DRAFT
DEVELOPMENT DOCUMENT FOR
EFFLUENT LIMITATIONS GUIDELINES
AND STANDARDS OF PERFORMANCE
INORGANIC CHEMICALS, ALKALI AND
CHLORINE INDUSTRIES
PREPARED BY GENERAL TECHNOLOGIES CORPORATION
FOR UNITED STATES
ENVIRONMENTAL PROTECTION AGENCY
UNDER CONTRACT NUMBER 68-01-1513
JUNE 1973
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NOTICE
I. -
The attached document is a DRAFT CONTRACTOR’S REPORT. It includes
technical information and recommendations submitted by the Contractor to the United
States Environmental Protection Agency (“EPA”) regarding the subject industry. It is
being distributed for review and comment only. The report is not an official EPA
publication and it has not been reviewed by the Agency.
The report, including the recommendations, will be under ong extensive review
by EPA, Federal and State agencies, public interest organizations and other interested
groups and persons during the coming weeks. The report and in particular the con-
tractor’s recommended effluent limitations guidelines and standards of performance is
subject to change in any and all respects.
The regulations to be published by EPA under Sections 304(b) and 306 of the
Federal Water Pollution Control Act, as amended, will be based to a large extent on
the report and the comments received on it. However, pursuant to Sections 304(b) and
306 of the Act, EPA will also consider additional pertinent technical and economic
information which is developed in the course of review of this report by the public and
within EPA. EPA is currently performing an economic impact analysis regarding the
subject industry, which will be taken into account as part of the review of the report.
Upon completion of the review process, and prior to final promulgation of regulations,
an EPA report will be issued setting forth EPA’s conclusions concerning the sublect
industry, effluent limitations guidelines and standards of performance applicable to
such industry. Judgements necessary to promulgation of regulations under Sections
304(b) and 306 of the Act, of course, remain the responsibility of EPA. Subject to
these limitations, EPA is making this draft contractor’s report available in order to
encourage the widest possible partidpation of interested persons in the decision mak-
ing process at the earliest possible time.
The report shall have standing in any EPA proceeding or court proceeding only
to the extent that it represents the views of the Contractor who studied the subject
industry and prepared the information and recommendations. It cannot be cited,
referenced, or represented in any respect in any such proceedings as a statement of
EPA’s views regarding the subject industry.
U. S. Environmental Protection Agency
Office of Air and Water Programs
Effluent Guidelines Division
Washington, D. C. 20460
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DRAFT
DEVELOPMENT DOCUMENT FOR
EFFLUENT LIMITATIONS GUIDELINES
AND STANDARDS OF PERFORMANCE
INORGANIC CHEMICALS, ALKALI AND
CHLORINE INDUSTRIES
PREPARED BY GENERAL TECHNOLOGIES CORPORATION
FOR UNITED STATES
ENVIRONMENTAL PROTECTION AGENCY
UNDER CONTRACT NUMBER 68-01-1513
JUNE 1973
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DRAFT
ABSTRACT
This document presents the findings of an extensive study of
the inorganic chemicals, chlor-alkali industry by the General
Technologies Corporation for the Environmental Protection Agency
for the purpose of developing effluent limitations guidelines,
Federal standards of performance, and pretreatment standards
for the industry, to implement Sections 304, 306 and 307 of
the “Act”.
Effluent limitations guidelines contained herein set forth the
degree of effluent reduction attainable through the application
of the best practicable control technology currently available
and the degree of effluent reduction attainable through the
application of the best available technology economically
achievable which must be achieved by existing point sources
by July 1, 1977 and July 1, 1983 respectively. The Standards
of Performance for new sources and pretreatment standards con-
tained herein set forth the degree of effluent reduction which
is achievable through the application of Lhe best available
demonstrated control technology, processes operating methods,
or other alternatives.
Based on the use of Level I technology, the best practicable
currently available treatment, 14 of the 25 chemicals under
study can be manufactured with zero discharge of process waste
water. With the use of Level II technology, the best economi-
cally achievable, all of the 25 chemicals can be manufactured
with zero discharge of process waste water. Zero discharge
of process waste water is also achievable as a new source per-
formance standard.
Supportive data and rationale for development of the proposed
effluent limitations guidelines and standards of performance
are contained in this report.
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFOR-
MA 1 rION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON
COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
111
DRAFT
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DRAFT
CONTENTS
Section Page
Conclusions 1—1
II Recommendations 1 1—i
II ! Introduction I l l—i
Purpose and Authority I l l—i
Summary of Methods used for Development -
of Effluent Limitation Guidelines and
Standards of Performance 111—2
General Description of the Industry 111—8
IV Industry Categorization IV—l
Introduction IV—l
Categorization Criteria IV—2
Industry Categories IV—3
Specific Industry Description by Category IV—5
V Water Use and Waste Characterization V—i
Introduction V—i
Specific Water Uses V—i
Process Waste Characterization V—5
Verification Sampling and Analytical
Methods V 3Q
Effluent Data Analysis V—136
VI Selection of Pollution Parameters VI—1
Primary Waste Water Pollution Parameters
of Significance VI—l
Secondary Waste Water Pollution Parameters
of Significance VI—1
Significance of Pollution Parameters VI—2
Rationale for Selection of Pollution
Parameters VI 2
VII Control and Treatment Technology VII—l
Introduction VII—l
General Methods for Control and Treatment
Practices Within the Industry VII—3
Specific Control and Treatment Practices
In the Industry VII—32
V
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Section Page
viir Cost, Energy, and Non-Water Quality Aspects VIII—l
Cost and Reduction Benefits of Treatments and
Control Technology VIII—l
Summary viii—i
Cost References and Rationales VIII-5
Definitions of Levels of Control and Treatment VIII—6
Cost of Control and Treatment Systems VIII-6
Cost Effectiveness Information by Category VIII-52
IX Effluent Reduction Attainable through the Appli-
cation of the Best Practicable Control Technology
Currently Available, Level I Effluent Guidelines
and Limitations Ix—i
Introduction IX—l
Effluent Reduction Attainable Using Level I
Treatment Technology IX—2
X Effluent Reduction Attainable Through the Appli-
cation of the Best Available Technology Economically
Achievable, Level II Effluent Guidelines and Limi-
tations x—i
Introduction x—i
Effluent Reduction Attainable Using Level II
Treatment Technology X—2
XI New Source Performance Standards and Pretreat-
ment Standards, Level III Guidelines and Limitations XI—l
Introduction XI—l
Effluent Reduction Attainable Using Level III
Treatment Technology XI—2
Pretreatment Standards XI—3
XII Acknowledgments XII—l
XIII References xiii—i
XIV Glossary xiv—i
v1
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LIST OF- TABLES
TABLE PAGE
1 U. S. Production of Inorganic themicals 111-30
(Metric Tons)
2 Inorganic Chemicals by Category IV-2
3 Plant Effluent from Calcium Carbide V-l5
- Manufacturing
4 Intake Water and Raw Waste Composition V-25
Date at Plant 152
5 Comparison of Plant Intake Water to V—27
Cooling Water Discharge at Plant 152
6 Plant 166 Verification Data V-42
7 Chemical Analysis of Bittern V43
8 Intake and Effluent Measurements at V-49
Plant 086
9 In-Plant Water Streams at Plant 141 V-51
10 Plant 185 Water Flows Y-54
1OA Composition of Intake & Effluent V-54
Streams of Plant 185
11 Plant 069 Process Water Effluent V-58
- After Treatment
12 Plant 096 Effluents V-62
13 Plant 096 Effluent Analyses V—63
14 GTC Verification Measurements at V-67
Plant 030
15 Measurements of Plant 168 Process Waste V-71
Streams Before and After Treatment
16 Plant 168 Cooling Water Measurements V-72
17 Raw Waste Load from Mercury Cell V-75
Process
vii
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TABLE PAGE
18 Monthly Mercury Abatement System Dis- V-80
charge During 1972 at Plant 130
19 Plant 130 Effluent Data V—81
20 GTC Measurements of Effluents from V-82
Plant 130
21 Plant 144 Intake Water - V-83
22 Plant 144 Effluent Data V-84
23 Raw Waste Loads at Plant 100 V94
24 Effluent Treatment Data for Plant 100 V-96
25 Composition of Plant 100 Effluent V97
Streams after Treatment -
26 Plant 100 Water Intake and Final Effluent V98
Verification Measurements
27 Raw Waste Loads from Chromate Manufacture V-I 01
28 Intake and Effluent Composition at V-104
Plant 184
29 GTC Analysis of River Water at the Exem- V-105
plary Chromate Facility 184
30 GTC Analysis of Waste Treatment Streams V-106
at Plant 184
31 Calcium Chloride Recovery Process V—1l3
32 GTC Verification Measurements at Plant 166 V-114
33 Sulfate Process Waste Streams Titanium V-116
Dioxide Manufacture
34 Future Treatment at Plant 122 V-119
35 Partial Discharges Data from Titanium Vl20
Dioxide Sulfate Plants
36 Composition of Plant 009 Effluent Streams V128
After Treatment
viii
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TABLE PAGE
37 GTC Verification Data of Plant 009 V-129
38 Typical Water-Borne Loads for In- VII—2
organic Chemicals of this Study
39 Approximate Treatment Efficiencies VII—13 to 16
and Costs
40 Raw Water and Anticipated Analysis VII 18 & 19
After Treatment
41 Water Quality Produced by Various Ion VII—2O
Exchange Systems
42 Special Ion Exchange Systems VII—22 to 23
43 Summary of Cost and Energy Irformation VIII 2 & 3
for Attainment of Zero Disch e
44 Isolation and Containment Costs VIII-9
45 Comparison of Chemicals for Waste Vill-li
Neutral i zation
46 Capital Costs for Lined Solar Evapora- VIII-16
tion Ponds as a Function of Capacity
47 Costs for Solar Evaporative Pond VIII-16
Disposal
48 Overall Costs for Demineralization VIII-21
49 Overall Costs for Demineralization VIII-22
50. Reverse Osmosis-Membrane Replacement VIII-26
Costs
51 Reverse Osmosis-Operating Costs VIII-27
52 Evaporator Characteristics VIII-28
53 Cost Estimates for Different Treatments VIII-49
54 Model Treatment Plant Calculations VIII-5O
Design and Cost Basis
lx
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TABLE PAGE
55 Aluminum Chloride VIII—53
56 Aluminum Sulfate VIII—54
57 Calcium Carbide VIII—56
58 Hydrochloric Acid VIII-57
59 Hydrofluoric Acid VIII-58
60 Lime-Air Pollution Costs Only VIII-60
61 Potassium Dichromates VIII—62
62 Potassium Sulfate VIII—63
63 Sodium Bicarbonate VIII—64
64 Solar Salt VIII—66
65 Sodium Silicate VIII—67
66 Sulfuric Acid (Sulfur Burning) VIII—69
67 Sulfuric Acid (Regen Plant) VIII—70
68 Hydrogen Peroxide (Organic Process) VIII—72
69 Sodium Metal VIII—73
70 Sodium Sulfite VIII-74
71 Calcium Chloride VIII—76
72 Sodium Chloride (Brine Mining) VIII—77
73 Mercury-Cell Chior-Alkali VIII—79
74 Diaphragm Cell, Chlor-Alkalj VIII-80
75 Hydrogen Peroxide-Electrolytic VII 1-81
76 Sodium Dichromate VIII-83
77 Soda Ash VIII-86
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TABLE PAGE
78 Titanium Dioxide (Chloride Process) VIII-87
79 Titanium Dioxide (Sulfate Process) VIII-89
Neutral i zati on Option
80 Titanium Dioxide (Sulfate Process) VIII-91
Acid Recovery Option
x l
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DRAFT
LIST OF FIGURES
FIGURE PAGE
1 Industry Categorization of Inorganic Ch nicals IY—6
Manufacturing
2 Standard Aluminum Chloride Flow Diagram IV-7
3 Standard Process Diagram for Aluminum Sulfate Manu- IV-9
facture -
4 Standard Calcium Carbide Flow Diagram IV—1O
5 Standard Hydrofluoric Acid Flow Diagram IV—11
6 Standard Calcium Oxide (Lime) Flow Diagram IV—13
7 Standard Hydrochloric Acid Flow Diagram IV—14
(Synthetic Process)
8 Standard Process Diagram for Nitric Acid IV—15
9 Coninercial Extraction of Potassium IV—17
10 Standard Process Flow Diagram for Potassium Dichromate IV-18
11 General Process Potassium Sulfate Flow Diagram IV—20
12 Standard Process Diagram for Sodium Bicarbonate IV—21
13 Process Diagram for Sodium Chloride (Solar Evapora- IV—23
tion Process)
14 Standard Liquid Sodium Silicate Flow Diagram IV—24
15 Standard Anhydrous Sodium Metasilicate Flow Diagram IV—25
16 Sulfuric Acid Plant Double Absorption IV—27
17 Sulfuric Acid Plant Single Absorption IV—28
18 Standard Process Diagram for Sodium Metal IV—30
19 Standard Process Diagram for Sodium Sulfate IV—31
xlii
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FIGURE PAGE
20 Standard Hydrogen Peroxide Flow Diagram IV-32
(Riedl-Pfleiderer Process)
21 Standard Process for Calcium Chloride Manufacture IV-34
22 Standard Process for Sodium Chloride Manufacture IV-36
(Solution Mining of Brines)
23 Standard Chlorine-Caustic Soda Flow Diagram-Diaphragm IV-37
Cell Process -
24 Standard Chlorine-Caustic Flow Diagram-Mercury Cell IV-39
Process
25 Electrolytic Process for Hydrogen Peroxide IV-41
26 Standard Sodium Dichromate Process Diagram IV-43
27 Solvay Process Sodium carbonate Flow Diagram IV—44
28 Standard Process Diagram for Titanium Dioxide IV-46
(Sulfate Process)
29 Flow Diagram of Existing Comercial Chloride Process IV-47
Plants (Titanium Dioxide)
30 Aluminum Chloride Waste Treatment V-6
31 Aluminum Sulfate Process & Treatment Flow Diagram V—9
of Plant 063
32 Aluminum Sulfate Process & Flow Diagram of Plant 049 V-10
33 Calcium Carbide Process Flow Diagram at Plant 190 V-13
34 Water Usage at Calcium Carbide Plant 190 V—14
35 Start-up Treatment System at Plant 121 V-li
36 Hydrofluoric Acid Process Flow Diagram at Plant 152 V-22
37 Effluent Recycle System at Plant 152 V-23
38 Flow Diagram for Lime Plant V-28
xiv
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FIGURE PAGE
39 NItric Acid Process Flow Diagram for Plant 114 V-30
40 Potassium Sulfate Process Diagram at Plant 118 V-36
41 Sodium Bicarbonate Process Flow Diagram at Plant 166 V-39
42 Sodium Silicate Manufacture at Plant 072 V—45
43 Double Absorption Contact Sulfuric Acid Process Flow V-47
at Plant 086
44 Flow Diagram at Calcium Chloride Plant 185 V—52
45 Hydrogen Peroxide Process Diagram fc. Plant 069 V-56
46 Waste Treatment on Downs Cell Plant (.. 6 V—60
47 Sodium Sulfite Process Flow at Plant 168 V—68
48 Mercury Cell Flow Diagram (Potassium hydroxide) V-74
at Plant 130
49 Histogram of Mercury Discharges from Plant 144 V-77
50 Mercury Abatement System at Plant 130 V—79
51 Diaphragm Cell Chlor-alkali Process at Plant 057 V—86
52 Sodium Hydroxide Concentration Facility at Plant 057 V-87
53 SchematIc Showing Waste Sources and Discharge at ‘ 1 —93
Plant 100
54 Chromate Manufacturing Facility at Plant 184 V—lOO
55 Solvay Soda Ash Process Flow Diagram at Plant 166 V—l08
56 Calcium Chlorine Recovery Process at Plant 166 V-ll2
57 Sulfate Process Flow Diagram at Plant 122 V—l 17
xv
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FIGURE PAGE
58 TtC1 4 Portion of Ti0 2 Plant 009 V-123
59 1102 Portion of Plant 009 V124
60 Treatment, TiC1 4 Portion of Plant 009 V-125
61 Treatment, 1102 Portion of Plant 009 V-126
62 Time Variation of Effluent Chloride Ion Concen— V—l37
tration at Plant 030
63 Frequency Distribution of Effluent Chloride V-138
Ion Concentration at Plant 030
64 Time Variation of Effluent Mercury Concentration V-139
at Plant 144
65 Frequency DistribCition of Effluent Mercury Con- V-140
centration at Plant 144
66 Time VariaUon of Effluent Mercury Daily Discharge V-14l
at Plant 144
67 . Frequency Distribution of Effluent Mercury Daily V—l42
Discharge at Plant 144
68 Time Variation of Effluent Chloride Ion Concen— V—l43
tration at Plant 144
69 Frequency Distribution of Effluent Chloride Ion V-l44
Concentration at Plant 144
70 Time Variation of Effluent Chloride Ion Daily V-145
Discharge at Plant 144
71 Frequency Distribution of Effluent Chloride Ion V-146
Daily Discharge at Plant 144
72 Time Variation of Effluent pH at Plant 144 V-l47
73 Frequency Distribution of Effluent pH at Plant 144 V-l48
xvi
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FIGURE PAGE
74 Model for Water Treatment and Control Systems- VIII-7
Inorganic Chemicals Industry
75 Model for Water Treatment System-Inorganic VIII-8
Chemicals Industry
76 CapItal Costs for Small Unlined Ponds VIII-l3
77 CapItal Costs for Large Unlined Ponds VIII-13
78 Construction Costs of Small Unlined Ponds VIII-15
79 CapItal Costs for Large Lined Ponds VIII-15
80 Installed Capital Cost for Carbon Adsorption VIII-l7
Equipment
81 Overall Costs for Carbon Adsorptio VIII-l7
82 Installed Capital Cost vs. Capacity or Demineral- VIII-2O
izat lon
83 Chemical Costs for Demineralization VIII-20
84 Installed Capital Costs for Reverse Osmosis VIII-23
Equipment
85 Costs for Reverse Osmosis Treatment VIII-23
86 Trade-off Bebieen Membrane P.ermeability (Flux) VIII-25
and Selectivity (Rejection and Product Water
Quality) for Cellulose Acetate Base Membranes VIII-25
87 Total Dissolved Solids VIII-29
88 Installed Capital Costs vs. Capacity for High VIII-32
Efficiency VTE or Multi-Stage Flash Evaporators
89 Overall and Total Operating Costs for VTE and VIII-32
Multi-Flash Evaporators
90 Capital Cost vs. Effects for Conventional Multi- VIII-34
effect Evaporators
xvii
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FIGURE PAGE
91 Steam Usage vs. Effects for Conventional Multi- VIII-35
effect Evaporators
92 Correlations of Equipment Cost - With Evaporator VIII-36
Heating Surface
93 Overall Costs for 6-Effect Evaporator Trea1 nent VIII-36
of Was tewater
94 Disposal Costs for Sanitary Land Fills VIII—42
95 Treatment Applicability to Dissolved Solids Range VIII—48
in Waste Streams
xvtll
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SECTION I
CONCLUSIONS
For the purpose of establishing effluent limitations guide-
lines and standards of performance, the inorganic chemicals
industry was divided into categories based on compositions
of the treated process effluents from exemplary plants with
respect to three parameters determined to be the most common
in the industry: total dissolved solids (TDS), total suspen-
ded solids (TSS), and heavy metals. This system, with low,
medium and high levels of TDS, low and high levels of TSS,
and presence or absence of heavy metals, limits the possible
categories to 12. Five of these possible 12 categories ac-
conimodated all of the twenty-five chemicals of this study.
Factors such as processes employed, raw materials used or
geographical location justified the use of subcategories.
Other factors, such as plant age, plant size and waste con-
trol technologies did not justify further segmentation of
the industry.
Based on the use of Level I technology, the best practicable
currently available treatment, 14 of the 25 chemicals under
study can be manufactured with zero discharge of process
waste water. With the use of Level II technology, the best
economically achievable, all of the 25 chemicals can be man-
ufactured with zero discharge of process waste water. Zero
discharge of process waste water is also achievable as a
new source performance standard.
This study included 25 of the major inorganic chemicals of
SIC categories 2812, 2816 and 2819. Phase II of this study
will include certain other inorganic chemicals and industrial
gases whose annual U.S. production volume exceeds 450 metric
tons (1,000,000 pounds).
1—1
NOTiCE : THESE ARE TENTATIVE RECOMMENDATiONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT 10 CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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DRAFT
SECTION II
RECOMMENDATIONS
No discharge of process waste water is recommended as the
Level I effluent limitations guidelines and new source per-
formance standard for all the fol1o ding chemicals/processes
in Category 1:
Aluminum Chloride
Aluminum Sulfate
Calcium Carbide
Hydrochloric Acid (Chlorine-Burning)
Hydrofluoric Acid
Lime
Nitric Acid
Potassium (Metal)
Potassium Chromates
Potassium Sulfate
Sodium Bicarbonate
Sodium Chloride (Solar)
Sodium Silicate
Sulfuric Acid
The Level I effluent limitations guidelines recommended for
the remaining chemicals/processes in categories 2, 3, 4 and
5 are as follows:
II — 1
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIE’N BY EPA.
DRAFT
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Monthly Average Values*
5Z
rn 0
c m
1 Z
=
— 1 —
mC
jwm
C-
9I
9
3
Chemical/Process
Hydrogen Peroxide,
(Organic)
Sodium (Metal)
Sodium Sulfite
Calcium Chloride
Sodium Chloride
(Brine Mining)
Mercury Cell,
Chior-Alkali
Diaphragm Cell
Chior-Alkali
Hydrogen Peroxide,
(Electrolytic)
Titania
(Sulfate Process)
TSS
( kg/kkg )
0.28 av.
0.32 max.
0.25 av.
0.05 av.
0.125 max.
25 ppm av.
0.125 av.
TDS
( kq/kkg )
21.5 av.
23 max.
51.5 av.
30 av.
36.5 max.
30.7 av.
6.0 av.
0.019 av..
0.29 max.
Iron
0.05 av.
titanium
0.0025 other
heavy metals
25 ppm of
heavy metals
expressed as
oxides.
0.26 av.
-organics
0.35 max.
organics
0
3.0 Na2SO3
av.
3.65
Na2SO3 max.
0
0
Category
2
Other
( kg/kkg )
Heavy
Metals
( kg/kkg )
0
0
0
0
0
0
0.325 av.
19.25 av.
0.00007 Hg
0
0.10 av.
19.25 av.
0.0025 Pb
0
0.0025 av.
1.0 av.
0.0002 CN—
0
0.0002 Heavy
Metal
Sodium Dichromate
0.125 av.
0.215 max.
88.5 av.
115 max.
0.0001
Cr+6
0.00125
Total
Cr
Sodium Sulfate
(See Sodium
Dichromate - By-Product)
4
Soda Ash
0.125 av.
1535 av.
0
0
5
Titania
0.205 max.
1.75 av.
1650 max.
315 av.
0
(Chloride.Process)
4.8 max.
430 max.
C
25 ppm av.
265 av.
0
*To convert from metric units to English units (lbs/toh) multiply the above
values by 2.
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DRAFT
The daily maximum values are twice the monthly average values
unless otherwise specified. All process water effluents are
limited to the pH range of 6 to 9. Exceptions to this range
must be considered on an individual case basis.
No discharge of process waste water is recommended as the
Level II effluent limitations guidelines and new source per-
formance standard for all the chemicals in categories 2
through 5.
The recommendations for cooling water and blowdown discharges
are:
Level I
An allowed discharge of all non-contact cooling waters .pro-
vided that the following conditions are met:
(1) No toxic or hazardous pollutants are added. Cooling
waters discharged must not have levels of chromate or
other toxic pollutants higher than that of the intake
water or receiving water, whichever is lower.
(2) Thermal pollution be in accordance with local standards.
Excessive thermal rise in once—through non—contact cool-
ing water in the inorganic chemical industry has not been
and is not expected to be a significant problem.
(3) No process waters be added to the cooling waters prior to
discharge.
(4) All non-contact cooling waters should be monitored to de-
tect leaks from the process and provisions should be made
for emergency treatment prior to release.
An allowed discharge of water treatment, cooling tower and
boiler blowdowns provided these do not contain toxic or other-
wise hazardous materials such as chromium or cadmium and are
within the required pH range.
Levels II and III
The same as Level I except that monitoring shall be required
for process leaks and provisions made for emergency holding
facilities for cooling water contaminated by leaks until such
time as they can be treated.
II — 3
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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DRAFT
These guidelines represent the degree of effluent reduction
attainable by existing point sources through the application
of the best practicable control technology currently avail-
able, and the best available technology economically achiev-
able. They also represent, for new sources, a standard of
performance providing for the control of the discharge of
pollutants which reflects the greatest degree of effluent
reduction achievable through application -of the best avail-
able demonstrated control technology, processes, operating
methods or other alternatives.
The technologies, on which such limitations and standards are
based, are discussed in detail in Section VII of this document.
II — 4
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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DRAFT
SECTION III
INTRODUCTION
1.0 PURPOSE AND AUTHORITY
The United States Environmental Protection Agency (EPA) is
charged under the Federal Water Pollution Control Act Amend-
ments of 1972 with establishing effluent limitations which
must be achieved by point sources of discharge into the nav-
igable water of the United States. The Act requires the
achievement by July 1, 1977 of effluent limitations which
require the application of the “best practicable control
technology currently available”, and by July 1, 1983, the
achievement of effluent limitations which require the ap-
plication of the “best available technology economically
achievable”.
Section 301(b) of the Act requires the achievement by not
later than July 1, 1977, of effluent limitations for point
sources, other than publicly owned treatment works, which
are based on the application of the best practicable control
technology currently available as defined by the Administra-
tor pursuant to Section 304(b) of the Act. Section 301(b)
also requires the achievement by not later than July 1, 1983,
of effluent limitations for point sources, other than pub-
licly owned treatment works, which are based on the applica-
tion 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,
as determined in accordance with regulations issued by the
Administrator pursuant to Section 304(b) to the Act. Section
306 of the Act requires the achievement by new sources of a
Federal standard of performance providing for the control of
the discharge of pollutants which reflects the greatest degree
of effluent reduction which the Administrator determines to
be achievable through the application of the best available
demonstrated control technology, processes, operating methods,
or other alternatives, including, where practicable, a stand-
ard permitting no discharge of pollutants.
III — 1
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DRAFT
Section 304(b) of the Act requires the Administrator to pub-
lish within one year of enactment of the Act, regulations
providing guidelines for effluent limitations setting forth
the degree of effluent reduction attainable through the ap-
plication of the best practicable control technology currently
available and the degree of effluent reduction attainable
through the application of the best control measures and prac-
tices achievable including treatment techniques, process and
procedure innovations, operation methods and other alternatives.
The regulations proposed herein set forth effluent limitations
guidelines pursuant to Section 304(b) of the Act for the inor-
ganic chemicals, alkali and chlorine industries source category.
Section 306 of the Act requires the Administrator, within one
year after a category of sources is included in a list pub-
lished pursuant to Section 306(b) (1) (A) of the Act, to
propose regulations establishing Federal standards of perfor-
mances for new sources within such categories. The Administra-
tor published in the Federal Register of January16, 1973
(38 F.R. 1624), a list of 27 source categories. Publication
of the list constituted announcement of the Administrator’s
intention of establishing, under Section 306, standards of
performance applicable to new sources within the inorganic
chemicals, alkali and chlorine industries source category,
which was included within the list published January 16, 1973.
2.0 SUMMARY OF METHODS USED FOR DEVELOPMENT OF EFFLUENT
LIMITATION GUIDELINES AND STANDARDS OF PERFORMJ NCE
The Environmental Protection Agency has determined that a
rigorous approach including plant surveying and verification
testing is necessary for the promulgation of effluent stand-
ards from industrial sources. A systematic approach to the
achievement of the required guidelines and standards includes
the following:
(a) Categorization of the industry and determination of
those industrial categories for which separate
effluent limitations and standards need to be set;
(b) Characterization of the waste loads resulting from
discharges within industrial categories and sub-
categories;
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(c) Identification of the range of control and
treatment technology within each industrial
category and subcategory;
(d) Identification of those plants having the best
practical technology currently available (ex—
emplary plants); and
(e) Generation of supporting verification data for
the best practical technology including actual
sampling of plant effluents by field teams.
The culmination of these activities is the development of
the guidelines and standards based on the best practicable
current technology.
This report describes the results obtained from application
of the above approach to the inorganic chemicals, alkali,
and chlorine industries. Thus, the survey and testing cov-
ered a wide range of processes, products, and types of wastes.
Studies of a total of twenty—five industries, listed in terms
of products below, are summarized in this report. A separ-
ate report covering the non-fertilizer phosphosus chemicals
industries was also generated under the same contract.
Inorganic Chemicals
Aluminum Chloride
Aluminum Sulfate
Calcium Carbide
Calcium Chloride
Chlorine
Hydrochloric Acid
Hydrogen Peroxide
Hydrofluoric Acid
Lime
Nitric Acid
Potassium Chromates
Potassium Hydroxide
Potassium Metal
Potassium Sulfate
Sodium Bicarbonate
Sodium Carbonate (Soda Ash)
Sodium Chloride
Sodium Dichromate
Sodium Hydroxide
Sodium Metal
Sodium Silicate
Sodium Sulfate
Sodium Sulfite
Sulfuric Acid
Titanium Dioxide
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2.1 Categorization and Waste Load Characterization
The effluent limitations guidelines and standards of per-
formance proposed herein were developed in the following
manner. The point source category was first categorized
for the purpose of determining whether separate limitations
and standards are appropriate for different segments within
a point source category. Such subcategorization was based
upon raw material used, product produced, manufacturing
process employed, and other factors. The raw waste charac-
teristics for each subcategory were then identified. This
included an analysis of (1) the source and volume of water
used in the process employed and the sources of waste and
waste waters in the plant; and (2) the constituents of all
waste waters including toxic constituents and other consti-
tuents which result in degradation of the receiving water.
The constituents of waste waters which should be subject
to effluent limitations guidelines and standards of perfor-
mance were identified.
2.2 Control and Treatment Technology
The full range of control and treatment technologies exist-
ing within each subcategory was identified. This included
an identification of each control and treatment technology,
including both inpiant and end-of-process technologies, which
are existent or capable of being designed for each subcate—
gory. It also included an identification of the amount of
constituents (including thermal) and the characteristics of
pollutants resulting from the application of each of the
treatment and control technologies. The problems, limita-
tions and reliability of each treatment and control technol-
ogy were also identified. In addition, the non—water quality
environmental impact, such as the effects of the application
of such technologies upon other pollution problems, including
air, solid waste, noise and radiation were also identified.
The energy requirements of each of the control and treatment
technologies were identified as well as the cost of the appli-
cation of such technologies.
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2.3 Development of Cost Data
Cost information contained in this report was obtained direct-
ly from industry during exemplary plant visits, from engineer-
ing firms and equipment suppliers, and from the literature.
The information obtained from the latter three sources has
been used to develop general capital, operating and overall
costs for each treatment and control method. Costs have been
put on a consistent industrial calculation basis of ten year
straight line depreciation plus allowance for interest at six
percent per year (pollution abatement tax free money) and in-
clusion of allowance for insurance and taxes for an overall
fixed cost amortization of fifteen percent per year. This
generalized cost data plus the specific information obtained
from plant visits was then used for cost effectiveness esti-
mates in Section VIII and wherever else costs are mentioned
in this report.
2.4 Data Sources
The data for identification and analyses were derived from a
number of sources. These sources included EPA research infor-
mation, published literature, qualified technical consultation,
on-site visits and interviews at numerous inorganic chemical
plants throughout the U.S., interviews and meetings with var-
ious trade associations, and interviews and meetings with var-
ious regional offices of the EPA. All references used in de-
veloping the guidelines for effluent limitations and standards
of performance for new sources reported herein are included
in Section XIII of this report.
