced to 1-2 mg/L by
flotation with Fe(OH)3 and NLS. Floe foam flotation of Cu was
compatible with several precipitation pretreatments (soda ash.
lime. Fe(OH)3, and A1(OH)3). although modifications were
needed to prevent Interference from excessive Ca or CO3-2.
Therefore, floe foam flotation can be used as a polishing
treatment. The flotation of mixtures of Cut2, Pbt2, and Zn+2
was conducted using Fe(OH)3 and NLS. The flotation of simple
and complexed cyanides and mixtures of metal cyanide complexes
was also conducted with Fe(OH)3 and NLS; a pH of =5 Is
optimum. A surface adsorption model for floe foam flotation
was analyzed and accounted for the effects of surfactant
concentration, lontc strength, specifically adsorbed Ions, and
surfactant hydrocarbon chain length. (AM)
Descriptors: Flotation; Industrial wastes; Wastewater
treatment; Pilot plants; Engineering; FlocculatIon; Ions;
Surfactants; Iron compounds; Aluminum compounds: Heavy metals;
Zinc; Nickel; Manganese; Chromium; Cobalt; Copper; Lead;
Chemical treatment; Adsorption
Identifiers: floe foam flotation
Industrial uastewaters:
8I-O1797
Foam flotation treatment of
Laboratory and pi lot scale.
Wilson, D J ; Thackston. E. L.
Vanderbllt Univ., Nashville. TN 37235
II.S Environmental Protection Agency. Office of Research and
Development Environmental Protection Technology Series
CorJfin FPTSBT Publ Vr Jun I98O
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DIALOG Flle4t: Pollution Abstracts - 7O-82/Apr (Copr, Cambridge Scl Abs) (Item 3O of 98) User23913 23Jun82
3174
10
B1-O1795
Sulflde precipitation of heavy metals.
Rob i nson, A. K., Sum, J. C.
Boeing Commercial Airplane Co., Manufacturing Research and
Development. P O. Box 3707, Seattle, WA 98124
U.S. Environmental Protection Agency. Office of Research and
Oeve1opment EnvIronmentaI Protect Ion Techno1ogy Ser1es
Coden: EPTSBT PubI Vr: Jun 198O
IIlus. 16 refs,
Abs. (Available from NTIS. Springfield. VA 22161)
Languages: ENGL!SK
TREATMENT CODES• I .(INVESTIGATIVE/OBSERVATION) ; 0
.(DESCRIPTIVE) ; E .(ECONOMIC/COMMERCIAL/MARKET)
The sulflde precipitation of heavy metals from Industrial
wastewaters was evaluated. Five processes were compared In
bench-scale, contInuous-flow equipment-convent tonal 1 Ime
processing, conventional lime processing plus filtration, lime
with a sulflde polishing and filtration, lime with sulflde.
and lime with sulflde plus filtration. Wastewater samples
from 14 metal work Ing Industrles were processed through the
bench-scale equipment using all 5 processes. Reductions In
the concentrations of Cd, Cr, Cu, N1, and Zn. plus selected
other metals, were measured by atomic absorption chemical
analysis. Capital and operating costs for the processes were
compared for 3 plant stzes-37 85 ro3/d (1O.OOO gpd). 757 m3/d
(2OO.OOO gpd). and 1.B93 m3/d (5OO.OOO gpd). To reduce the
levels of Cd. Cu, Ml. or Zn from a wastewater treatment plant
using conventional lime processing, the addition of a final
filtration should be considered first. If filtration does not
achieve the desired low levels, then a sulflde polIshlng
process with added filtration Is recommended. If reduction of
the levels of Cr, Pb, Ag, or Sn Is required, the conventional
lime process plus filtration 1s recommended. The sulflde
process did not s ignlficantly reduce the levels of these
metals. Details are Included on the use of a specific Ion
electrode for the control of sulflde additions. (AM)
DescrIptors• Heavy metals; Precipltat ion; Was tewater
treatment; Sulfur compounds; Industrlal effluents; L I me;
F11tratIon; Metal Industry wastes; Economics; Engineering;
Cadmium; Copper; Chromium; Nickel*, 2Inc; Chemical treatment
Ident 1flers: sulfIte precipI tat ion
Doc Type: JOURNAL PAPER CONFERENCE PAPER
TREATMENT CODES: T .(THEORETICAL/MATHEMATICAL) ; D
.(DESCRIPTIVE)
A model was developed to represent the 1IquId-phase
reduct Ion of Cr+6 by SO2, the s Imul tarieous compet 111 ve
reaction of DO with S02, and O2 reaeratlon. The model Is
applicable to both batch and continuous stirred tank reactors
and gives conservat1ve results compared to batch and
contInuous-flow data. Sulfur dioxide and Its salts reduce
Cr+6 to Cr+3. The reaction rate increases with Increasing
reactant concentratIon and temperature and decreasIng pH.
Residual Cr is lower In a batch reactor than 1n a continuous
reactor of equal residence time. DO competes with Cr+6 for
SO2. Oxygen-saturated cooling tower blowdown is the Initial
source of O2 to the reaction, and O2 enters the system by
reaeratlon as the DO concentration Is depleted. Reaeratlon
can be sIgnlfleant and Is a serlous enemy of chromate
reduction. (AM.FT)
DescrIptors: Mathematleal models; KInetIcs; Chromium; Heavy
metals; Cooling systems; Reduction; Sulfur compounds; Chemical
react Ions; Chemical treatment: Wastewater treatment; Sulfur
dloxIde; DO; AeratIon
Identifiers: cooling tower blowdown; Cr(VI); hexavalent Cr
81-01755
Kinetic model for chromate reduction In cooling tower
blowdown.
Kunz. R. G.; Hess, T. C.; Yen, A. F.; Arseneaux, A. A.
Air Products and Chemicals. Inc.. P.O. Box 538. Allentown,
PA 181O5
86th national meeting of the American Institute of Chemical
Engineers Houston. Texas Apr 1-5. 1979
Amerlean Institute of Chemical Engineers
Water Pol tut ion Control Federal Ion. Journal 52(9).
2327-2339, Coden: JWPFA5 Publ Yr- Sep 198O
1 Ilus. 29 refs.
Eng.. Fr , Ger., Port., Span abs.
Languages ENGLISH
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DIALOG Ftle41: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Sc I Abs) (Item 32 of 98) User23913 23Jun82
-J
BI-O1723
Pretreatment of Industrial discharges to publicly owned
treatment works.
Ongerth. J. E.; OeWalle. F. B.
Brown and Calduell Engineers. 6OO First Ave.. Seattle, WA
9B1O4
Water Pollution Control Federation. Journal 52(8),
2246-2256. Coden: JWPFAS Pub'l . Yr: Aug 198O
11lus. no refs.
Eng.. Fr., Ger., Port., Span, abs.
Languages: ENGLISH
Ooc Type: JOURNAL PAPER CONFERENCE PAPER
TREATMENT CODES: I .(INVESTIGATIVE/OBSERVATION)
The effectiveness of an Industrial pretreatroent program to
limit the discharge of toxic metals and organIcs Into publicly
owned treatment works was evaluated. Measured median
Industrial discharge concentrations were as follows: O.69 mg/L
Zn; O.65 mg/L Cu; O.17 mg/L Pb; O.29 rog/L Cr; O.1O mg/L Nl;
and O.O2 mg/L Cd. Analysis of wastewater from different
treatment plants showed the presence of 36 priority
pollutants. All groups but phth.alates showed an Increase with
Increasing plant flow and percentage of Industrial
.contribution, Indicating that Industrial pretreatment can
reduce wastewater concentration levels by >l/2. Primary
treatment was effective In removing high molecular weight
compounds, and secondary treatment can remove volatile
compounds through air stripping and additional adsorption and
degradation by bacterial solids. (AM)
Descriptors: Industrial effluents: Wastewater treatment;
Heavy metals; Toxic materials; Pollution control; Zinc; Copper
; Lead; Chromium; Nickel; Cadmium
Identifiers- pretreatment
8I-OI7O9
ChromatographIc behavior of humlc materials extracted from
Barberton sludge.
Marios. G. P.; Tsal, E.
Univ. of Akron, 3O2 E. Buchtel Ave., Akron, OH 44325
Water. Air. and Soil Pollution; an International Journal of
Environmental Pollution 13(3). 373-377. Coden: WAPLAC
Publ.Yr Sep 198O
Illus. refs.
Abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
TREATMENT COOES: I .(INVESTIGATIVE/OBSERVATION)
Humlc and fulvlc acids extracted from alkali treated
municipal sludge contain more higher molecular weight
materials than from secondary wastewater effluents. This
suggests that higher molecular weight materials (>3O.OOO) are
more easily entrapped on the protelnaceous surface of the
btomass. About 28% of the sludge COD Is humlc material. The
humtc acid fraction Is of a higher molecular weight than the
fulvlc acid fraction. The value of the E4-E6 ratio Indicates
that humlc materials of raw sludges are of recent origin.
While the higher molecular weight humlc materials (>3O.OOO)
would be easily adsorbed on the soil structure. the lower
molecular weight material may have a higher mobility In the
transport of heavy metals when the sludge Is applied to soils.
(AM.FT)
Descriptors: Acids; Alkalies; Sludges; Chrotnatography;
Bloraass; COD; Wastewater treatment; Sewage treatment; Organic
wastes; Effluents; Municipal wastewaters; Heavy metals
Identifiers: humlc acid; fulvlc acid; high molecular weight
materials
81-O17O3
Further studies on the Influence of zeolite type A on metal
transfer In the activated sludge process.
Perry, R.; Obeng, L. A.; Lester, J. N.
Univ. of London. Imperial College. Civil Eng. Dept.. Public
Health and Water Resource Eng. Section. London SW7 2BU.
E ngIand
Environment International 3(3). 225-23O, Coden: ENVIOW
Publ.Yr: 198O
11lus. refs.
Sum.
Languages: ENGLISH
Ooc Type: JOURNAL PAPER
TREATMENT CODES: I .(INVESTIGATIVE/OBSERVATION)
The effect of zeolite type A on metal (Cd, Cr, Cu. Nl. Pb.
Zn) removal by activated sludge was Investigated using
laboratory activated sludge simulations operated at constant
aerator sludge age and settler surface loading. Different
concentrations of raw zeolite and zeolite extracted from
washing powder (O, 15, 3O. 6O. I2O mg/L) were Introduced Into
the simulations. The zeolite was added at 2 degrees of Ca
exchanged for Na, 25% and 75% of the maximum exchange
capacity. Metals were added at concentrations typical of
mixed domestic-Industrial wastewaters. Apparently zeolite
does not adversely affect metal removal at the concentrations
and under the conditions used, but could slightly Improve
removal of Pb and, to a lesser extent, Zn and Cd. The
greatest .Improvement occurred on the Initial addition of
zeolite; however, the Improvement Is not as great as that
observed under conditions In the presence of detergent P04-3.
(MS.FT)
Descriptors: Heavy metals; Activated sludge process;
Simulation; Detergents; Lead; Zinc; Cadmium; Chromium; Copper:
Nickel: Surfactants; Sewage treatment; Wastewater treatment;
Pollutant removal; Phosphate removal
Identifiers: zeolite; metal removal; 6 heavy metals
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DIALOG F1le4t: Pollution Abstracts - 7O-82/Apr (Copr. -Cambridge Scl Abs) (Item 35 of 98) User 23913 23]un82
O
0
o
CHEEA3
8I-OI-IO9
Effluent rules are here for Inorganic chemicals.
Shaw. d. S.
World News, Washington, DC
Chemical Engineering 87(18), 53-55. Coden:
Pub I.Yr: Sep 8. I98O
11lus no refs.
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER '
EPA's new guidelines for Inorganic chemicals apply to
pollutants In the wastewaters of 152 out of 75O US Inorganic
chemical plants. but only IO7 will have to make changes to
conform. at an estimated cost of $41.2 million. Segments of
the Industry most seriously affected are titanium dioxide and
chromium pigment producers. The crux of the EPA effort Is the
determination of "best available technology'' (BAT), and the
requirement that this standard be Incorporated Into
Industrial-wastewater permits. Compliance with BAT Is
mandated by duly 1984. The guidelines are expressed
numerically, and any suitable technology can be used which
ensures compliance. The guidelines also propose slightly
revised "best practicable technology" (BPT) standards. EPA
also established somewhat more stringent standards than BAT
for firms which discharge Into municipal sewage treatment
plants and set standards for new plants. In most cases, BAT
translates Into BPT plus additional end-of-plpe treatment.
EPA Is still considering other options for the final rules and
Is seeking Information about the costs of complying with RCRA
to determine the effect these will have on the total cost of
meeting the various wastewater regulations. (FT)
Descriptors: EPA; Federal regulations;
wastes; Inorganic compounds; Wastewaters:
Chromium compounds; Pigments; Effluents
Identifiers: best available technology;
technology
Chemical Industry
Titanium compounds:
best practicable
Languages: ENGLISH
Doc Type: dOURNAL PAPER CONFERENCE PAPER
Rusting Is an oxidation process that converts fe from its
elemental state to Fe+2 or Fe+3. During oxidation. Fe has
potential for reducing substances fro
states, e.g., Cr+6. Thus. If the
passed through a stock of rusting tin
Sn and Fe to Sn+2 and Fe+2 oxidation
time, the Cr+6 Is reduced to Cr+3.
procedure over the standard method o
sizes of tin can and dlfferen
their higher oxidation
hromlc acid solution Is
ans It will oxidize the
tates, and at the same
he advantages of the
S03-2 or S02 reduction
wastewater feeding
characteristics to evaluate the effectiveness of the process.
The more heavily rusted tin cans are more effective In
reducing Cr+6. Generally. a retention time of 12 hr Is
required to reduce 9O/S of the Cr+6 to Cr+3, but for purposes
of design, a 24-hr retention time Is Ideal to reduce Cr+6
almost to negligible level. Calcium carbonate Is used as a
precipitating agent. The chemical cost of conventional Cr
treatment processes Is twice that of the new process using
rusted tin cans based on a IOO m3/d of combined wastewater
with 5 ppm SO2 and pH 3.O. (FT)
Descriptors: Waste reuse; Waste management: Materials
recovery; Tin; Chromium; Metal finishing industry wastes;
Waste treatment; Pollution control; Chemical oxidation;
Kinetics; Economics
Identifiers: rusted tin cans; Cr plating wastes
B1-OO759
Utilization of waste tin cans In the control of chromium
plating wastes.
Ouano. E. A. R ; Arellano, F.
Quezon City, Philippines
Second recycling world congress- New and better uses of
secondary.resources Manila, Philippines Mar 19-22, 1979
National Science Development Board of the Philippines-Asian
Recycling Association-Bureau International de la
Recuperation-United Kingdom Society of Chemical
Industry-United Kingdom "Conservation ft RecyclIng''-Unlted
Kingdom Institution of Metallurgists-Illinois Institute of
Technology-United States Research Institute-United Kingdom
Institution of Production Engineers-Clean Japan Center-dapan
Waste Management Association-United States Bureau of Mines
CONSERVATION & RECYCLING 3(3-4), 355-359. Coden:
CRECD2 Publ.Vr. 1979
iIlus. S refs
No abs.
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DIALOG Flle4t. Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Set Abs) (Item 37 of 98) User239t3 23junB2
to
(.0
8 I-OO66S
Wastewater treatment plant works overtime.
Frltch. G. H.
Howard R. Green Co . Green Engineering Bldg., Cedar Rapids,
IA 52401
Water and Wastes Engineering 17(9). 7O-73. Coden:
WWAEA2 Publ.Yr: Sep I98O
11lus. no refs.
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
The Amana, Iowa, wastewater treatment plant, operated and
maintained by Amana Refrigeration, Inc. (which contributes
>SO% of the design loading). Is described. The plant's
Industrial wastes-containing a high concentration of heavy
metals-and Its domestic wastes are segregated, with the latter
transported through gravity collector sewers to a pumping
station where It Is ground before being sent to a flow
equalization tank. A concrete splitter box divides the flow
equally to 2 aeration basins. Aerobic digestion Is
accomplished using a center flow mounted mixing system;
treated effluent Is disinfected by chlorInatIon. The system
has a hydraulic capacity of 3OO.OOO gpd and an organic
capacity of 51O Ib of BOD5/d. The segregated waste streams
are pretreated separately. An unusual filtering system then
removes metal hydroxides without prior clarification'. The
waste streams are segregated Into 2 categor1es-Cr+6 wastes and
acid-alkali wastes. Hexavalent chromium Is reduced to Cr-t-3
with sodium bisulfite under acidic conditions, blended with
the acid-alkali waste, and neutralized to precipitate
Insoluble metal hydroxides. Ferrous sulfate agglomerates the
gelatinous waste. which Is filtered through PVC filter tubes.
(FT)
Descriptors Wastewater treatment plants; Industrial wastes;
Aerobic process; Iowa; Engineering; Biological treatment;
Heavy metals; Domestic wastes; Wastewater treatment
Identifiers: Middle Amana; Amana Refrigeration, Inc..
drain field, which In turn reduces the required size of the
field. The units are also designed to keep untreated sewage
from entering the drain field. (FT)
Descriptors: Aerobic process; Sewage treatment; Aerobic
systems; Domestic wastes
Identifiers: Pennsylvania State Univ.; CA-15 and CA-5
aerobic treatment units: Chromaglass Corp.
81-OO599
Electrolytic ferrlte formation system for heavy metal
removal.
Nojlrl, N. ; Tanaka. N. ; Sato. K.; Sakal, V.
Mitsubishi Petrochemical Co.. Ltd,. Central Research Lab..
Aml-cho, Ibarakl-ken. Japan
Water Pollution Control Federation. Journal 52(7).
1898-1906, Coden: JWPFA5 Publ.Yr: Jul 198O
Illus. 3 refs.
Eng.. Fr.. Oer., Port.. Span. abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
An electrolytic coagulation process was developed for
removal of heavy metals from Industrial wastewaters. The
process consists of the following processes: an electro-bath,
In which Cr+6 Is reduced to Cr+3; polymer coagulation and
settling; and formation of ferrlte In the settled sludge.
Ferrlte sludge Is separated In a magnetic separator. The Cr
In ferrlte sludge Is not soluble In water. Phosphate and
silicon dioxide also are Incorporated Into the ferrlte sludge.
Supernatant water from the settling contains very little Cr.
(AM)
Descriptors: Electrochemistry; Heavy metals; Materials
recovery; Contaminant removal; Wastewater treatment; Ions;
Engineering; Mathematical analysis: Industrial effluents;
Separation processes; Chromium
Identifiers: electrolytic ferrlte formation
ASSOCIATION OF PENNSYLVANIA.
Publ.Yr: Jul-Aug 198O
81-00615
Aerobic sewage treatment system performance tested at Penn
State.
Anonymous
WATER POLLUTION CONTROL
MAGAZINE 13(4), 16-18.
1 Ilus. no refs.
No abs.
Languages: ENGLISH
Doc Type- JOURNAL PAPER
Two aerobic treatment units. CA-5 and CA-15. manufactured by
the Cromaglass Corporation have undergone 6 mo of tests at the
Pennsylvania State University Wastewater Treatment Plant and
have been approved by the Pennsylvania Department of
Environmental Resources. The CA-5 Is a 5OO-gpd model suitable
for single family dwellings that can remove 82/4 BOD and 84% of
the SS from. Incoming wastes. The batch processing system
offered by the Cromaglass units reduces the loading on the
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DIALOG Fllell: Pollution Abstracts - 7O-82/Apr (Copr Cambridge ScI Abs) (Item 4O of 98) User239l3 23JunB2
U)
o
o
8I-OO57S
Collection and analysis of purgeable organ I cs emitted from
wastewater treatment plants.
Pelltzzari, E. D.; Little, L.
Research Triangle Inst., Research Triangle Park, NC 277O9
U.S. ENVIRONMENTAL PROTECTION AGENCY. OFFICE OF RESEARCH AND
DEVELOPMENT. ENVIRONMENTAL PROTECTION TECHNOLOGY SERIES
Coden: EPTSBT Publ.Yr: Mar I98O
IIlus. IS refs.
Abs.
Languages: ENGLISH
An analytical method was developed for the analysis of
volatile priority pollutants In alrstreams passing through
wastewaters using a Tenax GC cartridge In combination with
GC-MS/computer. A sampling system was designed and Field
tested for sampling alrstreams passing through grit chambers
and activated sludge systems. Recovery of the volatile
priority pollutants was accomplished by thermal desorptlon,
purging with He Into a 1 Iquld-nl trogen-cooled Nl capillary
trap, and Introducing the vapors onto a GC column.
Characterization and quantification of the priority pollutants
was by MS using mass f ragmentography. The areas of
Investigation were as follows: the performance of a Tenax GC
sampling cartridge for the priority pollutants occurring In
the alrstreams passing through wastewaters; the design,
fabrication and evaluation of a field sampler; recovery
studies of priority pollutants from distilled water, raw
wastewater, and activated sludge using laboratory-simulated
conditions; a methods-of-addltIon study for priority
pollutants In raw wastewater and activated sludge; the
delineation of the GC/MS/COMP operating parameters for
priority pollutants collected on Tenax GC cartridges; the
application of the developed methods to the analysis of
priority pollutants; and evaluation of the accuracy and
precision of the collection methods for ''purgeable'' priority
pollutants In alrstreams from raw wastewater and activated
sludge basins. (AM)
Descriptors: Wastewater treatment plants; Engineering; Air
sampling; Activated sludge; Pollutant detection; Organic
compounds; Chemical analysis; Wastewaters; Gas chromatography;
Mass spectroscopy; Computer programs; Aromatic compounds;
Halogenated compounds
Identifiers: purgeable organIcs
8 I-OO564
Selected organic pesticides, occurrence, transformation, and
removal from domestic wastewater.
Saleh. F. Y.; Lee, G. F.; Wolf. H. W.
North Texas State Unlv , Denton, TX 762O3
WATER POLLUTION CONTROL FEDERATION. JOURNAL 52(1), 19-28,
Coden JWPFA5 Publ.Vr: Jan 1980
11lus. 16 refs.
Eng.. Fr.. Ger., Port., Span, abs
Languages- ENGLISH
Doc Type JOURNAL PAPER
A study was conducted on the characterization of chlorinated
organic pesticides In Dallas, Texas, municipal wasteuater.
The effects of biological wastewater treatment processes on
these compounds were also studied using a 3.785-m3/d nominal
capacity pilot plant with 2 activated sludge units.
Wastewater from different stages of treatment from a 2O4-ro3/d
overloaded high-rate trickling filter treatment plant was used
as feed to the activated sludge units. Analytical methods
Included electron capture GC on several columns of different
polarity and chemical derIvatIzatIon. Confirmatory tests,
e.g., TLC, extraction of p-value. and central processing
unlt-MS/GC, were used to confirm the compounds detected by
electron capture GC. Electron capture chromatograms of
wastewater showed characteristic fingerprints, consisting of
2O-25 peaks, which were constantly detected over a 2-yr
period. Thirteen compounds were confirmed. (AM)
Descriptors: Municipal wastewaters; Insecticides; Herbicides
; OrganochlorIne compounds: ChlorophenoxyacetIc acids: 2.4-D;
Dlazlnon; Organophosphorus compounds; Atdrln; DDE; DDT;
Pollutant detection; Pollutant removal; Wastewater treatment;
Texas; Biological treatment; Activated sludge process
Identifiers: Dallas; heptachlor epoxlde; 13 pesticides
81-OOSIO
Cooling-water treatment prevents excessive deposits.
Anonymous
CHEMICAL ENGINEERING 87(16). 91. Coden: CHEEA3
Publ.Yr: Aug II. 198O
11lus. no refs.
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Phosphate-based treatments are now replacing the chromate-
or chromate/Zn-based cooling water additives used to protect
against corrosion and deposition for the past 3O yr. A
patented system-Dlanodlc II-Involves the use of 2 additives
Injected successively Into the cooling-water system. The
first additive contains orthophosphate, polyphosphate and
phosphonate compounds, and a Cu corrosion Inhibitor, while the
second contains an Inhlbltor/dlspersant for calcium
orthophosphate. The system improves corrosion protection
without excessive deposition and allows greater changes in
water chemistry without affecting the coating. Operating
costs are 45% less than that of the conventional chromate
treatment. (FT)
Descriptors: Cooling waters: Wastewater treatment: Corrosion
; Materials protection; Phosphates: Water pollutants
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DIALOG Flle41. Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Scl Abs) (Item 43 of 98) User23913 23Jun82
U!
o
8 I -OO5O8
Evaluation of reverse osmosis membranes for treatment of
electroplating rlnsewater.
McNulty, K. J.; Hoover. P. R.
Abcor, Inc.. Maiden Dtv., Wilmington, MA OI887
U.S. ENVIRONMENTAL PROTECTION AGENCY. OFFICE OF RESEARCH AND
DEVELOPMENT. ENVIRONMENTAL PROTECTION TECHNOLOGY SERIES
Coden: EPTSBT Publ.Vr: May 198O
Illus. refs.
Abs. (Available from NTIS, Springfield. VA 22161)
Languages: ENGLISH
The RO system described functions by concentrating the
chemicals for return to the processing bath while purifying
the wastewater for reuse In the rinsing operation. The
effectiveness of the PA.-3OO. PBIL, NS-IOO. NS-2OO. SPPO. B-9,
and CA membranes were evaluated In tests on rlnsewater with
extreme pH and oxtdant levels. The PA-3OO membrane performed
well with copper cyanide. zinc cyanide, and chromic acid
rlnsewaters. while the NS-2OO and PBIL membranes performed
best with acid Cu rlnsewaters. After commercializing the
membranes, applications In various metal finishing,
non-ferrous metal, steel. and Inorganic industries may be
found. (FP.AM)
Descriptors: Reverse osmosis; Membranes; Wastewater
treatment; Metal finishing industry wastes; Waste treatment
Identifiers: electroplating rfnsewater
80-O8412
Management a control of heavy metals In the environment.
Anonymous
International conference: Management & control of heavy
metals In the environment London, England Sep 18-21. 1979
Commission of the European Communities-Institution of Water
Engineers & Scientists-Institution of Public Health
Engineers-Institute of Water Pollution Control-World Health
Organ)sat ion
664 pp Publ.Yr: 1979
Publ• Edinburgh, Scotland CEP Consultants
illus. index refs. for various papers
Abs.
Languages: ENGLISH
Doc Type: BOOK CONFERENCE PROCEEDINGS
Problems associated with management and control of heavy
metal-bearing wastes In marine, freshwater, and terrestrial
environments are discussed. Topics include health effects,
sources and pathways, analytical techniques, metal special Ion.
sludge treatment and disposal via land application. Industrial
sources, and waste management. The following metals are
considered: Cd. Pb. Zn. Kg, Se. Ag. As, V. Be. Co. Cr. N1, Sb.
Fe, Al, and Cu. (FP.FT)
Descriptors: Heavy metals; Waste disposal; Waste Management;
Marine environments; Freshwater environments; Terrestrial
environments; Toxicology; Public health; Measuring methods;
Sludge treatment: Sludge disposal; Land application;
Wastewaters; Books; Aquatic organisms; Sediments; Air
pollution; Conferences; Pollution control; Soils; Plants;
Chromium; Nickel; Antimony; Iron; Aluminum; Capper; Mercury;
Selenium; Silver; Arsenic; Vanadium; Beryllium; Mining;
Industrial wastes; Cadmium; Lead; Zinc; Cobalt
Identifiers: 16 metals; proceedings; metal speclatton
8O-O157O
Studies on the use of Inorganic gels In the removal of heavy
metals.
Srivastava, S. K.; Bhattacharjee, G.; Sharma, A. K.; Oberol.
C K.
Univ. of Roorkee, Chemistry Oept., Roorkee.
WATER RESEARCH 14(2). 113-I IS.
Publ.Vr: I98O
Illus. refs.
Abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Chromium ferrocyanlde gel shows
Cu+2. Tit. Zn+2. CO+2, Cd+2. Mnt2.
to separate and recover some heavy metal ions. e.g.. T1+,
Hg+2, Mg+2. and Fe+3. Some of these can be completely eluted
from the columns of this exchanger material, and the compound
can be used to treat wastewater rich In heavy metal ions. The
only drawback of this material Is the partial recovery of a
few metal Ions, e.g.. Co+2, Cd*2. Mnt2, Zn+2, and Pb«2 and the
irreversible uptake of Cu+2 and Agt. (AM.FT)
Descriptors: Inorganic compounds; Ion exchange; Ions; Heavy
metals; Wastewater treatment; Silver; Copper; Thallium; Zinc;
Cobalt; Cadmium; Manganese; Iron; Mercury; Magnesium;
Contaminant removal
Identifiers: chromium ferrocyanide gel; distribution
coeff iclents
U.P.. India
Coden: WATRAG
great affinity for Ag*,
and Fe*3 and has been used
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DIAIOG Flle4l- Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Set Abs) (Item 46 of 98) User239l3 23jun82
GO
O
K)
8O-O755I
Activated carbon process for treatment of uastewaters
containing hexavalent chromium.
Huang, C P.; Bowers. A. R
Univ. or Delaware, Newark, DE 19711
U.S. ENVIRONMENTAL PROTECTION AGENCY. OFFICE OF RESEARCH AND
DEVELOPMENT. ENVIRONMENTAL PROTECTION TECHNOLOGY SERIES
Coden. EPTSBT Publ.Yr: Jul 1979
Illus refs.
Abs (Available from NTIS, 6285 Port Royal Rd. .
Springfield. VA 22161)
Languages: ENGLISH
Doc Type- REPORT
The removal of Cr+6 from dilute aqueous solution by an
activated carbon process was Investigated. Two removal
mechanisms were observed- Cr+6 species were removed by
adsorption onto the Interior C surface and/or through
reduction to the trlvalent state at the external C surface.
The effects of Cr+6 concentrations, pH. C dosage, and extent
of mixing In the reaction vessel were studied In the batch
mode and In continuous flow packed column experiments In the
laboratory. The adsorptlve capacity of the C and the rates of
Cr+6 adsorption and reduction were determined. Thermal
regeneration of the exhausted C was examined, along with
caustic or acid stripping solutions and a combined
caustIc-thermal process. A case study Is presented and the
experimental data and rate expressions obtained from the data
are used to evaluate the design variables (pH. carbon dose.
Cr+6 concentration, and mixing In the reaction vessel).
Several Cr+6 treatment schemes are proposed, together with an
economic analysis of each scheme. (AM)
Descriptors: Wastewater treatment; Activated carbon;
Chromium; Heavy metals; Adsorption; Kinetics; Mathematical
analysis; Contaminant removal; Reduction; Economics
Identifiers: hexavalent Cr
8O-O752S
Examination of the applicability of cellulose Ion exchangers
for water and waste water treatment.
doergensen, S. E.
Royal Danish School of Pharmacy, Dept. of Chemistry AD, 2
Unlversltetsparken, DK-2IOO Copenhagen Oe, Denmark
WATER RESEARCH 13(12). 1239-1247, Coden: WATRAG
Publ.Yr 1979
Illus. refs.
Abs
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Three cellulose Ion exchangers were able to remove proteins,
azodyes. DBS. humlc acid, chromate. and heavy metal ions. The
selectivity of the Ion exchangers for removal of these
compounds Is very high, which explains their ability to remove
the examined compounds with high efficiency and capacity.
although the 3 cellulose Ion exchangers have only a small
capacity expressed as equivalents per liter. The mass
transfer coefficient was determined; only the Internal mass
transfer determines the uptake rate Theoretical column
calculations based upon the found mass transfer coefficients
were confirmed by pilot plant experiments (AM)
Descriptors: Ion exchange; Wastewater treatment; Water
treatment; Laboratory testing: Resins; Mathematical analysis;
Pilot plants; Feasibility studies
Identifiers: cellulose Ion exchangers; mass transfer
coef f Ic lent
8O-O751O
Processing chrome tannery effluent to meet best available
treatment standards.
Barber, L. K.; Ramirez, E. R.; Zemaltis, W. L.
A. C. Lawrence Leather Co., Inc., 1 Bridge St.. Winchester.
NH O347O
U.S. ENVIRONMENTAL PROTECTION AGENCY. OFFICE OF RESEARCH AND
DEVELOPMENT. ENVIRONMENTAL PROTECTION TECHNOLOGY SERIES
Coden: EPTSBT Publ.Yr: Jul 1979
Illus. refs.
Abs. (Available from NTIS. 5285 Port Royal Rd. .
Springfield. VA 22161)
Languages: ENGLISH
Doc Type: REPORT
To satisfy stream discharge requirements at its Winchester.
New Hampshire, chrome tan shearling tannery. the A. C.
Lawrence Leather Co.. Inc. selected primary and secondary
systems that are unique as applied to tannery effluent
treatment In the US. Primary clarification is accomplished by
means of coagulation and flotation, using electrolytic and
mechanical micro-bubble generation. The'secondary biological
section Is a CARROUSEL,TM a technical modification of the
Passveer oxidation ditch. During the 12-mo study. complete
analytical data representing winter and summer operating
conditions were acquired along with operating cost data. The
following parameters were analyzed. BODS; SS; N; NH3; Cr;
sludge volume; and fats, oils, and grease levels. These data
are presented and the design and operation of the system is
described. Possible applications of these principles to other
tannery wastewaters are suggested. (AM.FT)
Descriptors: Tanning Industry wastes; Wastewater treatment;
Water quality standards; Primary treatment; BOO; Secondary
treatment: Coagulation; Oxidation; Oils; Suspended solids;
Nitrogen; Ammonia; Chromium; Sludges
Identifiers: best available treatment; A. C. Lawrence
Leather Co., Inc.
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DIALOG F11e41: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Set Abs) (Item 49 of 9B) User239l3 23junS2
Ul
O
CJ
8O-O7458
Movement of heavy metals Into a shallow aquifer by leakage
from sewage oxidation ponds.
Ntssenbaum, A.; Wolfberg. A.; Kahanovlch. Y-; Avron. M.
Weizmann Inst. of Science. Isotope Dept., Rhovot. Israel
WATER RESEARCH 14(6), 675-679. Coden: WATRAG
Publ.Vr: I98O
Illus. rets
Abs.
Languages. ENGLISH
Doc Type- JOURNAL PAPER
The concentrations of Mn, Nl. Cu, Cd. and Cr were measured
In a shallow perched groundwater aquifer which underlies the
Dan Region Sewage Reclamation Project (Israel). The
contribution of effluents to the groundwaters has been
evaluated on the basis of C.I- concentration. Groundwater
containing >6O% effluents showed a lOO-fold decrease In Cu and
Mn 65O m away from the ponds, as compared with the near ponds
samples. Nickel and Cd showed only a small decrease In
concentration over 15O m. and then stayed constant. The*
concentrations of Cu and particularly of Mn In th^
groundwaters near the oxidation ponds Is equivalent to or
greater than In the ponds themselves. Copper and Mn are
mobilized from the precipitated sludge Into the Interstitial
waters. They percolate Into the groundwater near the ponds
and then are precipitated by Increasing aeration during the
movement of the water away from the pond area. Cadmium and Ml
form stable soluble organic chelates which are only slightly
removed by Interaction with the sandy soil of the aquifer. (
AM)
Descriptors: Groundwater: Aquifers; Israel; Effluents; Heavy
metals; Wastewater treatment plants; Sewage: Lagoons;
Activated sludge process; Manganese; Nickel; Copper: Cadmium;
Chromium; Chlorine compounds
Identifiers: Dan Region Sewage Reclamation Project
8O-O627O
The analysis and fate of odorous sulfur compounds In
wastewaters.
Jenkins. R. L ; Gute. J. P.: Krasner. S. W.; Balrd. R. B.
County Sanitation Districts of Los Angeles County. San Jose
Creek Water Quality Lab.. 1965 S Workman Mill Rd.. Whlttler.
CA 9O6O1
WATER RESEARCH 14(5). 441-448. Coden: WATRAG
Publ Yr: 198O
Illus. refs.
Abs.
Languages• ENGLISH
Doc Type: JOURNAL PAPER
GC coupled with the S-speclflc flame photometric detector
was used as the basis for developing an analytical system with
sensitivity In the ppb (mL odorEint/mL air) range for
organosulfur compounds. A high vacuum line for storage and
handling of standard compounds, and the use of gas syringes
are Integral features of the calibration system. Sampling
equipment was constructed and tested which allows the analysis
of gaseous organosulfur compounds In wastewaters, sewer gases,
and ambient air. Gaseous mixtures keep better than aqueous
solutions with respect to microbiological, chemical, or
physical losses. The analytical system was employed to trace
and characterize an odor Incident from a municipal treatment
plant to the Industrial discharger causing the problem.
Certain long-chain mercaptans which are not normally odorous
can decompose In aeration treatment facilities to produce low
molecular weight mercaptans which then cause an odorous
condition. (AM)
Descriptors: Odors; Sulfur compounds; Wastewaters; Pollutant
analysis; Gases; Organic compounds; Laboratory methods;
Organosulfur compounds; Gas chromatography
Identifiers: flame photometric detector
8O-O623!
A practical approach to Wastewater treatment for the metal
finishing Industry.
Olthof, M.
Duncan, Lagnese and Assoc , Inc.. 3185 Babcock Blvd..
Pittsburgh. PA 15237
WATER POLLUTION CONTROL ASSOCIATION OF PENNSYLVANIA.
MAGAZINE 12(6). 18-27. Publ.Yr: Nov-Oec 1979
11lus. no refs.
No abs.
Languages: ENGLISH
Ooc Type: JOURNAL PAPER
General guidelines for the development of a pollution
control program for a metal finishing plant are provided.
In-plant considerations for the design of a treatment ' system
Include water flow reduction, optimizing the dilution ratio.
counterflow rinsing, cascade rinsing. segregation, process
solutions, floor spillage, and dragout reduction. Practical
treatment methods Include hexavalent chromium treatment.
cyanide treatment, and general rinse water treatment.
Reference Is made to promising new technologies and their
potential application. The chemistry outlined forms the basis
for the design of Wastewater treatment facilities. A typical
flow schematic for a metal finishing plant Is presented.
Miscellaneous treatment approaches Include Integrated system.
Ion exchange. and RO. The potential for recovery of one of
the plating solutions should be evaluated during the planning
stage for pollution control facilities; Nl, Cr. Cu, and Zn
plating baths are possibilities. (FT)
Descriptors: Metal Industry wastes; Wastewater treatment;
Pollution control; Engineering; Ion exchange; Reverse osmosis;
Chromium; Cyanides
Identifiers. metal finishing Industry; hexavalent Cr
treatment; cyanide treatment; general rinse water treatment
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DIALOG Flle4t. Pollution Abstracts - 7O-82/Apr (Copr Cambridge Scl Abs) (Item 52 of 98) User23913 23junB2
CO
O
80-O6157
Treatment of dilute metal effluents In an electrolytic
preclpttator.
Brysort. A. W ; Oardis. K. A.
Univ. of the Wltwatersrand, Dept. of Chemical Eng., Jan
Smuts Ave , Johannesburg 2OO1, South Africa
WATER S. A 6(2). 85-87. Coden; WASADV Publ.Yr: Apr
)98O
I1lus. refs.
Abs
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Excessive concentrations of metals (n industrial effluents
may adversely affect the performance of sewage purification
works A1though there is exist Ing technology for treat ing
these effluents, It has not found wide application due to
costly equipment and chemicals and the absence of sufficient
space on most plants. The feasibility of removing these
metals from dilute solut ions by electrolytIc precfpltat ion
using a parttculate electrode Is investigated. A test plant
wa s cons t rue ted wh1ch was compact, did no t requt re the
addition of chemicals and could be operated by unskilled
personnel. The plant was Installed at an electroplating works
on the Wi twatersrand and was successful In treat ing wash
waters containing Cu, Nl, Cr, and 2n. (AM)
Descriptors: Heavy metals; Electric collectors; Industrial
effluents; Wastewater treatment; Nickel; Nickel; Chromium;
Copper; 2inc; Engineer ing; South Africa; Sewage treatment;
Feasibility studies
Ident If iers: Johannesburg; electrolyt1c preclpi ta tor
8O-O4555
Effects of treated effluent on a natural marsh.
Murdoch. A.; Capobtanco, J. A.
Canada Centre for Inland Waters, Process Research O*v.,
Geology Section. P.O. Box 5O5O. Burlington, Ontario L7R 4A6.
Canada
WATER POLLUTION
2243-2256. Coden:
51(9).
CONTROL FEDERATION. JOURNAL
JWPFA5 Publ.Yr: Sep 1979
11lus. refs.
Eng. . F r . Ger., Por t. . Span. abs.
Languages- ENGLISH
Doc Type: JOURNAL PAPER
Long-term effects of poor-quality wastewater treatment plant
effluent on a natural marsh on the western shore of Lake
Ontario were studied. The major contributor of N and P to the
marsh area was the treatment plant discharge. Metal
concentrat ions In the water were generalty low
(<1X1O-3-9OXIO-3 mg/L). Increased concentrations of Pb. Cr,
Zn, N, P, and organic C (<=3OO mug/g, 9O mug/g, 21O raug/g,
2.34%. 1.1O%, and O.87% of sediment dry weight, respectively)
were found in the sediment vert leal prof lie obtaIned from the
marsh area. The shoot standing crop of the dominant plant
spec Ies (Glycerla grand Is) was assoc(ated with amounts of P,
N, and organic C In the sediments. (AM)
Descr iptors: Wastewater discharges; Wet lands; Lake Ontarlo;
N11rogen; Phosphorus; Lead; Chrom1um; Z i nc; Carbon; Sed(men t s;
Plants; E nvIronmen t a 1 1mpac t; Nutrients
Identifiers: Glycerla grandis
of Wastewater (n the presence of
, USSR
No.
3.
9-11.
developed for comparat ive
posslb11 Ity of var fous
in wastewater purification.
8O-O34iO
(Biological purification
chemically bonded oxygen).
Karyukhlna. T. A,; Ksenofontov, V. A,
Kulbysheva Moscow Eng. Construction Inst
VOOOSNAB2HENIE I SANITARNAIA TEKHNIKA
Coden: VSTEAO Pub!.Yr: 1979
illus refs.
abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Thermodynamlc equat Ions were
assessment of ttie theoret ical
biochemical processes for use
Biochemical reduction of O-contatnlng anIons of Group III-VII
elements In the periodic table under anaerobic conditions was
accompan1ed by decreases 1n the concent r a 11on of organ i c
pollutants, dlssoclat ion of anIons. and the part la 1
demineralIzation of wastes. The calculations showed the
possIbl1i ty of biochemical reductIon of chromates and
bichromates. sulfates, nltrates. carbonates. selenates,
tellurates, tungstenates, and vanadates. For the f trst t troe,
lodates and bromates were reduced experimentally; the rate of
reduction of bromates was 3 mg O/g/hr of ash-free sludge while
that for lodates was 2.8 tng/g/hr. (AM.FT)
Descriptors: Wastewater treatment; Oxygen compounds; An Ions;
B1 o 1 og ical ox i da t * on; Chetn teal
ana lysis
IdentIfIers: anion reductIon;
nl trates; carbonates; selenates;
vanadates
treatment; Matheroatteal
chromates;
tellurates;
b ichromates;
tungstentes;
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DIALOG F1le41: Pollution Abstracts - 7O-82/Apr (Copr Cambridge Scl Abs) (Item 55 of 98) User239l3 23jun82
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8O-O3296
Analysis of selected trace organlcs In advanced wasteuater
treatment systems.
Bat id, R. ; Se,lna. M. ; Mask Ins, J.; Chappelle, D.
Los Angeles County Sanitation Districts. San dose Creek
Water Quality Lab.
9OGOI
WATER RESEARCH
Publ.Yr:
Illus.
1965 S. Workman Mill Rrt
Whlttler. CA
13(6). 493-5O2. Coden: WATRAQ
1979
• refs.
Abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Effluents through 4 different pilot tertiary wastewater
treatment systems were monitored for selected trace organic
compounds. The effects of using O3. and free and combined Cl
residuals In these systems were studied. Advanced treatment
of secondary effluent using various combinations of
flocculatlon (alum and polymer), dual media filtration, and
carbon adsorption were evaluated for production or removal of
volatile halogenated organlcs. PAHs, chlorinated pesticides,
and PCBs. GC methods were used; specific techniques and
analytical parameters are described. Salient results Included
drastic Increases In tr lhalomethane production using free Cl
residuals: no significant levels of trlhalomethanes with
disinfection using combined Cl species: =90% reduction In
tr lha lomethane levels by carbon adsorption; absence of
detectable quantities of PAHs; and significant decreases In
pesticide and PCB levels by carbon adsorption and
chlor Inat Ion. Statistical dependence of tr lha lomethane
production on soluble COO, SS. and chloramlne levels was
evident from multiple linear regression calculations. (AM)
Descriptors. Chemical analysis; Wastewaters; Organic
compounds; Gas chroma tography; Wastewater treatment;
Disinfectants; Aromatic compounds: PCB compounds; Pesticides
Identifiers: trlhalomethanes
for N removal, recarbohatIon and filtration. activated-carbon
adsorption for organlcs removal. RO for demlneralIzatIon. and
final chlorInatIon for disinfection. The COD and a broad
range of volatile and gas chromatographable substances were
measured In the plant Influent and effluent and In the
effluents of Individual processes. Lime treatment was
effective In removing COO and PCBs. while NH3 stripping and
activated-carbon contacting removed a broad range of volatile
compounds. Chlorlnatlon led to the formation of a variety of
halogenated compounds, mainly trthalomethanes. (AM)
Descriptors: Wastewater treatment plants; Water treatment;
California; Organic compounds; Pollutant removal: COO: Heavy
metals; Suspended solids
Identifiers. Water Factory 21; Orange Co.
BO-O32O4
Trace organlcs removal by advanced waste treatment.
Reinhard. M.; Dolce, C. J.; McCarty, P. L.; Argo, 0. G.
Stanford unlv . Dept. of Civil Eng.. Stanford. CA 943O5
91st annual meeting of the AOAC: Symposium on environmental
contamination by Industrial organic chemicals Washington, DC
Oct 1977
AMERICAN SOCIETY OF CIVIL ENGINEERS. ENVIRONMENTAL
ENGINEERING DIVISION. JOURNAL t05(EE4). 675-693. Coden:
JEEGAV Publ.Yr: Aug 1979
11lus. refs.
Abs.
Languages ENGLISH
Doc Type: JOURNAL PAPER CONFERENCE PAPER
The performance of an advanced waste treatment plant. Water
Factory 21, In Orange County, California, was Investigated
with respect to organlcs removal. The processes for treating
trIckIIng-f11ter effluent were lime treatment for SS and
heavy-metal removal. NH3 stripping and breakpoint Chlorlnatlon
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DIALOG rile41 Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Sol Abs) (Item 57 of 98) User23913 23jun82
3184
o
(T.
&
Feb
TECHNOLOGY
1979
13(2).
I6O-164,
I .(INVESTIGATIWE/OBSER-
BO-O1973
Textile plant wastewater toxlclty.
Rawlings. G. D.; Samfteld. M.
Monsanto Research Corp., Dayton, OH 454O7
ENVIRONMENTAL SCIENCE
Coden: ESTHAG Publ.Yr:
I I Ins refs.
ISSN: OOI3-936X
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
TREATMENT COOES: O .(DESCRIPTIVE)
VATION)
The American Textile Manufacturers Institute 1O, and are then oxidized to N and CO2 with the NaOCI
solution at pH 8.5. When the ORP reaches a range of 35O-4OO
nV (indicating that all cyanides have been oxidized) the
wastewater changes from a clear. transparent green to sky
blue. Complete oxidation takes MO mln. The treated water Is
allowed to settle for =2 hr, during which time small amounts
or metals, e.g., Cu and Ag. will be precipitated as Insoluble
hydroxides. (FT)
Descriptors: Industrial wastes; Wastewater treatment;
Chromium; Cyanides; Precipitation; Chemical oxidation;
Reduction; pH; Metals; Toxic materials
Identifiers: electroplating rlnsewaters; automated control;
sodium bisulfite; sodium hypochlorlte: hydroxides
toxic electroplating
INWABK
BO-O1928
Methods for neutralizing
rlnsewatei—part 3.
Marln, S.: Trattner. R. B.; Cheremlsinoff. P. N.
New Jersey Inst. of Technology, Newark, NJ O7IO2
INDUSTRIAL WASTES 25(5), 22-23, Coden
Publ.Yr Sep-Oct 1979
rcfs. i
ISSN: 0537-5525
No atos.
Languages: ENGLISH
Doc Type. JOURNAL PAPER
TREATMENT CODES: M .(METHODOLOGICAL) ; D .(DESCRIPTIVE)
In the removal of Cr from electroplating rlnsewater,
treatment Is intended to convert Cr+6 to Cr+3, and then
the
to
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DIALOG File41. Pollution Abstracts - 7O-82/Apr (Copr. Cambridge ScI Abs) (Item 59 of 98) User23913 23jut)82
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8O-OI89I
IBM Ouego give metal finishing wastes total treatment.
Forbes. J. M.
IBM, Owego. NV 13126
POLLUTION ENGINEERING 11(3). 46-49, Coder): PLENBW
Publ.Vr- Mar 1979
I Mus. no ref s.
ISSN: OO32-364O
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
TREATMENT COOES: A (APPLICATIONS) ; N .(NEW DEVELOPMENTS)
IBM's Federal Systems Division facility at Owego, New York.
has various plating and metal finishing operations Including
copper plating, cleaning, surface treatment, and etching, with
associated rinses that generate =5OO.OOO gpd of wastewater.
At the main facility there are 3 prime Industrial drain
systems, a general rinse drain for nonchrome, noncyanlde rinse
waters, an acid-alkali drain for Intermittent small volume
batch dumps of acids and alkali cleaners, and a chrome drain
to receive chrome waste rinse waters. The chrome and
acid-alkali wastes are pretreated before entering the general
rinse system. The general rinse system alone handles the bulk
of the wastes and begins with the collection and equalization
of wastes In a 5OO.OQO-gal lined lagoon. After passing
through a settling and skimming tank, the general rinse passes
through a demlneral tzer-neutral tzat Ion tank to two SOO-gpm
clariflers for removal of the metallic hydroxides and SS by
the filtering action of a sludge blanket. Results from the
past 2 yr have shown very successful system operation. with
effluent standards well within EPA limits. (FT)
Descriptors: Wastewater treatment; Wastewater treatment
plants; Engineering; New York; Pollutant removal; Metal
finishing industry wastes
Identifiers. IBM's Federal Systems Division; Owego
oxidation by sodium hypochlorlte or C12 plus sodium hydroxide
addition to the waste. Electrolytic decomposition and
ozonation are also effective treatments for cyanide wastes.
Chromium waste treatment Involves reduction and precipitation
processes Reducing agents Include ferrous sulfate. sodium
blsulfate. and sulfur dioxide; neutralizing compounds include
lime slurry or caustic. Batch treatment Is necessary In shops
having a total datly flow <3O,OOO gpd, whereas continuous
treatment Is recommended for volumes >3O.OOO gpd. (FT)
Descriptors: Metal finishing Industry wastes; Cyanides;
Chromium compounds; Wastewater treatment; Contaminant removal;
Chemical oxidation: Neutralization; Reduction
Identifiers: electroplating
8O-O1866
Methods for neutralizing toxic electroplating
rlnsewater-part t.
Marln. S.; Trattner, R. B.; Cheremlslnoff. P. N.; Perna. A.
J
New Jersey Inst. of Technology, Newark, NJ O71O2
INDUSTRIAL WASTES 25(3), 5O-52. Coden. INWABK
Publ.Yr. May-Jun 1979
11lus. no refs.
ISSN: O537-5525
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
TREATMENT CODES: M .(METHODOLOGICAL) ; A .(APPLICATIONS) ; D
.(DESCRIPTIVE)
Rlnsewaters from the electroplating process contain high
concentrations of cyanides and chromates. To comply with US
EPA discharge standards several chemical processes have been
developed to destroy the cyanides and chromates. For cyanide
the most common form of treatment is alkaline chlorlnation
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DIALOG Flle4t Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Sc I Abs) (Item 61 of 98) User23913 23JunB2
OJ
O
00
80-OI412
The EPA-proposed granular activated carbon treatment
requirement: Panacea or Pandora's box.
Peridygraf t, G. W. ; Schlegel . f E . ; Huston, H. J.
Baker ft Daniels
AMERICAN WATER WORKS ASSOCIATION. JOURNAL 71(2), 52-6O.
Codeii: JAWWA5 Publ . Vr : Feb 1979
no refs.
ISSN- OOO3-15OX
No abs.
L anguages: ENGLISH
Doc Type: JOURNAL PAPER
TREATMENT CODES: D .(DESCRIPTIVE) ; N .(NEW DEVELOPMENTS)
The feasibility of GAC treatment to accomplish the EPA's
desIred goal. a substantlal reductIon or removal of trace
amounts of synthetic organic chemicals (SOCs) In publIc
drinking supplies. Is questioned. No water system In the
world has used GAC treatment to satisfy the design criteria
prescribed by the proposed regulation. Although the European
GAC practice has been cited as support for the EPA-proposed
GAC requlrement. scrutIny demonstrates that rIver bank
f11tratIon or ground passage. not carbon treatment, Is
respons1b1e for much of t he organ1c remova1 In European
waterworks. The use of GAC for taste and odor control has
little. If any. bearing on Its efficacy to control organlcs.
The use of GAC In the food and beverage Industry.
Pharmaceuticals, municipal, and Industrial wastewater
treatment Is examined. Six alternatives to GAC are suggested.
Additional research Is needed to evaluate the chrotnatographtc
or desorptlon effects of GAC. GAC Itself may be a source of
harmful chemicals. Its large surface area providing a site for
many undesirable chemical reactions and an Ideal location for
bacterial growth that would subsequently be released Into the
fIna1 drink Ing water. The fInanetal effects and energy
consumptIon problems are examined. Engineers and cancer
specialists overwhelmingly oppose the regulation. (FT)
Descriptors: Act Ivated carbon; EPA; Water pur If leatIon;
PublIc concern; Feasibility studies; Federal regulatIons;
Economics; Engineering; Organic wastes; Water treatment plants
; PublIc health
Identifiers- trlhalomethanes; synthetic organic chemicals;
granular activated carbon; health risks
79-O6664
Residual heavy metal removal by an algae-Intermittent sand
filtration system.
FfHp. 0. S ; Peters. T.; Adams, V. 0.; Mlddlebrooks, E. J.
Utah State Unlv , Utah Water Research Lab. , Logan, Uf 8-1322
WATER RESEARCH 13(3), 305-313, Coden- WATRAG
Publ.Yr. 1979
11 Jus. refs.
Abs.
Languages ENGLISH
Doc Type. JOURNAL PAPER
A 1aboratory scale study was undertaken to determine the
feasibility of using algae growing In wastewater lagoons to
absorb res Idual heavy metals for subsequent complete remova1
by Intermittent sand filtration of the metal laden algae. In
semicootInuous cut tures the mixed algal fI ora natIve to
wastewater lagoons absorbed 7O% 9O% of the Cd and Cu from the
wastewater media. Chromium absorption was less by ratio (2O%
was absorbed), but the mass of Cr removed was much greater as
high levels of Cr were added. Only 1 alga (Osci1latoria sp. )
which was extremely resistant to Cr grew in the Cr exposed
cultures. Nearly total removal of the Cd and Cu was achieved
by the algae-Intermittent sand filter system. The net Cr
removal agreed with the accumulation analyses. (AM)
Descr iptors: Heavy metafs; Lagoons; Algae; Wastewater
treatment; F11tratIon; Copper; Cadmium; Chromium; Feas ibl1 Ity
stud1es; Contarn1nant remova1
79-O6658
Instrumental analysis In wastewater treatment.
McLean. D. A.; Phillips. S. L.
East Bay Municipal UtIIIty District. P.O. Box 24O55,
Oakland, CA 94623
ANALYTICAL CHEMISTRY 5O(14). 136IA-I376A, Coden:
ANCHAM Publ.Vr: Dec. 1978
11lus. refs.
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
The development of was tewa ter trea tment 1s rev 1ewed.
emphasizing the analytical methods used to monitor the
treatment processes. Early methods of analysis were manual,
I.e., gravimetric. tttrlmetrlc. and visual comparI son, and
rudimentary InstrumentatIon. The advent of AAS and GC
provided methods by which Individual elements or compounds
could be analyzed with high specificity and sensitivity.
Heavy metals could be analyzed for at low concentrations In
samples that contained high levels of Interfering substances.
Trace organic compounds were analyzed with developing GLC and
gas-sol Id chromatography technology; the analysIs of
chlorInated pestIcldes and polyentorInated aromat ics became
possible with the development of thermal conduct Ivlty; flame
lonlzatlon, electron capture, and alkali flame GC detectors.
Ins trumen taI methods whIch have been used the 1onges t 1n
mon1 tor 1ng was tewa ter treatment processes i nc1ude pH,
conduct ivity, ox idatIon-reduct ion potentlal, OO, turbidlty.
and Cl residual analysis (FT)
Descriptors: Wastewater treatment; Moni tor ing methods;
Chemical analysis; Hlstorleal rev lews
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DIALOG Flle41 Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Set Abs) (Item 64 of 9B) User239l3 23Jun82
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79-O6647
Investigation of soluble organic nitrogen compounds In
municipal secondary effluent.
Keller, J. V ; Leekte, J. O.; McCarty. P. L.
James M. Montgomery Consulting Engineers. Inc., 199O N.
California Blvd., Suite 444, Walnut Creek, CA 92707
WATER POLLUTION CONTROL FEDERATION. JOURNAL 5O(11),
2522-2529. Coden: JWPFAS Publ.Vr: Nov. 1978
Itlus. refs.
Eng., Fr., Ger., Port., Span. abs.