2.5 Exemplary Plant Selection
The following exemplary plant selection criteria were devel-
oped and used for the selection of exemplary plants.
2.5.1 Discharge Effluent Quantities
Plants with low effluent quantities and/or the ultimate of no
discharge were preferred. This minimal discharge may be due
to reuse of water and/or raw material recovery and recycling,
or to use of evaporation. The significant parameter was mini-
mal waste added to effluent streams per weight of product man-
ufactured. The amount of wastes considered here was those
added to waters taken into the plant and then discharged.
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2.5.2 Effluent Contaminant Level
Preferred plants were those with lowest effluent contaminant
concentrations and lowest total quantity of waste discharge
per unit of product.
2.5.3 Water Management Practices
Use of good management practices such as water re—use, plan—
fling and in-plant water segregation, and the proximity of
cooling towers to operating units where airborne contamina-
tion of water can occur were considered.
2.5.4 Land Utilization
The efficiency of land use was considered.
2.5.6 Air Pollution and Solid Waste Control
Exemplary plants must possess overall effective air and solid
waste pollution control where relevant in addition to water
pollution control technology. Care was taken to insure that
all plants chosen have minimal discharges into the environ-
ment and that exemplary sites are not those which are exchang-
ing one form of pollution for another of the same or greater
magnitude.
2.5.7 Effluent Treatment Methods and Their Effectiveness
Plants selected shall have in use the best currently available
treatment methods, operating controls, and operational relia-
bility. Treatment methods considered included basic process
modifications which significantly reduce effluent loads as well
as conventional treatment methods.
2.5.8 Plant Facilities
All plants chosen as exemplary had all the facilities normally
associated with the production of the specific chemical(s) in
question. Typical facilities generally were plants which have
all their normal process steps carried out on-site.
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2.5.9 Plant Management Philosophy
Plants were preferred whose management insists upon effective
equipment maintenance and good housekeeping practices. These
qualities are best identified by a high operational factor
and plant cleanliness.
2.5.10 Geographic Location
Factors which were considered are plants operating in close
proximity to sensitive vegetation or in densely populated
areas. Other factors such as land availability and differ-
ences in state and local standards were also considered.
2.5.11 Raw Materials
Differences in raw material purities were given strong con-
sideration in cases (e.g., Ti02) where the aznounts of wastes
are strongly influenced by the purity of raw materials used.
Several plants using different grades of raw materials were
considered for those chemicals for which raw material purity
is a determining factor in waste control. Chemicals where
this was expected to be of importance are titanium dioxide,
aluminum sulfate, the dichromates, and to a lesser extent
chlorine and sodium chloride.
2.5.12 Diversity of Processes
On the basis that all of the above criteria are met, consider-
ation was given to installations having a multiplicity of man-
ufacturing processes. However, for sampling purposes, the
complex facilities chosen were those for which the wastes
could be clearly traced through the various treatment steps.
2.5.13 Production
On the basis that other criteria are equal, consideration was
given to the degrees of production rate scheduled on water
pollution sensitive equipment.
2.5.14 Product Purity
For cases in which purity requirements play a major role in
determining the amounts of wastes to be treated and the degree
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of water recycling possible, different product grades were
considered as sub—categories.
2.6 Sampling of Exemplary Plants
The details of how the exemplary plants were sampled and the
analytical techniques employed are fully discussed in Section V,
paragraph 4.0 of this report.
The information, as outlined above, was then evaluated to de-
termine what levels of technology constitued the “best prac-
ticable control technology currently available,” the “best
available technology economically achievable” and the “best
available demonstrated control technology.”
3.0 GENER1½L DESCRIPTION OF THE INDUSTRY
Brief descriptions of each of these twenty—five industries
are presented in subsequent subsections. The thdustry
groupings used below combine similar industries in terms
of raw materials or product type and are not the same as
used in the industry categorization of Section IV C in
which industries are grouped by effluent characteristics)).
Process flow sheets for the industries may be found in
Sections IV and V. Production tonnages reported for 1971
were taken from Current Industrial Reports, Inorganic Chemicals,
U.S. Bureau of Census, Series M28A(71)-14.(l) These values
are summarized in Table 1, at the end of this section.
Also included are production tonnages for years prior and
subsequent to 1971, where available, and the number of plants
producing each chemical.
3.1 Aluminum Salts
3.1.1 Aluminum Chloride
The anhydrous product is produced by the reaction of gaseous
chlorine with molten aluminum metal (scrap or scrap—pig mix-
ture). The basic equation is:
2A1 + 3C12 - 2A1 Cl3
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Chlorine is introduced below the surface of the molten alum-
inum; the product sublirnes and is collected by condensation.
Waste gases are removed to a scrubber, which in some facil-
ities provide recycling capability and eliminates waste
streams. Annual U.S. production in 1971 totalled 26,399
metric tons (29,100 tons). The major use is as a catalyst
in the petrochemical and synthetic polymer industries.
A solution grade of aluminum chloride is also produced by
reacting hydrated alumina or bauxite ore with hydrochloric
acid. The 1971 production for the 28% solution product was
7,650 metric tons (8,400 tons).
3.1.2 Aluminum Sulfate
Aluminum sulfate is produced by the reaction of bauxite ore
with concentrated sulfuric acid (60°Be). The general equation
of the reaction is:
A1203 . 2H20 + 3H2S04 ÷ A12(S04)3 + 5H20
Ground ore and acid are reacted in a digester, from which
the products, aluminum sulfate in solution plus muds and
other insoluble materials from the ore, are fed into a set-
tling tank. The aluminum sulfate solution is clarified and
filtered to remove remaining insolubles, and is then sold as
solution or evaporated to yield a solid product. The insol-
uble materials are fed into settling basins in slurry form,
and the clear effluent is reintroduced into the process stream.
Annual U.S. production in 1971 was 1,084,080 metric tons
(1,195,000 tons). Aluminum sulfate, or filter alum, is used
for water treatment (flocculation and clarification) and in
treatment of paper mill waste, sewage, and other waste streams.
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3.2 Calcium Compounds
3.2.1 Calcium Carbide
This chemical is prepared by the reaction of quicklime with
carbon (in the form of coke, petroleum coke, or anthracite)
at 2000—2200°C (3632—3992°F) in a furnace similar to the
familiar arc furnace. The general equation for the reaction
Heat
is: 2CaO ÷ 4C - 2CaC2 + 02
Calcium carbide is used primarily in the manufacture of
acetylene (by reaction with water), but this use and the
tonnage production has been steadily decreasing. Still,
most calcium carbide plants are located in conjunction
with acetylene plants. Since the production process is
dry, the only major discharges are those effluents from
scrubbing furnace and kiln offgases. The U.S. production
in 1971 was 567,182 metric tons (625,338 tons).
3.2.2 Calcium Chloride
Most of the calcium chloride produced is extracted from
impure natural brines, but some of this salt is recovered
as a by—product of soda ash manufacture by the Solvay
process. In the manufacture of calcium from brines, the
salts are solution mined and the resulting brines are first
concentrated to remove sodium chloride by precipitation and
then purified by the addition of other materials to preci-
pitate sodium, potassium, and magnesium salts. The purified
calcium chloride brine is then evaporated to yield a wet
solid which is flaked and calcined to dry solid product.
Extensive recycling of partially purified brine is used to
recover most of the sodium chloride values.
Manufacture of calcium chloride from Solvay process waste
liquors is similar to the natural brine process except that
the stepwise concentration and purification is not required
because no magnesium is present. Evaporation and calcinincj
procedures are similar to those above.
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Significant wastes result from calcium chloride manufacture.
A typical spent brine treatment might include removal of or-
ganics by activated sludge processing, followed by settling
in ponds.
In 1971, U.s. production of calcium chloride was 1,101,281
metric tons (1,213,000 tons). Uses include de-icing of
roads, a stabilizer in pavement and cement, and dust control
on roads. Production is increasing as more uses and markets
are found, but potential production capability is much great-
er than that presently utilized. Calcium chloride is essen-
tially a by-product, but its price was relatively high in
past years because of the high cost of recovery. Recently,
however, increased recovery resulting from pollution abate-
ment measures has tended to cause calcium chloride supply
to exceed demand. Plants recovering this salt from natural
brines are located near mixed salt deposits, such as those
in Michigan, West Virginia, and California.
3.2.3 Lime (Calcium Oxide )
Lime is produced by calcining various types of limestone in
a continuous vertical or rotary kiln. The general equation
Heat
for the reaction is: CaCO3 + CaO + C02+.
Formerly coal or coke was used as fuel in vertical kilns,
but in recent years large gas-fired kilns have been widely
used. After calcination, the lime is cooled and then
packaged as lump lime or crushed and screened to yield pul-
verized lime. As the process itself uses no water, the
only wastes result from wet scrubbing of the gaseous kiln
effluent to remove particulates. These wastes are high pH
liquors which also contain suspended solids.
Annual U.S. production of lime is believed to total about
16,000,000 metric tons (17,600,000 tons). Approximately
20 percent of this production is “captive” (made and con-
sumed in the same facility), primarily in the sugar, alkali,
and steel industries. The remainder finds a variety of
chemical and industrial uses, including use as an alkali
and in hydrated lime manufacture. Principal growth areas
appear to be in basic oxygen steel production and in soil
stabilization.
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3.3 Chlorine, Alkalis, and Alkali Metals
3.3.1 Chlorine
The major chlorine production results from the electrolysis
of sodium or potassium chloride brines, in which process
caustic soda (NaOH) or caustic potash (KOH), respectively,
are also produced. The general equation for the electroly-
sis is (where M can be either Na or K):
dc
3 MCi + 2H20 -‘ C12+ + 2MOH + H2+
From the above equation it can be seen that hydrogen is also
a by—product of brine electrolysis.
Other sources (minor in size) of chlorine include the manu-
facture of hydrochloric acid and metallic sodium.
Two types of electrolysis cells are used. “Diaphragm” cells,
which are becoming favored over the “mercury” type, require
initial purification of the brine in order to produce high
grade products. The brine is then concentrated to near sat-
uration and fed to the anolyte where chlorine is formed at
the anode. The brine then flows through the diaphragm to
the catholyte where caustic is formed.
“Mercury” cells utilize mercury flowing along the bottom of
a steel trough as the cathode. A multiple anode is comprised
of horizontal graphite plates. The alkali metal forms an
amalgam with the mercury. The amalgam is decomposed external
to the cell by the addition of water which results in the
formation of hydrogen.
The chlorine gas from the cells is collected, cooled, dried
by contact with sulfuric acid, and then purified and lique-
fied for shipment, utilized on—site, or sold as gaseous
chlorine. Much of the unreacted salt in the brine is recy-
cled. Besides potential acidic and brine effluents from
both processes, some mercury is present in the spent brine
from the mercury cell process. The cost of removing mercury
from the effluent is relatively high, which accounts for
the shift back toward the diaphragm cells. Mercury cells
began to be widely used in the early 1950’s and reached a
high of almost 30 percent of the total production in 1968.
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The U.S. production of chlorine in 1971 totalled 8,482,660
metric tons of gas (9,352,437 tons) and 4,035,489 metric
tons of liquid (4,449,271 tons). At present, about 75 per—
cent of the production is in diaphragm cells, 20 percent in
mercury cells, and 5 percent from other sources. About
two-thirds of the production is utilized in the synthetic
organic chemical and plastics industries, and half of that
remaining is utilized in the pulp and paper industry (as a
bleaching agent). Other uses include the inorganic chemicals
industry, municipal water and sewage treatment, and many
others. Somewhat over half of the total production is
“captive”, primarily to the synthetic organic chemicals and
the pulp and paper industries. In recent years proximity
to markets has been the major factor in chlorine plant lo-
cation, in contrast to the cost of power and salt which
previously dominated plant economics.
3.3.2 Sodium Hydroxide (Caustic Soda )
Sodium hydroxide is produced from electrolysis of sodium
chloride brines as described above under chlorine. Raw
materials include mined rock salt, solar salt, and natural
brines. The caustic solution from the cathode of the elec-
trolysis cell is evaporated to about 50 percent by weight
sodium hydroxide. This may be sold as “standard-grade
caustic liquor”, concentrated to 73 percent, or further
refined through removal of chloride and chlorate by various
techniques. Refined caustic liquor may be sold, further
concentrated to 73 percent solids, or evaporated to dry-
ness and the anhydrous sodium hydroxide sold in solid
(flake or powdered) forms. Most of the product is sold in
the liquid form.
Caustic soda has many varied uses; mostly as an alkali.
It has also replaced soda ash (sodium carbonate) in many
uses, such as in the aluminum industry and other molten
salt processes, and is used to manufacture soda ash in one
plant. In 1971, the U.S. production of sodium hydroxide was
8,780,946 metric tons (9,681,397 tons) in liquid form
and 493,393 metric tons (543,983 tons) in solid form.
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3.3.3 Potassium Hydroxide (Caustic Potash )
Production methods for potassium hydroxide are very similar
to those for sodium hydroxide, except that mined potassium
chloride or potash brines are used as the raw material. The
U.S. production of potassium hydroxide in 1971 was 179,760
metric tons (198,192 tons). Caustic potash is used as an
alkali, particularly when very high purity is desired or
where other factors allow it to compete with sodium hydrox-
ide (captive production, for instance). Other uses include
the manufacture of potassium salts and organic compounds
containing potassium.
3.3.4 Sodium Metal
Sodium metal is manufactured by electrolysis of fused (molten)
sodium chloride at about 600°C (1072°F). The general equa-
tion is: dc
2NaC1 ÷ 2Na + C12+
The salt is mixed with alkali fluorides and calcium chloride
to sufficiently lower the melting point, and the charge is
then fused in a “Downs” cell, which is a closed rectangular
refractory-lined steel box with separate anode and cathode
compartments separated by an inorganic diaphragm. The graph-
ite or carbon anode is fed into the bottom of the cell, and
the cathode is iron or copper in an annular form.
Molten sodium formed at the cathode is transported to a col-
lection vessel, from which the metal is withdrawn from the
bottom, filtered, and packaged in the form of bricks of
various sizes. Very pure metal results from blanketing the
cell and other processing equipment with argon gas to pre-
clude oxygen from the system. Even the less pure product,
because of its reactivity, must be protected from air and
water throughout the production process.
The U.S. production of sodium metal in 1971 was 138,839
metric tons (153,075 tons). One of its major uses is in
the manufacture of tetraethyl lead and other organo—
metallic compounds. Other uses include production of
sodium cyanide, sodium peroxide, titanium, and zirconium.
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It is also used in liquid form as a nuclear reactor coolant
and as a light, thermally-conductive solid in various
applications.
3.3.5 Potassium Metal
Potassium is produced by the reaction of potassium chloride
with sodium vapor: Heat
KC1 + Na K + NaC1
Since it is relatively more reactive than sodium, the reac-
tion between potassium and carbon (plus a tendency to form
explosive carbonyls) precludes the manufacture of potassium
by electrolysis. Since it is more expensive than sodium,
potassium has very limited uses. Ma:jor uses include manufac-
ture of organo—potassium compounds and production of NaK
(sodium potassium alloys used in lard modification and as
a nuclear reactor coolant). Total U.S. production in 1972
was about 100 metric tons (110 tons).
3.4 Mineral Acids
3.4.1 Hydrochloric Acid
There are two major processes used for hydrochloric acid man—
ufacture. The process to be considered in this report is
direct reaction of chlorine with hydrogen, by:
C12 + H2 2HC1
The second major source of production for hydrochloric acid,
as a by—product of organic chlorination reactions, is the
dominant source. This source was studied under a different
program (organic chemicals). By-product hydrochloric acid
is typically of lower purity than that produced by direct
reaction.
In the production of hydrochloric acid by direct reaction,
hydrogen and chlorine gases are reacted in a vertical burner.
The product hydrogen chloride so formed is cooled and then
absorbed in water. Exhaust gases are scrubbed, and acid
values are recycled.
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End products may include strong acid (36 percent or 22°B )
from the cooler, weak acid (l8°B ) from the absorber column,
a mixture of these (20°Bé), or anhydrous HC1. The anhydrous
acid may be prepared by stripping gaseous HC1 from strong
acid. The condensate and column bottoms from this process
may then be recycled back into the hydrochloric acid recovery
process.
Approximately 90 percent of the current production is by-
product, and supply often exceeds demand. Uses include
pickling of steel, chlorination reactions (in place of
chlorine), and a variety of uses as an acid agent. Total
U.S. production in 1971 was 1,904,075 metric tons (2,099,371
tons).
3.4.2 Hydrofluoric Acid
Hydrofluoric acid is obtained by reacting the mineral flu-
orspar (CaF2) with concentrated sulfuric acid in a furnace.
The general reaction for this process is*:
Heat
CaF2 + H2S04 -‘- H2F2+ + CaSO4
The hydrofluoric acid leaves the furnace as a gas, which is
then cooled and absorbed in water prior to purification. In
the purification system, the crude acid is redistilled and
either absorbed in water to yield aqueous hydrofluoric acid
or compressed and bottled for sale as anhydrous hydrofluoric
acid. Final drying of the anhydrous gas is accomplished
with concentrated sulfuric acid. Aqueous acid is normally
shipped as 70 percent acid.
Most U.S. hydrofluoric acid production (probably 75-80 per-
cent) is captive to the fluorinated organics and plastics
industries. Total U.S. production in 1971 was 199,069 metric
tons (219,481 tons), and the production appears to be in-
creasing fairly rapidly. Fluorinated organics and plastics
comprise the major use industries, and another major use is
in the production of synthetic cryolite and aluminum fluoride.
*The symbol for hydrofluoric acid may be written HF, H2F2,
or HxFx.
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Most of the acid—grade fluorspar ore is imported. Waste
disposal problems and safety hazards are specialized and
severe because of the reactivity of the material.
3.4.3 Nitric Acid
This report covers production of nitric acid in concentra-
tions up to 68 percent by weight (azeotropic concentration).
More concentrated nitric acid, including fuming nitric acid,
and nitrogen pentoxide will be included in the Phase II
Report.
Nitric acid is produced by catalytic oxidation of ammonia,
first to nitric oxide (NO), and then to nitrogen dioxide
(N02), which is reacted with water under pressure to form
the acid. The overall reaction scheme is:
cat.
4NH3 + 5S02 4N0 + 6H20
2N0 + 02 + 2N02
3N02 + H20 + 2HN03 + NO
In the process, compressed, purified, and preheated air and
anhydrous ammonia are mixed and passed over a platinum—
rhodium wire—gauze catalyst at about 750°C (1382°F). The
resultant mixture of nitric oxide and excess air is intro-
duced, along with additional air, into a stainless steel
absorption tower in which the nitric oxide is oxidized and
the resulting nitrogen dioxide is reacted with water. The
bottom of the tower yields acid at 61 to 65 percent by
weight nitric acid. In a well-designed plant, the only
effluent wastes are treatment chemicals added to cooling
water.
Most of the U.S. nitric acid production is utilized in the
fertilizer industry, and the second largest use is in explo-
sives manufacture. Various uses as an acidic or pickling
agent account for much of the remaining production. Total
U.S. production in 1971 was 6,151,112 metric tons (6,742,130
tons).
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3.4.4 Sulfuric Acid
Almost all of the sulfuric acid production in this country
arises from catalytic oxidation of sulfur dioxide to sulfur
trioxide (S03) and its subsequent reaction with water to
form the acid. This method is called the “contact” pro-
cess, and the general reactions are:
2S02 + 02 2S03
S03 + H20 + H2S04
The source of the sulfur dioxide for acid manufacture varies
widely; raw materials include sulfur, refinery sludges, py-
rites (sulfide ores), spent acid solutions, recovered S02,
and by-product hydrogen sulfide. The sulfur, iron sulfide,
and hydrogen sulfide are burned in air according to (respec-
tively);
S + 02 S02
4FeS2 + 1102 ÷ 8S02 + 2Fe203
2H2S + 302 2S02 + 2H20
Sulfur dioxide from oxidation of iron sulfide or from roast-
ing of other sulfide ores is relatively impure and requires
removal of materials such as dust, moisture, arsenic, chlor-
ine, and fluorine, all of which would poison the catalyst
used in the contact process. Most of the U.S. production of
sulfuric acid arises from the use of sulfur or refining
sludge raw materials.
In the contact process, purified and dry sulfur dioxide is
mixed with air, heated, and introduced into a steel reactor
(converter) containing a platinum or vanadium pentoxide
catalyst. The resulting gas mixture is cooled and sent to
a succession of internally—cooled towers where the sulfur
trioxide is absorbed by oleum (acid plus excess sulfur triox—
ide) of successively decreasing sulfur trioxide concentra-
tions. Acid less than 97 percent concentration cannot be
used to absorb sulfur trioxide because of mist formation
and consequent sulfur trioxide losses. Various products are
sold, ranging in acidic strength from battery acid (33.5
percent H2 504, 50°Bé) to 70 percent oleum (70 percent free
S03 in H2S04). Iron or steel containers can be used for the
higher acid concentrations; dilute acid requires special-
ized containers of glass or lined with glass, rubber, or
lead.
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Total U.S. production in 1971 was 26,685,916 metric tons
(29,422,179 tons). About 60 percent of this production is
captive, much of it supplying the fertilizer, petroleum
refining, and explosive industries. There are many other
large-tonnage industrial uses, including the manufacture
of synthetic plastics, detergents, hydrofluoric acid, nu-
clear fuels, and various other organic and inorganic chem-
ical products.
3.5 Hydrogen Peroxide
Hydrogen peroxide (H202) is manufactured by three very dif-
ferent processes: (1) An electrolytic process; (2) Oxidation
of alkyl hydroanthraquinones; and (3) As a by-product in the
manufacture of acetone from isopropyl alcohol. This report
includes processes (1) and (2) above; the third process was
presumably considered under another study (organic chemicals).
In the electrolytic process, a solution of ammonium (or other)
bisulfate is electrolyzed, yielding anunonium persulfate at
the anode and hydrogen gas at the cathode. The persulfate
is then reacted with water (hydrolyzed) to yield hydrogen
peroxide and the original bisulfate. The general reaction
scheme is: dc
2NH4HSO4 ÷ (NH4)2S208 + H2+
(NH4)2S208 + H20 - 2NH4HSO4 + H202
The crude peroxide product emerges mixed with water, and can
be concentrated to desired levels by vacuum distillation or
low—temperature fractionation. The cathode liquor is filter-
ed and reused.
The alkyihydroanthraquinone oxidation process is portrayed
in general form below (“R t ’ represents the alkylanthraquinone
molecule, except for the two double—bonded oxygens):
Cat.
O=R=O + H2 ÷ HO-R-OH
HO-R-OH + 02 -‘ 0=R=O + H202
III — 19
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In this process, the alkylanthraquinone is reduced by hydro-
gen over a supported metal catalyst (typically palladium on
alumina), the product being the corresponding alkylhydroan-
thraquinone. This, in turn, is oxidized by oxygen in a
forced gas stream to reform the original alkylanthraquinone
plus hydrogen peroxide. The hydrogen peroxide is extracted
with water and the alkylanthraquinone is recycled.
Hydrogen peroxide is sold in a range of aqueous concentrations
from three percent to 98 percent by weight. The higher con-
centration materials are dangerously reactive. A stabilizer
(such as acetanilid) is typically added to the product to
retard decomposition. Uses are many and various and include
bleaching of textiles and paper, epoxidation, production of
peroxy-acid catalysts, oxidation of organic compounds, blow-
ing of foams, and a source of energy for both military and
civilian applications. The U.S. production in 1971 was
57,937 metric tons (63,878 tons).
3.6 Sodium and Potassium Salts
3.6.1 Sodium Chloride
Large quantities of this chemical are produced from brine or
seawater by three basic processes, and some rock salt is sold
in the purity obtained from the mine (for uses where impuri-
ties are not important). Pretreatment of the brine before
sodium chloride recovery depends on the impurities present.
Brines obtained from dissolution in water pumped through an
underground salt deposit will typically also contain cal-
cium sulfate, calcium chloride, and magnesium chloride, plus
traces of hydrogen sulfide and iron. These impurities are
removed or controlled by various methods. Sodium sulfate
often is another impurity, and it is removed during salt
purification.
In the Hgrainertu process, saturated and pretreated brine is
heated in a flat, open pan (or grainer). Flat crystals of
sodium chloride form on the quiescent surface of the solu-
tion and fall to the bottom of the grainer. There they grow
until they are removed by a submerged rake system.
III — 20
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DRAFT
Recovered crystals are subsequently washed, dried, classi-
fied as to size, and packed. Brine pretreatment allows
sodium chloride purities of 99.98 percent by this method.
In the tt vacuum pan” system, pretreated brine enters vacuum
evaporators which remove water and allow sodium chloride
crystals to precipitate out. The crystals are then washed,
filtered, and dried prior to packing. The ‘ t Alberger” pro-
cess is similar except that an open evaporator is used to
remove water sufficiently to allow precipitation of salt
crystals. These crystals are centrifuged to remove liquid,
dried, and packed. The feed to the open evaporator includes
saturated brine and a slurry of sodium chloride crystals in
brine. This slurry is the liquid effluent from the evapora-
tor with some of the water removed by evaporation.
A wide variety of solid products are available, with various
particle sizes, solid forms, purities, and additives. Exact
production figures are not available, but current production
appears to be between 40,000,000 and 50,000,000 metric tons
(44,000,000 and 55,000,000 tons) per year. Because salt
sources are widespread and the product is relatively inexpen-
sive, production facilities are localized and operated on a
relatively low profit margin. Major salt deposits in the
U.S. include a large bed extending from western New York
through much of Michigan, brine wells in the Ohio Valley, a
large bed under central Kansas and northern Oklahoma, and
salt domes in Texas and Louisiana.
Practically all chemical compounds containing sodium or chlor-
ine are derived from salt. The chemical industry utilizes
almost all of the brine produced and over half of the rock
salt production. About three percent of the production is
used as table salt, although more than this is utilized in
the food processing industry.
3.6.2 Sodium Carbonate
Sodium carbonate, or soda ash, is produced by the “Solvay”
(ammonia-soda) process and by mining of naturally—occuring
deposits in California and Wyoming. Production by mining
is less than that from the Solvay process. In the mining
III — 21
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DRAFT
process, trona (sodium sesquicarbonate, Na2CO3.NaHCO3.2H20)
is brought to the surface in solid form, crushed and ground,
and dissolved in water. The solution is clarified, thicken-
ed, filtered, and sent to vacuum crystallizers, from which
part of the soda ash is recovered in solid form. The remain-
ing solution is cooled to precipitate additional soda ash and
bicarbonate. These solids are then dewatered and calcined to
yield soda ash.
The Solvay process involves a reaction in aqueous solution
(under pressure) between ammonia, brine (NaC1), and carbon
dioxide to yield sodium bicarbonate, which is then converted
to soda ash by heating. Ammonia is recovered by the addition
of slaked lime to the used liquor. The general reaction is
as follows: Formation of Aimnoniuin Bicarbonate
NH3 + H20 - NH4OH
NH4OH ÷ C02 - NH4HCO3
Conversion to Sodium Bicarbonate
NH4HCO3 + NaC1 NaHCO3 + NH4C1
Conversion to Soda Ash
Heat
2NaHCO3 Na2CO3 + C02 + H20
Recovery of Ammonia
2NH4C1 + Ca(OH)2 2NH3 + CaC12 + H20
The saturated brine is purified of other metal ions by preci-
pitation, and then picks up ammonia in an absorber tower.
Animoniated brine is reacted with carbon dioxide in a carbon-
ating tower, and the resulting bicarbonate precipitates as
the sodium salt, forming a slurry. The slurry is filtered
to remove the solid bicarbonate which is calcined to yield
the light ash product. Dense ash is made by successive hy-
dration and dehydration of the light ash. The carbon dioxide
and ammonia are recycled. Calcium chloride is also being re-
covered now in some plants.
Many soda ash plants are associated with producers of glass
(largest user industry) or with sources or raw material such
as coke-oven plants (by-product ammonia), the cement industry
(utilization of lime sludge), or solid carbon dioxide produc-
ers. Soda ash competes with caustic soda and other chemicals
in a variety of applications other than glass manufacture.
III — 22
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Large amounts are used in the non-ferrous metals industry and
in the production of bicarbonate and washing soda. Several
types of products are sold commercially. Production figures
for the U.S. in 1971 are as follows:
Finished Light Ash — 1,676,621 metric tons (1,848,535 tons)
Finished Dense Ash — 2,120,467 metric tons (2,337,891 tons)
Natural Ash — 2,598,321 metric tons (2,864,742 tons)
Total — 6,395,409 metric tons (7,051,168 tons)
3.6.3 Sodium Bicarbonate
Sodium bicarbonate, also known as baking soda, is made by the
reaction of sodium carbonate with water and carbon dioxide
under pressure. The bicarbonate so formed precipitates from
solution and is filtered, washed, dried, and packaged. The
general process reaction is: Na2CO3 + H20 + C02 - 2NaHCO3
The case of sodium bicarbonate is an example of processes
where it is more economical to purify a raw material (sodium
carbonate) to obtain a pure product then to purify an impure
end product (the intermediate bicarbonate in the Solvay pro-
cess). Sodium bicarbonate is typically a minor product of
soda ash manufacturers.
Total U.S. production in 1971 was 158,305 metric tons (174,537
tons). Major industrial users include food processing, chemi-
cals, pharmaceuticals, synthetic rubber, leather, paper, and
textiles. It is also used in fire extinguishers to form carbon
dioxide and in food preparation.
3.6.4 Sodium Silicate
Several forms of sodium silicate are manufactured including
both liquid and anhydrous (solid or powder) forms of sodium
metasilicate (Na2SiO3), sodium orthosilicate (Na4SiO4), and
sodium tetrasilicate (Na2Si4O9). The liquid forms are gener-
ally sold in 20 to 50 percent by weight aqueous solutions
called “water glass” (so-called because they solidify to a
glass which is water-soluble). The general production pro-
cess involves reaction of caustic soda (NaOH) and silica
(Si02), with the relative proportions of the reactants used
III — 23
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determining the product composition. Equations for the sev-
eral reactions are: Sodium Metasilicate
Heat
4NaOH + 2SiO2 Na2SiO3 + 2H20
Sodium Orthosilicate
Heat
4NaOH + Si02 Na4SiO4 + 2H20
Sodium Tetrasilicate
Heat
2NaOH + 4SiO2 Na2Si4O9 + 1120
Sodium silicates other than those listed above can be pro-
duced by further variation of the caustic-silica reactant
ratios.
In a typical process, caustic soda and silica sand are mixed
in the desired proportion and charged to a furnace. Water
and steam are added to the product under pressure to complete—
ly dissolve the silicate. The liquid product is then stored
or used to produce silicate in solid form. The production of
solid silicate from silicate solution essentially involves
evaporation of the water, although the silicate in solution
may be further reacted with caustic during the process if a
higher sodium crude content is desired in the solid product.
This is typically the case in the production of sodium meta-
silicate (anhydrous) from tetrasilicate water glass. The
dried anhydrous silicate is screened and milled to achieve
the desired particle sizes.
Silicate plants are relatively simple, and many are captive
to soap or catalyst manufacturers or other users. One of the
major uses is in the manufacture of silica gel. In 1971, the
U.S. production of sodium silicate in water glass form was
569,701 metric tons (628,116 tons), and that of anhydrous
sodium metasilicate 244,808 metric tons (269,910 tons).
3.6.5 Sodium Sulfate
Sodium sulfate (salt cake) is produced as a by-product from
sodium dichromate manufacture, by direct mining and natural
brine recovery operations, and as a by-product of organic
III — 24
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syntheses. Most of the U.S. production arises from produc-
tion of rayon and various organic chemicals and is thus not
covered in this report. Production from mining and natural
brines (in southwestern U.S.) is also not considered here,
a major reason being that apparently no effluent wastes re—
suit from these operations.
In sodium dichromate manufacture, soda ash, lime, and chrome
ore are reacted and the products leached with sulfuric acid
to convert the chromate to dichromate. The leachate, con-
taining sodium sulfate in addition to sodium dichromate, is
partially evaporated to the point where the sulfate is pre-
cipitated. The solid sulfate is filtered out, dried, and
sold. The chromate conversion reaction in which the sulfate
is formed is: 2Na2CrO4 + H2S04 - Na2Cr2O7 + H20 + Na2SO4
Since sodium sulfate is primarily a by-product material, the
supply often exceeds the demand. In addition, the natural
product is relatively abundant and limited in competition
only by distance from the markets. The largest use is in the
kraft pulp and paper industry. Another major use is as a
“builder” in detergents. Total U.S. production in 1971 was
764,409 metric tons (842,788 tons) of high purity sodium
sulfate and 465,785 metric tons (513,545 tons) of Glauber’s
salt (Na2SO4.10H20). The dichroinate by-product is sometimes
called “chrome cake”. Present production of this form of
sodium sulfate is estimated to be 110,000 metric tons
(121,000 tons) per year.
3.6.6 Sodium Sulfite
The most important method of sodium sulfite manufacture con-
sists essentially of reacting sulfur dioxide with soda ash
(Na2CO3). Another source is as a by-product from the produc-
tion of phenol through the reaction of sodium benzene sulfo-
nate with sodium hydroxide. The latter is not considered in
this report.
In the soda ash-sulfur dioxide reaction process, the sulfur
dioxide gas is passed into a solution of sodium carbonate
until the product is acidic. At this point the solute con-
sists primarily of sodium bisulfite (NaHSO3), which is then
III — 25
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DRAFT
converted into sodium sulfite (Na2SO3) by the further addition
of soda ash and boiling until all the carbon dioxide is evolv-
ed. The overall reaction is: S02 + Na2CO3 ÷ Na2SO3 + C02+
Sodium sulfite is a mild reducing agent, and is widely used as
an antioxidant. Specific uses include bleaching and stabiliza-
tion of yarns, textiles, and paper, preservation of foodstuffs
and photographic developers, and as a boiler feed water addi-
tive. The paper industry is the largest consumer. Total U.S.
production in 1971 was 185,393 metric tons (204,402 tons).
3.6.7 Sodium Dichromate
Sodium dichromte (Na2Cr2O7) is prepared by calcination of a mix-
ture of chrome ore (typically chromite, FeO.Cr203), sodium
carbonate, and lime, followed by a water leach and conversion
of the soluble chromates to dichromate with sulfuric acid.
The overall reaction scheme is: -
Formation of Chromate
4(FeO.Cr203) + 8Na2C03 + 702 -‘ 8Na2CrO4 + 2Fe2O3+ + 8C02+
Conversion to Dichromate
2Na2CrO4 + H2S04÷ Na2Cr2O7 + H20 + Na2SO4+
After the leaching operation, calcium salts are precipitated
by pH adjustment and then removed along with the iron oxide.
The leachate containing the soluble chromate is then acidi-
fied by addition of sulfuric acid, forming the dichromate and
sodium sulfate. The sulfate is removed (see section on sodium
sulfate), and the dichromate solution is partially evaporated
and removed to a crystallizer where sodium dichromate crystals
are allowed to form. The crystals are centrifuged to remove
excess water and then dried and packed for shipment.
Other chromate products are often made in the same plant, in-
cluding production of “chrornic acid” (sold as the liquid solu-
tion of Cr03) by treatment of sodium dichromate with sulfuric
acid, and sodium chrornate, produced either by the chromite ore
reaction above (crude chromate) or by reaction of sodium dichro—
mate with soda ash (very pure proäuct).
III — 26
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Sodium dichromate is the major product of the industry. It
is sold as the familiar orange-colored dihydrate (Na2Cr2O7.2H20).
Current production is estimated to be between 100,000 and
150,000 metric tons (110,000 and 165,000 tons). The major
demand for this chemical is in the manufacture of pigments.
Other uses include leather tanning, metal treatment, and
corrosion inhibition.
3.6.8 Potassium Dichromate
Most of the potassium dichromate manufactured in the U.S.
is made by reacting sodium dichromate dihydrate solution
with potassium chloride according to the following:
Na2Cr2O7.2H20 + 2KC1 K2Cr2O7 ÷ 2NaC1 + 21120
The potassium dichromate is crystallized from the solution
and the sodium chloride is recovered as a solid waste because
it is contaminated with the chromate.
A relatively pure product results which requires only removal
of the water prior to sizing and packaging. The major uses
of potassium dichromate are as a glass pigment and a photo-
graphic development chemical. Estimated current production
in the U.S. is 4,000 to 4,500 metric tons (4,400 to 5,000
tons) per year.
3.6.9 Potassium Sulfate
The bulk of the poLassium sulfate manufactured in the U.S.
is prepared by the treatment with potassium chloride of
dissolved langbeinite, a naturally—occuring potassium—
magnesium sulfate niineral, K2S04.2MgSO4. Mined langbeinite
is crushed and dissolved in water to which potassium chlor-
ide is added. Partial evaporation of the solution results
in selective precipitation of potassium sulfate which is re-
covered by centrifugation or filtration, dried, and sold.
Magnesium chloride may be economically recovered as a by-
product, if the raw material is of sufficiently high quality.
III — 27
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Total U.S. production of potassium sulfate in 1971 was
407,916 metric tons (449,742 tons). Much of this finds
agricultural use, particularly for tobacco and citrus.
3.7 Titanium Dioxide
Titanium dioxide is the most widely used white pigment. It
is produced by two methods termed the “sulfate” process and
the “chloride” process.
In the chloride process titania (T102) ores are chlorinated
to produce titanium tetrachloride. Coke is included to pro-
mote the reaction. The resulting titanium tetrachloride is
oxidized to titanium dioxide and chlorine (which is recycled).
A general reaction scheme using rutile (Fe203.Ti02) as the raw
material is shown below:
Chlorination Reaction
Ti02 (+ Fe203) + 2C12 + C TiC14 + C02 (+ FeC13)
Oxidation Reaction
TiC14 + 02 - Ti02 + 2C12
The chlorination reaction above is only approximate because
the iron chloride which results may be a mixture of several
chlorides, and some carbon monoxide is formed. The actual
products and product ratios will depend on the raw material
and the reactant ratios used.
Impurities in the system, including the iron and other metals
(Al, V, etc.) chlorides, entrained coke and ore, carbon mon-
oxide and dioxide, and hydrogen chloride (HC1) all have to
be removed prior to the oxidation reaction, which creates
significant effluent waste control problems. After chlor-
ination the products are cooled to condense the undesired
metal chlorides. Solids are separated by centrifugation or
filtration, and the gaseous titanium tetrachioride is con-
densed. A number of techniques are used to further purify
the tetrachioride.
After purification the titanium tetrachioride is vaporized
and passed into a reactor with heated air or oxygen. The
solid titanium dioxide particles are mechanically separated
from the gas stream, calcined, ground, surface—treated, and
packed.
III — 28
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In the sulfate process, titania-bearing ores are dissolved in
sulfuric acid to produce titanium sulfate as an intermediate
product. The acid solution is clarified, a portion of the
iron sulfates is removed by crystallization, and the titanium
sulfate is hydrolyzed to form a white, non-pigmentary hydrate.
The hydrate is calcined to form crystalline titanium dioxide,
which is milled, surface treated, and packaged for sale. Pro-
duct quality from the sulfate process is not so dependent on
ore quality as is that from the chloride process.
A general reaction scheme for the sulfate process using ilmen—
ite containing various iron oxides (FeO and Fe203) is presented
below:
Acidification
FeO(Fe203).Tj02 + 5H2S04 FeSO4 + Fe2(S04)3 + TiOSO4 + 5H20
Hydrolysis to Form Hydrate
TiOSO4 ÷ 2H20 Ti02.H20 + H2S04
Calcination
Heat
Ti02.H20 Ti02 + H20
Various grades, purities, and surface finishes of several
crystalline forms are sold commercially. The pigment is
also sold mixed with 50 to 70 percent calcium sulfate.
Although the paint industry is the major user, various types
of titanium dioxide are used in paper, inks, fabrics, rubber,
and floor coverings. Total U.S. production in 1971 was
614,720 metric tons (677,751 tons). Domestic ore is found
in New York and Florida, plus lesser amounts in North Carolina,
Virginia, and Idaho. The remaining ore supply is imported,
much of it from Canada and India. Most of the production of
this pigment is captive to the large paint manufacturers.
III — 29
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TABLE 1.
U.S. Production of Inorganic Chemicals (Metric Tons)
1973 ( Est.) 1972
1971 1970
No. of
Plants
1969 (1971)
A1C13
30,844
26,399
28,485
35,834
5
A12(S04)3
1,019,670
1,084,080
1,080,451
1,136,696
100
CaC2
447,240
566,988
717,579
776,546
7
CaC12
861,821
1,100,409
1,006,000
1,066,843
9
C12(g) 9,480,031
8,952,052
8,483,947
8,857,700
7,801,748
63
HC1 2,131,873
1,996,703
1,904,171
1,827,060
1,733,621
83
HF
301,184
199,126
203,571
200,940
13
H202
68,039
58,060
55,338
58,967
5
Lime
.
15,422,060
97
HNO3 6,731,276
6,369,311
6,116,208
6,059,055
5,844,960
72
K2Cr2O7
(Estimated)4,309
2
KOH
161,478
179,622
158,756
160,570
13
K 9].
.
59
285
1
K2S04
407,959
296,285
277,143
7
NaHCO3
158,756
129,727
124,284
5
Na2CO3, total-
6,768,470
6,396,526
6,350,260
13
Synthetic 3,991,592
3,929,904
3,878,194
3,985,242
4,118,597
7
NaC1
39,008,740
85
Na2Cr2O7 (& chromate)
124,284
125,191
139,706
138,798
6
NaOH 9,797,544
9,196,084
9,276,006
9,199,712
8,996,504
62
Na
138,799
155,128
149,685
5
Sodium Silicate
601,460
569,709
569,709
596,017
33
Na2SO4
1,236,486
1,230,136
1,245,558
1,341,719
40
Na2SO3
185,065
222,259
205,930
6
H2S04 29,664,786
27,257,130
26,691,000
26,784,489
26,795,375
150
Ti02 644,098
623,233
615,068
594,203
602,367
14
Q
m
H
H
H
I-
LL.
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DRAFT
SECTION IV
INDUSTRY CATEGORI ZATION
1.0 INTRODUCTION
The recommendation for the inorganic chemical industry cate-
gorization is based on three categorization criteria: the
level of wastes from exemplary plants with respect to diss-
olved solids, suspended solids and toxic and metal effluents
other than the alkali and alkaline earth metals. At three
levels of effluents for dissolved solids, metals and toxic
pollutants, two levels of effluent for suspended solids and
two levels (present and absent) for the potential maximum
number of categories is 12. Assessment of the 25 chemicals
of Phase I yields only 5 of this maximum number of categor-
ies, an eminently manageable number. This is shown in Table 2.
Using subcategorizations to handle exceptions, this number
should not enlarge greatly, even in Phase II. Another very
desirable effect of this method of categorization is that it
can cope with the fact that many of these chemicals are often
made in integrated facilities with common discharge points.
The inorganic chemicals industry is so large and diverse that
neither raw materials nor processes provide a workable basis
for subcategorization of the industry. Water use is deter-
mined by the needs of the individual plant and is primarily
determined by the availability and quality of water supply
sources and the degree of water recycling employed in the
specific process, so that water usage also does not lend it-
self to categorization.
Factors such as age of plant, size of plant, geographical lo-
cation, product purity and waste control technologies do not
generally justify further segmentation of the industry. The
occasional exception to this has been noted; e.g., solar pro-
cess production of sodium chloride and brine production of
sodium chloride are in different categories. However, the
example cited and other exceptions fit much better into the
selected categorization scheme than into any other rationale
considered. Similarities in waste loads within the categories
and the availability of treatment and control technologies
also substantiate this.
‘V-i
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2,0 CATEGORIZATION CRITERIA
It was determined that the most effective method of categor-
ization was based on the kilograms of pollutant per metric
ton (kg/kkg) of production in the treated effluent from ex-
emplary plants. The principal pollutants from the inorganic
chemicals industry are suspended solids, dissolved solids,
heavy metals and toxic pollutants.
2.1 Level of Effluents with Respect to Chosen Effluent
Parameters
2.1.1 Suspended Solids
The concentrations of suspended solids were grouped into high
and low levels, with 0.5 kilograms of effluent per metric ton
of product (one pound per ton) being the dividing point.
TABLE 2. Inorganic Chemicals by Category
Exemplary Plant
Effluents*
Category Phase I Chemicals Metals** DS SS
1 CaC2, H2S04, HNO3, Lime, HF, L L
K, A1C13, HC1***, Alum, K2S04,
NaC1(Solar), K2Cr2O7, NaHCO3,
Na2SiO3
2 Na, Na2SO3, H202(organic), M L
CaCl2, NaC1(brine mining)
3 C12 (diaphragm & Hg cells), + M L
NaOH, KOH(diaphragm & Hg
cells), H202(elec.), Na2Cr2O7,
Na2SO4 0
4 Soda Ash(Solvay Process) - H L
5 Ti02 (sulfate and chloride) + H H
*Key: +, -: present or absent in significant amounts.
**“heavy metals” plus titanium and toxic pollutants such as
cyanide.
***Chlorine_burnjng process.
IV-2
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2.1.2 Total Dissolved Solids
Total dissolved solids is the singularly major pollutant of
the inorganic chemical industry. Low dissolved solids is
defined as less than one kilogram per metric ton of product.
The medium range of dissolved solid encompasses the range
from 1 to 25 kilograms per metric ton of product. The high
range of dissolved solids is defined as greater than 125
kilograms per metric ton of product.
2.1.3 Heavy Metals and Toxic Pollutants
Heavy metals and toxic materials were grouped by their pres-
ence or absence. Quantities are orders of r’agnitude smaller
than suspended solids or total dissolved solids, but the cri-
teria, because of safety and health reasons, dealt solely
with their presence.
3.0 INDUSTRY CATEGORIES
The inorganic chemicals industry may be divided for the pur-
poses of this study into five discrete categories based on
the nature of the wastes produced in the manufacture of spe-
cific products. The five categories (also portrayed in
Table 2) are:
1. Low suspended solids and dissolved solids with no
heavy metals present;
2. Medium in dissolved solids, low in suspended solids
without heavy metals present;
3. Mediun in dissolved solids, low in suspended solids
with heavy metals present;
4. High -in dissolved solids, low in suspended solids
with no heavy metals present;
5. High in both dissolved and suspended solids with
heavy metals present.
The 25 chemicals investigated in this program were fitted
into the above categories as follows:
Category 1 — characteristic - no heavy metals, low dissolved
and suspended solids.
Chemicals: a. aluminum chloride (anhydrous)
b. aluminum sulfate
c. calcium carbide
IV—3
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d. hydrochloric acid (chlorine burning process)
e. hydrofluoric acid
f. lime
g. nitric acid (non-fuming)
h. potassium metal
i. potassium dichromate
j. potassium sulfate
k. sodium bicarbonate
1. sodium chloride (solar evaporation)
m. sodium silicate
n. sulfuric acid (sulfur burning, contact process).
Category 2 - characteristic - medium dissolved solids, low
suspended solids with no heavy metals present.
Chemicals: a. calcium chloride (brine extraction)
b. hydrogen peroxide (organic process)
c. sodium chloride (brine extraction)
d. sodium metal
e. sodium sulfite.
Category 3 - characteristic - medium in dissolved solids, low
in suspended materials with heavy metals present
Chemicals: a. chlorine (diaphragm and mercury cell process)
b. sodium hydroxide (diaphragm and mercury cell
process)
c. potassium hydroxide (diaphragm and mercury
cell process)
d. hydrogen peroxide (electrolytic)
e. sodium dichromate
f. sodium sulfate S
Category 4 - characteristic - high in dissolved solids, low
in suspended solids with no heavy metals present
Chemicals: a. soda ash (Solvay Process)
Category 5 - characteristic - high in dissolved and suspended
solids with heavy metals present
Chemicals: a. titanium dioxide (by the sulfate and chloride
processes)
In the above breakdown of the inorganic chemicals industry
into categories of wastewater characteristics, the following
definitions have been chosen for “high and low” in describ-
ing concentrations of dissolved and suspended solids:
IV-4
DRAFT
-------
DRAFT
Dissolved Solids Suspended Solids
low <1 kg/kkg of product <0.5 kg/kkg of product
(<2 lbs/ton of product) (<1 lb/ton or product)
medium 1-125 kg/kkg of product
(2—250 lbs/ton of product
high >125 kg/kkg of product >0.5 kg/kkg or product
- - (>250 lbs/ton of product) (>1 lb/ton of product)
A schematic breakdown showing where the individual chemicals
fall with respect to these categories is shown in Figure 1.
4.0 SPECIFIC INDUSTRY DESCRIPTION BY CATEGORY
4.1 Category 1 Chemicals
The inorganic chemicals studied were divided into five basic
categories based on the nature of wastes produced. The pro-
cess and raw materials used for each of the chemicals and
processes in Category I are discussed below.
4.1.1 Aluminum Chloride (anhydrous )
Aluminum chloride is made by reaction of chlorine with molten
aluminum. The aluminum chloride formed vaporizes and is col—
lected on air cooled condensers. The tail gases leaving the
condensers are the only source of wastes. A standard process
diagram is shown in Figure 2.
There are three types of products ma nufactured, all from the
same general process:
(1) Yellow — this product is made using a slight excess
of chloride (0.0005%) and may contain some iron due
to reaction of the chlorine with the vessel;
(2) White — this product has a stoichoimetric aluminum!
chlorine starting ratio; and
(3) Grey — this product contains 0.01% excess aluminum.
The unreacted aluminum raw waste load is higher for
this gray material.
In most cases it makes little difference which of the above
grades is employed. In some pigment and dye intermediate
IV-5
DRAFT
-------
o HEAVY METALS AND TOXIC IONS ABSENT
HEAVY METALS OR TOXIC IONS PRESENT
kg/kkg lb/ton ÷ 2
FIGURE I
INDUSTRY CATEGORIZATION. OF
INORGANIC CHEMICALS MANUFACTURING
DRAFT
DRAFT
CATEGORY 5•
I 1-= .•
QSODA
- ASH.
CATEGORY 4
Na 2
• 10,000
I.,000 —
4
CHLORIDE
• TiO 2 SULFATE
Cl 2 DIAPHRAGM.
Na2S030 0
2&3
CATEGORIES
- H2O2ELWTROLYTIC —
Na
H 2 0 2 ORGANIC
CI 2 Hg CELL
Q NaCI BRINE. MINING
Ai d 3
ALUM
CaC 2 .
HCI
HF
LIME
HNO3
7
0.1
0.00I
K.
K 2 Cr 2 O 7 T CATEGORY I
1(2 504
NCHCO 3
NaCI (SOLAR)
Na 2 5i0 3
1 H 2 S0 4
0.01 0.1
TOTAL SUSPENDED. SOLIDS
LEGEND:
I0
(Ib/ton)
100
-------
CHLORINE
ALUMINUM
GASES
(C 12 +
PARTICULATE
Al Cl 3 )
(NaOH)
WATER VENT
WASTE AId 3 WASTE
(DROSS, SOLID) PRODUCT AUOH) 3
(NaCI)
(NaOCI)
HC I
FIGURE 2
STANDARD
CHLORIDE FLOW
WASTE
D
‘1
-I
ALUMINUM
DIAGRAM
-------
DRAFT
applications, the yellow material is preferred because it is
free of elemental aluminum.
Aluminum chloride is also made from the reaction of bauxite,
coke and chlorine. About 80 percent of all aluminum chloride
made is anhydrous. A solution grade of aluminum chloride is
also produced by reacting hydrated alumina or bauxite ore with
hydrochloric acid.
4.1.2 Aluminum Sulfate (Alum )
Aluminum sulfate is prepared by reaction of bauxite ore with
sulfuric acid. The ore and sulfuric acid are reacted in a
digester and the resulting aluminum sulfate solution, contain-
ing muds and other insolubles from the ore, is then fed to a
settling tank, where the insolubles are removed by settling
and filtration. The filtered product liquor is then either
shipped as liquid aluminum sulfate solution or evaporated to
recover a solid product. A typical diagram is shown in
Figure 3. S
4.1.3 Calcium Carbide
Calcium carbide is manufactured by the thermal reaction of
lime and coke as is shown in Figure 4. Lime and dried äoke -
are reacted in a furnace and the product is then cooled,
crushed, screened, packaged and shipped. The only wastes
from the process are air—borne dusts from the furnace coke
dryer and screening and packing station. Currently, dust
from the coke dryer is collected in bag filters. Bag filters
are also now being used on the furnace and the packing areas.
All collections re returned to the furnace.
4.1.14 Hydrofluoric Acid
Hydrofluoric acid is manufactured by reaction of sulfuric
acid with fluorspar ore (mainly calcium fluoride). The re-
action mixture is heated and the hydrofluoric acid leaves
the furnace as a gas, which is cooled, condensed and sent on
to a purification unit. There the crude hydrofluoric acid
is redistilled and either absorbed in water to yield aqueous
hydrofluoric acid or compressed and bottled for resale as an—
hydrous hydrofluoric acid. A general process flow diagram is
shown in Figure 5.
IV-8
DRAFT
-------
DRAFT
SULFURIC BAUXITE
ACID ORE
WASHOUT — DIGESTER
WASTES
(MUDS, A 1 2 (S0 4 ) 3 ,
H 2 S0 4 )
SETTLING
WASTE TANK
(MUDS)
____1 ____ ______
LIQUID
______ ____ALUMINUM
(MUDS) J FILTRATION >J STORAGE
WASTE
> SULFATE
PRODUCT
_ 1 _
EVAPORATION
•1 1 ’
SOLID STEAM
ALUMINUM
SULFATE
PRODUCT
FIGURE 3
STANDARD PROCESS DIAGRAM FOR
ALUMINUM SULFATE MANUFACTURE
Iv — 9 I
DRAFT
-------
GAS VENT
FIGURE 4
STANDARD
CARBIDE
COKE
L.
COAL
A
•11
-I
CALCIUM
FLOW DIAGRAM
-------
DRAFT
ACID ABORBERS
WATER
‘1 ’
E JECTOR
1
WASTE
HYDROFLUORIC
FIGURE 5
ACID FLOW
— ——-I
CALCIUM
FLUORIDE
L_
WATER
I.
1
PRODUCT
I-— TO ACID STORAGE
DIAGRAM
D 1 F AF 1
-------
DRAFT
4.1.5 Lime
Lime is manufactured by the thermal decomposition of limestone
in a kiln. The limestone is first crushed then added to the
kiln, wherein it is calcined to affect decomposition. The
product lime is then removed from the kilns, marketed as quick-
lime or slaked by reaction with water and then marketed. A
process flow chart is given in Figure 6.
4.1.6 Hydrochloric Acid
Hydrochloric acid is manufactured principally by two processes:
(1) as a by—product of organic chiorinations and (2) by direct
reaction of chlorine with hydrogen. The by-product acid is
being studied under the organic chemicals program and the di-
rect burning process falls within the scope of this program.
Hydrochloric acid is also manufactured by the Salt or Mannheim
Process involving the reaction of sulfuric acid and salt and
by the Hargreaves Process in one plant involving the reaction
of salt, sulfur dioxide, air and water. Both these processes
produce sodium sulfate as a by-product and do not produce a
significant quantity of hydrochloric acid compared to the
total U.S. production. The by-product acid accounts for ap-
proximately 80 percent of the total U.S. production.
In production of hydrochloric acid by chlorine burning, hy-
drogen and chlorine are reacted in a vertical burner and the
product hydrogen/chloride formed is condensed in an absorber
from which it flows to a storage unit for collection and sale.
A standard process diagram is given in Figure 7.
4.1.7 Nitric Acid
Practically all nitric acid is manufactured from ammonia by
a catalytic oxidation process. Ammonia is first catalytically
oxidized to nitric oxide, which is then further oxidized to
nitrogen dioxide. The nitrogen dioxide is then reacted with
water to yield nitric acid. A standard process diagram is
presented in Figure 8. This program study covers only commer-
cial 61—65% nitric acid. Fuming (i.e., more than 70%) nitric
acid and nitrogen pentoxide are made only at a few facilities
and are not covered in this report. Also not covered in this
report is a minor process for the production of nitric acid
involving the reaction of sodium nitrate and sulfuric acid.
IV — 12
DRAFT
-------
(DRY SCRUBBER...WASTE
>C0 2 TOc PRECIPITATOR WASTE
1.. COLLECTION OR USE
COOLING
.
FIGURE 6
STANDARD
CALCIUM OXIDE (LIME) FLOW DIAGRAM
LIMESTONE—
COKE
MIXING
WEIGHT
CALCI NING
WATER VENT
‘T ’
SLAKING
IL
LIME
PRODUCT
1
—I
SCREENING
_‘I,_
MILK OF LIME
Ca(OH) 2
PRODUCT
-------
HYDROGEN•
CHLORiNE-
PROCESS
WATER
COOLER
if
COOLING
WATER
1
220 B
ACID
HYDROCHLORIC ACID FLOW
FIGURE 7
STANDARD
E IAGRAM (SYNTHETIC
‘-I
-J
BURNER
PROCESS
WATER VENT
‘1
-I
PROCESS)
-------
WASTE
WATER GASES
AMMONIA - . _____
COOLER
(ANHYDROUS) EVAPORATOR HI TOR ABSORBER
D
‘-4
‘1
________ ________ -4
1 - AIR
AIR COMPRESSOR FILTER
\J,
NITRIC ACID
(61 -65%)
FIGURE 8
STANDARD NITRIC ACID PROCESS FLOW DIAGRAM
-------
DRAFT
4.1.8 Potassium
For the commercial preparation of potassium metal, potassium
chloride is melted in a gas fired melt pot and is fed to an
exchange column as is shown in Figure 9. The molten potassium
chloride flows down over Raschig rings in the packed column,
where it is met by ascending sodium vapors coming from a gas-
fired reboiler. An equilibrium is established between the
two, yielding sodium chloride and elemental potassium as the
products. The sodium chloride formed is continuously with-
drawn at the base of the apparatus and is normally sold. The
column operating conditions may be varied to yield either
pure potassium metal as an overhead product or to vaporize
sodium along with the potassium to produce sodium-potassium
(NaK) alloys of varying compositions. Potassium metal of
over 99.5% purity can be continuously produced.
Unlike lithium and sodium which are produced by electroylsis,
potassium reacts with carbon electrodes, and also can form
an explosive carbonyl in electrolysis. Therefore, the thermo-
chemical route using the reaction between sodium metal and
potassium chloride has proved most practical and economical.
Production of potassium was about 90 metric tons per year in
1972, essentially all of it originating from one facility.
Figure 9 describes this operation in which no process water
is used and from which there are no water-borne effluents.
4.1.9 Potassium Dichroxnate
Potassium dichromate is prepared by reaction of potassium
chloride with sodium dichromate. Potassium chloride is add-
ed to a dichromate solution, which is- then pH adjusted, sat-
urated, filtered and vacuum, cooled to precipitate crystalline
potassium dichron ate which is recovered by centrifuging, dried,
sized and packaged. The mother liquor from the product centri-
fuge is then concentrated to precipitate sodium chloride which
is removed as a solid waste from a salt centrifuge. The pro-
cess liquid is recycled back to the initial reaction tank.
Figure 10 is the standard process diagram.
IV — 16
DRAFT
-------
DRAFT
FIGURE 9
COMMERCIAL EXTRACTION OF POTASSIUM
IV - 17
MOLTEN KCI (1550°F)
CONDENSATION
1
(OR
ALLOY)
NaK
( HEAT
Na
NaCI
SLAG
WITH
HEAT HEAT
RECEIVER (1620°F)
DRAFT
-------
FIGURE IC
STANDAND POTASSIUM DICHROMATE PROCESS FLOW DIAGRAM
C
1
-l
-------
DRAFT
4.1.10 Potassium Sulfate
The bulk of the potassium sulfate manufactured in the U.S.is
prepared by reaction of potassium chloride with dissolved
langbeinite ore (potassium sulfate—magnesium sulfate). The
langbeinite is mined and crushed and then dissolved in water
to which potassium chloride is added. Partial evaporation
of the solution produces selective precipitation of potassium
sulfate which is recovered by centrifugation or filtration
from the brine liquor, dried and sold. The remaining brine
liquor is either discharged to an evaporation pond, reused
as process water or evaporated to dryness ro recover magne-
sium chloride. The fate of the brine liquor is determined
by the saleability of the magnesium chloride by-product and
the cost of water to the plant. A general process diagram
is shown in Figure 11.
4.1.11 Sodium Bicarbonate
Sodium bicarbonate is manufactured by the reaction of soda
ash and carbon dioxide in solution. The product bicarbontate
is separated by thickening and centrifugation and is then
dried, purified and sold. A standard process diagram is
shown in Figure 12.
4.1.12 Sodium Chloride (Solar Salt )
Sodium chloride is produced by three methods:
(1) solar evaporation of brine;
(2) solution mining of natural salt; and
(3) conventional mining of rock salt;
In the first two operations, there are wastes arising from
recovered product purifications. In the third case, the
mined mineral is frequently soldas—is to users. In some
cases the rock salt is purified, but in these cases, the
methods used. are the same as those employed with solution
mined brines. In this report, only the first two methods
of sodium chloride production are covered, as contacts with
the industry have revealed that there are no water-borne
wastes normally associated with mining operations.
IV — 19
DRAFT
-------
DRAFT
K-MAG (K 2 S0 4 MgSQ 4 )
FERTILIZER GRADE SULFATE
(HIGH GRADE K 2 S0 4 )
STANDARD POTASSIUM
FIGURE I I
SULFATE PROCESS
DIAGRAM
iv D FT
-------
DRAFT
WASTE
SODA ASH
WATER
CHARGING
MIXING
FEEDING
CARBONATING
CENTRI FUGING
DRYING
COLLECTING
SCREENING
AND/OR
MILLING
> VENT
______ (‘1 1
“2
PRODUCT
>TO
STORAGE
PRODUCT
>TO
STORAGE
FiGURE 12
STANDARD SODIUM
FLOW
IV - 21
BICARBONATE PROCESS
DIAGRAM
DRAFT
-------
DRAFT
In the solar evaporation process, salt water is concentrated
by evaporation over a period of five years in open ponds to
yield a saturated brine solution. After saturation is reached,
the brine is then fed to a crystallizer, wherein sodium
chloride precipitates, leaving behind a concentrated brine
solution (bittern) consisting of sodium, potassium and mag-
nesium salts. The precipitated sodium chloride is recovered
for sale and the brine is then further evaporated to recover
additional sodium chloride values and is either stored, dis-
charged back to salt water or further worked to recover potass-
ium and magnesium salts. A process diagram is shown in Figure 13.
4.1.13 Sodium Silicate
Sodium silicate is manufactured by the reaction of soda ash
or anhydrous sodium hydroxide with silica in a furnace, fol—
lowed by dissolution of the product in water under pressure
to prepare sodium silicate solutions. In some plants, the
liquid silicate solutions are then further reacted with
sodium hydroxide to manufacture metasilicates which are then
isolated by evaporation as products. Figures 14 and 15 are
typical process diagrams. -
4.1.14 Sulfuric Acid
Sulfuric acid is manufactured primarily by the contact pro-
cess, which involves the burning of sulfur to sulfur dioxide,
the catalytic oxidation of sulfur dioxide to sulfur trioxide
and reaction of the sulfur trioxide with water to yield sul-
furic acid. Within the contact process, there are three sub-
categories of plants: -
(a) double absorption - paired sulfur trioxide adsorption
towers and catalyst beds in series are u ed to maximize con-
version of sulfur dioxide so that tail gas scrubbers are not
required;
(b) single absorption - single absorption towers and
catalyst beds are used and tail gases frequently have to be
scrubbed to remove sulfur oxides;
Cc) spent acid plants - these plants use spent sulfuric
acid in place of, or in addition to, sulfur as a raw material.