Languages: ENGLISH
Doc Type. JOURNAL PAPER
The ability of anlon and cation exchange resins and granular
activated carbon to remove soluble organic nitrogen and other
soluble organIcs from fIItered municipal activated sludge
effluent was studied Ion exchange, particularly using cation
exchange res 1ns, couId be used as an expens\ve po11sh f ng
treatment to remove N5O% of the soluble organic fraction
remaInlng af ter adsorptIon wlth high dosages of act fvated
carbon. Before and after activated carbon contacting of
secondary effluent, more of the soluble organic nitrogen was
positively charged, and more of the soluble COD was negatively
charged, Sephadex column chromatography indicated that
activated carbon contacting removed a significant fraction of
the soluble organic nitrogen and soluble COO present In
secondary effluent. (AM)
Descr(ptors: Resins; Ion exchange; Act fvated carbon;
Wastewater treatment; Nitrogen; COD; Activated sludge process;
AdsorptIon; Tertlary treatment
Identifiers: anlon exchange resins; cation exchange resins
79-O6623
Treatablllty evaluation of general organic matter. Matrix
conception and Its application for a regional water and waste
water system.
Tarobo, N.; Kamel, T.
Hokkaido Univ., Faculty of Engineering, Dept. of Sanitary
Engineering. Sapporo, O6O Japan
WATER RESEARCH 12111), 931-95O, Coden: WATRAG
Publ.Yr- 1978
1\lus. refs.
Abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Group Ing of organic compounds In wastewater treatablItty
evaluation can be performed by gel chromatography. Using
Sephadex G 15 gel with 2-stage elutlon of distilled water and
O. IM ammonium hydroxide solution, general organic compounds In
a regional water and wastewater system are characteristically
grouped Into 6 groups. The treatabt11ty of each group Is
characterized by the ratio of TOC:E 26O (UV absorbance at 26O
nro). Only a port Ion of TOC, which is Insens11Ive to UV
absorbance at 26O nm, can effectively be removed by aerobic
bIo1og1ca1 processes Sma11 organ ic compounds are
b iologlcalIy decomposed readlly unt11 TOC:E 26O rat to of
4O-5O'1 Is obtained Large organic compounds are effectively
removed by coagulation with Al followed by sedimentation and
sand f 11tratIon. For smaIler organic compounds. coagulatIon
Is Ineffective; activated carbon adsorption Is effective for
TOC: E26O ratios of N5O.' (MS)
Descr tptors: Wastewater treatment; TOC; Ultraviolet
radiat1on; Biological treatment; Physicochemlcal treatment;
Engineering; Liquid chromatography; Organic compounds
Ident 1flers: treatablllty criteria; gel chromatography
79-O5437
Direct analytical procedure for determination of volatile
organic acids In raw municipal wastewater.
Narkls, N.; Henf eld-FuMe. S.
Technlon-Israel Inst, of Technology, Environmental
Engineering Labs.* Technlon City, Haifa, Israel
WATER RESEARCH 12(7), 43T-446. Coden: WATRAG
Publ.Vr: 1978
11lus. refs.
Abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
A direct analytical method for 1dent If teat Ion and
determtnatIon of the Individual volatIle acids In raw sewage
was developed- The proposed procedure Is rapid, omitting
tedious sample pretreatment, and thus avoiding possible losses
Involved In steam distillation. evaporation, or extraction.
Raw sewage Is directly Injected Into a gas chromatograph. with
Carbowax 20 M on acid washed Chromosorb W column and a flame
lonlzatIon detector. Sample preparetIon Is confIned to
addition of solid metaphosphorIc acid to the raw sewage, and
removal of precipitated proteins and SS by centr1fugation.
Volat1le acids content tn raw muntcIpal sewge In Ha 1 fa,
Israel. was »n the range of ISO-16O mg/L, of which 12O-125
mg/L was acetic acid, 3O-33 mg/L proplonic acid, 6-8 mg/L
butyric acid, 2 mg/L Isovaterlc acid. and O.5-1 mg/L valeric
acid. (AM)
Descriptors: Gas chromatography; Ac 1ds; Sewage; IsraeI
Ident Iflers: Ha ifa; acet tc acId; proplonic acid; butyrIc
acid; Isovalerlc acid; valeric acid
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DIALOG F11e41: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge ScI Abs) (Item 67 of 98) User23913 23Jun82
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M
O
79-OS426
Effects of chlorlnation of some volatile organIcs in primary
municipal sewage effluent.
Mori. B. T.; Hall. K. J.; Blazevlch. J. N.
Health and Welfare Canada, Health Protection Branch. 1OO1 W-
Pender St.. Vancouver, B.C.. Can.
JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A:
ENVIRONMENTAL SCIENCE AND ENGINEERING A 13(7). 445-467,
Coden: JESEDU Publ.Vr: 1978
i1lus refs.
Abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
The effects of chlorlnation on volatile organic components
of prImary municipal sewage effluent were Invest Igated.
Primary sewage effluent had TOCs of 5O mg/L after filtration
through 1 1 glass fitters and 38 mg/L after filtration through
O.45 1 membrane filters. Chlorine doses of O-1O3 mg/L had no
measurable effect on the TOC value. GC-electron capture
analysis Indicated that 19-21 new peaks consistently resulted
from chlorlnatlon at treatment plant dosages. Seventeen to 19
of these peaks were neutral or basic compounds. GC with a
microelectrolyt Ic conductIvt ty detector demonstrated that
O.OI% of the Cl applied to primary effluent at treatment plant
levels ends up In stable, volatile chlorInated organic
compounds. Furthermore, 4O% of the volatile organically bound
Cl In chlorinated-dechlorInated primary effluent resulted from
the chlorlnation process. Three of the compounds resulting
f rom ch1 or\na 11on, I.e., ch1orobenzene. 1.3-dIch1orobenzene
and a-chlorotoluene. were positively Identified by GC-MS. The
•concentrations of these compounds were in the Ig/L range; 61
other compounds were also Identified with varying degrees of
certainty. None of these latter compounds appeared to be
formed by the chlorInalion-dechlorInatIon process. (AM)
Descriptors: Chlorlnation; Municipal wastewaters; Sewage
treatment; Gas chromatography; Mass spectroscopy; Wastewater.
treatment
removed from the filter as a slurry With decreasIng
hydraulIc detent Ion t ime the metal remova1 percentage
decreased while the metal content In the bottom slurry
Increased. Most metals were removed In the lower port Ion of
the f 11ter. Copper was assoclated wlth the largest sol Ids
part Ides, but also showed the largest var tat Ion In
concentratIons and largest decrease In removal eff fc fancy at
decreasing hydraulic detention times. (AM)
Descr iptors: Copper; Zinc; Nickel; Chromium; F1 Iters;
Anaerobic systems; Heavy metals; Wastewater treatment
IdentIfiers. metal removal
79-O4165
Heavy metal removal with completely mixed anaerobic filter.
DeWalle. F. B.; Chlan. S. K.; Brush. J.
Univ. of Washington. Oept, of Environmental Health. Seattle.
WA 98IO5
WATER POLLUTION CONTROL FEDERATION. JOURNAL 51(1). 22-36,
Coden: JWPFA5 Publ.Yr: Jan. 1979
11lus refs
Eng.. Fr.. Ger., Port.. Span, abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
A completely mixed anaerobic filter was subjected to various
leachate loadings. At each detention time samples were taken
from the Influent, effluent, and other sampling ports for AAS
heavy metal analysis. The fitter was effective In removing
heavy metals, the effectIveness increasing with increas ing
meta I concentratIons In the effluent The metals were
precipitated as sulfides. carbonates. and hydroxides and were
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DIALOG File41- Pollution Abstracts - 7O-82/Apr (Copt- Cambridge Scl Abs) (Item 69 of 98) User23913 23JunB2
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TECHNOLOGY
1978
Plating Effluent Treatment
12(8),
896-899.
79-O2832
A clean water project In Poland.
KleszkowskI. M.; Jackson. G. S.
Inst. of Precision Mechanics,
Dept., OO-967 Warsaw. Pol.
ENVIRONMENTAL SCIENCE &
Coden. ESTHAG Publ.Vr: Aug.
Illus. refs.
Sum.
Languages: ENGLISH
Ooc Type JOURNAL PAPER
Wastewaters produced In metal finishing operations contain
such pollutants as cyanides, chromates. heavy metals. mineral
acids. alkalis, oils. greases. detergents, and organic
solvents. The most common effluent treatment consists of
well-known, conventional chemical procedures which can be done
either continuously or batch-wise. They Involve several
operations, such as alkaline chlorlnatlon of segregated
cyanide solutions, reduction of segregated chrornate solutions,
and final neutralization of mixed effluents and precipitation
of metal hydroxides. followed by land fill disposition. A
schematic diagram of such an effluent treatment plant Is
presented. Applied research for the Polish metal finishing
Industry Is conducted by the Institute of Precision Mechanics,
In Warsaw, which has developed several new effluent treatments
and material recovery techniques. The most promising Include
evaporative recovery of plating bath constituents from rinse
waters, RO systems for some plating solutions, Improved Ion
exchange systems for single metal recovery from separated
rinse streams, secondary polishing systems for final effluent
purification. rinse water purification steps prior to
evaporative recovery of RO. foreign metal recovery and other
impurity removal from metal finishing solutions.
ultrafIItratlon methods for water reclamation. and
solidification of metal finishing sludges containing mixed
metallic hydroxides. Other promising techniques Include
possible utilization of sulflde precipitation of heavy metals.
solvent rinsing. Ion flotation, C adsorption, and recovery of
metals from hydroxide sludges by solvent extraction (FT)
Descriptors: Metal finishing Industry; PollutIon control;
Materials recovery; Reverse osmosis; Ion exchange; Engineering
; Cleaning process; Heavy metals; Poland
Identifiers plating Industry: Polish Institute of Precision
Median Ics
JFRBAK Publ.Yr: May 1978
Illus refs.
Eng.. Fr. abs.
Languages: ENGLISH
Doc Type: CONFERENCE PAPER
The petroleum hydrocarbon content of sediment cores
collected from Narragansett Bay and Rhode Island Sound were
compared to a relatively unpolluted sediment core from the
Gulf of Maine. Organic components were extracted from the
saponified sediment using a toluene*methanol mixture and
separated by column chromatography and TLC. GLC analysis
identified and quantified 3 hydrocarbon types, unbound. bound
or associated with the clay mineral or kerogen matrix, and
bound or associated with humlc substances. In general
9O%-1OO% of the hydrocarbons were. In the unbound form and
could be easily extracted with organic solvents. The
petroleum hydrocarbons decreased with depth at all stations.
Blogenlc hydrocarbons (nC25. tiC27. nC29, and nC31) made up an
Increasingly greater percentage of the total with increasing
depth. The hydrocarbons In the Narragansett Bay sediments and
near surface Rhode Island Sound sediments strongly resembled
the hydrocarbons previously reported for the Providence River
and upper Narragansett Bay. These petroleum-I Ike hydrocarbons
were largely Introduced to the river and bay through chronic
Inputs from a municipal wastewater treatment plant. The
hydrocarbons then undergo sedimentation throughout the entire
bay and Into Rhode Island Sound. Preliminary calculations
Indicate that KO.2 million t of petroleum hydrocarbons may be
transported to the marine environment annually from municipal
treatment plants. Most of these hydrocarbons appear to
accumulate In estuartne and coastal sediments. (AM)
Descriptors: Sediments; Petroleum; Hydrocarbons; Wastewater
treatment plants; Municipal wastes; Marine environments;
Estuaries; Rhode Island; Chromatography
Identifiers: Narragansett Bay; Rhode Island sound;
Providence River; Gulf of Maine
79-O1659
Contribution of chronic petroleum Inputs to Narragansett Bay
and Rhode Island Sound sediments.
Van Vleet, E. S.; Oulnn, J. G.
Univ. of California at San Diego. Inst. of Marine Resources,
La Jolla. CA 92O93
Symposium on recovery potent la
environments Halifax. N.S , Can.
Recovery potential of oiled marine northern environments.
Symposium papers. Edited by j; C. Stevenson. In CANADA
FISHERIES RESEARCH OOARD. JOURNAL 35(5). 536-543. Coden
of oiled marine northern
Oct. 1O-14. 1977
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DIALOG FMe4t Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Scl Abs) (Item 7t of 98) User23913 23junB2
79-OO626
Wastewater from platfng works-required pretreatment and
disposal of concentrates.
Imhoff, K. R
Ruhrverband und Ruhrtalsperrenverein, Kronpr inzenstrasse 37.
43OO Essen I, FRG
International conference on advanced treatment of wastewater
Johannesburg. S. Afrlea June 13-17, 1977
Advanced treatment and reclamation of wastewater: Conference
proceedings. In PROGRESS IN WATER TECHNOLOGY 1O(1-2),
419-43O, Coden: PGWTA2 Publ.Vr: 1978
Ulus. refs. (Some In Ger. )
Sum,
Languages: ENGLISH
Doc Type: CONFERENCE PAPER
The Ruhrverband ensures that the wastes of metal finishing
establ ishments In the Ruhr catchment are recycled to the
chemical Industry; the sale of the wastes covers only
transportatIon costs, but there are savings compared to
chemical prectpltat Ion and sludge disposal. Wastewater Is
treated In 118 mostly small plants. Cyanide and
chroinate containing wastewaters must be collected separately
and pretreated. The central decontamination plant at
Iserlohn. and the central treatment plant at Helllgenhaus are
described. To supplement the system of wastewater treatment
plants 4 Impoundments were constructed In the Ruhr valley.
The central wastewater treatment plants ellmlate 6O% of the
Influent heavy metals. During low flow In the lower Ruhr
river a ratio between clean water and treated wastewater of
7O:3O Is malntaIned on the average. From this mixture
waterworks abstract their water and prepare drinking water by
artificial groundwater recharge. (FT)
Descriptors: Federal Republic of Germany; Metal finishing
Industry wastes; E ffluent treatment; Wastewater treatment
plants; Industrial effluents; Municipal water supplles; Waste
reuse
Ident 1f1ers Ruhr vaI Iey
Increase the reaction rate; add a reducing agent; raise pH OB
to precipitate chromium hydroxide; and clarify the effluent to
minimize chromium hydroxide carryover. A several fold excess
of reduc fng agent 1s requIred to reduce the chroma te
quantitatively. The amount of acid, reducing agent, and
alkali vised is a function of the complete chemical composition
of the blowdown. the reducing agent used. and the discharge
restr1ctIons. Electrochemlcal reductIon Involves a series of
Fe anodes connected to an electrical source; the block of
anodes is placed In a reservoir through which the blowdown
flows. Efficiency of chromate removal Is decreased when other
oxidizing agents are present In solution. A conservative
estimate of electrode usage Is 4 Ib/lb of Cr. Current flow,
arrangement of electrodes. and level of gas-1tquid Interface
affect the pattern of electrode dissolution. Chrornate can be
selectively removed from blowdown by Ion exchange with CI-.
sulfate, or hydroxide. Anlon resins will not remove trlvalent
Cr or Zn. A major advantage of ton exchange Is that no sludge
Is produced. Ion column rinse and backwash are returned to
the cool Ing tower. Chemical reductIon Is general 1y the most
economical. The major drawback of both reduction systems is
the need for sludge disposal facilities. (FT)
Descriptors: Chromium compounds; Cooling waters; Wastewater
treatment; Water reuse; Reduction; Ion exchange
Ident Iflers: blowdown
79-OO567
Chrornate handling systems for cooling tower blowdown.
Roensch. L. F.; Feltes, A. L.; Oberhofer. A. W.
Natco Chemical Co.. 29O1 Butterfleld Rd.. Oak Brook. IL
6O521
Fifth annual Industrial pollution conference Atlanta. Ga.
Apr. 19-2*. 1977
F|fth annual Industr tal pollutIon conference• Proceedings.
Edited by L. Delpino and A. Krlgman pp. 121-135 Publ.Yr-
1977
Pub): McLean. Va. Water and Wastewater Equipment
Manufacturers AssocI at ton
11lus. refs.
Abs.
Languages: ENGLISH
Doc Type: CONFERENCE PAPER
Removal of hexavalent chroinate by chemical reduc t Ion
requires the following 4 steps lower blowdown pll to 3-4 to
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DIALOG F11e41- Pollution Abstracts - 7O~B2/Apr (Copr. Cambridge Sc 1 Abs) (Item 73 of 98) User23913 23jun82
U)
H
OJ
79-OO47O
Chlorinated tyroslne in municipal waste treatment plant
products after superchlorlnatton.
Burleson, J. L. ; Peyton. <3. R. ; Glaze, W. H.
North Texas State Univ., Dept. of Chemistry and Inst. of
Applied Sciences, P.O Box 5O57. Denton. TX 762O3
BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
19(6), 724-728. / Coden: BECTA6 Publ.Yr: June 1978
IIlus. refs.
Sum,
Languages: ENGLISH
Ooc Type: JOURNAL PAPER
1 One mil It liter of a 28-lm C12/1 aqueous solution was added
to 1 ml of a 2Q-lra/l tyroslne solution adjusted to pH *-2.
The react Ion proceeded for 3O min, and the mixture was
extracted with I ml of ether. Analysis of the extract by
GC-MS showed approximately equal proportions of mono- and
d(chlorinated phenylacetonitr He and phenylacetaldehyde;
analysis of the N-heptafluorobutyryl n-propyl ester derivative
confirmed the presence of chloro- and dlchlorotyrosIne, which
were also found In effluent from superch}orinatton facilities
in use at 3 municipal waste treatment plants. The extent to
which these and other possible chlorinated amino acids occur
In superchlorinated waste products Is not known, but is under
Investigation. (FT)
Descriptors: Municipal wastewaters; Water; Chiortnation;
Ami no ac Ids: Gas chromatography; Mass spectroscopy.;
Chior 1nated hydrocarbon compounds; Sewage treatment; Sewage
treatment plants; Effluents
IdentIflers: tyrosine; superclorination
78-O4472
Cooling water and boiler possibilities for wastewater reuse.
Morresi. A. C.; Cheremisinoff, P. N.
Hoffmann-La Roche
INWA8K
33-34,
Coden:
INDUSTRIAL WASTES 24(2),
Publ.Yr: Mar.-Apr. 1978
i1lus. no refs.
No abs.
L anguages: ENGLISH
Doc Type: JOURNAL PAPER
Cooling towers offer the most readily available source for
recyclable water. Cooling towers handling large quantities of
water (N1OO.OOO gpm) can use a variety of wastewaters as
makeup. The water conservation benefit of cooling towers must
be economically justified by balancing the reduced cost of
waste treatment against any additional treatment costs needed
to produce a reuse stream of acceptable quality, If cooling
towers are made secondary users of water. the blowdown will
contain more contaminants and require additional treatment
before discharge If water with a low dissolved solids
content is used as makeup, windage may remove enough
Impurities so that a blowdown stream is not required. If
contaminated water can be used in a cooling tower, the tower
can serve as an equalization facility to protect downstream
waste treatment from shock loads of pollutants. AM cooling
tower reuse plans must Insure that the prime function of
cooling towers-providing cool water to heat exchangers without
causing seal ing, st inttng, or corrosion problems-Is not
Impaired. Cooling tower blowdown has been used as wash water,
utility water, flare drum seal water, pump coolant, and tank
field water. If chromates are used as corrosion Inhibitors In
the cooling tower, ion exchange can recover them and make the
cool ing water acceptable for reuse. Feed water for
low-to-medium pressure boilers (N65O psf) requires softening.
deaeratlon, and silica removal. High-pressure boilers require
demtiteral ized. deaerated water. Low-pressure steam has been
generated in unflred waste heat boilers from some wastewaters.
Clean stream condensete is extensively recycled, but boiler
blowdown Is seldom used. High-pressure boiler blowdown can
sometimes be used as makeup water for low-pressure boilers (
FT)
Descriptors: Water reuse; Wastewaters; Wastewater treatment;
Waste reuse; Cooling systems; Cooling waters; Boilers
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Flle4l Pollution Abstracts - 7O-82/Apr (Copr Cambridge Sc I Abs) (Item 75 of 98) User239l3 23jun82
78-O4471
Treatment of plating wastes from the automotive Industry.
Cull Inane. M. J. , Jr.; Dietz, J- D.
Clark, Dletz and Assoc.-Engineers, Inc.
INDUSTRIAL WASTES 24(2). 29-32. Coden: INWABK
Publ.Yr: Mar.-Apr. 1978
i1lus. no refs
Sum.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Water conservation measures recommended for a Mississippi
plant Include us Ing spring-loaded shutoff nozzles on water
hoses, collecting and returning steam condensate for boiler
water makeup, using recycled water tn the buff ing process, and
using counterflow rinsing in the plating operation. Several
was tewa ter segrega 11on prac11ces were a1 so recommended. To
meet federal standards, the most cost-effectIve effluent
treatment was reduction followed by chemical precipitation.
CompIe te t rea tmen t and dIrec t d 1 scharge was more cos t
effectIve than pretreatment and discharge to the municipal
waste system. The opt imum rinse system is a modif led
countercurrent system with 5 rinse tanks, which reduced water
consumption from K40O gpm to ~J6O gpm. Features incorporated
in the treatment design include addition of an acid feeding
system for raw waste pH adjustment and use of the abandoned
oxidation pond to equalize shock loadings. The treatment
process Included the following: reduction of Cr+6 In a
continuous flow system; equalization of flow wastes; raw waste
pumping; pH adjustment in a flash mix tank; ahd coagulation
and settling in a reactor-clarifler. Provision is made for
future add! t ion of f i 1 ters and f.inal pH adjustment. Vacuum
filtration and landfill ing is the chosen method of sludge
disposal. Problems since plant startup In March (977 have
been minimal. Water consumption could be reduced a further
4O%~5O% If recycle systems and more stringent water
conservation measures were used, but these measures do not
appear to be economically justified at the present. (FT)
Descriptors; Mississippi; Automotive industry wastes; Metal
f inishing industry wastes; Chromium compounds; Water
conservat ion; Wastewa ter treatment; Wastewater treatment
plants; Industrial effluents; Reduction; Coagulation
The chemistry, environmental dtstrIbut Ion, metabolIsm,
biological effects on plants and animals, and biological
effects on man of As and As compounds are discussed In detail.
The degree of As air pollution due to smelter^ operations and
pest icIde use should decrease If currently proposed
occupatlonal and environmental standards are promulgated.
Arsenic pollution from coal burning is widely dispersed, which
minimizes its danger to public health. Common use of shale
oil would require removal of As from the oil or more careful
monitoring of As. While food supplies normally contain As.
the concentrations are very rarely harmful. Water supplies
generally contain negliglble quant 11les of As. Industr ial
effluents often contain As. but the problem is minimized by
the self-purification of receiving waters and the Improved
qualtty of wastewater discharges. Use of As pesticides was
greatly reduced wlth the Introduct ion of chlor inated
hydrocarbon and organophosphorus chemicals. With Increasing
restrlet ions on these, however, As chemicals may again be
widely used. requiring careful monitoring. Little or no
qual1 tat ive informatIon Is ava I (able regarding the fate of
arsen leaIs in the ecosphere. so ft is not possible to state
with any certainty whether As Is building up In any sector.
Individual As compounds can be determined only after isolation
by volatilization, paper chromatography, GC. or
electrophoresls. The continued concern about the association
be tween InorganIc arsenic and cancer has ra Ised ques 11one
regarding the Imp!icat tons of widespread dispersion of
inorganic arsenicals In the environment. Recommendations for
future research areas and protocols are given, (SS & FT)
Descriptors: Books; LIterature reviews; Arsenic; Arsenic
compounds; Hetaboli sm; Humans; P1 ant s; An1ma1s; F oods;
PestIcldes; SmeltIng; Chemistry; Pollutant detect 1
78-O3967
Arsenic.
Natlonal Research Councl1-Dtv . of Medical Sciences-Commlttee
on Medical and Biologic Effects of Environmental Pollutants
2 lot Constitution Ave. NW. Wash. DC 2O4I8
Medf ca1 and Biologic Effects of Env tronmentaI Po11u t ant s
332 pp Publ.Vr: 1977
Publ : Washington, D.C. National Academy of Sciences
Illus.' Indexes numerous refs. (Some in Chin.; Croatian;
Czech ; Dan.; Fr.; Ger.; Ital.; Japanese; Norw.; Pol.; Port.;
Russ. ; Span )
No abs. Price. $13 75 (pbk.)
Languages ENGLISH
Doc Type BOOK
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DIALOG Flle4l Pollution Abstracts - 7O-B2/Apr (Copr Cambridge Set Abs) (Item 77 of 98) User23913 23JunB2
UJ
M
Ul
78-O3385
Electrolysis.
Vlahakis. J.; Ouellette. R.
Electrotechnology Vol. (• Wastewater treatment and
separation methods. Edited by R. P Oueltette. J. A King and
P. N. Cheremlslnoff 193-237. Publ.Vr: 1978
Publ: Ann Arbor. Mich Ann Arbor Science Publishers
Illus. refs.
No abs.
Languages: ENGLISH
Doc Type: BOOK CHAPTER
The most Important Industrial applications of electrolysis,
a chemical process by which chemical reactions are produced
electrically In solutions or molten salts, are metal recovery
and electroextractIon, electrochemical organic synthesis, and
electroconcentratIon of solids. Among many specific potential
applications are the manufacture of propylene oxide from
propylene and water. the treatment of acid mine drainage to
recover Fe. reducing the COD of cheese whey waste, the
recovery of fatty minerals from edible fats, the regeneration
of chromated At deoxldtzers, the treatment of domestic wastes.
cyanide and organic waste treatment, and electroflotation.
Electrolytic processes produce less pollution than many
conventional techniques, and also compare favorably. on an
economic basis, with them. Electrolysis Is energy competitive
with other chemical routes for manpfacturIng chemical
compounds and, as environmental standards become more strict,
shoud become more popular In metal recovery and waste
treatment applications. (FT)
Descriptors: Electrochemistry; Reduction; Oxidation; Metals;
Wastewater treatment; Water purification; Organic wastes; Mine
drainage; Materials recovery; Chemical wastes; Waste treatment
; Technology
Identifiers: electrolysis
78-O333O
Aluminum manufacturer removes chromium.
Anonymous
INDUSTRIAL WASTES 24(1), 24, 34. Coden: INWABK
Publ.Vr: Jan.-Feb. 1978
11lus. no refs.
No abs.
Languages ENGLISH
Doc Type: JOURNAL PAPER
A New Hampshire aluminum company Installed a Hussong/Couplan
Chrome Removal Treatment System to treat Its raw effluent.
The effluent contains 164 mg/1 total Cr. 136 mg/1 hexavalent
Cr. 62O mg/1 total P. and 22.8 mg/1 Al. The decision was
Dased on 2 factors. The system reduced the pollutants to the
lowest concentrations In the final effluent and met, by a
comfortable margin, the requirements of the final EPA
regulations and the local municipal sewer code. Another
Hussong/Couplan System employing sphagnum peat as the
treatment medium can readily be tied Into the existing system.
In a series flow arrangement, at a later date. Changing
conditions can be met without costly, extensive replacement or
modification of the present system. The Hussong/Couplan
System treats the wastewaters with ferric chloride (FeC13) and
sodium sulfide (Na2S) at a pH In the 5-7 range In such a way
as to obtain a specific molar ratio of Cr6+6. FeCI3, and Na2S
In the effluent. A massive precipitate Is formed which
carried down virtually all of the Cr, both hexavalent and
trtvalent. The system at the Al plant Is a 6.OOO gpd system
and Is composed of 3 holding-batch tanks, chemical adders.
misers, controls, and sensors. To Insure the continuing
purity of the discharge, colorlmetrlc checks are made at the
precipitation tank. (FT)
Descriptors: Chromium; Aluminum; Metal Industry wastes;
Effluent treatment; Industrial effluents; Precipitation;
Contaminant removal
Identifiers. Hussong/Couplan Treatment System
78-O332O
Organochlorlnated residues In wastewaters before and after
treatment.
Martin. G. B.; Gosselln, C.
Unlverslte Laval, Centre de Recherches en Nutrition, Oue
GIK 7P4, Can.
JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH-PART A AI3(I).
1-11, Coden: JESEDU Publ.Yr: 1978
Illus. refs.
Abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
PCBs and pesticides were measured In effluent from the
primary treatment sand deposition stage and from the secondary
oxidation basin stage of the treatment plant of a small
Quebecois town. During a 24-hr sampling period, the secondary
treatment reduced TOE concentrations from a mean of O.O8 ppb
to a mean of O.O3 ppb; DDT concentrations were so close to the
detection limit that no conclusions can be drawn. PCBs were
reduced from 1.29 to O.38 ppb. Over a 5-d sampling period,
PCB concentrations were O.5O-2.OO ppb before secondary
treatment and O.02-O.6O ppb after It. The pattern of PCB
chromatograms was affected by the treatment, with an Increase
in the proportion of the less chlorinated PCBs evident. (FT)
Descriptors: PCB compounds; Pesticides; DDT; Organochlorine
compounds; Wastewater treatment
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DIALOG F11e41: Pollution Abstracts - 7O-82/Apr (Copr Cambridge Sci Abs) (Item 8O of 98) User-23913 23junB2
U)
78-O3235
The distribution of heavy metals In anaerobic digestion.
Hayes, T. D. ; The is, T. I.
Cornel 1 Univ., Dept. of Agr fculturat Engineer ing, Ithaca. NY
H850
WATER POLLUTION CONTROL FEDERATION. JOURNAL 5O(I). 61-72,
Coden: JWPFA5 Publ.Yr: Jan. (978
1 Ilus. refs.
Eng., Fr., Ger,, Port., Span. abs.
Languages. ENGLISH
Doc Type: JOURNAL PAPER
Bench scale anaerobic digesters using municipal wastewater
sludge were dosed with different levels of heavy metals (Cr+3.
Cr + 6, Cd, Cu+2. Ml , Pb. and Zn) to determine thetr
distrIbutIon and note their effects under operating
conditions Dos ings were made In both a stepwlse and pulse
manner. Characteristic responses observed during periods of
digester distress Included Increased volatile acids and total
organic carbon, decreased gas product Ion and methane
compos 11Ion, and depressed values of pH. The order of
toxiclty established 1n this study was NIK CuKPbKCr+6JCr+4KZn.
Toxic limits for Cd were not reached. Metals were rapidly
removed from digester supernatant in excess of 95%. The total
Insoluble portion was divided between Inorganic precipitates
and the blomass fraction. Between 3Q% and 6O% of the metals
were associated with the bacterlal eel Is. Tox1c effects
became apparent at or near the maximum metals taken up by the
digester component. (AM)
DescrIptors: Anaerobic process; Sludge digest Ion;
Distribution; Chromium; Copper; Cadmium; Nickel; Lead; Zinc;
MunlcIpal wastewatens; Pollutant removal; Heavy metals
proton activity In the solut ion and was & max Imum at a moJe
rat la of protons:Cr+6 of 1 O. DesorptIon studies were
performed at d1fferent pH values w1th various ac ids and sod turn
hydroxide (NaOH). Alkaline desorptlon was more effective than
the acid desorption. The Cr+6 was desorbed In the alkaline pH
regions, whereas Cr+3 was the prevailing species in the case
of acid desorptlon. Using NaOH, K8O% Cr was desorbed at a pi I
value close to 14. At a Cr+6 concentration higher than the
Initial proton concentration, an amount equal to the initial
amount of protons Is first adsorbed, with any rema inlng
removal of Cr being by hydro!yt ic adsorpt ion. At a
concentrat Ion lower than the Initial proton concentrat ton,
reduction of Cr+6 to Cr+3 takes place, with reduced Cr+3
remaining in solution at low pH values. The degree of
reduction is a function of the proton:Cr+6 ratio, the initial
pH value, and the amount of activated carbon In solution. The
final form of adsorbed Cr within the activated carbon is in
the hexavalent form. An activated carbon column configuration
produced significant Cr+6 removal when the proton:Cr+6 ratio
1s 1.0. (FT)
Descriptors; Activated carbon; Adsorption; Chromium;
Contaminant removal; Wastewater treatment
78-O2754
Chromium removal with activated carbon.
Kim, J. I.; Zoltek, J., Jr.
Unlv of Flor Ida, Dept. of Environmental Engineer Ing
Sciences. Gainesville, FL 32611
Eighth International conference on water pollution research
Sydney. Australia Oct. 17-22, 1976
Eighth International conference on water pollution research.
Edited by S. H Jenkins. In PROGRESS IN WATER TECHNOLOGY 9(1)
143-155, Coden: PGWTA2 Publ.Vr; 1977
i1lus. refs.
No abs.
Languages: ENGLISH
Doc Type: CONFERENCE PAPER
Mechanisms responsible for Cr adsorption and reduction by
activated carbon are described and results are presented to
help in the development of a process for Cr+6 removal. The
activated carbon used was Flltrasorb 4OO and the Cr levels
were determined by AAS. A solution of Cr+6 in the presence of
activated carbon was reduced to Cr+3 to a greater extent as
the pH was Increased. Total Cr adsorption Increased to a
maximum with Increasing pH up to an Initial Cr+6 concentration
of 3OOM, after which the adsorption decreased. The total
amount of Cr adsorbed was a direct funct ton of tho initial
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DIALOG F1le41' Pollution Abstracts - 7O~82/Apr (Copr Cambridge Scl Abs) (Item 82 of 98) User239l3 23Jun82
reverse osmosIs and
UJ
7S-O257O
Present art and status of
ultrafIItratlon In Japan.
Ohya. H.
Yokohama National Univ.. Dept. of Chemical Engineering.
V ok ohama, Japa n
International Congress on Desalination Tokyo, Japan Nov.
27-Dec. 3. 1977
Proceedings of the Internet ional Congress on OesalinatIon
and Water Reuse: Vols. I and 2. In DESALINATION 22(1-3).
223-233, Coden: OSLNAH Publ.Yr; Dec. 1977
lllus no refs.
Sum.
Languages: ENGLISH
Ooc Type: CONFERENCE PAPER
.Japan will have a water supply deficit of 70 billion TPY by
1985. The deficit can be made up by desalination and by
multiple reuse of process water. RO seems most economical for
water reuse applications. In a typical system, the wastewater
Is divided Into a low salinity stream treated by conventional
tertiary treatment systems and a high-salinity system treated
by RO. Flow charts for systems processing Ion exchange
regenerating reagent, soybean fermentation wastes, and bean
paste wastes are presented. Manufacturers, distrIbutors,
licensees and sublicensees of RO and ultraf11tratIon systems
In Japan are listed. The capacities of RO units distributed
by Japanese companies are 1tsted. Typical operattonal data
are given for a new type of cellulose acetate, hollow fine
fiber module designed to minimize fouling deposits on membrane
surfaces (Hoilosep). A tubular module using plast ic
reinforced porous fiberglass tubes as support Is described. A
new polyheterocycl1c pol y benz ttnldazo lone membrane which can
wlthstand strong acid has shown promise In concentrating
chromic acid rinses. (FT)
DescrIptors: Japan; Reverse osmosis; F11tratIon; Membranes;
Wastewater treatment; Food processing Industry wastes;
Industrlal effluents; OesalinatIon; Technology
Identifiers- ultraf11tration
coagulation-sedimentat ton for both r tnslng water and used
bath. Such treatment does not satIsfy recent municipal
regulations. A new process treats rinse water, containing the
bulk of cyanide and Cr wastes, with Ion exchangers; acid or
aIkalIne wastewater Is treated by chelate res in af ter
coagulation-sedimentation. The treated water can be returned
to the shop. The mixed bed exchanger consists of a strongly
acid and a weakly basic an Ion exchange resin after an
activated carbon filter, followed by a strongly basic an Ion
exchanger. At the near neutral pH value of the wastewater
made possible by this system, complex cyanides are not
precipitated nor cyanide gas produced; free cyanide which
passes the mixed bed exchanger Is caught by the strongly basic
exchanger. Regenerat ton water and deter lorated bath are
treated with sodium hypochlorlte and ferric sulfate. Chromium
(III) Is treated with other cations with a strongly acid
exchange resin; hydrogen chromate and chromate Ion are treated
with other antons by weakly basic exchange resins. Wastewater
containing heavy metals other than cyanide and Cr Is treated
by coagulation and sedimentation, sand filtration, and chelate
resins which adsorb the metals selectively In series. (FT)
Descriptors: Wastewater treatment; Cyanides; Metal fInlshlng
1ndustry wastes; Chrom1urn; Heavy metaIs; Ion exchange;
Industrial effluents; Resins
78-O256O
An experience on re-use of waste water discharged from
plating shop.
Mural. Y.; Yamadera. T.; Koike. Y-
Hitachi Plant Engineering ft Construction Co., Water & Waste
Water Treatment Otv.. Tokyo, Japan
InternatIonal Congress on DesalInatIon Tokyo, Japan Nov.
27-Dec. 3, 1977
Proceedings of the International
and Water Reuse: Vols. 1 and 2
97-IO4, Coden: OSLNAH Publ.Yr
IIlus. refs.
No abs.
Languages: ENGLISH
Doc Type' CONFERENCE PAPER
Convent ional treatment processes for metal plat ing
was tewaters cons 1st of ox IdatIon, reductloo. and
etal
Congress on Desal(nation
In DESALINATION 22(1-3),
Dec. 1977
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DIALOG Flle4l: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge ScI Abs) (Item 84 of 98) User239l3 23jun82
3196
U>
(-•
CO
78-O2556
An Integrated Industrial waste water treatment system using
electroflotatlon and reverse osmosis.
Roth, H. P.; Ferguson, p. V.
Swissair Engineering, Metals Technology Section. Zurich.
Switz
International Congress on Desalination Tokyo, Japan Nov
27-Dec. 3. 1977
Proceedings of the International Congress on Desalination
and Water Reuse. Vols. I and 2. In DESALINATION 22(1-3),
49-63. Coden: OSLNAH Publ.Vr: Dec. 1977
Illus. refs.
Sum
Languages: ENGLISH
Doc Type: CONFERENCE PAPER
At the Swissair Maintenance and Overhaul Base In Zurich,
wastewater and process effluent treatment Is centralized
except 'for cyanides and chromate plating wastes
detoxification. The central treatment for wastewater consists
of clarification stages, neutralization, and sludge treatment
performed by electroflotatIon. Process water treatment,
consisting of a desalination stage. Is performed by RO,
Including necessary pro- and post treatment equipment. In the
electroflotatlon process, electrolytleally produced minute gas
bubbles which adhere to flocculatfon particles are used to
separate clarified water from the sludge phase. Batch
treatment times are 2O-3O mln. The sludge layer which forms
on top of the tank Is sklmrned pneumatically at regular
intervals. In this facility. electroflotatIon Is laid out In
2 Independent lines with a capacity of 2O m3/hr each. The
outlet stream contains J5 ppm SS. Intermediate treatment
consisting of post-alum flocculatlon followed by multimedia
pressure filtration, and pH and scale Inhibitor conditioning
prepares the stream for RO. Modified cellulose acetate spiral
module membranes are used. Design recovery rate Is 8O54 on a
capacity of 72O m3/d. Automatic flushing devices control
membrane fouling. Average salt rejection rates are 98 4%.
Dally plant utilization Is 16 hr-13 hr for waste and 3 hr for
city water. The city water stream has a beneficial effect on
membrane flux performance restoration; the bank flushing
system needs to be used only every 4 wk. Permeate
posttreatment Includes degas IfIcatIon, pH adjustment, and
carbon bed filtration. Operational costs of the facility are
calculated at about $I.92/I.OOO gal. (FT)
Descriptors Switzerland; Wastewater treatment; Reverse
osmosis; Flotation; Desalination; Industrial effluents;
Neutralization; Sludge treatment
Identifiers- electroflotatIon; Swissair; Zurich
Uppsala, Sweden
WATER RESEARCH
1977
11(9), 8OI-8O5.
refs. (Some In Scan.)
Coden- WATRAG
Publ.Yr:
Illus.
Abs.
Languages: ENGLISH
Doc Type- JOURNAL PAPER
In order to fulfill the objective of a water control program
based on frequent sampling In several wastewater treatment
plants, rivers. and lakes, a simplified method for measuring
COD was developed. • The procedure. called the RR method.
Includes small sample and reagent volume, rapid addition of a
mixture of all reagents to the sample, exclusion of mercury,
and autoclavlng at !2OdegC for 1 hr In flasks with fitted
glass stoppers. To avoid dilution before analysis, the method
was adapted for wastewater (IO-3OO mg/1 O2) and fresh water
(IO-IOO mg/1 O2). Parallel analyses on different types of
water samples according to standard methods showed that the
yield by the RR method was about 1O% lower. With water from
the wastewater treatment plant at Uppsala (COD around 2O mg/1
02), the two methods gave an identical result. The somewhat
lower yield was mostly due to decreased dlchromate
concentration and oxidation temperature The lower oxidation
potential made correction for chloride Interference
unnecessary below I g/l CI-. The RR method also showed a good
correlation to the values for potassium permanganate-consumpt-
ion. Parallel analyses of 318 samples from 14
wastewater-receivlng lakes gave the correlation coefficient
r-+0.90. (AM)
Descriptors: COD; Acids; Chromium compounds; Water sampling;
Sweden; Wastewater treatment plants; Lakes; Rivers; Measuring
methods
Identifiers: acld-dlchromate; autoclavlng; Uppsala; RR
method
78-OI295
A mercury-free accelerated method for determining the
chemical oxygen demand of large numbers of water samples by
autoclavlng them under pressure with acld-dlchromate.
Rydlng. S. -O.; Forsberg, A.
National Swedish Environment Protect Ion Board, Inst. of
Physiological Botany. Algal Assay Lab., Box 54O, S-751 21
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DIALOG Fi!e41: Pollution Abstracts - 7O-82/Apr (Copr Cambridge Scl Abs) (Item 86 of 98) Usei-23913 23)un82
CO
H
78-O1288
Advanced treatment methods for electroplating wastes.
Jakobsen. K.; Laska, R.
EPA, Office of Energy. Minerals, and Industry. 4OI M St. SW,
Wash.. DC 2O46O
9(tO),
42-46.
Coden: PLENBW
POLLUTION ENGINEERING
Publ.Vr: Oct. 1977
11lus. no refs.
Sum.
Languages. ENGLISH
Doc Type: JOURNAL PAPER
The EPA withdrew Its metal finishing Industry effluent
guidelines because they appeared potentially destructive to
the economic viability of the Industry. The EPA Is sponsoring
projects to help electroplaters achieve control of effluents
economically and effectively. Ion exchange and reverse
osmosis show the most technical and economical promise of the
several control technologies under development, but each
technology wilt optimally apply to specific wastewater
streams. Pilot and full scale demonstrations showed that
chromate solution recovered by Ion exchange can be recycled
Into product manufacture without sacrificing product quality.
The chromate composition of a demonstration plant effluent Is
being reduced from 2.7OO ppm to 1-2 ppm. The treatment system
was designed to treat 6O gpm of Influent and discharge an
effluent which Is within statutory limits for pH and heavy
metal content. A demonstration combined reverse osmosis with
solar evaporation for disposal of removed contaminants and
achieved zero discharge to navigable waters. Water
consumption was cut by 75O.OOO gal/mo. (FT)
Descriptors: Federal agencies; Federal regulations;
Wastewater treatment; Metal finishing Industry waste's; Reverse
osmosis; Ion exchange
Identifiers: EPA
78-OO417
Rate . of mlcroblal transformation of polycycllc aromatic
hydrocarbons: A chromatographIc quantification procedure.
Herbes. S. f.. ; Schwal I, I. R. ; Williams, G. A.
Oak Ridge National Lab., Environmental Science Dlv.. Oak
Ridge. TN 37B3O
APPLIED AND ENVIRONMENTAL MICROBIOLOGY 34(2), 244-246,
Coden: AEMIDF Publ Yr: Aug. 1977
tllus. refs.
Abs.
Languages ENGLISH
A chromatographtc procedure was developed for Isolating and
quantifying mlcroblal transformation products of qtC-laba'led
polycycllc aromatic hydrocarbons. PAH-ut111zing cultures were
Isolated From an oil-drilling site and a wastewater treatment
unit. Microorganisms were grown by Inoculation of soil and
wastewater samples Into autoclaved basal Inorganic medium
saturated with naphthalene or phenanthrene; several bacterial
strains were Isolated. PAH transformation rates were
determined by centrifuglng cells from an exponential culture,
washing them, and suspending them In a hydrocarbon-free basal
medium. A qtC-labeled PAH compound was added in 4 II of
acetone, and the culture Incubated at 23.C for 2-3 d.
Extracts were combined and evaporated to near dryness. and the
residue redlssolved In benzene. Transformation rates of
naphthalene, anthracene. benz(a)anthracene, and benz(a)pyrene
by a mixed bacterial population were measured. With this
procedure, extremely slow or Incomplete transformations may be
quantified that would not be detectable by previously used
techniques. (AA & from Text)
Descriptors: Aromatic compounds; Hydrocarbons; Cyclic
compounds; Bacteria; Chromatography; Effluents: Carcinogens;
Water pollutants; Microorganisms
Identifiers: PAH
77-05373
Removing soluble metals from wastewater.
METZNER. A.V.
Ecodyne Corp., Industrial Waste Treatment Dlv.
Water & Sewage Works. 124(4): 98-1O1. Apr. 1977 Publ.Yr:
1977
Languages: ENGLISH
Descriptors: ZINC; CHROMIUM; WASTEWATER TREATMENT: COPPER;
TECHNOLOGY; IRON; NICKEL
Identifiers: METAL REMOVAL; CYANIDES
77-O524O
The sulfex heavy metal waste treatment process.
FEIGENBAUM. H.N.
Permutlt Co.. E. 49 Midland Ave.. Paramus. NJ O7652
Proceedings of the Fifth Annual Industrial
PolluttonConference. Edited By L. Delplno and A. Krtgman.
Mclean.Va.: Water and Wastewater Equipment ManufacturersAssoc-
latlon. 1977. 629-642 Publ.Yr: 1977
Languages: ENGLISH
Descriptors: IRON; COOLING WATERS; CHROMIUM COMPOUNDS; METAL
FINISHING INDUSTRY WASTES; SULFUR COMPOUNDS; CHROMIUM; HEAVY
METALS; WASTEWATER TREATMENT
Identifiers: SULFEX: PERMUT1T COMPANY
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DIALOG File.11. Pollution Abstracts 7O-82/Apr (Copr Cambridge Scl Abs) (Item 9O of 98) Usor23913 23jun82
77-O521S
Chromate handling systems for cooling tower blowdown.
ROENSCH, L.F.
Nalco Chemical Co.. 29O1 Butterfield Rd., Oak Brook. 1L6OS21
Proceedings of the Fifth Annual Industrial
Pol Hit ionConf erence. Edited By L., Delptno and A. Krlgman.
Mclean.Va.: Water and Wastewater Equipment ManufacturersAssoc-
iation, 1977. pp. 121-135 Publ.Yr: 1977
Languages: ENGLISH
Descriptors: COOLING WATERS; ECONOMICS; ION EXCHANGE;
WASTEWATER TREATMENT; CHROMIUM COMPOUNDS
74-O2237
Petroleum hydrocarbons and fatty acids in Wastewater
effluents.
QUINN, J.G.
WHOI, Main St., Woods Hole, MA 02543
Water Pollution Control Federation. Journal. 45(1) 7O4-712.
Apr. 1973 Publ.Vr: 1973
Languages: ENGLISH
Descriptors: CHROMATOGRAPHY; EFFLUENTS; HYDROCARBONS; LIP1DS
; PETROLEUM; WASTE WATER TREATMENT PLANTS
Identifiers: FATTY ACIDS
77-OO4O7
• Waste treatment for a metal finishing plant.
YOUNG. R.A.
'Pollution Engineering, 1301 S. Grove Ave., Barrlngton,
IL6OOIO
Pollution Engineering. 8(9): 4O-41. Sept. 1976 Publ.Yr:
1976
Languages: ENGLISH
Descriptors: MARYLAND; WATER QUALITY; ENGINEERING; METAL
FINISHING INDUSTRY WASTES; CHROMIUM; WASTEWATER TREATMENT
Identifiers. GENERAL ELECTRIC CO.
76-O5299
(jj Pollution abatement through the treatment of Industrial
to waste water with Ion exchange resins.
O WAITZ, W.H.. JR.
Rohm and Haas Co.. i Pollution Control Research Dept..
SOOORichraond St., Philadelphia. PA 19137
Institute of Environmental Sciences: 22nd AnnuatTechnlcal
Meeting. Mt. Prospect, 111 : Institute ofEnvironmental
Sciences. 1976. pp. 491-495 Publ.Yr: 1976
Languages: ENGLISH
Descriptors: WASTEWATER TREATMENT; RESINS; ECONOMICS;
CYANIDES; METALS; BORON; ION EXCHANGE; INDUSTRIAL EFFLUENTS
Identifiers: CHROMATFS
72-O6467 72-5TF-OO98I
Contlnous effluent analysis halts chromate batch tests.
ANONYMOUS,
UNKNOWN
Chemical Processing. Chicago, 34(12): 9, Mld-Nov. 19
Publ.Yr- 1971
Languages: ENGLISH
Descriptors: COLORIMETRY; WASTEWATER TREATMENT; CHROMATES
Identifiers: TURBIDIMETERS
72-O1025 72-1TF-OO228
Chromate pollution of watei—detection, effects, and
prevention: A bibliography.
STEMPLE. RUTH
AEC, Oak Ridge National Lab.. V-12 Technical Library. TN
U. S. Atomic Energy Commission. Oak Ridge
Nat tonal Laboratory. Oak Ridge. Tenn. Report No. ORNL TM-345O.
20pages. Oct 1971 Publ.Yr; 1971
Languages: ENGLISH
Descriptors: INDUSTRIAL WASTES; WATER POLLUTANTS; WASTEWATER
TREATMENT; CHROMATES
Identifiers: BIBLIOGRAPHY
74-O3343
Gas-liquid chromatographtc separation of sulfur from
chlorinated pesticide residues in wastewater samples.
KUO. C.L.
County Sanitation Districts of Los Angeles County, 21O1S.
Workman Mill Ln.. Whlttler. CA 906O1
Bulletin of Environmental Contamination andToxIcology. 9(2).
1O8-II5. Feb 1973 Publ.Yr: 1973
Languages- ENGLISH
Descriptors: CHLORINE; CHROMATOGRAPHY; HALOGENATEO
PESTICIDES; MEASURING METHODS; PESTICIDE RESIDUES; SULFUR
REMOVAL; WASTE WATERS
Identifiers GLC
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DIALOG Ft)e4l Pollution Abstracts - 7O-B2/Apr (Copr Cambridge Set Abs) (Item 97 of 98) Usei-23913 23jun82
7I-O4278 71-3Tf-OO4O7
Uptake of nitrosyl 106-ruthenlum on chit In and chltosan from
waste solutions and polluted sea-water.
MUZZARELLI, RICCARDO A. A.
Univ. of Bologna, Clamtclan Chemical Inst., It.
Water Research. New York. 4(6): 451-455. June 197O
Publ.Vr: 197O
Languages: ENGLISH
Descriptors: POLYMERS; CHROMATOGRAPHY; RADIOACTIVE WASTES;
CHELATION; WASTEWATER TREATMENT
Identifiers- RADIONUCLIDE UPTAKE
71-O2852 7I-2TF-OO342
Rid sewage of toxic Inorganics.
FULMER. MARY
Columbus. OH
Water and Wastes Engineering. New York, 8(l>. 26-27,Jan.
1971 Publ.Yr: 1971
Languages: ENGLISH
Descriptors: CHROMIUM; INDUSTRIAL WASTES; ION EXCHANGE;
WASTEWATER TREATMENT; SEWAGE
OJ
fo
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DIALOG F11e41: Pollution Abstract's - 7O-82/Apr
(Copr. Cambridge ScI Abs) (Item 1 or 61) User 239 K) 23jun82
32OO
U)
to
NJ
Priority Pollutants In Large Municipal Treatment
19SO
PP-
144-150,
82-O2O74
Fate of
Plants
Lue-HIng, C.j Lord!, D.T.; Kelada, N.P.
Metro. Sanitary Olst. Greater Chicago, IL
AIChE Nat. Mtg. Boston. Portland. Chicago
IN "WATER - 198O VOL. 77, NO. 209.
Publ.Yr: t9Bt
AICHE. 345 EAST 47 ST., NEW YORK, NY 1OO17
SUMMARY LANGUAGE - ENGLISH
Languages: ENGLISH
The U.S. Environmental Protection Agency has Issued a list
of 129 priority pollutants which Include metals, cyanides,
phenols. pesticides and other organtcs. The Metropolitan
Sanitary District of Greater Chicago (MSOGC) which operates
seven treatment plants has regulated heavy metals, phenols and
cyanides for a number of years. The heavy metals found In the
Influents Include chromium, copper, zinc. Iron, nickel, and
cadmium. Substantial but variable removals do occur with the
effluents reaching some background level for a specific metal.
These metals are found to concentrate In the treatment plant
sludges- The results of a screening of the occurrence of the
priority organlcs at four of the MSDGC treatment plants showed
relatively few organlcs occurring In detectable quantities.
The concentrations of those found were highly variable but
generally less than 1OO mu g/1 In the influents and less than
2O mu g/1 In the effuents.
Descriptors: pollutants; organic compounds; heavy metals;
effluents; wastewater treatment plants; sludge; cyanides:
phenol; pesticides; contamination ^
B2-OO55O
Method and Apparatus for Removing Biodegradable Compounds
Frcm Wastewater
Bhattacharyya, A.
Republic Steel Corp.
Buffalo, NY
U.S. PAT. OFF. GAZ
1981
Pat. No. 4.271.O13
Languages: ENGLISH-
A method for removing biodegradable compounds selected from
the group which Include oils, volatile organlcs. phenol Ics
free and fixed ammonia compounds, thlosulfates, thlocyanates.
cyanides, sulffdes and the like from a feed wastewater:
distilling said wastewater to remove said free ammonia
compounds, oils and volatile organlcs.
Descriptors: BlodegradatIon: Ammonia compounds; Cyanides;
Wastewater treatment; Patent; Instruments; Pollution control
equipment
Cleveland,
VOL. 1O07, NO.
OH Hanna Furnace Corp..
1. p. 274, Publ.Yr:
Kult. W.J.M.; Babcock, A.R.
Cominco Ltd., Vancouver, Can
U. S. PAT. OFF. GAZ. VOL. IOO3. NO. 2 . p. 7O3 ,
Publ.Yr: 1981
Pat. No. 4.25O.03O
Languages: ENGLISH
A method for the removal of dissolved free and complex
cyanides from water-containing effluent which comprises
controlling the pH of said effuent In a range of about 7.O to
8.5 and contacting said effuent with an effective amount of an
Insoluble solid Iron sulflde chosen from at least one of
ferrous sulflde and ferric sulflde having particle sizes
smaller than about 3QO mu for a period of at least about 5
minutes to remove said dissolved free and complex cyanides to
a desired level, said effective amount being sufficient to
give a weight ratio of said Iron sulflde to total cyanide tn
said effluent of greater than about 2:1.
Descriptors: Cyanides; Effluents; Wastewaters; pit;
Wastewater treatment; Water purification
81-O388O
Response of Methane Fermentation to Cyanide and Chloroform
Vang, J.; Speece. R.E.; Parkin. G.F.; Kocher, W.; Gossett.
J.
Drexel Univ.. Phi la., PA
Tenth Int. Conf. IAWPR Toronto, Ont. Jun. 23-27, 198O
WATER SCI. & TECH. VOL. 13. NO. 2 . Publ.Yr: 1981
Languages: ENGLISH
The anaerobic digestion process has excellent potential for
the treatment of warm Industrial wastewaters. However this
process is generally considered to be especially sensitive to
many toxicants which occur occasionally or chronically In
Industrial wastewaters. Cyanide and chloroform were selected
as sample toxicants which show Inhibition of methane
production at concentrations less than 1 mg/1. This study was
directed toward an evaluation of the inhibition pattern of
these two toxicants. The effect of toxicant concentration on
methane production recovery pattern was determined. Suspended
growth systems were to study toxlclty acclimation
characteristics and recovery patterns.
Descriptors: Industrial effluents; Toxicants; Cyanides;
Methane; Anaerobic digestion; Chloroform
B1-O395I
Process for the Removal of Cyanides From Effluent
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DIALOG rilell Pollution Abstracts - 7O-82/Apr (Copr. Cambridge SO Abs) (Item
5 of 61) User-23913 23Jun82
8I-O38I9
lon-Precipltate Flotation of Iron-Cyanide Complexes
Bucsh, R.O ; Spottlswood, D.J.; Lower, O.W.
Int. Nickel Inc . SterlIng Forest. N.Y.
U. WATER POLLUT. CONTR. FED, VOL. 52, NO. 12 . pp.
2925-293O . Publ.Yr: 198O
Languages: ENGLISH
An ion-precipitate flotation process Is proposed to remove
Iron-cyanide complexes from wastewaters. A quarternary amlne,
trlcaprylmethyl ammonium chloride, Is used to precipitate the
Iron-cyanide complexes as a waxy solid, a material that Is
floated Both cyanide and ferrocyanlde removal are Included,
but the emphasis of this work Is on ferrlcyanlde removal. The
variables studied were: surfactant dosage, the presence of
chloride Ion, solution flow ra'te. airflow rate. Initial
ferrlcyanlde concentration, and the pH of the feed.
Descriptors. Ions; Flotation; Wastewaters; Solids; Flow
rates; Chemical compounds; Iron compounds
Identifiers: Iron-cyanide
81-OI797
Foam flotation treatment of Industrial wastewaters:
Laboratory and pilot scale.
Wilson. D. J.; Thackston. E L.
Vanderbllt Univ., Nashville. TN 37235
U S- Environmental Protection Agency. Office of Research and
Development. Environmental Protection Technology Series
Coden EPTSBT Publ.Yr: Jun I98O
M lus. 9O refs.
Abs. (Available from NTIS. Springfield, VA 22161)
Languages: ENGLISH
TREATMENT CODES: D .(DESCRIPTIVE) ; I .(INVESTIGATIVE/OBSER-
VATION)
A floe foam flotation pilot plant removed Pb and Zn In •
dilute aqueous solution to quite low concentrations. Design
Improvements are presented. The floe foam flotation of Zn Is
'readily carried out with aluminum hydroxide (A1(OH)3) and
sodium lauryl sulfate (NLS). Chromium hydroxide Is floated
with NLS. but adsorbing colloid flotation of Crt3 with ferric
hydroxide (Fe(OH)3) or AI(OH)3 yielded better results. Cobalt
and N1 levels are reduced to =1 mg/L by flotation with AI(OH)3
and NLS. The Mn+2 levels can be reduced to 1-2 mg/L by
flotation with Fe(OH)3 and NLS. Floe foam flotation of Cu was
compatible with several precipitation prelreatments (soda ash,
lime. Fe(OII)3, arid AI (OH)3 >. although modifications were
needed to prevent interference from excessive Ca or CO3-2.