While the acid production parts of these plants are the same
as those for single absorption, these plants are unique be-
cause of the spent acid pyrolysis units used to convert the
waste sulfur acid raw materials to a sulfur dioxide feed stream.
IV — 22
DRAFT
-------
SALT DEPOSITED
FOR HARVEST
BRINE
RESIDUAL SALT
DEPOSITED
DRAFT
SEA WATER a 3°Bé
BRINE a 7.5°Bé
\1’
BRINE a 12° 86
‘I,
BRINE a 16° Be
BRINE a 200 Be
FIGURE 13
STANDARD SOLAR SALT PROCESS
FLOW DIAGRAM
1ST YEAR
CONCENTRATOR
2ND YEAR
CONCENTRATOR
3RD YEAR
CONCENTRATOR
4Th YEAR
CONCENTRATOR
5Th YEAR
CONCENTRATOR
BRINE
a 24.6° B6 SATURATED (PICKLE)
CRYSTALLIZER
RESIDUAL SALT
DISSOLVED IN
SEA WATER
a 30°BÔ
(BITTERN)
F
HOLDING
POND
,, / /f
BRINE a
\1/
,//
32° Be
STORAGE
POND
BITTERN STORAGE
D F1 3
-------
DRAFT
SILICA SODA
SAND - ASH
WEIGHING WEIGHING
‘ j, ‘1 ,
MIXING
FURNACE_J WATER GAS
I ___
WASTE
CONVEYOR BOILER
WATER f STEAM — — — _>EXCESS
STEAM
I PRESSURE
LDISSOLVING
AIR VENT
RECEIVING
TANKS J
PRODUCT
STORAGE
FIGURE 14
STANDARD LIQU!D SODIUM SILICATE
FLOW DIAGRAM
IV - 24
DRAFT
-------
WATER STEAM AIR VENT
_ I 1
I CYCLONE
DiSSOLVER [ SCRUBBER SEPARATOR
WATER
__ _IJ fNINGH__
STEAM I
_______ ___ ___ ____
______________________ SURGE
LIQUID SILICATE >1 REACTOR DRYER
AQUEOUS NaOH IH0T AIR MILLING
_________ RODUCT
WATER AIR _____
FUEL HEATER
‘r >AIR VENT
AIR
FIGURE 15
STANDARD ANHYDROUS SODIUM METASILICATE
FLOW DIAGRAM
-------
DRAFT
In this prgram only the first two types of plants are consid-
ered. As far as can be determined, the third class of plant
belongs to a separate category. A spent acid plant was not
found within the inorganic chemical industry, however, one
may exist within a petroleum complex.
In the double absorption contact process, sulfur is burned to
yield sulfur dioxide which is then passed through a catalytic
converter with air to produce sulfur trioxide. The sulfur
trioxide is then absorbed in 95-97% sulfuric acid. The gases
emerging from the absorber are then fed to a second converter
to oxidize the remaining sulfur dioxide to sulfur trioxide
which is then absorbed in a second absorption tower, and the
tail gases are vented to the atmosphere.
As in other versions of the contact process, 95—97% sulfuric
acid is used in the absorption towers. Pickup of sulfur tn-
oxide in this medium converts it to 98% acid. Some of this
acid is drawn off for sale and the remainder is diluted back
to 96-97% and recirculated through the absorption towers. A
process flow diagram is given in Figure 16.
The single absorption process differs from that previously de-
scribed only in the arrangement of the converters and absor-
bers. The rest of the process is the same. For the single
absorption process, the sulfur dioxide is passed through one
or more converters and then into one or more absorbers prior
to venting to the atmosphere as is shown in Figure 17. This
arrangement is less effective for both conversion of sulfur
dioxide to sulfur trioxide and for absorption of the sulfur
tnioxide into the absorber sulfuric acid. As a result, the
tail gases may have to be scrubbed and tklis may create a
water-borne waste not present for double absorption plants.
4.2 Category 2 Chemicals
The manufacturing processes whose effluents are characterized
by medium dissolved solids content, low levels of suspended
solids and no heavy metals are described below.
4.2.1 Sodium
Sodium is manufactured by electrolysis of molten salt in a
Downs Cell. After salt purification to remove magnesium salts
IV — 26
DRAFT
-------
ADSORPTION
TOWER NO. 2
SO 2 PRODUCTION
AND COOLING
D
‘1
-4
FIGURE 16
SULFURIC ACID PLANT DOUBLE ABSORPTION
-------
L __
L __
DRAFT
SO 3
sa 3
STEAM
WASTE(SOLID)
WASTE (SOLID)
(SPENT CATALYST)
HOTA TOBOILER
>WASTE (SOLID)
(SPENT CATALYST)
SO 3
—
I— — — —-I
... ) OLELJM ABSORBER
(OPTIONAL)
XI I
L i COOLER
o ) -‘
—r
WATER
-— -
OLEUM STORAGE
L J
FIGURE 17
STANDARD SULFURiC ACiD SINGLE . BSORPTION
FLOW DIAGRAM (CONTACT PROCESS)
AIR
AIR COOLER
CONVERTER NO 2
HOT AIR TO BOILERS
Iv - P AFT
-------
DRAFT
and sulfates, the sodium chloride is dried and fed to a Downs
electrolytic cell, where calcium chloride is added to give a
low-melting CaC12NaC1 eutectic, which is then electrolyzed.
Sodium is formed at one electrode, collected as a liquid, fil-
tered and sold. The chlorine liberated at the other electrode
is first dried with sulfuric acid á’nd then purified, compressed,
liquefied and sold. A detailed standard process diagram is
given in Figure 18.
4.2.2 Sodium Sulfite
Sodium sulfite is manufactured by reaction of sulfur dioxide
with soda ash. The crude sulfite formed from this reaction is
then purified, filtered to remove inso].ubles from the purifi-
cation step, crystallized, dried and shipped. A standard pro-
cess diagram is shown as Figure 19.
4.2.3 Hydrogen Peroxide (Organic Process )
Hydrogen peroxide is manufactured by three different processes:
(1) an electrolytic process (b) an organic process involving
the oxidation and reduction of anthraquinone and (c) as a by-
product of acetone manufacture from isopropyl alcohol. In this
study only the first two processes are covered. The, third,
presumably, will be covered in another study, along with ace-
tone manufacture.
In the organic process, anthraquinone is first catalytically
hydrogenated to yield a hydroanthraquinone then oxidized to
anthraquinone with peroxide being produced. The peroxide is
extracted from the reaction medium with water and the organic
solvent and anthraquinone are recycled. The recovered perox-
ide is then concentrated, purified and shipped. A detailed
general process flow sheet is presented in Figure 20.
4.2.4 Calcium Chloride
Calcium chloride is produced by extraction from natural brines.
Some material is also recovered as a by-product of soda ash
manufacture by the Solvay Process. The latter is discussed in
the soda ash waste treatment section since the partial recovery
of calcium chloride is a waste abatement procedure.
IV — 29
DRAFT
-------
DRAFT
SOLUTION
MINING
SATURATED
NaCI
jcRU E
WASTE
TO CAPTIVE4
P ROCESS
/
EVAPORATION
AND
Fl LTRATION
ELECTROLYSIS
(DOWNS)
Cf
BAROMETRIC
CONDENSER
COOL
AND
FILTER
FIGURE 18
STANDARD CHLORINE-SODIUM DOWNS CELL
PROCESS FLOW D 1AGRAM
IV - 30f
DRAFT
ROCK
AND
DISSOLVE
NaCI NaCI
BaCI 2 )
BRINE
PURIFICATION
FILTRATION
> WASTE
I
I
DRYER
Na CI
‘1 ’
“
WASTE
r ,r 1 i _____
%I 2
H 2 S0 4 )
COOL ING
AND
DRYING
PURl FICATION
AND
COMPRESSION
‘V
WASTE
>WASTE
LIME
EMERGENCY
LIME
ABSORPTION
WASTE
I
TO
SALE
-------
SODA
FIGURE 19
SULFITE
x l
-n
—I
PRODUCT
STANDARD SODIUM
PROCESS
FLOW DIAGRAM
-------
DRAFT
RANEY
NICKEL
FIGURE 20
STANDARD
HYDROGEN PEROXIDE FLOW DIAGRAM
(RIEDL— PFLDDERER PROCESS)
IV - 32
3
I L .
0
z
0
DRAFT
-------
DRAFT
In the manufacture of calcium chloride from brines, the salts
are solution mined and the resulting brines are first partly
evaporated to remove sodium chloride by precipitation. The
brine is then further purified by addition of other materials
to remove sodium, potassium and magnesium salts by precipita-
tion and further evaporation, and is then evaporated to dry-
ness. The recovered calcium chloride is then packaged and
sold. A standard process diagram is presented in Figure 21.
4.2.5 Sodium Chloride (Solution Mining of Brines )
Saturated brine for the production of evaporated salt is usu-
ally obtained by pumping water into an underground salt deposit
and removing a saturated salt solution from an adjacent inter-
connected well, or from the same well by means of an annular
pipe. Besides sodium chloride, the brine will normally contain
some calcium sulfate, calcium chloride and magnesium chloride
and lesser amounts of other materials.
The chemical treatment given to brines varies from plant to
plant depending on impurities present. Typically, the brine
may be first aerated to remove hydrogen sulfide and, in many
cases, small amounts of chlorine are added to complete sul-
fide removal and oxidize all iron salts present to the ferric
state. The brine is then pumped to settling tanks where it
is treated with soda ash and caustic soda to remove most of
the calcium, magnesium and iron present as insoluble salts.
After clarification to remove these insolubles, the brine is
then sent to multiple effect evaporators. As water is re- -
moved, salt crystals form and are removed as a slurry. After
screening to remove lumps, the slurry is then washed with
fresh brine.- By this washing, fine crystals of calcium sul-
fate are removed from the mother liquor of the slurry and
returned to the evaporator. Eventually the calcium sulfate
concentration in the evaporator builds up to the point where.
it must be removed by “boiling out” the evaporators.
The washed slurry is filtered, the mother liquor is returned
to the evaporators and the salt crystals from the filter are
dried and screened. Salt produced from a typical brine will
be of 99.8 percent purity or greater. Some plants do not
treat the raw brine, but control the calcium and magnesium
IV — 33
DRAFT
-------
SOLVAY WASTE LIQUOR.
OR PURIFIED BRINE
FIGURE 21
FOR CALCIUM CHLORIDE MANUFACTURE
‘ —I
CA )
CALCIUM CALCIUM
CHLORIDE CHLORIDE
(SOLUTION) (SOLID)
(ANHYDROUS) (FLAKES)
STANDARD
PROCESS
-------
DRAFT
impurities by watching the concentrations in the evaporators
and bleeding off sufficient brine to maintain a predetermined
level. By such methods, salt of better than 99.5 percent pur—
ity can be made.
In either case, the final screening of the dried salt yields
various grades depending on particle size. A detailed process
diagram is shown in Figure 22.
4.3 Category 3 Chemicals
The processes whose effluents are charcterized by medium diss-
olved solids content, low levels of suspended solids and the
presence of heavy metal salts are described as follows:
4.3.1 Chlorine - Sodium (or Potassium) Hydroxide -
( Chior—Alkali Plants )
In the diagram cell process, Figure 23, sodium chloride brines
are first purified by addition of sodium carbonate, lime,
flocculating agents and barium carbonate in the amounts re-
quired to precipitate all the magnesium, calcium and sulfate
contents of the brine. The brine is filtered to remove the
precipitated materials and is then electrolyzed in- a diaphragm
cell. Chlorine, formed at one electrode, is collected, cooled,
dried with sulfuric acid, then purified, compressed, liquified
and shipped. At the other electrode, sodium hydroxide is
formed and hydrogen is liberated. The hydrogen is cooled, pur-
ified, compressed and sold and the ‘sodium hydroxide formed,
along with unreacted brine, is then evaporated at 50% concen-
tration. During the partial evaporation, most of the unreacted
sodium chloride precipitates from the solution, which is then
filtered. The collected sodium chloride is recycled to the
process and the sodium hydroxide solutions are sold or further
evaporated to yield solid products.
For cases where potassium hydroxide is manufactured as a co—
product with chlorine, purified potassium chloride is used
instead of sodium chloride as the starting material. Other-
wise, the process is identical.
IV — 35
DRAFT
-------
STANDARD
FIGURE 22
MULTIPLE- EFFECT EVAPORATION
PROCESS FLOW DIAGRAM
SODIUM CHLORIDE
AIR
PURIFIED
BRINE
SETTLING
TANKS
BRINE
(WASTE)
SODIUM
CHLORIDE
1
-I
-------
TO PROCESS
VENT
w
-J
TE
(PURIFICATION MUDS
CaCO 3 , Mg(OH), ETC.)
EVAPORATION
AND
NaCI RECOVERY
50%
NciOH
SALE
WA STE
(CHLORINATED
HYDROCARBONS)
(INSOLUBLES
N SALT)
SOLID
NaOH
SALE
X PROPF?IETs4RY INGREDIENTS
(POLYELECTROLYTES,
FLOCCULANTS, ETC.)
FIGURE 23
STA NDARD
CHLORINE -CAUSTIC SODA FLOW DIAGRAM — DIAPHRAGM
TO
1
WASTE
WATER
(NaOCI)
LOW
I2
SALE
UTY
CELL PROCESS
-------
DRAFT
4.3.2 _ Chlorine—Sodium Hydroxide (Mercury Cell Process )
Figure 24 shows a standard process diagram for sodium hydrox-
ide/chlorine production by the mercury cell process. The
raw material, salt, is dissolved and purified by addition
of barium chloride, soda ash, and lime tq remove magnesium
and calcium salts and sulfates prior to electrolysis. The
insolubles formed on addition of the treatment chemicals
are filtered from the brine and the brine is fed to the mer-
cury cell, wherein chlorine is liberated at one electrode
and a sodium—mercury amalgam is formed at the other.
The chlorine formed is cooled, dried with sulfuric acid, pur-
if ied to remove chlorinated organics, compressed and sold.
The mercury—sodium amalgam formed during electrolysis is sent
to a denuder where it is treated with water to decompose th
amalgam forming sodium hydroxide and hydrogen. The mercury
is returned to the electrolysis cells. The hydrogen liberated
is cooled, scrubbed to remove traces of mercury, compressed
and sold.
The sodium hydroxide formed at the denuders is filtered, con-
centrated, and sold. Waste brines emerging from the electrol-
ysis cells are reconcentrated and recycled as shown in Figure 24.
4.3.3 Chlorine—Potassium Hydroxide (Mercury Cell Process )
The flow diagram is the same used in the previous section,
4.3.2, except potassium chloride is used as a raw material
instead of sodium chloride. Potassium chloride is normally
purchased in purities of 98.4 to 99.5 percent. The potassium
chloride is used to prepare a saturated brine solution, to
which may be added barium chloride and potassium carbonate to
remove magnesium and calcium salts and sulfates as insolubles,
which are then filtered from the brine and sent to waste
treatment. The purified brine is then electrolyzed in mer-
cury cells, where chlorine is liberated at one electrode and
a potassium mercuiy amalgam is formed at the other. Decompo-
sition of the amalgam with water yields 50 to 55 percent po-
tassium hydroxide, hydrogen and mercury. The mercury is re-
cycled to the electrolytic cells, the caustic solutions are
cooled, filtered and the potassium hydroxide values are then
recovered. Waste sludges from the potassium hydroxide recovery
IV — 38
DRAFT
-------
C t
0
L i i
oO .J
c% lO -
U C J
Z 0 x CONDENSATE
U __
0
0
BRINE LU
IONN CI PURIFICATION EVAPORATION 0
112 COOL
AND
TREAT
FILTRATION c i •
o Z
_______ ______ z 0
WA E I SALT W TE
i PURIFICATION
______________________________________________ ELECTROL CI
__ __H T
I ‘NaCI SATURATION Hg COOLING
______________________________________________ 2. AND
DISSOLVE [ — DRYING
1
WASTE
SOLAR NaCI SPENT SALT 50% WASTE
TO PROCESS
_______________________________________ PU GE)
DISSOLVE PURIFICATION Cl 2 TO
_________ AND
>LIOUIFICATION
___________ COMPRESSION
W ’kTE —
X: PROPRIETARY INGREDIENTS CAUSTIC 4,
(POLVELECTROLYTES FILTRATION WASTE
FLOCCULANTS, ETC. — NaOH
WA+TE
FIGURE 24
STANDARD
CHLORINE-CAUSTIC FLOW DIAGRAM MERCURY CELL PROCESS
-------
DRAFT
are sent to the abatement system. The hydrogen liberated
by amalgam decomposition is cooled, compressed and shipped.
The condensates recovered from hydrogen compression are
sent to the waste abatement system.
The chlorine is dried, liquefied and sold. The drying acid
is sold or reused and the wastes recovered from the chlo-
rine liquefaction are sent to the waste abatement system.
Depleted brines from the electrolysis are refortified with
fresh potassium chloride and returned to the purification
step to minimize the amounts of potassium chloride lost
the process. -
4.3.4 Hydrochloric Acid (With Chlorine Plant )
The process used is the same as discussed in Section 4.1.6.
The chlorine plant at the same facility merely serves as a
raw material source.
4.3.5 Hydrogen Peroxide - Electrolytic Process
In the electrolytic process for the production of hydrogen
peroxide, a solution of aimnonium bisulfate is electrolyzed.
Hydrogen is liberated at the cathodes and arninonium bisul-
fate and hydrogen peroxide, which is then separated by
fractionation from the solution. The ammonium bisulfate
solution is then recycled and the peroxide is recovered for
sale. The only waste is a stream of condensate from the
fractionation condenser. A detailed process flow sheet is
shown in Figure 25.
4.3.6 Sodium Dichromate/Sodium Sulfate -
Sodium dichromate is prepared by calcining a mixture of
chrome ore (FeO.Cr203), soda ash and lime, followed by water
leaching and acidification of the soluble chromates. The
insoluble residue from the leaching operation is recycled
to leach out addi ional material.
During the first acidification step, the chromate solution
pH is adjusted to precipitate calcium salts. Further acidi-
fication converts the chroinate to the dichromate and a
IV — 40
DRAFT
-------
COOLING WATER
ANODE LIQUOR
WATER
PEROX IDE
(65°/a
FIGURE 25
STANDARD HYDROGEN PEROXIDE ELETROLYTIC PROCESS FLOW DIAGRAM
EN
PEROXIDE
(8O-85%)
1
—I
-------
DRAFT
subsequent evaporation step crystallizes sodium sulfate
(salt cake) out of the liquor. The sodium sulfate is then
dried and sold. The solutions remaining after sodium sul-
fate removal are further evaporated to recover sodium di—
chromate. A standard process flow sheet for sodium dichro—
mate and sodium sulfate is given in Figure 26.
4.4 Category 4 Chemicals
The processes whose effluents are characterized by high dis-
solved solids content, low levels of suspended solids, and
an absence of heavy metals are described as follows.
4.4.1 Soda Ash
Soda ash is produced by two methods; mining and the Solvay
Process. As there are no water—borne wastes associated with
the mining operations, only the manufacture of soda ash by
the Solvay Process was considered in this program.
In this process, raw sodium chloride brine is purified to
remove calcium and magnesium compounds. It is then reacted
with ammonia and carbon dioxide, produced from limestone
calcination, to yield crude sodium bicarbonate which is re—
covered from the solution by filtration. The bicarbonate
is calcined to soda ash and the spent brine—ammonia solu-
tion is reacted with slaked lime and distilled to recover
ammonia values for process recycle. The calcium chloride
formed as a by-product during the distillation is either
discharged as a waste or partially recovered by evaporation.
A process flow diagram is given in Figure 27.
4.4.2 Sodium Bicarbonate (Integral with Soda Ash Plant )
in this case, the process used is the same as that described
in section 4.1.11. The adjacent soda ash plant serves sim-
ply as a raw material source.
4.5 Category 5 Chemicals
The processes whose effluents are characterized byhaving
high concentrations of dissolved and suspended solids with
heavy metals present are described below.
IV — 42
DRAFT
-------
SODIUM
DRAFT
FIGURE 26
STANDARD SODIUM DICHROMATE
PROCESS DIAGRAM
CHROMITE
LIMESTONE ORE
SODA
H 2 Sch
— WASTE
1
STEAM
r
L
WATER
f AF 3 I
-------
PRECI PITATOR
11 ’C0 2 WATER L s
I __
Li ME
S..
KiLN
LIMESTONE-. 1 ’f
COKE
RECYCLE NH 3
FIGURE 27
PROCESS SODIUM CARBONATE
STEAM + CO 2
It
CALCINER
-NaHCO 3
‘ ENT BRIP
+NH 4 CI ____
—Ca(OH) 2
V
WASTE(CaCI 2 AND NaCI)
r-•’ OPTIONAL_CaCI2 RECOVERY
— — — . — —
I I
I I
I I
I I
CaCI 2 I
L ’!L__! LJ
FLOW DIAGRAM
E
BRINE—
BRINE
PURIFICATION
REACTOR
1
WASTE
(PURIFICATION MUDS,
CaCO 3 , Mg(OH) 2 ,ETC.)
SODA ASH
STORAGE
SLAKER
N H 3
ST ILL
0
-n
—I
SOLVAY
-------
DRAFT
4.5.1 Titanium Dioxide (Sulfate Process )
In the sulfate process, ground ilmenite ore (FeO.Ti02) is
digested with concentrated sulfuric acid at high tempera-
tures. The acid used is normally about 150 percent of the
weight of the ore. In some cases, small amounts of anti—
many trioxide are also added. The resulting sulfates of
titanium and iron are then leached from the reaction mass
with water and any ferric salts present are reduced to
ferrous salts by treatment with iron scrap to prevent col-
oration of the final titanium dioxide product.
After these operations, the solutions are clarified, cooled
and sent to a vacuum crystallizer. There, ferrous sulfate
crystallizes out and is separated from the mother liquor
by centrifugation. This material is either sold or dis-
posed of as a waste.
The mother liquor is clarified by filtration after addition
of filter aids and further concentrated by vacuum evapora-
tion. Seed crystals or other nucleating agents are added
and the concentrated liquor is treated with steam to hydro-
lyze the titanyl sulfate present. This precipitates as
acidic hydrated titanium. The precipitate is collected JDy
filtration, washed several times and calcined at 900—950°C
to yield titanium dioxide. This calcined product is ground,
and further processed to yield a purer product. A stand-
ard process flow diagram is given in Figure 28.
4.5.2 Titanium Dioxide (Chloride Process )
In the manufacture of titanium dioxide by the chloride pro-
cess, titanium dioxide-bearing ores are chlorinated to
produce titanium tetrachloride, which is purified to remove
ore contaminants, and oxidized to form pure, pigmentary
titanium dioxide. The pigment is caicined, wet-treated,
milled, and packaged for sale.
The flowsheet of Figure 29 is typical of existing coinmer-
cial chloride process plants. Ores containing titanium
dioxide, iron, aluminum, vanadium, plus other minor trace
impurities are dried to remove moisture, then fed up to a
IV — 45
DRAFT
-------
DRAFT
STANDARD
FIGURE 28
SULFATE PROCESS TITANIUM DIOXIDE
FLOW DIAGRAM
ORE
FLOCCULANTS
VACUUM’
VACUU
WATER
STRONG CUT TO
WASTE DISPOSAL
WATER
i<, L
WATER\ 5
24
KILN GAS
TREATMENT AGENT
FINISHED --T
Iv - I AFT
-------
DRAFT
FINISHED Ti0 2
STAN DIARD
TITANIUM
DIOXIDE
N 2 , CO 2
CHEMICAL
C0 2 , N , CO
CHLORINE
WATER
TREATMENT AGENT
FIGURE 29
CHLORIDE PROCESS
FLOW DIAGRAM
-------
DRAFT
high temperature fluidized bed chlorinator. Coke needed to
promote chlorination is also dried and fed to the reactor.
When chlorine is injected, the following typical reaction
occurs (written for ilmenite ore*):
C(s) + TiFeO3(s) + C12(g) + TiC14(g) + FeClx(g) + C02(g)
+ C0(g)
The gaseous reaction products contain titanium tetrachlo-
ride, ferrous and ferric chlorides, carbon monoxide and
dioxide, hydrogen chloride (from the hydrogen in the coke
and ore, etc.), entrained coke and ore, plus all other
chlorinated impurities in the ore. These pass to a long
cooling train which cools the product stream so that all
of the iron chlorides and most of the remaining metal
chlorides condense. Solids are separated from the gaseous
titanium tetrachiorides by centrifugation or other mechani-
cal means and slurred in water for discharge from the pro-
cess as raw waste.
The remaining gaseous titanium tetrachioride is then con-
densed. Non—condensable reaction gases containing small
amounts of titanium tetrachioride, silicon tetrachioride
and hydrogen chloride, are water scrubbed, then vented.
Crude titanium tetrachloride is purified to remove traces
of silicon, vanadium, iron, magnesium, manganese, aluminum,
chromium, etc., by many varied techniques including distil-
lation; absorption, ion exchange, and chemical precipitation
with hydrogen sulfide, inorganic salts, or organic com-
pounds. All methods yield a pure titanium tetrachioride
fraction, and a contaminant sludge which is slurred in water
and discharged with the cooling tower waste.
The pure titanium tetrachioride is vaporiz d, superheated,
and added to the oxidation reactor with hot air or oxygen
to form a pure, finely divided, pigmentary titanium dioxide
according to: TiC14 + 02 - T102 + 2C12
The oxidation reactor product stream, consisting primarily
of chlorine, nitrogen, and suspended titania is cooled and
the titanium dioxide separated mechanically by means of
cyclones, bag filters, or precipitators for further
processing.
IV — 48
DRAFT
-------
DRAFT
chlorine and nitrogen from the oxidation product stream
are fed to the chlorinator with make-up chlorine to pro-
duce more titanium tetrachioride. The recovered pigment
is calcined and surface treated to impart desirable optical
or physical properties. The titanium dioxide is ground to
sub—micron sized particles, and packed as finished product.
IV — 49
DRAFT
-------
DRAFT
SECTION V
WATER USE AND WASTE CHARACTERIZATION
1.0 INTRODUCTION
This section discusses the specific water uses in the Inor-
ganic Chemicals, Alkali and Chlorine Industry, and the
amounts of waste effluents contained in these waters. The
process wastes are characterized as raw waste loads emanat-
ing from a typical process before treatment and the amount
of water-borne waste effluent after treatment. Also includ-
ed in this discussion are verification sampling data measured
at specific exemplary plants for each chemical in the cate-
gories set forth in Section IV. A description of the analy-
tical techniques used for this verification of plant data is
also provided.
2.0 SPECIFIC WATER USES
Water is used in inorganic chemical processing plants for six
principal purposes plus other miscellaneous uses. The prin-
cipal uses are:
Non—contact cooling water
Contact cooling or heating water
Contact wash water
Transport water
Process and dilution water
Auxiliary process water
The quantity of fresh water intake to plants in this industry
generally ranges from 38-75,700 cu rn/day (10,000 GPD to
20,000,000 GPD). In general, the plants using very large
quantities of water use it for once—through cooling or as
cooling water which is partially recycled.
2.1 Non-Contact Cooling Water
Many chemical processes operate more quickly or more efficient-
ly at high temperatures, or generate heat during exothermic
reactions. Cooling water is often used to control or reduce
these temperatures. If the water is used without contacting
v-i
DRAFT
-------
DRAFT
the reactants, such as in a tube—in-shell heat exchanger or
trombone cooler, then the water will not be contaminated with
process effluent. If, however, the water contacts the reac-
tants, then contamination of the water results and the waste
load increases. Probably the single most important process
waste control technique, particularly with regard to feasi-
bility and economics of subsequent treatment, is segregation
of non-contact cooling water from contact cooling and process
water.
The non-contact cooling water in the industry is generally of
two types. The first type is recycled cooling water which is
cooled by cooling towers or spray ponds. The second type is
once—through cooling water whose source is generally a river,
lake or tidal estuary, and this water is usually returned to
the source from which it was taken.
The only waste effluent from recycled water would be water
treatment chemicals and the cooling tower blowdown which gen-
erally is discharged with the cooling water. The only waste
effluent from the once—through cooling water would be water
treatment chemicals which are generally discharged with the
cooling water. The cooling water tower blowdown may contain
phosphates, nitrates, nitrites, sulfates and chromates. The
water treatment chemicals may consist of alum, hydrated lime,
or alkali metal ions (sodium or potassium) arising from ion
exchange processes. Regeneration of the ion exchange units
is generally accomplished with sodium chloride or sulfuric
acid, depending upon the type of unit employed.
2.2 Contact Cooling or Heating Water
This water comes under the general heading of process water
because it comes into direct contact with process reactants.
Primary examples of this type of water use are steam drum
dryers and barometric condensers. Water is required in very
large quantities for use in the barometric condensers used
to provide reduced pressure for the operation of multiple—
effect evaporators. For a large triple—effect evaporator
such as that used for salt evaporation, flows of 3,785—41,600
Cu rn/day (1 to 11 million gallons per day) are not unusual.
V-2
DRAFT
-------
DRAFT
A waste effluent problem with the barometric condenser usage
arises from the product vapors and carry-over from the last
effect (stage) of the evaporator which are entrapped in the
flow of condenser water. Because this condenser water is
normally used in high volume, it is usally discharged with-
out treatment.
Other direct contact cooling or heating water usage such as
that for contact steam drying, steam distillation, pump and
furnace seals, etc., is generally of much lower volume than
the barometric condenser water and is easier to treat for
waste effluents.
2.3 Contact Wash Water
This water also comes under the heading of process water be-
cause it comes into direct contact with either the raw mater-
ial, reactants or products. Examples of this type of water
usage are ore washing to remove fines, filter cake washing
to remove entrained particles, cleansing of insoluble product
vapors, and absorption process wherein water is reacted with
a gaseous material to produce an aqueous solution. Waste
effluents can arise from all these washing sources, due to
the fact that the resultant solution or suspension may con-
tain impurities or may be too dilute a solution to reuse or
recover and is thus discharged.
2.4 Transport Water
Water is often used in the inorganic chemical industry for
transporting reactants or products to various unit operations
either in solution, suspension or slurry form. A good exam-
ple of this is solution-mined salt or brine. Water is pumped
into a salt cavity at the rate of 3900 liters of water per kkg
(936 gallons per ton) of salt. The salt is dissolved, and the
resulting brine is forced to the surface under pressure where
it can be fed to evaporators to produce dry salt, or fed to
electrolytic cells where it is used to produce chlorine and
alkali. Wastes resulting from these types of operations are
generally dilute solutions or suspensions which could be re-
used upon concentration or could be returned to the source.
In cases where transport water is carrying a solid product,
V-3
DRAFT
-------
DRAFT
it normally is separated from the product by filtration, eva-
poration, or drying. The resultant liquor or condensate gen-
erally contains dissolved product, reactants or impurities,
and often is discharged.
2.5 Process and Product Water
The process or product water generally is that which comes in
contact with the product and stays with the product as an in-
tegral part. Typical examples include digestion water used
for sodium silicate manufacture and water used in acid absorp-
tion towers. Likewise, water may be added to a high concen-
trated product to form a more dilute product. The source of
these waters is generally fresh water supplies, steam conden-
sate, dilute product streams, or a combination of these sources.