Therefore, floe foam flotation can be used as a polishing
treatment. The flotation of mixtures of Cu+2, Pb+2, and Zn*2
was conducted using Fe(OH)3 and NLS. The flotation of simple
and complexed cyanides and mixtures of metal cyanide complexes
was also conducted with Fe(OH)3 and NLS; .a pH of "5 Is
optimum. A surface adsorption model for floe foam flotation
was analyzed and accounted for the effects of surfactant
concentration, ionic strength, specifically Adsorbed Ions, and
surfactant hydrocarbon chain length. (AM)
Descriptors- Flotation; Industrial wastes: Wastewater
treatment; Pilot plants: Engineering; Flocculation: Ions;
Surfactants; Iron compounds; Aluminum compounds; Heavy metals;
Zinc; Nickel; Manganese; Chromium; Cobalt; Copper; Lead;
Chemical treatment; Adsorption
Identifiers: floe foam flotation
81-01743
Mechanism and kinetics of cyanide ozonatlon In water.
Zeevalkink, iS. A.; Vlsser, D. C.; Arnoldy, P.; Boelhouwer,
c.
Univ. of Amsterdam, Lab. of Chemical Tech.. Plantage
Muldergracht 3O. Amsterdam, Holland
Water Research 14(lo), 1375 1385, Coden: WATRAG
Publ.Yr: I98O
11lus. refs.
Abs.
Languages: ENGLISH
Doc Type-. JOURNAL PAPER
TREATMENT CODES: T .(THEORETICAL/MATHEMATICAL) ; D
.(DESCRIPTIVE) ; I .(INVESTIGATIVE/OBSERVATION)
The rate of oxidation by 03 of potassium cyanide into
cyanate was measured In alkaline aqueous solutions buffered at
a pH of II.a and a temperature of 2OdegC. The Initial cyanide
concentration was usually 1OO g/m3. Under these conditions,
the reaction rate can, within the experimental error, be
described by an equation which is of first order in O3 and
Independent of the cyanide concentration. The reaction rate
Is so large that the conversion Is limited by mass transfer.
Mass balances show that 1 mole of O3 oxidizes 1 mole of
cyanide. The oxidation of cyanide Is part of a reaction
sequence similar to the O3 decomposition mechanism. For both
react ions-cyanide oxidation and O3 decay-mechanisms are
proposed. The kinetics predicted for the O3 decay are In
agreement with experimental data. The mechanism proposed for
the cyanide oxidation predicts a reaction rate equation which
has been supported by experimental evidence. (AM)
Descriptors: Kinetics; Ozonatlon; Mathematical analysis;
Wastewater treatment; Nitrogen compounds; Chemical treatment;
Metal finishing Industry wastes; Chemical reactions;
Engineer Ing
Identifiers: cyanide ozonatlon
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DIALOG rile4l Pollution Abstracts - 7O 82/Apr (Copr. Cambridge Scl Abs) (Item a of 61) Usei-23913 23Jun82
U)
K)
81-OO537
Automatic water quality analyzers for wastewater collection
and treatment
Murakami, K.
Ministry of Construction. Public Works Research Inst.. Water
Quality Section, Toyosato-cho, Tsukuba-gun. Ibarakl-ken, Japan
WATER POLLUTION CONTROL FEDERATION. JOURNAL 52(5).
938-942, Coden JWPFA5 Publ.Yr: May 198O
no refs.
Eng., Fr.,
Languages:
Ger., Port., Span. abs.
ENGLISH
Doc Type: JOURNAL PAPER
The current status of automatic water quality analyzers and
sensors for wastewater collection and treatment systems In
Japan Is described. If automatic analyzers for cyanide, Cr,
Cd. and measurement and recording of organic loading
discharged from wastewater treatment plants are to be
Implemented In Japan, automatic analyzers for organic
substances will have to be used widely. The performance of
automatic analyzers and sensors for treatment process controls
was evaluated at various locations. (AM)
Descriptors. Heavy metals; Toxic materials; Water quality;
Monitoring Instruments; Wastewater treatment; Japan
Identifiers: automatic analyzers and sensors'
BI-OO522
Inhibitory effects on nitrification by typical compounds In
coke plant wastewaters.
Ramadorl. R.; Beccarl, M.; Passlno, R.; Tandol, V.
IRSA-CNR. Via Reno 1-OO198 Rome. Italy
ENVIRONMENTAL TECHNOLOGY LETTERS 1(5). 245-252.
Publ.Yr: May 198O
1 Ilus 16 refs.
Abs.
Languages- ENGLISH
Doc Type: JOURNAL PAPER
Nitrifying sludge for the nitrification kinetic studies was
obtained from a steady state laboratory biological plant,
mixed with a synthetic NH3 substrate to a predetermined
concentration, and then Introduced Into a batch reactor. The
kinetics were monitored by determining the amount of alkail
used up In neutralizing the acidity produced during oxidation
of NH3 to NO2-. The method Is automated and gives more
accurate results than those obtained with respIrometrIc
methods. Aniline. qulnollne, pyrldlne and sulfides are
significant Inhibitors. (FT)
Descriptors. Nitrification; Coke; Industrial effluents
Wastewaters; Biological treatment; Aromatic compounds
Chemical reactions: Nitrogen compounds; Sulfur compounds
Mathematical analysis; Laboratory methods; Thermodynamics
Kinetics; Bacteria
Identifiers: nitrification Inhibition; coke plan
wastewaters: 6 Inhibitor types; aniline; qulnollne; cyanides
phenols; pyrldlne; methylpyrIdlne; sulfides; thiocyanates
Ni trosomas
8I-OO5O8
Evaluation of reverse osmosis membranes for treatment of
electroplating rlnsewater.
McNulty, K J.; Hoover. P. R.
Abcor, inc., Walden Div., Wilmington, MA O1887
U.S. ENVIRONMENTAL PROTECTION AGENCY. OFFICE OF RESEARCH AND
DEVELOPMENT. ENVIRONMENTAL PROTECTION TECHNOLOGY SERIES
Coden: EPTSBT Publ.Yr: May 198O
tllus. refs.
Abs. (Available from NTIS. Springfield. VA 22161)
Languages: ENGLISH
The RO system described functions by concentrating the
chemicals for return to the processing bath white purifying
the wastewater for reuse In the rinsing operation. The
effectiveness of the PA-3OO, PBIL, NS-IOO, NS-2OO, SPPO. B-9,
and CA membranes were evaluated In tests on rlnsewater with
extreme pH and oxldant levels. The PA-3OO membrane performed
well with copper cyanide, zinc cyanide, and chromic acid
rlnsewaters. while the NS-2OO and PBIL membranes performed
best with acid Cu rlnsewaters. After commercializing the
membranes, applications In various metal finishing,
non-ferrous metal, steel, and Inorganic Industries may be
found. (FP.AM)
Descriptors: Reverse osmosis; Membranes; Wastewater
treatment; Metal finishing Industry wastes; Waste treatment
Identifiers: electroplating rtnsewater
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DIALOG Mle41: Pollution Abstracts - 7O-B2/Apr (Copr Cambridge Scl Abs) (Item 11 of 61) User23913 23JunB2
U)
(O
Ul
8 I-OO4OO
Calorlmetrlc studies of b lodegradatIon processes In
biological uastewater treatment.
Fortler, d. -L.; Reboul. B.; Philip, P.; Slmard, M. -A.;
Picker, P.; Jollcoeur. C.
• Unlverslte de Sherbrooke, Centre d'ApplIcatIons en
CalorImetrie et Thermodynamlque. Sherbrooke, Quebec J1K 2R1,
Canada
WATER POLLUTION CONTROL FEDERATION. JOURNAL 52(1), 89-97,
Coden: JWPFA5 Publ.Yr: dan 198O
Ulus 25 refs.
1 Eng., Fr., Ger., Port., Span. abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
The heat associated with blodegradatIon reactions In culture
suspensions was Investigated by using flow mlcrocalorImetry.
Bacterial cultures obtained In batch or continuous recycling
processes (activated sludge) were mixed with synthetic
biodegradable effluents, and the heat output was monitored as
a function of time. With batch cultures, experiments were
conducted at various growth stages and COD levels. The
response of both types of cultures to a sudden change In the
COD content of the effluent and to the addition of toxic
contaminants (e.g.. cyanide, Cd, Cr, Cu. and phenol) was also
studied. The heat flux measured Is In general accordance with
the data obtained by resplroraetrIc techniques. Moreover, the
fast response of the flow mlcrocalorImeter makes It possible
to follow the kinetic response of the system after composition
changes. The calorImetrIc method shows promise for
applications In the control of biological wastewater
treatment. (AM)
Descriptors: BlodegradatIon; Biological treatment;
Wastewater treatment; Activated sludge process; Bacteria;
Measuring methods; Monitoring methods; Engineering; Kinetics;
Oxygenatlon; COD; Effluents; Absorption spectroscopy
Identifiers: calorlmetry
BO-O7619
The Environmental Impact of refinery effluents (EIRE study):
CONCAWE's assessment.
Bolsvleux, P.; Bonnier, P. E ; Goethel, G. F.; Jenkins, R
H.; Lemlln. J. S.: Lev!. J. D.; Marmln. A.; Paululs. C. D. A.;
Rotter I, S-; Slbra, P.; Verschueren, K.
CONCAWE. Water Pollution Management Group, The Hague.
Nether Iands
STICHTING CONCAWE. REPORT Coden: CONRD3 Publ.Yr. Feb
198O
11lus. no refs.
Sum.
Languages: ENGLISH
Doc Type: REPORT
The environmental Impact of refinery liquid effluents Is
reviewed. Refinery effluents In general are not a major
source of pollution because of substantial achievements by the
oil refining Industry In reducing hydrocarbon discharges. The
existing parameters. as measured by current techniques.
provide an adequate assessment of refinery effluent quality.
Recent legislative proposals designed to control the
concentration of specific compounds would be difficult to
Implement for refinery discharges. Most hydrocarbons display
short life under normal environmental conditions. High
molecular weight compounds, e.g., polynuclear aromatlcs which
persist for some time, can be reduced to prevailing background
levels by modern effluent treatment techniques. Heavy metals
can also be reduced to background levels In water treatment
plants at refineries. Other pollutants found In refinery
effluents (phenols. NH3, sulfldes, and cyanides) are normally
reduced by preliminary treatment and can be further reduced to
very low levels by biological treatment. (FT.MS)
Descriptors: Environmental Impact; Refineries; Effluents:
Hydrocarbons; Petroleum Industry; Aromatic compounds; Heavy
8O-O7559
A process for simultaneous removal of cadmium and cyanide.
Poon, C. P. C.; Soscla, K. P.
Univ. of Rhode Island. Kingston. RI O2881
INDUSTRIAL WATER ENGINEERING 17(2). 28-3O, Coden:
IWEGAA Publ.Yr: Mar-Apr 198O
Illus. refs.
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
A compact reactor was used In which seawater or sodium
chloride solution was electrolyzed below a column of metal
finishing waste containing both cyanide and Cd. The chemicals
generated from the seawater electrolysis rose In the reactor.
bringing about reactions that completed the treatment process.
A combination of lower power Input and a deeper wastewater
column Is more effective In treatment. Several series of
experiments were conducted. For experiments using lower Cd
concentrations, values were obtained <4.189 mg/kWh with the
lowest one at *2,OOO mg/kWh. The effect of Initial Cd
concentration Is Illustrated. Greater removal per unit power
consumption was achieved with greater rinse water depth. (FT)
Descriptors: Cyanides; Cadmium; Heavy metals; Contaminant
removal; Seawater; Laboratory methods; Electrochemistry: Metal
finishing Industry wastes; Wastewater treatment
Identifiers: electrolysis
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DIALOG Flle4l: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge ScI Abs) (Item 14 of 61) User239t3 23junB2
3204
CO
N)
8O-O75O6
Cyanide problems In municipal wastewater treatment plants.
lord*-. D. T. ; Lue-HJng, C. ; WhHebloom, S, W. ; Kelada. H. ;
Dennlson, S.
Metropolitan Sanitary District of Greater Chicago, Research
and Development Dept,, IOO E. Erie St., Chicago, It 6OGII
51st annual conference of the Water Pol tut Ion Control
Federation Anaheim, California Oct 1-6, 1978
Water Pollution Control Federation
WATER POLLUTION CONTROL FEDERATION, JOURNAL 52(3).
597-6O9, Coden: JWPFA5 Publ.Yr: Mar 198O
11lus. refs.
E ng., F r.„ Ger., Por t., Span. abs.
Languages: ENGLISH
Ooc Type: JOURNAL PAPER CONFERENCE PAPER
Data from daily monitoring of wastewater effluents from the
treatment plants of the Metropolitan Sanitary District of
Greater Chicago Indicated that a 11 effluents occasionally
exceed the limit of 0-O25 mg cyanlde/L set by the Illinois
Pol Hit ion Control Board. Of the larger plants serving
industrialized areas, the Calumet plant, which receives wastes
from 5 major steel mills, averaged O.O95 mg/L. and plants
serving electroplating Industries had averages of O.O27-O.O7
mg/L. The major proportion of the cyanide Is in the complex
form. The plants serving Industrlal areas averaged
O.OSO-O.O96 kg cyanide removed per gnflHHter treated
wastewater. A revised standard for discharges to 1111nois
waters of O. ID mg/L was established as a total cyanide monthly
average and O.2O mg/L for arty 24-hr composite. (AM)
Descriptors: Cyanides; Wastewater treatment plants;
MtmtcIpal wastewaters; 111 toots; Industrial wastes; Toxic
mater ials
Ident Iflers: Chicago; MetropolI tan Sani tary District of
Greater Chicago
feasible, the proposed alternative approach centers on setting
limits on certain, more commonly regulated, parameters which
can be agreed upon and which will not result In great Iy
Increased compliance monitoring costs. Certain parameters
(TSS, BOO. cyanide, etc.) will be used as indicators of toxic
pollutants. While the verdict Is not yet delivered concerning
this approach. the trend seems to be toward permi t
consoltdat ton, or the * 'one stop'' permi t. Another Ini t iat *ve
aimed at '"forcing'' technology, and curbing violations may
well be the increased use of criminal statutes to enforce laws
and regulatIons. Under these guide IInes, most str tngent
action would be taken against violators when health and
environmental damage or risk are great (especially If the
discharge violations involve toxic or hazardous pollutants),
when data are withheld for falsified. or where there are
flagrant cases of wltIful or negligent misconduct. (FT)
DescrIptors: Wastewater treatment; Government regulat ions;
Leg!slat ion; Pollut ion control; Industrlal effluents;
Technology; EPA; Toxic materials
IdentIf iers: best avallable technology economically
ach1evabIe
8O-O7031
Does the permit system force technology?
Josephson, J.
E S & T, 1155 Sixteenth St NW, Washington, DC 2OO36
E S « T 13(8), 911-912. Coden: ESTHAG Publ.Vr: Aug
1979
no refs.
No abs.
Languages- ENGLISH
Doc Type: JOURNAL PAPER
''Forcing'' may be defined either as compelling the use of
known technology, which might not otherwise be used to meet
guidelines, or as pushing water pollution control technology
beyond Its present 1imtts. Cases in which the
state-of-the-art might have to be pushed occur where
regulations require that discharges may have to meet standards
of ''best avallable technology economically avallable'' by
1984-87. One example of absolute requirements for this
involves treatment requirements for any effluent contaIntng
toxic substances. To control toxics. EPA suggests the direct
1 irni tat Ion of spec* f Ic to* icants , where feas Ible. When not
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DIALOG F1le4l- Pollut(on'Abstracts - 7O-82/Apr (Copr. Cambridge ScI Abs) (Item 16 of 61) User239t3 23jun82
8O-O6267
Kinetics of reaction of cyanide and reduced sulfur species
In aqueous solution.
Luthy. R. G.; Bruce. S. G.. Jr.
Carnegie-Mellon Univ., Dept. of Clvlt Eng. . Pittsburgh, PA
15213
E S '& T 13(12). 1481-1487. Coder): ESTHAG Publ.Yr:
Dec 1979
iI lus. refs.
Abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Interactions of cyanide and reduced S species In aqueous
solution 'can produce thlocyanate. Kinetics of the reactions
of cyanide and polysulflde and cyanide and thlocyanate were
Investigated. The reaction of cyanide and polysulflde ts
mixed order and the order decreases from 1.9 to 1.3 as pH
Increases from 8.2 to 12; this Is largely accounted for by a
decrease In reaction order with respect to cyanide as pH
Increases above the pKa for hydrogen cyanide. Catalysis and
Inhibition studies showed that high concentrations of NH3 were
inhibitory and that coal char fines were catalytic. The rate
of reaction of cyanide and polysulftde Is °»> = 3 orders of
magnitude faster than reaction of cyanide and thtosutfate
depending on pH value. A neutral or slightly alkaline
solution containing the order >=1O-3 M total sulflde may form
polysulflde on exposure to O2 and In the presence of cyanide
there should be reaction to yield thlocyanate. (AM)
Descriptors: Kinetics; Cyanides; Sulfur compounds;
Wastewaters; Chemical reactions; Coal conversion; Oxidation;
CatalysIs
Identifiers: thlocyanate; coke effluents; sulflde
8O-O6231
A practical approach to uastewater treatment for the metal
finishing Industry.
Olthof. M.
Duncan, Lagnese and Assoc.. Inc., 3185 Babcock Blvd..
Pittsburgh. PA 15237
WATER POLLUTION CONTROL ASSOCIATION Of PENNSVLVANIA.
MAGAZINE 12(6). 18-27, Publ.Vr: Nov-Dec 1979
11lus. no refs.
No abs.
Languages: ENGLISH
Doc Type. JOURNAL PAPER
General guidelines for the development of a pollution
control program for a metal finishing plant are provided.
In-plant considerations for the design of a treatment system
Include water flow reduction, optimizing the dilution ratio,
counterflow rinsing, cascade rinsing, segregation, process
solutions, floor spillage, and dragout reduction. Practical
treatment methods Include hexavalent chromium treatment,
cyanide treatment, and general rinse water treatment
Reference Is made to promising new technologies and their
potential application. The chemistry outlined forms the basis
for tiie design of wastewater treatment facilities. A typical
flow schematic for & metal finishing plant Is presented.
Miscellaneous treatment approaches include Integrated system,
Ion exchange. and RO. The potential for recovery of one of
the plating solutions should be evaluated during the planning
stage for pollution control.fad I Ities; Ni, Cr, Cu. and Zn
plating baths are possibilities. (FT)
Descriptors: Metal Industry wastes; Wastewater treatment;
Pollution control; Engineering; Ion exchange: Reverse osmosis;
Chromium; Cyanides
Identifiers: metal finishing Industry; hexavalent Cr
treatment; cyanide treatment; general rinse water treatment
8O-O6I58
Removal of Inorganic pollutants from wastewater during
reclamation for potable reuse.
Smith, R.; Slebert, M. L.; Hattlngh. W. H. J.
CSIR. National Inst. for Water Research. P.O. Box 395.
Pretoria OOO1, South Africa
WATER S. A 6(2). 92-95, Coden: WASADV Publ.Vr: Apr
I98O
IIlus. refs.
Abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
The effectiveness of a pilot water reclamation plant for
removing certain toxic and aesthetically undesirable inorganic
chemical constituents from wastewater designed for potable
reuse Is described. Process stages Include high lime
treatment, primary clarification, ammonia stripping, secondary
clarification, sand filtration, chlorinatIon, and activated
carbon adsorption. The high lime and activated carbon
treatments were the most significant for the removal of Cd,
Cu, Pb, Hg, and Zn, while the chlorlnatlon stage was the most
effective for cyanide removal. High lime treatment alone was
sufficient for the complete removal of highly toxic Cd and Pb
Concentrations of all 6 substances Investigated were reduced
to below the detection limits of the analytical methods used.
(AM.FT)
Descriptors. Cyanides; Wastewater treatment; Pollutant
removal; Heavy metal£; Pilot plants; Toxic materials;
Inorganic compounds; Potable waters; ChlorInation; Mercury;
Activated carbon; Engineering; South Africa; Cadmium; Copper:
Lead; Zinc
Identifiers: Pretoria; Stander Water Reclamation Plant
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DIALOG Flle41: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Scl Abs) (Item 19 of 61) User23913 23Jun82
LO
M
CD
8O-O6116
Bench-scale testing for residual waste treatment.
Vuceta, J. ; Anderson, J. R.; TeKlppe. R. J.; Catkins, R. J,;
Bishop, W. J.
James M. Montgomery Consulting Engineers, inc., 555 E.
Walnut St., Pasadena, CA 91101
BOth annual conference of the Water Pol tut Ion Control
FederatIon Philadelphia, Pennsylvania Oct 2-7, 1977
Water Pollution Control Federation
WATER POLLUTION CONTROL FEDERATION. JOURNAL 5I(1O).
2366-2383, Coden: JWPFA5 Publ.Yr: Oct 1979
11lus. refs.
Eng.. Fr.. Ger., Port., Span. abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER CONFERENCE PAPER
The most ef feetIve technologies for central I zed treatment of
varlous Industrlal res Idual wastes generated in Ventura
County. California, were determined. Steps required for a
successful treatment of metallic wastes Include cyanide and
cyanate oxidation, Cr (VI) reduction, hydroxide and sulftde
precipitation, coagulation and flocculatIon, and filtration.
Ion exchange and carbon sorptlon are not usually required.
Coagulation and flocculatIon of nonmetallie toxic wastes,
followed by filtration and carbon sorptlon. Is more effective
In the removal of1 toxic nonmetal11c substances from
wastewaters than foam fract ionatIon coupled with carbon
sorptlon. A batch mode of operation Is superior to continuous
flow. (AM)
Descriptors: Waste treatment; Filtration; Heavy metals;
CoagulatIon; Flocculat ion; Industrial wastes; Wastewater
treatment; Cyanides; CalIfornla; Ox Ida11on; PrecIpI tat Ion;
Toxic materials
Ident if iers: bench-scale test Ing; Ventura County
8O-O5527
Industrial pretreatment.
Her Itage, J.
EPA Journal, 4OI M St. SW. Washington, DC 2O46O
U.S. ENVIRONMENTAL PROTECTION AGENCY. EPA JOURNAL 5(7),
17-18, Coden: EPAJOB Publ.Vr. Jul-Aug 1979
no refs.
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
The cleanup program announced by the EPA will remove toxic
chemicals, e.g., cyanide, hexavalent Cr, Cd, and. Pb, from
Industrial wastes currently being discharged Into municipal
plants. The pretreatment standards wl11 affect =3O,OOO
Industrlal plants. cover 34 major Industrlat types, and
control discharges off 129 toxic Industrial pollutants. The
standards will set numerleal limits on the quant 11les of
spec If ic pot 1utants that can be discharged by a plant In an
Industry category To sfmplIfy the pretreatment Job. EPA Is
demonstrating new technology To back up the pretreatment
action. the Clean Water Act, Clean Air Act, RCRA. and TSCA
will be Implemented (FT)
DescrIptors: EPA; Federal regulatIons; ToxIc mater la Is;
Chemicals; Industrial wastes; Water pol1utants; Wastewater
treatment plants; Technology; Effluent standards
IdentIfIers: cleanup program; RCRA; TSCA
8O-O4756
Electrodfalysls of effluents from treatment of metallic
surfaces.
Kagaku Kojo. Feb 1979. Translated by Bureau of Reclamation.
Denver„ CO
Itol. S.
Asahl Glass Co., Specialty Chemicals and Plastics Marketing
DIv., 1-2-1 Marunouchl, Chiyoda-ku, Tokyo, 1OO Japan
DESALINATION 28(3), 193-2O5, Coden- DSLNAH Publ Yr:
Mar 1979
(1 lus. refs.
Sum.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Eleetrodlalysis Is applled for treatment of effluents front
washing after galvanization. and specifically from washing
after Ni gatvanizat ion. This method Is useful for recovery of
galvanlzatIon reagents used In varlous processes.
E1ec t rod1a Iys1s Is probab1y app1 Icab1e for t reatment o f
ef fluents from washIng af ter cyanIde ga1 van i za 11on or
galvanization with.other substances. To establish a closed
system for the effluents discharged durIng the treatment
processes for metal 1Ic surfaces, techniques for
Industrialization of electrodialysls were developed not only
for the recovery of usefuI components, but a 1 so for recyc1ed
use of water. IndustrialIzatIon of electrodialysls is
expected in the near future. To establish these techniques.
technIca1 deveIopment • 1s needed no t on t y In 1on-exchange
membranes and electrodlalyzers, but also in systemat tzed
processes, including all related techniques. eg,.
pretreatments. (MS)
Descriptors: Industrial effluents; Metal finishing industry
wastes; Water recyclIng; Dialysis; Materials recovery;
Etectrochemlstry; Wastewater treatment
Ident ifiers: electrodialysls; galvanization
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DIALOG Flte4l. Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Scl Abs) (Item 22 of 61) User239l3 23Jun82
BO-O4557
Cyanide and thlocyanate In coal gasification wastewaters.
Luthy, R. G ; Bruce, S. G. . Jr.; Walters. R. W.; MaMes, D.
U.
Carnegie-Mellon Univ , Dept of Civil Eng., Pittsburgh, PA
15213
WATER POLLUTION CONTROL FEDERATION. JOURNAL 51(9).
2267-2282. Coden. JWPFA5 Publ.Yr: Sep (979
I Ilus. refs.
Eng., Fr., Ger.. Port., Span. abs.
Languages• ENOLISH
Doc Type: JOURNAL PAPER
Procedures for preservation and Identification of cyantde
and thfocyanate In coal gasification wastewater, possible
pathways for aqueous-phase formation of thlocyanate, and
reaction of cyanide and polysulfIde-S to produce thlocyanate
were Investigated. Cyanide preservation procedures require
removal of sulfide and high levels of carbonate. An
analytical procedure for thlocyanate determination based on a
Cu-pyrldtne coloMroetrtc method with preextractIon was tested
successfully on most samples. The reaction of cyanide with
polysulfIde-S was =1.54t/-o.2S with a rate constant of =O.24
(M/L)-O.54/mln. Control of cyanide polysul f Ide reaction
requires selective control of sulfide oxidation kinetics. (AM
)
Descriptors: Wastewaters: Cyanides; Energy sources; Coal
gasification; Chemical reactions; Absorption spectroscopy;
Organosulfur compounds; Oxidation; Contaminant removal
Identifiers: thlocyanate; polysulflde; preservation
BO-OI965
Hydrogen peroxide In sewage treatment.
Sims. A. f. E.
Interox Chemicals, Ltd., Moor-field Rd. . W! dries, Cheshire WAS
OUU, England
ENVIRONMENTAL POLLUTION MANAGEMENT 9(4), IO7-I1O.
Coden. EVPMBX Publ.Vr. Ju'l-Aug 1979
11lus. no refs.
ISSN: O367-I5OX
No abs.
Languages: ENGLISH
Doc Type JOURNAL PAPER
TREATMENT COOES: O .(DESCRIPTIVE) ; M .(METHODOLOGICAL) ; A
.(APPLICATIONS.)
The most notable advantage of using hydrogen peroxide (H2O2)
In wastewater treatment Is Its ability to control the odor and
corrosion problems caused by H2S. Hydrogen peroxide converts
available sulfide to Inert S and provides a preferential
source of consumable O2 to prevent further sulfide formation.
The preferred method of administration Is by injecting the
11202 directly Into the main using a positive-action metering
pump operating In conjunction with the sewage flow. It can
also be used to control sulfide In sludge as welt as upgrade
biological oxidation systems. In treating Industrial
effluents, H2O2 oxidizes cyanide to relatively nontoxlc
cyanate and btodegrades phenols. (FT)
Descriptors: 'Oxldants; Wastewater treatment; Chemical
oxidation; Odors; Corrosion; Hydrogen compounds; Contaminant
removal
Identifiers: hydrogen peroxide
toxic electroplating
8O-OI928
Methods for neutralizing
rlnsewater-part 3.
Marin, S.; Trattner, R. B.; CheremlsInoff, P. N.
New Jersey Inst. of Technology, Newark, NJ O7 |O2
INDUSTRIAL WASTES 35(5). 22-23. Coden: INWABK
Publ.Yr: Sep-Oct »979
refs.
ISSN: O537-5525
No abs.
Languages: ENGLISH
Ooc Type: JOURNAL PAPER
TREATMENT CODES: M .(METHODOLOGICAL) ; D .(DESCRIPTIVE)
In ' the removal of Cr from electroplating rlnsewater, the
treatment Is Intended to convert Cr+6 to Cr + 3, and then to
precipitate It as the Insoluble hydroxide. The reduction is
performed with sodium bisulfite (NaHSO3) at a pH of 2.O, with
the precipitation occurring at pH 8.5. using caustic for the
pH adjustment. A pH recorder-controller Is used to measure
the pH and add the NaHSO3 under automatic oxidation-reduction
potential (ORP) control. When the ORP Indicates a value of
3OO mV, the chromates are reduced. and the addition Is
stopped. After 15 mln of mixing, the pH Is adjusted to 8.5.
and after = 15 mln of additional stirring. the precipitated
hydroxides are allowed to settle. In the removal of cyanide
and alkali wastes, the cyanides are 1st converted to cyanates
with a 15% solution of sodium hypochlorite (NaOCl) at a pH
>1O. and are then oxidized to N and CO2 with the NaOCl
solution at pH 8.5. When the ORP reaches a range of 35O-4OO
mV (indicating that all cyanides have been oxidized) the
wastewater changes from a clear, transparent green to sky
blue. Complete oxidation takes =1O mln. The treated water Is
allowed to settle for = 2 hr, during which time small amounts
of metals, e.g., Cu and Ag. will be precipitated as Insoluble
hydroxides. (FT)
Descriptors: Industrial wastes; Wastewater treatment;
Chromium; Cyanides; precipitation; Chemical oxidation;
Reduction; pH; Metals; Toxic materials
Identifiers: electroplating rinsewaters; automated control;
sodium bisulfite; sodium hypochlorite; hydroxides
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DIALOG F1le4(- Pollution Abstracts - 7O~82/Apr (Copr. Cambridge Sc I Abs) (Item 25 of 61) User23913 23junB2
CO
U>
O
ao-ot866
Methods for neutralizlng
r i nsewater-part 1.
Mar In, S.; Trat tner, R. B,; Chereraislnoff. P. N.; Perna. A.
toxic electroplating
New Jersey Inst. of Technology, Newark, NU O71O2
INDUSTR1AL WASTES 25(3), 5O-52. . Coden: INWABK
Publ.Yr; May-Jun 1979
11lus. no ref s.
ISSN- O537-5525
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
TREATMENT COOES: M .(METHODOLOGICAL) ; A .(APPLICATIONS) ; D
.(DESCRIPTIVE)
R1nsewat er s f rom the e1ec t rop1 a 11 ng process conta In high
concentrations of cyanides and chromates. To comply with US
EPA d1scharge standards severa1 chem1ca1 processes have been
developed to destroy the cyanides and chromates. For cyanide
the most common form of treatment Is alkaline chlortnatlon
oxidation by sodium hypochlorite or CI2 plus sodium hydroxide
add It Ion to the waste. Electrolytic decomposition and
ozonation are also effective treatments for cyanide wastes.
Chromium waste treatment Involves reduction and precipitation
processes. Reducing agents Include ferrous sut fate, sod Iurn
blsutfate. and sulfur dioxide; neutralizing compounds Include
lime slurry or caustic. Batch treatment Is necessary in shops
having a total dally flow <30,000 gpd, whereas continuous
treatment Is recommended for volumes >3O,OOO gpd. (FT)
DescrIptors: Metal finishing Industry wastes; Cyanides;
Chromium compounds; Wastewater treatment; Contaminant removal;
Chemlea I ox IdatIon; NeutralIzatIon; ReductIon f
IdentIf iers: electroplatIng
which gave a complete kill In =3O sec, while 5.O mg/L of Cl
failed to give & complete kill after 5 mln of contact time.
As an oxldant, CIO2 Is selective to some compounds considered
wastewater potlutants. SulfIde-containlng gases and waste
produc t s 'of petro1eum refIn ing, coa\ cok1ng, b1ack I1 quor
evaporations, viscose rayon manufacturing, and natural gas
purification are frequently scrubbed with alkaline solutions
and require treatment before discharge. Between pH 5.O and
9.O an average of 5.2 parts by weight of CIQ2 oxidizes t part
by weight of H2S, expressed as sulflde ion. Instantaneously to
the sulfate ton. C1O2 oxidizes simple cyanide to cyanate
and/or CO2 and N. It can also be used over a wide pH range and
In organic contaminated systems for btocontrol and for the
control of industrial odors. These capabt11tles, combined
wi th an on-si te technology that adapts eastly to ex 1st Ing
process facilities, make it a logical choice when considering
wastewater treatment alternatives. (FT)
Descriptors: Chlorine compounds; Wastewater treatment;
DIsInfectants; Ox IdatIon; Water treatment; Odors; Pollutant
removal
Identifiers: chlorine dioxide
8O-O1856
Disinfection and oxidation of wastes by chlorine dioxide.
Rauh. J. S.
OHn Corp., Olin Water Services. 3155 Flberglas Rd. . Kansas
City. KS 66t15
JOURNAL OF ENVIRONMENTAL SCIENCES 22(2), 42-45, Coden:
JEVSAG Publ.Vr: Mar-Apr 1979
11lus. refs.
ISSN: OO22-O9O6
No abs.
Languages ENGLISH
Doc Type: JOURNAL PAPER
TREATMENT CODES: M .(METHODOLOGICAL)
Although in acidfc, organic-free environments. Cl shows a
slight advantage over chlorine dioxide (C1O2) (n dosages
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DIALOG Ftle4l: Pollution Abstracts - 7O-B2/Apr (Copr. Cambridge Sc I Abs) (Item 27 of 6O User23913 23JunB2
CO
CO
525B9-B2629.
Coden FEREAC
G .(GENERAL OR REVIEW)
regulation
8O-O1339
Effluent guidelines and standards; electroplating point
source category; pretreatment standards for existing sources.
c/o E. P. HaU. Effluent Guidelines Olv. (WH-652), 4OI M St.
SW. Washington, DC 2O46O
FEDERAL REGISTER 44(175).
Pub! .Yr: Sep 7, 1979
H lus. no ref s .
Sum .
Languages: ENGLISH
Ooc Type: JOURNAL PAPER
TREATMENT CODES: D .(DESCRIPTIVE)
W .(NEWS)
Effective Oct. 9. 1979. this regulation limits the
concentrations or mass and requires pretreatment of certain
pollutants that may be Introduced Into publicly owned
treatment works by operations In the electroplating point
source category. For plants with a flow of >=38,OOO L/d, the
promulgated standards specifically limit Indirect discharges
of cyanide, Pb. Cd. Cu, Nl. Cr, Zn, and Ag, and total metal
discharge, the sum of the Individual concentrations of Cu, Nl,
Cr, and Zn. For plants with a process wastewater flow of
<38.OOO L/d. these standards 1 Iml-t only Pb, Cd. and cyanide.
The specific numerical limitations are given. (FT)
Descriptors: EPA: Federal agencies; Federal regulations;
Wastewater discharges; Metal finishing Industry wastes;
Cyanides; Heavy metals: Water pollutants; Industrial effluents
; Effluent standards
Identifiers: final rule; electroplating point source
category
control parameters In the treatment of water and wastewater
are flow rate, level, pH, oxidation-reduction potential. and
residual Cl. Additional parameters commonly used to evaluate
the degree -of treatment Include conductivity, temperature,
turbidity, and DO. Several other parameters are measured
using more sophisticated methods, e.g.. Ion selective
electrodes and cyanide and TOC analyzers. These methods are
relatively new and generally require pretreatment of the
sample to remove Interfering agents In free or combined form
or to change the parameter to a more desirable one. All the
systems described share the common goals of releasing the
operator from manually making adjustments and providing for
more efficient use of chemicals and energy. (FT)
Descriptors: Wastewater If-eatment plants; Water treatment
plants; Monitoring Instruments; Engineering; Data systems;
Technology
Identifiers: automated control
8O-OO487
Plant demands require reliable Instrumentation.
McClaln. T. L.; Goswaml. S. R.
R. E. Warner S Assoc.. 2130 W. Park Dr.. Loraln. OH 44OS3
WATER AND WASTES ENGINEERING 16(2), 26-31. 66-67,
Coden: WWAEA2 Publ Yr: Feb 1979
11lus. refs.
ISSN: OO43-115X
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
TREATMENT CODES: M .(METHODOLOGICAL) ; A .(APPLICATIONS)
Available control parameters for wastewater treatment plants
are listed, and their applications are discussed. The
closed-loop system, the pacing system, and the radio
controlled system are schematically diagrammed. The
closed-loop system Is comprised of a process; a measuring
subsystem; and a controlling subsystem consisting of the
controller, the final control element, and the control agent.
The pacing system Involves the controlled feeding of a
''slave'' material In proportion to the ''master'' material.
This system can be modified to a true automatic loop by
developing a radio control system In which both flows are
measured and brought to a radio controller system where their
quotient Is compared to the desired ratio. Major process
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DIALOG File-It: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Sci Abs) (Item 29 of 61) User239l3 23junB2
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•to
79-O6686
Photo processing sludge; New Cornstock lode?
Frank. A.
Sludge Magazine, P.O. Box IO67. Silver Spring. MD 2O9IO
SLUDGE MAGAZINE 2(1). 22-26. Publ.Yr: Jan.-Feb. 1979
illus no refs
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
The combination of new technologies, favorable economics,
and stringent pollution controls is leading to In-plant
recovery. especially wfthln the photoprocessIng Industry.
There Is no typical photographic processing effluent,
according to the Industry's trade association, but faced with
the possibility of Industry-wide regulation under the Federal
Water Pollution Control Act, the trade association sponsored
the ANSI development of a standard to Identify those
substances which might be present and establish acceptable
analytical techniques. The standard identifies 30 elements
and characteristics that may be found In photo processing
effluent. Only Ag and total cyanides have received regulatory
cognizance to date. Effluent standards designed to restrict
direct discharges of Ag and cyanides were established by the
EPA In July 1976. New standards are expected from the EPA by
Feb. 1, 198O. which could be so stringent as to preclude
large concentrations of Ag and cyanides from accumulating In
municipal treatment plant sludge. Many photo processors are
not waiting for EPA's new regulations for reasons of
economics. Silver. at $1.25-$5/oz. is reason enough to
pretreat wastewaters. Eastman Kodak Company markets a simple.
Inexpensive Ag recovery system suitable for smaller
processors. Pilot tests using a 2-stage disposal cartridge
filtration system had a Ag recovery of 99.99%. Filter press
and sludge evaporation techniques are examined. To assess the
leaching potential of Ag and ferrocyanlde column tests were
performed under conditions simulating landfill; Ag and
ferrocyanide were released from sludges in particulate form
only and were rapidly filtered and bound within the soil. (FT
)
Descriptors: Economics; Technology; EPA; Silver; Cyanides;
Materials recovery: Photography; Leaching; Feasibility studies
; Federal regulations; Industrial effluents
Identifiers: Eastman Kodak Co.; Federal Water Pollution
Control Act
Doc Type: JOURNAL PAPER
The efficiency of the 2nd stage activated sludge treatment
of coke plant effluents depends substantially on an effective
quality equalization of the wastewater and consistent ammonia
(NH3) stripping pretreatment. In a pilot plant study, warm
weather conditions favored the necessary NH3 oxidation. The
studied system showed J9O% NH3 oxidation and was characterized
with very fast recoveries from shock NH3 loadings. The mixed
liquor temperature was an Important factor affecting the
performance of the nitrification unit. An effective
nitrification can be achieved under winter conditions with the
application of a heating system In the aeration tank. (FT)
Descriptors: Activated sludge process: Coke; Industrial
effluents; Biological treatment; Cyanides; Ammonia;
Nitrification; Pilot plants; Laboratory methods: Wastewater
treatment
Identifiers: coke plant effluents
79-O6677
Second-stage activated sludge treatment of coke-plant
effluents.
Gariczarczyk, J. J.
Univ. of Toronto, Dept
Ontario MSS 1A4. Canada
WATER RESEARCH 13(4).
Publ.Yr: 1979
Illus. refs.
Abs.
Languages ENGLISH
of Civil Engineering, Toronto.
337-342. Coden: WATRAG
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DIALOG FHe41: Pollution Abstracts - ?O-82/Apr (Copr. Cambridge ScI AbsI (Item 31 of 61) User23913 23jun82
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OJ
79-O4997
The Impact of toxic pollutants on disposal from wastewater
systems.
Schwartz. H. G.. Jr.; Buzzelt. J. C.. Jr.
Sverdrup Corp., 8OO N. Twelfth Blvd., St. Louts, MO 631O1
INDUSTRIAL WATER ENGINEERING 15(6). I4-2O, Coden:
IWEGAA Publ.Yr: Oct.-Nov. 1978
Itlus. refs.
Sum.
Languages. ENGLISH
Doc Type: JOURNAL PAPER
A broad overvlew Is provided o.f the current state of
knowledge regarding the effect's of tox Ic pol lutants of
publicly owned treatment works (POTWs) on the water, land, and
air environments to which they may ultimately be released.
The 65 classes of pollutants referenced In the Clean Water Act
contaIn 129 spec!fIc elements or compounds Ident1fled as
prlor Ity pollutants. These Include 13 metals and 114
organlcs. plus cyanides and asbestos. The need for
control 1 ing their discharge Is apparent. Many of them can
Interfere with the efficient operation of POTWs, or pass (
through them to affect the environment adversely Metals can ^
Inhibit biological processes or accumulate In waste sludges,
preventing them from being used for agricultural purposes. *
Incineration of contaminated sludges may release the metals to
the atmosphere, and leaching from landfills may return them to
the aqueous environment. Organlcs can have similar Impacts.
Some of them can be strIpped from the waste stream and
discharged to the atmosphere during waste treatment.'
EstablIshment of equltable pretreatment standards will be
difficult, especially In the area of organic compounds. There
Is little information available regarding sources, quantities.
treatabiltty. variability, health effects. and environmental
Impact of these pollutants at the low concentratIons
encountered, but EPA has embarked on an extensive program to
deveIop an adequate da ta base upon whIch to formulate
standards. (FT)
Descr fptors: Wastewater treatment plants; ToxIc materlals;
Organic compounds; Metals; Environmental Impact; Federal
regutatIons; Water qua!Ity standards; EPA
Identifiers: Clean Watdr Act
79-O3874
Pre-treatment of coke-plant effluents.
Ganczarczyk, J. J.
Unlv. of Toronto, Dept. of Civil Engineering, Toronto 181,
Ont. M5S 1A1. Can.
TORONTO. UNIVERSITY. DEPT. OF CIVIL ENGINEERING PUBLICATION
Coden: PUTED9 17 pp Publ.Yr: June 1978
Ulus. refs.
Abs.
Languages. ENGLISH
In the majority of North American coke-plants, the effluents
are composed of excess flushing 1iquor and condensates from
pr imary and f inal coolers and the benzol plant. At some
plants wastewaters from ammonium sulfate crystalIzatIon, tar
still, gas desulfurIzers and cyanide strippers contribute to
these effluents. The effluents contain biodegradable (BOD)
and non-biodegradable organlcs, spec IfIc organlcs (e.g.,
phenols), cyanide, thlocyanate, other minera 1 sulfur compounds
and ammonia. Their flow may vary widely depending on coal
moisture content and the specific design and operation of the
plant. The methods and strategies of pretreatment for
coke-plant effluents practIced In some typical plants are
discussed. A statistical analysIs of an ammonia stripping
tower performance Is also presented. Pretreatment of
coke-plant effluents seriously effects the performance of the
subsequent wastewater biological treatment (carbonaceous
oxidation and nitrification). An example Illustrates the
effectiveness of blohydrolysls of thlocyanate measured in a
fulI-scale treatment process and In ptlot-scale nitrification
exper Intents. (AM)
DescrIptors: Industrlal effluents; Wastewater treatment;
AmmonIa; BOD; Organ1c compounds; Cyan Ides; Coke; Sulfur
compounds; Nttrlftcatlon; Chemleal ox 1 da 11on
^9-03136
Waste water treatment at Climax.
Gott. R. D.
Climax Molybdenun Co., Climax Mine. Climax, CO 8O429
1977 Amerlean Mining Congress mining convent Ion. San
Francisco, Calif. Sept. 11-14. 1977
American Mining Congress: 1977 mining convention: Session
papers. Set No. 5. Environmental Controls I ft II 3O pp
Publ Yr: (n.d.)
Publ: Washington. D.C. American Mining Congress
11lus. no refs.
No abs.
Languages: ENGL 15(1
Doc Type: CONFERENCE PAPER
Process defInltIon for wastewater treatment at C1imax
Incorporates countercurrent Ion exchange for Mo removal,
followed by Swift electrocoagulatlon-electrof totat Ion for
heavy metals removal with a polIshlng f11ter for f inal
effluent clarification. Sodium hypochlor1te Is added prior to
the electrof totat Ion basIn as an oxldant for cyanide
destruction. Pilot scale operations Indicate essentially all
the Fe and Mn and K 9O% of the Zn, Cu, Mo, and cyanide are
removed. The Mo removed by the Ion exchange unit Is processed
by solvent extraction-crystallization producing a marketable
sodium molybdate. Skim electroflotatIon products will be chem
fixed and returned to the tailing area for Impoundment. The
inclusion and adaptation of the Swift Lectro Clear process to
treatment of process water at Climax is considered a first for
the mineral Industry. (MS)
DescrIptors: Molybdenum; Wastewater treatment; M ineral
recovery; Mining wastes; Ion exchange
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DIALOG FUe41: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Scl Abs) (Item 34 of 61) User23913 23Jun82
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79-O3O61
Industrial applications of ozone.
Stopka, K.
U.S. Ozonalr Corp.
INDUSTRIAL WASTES 24(3). 23-24. Coden: INWABK
Publ.Yr: May-June 1978
1Ilus. no refs.
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
European and Japanese f tsherles use ozone (O3) for
stertlIzatIon purposes. Improved treatment of Industr tally
contaminated wastewater Is obtained by enriching the air used
for oxygenation with 5% 03. Sulfuric acid Is added to pH 2-4,
along with .OS-I g of ferric or aluminum chloride, followed by
alkaltzation to pH 6.5-7.5 with line. This precipitates most
organlcs. sol ve'nts. oils, res Ins, fatty esters, and toxic
metals. At a retention time of 6-1O mln, 2O mg/L of O3
usually will produce an effluent acceptable to most
environmental requirements„ Cyanide decompos11 ion can be
speeded up by as much as 1OO times through Cu catalysis. With
appropriate pretreatment, ozonatlon of composite wastewater
from a res in manufacturer reduced phenol from 272 to O.
formaldehyde from 376 to O. and total SS from 2.47O to 16O
mg/L. The COD In acidic wastewater from an edible oil
processing plant was reduced from 1O.5OO to 32O mg/L, a 96%
reduction. For industries requiring ultrapUre water, the
treatment system consists of an electrolytic coagulator tank,
a 2O1 filter, an Ion exchange bed. an O3 system with 2% O3
concentration from predrled air and efficient contactors able
to dissolve Instantly 1 mg/L 03 Into the 1iqutd. and an
act ivated carbon fIIter and O.2I filter on discharge.
IncorporatIon of an ozonatIon unlt before a RO unlt can
prevent membrane clogging. (FT)
Descriptors: Ozonatlon; Wastewater treatment; Engineering
of metal hydroxides, followed by land fill dlsposItIon. A
schemat1c diagram of such an effluent treatment plant Is
presented. Applled research for the Polish metal f inlshlng
Industry Is conducted by the Institute of Precision Mechanics,
In Warsaw, which has developed several new effluent treatments
and material recovery techniques. The most promising Include
evaporative recovery of plating bath constituents from rinse
waters, RO systems for some plat Ing soJut Ions, 'improved Ion
exchange systems for single metal recovery from separated
rinse streams, secondary polishing systems for final effluent
purlfIcat Ion. rinse 'water purification steps prior to
evaporative recovery of RO, foreign metal recovery and other
impur tty removal from metal fInlshlng solutIons,
ultraf11tratIon metHods for water reclamation. and
sol id If leatIon of metal fIntshfng sludges containing mlxed
metal 11c hydroxides. Other promising techniques Include
possible utilization of sulflde precipitation of heavy metals,
solvent rIns Ing, Ion flotat ion, C adsorptIon, and recovery of
metals from hydroxide sludges by solvent extraction. (FT)
DescrIptors: Metal fInlshlng Industry; Pollut ion control;
Materials recovery; Reverse osmosis; Ion exchange; Engineering
; Cleaning process; Heavy metals; Poland
Ident If1ers: plat ing Industry; Polish Inst1tute of Precis ion
Mechanics
79-O2832
A clean water project In Poland.
Kteszkowskf, M.; Jackson, G. S.
Inst of Precision Mechanics. Plating Effluent Treatment
Dept.. OO-967 Warsaw. Pol.
ENVIRONMENTAL SCIENCE & TECHNOLOGY 12(8), 896-899.
Coden- ESTHAG Publ.Yr: Aug. 1978
11lus. refs.
Sum.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Wastewaters produced In metal finishing operations contain
such pollutants as cyanides, chromates, .heavy metals, mineral
acIds, aIkalis, oils, greases, detergents, and organic
solvents. The most common effluent treatment consists of
well-known, conventional chemical procedures which can be done
e i ther contInuously or batch-wise. They involve several
operat ions, such as alkaline chlor inat ion of segregated
cyanide solutions, reduction of segregated chromate solutions.
and final neutralization of mixed effluents and precipitation
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3213
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CO
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79-OO693
Eva1ua t1on of EPA recommended treatment and controI
technology for blast furnace wastewater.
Wong-Chong, G. M.; Caruso, S. C.
Carnegie-Mel Ion Inst. of Research, 5OOO Forbes Ave.,
Pittsburgh. PA 15213
AMERICAN SOCIETY OF CIVIL ENGINEERS. ENVIRONMENTAL
ENGINEERING DIVISION. JOURNAL 1O4(EE2), 3O2-32I, Coden:
JEEGAV Publ.Vr: Apr. 1978
11lus. refs.
Abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
An evaluation of the EPA-recommended technology for treating
blast furnace wastewater, esstenlaity SS removal and
rec trculatIon of water, Found the technology Inadequate to
produce effluent qual1ty In compllance with the 1977
guIdelInes that Include ammonia (NH3). cyanide (CN), and
phenol. The evaluatIon examined an extensive data base
consisting of reponses to a questionnaire, long-term plant
operation data, a field survey, and a literature review, while
the EPA effluent limitation guidelines were developed from a
very limited data base. Alkaline chlorination and gas liquid
mass transfer were examined for controlling NH3, CN, and
phenol. Suspended solids removal from the blast furnace
scrubber and cooler wastewater can be achieved by gravity
settling Effluent SS levels of about SO mg/1 can be reliably
achieved In clarlflers with the aid of a flocculant. The
water usage for scrubbing and cooling blast furnace can be
sIgnlfleantly reduced by conduct Ing materlal and energy
balances around the scrubber cooler system. The control of
the scrubber and cooler water pH may offer a feasible and
probably least costly alternative to controlling the NH3 or CN
and phenol content of the blowdown to comply with effluent
limitations at some blast furnace plants. The EPA-proposed
use of alkaline chlorlnatlon Is effective for the removal of
free CNs. but uses costly chemicals. This process will not
destroy the complex Iron cyanides and can create a problem by
releas Ing chloroorganlcs to the receiving .waters. In almost
all cases, once-through systems were within the 1977 limits
for all parameters except SS. (FT & SS)
DescrIptors; Technology; Wastewater treatment; Water
pollution control; Effluent standards; EPA; Furnaces; Cooling
waters; AmmonIa; Cyan1des; Organic compounds; Water reuse;
Chlorlnatlon; Suspended sol Ids; Scrubbers; pH
IdentIflers: phenol
proceedings. In PROGRESS IN WATER TECHNOLOGY 1O(1-2).
419-430, Coden: PGWTA2 Publ.Vr: 1978
Illus. refs. (Some In Ger.)
Sum.
languages: ENGLISH
Doc Type: CONFERENCE PAPER
The Ruhrverband ensures that the wastes ,of metal finishing
establIshments in the Ruhr catchment are recycled to the
chemical Industry; the sale of the wastes covers only
transportatIon costs, but there are sav tngs compared to
chemical precipitation and sludge disposal. Wastewater Is
treated In 118 mostly smalI plants. Cyanide and
chromate-contalnlng wastewaters must be collected separately
and pretreated. The central decontamtnatIon plant at
Iserlohn, and the central treatment plant at Helllgenhaus are
described. To supplement the system of wastewater treatment
plants 4 Impoundments were constructed In the Ruhr valley.
Inf luen
river a
7O:3O
water wo
artlf 1c
heavy me ta 1 s . Dur 1 ng 1 ow f 1 ow In the 1 ower Ruhr
ratio between clean water and treated wastewater of
s maintained on the average. From this mixture
ks abstract their water and prepare drinking water by
al groundwater recharge. (FT)
DescrIptors: Federal Republ1c of Germany; Metal fIntshing
Industry wastes; Effluent treatment; Wastewater treatment
plants; Industrial effluents; Municipal water supplies; Waste
reuse
IdentIflers: Ruhr valley
79-OO626
Wastewater from plating works-required pretreatment and,
disposal of concentrates.
Imhoff. K R
Ruhrverband und Ruhrtalsperrenvereln, KronprInzenstrasse 37,
43OO Essen 1, FRG
International conference on advanced treatment of wastewater
Johannesburg, S. Afrlea June 13- 17, 1977
Advanced treatment and reclamatIon of wastewater: Conference
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DIALOG F11e41: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge ScI Abs) (Item 38 of 61) User23913 23Jun82
CO
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'CT>
79-O0591
The Sulfex heavy metal waste treatment process.
Felgenbaum. H. N.
Permutlt Company. Inc.. E. 49th St. and Midland Ave..
Paramus. NJ O7652
Fifth annual industrial pollution conference Atlanta, Ga.
Apr. 19-21. 1977
Fifth annual Industrial pollution conference: Proceedings.
Edited by L. Delplno and A. Krlgman pp 629-642 Publ.Yr:
1977
Publ: McLean. Va. Water and Wastewater Equipment
Manufacturers Association
Illus. no refs.
Abs.
Languages . ENGLI SI I
Doc Type: CONFERENCE PAPER
The Sulfex process removes heavy metals from solution In the
form of s- precipitates. The Iron sulflde (FeS) used as the
source of S- Is added to the system as a slurry prepared by
combining ferrous sulfate, a soluble sulflde, and lime. The
insoluble FeS forms a sludge blanket In a properly operated
precipltator which serves as a source of excess unreacted S-.
The metal residuals in the effluent are normally lower than
can be obtained by the hydroxide process. The Sulfex process
overcomes complexing and chelatlng agents. Hexavalent Cr can
be reduced and removed In one step along with other metals and
does not have to be segregated for pretreatment. Cost savings
may be realized by not having to use alkalis to raise pH above
B-9 as is necessary for hydroxide precipitation along with
additional acid to readjust the pH to acceptable discharge
range. Dual media pressure filters are provided for polishing
removal of SS carried over from the reactor. Cyanide bearing
wastes must be pretreated. (FT)
Descriptors: Heavy metals; precipitation; Effluent treatment
; Metal finishing Industry wastes; Wastewater treatment;
Industrial effluents; Sulfur compounds; Cyanides
Identifiers. Sulfex
DO. temperature, conductivity, redox potential, and turbidity
have been In use for many years In wastewater treatment
plants. Water equality monitoring systems composed of these
sensing systems with their associated amplifiers, recorders,
alarm circuits, and central data processors are in operation
In many countries. Many units are used at the outfall from
wastewater and sewage treatment plants for supervision of the
neutralization control loop. the effectiveness of the O2
control system of an activated sludge process, or the
efficiency of a final clarification stage. Some of the
available Ion-selective and gas-permeable membrane sensors
have immediate application to wastewater and sewage plant
control. The nitrate analyzer should be used for
determination of nitrate levels before and after
denitrIfIcatIon stages. It Is preferable to use 1 analyzer
with automatic switching of the 2 samples On Industrial
wastewaters, the F- and cyanide monitors have been used with
success. COO measurement has been automated. Because the
O.S-2 hr analysis time Is thought too slow for real time
control. or because correlation with BOD Is considered
Inadequate, other analyzers are being developed for TOC and
total C. (FT)
Descriptors: Monitoring Instruments; Wastewater treatment
plants; Sewage treatment plants; Water quality: Pollutant
analys is
Identifiers: automated control
79-OO496
The use of automatic analysers on waste water treatment
plant.
Meredith. W. D.
Kent-Belgium S.A., Place du Nouveau Marche aux Grains 1O.
1OOO Brussels. Bel.
International workshop on Instrumentation and control for
water and wastewater treatment and transport systems London
and Stockholm May 1977
Instrumentation and control for water and wastewater
treatment and transport systems: International workshop .
proceedings. In PROGRESS IN WATER TECHNOLOGY 9(5-6). 71-74.
Coden: PGWTA2 Publ Yr: 1978
11lus refs
No abs
Languages ENGLISH
Doc Type CONFERENCE PAPER
Continuous measurement and control of such variables as pH.
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DlAtOG File41. Pollution Abstracts - 7O82/Apr (Copr. Cambridge Set Abs) (Item 4O of 61) User23913 23jun82
78-O3385
Electrolysis.
Vlahakls. J. ; Ouellette, ft
E lecti-o techno logy: Vol . I: Wastewater treatment and
separation methods. Edited by R. P. Ouellette, J. A King and
P N Cheremlstnoff 193-237, Publ.Yr: 1978
Pub! Ann Arbor, Mich. Ann Arbor Science Publishers
1 Ilus. refs.
No abs.
Languages- ENGLISH
Doc Type: BOOK CHAPTER
The most important Industrlal applicatIons of electrolysis,
a chemical process by which chemical reactions are produced
electrically In solutions or molten salts, are metal recovery
and electroextract(on, electrochemical organic synthesis, and
electroconcentratIon of solids. Among many specific potential
applIcat ions are the manufacture of propylene oxide from
propylene and water, the treatment of acid mine drainage to
recover Fe. reducing the COD of cheese whey waste, the
recovery of fatty minerals from edible fats, the regeneration
of chromated Al deoxldlzers, the treatment of domestic wastes.
cyanide and organic waste treatment t and electroflotatIon.
E)ectroIyt fc processes produce less polJut ton than many
conventional techniques. and also compare favorably. on an
economic 'basis, with them. Electrolysis Is energy competitive
w1th other chemical routes for manufacturing chemical
compounds and, as environmental standards become more strict,
shoud become more popular in metal recovery and waste
treatment applIcatIons. (FT)
Descriptors: Electrochemistry; Reduction; Oxidation; Metals;
Wastewater treatment; Water purification; Organic wastes; Mine
dratnage; Matertals recovery; Chemical wastes; Waste treatment
; Technology
Ident1f iers: electrolys ts
78-O3333
Decontamination of water containing chemical warfare agents.
Ltndsten. D. C.
US Army Mobility Equipment Research and Development Command,
Petroleum/Environmental Technology Olv., Ft. Belvolr, VA 22O6O
AMERICAN WATER WORKS ASSOCIATION. JOURNAL 7O(2), 9O-92,
Coden: JAWWA5 Publ.Yr: Feb 1978
I Ilus. no refs.
Sum.
Languages. ENGLISH
Doc Type. JOURNAL PAPER
The maximum permissible concentrations (MFC) of chemical
agents In water serve as thresholds to determine contamination
and measure the success of decontamination. The presence of
chemical warfare agents In water can be determined by
detection kits, by dead fish or other aquatic life, unusual
odors from the water. an unusually high C1 demand, or
intelligence reports. There (3 presently no field method for
quantitative analysis of agents In water or for detection at
any level below the MPC F'or some agents, detection at the
MPC level is not available The standard army ERDLator water
purification unit ts ineffective when used directly against
most chemical warfare (CW) agents. A pretreatment procedure.
consisting of superchlor1natIon with 7O% calcium hypochlorlte
to fOO ppns available Cl, followed by a dechlorInatIon with 6OO
ppm of activated carbon, was developed, and proved effective
at removing CW agents to the MPC levels. Safe levels were
also achieved by distillation of water contaminated with HN-3
and HD (blister agents), but not with OA, GB. VX (nerve
agents), and AC (cyanide). RO was successful for removing
only sodium hydrogen arsenate. Waste slurries developed as a
result of using army field equipment should be disposed of
properly by burial, exposure to weathering processes, or
destruction by decontaminating chemicals. (FT)
Descriptors: Contaminant removal; Contaminants; Pollutant
detect ion; Chemtea 1 pollutants; Chior 1nat ton; Reverse osmos1s;
Distillation; Wastewater disposal
Identifiers: chemical warfare agents
78-O3214
Analysis of cyanides In coke plant Wastewater effluents.
Barton, P. J.; Hammer, C. A.; Kennedy, D. C.
Univ. of Missouri. St. Louis, MO 63121
WATER POLLUTION CONTROL FEDERATION. JOURNAL 5Q(2).
234-239, Coden: JWPFA5 Publ.Yr: Feb. 1978
IIlus refs.
Eng., Fr., Ger., Port., Span, abs.
Languages; ENGLISH
Doc Type: JOURNAL PAPER
Experimental results are presented comparing various methods
for the analysis of simple and complex cyanide In coke plant
wastewaters. Analyses were performed on synthetic solutions
containing various combinations of cyanides (CM-), Fe(CN)6-3,
and SCN-. Additional analyses were performed on actual coking
plant wastewaters with and without standard addition. Simple
and complex cyanides In these wastewaters cannot be reliably
measured by either the Standard Methods or the ASTM procedures
owing to the Interference of sul f ides produced by the
decomposition of thtocyanates during the distillation step. A
simple modifIcatIon is demonstrated to remove sulfIde
Interference by treat Ing the distillate with cadin turn
carbonate. Additionally, the distillation procedure employing
Cu2CI2 as the catalyst Is shown to give consistently lower
results than the magnes1um chloride procedure owing to air
oxidation of Cu+1 to Cu+2 during distillation. A simple
experImental modif teat ton is demonstrated which Increases the
recovery of cyanide when the CU2C12 distillation procedure is
employed, (AM)
Descriptors: Wastewater treatment; Effluent treatment;
Industrial effluents; Coke; Cyanides; Distillation;
analysis
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DIALOG F11e41: Pollution Abstracts - 7O-82/Apr (Copr. CambMclge Sct Abs) (Item 43 of 61) User23913 23jun82
CO
CO
00
Congress on Desa!tnatlon
In DESALINATION 22(1-3).
Dec. 1977
wa ter and used
recent municipal
78-O256O
An experience on re-use of waste water discharged from metal
plating shop.
Mural. Y.; Yamadera, T.; Koike. V.
Hitachi Plant Engineering & Construction Co.. Water & Waste
Water Treatment Dlv., Tokyo, Japan
International Congress on Desalination Tokyo. Japan Nov.
27-Dec. 3. 1977
Proceedings of the International
and Water Reuse: Vols. 1 and 2
97-1O4, Coden. DSLNAH Publ.Yr
11 Kis ref s.
No abs.
Languages: ENGLISH
Doc Type- CONFERENCE PAPER
Conventlona) treatment processes for metal plat ing
wastewaters cons 1st of ox Idat ion, reductIon, and
coaguI at ion-sedimentat ion for both r1ns ing
bath. Such treatment does not satIsfy
regulations. A new process treats rinse water, containing the
bulk of cyanide and Cr wastes, with ton exchangers; acid or
alkaline wastewater is treated by chelate resin after
coagulation-sedimentation. The treated water can be returned
to the shop. The mixed bed exchanger consists of a strongly
acid and a weak 1y basic anIon exchange resin after an
activated carbon filter, followed by a strongly basic an*on
exchanger. At the near neutral pH value of the wastewater
made possIbie by this system. complex cyanides are not
precipitated nor cyanide gas produced; free cyanide which
passes the mixed bed exchanger is caught by the strongly basic
exchanger. RegeneratIon water and deterlorated bath are
treated with sodium hypochlortte and ferric sulfate. Chromium
(III) Is treated with other cations with a strongly acid
exchange resin; hydrogen chromate and chromate Ion are treated
with other anions by weakly basic exchange resins. Wastewater
containing heavy metals other than cyanide and Cr is treated
by coagulation and sedimentation, sand filtration, and chelate
resins which adsorb the metals selectively In series. (FT)
Descr iptors: Wastewater treatment; Cyanides; Metal fInishing
Industry wastes; Chromium; Heavy metals; Ion exchange;
Industrial effluents; Resins
Doc Type: CONFERENCE PAPER
At the Swissair Maintenance and Overhaul Base In ZurIch,
wastewater and process effluent treatment Is centralIzed
except for cyanides and chromate plat ing wastes
detoxification. The central treatment for wastewater consists
of clarification stages, neutralization, and sludge treatment
performed by electroflotat ion. Process water treatment.
cons 1st ing of a desalInatIon stage, is performed by RO,
Including necessary pre- and posttreatment equipment. In the
electroflotatIon process, electrolyt leal ly produced minute gas
bubbles which adhere to flocculatIon particles are used to
separate clarIf led water from the sludge phase. Batch
treatment times are 2O-3O min. The sludge layer which forms
on top of the tank Is skImmed pneumatleally at regular
Intervals. In this factitty, electroflotatIon Is laid out in
2 Independent lines with a capacity of 2O m3/hr each. The
out let stream contains J5 ppm SS. Intermediate treatment
cons 1st Ing of post-alum flocculatIon followed by multimedla
pressure filtration, and pH and scale inhibitor conditioning
prepares the stream for RO. Modified cellulose acetate spiral
module membranes are used. Design recovery rate Is 8O% on a
capacity of 720 m3/d. Automatic flushing devices control
membrane fouling. Average salt rejection rates are 98.4%.
Daily plant utilization Is 16 hr-13 hr for waste and 3 hr for
city water. The city water stream has a beneficial effect on
membrane flux performance restoration; the bank flushing
system needs to be used only every 4 wk. Permeate
post treatment Includes degas If teat Ion, pH adjustment, and
carbon bed filtration. Operational costs of the facility are
calculated at about $1.92/t.OOO gal. (FT)
DescrIptors: Swt tzerland; Wastewater treatment; Reverse
osmosis; Flotation; DesalInation; Industrial effluents;
Neutralizat ion; Sludge treatment
Ident 1f iers: electroflotat ton; Swissair; ZurIch
78-O2556
An Integrated Industrial waste water treatment system using
electroflotatIon and reverse osmosis.
Roth. H. P.; Ferguson, P. V.
SwIssair Engineer Ing. Metals Technology Sect ton. Zurich,
Switz.
InternatlonaI Congress on Desalinat ton Tokyo, Japan Nov.
27-Dec. 3, 1977
Proceedings of the International Congress on Desalination
and Water Reuse: Vols. 1 and 2 In DESALINATION 22(1-3).
49-63, Coden: DSLNAH Pub I.Yr• Dec. 1977
i1lus refs
Sum.
Languages ENGLISH
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DIALOG Flle41. Pollution Abstracts - 7O~82/Apr (Copr. Cambridge Scl Abs) (Item 45 of 6|) User239l3 23Jun82
to
CO
78-O2439
Cyanide removal from petroleum refinery wastewater using
powdered activated carbon.
Huff. J. E.; Bigger, 0. M.
I IT Research Inst., Chicago. IL 6O6O6
ILLINOIS INSTITUTE FOR ENVIRONMENTAL QUALITY. IIEQ DOCUMENT
Coden: 110002 1OO pp. Publ.Vr: June 1977
I Itus. refs.
Abs.
Languages: ENGLISH
Doc Type; REPORT
A 2-phase program, consisting of batch tests and continuous
tests, was conducted to determine the basic chemistry and
cyanide removal efficiency of the adsorption and catalytic
oxidation of cyanide by powdered activated carbon (PAC) and
cuprlc chloride CuCI2. In the 1st phase, the operating
variables of pH, Cu dosage, mode of Cu addition, C dosage, and
type of C were Investigated. A pH near neutral (pH 6-8.5) was
desirable to obtain low equilibrium cyanide In the aqueous
phase while maintaining a low Cu level. Cyanide removals K95%
were readily achieved In the batch tests using 25O mg/1 of
powdered carbon and I.O-t.S mg/1 Cu on solutions containing
O.5 mg/1 Iron cyanide. The most Important factors In cyanide
removal were the Cu concentration and C concentration In the
solution. Phase II was a series of continuous tests using 2
laboratory-scale activated sludge units and actual refinery
wastewater. Both C and Cu were added to the aeration basin,
and organic removal and cyanide removal performances were
monitored. Cyanide can be successfully removed though the
addition of PAC and CuC12 Into an activated sludge unit. The
biological efficiency did not Indicate any detrimental effects
from the Cu add11 ton (wlth the except Ion of the first test
where the aeration basin was slug-dosed). More C is required
than predicted In the batch tests due to the organ (cs
competing with cyanide for the active sites on the C. This
process requires little or no capital expenditure and should
provide many refineries with an economic approach for reducing
eff tuent cyanide concentratIons. (AM)
Descriptors: Cyanides; Reftnerles; Petroleum industry wastes
; Industrla I effluents; Wastewater treatment; Pollutant
removal; Activated carbon; Copper compounds; Economics
Identifiers- cuprlc chloride; powdered activated carbon
effluents were Na. N, and Cl. Less abundant elements were C.
K, Fe. Ca, Zn. and Mg. Trace quantities of Br„ Mn, Au, Sb,
and Al were also found. Elements usually considered tox1c*Hg.
Pb, cd. and As-were present only In neglIglble amounts.
Organic resistant compounds after Initial carbon treatment
were F6% of the total organic content in secondary effluent.
but Wt/2 of these were adsorbed upon recycling. Most organic
res Is tant compounds were stnal 1 molecules of J24O nm, and
Included chlorinated hydrocarbon, aliphatic acids and salts.
aromatic amines, and phenolic compounds. Major Inorganic
compounds Included Na and Ca chlorides, nitrates, sulfates,
and phosphates. The amount of sI tuple cyanides were
neglIglble. Most of the res 1s tant compounds or the 1r
character 1stIcs found In this study are- in agreement wlth
prevlous ubservations and in general are reasonable. The
compounds classified should give a better understanding of the
res Is tant compounds and serve as a base for fur ther
investigation of their nature. (MS)
DescrIptors: Wastewater treatment; Munlc ipa1 was tes;
Absorption; Activated carbon; Heavy metals; Trace elements;
Organic compounds
IdentIflers: carbon adsorptIon-resistant compounds
78-O1353
Compounds resistant to carbon absorption tn municipal
wastewater treatment.
Chow, 0. K,; Davtd, M. M.
Weyerhaeuser Co.. Tacoma. WA 94BO1
AMERICAN WATER WORKS ASSOCIATION. JOURNAL 69(1O). 555-561
Coden: JAWWA5 Publ Vr: Oct. 1977
1 Ilus. numerous refs.
Sum.
Languages• ENGLISH
Doc Type- JOURNAL PAPER
The most Important elements In compounds resistant to the
carbon adsorpt Ion trea t merit of b lol og lea I and secondary
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DIALOG Flle4l: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Set Abs) (Item 47 of 61) User239l3 23Jun82
78-OI275
Physical-chemical treatment of Cleveland district coke plant
waste waters.
Naso, A. c.: John. E. T
Cleveland District Coke Plant
American Iron & Steel Institute 85th General Meeting. New
York. N.V. May 25. 1977
B pp Publ.Yr: { 1977?)
Publ: (n.p.) American Iron and Steel Institute
11lus. refs.
No abs.
Languages: ENGLISH
Reduction of organlcs-pr Inclpal ly phenols, free and
emulsified oils, SS. and cyanides-has been the major problem
In coke plant wastewaters. The sources of this pollution are
excess flushing liquor, barometric condenser water from
crystal sulfate plants, and Intercepting sump water from light
oil plants. Typical contaminant loadings and flow rates from
the above streams In one of the Republic Steel Corporation's
coke plants are tabulated. Discussed are the Investigations
that culminated In the development of a modular system and the
Installation and Initial operation of the organic and phenol
remover, SS and oil removal, and ammonia removal modules of
the system. Organic removal techniques revolved around the
use of activated carbon and were capable of removing organlcs
below a level of O. 1 mg/1, as phenol. Free and emulsified
oils should be removed from the feed waters prior to contact
with the activated carbon. Dissolved gas flotation can
effectively remove SS and free and emulsified oils only If an
anlonlc polyelectrolyte Is added to cause flocculatlon and a
low O2 gas Is used for flotation. Caustic soda Is best for
removing ammonia from crude ammonia liquor, advantages of this
system are listed. Two major process modifications were
necessary. One Involved replacing the barometric condenser
with a surface condenser for cooling the vapors from the
crystal IIzer In the ammonium sulfate plate. The other was the
termination of light oil refining, thus eliminating the
neutral gums and thereby reducing the emulsifIcatIon problem
In the intercepting sump water. The treatment facility was
designed to handle 2 streams, one of 22O gpm and one of 44O
gpm. Characteristics of these 2 streams are listed.
Operational experiences at start-up are discussed and those
areas which presented significant problems are outlined. (SS)
Descriptors: Coke; Ammonia; Industrial effluents; Organic
wastes; Wastewater treatment; Suspended solids; Contaminant
removal; Physlcochemical treatment
Identifiers: phenols; Republic Steel Corp.
78-OO476
"Oxyphotolysls"-process for effluent contaminants.
Harwood. R. H.
Ventron Technology Ltd.
RECYCLING & WASTE DISPOSAL 2(6-7), 156-157.
RWDIDB Publ.Yr. July Aug. 1977
I I lus no ref s
Sum
Languages: ENGLISH
A new broad-spectrum effluent treatment process has recently
been Introduced to the European market This tertiary
treatment process Is capable of meeting projected discharge
limits. Due to the energy Input from UV radiation, the
available oxidation energy per molecule of ozone (O6) is
increased by N35%. The Oxyphotolysis process thus makes more
efficient use of the supplied O6. This process was originally
developed as a treatment method for metal-complexed cyanide
wastes from the electroplating Industry. Chlorinated organlcs
are. for the most part destroyed by the process. Organic
thlophosphorus pesticides, such as malathton, are also
decomposed by the treatment. This process compares favorably
with that using ozone alone, in the decolorizing of unbleached
kraft mill effluent. Treatment of an effluent stream of
I.OOO.OOO gpd would require a dosage of S.OOO Ib/d 06 using O6
alone. With Oxyphotolysis, dosage would be 1,35O Ib/d O6.
The Oxyphotolysis method Is also capable of treating a wide
range of chemical contaminants. (from Text)
Descriptors: Effluents; Wastewater treatment; Engineering;
Ozonation; Cyanides: Metal finishing Industry wastes; Paper
Industry wastes; Tertiary treatment; Chlorinated hydrocarbon
compounds; Pesticides; Photolysis
Identifiers: Oxyphotolysis
77-OS373
Removing soluble metals from uastewater.
METZNER, A.V.
Ecodyne Corp., Industrial Waste Treatment Dlv.
Water & Sewage Works. 124(4): 98-IOt. Apr. 1977 Publ.Yr-
1977
Languages: ENGLISH
Descriptors: ZINC; CHROMIUM: WASTEWATER TREATMENT; COPPER:
TECHNOLOGY: IRON: NICKEL
Identifiers: METAL REMOVAL; CYANIDES
77-O33O8
Evaluation of the toxic effect of CO-2+ and CD(CN) 4-2- Ions
on the growth of mixed mlcroblal population of activated
sludges.
MORQZZI. G.
Universlta DeglI Studl dl Perugia. Facolta di
Science.1st Ituto dl Iglene, Via del Gtochetto. O61OO
Perugia,Ital.
Science of the Total Environment. 7(2): 131-143. Mar.1977
Publ.Yr: 1977
Languages: ENGLISH
Descriptors: WASTEWATER TREATMENT; MICROORGANISMS; CYANIBtS-j
ACTIVATED SLUDGE; GROWTH: TOXICITY: CADMIUM
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DIALOG File41- Pollution Abstracts - 7O-B2/Apr (Copr. Cambridge ScI Abs) (Item 51 of 61) User23913 23JunB2
77-O1457
Wastewater and sludge control in the Canadian metal
finishing Industry: Segment Including chemical, electrolytic
treatment; electrochemical machining and polishing; cyanide
hardening.
BUFFA. L.
Canada Dept. of the Environment, Environmental
ProtectlonServtce, Abatement and Compliance Branch, Ottawa
Ont.KtA OH3, Can.
Canada. Water Pollution Control Directorate.Environmental
Protection Service Report Series. Economtcand Technical Review
Report EPS 3-WP-76-1O. Dec. 1976.46 pp Publ.Vr: 1976
Languages: ENGLISH
Descriptors: METAL FINISHING INDUSTRY WASTES: ECONOMICS:
CANADA; WASTEWATER DISCHARGES; SLUDGES; 'INDUSTRIAL EFFLUENTS
Identifiers- FISHERIES ACT; CONTROL TECHNOLOGY
Descriptors: CYANIDES; INDUSTRIAL EFFLUENTS; METAL INDUSTRY
WASTES; PH; POLLUTION CONTROL EQUIPMENT; WASTEWATER TREATMENT
Identifiers. METAL PLATING BATHS
72-O7743 72-6TF-O1173
Plating and cyanide wastes.
SMITH, STUART E.
Environment/One, Schenectady, NY
Water Pollution Control Federation. Wash., D.C.
Journal.44(6): 11OO - 11O4, June 1972 Publ.Yr: 1972
Languages: ENGLISH
Descriptors: CYANIDE WASTES; METAL FINISHING INDUSTRY;
INDUSTRIAL WASTES; WASTEWATER TREATMENT
Identifiers: 1971; LITERATURE REVIEW; METAL PLATING
LJ
J^
I-1
77-O1344
Detoxification of hardening salts by high pressure steam
treatment (the terra!ysIs process).
SALOMONSSON, G.
Terra Bona AB, Drottnlnggatan 25, 7O2 1O Oerebro, Sweden
Second International Congress on Industrial Wastewaterand
Wastes. Edited by S. H. Jenkins. In Progress In
WaterTechnology, 8(2-3): 163-167, 1976 Publ.Yr: 1976
Languages: ENGLISH
Descriptors: WASTEWATER TREATMENT; BARIUM COMPOUNDS;
CYANIDES; METAL INDUSTRY WASTES
Identifiers: TERRALYSIS PROCESS; HARDENING SALTS
76-O5299
Pollution abatement through the treatment of Industrial
waste water with Ion exchange resins.
WAITZ, W.H. , JR.
Rohm and Haas Co., Pollution Control Research Dept.,
SOOORtchmond St.. Philadelphia. PA 19137
Institute of Environmental Sciences: 22nd AnnualTechnical
Meeting. Mt. Prospect, 111.: Institute ofEnvironmental
Sciences, 1976 pp. 491-495 Publ.Yr: 1976
Languages: ENGLISH
Descriptors: WASTEWATER TREATMENT; RESINS; ECONOMICS;
CYANIDES; METALS; BORON; ION EXCHANGE; INDUSTRIAL EFFLUENTS
Identifiers CHROMATES
72-O6935 72-STI-OO771
Integrated waste water treatment for reusage after cyanide
type plating (3,682,701).
LANCY. LESLIE E.
Ellwood City, PA
Official Gazette. U. S. Patent Office, 9O1(2)•623-624,Aug 8.
1972 Publ.Yr: 1972
Languages: ENGLISH
Descriptors: PATENTS; CYANIDE WASTES; WASTEWATER TREATMENT
Identifiers: ASSIGNOR TO LANCY LABS. INC.. ZELIENOPLE, PA
"72-O2641 72-2TF-OO586
Giving cyanide the treatment.
ANONYMOUS,
UNKNOWN
Chemical Week, I1O(2): 55. 57, Jan. 12. 1972 Publ.Yr: 1972
Languages: ENGLISH
Descriptors: METAL FINISHING INDUSTRY; WASTEWATER TREATMENT;
CYANIDE; TOXIC WASTES
Identifiers: ELECTROPLATING WASTES
76-04259
Instrumentation and automatic control at cyanide waste
treatment.
DIGGENS. A.
Orion Research. Inc.. 380 Putnam Ave.. Cambridge, MA02I39
PollutIon Engineering, 8(3): 43-45, Mar. 1976 Publ.Yr:
1976
Languages ENGLISH
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DIALOG Filed): Pollution Abstracts - 7O-B2/Apr (Copr. Cambridge Scl Abs) (Item SB of 61) User23913 23JunB2
7I-O6822 7I-5TF-O1O68
Elimination of cyanides In the waste waters of the
metallurgical Industry.
MALAFOSSE. J.
L-AIr Llqulde. Lyon, Fr.
See Citation No. 71-5TF-1057. 14 pages. 197O Publ.Yr:
I97O
Languages: ENGLISH
Descriptors WASTEWATER TREATMENT; CYANIDE WASTES: METAL
INDUSTRY
Identifiers: CN ION OXIDATION
71-05413 71-4TF-00660
New process detoxifies cyanide wastes.
MALIN. H. MARTIN. JR.
Environmental Science and Technology, Wash.. DC
Environmental Science and Technology. Wash., D. C.,S(6).
496-497 June 1971 Publ.Yr: 197t
Languages: ENGLISH
Descriptors: CHEMICAL POLLUTANTS; WASTEWATER TREATMENT;
CYANIDE WASTES; OXIDATION
Identifiers: E.I. DU PONT OE NEMOURS; KASTONE PROCESS
7I-O28B4 71-2TF-OO374
Effects of radiation on municipal and Industrial wastewater.
OLESEN, D. E.
Battelle Memorial Inst.. Pacific Northwest Lab.. Waterand
•j£ Waste Management Section, Rlchland, WA
^ See Citation No. 71-2TF-O373 p. 43. 1968 Publ.Yr: 1968
Languages: ENGLISH
Descriptors: RADIATION: PHENOL; CYANIDE WASTES: PETROLEUM
WASTES; MICROORGANISMS; WASTEWATER TREATMENT
Identifiers: ABSTRACT ONLY; RADIATION TREATMENT
7O-O68O7
Removal of organic nitrites from wastewater systems.
LUTIN. PHILIP A.
Hensley-Schmldt, Inc., Chattanooga. TN
See Citation No. P7O-O68OS. pp. 1632-1642, Sept. 197O
Publ.Yr: 197O
Languages: ENGLISH
Descriptors: ACTIVATED SLUDGE: CYANIDE WASTES: OXIDATION;
WASTEWATER TREATMENT
Identifiers: ORGANIC NITRITE REMOVAL
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DIALOG Flle4l- Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Set Abs > (I tern
I of 69) User 23913 23jun82
U>
*i
Ul
82-O2O5O
Treatment of Metal Containing Hastewater With Calcium
SulfIde
Kim, B.M
GE Co. Schenectady, NY
AlChE Nat. Mtg. Boston, Portland. Chicago 19BO
IN "WATER - I98O VOL. 77. NO. 2O9. pp. 39-48. Publ.Yr:'
19B1
• AICHE. 345 EAST 47 ST.. NEW YORK, NY 1OOI7
SUMMARY LANGUAGE - ENGLISH
Languages- ENGLISH
Recent promulgation of stringent environmental regulations
often requires a process of heavy metals removal more
effective than hydroxide precipitation. Sulflde precipitation
using calcium sulflde slurry was Investigated for cleanup of
heavy metals. Methods for preparing and delivering calcium
sulflde slurry were developed and several processes using such
methods are described. Wastewater samples were treated with
these processes and their applicabilities are presented.
Descriptors: wastewater treatment; heavy metals;
precipitation; water sampling; sulfur compounds; purification
82-O2O49
Precipitation of Heavy Metals With Sodium Sulflde:
Bench-Scale and Full-Scale Experimental Results
Bhattacharyya, D.; Jumawari, A.B.; Sun. G.; Sund-Hagelberg.
C.; Schwltzgebel. K
Dept. Chera. Eng. Univ. KY Lexington, KY 4OSO6
AIChE Nat. Mtg. Boston, Portland, Chicago I98O
IN "WATER - 19BO VOt. 77. NO. 2O9. pp. 3t-38, Publ.Yr:
1981
AICHE. 34S EAST 47 ST.. NEW YORK. NY 1OOI7
SUMMARY LANGUAGE - ENGLISH
Languages: ENGLISH
The results of an extensive Investigation Involving both
laboratory-scale and full-scale sulflde precipitation behavior
of heavy metals and arsenic are presented. The feasibility of
a combination of hydrox Ide-sulf Ide precipitation (at pH 8-9)
process, and a process involving sulflde precipitation (at pH
3-5) followed by lime precipitation. Is established to achieve
a high degree of separation of heavy metals and arsenic from
smelter wastewaters. For precipitation of arsenic and zinc
sulflde at pH < 5. the side reaction between dissolved sulfur
dioxide (If present In wastewater) and sulflde must- be
considered In process design
Descriptors- heavy metals; precipitation; arsenic; sulfur
compounds; separation; wastewater; feasibility studies
1980
IN "I98O NAT. CONF. ENVIRON. ENS. Publ.Yr- 19BO
ASCE, 345 EAST 47TH ST., NEW YORK. N.Y.
Languages: ENGLISH
The objective of this study was to develop an innovative
technology to precipitate and remove toxic metals from
municipal wastewater without simultaneously removing the
largely organic suspended and settleable solids. To achieve
this, an upflow expanded sand bed was used with lime feed to
nucleate precipitation of metals, calcium carbonate and
calcium hydroxylapatIte on the sand grains. This new process
could be. used for pretreatment of municipal wastewater ahead
of conventional treatment to remove heavy metals Into a
relatively small volume of granular precipitate. thus leaving
the primary and secondary wastewater treatment sludges with a
lower metals content and making them more suitable for
agricultural use.
Descriptors: Municipal; Heavy metals; Toxic materials;
Precipitation; Secondary treatment; Wastewater treatment
81-0544t
Comparative Metals Precipitation Techniques
Croy, L.P.; Knocke, W.R.
Dept. Civil Eng.. VA Polytech. Inst. St Univ.. Blacksburg,
VA
19BO Nat. Conf. Environ. Eng. New York, N.Y. dul. 8-IO.
I9BO
IN "I98O NAT. CONF. ENVIRON. ENG. Publ.Yr: I98O
ASCE, 345 EAST 47TH ST.. NEW YORK. N.Y.
Languages: ENGLISH
The treatment of metal-laden electroplating wastewaters has
been through the use of hydroxide precipitation techniques.
This process, somewhat traditional. Is relatively Inexpensive
due to the fact that the main chemical cost relates to the
purchase of lime. However, certain problems have developed
with this method of treatment: (1) ever-tIghtening discharge
standards have begun to exceed the technological capabilities
of hydroxide precipitation; (2) the use of complex Ing agents
In electroplating operation has tended to reduce the
efficiency of hydroxide precipitation systems; and (3) the
resulting metal hydroxide sludges have been shown to be
difficult to thicken and dewater. Thus, It was proposed that
alternate precipitation schemes be Investigated. Patterson et.
al . examined carbonate precipitation of metals and concluded
this process offered no significant benefits In excess of
those obtained with hydroxide precipitation.
Descriptors- Wastewater treatment; Sludge dewatering;
Precipitation; Metals; Economics
8 I-O5586
Pretreatment of Sewage for Heavy Metal Removals
Huang, J -C.; McCole. P.M.
Dept Civ. Eng . Univ. MO, Rol\a
I9BO Nat Conf Environ. Eng New York, N Y. dul .
8- IO,
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DIALOG FHe4l: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Sc* Abs) (Item 5 of 69) User239l3 23Jun82
flI-O4O25
Filtration for Treating Metal-Finishing Wastes
Yeh. C.H.H.; Ghosh. M.M.
198O Nat. Conf. Environ Eng. New York. N.Y. dul . 8-1O.
19BO
IN "198ONAT. CONF. ENVIRON. ENG." Publ.Yr: 19BO
ASCE. 345 EAST 47TH ST.. NEW YORK, N.Y.
Languages: ENGLISH
The treatment and methods for recovering metals From such
wastes Include chant lea! prectpl tat ton. cementatIon.
electrodeposl tIon. solvent extract Ion, reverse osmosis, and
Ion exchange (1). The selection of a method depends on the
concentration of metals In the wastewater and the ultimate
disposal requirement. In one recovery scheme, the "drag-out"
metals in the voluminous rInse water Is fIrst concentrated
us t ng I on exchange. Then, the concentrated metals In the
regenerat ion back-wash are precipitated and recovered as
hydrated oxides. The process water containing carry over metal
hydroxide floes from the settling and dewatertng steps Is
polished by filtration, thereby making the scheme a totally
"captive" one. Therefore, filtration using either granular
media or precoated septum forms an Integral part of 'this
treatment scheme.
Descr fptors: Industrial wastewaters; Metal fInfshtng
Industry; Wastes; Water pur If leatIon; Filtration
81-O4OI2
Ferrite Process for Treatment of Wastewater Containing Heavy
Metals
IguchI, I.; Kamura. T.; Inoue, M.
Rockwell Internal., Golden. CO Rocky Flats Plant
Publ.Yr: 198O
NTIS. SPRINGFIELD, VA
RFP-Trans-284
Languages: ENGLISH
The ferrlte process as a unique process In the field of
wastewater treatment technology Is Introduced, and the
stabl1IzatIon treatment of electrostat tc precipttator (EP) ash
generated from municipal Incinerators using this process Is
discussed. Informal Ion Is presented on the propertles of
ferrltes, the distribution and concentration of heavy metals
In and the solubility of EP ash, heavy metal leaching, an EP
ash treatment device. and the money savings possible by using
the ferrIte process as compared wl th other stablIIza tIon
methods.
DescrIptors: Wastewater treatment; Heavy metals; Ash;
IncInerators; Leaching; PollutIon dlspersal
198O
IN HI98ONAT. CONF. ENVIRON. ENG." Publ.Yr I98O
ASCE. 345 EAST 47TH ST., NEW YORK, N.Y.
Languages: ENGLISH
The presence of heavy metals In water and wastewater has
been a subject of public concern for several decades. Much has
been publIshed on the adverse effect of heavy metals to
animals and man. In order to safe-guard public health. It Is
essentla I that heavy metals be removed from the aquat1c
environment. The presence of foreign Ions that may modify the
chemical equilibrium picture of the metal solution and thereby
af feet the treatment ef f1cIenty has been essentIa 11y
overlooked. It Is too obvious that complex formation can alter
the chemical characteristics of the metal Ions and affect the
removal mechanisms regardless of the treatment process
employed. It Is therefore the purpose of this study to
Investigate the effect of complex formation on the removal of
heavy metals from water and wastewaters exmpllfled by chemical
precipitation and adsorption processes.
DescrIptors: Heavy metals; Water pollutants; Wastewater
treatment; AdsorptIon; Publ1c health; Ions; PrecIp1tat ion;
Aquat1c environments
81-O39O5
Pretreatment of Sewage for Heavy Metal Removals
Huang. J.-C.; McCole. P.M
Univ. MO. Rolla
198O Nat. Conf. Environ. Eng. New York, N.Y Jul. B-1O.
1980
IN M9BO NAT. CONF. ENVIRON. ENG." Publ.Yr: 198O
ASCE, 345 EAST 47TH ST., NEW YORK, N.Y
Languages: ENGLISH
The objective of this study was to develop an Innovative
technology to precipitate and remove tox fc metals from
municipal wastewater wlthout simultaneously removing the
largely organic suspended and settleable solids. To achieve
this, an upflow expanded sand bed was used with lime feed to
nucleate preclpitat Ion of metals, calcium carbonate and
calcium hydroxylapat1te on the sand grains. This new process
could be used for pretreatment of municipal wastewater ahead
of conventional treatment to remove heavy metals Into a
relatively small volume of granular precipitate, thus leaving
the primary and secondary wastewater treatment sludges with a
lower metals content and makIng them more suI table for
agrleuIturaI use.
DescrIptors: MunlcIpal wastewaters; Heavy metals; Toxic
materlals; PrecIpltat Ion; Wastewater treatment; Secondaiy
treatment
81-O39O6
Effect of Complex Formation on the Removal of Heavy Metals
From Hater and Wastewater
Huang, C.P.; Bowers, A.R.
Dept. Civil Eng., Univ. DE. Newark
19BO Nat. Conf. Environ. Eng. New York. N Y. Jul 8-IO.
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D(ALOG Ftlell Pollution Abstracts - 7O-B2/Apr (Copr. Cambridge Scl Abs) (Item 9 of 69) User239l3 23Jun82
Industrial wastewaters:
LO
*=.
Ul
81-OI797
Foam flotation treatment of
Laboratory and pilot scale.
Wilson, D d. ; Thackston, E. L.
Vanderbllt Univ., Nashville. TN 37235
U.S. Environmental Protection Agency. Office of Research and
Development. Environmental Protection Technology Series
Coden: EPTS8T Publ.Vr: dun I960
11lus. 9O refs.
Abs (Available fromNTIS. Springfield. VA 22161)
Languages: ENGLISH
TREATMENT CODES: D .(DESCRIPTIVE) ; I .(INVESTIGATIVE/OBSER-
VATION)
A floe foam flotation pilot plant removed Pb and Zn In
dilute aqueous solution to quite low concentrations. Design
Improvements are presented. The floe foam flotation of Zn Is
readily carried out with aluminum hydroxide (A1(OH)3) and
sodium lauryl sulfate (NLS). Chromium hydroxide Is floated
with NLS, but adsorbing colloid flotation of Cr+3 with ferric
hydroxide (Fe(OH)3) or AI(OH)3 yielded better results. Cobalt
and Nl levels are reduced to =1 mg/L by flotation with AI(OH)3
and NLS. The Mn*2 levels can be reduced to 1-2 mg/L by
flotation with Fe(OH)3 and NLS. Floe foam flotation of Cu was.
compatible with several precipitation pretreatments (soda ash,
lime, Fe(OH)3, and A1(OH)3), although modifications were
needed to prevent Interference from excessive Ca or CO3-2.
Therefore. floe foam flotation can be used as a polishing
treatment. The flotation of mixtures of Cu*2, Pbt2. and Zn+2
4as conducted using Fe(OH)3 and NLS. The flotation of simple
and complexed cyanides and mixtures of metal cyanide complexes
was also conducted with Fe(OM)3 and NLS; a pH of -5 Is
optimum. A surface adsorption model for floe foam flotation
was analyzed and accounted for the effects of surfactant
concentratIqn, Ionic strength, specifically adsorbed Ions, and
surfactant hydrocarbon chain length. (AM)
Descriptors: Flotation; Industrial wastes; Wastewater
treatment; Pilot plants; Engineering; FlocculatIon; Ions;
Surfactants; Iron compounds; Aluminum compounds; Heavy metals;
Zinc; Nickel; Manganese; Chromium; Cobalt; Copper; Lead;
Chemical treatment: Adsorption
Identifiers: floe foam flotation
wastewaters was evaluated. Five processes were compared in
bench-scale, continuous-flow equ Ipment -convent lonal lime
processing, conventional lime processing plus filtration, lime
with a sulflde polishing and filtration. lime with sulflde,
and lime with sulflde plus filtration. Wastewater samples
from 14 metal working Industries were processed through the
bench-scale equipment using all 5 processes. Reductions In
the concentrations of Cd, Cr. Cu, Nl. and Zn. plus selected
other metals, were measured by atomic absorption chemical
analysis. Capital and operating costs for the processes were
compared for 3 plant slzes-37.85 m3/d (1O.OOO gpd). 757 m3/d
(2OO.OOO gpd). and 1.893 m3/d (5OO.OOO gpd). To reduce the
levels of Cd, Cu. Nl, or Zn from a Wastewater treatment plant
using conventional lime processing. the addition of a final
filtration should be considered first. If filtration does not
achieve the desired low levels, then a sulfide polishing
process with added filtration Is recommended. If reduction of
the levels of Cr, Pb, Ag, or Sn Is required,
lime process plus flltrat >n Is recommended.
process did not significantly reduce the
metals. Details are Included on the use of
electrode for the control of sulflde additions. (AM)
Descriptors: Heavy metals; Precipitation; Wastewater
treatment; Sulfur compounds; Industrial effluents; Lime;
Filtration; Metal Industry wastes; Economics; Engineering;
Cadmium; Copper; Chromium; Nickel; Zinc; Chemical treatment
Identifiers: sulflte precipitation
the conventional
The sulflde
levels of these
specific Ion
BI-O1795
Sulflde precipitation of heavy metals.
Robinson, A. K ; Sum, J. C.
Boeing Commercial Airplane Co.. Manufacturing Research and
Development. P.O. Box 37O7. Seattle, WA 98124
U.S. Environmental Protection Agency. Office of Research and
Development. Environmental Protection Technology Series
Coden: EPTSBF Publ.Vr: dun I98O
1llus. 16 refs.
Abs. (Available fromNTIS. Springfield. VA 2216°))
Languages: ENGLISH
TREATMENT CODES: I .(INVESTIGATIVE/OBSERVATION) D
.(DESCRIPTIVE) : E (ECONOMIC/COMMERCIAL/MARKET)
The sulflde precipitation of heavy metals from Industrial
-------
DIALOG Flle41: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Scl Abs) (Item II of 69) User23913 23JunB2
U)
£*
CTi
An economical answer to
14-16,
One Cul 1 Igan
Coden: INWABK
(CASE STUDY)
reclaiming
and reusing
8I-OI778
Water and uasteuater reclamation:
Industrial wastes and pollution.
Mulvlhtll, J.
Cul I Igan (ISA. Industrial Water Reclamation,
Pkwy.. Northbrook, IL 6OO62
Industrial Wastes 26(4),
Publ.Yr: Jul-Aug 19BO
1 1 lus . no ref s .
No abs .
Languages: ENGLISH
Doc Type: JOURNAL PAPER
TREATMENT COOES: C
.(ECONOMIC/COMMERCIAL/MARKET)
Many companies are economically
heated process water, cooling water. Industrial coolants or
lubricants. wash water and detergents, and demlneral Ized
water. Systems range from SO to 3.OOO gpm. Examples of water
reclamation systems are provided. Including a large truck
terminal In New Jersey, a 120-room motel, a coal processing
plant, a rolling steel mill, a cannery, and a metal conduit
manufacturer. Oxidation, precipitation, and coagulation
properly coupled with physical processes can produce dramatic
and cost effective results. The use of simple sel f -cleaning
screens, cyclone separators. and multimedia and carbon
pressure filters can remove contaminants efficiently. Ion
exchange, membrane/ul tra-f 1 1 trat Ion, and RO processes are
finding more applications In wastewater reclamation systems;
these processes make It possible to filter In the submlcron
range and remove substances classified by molecular weight,
without chemical addition, which can cause problems In a
reclaim environment. The processes for advanced wastewater
treatment gaining the greatest acceptance fall Into the
phys leal -chemical treatment category as opposed to biological
system-,. (FT)
Descriptors: Wastewaters; Water reuse; Economics; Water
pollution control; Contaminant removal; Pollution control
equipment; Wastewater treatment
the following: precipitation, coagulation, and complexatIon:
cementation; electrolytic recovery and electrodlalysls:
solvent extraction; liquid membranes and charged membrane
ultraf11tratIon; RO; ozonatlon; foam separation; Ion exchange;
and evaporative recovery. Miscellaneous treatment methods and
adsorbents, and ultimate disposal are also discussed. (FP.FT)
Descriptors: Heavy metals; Wastewater treatment; Contaminant
removal; Precipitation; Coagulation; Dialysis; Solvent
extraction; Books; Membranes; Filtration; Reverse osmosis;
Ozonatlon; Ion exchange; Evaporation; Waste disposal
Identifiers: state-of-the-art
B1-O1768
Removal of heavy metals from wastewaters.
Beszedlts. S.; Wei, N. S.
B & L Information Services, P.O. Box 45B. Station L,
Toronto, Ontario M6E 2W4, Canada
Publ.Yr: 198O
B & L Information Services
Publ: Toronto. Ontario Canada
IIlus. numerous refs.
No abs. Price: $25.SO
Languages. ENGLISH
Doc Type: BOOK
TREATMENT COOES: D .(DESCRIPTIVE) ; A .(APPLICATIONS) ; M
.(METHODOLOGICAL) ; C .(CASE STUDY)
A state-of-the-art review describes available methods for
the removal, recovery, and disposal of heavy metals, e g.. Cd,
Cu, Fe. Pb. Hg. Mi, Ag, and Zn. Applications of the methods
are 1 J. 1 ysjr_a^ted In case studies. Methods discussed Include
-------
DIALOG Flle;
Waste treatment; Pollution control; Chemical oxidation;
Kinetics; Economics
Identifiers: rusted tin cans; Cr plating wastes
a I-00759
Utilization of waste tin cans In the control of chromium
plating wastes.
Guano. E. A. R.; Arellano, F-
Ouezon City, Philippines
Second recycling world congress: New and better uses of
secondary resources Manila. Philippines Mar 19-22, 1979
National Science Development Board of the Philippines-Asian
Recycling Association-Bureau International de la
Recuperation-United , Kingdom Society of Chemical
Industry-United Kingdom ''Conservation » Recycl Ing"-Unl ted
Kingdom Institution of Metallurgists-Illinois Institute of
Technology-United States Research Institute-United Kingdom
Institution of Production engineers-Clean Japan Center-Japan
Waste Management Association-United States Bureau of Mines
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DIALOG Mle41- pollution Abstracts - 7O-82/Apr (Copr. Cambridge Scl Abs) (Item 15 of 69) User239l3 23Jun82
CO
8I-OO682
Chemically treating wasteuater: An update.
Qckershausen. R. W.
Bergenfleld, NJ O7621
Water & Sewage Works (Reference Issue). R5I-RS2. RIIO.
Coden: WSWOAC Publ.Vr. Jun I98O
Illus. 4 refs.
Slim.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Many US and Canadian treatment plants use chemical treatment
methods to reduce P In plant effluents. Phosphorus Is
precipitated readily'by Al. fe, and Ca salts resulting In high
SS and BOD reductions. Precipitation reactions are given for
the various salts. A list of wastewater coagulants. and
statistics on P. SS. and BOD reductions using chemical
treatment are given for various treatment plants.
Polyelectrolyte Influence on SS and BOD and points where
addition of the coagulants are most effective are discussed.
The possibilities for removal of potentially harmful metals by
coagulation from drinking water may also be possible. (SS)
Descriptors: Chemical treatment; Wastewater treatment; BOD;
Suspended solids; phosphorus removal; Contaminant removal:
Precipitation; Coagulation; Salts; Metals
Identifiers: polyelectrolytes
B1-OO673
Greenville, Maine-two years later.
Cote, D. R.'
Edward C. Jordan Co.. Inc., 379 Congress St., Portland. ME
O4II1
1979 fall meeting of the New England Water Pollution Control
Association Portland. Maine Oct 22-24. 1979
New England Water Pollution Control Association
New England Water Pollution Control Association. Journal
14(1), S4-6O, Coden: JNEWA6 Publ.Yr: Apt- I98O
I refs.
No abs.
Languages: ENGLISH
Doc Type- JOURNAL PAPER CONFERENCE PAPER
When Greenville, Maine's, advanced wastewater treatment
plant could no longer meet Its discharge permit limitations,
land application was selected as the method of waste disposal.
Effluent from 3 treatment lagoons is pumped to one of two
IB-million gal storage lagoons, which allow for storage during
the winter months. Spray Irrigation to the 160-acre site
takes place during May to Nov. Based on the design flow of
0.17 mgd and a maximum application rate of f.33 tn/wk. = 7O
acres of land are required to handle the waste flow. An
additional 7 acres are required to handle precipitation which
falls on the lagoons. Effluent Is delivered to the Irrigation
system by three 5O-hp centrifugal pumps. To monitor
groundwater quality, monitoring wells are sampled before and
during the spraying season and laboratory analyses are
conducted for pH. N03-. N02-. total Kjeldahl N. total PO4-3,
C1-, specific conductivity, TOC, COD, TDS. and heavy metals.
Results after 1 spray season Indicate a slight lower-Ing of
groundwater pH, a very slight increase In PO4-3, and a small
Increase In N03-. Operational problems during the 1st year
have been minimal. (FT-)
Descriptors: Land application; Wastewater treatment;
Engineering; Biological treatment; Wastewater disposal;
Irrigation; Maine; Water pollution control
Identifiers: Greenville
8I-OO665
Wastewater treatment plant works overtime.
Frltch, G. H.
Howard R. Green Co., Green Engineering Bldg., Cedar Rapids.
IA S24O1
Water and Wastes Engineering 17(9), 7O-73. Coden:
WWAEA2 Publ.Vr: Sep I98O
11lus. no refs.
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
The Amana, Iowa, wastewater treatment plant, operated and
maintained by Amana Refrigeration, Inc. (which contributes
>8O% of the design loading), fs described. The plant's
Industrial wastes-containing a high concentration of heavy
metals-arid Its domestic wastes are segregated, with the latter
transported through gravity collector sewers to a pumping
station where It Is ground before being sent to a flow
equalization tank. A concrete splitter box divides the flow
equally to 2 aeration basins. Aerobic digestion Is
accomplished using a center flow mounted mixing system;
treated effluent Is disinfected by chlor Inat ion. Tlie , system
has a hydraulic capacity of 3OO.OOO gpd and an organic
capacity of 5IO Ib of BOOS/d. The segregated waste streams
are pretreated separately. An unusual filtering system then
removes metal hydroxides without prior clarification. The
waste streams are segregated into 2 categorles-Cr+6 wastes and
acid-alkali wastes. Hexavalent chromium Is reduced to Cr+3
with sodium bisulfite under acidic conditions. blended with
the acid-alkali waste, and neutralized to precipitate
Insoluble metal hydroxides. Ferrous sulfate agglomerates the
gelatinous waste, which is filtered through PVC filter tubes.
(FT)
Descriptors: Wastewater treatment plants; Industrial wastes;
Aerobic process; Iowa; Engineering; Biological treatment;
Heavy metals; Domestic wastes; Wastewater treatment
Identifiers: Middle Amana; Amana Refrigeration, Inc .
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DIALOG Flle41: Pollution Abstracts - 7O-B2/Apr (Copr. Cambridge Set Abs) (Item 18 of 69) User239I3 23Jun82
W
*.
(D
8I-OO648
A design study of biochemical combined uasteuater treatment
plant.
Rantala, P.
National Board of Waters, Tampere Water District. Box 297,
SF-33IO1 Tampere to. Finland
Workshop on treatment of domestic and Industrial wastewaters
In large plants Vienna. Austria Sep 3-7. 1979
Internet tonal Association on. Water Pollution Research
Progress in Water Technology 12(3), 271-278. • Coden:
PGWTA2 Publ.yr: 198O
I1lus. no refs.
Abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER CONFERENCE PAPER
The design study for upgrading the existing chemical
wastewater treatment plant In the city of Tampere (Finland)
was conducted In 1975-78. Various process modifications,
e.g., trickling filters and activated sludge combined with
chemical precipitation, were studied. Almost 1/2 of the
wastewater flow originates from Industry-text Ile, metal, and
paper board mill. Simultaneous ferrous precipitation process
was the most satisfactory treatment method. Laboratory scale
studies showed that paper board mill effluent can easily be
treated together with the municipal wastewater. The paper
board mill wastewater apparently has some good characteristics
In combined treatment. Pilot scale and laboratory scale
studies are also presented. (FT AM)
Descriptors: Precipitation; Wastewater treatment plants;
Engineering; Chemical treatment; F.lnland; Industrial wastes;
Paper Industry wastes; Metal Industry wastes; Textile Industry
wastes
Identifiers: Tampere
methods used to remove heavy metals contaminants from mill
process waters Include solvent extraction. activated carbon,
synthetic polymeric adsorbents. and electrodlalysIs. Should
recovery of the heavy metals from the resultant sludges not be
a cost-effective alternative, the sludges must ultimately be
disposed of at an environmentally safe site. Case histories
are presented which show how some members of the Canadian
mining Industry are meeting pollution control problems at
mining operations. The projects each required a significant
capital commitment and are positive contributions to Improved
environmental quality, (FT)
Descriptors: Canada; Mining; Pollution control;
Environmental protection; Wastewater treatment; Heavy metals;
Contaminant removal; Lime; Mine drainage; Acidic wastes
Identifiers: Brunswick Mining and Smelting Corp. Ltd.;
Hudson Bay Mining and Smelting Co. Ltd.
81-OO577
A glittering future foreseen for the Canadian mining
Industry.
Bhagat, T.
Water S Pollution Control. I45O Don Mills Rd., Don Mills.
Ontario M3B 2X7, Canada
WATER AND POLLUTION CONTROL 118(5), 11-12, Coden.
WPCOAR Publ.Vr: May 198O
11lus. no refs.
No abs.
Languages- ENGLISH
Doc Type: JOURNAL PAPER
The $12 bllIlon/yr- Canadian mining Industry has undertaken a
mul11-bj11 ion dollar development program of new mines,
expansions, and re-openings. Hundreds of millions of dollars
are also being spent on smelter construction. plant
Improvements, and environmental control. An estimated
. $45O-$55O million was spent on environmental control and
Improvement between 1971 and 1975. Treatment techniques
available for removal of heavy metals from mine and mill
wastewaters Include precipitation, cementation. Ion exchange.
charged tnombrane vil traf 11 trat ton. and ozonation. Other
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DIALOG Ft1e41- pollution Abstracts - 7O-82/Apr (Copr, Cambridge Scl Abs) (Item 2O of 69) User239!3 23Jun82
the overland flow (grass
U)
Ln
O
81-OO4B3
Removal of pollutants In
filtration) system.
Scott. T. M.; Fulton, P. M.
Melbourne and Metropolitan Board of Works Farm. Werrlbee,
VIctor ia, Austral la
Developments in land methods of wastewater treatment and
uti1 I sat Ion Melbourne, Austral la Oct 23-27. 4978
International Association on Water Pollution Research-Austr-
alian National Committee of the International Association on
Water Pollut ion Research-Austral Ian Water and Wastewater
Association-International Association of Hydraulic Research~M-
eIbourne and Metropo11 tan Board of Works-UnIver s11 y of
Me Ibourne-Commonwealth Scientific and Industrial Research
QrganlsatIon
PROGRESS IN WATER TECHNOLOGY 11(4-5). 3O1-313. Coden:
PGWTA2 Publ.Yr: 1979
11lus. refs.
Abs.
Languages- ENGLISH
Doc Type- JOURNAL PAPER CONFERENCE PAPER
In the overland flow system at Melbourne, Australia, the
sewage Is given primary sedimentation and passed to Irrigation
areas. A design hydraulic loading on the system of O.23
ML/ha/d can be achieved ' with corresponding BOD5 and SS
loadings of 9O and 4O kg/ha/d. respectively. Both BOD and TOC
decayed In exponential form from mean levels of 5O7 mg/L and
35O mg/L to 24 mg/L and 65 mg/L. respectively. with TOC
approaching a non-decaying residual of 56 mg/L. Suspended
solids reduction was of an exponential nature with a residual
of 22 mg/L. Methylene Blue Acttve Substances showed a similar
decay to levels <1 mg/L. The removal of N was complex and to
some extent unexplaIned. The main N losses could be
attributed to plant uptake and stripping of NH3 from the
wastewater. Organic N loss followed a 1 Inear regression.
Smal1 amounts of NO3- appeared late In the system. The
overa 11 reductIon In N concentrat Ion was 3O%. Little P
removal was evident, with the system exhibiting an apparent
Increase and then a decrease to about the original level.
Precipitation of heavy metals as suI fides In the anaerobic
section of the system was rapid and generally linear with very .
small residuals of unknown organic complexes. The overland
flow system Is effective In the removal of BOOS, SS, and heavy
metals but only moderately efficient In the removal of
nutrients. (AM)
Descr tptors: Pollutant removal; Wastewater treatment; Land
applteat ion; Grasses; N1trogen; phosphorus; Uptake; F11tratIon
; Nutrients; BOD; TOC; Suspended solids
Ident 1flers: overland flow; grass f11tratIon
25NQAA Publ.Yr: 198O
11lus refs.
Sum.
Languages: ENGLISH
Convent ional methods for reducIng Cd concentrat ions in
wastewater Involve neutralization processes using hydroxides
or carbonates followed by separation of the solids by gravity
sedtmentatIon or f M tratIon. On a sroaller scale, su)fIde
precipitation, Ion exchange and neutralization precipitation,
RO, Ion flotat ion, liquid-liquid extraction, electrolysis, and
cementation processes can be used. Electrostatic and cloth
filters and wet scrubbing devices find application In removal
of airborne Cd. To reduce the Cd In dumps. the proportion of
Cd In the refuse must be reduced, the amount of refuse must be
reduced, or Cd-containing products must be produced. Studies
conducted by the Bavarian Industrial Institute have assessed
the efficiency of neutralization and carbonate precipitation
techniques In pure solutions and In effluent samples from an
electroplatIng works. Costs for reducIng Cd emissions in
water and air are also presented. (FT.MS)
Descriptors: Cadmium; Heavy metals; Economics; Air pollution
control; Water pollutIon control; Sedlmentat ion; F11ters;
F11tratIon; Preclpt tat Ion; Ion exchange; Electrochemistry;
Scrubbers; PollutIon control equipment; Sulfur compounds
Identifiers: carbonates; hydroxides
8O-O8496
Methods and costs of preventing cadmium emissions.
Rauhut, A.
Landesgewerbeanstalt Bayern. Nuremberg, Federal Republic of
Germany
COMMISSION OF THE FUROPCAN COMMUNITIES. PUBLICATION Coden:
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DIALOG F1te41: Pollution Abstracts - 7O-82/Apr (Copr Cambridge Scl Abs) (Item 22 of 69) User239l3 23Jun82
U)
1 cn
8O-O84O3
Toxic control-the trend of the future.
Foess. G. W. ; Ericaon. W. A.
CH2M HILL, 2929 N. May-fair Rd. , Milwaukee. W! 53222
WATER AND WASTES ENGINEERING 17(2). 21-27, Coder-:
WWAEA2 Pub!.Vr: Feb I9SO
11 Jus. refs.
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Federal regulations have been promulgated to control the
quantity of toxics that can be discharged to the public sewers
by Industry and the quantity that can be released by publicly
owned treatment wopks (POTW) to the air, land. and aqueous
environment. On June 26, 1978, EPA publIshed Its regulatory
program governIng Indus trla I dIscharges Into POTW. EPA
published water quality criteria for the 65 priority toxic
pollutants In 1979. On Sept. 13, 1979. EPA published
crIterla for acceptable sol Id waste disposal, Including the
disposal and utilization of wastewater treatment plant sludge.
Air emissions of toxics from POTWs are governed by OSHA air
quality standards and by applicable requirements developed for
state Implementation plans under the Clean Air Act. Virtually
a 1 I municipal wastewaters contain most of the prior I ty
pollutant metals and some of the organlcs. Investigations of
the performance and removal mechanisms of unit processes with
respect to toxics have been performed. Unit processes
discussed Include primary sedlmentatIon, act Ivated sludge,
chemical oxldatIon, chemical preclpltat ion and coagulatIon,
activated carbon adsorption, chelatlon, Ion exchange. RO.