In general, waste loads from this water usage are minimal.
26 Auxiliary Process Water
This water is used in medium quantities by the typical plant
for auxiliary operations such as ion exchange regenerants,
make-up water to cooling towers with a resulLant cooling tower
blowdown, make-up water to boilers with a reL itant boiler
blowdown, equipment washing, storage and shipj .ing tank washing,
and spill and leak washdown. The water effluents from these
operations are generally low in quantity but highly concentra-
ted in waste materials.
2.7 Miscellaneous Water Uses
These water uses vary widely among the plants with general
usage for floor washing and cleanup, safety showers and eye
wash stations, sanitary uses, and storm run-off. The resul-
tant streams are either not contaminated or only slightly
contaminated with wastes. The general practice is to dis-
charge such streams without treatment except for sanitary
waste.
V-4
DRAFT
-------
DRAFT
3.0 PROCESS WASTE CHARACTERIZATION
3.1 Category 1 Chemicals
3.1.1 Aluminum Chloride
Aluminum chloride is made by reaction of chlorine with molten
aluminum. The aluminum chloride formed vaporizes and is col-
lected on air cooled condensers. The tail gases leaving the
condensers are the only source of wastes downstream of the
reaction zone. Plant 125 is the exemplary plant for this
product/process. -
3.1.1.1 Raw Waste Load
In the process described above, there are two sources of waste-
uncondensed aluminum chloride and chlorine in tail gases and
unreacted aluminum metal. At the exemplary facility, the first
waste is utilized to manufacture another product and the unre-
acted aluminum is disposed of as a solid waste.
The raw waste loads are shown below:
Waste Product Source Kg/Kkg of Product
Average Range
A1C13 Tail Gases 80 64—96
Unreacted Aluminum Reactor 22
3.1.1.2 Treatment at Exemplary Plant
There is an integrated blower system to exhaust the plant,
packing station, condensers, etc. P l1 blower exhaust is
treated in an absorption tower where, as shown in Figure 30,
the aluminum chloride and chlorine vapors are absorbed into
a recycling scrubber system. From this scrubber, about
0.032 liter/second (0.5 GPM) of solution is drawn off, fil-
tered and further treated to produce a 28% aluminum chloride
solution which is sold. There are no waste streams.
V-5
DRAFT
-------
BLED
(V2GPM) L
FIGURE 30
SCRUBBER SYSTEM FOR TREATMENT OF
ALUMINUM CHLORIDE WASTES AT PLANT
0•i
GASES
ALUMINUM
CHLORIDE
SOLUTION
V25
-------
DRAFT
The water input and use for the scrubber system is shown below:
Water Input Quantity Use
Well 2725 liters/day (720 GPD) Makeup water for
scrubber s
Water Usage Quantity % Recycled
Scrubbers 2725 liters/day (720 GPD) None, water used
to make 28%
A1C13 product
The characteristics of the 28% aluminum chloride solution re-
covered for sale are tabulated below:
Aluminum Chloride Solution
ACS— 0002
Technical Grade
A1C13 % 28 mm.
Baume’at 15°C 32° mm.
Total aluminum as aluminum oxide, % 10.5 mm.
Color, APHA 100 max.
Free Aluminum, % 0.1 max.
Fe 25 ppm
Heavy metals 10 ppm
Sulfate 500 ppm
Free Acidity as % HC1 0.2 max.
Freezing point —30 F
Density at 15°C, g/cc (lb/gal) 1.28 (10.7)
3.1.1.3 Miscellaneous Process Information
There are three types of aluminum chloride manufactured, all
from the same process:
1. Yellow —- this product is made using a slight excess
of chloride (0.0005%) and may contain some iron due
to reaction of the chlorine with the vessel.
2. White -- this product has a stoichiometric aluminum!
chloride ratio.
3. Grey —— this product contains 0.01% excess aluminum.
The unreacted aluminum raw waste load is higher for
the grey material.
V-7
DRAFT
-------
DRAFT
Industrially, it generally makes little difference which of
the above grades is employed. In some pigment and dye inter-
mediate applications, however, the yellow material is pre-
ferred as it is free of elemental aluminum.
3.1.1.4 Effluent
There is no water-borne effluent for this facility. The only
emerging wastes are air-borne.
3.1.2 Aluminum Sulfate
Aluminum sulfate is prepared by reaction of bauxite ore with
sulfuric acid. The ore and sulfuric acid are reacted in a
digester and the resulting aluminum sulfate solution, contain-
ing muds and other insolubles from the ore, is then fed to a
settling tank, wherein the insolubles are removed by settling
and filtration. The filtered product liquor is either shipped
as liquid aluminum sulfate solution or evaporated to recover
a solid product. There are two exemplary plants for this
product/process - plants 049 and 063. Figure 31 shows a de-
tailed process diagram including waste treatment for plant 063,
and Figure 32 is a similar diagram for plant 049.
3.1.2.1 Raw Wastes
Raw wastes from the process include muds (insolubles) from
the digester, settling tank and filtration unit as well as
washwaters from vessel cleanouts. At the 049 facility these
wastes are -treated in a settling basin to remove the muds
and the waters and then recycled for reuse. A similar re-
cycling system is used in the 063 facility.
Raw wastes from aluminum sulfate manufacture are listed below:
Waste Products Process Source Kg/Kkg of Product
Spent alum muds* Mud washing 170 (avg) (Plant 049)
100 (avg) (Plant 063)
Low alum water Mud washing 800 (avg)
*The raw material bauxite contains 54—56% of soluble A1203,
about 3.5% Ti02, about 5.5% Si02, about 1.5% Fe203 and the
rest water of hydration. The muds have approximately the
following compositions: 40% Si02, 40% Ti02, 20% A].203,
0.5% A12(S04)3.
V-8
DRAFT
-------
DRAFT
BAUXITE SULFURIC ACID
WATER ) REACTION TANK F
NO. I
_____ 1 _____
REACTION TANK
NO. 2
_‘ _ LU
-J
I:i3
REACTION TANK
NO.3
_\ _
LU
>
ERFLOW CLARIFIER NO. i U i ’ ERFWW
DILUTION
WATER ___________________
. .
LIQUID ALUM CLARIFIER NO. 2
PRODUCT STORAGE
STEAM HEATED
EVAPORATOR FLOOR WASHINGS CLARIFIER NO. 3
(BATCH TYPE)
STEAM DRY
ALUM PRIMARY
LU
PRODUCT SETTLING POND
L CLEAR WATER
HOLDING POND
FIGURE 31
ALUMINUM SULFATE PROCESS AND TREATMENT
FLOW DIAGRAM AT PLANT 063
v-9
DRAFT
-------
AIR STEAM WATER
BAUXITE J ______ _____ _____ ___________
_______ SETTLING ‘CLEAR
FILTERED LIQUID ALUM
STORAGE
TANK JALUM > PRODUCT
STORAGE
WATER ) DIGESTER AND MUD
j,,WATER
TANK TRUCKS
CLEAR
LIQUID
______ FRESH WATER
SULFURIC
ACID - WASH TANK WASH TANK —-—-> WATER AND MUD
STORAGE WATER ._!! 2_? TO POND
AND — OVERFLOW WATER
___________ WASHED ____________ ___________ FROM POND
UNREACTED
BAUXITE
FIGURE 32
ALUMINUM SULFATE PROCESS AND TREATMENT
FLOW DIAGRAM AT PLANT 049
-------
DRAFT
3.1.2.2 Treatment
At these plants all waters are fed to a settling basin where
muds are removed and impounded, and the clear effluent is
then used back in the process. A breakdown of water use at
both facilities is shown below:
Input Quantity Comments
Type Plant cu rn/day liters/kkg
Well 049 47 (12,400 1650 (396 gal/ton) No Pretreatment
:cPD) Required for
Well• 063 7b (20,000 2090 (500 gal/ton) Either
•GPD)
S of Process
Process Water Quantity Stream Recycled
Type Plant cu rn/day liters/kkg
Process 049 77 (20,400 2720 (652 gal/ton) 30*
GPD)
Process 063 87 (23,000 2400 (575 gal/ton) All excess pro—
GPD) cess water*
*R ining water shipped-with product. Aluminum sulfate sol-
utions are made at both plants.
3.1.2.3 Effluent
These plants have no process or cooling water effluent.
3.1.3 Calcium Carbide -
Calcium carbide is manufactured by the thermal reaction of
lime and coke. Lime and dried coke are reacted in a furnace,
and the product is then cooled, crushed, screened, packaged
and shipped. The only wastes from the process are air-borne
dusts from the furnace, coke dryer and screening bag filters.
flag filters are also now being installed in the furnace and
the packing areas. All collections are returned to the furnace.
V — 11 -
DRAFT
-------
DRAFT
3.1.3.1 Raw Wastes
The process locations of the sources of raw waste in plant 190
are shown in Figure 33. A listing of the raw wastes and amounts
is given below. All but the cooling tower blowdowns are treat-
ed, or will be treated by installations to be completed by
July 1973, by dry collection methods. The blowdown wastes are
intermittent and are currently untreated. This data was fur-
nished by the manufacturer.
Waste Product* Kg/Kkg of Product
Average Range
1. Fine Petroleum Coke 50 30 - 70
2. Stack Dust 85 70 — 115
3. Packing Dust 10 6 - 11
4. Cooling Tower Blowdown 0.5 - 1
and Cooling Water
Treatment Chemicals
*The first waste is collected by bag filters and recycled.
Waste products 2 and 3 are now being exhausted to the air
but will be collected and recycled by bag filters similar
to those now collecting the coke fines when installation
is completed in July, 1973. The fourth waste is currently
untreated.
3.1.3.2 Exemplary Plant Effluents
Figure 34 shows schematically the source and disposition of
the water usages at this exemplary plant. Table 3 lists the
effluent wastes data supplied by plant 190 and GTC’s verifi-
cation measurements. (These data are the same as presented
to the Corps of Engineers in plant 190 4 s permit application,
except for pH and flow, which were given to us at the time
of our visit). Agreement for the one set of grab samples
taken is reasonably good. The sample was taken by plant per-
sonnel in the presence of the GTC engineer, not by the GTC
sampling crew, which did not visit this facility.
Considerable amount of chlorides and sulfates are discharged
intermittently due to cooling tower blowdowns and use of
water treatment chemicals. These wastes could also be treated,
V- 12
DRAFT
-------
FIGURE 33
cALCIUM CARBIDE PROCESS FLOW
DIAGRAM At PLANT 190
I
I - ’
0
-------
I
4 ONNEL
I
( 1
-
-
DRAFT
DOMESTIC SEWAGE 4
— 1
I I
TOTAL
RETENTION
LAGOON
(2.2 ACRES) I
LIFT
I STATION
(1700 GPD)
/
—FURNACE *—
I
SOFTENER
25,000 GPD
PROCESS TREATEDP WATdER
4 EI [
COMPRESSOR I
INERT
GENERATION I
‘dTRANSFORMERI_?
I
H
WELL
I I
COOLING I
TOWER
EVAR
COOLER
COMPRESSOR
— LAB. —
&- MAINT. — I
PACKNG I
— OFFICE E— I
L __ I
I FIRE
HYDRANT
CITY WATER—
(AVG. USAGE = 40,000 GPD)
-
-4
PRI MARY
CRUSHER
BLOWDOWN <
(5-10 6PM)
FIGURE 34
WATER USEAGE AT PLANT 190
CALCIUM CARBIDE FACILITY
V—14
DRAFT
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DRAFT
TABLE 3. Plant Effluent from CaC2 Manufacture
(All units ppm unless specified)
Cooling
Waste Product Intake Water Tower Water
PTiht GTC Plant GTC
Data Verifcn. Data Verifcn .
Total suspended solids 3.5 0 48 0
Flow (Cu rn/day) 152 (a,b) 13 (a,b)
Total dissolved solids 238 (a) 1930 (a)
Conductivity (as NaC1) Cc) 95-100 Cc) 810
BOD 80 (a) 308 (a)
COD 15 <25 170 75
7.6 7.5 7.6 8.0
Alkalinity (as CaCO3) 99 90 ‘t 68 165
Nitrate (as N) 0.45 0.27 12 9.8
Zinc 0.01 (a) 2.8 (a)
Phosphorus Total (phosphate) 0.27 0.32 0.55 1.30
Color (APHA Units) Nil <10 675 20
Aluminum 0.15 (a) 0.17 (a)
Turbidity (FTU) 0 <5 18 <10
Fluoride 0.45 (a) 0.95 (a)
Total hardness (as CaCO3) 140 136 404 750
Calcium hardness (as CaCO3) (c) 118 Cc) 675
Sulfate 55 51.5 290 690
Chloride 46 36 198 95
Iron - N.L. 0.08 <0.03 0.195
Chlorine (as C12) Cc) 0 Cc) <0.1
(a) Not measured
(b) Flow varied frequently, depending on response of level-
monitoring valve
Cc) Not in furnished data.
V — 15
DRAFT
-------
DRAFT
and in an ideal plant would be remov d either by evapor tion
or reverse osmosis. There is no p oàess water effluentin
this exemplary plant.
3.1.3.3 Treatment Comments -
Plant 190’s policy is to recover and recycle all possible
air-borne dusts by dry collection techniques. This approach
eliminates all process water wastes. The cooling tower blow—
down and incoming water treatment regenerants are the only
water effluents. These non-process water effluents are common
to almost all inorganic chemical (as well as many other) fa-
cilities.
3.1.4 Hydrochloric Acid
Hydrochloric acid is manufactured principally by two processes:
Cl) As a by-product of organic chiorinations; and (2) By direct
reaction of chlorine with hydrogen. Our efforts for this chem-
ical were limited to the second process. In this process,
hydrogen and chlorine are reacted in a verti’a1 burner. The
hydrogen chloride formed is condensed in an bbsorber from which
it flows to a storage unit for collection and sale. The ar-
rangement used at the exemplary facility (plant 121) is similar
to the standard flow diagram shown in Section IV. The special
waste treatment system used during startup of this facility
startup is shown in Figure 35.
3.1.4.1 Raw Waste Load
The raw waste loads from hydrochloric acid manufacture are pre-
sented below. Some of these are markedly dependent on condi-
tions, with most of the wastes being produced during startups.
There are no water-borne wastes during periods of normal oper-
ation. I
V — 16
DRAFT
-------
DRAFT
NaCH + WATER VENT
— SCRUBBER
WATER
4
STARTUP CIt ABSORBER
WASTE L_ ________
z5
NaOHsWATER j
NEUTRALIZATION
VESSEL
F T
FIGURE 35
STARTUP WASTE TREATMENT SYSTEM
AT PLANT 121
V — 17
DRAFT
-------
DRAFT
Waste Products Process Source Amount of Product
1. Chlorine* Burner Run — Startup - 100 kg/kkg
Chlorine—rich (average) (5-200 range)
Operation - 5 kg/kkg
(average) (0-10 range)
Shutdown — no waste
2. HC1** Startup - 4.5 kg/day
Operation — none
Shutdown — none
3. NaOH*** Neutralization Startup - depends on HC1
reaction and Cl2 to be neutralized
products Opöration - none
(NaC1 and Shutdown - none
NaOCl)
*Emerges in vent gas during normal operation, neutralized
during startup by NaOH.
**Al l neutralized during startup.
***Caustic (NaOH) used has 12% NaC1 present and is cell liquor
from chlorine plant also in the complex.
3.1.4.2 Treatment
Al]. treatment is performed during startup of the facility.
During normal operation, there are no water-borne wastes to
be treated. Water use at the facility is listed below!
V - 18
DRAFT
-------
DRAFT
A. Input
Type Quantity Comments on Content
Cu rn/day liters/kkg
Lake 5,680 15,650 TDS—300 ppm, SS—10 ppm,
(150,000 (3,750 gall C1—65 ppm, S03—34 ppm,
GPD) ton) CaCO3-200 ppm, Ca(HCO3)2—
2—250 ppm.
Well 1,135 3,130 Same as lake water except
(30,000 (750 gal/ton) lower in sulfate, low SS
GPD) (less.than 10 ppm).
B. Water Use
Type Quantity % Recycled
cu rn/day liters/kkg
Coo ling 1,135 3,130 0
(30,000 (750 gal/ton)
GPD)
Process 760 2,085 - 0
(20,000 (500 gal/ton) (Leaves as part
GPD) of product)
Disposal 4,545 12,520 0
from neut— (120,000 (300 gal/ton)
raTlization GPD)
tank**.
Miscellan— 380 1,040 0
(10,000 (250 gal/ton)
GPD)
*phogphate treatment used for this water. About 0.5 ppm
excess phosphate is employed.
**For safety purposes, continuous water flow is maintained
into the neutralization tank even during normal process
operation when no effluent or NaOH are introduced.
The effluents from the process streams before sewer at plant
121 are listed below:
V-l9
DRAFT
-------
DRAFT
Stream No. Cu rn/day liters/kkg
9 4
1. Neutralizing 4,355 (115,000 GPD) 12,000 ( ,875 gal/ton)
Reactor
2. Neutralizing 190 (5,000 GPD) 520 (125 gal/ton)
Siphon Tank*
3. Test Sink and 380 (10,000 GPD) 1,040 (250 gal/ton)
Washdown
4. Cooling Water 1,135 (30,000 GPD) 3,130 (750 gal/ton)
*Siphon Tank is 26,500 liters and has less than 4 liters
drainage per day. It is operated batchwise with excess
caustic always present. When the alkali content has been
neutralized, it is disposed 4 of.
After treatment, these streams are fed to a common equaliza-
tion pond for pH adjustment and suspended solids settling
prior to discharge. Effluent after this treatment (for the
total complex) contains less than 10 ppm of suspended solids
and 2588 ppm chlorides and sulfates, mostly from other pro-
cesses.
3.1.4.3 Effluent
The plant effluent is given below. There are no wastes during
normal operation. All of the wastes arise from startup opera-
tions. In addition, there is an air—borne chlorine vent gas
waste as noted earlier.
Constituents Stream No. 1 Stream No. 2 Stream
Present Operation/Startup Operation/Startup No. 3 No. 4
Total 1O*ppm 10 ppm No Batch Same as lake
Suspended Effluent for a water
Solids number
Total 300*ppm 40,000- of pro-
Dissolved 50,000 cesses;
Solids 90—180 kg
BOD 0 ppm 10 ppm of C12 neu-
tralized per
COD 0 ppm 0 ppm month and
disposed of
pH 6 5—10.0 6.5—10.0 in this
9 avg. 9 avg. stream
*Same as lake water -
V — 20
DRAFT
-------
DRAFT
All of the chlorine-burning HC1 plants for this study are lo-
cated within chior-alkali complexes. At present, there are
four such facilities:
1. Pennwalt - Portland Oregon
2. Detrex - Ashtabula, Ohio
3. Vulcan - Newark, New Jersey
4. Hooker - Montague, Michigan
The 121 plant is exemplary because of two considerations:
1) Unlike the other facilities, hydrochloric acid wastes
are easily segregable. At other plants these wastes
are mixed with chior—alkali wastes before treatment;
and
2) Unlike some other facilities, there are no hydro-
chloric acid wastes during normal operations.
Sampling of this facility presented problems in that all
waste discharges occurred only during plant startup.
This facility could be further improved by: (1) More effi-
cient scrubbing of process tail gases to remove chlorine
and use of the resulting chloride/hydrochloric solutions
formed elsewhere in the facility; and (2) Reuse of the so-
dium chloride formed by acid neutralization.
3.1.5 Hydrofluoric Acid
Hydrofluoric acid is manufactured by reaction of sulfuric
acid with fluospar ore (mainly calcium fluoride). The re-
action mixture is heated and the hydrofluoric acid leaves
the furnace as a gas, which is cooled, condensed and sent
to a purification unit. There the crude hydrofluoric acid
is redistilled and either absorbed in water to yield aqueous
hydrofluoric acid or compressed and bottled for sale as an—
hydrous hydrofluoric acid.
At an exemplary plant (plant 152), the calcium sulfate by-
product from the reactor is slurried with water and sent to
waste treatment. Also, all tail gases are scrubbed and the
scrubbed water sent to the waste abatement system. A gen-
eral process flow sheet was shown earlier in Section IV.
Figure 36 shows a detailed process diagram for the exemplary
facility, and Figure 37 shows the wastewater recycling sys-
tem in use at this plant. The production rate at this fac-
ility is 36/kkg per day (40 tons per day).
V-2l
DRAFT
-------
FLUORSPAR
FIGURE 36
PROCESS FLOW
GAS FUEL
AND AIR
HYDROFLUORIC ACID
DIAGRAM OF PLANT 152
-------
FIGURE 37
RECYCLE SYSTEM
0
-I
EFFLUENT
AT PLANT 152
-------
DRAFT
3.1.5.1 Raw Waste Load
The waste product from hydrofluoric acid manufacture are
shown below. Wastes consist of materials from the furnaces,
which include calcium sulfate, calcium fluoride and sulfur-
ic acid, plus fluoride-containing scrubber wastes.
Waste Products Process Source kg/kkg of Product (avg )
1. CaSO4 Kiln (reactor) 3,620
2. H2S04 Kiln (reactor) 110
3. CaF2 Kiln (reactor) 63
4. HF Kiln (reactor) 1.5
5. H2SiF6 Scrubber 12.5
6. Si02 Kiln (reactor) 12.5
7. S02 Scrubber 5
8. HF Scrubber 1
The water use within plant 152 is shown below.
Type Total Quantity % Recycled
cu rn/day liters/’-.kg
Cooling 3,270 (864,000 90,140 (2 600 0
(river water) GPD) gal, ton)
Slurry and 3,270 (864,000 90,140 (21,600 100
Scrubber GPD) gal/ton)
3.1.5.2 Treatment in Exemplary Plant
All procesâ and scrubber waste waters are totally recycled.
The waters used to slurry and remove the calcium sulfate
from the furnaces and scrubber waters are fed to a pond sys-
tem after being treated with caustic or soda ash and lime to
precipitate fluorides and adjust the pH. In the pond system,
the insolubles are settled out and the waters are then reused
in the process as shown in Figure 37.
3.1.5.3 Exemplary Plant Effluent
All process water containing raw waste is recycled and only
cooling water is discharged from this facility. Table 4 shows
the compositions of process waters before and after neutrali-
zation and of the river intake water which is essentially the
V-24
DRAFT
-------
DRAFT
TABLE 4 Intake Water and Raw Waste Composition Data*
at Plant 152
Raw Waste Recycle Intake
Into Water Fran River
DetermInation Units Treatn nt Treatment Water
].un’inum pg/i 7400 2200 2600
Beryllium Be 66 64 20
Calcium Ca m g/i 640 450 12.2
Cadmium 0.1 pg/i 16 12 2
cobalt Co U 300 280 26
thranium Cr “ 46 22 4
Copper Cu 44 28 4
Irai Fe “ 3100 780 1060
Magnesium Mg mg/i 6.0 6.4 3.2
Manganese Mn pg/i 100 106 68
Molybdenum Mo 56 56 26
Nidcel Ni “ 80 68 4
Leal Pb “ 132) 3400 82)
Titanium Ti 240 22) 20
Zinc Zn U00 880 440
Barium Ba 740 102) 1280
Potassium K 6.4 8.6 0.6
Sa3 .ium Na 490 660 4.2
Tin Sn pg/i 140 140 24
krutonia-Nitrogen mg/i N 0..23 0.05 0.23
13.4 - -
Fluoride Tftj/l F 13.0 12.5 0.2
Total Suspd Solids m /l 16596 59 21
Total Solids 22015 3758 124
Total Vol. Solids 1220 340 58
Total Dissolved 4250 3572 132
Solids
Nitrate mg/i N 0.26 0.20 0.13
Nitrite 0.02 0.01 0.20
Nitrogen I jeidahl “ 0.57 0.46 0.46
Phosphate Total “ P 1.60 0.96 0.02
Sulfate “ S 880 767 7
Arsenic pg/i 77 49 74
pH — 3.86 7.22 7.17
TOC mg/i 4 6 5
Data furnished by manufacturer
V- 25
DRAFT
-------
DRAFT
same as the cooling water effluent. Low fluoride levels are
easily maintained because of segregation of discharged cool-
ing waters from the process water.
GTC verification measurements, shown for the plant intake
water and the outflow of cooling water, are given in Table 5.
These data verify that there is no fluoride discharge from
this facility. The similarity of the intake and cooling
water discharge verifies that there is no process water leak-
age into the cooling stream, and therefore there is no pro-
cess water discharge from this exemplary hydrofluoric acid
manufacturing plant.
3.1.6 Lime -
Lime is manufactured by thermal decomposition of limestone
in a kiln. The limestone is first crushed, then added to
the kiln, wherein it is calcined to effect decomposition.
The product lime is then removed from the kilns, marketed
as is, or slaked by reaction with water and then marketed.
A process flowchart is given in Figure 38 descriptive of
the general process at the exemplary plant (:lant 007).
3.1.6.1 Raw Waste Load
The raw wastes produced from lime manufacture are shown be-
low. These consist of fine dusts collected from the plant
gas effluent by scrubbing systems. At the exemplary facility
this dust removal is achieved by use of bag filters and other
dry particulate collection equipment. No wet scrubbing tech-
niques are employed.
kg/kkg of
Waste Product Process Sourc Product
Dry Particulate Matter Kiln gases 67 (no effects
(Dry collector) of startup &
shutdown)
3.1.6.2 Treatment at Exemplary Plant
Plant water usage is described below. All cooling water is
recycled and all process is consumed in the manufacture of
V-26
DRAFT
-------
DRAFT
TABLE 5 CaT!parison of Plant Intake Water and Cooling
Water Discharge at Plant 152*
________ Intake Discharge Units
Flow Not Measured 3,270 cu nVday
(864,000) CGPD)
TEnperathre Not Measured 18 (64) °C (°F)
Color ( pparent) 50 50 Units (APHA)
Turbidity 19 19 FI’U
Conductivity 65 65 ng/l NaC1
135 135 micrcznhos/cni
Suspended So1i 1s 7 12 n /1
7.40 7.50 —
1 cidity: Total 0 0 ugh Caa) 3
Free 0 0 ugh CaCD 3
alkalinity (Total) P 0 0 mg/i CaC) 3
T 0 30 rtg/1 CaO) 3
Hardnsss: Total 50 50 mg/i C 3
Halogens: Ch1orir 0 0 mg/i Cl 2
F]jx)ride 0.2 0.2 mg/i F
Sulfate 25 22 mg/i ()42
Nitrogen (Total) 0.2) 0.14 mg/i N
Heavy Metals: Iron 0.25 0.25 mg/i Fe
Chrat ate(Cr 6 ) < 0.02 <0.02 mg/i r 6
Oxygen (Dissolved) U ]D.4 mg/i 02
aD 25 0 mg/i
Data fran GPC verification saupling
V-27
DRAFT
-------
‘I,
PRODUCT RECOVERY
FIGURE 38
FLOW DIAGRAM FOR LIME PLANT
V-28
007
DRAFT
VENT
4’
KILN
DRY
BAG
COLLECTORS
LIMESTONE
NATURAL GAS )
QUICKLIME :
CD
z
_J ia
0 -
0 <
AIR
COOLER
HAMMER
MILL
I I____
“
SOLID
WASTE
MAKE -UP
WATER
/
CO 21 KILN GASES
PARTICULATE
MATTER
COOLINC WATER
PROCESS WATER
NON-CONTACT
VENT
COOLING
TOWER
DRY
BAG
COLLECTOR
COOLING WATER
HYDRATOR
I .
PARTICLE
SIZING
BULK
HYDRATED
LIME
STORAGE
HYDRATED
LI ME
PACKAG ING
DRAFT
-------
DRAFT
hydrated lime.
Due to the use of dry waste collection techniques, there is no waterborne
effluent from the facility. Ninety—five percent or better solids collection
at the kiln collector has been the experience of this plant.
A. Water Inputs to Plant
Type Quantity, liters/day Coments
Municipal 174,100 max (46,000 GPD) Untreated
+ amt. evaporated on
cooling tower
B. Water Flows Quantity %Recyc led
liters/day liters/kkg
Cooling 272,500 1000 100% of
(Bearings on (72,000 GPD) (240 gal/ton) unevaporated
tube mill and
pistons on
hydrator pump)
Process 174,100 635 0
(Hydrator) (46,000 GPD) (152 gal/ton)
3.1.6.3 Effluent at Exemplary Plant
There is no waterborne effluent.
3.1.7 Nitric Acid
Nitric acid is manufactured from aninonia by a catalytic oxidation process.
Minonia is first catalytically oxidized to nitric oxide, which is then fur-
ther oxidized to nitrogen dioxide. The nitrogen dioxide is then reacted
with water under pressure to yield nitric acid. The exemplary plant (plant
114) manufactures only commercial 63% nitric acid. Fuming (i.e., more than
70%) nitric acid and nitrogen pentoxide are made only at a few facilities
and are not covered in this report. The flow diagram for plant 114 is given
In Figure 39.
3.1.7.1 Raw Waste Load
The raw waste load from nitric acid production at the exemplary plant is
listed below. There are no nitrates in the waste. All weak nitric acid
V-29
DRAFT
-------
DRAFT
HIGH PRESSURE
I D STEAM TURBINE
TAIL GAS TO CATALYTIC
COMBUSTER, GAS EXPs
TURBINE GAS BOILER
AND VENT.
COOLING
PRODUCT ITRIC ACID
FIGURE 39
NITRIC ACID PROCESS FLOW DIAGRAM
FOR PLANT 114
V-30
DRAFT
-------
DRAFT
lost in manufacture is recycled to the process at this facility. The wastes
consist only of water treatment chemicals used for the cooling water.
Waste Products Process Source kg/kkg HNO 3 (avg)*
1. Lime Boiler Feedwater 0.47
2. Calcium and
Magnesium Boiler Feedwater 0.6
Carbonates
3. D : te Boiler 0.0016
4. Sodium Sulfate Boiler 0.0008
5. Sulfuric Acid Cooling Tower 0.0016
6. Chlorine Cooling Water Treatment 1.0
*
Values not affected by startup and shutdown.
3.1.7.2. Treatment at Exemplary Plant
Plant water use is shown below and describes the large amount of water and
weak acid recycling at the plant. Only cooling water is discharged, and
this waste stream is currently untreated. A settling basin may be installed
in the future at plant 114 to settle out suspended materials from the cooling
water prior to discharge.
A. Water Inputs
Type Quantity
cu m/day liters/kkg
Well 3,815 13,150
(1,008,000 GPD) (3,150 gal/ton)
B. Water Use Quantity % Recycled
cu rn/day liters/kkg
Cooling 31,000 106,800 95
(8,000,000 GPD) (25,000 gal/ton)
Process stream 775 2,670 75*
(200,000 GPD) (6,250 gal/ton)
*Recyc1ed weak nitric acid from condensates, etc. is 89 cu rn/day (23,000 GPD).
V-31
DRAFT
-------
DRAFT
3.1.7.3 Effluent from Exemplary Plant
The plant effluent streams are shown below. Wastes dfscharged are only water
trea ent chemicals.
Effluent
Stream No. Sources cu rn/day liter/kkg
Boiler Feedwater Treath ent 5 (1,250 GPD) 16 (3.9 gal/ton)
2 Boiler Biowdowns 30 (7,800 GPD) 85 (24.4 gal/ton)
3 Tower Water Blowdowns 3600 (95,000 GPD) 1240 (297.0 gal/ton)
(All streams tie into common effluent header before discharge.)
Because of recycling of some water and of all nitrogen-containing streams,
this plant is exemplary. However, as in many other cases, cooling waters are
untreated prior to discharge. The plant effluents are listed below.