Incineration, and wet-air oxidation. (FT)
DescrIptors: Wastewater treatment; Toxic mater(a)s;
Legislation; Incineration; Sedimentation; Activated sludge;
Oxidation; Chelatlon; Precipitation; Coagulation; Activated
carbon; Ion exchange; Industrial effluents; Sludge disposal;
Po))utant removal; Reverse osmosis; Water quaIt ty acts;
F edera1 regu1a 11ons
Identifiers: Clean Water Act
removed In the ground by preclpltat Ion. While aerobic
conditions in the ground are of special advantage. biological
oxidation of organlcs also occurs under anoxlc conditions If
N03- Is present1. However, organochlorIne compounds are
difficult to remove In the ground If their C1 content Is
excessively high. Other treatment steps have to be used
before or after ground filtration to remove nonbfodegradabIe
organlcs or to alter them Into biodegradable ones. Along the
Rhine River, bank filtration generally removes 75% of the
dissolved organ(cs, and It Is onIy as a result of bank
f11tratIon that later treatment steps Insure a high qua I 1ty
drink Ing water. For this reason, all water utilities In
Germany that rely on surface supplies use ground filtration in
one way or another as part of their treatment scheme. (FT)
Descriptors: Filtration; Rivers; Water treatment; Rhine
River; Contaminant removal; Potable waters; Pollution control;
Fresh waters; FederaI Republie of Germany; Water reuse;
Organic compounds; COD; Organochlorine compounds; Wastewater
treatment
Identifiers: rlverbank filtration
8O-O7627
Experience with rlverbank filtration along the Rhine River.
Sonthelmer, H.
Univ. of Karlsruhe, Engler-Bunte Inst.,
Federal Republ1c of Germany
AMERICAN WATER WORKS ASSOCIATION. JOURNAL
Coden: JAWWA5 publ.Yr- Jul f98O
11lus. refs.
Abs,
Languages. ENGLISH
Doc Type: JOURNAL PAPER
A comparison of dissolved organic chlorine
values found In the Rhine and In bank-filtered water shows a
substantlal reduct ton In the overa11 organic content of the
bank-f11tered water. There Is a nearly constant removal of
=1O mg/L COD and 3.5 mg/L DOC. and removal ts apparently
Independent of the rIver wa ter qua Ii ty. Heavy meta Is can be
0-75OO Karlsruhe.
72(7) , 386-39O,
(DOC) and COD
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DIALOG Flle4l. Pollution Abstracts - 7O-82/Apr (Copr. Cambridge ScI Abs) (Item 24 of 6,9) User23913 23jun82
U>
Ul
U)
BO-O745B
Movement of heavy metals Into » shallow aquifer by leakage
from sewage oxidation ponds.
Nlssenbaum. A.; Wolfberg, A.; Kahanovlch, V.: Avron. M.
Welzmann Inst. of Science, Isotope Dept., Rhovot, Israel
WATER RESEARCH 14(6). 675-679. Coden: UATRAG
Publ.Vr: I98O
(Ilus. refs.
Abs.
Languages. ENGLISH
Doc Type: JOURNAL PAPER
The concentrations of Mn, Nl. Cu. Cd. and Cr were measured
In a shallow perched groundwater aquifer which underlies the
Dan Region Sewage Reclamation Project (Israel). The
contribution of effluents to the groundwaters has been
evaluated on the basis of Cl- concentration. Groundwater
containing >6O% effluents showed a lOO-fold decrease In Cu and
Mn 65O jn away from the ponds. as compared with the near ponds
samples. Nickel and Cd showed only a small decrease In
concentration over ISO m, and then stayed constant. The
concentrations of Cu and particularly of Mn In the
groundwaters near the oxidation ponds Is equivalent to or
greater than in the ponds themselves. Copper and Mn are
mobilized from the precipitated sludge Into the Interstitial
waters. They percolate Into the groundwater near the ponds
and then are precipitated by Increasing aeration during the
movement of the water away from the pond area. Cadmium and Nl
form stable soluble organic chelates which are only slightly
removed by Interaction with the sandy soil of the aquifer. (
AM)
Descriptors: Groundwater; Aquifers; Israel; Effluents; Heavy
metals; Wastewater treatment plants; Sewage; Lagoons;
Activated sludge process: Manganese; Nickel; Copper; Cadmium;
Chromium; Chlorine compounds
Identifiers: Dan Region Sewage Reclamation Project
BO-O6157
Treatment of dilute metal effluents In an electrolytic
preclpltator.
Bryson, A. W.; Dardls. K. A.
Univ. of the Witwatersrand. Dept. of Chemical Eng., Jan
Smuts Ave.. Johannesburg 2OOI, South Africa
WATER S. A 6(2). 85-87. Coden: WASADV Publ.Vr. Apr
I98O
Illus. refs.
Abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Excessive concentrations of metals In industrial effluents
may adversely affect the performance of sewage purification
works. Although there Is existing technology for treating
these effluents. it has not found wide application due to
costly equipment and chemicals and the absence of sufficient
space on most plants. The feasibility of removing these
metals from dilute solutions by electrolytic precipitation
using a partlculate electrode Is Investigated A test plant
was constructed which was compact, did not require the
addition of chemicals and could be operated by unskilled
personnel. The plant was Installed at an electroplating works
on the WItwatersrand and was successful in treating wash
waters containing Cu, Nl, Cr, and Zn. (AM) '
Descriptors: Heavy metals; Electric collectors; Industrial
effluents; Wastewater treatment; Nickel; Nickel; Chromium;
Copper; Zinc; Engineering; South Africa: Sewage treatment;
FeaslbllIty studies
Identifiers: Johannesburg: electrolytic preclpltator
8O-O6II6
Bench-scale testing for residual waste treatment.
vuceta. J.; Anderson, J. R.; TeKlppe, R. J.; Calkins, R. J ;
Bishop, W. J.
James M. Montgomery Consulting Engineers. Inc.. 555 £.
Walnut St., Pasadena, CA 9IIOI
5Oth annual conference of the Water Pollution Control
Federation Philadelphia, Pennsylvania Oct 2-7. 1977
Water Pollution Control Federation
WATER POLLUTION CONTROL FEDERATION. JOURNAL 5K1O).
2366-2383, Coden: JWPFA5 Publ.Vr: Oct 1979
Illus. refs.
Eng.. Fr.. Oer., Port., Span. abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER CONFERENCE PAPER
The most effective technologies for centralized treatment of
various Industrial residual wastes generated In Ventura
County, California, were determined. Steps required for a
successful treatment of metallic wastes Include cyanide and
cyanate oxidation, Cr (VI) reduction, hydroxide and sulflde
precipitation, coagulation and flocculation. and filtration.
Ion exchange and carbon sorptlon are not usually required.
Coagulation and flocculation of nonmetaltlc toxic wastes.
followed by filtration and carbon sorptlon. Is more effective
In the removal of toxic nonmetalllc substances from
wastewaters than foam fractlonatIon coupled with carbon
sorptlon. A batch mode of operation is superior to continuous
flow. (AM)
Descriptors: Waste treatment; Filtration; Heavy metals;
Coagulation; Flocculation; Industrial wastes; Wastewater
treatment; Cyanides; California; Oxidation; Precipitation:
Toxic materials
Identifiers, bench-scale testing; Ventura County
-------
DIALOG Flle4i: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Scl Abs) (Item 27 of 69) User239l3 23JunH2
U>
8O-O4673
Hydroxide/modified sulflde precipitation system removes
heavy metals from effluent.
Rogers, K. W ; Wojtklewlcz. J. R.; Marls. J.
Chemical and Environmental Services
CHEMICAL PROCESSING. CHICAGO 42(IO), 32-34, Coden:
CHPCAI Publ.Yr: Sep 1979
I Ilus. no ref s.
No abs.
Languages: ENGLISH
Doc Type. JOURNAL PAPER
A modified method ofjsulflde treatment, where the sulflde
Ion concentration Is easily and Inexpensively controlled so
that the feed matches the sulflde demand of the uastewater. Is
presented. The formation of colloidal precipitates Is avoided
In this treatment for heavy metals In effluent waters. The
modified sulflde process uses an Insoluble sulflde salt, and
Is used In conjunction with standard hydroxide precipitation.
The system functions automatically and requires very little
chemical attention. The cost runs -$2.44/1 .OOO gal of
wastewater. The sys'tem has met EPA requirements, saved water.
reduced the hydraulic load on the municipal system. avoided
municipal user charges, and protected the environment. (FT) •
Descriptors: Heavy metals; Pollutant removal; Effluents;
Wastewater treatment; Sulfur compounds; Precipitation
Identifiers: hydroxIde/sulfIde treatment
8O-O359O
Sludge application: Remove heavy metals two ways.
LewandowskI, G. A.; Abd-EI-Bary, M. F.
New Jersey Inst. of Technology, Newark, NJ O7IO2
WATER & SEWAGE WORKS 127(1), 44-45, Coden: WSWOAC
Publ,Yr: Jan 198O
I Ilus. refs.
No abs
Languages. ENGLISH
Ooc Type: JOURNAL PAPER
To develop agricultural use of municipal sludge as a means
of disposal, methods of removing heavy metals from the sludge
were Investigated. Heavy metals can be eliminated from sludge
at the municipal treatment plant by physlcochemlcal means,
following the primary settler, or treating the combined sludge
prior to digestion. Heavy metals can also be removed at their
source by activated carbon adsorption, adsorption on clay. Ion
exchange, cementation, or electrolysis. The most commonly
used technique Is chemical precipitation as an hydroxide.
carbonate. or sulflde The sequence for heavy metal
precipitation generally Involves equalization, precipitation,
clarification, filtration, and land disposal of the filtered
sludge or metals recovery. Since the volume of Wastewater Is
much smaller at the source than at a receiving municipal
treatment plant, capital and operating costs for heavy metals
removal are less at the source In most cases. The potential
for metals recovery and reuse should be higher at the source
of waste generation, and as disposal costs rise, recovery may
become much more attractive. (FT)
Descriptors: Land application; Sludge disposal; Heavy metals
; Pollutant removal; PhysIcochemicaI treatment; Activated
carbon; Adsorption; Precipitation; Economics
Identifiers: metals recovery
8O-O2682
Management of radlonuclIdes from reprocessing plant gaseous
effluents.
Zabaluev. Y. V.
IAEA. Dlv. of Nuclear Safety and Environmental Protection,
Waste Management Section, Kaerntner Ring II, P.O Box 59O.
lot I Vienna, Austria
INTERNATIONAL ATOMIC ENERGY AGENCY. BULLETIN 21(1), 23-31
Coden: IAEBAB Publ.Yr: Feb 1979
Hlus. refs.
ISSN: 0020-6067
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
TREATMENT COOES: 0 .(DESCRIPTIVE) ; M .(METHODOLOGICAL)
Although current practice at reprocessing plants Is to
discharge most of the gaseous radionuclIdes Into the
environment, methods exist for removing the nuclIdes from the
gas stream prior to discharge. Proposed processes for 85Kr
removal Involve cyrogenlc distillation, fluorocarbon
absorption, adsorption, diffusion, and selective membrane
processes. Liquid scrubbing and sorptlon on solid materials
are 2 alternative methods for trapping 1291 from off-gases.
Options developed for tritium recovery Include volatilization
and collection prior to dissolution, isotroplc enrichment and
collection from liquid effluents. and aqueous recycle with
removal and solIdfIcatIon of a small side stream. For
storage, 85Kr should be encapsulated, preferably embedded In a
metal matrix while 1291 may be held In precipitates from
scrubbing liquids. In Ag molecular sieves and other solid
absorbents, or In charcoal filters Impregnated with doping
agents. Wastewater containing tritium may be stored In sealed
containers prior to disposal, while more concentrated forms of
tritium should be Immobilized In a durable solid. (FT)
Descriptors: Radioactive wastes; Waste management; Krypton;
Iodine; Radio Isptopes; Waste disposal; Nuclear ' fuels;
Radioactive effluents; Gaseous wastes; Hydrogen
Identifiers: fuel reprocessing plants; kr-85; 1-129; removal
processes; tritium
-------
DIALOG Flle41 Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Set Abs) (Item 3O of 69) User23913 23jun82
Ul
Ul
BO-O1928
Methods for neutralizing toxic electroplating
rInseuater-part 3.
Martn, S.; Trattner, R. B.; Cheremlslnoff. P. N.
New Jersey Inst. of Technology, Newark. NJ O71O2
INDUSTRIAL WASTES 25(5). 22-23. Coder! • INWABK
Publ Vr: Sep-Oct 1979
refs.
ISSN. O537-5525
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
TREATMENT CODES: M .(METHODOLOGICAL) ; D .(DESCRIPTIVE)
In the removal of Cr from electroplating rlnsewater, the
treatment Is Intended to convert Cr+6 to Cr+3. and then to
precipitate It as the Insoluble hydroxide. The reduction Is
performed with sodium bisulfite (NaHS03) at a pH of 2.O. with
the precipitation occurring at pH 8.5, using caustic for the
pH adjustment. A pH recorder-control Ier Is used to measure
the pH and add the NaHSO3 under automatic oxidation-reduction
potential (ORP) control. When the ORP Indicates a value of
3OO mV. the chromates are reduced. and the addition Is
stopped. After 15 mln of mixing, the pH Is adjusted to 8.5,
and after =15 mln of additional stirring, the precipitated
hydroxides are allowed to settle. In the removal of cyanide
and alkali wastes, the cyanides are 1st converted to cyanates
with a 15% solution of sodium hypochlorlte (NaOCI) at a pH
>IO, and are then oxidized to N and CO2 with the NaOCI
solution at pH 8.5. When the ORP reaches a range of 350-40O
mV (Indicating that all cyanides have been oxidized) the
wastewater changes from a clear, transparent green to sky
blue. Complete oxidation takes =IO mln. The treated water Is
allowed to settle for -2 hr, during which time small amounts
of metals, e g., Cu and Ag, will be precipitated as Insoluble
hydroxides (FT)
Descriptors. Industrial wastes; Wastewater treatment;
Chromium; Cyanides: Precipitation; Chemical oxidation;
Reduction; pH; Metals; Toxic materials
Identifiers: electroplating rlnsewaters; automated control;
sodium bisulfite; sodium hypochlorite; hydroxides
Rlnsewaters from the electroplating process contain high
concentrations of cyanides and chromates. To comply with US
EPA discharge standards several chemical processes have been
developed to destroy the cyanides and chromates. For cyanide
the most common form of treatment Is alkaline chlorlnatlon
oxidation by sodium hypochlorlte or C12 plus sodium hydroxide
addition to the waste. Electrolytic decomposition and
ozonatlon are also effective treatments for cyanide wastes.
Chromium waste treatment Involves reduction and precipitation
processes. Reducing agents Include ferrous sulfate. sodium
btsulfate, and sulfur dioxide; neutralizing compounds Include
lime slurry or caustic. Batch treatment Is necessary In shops
having a total dally flow OO.OOO gpd, whereas continuous
treatment Is recommended for volumes >3O,OOO gpd. (FT)
Descriptors: Metal finishing Industry wastes; Cyanides;
Chromium compounds: Wastewater treatment; Contaminant removal;
Chemical oxidation; Neutralization; Reduction
Identifiers: electroplating
toxic electroplating
8O-O1866
Methods for neutralizing
rInsewater-part 1.
Marin. S.; Trattner. R B ; CheremlsInoff. P. N.; Perna, A.
J.
New Jersey Inst. of Technology, Newark, NJ O71O2
INDUSTRIAL WASTES 25(3), 50-52. Coden- INWABK
Publ.Vr. May-Jun 1979
11 Ius. no refs
ISSN 0537-5525
No abs.
Languages ENGLISH
Doc Type. JOURNAL PAPER
TREATMENT CODES: M .(METHODOLOGICAL) ; A .(APPLICATIONS) ; D
(DESCRIPTIVE)
-------
DIALOG F11e41: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Scl Abs) (Item 32 of 69) User23913 23Jun82
8O-O1B25
Plant variables determine phosphorus removal methods.
King. P. H ; Haze!wood. R. D.; Tllley. A. R.; Randall. C. W.
Virginia Polytechnic Inst. and State Univ., Dept. of Civil
Eng.. Blacksburg. VA 24O6I
WATER & SEWAGE WORKS Reference Number. R-82-R-86,
Coden: WSWOAC Publ.Yr. 1979
11 Ius. refs.
ISSN: 0043-1125
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
TREATMENT CODES', D .(DESCRIPTIVE) ; M .(METHODOLOGICAL)
Chemical preclpltat Ion methods utilizing time and alum
metal lie salts added prior to pr Imary sedlmentatIon and as
add-on tertiary treatment with mixing and sedimentation are
discussed. The primary and tertiary sludges were generated
after conventional treatment processes and collected after
secondary clarification but before chlorInatton. Lime and
alum were added to separate samples and mixed for 20 and 3O
mtn, respectively. The mixture was allowed to settle 1 hr
before analysis. Phosphorus content was determined by the
vanadomoIybdophosphoric acid colortmetrIc method and total
solids by gravimetric analysis. Sludge dewaterlng properties
were determined by the Buchner funnel specific resistance test
and by gravity drainage In sand drying beds. Primary sludges
had greater dewaterlng properties than tertiary sludges, and
alum sludges, whether primary or -tertiary, were more difficult
to dewater than lime sludges. Optimum mixing time for alum
sludge was 1.5 mln, while for primary lime sludge,, resistance
decreased over a range of mixing times. In tertiary systems,
alum sludge mixing time was optimum after 15 sec, but mixing
time had little effect on lime sludges. Polymer treatment
generally accelerated the gravity drainage phase of sand-bed
dewater ing, whlle air drying rates were unaffected by the
polymer. (FT)
Descriptors: Chemical treatment; Preclpi tat ion; Wastewater
treatment; Sludge dewaterIng; Aluminum compounds; L(me; •
Polymers; Phosphorus removal
metallic ions or both kinds of Ions, depending on the needs of
the operation. Loaded resins are not regenerated in the
electroplating operation but are collected by an operating
company and exchanged for regenerated resins, thereby
eliminating the need to regenerate Ion exchanger resins and to
treat the eluates in a detoxicatlon plant. The essential
sys tern component Is the modu1ar 1on exchanger co1umn with
easI1y replaced cartridges regenerated In a central
Installation when they are charged. The cartridges are easy
to handle and do not require special training for monitoring
and operation. The system can be used for automatic water
recyclIng systems, maintenance of process baths, pre- and
after-treatment baths, separate treatment of rinse baths for
metal recovery, and eltmtnat ton of toxic metals or
complex-forming agents. The Dornter-developed system offers
the following advantages: modular concept Ion, smal1
dimensions, low cost. easy hand!Ing and high operat tonal
safety, and maintenance of prescribed wastewater quality. (
SS.FT)
DescrIptors; • Wastewater treatment; Economics; Metals;
Recycling; Ion exchange; Preclpltat ton; Metal industry;
Technology
XdentIflers: electroplatIng operat ions; modular ion
exchanger column
8O-OO418
RMA-a waste water treatment system for electro-pSating
operations.
Anonymous
Coden: DOPOAC Publ.Vr:
DORNIER POST No. 2. 31-33.
1979
11lus, no refs.
ISSN: OO12-5563
No abs.
Languages. ENGLISH
Doc Type: JOURNAL PAPER
Dornier has developed a cost-effective system for recycling
metals from wastewater which brings wastewater treatment and
metal recycling wlthin the reach of medium and smal^
electroplatIng operat ions . Metals are recycled us Ing high
quant 11 ies of wastewater treated by precIpI tat Ing only
-------
DIALOG FI1e41. Pollution Abstracts - 7O-8?/Apr (Copr. Cambridge ScI Abs) (Item 34 of 69) User239l3 23jun82
U>
U1
79-O4I65
Heavy metal removal with completely nixed anaerobic filter.
DeWalle. F B.; Chian. S. K.; Brush. J.
Univ. of Washington. Dept. of Environmental Health, Seattle.
WA 98IO5
WATER POLLUTION CONTROL FEDERATION. JOURNAL 51(1). 22-36,
Coden. JWPFAS Publ.Vr: Jan. 1979
11lus. refs.
Eng.. Fr., Ger. . Port.. Span, abs.
Languages: ENGLISH
Doc Type- JOURNAL PAPER
A completely mixed anaerobic filter was subjected to various
leachate loadings. At each detention time samples were taken
from the Influent, effluent, and other sampling ports for AAS
heavy metal analysis. The filter was effective In removing
heavy metals. the effectiveness Increasing with Increasing
metal concentrations in the effluent. The metals were
' precipitated as sulftdes, carbonates, and hydroxides and were
removed from the filter as a slurry. With decreasing
hydraulic detention time the metal removal percentage
decreased while the metal content In the bottom slurry
Increased. Most metals were removed In the lower portion of
the filter. Copper was associated with the largest solids
particles, but also showed the largest variation In
concentrations and largest decrease In removal efficiency at
decreasing hydraulic detention times. (AM) T
Descriptors: Copper; Zinc; Nickel; Chromium; Filters;
Anaerobic systems; Heavy metals: Wastewater treatment
Identifiers: metal removal
79-O416O
Influence of pH on purification of zinc-containing solutions
by electrocoagulatIons
Zhurnal Prlkladnol Khtmii. 51(6).1335-1239, June i978
Gnusln. N P.; Vltul'skaya, N. V.; Zabolotskaya. L. I.-, et
al .
Kuban' State Univ.. Uttlsa Sedlna 4, Krasnodar Kraevoj, USSR
JOURNAL OF APPLIED CHEMISTRY OF THE U.S.S.R 51(6).
1187-1189. Coden: JAPUAW Publ.Yr: 1978
11lus. refs. (Some In Russ.)
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
The effectiveness of electrocoagulatIon is determined by the
product of the anodic current efficiency, and the coefficient
K. which Is a measure of the tendency of Zn Ions to
coprecIpitat Ion with iron hydroxide. An Investigation Is
reported which was made to determine the quantitative
dependence of these 2 quantities on the solution pH.
Experiments were conducted In a model galvanizing electrolyte
containing 2OO g/L of zinc sulfate, 3O g/L of sodium sulfate.
and 30 g/L of aluminum sulfate diluted with distilled water to
a Zn-ion concentration of 4O mg/L. The solution pH was varied
from 3 to 7 by adding either hydrochloric acid or caustic
soda. Experiments were performed at various current densities
and flowi-ates. The current efficiency was determlnpd from the
amount of Fe dissolved, and the coefficient K from the ratio
of Zn:Fe concentrations in the precipitate. The
Investigations at various Initial pH values Indicated that the
current efficiency depends on both the quantity of
electr Icl ty/unlt volume, and on the solution pll. but that the
coprecfpltat Ion of the 2 metals Is Independent of the pH. (FT
)
Descriptors: Coagulation; Precipitation; Zinc; Iron; pM;
Electrochemistry; Wastewater treatment
Identifiers: electrocoagulation
79-O3I45
Treatmente of base metal mine drainage at pilot scale.
Huck, P. M.; LeClalr, B. P.
CANADA. ENVIRONMENTAL PROTECTION SERVICE REPORT SERIES.
TECHNOLOGY DEVELOPMENT REPORT Coden. TORSDY 94 pp
Publ.Yr. July I97B
11lus. - refs.
Eng.. Fr. abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
The suitability of conventional precipitation and
sedimentation techniques to remove Pb, Zn. Cu and Fe from
various types of acid mine drainage in Northeastern New
Brunswick was investigated at pilot scale. A O.3-1.O L/sec
pilot plant was designed for lime and polymer addition.
flocculatIon, clarification, filtration and sludge recycle.
Optimum operating ranges were determined for the Individual
unit processes and data on attainable levels of extractable
and dissolved metals are presented. Experiments were also
conducted to compare two-stage lime neutralization to single
stage neutralization and to Investigate sludge dewaterablI Ity
and effluent toxlcity. Average extractable metal levels
attained as clarlfler overflow concentrations were O.25 mg/L
Pb. O.36 mg/L Zn, O.OS rog/L Cu and O 28 mg/L Fe. Further
reductions were achieved by sand filtration. Dissolved metal
levels in the clarlfler overflow were about equal to
extractable metal levels and were unaffected by further
polishing. No performance were advantages discerned using
two-stage neutralization compared to single stage. Sludge
recycle proved to be an effective technique to Increase
clarlfler sludge density. Sludge dewater Ing tests Indicated
that the sludge could be effectively dewatered by vacuum or
pressure filtration. Bloassay tests showed median lethal
times for salmonid test fish to be consistently In excess of
the 96 hr maximum test period provided that the pH was
adjusted to near neutral values before tests were conducted.
(AH)
Descriptors: Mine drainage; Lead; Zinc; Copper; Iron; Pilot
plants; Wastewater treatment; Canada
Identifiers- New Brunswick
-------
DIALOG File4l Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Set Abs) (Item 31 of 69) User23913 23jun82
(J\
03
79-O3O64
Methods of estimating sludge from power plant systems.
Kuppusamy, N.
Puerto Rico Water Resource Authority, PR
INDUSTRIAL WASTES 24(3), 32-33. Coden: INWABK
Publ.Yr: May-June 1978
iIlus. no refs.
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Construction and operation of wastewater treatment plants In
power generating station will result If Industry Is to comply
with existing NPOES pemlts. Estimation of the resultant
sludge from such a chemical treatment system will enable an
Industry to preplan a method for handling the sludge. The
sludge obtained by the treatment of continuous wastes can be
computed by assuming a conservative value of I.OOO ppm of TSS
In the original effluent before treatment. The quantity of
dry sludge will be 8.34X10-3 Ib/gal of waste treated, a
negligible amount compared with the sludge obtained due to the
processing of Intermittent waste from air preheater washings,
fan washings, and waterside and fireside cleaning of the
boiler. There Is no hard and fast rule for calculating sludge
amounts from treatment of Intermittent wastes because of their
heavy metal contaminants. To establish a relationship between
the concentration of Fe In the effluent and the resulting
sludge. air preheater wash composite samples were collected
from the cleaning of various units of 4 fossil plants. After
adjusting pH to 8 5 with calcium hydroxide to precipitate
heavy metals, the quantity of resulting sludge was estimated.
The relationship was linear for Fe concentrations up to 2O.OOO
ppm. The same relationship was applicable for sludge
calculation due to treatment of fan washings. Estimation of
the sludge due to the chemical cleaning of the boiler was done
in the same way for all phases of the cleaning except the Cu
removal phase. This curve can be used in conjunction with the
other data to predict sludge quantities. (FT)
Descriptors: Electric power plants; Sludges; Wastewater
treatment plants
79-O3O61
Industrial applications of ozone.
Stopka, K.
U.S Ozonalr Corp.
INDUSTRIAL WASTES 24(3). 23-24. Coden: INWABK
Publ.Yr: May-June 1978
I Ilus. no refs
No abs.
Languages- ENGLISH
Doc Type. JOURNAL PAPER
European and Japanese fisheries use ozone (O3) for
sterilization purposes. Improved treatment of Industrially
contaminated wastewater is obtained by enriching the air used
for oxygenatlon with 5% 03. Sulfurlc acid is added to pH 2-4.
along with .O5-1 g of ferric or aluminum chloride, followed by
alkalIzation to pH 6 5-7.5 with lime. This precipitates most
organlcs. solvents, oils, resins. fatty esters, and toxic
metals. At a retention time of 6-IO mln, 2O mg/L of O3
usually will produce an effluent acceptable to most
environmental requirements. Cyanide decomposition can be
speeded up by as much as 1OO times through Cu catalysis. With
appropriate pretreatment. ozonation of composite wastewater
from a resin manufacturer reduced phenol from 272 to O,
formaIdehyde from 376 to O. and total SS from 2.47O to t6O
mg/L. The COD in acidic wastewater from an edible oil
processing plant was reduced from 1O.5OO to 32O mg/L. a 96%
reduction. For industries requiring ultrapure water. the
treatment system consists of an electrolytic coagulator tank.
a 201 filter, an Ion exchange bed. an O3 system with Tl, O3
concentration from predried air and efficient contactors able
to dissolve Instantly 1 mg/L O3 Into the liquid, and an
activated carbon Filter and O.2I filter on discharge.
Incorporation of an ozonation unit before a RO unit can
prevent membrane clogging. (FT)
Descriptors: Ozonation; Wastewater treatment; Engineering
79-O3O6O
Diesel component plant cuts water consumption with reuse and
recycling.
Anonymous.
INDUSTRIAL WASTES 24(3). 2O-22, Coden: INWABK
Publ.Yr: May-June t978
11lus. no refs.
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
About 9O.OOO GPD of plant wastewater required pretreatment
before discharge Into the sanitary sewer, including 3.OOO gal
of softener regenerants, 3.2OO gat of boiler blowdown. 63.8OO
gal of process rinses. and 2O.OOO gal of oil water from floor
washings, spent coolants, and wash tanks. A batch process Is
used for water treatment. The system Includes four tB.OOO gal
primary holding tanks. Each batch Is treated chemically to
remove oils and precipitate metals as hydroxides. The best
results were obtained when alum was used to coagulate the oil
and lime to neutralize the remaining liquid and precipitate
heavy metals. The alum works even under anaerobic conditions.
The wastewater treatment facility consists of a grit chamber,
a raw waste wet well, 4 batch tanks for waste treatment. a
9.5OO gal storage tank for waste oils. a 9.OOO gal storage
tank for sludge. and 2 outside drying beds. The plant's
average monthly consumption of 16 mgd Is 4O% below the
original estimates, at a savings of about $6.OOO/mo. (FT)
Descriptors: Industrial effluents; Effluent treatment; Water
reuse; Water recycling: Wastewater treatment; Automotive
Industry wastes
Identifiers: dlesel component Industry
-------
DIALOG FUe4l Pollution Abstracts - 7O-82/Apr (Copr Cambridge Scl Abs) (Item 4O of 69) Usec-23913 23Jun82
CO
Ul
79-O3OOO
Advanced wastewater treatment nature's way.
Ember. L R,
Environmental Science & Technology, 1155 16th St. NW. Wash.,
DC 2OO36
ENVIRONMENTAL SCIENCE & TECHNOLOGY 12(9), IOI3-1O14,
Coden: ESTHAG Publ.Vr: Sept. 1978
i I lus. no ref s. -\
Sum. '
Languages ENGLISH
Doc Type- JOURNAL PAPER
Five interconnected hyacinth ponds, designed to handle a
iOO,OOO-gpd flow and sized for a 6-d maximum retention period,
receIved chlorInated secondary effluent from an actIvated
sludge treatment plant receiving domestic wastes and operating
at 95+% BOD and SS removal efficlences. By Incorporating the
nutrients Into their blomass the plants reduced N levels from
IO-3O to O.6 mg/L, and P levels from 5 to 3.5 mg/L. Harvested
hyacinths can be dried, mixed with sludge, and processed as
fertilizer. or used to produce methane. An alum or ferric
chloride precipitation step may be needed to meet forthcoming
tert iary P standards. The hyacinths reduced the effluent
col I form count to zero and the chlorinated hydrocarbon
concentration to about O.O05 mg/L (5O%): trace metals were
reduced to J O OO1 mg/L. (FT)
Descr tptors: Flor Ida; Wastewater treatment; TertIary
treatment; Phosphorus removal; Nltrogen removal; Col I forms:
ChlorInated hydrocarbon compounds; Plants; Wastewater
treatment plants
Ident if1ers: water hyacinths; Coral SprIngs
and mat er i aI recovery t echn1ques T he mos t prom i s i ng 1nc t ude
evaporative recovery of plating bath constituents from rinse
waters. RO systems for some plating solutions, improved Ion
exchange systems for s ingle metal recovery from separated
rinse streams, secondary polishing systems for final effluent
pur I f lea t ion, r ins-e water pur If 1 cat ion steps pr lor to
evaporative recovery of RO, foreign metal recovery and other
ImpurIty removal From metal f inlshing solutIons,
ultraf111rat Ion methods for water reclamation, and
sol IdIfIcat Ion of metal fInlshlng sludges conta in ing mixed
metal 1Ic hydrox ides. Other promis ing techniques Include
possible utilization of sulflde precipitation of heavy metals.
solvent rIns ing, ion flotat ion, C adsorptIon, and recovery of
metals from hydroxide sludges by solvent extraction. (FT)
Descr iptors: Metal fInlshing Industry; PollutIon control;
Materials recovery; Reverse osmosis; Ion exchange; Engineering
; Cleaning process; Heavy metals; Poland
Identifiers: plating Industry; Polish Institute of Precision
Mechanics
TECHNOLOGY
1978
Plating Effluent Treatment
12(8). 896-899.
79-02832
A clean water project In Poland.
Kleszkowskl, M.; Jackson, G. S.
Inst. of Precision Mechanics,
Dept ¥ OO-967 Warsaw, Pol.
ENVIRONMENTAL SCIENCE &
Coden: ESTHAG Publ.Yr- Aug.
t1lus. refs.
Sum.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Wastewaters produced In metal finishing operations contain
such pollutants as cyanides, chromates, heavy metals, mineral
acids, alkal Is. oils, greases, detergents. and organic
sol vents. The most common effluent treatment cons ists of
well-known, conventional chemical procedures which can be done
elther contInuously or batch-wise. They Involve several
opera t i ons. such as a 1ka11ne ch1or Ina t i on of segrega t ed
cyanide solutions, reduction of segregated chromate solutions,
and final neutralization of mixed effluents and precipitation
of metal hydroxides. followed by land fill disposition. A
schemat ic diagram of such an effluent treatment plant Is
presented. Applied research for the Polish metal finishing
Industry Is conducted by the Institute of Precision Mechanics,
In Warsaw, which has developed several new effluent treatments
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DIALOG Ffle41 Pollution Abstracts - 7O~82/Apr (Copr. Cambridge Set Abs > (Item 42 of 69) User239l3 23junB2
CO
CTi
O
79-O259I
Wet electrostatic preclpltator cuts opacity to 10% or less.
Rockenbach. D,
Ferndale. WA 98248
2B-3O,
Coden:
gases from bake
Intalco Aluminum Co.
CHEMICAL PROCESSING. CHICAGO 41(10),
CHPCAI PubI Yr. Sept. 1978
i1lus. no refs.
Sum.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
The existing scrubber system for exhaust
ovens at a Washington State aluminum plant was not capable of
meeting new air quality codes or wastewater specifications
w t thout add on equipment. Four vert leal wet electros tatIc
precipltators with Integral precondit(oners were chosen
because of their low cost, materials of construction, high
operating velocities, and ease of Installation. Water for the
precfpltator and preconditloner Is treated In separate loops.
No preconditloner loop water is allowed into the precipltator
loop. Hydrated lime Is used for precipitation of F. The
system Is closed loop except for evaporation and the small
amount of IIquor that escapes with the sludge. The wet
prectpltator Is fabricated from corrosion resistant fiberglass
with Hastelloy discharge electrodes. Partlculate efficiencies
during acceptance testing were 9t%~97% with 4 units operating.
Condenslble tars account for t2% of Inlet of 73% of outlet
particulates. for a 67% collection efficiency. The system Is
designed to run In the acid mode while collecting f- but could
be modified to the basic mode to maximize sulfur dioxide
removal. OperatIon is fully automatIc. (FT)
Descriptors- Emission control equipment; Electrostatic
prec Ipitators; Metal 1 ndus try ; A1 urn I nutn; F1 uor 1 des
Iserlohn, and the central treatment plant at He!1Igerthaus are
described. To supplement the system of wastewater treatment
plants 4 impoundments were constructed In the Ruhr valley
The central wastewater treatment plants elimiate 6O% of the
Influent heavy metals. During low flow in the lower Ruhr
river a ratio between clean water and treated wastewater of
7O:3O Is maIntalned on the average. From this mixture
waterworks abstract their water and prepare drinking water by
art IfIcial groundwater recharge. (FT)
DescrIptors: Federal RepublIc of Germany; Metal f inlshlng
Industry wastes; Effluent treatment; Wastewater treatment
plants; Industrlal effluents; MunlcIpal water supplies; Waste
reuse
tdentIflers: Ruhr valley
79-OOG26
Wastewater from plating works-required pretreatment and
disposal of concentrates.
Imhoff. K R.
Ruhrverband und Ruhrtalsperrenvereln, Kronprinzenstrasse 37.
43OO Essen 1, FR6
International conference on advanced treatment of wastewater
Johannesburg, S. Africa June 13-17, 1977
Advanced treatment and reclamation of wastewater: Conference
proceedings. In PROGRESS IN WATER TECHNOLOGY IO(t-2) .
419-43O. Coden: PGWTA2 Publ.Vr: 1978
11lus. refs, (Some in Ger.)
Sum
Languages: ENGLISH
Doc Type. CONFERENCE PAPER
The Ruhrverband ensures that the wastes of metal finishing
establishments In the Ruhr catchment are recycled to the
chemical industry; the sale of the wastes covers onIy
transportation costs, but there are savings compared to
chemical prec1pI tat ton and sludge disposal. Wastewater Is
treated in 118 most\y smalI plants. Cyanide and
chromate-contaIning wastewaters must be collected separately
and pre trea ted. The cen t ra1 decontamIna t i on p1 ant at
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DIALOG Ft)e4t: Pollution Abstracts - 7O-B2/Apr (Copr. Cambridge Scl Abs) (Item 44 of 69) User239l3 23JunB2
U>
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DIALOG Flle4l Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Sc I Abs) (Item 64 of 69) User23913 23Jun82
7B-OO236
The choice Is yours with phosphorus removal.
Syal, R. K
John David Jones & Assoc., Cuyahoga Falls, OH
WATER AND WASTES ENGINEERING 14(8), 47-5O. Coden:
WWAEA2 Publ.Yr: Aug 1977
11lus no refs.
Sum.
Languages-. ENGLISH
Factors to consider In selecting the most economical method
of P removal from domestic and Industrial wastewaters Include
characteristics of the particular waste. size and type of
basic treatment system, degree of operational and maintenance
attention available, availability and cost of chemicals, and
degree of removal required. Phosphorus In raw wastewater Is
found as orthophosphate fon, polyphosphates or condensed
phosphates, and organic phosphate. Of these, the 1st Is the
easiest to remove by precipitation. Lime and the salts of A1
and Fe are the most commonly used chemicals. The use of lime
Is limited to the primary and tertiary P removal process due
to the tncompatabll Ity of optimum lime precipitation pH
conditions and the maintenance of an optimum environment for
mlcroblal life. Alum or ferrous chloride addition to
activated sludge, or chemical-biological methods, are the most
promising. When planning the system. the designer should be
cognizant of the P levels In the effluent SS. If total P
residuals of JO. 5 mg/t are required, a multimedia filtration
system Is recommended. The advantages of metal addition for
removal are ease of operation, relatively small additional
solids causing Increases In sludge density and dewaterabl1 Ity,
and flexibility to changing conditions. (from Text)
Descriptors: Phosphorus removal; Wastewater treatment;
Aluminum compounds; Iron compounds; Lime
77-OO391
Removal of heavy metals from Industrial effluents.
ROUSE, J.V. ~ •
EPA, National Enforcement Investigations Center, Su1te9OO,
Lincoln Tower. I860 Lincoln St.. Denver. CO 8O2O3
American Society of Civil Engineers. EnvlronmentalEnglneer1 -
ng Division. Journal. 1O2(EE5)- 929-936, Oct.1976 Pub) Yr-
1976
Languages. ENGLISH
Descriptors: INDUSTRIAL EFFLUENTS; HEAVY METALS; ION
EXCHANGE: WASTEWATER TREATMENT; SORPTION; PRECIPITATION;
NEUTRALIZATION; POLLUTANT REMOVAL
Identifiers. REVERSE OSMOSIS: CEMENTATION
Water Research. IO(IO): 9O3-9O7. 1976 Publ.Yr- 1976
Languages: ENGLISH
Descriptors: IRON; PHOSPHATE REMOVAL; ALUMINUM; WASTEWATER
TREATMENT; PRECIPITATION; METALS; COAGULANTS
76-O3343
Heavy-metals recovery promises to pare water-cleanup bills.
Ricci. L.J.
Chemical Engineering, 1221 Avenue of the Americas, NewYork.
NY 1OO2O
Chemical Engineering. 82(27): 29-31. Dec. 22. 1975
Publ.Yr- 1975
Languages: ENGLISH
Descriptors: ADSORPTION; ELECTROCHEMISTRY; ION EXCHANGE;
MATERIALS RECOVERY; METALS; POLLUTION CONTROL EQUIPMENT;
PRECIPITATION; RECYCLING; WASTEWATER TREATMENT
76-O138S
Wastewater treatment at Swedish steel mills.
HALLEN. L.
Vlak AB, Industrial Wastewater Section. Fack, 162
10Vae111ngby, Sweden
Water Pollution Control Federation. Journal, 47(4)-.773-782 .
Apr. 1975 Publ.Yr: 1975
Languages: ENGLISH
Descriptors: FILTRATION; INDUSTRIAL EFFLUENTS; METAL
INDUSTRY; PRECIPITATION; STEEL; SWEDEN: WASTEWATER TREATMENT
Identifiers: MAGNETIC SEPARATION
7B-O4423
Techniques for removing metals from process wastewaters.
OELLINGER, R.W.
Univ. of Maryland. Dept. of Chemical Engineering.
CollegePark. MO 2O742
Chemical Engineering. 81(8): 79-85. Apr. 15. 1974 Publ.Yr:
1974
Languages: ENGLISH
Descriptors: CHEMICAL TREATMENT; ION EXCHANGE; ION REMOVAL;
METALS; POLLUTANT REMOVAL; PRECIPITATION; TRACE ELEMENTS:
WASTE WATER TREATMENT
Identifiers: HEAVY METALS
77-OO229
Comparison of iron(III) and aluminum In precipitation of
phosphate from solution.
HSU. P H.
Rutgers Univ.. Dept of Soils and Crops. New Brunswick.
NJOB903
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UJ
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to
Print a/5/t-19
DIALOG Fi)e41. Pollution Abstracts - 7O-82/Apr (Copr -CambrIdge ScI Abs) (Item
19) User23913 23jun82
82-OOG22
Local Source Control Program for Metal Finishing Plants
Lo. M.P ; Caballero. R C.; Kremer, J.
Sanitation DIs Los Angeles County,
Waste Sec.
VOL 27, MO. 6.
PP
16-21.
Publ.Yr ;
Indus t.
Whittier, CA
INDUS!. WASTES
1981
Languages ENGLISH
from the experience of the Districts In the past 6 years, a
loca1 source control program has effected a sIgnlfleant
reduction of pollutants from metal finishing companies. Most
have complled with their effluent 11mlts through good
housekeeping measures. Many high production companies have
installed elaborate end-of-pipe treatment systems. Successful
functioning of either type of basic pretreatment system In
dependent upon adequate Involvement of company management In
proper operatIon and maIntenance of the system. Rigorous
enforcement of the Phase I limits by the Sanitation Districts
has encouraged company owners to give close attentIon to
pollution control.
Descriptors: Effluents; PollutIon control; Metal fIntshlng
Industry; DlspersIon; Caltfornla; Water qualIty
81-O1757
Effects of cadmium on the completely mixed activated sludge
process.
Weber. A S.: Sherrard. J. H.
Untv of California, Davis, CA 95616
Water Pot IutJon Control FederatIon.
Journa1
52(9),
2378-2388. Coden: JWPFA5 Pub!,Yr: Sep 198O
11lus 26 refs.
Eng., Fr. , Ger., Port.. Span, abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
TREATMENT CODES: I . (INVESUGATS VE/OBSERVAT ION> ; T
.(THEORETICAL/MATHEMATICAL)
A laboratory study was conducted to measure the effect of Cd
on COD removal efficiency, degree of nitrification, and the
kinetic coefficients Ymax (the maximum yield coefficient) and
b (the microorganism maintenance coeff fclent). Data were
obtained from the operation of bench scale reactors which were
fed O. 5.15, and 9.98 mg/L solutions of Cd. Mean cell
residence time was used as the primary operational control
parameter, and values between =3 and 15 d were used to obtain
data. COD removal effIciencies of al1 reactors were
Independent of the mean eel I residence tIme for the range
studied. The COD removal eff Iciencies for the reactors
containing Cd were slightly less than those obtained for the
control reactor. No distinguishable difference was obtained
for the kinetic coefficients Ymax and b. Nttr1fIcatIon,
however, was significantly altered In the presence of Cd The
degree of n1trIf1ca 11on decreased as Cd concentra tIons
Increased at a given mean cell residence time (AM.FT)
Descriptors Cadmium; Activated sludge process; Heavy metals
; Toxlci ty; NltrIfleat ion; COD; Kinetics; Mathemat fcal
analys is;
treatment
Tox ic mater la Is; Laboratory test 1ng
R iolog(ca1
81-OO579
Why Is Rotunda still an RO success?
Suroral1. H.; Schomaker. B
Rotunda West
WATER AND WASTES ENGINEERING 17(7), 24-28. Coden:
WWAEA2 Publ.Yr: Jul 198O
11lus. no refs.
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
A RO water treatment plant In Rotunda West, Florida, In
operation since Jan. 1973, treats SOO.OOO gpd of water, with
the hIghes t IDS va1ue on record. Early prob1ems were
encountered wi th the wel1s pump Ing sand, silt, H2S, and 02.
The problems were corrected by lining the well casing with
PVC.. replacing pump metal He parts, and Installing foot
valves on the suction column below the pumps. The plant has
performed successfully since that time, primarily because of
good operation and maintenance procedures and the use of B-9
hollow fiber membranes. To date, 40 of the original 66
perineators are still In use. Their longevity 1s attributed to
proper and conservat1ve eng ineerIng desIgn and rev lew by
qua 11f i ed per sonneI. (FT)
DescrIptors: Reverse osmosIs; Water treatment plants;
Flor Ida; Membranes
Identifiers: Rotunda West
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DIALOG File4l- Pollution Abstracts - 7O-82/Apr ( Copr Cambridge Sc 1 Abs> (Item 4 of 19) User23913 23JunB2
UJ
-O
OJ
8O-O7062
The economIc 1mpac t of proposed iregu1a 11 cms to reduce
particulate emissions from steel mills and industrial fugitive
sources, R78-10 and R78-11.
ILLINOIS INSTITUTE OF NATURAL RESOURCES IINR DOCUMENT
Pufol Yr• Apr 1979
11lus. numerous refs.
Sum.
Languages: ENGLISH
The benef1ts and costs of the proposals submitted by
Interlake, Inc. and by Granite City Steel are examined.
Quest Ions to be answered concerning the benef1ts of the
regulations Include what reductions In morbidity and mortality
can be expected, what reductions In crop damage and materials
can be expected. and what Improvements In recreation and
aesthetics will result. The question of costs will examine
cap Ital„ operatIon, and maintenance costs as wel1 as the
effect they will have on the price of goods and services of
the producer. Control strategies are evaluated and pollution
sources analyzed. Results of the study are presented, but
their Interpretation ts difficult due to the large amount of
uncertainty associated with the benefits and costs. (AM)
Descriptors: Economics; Cost-benef1t analysis; State
regulatIons; PartIculates; EmlssIon control; Metal Industry;
Air pollutlon control; Environmental Impact; 111(noIs
Ident 1flers• Granlte City Steel; Interlake. Inc.
8O-O2062
Lots of hazardous waste finds a home In Kansas.
Anonymous
NATIONAL WASTE NEWS 2(11), 15-18, Coden NWNED5
Publ.Yr: Nov 1979
11lus. no refs.
No abs
Languages. ENGLISH
Doc Type: JOURNAL PAPER
TREATMENT CODES: C .(CASE STUDY) ; O .(DESCRIPTIVE)
The Kansas Industr tal Environmental ServIces, Incorporated
disposal site Is located In a 90-ft layer of Wellington-Admire
clay beneath which 1s a small nonpotable aquifer The site
began operation fn 1977 and has a life expectancy of 1O-15 yr.
Prior to startup, 1OO permeability studies were conducted on
the 8O-acre site, and 6 perimeter and 4 Internal monitoring
wells were dug to regularly check for leachate. The site
accepts plating wastes, heavy metal slurries and sludges,
concentrated acids, caustIcs, paint sludges, oils and
so1ven t s, cyan Ide compounds, and m1see 11aneous organIc
chemicals Two evaporation lagoons and 4 ponds are used for
evaporation and neutralization of certain wastes, whereas 2
silt trenches and an area fill are employed for landfill Ing
drums. The ftrm Is Involved In a waste stream reduction
program, and the property is landscaped to allow surface water
to drain Into holding and evaporation lagoons. In addition to
a tIght maIntenance program, the f1rm emphasizes safety by
using safety-related equipment and conducting a safe driver
education course (FT)
OescrIptors: Kansas; Disposal sites; Aqui fers; Hazardous
mater la Is; LandfIlls; MaIntenance; Sludge disposal; Acids;
Oils; Solvents; Cyanides; Waste management
Ident Iflers: Kansas Industrla I Environmental Services, Inc.;
permeability studies; safety measures; plating wastes: heavy
metal slurries; caustIcs
8O-O054O
30 years of refuse-fired boiler experience.
Velzy, C. 0.
Charles R Velzy Assoc., Inc , 355 Main St., Armonk, NY
1O504
Engineer Ing FoundatIon conference, uni t operations In
resource recovery engineer Ing RIndge, New Hampshire Jul
1978
RESOURCE RECOVERY AND CONSERVATION 4(1). 83-98, Coden:
RRCODN Publ.Yr: May 1979
tllus refs.
ISSN: O3O4-3967
Abs.
Languages- ENGLISH
Doc Type: JOURNAL PAPER CONFERENCE PAPER
TREATMENT CODES: D .(DESCRIPTIVE)
The town of Hempstead. New York, began operatIng
energy-from-refuse plants In I95O, Incorporating waste heat
boilers and producing power totally Independent of the local
power system. The experiences gained In the areas of boiler
tube metal wastage, boller foul Ing. particulate emission
control, and maintenance and availability are described. With
effective use of overflre air, judicious use of protective
coat Ings, conservat1ve volume and veloclty In the furnace and
convection bank, and limitation of steam temperatures, tube
wastage can be avoided. Careful select Ion of tube
conf iguratIon and spacIng to achieve conservat1ve gas
velocltles along with proper locatIon of sootblowers can
eliminate convection bank tube fouling In incinerator boilers.
Properly cooled walIs along the grate 1Ine shed slag
effectively; however, design of these walls Is critical to
their operation and maintenance experience. A property sized
2-fleld electrostatic predpltator following a well operated
furnace and boiler Is apparently more than adequate to comply
with present federal regulations related to dry partIculates
(AM)
DescrIptors: Refuse disposal; Heat recovery; New York,
Municipal wastes; Resource management; Energy sources; Fuels;
Incinerators; Engineer Ing
IdentIflers: Hempstead
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DIALOG FJle41 Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Sc* Abs) (Item 7 of 19) User23913 23Jun82
32.5*
water treatment system for electro-plating
No. 2.
31-33.-
Coden: DOPOAC PubI.Y r:
8O-OO418
RMA-a waste
operations.
Anonymous
DORNIER POST
1979
I1 Jus. no refs.
ISSN. OO12-5563
No abs
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Dornier has developed a cost-effective system for recycling
metals from wastewater which brings wastewater treatment and
metal recycling within the reach of medium and smal1
electroplating operations. Metals are recycled using high
quant * tles of wastewater treated by preclpl tat Ing only
metallic Ions or both kinds of tons, depending on the needs of
the operation. Loaded resins are not regenerated In the
electroplating operation but are collected by an operating
company and exchanged for regenerated resins, thereby
eliminating the need to regenerate Ion exchanger resins and to
treat the eluates In a detoxIcatIon plant. The essential
system component Is the modular ion exchanger column wlth
easily replaced cartrIdges regenerated In a central
Installation when they are charged. The cartridges are easy
to handle and do not require special training for monitoring
and operation. The system can be used for automatic water
recycling systems, maintenance of process baths, pre- and
after-treatment baths, separate treatment of rinse baths for
meta 1 recovery, and elImlnatIon of toxIc meta 1s or
complex-forming agents. The Dornier-developed system offers
the following advantages: modular concept Ion, smal1
dimensions, low cost, easy hand!Ing and high operational
safety. and maintenance of prescribed wastewater quality (
SS FT)
Descriptors: Wastewater treatment; Economics; Metals;
RecyclIng; Ion exchange; Preclpltat ton; Metal Industry;
Technology
IdentIflers. electroplating operatIons; modular Ion
exchanger column
and a centrIfugally-operated check valve to assure a positive
shaft seal when shut down. The desIgn provides trouble-free
operation with minimal maintenance. Pumps now In use, each
with a 12-ln suction, a 10-In discharge, and a 21-in Impeller,
are being used to reclrculate solutions of dilute sulfuric
acid (H2S04) and hydrofluoric with a specific gravity of 1.O5
at 145degF and solutions of dilute II2SO4. metallic dust, and
fluorides at 145degF and 134degF (FT)
Oescr iptors: Pumps; Machinery; Engineer Ing; Plastics;
Corrosion; Acids; Smelting; Air pollution control; Pollution
control equipment; Technology
79-O5O96
Packtngless plastic pumps for flow rates to 5,000 gpm.
Anonymous.
CHEMICAL PROCESSING CHICAGO 41(13), 76. Coden: CHPCAI
Publ.Vr: Mid-Nov. 1978
11lus. no refs
No abs.
Languages: ENGLISH
Doc Type JOURNAL PAPER
An acid-resistant, double volute, centrifugal pump, designed
to operate at 5.OOO gpm and heads N18O ft. Is constructed of
modified phenolic resin and carbon-fiber reinforced plastic to
withstand erosion arid corrosive attack by a wide range of
aggressive substances. The pack Ingless design uses and
expelter to create a hydraulic seal when the pump Is running
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DIALOG FUe41 Pollution Abstracts - 7O~82/Apr (Copr. Cambridge Set Abs) < I tern 9 of t9) User23913 23Jun82
79-O4326
A natural environment for resource recovery.
Casterbrook. G, E.
Waste Age, 63tf Gross Point Rd.. Nltes. IL 6O64S
WASTE AGE 9(8). 5O-62, Coden: WAGEAE Pub! , Yr: Aug.
1978
I1lus. no ref s.
Sum.
Languages. ENGLISH
Ooc Type: JOURNAL PAPER
When Monroe County, New York, ran short of landfill space In
the early 1970s and began evaluating new sites, the voters
selected an advanced $5Q.4 million resource recovery plant to
recycle the county wastes The plant designed and scheduled
to be operated by Ray theon Serv ices of CambrIdget
Massachusetts, should start-up early in 1979. Jt was financed
by a $3*.9 million county general-obltgatIons bond and a $18.5
million New Vork State grant from an omnibus bond Issue The
2OOO TPD facility will produce about 65% of the Infeed as RDF.
It 1s also designed to recover ferrous metal. A!, mixed-color
glass, and lesser by-products. The process combined original
Raytheon concepts and materials recovery techniques pioneered
by the BOM. Four shredding stations use a total of 7
shredders. The bulk of the coarse-shredded material wfll
proceed to \ of 4 rotary classifiers, big barrels which turn
slowly while air blows through at 15 or 2O mph. Heavy
materials drop to a conveyor. Light materials reaching the
top of the rotary classifiers will be blown through a fine
screen Into combustible shredders and stored as RDF. The
heavy material Is destined for a more complex treatment-the
separat ton Into residue classes and segregation of the
remaIn Ing RDF stock, The plant also Includes a water
treatment module. Involving a static sieve, filters, and
holding tanks for surges. The multistage shredding operation
should slash maintenance costs, and tne shredder 12 In pass Is
so wide that It wfll not detonate explosives. The RDF will be
transported to Rochester Gas and Electric and used to operate
the recycling plant Itself. The county legislature passed an
ordinance requfrIng all pr1vate refuse haulers to patronize
the plant. (FT)
Descriptors: Solid waste disposal; Materials recover.y; Fuels
; Municipal wastes; New York; Waste management; Waste
treatment plants; Waste recycling
Identifiers: Monroe County; Raytheon Services Co.
PGWTA2
refs.
Publ.Yr 1978
Coden.
illus.
Abs.
Languages- ENGLISH
Doc Type. CONFERENCE PAPER
Water quality monitoring networks should be based on a
flexible modular system of telemetrlc and data processing
modules capable of containing appropriate mathematical models
and deploying only the minimum of robust and reliable sensors
necessary to ach I eve a g 1 ven object I ve . The f o 1 1 ow I ng
sign If leant detertninands are considered: temperature, OO ,
organic matter. SS, C1-, F-, nitrate, ammonia, heavy metals.
trace organlcs, and toxlclty. Sensors should be accurate,
reliable, and require little maintenance. They should be
Interchangeable with others of the same type wt thout
reel ibrat ion. and unaffected by changes In other variables.
They should be Inexpensive, and provide art output easily
connected to the telemetry system Use of dupl Icate sensors
f n a mode such tha t one measures samp I e and the o ther
standard, coupled wl th the abi I ( ty to swl tch streams to
conf irm or deny unusual qua! I ty data , provide automat Ic
calibration, and extend duty cycles, has enabled satisfactory
performance to be achieved from many ex I st ing sensors.
Computers can be used to calculate funct Ions of several
determinants or pollution Indexes so that alarms can be based
on a number of factors taken together. The phys tcochem teal
monitoring scheme In the River Wear uses dual sensors for the
measurement of DO, temperature, turbtdl ty , organic matter , and
ammonia. Opera t Ion of the monl tors Is control led by a
minicomputer at the treatment plant . The dual sensor system
was used to monl tor DO in sett led sewage at Washington
Wastewater Treatment Works. During design, construction, and
commtss toning. It Is advisable to spend effort on staff
training and motivation. (FT)
Descriptors. United Kingdom; Technology; Monitoring systems;
Wastewater treatment plants; Computers; Water quality; Rivers;
Telecommuntcat tons; Monitor Ing Instruments
I dent If lers : telemetry ; sensors
79-OO491
Improvements fn sensor and system technology.
Briggs. R.; Page, H. R. S.; Schofield. J. W.
Water Research Centre, Stevenage Lab., Stevenage,
Hertfordshire SGI ITH, Eng
Internaliona1 workshop on Instrumenta tIon and control for
water and Wastewater treatment and transport systems London
and Stockholm May 1977
Instrumental ion and control for water and Wastewater
treatrnent and transport systems: Internatlonal workshop
proceedings. In PROGRESS IN WATER TECHNOLOGY 9(5-6), 43*52.
-------
DIALOG Flle4l: Pollution Abstracts - 7O~B2/Apr (Copr Cambridge Scf Abs) (Item II of 19) User23913 23Jun82
Mechanical Engineering. S-22O O7
clean air conference Brisbane, Austral la
78-04157
The expanding role of high ratio fabric filtration In the
metallurgical industries.
Erlesand, 1. ; Stragerk. S,
Lurid Univ. of Technology.
Lund, Sweden
Internat tonal
May 15-19, 1978
Proceedings of the international clean air conference: Clean
alt -the continuing cha Mange. Edited toy E. T. White. P.