Parameter Concentration or Value
Average Range Units
Total Dissolved SolIds 80 50-100 mg/i
Total Dissolved Solids 239 200-250 mg/i
BOD 5 - mg/i (02)
COD 10 — mg/i (02)
pH 7.8 7.5-8.5 -
Temperature 25 24-27
Turbidity 125 - JTU
Color 330 - PTC O
Conductivity 500 - pmhos
Alkalinity (Total) 300 mg/i
Hardness (Total 300 mg/i
Chloride 18 mg/i
Fluoride 0.2 mg/i
Sulfite 0.2 mg/i
Sulfate 60 mg/l
Phosphates 0.4 mg/i
Nitrate 0.2 mg/l
Iron 7.5 mg/i
Manganese 0.2 mg/l
A plant visit verified that only cooling water is discharged from plant 114.
v-3 2
DRAFT
-------
DRAFT
3.1.8 Potassium Metal
For the commercial preparation of potassium metal (K), potassium chloride
is melted in a gas-fired melt pot and is fed to an exchange column, as was
shown in the standard process flow diagram, Figure 9, in Section IV. The
molten potassium chloride flows down over steel Raschig rings in the packed
column, where it is met by ascending sodium vapors corning from a gas-fired
reboiler. An equilibrium is established between the two, yielding sodium
chloride and elemental potassium as the products. The sodium chloride formed
is continuously withdrawn at the base of the apparatus and is normally sold.
The column operating conditions may be varied to yield either pure potassium
metal as an overhead product or to vaporize sodium along with the potassium
to produce sodium potassium (NaK) alloys of varying compositions. Potassium
metal of over 99.5% purity can be continuously produced by this process.
Production of potassium in the United States was about 90 kkg/yr (100 tons/yr)
in 1972, essentially all of it originating from one facility - plant 045.
Contacts with this manufacturer have revealed that the process diagram accur-
ately describes their operation in which no process water is used and from
which there are no waterborne effluents. Hence, there appears to be no
waterborne effluent streams from the manufacture of this material.
3.1.9 Potassium Dichromate
Potassium dichromate is prepared by reaction of potassium chloride with sodium
dichromate. Potassium chloride is added to the dichromate solution, which is
then pH-adjusted, saturated, filtered and vacuum cooled to precipitate crystal-
line potassium dichromate. The product is recovered by centrifugation, dried,
sized ar d packaged. The mother liquor from the product centrifuge is then
concentrated to precipitate sodium chloride which is removed as a solid waste
from a salt centrifuge. The protess liquid is recycled back to the initial
reaction tank. The exemplary plant is plant 002, and its process flow dia-
gram is the same as Figure 10, Section IV, the standard flow diagram.
3.1.9.1 Raw Waste Loads
The raw wastes from potassium dichromate manufacture are listed below. These
are crystalline sodium chloride and filter aids which are solid wastes and
are hauled away for landfill disposal by a contractor.
Waste Products Process Source kg/kkg of Product
NaC1 Centrifuge 400
Filter aid Filter 0.85
V-33
DRAFT
-------
DRAFT
3.1.9.2 Treatment at Exemplary Plant
Plant water usage is given below. All process waters are recycled. The only
wastes currently discharged emanate from contamination of once-through cool-
Ing water used on the barometrIc condensers on the product crystallizer.
Plant 002 has plans to replace the barometric condensers with heat exchangers
using non-contact cooling water by the end of 1973. This will eliminate the
hexavalent chromium waste completely. With this change, no process waters
will be discharged.
A. Water Inputs to Plant
Type Quantity Cooiiients
cu rn/day liters/kkg
River 1,325 97,200 Untreated except for
(350,000 GPD) (23,300 gal/ton) macrofiltration
Municipal 245 18,100 Untreated
(65,000 GpD) (4,330-gal/ton)
B. Water Usage Quantity - % Recycled
cu rn/day liters/kkg
Cooling 1,325 97,200 0
(350,000 GPD) (23,300 gal/ton)
Process 245 18,100 100
(makeup) (65,000 GPD) (4,330 gal/ton)
3.1.9.3 Effluent at Exemplary Plant
Presently, the only effluent is cooling water, possibly contaminated with
hexavalent chromium in the barometric condenser. Replacement of the conden-
ser with a non-contact heat exchanger will eliminate cooling water contamina-
tion, although a larger amount of water will have to be used for the less
efficient non-contact heat exchanger.
3.1.10 Potassjum Sulfate
The bulk of the potassium sulfate manufactured in the United States is
prepared by reaction of potassium chloride with dissolved langbeinite (potas-
sium su1fate-magnesi nisulfate). The langbeinite is mined and_cru hed and_
then dissolved in water to which potassium chloride is added. Partial
evaporation of the solution produces selective precipitation of potassium
v-34
DRAFT
-------
DRAFT
sulfate which is recovered by centrifugation or filtration from the brine
liquor, dried and sold. The remaining brine liquor is either discharged
to an evaporation pond, reused as process water or evaporated to dryness to
recover magnesium chloride. The fate of the brine liquor is determined by
the saleability of the magnesium chloride by-product (depending on ore
quality) and the cost of water to the plant. A diagram for the process used
at the exemplary facility plant 118) is given in Figure 40.
3.1 .10.1 Raw Waste Load
The table below presents a list of the raw wastes expected for potassium
sulfate manufacture:
Waste Product Process Source kg/kkg of Product
Average Range
Muds,(silica, alumina, Dissolution of langbe— 15
clay and other mite ore
insolubles)
*
Brine liquor Liquor remaining after 0-2000
(Saturated magnesium removal of potassium
chloride solution) sulfate
*Part of the magnesium chloride is recovered for sale and part of the
remaining brine solution is recycled for process water. The high value
corresponds to the case of no recycling or recovery of magnesium chloride.
These b’rines contain about 33% solids.
The wastes consist of muds from the ore dissolution and waste magnesium
chloride brines and are not affected by startup or shutdown. The latter
brine can sometimes be used for magnesium chloride production if high grade
langebeinite ore was used. Composition of the brine solutions after potas-
sium sulfate recovery is:
Potassium 3.19%
Sodium 1.3%
Magnesium 5.7%
Chloride 18.5%
Sulfate 4.9%
Water 66.7%
V-35
DRAFT
-------
WATER
1 _______
KcI DISSOLVER —4 FILTRATION —)WASTE MUDS
WATER
VAPOR
LANGBEINITE RE REACTOR J ) FILTRATION E ION EVAPORATOR
PRODUCT _______
K 2 S0 4
CL.ARIFIER
BRINE LIQUOR FOR RE-USE
PRObUCT
MgCI 2
FIGURE 40
POTASSIUM SULFATE PROCESS DIAGRAM AT PLANT 118
-------
DRAFT
The amount of brtne produced is about 650 kg of solids/kkg of potassium
sulfate (1300 lb/ton) after evaporation. For higher grade ores, the sodium
content ts lower. The data presented above were supplied by plant 118.
3.1.10.2 Treathient at Exemplary Plant
The muds listed above are separated from the brine solutions by filtration
after dissolution of the langbeinite ore. These are recovered and disposed
of as landfill on the plant site. The brine wastes, containing mostly mag-
nesium chloride, are either disposed of or treated in three different
manners:
1. Evaporation with recovery of magnesium chloride for
sale. This is practiced only when high grade ores
are processed.
2. Reuse of the brine solution in the process in place
of using process water. This is nonnally done to a
considerable extent.
3. Disposal of the brines in evaporation pits.
At plant 118, all three of the above options are practiced, depending on the
quality of the ore being processed.
Water use at plant 118 is described below:
Water Inputs:
Type Quantity Water Purity
cu rn/day (MGD) 1/kkg (gal/ton )
Well Water 3,790 (1.0 8.360 (2,000) 40 ppm total
solids
Water Flows:
Type Quantity % Recycled
cu m/da (MGD) i fkkg (gal/ton ]
Cooling 13,600 (3.6) 30,000 (7,200) 60-70% (remainder
evaporated)
Process 2,270 (0.6) 5,010 (1,200) 67% recycled
33% lost either by
evaporation or re-
moval from system
with product or
by—product.
y—37
DRAFT
-------
DRAFT
There are no effluent streams from the plant since much of the water is
recycled. Most of the water losses occur during the process evaporation
steps.
3.1.10.3 Effluent
There is no waterborne effluent from the plant. Any waste brine is evaporated
to dryness.
3.1.11 Sodium Bicarbonate
Sodium bicarbonate is manufactured by the reaction of soda ash and carbon
dioxide in solution. The product bicarbonate is separated by thickening and
centrifugation and is then dried, purified and sold. A detailed process
diagram for the exemplary facility isgiven in F gure 41. This facility
ts plant 166, and it is located within a Solvay process complex.
3.1.11.1 Raw Waste Load
A listing of raw wastes produced in bicarbonate manufacture at plant 166 is
shown below. These consist of unreacted soda ash, solid sodium bicarbonate,
boiler wastes and ash from power generation equipment. The ash is treated
as a solid waste.
Waste Product Process Source g/kkg of Product
Range
1. Na 2 CO 3 Slurry thickener overflow 38.0 0—375
2. Ash Power generation 17.9
3. Water purif. Boiler feed water purification 0.3
sludge
4. NaHc0 Slurry thickener overflow 10.0
The quantity of slurry thickener overflow depends upon the operation of
another plant utilizing this by—product. The overflow is not constant, and
occurs only when the sister plant mentioned above cannot absorb the entire
flow. Consequently, the value shown above is based on an annual average,
with a wide variation in flow over the period.
3.1.11.2 Waste Treatment at Plant 166
The water usage at plant 166 is shown below. Most of it is used for cooling
purposes.
V .38
DRAFT
-------
RECYCLE LIQUOR
OVERFLOW
1’
SODA ASH
__________________ RECYCLE I RECYCLE
LIQUOR 1 LIQUOR
TANK
. 11
LIQUID
I OVERFLOW
_________________________ ____________________________________________ I
FLASH
RIFUGES
SCRUBBER DRYERS L 8 )
(2)
a,
‘kUCT
• PRO
TO COOLER CURER CO 2
CLASSIFICA
TION (40%)
: - - - I XING SAND PRESSURE —
SODA I TANK I I FILTERS LEAF CARBONATING THICKENERS
COLUMNS (3)
(2) L (2) FILTER (8)
OISSOLY s LIQUOR j
FILTER
BACK 1 WASH BAC I ’WASH ‘1’ ‘1’
SODIUM
(SODIUM SEWER MILL
SESQUICARBONATE SEWER SUSQUICARSONATE WATER
PURGE)
FEED SODIUM
SESQUICARBONATE
PURGE
FIGURE 41
SOLVAY SODIUM BICARBONATE PROCESS FLOW DIAGRAM AT PLANT 166
-------
DRAFT
Water Inputs to Plant :
Type
Lake
Municipal
Water Usage:
Type
Cooling
Process
Cu rn/day (MGD )
1,430 (0.378)
119 (0.0315)
cu rn/day (MGD )
1,430 (0.378)
119 (0.0315)
5,430
(1,300)
455
(109)
l/kkg
(gal/ton)
5,430 (1,300)
455 (109)
Comments
Chlorinated prior to
use as cooling water.
% Recycled
None
Treatments are carried out for the two emerging waste streams. These streams
are fed to settling ponds to remove suspended solids and then discharged.
Stream
Settling
Pond Over-
flow
Cooling
Water
(Discharge)
Source
Slurry thick-
ener
Various heat
exchange de-
vices found
throughout
plant
Treatment
Settling Pond
a) Containment
of wastes
b) Cooling water
segregation
c) Some water
recycling
d) Collection and
sampling of
wastes
effluents.
Tabulated
The plant effluent contains 20,000 mg/l of dissolved solids (mostly dissolved
carbonates), amounting to 5.75 kg/kkg of product (11.5 lb/ton). All of the
bicarbonate wastes are treated along with chlor-alkali and soda ash wastes at
V-40
Cu rn/day (MGD )
76 (0.020)
1,430 (0.378)
Disposal
Plant Effluent
Effluent
3.1 .11.3
Individual effluents from this plant are combined with other sewer
Some wastes are treated in conjunction with soda ash plant wastes.
loads are based on reasonable allocations.
Effluent at Plant 166
DRAFT
-------
DRAFT
the 166 facility in a common treatment system prior to discharge. There
are no net effluent loads to the cooling water based on average daily opera-
tion. There are no organics in the plant effluent.
Plant 166 has plans to use the weak slurry thickener overflow, which con-
stttutes their present major source of waste, as a source of liquid for the
product dryer scrubber and to recycle this liquid (concentrated with respect
to sodium carbonate) back to the process. These process changes will elimi-
nate the discharge of process wastewaters.
GTC verification measurements on the plant intake water, cooling water, and
effluent are given in Table 6. The similarity of composition of plant intake
and cooling water discharge verifies segregation of cooling water from
process water. The process effluent measured is the effluent of the whole
plant complex and hence is not indicative of that of an isolated bicarbonate
unit.
3.1.12 Sodium Chloride (Solar )
Sodium chloride is produced by three methods:
1) Solar evaporation of seawater;
2) Solution mining of natural brines;
3) Conventional mining of rock salt.
In the solar evaporation process, sea water is cor centrated by evaporation
over a period of five years in open ponds to yield a saturated brine solu-
tion. After saturation is reached, the brine is then fed to a crystallizer,
wherein sodium chloride precipitates, leaving behind a concentrated brine
solution (bittern) consisting of sodium, potassium and magnesium salts.
The precipitated sodium chloride is recovered for sale and the brine is then
further evaporated to recover additional sodium chloride values and is then
either stored, discharged back to salt water or further worked to recover
potassium and magnesium salts. The exemplary plant solar process is well
represented by the standard process flow diagram, Figure 13, in Section IV.
3.1.12.1 Raw Waste Load
In the solar evaporation process, all of the wastes are present in the
bittern solution which is presently stored at all facilities. Typical bit-
tern analysis for the exemplary 059 facility is given in Table 7. No bittern
is discharged from this facility. The bittern is stored and, in the past,
has been worked for recovery of other materials.
3.1.12.2 Treatment at Exemplary Plant
At plant 059, treatment consists of storage and further use of the bittern
V-4 1
DRAFT
-------
DRAFT
TABLE 6. Plant 166 Verification Data
Plant
Bicarbonate Canplex
Pararreter Plant Intake Cooling Water Effluent
Measured Furnished
*
Flcw, Cu nVday (M( )) Not rreas- 188,OCX) (49.5) Not Measured 17,4(X) (4.6)
ured
Ta:rperature, °C 11.2 Not Measured Not Neasured
Color ( pparent) < 20 270 275
.APHA Units
Turbidity,FIU <10 27 30 0
Conductivity,
mg/i NaC1 2000 1800 67,000
micranhos/an 3930 3400 118,000
Suspended Solids,
mg/i 5 160 206
Dissolved Solids,
mg/i 2850 2560 76,000
pH 7.80 7.75 10.8
2 cidity:
ta1,mg/i Ca03 3 0 0 0
Free ,mg/1 Ca03 3 0 0 0
Alkalinity (TbtalJ
P ,mg/1 Ca03 3 0 - 0 460
T,mg/l CaCt 3 195 171 305 610
Hardness:
Total,mg/l CaOD 3 1300 1428 1000 45,000
Calcium,mg/i Ca(D 3 1250 571 950 45,000
Halogens:
Chlorine ,mg/1 <0.1 1.9 0
Chloride ,mg/l 1525 1275 —
F luoride,mg/] 0.45 0.50 1.36
Su lfate,mg/1 170 130 640
Phosphates
¶Lt)ta l,mg/1 1.1 1.0 0.7
Nitrogen
Total,mg/1N 0.55 0.43 1.7
Heavy Metals: Iron
mg/i Fe 0.07 0 0.48
C1irat ate,mg/1 &-6 <0.01
Oxygen (Dissolved),
m j/10 2 4.7 13 4
*
Furnishes oDoling water to whole plant
V-42
DRAFT
-------
DRAFT
TABLE 7. th nical Analysis of Bittern
Constituent
pH 7.8
Total Solids, p in 241550
Total. Volatile Solids, p n 86600
Total Susper ed Solids, ppn 1760
Total Dissolved Solids, p n 239790
Alkalinity as CaOD 3 , ppu 2800
BOD, ppn 198
(tD, ppn 6350
Am tonia as N, p iu 0.702
Kjeldahl Nitrogen Total, ppn 32.610
Nitrate as N, ppn 37.50
Phosphorus Total as P, ppn 0.22
Chloride, ppn 158000
Cyanide, ppn <0.04
Fluoride, p in 74.90
Phenols, ppb 64.10
Sulfate as S, ppii 21000
Sulfide as 5, p in <2
‘LOC, p xn 900
Aluminum, p b 2500
Arsenic, prb 4°
Cadmium, ppb <20
Calcium, ppit 450
CI)rcznium, ppb <20
Iron, ppb 6500
Lead, ppb <20
Nerc,xry, p b <1
Sodium 5500
Titanium, ppb <20
Zinc, p b 190
V-43
DRAFT
-------
DRAFT
materials. There is no waste discharge. The plant water usage is:
Type Use Source cu rn/day (MGD) 1/kkg (gal/ton) Recycle
Process Refining Well 2,270 (0.60) 894 (214) 100%
process
Process Raw Material Bay 327,000 (86.4) 129,000 (30,900) None
3.1.12.3 Effluent of Exemplary Plant
As the bitterns are stored and further worked, there is no discharge. Even-
tual total evaporation after further bittern use yields only solid wastes.
Sufficient land and ponding area is available at the 059 facility to store
bitterns for the next 30-50 years without difficulty.
3.1.13 Sodium Silicate
Sodium silicate is manufactured by the reaction of soda ash or anhydrous
sodium hydroxide with silica in a furnace, followed by dissolution of the
product in water under pressure to prepare sodium silicate solutions. In
some plants, the liquid silicate solutions are then further reacted with
sodium hydroxide to manufacture metasilicates which are then isolated by
evaporation and sold. Figure 42 shows the total system diagram for the
exemplary facility at plant 072.
3.1.13.1 Raw Waste Load
The raw waste loads for plant 072 are listed below. These wastes consist
mostly of sodium silicate and unreacted silica:
Waste Products Prpcess Source Avg. kg/kkg of Product
Sodium Silicate Scrubbers 37
Si0 2 Scrubbers 2.85
NaOH/Silicates Washdowns 0.39
3.1.13.2 Treatment and Effluent of the Exemplary Plant
All scrubber and washdown waters are sent to a totally enclosed evaporation
pond. There is no plant effluent. Since this exemplary plant is in an area
of normal rainfall and humidity for the humid areas of the United States, the
evaporation ponding technique appears generally applicable.
DRAFT
-------
CLEAN
GAS WATER
‘1’ I
WATER TO
WATER VAPOR, SCRUBBER EVAPORATION POND
NaOH(MOLTEN)
FURNACE
COOLER GRANULIZER
S 10 2
SILICATE GLA
a,
1
SILICATE PRODUCT
FIGURE 42
SODIUM SILICATE MANUFACTURE AT PLANT 072
-------
DRAFT
3.1.14 Sulfuric Acid (Sulfur-Burning )
Sulfuric acid is manufactured primarily by the contact process which involves
catalytic oxidation of sulfur dioxide to sulfur trioxide and reaction of the
sulfur trioxide with water to yield sulfuric acid. Within the contact pro-
cess, there are three subcategories of plants,
(1) Double absorption - paired sulfur trioxide absorption towers and
catalyst beds in series are used to maximize conversion of sulfur dioxide so
that tail gas scrubbers are not required;
(2) Single absorption - single absorption towers and catalyst beds are used
and tail gases frequently have to be scrubbed to remove sulfur oxides; and
(3) Spent acid plants - these plants use spent sulfuric acid in piece of,
or in addition to, sulfur as a raw material. While the acid production
parts of these plants are the same as those for single absorption, these
plants are unique because of the spent acid pyrolysis units used to con-
vert the waste sulfuric acid raw materials to a sulfur dioxide feed stream.
In this section, we will consider only the first two types of plants. As
far as we can determine, the third class of plant belongs in a separate
category. We have not found an exemplary spent acid plant within the Inor-
ganic Chemical Industry; however, one may exist within a petroleum complex.
3.1.14.1 Double Absorption
In the double absorption contact process, sulfur is burned to yield sulfur
dioxide which is then passed through a catalytic converter with air to
produce sulfur trioxide. The sulfur trioxide is then absorbed in 95-97%
sulfuric acid. The gases emerging from the absorber are then fed to a
second converter to oxidize the remaining sulfur dioxide to sulfur trioxide
which is then absorbed in a second absorptioa tower, and the tail gases are
vented to the atmosphere. Figure 43 shows a detailed process flow sheet
for plant 086, which is the exemplary plant.
3.1.14.1.1 Raw Waste Loads
At plant 086, only cooling water is discharged. In double absorption plants,
the tail gases are sufficiently depleted of sulfur oxides that there is no
need for gas scrubbers. Also, at this plant, use of extensive maintenance
and leak prevention has been employed to prevent discharge of any product
acid.
3.1.14.1.2 Treatment at Exemplary Plant
The table below shows water usage at plant 086. Most of the water usage is
V-46
DRAFT
-------
SULFUR AIR
SULFUR
BURNER BLOWER
__________ — [ 1 TURBINE
EXPOR1 4 STEAM
FEED I WASTE
MUNICIPAL W TER— SOFTENER ‘ ) _________ Jii .__- [ NG
WATER I HEAT PROCESS
HEATER [ BOILERS _______
BACK WISH BLOWDOWN ____________
-1 TO fER
TO RIVER RIVER 1 WATER
____ ‘I,
s..EGEND : I CONVERTER 1 ACID
) I AND
WATER OR STREAM FLOW MUNICIPAL WATER ABSORPTION ‘ COOLERS
— — — — PROCESS FLOW SYSTEM J [ ___________
SULFURIC TO
ACID RIVER
FIGURE 43
DOUBLE ABSORPTION CONTACT SULFURIC ACID PROCESS
FLOW DIAGRAM AT PLANT 086
-------
DRAFT
for cooling. Process water is consumed to make sulfuric acid and is not
discharged. The only plant effluent is the cooling water used in the heat
exchangers and associated water treatment chemicals.
Water Inputs to Plant:
Type cu rn/day (MGD) l/kkg (gal/ton) Coimiients
River 35,200 (9.30) 55,600 (13,300) Used for cooling only
Municipal 1,020 (Q27) 1,610 (386) Used for process steam
and cooling
Water Usage:
Type Source cu rn/day (MGD) l/kkg (gal/ton) % Recycled
Cooling River 35,200 (9.30) 55,600 (13,300) 0
Municipal 295 (0.078) 463 (111) 0
Process Municipal 117 (0.031) 184 (44) 0
Steam Municipal 610 (0.161) 960 (230) 0
3.1.14.1.3 Effluent of Exemplary Plant
The only effluent from the facility is once-through cooling water. Table 8
shows GTC verification measurements for the water intake and effluent. Com-
parison of these two shows that no process water effluent is added to the
cooling waters.
While this plant is exemplary with respect to both air emissions and lack of
sulfuric acid discharges, it could be further improved by use of a recycling
system for the cooling water.
3.1.14.2 Single Absorption
The single absorption process differs from that previously described only
in the arrangement of converters and absorbers. The rest of the process is
the same. For the single absorption process, the sulfur dioxide is passed
through one or more converters and then into one or more absorbers prior to
venting to the atmosphere. This arrangement is less effective for both con-
version of sulfur dioxide to sulfur trioxide and for absorption of the sulfur
trioxide into the absorber sulfuric acid. As a result, the tail gases may
have to be scrubbed, and this may create a waterborne waste not present for
double absorption plants. The exemplary plant is plant 141.
V-48
DRAFT
-------
DRAFT
TABLE 8. Intake and Effluent asureiients at
Plant 086
Paraneter Intake Effluent
F1a i a.i n\/day (MD) Not Measured 11,350 (3.0)
Tenperature 13°C 26.5
color (apparent- 40 40
APH std.)
TurbidIty (FTU) 10 15
conductivity 17,500 mg/i (NaC1) 18,000 mg/i (NaC1)
Suspended Solids 10 mg/i 5 mg/i
7.5 7.43
2 cidity: Total
Free
Alkalinity ( btai) P 0 0
T 93 mg/i (CaCX) 3 ) 91 mg/i (CaCX) 3 )
Hardness: Tota]. 3300 mg/i (CaCX) 3 ) 32(X) xn j/i (CaOD 3 )
Calcium 600 “ II 590 “ U
Halogens: Chlorine
Chloride 10,000 mg/i 10,000 mg/i
Fluoride
Sulfate 1,300 mg/i 1,500 mg/i
Phosphates (Ortho) 0.70 mg/i 0.68 mg/i
Nitrate 0.24 mg/i N 0.26 mg/i N
Heavy Mef- 1 :
Iron 0.28 mg/i 0.32 mg/i
thranate -
Oxygen (Dissolved) 6.4 mg/i
Sulfite << 1 mg/i << 1 mg/i
aD
V-49
DRAFT
-------
DRAFT
3.1 .13.2.1 Raw Waste Loads
For this process, there are no wastes from the sulfuric acid process itself.
Wastes arise only from the use of water treatment chemicals. The raw wastes
are iron, silicon, calcium and magnesium salts from water treatment.
3.1.14.2.2 Treatment at Exemplary Plant
Most of the cooling water used at this plant is recycled and only 5 percent
emerges from the plant. This is sent to evaporation ponds, from which there
is no discharge. The water input is well water in the quantity of 606 cu rn/day
(0.160 MGD) or 1,670 l/kkg of product (400 aI/ton). This water is used as
follows:
Type cu rn/day (MGD) 1/kkg (gal/ton) % Recycled
Cooling 560 (0.148) 1,540 (370) 95
Process 45.5 (0.012) 125 (30) 0
Sanitary Insignificant 0
3.1.14.2.3 Effluent of Exemplary Plant
All waterborne wastes are sent to an evaporation pond. There is no discharge.
Table 9 shows GTC verification measurements on the intake water, the effluent
going to the evaporation pond, and the evaporation pond water, respectively.
3.2 Category 2 Raw Waste Loads and Exemplary Plant Data
3.2.1 Calcium Chloride
Calcium chloride is produced by extraction from natural brines. Some material
is also recovered as a by-product of soda ash anufacture by the Solvay process.
The latter will be discussed in the soda ash section (Category 4, Section 3.4.1).
In the manufacture of calcium chloride from brines, the salts are solution
mined and the resulting brines are first partly evaporated to remove sodium
chloride by precipitation. The brine is then further purified by addition of
other materials to remove sodium, potassium and magnesium salts by precipit t-
(Ion and further evaporation, and is then evaporated to dryness to recover
calcium chloride which is then packaged and sold. Figure 44 shows the detailed
separation procedure used at the exemplary plant, plant 185. Bromides and
iodides are first separated from the brines before sodium ctiloride recovery is
performed. There is a large degree of brine recycling to rerfflve most sodium
chloride values. The composition of the brine is:
50
DRAFT
-------
DRAFT
1 BLE 9. In—Plant Water Streaii at Plant 141
* Evaporation
Paran ter Well Intake Water Surrp to Ponds Pond
Flow Unable to n asure
Tenperature (° C) 19 24.6 17.5
Color (Apparent-APHA) 1(X) 0 35
Torbidity (FTU) 35 <10 10
Conductivity (as NaC1) 410 360 790 (NaC1)
Suspended Solids 40 4700 0
pH 7.0 8.5 7.7
Acidity: Total 0 0 0
Free 0 0 0
Alkalinity (Total) P 0 0 0
T 475 120 105
Hardness: Total 410 250 5(X)
Calcium 275 112 400
Halogens:
Chlorine 0 0 0
Chloride 18.5 20 22.5
Fluoride 0.35 0.6 0.77
Sulfate 78 340 680
Phosphates (Total) 1.6 0.64 0.12
Nitrogen (Total) 0.03 0.18 0
Heavy Metals:
Iron 18 9 4
chranate 0 0.16 003
ygen O isso1ved) 5.3 5.5 7.9
ODD <25 575 70
*Ail units mg/i unless otheiwise specified.
v_si
DRAFT
-------
SEPARATOR J
j__
INVENTORY
.__
[ SCRUBBER
. ‘I ,__
.1I
FLAKER AND DRYER
COOLING WATER
FROM PROCESS
rt_
L
-I
COOLING I
TOWER
WASTE
FIGURE 44
CALCIUM CHLORIDE FLOW DIAGRAM.
AT PLANT 157 --
V- 52
DRAFT
BRINE_______
WELL -
COOLING
WATER _____
CaCI 2 LIQUOR . -
38% SOLUTI&’l
. IODIDES, BROMIDES AND
MAGNESIUM TO OTHER PROCESSES
( STEAM
> CONDENSATE
F-’? CONDENSATE
WASTE
L’ \ ‘ ___
NaCI SEPARATOR
j
NaCI DISSOLVER
/
CaCI 2 (SOLUTION)
TO CHLOR-ALKALI
PURl FICATION
PROCESS_____
WATER
VENT TO
EXHAUST
WASTE <
COOLING
____WATER
( STEAM
> ONDEN SATE
COOLING
>WATER
EVAPORATOR
‘I’
ANHYDROUS PRODUCT
DRAFT
-------
DRAFT
CaC1 2 19.3%
MgC1 2 3.1%
NaC1 4.9%
KC1 1.4%
Bromides 0.25%
Other minerals 0.5%
Water Balance
3.2.1 .1 Raw Waste Load at Exemplary Plant
The raw wastes expected from calcium chloride manufacture at plant 185
arise from blowdowns as well as from the several partial evaporation steps
used. Most of the wastes are weak brine solutions:
Waste Products Process Source kg/kkg Produce (avg. )
NH 3 Evaporators 0.55
CaC1 2 Evaporators 29
NaCl Evaporators 0.50
CaC1 2 Packaging 0.70
*NaC1 & KC1 Brine Separation 45.5
*NaC 1 Secondary Brine 110.0
Separation
*Recycled or used elsewhere.
3.2.1 .2 Treatment at Exemplary Plant
At plant 185, the waste brine streams are passed through an activated sludge
treatment to remove organics and are then passed to a settling basin to remove
suspended matter, adjusted to neutral pH, fed into a second pond to further
settle suspended matter, and finally discharged. Future plans at the 185 plant
call for changes in the evaporators to reduce calcium chloride discharges and
eliminate ammonia from the discharges. More recycling of spent brines is
also planned. Table 10 gives a detailed breakdown of current water usage at
plant 185.
3.2.1.3 Effluent of Exemplary Plant
Table 1OA lists the river intake and effluent compositions at plant 185.
v- 53
DRAFT
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DRAFT
‘J BIE 10. Plant 185 Water Flows
A. Iflpits
Type c i n day (Mi)) ] ./kkg (gal/ton )
River (± 44%} 31,100 (8.208) 62,700 (15,000)
Lake 545 (0.144) 1,100 (263)
B. Water Usage
Type oa nVday ( ) Vkkg (ga]/ton) % 1èc v1ed
Coolir 58,500 (15.5) 118,000 (28,300) 46
Pro ss 164,000 (43.2) 330 (79) 0
Washdcwn 2,180 (0.576) 4,390 (1,052) 0
Washout 680 (0.180) 1,370 (329) 10
TAB lE bA. Cat osition of Intake and Effluent Stream
of Plant 185
___________ Intake Effluent Stream No. 1
- Plant GTC Plant arC
Data ? èasuren nt Data Maasurenent
Flc,iz, ai nVday (MGD) 31,600 (8.35) ** 31,600 (8.35) **
Total Suspended Soil 42 8 — 29
Total Dislvd,Solids 353 293 2,693 309
3 — 1.1 —
8.3 8.3. 6.7—8.0 9.1
Turbidity (FTU) 5.3 0 18.2 25
Color ( PHA Units) 20 70 60 80
Conductivity (NaC1) 476 520 5,390 340
Hardness (Ca) 200 179 700 169
Sulfate 110 36 312 36
Nitrate <0.2 0.29 <0.2 20
?innxxaa 0.]. 0.60 2.0 8.8
Organic Nitrogen 0.2 — 2.7 —
Iran 0.4 0.30 1.0 009
Copper
Chranate 0.1 0.1
Manganese 0.05 0.1
Zinc 0.1 — 0.85 —
Ibta]. Alkalinity 160 170 67 235
CaC0 3 )
mg/l unless otherwise speci.fied
**m surement not possible due to physical constraints of location
V- 54
DRAFT
-------
DRAFT
The effluent consists mostly of weak brine solutions (neutral pH). These
discharges are expected to be reduced in the near future.