Hetherlngton and B. R. Thlele pp. 239-254 Publ.Vr: 1978
Pobl : Ann Arbor, Mich Ann Arbor Science Publishers
i 1 lus . no ref s .
No abs.
Languages: ENGLISH
Doc Type- CONFERENCE PAPER
The experience so far from full-scale Installations with
FLAKT high-ratio filters (HRFs) for cleaning metallurgical
fumes shows that the approach was in the right direction. The
use of HRFs. with filtering velocities somewhat K3 times
larger than with low-ratio filters (LRFs), has decreased the
size of the fabric filter tremendously. The ground space
required is «J5Q% than for the LRF , and the total volume,
estimated from the ground floor to the roof, (s 75% less than
for the LRF. Because of Its smaller size* the HRF has a total
power consumption somewhat less than the LRF. Inspection of
bags taken out after 1 year of operation does not show any
significant wear The cleaning sequence for the FLAKT HRF Is
always control led by the pressure df f ferent (al across the
filter, which minimizes the wearing of the bags. Considering
the advantages for inspection and maintenance, for having fans
downstream of the filter, and the about 2OJ4 lower Investment
cos t , there I s a good chance that In the very near future the
HRF will completely replace the conventional LRF. As further
development is continuing to increase the length of the bags
to 6-7 m and perhaps more, the advantage over LRFs will
stead) ly Increase. (FT)
Descr ip tors . Metal Industry; Industr la I emlss Ions ; Emission
control; Filters; Filter media; Dusts
Identifiers: high-ratio filters; low-ratio filters; FLAKT
aqueous solution obtained from the ore by leaching. Flotation,
or other chetn leal or ptiys leal process , or a h Igh- tempera lure
smelt of fused salts cons 1st Ing of the ore Itself after
SUi table treatment. New methods are tabulated for the
recovery of about 17 metals, and show. In addition to the
extracted metal, the source mater la I„ the method of recovery,
and the developer of the method. In addition, the actual
process Is described In detail. Besides such Incentives as
process stmplIf Icat Ion and by-product recovery, which are
ma Inly geologtca1 In nature, there are technoIog1ca t and
economic advantages to electrochemical metal recovery The
Introduction of electrolytic techniques can reduce the number
of milting operations, avoid complicated chemical procedures,
reduce f ossi1 fuel eonsumpt ion, and make transportation of
voluminous, heavy ore concentrates unnecessary Economic
advantages can be derIved from savings In energy and
mater tals, and redact ton of capital, operat1on, and
maintenance costs, The avoidance of thermal processes
Involving calcination of the ore, decomposition of ore at high
temperatures, emission of flue gases from the fuels used, and
of chemical gaseous species and particutates from the minerals
is invaluable. Wastewaters and other residues or tatHngs In
aqueous solutions are amenable to recovery of the included
metals by electrolysis. The mater ial dispersed to the
environment or going back to the water table can be purified
to meet pollution standards. (FT)
Descriptors: Metals; Metal industry; Mining;
Electrochemlstry; SmeltIng; Economics; Engineer Ing; Mater ials
recovery; Technology; Pollution control; Water purification;
Wastewater treatment
Identifiers: electrolytic metal extraction from ores
78-O397I
Electrochemical recovery of metals.
Barbler, M.
EIectrotechnology: Vol . 1 Wastewater treatment and
separation methods. Edited by R P. Ouellette, J. A. King and
P. N. Cheremlsinoff 239-342 Publ.Vr: 1978
publ: Ann Arbor, Mich. Ann Arbor Science Publishers
11lus numerous refs (Some In Fr,; Ger.)
No abs.
Languages- ENGLISH
Doc Type: BOOK CHAPTER
S tcttus tnforroat ion on current research and deve1opment of
new processes for electrow Inning metals from minera Is is
presented Interest (s focused on methods which have
electrolysis as a common base, the electrolyte being either an
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D1AIOG Flle4l Poilution Abstracts - 7O-82/Apr (Copr. Cambridge Set Abs) (Item 13 of 19) User239l3 23JunB2
-4
78-03453
Viable recycling-fact or fiction.
Dodsworth, M. F.
Council of the Borough of Harrogate* £ng,
SOLID WASTES 68(1). 6-15. Coden: SOWAD3 Publ.Vr:
Jan. 1978
i1lus. no ref s
No abs.
Languages: ENGLISH
Under proper management, recycltng plants can be
economically feasible. About 22O T refuse are processed at
the Harrogate site every week. Large appliances, car parts,
and other easily removable scrap are removed and deposited at
an outside dump area In groups of ferrous and nonferrous
scrap. Glass recyc!Ing proved to be totally uneconomic.
Paper recycling was done using a Scapa Htndte HB4 with a
shredder. Shredding Increased paper bale weights from an
average of 5-6,5 cwt. A separate salvage operation, which has
been In use for a number of years. collects free-of-change
paper and cardboard from commercial premises. During the
domestic collection round. refuse workers place separated
paper on racks fitted to the sides of the collection vehicles.
Tip personnel at the refuse sites receive bonuses based on the
amount of reclaimed paper they separate. Increasing prices of
recycled paper may result In the profitable operation of a
proj ec t In whlch paper f s purchased from voluntary
organizations. The recycling plant at Harrogate produces 2
grades of paper, mixed and ftberboard. Two men could process
N5O T of recycled paper In a normal work week In addition to
routine maintenance and loading trailers. Success of any
recycling scheme Involves minimal labor costs, maximum use of
collection vehicles. and maximum cooperation between workers,
the public, and other various organizations. (FT)
Descriptors: England; Paper wastes; Waste recyclIng; Waste
reuse. Solid wastes; Economics; Scrap metals; Glass
Ident1flers: Harrogate
78-O337O
Electrodlalysfs In advanced waste water treatment.
Korngold. E.; Kock, K.; Strathmann. H.
Bon Gurton Univ., R & D Authority. Beer Sheva, Israel
International symposium on membranes: Desalination and waste
water treatment Jerusalem. Israel Jan. 8-12, 1978
International symposium on membranes: Desalination and waste
water treatment Proceedings. In DESALINATION 24(1-3),
129-139. Coden: DSLNAH Publ.Yr: Jan. 1978
Ulus. ref s.
No abs.
Languages- ENGLISH
Doc Type CONFERENCE PAPER
ETectrodlalysIs (ED) can be successfully applied only to
Industrial effluents with a relatively low salt concentration
which do not contain an excessive amount of organic fouling
nnd poisoning materials. Applicable effluents Include those
produced In t he elect ropIa 11ng. semIconduct or„ and
pharmaceutical industries The advantages of ED over other
treatment processes Include the savIngs on water costs
result ing from complete recyc1 ing of wa ter and vjastewater
cons 11tuents, low Investment costs, contInuous oper at ion at
relatively low energy costs. and automatic operation with a
^minimum of maintenance. The following examples of successful
ED applications are given, regeneration of chemical Cu plating
baths; recyclIng rIns Ing waters from chemical plat ing
processes; recycling electroplating rinsing water; recycling
rIns Ing water from a phosphate plat Ing process; arid recovery
of sulfurIc acid from pickling solutions. (FT)
Oescriptors: Dialysis; Industr lal ef fluents; Eff Kient
treatment; Metal finishing Industry wastes; Waste recycling;
Tertlary treatment
Identifiers: electrodiatysis
78-02305
Arsenic removal from roaster off-gases.
Goodfellow, H. D.; Nennlger, E H.; Twlgge-Molecey. C,; et
al
Can.
Fourth internat tonal clean air conference Tokyo, Japan
May 16-2O. 1977
Fourth international clean air conference: Paper abstracts
p. 195 Publ.Vr: Mar. 15. 1977
Pubi: (n.p ) Japanese Union of Air Pollution Prevention
AssoclatIon
Abs. on t y
Languages; ENGLISH
Doc Type: CONFERENCE PAPER
A system to remove As from a roaster gas was designed in
1972-73 and was commissioned In 1974 for a gold mining
operation In northern Ontario. The gold recovery operation
requires the roasting of arsenical pyrite. The gas system
Includes the removal of entrained dust after the cyclones by a
hot electrostatic preclpltator followed by the sublimation of
arsenic trfoxlde (As2O3) In a unique mixing vessel by direct
contact with Induced ambient air. The mixer Is designed to
maintain the Interface between hot and cold gases away from
the walls and to operate at low energy losses. eliminating
surface butIdup and assocIated maIntenance requirements.
Sublimed As2O3 Is removed in a high-efficiency shaker bag
f H ter before emission from a 1tght-weight. insulated,
metaltIc stack. Operat tng data are presented wt th some
experimental data from the development stage of mixer design.
(AM)
Descriptors: Arsenic compounds; Mining; Canada; Gold;
Gaseous waste treatment; A *r pollutIon control; Pollutant
removal
Ident If1ers' roas ters; arsenic removaI; Ont.; abs tract on I y
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DIALOG I-IIall: Pollution Abstracts - 7O-82/Apr (Copr Cambridge Set Afos) (Item 16 of 19) User2331',) 23jun&2
LO
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DIALOG Ftle41: Pollution Abstracts - 7O-82/Apr (Copr Cambridge Sc I Abs) (Item 18 oi 19) User239l3 23jun82
78-O1296
A sampler for collecting evolved gases from sediment.
Chau. V. K-: Snodgrass, W J. ; Wong. P. T. S.
Canada Centre for Inland Waters. Burlington, Ont L7R 4A6.
Can.
WATER RESEARCH 11(9), 807-8O9, Coden: WATRAG
Publ. Yr- 1977
11lus. refs.
Abs.
Languages: ENGLISH
A lightweight„ sImple-operatIon sampler was successful1y
applled In studies of the product Ion of methane, carbon
dioxide, N, and O. The sampler Is stainless steel cone 58.5 cm
in diameter and 33-7 cm high. It Is a hand-operated.
sel f -conta fried unl t Gases are col lee ted by water
displacement. The sampler sits on the bottom with the feet
placed away from the gas-evolving area, rather than on thrusts
In the sediment. The sediment tn the sampling area Is exposed
to allow maintenance of natural fauna. The sampler has no
grid bars so the gas evolution Is not caused by mechanical
dIs turbance; Its samp1e bo111e Is de tachab1e 'and can be
replaced In the field. It Is currently used In studies of the
product Ion of volatlie organo-metal1Ic compounds. such as
(CH3)4Pb,
-------
APPENDIX B
METRIC-ENGLISH UNITS CONVERSION
English
1 horsepower (HP)
1 ga lion
1 gallon
1 ft
1 ft2
1 ft3
1 GPD/ft2
1 lb/gallon
1 ft/sec
1 lb
Metric
745.7 Watts
0.0037854 m
3.7854 L
0.3048 m
0.0929 m2
0.0283 m3
0.0407 m3/day/m4
1.20 x 10 mg/L
18.288 m/min
453.59 g.
380
-------
APPENDIX B
REGULATIONS AFFECTING THE
METAL FINISHING INDUSTRY
381
-------
Friday
July 15, 1983
Part ill
Environmental
Protection Agency
Electroplating and Metal Finishing Point
Sourca Categories; Effluent Limitations
Guidelines, Pretreatment Standards, and
New Source- Performance Standards
382
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32482
Federal Register / Vol. 48. No. 137 / Friday, July IS. 1983 / Rules and Regulations
ENVIRONMENTAL PROTECTION
AGENCY
40 CFH Parts 413 and 433
[OW-fflL-2383-7]
Electroplating and A/total Flnisnfng
Point Source Categories; Effluent
Limitations Guidelines, Pretreattnent
Standards, and New Source
Performance Standards
AGSNCY: Environmental Protection.
Agency (EPA).
ACTON: Final rule.
- - JT; Thii regulation limits the
pollutants that electroplating/metal
finishing facilities may discharge to
waters of the United States or to
publicly owned treatment works
(POTW). The Metal Finishing
Regulations provide effluent limitations
baaed on "best practicable technology"
and "best available technology" and
establish new source performance
standards and pretreatment standards
under the Clean Water Act la addition.
this nil? amends the pretreatment
standards for existing sources for the
Electroplating Point Source Category.
The preamble summarizes the legal
authority, background, technical and
economic bases, and other aspects of
the regulation as well as a summary of
comments on the proposed regulation
and on the record supporting ch*
proposed regulation. The abbrevtationsk
acronyms, and other terms used in the
preamble are denned in Appendix A.
(See "Supplementary Information"
befow for complete fable of contentsf.
The Snai ml* i« suppose* by EPA's
technical conclusions detailecLJo the
Development Document forSfftuent
Limitations Guidelines, an&Startthais
far the Metai Frnishinf Point Soots*
Category, June. 1983. The Agency's
economic analysis is found in Economic
Analysis of Effluent Standards and
Limitations for the Metal Finishing
Industry, June 1983. Further supporting
materials are Sled in the record
supporting this rulemaking.
BATES: In accordance, with 40 CFR
100.01 (45 FR 28048} this regulation shall
be considered issued for the purposes of
judlcal review at 1:00 p.m. Eastern time
on July 29,1983. These regulations shall
become effective August 29,1983.
The compliance date for the BAT
regulations is as soon as possible, but no
later than July 1.1984.
The compliance date for New Source
Performance Standards (NSPS] and-
Pretreatment Standards for New
Sources (PSNS) is the date the new
source begins operations. The
compliance date for Metal Finishing
Pretreatment Standards for Existing
Sources (PSES) is February IS, 1986 for
metals and cyanide. Metal Finishing:
PSES establishes two levels of toxic.
organic control: the less stringent must
be met by June 30. 1984 for most plants
and by July 10, 1985 at plants also
subject to Part 420 (Iron and Steellr the
more stringent must be met by February
IS. 1986. In addition. Electroplating PSES
requires toxic organic control by July 15,
1988.
Under Section S09(b)(l) of the Clean.
Water Act judicial review of this
regulation can be obtained only by filing
a petition for review in the United States'
Court of Appeals within 90 day* after
these regulations are considered issued
for the purposes of judicial review. .
Under Section 509(b)(2) oi the Oeaa
Water Act the requirements of the
regulations may not be challenged in
later civil or criminal proceedings
brought by EPA to enforce these.
requirements.
Reporting provisions' in 40 CFR 413.03-
and 433.12 will be reviewed by OMB
under the paperwork reduction act and
are not effective- until approved.
Aoomss: Tecamcal information may be
obtained by .writing to Mr. Richard.
Kincifc. Effluent Guidelines Division
(WH-552), Environmental Protection
Agency, 401 M St. S.W, Washington.
D.C. 20480, Attention: Metal Finishing
Rule* Approximately two weeks faaa
publication, to* record for this
rulemaking will be available for
"aaaectioa and* copying at the EPA •
Public Information Reference Unit.
Room-240* {Rearf PM-213 (EPA Libraryji
The EBA pdtticisfonnation reguiaooB
(40 CFR Part 2f onvides that a
reasonable-fee1 may be charged for •
sopging. Copies, of. the technical and
economic, documents may be obtained
Sum the. National- Technical Information
Service. Springfield. Virginia 22I8I (703/
487-4850). Copies of both document*
will be available for review In me public'
record at EPA headquarters and
regional libraries.
Mr. Richard Kinch. Effluent Guidelines
Division (WH-332), EPA. 401 M Street.
S.W., Washington. D.C 20460. or by
calling (202) 382-7159. Economic
information may be obtained by writing
Ms. Kathleen Ehrensberger. Economics
Branch (WH-586), Environmental
Protection Agency, 401 M St. S.W.,
Washington. D.C 20480. or by Bailing
(202) 382-5397.
3UPKEMINTAHY INFORMATION:
Organization of This Nonca-
!. Legal Authority
II. Background
•*. The Claan Water Act
3. Pnor EPA Regulations
C Overview of the Industry
JE. Scope of this Rulemaking
[V. Data Gathering Efforts
V. Sampling and Analytical-Program
VI. Industry Subcategonzation
Vtt, Available Wastewater Control and
Treatment Technology
A. Status ot In-Ptacs Technology
3-. Control Treatment Options
vnt Ganeral Criteria tor Lumtations
A. 3PT Effluent Limitations
3. BAT Effluent Limitations •
C 3CT Effluent Limitations
C 3CT Effluent Limitations
0. New Source Performance Standards
E. Pretreatment Standards for Existing
Sooreas
f. Rretreaanent Standards foi>New Sources
DC Summary of Final Regulations
. A. Pan 433
3: Pan 413
X,Qenvaaon of the Limitations
XL Changes from the Proposed Limits
XHL Pollutants and Subcategones Not
Regulated
A. Exclusionjjf Toxic Pollutants
E Exclusion of Subcategones
Xffi Costs. Effluent Reduction Benefits, and
Economic Impacts
A. Costs and Economic Impacts
3. Executive Order 12231
C Regulatory Flexibility Analysis
O.SBA Loans
XIV. Non-Water-Quality Environmental
Impacts
A. Air Pollution
a Noise
C Radiation
aSbfidWaste
E,So«tgy
XV. Best Management Practices (BMPsI
XVL C/pMt and Bypass Provisions
XVTL Variances and Modifications
XVm. Implementation of Limitations and
Standards
' A. Relation to NPDES Permits
3. Indirect Dischargers
C. Applicability and Compliance Dates
0. Enforcement
XIX Summary of Public Participation
XX. Availability oi Technical Information
XXL OMB Review
XXH. List of Subjects
XXm Appendices
A. Abbreviations. Acronyms, and Other
Terms Used in This Notice
3'. Pollutants Excluded From Regulation
C, Unit Operations in the Metai Finishing
Industry
L. Legal Authority
This regulation is being- promulgated
under the 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 U.S.C. 12S1
etseq.. as amended by the Clean Water
Act of 1977, Pub. L. 95-217) (the "Act")
and as further amended. This regulation
is also being promulgated in response to
the Settlement Agreement in Natural
Resources Defense Council. Inc. v
383
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Federal Register / Vol. 48. No. 137 / Friday. July 15. 1983 / Rules and Regulations 32463
Train. 8 ERC 2120 (D.D.C 1978), as
modified. 12 ERC 1333 (D.D.C. 1973).
modified by Order dated October 28.
1962.
tt, Background
A. The Clean Water Act
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).
• Section 301(b)(l)(A) set a deadline
of July 1.1977. for existing industrial
direct dischargers to achieve "effluent
limitations requiring the application of
the best practicable control technology
currently avaiiable" ("BPT"].
• Section 301(b)(2)(A) set a deadline
of July 1.1983. for those dischargers to
achieve "effluent limitations 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" ("BAT1).
• Section 306 required that new •
industrial direct dischargers comply
with new source performance standards
("NSPS"), based on best available
demonstrated technology.
• Sections 307 (b) and (c) required
pretreatmerit standards for new and
existing dischargers to publicly owned
treatment works f^'POTW"]. The Act
made pntnatment standards
enforceable directly against dischargers
to POTWs (indirect dischargers), unlike
the requirements for direct dischargers
which were to be incorporated into
National Pollutant Discharge
Elimination System (NPDES) permits
issued under Section 402.
• Section 402(a)(l) allows
requirements for direct dischargers to be
set case-by-case. However, Congress
intended control requirements to be
based for the most part on regulations
promulgated by the Administrator of
EPA.
• Section 304(b) required regulations
that establish effluent limitations
reflecting the ability of BPT and BAT to
reduce .effluent discharge.
• Sections 304(c) and 308 of the Act
required regulations for NSPS.
• Sections 304(g), 307(b), and 307(c)
required regulations for pretreatment
standards.
• In addition to these regulations for
designated industry categories. Section
307(a) required the Administrator to
promulgate effluent standards
applicable to all dischargers of toxic
pollutants.
• Section 308 gave the Administrator
authority to collect information
necessary to develop and enforce
regulations.
• Finally, Section 50l(a) authorized
the Administrator to prescribe any
additional regulations "necessary to
carry out his functions" under the Act
EPA was unable to promulgate many
of these regulations by the deadlines
contained in the Act and as a result—in
1978. EPA was sued by several
environmental groups. In settling 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
meet a schedule for controlling 65
"priority" pollutants and classes of
pollutants. In carrying out this program
EPA must promulgate BAT effluent
limitations guidelines,-pretreatment
standards-and new source performance
standards for 21 major industries. See
Natural Sesouceas Defense Council Inc.
v. Train. 3 ERC 2120 (DJ3.C. 1978),
modified. 12ERC 1333 (D.D.C. 1979).
modified by Order dated October 28,
1982.
Several of the basic elements of the
Settlement Agreement program wen
incorporated into the Claan Water Act
of 1977. This law also makes several
other important changes in the Federal
water pollution control program.
• Sections 301(b)(2)(A) and
301(b)(2!(Q of the Act now set July 1. -
1984 as the deadline for industries to
achieve effluent limitations requiring
application of BAT for "toxic"
pollutants. 'Toxic" pollutants hen
includes the 65 "priority" pollutants and
classes of pollutants which Congress
declared "toxic" under Section 307(aj of
the Act \ ->
• Likewise. EPA's programs for new
source performance standards and
pretreatment standards an now aimed
principally at controlling toxic
pollutants.
• To strengthen the toxics-control
program. Section 304(e) of the Act
. authorizes the Administrator to
prescribe certain "best management
practices" ("BMPs"]. These BMPs are to
prevent the release of toxic and
hazardous pollutants from: (1) Plant site
runoff, (2) spillage or leaks. (3) sludge or
waste disposal, and (4) drainage from
raw material storage if any of those
events are 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.
• 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)(E)
requires "effluent limitations requiring
the application of the best conventional
pollutant control technology" ("BCT"}—
Instead of. BAT—
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32464
Federal Register / VoL 48. Mo. 137 / Friday, July 15. 1983 / Rules and Regulations
several metal finishing operations other
than, and in addition to. electroplating.
Part 413 (electroplating) currently
applies only to flows from, the six
specified electroplating processes.
These Part 433 (metai mushing
regulations} will apply- to- those
electroplating streams and also' to-
wastestreams from most other metai
finishing operations, within the same
plants. Tha Fart 433 PSES will apply
only to plants, already covered by Part
41% however Pact 433* will often cover
additional wastewater within the same.
plants-Tims the Part 433, limits, on
discharge o£ toxic metals* toxic, organics.
and cyanide wuXanply M "VM^ faraliHtt^
in the elacttopiatihg/metal finishing,
industry. ' '
The industry cantoe. divided '""*" t&a
sectors indicated: oa Table L FaoEBaa.
are either "captives'.* [those which in. a,
calendar year own more tfiaaSOSS (ana
basis) of the materials undergoing metal
R i u'ufn'n^fe nr ~fyfy shops" CtSOSe w.nich
in a" calendar year do oat awnmortt ffrQ«i
50% fares' basisf of material undergoing
Captrres- can be farther divided by
two. definitional "integrated" piano are-
those which, prior to treatment combine
electroplating waste streams witfc
significant process1 wast? streams' not
covered hytheeiei.Quy/affuj category
"non-integrated** faotitfes are tftose
which have significant wastewater-'
discharges only from* operations.
addressed by the* eteulruplu1 ting
category. Many captives.~(5WTare
"integrateo?* facilities: Whereas captives
often have a complex range of"
operations* job shops' tonally perform*
fewer operations. In-theory job shops
can be divided like- captive*, in-
actuality, however, approximately 97^
of all job' shops ia this industry are
"non-integrated".
Finally, the- entire industry can- be
divided inWdirecf and "Indirect"
dischargers; "Directs/* discharge
wastewaters to waters' of the United
States and-are snbfect toNPDES permits
incorporating BFT. BAT. and BC7
limitations or NSPS." "Indirects"
discharge to- POTWs and are subiect (o
PSESorPSNS.
As. discussed above, the
electroplating/metal fiaiahuig. industry is
currently covered by Part 413 PSES Cor
the Electroplating Category promulgated
on, September 7.1373. and amended on
January 23,1981. The effect of today's
amendments- is to create a new
category—Metal Finishing (Part 433}—
and to shift most eiectroplaters to it
replacing their current PSES with new
limits which apply uniformly to
discharges from their electroplating and
other metai finishing operations. This
meets industry's requests for equivalent
limits for process- lines often found
together and greatly reduces the need to
rely on the Combined Waste Stream
Formula for integrated metal- finishing
facilities. Direct discharger and new
source- requirements are- also being:
regulations.
Indirect discharging' job shop1
eiectroplatersand independent printed
circuit board manufacturers however.
would be left tinder the existing Part 413
PSES for Electroplating and are- -
exempted from- Part 432 This ia
consistent with-»1980 Settlement
Agreement in wnicir the Nafionaf
Association1 of Metal Finishers- (NAMFJ,
and the* ins finite* for* strercofflteutJJitf. and
Packaging: Electronic Orcnits (UPEC?
agreed nof to cnaileng»tne> Parr 443
PSES h* fBC&xst Sot tus*198X aiueiiumefl ts
and9 2?^^ CDmmxtm&m* tnaC tns Agency
more stringent standards fartfiose'
TASC* fc—3»ej«oowi»orTHe'
&ecrmPUkTiNa/MerM..BN(siHiNa INOUSTMT
CNunav <* QMMI a* xonr 11*701
would apply to discharges from the
second operation.
The following, regulations will take
precedence over metal finishing (Part
433) and electroplating (Part 413) wnen
such an overlap occurs:
Nonferrous metal smelting and refining
(4OCER'Part 421)
Coil coating (40 CFR Part 465)
Porcelain enameling (40 CFR- Part 486)
Battery manufacturing (40 CFR Part 481)
Iron and steel (40 CFR Part 420J
Metal casting foundries (40 CFR Part
484).
Aluminum forming (40 CFR Part 467)
Copper forming (40 CFR Part 466)
Plastic-molding1 and forming (40 CFR
Part483r
In. addition. EFA is. excluding, from the
nrstai ftaisaing.fPart 433) regulation: (1)
Metallfc'piatamakmg.and gravure
cyUnderpreparanon conducted witftin
printing- and. publishing facilities: and (2)
existing source fob shops and
"independent•prnrted circuit board
manufacturers which introduce
pollutants'into a publicly owned
treatment works. As-noted above, the
standards' do- not apply to facilities
unless they perform- at feast one of the
foilowingr electroplating, eiectroless,
plating; anododng,. coating* chemical
etching and ""iifttg? or printed circuit
Tie- Metal FSrisning, Category covers-
plants which perform one or more o£ the
following six operations: electroplating.
electroless. plating, anodizing, coating \
[phoapnaongr ^^^«i»Hffgl amj coloong).
chemical atrhin^ qiftH
circuit board manufactnre. If a plant
performs any of. taom six operations
then discharges- from the 4ft operations
listed in Appendix C are*cov«red-by
these standards.
In. some cases, another industrial
category may cover wastawster
dischazgea frum a. mntaJ fimahma
operation. In such, cases, the more
specific standards of the other Part(a}
will apply to toose- waatewater streams
which, appear to- bs covered by both.
regulation*, rot axampia, if a plant
performs coating operations in
preparation for painting and also
performs electroless plating as part of a
porcelain enamellng-procass* then these
Part 433 standards would apply to
discharges from the coating operation:
while Part 486 (porcelain enameling)
Tne most important pollutants of
GODC8T9 lOUQu jfl fflBtST SD2SIUI3S
indnstry wastewatersjre: (1) toxic
nretals (cadmnmt* copper, chromium.
nickel, lead, and ancjr (2) cyanide: (3)
'toxurorgaaics (lumped together as total
toxic organies); and (4) conventional
pollutants-(TSS and oil and grease).
These and other chemical constituents
degrade water quality, endanger aquatic
life and human health, and in addition
corrode equipment generate hazardous
gas, and cause treatment plant
malfunctions and problems in disposing
of sludges containing toxic metala.
These plants manufacture a variety of
product! that are* constructed primarily
of metals. The operations, which involve
materials that begin as raw stock (rods.
ban. sheet castings, forgmgs. etc-),' can
include the most sophisticated surface
finishing technologies.-These facilities
include both captives and job shops.
They 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 Urge facilities employing
thousands of production workers.
Because of differences in size and
processes, production facilities are
custom-tailored to the individual plant.
Some complex products may require the
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use of nearly all of the 46 unit operations
metioned above; a simple product may
require only one.
Many different raw materials are used
by these plants. Basis materials (or
"workplaces") -are mostly metals; from
common copper and steel to extremely
expensive high-grade alloys and
precious metals. They can also include
plastics. Solutions used in unit
operations can contain acids, bases,
cyanide, metals, completing agents.
organic additives, oils, and detergents.
All these materials may enter waste'
streams during production. - -
Water use within, the metal finishing
industry-is discussed fully in Section V
of the development document (see
summary above). Plating and cleaning
operations are-typically the biggest
water users. While moat matai finishing
operations ose-water, some may use
none at all Water use depends heavily
on the type—and the flaw rate—of the
rinsing used. Product quality
requirements often dictate me. amount of
rinsing needed for specific parts. Parts
involving extensive surface preparation
will generally require larger amounts of
water in rinsing.
10. Scope of tfr"« Ruieznaking
This regulation establishes Pan 433-
3PT, BAT, NSPS. PSE& and PSNS for
the Metal Finishing Pauit Source-
Category and amends Part 413.PSES for
the Electroplating Point Sonrce
Category. The BAT goal is to achieve, by
July 1,1984. the beat available
technology economically achievable
that will result in reasonable further
progress toward the national goal of
eliminating the discharge of all
pollutants. This regulation does not alter
the existing metal and cyanide
standards for job shop electroplaters
and printed circuit board manufacturers
discharging to POTWs.
EPA first studied the electroplating/
metal finishing industry to determine
whether differences in-raw materials.
final products, manufacturing processes.
equipment age and size of plants, water
use. wastewater constituents, or other
factors required separate effluent
limitations and standards for different
industry subcategones. This study
involved a detailed analysis of
wastewater discharge and treated
effluent characteristics, including, (a)
the sources and volume of water, the
processes, and the sources of pollutants
and wastewater in the plant and (b| the
constituents of waste,waters, including
toxic pollutants. This analysis enabled
the Agency to determine the presence
and concentrations of toxic pollutants
on the major wastewater discharges.
EPA also identified several distinct
control and treatment technologies (both
m-plant and end-of-pipa), including
those with potential use in the
electroplating/metal finishing industry.
The Agency analyzed bothjiistoricai
and newly generated data on the
performance of these technologies.
including their non-water quality
environmental impacts on air quality,
solid waste generation, water scarcity,
and energy requirements.
Cost curves were used to estimate the
cost of each, control and treatment
technology. These coat curves, were
developed by applying standard
engineering, analyses to metal finishing.
wastewater characteristics. Unit process
costs were than dedved by applying
model plant characteristics, (production
and flow) to U» unit coat carve of-each
treatment process. These unit proca**
costs were added together to yield tha
total cost at each treatment level.
By considering these factor&.E?A.wa*
- able to ff^Br^ctaragg the various>control
and treatment technologies, used, a* the
baees for efSuant limitations, new
source and pretreatment standards.
However, the regulations do not require
any particular technology. Rather., they
require plants- to achieve, effluent
limitations (mg/T) which reflect the
proper operation of these technologies.
or equivalent technologies. Some
faciUties are already successfully using
technologies other- than those*relied on
by the Agency, such as dragout control,
recycle, and recovery, to achieve these
values.
rv.Data.Ca
»« Effort.
To develop the regulation. EPA began
with a review of previous work an the
electroplating/metal finishing industry.
The major source of information on this
is the Draft Development Document for
Effluent Limitations and Standards for
the Metal finishing Point Source
Category (June 1980). Several studies
completed before' this development
document was published also
contributed technical information to the
metal finishing data base for the
following segments of the industry:
• Machinery and Mechanical
Products Manufacturing.
• Electroplating.
• Electroiess Plating and Printed
Circuit Board Manufacturing (Segments
of the Electroplating Category).
• Mechanical and Electrical Products.
We also gathered data on the metal
finishing industry from literature
surveys, inquiries to professional
contacts, seminars and meetings, and
the survey and evaluation of
manufacturing facilities.
We contacted all Federal EPA regions.
several State environmental agencies.
and numerous suppliers and
manufacturers for the metal finishing
industry to collect information on: (1)
Permits and monitoring data. (2} the use
and properties of materials. (3) process
chemical constituents, (4) waste
treatment equipment (5) waste
transport. (6) and various process
modifications- to mmm™« pollutant
generation.
Under the authority- of Section 308 of
the Clean Water Act the Agency sent
three different data collection portfolios
(DCPs) to-various industries within the
Metal Brushing Point Source Category.
The first DCP obtained 4ata from 339 of
1.422 plants originally contacted from
the machinery and mechanical products
industry. The data indnded general
plant information on raw materials
consumed, specific processes used.
composition- of effluent streams, and
wastewater treatment; The second DC?
obtained date from. 38S of the 900 plants
originally contacted, in the mechanical
and electrical products industries. These
data covered, general plant
characteristics, unit operations
performed, plating-type operations.
wastewater treatment facilities, and
waste transport We sent the third DC?
to 1-883 companies involved in
electroplating. Approximately 1130
plants sent back economic analysis data
and information on general plant
characteristics, production history.
manufacturing processes, process and
waste treatment wastewater
characteristics, and treatment costs.
EPA and its contractors, also, visited
210 manufacturing facilities, to^iaiiect
• wastewater samplaund. pertinent
technical information-on-mAnufacturing
processes, and various, treatment
techniques.
V. Sampling and Analytical Program
EPA focuoad it* sampling and. analysis
on the toxic- pollutants designated in the
Clean Water Act, However, we alao
sampled and analyzed conventional and
, Prior to
undertaking, sampling-programs in
support of n'tomitking actiona. EPA had
to identify specific- toxic pollutants that
would be appropriate subjects for
investigation. The list of 65 pollutants
and classes of pollutants potentially
includes thousands of specific
compounds, the analyses of which could
overwhelm private and government
laboratory resources. To make the task
more manageable, therefore. EPA
selected 129 specific toxic pollutants for
study in this rulemaking and other
industry niicrnakings. The criteria for
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32488 Federal Register / Voi. 48. No. 137 / Friday. July IS 1983 / Rules and Regulations
choosing these pollutants inducted the
frequency of their occurrence in water.
their chemical stability and structure.
tha amount of the chemical produced.
and the availability of chemical
standards for measurement
In addition to the original 123 toxic
pollutants (of which three are now
considered nonconventional poHuiaats).
EPA checked for the presence.
frequency, and concentration of xyleoas.
alkyi epoxides. gold, fluoride.
phosphorus, oil and grease. TSS. pH.
aluminum* barium/ indium, magnesium*
molybdenum, osmium, palladium.
platinum, rhodium, ruthenium, sodium.
tin. titanium, vanadium, yttrium, *^
total phenols.
The criteria used to select plants for
sampling visits we«-..(1.) A large
percentage of the plant13 effluent
discharge should result from the
manufacturing processes listed in
Appendix C, (2) the physical layout of
plant plumbing should facilitate
sampling of the wastewater type under
study; (3) 'the plant must have waste
treatment in place; (4) the mix of plants
visited should contain discharges to
both surface waters and pubiicaly .
owned treatment works: and (5) the
selected plants should provide a
representative geographical distribution
to avoid a data bate that concentrates
on a unique geographical condition.. HP A
sampled 210 faculties' to identify
pollutants in plant wastewatera, B*tore .
visinng a plant. EPA reviewed all
available data on manufacturing
processes and. waste treatment We •
selected representative, points at which
to sample the raw wastewater entering
the treatment systems and the final
treated- effluents. Finally, we prepared.
reviewed, and approved a detailed '
sampling plan showing the selected
sample points and the overall sampfeag
procedure.
Based on this sampling plan, we then
took samples at each sample point for l.
2 or 3 consecutive days. The samples
were divided, into two analytical groups.
Within each group the samplee were
subjected to various analyses,
depending on the stability of the
pollutants to be analyzed, the various
levels of analysis wera.conducted ac (1)
Local laboratories. (Z) EPA's Chicago
laboratory, (3) contracted gas
chromaiograpjiy/mass spectrometry
(GC/MS) laboratories, and'(4) tha
sampling contractor's, central laboratory.
The sampling and analysis methods are
outlined in the Development Document
The acquisition, preservation, and
analysis of the water samples followed
the relevant methods set forth- in 40 CFR
136. Although the Agency has not
promulgated analytical methods for
many organic toxic pollutants under
Section 304(h) of the Act. a number of
these methods have been proposed for
40 CFR138 (44 FR 69484. December 3.
197% 44 FR 75028, December 18.1979).
VL Industry Suhcatagorizatian
In developing this regulation, the
Agency considered whether different
'effluent limitations and standards are
appropriate for different segments of the
metal finishing industry. The Act
requires EPA- to consider a number of
factors to determine if subcategorization
is needed. These factors include raw
materials, final products, manufacturing
processes, geographical location, plant
size and age. wastewater
characteristics, non-water-quality
environmental impacts, treatment costs.
energy costs, and solid waste
generation.
The metal finishing industry
comprises 45 unit operations. These
processes generate wastawater that falls-
into five waste groups, aaoh requiring
different treatment tor reduce the
discharge of pollutants. The five groups
are metals, cyanide, hexavalent
chromium, ails, .and solvents, with.
significant toxic organic* pollutants
potentially present in the last two.
These wastes occur in a wide variety
of combinations. Throughout the
industry, however the wastestreame are
alike in one critical sense; they all
respond similarly to the treatment
system which is already most widely
used in the industry. That system was
selected as EPA's model technology. Its
major components; io. precipitation and
clarification, are used for all waste
streams. After isolated treatment ot
hexavalent chromium, cyanide, and oil
and grease, pollutants in these waste
streams an further reduced by passage
through the precipitation-clarification
system which is also used for metal-
bearing wastes.
The-Agency has determined that the
Metal Finishing-Point Source Category
need not be subcategorized for
regulation. A set of concentration based
limitations, based on the performance
capabilities of the modal technology,
can be applied to ail metal flashing
process effluents.
EPA haajiowever decided to-exempt
indirect discharging job shops and
independent printed circuit board
manufacturers from the Part 433 PSES.
This has an effect similar to placing
them in a separate sub-category. As
noted above, this is consistent with tha
1980 Settlement Agreement in which the
National Association- of Metal Finishers
promised to withdraw its legal challenge
to those Part 413 PSES if SPA did not.
for the next several years, make them
significantly mare stringent
The Agency considered, but decided
against production based standard.
With the wide range of operations.
product quality requirements, existing
process configurations, and difficulties
in measuring production, no consistent
production normalizing relationship
could be found. Concentration baaed
limits, however, can be consistently
attained throughout the industry.
VO. Available Wastewater Control and
Treatment Technology
A. Status ofla-Placa Technology
Installed control and treatment
technologies in the metal finishing
industry generally consist of some form
of alkaline precipitation and
clarification installed at "end-of-pipe" to
remove metals. When cyanide or
hexavalent chromium wastes are
present these, waste waters are
generally segregated and treated
upstream.
3. Control Treatment Options
We examined the following control
treatment options:
Option l: Precipitation and
clarification. Stream segregation for
cyanide, hexavalent chromium and
concentrated oily wastes fallowed by
cyanide destruction, chromium
reduction and emulsion breaking
skimming as necessary. Solvent waste
segregation and removal by hauling.
Option 2: Option 1 plus filtration.
Option 3: Option l plus in-piant
control for cadmium.
VUL Qeaeni Criteria for Effluent
A. 3PT Effluent Limitations
The factors considered in defining
best practicable control tachnoigy
currently available (BPT) include: (1)
The total cost of applying the technology
relative to the effluent reductions- that
result (2) the age of equipment and
fatalities involved. (3) the processes
used. (4) engineering aspects of the
control technology, (5) process changes.
(8) non-water-quality environmental
impacts (including energy requirements).
(7} and other factors, as the
Administrator considers appropriate. In
general the BPT level represents the
average of the best existing
performances of plants within the
industry of various ages, sizes.
processes, or other common
characteristics. When existing
performance is uniformly inadequate.
BPT may be transferred from a different
subcategory or category. BPT focuses on
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Federal Register / Vol. 48. No. 137 / Friday, July 15. 1983 / Rules and Regulations
32467
end-of-pipe treatment rather than
process changes or internal controls.
except when these technologies ara
common industry practice.
• The cost/benefit inquiry for BPT is a
limited balancing of costs versus
benefits, committed to EPA'3 discretion,
which does not require the Agency to
quantify benefits in monetary terras. See
s.g., American Iron and Steel Institute v.
EPA, 528 F. 2d 1027 {3rd Or. 1975). In
balancing costs against the benefits of
effluent reduction. EPA considers the
volume and-nature of existing
discharges, the volume and nature of
discharges expected after application of
BPT. the. general environmental effects
of the pollutants, and the cost and
economic impacts of the required level
of pollution control. The Act does not
require or permit consideration of water
quality problem* attributable to
particular point sources, or water
quality improvements in particular
bodies of water. Therefore. EPA has not
considered these factors. See
Weyerhaeuser Company v. Castle, 590
F. 2d 1011 (D.C. Cir.'l97a).
B. BAT Effluent Limitations
The factors considered in defining
best available technology economically
achievable (BAT] include the age of the
equipment and facilities involved, the
processes used, engineering aspects of
the control technology, process changes.
non-water-quaiity environmental
impacts (including energy requirements).
and the costs of applying suck
technology (Section 304(b)I2)(B]). The
BAT level represents the best
economically achievable performance of
plants of various ages, sizes, processes.
or other shared characteristics. As with
3PT. uniformly inadequate performance
within a category or subcategory may
require transfer of BAT from a different
subcategory or category. Unlike BPT,
however. BAT may include process
changes or internal controls, even when
these technologies are not common
industry practice.
The statutory assessment of BAT
"considers" costs, but does not require a
balancing of costs against effluent
reduction benefits (see Weyerhaeiaery.
Castle, supra}. In developing BAT.
however. EPA has given substantial
weight to the reasonableness of costs.
The Agency has considered the volume
and nature of discharges, the volume
and nature of discharges expected after
application of BAT. the-general
environmental effects of the pollutants.
and the costs and economic impacts of
the required pollution control levels.
' Despite this expanded consideration
of costs, the primary factor for
determining BAT is the effluent
reduction capability of the control
technology. The Clean Water Act of
1977, establishes the achievement of
BAT as the principal national means of
controlling toxic water pollution from
direct discharging plants.
C. BCT Effluent Limitations
The 1977 amendments added Section
301(b)(2)(E] to the Act establishing
"best conventional pollutant control
technology" fBCTffor discharges of.
conventional pollutants from existing
industrial point sources. Section
304(B)(4) specified the following as
conventional pollutants: BOD,TSS. fecal
coliform. and pH. The Administrator
designated oiLand grease-as
"conventional" on July 30.1979. 44 FR
44501.
3CT is not an additional limitation but
replaces BAT for the control of
conventional pollutants. In addition to
other factors, specified in section
304(bj(4)(B). the ACT require*-that BCT
limitations be a**e**ed ia light of. a (wo
part "cost-ceeaonablenee*" test
American Paper Institute v. SPA, 680 F.
2d 954 (4th Or. 1381); The first test
compares the cost for private, industry to-
reduce its conventional pollutants wiin
the costs to-publicly owned.treatment
works for similar levels of reduction in
their discharge of.theae pollutants. The
second test examine*, the coat-
affectivermss of additional industrial
treatment beyond BPT. EPA must find
that limitation* are "reasonable" under
both tests before-establishing them as
BCT. In no cage may BCT b« less
stringent than BPT.
EPA published its methodology for
carrying out the BCT analysis on August
29.1979. (44 FR 50732). In the. case
mentioned above, the Court of Appeal*
ordered EPA to correct data error*
underlying EPA's. calculation of the first
test and to. apply the second coat test
(EPA had argued that a second coat test
was not required).
BCT limitations for this industry were
proposed on October 29.1982 (47 FR
49176). They were accompanied by a
proposed methodology 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 ruiemalting or in this one.
D. New Source Performance Standards
The basis for new source performance
standards (NSPS) under Section 306 of
the Act is the-hest available
demonstrated technology. New plants
have the opportunity to design the best
and most efficient metal finishing
processes and wastewater treatment
technologies. Therefore. Congress
directed EPA to consider the best
demonstrated process changes, m-plam
controls, and end-of-pipe treatment
technologies that reduce pollution to the
maximum extent feasible.
£ Pretreaanent'Sfandards for Existing
Sources
Section 307(b j of the Act requires EPA
to promulgate pretreatment standards
. for existing sources (PSES), which
industry must achieve within three years
of promulgation. PSES are designed to
prevent the discharge of. pollutants
which pass through, interfere with, or
are otherwise incompatible-with the
operation of POTW s.
The legislative history of the 197? Act
indicates that pretreatment standards
are to be technology-based, analogous
to the best available technology for
removal of toxic pollutants. The General
Pretreatment Regulations which serve-as
the framework for the final metal
fir^«hmg pretreatment standards are in
40 CFR Part 403. 49 FR 9404 Qanuary 23.
1981).
EPA ha* generally determined that
there is pas* through of pollutants if the
percent of pollutants removed by a well-
operated POTW achieving secondary
treatment is las* than the percent
removal by the BAT model treatment
system. A study of 40 well-operated
POTW 3 with biological treatment and
meeting secondary treatment criteria
showed that regulated metals are
typically removed at rates varying from
20 to 70%. POTWs with only primary
. treatment have even lower rates of
removal In contrast, SAT level
treatment by metal finishing industrial
facilities can-achieve removals of
approximately 97% or more. Thus it is
evident that metals from this industry do
pass through POTWs. As for toxic
organic! data from the same POTWs
illustrate a wide range of removal, from
0 to greater than 99%. Overall POTWs
have removal rates of toxic organics
which are lea* effective than the metal
finishing TTO technology basis of no
dumping of toxic organic wastes. The
POTWs effluent discharge of specific .
toxic pollutants ranged from 0 to 4.3
milligrams/liter. Many of the pollutants
present in metal finishing wastes, at
sufficiently high concentrations, can
inhibit biodegradation in POTW
operations. In addition, a high
concentration of toxic pollutants in the
sludge: can limit POTW use of sludge
management alternatives, including the
beneficial-use of sludges on agricultural
iands.
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32468 Federal Register / Vol. 48. No. 137 / Friday. July 15. 1983 / Rules and Regulations
Section 307 oi the Clean Water Act
provides that POTWs may grant credit
to indirect dischargers, based on the
degree of removal actually achieved at
the POTW. EPA has General.
Pretreatment Regulations regulating
POTWs' authority to grant such credits.
A Federal Register notice of
September 2& 1982 explained EPA's
latest data and proposed national
removal credits for well operated
POTW's achieving the national
secondary treatment limits. See 47 FR
42898. That proposal is not being relied
on in this ruiemaking: however if such
credits are available the costs of today's
standards could be sustantially reduced,
F. Pretreataient Standards for f/ew
Sources
Section 307fcj of the Act requires EPA
to promulgate pratreatment standards
for new sources (PSNS) at the same time
that it promulgates NSPS. These
standards are intended to prevent the
discharge of pollutants which pasa
through, interfere with, or an otherwise
incompatible with a POTW. New
indirect dischargers, like new direct
dischargers, have the opportunity to
incorporate the best available
demonstrated technologies—including
process changes, in-plant controls, and
end-of-pipe treatment technologies—and
to select plant sites that ensure the
treatment system can be.adequateiy
installed. Therefore.'the Agency sets
PSNS after considering the same criteria
considered for NSPS. PSNS will have
affluent reduction benefits similar to
NSPS.
DC, Summary of Final Regulations
In the electroplating/metal finishing
industry, the pollutants of concern are
cadmium, chromium; copper, lead.
nickel, silver, zinc, cyanide, toxic
organics. TSS. oil and grease, and pH.
The treatment option selected for each
effluent limitation, pretreatment
standard and new source performance
standard is based on the criteria
specified in the Clean Water Act The
technologies are discussed in more
detail in the Development Document for
this ruiemaking.
A. Part 433
The pollutants being regulated under
3PT limitations are cadmium, copper.
chromium, nickel, lead, silver, zinc, total
cyanide. TSS. oil and grease and pH.
Total toxic organics (TTO) is also being
regulated. Compliance with the TTO.
limit basically involves not dumping
concentrated toxic organic wastes, e.g..
solvent degreasers and paint stoppers.
Other sources are generally small.
infrequent and of low concentrations.
For SPT. EPA is setting limits
achievable by technology- based on
precipitation and clarification far all
metal finishing effluents. In addition, for
cyanide or hexavaient chromium the
technology basis incorporates
techniques to destroy cyanide and
reduce hexavaient chromium to its
trivalent state. These effluent limitations
reflect the average of the best existing
control technologies widely used, in the
industry and remove approximately 97.9
percent of the raw waste of toxic metals
'and cyanide, and 99 percent of the toxic
orgamcs discharged. The technology is
consistent with that used as a basis for
PSE5 for the electroplating industry
(January 28.1981.40 FR 9462) and the
March 28.1974. suspended. BPT
limitations. The limitations are derived
in the manner discussed in the following
section. They are generally more
stringent than those found in currently
effective electroplating, pretrsatment
regulations, because EPA is now- using a
revised and updated data base.
For SAT. EPA is establishing
limitations for the toxic pollutants and.
at a level equivalent to BPT. The Agency
seriously considered setting SAT and
SAT-level PSES limitations based on
BPT level technology plus filtration.
Filtration would have led to an
additional capital cost of almost S1.2
billion. In light of the statutory mandate
to consider cost in setting BAT, EPA
decided to refect the filtration option.
because of its very high aggregate cost
on a nationwide basis. We did not select
ini-plant cadmium control because it can
require significant re-engineering of
process water flow and of product and.
equipment handling, on a plant-by-plant
basis. The changes vary widely and in
many cases could be difficult for
existing plants to apply. The compliance
date for BAT is no later than July 1.
1984. the maximum time allowed by the
Act
For NSPS. EPA is establishing .
limitations based on BPT/BAT
technology plus in-plant control of
cadmium. This additional control takes
advantage of a new plant's ability to
achieve effluent reductions of 89%
beyond BAT cadmium levels. The
pollutants regulated under NSPS are the
same as those regulated under BPT
limitations.
For PSES in the Metal Finishing
Category, limitations are based on
technology equivalent to BAT and BPT.
The pollutants regulated under this
PSES are the same as the toxic
pollutants regulated under BPT (BAT]
limitations. A study of 40 well-operated
POTWs with biological treatment and
meeting secondary treatment criteria
showed that regulated metals and
cyanide are typically removed at rates
varying from 20 to "0%. POTWs with
primary treatment have even lower
rates of removal. In contrast, metal.
finishing PSES-ievei treatment can
achieve removals of approximately 97".
Thus it is avident that metals and
cyanide from this industry do pass
through POTWs. As for toxic organics.
data from the same- POTWs illustrates a
wide range of removal, from 0% to
greater than 99%. Overall POTWs have
removal rates of toxic organics which
are less effective than the metal
finishing TTO technology basis of no
dumping of toxic organic wastes. The
POTWs effluent discharge of specific
toxic pollutants ranged from 0 to 4.3 ms/
1. Many of the pollutants present in
metal finishing wastes at sufficiently
high concentrations can inhibit
biodegradation in POTW operations. In
addition, a high concentration of toxic
pollutants in the sludge can limit POTW
use of-sludg* management alternatives.
including the beneficial use of sludges
on agricultural lands.
The compliance date for the metal
finishing PSES is
February 15.1986 for metals, cyanide.
and TTO. Agency analysis indicates
that facilities can plan, design, and
install the necessary equipment in 31
months, which will be allowed by the
specified compliance date. There is also
a June 30.1984 compliance date for an
interim toxic organic limit, which can be
met by in-house management and
handling controls.
For PSNS. limitations are based on
technology equivalent to NSPS. The
pollutants regulated under PSNS are the
same as the toxics regulated under
NSPS. As with PSES. these pollutants
are necessary for control in PSNS to
prevent pass through, interference, and
sludge contamination.
&, Part 413.
Indirect discharging-job shops and
independent printed circuit board
manufacturers will continue to be
regulated under the existing PSES for
Electroplating. This is consistent with a
1980 Settlement Agreement in which the
National Association of Metal Finishers-
and the Institute for Interconnecting and
Packaging Electronic Circuits agreed not
to challenge, the Part 413 pretreatment
standards for existing source
eiectroplaters. in return for the 1981
amendments and. an EPA commitment
that in light of their economic
vulnerability, EPA did not plan to
develop significantly more stringent
standards for those plants for the next
several years.
389
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Federal Register / Vol. 48, No. 137 / Friday, July 15. 1983 / Rules and Regulations 32469
Control of toxic organics is being
added to the requirements far facilities
- under the Electroplating PSES.
Examination of the technology
requirements, costs, economic impact
and timing indicates that requiring
control of toxic organics is consistent
with the Settlement Agreement
First it will not increase the economic
vulnerability of job shops or
independent printed circuit board
manufacturers. Compliance with the
toxic organic standards can be achieved
by good management practices (i.e., not
dumping waste solvents into the
wastewaters). No additional end-of-pipe
technology (beyond that already
required by Part 413) is necessary.
Economic analyses reveal that control of
toxic organics does not impose
significant additional costs or impacts.
Second, these facilities are being
allowed 3 years to comply with the toxic
organic standard. Thus, even if control
of T7Q were considered "more
stringent", the time allowed for
compliance will amount to a years from
the date of the Settlement Agreement
That fulfills the Agency's obligation not
to develop more stringent standards for
these facilities in the next several years.
X. Derivation of the Limitation*
EPA began development of these
standards by building on the
information obtained in developing the
Electroplating Pretreatment Standards.
For Metal Finishing. 2783 companies
were contacted aa part of two surveys
(one of .1190 plants and the other of 365
plants) and 1555 useable questionaire
responses were obtained. The Agency
also selected 322 plants for visits and/or
obtained long term self-monitoring data
on them.
The data gathering effort was the
basis for the Agency's first two critical
determinations. First pursuant to
Section 307(b) of the Act EPA identified
those pollutants that would pass through
or interfere with a POTW, or its sludge.
Second. EPA discovered that a basic
and "classic" pollution control
technology was widely practiced in the
industry. The system is designed to
remove toxic metals from raw
wastestreams and if has two principal
components—precipitation and -
clarification. Of 1190 surveyed plants.
689 reported treatment present, of these.
428 facilities practiced the precipitation
of metals through pH adjustment of
wastewater.
EPA then analyzed the data to
discover what those classic-and
commonly used treatment devices could
achieve. For each regulated pollutant
EPA looked for two key figures: The
average concentration that properly
operated technology would achieve over
time, and the variability from that
average that would be inevitable even
at well-operated plants.
To find long-term concentration
averages. EPA examined its file of 322
pjants which had been visited and/or
had sent long-term self-monitoring data
to EPA. Of these plants EPA had
sampled 72 with precipitation and
clarification. After deletions for
improper treatment dilution, andiow
raw waste concentrations, 30 plants
(sampled by EPA from 1 to 8 days) wen.
used for developing the long-term
concentration averages. For these
plants. EPA had obtained detailed
information on treated and untreated
(raw) wastewater characteristics.
For most pollutants the average of this
data was used for the long-term average.
EPA sampled data for cadmium and
lead appeared too low to represent the
range-of raw wastes in the industry. For
these, parameters EPA used available
self-monitoring data to calculate the
long-term average. Although the Agency -
has less information on which to judge
the adequacy of treatment is the self-
monitoring data, these higher values
wen used by the Agency to compensate
forthe relatively low raw waste
cadmium and lead at EPA sampled
plants. The avenge, of the self-
monitoring data for lead and cadmium
was used for the long-tenn average.
The regulations specify dairy and
monthly average maximum*. Thus, the
limits are developed from- the Agency
assessment of long term concentration
averages multiplied by variability
factors. If a plant intends to consistently
comply with the regulatory limit it
should use the long term concentration
average as the basis for design and •
operation. The following long-term
concentration avenges wen found to be
attainable by the technology EPA
assessed, and wen costed in this -
rulemaking. They are presented here as
guidance to dischargers and control
authorities:
Lang Tarn Concentration Average*
lmq/11
040mm, (Tl
ChramwmfT)
Caw (T)
0.13
0.57S
0815
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32470 Federal Ragiatar / Vol. 48. No. 137 / Friday, July 15. 1983 / Rules, and Reguiatioaa
from 0.17*lo O20 mg/1,anc changed
from 0.582 to 0.549 mg/1. and cadmium
changed from 0.19 to ai3- mg/t
The derivation of the proposed TTO
limit did not distinguish differences
between plants. Comments-suggested
that plants with certain processes
should b* allowed a higher limit EPA in
response, examined grouping of plants
by sources of TTO: e.g, these that
perform solvent degreasing. and/or
painting, plants which- performed both.
solvent degreasing and painting'had
higher raw -waste TTD than any other-
process group. The final TTO Hnritis-
based on that process gtuupiug. which is
a conservative assumption since H had
Furthermore. EPA is now promulgating
two ITtj limits for plaints i.uveteil by
Part 433. Tire first is based soieiy on
background levels found prior to end-of-
pipe- tmttiBent. It most be met by JmiQ-
30.1384. accept that plants covered by
Part 430 (arm and ategij need not meet It
mrtfl fui? 10.1383. The-seedhdiTTO limit
is baaed 90 effluent data andtakes into
3ccotmt t&o AOCUuOfiu rviXLWBfl
acutfivoa by 9nd*ot*pTp* tmtmnt. 'Hits
36GODGL uxrat iznst TW met by Frornary
IS, 198ft Most facilities should be able
to meet this limit after installing «nd-crf-
pipe tteauneatto meet the electroplating
PSES of Pait«3. However Part 433
allows the period until February 15.1368.
in caavaddrticmsi process stream* -
present -special cotnpSaitce problems.
For PSES. job shops and independent.
printed circuit board manufacturers are-
regulated only -under Part «3. They will
have until July 141988 to comprjr-witt*
,. TTO. Thus "seveai years'* will nave
fboowad the SettJemaw Agreement of
1980,
In .calculating variability factors.
dmtgjw -were mode to bom- the daily
*M^^^iiiTp *MMflajy^|y 30j thirty day*
vaoabiliiy. First the daily maximum
variability wea-calcaiatecHn the
proposai by using Jogtffirmal ataastica
lor pfaat* with lew than 100 jaapfcaf
days-aod a nonparamatnc procedure-far
plants reporting 100 or more
observations. For the final regoctaoa 4se
Agency found that the larger data sots '
had a good fit to the lognormai
distribution. Thus the Agency ia-unai
the lognormai procedure for all data
sets. -Second. 30 day limits baaed oo tn» •
average of 30 samples have bean-
replaced with a monthly avenge baaed
on 10 samples per reporting period. This
is consistent with other recent Effluent
Guidelines for similar industrial
categories.
In addition, the Agency responded to
comments that tba,statistical
methodology used in proposal did not
predict percent exceedancaa of,th« 30
day limits consistently with the 98%
criterion used to derive the limits. The-
mam. reason for thia waa that day to day
dependence in the data was nut
accounted for in dornrinj the proposed
limits. In deriving the 10 sampl* monthly
iimita. the Agency examined data
dependence -ia tares ways. First, by
fitting diet data to a ataouicai time-
series nrvjflii n**uMii't1 gy incorporating,
direct computations of auto-carmacions
into derivations of tha linritx and tfard.
by Sittog oburved jaqnaBcaa of 10 day
average* to a lognomiai distribiirinn.
The fiuai monthly limits were
determuiaal by fittotg observed
sequence* of 10 day averages to a
lognonnal disaiboaoa beeaoae this
provideii the aaet aaafantoiy at to the
data. The ytivwk e£foct of these
statistical changes, ws ta aa» aoma
limits.
Another change ia that aa alternative
^rfffltiHkkf ffya^y^ limiti* "^^^^
avaUabte to ^alirjeswim agnSflcant
form*
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Federal Register / Vol. 48. No. 137 / Friday, July 15. 1983 / Rules and Regulations 32471
municipalities and permit writers to
monitor 10 days per month, the total
annual costs increase by SSI million
from S118 million to $179 million. No
'closures or employments effects are
projected to result from this level of
monitoring; the average increase in cost
of production would be 0.03 percent
versus the 0.02 percent presented above.
The Agency has determined that this
regulation would be economically
achievable even if all facilities are
required to monitor 10 days a month. No
measureable balance of Bade effect is
expected from this regulation due to the
estimated small change in the pnce of
metal'finishing products.
3PT
Direct discharging facilities are not
expected to incur costs to comply with
the metals and cyanide limitations
because these facilities are already
covered by NPDES permits which set
BPT limits on case-by-case best
engineering judgments. A1981 survey of
randomly selected permits indicates that
nearly all existing permits specify limits
equivalent to, or more stringent than.
those contained in-this regulation.
Direct discharging facilities may incur
costs to comply with the limitation on
total toxic organics. EPA assessed, TTO
compliance costs on the assumption that
ail plants would incur baseline "
monitoring costs of $1.304 an a one time
basis. EPA believes that almost all
plants will then comply through the
certification process. Nevertheless, EPA
assumed that those facilities which
currently dump would not be able to use
the certification process and would
incur annual compliance costs. (This
same procedure was used for TTO
compliance under PSES.j EPA has
assumed that the annual BPT
compliance costs could be $29.000 for
job shops, $34.700 for independent
printed circuit board manufacturers and
3488.000 for captive shop facilities.
These costs apply to 10 out of 388 direct
discharging job shops, 12 out of 44 direct
discharging independent printed circuit
board manufacturers, and 182 out of
2.500 direct discharging captive shop
facilities. Increases in the cost of
production resulting from the control of
TTO are not expected to exceed 0.9
percent. No closure or employment
effects are projected for these sectors.
air
Since the BAT limitations are the
same as the BPT limitations, there is no
incremental cost or impact associated '
with compliance with the BAT
limitation:.
PSES
Indirect discharging job shop and
independent printed circuit board
facilities are expected to incur costs
only to comply with the TTO limitation
which is-being added to the
electroplating pretreatment standards in
Part 413. This TTO limitation is included
in the regulation because compliance
will significantly reduce toxic organic
pollution and will cause negligible
economic impacts on these industry
sectors. EPA is not imposing metals and
cyanide limitations more stringent than
those specified in the existing applicable
pretreataent standards despite
evidence that such limits can be reliably
achieved by the technology that forms
the basis of the current standards. This
is consistent with a March 1980
Settlement Agreement in which the
relevant trade-associations agreed-not to
challenge the Part 413 pretreatment
standards for existing source
eleclropiaterSe
Approximately 77 of an estimated
2.734 indirect discharging job shops and
38 of the 327 indirect independent
printed circuit board manufacturers are
assumed to incur'costs to comply with
the TTO standard. Annual costs of
$222,500 and $254.300 respectively are
projected for the two sectors. The
average annual cost per facility to
comply with the TTO limitations is
approximately $2900, primarily for
sampling and analysis. No closures or
employment, effects are projected for
these sectors. Production cost increases
an expected not to exceed 0.03 percent
for the two sectors.
Non-integrated indirect discharging
captive facilities-with effluent flows
greater then 10,000 gallons per day an
assumed to incur additional costs to
comply with the TTO standard. Control
of metals and cyanide can be achieved
through capital investment already
required by currently effective
electroplating regulations. Although the
metals and cyanide standards
promulgated today are more stringent
than those in the currently effective
electroplating regulations, they can be
met through use of the same pollution
control equipment relied on to meet the
electroplating pretreatment standards.
The $167.500 of annual costs associated
with control of TTO applies to 58 of the
900 nonintegrated captive indirect
dischargers with flow-greater than
10,000 gpd. No closure or divestitures
are expected to occur.
Non-integrated indirect discharging
captive facilities with flows less than
10.000 gallons per day will incur costs
from both the metals and cyanide
standards and the TTO standards.
Unlike the prior-group with Hows greater
than 10.000 gpd, this group was
generally exempt from Part 413's
precipitation/ clarification based
pretreatment standards. Their inclusion
in-the metal finishing standard could
necessitate investments in both end-of-
pipe and in-plant treatment
technologies. The cost for these facilities
to comply with the metals and cyanide
* standards totals $11.8 million annually.
These costs apply to 912 out of an
estimated 2850 nonintegrated indirect
discharging captive facilities with flows
less than 10.000 gpd. Data indicate that
the remainder of these plants already
have adequate treatment in place. The
annual cost to comply with the TTO
standard is $534.600; this applies to 135
facilities. The average increase in the
cost of production is approximately one
percent No closure or employment
impacts an projected.
Of the.3.750 facilities in the last
industry sector, integrated indirect
discharging captives. 1.200 may incur
aggregate costs of $104 million annually
to comply-with the metals and cyanide
standards and 243 of these facilities may
incur costs of approximately.$705,000
annually to comply with the TTO
standard. Integrated shops perform
metal finishing operations in addition to
electroplating processes. Thus, they are
affected by the existing electroplating
standards as well as by today's
regulation. EPA anticipates that the
integrated facilities will comply with the
metal finishing standards by treating
their total process discharge through a
jingle treatment system that would be
more costly, than the one required solely
to treat electroplating waste-waters.
The costs indicated above reflect the
additional costs of complying with the
metal finishing standard: the
electroplating costs were reviewed in an
earlier regulation 40 CFR Part 413. 44 FR
52590, September 7.1979 and they serve
aa the baseline for determining the
impacts of the metal finishing regulation.
To determine the baseline costs required
to comply with the electroplating
pretreatment standards, EPA first
revised its earlier estimates, based on
updated surveys of treatment in place.
improved estimates of the population of
affected captive shops, and calculated
costs attributed to the electroplating
flow of integrated captive indirect
dischargers. The revised estimate (in
1982 dollars) indicates that this sector's
costs for compliance with the
electroplating pretreatment standards
are $512 million in capital costs and $169
million in annual costs, including
interest and depreciation. EPA now
estimates that the major economic
392
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32472
Federal Register / Vol. 48. No. 13? / Friday, July IS, 1983 / Rules and Regulations'
effects of that regulation would be 24
plant closures and six electroplating
divestitures which could result in 896
job losses and 34 job transfers.
In estimating the economic impact ox
today's metal finishing regulation. EPA
assessed the costs of treating the
additional Sows covered by today's
regulation at the model plants used in
the electroplating analysis. The costs .
used in conducting the economic impact
analysis reflect the cost of treating ail-
process flows, expect for the six
electroplating process streams- specified
in Part 413. To the extent these flows
include processes oat regulated under
metal sighing, tiie costs and resulting
impacts overstate the effect of thametai
finishing regulation.
SPA's estimates of the effects of these
regulations ace based on a sample of
approximately 1.100 plants. The results
heve been extrapolated to the Cull
population of &750 plants in this- sector.
For each model plant the analysis
determines the- incremental incr&ase in
the-costs of production to comply with
the metal fin
plant's compfiancs casts relative- to
sales are high, the analysis projects
metal finishing process One divestitures
or plant closures. Additional impacts.
thus, are those due to today's metal
finishing ragiilajinn nniy. IgyegQQeBi
costs are expected to total
approximately 33S1 million, while
annual costs are projected to be
approximately S118 million, '"^"fting
interest and depreciation. The annual
costs represent approximately n ??
percent of the 280 billion «"»"«! valoe of
shipments from integrated 'T*^*yrt
captive plants. EPA's analysis protects.
that this would lead to oe plant closures
or process line divestitures, and that no-
employment disruption would result
The TTO portion of these total a"m"'1
costs shown above is approximately
5705.000. TTO costs apply to 243 of the
3750 integrated indirect discharging
capove- facilities.
Finally, EPA assessed the combined
impact of today's regulation -and the
electroplating pretreatment regmatioa
on the captive integrated indirect
discharging sector of me industry* Tliis
analysis, like those for eledropiating
and metal {hushing alone, was based on
costs for the treatment technology used
for the development of the limitalfrms.
Some- plants may receive removal
credits or install less expensive
technology. In addition. EPA has
deferred the compliance, date lor
integrated facilities, thereby allowing
plants additional time to plan for
compliance and not be subject to
treaonent.costs. This analysis avi^t^t
that the combined investment for the
captive integrated indirect discharging
sector for bom regulations was 3827
million, with animal costs of S274
million, including, interest and
depredation. Thirty plants (out of 3J50)
might divest their electroplating lines or
dose, and 980 jobs (out of 450.000) could
be lost or displaced. These impacts are
the seme as those due to the
electroplating preoeatment standards
alone. No additional closures,
divestiture's, or* uitemploymB&t effects.
are expected from the more stringent
standards promulgated today.
ffSPSandPSNS
Finally, the noairementa for new
sources are the same-as those for
existing sotsrssa* except that cadmium
must be controlled more stringently. The
incremental cost of compliance wrth the
cadmroa-contrBi ranges from 314.000 to
$24.000 par facility depending on the
water flow. Tisse costs represent
between CUE and 2.0 percent of
• projected vataairf sales for these
facUitiesk Since cadmntm plating occurs
at only abort 153S-of tha facilities and in-
plant consols frlt" be designed into new
facilities, there is expected, to be no
competttr™ disadvantage for new
sources iniiHnn to enter the industry.
Total Toxic Organic!
EPA's ""••""•"' analysis of tfae-TTQ
limit had its own costing memodoigy. Its
results were incorporated into the
impact analyses for the other specified
limits. £PA .believes, however, mat a
ceroficatioa procedure will make these.
costs unnecessary in almost all cases. •
Tie, Agency- is offering the
certificaaoa- procedure as as alternative
to self-monitoring because frequent.
monitoring Jar toxic orgaaics could be
expensive. Under* the certification
procedures facilities •**"* identify ****
toxic organics jjsed and certify mat the
resultant wastes are being properly
hauled. The Agency axpecti that almost
all plants mflcartify.
Some plants aay still be required to
monitor. However, estimating the.
number of £aeilltias mat may still be
requind to monitor TTO must be
anrrsnrilisiied indirectly, because dun
is oo history to indicate how cootroi
authooties will apply toxic organic
requiremeDB) JM*J certification
alternatives to .monitoring. The Agency
exsmuwd rwo indicators of the need to
require monitoring. Tha first was tha
percentage of plants that currently dump
waste solvent degreaaen. This
percentage may approximate the
population .size that control authorities
need to-chadc. Only 24* of the captives
use solvent degreasing. which is the
primary source of potential toxic organic
violations in these wastewaters.
-Comparable figures are 10.3% for ]ob
shops and 100% for printed circuit board
manufacturers.
Thes* wastes can profitably be
recovered by the plant and some waste
haulers, who pay for waste solvents.
have been identified, and are cited in
the public record. Approximately 73% of
the facilities which ""»•"» solvent
degreasers. already properly dispose of
this -waste. However even the 27% of the
population who now dump their
solvents will probably stop that practice
and be eligible for certification. In
addition some of the solvent degreasers
that these plants use do not contain any
toxic organic*. Other sources of toxic
orgaaics present at metal .finishing
plants may compensate for the Agency's
conservative assessment on decreasing
but this should not be significant since
dumped solvent degreasers are clearly
the single most' significant source of
TTO ia wastewaters. Thus this
approach leads to a conservative
overestunatioa by the Agency.
The second approach was to examine
the percentage of ERA sampled data
which exceeded the TTO limit and to
consider this as a measure of the
fraction of facilities needing monitoring.
This was 2J percent of the data (i-a.
97.4* of sampled data already complies
with the TTO limit). The 2.3 percent
exceedance rale of the TTO limit during.
EPA's «jn»p«ng supports the need for
certification and for control authorities
to establish reasoned plant specific
monitoring frfianeacias.
For purposes of fmnnnm; analyses
the number of facilities coated for TTO
monitoring wes estimated to be
equivalent to-the number of facilities
currently dumping solvents. The
economic impact analysis also
performed two sensitivity analyses. The
first was wits a greater number of plants
monitoring for TTO. The second
a*mmrm**i that pleats monitored for TTO
monthly instead of quarterly. Both
changes led ttkoniy slightly different'
impacts. AU.scenarios--were.found to-be
acceptable and economically
achievable.
Sunwtufy
The Agency concludes that the final
regulation is economically achievable.
and the impacts are justified uTlight of
the affluent nriwrtt'™ achieved. The
metal fi««^"^ regulation will remove
an additional 20 million pounds per year
of metals and cyanide and 10 million
pounds per year of toxic organic*,
393
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Federal Register / Vol. 48, No. 137 / Friday, JuJy IS. 1983 / Rules and Regulations
32473
3. Executive Order 12291
Under Executive Order 12291 the
Agency must determine whether a
regulation is "Major" and therefore
subject to the requirements of a
Regulatory Impact Analysis. Major rules
impose an annual cost to the economy
of S100 million or more or meet other
economic impact criteria. Based on the
Agency's estimates this regulation could
have an annual effect on the economy of
more than 5100 million, making it a
major regulation.
Executive. Order 12291. does not
require-a Regulatory Impact Analysis
where its consideration would conflict
with the development of-regulations.
pursuant to a court order, as with tins.
metal finishing regulation. EPA. has
prepared, however, an-analysis that
contains, many of the element* of. a
Regulatory Impact Analysis-, A-cop? of
the analysis cao.be obtained.fram.Aiec
Mcflnde, Monitoring and-Data,Suppon
Division. WH-553, US. EPA, 401M.
Street S.W., Washington, D.C 20480..
C. Regulator? Flexibility Analysis
Pub. L 99-354 requires that a
Regulatory Flexibility Analysis' be
prepared for. regulations, that have a
significant impact on a. substantial
number of small entities. The analysis,
may be done in conjunction with, or. as-
part of. any other analysis conducted by
the Agency.
A small busine9*.anaiy*tt is.uiciuded.
in the economsc.impact,analy«»s,Tai»,
analysis shows that there wiQ not ha-a.
significant impact on any segment of the
industry, large or small. Therefore, a
formal Regulatory Flexibility Analysis
was not required.
D. SBA Loaar
The agency is continuing to. encourage
small plants—including circuit board
manufacturers—-to use-Small Business.
Administration (SBA] financing as
needed for pollution control equipment.
The three basic programs are: (1) TSe
Guaranteed Potation Control Bond
Program. (2) the Section 503 Program.
and (3) the Regular Guarantee Program.
All the SBA loan programs are- only
open to businesses that have: {a) net
assets less than 56 million, and (fa) an
average annual after-tax income of less
than S2 million, and (c) fewerthan 2SO
employees.
For further information and specifics
on the Guaranteed Pollution Control
Bond Program contact: U.S. Small
Business Administration. Office of
Pollution Control Financing. 4040 North
Fairfax Drive. Rossiyn, Virginia 22205
(703) 235-2902,
The Section 303 Program, as amended
in [uly 1980. allows long-term loans to
small and-medium sized businesses.
These loans are made by SBA approved
local development companies. These
companies are authorized to issue
Government-backed debentures that are
brought by the Federal Financing Bank.
an arm of the U.S. Treasury.
Through SBA's Regular Guarantee
Program, loans are made available by
commercial banks and.are guaranteed
by the SBA. Tiia-program has. interest
rates equivalent to markat.rates.
For additional inforn»tioB.on.the
Regular Guacante»aad.Sectioni503.
ProgramfrcaatactyaaE district or local'
SBA- Offiea, Thsseoordiiutor ae EPA
headquartarsi.is-.Ms. FrancatQeaeette
who may>be:reacind-at.(2a2T38Zr-33Z&
XrV..Non-Water-<2uality Environmental
The eirn
form of pollutunranp
environmental-problems- Sections'
and 30&of the Actrequirt EPA to
consider the- non-wwer-onaiity
other
requirements) of. aertaa- regulations. To-
comply, EPA eoimdei etfctfaeegeet -of
this,regnlatje»os-air: noraevpadrenon.
and aoiiriv waste-ijeiiBi aiiuiu aggie.
balantinffpotiatioirptoblems\ags0ist
each otinraaevafouiat energy use-is
difficult EPA bOHVf^That'ias'fmai
regulaaon.hujjt1 JBI imii-gvergU:narlonai
goals*
Thrfc^owinsrarertnenon-water*
quality envnrsnnental impacts
(including energy reqrnrenientsl
associated with, today's regniaJlotr.
A. Air Poilotaa
Compliance, with the.BPC.aKT, NSPS,
PSES, and PENS will not.create any-
substantial air pollution-problems.
Alkaline chlorinatSon for cyanuia.
destruction endchromiuni reduction
using sulfur dioxide may produce some
emissions to the atmosphere*
Precipitation and-danfication. the major
portion of the technology basis, should-
not result in any air pollution problems.
In addition, control of total toxic
organics at the source will result in a
decreaseurtne- volatilization of solvents
from streams and POTWs.
£. Nois*
None of the wastewater treatment
processes cause significant
objectionable noise.
C Radiation
None of the treatment processes pose
any radiation hazards.
0. Solid Waste
EPA has considered the effect these
regulations would have on the
accumulation of hazardous waste. »•
defined under Section 3001 of the
Resource Conservation and Recovery
• Act (RCRA). SPA estimates that the BPT
and BAT limitations will not contribute
to additional solid or hazardous wastes.
However. PSES will increase the solid
wastes'from these plants by
approximately 185.000 metric tons per
year. This sludge'can be hazardous
because it will necessarily contain.
additional'quantities (and
concentrations) of toxic-metal
pollutants. Disposal of these wastes was
coated as though they were hazardous.
EPft'3 Office ofSoadrWaste has -
anaiyzed-tbe saiid*waste-management
and disposal costs* required' by the
industry!} compliance- with RCHA
requirements. Some-results-were*
.pubnshettin-45711 33986 (May 19,1980f.
In addition. RGMjcostB'havebeen
included in.tnwcostt.-antr economic
impact anaiyswdtmng^'tJie development
of this regoiation. However, since
November 1990. EPA- na* received: 196
petitions to-deiis* wastes, from' metal
finishing>faciUtiea.-S«venty-«euen.ha-ve
been granted. 104.are-pending, and 15
have been-rejected.. Thus it-appears- that
the.deosion.to cost jll.-sol '
overstated. likely. co«ts^ Furthermore-, the
Agency has.not assessed the savings
Hkeiy to occur because of reduced
contamination. of.POXW sludges. Those
savings-are likely to becanajderabie,
EPA estiaiatefcthat achioving; the BPT
and BAT effluent limitations will not
increase electrical energy consumption.
The Agency estimates that PSES will
increase eieetncar-gnergy consumption
by approximater? 142 million kilowatt-
hours per year. For a typical existing
indirect discharger, tins-will increase
energy con»umpaon less- than one
percent of the total energy consumed for
production*
The- energy requirements for NSPS
and PSNSarfceXnnated.to.besirnslar to
energy reqriiien»nr.forBAT. However.
this can.oiriy be quantified in inwh/year
after pro-ecttons.are-made fornew piant
construction.
XV. Best Management Practices (BMPs)
Section 304(e) oftha-aean Water Act
authorizes the Administrator to
prescribe "best management practices"
("BMPs"1. EPA.may develop BMPs that
apply to all industnai.sites or to a
designated industrial category, and -may
offer guidance to permit authorities in
394
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32474 Federal Register / Vol. 48. No. 137 / Friday. July 15. 1983 / Rules and Regulations
establishing management practices
required by unique circumstances at a
given plant
Although EPA is-not prescribing them
at this time, future BMPs could require
dikes, curbs, or other measures to
contain leaks and spills, and couid
require the treatment of toxic pollutants
in these wastes.
XVL Upot and Bypass- Pluntsiuas,
A recurring issue is whether industry
limitations and standards should include
provisions that authorize noncompliance
during "upset" or "bypasses." An upset
sometimes called an "excursion," is-
unintentional noncompliance beyond
the reasonable control of the permittee.
EPA believes that upset provision* are*
necessary, because upsets will
inevitably occur, even if the control
equipment is properly operated. Because)
technology-based limitations can require
only what technology can achieve, many
claim that liability for upsets is
improper. When confronted with thu
issue, courts have been divided on tfaa
questions of whether an explicit upset or
excursion exemption is necessary or
whether upset or excursion Incidents
may be handled througn.EPA's
enforcement discretion. Compare
Marathon Oil Co. v. EPA. 564 F. 2d 1253
(9th Clr. 1377) with WeyernaeiMarv.
Castle, supra and Cam Refiners
Association, at oJ. v. Coatit, No. 78-1009
(8th Or. April 2.1979). See also
American Petroleum Institute v. EPA.
340 F. Zd 1023 (10th Or. 1978); CPC
International Inc. v. Train. 340 F. 2d
1320 (8th Or. 1978): FMC Corp. v. Tram.
539 F. 2d 973 (4th Of. 1978).
Unlike an-upaet—which is an
unintentional episode—a bypass is an
intentional aoncompiiance to
circumvent waste treatment facilities
during an emergency.
EPA has both upset and bypass
provisions in NPDES permits, and die
MPDES regulations- include upset and
bypass permit provisions. See 40 CFR
Part 122.4-1. 48 FR14151.14168 (April 1.
1983). The upset provision establishes
an upset as an affirmative defense to
prosecution for violation of technology-
based effluent-limitations. The bypas*
provision authorizes bypassing to
prevent loss of life, personal injury-, or
severe property damage. Since
permittees in the metal finishing
industry are entitled to the upset and
bypass provisions in NPDES permits.
this regulation need not repeat these
provisions. Upset provisions are also
contained in the general pretreatnaM
regulation.
XVTL Variance* and Modifications /
Federal and Slate NPDES permits to
direct dischargers must enforce these
effluent standards. The pretreatmem
limitations apply directly to indirect
dischargers.
The only exception to the BPT effluent
limitations is EPA'a "fundamentally
different factors" variance. See £ /.
dufont de Nemours and Co. v. Train.
supra: Weyerhaeuser Ca. i. Castle,
supra. This variance recognizes
characteristics of a particular discharger
in the category regulated that are
fundamentally different from the
characteristics considered in this
rulemaking. Although this variance
clause was set forth in EPA'a 1973-1978
industry regulations, it need not be _
included in this regulation. See 40 CFR
Part 123-30,
Dischargers subject to the BAT
limitations an also eligible for EPA'a
"fundamentally different factors"
variance. BAT limitations for
nonconventional pollutants may be .
modified under Sections 301(c) and
301(gj of the Act These statutory
modifications do not apply to toxic or
conventional pollutants; According to.
Section 301(j)(l|(B). applications for
these modifications must be filed wr&n
270 days after promulgation of final
effluent limitatiens«andr standard* See
43 FR 408S9 (Sept 13. 1978). These Part
413 and Part 433 regulations do not
regulate any non-conventional non-
toxic, pollutants. If any of the regulated
pollutants are declared non-toxic and
non-conventional in the future, then
dischargers may seek 301(cj or 30l(gJ
modifica tions*
Indirect dischargers subject to PSES
are eligible for the "fundamentally
different factors" variance and for
credits for toxic pollutants removed by
POTW. Sea 40 CFR 403.7; 403.13: 49 FR
9404 (January 28. 1981). Indirect
dischargers subject to PSNS are only
eligible for the credits provided for in 40
CFR 403.7. New sources subject to N5PS
are not eligible forEPA's
"fundamentally different factors"
variance or any statutory or regulator-.
modifications. See £ /. dufont de
Nemours v; Train, supra.
. Implementation of UmitadiMM
and Standards
A. Relation to NPDES Permits.
The BPT, BAT. and NSPS in this
regulation will be applied to individual
metal finishing plants- through NPDES
permits issued by EPA or approved
State agencies under Section 402 of the '
Act The preceding section of this
preamble discussed the binding effect of
this regulation on NPDES permits. -
except when variances and
modifications are expressly authorized.
This section adds more detail on the
relation between this regulation and
NPDES permits.
EPA has developed the limitations
and standards in this regulation to cover
the typical facility for this point source
category. In specific cases, the NPDES
permitting authority may have to
establish permit limits on toxic
pollutants that are not covered by this
regulation. This, regulation does not
restrict the power of any permit-issuing
authority to comply with law or any
EPA regulation, guideline, or policy. For
example, if this- regulation does not
control a particular pollutant, the permit
issuer may still limit the pollutant on a
case-fey-case basis, when such action
conforms with the purposes of the Act
la addition, if State water quality
standards or other provisions of State or
Federal law require limits on pollutants
not covered by this regulation (or
require more stringent limits on covered
pollutants), the permit-issuing authority
must apply those limitations.
3. Indirect. Dischargers
• For indirect dischargers. PSES and
PSNS are implemented under National
Pratteatment Program procedures
outlined in 40 CFR Part 403. The table
below may be of assistance in resolving
questions about the operation of that
program. A brief explanation of some of
the submissions indicated on the table
follows:
A "request for category determination
request" is a written request submitted
by an indirect discharger or its POTW,
for a certification on whether the
indirect discharger falls within a
particular subcategory listed in a
categorical pretreatment standard. This
assists the indirect discharger m
knowing just which PSES or PSNS limits
it will be required to meet See 40 CFR
403.8(a).
A "request for fundamentally different
factors variance" is a mechanism by
which a categorical pretreatment
standard may be adjusted, making it
more or less stringent on a case-by-case
basis. 0 an indirect discharger, a POTW.
or any interested person believes that
factors relating to specific indirect
discharger are fundamentally different
from-those factors considered during
development of the relevant categorical
pretreatment standard and that the
existence of those factors justifies a
different discharge limit from that
specified in the categorical standard.
then they may submit a request to EPA-
for such a variance. See 40 CFR 403.13.
395
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Federal Register /'Vol. 48. No. 137 / Friday. July 13. 1983 / Rules and Regulations 32475
A "baseline monitoring report" is the
first report an indirect discharger must
file following promulgation of a
standard applicable to it The baseline
report includes: an ^identification of the
indirect discharger a description of its
operations: a report on the flows.of
regulated streams.and the-result* of
sampling analyses to determine levefo of
regulated pollutants m those streams: a
statement of the discharger's
compliance or noncampiiance with the
standard- and a description of any
additional steps required to achieve
compliance. See 40-CTR 403.12(b)
A "report on compliance" is required
of each indirect discharger within 90
days following the date for compliance
with an applicable categorical
pretreatment standard.-The report must
indicate (he nature and concentration of
ail regulated pollutants is the facility's
regulated process wastestreams: the
average and maximum daily flows of the
regulated streams: and a statement of
whether compliance is consistently
being achieved, and if not what
additional operation and maintenance
and/or pretreatment is necessary to
achieve compliance. See 40 CFR
403.12(d)
A "periodic compliance report'" is a
report on continuing.compliance with all
applicable categorical pretreatment
standards. It is submitted twice per year
[June and December) by indirect
dischargers subject to the standards.
The report shall indicate the precise
nature and concentrations of the'
regulated pollutants in its discharge-to
the POTW; the average and maximum
daily flow rates of the facility; the
methods used by the indirect discharger
to sample and analyze-the data, and a
certification that these methods
conformed to those methods outlined in
the regulations. See 40 CFR 403.12(ej
TABLE 2.—(NOIRECT DISCHARGERS SCHEDULE FOR SUBMITTAL AND COMPLIANCE
Oiwor am
ptnoo
(tarn suaimffta to
P«au««t tor emaoir MM*
of santf-1
[ in * Ann aamaa on i
coma* Canvat
BCuiniiimiii niuur...i
1 Oiraaer « at CtMf wiimumuw OfHMr q» •. Warn <*mM* pqtmnon eamrai aMney VMR «n moron M prwri.iCB.tnto
or a» £P* A^onl W««r Qtviwon Qnctor. rf SUM oo-n not n«M «> MffO^tu^MBiMiH orogram
1 Control Autnamy * «) POTW it
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32478 Federal Register / Vol. 48. No. 137 / Friday. July 15. 1983 / Rules and Regulations
The compliance dates (or the two
categories are presented in Table 4. 3PT.
SAT. PSNS. and NSPS compliance dates
are specified by the Clean Water Act.
The compliance dates for Electroplating
PSES were set in the Federal Register on
September 28.1982. See 47 FR 42898.
Today's regulation allows facilities 3
years to comply with the Electroplating
PSES for toxic organics consistent with
the Settlement Agreement with NAMF.
For metal finishing, the Agency is
allowing 31 months for compliance with
all parameters. In addition an interim
TTO limit has been established for
compliance by June 30,1984; except for
metal finishing wastewaters from plants
which are also subject to Part 420 (iron
and steel), which must comply by July
10; 1985. This last exception is pursuant
to a settlement agreement with the steel
industry in which SPA agreed that
pretreatment requirements would apply
to steel discharges in luly 1985. It is '
passible that control of TTO in metal
finishing waste streams could, in some
cases, lead steel facilities to install
treatment technology on the discharge
from their steel processes. Therefore.
EPA has decided to allow plants
covered by Part 420 until June. 1985 to-
comply with the TTO limit
TABW 4.—COMKMMCS Ores
MM* =*•«••) PSES H*
i, CVMVW mq TTO. i
1 Par 91MB FaaMMB «• *w TTO am i«
D. Enforcement
A- final topic of concern is the
operation of EFA's enforcement
program. This was an important
consideration in developing this
regulation. EPA deliberately sought to
avoid standards which would be
exceeded by routine fluctuations of
well-designed and operated treatment •
systems. These standards were
developed so as to represent limits
which such a plant would.meet
approximately 99% of the time.
The Clean Water Act is a strict
liability statute. EPA emphasizes.
however, that it can exercise discretion
in deciding to initiate enforcement
proceedings (Sierra Club v. Train. 557 F.
2d 435, 5lh Or.. 1977). EPA has
exercised, and intends to exercise, that
discretion in a. manner that recognizes
and promotes good-faith compliance.
XIX Summary of Public Participation
-At the time of publication of the
proposed metal finishing regulation .
(August 31.1982). EPA solicited
comments on the proposed rules and. in
particular, an six specific issues. Ninety-
one cammenten responded to these and
other issues relating to the electroplating
and metal finishing standards. The
following parties submitted comments:
Air Transport Association of America
Alpha Industries Inc.
The Aluminum Association incorporated
• American Airlines
American Fouadrymen's Society
American Hoc Dip Galvamzen
.American Metal Stamping Association
Anorock Corporation
Anaconda Aluminum Company
• Ansul Fire Protection
Apollo Metala. Inc.
American Telephone-and Telegraph
Company
Atwood
Sabcoek and WUcox
3ausch•
PEC Industries
Pioneer Metal Finishing. Inc.
Porcelain Enamel Institute
Porcelain Metals Corporation
Praegttzer Industries inc.
Raytheon Company
Republic Airlines
Raxnora ,
Reynolds Aluminum
Rockford Area Chambers of Commerce
R.8. Donnelley and Sons
Sanders Associates Inc.
Sanitary District of Rockford
Sperry Corporation
Square 0 Company
State of Connecticut Department of
Environmental Protection
State of Vermont Agency of Environmental
Conservation
State of Wisconsin Department of Natural
Resources
United Airlines
397
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DIALOG F11e4I Pollution Abstracts - 7O-82/Apr (Copr Cambridge Scl Abs) (Item 46 of 69) User23913 23junfi2
cr*
K)
78-O5459
An In-depth, cross-flow separation technique for the removal
of suspended solids from wastewaters.
Sundararo. T. R. ; Santo. J. E. ; Shaplra. N. I.
HydronautIcs, Inc., Applied Science Dept.
INDUSTRIAL WATER ENGINEERING 15(1), 9-1O, 12-18,
Coden- IWEGAA Publ.Yr- Jan.-Feb. 1978
11lus. refs.
Abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Results are presented from smalI-scale tests on the
microf111rat Ion of a variety waste effluents utl1 I zing
microporous tubes (Hydroperm), developed by Hydronaut tcs,
Incorporated. These thick-walled, tubular microfliters, which
can be made from many common thermoplast tcs (such as
polyethylene and nylon), enable almost the total removal of 5S
even at very low (about 5 ps1) filtration pressures. The
unique feature of the tubes Is that their pore structure can
be controlled during the production process; thus, optimum
fII trailon performance Is obtained for different waste
effluents by tailoring the tubes to the characteristics of a
given effluent under cons tderat ton, through a serles of
systemat1c. laboratory screening tests. Some results on
dewaterfng of waste sludges produced as an end product of
other treatment methods like dissolved air flotation are also
described. The filtration technique Is also capable of heavy
metal removal from waste streams provided that the metals can
be precipitated .in the hydroxide form by 1 1me addition or by
some other approprlate chemical treatment. Tests with
battery-waste effluents containing 7 to 8 ppro Pb Indicated
that the Pb level In the permeate was reduced to O.O18 ppm. <
AM)
DescrIptors: Suspended sol Ids; Effluent treatment; Pollutant
removal; F11trat ton; Industrla! effluents; Heavy metals;
Sludge dewatering; F11ter media; Engineering; FlIters;
HydraulIcs
I dent iflers: Hydroperm
acid mine drainage (AMD) converts the sulfate on the resin to
the monovalent blsulfate ion, freeing a resin exchange site
which may then be occupied by another an Ion. At Sml th
Township, a strong-acid cat ion exchanger Is coupled to the
Sul-bISul anIon exchanger. The effluent from the cat Ion
process-chiefly sulfurIc acId (H2SO4)- Is treated by the an I on
column to remove the free mineral acid of the AMD and the end
product, af ter chlor1natIon, meets potable standards. The
Desal process Incorporates a weak-base an ion exchange res In
which operates In the bicarbonate form to convert metal
sulfates to their bicarbonates, capable of being precipitated
by Al and Fe+3. Lime treatment removes the remaining cations,
except Na. Another process uses 2 res Ins-an H+-form,
strong-acid cation exchanger, and a weak-base anIon exchanger
In the free-base (OH-) form. In the cation column, H+ are
exchanged for the metal Ions of the AMD, leaving the cation
effluent predominant1y H2SO4 wlth res idual concentrat Ions of
metals. The effluent then enters the weak-base anIon
exchanger, where the acid Is absorbed by the resin. As the
anlon effluent contains residual levels of Fe and Mn. It Is
1 line-neutral ized to pH 9- 1O, f 11 tered, and adjusted to
neutrality. Either hydrochloric acid or H2SO4 may be used to
regenerate the cation column, producing a waste stream of
excess H2SO4 and sulfates of Fe, Al, Na, Mn, Ca. and Mg.
Regeneration of the anlon exchanger Is effected with sodium
hydroxide, and produces a waste stream composed mainly of
sodium sulfate. (FT)
Descriptors: Mine drainage; ion exchange; Potable waters;
Pollutant removal; Chemical react Ions; Ions; Res Ins; Acidic
wastes; Wastewater treatment
Ident Iflers• Sul-bISul process; Desal process
78-O5378
Invest 1 gat 1 on of 1 on exchange treatment of ac Id ml ne
drainage.
Wllmoth, R. C ; Scott, R. B. ; Kennedy/ J. L.
EPA, Industrial Environmental Research Lab., ClnclnnattI. OH
45268
Seventh sympos1 urn on coa1 mIne dra1nage research
Louisville. Ky. Oct. 18-2O, 1977
Seventh symposium on coal mine drainage research: Papers
pp. 88-1O6 Publ.Yr: 1977
Publ: Washington, D.C. Nat ional Coal Assoc1at Ion
11lus. refs.
No abs.
Languages: ENGLISH
Doc Type CONFERENCE PAPER
In the SuI-blSul Ion exchange process, the sulfate form of a
strong-acid anlon exchanger is used. The acidic nature of the
-------
DIAIUG FUe41: Pollution Abstracts - 7O-82/Apr (Copr Cambridge ScI Abs) (Item 48 of 69) User239l3 23Jun82
U)
78 O5312
Quality and treatment of coal pUe runoff.
Cox, D. B ; Chu. T. -Y. J.; Ruane, R. J.
TVA, Div. of Environmental Planning, 246 4O1 Bldg.,
Chattanooga, TN 374O1
Third symposium on coal preparation Louisville, Ky. Oct.
I8-2O, 1977
Third symposium on coal preparation: Papers pp. 252-275
Pub I Vr: 1977
Publ: Washington, D.C, Natlonal Coal Assoclat ton
11lus. refs.
No abs
Languages. ENGLISH
Doc Type: CONFERENCE PAPER
The water quality of coal pile drainage Is affected by the
leaching of oxidation products of metallic suSfides associated
with the coal. Runoff treatment methods of 2 TVA plants (J
and E) are summarized. A rainfall-runoff relationship can be
used to estimate detention basin design and to calculate acid
loads to ash ponds. The pH of the drainage from the 2 plants
was simitar desplte a dlfference In the S content of their
coal supplies, but acidity was higher at plant J despite the
similar pHs. Concentrations of 70S were somewhat higher at
plant J; most of the dissolved solids were sulfates. Iron
concentrations at both plants are lower In range and mean than
values encountered by other Investigators; Mn levels were
comparable or lower to those found In previous work. Lead.
Ba. and Ti were low or below the limits of detection; most
trace element mean concentrations at plant J are 3-8 times as
high as those at plant E. Mercury concentrations exceeded.EPA
water qualIty criteria at both plants, while As and Se
exceeded criteria only at plant J. Other metal Ion
concentrations are below the limits of toxlclty. Transfer of
the drainage to an ash pond for neutralIzatIon and
precipitation appears to provide adequate treatment. (FT)
Descr iptors: Runoff; Wastewater treatment; Eleetrie power
plants; Water qualIty measurements; Coal; Storage; Leaching;
pH; Heavy metats; Precipitation
Identifiers: coal storage piles
metals, and suspended participates. At the Belpre Coal Dock
on the Ohio River. It was decided to treat the runoff by lime
neutralization, aeration, and settling of precipitated calcium
sulfate, metallic oxides, and hydroxides. From rainfall data
from a nearby weather station. It was determined that a
treatment rate of 45 gpm with a recycle of a portion of the
treated wastewater and sludge would produce the desired
effluent and sludge density from the runoff from the 7.5 acres
of the storage area. Runoff Is diverted to a 2O7,OOO-gal
equalization basin. It then flows Into the concrete treatment
sump where 2% 11me slurry is added on demand from a pit
controller. The treated water is pumped to a 79,OOO-gal,
2-compartment settling basin; the clarified water Is decanted
and discharged to the Ohio River. Both equalization and
sett I Ing basins are clay-1Ined to prevent seepage Into
groundwater. To create a denser sludge, a portion of the
naturalized wastewater Is diverted back to the Inlet of the
treatment sump. A sludge density of 3O%-4Q% is thus obtained.
At power plants, the sludge Is burned with the coal. final
effluent from the runoff treatment has a pH of 6.5-7.5. U1
mg/l Fe, greater alkalinity than acidity, and J2O mg/1 TSS.
In a similar facility handling western coal, only SS need be
treated. The system consists of primary sett)ing and
collect ion ponds, a chemical trea tment uni t to add alum
coagulant, and a 2-compartment settling basin. (FT)
Descr iptors: Runoff; Wastewater treatment; Coal; Storage;
NeutralizatIon; SedlmentatIon; Set11 Ing basins; Sludges:
Prec ipltat Ion
Identifiers, coal storage piles; storm water runoff
78-O53I1
Treatment of precipitation runoff from coal storage plies.
Ferraro. F. A.
Amerlean Electr tc Power Service Corp., Environmental
Engineering Division. P.O Sox 487. Canton. OH 447O1
Third symposium on coal preparation Louisville, ky. Oct.
1S-2O, 1977
Third symposium on coal preparation. Papers pp. 243-251
Publ Yr; 1977
Publ. Washington. O.C Natlonal Coal AssoctatIon
11lus, no refs.
No abs.
Languages. ENGLISH
Doc Type: CONFERENCE PAPER
Precipitation runoff from coal storage piles can produce
was tewater conta in ing object ionable amounts of ac tdi ty.
-------
DIALOG FI1e4t: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Set Abs) (Item SO of 69) User23913 23Jun82
CT*
78-O45O7
Physical-chemical unit operations for the treatment of wood
preserving wastewaters.
Aver 111, D W.; Schmidtke. N. W. ; Netzer, A.
Fisheries and Erw trorwnent Canada, Environmental Protection
ServIce, Wastewater Technology Centre, P.O. Box 5O5O,
Burlington, Ont, L74 4A6, Can.
Technology transfer seminar on the timber process Ing
Industry Toronto, Ont., Can. Mar. 1O-11. 1977
Techno1ogy transfer semInar on the tImber process i ng
Industry: Proceedings. In CANADA. WATER POLLUTION CONTROL
DIRECTORATE. ENVIRONMENTAL PROTECTION SERVICE REPORT SERIES.
ECONOMIC AND TECHNICAL REVIEW REPORT EPS 3-WP-78 - I pp.
63-IO7 Publ.Yr: Jan. 1978
t1lus. numerous refs.
No abs.
Languages: ENGLISH
Doc Type: CONFERENCE PAPER
The 3 elements of Wastewater treatment process design are
removal of pollutants which form unstable suspensions, removal
of pollutants which form stable suspensions, and removal of
pollutants In solution. Gravity separators remove 60%-9O% of
settleable and floatable materials and separate those
materials which are lighter and heavier than water. Dissolved
air flotation can remove N95% of free oil and some emulsified
oil. Granular media filtration removes N95% of free oil;
subsequent separation of oil and creosote from the backwash
water Is required. CoaguiatIon, followed by sedjmentation,
flotation, or filtration, removes about 95% of emulsified oil.
N9O% of COD, most of the pentachlorophenol, and some phenol.
Flotation and filtration require less land area than
sedimentation. Flotation may be more effective for
thickening. Filtration requires a separate backwash storage
and separation tank If the backwash water Is not returned to
the head of the plant and clarified In the separator. Heating
Is ef fect1ve for treatment of water In oil emuIs ions by
evaporation. Chemical reduction and precipitation can produce
total residual metal ton concentrations 01 mg/1. Chemical
ox 1da 11on and precIp11a 11on can produce res IduaI As
concentrations O.5 mg/I. Chemical oxidation removes phenol
and pentachlorophenol. Adsorption on activated carbon can
result In effluent concentrations 01 mg/1 for many Wastewater
const 1tuents Including phenol and pentachlorophenol.
Adsorption requires a relatively high degree of pretreatment
to prevent fouling of the carbon surface. Solvent extraction
can remove phenol and pentachlorophenol from wastewaters, and
provide the potential for direct reuse of reclaimed
pentachlorophenol. (MS)
Descriptors: Physlcochemlcal treatment; Lumber industry
wastes; Industrial effluents; Effluent treatment;
Sedimentation; Flotation; Coagulation; FlItratIon; Reduction;
Chemical ox IdatIon; AdsorptIon; Sol vent extract Ion; Act Ivated
carbon; Oils; Organic compounds
Ident 1flers: wood preservat ives; phenols
Treatment of plating wastes from the automotive Industry.
Cullinane, M. 0., Jr.; Otetz, J. D.
Clark, Dletz and Assoc.-Engineerse Inc.
INDUSTRIAL WASTES 24(2). 29-32, Coden• INWABK
Publ.Yr, Mar.-Apr. I97B
t1lus. no refs.
Sum.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Wa ter conserva t i on measures recommended for a Mtsstsst pp t
plant Include using spring-loaded shutoff nozzles on water
hoses, collecting and returning steam condensate for boiler
water makeup, us Ing recycled water In the buff ing process, and
using counterflow rinsing in the plating operation. Several
Wastewater segregation practices were also recommended. To
meet federal standards, the most cost-effecttve effluent
treatment was reduct ion followed by chemical precipi tat ion.
Complete treatment and direct discharge was more cost
effect tve than pretreatment and discharge to the municipal
waste system. The optImum rInse system 1s a modifled
countercurrent system with 5 rinse tanks, which reduced water
consumption from K4OO gpm to J6O gpm. Features incorporated
In the treatment design Include addition of an acid feeding
system for raw waste pH adjustment and use of the abandoned
oxidation pond to equalize shock loadings. The treatment
process included the following: reductIon of Cr+6 in a
contInuous flow system; equalIzatIon of flow wastes; raw waste
pumping; pH adjustment tn a flash mix tank; and coagulation
and settling In a reactor-clarIfier. Provision is made for
future addition of filters and final pH adjustment. Vacuum
filtration and landfill Ing is the chosen method of sludge
disposal. Problems since plant startup in March 1977 have
been minimal. Water consumption could be reduced a further
4O%-5O% If recycle systems and more strIngent water
conservation measures were used, but these measures do not
appear to be economically justified at the present. (FT)
Descr tptors: MissIssIppi; Automot ive industry wastes; Metal
fInIshIng 1ndus try was t es; ChromIurn compounds; Wa t er
conservat ion; Wastewater treatment; Wastewater treatment
plants; IndustrIa I effluents; Reduct ton; CoagulatIon
78-O4471
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DIALOG FHe41: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Scl Abs) (Item 52 of 69) User23913 23JunB2
U>
O^
Ui
78-O4274
Application and determination of organic polymers.
Wang. L. K.; Wang. M. H.; Kao, J-F.
Stevens Inst. of Technology„ Castle Pt. Stat 4on, Hoboken. Nvl
O7O3O
WATER, AIR. AND SOIL POLLUTION 9(3), 337-348. Publ.Yr:
Apr. 1978
t1lus. numerous refs.
Abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Varlous app)(cat tons of water-soluble and water-dlspers1ble
polymers In the f 1 elds of environmental, chemical„ and
blomedical engineering are reviewed. Catlontc electrolytes
are powerful primary coagulants because the colloidal matters
In natural systems are generally negatively charged. They can
be used not only for water purification and sewage treatment
but also for oil-water separatIon, corrosion control,
flocculatIon of Fe-ore siIroes, Improvement of 1Ime
precipitation processes, clarification of titanium sulfate
liquor, removal of heavy metals, killing of viruses, dredging
treatment„ and Industr1a1 wastewater treatment. In water
qualIty control. nonIonic polymers usual 1y functIon s
coagulant aids. coating the floe particles so that when flo s
collide, they adhere and form larger masses. Anton polyme s
are negatively charged and In the water softening proces .
where precipitation particles are positively charged, c n
function as primary coagulants. In general. In the tttratlon
of cat Ionic polyelectrolytes, polyvlnyI-sulfur1c acid
potassium Is used as a standard tItrant. The cat tonic
polyelectrolyte shows a light blue color In the presence of
Toluldlne Blue O dye (TBO), and the blue color turns bluish
purple at endpotnt. in the tttratlon of antonic electrolytes.
t,5-dimethyl -f,5-dlazaundecamethylene polymethobromlde Is
used, and the antonic polyelectrolyte shows a bluish color In
the presence of TBO, which turns light blue at endpotnt. (FT)
DescrIptors: Polymers; AnIons; Cat Ions; Wastewater treatment
; Water treatment; Coagulants; Water polIutIon control;
Chemleal analysIs
Identifiers: polyelectrolytes; Toluldlne Blue 0
coal gas IfleatIon, coal gas IficatIon. f Ixed-bed coal
gasification, and the COGAS process; reclaimed rubber by
high-speed commlnutIon; aerosol removal by sound wave
bombardment; drinking water purification by adsorption; Hg
recovery by chemical treatment; fluegas treatment for
sulf1te-pulplng boilers by scrubbing; heavy metal removal from
waste by sulflde precipitation; nuclear waste disposal by Ion
exchange and by vitrification; odor abatement In kraft pulp
mills by In-dlgester oxidation; participate removal from flue
gas by electrostatic precipitation; sludge drying by toroidal
dryer; solvents recovery; sulfate removal from 11 tan turn ox tde
waste by flocculatlon and by neutralization; sulfur dioxide
removal from stack gases by membrane electrodfalysIs and by
scrubbing; trInItrotoluene removal by surfactant treatment;
vapor recovery by carbon adsorption; waste Incineration by
molten-salt combustion; wastewater purification by biological
treatment; wastewater sterilization by oxygenatlon. carbon
adsorption. and Irradiation, and by UV oxidation; bleached
pulp by nonsulfur pulping; coal combustion by flutdlzed bed;
flue gas conditioning by sulfur trIoxtde generator; river
oxygenation by boat mounted O2 separation plants; and reverse
osmosIs by membrane. Several other processes Involving
Inorganic chemicals, metals, organic chemicals, petroleum and
fuels, plastics, etc. are discussed. (SS)
Descriptors: Technology; Chemicals; Petroleum; Fuels; Coal
gas f f teat 1on; Industrial plants; Air pollut ion control; Water
pollution control
78-O3975
New processes and technology alert.
Anonymous
CHEMICAL ENGINEERING 85(2), 141-151. Coden: CHEEA3
Publ.Yr: Jan. 16, 1978
no refs.
Sum.
Languages. ENGLISH
Doc Type: JOURNAL PAPER
The user, features, current status, and salient remarks are
tabulated for the following new products and processes:
ammonium sulfite from flue gas desulfurtzatIon; carbon black
from high temperature pyrolysIs of tIres; automotIve
lubrication olI reclaimed by solvent extract ton and
distillation; synthetic natural gas produced by fluId I zed beet
-------
DIALOG Flle41: Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Sc I Abs) (Item 54 of 69) User239l3 23Jun82
LO
01
CTi
78-O333I
Sodium bicarbonate helps metal plant meet Federal standards.
Barber, N. R.
and Dwight Co.
Inc.
P.O. Box 369 Piscataway. NJ
29. Coden: INWABK
26.
Church
O8854
INDUSTRIAL WASTES 24(1).
Publ.Yr: Jan. -Feb. 1978
H I us . no ref s .
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Treatment of toxic metal wastes with sodium bicarbonate
(NaHCO3) precipitates the metals and holds the pH at optimum
level. The treatment appears to be cost-effective, based on
theoretical studies of metal precipitation with hydroxides and
carbonates. Although NaHC03 Is not as efficient In removing
metal from solution as some other bases, it has the advantage
of neutralizing excess acidity and thus helps meet wastewater
discharge standards. The use of NaHCO3 In place of lime
eliminates many of the problems associated with the handling
and application of lime. Since the NaHC03 acts as a buffer to
maintain alkalinity near the optimum level, treatment plants
can be of a simpler design. Because this buffering action Is
automatic, there Is no need for complicated pH measurement and
application control systems. In small to moderate size.
systems, a dose of bicarbonate once or twice a day should
maintain pH at optimum levels for metal precipitation.
Although NaHCQS treatment does not precipitate all metals It
can be mixed with a suitable carbonate to Increase Its range.
A principle advantage of the bicarbonate-carbonate mixture Is
that It can be used to maintain an optimum pH over long
periods of time despite varying levels of effluent pH and of
metal In the effluent For Industrial plants In the 2OO.OOO
gpd-5OO.OOO gpd range, bicarbonate treatment systems may be
cost-effective (FT)
Descriptors: Metals; Wastewater treatment; Industrial
effluents; Precipitation; Effluent treatment; Chemical
treatment
Identifiers: sodium bicarbonate
regulations and the local municipal sewer code. Another
Hussong/Couplan System employing sphagnum peat as the
treatment medium can readily be tied Into the existing system.
In a series flow arrangement, at a later date. Changing
conditions can be met without costly, extensive replacement or
modification of the present system. The Hussong/Couplan
System treats the wastewaters with ferric chloride (FeC13) and
sodium sulflde (Na2S) at a pH In the 5-7 range In such a way
as to obtain a specific molar ratio of Cr6+6, FeCI3, and Na2S
In the effluent. A massive precipitate Is formed which
carried down virtually all of the Cr, both hexavalent and
trtvalent. The system at the Al plant Is a 6.OOO gpd system
and Is composed of 3 holding-batch tanks. chemical adders.
misers, controls, and sensors. To Insure the continuing
purity of the discharge, colorlmetrlc checks are made at the
precipitation tank. (FT)
Descriptors: Chromium; Aluminum; Metal industry wastes;
Effluent treatment; Industrial effluents; Precipitation;
Contaminant removal
Identifiers: Hussong/Couplan Treatment System
Coden: INWABK
78-O333O
Aluminum manufacturer removes chromium.
Anonymous
INDUSTRIAL WASTES 24(1). 24. 34.
Publ.Vr- Jan.-Feb. 1978
11lus. no refs.
No abs
L anguages: ENGLISH
Doc Type: JOURNAL PAPER
A New Hampshire aluminum company installed a Hussong/Couplan
Chrome Removal Treatment System to treat its raw effluent.
The effluent contains 164 mg/l total Cr. 136 mg/l hexavalent
Cr, 62O mg/l total P. and 22.8 mg/l Al. The decision was
based on 2 factors. The system reduced the pollutants to the
lowest concentrations In the final effluent and met, by a
comfortable margin. the requirements of the final EPA
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DIALOG Flle41 Pollution Abstracts - 7O-B2/Apr (Copr. Cambridge ScI Abs) (Item 56 of 69) User239l3 23jun82
3244
Ul
CTi
78-O3235
The distribution of heavy metals In anaerobic digestion.
Hayes. T. D.; Thels. T. L
Cornell Univ.. Dept. of Agricultural Engineering. Ithaca, NY
I485O
WATER POLLUTION CONTROL FEDERATION. JOURNAL 5O(I). 61-72.
Coden: JWPFA5 Publ.Yr: Jan. 1978
Illus. refs.
Eng.. Fr., Ger., Port.. Span, abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
Bench scale anaerobic digesters using municipal wastewater
sludge were dosed with different levels of heavy metals (Cr+3,
Crt6. Cd. Cu+2. Nl, Pb, and Zn) to determine their
distribution and note their effects under operating
conditions. Doslngs were made In both a stepulse and pulse
manner. Characteristic responses observed during periods of
digester distress Included Increased volatile acids and total
organic carbon. decreased gas production 'and methane
composition, and depressed values of pH. The order of
toxlclty established In this study was NIK CuKPbKCr(6|Cr+4KZn.
Toxic limits for Cd were not reached. Metals were rapidly
removed from digester supernatant In excess of 95%. The total
Insoluble portion was divided between Inorganic precipitates
and the blomass fraction Between 3OX and 6O% of the metals
were associated with the bacterial .cells. Toxic effects
became apparent at or near the maximum metals taken up1 by the
digester component. (AM)
Descriptors: Anaerobic process; Sludge digestion;
Distribution; Chromium; Copper; Cadmium; Nickel; Lead; Zinc;
Municipal wastewaters; Pollutant removal; Heavy metals
acid and a weakly basic anlon exchange resin after an
activated carbon filter, followed by a strongly basic anlon
exchanger. At the near neutral pH value of the wastewater
made possible by this system, complex cyanides are not
precipitated nor cyanide gas produced; free cyanide which
passes the mixed bed exchanger Is caught by the strongly basic
exchanger. Regeneration water and deteriorated bath are
treated with sodium hypochlorlte and ferric sulfate. Chromium
(III) Is treated with other cations with a strongly acid
exchange resin; hydrogen chromate and chromate Ion are treated
with other anIons by weakly basic exchange resins. Wastewater
containing heavy metals other than cyanide and Cr Is treated
by coagulation and sedfjnentat Ion, sand filtration, and chela te
resins which adsorb the metals selectively In series. (FT)
Descriptors: Wastewater treatment; Cyanides; Metal finishing
Industry wastes; Chromium; Heavy metals: Ion exchange;
Industrial effluents; Resins
78-O2S6O
An experience on re-use of waste water discharged from metal
plating shop.
Mural, V.; Yamadera, T.; Koike, ¥.
Hitachi Plant Engineering & Construction Co., Water & Waste
Water Treatment Dlv., Tokyo, Japan
International Congress on Desalination Tokyo, Japan Nov.
27-Dec. 3. 1977
Proceedings of the International
and Water Reuse: Vols. I and 2
97-1O4, Coden: DSLNAH Publ.Vr
Illus. refs.
No abs.
Languages ENGLISH
Doc Type: CONFERENCE PAPER
Conventional treatment processes for metal plating
wastewaters consist of oxidation, reduction. and
coagulation-sedimentation for both rinsing water and used
bath. Such treatment does not satisfy recent municipal
regulations A new process treats rinse water, containing the
bulk of cyanide and Cr wastes, with Ion exchangers; acid or
alkaline wastewater Is treated by chelate resin after
coagulation-sedimentation. The treated water can be returned
to the shop. The mixed bed exchanger consists of a strongly
Congress on Desalination
In DESALINATION 22(1-3),
Dec. 1977
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DIALOG F11e4l' Pollution Abstracts - 7O-82/Apr. (Copr Cambridge Sc I Abs) (Item 58 of 69) User23913 23jun82
U)
oo
78-O2557
RO applications In wastewater reclamation for re-use.
Sato. T.; Imaizuml, M.; Kato, 0.j et a).
Kurlta Water Industries, Japan
International Congress on Desalination Tokyo, Japan Nov.