3.2.2 Hydrogen Peroxide (Organic Process )
Hydrogen peroxide is manufactured by three different processes: (1) An
electrolytic process; (2) An organic process involving the oxidation and reduc-
tion of anthraquinone; and (3) a by-product of acetone manufacture from
isopropyl alcohol. In this study, we considered only the first two processes.
In the organic process, anthraquinone (or an alkylanthraquinone) in an organic
solvent is catalytically hydrogenated to yield a hydroxyanthraquinone. This
material is then oxidized with oxygen or air back to anthraquinone, with
hydrogen peroxide being produced as a by-product. The peroxide is water—
extracted from the reaction medium, and the organic solvent and anthraquinone
are recycled. The recovered peroxide is then purified and shipped. Figure 45
shows a specific flowsheet for the exemplary facility, plant 069, including
part of the waste abatement system.
3.2.2.1 Raw Waste Loads
Operation
Waste Products Process Source Avg. Range (kg/kkg )
Sulfuric Acid Ion Exchange Units 12.5 - 15
Trace Organics Contact Cooling 0.17 - 0.35
Hydrogen peroxide Purification Washings 20 - 25
The process runs continuously except for shut-down approximately 10 days per
year. Total discharge will normally be no higher during start-up and shut-down
periods than under operation at capacity.
3.2.2.2 Treabuent at Plant 069
Water usage at plant 069 is described by the data given below:
Water Input to Plant . Well water at 26,500 cu rn/day (7.0 MGD) having the
following composi tion:
Total Solids 110-125 ppm
Carbon Dioxide 30-60 ppm
Total Hardness 80-100 ppm
Fe 1-3 ppm
Cu 0.03—0.06 ppm
Zn 0.02 ppm
Sulfate 2-7 ppm
Alkalinity (CaCO 3 ) 70-110 ppm
V- 55
DRAFT
-------
ORGANIC REACTION MED ViM
CRGAN
SOLVENT EXTRACTION
HYDROGENATION OXIDATION AND WATER
PURIFICATION TREATMENT
I1’ SHIPPING
U’
_ ___ __ ___I D
CRGIICS I —1
H 2 0 2
__________________I PRODUCT
H 2 0 2 H 2 0 2 H 2 S0 4
ST’kRM
DITCH
FIGURE 45
HYDROGEN PROXIDE PROCESS DIAGRAM FOR PLANT 069
-------
DRAFT
Water Usage
Type cu rn/day (MGD) % Recycled
Cooling 31,000 (8.2) 25% recycled
35% of remainder
used twice
Process 1,360 (0.36)
Most of the water is used for cooling, and a relatively large fraction of this
water is recycled. -
The data below describes the treatment of the waste stream emerging from the
peroxide plant. Peroxide is decomposed by iron filings, and organic solvent
losses are minimized by a skinning operation:
Waste Stream Source cu rn/day (MGD) Treatment Final
_____________ _______________ Disposal
Process Process 25,000 (6.6) 1. Peroxide reacted with River
Effluent iron filings
2. Skinners used to trap
organics for recovery
3. Waste sulfuric acid is
- collected and discharged
at a controlled rate
4. Solids (alumina &
carbon) are hauled to
landfill
The effectiveness of the treatments in use-is:
- Qualitative Waste Reduction
Method Rating Accomplished
Reduction Generally satisfactory 80% reduction of peroxide
to water and oxygen
Skimming Generally satisfactory 60-70% of organics
recovered.
3.2.2.3 Effluent of Plant 069
The effluent composition after treatment is given in Table 11. The wastes
consist of unreacted peroxide and a small amount of organics and sulfates.
- v_57
DRAFT
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DRAFT
‘J IBIE 11. Plant 069 Process Water Effli nt After Txeai rent
VerIficaticm Sarrple
* Plant Data Cit Plant 069
O nstithents Average Range Z1easui enent asurenent
TOtalSuspendedSoH i 15—20 9 9
Total Dissolved SoTh 310 -.330 98 117
- 6— i
40 50 324
6—9 6.4 6.6
Terperature 30°C 27°C
T.O.C. 5—15 —
Hydrogen Peroxide 60 — 80 37.8
Tuthidity < 25 Jadcson 12 <25
Qlor(APEA Units) 20 - 20 50 JO
acidity (Free) 40 — 50 46
acidity Total 0 -
Alkalinity (Total) 150— 195 61
Hardness (Total) 90 — 105 92
thioride 2 5 7
Sulfate 40 — 75 43 52
Irc i 2 — 3.5 1.6 0.26
— 0.08 - 0.09
F1a z 25,000 Cu nVday 26,900 cu zri/
(6.6I ) day(i.u p)
* mg/i iess otherwise specified
V- 58
DRAFT
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DRAFT
3.2.3 Sodium Metal
Sodium is manufactured by electrolysis of molten sodium chloride in a Downs
electrolytic cell. After salt purificatior to remove calcium and magnesium
salts and sulfates, the sodium chloride is dried and fed to the cell, where
calcium chloride is added to give a low-melting CaC1 2 -NaC1 eutectic, which
is then electrolyzed. Sodium is formed at me electrode, collected as a
liquid, filtered and sold. The chlorine liberated at the other electrode is
first dried with sulfuric acid and then purified, compressed, liquefied and
sold. Figure 46 shows the process in use and waste treatment facilities at
the exemplary facility, plant 096.
3.2.3.1 Raw Waste Loads
There is no waste during operation of an individual cell for the molten salt
electrolysis step in the Downs cell process. The cells are run in banks, and
individual cells are cleaned out and refilled after the electrolyte is
depleted. It is from this cleaning and refilling of individual cells that all
of the wastes arise.
The wastes produced by sodium manufacture at plant 096 are shown below. Several
of the expected wastes are not present. This is due to the reuse of materials
in other parts of the facility to make otherproducts, for example, the sulfuric
acid used in drying the chlorine.
Waste Products Process Source kg/kkg of Product
NaC1 Process 50 — 65
Misc. Alkaline Salts Process 25 — 35
Ca(OC1) 2 Chlorine Recovery 45 - 75
Fe Cooling Tower 0.065 - 0.095
The process does not normally shut down. The discharges result from the re-
placement of cells. The hypochlorite wastes are consumed in on—site oxidation
of cyanide wastes produced in the same plant.
3.2.3.2 Treatment at Exemplary Plant
In this plant, cooling tower blowdowns and residual chlorine from tail gas
scrubbers are discharged without treatment. The stream containing calcium
hypochlorite wastes is not discharged but is used to treat cyanide wastes.
Cooling water is discharged without treatment and tank wash and runoff water
are first ponded to settle out suspended materials and then discharged.
The water input to the plant is well water in the amount of 2,730 cu rn/day or
V- 59
DRAFT
-------
C D
o
U
¶ I
PROCESS
______
I CI2) 0dhJdT
:FTTL ER IFI
d- Iii
EQUIPMENT REPAIR I -
I-,
g z
0
g.
z I—
nf
oz
£fl4
FIGURE 46
WASTE TREATMENT ON DOWNS CELL AT PLANT 096
-------
DRAFT
46,300 1/kkg of product (11,100 gal/ton), having an impurity content of
Total Solids 110-125 ppm
CO 2 30-60 ppm
Hardness (as Ca) 80-100 ppm
Fe 1-3 ppm
Cu 0.02-0.06 ppm
Zn 0.02 ppm
Sulfate 2-7 ppm
Alkalinity (CaCO 3 ) 70-100 ppm
The water use within the plant is as follows:
Use Flow Amount Recycle
Cooling 29,100 cu rn/day 497,000 1/kkg 90% recycled
(7.7 MGD) (119,000 gal/ton)
Process 530 cu rn/day 9,000 l/kkg 2%
(0.14 MGD) (2,150 gal/ton)
The 2% recycled process water is used in the calcium hypochiorite absorber.
Table 12 lists the various plant waste streams and their compositions.
3.2.3.3 Effluent of Exemplary Plant
These stream effluents consist mostly of dissolved sodium chloride and other
chlorides. Table 13 shows the results of analyses of simultaneous samples from
three of the waste streams (those corresponding to streams 2, 3, and 4 of Table
12) performed by plant 096 and GTC. Good agreement bel *,een the results was
generally obtai ned.
Thts facility is exemplary in having good pH and suspended solids control and
reuse of some wastes, but there are large amounts of chlorides being discharged
which could be recycled for process reuse.
3.2.4 Sodium Chloride (Solution Mining of Brines )
Sodium chloride is produced by three methods:
1. Solar evaporation of seawater;
2. Solution mining of natural brines;
3. Conventional mining of rock salt.
In the first two types of operations, there are wastes arising from recovered
V-61
DRAFT
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DRAFT
TABLE 12.. Plant 096 Effluents
Stream NO. Stream No. Stream No. Stream No.
nstituents 1* 2** 3*** 4****
Flow, Q.1 nVday 409 (0.108) 133 (0.035) 1,79) (0.470) 409 (0.108)
D)
T.S.S. 30—50 50-70 5—10
T.D. S • 400 - 600 300 - 400
BOD
aD
pH 6.5 — 7.5 10.5 — 12.0 6.7 — 7.5
Fe 2 1—2 2—3 —
C i’wide 100 — 150 10,000 — 30,000 50 — 100 13,000
Chlorin. 4,000 — 6,000 2) — 100 —
Sulfate — 25—50 —
To€al !ardness 180 - 225 —
Phpsphate 0.2
t±id.t y (Fm) 25—30 40 — 60 125
Q, lor 15 I%PI 15 PHA 15 APHA
Acidity (Free) 20-30 20-30
Alkalinity — 4,000 — 6,000
(Total)
Hardness (Ca) 25,000 — 35,000
* - () o1Ir Tower B1cwd n, 2
** - Calcium HypodLiorite Used to Treat Cyanide Wastes in .Arx)ther
Process
- Gooling Water
- Runoff, Excess Calcium Hypochiorith, Tank Washup
Not There is also 2,270 ]/day (600 ‘D) used sulfuric acid sent for
use elsewhere in the u aty1ex ax not discharged into surface
strearis.
All units irg/1 unless otherwise specified.
V-62
DRAFT
-------
Paraueter
TABLE 13.
DRAFT
*
Plant 096 Effitent Analyses
Effluent Stream
No.2 No.3
No. 4
____ ci .i
nVday ( 1w)
Plant
133 (0.035)
1,590 (0.42)
Plant
GTC
Jackson
Plant
Solids
Plant
Solids
Plant
Plant
Plant
d c
• Plant
G2C
Plant
d c
*
n /l unless otherwise specified
6.5
6.55
48
0
0
121
125
0.33
0.1 -2
V— 63
6.45
6.44
57
0.6
0.2
92
90
26
10
0.69
2.7
11.9
11.9
4500
64,000
2,400
17, BDO
26,500
0.92
0.7
TexTperatuxe —
Plant
dc
ODlor (True) - APHA Units
Turbidity
Units
21.5 22
15 15
300 30
26 <25
82 ao
39
39
DIssolved
15
260
58
45
137
90
3 OO
574
47’?
6
‘I
355
266
19.5
Plant
dc
acidity (Free )
Plant
arc
A]J ai inity (Ca
Plant
arc
thlorine
thloride
Sulfate
Fe
37.5
DRAFT
-------
DRAFT
product purifications. In the third case, the mined mineral is frequently
sold as-is to users. Fn some cases the rock salt recovered is purified, but
in these cases, the methods used are the same as those employed with solution-
mined br nes. In this report, we discuss the first two methods of sodium
chloride production, as contacts with the industry have revealed there are no
waterborne wastes normally associated with the conventional mining operations.
Solar evaporation processes were discussed previously in Subsection 3.1.12.
Saturated brine for the production of evaporated salt is usually obtained by
pumping water into an underground salt deposit and removing the saturated
salt solution from an adjacent interconnected well, or from the same well by
means of an annular pipe. Besides sodium chloride, the brine will contain
some calcium sulfate, calcium chloride, magnesium chloride, and lesser amounts
of other materials including iron salts and sulfides.
The chemical treatment given to brines varies from plant to plant depending
on impurities present. Typically, the brine is first aerated to remove hydro-
gen sulfide and, in many cases, small amounts of chlorine are added to complete
sulfide removal and oxidize all iron salts present to the ferric state. The
brine is then pumped to settling tanks where it is treated with soda ash and
caustic soda to remove most of the calcium, magnesium and iron present as
insoluble salts. After clarification to remove these insolubles, the brine
is sent to multiple-effect evaporators. As water is removed, salt crystals
form and are removed as a slurry. After screening to remove lumps, the slurry
is washed with fresh brine to remove fine crystals of calcium sulfate from the
mother liquor of the slurry. These solids are returned to the evaporator.
The calcium sulfate concentration in the evaporator eventually builds up to
the point where it must be removed by “boiling out” the evaporators.
The washed slurry is filtered, the mother liquor is returned to the evaporators,
and the salt crystals from the filter are dried and screened. Salt thus pro-
duced from a typical brine will be of 99.8 percent purity or greater. Some
plants do not treat the raw brine, but control, the calcium and magnesium impuri-
ties by watching the concentrations in the evaporators and bleeding off suffic-
ient brine to maintain predetennined levels. By such methods, salt of better
than 99.5 percent purity can be made.
In either case, the final screening of the dried salt yields various grades
depending on particle size. The exemplary facility at plant 030 is similar
to the standard flow diagram, Figure 22, shown in Section IV.
3.2.4.1 Raw Waste Load
A detailed list of the raw wastes and their process sources is shown below.
These include wastes from the multi ple evaporators and dryers, sludges from
basic purification, as well as water treatment chemicals used for the cooling
water:
V-64
DRAFT
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DRAFT
Waste Products Process Source Ave.kg/kkg of Product
NaOH Botler blowdown 0.0055
Na 3 PO 4 “ I’ 0.0015
Na 2 SiO 3 “ U 0.0025
Na 2 SO 3 1 0.0015
NaC1 & CaSO 4 Purge from multiple 0.045
evaporator
NaC1 Evaporator 0.04
NaC1 Barometric condenser 1.1
NaC1 Miscellaneous sources
Brine sludges Brine purification 91 kkg/year
The brine sludges are returned to the brine wells for settling and disposal.
3.2.4.2 Water Usage and Treatment
Well water for brine field use is taken into the plant at a rate of 2,240 cu m/
day (0.59 MGD). This corresponds to 2030 l/kkg of product (536 gal/ton). Lake
water for cooling and other uses is drawn into the plant at a rate of 47,700 Cu
rn/day (12,58 MGD). This is used as follows:
Use Flow - Recycle
Cooling (barometric con- 41 ,700 cu rn/day - none
densers) (11.01 MGD)
Other (dust collection 6,100 Cu ru/day 90%+ recycled
pumps) (1.61 MGD)
Treatments of the effluent streams are as follows:
Stream No. Source Treatment
1 Condenser Discharge To Lake
2 Storm Drain To Lake
3 Tunnel Line (Lake Water) To Lake
4 Ash Lime Discharge Recycled
V-65
DRAFT
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DRAFT
The storm drain flow cited above was 3,790 cu rn/day (1 .0 MGD) on the average.
3.2.4.3 Effluent
The plant effluent streams #1 and #2 after treatment were portrayed by the
plant personnel as consisting solely of streams containing 100 ppm chloride
at a pH of 8.2. Chloride concentration at the plant intake was given as 70-80
ppm, with a pH of 8.2. Table 14 shows GTC verification measurements on the
plant intake and condenser discharge (stream #1) effluent. Only a small amount
of chloride has been added to the water used. The chloride content and pH
as stated are verified within a reasonable margin.
3.2.5 Sodium Sulfite
Sodium sulfite is manufactured by reaction of sulfur dioxide with soda ash.
The crude sulfite formed in this reaction is then purified, filtered to remove
insolubles from the purification step, crystallized, dried and shipped. A
process diagram for the exemplary facility, plant 168, is given in Figure 47.
3.2.5.1 Raw Waste Loads
A listing of the raw wastes produced from sodium sulfite production is given
below. These consist of sulfides from the purification step and a solution
produced by periodic vessel cleanouts containing sulfite and sulfate.
Waste Products Process Source kg/kkg of Product
Average Range
Metal sulfides Filter wash 0.755 0.19 - 1.44
Na 2 SO 3 /Na 2 SO 4 Dryer ejector
sol ution
Na 2 SO 3 /Na 2 SO 4 Process cleanout
solution
Cleanouts of various process vessels produce shock loads up to 9.1 kkg (10 tons)
of sodium sulfite and sulfate (dry basis). Cleanouts are conducted 3-6 times
per year. For this, separate tanks are used for surge capacity with bleed into
the treatment unit over a 5-10 day period.
3.2.5.2 Water Use and Treatment at Exemplary Plant
Approximately 10,900 cu rn/day (2.88 MGD) of river water and 13,250 to 28,400
liters/day (3,500 to 7,500 GPD) of municipal water are taken into the plant.
The stated analysis and GTC verification of the river water intake is:
V- 66
DRAFT
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DRAFT
ThBLE 14. GTC Verification Neasurenents at Plant 030*
Coix enser
Paraneter Intake Discharge
Plow, c i i ni/day (MCD) -37,900 (10) 37,900 (10 .o)
Tenperature, °C 13 22.5 — 23.0
ODlor, APHA Std. 40 40
Turbidity,. (Flu) 10 15
ODnductivity (NaC1) 225 320
Suspended Solids 0 0
pH 8.0 8.1
Acij9 ty: Total 0 0
Free 0 0
A]Jcalii ity (Total) P 0 0
T 139 140
Hardness: Total 171 189
Calcium 128 147
Halogens: Chloride 65 120
Sulfate 13 37
Phosphates 0.07 0.1
Nitrogen 0.17 0.17
Heavy Metals: Iron 0.24 0.23
Oxygen (Dissolved) 2.8
ODD 55 50
* mqJl unless othetwise specified.
V-67
DRAFT
-------
CONDENSATE
WATER
( \1 /
SO 2 Nci 2 CO
\I, \L
CL ’AN
WATER
DRAFT
SMALL RECYCLE
NaOH
CuCI2 )
NaHS
CITY ______
WATER
REACTOR
- j /
TREATMENT
Fl RA ION
CRYSTALLIZATION
L 1
OXIDATION
COOLER
‘
\1/
HOLDING
‘
‘V
—-——-)
r-
----I
CENTRIFUGE
FILTRATION
RIVER WATER
CITY ______
WATER
SODIUM SULFITE
AT
DRYING
‘4,
SOLIDS
PRODUCT
Na 2 SO 3
FIGURE 47
PROCESS FLOW DIAGRAM
PLANT 168
V- 68
DRAFT
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DRAFT
Stated Concentration (mg/i ) GTC
Parameter Average Range Measurements (mg/i )
pH 6.80 5.68-7.12 7.00
Suspended Solids 28 10-45 10
BOD 14.8 1.4-38.5 -
Iron 2.6 1.5-4.9 0.9
Copper 0.02 0.01-0.02
Chromium 0.01 0.01-0.02
Zinc 0.49 0.08-i .84
Nickel 0.01 0.01-0.02
Lead 0.02 0.01-0.07 <0.1
Dissolved Solids 168
The in-plant use of the water intake is as follows:
Use Flow cu rn/day (MGD) Percent Recycle
Indirect cooling Approx. 10,900 (2.88) 0
Process (conden- Approx. 7.6 (0.002-) 0
sate) -
D ’er, Ejector, 13.25 to 28.4 (0.0035 to 0.0075) - 0
Filter Wash
The principal waste streams operating on a continuous basis consist of flows- -
-f, om the dryer ejector and filter washing operations. These waters are treated
by aeration and filtration prior to discharge. Vessel washouts are also sub-
jected to the aeration and filtration procedure. The performance experience of
oxidation and filtration treatment processes at this plant is:
Qualitative Waste Reduction
Method Rating - Accomplished
-Oxidation Excellent 94% oxidation of sulfite..
to sulfate
Filtration Excellent 98% suspended solids
removal
3.2.5.3 Effluents f Exemplary Plants
Compositions of the process effluents streams after treatments are given below.
The waste strea ater aeration treatment and the same stream after it has been
subjected to a final filtration prior to discharge are shown. The cooling stream,
V-69
DRAFT
-------
DRAFT
which consists of untreated river water, has the same composition as measured at
the intake. The GTC measurements for verification of the process effluents and
cooling water are given in Tables 15 and 16, respectively.
After Aeration After Final Filtration
Constituents Ave. Range Ave. Range
Total Suspended Solids 0.22% 0.07-0.41% 97 ppm 3-240 ppm
Total Dissolved Solids 5.7% 4.64-6.95% 5.7% 4.64-6.9%
BOD 5 56.8 ppm 46-71 ppm 56.8 ppm 46-71 ppm
COD 118 ppn 64-161 ppm 118 ppm 64-161 ppm
pH 9.8 9.7-9.9 9.8 9.7-9.9
Temperature 65°C 43°C 38-49°C
3.3 Category 3 Raw Waste Loads arid Exemplary Plant Data
3.3.1 Mercury Cell Process Chior-Alkali (Chlorine, Sodium Hydroxide, and
Potassium Hydroxide )
Cc qstic and chlorine are produced from salt or potassium chloride raw materials
in the mercury cell process, depending on whether caustic soda or caustic potash
is to be produced. The raw material is dissolved and purified by addition of
barium carbonate, soda a:i, and lime to remove magnesium and calcium salts and
sulfates prior to electrolysis. The insolubles formed on addition of the treat-
ment chemicals are filtered from the brine. The brine is then fed to the mer-
cury cell, wherein chlorine is liberated at one electrode and a sodium-mercury
amalgam is formed at the other.
The chlorine formed is cooled, dried in a sulfuric acid stream, purified to
remove chlorinated organics, compressed and sold. The mercury-sodium amalgam
also formed during electrolysis is sent to a “denuder” where it is treated with
water to decompose the-analgam-. Sodium hydroxide and hydrogen. are formed in.
the reaction. The mercury liberated is returned to the electrolysis cells.
The hydrogen is cooled, scrubbed to remove traces of mercury, compressed and
sold.
The sodium hydroxide formed at the denuders is filtered, concentrated, and sold.
Waste brines err.er;i g from the electrolysis cells are concentrated and recycled.
3.3.1.1 Exemplary Plants
Two exemplary faci1 ties, plants 130 and 144, and one qualified exemplary
facility, plant 03, have Deen selected and studied in detai. Plant 130
produces potassium hydroxide and plants 144 and 098 produce sodium hydroxide.
V- 70
DRAFT
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DRAFT
TAB L E 15. asurenents of Plant 168 Pro ss Waste
Streams Before and After Treatrtent*
Par reter Before After
(Batch Process) (Batch Proc ss)
Tenperatire, °C 76.7 76.7
ODlor (Apparent) .PJPHA Std. > 500 > 500
Turbidity, vru > 500 380
T -/a/ t)sgo1Vc d / 1 ’d 88;) o - q3;qOo
I Suspended Solids 180 2,oio
pH 11.0 11.2
Acidity: Total
Free
A]kalinity (Total) p 9 ,OCO 2,500
T 24,000 4,800
Hardness: Total
Calcium
Haiigens: 1oride 30,000 65
Sulfate 230,000 160,000
Phosphates
Nitrogen (Total)
Heavy Netals: Iron
thromate
Hydrogen Sulfide 0 0
Sulfite 60,000 170
COD 8,000 250
*
mg/i, unless otherwise specified.
**
This sample was collected from the full oxidation tank just before
the waste treatment process was begun. This was necessary because
the waste lines to the tank are not accessible for sample and the
only outlet valve is on the tank itself.
V-7 1
DRAFT
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DRAFT
TABLE 16. Plant 168 Cooling Water Neasur nts
Paraiteter Intake Effluent
T nperature 17°C 21
Color (Apparent) 95 APHA Std. 65
Turbidity 25 FlU 15
Conductivity 130 (mg/i NaC1) 120
Suspend 1 Solids 10 (mg/i) 8
pH 7.CO 7.08
.1 cidity: . Total 0. 0
Free 0 0
Alkalinity (Tota],) P 0 0
T 40mg/i 40
Hardness: Total 73 mg/i 76
Calcium 50 mg/i 51
Halcgens: ChlorIde 24 mg/i 24
Sulfate 53 mg/i 55
Phosphates 0.72 - 0.66
Nitrate 0.33 0.32
Heavy Metals: Iron 0.86 mg/i 0.78
Hydrogen Sulfide 0 mg/i 0
Sodium Sulfite 3 mg/i 4
V-72
DRAFT
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DRAFT
• Plant 09.8 iscOnsideredas an!exemplary’plant with the qu ification that it
is located outside &f-the United”States; it is included because itsmercury
• recovery system is of special-note: The process flow diagram-for plant 130 is
shown in Figure 48.
3.3.1.2 Raw Waste Loads
Raw waste loads for this process are presented in Table 17, which gives overall
- figures based on twenty-one facilities, plus partial data as furnished from
- plants -O98.and 130 The chief-raw wastes include purification.muds (CaCO 3 ,
Mg(QH) 2 and BaSO 4 ) from brine purification, some spent brine materials from
caustic recovery, and condensates from chlorine and hydrogen compressions. The
sulfuric acid used to dry the chlorine is not a waste in plant 130 as it is
recovered for sale.
In the caustic potash plant, plant 130, the brine muds and potassium chloride
make up the bulk of the primary waste. A small amount of copper sulfate cata-
lyst is also wasted. This catalyst is used in trea1 iient of waste chlorine.
Specifically, the chlorine is reacted with excess sodium hydroxide in the pres-
ence of copper sulfate to produce sodium chloride, water and oxygen. The sodium
chloride so produced is sent to the waste treal iient facilities.
3.3.1.3 Treatment
At ptant 144, the wastes êrñerging from chlor-a}kali manufacture are senT to a-
series of two settling ponds,-with the exception of those from-the cell building;
which are sent to a mercury treatment unit first. The wastes front-chlorine
drying, brine preparation, salt saturation and caustic loading are sent directly
to the two settling ponds described above, where suspended solids are removed
-and the pH adjusted prior to discharge. Two emergency ponds are in parallel -with-
these two ponds and wastes can be diverted to them for special treatment if
needed. - -
Mercury-containing wastes from the cell building are first treated prior to —
being sent to the central waste treatment system. The effectiveness of treat-
“ihentbased on six months of data (129-days-of measurements)—is, in-summary:-
Mercury Concentration Mercury Concentration Average Removal
to Secondary Treatment (rig/i) after Treatment (mg/i) Efficiency (1 )
Average 44.3 0.43 99.0
Maximum Values 1920.0 15.0
Minimum Values 0.48 0.01
Approximately 99 percent removal of mercury is achieved with the mercury losses
V-73
DRAFT
-------
KOH INLET BOX END BOX
pH VENT ID VENT TO
KCI WATER
ADJUST ATMOSPIICRt. NaOH SCRUBBER
______________ ______________ 1, 120pO0
2KCI+2Hg > 2KHg + Cl 2
________________ ________________ ________________ ________________ I__AMPS
PURIFIER AND PURIFIED I PRiMARY CE 1 CI 2 TO UQUIFACTION
I I SATURATED I 1 _____
I FROM CELLS AT I
DEPt.ETED BRINE _____ SATURATOR BRINE FEED Hg >J 2I(.Hg+2H 2 O >21(0K +2Hg+ 14 2
__________ DEPLETED BRINE TO SATURATION AND PURIFIC I1ON
pH 2-2.5 _________
1 K Hg
_____________________________ 1’
} DEMINERALIZED TER
BRINE FILTER
hILI,Il,, I IIl,Itt ij
SLUDGE TO
ABATEMENT ____________
DECOMPOSER
1(0K 50-55°/4# H 2
____ ‘I ,
INDIRECT COOLING- J
COOLING COMPRESSION H 2 TO USERS:
(I FUEL IN BOILERHOUSE -n
(2.) OTHER PLANT USES .—
__ ‘I,
CONDENSATE ’
FILTER RECYCLE J
*2 * 1
SLUDGE SALES OVERFLOW
TO 1(0 1 1 TO
ABATEMENT ABATEMENT
SYSTEM SYSTEM
FIGURE 48
MERCURY CELL FLOW DIAGRAM (KOH) AT PLANT 130
-------
‘ThBIE 17. Raw Waste Loads from I rcuxy Cell Process
(All Aitounts in kg/kkg of thlorine)
O nstituent
Based on 21 Facilities
Mean Range
Plant 098
Plant
Mean
130
Range
PurifIcat.ton nuds
CaOD 3 & M (OH) 2
NaOH
NaC1
KC1
H2S04
Chlorinated Hydro-
carbons* *
Na 2 SO 4
C12 (as Ca(OC1) 2 )
Filter aids
Mera y
Carbon, graphite
OiSO 4
1.83
0.0018
O 0.004
*can be converted to 1I ’1xn of product by multiplication by 2.0.
**depends markedly on grade of chlorine produced.
V—75
DRAFT
16.5
0.5 — 35
7.25
7.5
6.8
—
13.5
0.5 — 32
211
15—500
40
35—45
0
50
45—54
16
0—50
11.3
0
—
0.7
0—1.5
—
—
—
0
15.5
0—63
11
0—75
0.85
0—5
0.15
0.02 — 0.28
20.3
0.35 — 340
0
DRAFT
-------
DRAFT
from the facility being kept to about 0.0045-0.0237 kg/day (0.01—0.05 lb /day)
for the most part. Figure 49 gives a histogram of the mercury discharges on a
daily total quantity basis. The mean value of this discharge parameter is
0.0178 kg per day (0.03882 pound per day) or 0.000070 kg per kkg of chlorine
(0.000140 pound per ton of chlorine.) Ninety-one percent of the measurements
fell below twice these mean values.
At plant 098 several of the streams are completely recycled to minimize brine
wastes. Treatment of mercury-containing streams makes use of sodium sulfide
- to precipitate mercury and mercury sulfides. These materials are filtered from
the streams, recovered as solids and treated with sodium hypochiorite to
recover mercury (as chloride). The leached solids can then be safely discarded
and the mercury chloride-containing solutions can be used for brine makeup and
returned to the cells where the mercury chloride is decomposed to elemental
mercury for reuse. The details of this procedure are given in U. S. Patent
3,691,037, September 12, 1972.
The mercury effluent and chlorine treatment effectiveness at plant 098 are as
follows:
Qualitative Waste Reduction
Method Rating* Accomplished
Mercury Recover Excellent 97% recovery of
mercury
Chlorine Excellent 100% removal of chior-
Neutralization me from waste
System gas stream
Hydrogen Peroxide Good 100% removal of avail-
Treatment of able chlorine
liquid effluent
*As rated by plant personnel.
The amounts of mercury discharged and recovered from the sulfide treatment sys-
tem over a two month period in 1972 from this plant amount to an average of
0.0108 kg (0.0237 pounds) per day or 0.000069 kg/kkg (0.000138 pounds per ton)
of chlorine. Analysis of the data for the two-month period showed that the
average mercury recovery was 258 kg (568 pounds) per day or 7.5 kg/kkg (15.0
pounds per ton) of chlorine.
V-76
DRAFT
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FIGURE 49
FROM PLANT
C l)
CD
z
4
w
Li..