27-Dec. 3. fl977
Proceedings of the International Congress on Desalination
and Water Reuse: Vots. 1 and 2. In DESALINATION 22(1-3),
65-76, Coden: DSLNAH Publ.Yr: Dec. 1977
11lus. refs.
Sum.
Languages: ENGLISH
Doc Type: CONFERENCE PAPER
The operation of a 37O-m3/d RO plant using ROGA spiral-wound
modules to treat metal plating wastewater for reclamation 1s
described. To facilitate achievement of 92% recovery. sodium
hydroxide was substituted for calcium hydroxide In the primary
neutraltzatIon stage, prevent Ing precipitation of calcium
sulfate on the membrane surface. The RO feed Is measured by
filtration time and color. A nonionic polyelectrolyte with
ferric chloride Is used for coagulation and clarffIcatton.
followed by gravity type dual layer filtration at a velocity
of 8 m/hr. TDS in the RO permeate are J1O% that of the RO
feed. The permeate Is further demtnera)fzed by Ion exchange.
Brine COO is removed t>y an activated carbon filter. and heavy
metals are adsorbed by Ion exchange resins. Backwash wastes
from f11ters and regenerat ion wastes from the heavy metal
removal unit are recycled to the neutralization tank. The
membranes are chemically cleaned once or twice a year; over 18
mo, the flux decline has been very slight. In a RO plant for
etching process wastewater. coagulation is with polyalumtnum
chloride, with further pretreatment by gravity type dual-layer
filter, polIshlng sand filter, and 2O-I safety filter.
Permeate water quality Is 78 ppm TDS. compared to I.2OO pprn In
the feed water. The product water Is used for rIns Ing
purposes. Another RO plant treats laboratory wastewater.
Water recovery Is 9O%, Water reclamation from brine wastes Is
made by an evaporation process, so that overall water recovery
1 s 97%,- 98%. Recovered wa ter Is used for blot og 1 ca I
experiments and cooling towers. (FT)
Descriptors; Japan; Reverse osmosis; Industrial effluents;
Wastewater treatment; Wastewater treatment plants; Metal
f in Ishing industry wastes; Water reuse
Sum.
Languages: ENGLISH
Doc Type: CONFERENCE PAPER
A Jar Based Batch Settling Test (JBBST) was used to evaluate
the performance characteristics of commercial polyelectrolytes
for use in the flocculatIon of domestic wastewater subsequent
to coagulat ion by a metal He coagulant. Performance
evaluation by the JBBST technique relies on the measurement of
floe settling rate which can be used to predict continuous
clarlfler effluent concentrations as a function of clarlfier
overflow rate. Thirty-two dlfferent commerclal
polyelectrolytes were examined initially by JBBST for domestic
waste water clarification and P removal in conjunction with
alum. A mid-range hydrolysis (1O%-2O%) anlonic polyacrylamlde
Is the most suitable polyelectrolyte for such applicat ion.
Extens 1ve tests were undertaken wlth dlfferent
polyelectrolytes, at severa 1 dosages and 2 dIfferent
wastewater plants. At all probablI I ties, the mid-range
hydroIys f s po\yacryI am t de Is super tor to the h igh percent
hydrolysis poI ye1ectrolytes usua11y recommended by
manufacturers for this application. (AM)
DescrIptors: Domestic wastes; Wastewater treatment;
Flocculat ion; Secondary treatment
Ident If iers: polyelectrolytes; comparatIve evaluatIon
78-O2522
Comparative evaluation of commercial polyelectrolytes for
flocculating alum precipitated domestic wastewater.
Benedek. A.; Banes I„ J. J.
McMaster Univ., Dept. of Chemical Engineer ing, Haml1 ton 16,
Ont. L8S 4L7, Can.
Eighth International conference on water pollution research
Sydney, Austral la Oct. 17-22. 1976
Eighth international conference on water pollution research.
Edited by S. H. Jenkins In PROGRESS IN WATER TECHNOLOGY 9(1)
32--I2, Coden PGWTA2 Publ . Yr. 1977
1 Ilus refs
-------
IALOG Flle41- Pollution Abstracts - 7O-82/Apr (Copr. Cambridge Set Abs) (Item 6O of 69) User239t3 23jun82
3246
U)
CTi
control of
Research
Coder.: ENFIAG Publ.Yr: Oct.
In
flue gas
sulfur
from pulverized
dioxide (SO2).
/8-O1987
Optimization of waste disposal systems in
environmental Impact of coal-fired utilities.
Breltsteln, L : Ellison. W.; Warner, M.; et al.
NUS Corp., Environmental Safeguards Division, 4
PI.. Rockvtlle, MO 2OB5O
COMBUSTION 49(4). 35-4O.
1977
i1lus. refs.
No abs.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
The principal contaminants
coal-fired boilers are parttculates
nitrogen oxides (NOx). and smaller amounts of carbon monoxide.
hydrocarbons, aldehydes, and toxic trace elements. The
principal wastewaters from steam electric generating plants
are low volume waste, ash sluice, metal cleaning waste, boiler
blowdown, once-through condenser cooling water, cooling tower
blowdown, and materlal-storage and construction runoff. The
principal solid wastes are bottom ash, dewatered fly ash, and
flue gas desulfurIzatIon (FGO) sludge. containing dissolved
solids. COD. and trace elements. Cooling systems produce both
chemical and thermal wastes. FGD systems for SO2 control cost
$6O-$75/kw for a SOO-Mw plant. Participates are removed by
electrostatic preclpltators at a. capital cost of tS-$2O/kw.
Emission limits for NOx are now met solely through design
engineering. Effluents are brought Into compliance with 1977
regulations through neutralization, oil removal, mixing,
precipitation, flocculatIon. sedimentation, pH adjustment, and
settling. Systems may or may not be mechanical equipment
Intensive; costs will be S2-$B/kw generating capacity. The
1983 effluent requirements will necessitate Incremental
expenditures of $5-$15/kw for bottom ash sluice water and
$1-$2/kw for cooling tower blowdown. FGD solid waste
stabilization methods Include pug mill mixing and landfill
compaction of filter cake, dry fly ash. and other dry
additives. and feeding silicate additives to FGD slurry
discharge flow to pond disposal sites; capital costs are
$IO-$5O/kw. Cooling lakes and ponds, evaporative rectangular
mechanical draft towers, and hyperbolic natural draft towers
are used for cooling surface waters. Liquid and thermal
discharge control systems are highly site dependent. (FT)
Descriptors: Coal; Boilers; Industrial emissions; Industrial
effluents; Electric power plants; Thermal discharges; Cooling
systems; Federal regulations; Economics; Engineering: Solid
wastes; Flue gas desulfurIzatIon; Environmental Impact;
Pollution control
lllus. refs.
Sum.
Languages: ENGLISH
Doc Type JOURNAL PAPER
The most commonly used treatment for removal of fluorides
involves the addition of a soluble Ca salt, forming Insoluble
calcium fluoride. Effluents treated in this manner generally
have concentrations of fluorides from 12 to 3O mg/l. Any
fluoride that Is complexed will not readily react with a Ca
salt. The Ca salt must be present In enough quantity to
completely precipitate the soluble fluoride. The pH must also
be controlled to a range predetermined by experimentation.
usually between 8 and 9, or KI2. Factors affecting the
required pH range include the characterIsts of the waste
stream and the specific treatment process. Heavy metals and
fluorides may be removed simultaneously. Reaction times vary
from 3O mln to 24 hrs. Fluorides can be removed either by
batch treatment or by a continuous flow-through process.
Continuous treatment Is preferred for KIOQ.OOO gpd.
Continuous treatment typically utilizes an equalization tank.
a reaction tank, sludge-handling systems, and instrumentation.
A process flow chart for sludge handling Is provided and each
step of the continuous treatment procedure Is discussed.
Hydrofluoric acid solutions must be neutralized, usually with
lime, either prior to or at the same time as the precipitation
step. Aluminum sulfate (alum) has been used to lower F-
concentratIon and the efficiency of the alum flocculatlon
affects the extent removal. Alum treatment also Increases the
amount of sludge and results In thickening and mechanical
dewaterlng. The alum can possibly be recovered from the
sludge using the proper technology. Activated alumina can
reduce F- levels to J2 mg/l. Significant factors affecting
this process are discussed. (FT)
Descriptors: Fluorides; Industrial effluents; Wastewater
treatment; Pollutant removal; Aluminum compounds
Identifiers: alum preclpltat Ion
78-OI271
Reducing fluoride In Industrial wastewater.
Paulson, C G
Industrial Pollution Control, Inc., 46 Riverside Ave.,
Westpost, CT O688O
CHEMICAL ENGINEERING 84(22). 89-94, Coden CIIEEA3
PubI.Yr Oct. 17, 1977
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DIALOG F1te41 Pollution Abstracts - 7O-82/Apr (Copr Cambridge Scl Abs) (Item 62 of 69) User23913 23Jun82
UJ
-0
O
45 Riverside Ave. ,
Coden : CHEEA3
78-0127O
Heavy metals removal.
Lanouette, K H.
Industrial Pollution Control, Inc.,
Westport, CT O688O
CHEMICAL ENGINEERING 84(22). 73 -BO,
Pub) .Yr: Oct. 17, 1977
I I lus . ref s .
Sum.
Languages: ENGLISH
Doc Type: JOURNAL PAPER
The mos t common me t hod for the remova 1 of 1 nor gan I c heavy
metal s Is chemical prec (pi tat Ion. Typical f Inal concent rat Ion
level s are given for this method, and specif Ic treatment
methods are discussed. Including batch and continuous systems.
Batch treatment systems can be designed for flows JSO.OOO gpd
and usual ly consist of 2 tanks. When wastewater
characteristics are uniform or when large volumes must be
handled. a continuous system Is applicable. It Is best to
remove suspended heavy metals from the chemically treated
ef f Utent by f 1 1 trat Ion. Sludge hand I Ing may consist of
dewater Ing by centrifugal Ion, plate and frame f 1 1 ters, or
sludge-drying beds. Recovery of metals from sludges Involves
acid digestion. neutralization. and electrolysis. Chemical
precipitation of heavy metals Is usually accomplished with
lime, caustic, and sodium carbonate. Costs and procedures
involved with using these chemicals are considered. Alternate
removal methods are activated carbon adsorption, ton exchange.
reverse osmos Is. and cementat Ion. The aspects of each
procedure are discussed. Precipitation removal techniques for
Cd Include pH adjustment with lime or caustic to a pH of about
11. or with sodium carbonate to a pH of 9.5-1O. Hexavalent Cr
can be precipitated by adjusting the pH and adding a reducing
agent , usual ly sodium dlox Ide or r sodium metablsul f 1 te .
Trlvalent Cr is precltltated at a pH of 7.5 8.5 with time or
caustic. Other means for Cr removal Include activated carbon.
ion exchange, and biological treatment. Precipitation of Pb
with lime, caustic, or soda ash Is useful. Studies Indicate a
combination of trlsodlum phosphate and caustic is the most
effective system. Mercury Is precipitated by an acid pH
adjustment and the addition of sodium sulflde; separation Is
accompl (shed by f 11 trat Ion Silver is recovered by
electro) ys is and cementat Ion. Pr imary sources and spec! f Ic
treatments for each of the above metals are outlined. (FT)
Descriptors: Heavy tnetals; Industrial effluents; Pollutant
remova I ; Wastewater treatment ; Sludge treatment
su If Ides or elemental
system is out 1 Ined.
act Iva ted- sludge system
5- 1O mg/l was reported.
for a manufacturer of
Doc Type- JOURNAL PAPER
The advanced techniques of electrodlal ys Is . ion exchange and
RO now seem feasible for control of selected S-containlng
effluents and may become practical for recovery processes as
well. Biological treatment of 5 containing wastes may involve
either aerobic or anaerobic bacteria. For reduced forms of S.
aerobic treatment Is feasible, typically producing
thlosul fates or sot fates as the end products Anaerobic
treatment is appl 1 cable to ox Id I zed) forms of S to yield
S. The chemistry of each biological
Sat Isf actory operat Ion of an
with Inf luent S-2 concentrat Ions of
Biological waste treatment studies
textile chemicals and dyestuffs show
that highly variable S-2 levels (ranging from 1O to 65 mg/l In
the plant waste discharge) Inhibited biological treatment.
Aerobic biological treatment Is effect I ve only when the
Influent concentrations are relatively constant and sufficient
O2 for oxidation Is available. The primary end product of
biochemical ox 1 da t ion of thlosul fate Is sulfate (S04-2 ) ,
Biological treatment In a pulp and paper mill can remove K95%
of the S In wastewater containing K2OO mg/l of sulf Ite.
Anaerobic bacteria can remove S from wastes, but the reaction
generates disagreeable S-2 odors . Sul f ate concentrat Ions JtOO
mg/ 1 avo Id s t gn 1 f 1 cant S - 2 odor I n an anaerob i c 1 agoon .
Chemical treatment by oxidation or precipitation is effective.
Oxidation with 02. H20. C12. and other oxldants Is described.
Precipitation with heavy metals such as Fe. Zn, Pb. Ag, and Cu
Is an effective treatment method. Activated carbon adsorption
gained wide acceptance In general wastewater treatment and now
appears to be a v table method for remov ing S compounds .
Pro treatment wastewater to remove part leu la tes may be
necessary . ( FT ) *
Oescr 1p tors . Sul fur compounds ; Sul fur removal ; Wastewater
treatment ; Reverse osmos ts; Industr lal effluents; B lologlcal
treatment ; Chemical treatment ; Ion exchange
I dent if lers: sulf a tes; sul f Ides; sulf I tes; electro-dialysis
78-O1269
Controlling sulfur compounds In wastewaters,
Watklns, J. P
Hydrosclence, Inc . 363 Old Hook Rd.. Westwood. NJ O7675
CHEMICAL ENGINEERING 84(22). 61-65. Coden• CHEEA3
Publ.Yr. Oct. 17. 1977
11lus, refs
Sum
Languages ENGLISH
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Federal Register /• Vol. 48. No. 137 / Friday, July 15. 1983 / Rales and Regulations 32477
Whirlpool Corporation
York Metal Finishing Co.
The major issues raised by
commenters are addressed in this
section. A summary of ail comments
received and of our responses is
included in the public record for. this
regulation.
1. Comment: Many commenten
objected to the certification language-
EPA proposed as an alternative to TTO
Monitoring. One commenter pointed out
that EPA bad recently proposed new
certification language for signatories to
permit applications and reports (40 CFR
122.6) as part of a settlement agreement
in the consolidated permits litigation,
(NRDC v. EPA, and consolidated cases.
No. 80-1607. O.C. Or.) and suggested
that EPA adopt that language here.
Response: EPA agrees that changes in
the certification language are warranted.
First we believe it is appropriate to
modify the proposed- language to accord
more closely with the certification
language agreed to in the consolidated
permits settlement agreement
concerning 40 CFR § I2i22, formerly
§ 122.8. 47 FR 2S54B. 2SS33 (June 14,
1982). We do not see a significant
enough difference between this
regulation and § T.2Z2Z to justify
substantially different language. Thus.
we have adapted the proposed
settlement language with minor
differences reflecting the particular
nature of the TTO certification
requirement This language is
substantially similar to that now
available for the electrical and
electronics industry (Phase I). SSB 48 FR
15382. April 8.1983.
Second, we-have amended the
language to allow the diacnarger to
certify that "no dumping of concentrated
toxic organics into the wastewater has
occurred since filing the last discharge
monitoring report" The proposed
language appeared to require the
discharger to certify that lie is in
compliance with the limit: we recognize
that it may be difficult to certify to this
language in the absence of monitoring.
Now. the discharger will be allowed to
certify as-to his toxic organic
management practices. However.
because the new wording is less precise
(i.e.. no "dumping of concentrated toxic
organics"} and because some
commenters pointed to the need for
more specificity about certification
procedures, we are adding more explicit
language requiring the discharger to
describe his toxic organic management
plan. The proposed language would
have required the discharger to specify
the toxic organic compounds used and
the procedure used to prevent excessive
wastewater discharge of toxic organics.
whereas the final language requires the-
discharger to submit a toxic organic
management plan that specifies to the
permitting or control authority's
satisfaction the-toxic organic
compounds used: the method of disposal
used instead of dumping, such as resale.
reclamation, contract hauling, or
incineration: and procedures for
assuring that toxic organics do not
routinely spill or leak into the
wastewater. The discnarger must also
certify that the facility is implementing
the toxic organic management plan.
Finally, for direct dischargers, the
solvent management plan will be
incorporated aa a condition of their
NPOES permits. A similar requirement
does not exist for indirect dischargers
because under the Clean Water Act
permits are not issued for them by the
control authority. However, the
pretreatment standard does require
indirect dischargers to implement the
plan which they, submit to the control
authority. Both these requirements
reinforce the discharger's responsibility
to implement his certification statement
Addition of certification language is
intended to reduce monitoring burdens.
it does not in any way dinusfl.the
discharger's liability for noncompliance
with-the TTO limitation.
2, Comment: Several commenters
questioned EPA's estimate of minimal
costs for TTO control stating that-
signficant costs would be incurred from
solvent disposal and from compliance
monitoring. A number of commenters
questioned the statement that costs for
solvent disposal could be offset by
reclamation of these wastes.
Response: The Agency recognizes that
costs can bs associated with proper
solvent management* and compliance
monitoring. However." the. Agency does
not believe these costs will be
significant for the majority of the
facilities in the industry. 24% of the
captives. 10.3% of the job saops.and
100% of the printed circuit board
facilities perform solvent decreasing. An
estimated 73 percent of the facilities
using solvent decreasing are already
practicing proper disposal of these
wastes and would, therefore, not be
expected to incur additional costs to
comply with the electroplating or metal
finishing TTO limits. Facilities not
presently practicing proper solvent
management would need to implement
practices such aa contractor removal
and/or reclamation.
Costs of proper solvent disposal can
be offset by solvent reclamation. In
response to comments, the Agency
contacted representatives of national
solvent reclamation associations. These
representatives indicated that solvent
reclamation is a widespread, readily
available, and growing practice. In
addition to the numerous plants with on-
site reclamation facilities, it is estimated
that more than 100 independent
reclaimers are in operation throughout
the country and that reclaimers will pay
for spent solvents especially if the
solvents are segregated and there is a
market demand for the particular
solvents.
The Agency recognizes that frequent
monitoring for TTO can be expensive.
The Agency has attempted to reduce the
cost by establishing the certification
alternative and by allowing monitoring.
when.necessary, to be limited to those
toxic organics likely to be present in the
wastewater of a plant The Agency
believes that almost all facilities will be
able.to certify in lieu of monitoring.
However, in response to comments on
the cost of compliance monitoring, the
Agency has re-assessed its cost estimate
to consider quarterly monitoring for
TTO. This frequency is reflective of a
common monitoring frequency required
by control authorities. For the reasons
explained in section IX above. EPA
believes that its. economic analyses of
the impacts of the TTO limit are
conservative and fully state or overstate
the likely actual economic impacts.
3. Comment: Some commenters
pointed out that the new source limits
for cadmium were not supported by
historical performance data. However,
no commenten submitted data on
performance capabilities of new source
technology.
Response: New source standards for
cadmium are based on control
technology which is designed-to reduce
cadmium in wastewater discharge from
cadmium sources, e.g. cadmium plating,
chromating of cadmium plated parts.
and acid.cleaning of cadmium plated
parts. The new source standards for
cadmium are based on the amounts of
cadmium expected as a background
level to be found in wastewaters from'
plants not involved with cadmium
plating. The standards were determined
from data on concentrations observed in
untreated wastewater from metal
finishing plants that do not plate
cadmium. It represents the amount of
cadmium present from incidental
sources, when the principal cadmium
sources are full controlled. The data
consist o/ si observations from 27
plants. The data were divided into
statistically homogeneous groups by
plant. The average upon which the
standards were based was taken from
the group with the highest average
cadmium concentration. Estimates of
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Federal Register / Vol. 48. No.. 137 / Friday, July 15. 1383 / Rules and Regulations
variability used in determining the limits
wen obtained from the two highest
groups.. This was somewhat
conservative, because precipitation/
clarification systems should achieve
significant tether removals from these
raw waste streams.
The Agency also cheeked the
consistency of th* limit with data from
EPA sampled precipitation/ clarification
systems. These data indicated that the
new source limit could be achieved
alternatively by using precipitation/
clarification, rather than total control, of
the principal cadmium source. Tail
review included plants with ca^nftinnft
raw wastes of from CLQ12 to, T-33 mg/L
The Agency also reviewed the data base.
used to develop the cadmium limit to
venfy that it 'm^idqd all available data
from lion-cadmium plating plants* Prior
to promulgation costs wen also re-
gxamined to fart™^ expenses for
control of nhmrnattng and acid cleaning
of nafftrfliiffi plated parts* in. iftdition to
rnntTnllinarfT^flyn^t^ plating whtcll Was
assassed-in the proposal.
4. Comment. Cj?niTnttn*ftrt suggested
various averaging times as the basis, for
monthly limitations. mi-lnrting 4-day. 30-
day. and "TP day averages.
Response: The Agency has evaluated
the merits of the suggested alternatives
and decided that an average of ten-
samples (obtained within, a one-month,
period) would provide a reasonable
basis for monthly limitations.
minimizing, the number of samples
necessary.
Although it is not anticipated that a
irntonng frequency or 10 times per*
month will always be required, the cost
of this frequency of monitoring is-
presented in the economic impact
analysis to the metal finishing
regulation. That frequency was selected
because if facilities sample 10 times per
. month they can expect a compliance
rate of approximately » percent if they
are operating at the expected mean and
variability, Plant personnel, in
agreement with the control authority.
may choose to- take fewer samples if
their treatment system achieves better
long- term concentrations at- lower
variability than the basis for the limits.
or if plant personnel are willing to
accept a statistical possibility of
increased violations. The 10 sample
monthly limit is consistent with other
regulations and recent proposals for
other metals industries, e.g« porcelain
enameling, coil coating, batteries.
copper, and aluminum forming.
The 4-day average is-an inadequate
measure of treatment system
performance over extended periods.
This basts was used forth*
electroplating rules only under the
special circumstances of a Settlement
Agreement.
The N-day average suggested by two
commenters was considered by the •
Agency but was rejected as
unnecessarily complex and likely to
create confusion for hath dischargers
and control authorities*
on the desirability or need to rescind the
electroplating regulations for captive
electroplates upon the compliance date
Response: The Part 413 Electroplating
PSES will no longer o* applicable to
captive electroplating when they must
comply with, the Metal Finishing PSES-
for metals and cyanide is reached.
Captive eiectroolaters will then b»
regulated under the Part 433 Metal
Finishing PSES. Then is no need to
maintain two sett of requirements for*
the same pollutants at th* same plants.
It for some reason. Part 433 should
become inapplicable, than Part 413 will
apply to them.
9. Commexrc TOM majority of
commenters responding to the question*
of- the PSES compliance data-stated that
March 30.1984 would not provide
sufficient tin* for compliance.
Response: To allow facilities
sufficient **m^ to i™q*gii or upgrad* th*~
necessary treatment systems, the
Agency is establishing the compliance'
date of th* Tmf*ai finishing omffi foe*
metals and cyanide-to be 31 months
from th* date of promulgation!. This
extension-is based on an-Agency study*
which showed that 31 months is-
required to planrdnign. and ^nft^Ji th*
reconu&flttded treatment technology.
This extension due* not apply ta
compliance with the-toxic organics limit
howeveg.Por Metal Finishing PSES. an
intenm.TTQ level must be achieved by>
Juna.20.138*. based on.no. und-of-pipa
treatment and th* final TTO limit based
on end-of-pipe treatment most be
achieved 31 months from the date of
promnlgaaon.FgrElecatipiating.PSES.
the TTO.cnoipliaiiea-dats.is 3 years from
promulgation, of this ruiemakaig. That
allow* th* joo- shop and £PC3M sectors-
the maarhmiitv allowable time-for
corapoaac* under the Clean Water Act
(CWA).
7. Comment: Commenten stated mat
the proposed lead limit was not
achievable based on the technology
recommended. Some argued that plants-
with high raw wast* lead values wen
not adequately represented in the data
base. One commenter submitted
additional data.
Response: The- Agency reviewed the-
lead data base to assure mat all usable
data from plants having a lead source
wen included. EPA did consider some
additional self-monitoring data that
were found to be applicable and
excluded data from an onginaHy-
considerad plant which was not
adequately controlling waatewaters. The
revised EPA data base was used to
derive a final lead limit. The daily
maximum for lead has been changed
slightly from OS7 mg/l to 0.89 tng/U The
Agency also examined data submitted
during the comment period. These data
were not included because of
inadequate treatment design and/or
operation. For example. TSS values as
high as 119 mg/l were submitted, oil and
grease was as high as 1395 mg/l and
hexavalent chromium was as high as
LJ3 mg/L An examination of the
possible ejract of including the
commeater's data for lead revealed that
only a-slight change in the limit would
hava occurred.
3. Comment: Some commenters
suggested a small plant exemption from
the Metal Finishing regulations, arguing
that an exemption should be granted
similar to that provided by Part 413 for
plants discharging less than 10.000
gallons per day.
Response: Small indirect discharging
facilities (<10.000 GTO discharge) were
given less stringent requirements in the
Electroplating Pretreatment Standards.
Many of these facilities are job shops
and for th* caasons stated above will
not be covered by the Part 433
requirements*
The Agency re-examined the effect of
the Part 433 metal finishing regulations
on small facilities; and. has determined
that because job shops and IPCBMs are
exempted from the metal finishing PSES
then would be- no significant economic
impacts if the remainder were covered
by the- metal figiahiflg standards. For
indirect captives discharging less than
10:000 GPD. the investment cost would
amount to S38 million with annual costs
of S12 million. There ars-no-estimated
plant-closure or divestitures. A small
facility exemption is not warranted for
the Metal Finishing regulation.
9. Comment: Some eonunenters stated
that tire-addition of a TTO limit, to the
Electroplating PSES is a violation of the
NAMF Settlement Agreement
Response: Under the March 1980
Settlement Agreement the Agency
agreed that:
any further SAT analog standards will b»
bued on tnatnat tecasaiogy compatible
with tiis modal teehnolxgy upon which these
stuujaaiM wwa baaed .... la developing
BAT analog standards for the industry. EPA
will lake into account the cumulative impact
of th«»« "UPP regulations in determining
what is "KonoaneaUy achievable." * ' ' As-
to thw jupuuni of the meta> finishing industry
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32479
that u economically vulnerable. EPA does
not believe that more stringent regulations
are now economically achievable. Therefore.
EPA does not plan to develop more stringent
new pretreamem standards for the |ob shop
metal finishing segment in the next several
yean. Nor does EPA plan to develop in the
next several yean more stringent standards
for the independent printed circuit board
segment where significant economic
vulnerability also exists.
EPA is not imposing metals and
cyanide limitations more stringent than
those specified in the Part 413 existing
applicable pretreatment standards,
despite evidence that such limits can be
reliably-achieved by the technology that
forms the basis of the current standards.
Indirect discharging job_3hop and
independent printed circuit board
facilities are expected to incur costs
only to comply with the TTO limitation
which is being added to the
electroplating pretreatment standards in
Part 413. This TTO limitation is included
in the regulation because it will
substantially reduce a significant toxic
problem, while compliance will cause
negligible economic impacts on these
industry sectors. Compliance with the
toxic organic standard can be achieved
by good management practices (i.a.. not
dumping waste solvents into the
wastewaters). No additional end-of-pipe
technology (beyond that required for
metals removed) is necessary.
Even under very conservative
estimates only 77 of an estimated 2734
indirect discharging job shops and 88 of
the 327. indirect independent printed
circuit board manufacturers may incur
costs to comply with the TTO standard.*
Total annual costs for all plants of
S222.500 and S254.300 respectively are
projected for the two sectors. The
average annual cost per facility to
comply with the TTO limitations is
approximately $2900, primarily for
sampling and analysis. No closures or
employment effects are projected for
these sectors. Production cost increases
are expected not to exceed 0.03 percent
for the two sectors.
The economic impact analysis also
performed two sensitivity analyses: the
first with a greater number of plants "
monitoring and. the second, with plants
monitoring monthly instead of quarterly.
Both changes led to only slightly
different impacts. At most only one
plant would be affected. All scenarios
were found to be acceptable and
economically achievable. Thus the TTO
limits are not "more stringent
standards" in the sense of the
Settlement Agreement, which expressly
tied "stringency" to "economic
vulnerability".
Finally, the TTO limits need not be
complied with before 1988. Thus, even if
control of TTO were considered
significantly more stringent the time
allowed for compliance will amount to 3
years from the date of the Settlement
Agreement. That fulfills the Agency's
1980 obligation not to develop
significantly more stringent standards
for those facilities for the next several
years. :
10. Comment Some commenters
stated that the proposed TTO limit could
not be met using a combination of
solvent management and common
metals treatment. Several commenters
also pointed out that plants previously
in compliance-with the metals
limitations under'Electroplating PSES
may now require installation of common
metals treatment to meet the TTO limit
Response: The Agency has reviewed
the TTO data base, reevaluated the
mean and variability factor, and revised
the effluent limit for TTO. The major
factor contributing to the change was
the examination of the TTO levels at
certain groupings of plants. The most
notable discovery was that plants that •
performed both 30! vent .decreasing and
painting tedded to have the highest
background concentrations of any
process grouping. The limit has been
based on these plants. Where plants are
otherwise subject to a regulation whose
technology basis includes precipitation/
clarification for removal of metals, the
TTO. limit has been based on effluent
data from precipitation/clarification -
treatment systems. We have also
established'a TTO limit of 4.57 mg/1
based on only management practices.
This limit is. being used as an interim
requirement prior to installation of
pollution/equivalent to precipitation/' ,
clarification, and for plants discharging
less then 10.000 gpd and now covered by
the Part 413 Electroplating PSES. Thus
today's regulation specifies an interim
TTO limit for-small plants (<10,000
gallons per day)Jbecauae these plants
may not already have common metals
treatment in place. Furthermore, the
Agency notes that most facilities should
be capable of achieving compliance with
the ultimate TTO standard even without
end-of-pipe treatment, simply through
strict management control of toxic
organics. 89% of the TTO data prior to
and-of-pipe treatment would comply
with the final TTO limit baaed on the
inclusion of precipitation/clarification.
11. Comment: Several commenters
recommended an amenable cyanide
limit as an alternative to a total cyanide
limit because amenable cyanide more
accurately reflects the performance of
alkaline chlonnation treatment.
Response: Most facilities should be
able to meet the total cyanide limit.
However, sufficient information has
been presented on cyanide formulations
and formation of complexes to support
the possibility that a significant
population could fail to meet the
limitations. The technology basis is
alkaline chlorination which destroys
amenable cyanides. Thus, the final rules
include an alternative cyanide limit for
plants generating significant quantities
of complexed cyanide. The data and
basic calculations for the alternative
cyanide limit were presented in the
proposed development document The
Agency rejected specifying a limit only
for amenable cyanide. While complexed
cyanide are substantially less toxic, a
review of literature indicates that
significant transformation! of complexed
cyanides into amenable cyanides will
occur in the aquatic environment due to
the presence of sunlight If any water
quality problems occur due to the use of
this alternative, the control authority
should examine alternative
technologies, i.a.. precipitation with
ferrous sulfate.
12. Comment: Several commenters
suggested that fluoride, iron, and
hexavalent chromium be regulated.
Response! The Agency did not
establish limitations for fluorides, iron.
or hexavalent chromium because it was
determined that these parameters were
(1) not present in sufficiently high
quantities to warrant regulation or (2)
would be removed by controlling a
regulated parameter.
The historical performance data for
flouride in effluent from plants with
Option 1 treatment systems shows that
the mean concentration was 8.53 mg/1:
well below levels required by
categorical regulations-for other
industries. i.e.. Inorganic chemicals, and
electrical and electronic components
(phase U.
Iran was not-selected for regulation
because it would be substantially
reduced during proper precipitation/
clarification treatment Thus control of
regulated pollutants will also effect
control of iron.
A limit was not established for
hexavalent chromium because it will be
controlled by regulating total chromium.
The technology basis does include the
cost for hexavalent chromium stream
segregation and reduction. As stated in
the development document chemical
hexavalent chromium reduction can
readily achieve final hexavalent
chromium concentrations of 0.18 mg/1
for a daily maximum and 0.10 mg/1 for a
maximum monthly average.
Additionally, monitoring for total
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chromium has a distinct cost advantage
over monitoring for hexavaient and
subsequently tnvalent chromium. IX any
of these or other parameters cause
problems with achieving local water
quality requirements, than the control
authority must specify further
requirement* an a piant-by-plant basis.
13. Comment; Several commenters
stated that EPA's method for
distributing costs for indirect
dischargers between the Part 413
electroplating and the Part 433 metal
finishing regulations is misleading and
unrealistic. Electroplating comptianca
costs for captive indirect dischargers
have not yet been incurred. When ties*
plants do comply, it will be with both
regulations in a one-time investment.
Therefore, no costs should be attributed
to Electroplating; rather, all costs should
be considered as Metal Finishing
compliance costs.
Response: The fact that a company
may make a one time investment doesn't
necessarily mean that all the costs
should be attributed to the Part 433.
Metal Finishing Standard. The
compliance date for Part 433 is now
generally two yean after compliance
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Fadaral Register / Vol. «. No. 137 / Friday, July 15. 1S83 / Ruies and Regulations
32481
economic impacts to comply -with Metal
Finishing Guidelines.
Response: The commenters are
correct. The agency has sines analyzed
the impact on indirect discharging
captives with metal Blushing process
flows of less than 10.000 gpd. The
analysis concluded that a total of 312
plants will incur compliance costs. The
total capital cost of compliance for tais
universe is estimated at-S35 million with
annual costs -of S12 million. No closures
or employment effects an protected for
this industry segment
18. Comment: Caranenters questioned
the assumption that the metal finishing
demand curve is inelastic.
Response; Metal finished, products
_ face a wide range of demand
elasticities. However, there are no good
substitutes for metal finishing due to the
quality it imparts on materials. As a .
result, an increase in the cost of metal
finishing will not bring a more than
proportional decrease in the use of
metal finishing. The analysis assumed
that demand for metal finishing is in the
meiasac range but did not assume that
all cost increases could be passed -
through. In fact the captive closure
analysis assumes that a plant's captive
operations will not be able to pass
through a pollution contra! cost increase
if It amounts to more than S percent of
their total revenue. If the ratio of annual
cosls to total revenue was larger than S
percent the plant was projected to
ciose.
19. Comment: Commenters stated that
they thought captive facilities will be al
a competitive disadvantage because job
shops are exempted from metal finishing
standards.
Response: Captives are very rarely in
direct competition with job shops, vying
for the same customers. Captive platers.
by definition, service their own firm's
needs. A captive firm will maintain a
plating process for its cost advantages.
scheduling control and specialty
processes. In the Agency's survey at -
captive facilities, aver 64 percent
indicated they performed metal finishing
m-house because it was either less
expensive to do so or the work flow
didn't allow interruption of work. It 15
true that job shops will ofterf'receive a
caotive's overflow work, but this doe*
not make them price competitors. Also.
almost three-fourths of the indirect
discharging captive facilities and all
direct discharging captives and job
shops already have treatment in place.
To the extent there may be changes in
the competitive position of captives
versus job shops, most of these changes
would have occurred already. Finally.
indirect discharging job shops were
exempted from the metal finishing
regulation specifically because of their
economic vulnerability. Job shops tend
to be much smaller than captives; they
average 26 employees and SL2 million in
sales versus over 100 employees, and 314
million in sales for captives.
20. Commenc A comment was made
that the definition of a job shop may
force some "job shops" to be classified
as captives.
Response £PA proposed a definition
of job shops based on 50% ownership of
treated matanat This is in accord with
existing practice by an overwhelming
portion of th« affected industry. An
examination of the survey of job shops
revealed thaf9S% of th« facilities stated
that their work was either 100% job
ordered or 100% captive. Only OJ8% of
the facilities reported that more than
25%. but less than 50%. of their
production-was dona an materials
owned by others.
The final definition of a job shop has
been modified slightly, makiag.the
measurement of "not more than 50%
ownership" on a yearly basis. This
responds to a umuuemeis' f«ar of
repeated reclassification as a resultof
business transactions. Now facilities
will not be redaswfied on a day-to-day
basis.
The definition is also appropriate
because, the fad that a facility is
purchasing materials to be processed
indicates some availability of capital. If
so the less stringent Part 413 ,
requirements are less appropriate for
The agency considered various job
shop definitions from commantors and
trade association by-laws, including:
" "As its major operation the
application of a surface'treatment to die
products of others."
• "A shop which has purchased
orders from more than SO percent of the
materials in process."
• "Parts to be Smshed are transported
from the customer's plant to the
finishers and then back."
• "As its major operation the
application of a surface treatment to the
products T>f others."
• "A metal finisher who works to
other's specifications, making his
services, available to the public at all
times."
While some of these, notably the first
are close to the proposed and final
definitions, all suggestions included
substantial ambiguity. In light of the
relaxed standards for job shops it is
important that the definition be precise
and that captive shops not evade Part
433 merely by taking on nominal outside
orders. EPA therefore chose a bright-line
test that clearly expressed the
overwhelmingly prevailing practice in
the industry.
EPA's definition is consistent with our
1978 survey of the industry, which asked
for the "percent of electroplating done
on materials owned by others (basis
area plated)" and further defined a |ob
shop as "a manufacturing operation
performing work on materials owned by
others."
XX Availability of Technical
information
The basis for this regulation is
detailed in four major documents-
Analytical methods are discussed in
Sampling cad Analysis Procedures for
Screening of Industrial Sffluanta for
Priority Pollutants. EPA's technical
coociusioas are detailed in Development
Document for Effluent Guidelines, New
Soaree Performance Standards and
Prstreattnent Standards for the Metal
Finishing Point Source Category. The
Agency's economic analysis is
presented in Economic laipaet Analysis
of Effluent Unutaeiom and Standards
for the Metal Finishing industry. A
summary al the public comments
received on the proposed regulation is
presented in a report 'Responses to
Public Comments, Proposed Metal
Finishing Effluent Guidelines and
Standards," which, is part of the public
record for this regulation.
Technical information may be
obtained by writing to Richard Kinca.
Effluent Guidelines Division (WH-552)
EPA. 401 M Street S.W.. Washington.
D.C. 20480 or by calling (202) 382-71S9.
Additional information concerning the
economic impact analysis may be
obtained from Ms. Kathleen
Ehrenaberger. Economics Branch fWH-
588). EPA. 401 M Street S.W.
Washington. D.C 20460 or by calling
(202) 382-6307.
Copies of the technical and economic
documents will be available from the
National Technical Information Service.
Springfield. Virginia 22181. (703) 487-
4650.
XXL OMB R*TWW ,
This regulation was submitted to the
Office of Management and Budget for
review, as required by Executive Order
12291.. No written comments were
received.
In accordance with the Paperwork
Reduction Act of I960 (Pub. L 96-511).
the reporting and recordkeeping
provisions in 40 CFR 413.03 and 433.12
that are included in this regulation will
be submitted for approval to OMB. They
are not effective until OMB approval has
been obtained and the public is notified
402
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32482 Federal Register / Voi. 48. No. 137 / Friday, July 15. 1983 / Ruies and Regulations
to that effect through a technical
amendment to this regulation.
XXH. LUt of subjects
40 CFR Part 413
Electroplating. Metals. Water
pollution control. Waste treatment and
disposal.
40 CFR Part 433
Electroplating. Metals. Water
pollution control. Waste-treatment and
disposal. -
Dated: July 5.1983.
William 0. Rudnfetuu*.
Administrator.
Authority: Sees. 301. 304, 306. 307. 308. and
301 of the Clean Water Act (the Federal
Water Pollution Control Act Amendments of
1373. 33 U.S.C. 1231 at. saq.. 39 amended by
the Claan Water Act of 1977-. Pub. L 95-217;.
(Note.—These appendices will not appear
in the CFH.|
XXIU. Appendices
Appendix A—Abbreviations, Acronyms,
and Other Terms Used in This Notice
Act—The Clean Water Act.
Agency—The U.S. Environmental
Protection: Agency.
SAT—The best available technology
economically achievable under Section
304(b)(2)"(B)oftheAct
SCT—The best conventional pollutant
control technology, under Section
304(b)(4)of the Act
BMPS—Beat management practices
under Section 304(e) of the Act.
BPT—The best practicable control
technology currently available under
Section 304fb)(l) of the Act
Captive—A facility which owns more
than 50% (annual area basis) of the
materials undergoing metal finishing.
Clean Water Act (also "the Act"]—
The Federal Water Pollution Control Act
Amendments of 1972 (33 U.S.C 1251 at
seq.), as amended by the Clean Water
Act of 1377 (Pub. L 9S-217).
Development Document—
Development Document for Effluent
Limitations, CuideJines. and Standards
for the Metal Finishing Point Source
Category, EPA 440-1-SO-091-A. June
1980.
Direct discharger—A facility that
discharges or may discharge pollutants
into waters of the United States.
Indirect discharger—A facility that
discharges or may discharge pollutants
into a publicly owned treatment works.
Job Shop—A facility which owns not
more than 50% (annual area basis) of the
-materials undergoing metal Snishing.
Integrated facility—One that performs
electroplating operations (including
electroplating, eiectroless plating,
chemical etching and milling, anodizing,
coating, and printed circuit board
manufacturing] as only one of several
operations necessary for manufacture of
a product at a single physical location.
and has significant quantities of process
wastewater from non-electroplating
operations. In addition, to qualify as
"integrated." a facility must combine
one or more plant electroplating process
wastewater lines before or at the point
of treatment (or proposed treatment)
with one or more plant sewers carrying
process wastewater from non-
eiectroplating manufacturing operations.
NPDES Permit—A National Pollutant
Discharge Elimination System permit
issued under Section 402 of the Act
NSPS—New source performance
standards promulgated under Section
306 of the Act
POTW—Publicly owned treatment
works.
PSES—Pretreatment standards for
existing sources of indirect discharges
promulgated under Section 307(b) of the
Act.
PSNS—Pretreatment standards for
new sources of direct discharges.
promulgated under Section 307 (b) and
(c) of the Act
RCRA—Resource Conservation and
Recovery Act (Pub. L 9*-380) of 1978.
Amendments to Solid Waste Disposal
Act. as amended.
TTO—Total Toxic Organic* is the
summation of all values greater than .01
milligrams per liter for each of the
specified toxic organics.
Appendix B—Pollutants Excluded From
Regulation
(1) Toxic Pollutants—found in only a
small number of sources and effectively
controlled by the technologies on which
the limits are based:
Antimony
Arsenic
Astaeatoa
Beryllium
Mercury
Selenium
Thallium
(2J Conventional Pollutants:
BOB
Kecal Coliforra
Appendix C—Unit Operations in tin
Metal Finishing Industry
1. ©Electroplating
2. Electroless Plating
3. Anodizing
4. Coating (Chromating, Phosphating,
and Coloring)
5. Chemical Etching and Milling
3. Printed Circuit Board Manufacturing
?. Cleaning
3..Machining
9. Grinding
10. Polishing -
11. Tumbling
12. Burnishing
13. Impact Deformation
14. Pressure Deformation
15. Shearing
18. Heat Treating
17. Thermal Cutting
18. Welding
19. Brazing-
20. Soldering
21. Flame Spraying
22. Sand Blasting
23. Other Abrasive let Machining
24. Electric Discharge Machining
25. Electrochemical Machining
28.. Electron Beam Machining
27. Laser Beam Machining
28. Plasma Arc Machining
29. Ultrasonic Machining
30. Sintering
31. Laminating
32. Hot Dip Coating
33T Sputtering
34. Vapor Plating
35. Thermal Infusion
36. Salt Bath Descaling
37. Solvent Decreasing
38. Paint Stripping
39. Painting
40. Electrostatic Painting
41. Electropainting
42. Vacuum Metalizmg
43. Assembly
44. Calibration
45. Testing
4ft Mechanical Plating
PART 413—€LECTROPLATING POINT
SOURCE CATEGORY
For the reasons stated above. EPA is
amending Part 413~of 40 CFR, Chapter I
as follows:
1. Section 413.01 is amended by
revising paragraph (a) to read as
fallows:
J 41101 AppflaMHiy and compriamce
(a) This part shall apply to
electroplating operations in which metal
is electroplated on any basis material
and to related metal finishing operations
as set forth m the various subparts.
whether such operations are conducted
in conjunction with electroplating,
independently, or as part of some other
operation. The compliance deadline for
metals and cyanide at integrated
facilities shall be June 30.1984. The
compliance date for metals and cyanide
at non-integrated facilities shall be April
27,1984. Compliance with TTO for all
facilities shall be July 15.1988.' These -
1 The Consent Q«m in MRDC v. Train. 12 SRC
1833 (D.D.C. 1979) specifies a compliance date for
PSES of no later than iune 20.1964. EPA has moved
for a modification of that provision of the Decree.
Should the Court deny that motion. EPA will be
required to modify this compliance date~—
accordingly.
403
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Federal Register / Vol. 48. No. 137 [ Friday. July 15. 1983 / Rules and Regulations 32483
Part 413 standards snail not apply to a
facility which must comply with aJl the
pollutant limitations listed in f 433.15
(metal finishing PSES).
2. Section 413.02 is amended by
adding a new paragraph (i). aa follows
§413.02
(i) toe terra TTO" shall mean total
toxic organics. which is the summation
of all quantifiable values greater than
0.01 milligrams per [iter for the following
toxic orgarucs:
Acniein
AcryJonitnle
Benzane
Bsnzidine
Carbon tetrachiontjts
(tetrachloroinethane)
C&torobeazaa*
t.2.4-
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32484
Federal Register / Vol. '48. No. 137 / Friday, fuly 15. 1983 / Rules and Regulations
submitting a certification in lieu of
monitoring pursuant to I 413.03 of this
regulation must implement the toxic
organic management plan approved by
the control authority.
5. Secton 413.24 is amended by adding
paragraph (f), (gj and (h). as follows:
341124 prxrattMnt standard* for
(f) la addition to paragraphs (a) and
(b) the following limitation snail apply
for plants discharging leas than 38.0001
(10.000 gal] per calendar day of
electroplating process wastewaten
(g} In- addition to paragraphs (a|, (c),
(d), and (a) the following limitation shall
apply for plants discharging 38.0001
(10.000 gal] or more per calendar day of
electroplating process wastewatan
MM Mr
an \
(h) In addition to paragraphs (a), (b).
(c), (d). (e), (f), and (3) the following
shall apply: An existing- source
submitting a certification in lieu of
monitoring pursuant to \ 413.03 of this
regulation must implement the toxic
organic management plan approved by
the control authority.
a. Section 413.44 is amended by -
adding paragraph (f), (gj. and (h), as
follows:
141X44 PrvftMttnntstmteni* to-
ff) In addition to paragraphs (a) and
(b) the-following limitation shall apply
for plants discharging lets than 38.0001
[10.000 gai) per calendar, day of
electroplating process wastewaten
mum lor
any I
aw
[g) In addition to paragraphs (afc (c),
(d). and (e) the following limitation shall
apply for plants discharging 38.0001
(10.000 gal) or more per calendar day of
electroplating process wastewater:
(b) In addition to paragraphs (a), (b),
(c). (d), (eUO. and (gj the following
shall apply: An existing source
submitting a certification in lieu of
monitoring pursuant to \ 413.03 of this
regulation must implement the toxic
organic management plan approved by
the control authority.
7. Section 413.54 is amended by
adding paragraph (f), (g), and (hi. as.
follows:
I (or
(f) In addition to paragraphs (a) and
(bj the following limitation shall apply
for plants discharging leas than 38.0001
(10.000 gal] per calendar day of •
electroplating process wastewaten
(g) In addition to paragraphs (a), (c),
(d). and (e) the following limitation shall
apply for plants discharging 38.0001
(10,000 gal) or more per calendar day of
' electroplating process waterwaten
(h) In addition to paragraphs (a), (b),
(c}. (d), (e). (f), and (g> the following
shall apply: An existing source
submitting a certification in lieu of
monitoring pursuant to 5 413.03 of this
regulation must implement the toxic
organic management plan approved by
the control authority.
a. Section 413.94 is amended by
adding paragraphs (f), (g), and (h), as
follows:
§413.64 Pl«UMUii«
Mentetor
(f) In addition to paragraphs (a) and
(b) the following limitation-shall apply
for plants discharging less than 33.0001
(10.000 gal) per calendar day of
electroplating process wastewater
mum tor
! ** i
i a*
(gj In addition to paragraphs fa), (c),
(d), and (e) the following limitation shall
apply for plants discharging 39.0001
(10,000 gal) or more per calendar day of
electroplating process wastewaten
(h) In addition to paragraphs (aj, (b|.
(cj, (dK(e), (f), and (g) the following
shall apply: An existing source
submitting'a certification in lieu of
monitoring pursuant to I 413.03 of this
regulation must implement the toxic
organic management plan approved by
the- control authority.
9. Section 413.74 is amended by
adding paragraphs (f). (gj and (h). as
follows:
§4117*
ototfngs
(f) In addition to paragraphs (a) and
(b) the following limitation shall apply
foe plants discharging less than 38.0001
(10.000 gal) per calendar day of
electroplating process wastewater-
is) In addition to paragraphs (a), (c),
(d). and (e) the following limitation shall
apply for plants discharging 38.0001
(liooffgai] or more per calendar day of
electroplating process wastewaterr
no
(h) In addition to paragraphs (a), (b),
(c), (d). (e|. (f). and (g) the following
shall apply: An existing source
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Federal Register / Vol. 48, No. 137 / Friday. July IS. 1983 / Rulas and Regulations
32485
submitting a certification in lieu of
monitoring pursuant to § 413.03 of this
regulation must implement the toxic
organic management plan approved by
the control authority.
10. Section 413.84 is amended by
adding paragraphs (f). (g) and (h). as
follows:
§ 41X84 PfWMUmnt standard* for
(!) In addition to paragraphs (a) and
(bj the following limitation shall apply
for plants discharging less than .38.000 1
(10.000 gal) per calendar day of
electroplating process waste water
(g) In addition to paragraphs (a), (c),
(d), and (e) the following limitation shall
apply for plants discharging 38.0001
(10.000 gal) or more per calendar day of
electroplating process wastewater:
Pqdunm or MMMNK orapvny
TO.....
fh| In addition to paragraphs (a), (b),
(c). (d). (e). in. and (g) the following
shall apply: An existing source
submitting a certification in lieu of
monitoring pursuant to § 413.03 of this
regulation must implement the toxic
organic management plan approved by
the control authority.
In addition, for the reasons stated
above. EPA is establishing a new Part
433 to Title 40 of the Code of Federal
Regulations to read as follows;
PART 433— METAL FINISHING POINT
SOURCE CATEGORY
Flo
fHng Su
eqory
S«c.
433.10 Applicability: description of the maul
finishing point source category.
433.11 Specialized definitions,
433.12 Monitonng requirements.
433.13 Effluent limitations representing the
degree of effluent reduction attainable by
applying the best practicable control
technology currently available (BPT).
433.14 -effluent limitations representing the
degree of effluent reduction attainable by
applying the best available teohnoiogy
economically achievable (BAT).
433.13 Pmreatment standards for existing
sources (PSES).
433.18 New source performance standards
(NSPS).
433.17 Ptetreatment standards for new
sources (PSNS).
433.13 (Reserved)
Authority: Sec. 301. 304(b). (c). (e). and (g).
308(b| and (e). 3O7(b) and (c). 308 and SOI of
the Clean Water Act (the federal Water
Pollution Control Act Amendments of 1971.
as amended by the Clean Water Act of 1977)
(the "Act"]; 33 U.S.C. 1311.1314(b| (c), (e).
and (g). 1316(b) tod (c|. !317(bl and (c). 1318
and 1361: M Slat 818. Pub. L. 92-500:91 Stat
1567, pub. L.99-a7.
Subpart A—M«tal Finis
Sutwatagery
§433.10 AppffcaMHty;
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32486
Federal Register / Vol. 48. No. 137 / Friday, July 15, 1983 / Rules and Regulations
Benzo(a]pyrene (3.4-benzopyrene|
3.4-3enzot1uoranthene I benzoib | fluoranthene I
11.12-benzotluoramhene
(benza(k)fluorantheiw)
Chrysene
Acenaphthylane
.Anthracene
1.12-benzoperyien»(benzo(ghi)perylene|
Fluorane
Phenanthrene
1.2.5.8Kiibenzamhracene-
(dibeH2o(a.h)anthracene
Indeno(l.i3-cd) pyrene (2.3-o-phenlene
pyrene)
Pyrene
Tetrachloroethytene .
Toiiwne
Tnchloroethyleiu
Vinyl chlonde (chloroethyiana)
3.3-dichlorobenzidiiie
1.1-dichloroethyiena
l,2-ffai»dichloroethylen«
2.4-dichloraphenai
1.2- bant practlcaPta control
tecnnoteBD cummiyanrilaM* (BPT).
(a) Except as provided in 40 CFR
125.30-32. any existing point source
subject to this subpart must achieve the
following effluent limitations •
representing the degree of effluent
reduction attainable by applying the
best practicable control technology
currently available (HPT):
SPT &RUSNT LIMITATIONS
Cooo«r ("0 LLU. .......
sine rn
TTT}
T53 _
! 0.8> i
- i 3TT |
i 138 1
1 TW '
1 Q^3 1
„_. j 2.81
,„ „„ I i 20 1
.. ._! 113 ;. ...
..1 ffl
107
043
i:a
02«
1 48
ass
:i
i1)
' wmn wai.0,
(b) Aitemativeiy, for mdustnai
faculties with cyanide treatment ard
upon agreement between a source
subject to those Hmits and the pollution
control authonty. the following
amenable cyanide limit may apply '.n
place of the total cyanide limit specified
m paragraph (a) of this section:
, Mommy
for i av«raq«
o
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Faderal Register / Vol. 48. No. 137 / Friday. July IS. 1983 / Rules and Regulations 32487
BAT Si=RU6NT LIMITATIONS—Conanuad paragraph (a) of this section:
(b) Alternatively, for industrial
facilities with cyanide treatment and
upon agreement between a source
subject to those limits and the pollution
control authority, the following
amenable cyanide limit may apply in
piace of the total cyanide limit specified
in paragraph (a) of this section:
(c) No user subject to the provisions of
this subpart shall augment the use of
-process wastewater or otherwise dilute
the wastewater as a partial or total
substitute for adequate treatment to
achmve compliance with this limitation.
5*33.15 PratrwmMnt stmoanto for
nutting soure** (PSES),
(a) Except as provided in 40 CFR 403.7
and 403.13. any existing source subject
to this subpart that introduces pollutants
into a publicly owned treatment works
must comply with 40 CFR Part 403 and
achieve the following pretreatmant
standards for existing sources (PSES):
(c) No user introducing wastewater
pollutants into a publicly owned .
treatment works under the provisions of
this subpart shall augment the use of
process wastewater as a partial or total
substitute for adequate treatment to
achieve compliance with'this standard.
(d) An existing source submitting a
certification in lieu of monitoring
pursuant to ! 433.12 (a) and (b) of this
regulation must implement the solvent
management plan approved by the
control authority.
(e) An existing source subject to this
subpart shall comply with a daily
maximum pretnatment standard for
TTOof4J7mg/L
(f) Compliance with the provision* of
paragraph (c). (d), and (e) of this section
shall be achieved as soon as possible.
but not later than June 30.1984. however
metal finishing facilities which are also
covered by Part 420 (iron and steel]
need not comply before July to, 1966.'
Compliance with the provisions of
paragraphs (a), (b), (c] and (d) of this
section shall be achieved as soon as
possible, but not later than Feburary 15.
1980.'
5433.1* H«w aoure* tMrtommta*
FOR Au, PUWTS EXCEPT JOB SHOPS
»NO INOEKNOeNT PRINTED CWCUT BOAflO
MANUFACTURERS
(a) Any new source subject to this
subpart must achieve the following
performance standards;
NSPS
(b) Alternatively, for industrial
facilities with cyanide treatment upon
agreement between a source subject to
those limits and the pollution control
authority. The following amenable
cyanide limit may apply in place of the
total cyanide limit specified in
MMs 10 n 9.0,
' Tha CoOMnt Doene in NRDC v. Tram. 12 ERC
1833 [O.O.C, 19791 speaflM a comptiancB da« for
PSES of no lanr than June 30. 1964. EPA has oi
for a modification of (hat provision at th« Oacrm.
Should th« Court dany.thal motion. ^A wtit br
required to modify tht* compliance date
accordingly
(b) Alternatively, for industrial'
facilities with cyanide treatment and
upon agreement between a source
subject to those limits and the pollution
control authority, the following
amenable cyanide limit may apply in
place of the total cyanide limit specified
in paragraph (a) of this section:
(c) No user subject to the provisions of
this subpare shall augment the use of
process wastewater or otherwise dilute
the wastwater as a partial at total
substitute for adequate treatment to
achieve compliance with this limitation.
5 433.17 Pieti'MUmm lUrxUnM for new
(a) Except as provided in 40 CFR
403.7, any new source subject to this
subpart that introduces pollutants into a
publicly owned treatment works must
comply with 40 CFR Part 403 and
achieve the following pretreatment
standards for new sources (PSNS):
PSNS
sfc«
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32488- Federal Register / Vol. 48, No. 137 / Friday. July 15. 1983 C Rules and Regulations
(c) No user subject to the provisions of
this subpart shall augment the use at
process wastewater or otherwise dilute
the wastewater as a partial or total
substitute for adequate treatment to
achieve compiiance-with this ITmUation.
[dl An existing source submitting a
certification in lieu of monitoring
pursuant to $ 433.12 (a) and (bj of this
regulation must implement- the solvent
management plan approved by the
control authority.
[FH OOC.
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APPENDIX C
METRIC-ENGLISH UNITS CONVERSION
English
1 horsepower (HP)
1 gallon
1 gallon
1 ft
1 ft2
1 ft3
1 GPD/ft2
1 Ib/gallon
1 ft/sec
1 Ib
Metric
745.7 Watts
0.0037854 m3
3.7854 L
0.3048 m
0.0929 m2
0.0283 m3
0.0407 m3/day/m2
1 .20 x 105 mg/L
18.288 m/min
453.59 g.
410
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