0
I—
z
w
C-,
a:
w
a-
0.01
1
-1
MERCURY DiSCHARGE (KG PER DAY)
0.04
0.05
HISTOGRAM OF
MERCURY DISCHARGES
144
-------
DRAFT
At the plant 130 mercury cell facility, brine filter sludges, potassium hydrox-
ide recovery wastes and other waste streams are fed into a common treatment
system, wherein the wastes are treated with sodium hydrosulfide arid flocculants.
The insoluble mercury products from treatment are removed by settling and fil-
tration and the wastes are then discharged. The mercury content of the wastes
is recovered by distillation from the recovered sludges. The mercury treatment
system is shown in Figure 50.
Table 18 summarizes the mercury effluents from the plant 130 as a result of
treatment over a one-year period. The mean mercury effluent level of 0.0073 kg
(0.016 pound) per day corresponds to a value of 0.000057 kg/kkg of chlorine
(0.000114 pound per ton of chlorine), remarkably similar to the 0.000069 kg/kkg
(0.000138 lb/ton) calculated for the 098 plant and the 0.000070 kg/kkg (0.0001 .10
lb/ton) for the 144 mercury cell plant.
3.3.1.4 Effluent of Exemplary Plants
The general characteristics of the 098 plant discharge are listed below. The
seawater cooling water stream is mixed with the process water effluent prior to
discharge, hence the high TDS:
Average Range
Total Suspended Solids, ppm 5 5—10
Total Dissolved Solids, ppm 20,000-25,000 (sea
water)
pH 7.1 6.7-8.5
Tempera tu re, °C £° F’) 1 2 Cr4) 10-19 ( —&6)
Hydrogen Peroxide, ppm 0 0-1.0
Sodium Sulfide, ppm 0 0-0.5
Free Chlorine, ppm Max. 0.08
Mercury, ppb Max. 8.0
Tables 19 and 20 give the plant 130 effluent stream data and GIC verification
date. Tables 21 and 22 give the plant 144 intake and effluent streams data
and GTC verification data.
3.3.2 Diaphragm Cell Chior—Alkali Process (Chlorine/Sodium Hydroxide )
The plant 057 facility to be described in this section is part of an integrated
complex making l.aSC of a considerable amount of recycling and reuse technology.
The discussion below demonstrates that this facility comes fairly close to the
“zero discharge” goal.
V-78
DRAFT
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AREA 3 OUTFALL
ACID SULFIDE
I. ADJUST TO pH 7
2.ADD SULFIDE I
3. ADD FLOCCULANT
4. SETTLE
‘5. DECANT
HgS RECOVERY
FIGURE 50
ABATEMENT SYSTEM AT
DRUMS
C
-n
—I
MERCURY
PLANT 130
-------
DRAFT
TAHL.E 18. Monthly Mercury Abatement System Discharge
During 1972 at Plant 130
Avg. Avg.
Volune Total Hg Daily Hg . Avg.
Discharge Discharge Discharge ppb
Month aim(gal)/day ( Ib) kg( lb)/day Hg
Jan 144 (37,916) 0.369 (0.813) 0.012 (0.026) 82
Feb 118 (31,030) 0.327 (0.719) 0.011 (0.024) 92
Mar 92 (24,195) 0.198 (0.435) 0.0064 (0.014) 69
. pr 112 (29,616) 0.184 (0.404) 0.0059 (0.013) 53
May 115 (30,339) 0.318 (0.700) 0.010 (0.023) 91
Jun 134 (35,277) 0.214 (0.471) 0.0068 (0.015) 51
Jul 124 (32,709) 0.225 (0.494) 0.0073 (0.016) 59
137 (36,169) 0.302 (0.665) 0.0096 (0.021) 72
Sep 131 (34,435) 0.127 (0.280) 0.0041 (0.009) 31
Oct 129 (34,024) 0.133 (0.293) 0.0041 (0.009) 33
Nov 126 (33,339) 0.176 (0.377) 0.0055 (0.012) 43
Dec 118 (31,135) 0.114 (0.251) 0.0036 (0.008) 31
Avg. 123 (32,516) 0.224 (0.492) 0.0073 (0.016) 59
StatIstIcal Sumar: Mercury Abateuent System Jan-Aug 1972 - Total of
244 Days
Daily Mercury Daily Volume
Discharge, Discharge,
kg (lb)/day cu m (gal)/day
Mean 0.0386 (0.019) 122 (32,164)
Range, Max. 0.0545 (0.120) 292 (63,945)
Standard Deviation 0.0377 (0.017) 40 (10,492)
90% of Values 0.0182 (0.040) 173 (45,594)
V -80
DRAFT
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DRAFT
TABLE 19. Plant 130 Effluent Data*
Cont ninant Outfall Outfall Outfall
**
or Paran ter #1 #2 #3 Intake
Flow,a.i rn/day (MG)) 9,460 (2.5) 13,3(0 (3.5) 42,4W (11.2)
Total Suspended
Solids, ppm 5 —
8 — II 8 — 9 8 — 9
Color (APHA units) < 5
conductivity, i xthos — 287
Hardness, (Total) 4(0 134
(CaW 3 ) ppm
chloride, ppm 1252 , 22
Free chlorine, ppm 0 0
F luoric3e,ppm <1 <1
Phosphates (as P) ,ppm - 0.1
Nitrate (as N), ppm 1.92 1.92
Iron, ppm 1.2 1.0
Copper, ppm <0.01
cb omiuin, ppm <0.01 <0.01
Manganese, ppm <0.01
Vanadium, ppm
Arsenic, ppm 0.28
Mercury, ppb 1.2 1
Lead, ppm 0.1 0.1
Sulfate, ppm 39 18
Turbidity, ppm 16
* Data si. plied by Plant 130
** Main outfall, outfalls 1 & 2 feed into 3
This waste stze n contains potassium carbonate manufacturing effluent also;
V-81
DRAFT
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DRAFT
TABlE 20. GTC Measurements of the Effluents Fran
Plant 130
Hg Cell
River Chlorine Major
Parameter ( Intak.e) Liquefaction* Abatenent* Outfall*
Fl , cn nVday (MG)) Not Measured 8,540 (2.25) 16,700 (4.28) 42,000 (11.1)
Tenp., °C 2.0 11.95 10.1 8.5
Color, Apparent, 60 60 180 150
APHA Un.tts
¶Thxthidity, FlU 23 19 55 50
Conductivity, 230 240 320 370
p
Suspended Solids, 70 210 75 210
ppm
pH 7.8 11.9 9.4 :10.5
AlkaLinity (Total)
P (CaCD 3 ) ppm 0 40 30 25
T (CaO ) 3 ) ppm 97 19) 135 200
Hardness, (Total)
(CaO) 3 ) pp n 145 60 140 65
Calcium (CaC) 3 ) 115 25 110 35
ppm
Chlorine, ppm 0 <0.2 <0.3 0
Chloride, p xn 35 47.5 60 48.5
Fluoride, ppm 0 0 0 0
Sulfate, ppm 45 44 41 40
Phosphates (Total) 0.38 0.4 0.42 0.37
ppm
Nitrogen (Total) 1.55 0.45 0.13 0.38
ppm
Iron, ppm 0.19 0.5 0.7 0.4
Dissolved oxygen, ** 8.3 7.6 8.5
Mercury, p b < 5 < 5 < 5 < 5
* Corresponds to outf 11s #1, 2 and 3. respectively on Table 19.
Unable to detern ine at tenperature bela’i 5°C.
V-82
DRAFT
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DRAFT
TABlE 21. Plant 144 Intake Water*
crc
Parait ter Plant Data Measurenent
T r erature 8 - 24°C 19°C
Color (Apparent) 175 Units (APHA)
Tuthidity 50 FlU
ConductIvity 75 microithos/citi 26 NaC1; 55 rniczcrrthos/cin
Suspended SoTh5 10 10
Dissolved SoTh 65
6.6 6.7
2 cidity: Total 0 CaOD 3
Free 0
A])clinity (Total) P - 0
T 18 16
Hardness: Total 15
Calcium <
Halogens: Chlorine 0.18
thioride 15
Fluoride 0.1
Sulfate 8 -
Phosphates (‘Ibtal) 0.34
Heavy Netils: Iran 0.48
thra ate (Cr+ 6 ) < 0.02
Oxygen (Dissolved) 12
QJD 15 10
*
rrg/i i.rnless otheiwise specified.
V-83
DRAFT
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DRAFT
TABLE 22. Plant 144 Effluent Data*
Plant GTC
Parameter Data MeasurenErits
Flcw, cu rn/day (MCD) 5,3(X) (1.9) 8,360 (3.0)
T perature 32 - 38°C 33°C
Color (Apparent) 30 Units (APHA)
¶flirbidity 10 FTU
Conductivity 1525 micrornhos/an 1050 NaC1; 2000 microxthos/art
Suspended Solids 0 0
Dissolved So14i s 1455 1 1 17
7.0 7.5
Acidity: Total 0 Ca0D 3
Free 0 “
A]kalinity (Total) P 0
T 60 14
Hardness: Total - 20 “
Calcium < 10
Halogens: i1orine 0
1oride 1020
Fluoride 0.5
Sulfate 107
Phosphates (Total) 0.18
Heavy Met- •I : Iron 0.42
Chrcxnate (Cr+ 6 ) < 0.02
Oxygen (Dissolved) 10
(XDD 8 5
Mercury 3 ppb <5 ppb
*mg/1 unless ot exwise specified
V- 84
DRAFT
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DRAFT
Sodium chloride brines are first purified by addition of
sodium carbonate, lime, flocculating agents and barium
carbonate in the amounts required to precipitate all the
magnesium, calcium and sulfate contents of the brine. The
brine is then filtered to remove the precipitated materials
and electrolyzed in a diaphragm cell. Chlorine, formed at
one electrode, is collected, cooled, dried with sulfuric
acid, then purified, compressed, liquefied and shipped. At
the other electrode, sodium hydroxide is formed and hydro-
gen is liberated. The hydrogen is cooled, purifed, compress-
ed and sold; and the sodium hydroxide formed, along with Un-
reacted brine, is evaporated to 50% concentration. During
the partial evaporation, most of the unreacted sodium chlor-
ide precipitates from the solution, which is then filtered.
The collected sodium chloride is recycled to the process,
and the sodium hydroxide solutions are further evaporated
to yield solid products.
Figure 51 shows the flow diagram of a 1810 kkg (2000 ton) per
day chlorine—caustic soda plant at plant 057. A new 2080 kkg
(2300 ton) per day chlorine-caustic soda plant also exists in
this facility. The sodium hydroxide product from these two
plants is concentrated in another portion of plant 057. This
function is illustrated in Figure 52. All three of these
facilities (all parts of plant 057) will be discussed below.
3.3.2.1 Raw Waste Loads
There are no brine wastes from plant 057 and several of the
other waste streams are diverted for other uses in the complex.
This stream diversion and maximal raw material utilization
has served to minimize the wastes to be treated. The raw
wastes from the older plant are:
Waste Product Process Source kg/kkg of Chlorine
1. NaOC1 - Gas Scrubber 1.13
- - (Startup and startdown)
2. NaHCO3 Gas Scrubber 2.49
(Wastes are ponded for
recycle
3. c:rilorinated Liquefaction 0.35
Organics
4. B:i e Sludge Brine Treatment 10.5
5. Spent Suif ric Acid Chlorine Drying 1.0
6. Chron ates Cooling Tower 0.000363
7. Suspended Sc2 ids Cooling Tower 0.0333
V-85
DRAFT
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DRAFT
NOTE:
o WASTE
STREAMS
RIVER WATER
BRINE WELLS
NaCI
NaOH
U)
2
2
SOLIDS
(LANDFILL)
NaOH STORAGE
AND DISTRIBUTION
H 2 DISTRIBUTION
AMMONIA PLANT
RIVER WATER AND SEA WATER
CHLORINATED WATER
H 2 S 0 4
RIVER WATER
SEA
FIGURE 51
DIAPHRAGM CELL CHLOR—ALKALI
AT PLANT 057
V -86
DRAFT
DISTRIBUTION
WATER
HYDROCARBONS
PROCESS
-------
NaOH 8 NaCI.., _______ _______
______ COOLIN ______
EVAPORATORS 1 FILTERS C 1 1 1 PURIFIERS
FILTERS
FROM CELLS
EQUIPMENT J _____ _____ ___________
1
- 1
WASTE OTHER SLURRY SALT PRODUCT
ENTRAINMENT PLANT TO BRINE TO
USE TREATING RECOVERY
SYSTEM
FIGURE 52
SODIUM HYDROXIDE CONCENTRATION FACILITY AT PLANT 057
-------
DRAFT
The raw wastes from the new plant are:
Average
Waste Product Process Source kg/kkg of Chlorine
1. Weak Caustic Cells 6.25
2. Spent Sulfuric Chlorine Drying 4.05
Acid
3. NaOC1 Tail Gas Scrubber 7.50
4. Carbonate Sludge Brine Treating 12.25
(CaCO3)
5. Chlorinated Chlorine Purification 0.70
Hydrocarbons
The raw wastes from the caustic plant are:
Average
Waste Products Process Source kg/kkg of Product
1. NaOH Entrainment 4.4
2. NaCl Entrainment 5.1
3. NaOH Filter Wash 17.6
4. NaC1 Filter Wash 20.3
3.3.2.2 Treatment
Many of the chior-alkali waste streams, including brine wastes,
are either recycled or put to use elsewhere in the complex.
This section discusses treatment of those streams which are
discharged.
The older chior—alkali plant takes in 2,720 cu rn/day (0.72 MGD)
of river water for cooling makeup and process water, as well
as 54 Cu rn/day (0.0144 MGD) of well water for potable use.
About 98.5% of the total cooling water flow of 109,000 cu rn/day
(28.8 MGD) is recycled, and 90% of the process water flow of
6040 Cu zn/day (1.6 MGD) is recycled. Of the potable water in-
take, 10% is recycled.
V-88
DRAFT
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DRAFT
The waste treatment within this older plant is:
Flow, 1/day Treatment Final
Stream No./Source ( GPD) Method Disposal
1/Gas Scrubber 409,000 Sunlight decompo— To plant
(108,000) sition of NaOC1 waste water
system
2/Spent Sulfuric 2,890 Other plant use Used
Acid (765)
3/Chlorine lique- 492 Incineration
faction (130)
4/Brine Treating 327,000 Solids to land- Brine recycled
(86,400) fill
5/Cooling Tower 75,700 None To plant
Blowdown (20,000) waste water
system
Waste chlorine in the tail gas is reduced by 80% in an absorp-
tion process, and the remaining chlorine is removed by scrubbing.
These two processes are used in series to attain complete remov-
al of chlorine from the tail gas. Ponding is stated to be 100%
effective in removal of solids, due to recycle of brine.
Future treatment plans which will further reduce the wastes to
the. point where the facility will approach the zero discharge -
goal are: -
Estimated
Installation Estimated
Method Time Performance
1. Chlorinated hydrocarbon 2 years 100%
- waste burner - -
2. Catalytic conversion 1 year 100%
of g. ubber effluent
- to remove sodium
hypochiorite -
3. Neutralization of 1 year -100%
scrubber effluent
to remove sodium
carbonate -
V-89
DRAFT
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DRAFT
At the newer chior—alkali facility in plant 057, river water
intake is 10,450 cu rn/day (2.76 MGD) and seawater ,iptake is
51,200’cu rn/day (15.14 MGD). The cooling water flow is 61,000
cu rn/day (16.13 MGD), which is all non-Contact except for the
water chlorination step. Process water flow is 6,530 cu rn/day
(1.726 MGD), which is mainly as brine. Other process water
uses are compression cooling, hydrogen cooling, chlorine cool-
ing and absorption. There is less recycling of water here
than in the older plant. The effluent stream which is not re-
cycled arises from the tail gas scrubber, which has a flow of
133,000 liters per day (35,000 GPD) or 141 liters/kkg (37.2
gal/ton) based on chlorine product. This is disposed of com-
pletely in the plant waste system. It contains sodium hypo—
chlorite. The disposal of this material will be eliminated
by mid-suinnier 1973, and the tail gas will be used to xnanufac-
ture hydrochloric acid product, thus eliminating a waste stream.
When this happens, the older process should be close to a non-
discharge system.
The water intake to the caustic plant is:
cu rn/day (MGD )
river water 1,890 (0.50)
seawater 90,900 (24.0)
well water 57 (0.015)
The river water is treated; the well water is not. The in-
plant water flows are: -
cum/day (MGD) % Recycled
Forced Draft cooling 6,540 (1.73) 95
Process 1,300 (0.344) 0
Washdowns 265 (0.070) 0
Entrainment Seawater 90 O0 (24.0) 0
The only effluent to be treat: is 4.4 kg/kkg of sodium hy-
droxide and 5.1 kg/kkg of- sodi chloride in a 90,900 cu rn/c
seawater waste stream (the entrainment system). This stream
is presently discharged without treatment. Future plans call
for it to be neutralized prior to discharge. Chlorine values
in this strear are considered to be too low to be worthwhile
for other plant usage.
v-go
DRAFT
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DRAFT
These three facilities are being improved to further reduce
discharges. When all of the improvements cited in this sec-
tion’häve been completed, this whole chior-alkali facility
should approach the zero discharge goal.
3.3.2.3 Effluents
The effluents from the newer chior-alkali facility, the older
facility and the sodium hydroxide plant are shown below. The
relative amounts of waste produced are quite small and will be
reduced in the future.
Older Plant :
Constituents Average Concentration, ppm
Present Stream No. 1 2 3 4 5
Total Dissolved 18,330 — 1200 820
Solids (mostly
chlorides)
Total Suspended 14 — 22,500 256
Solids
SOD 0 0 0 0 0
COD 0 0 0 0 0
pH 7.8 1 — 11.0 7.0
Temperature 38°C Ambient 31°C Ambient 32°C
Chrornate 10
Newer Plant :
Dissolved Solids 103,090 (chlorides, hypochiorites)
Alkali Plant :
NaOH 25
MaCi 28.9 (added to seawater)
3.3.3 Hydrogen Peroxide (Electrolytic )
Hydrogen peroxide is manufactured by three different processes:
(1) An electrolytic process; (2) An organic process involving
the oxidation and reduction of anthraquinone; and (3) As a by-
product of acetone r anufacture from isopropyl alcohol. In this
V-91
DRAFT
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DRAFT
study, only the first two processes are considered. The or-
ganic process was discussed under Category 2. -
In the electrolytic process, a solution of arninonium bisulfate
is electrolyzed, hydrogen is liberated at the cathodes of the
cells used, and aTnmoniurn persulfate is formed at the anode.
The persulfate is then hydrolyzed to yield ainmonium bisulfate
and hydrogen peroxide which is separated by fractionation from
the solution. The ammonium bisulfate solution is then recy-
cled, and the peroxide is recovered for sale. The only waste
is a stream of condensate from the fractionation condenser.
Figure 53 shows the process waste treatment system at the ex-
emplary plant, plant 100.
3.3.3.1 Raw Waste Loads
Table 23 lists the raw wastes from peroxide manufacture at
plant 100. These consist of aimnonium bisulfate losses, ion
exchange losses, boiler blowdowns and some cyanide wastes
from the special batteries used in electrolysis.
3.3.3.2 Plant Water Use
Plant water intake and use are as follows:
Flow, cu in/day Amount, 1/kkg -
Water ( MGD) ( gal/ton) Use
Municipal 7.2 (0.0019) 601 (114) Drinking,
Washing,
Sanitary
Well 41,600 (11.0) 3,480,000 76 cu rn/day
(884,000) demineralized
- for process
water, rest
used as cooling
Of the 76 cu rn/day of process water, 31% is used in the pro-
duct. Recycle flow of process water is 132 cu rn/day and re-
cycle flow of stean is 305 cu in/day (liquid basis). About
25.5 cu rn/day is boiler blowdown. None of the cooling water
is recycled.
V-92
DRAFT
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WATER SUPPLY
3 DEEP WELLS
YELLOW
w
SOLUTION w
____ _____________ DEIONIZER
SLUDGE SLUDGE COOLING WATER
U i
_____________ C-)
SETTLING SETTLING FOR HEAT WATER
I.- (
TANK TANK EXCHANGERS DEIONIZERS Ui
CONDENSERS ____________ Z
Ui
i C.)
____________ ____________ ______ ______ ____________ L . C1
I I EFFLUENT’? BOILERS
0
L&JF.
(A)
REGENERATION
2 ui
1,000 GAL/DAY
I (INTERMITTENT DISCHARGE) ______________
1,000 GAL/WEEK
(INTERMITTENT DISCHARGE ONCE A WEEK) 7,000 G 1 AL./DAY U i OW
CONTINOUS BOILER iii
_____________________________ ___________________ BLOW j,DOWN
4,
TOTAL STREAM
II MILLION GPD
FIGURE 53
SCHEMATIC SHOWING WASTE SOURCES AND DISCHARGE AT PLANT 100
-------
DRAFT
TABLE 23 Raw Waste Loads at Plant 100
Waste PrOceSS kg of Peroxide
Product Source C eration Startup Shutda,m
1. Blue prus- Purif. 0.18 No significant difference
slate sludge during startup & shut-
d n periods. Plant runs
2. Gray sludge Battery (5 thnes oDntirnxusly; shuts duwn
rebuild per .year) once per year
3. Ion Exchange Deionizer
sludge regen.
4. H S0 4 Plant solu- 0.0018
tion loss
4 2 4 Plant solu- 0.012
t .ton loss
6. Water flaw Cooling 2000-2900
7. HC1 Deioriizer 1.3
regen.
8. NaOH Deionizer 0.33
zegen.
9. Steam Boiler 581
oondensate b1 a wd n
EL’fl’S: H 2 S0 4 and ( NH 4 ) are used to replenish plant solution.
Na 4 Fe (CN) is oonverted to (NH 4 ) 4 Fe ) 6 through ion
exchange (yeflaw solution).
NH 4 SO is oxidized in the batteries and is used for
better current efficiency.
HC1 and N H are used for regeneration of demirieralized
water ion exchange resins.
V-94
DRAFT
-------
DRAFT
3.3.3.3 Waste Treatment
Table 24 lists the various plant effluent streams, their
sources, values and treatments. Treatments consist of ion
exchange for pH control and recovery of some process mater-
ials, and recovery of platinum in the waste streams. After
this, wastes are discharged.
Performance information on the pH control and ion exchange
technology used for waste abatement in this plant is:
Qualitative Waste Reduction
Method Rating Accomplished
1. pH Control Good 99+%
2. Process change Excellent CN- load reduced 98% -
Additional concentration to
discharge stream less than
0.01 ppm
3. Monitoring Good Reduces unknown discharges
and allows quick operation
response.
3.3.3.4 Plant Effluent
Table 25 lists the compositions of the various effluent streams
after treatment. These streams are then mixed prior to dis-
charge. Table 26 shows a GTC analysis of the intake water
and final effluent after mixing. Only very small amounts of
materials are introduced into the waters used, and cyanides
in the effluent are negligible.
3.3.4 Chromate Manufacture (Sodium Dichromate and Sodium
Sulfate )
Sodium dichrornate is prepared by calcining a mixture of chrome
ore (Fe.Cr203), soda ash and lime, followed by water leaching
and acidification of the soluble chromates. The insoluble
residue from the leaching operation is recycled to leach out
additional material.
V-95
DRAFT
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DRAFT
BLE 24 Effluent Treatn nt Data for Plant 100
A. Water Streams
Stream No. Source 1/day (GPD) 1/kkg (gal/tczi )
1. low Exchange Demineralized 3,790 (1,000) 317 (76)
Regenerant
2. Blue Prussiate Filters 568 (150) 47.6 (11.4)
Supernatant (avg. 3Jwk)
(filter back-
wash)
3. Yellow Solution Ion Exchange 568 (150) 47.6 (11.4)
(avg. l, k)
4. Boiler Blowdown Boilers 26,500 (7,000) 2,210 (530)
B. Trea1 nts
Final
Stream No. Disposal
( same as above) Treatment Method System
1 Anion and cation regener- Plant effluent
ants are mixed to control
pH and slowly released
2 Settled for p1atin rri recxv- Plant effluent
ery, s fphoied and
filtered*
3 Backwash recycled to process Plant effluent
and regenerant is dis—
charged
4 Dilution Plant effluent
* Sludges recovered here are sent to refiners for recovery of platinum
values.
V-96
DRAFT
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DRAFT
TP 1 BIE 25 Car osition of Plant 100 Effluent Streaire
after Treatnen . *
O nstituents Stream Stream Stream Stream
__________ No.1 No.2 No.3 No.4
‘lbtal Suspended 1856 as 0
Solids Ca00 3 U1V.
during
regeneration
Total Dissolved 0 nparab1e 200-400 40,000 1000
Solids to raw water
BOD Same as raw
water
Same as raw
water
pH 6.5—8.5 4 7 8
rrperathre 17°C -18°C 18°C
Organics 0
0 nductivity 7160
rtho/an
Alkalinity 400
Free Cyanide < 2 < 2 0
Phosphate 30
Chloride 20-30 (as
NaC 1)
*A1l units ppm unless otherwise specified
V-97
DRAFT
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DRAFT
TABlE 26 Plant 100 Water Intake and Final Effluent
Verification Measurenents*
Well Water Outfall
Conductivity 120 (As NaC1) 120 (As NaC1)
240 (i.utho/aa) —
0 0
T wbidity 0 0
SS 0 0
pH 6.88 7.04
èu1p iate 18 21
Nitrate 3.3 2.3
Ph sphate .35 .36
Iron < .02 < .01
Ch lo.ride
6.5 7.5
Hardness (Ca) 65 70
Total Hardness 95 90
*
irg/l except as r ted
V-98
DRAFT
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DRAFT
During the first acidification step, the chromate solution
pH is adjusted to precipitate calcium salts. Further acid—
if ication converts it-to the dichromate and a subsequent
evaporation step crystallizes sodium sulfate (salt cake) out
of the liquor. The sulfate is then dried and sold. The sol-
utions remaining after sulfate removal are further evapora-
ted to recover sodium dichrornate. Chromic acid is produced
from sodium dichromate by reaction with sulfuric acid. Sodium
bisulfate is a by-product. Figure 54 shows a detailed f low—
sheet for the exemplary facility at plant 184.
Plant 184 manufactures only- the sodium dichromate and chromic
acid. However, some other chromate plants, none of which are
exemplary, do convert part of their chromic acid products to
potassium dichromate. All of this latter material is made in
plants that produce other chromates but the plant 184 facility
is, to our knowledge, the only exemplary chromate facility,
based on effluent quality.
3.3.4.1 Raw Wastes
Table 27 gives the raw waste loads expected from the manufac-
ture of sodium dichrornate. The bulk of the waste originates
--from-the-undigested portions of the ores used. These mater—
ials are mostly so-lid wastes. The wastes arising-from spills
sand washdowns contain most-of the hexavalent chromium. The
wastes from water treatment and boiler blowdowns are princi-
pally dissolved sulfates and chlorides.
3.3.4.2 Plant Water Use
Water Intake:
Type cu rn/day (MGD) Comments
River — -- 1,880 (0.497) Water-to boilers is softened
Well 273 (0.072) Water is filtered, softened
- and chlorinated
V-99
DRAFT
-------
DRAFT
CHROMATE
FIGURE 54
MANUFACTURING FACILITY
AT PLANT 184
v-i 00
SULFURIC
ASH
10 RIVER
DRAFT
-------
DRAFT
TABLE 27 Raw Waste Loads from Chromate Manufacture
A. Manufacture of Na 2 Cr 2 O 7 and Na 2 SO 4 :
kg/kkg of
Waste Product Process Source Na 2 Cr 2 O 7 Product
Average Range
1. Chromate wastes Residues 900
(Materials not
digested in U 2 S0 4 )
*
2. Washdowns 0.75 0.5-1
spills, etc.
3. Blowdown Boilers and 0.5-1
cooling towers
B. Manufacture of Chromic Acid:
No additional wastes
* ]ncludes contributions from the chromic acid unit.
V — 101
DRAFT
-------
DRAFT
Water Use:
Type Cu rn/day (MGD) % Recycled
Cooling 40,900 (10.8) 98.2
Process 922 (0.243) 100
Products and 800 (0.211) 0
Evaporation
Waste Treatment 1,320 (0.348) 0
Sanitary 38 (0.010) 0
3.3.4.3 Waste Treatment
Treatment of wastes consists of treating the waters with
pickle liquor to effect reduction of chromates present and
then lagooning all effluent waters to settle out suspended
solids. This treatment removes 99% of the hexavalent chrom-
ium and the discharge contains <0.01 ppm. When full, the
lagoon discharges to a nearby river.
Chromate waste control in this plant is excellent. All
rainwater, washdowns, spills and minor leaks in the part
of the plant which handles hexavalent chromium are cap-
tured in the area’s sumps and used in the process. Storage
facilities are provided to contain a heavy rain and return
the water either to the process or to treatment. Separate
rainwater drainage is provided for areas not handling hex—
avalent chromium. Sewers are continuously monitored. Even
cooling tower and boiler blowdowns go through the process
waste treatment, as do all waste sludges. A batch system
is used in the treatment process. Each batch is treated and
analyzed before release to the lagoon.
3.3.4.4 Effluent
Data on the effluent from this exemplary chromate treatment
facility are presented below:
V - 102
DRAFT
-------
DRAFT
Discharge from Settling Basin
Average Range
Flow, Cu rn/day (MGD) 1,320 (0.348)
Total Suspended Solids 14 mg/i 1-24 mg/i
Total Dissolved Solids 10,000 mg/i 5,000—13,000 mg/i
(mostly chlorides)
pH 7.2 6.0 — 8.5
Cr+3 0.14 mg/i 0.01 — 0.31 mg/i
(mostly in form of suspended solids)
Cr+6 0.01 mg/i
The chromium content has been reduced to negligible values. -
However, the amount of sodium chloride being discharged is
significant. Based on the porous nature of the present la -
goon walls and the high dissolved solids content discharged
into the river, this plant is considered exemplary from the
standpoint of chromates control and treatment only.
Table 28 gives a more detailed presentation for the river
intake and plant effluent from this faciliby. The cornposi-
tion of river water taken near the p]ant and the plant ef flu-
ent determined on two separate occasions are shown as a
range of values. These data were furnished by the plant.
Tables 29 and 30 present data obtained by the GTC mobile
sampling laboratory for this facility. Table 29 shows an
analysis of river water drawn adjacent to the plant. Table 30
shows the compositions of waste stream before and after
passage .through the pickle liquor treatment unit. During
sampling at this facility, it was not possible to obtain an
effluent sample because treatment ponds were being switched
over and the newer pond w&s not yet filled to overflow level.
Since the first pond required several months to fill, overflow
level in the new pond was not reached in time for analysis
during this study.
3.4 Category 4 Raw Waste Loads and Exemplary Plant Data
3.4.1 Soda Ash
Soda ash is produced by two methods; mining and the Solvay
Process. As there are no water-borne wastes associated with
the mining operations, our detailed treatment of soda ash will
V — 103
DRAFT
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DRAFT
Analysis of Mineral Solids:
Silica (Si0 2 )
Iron Oxide Fe 2 O 3 )
Alumina (A1 2 0 3 )
Lime (CaO)
Magnesia (MgO)
Sulphate (SO 3 )
Chloride (Cl)
Soda (Na 2 0)
Manganese (Mn)
Fluoride.(F)
Biochemical Oxygen Demand (BOD)
5-day (mç /l)
Color (Pt-Co)
River
Water
79
45
34
2.0
0.0
1.6
15
0.88
6.4
2.6
0.4
0.8
5.6
2.0
6.8
8.9
5.7
0.0
0.0
less than 5
130
Plant
Effi uent
330 - 334
93 - 104
230 - 232
0.0
0.0
1.0 - 17.0
209.3 - 238.7
12.2 — 12.8
7.4 - 8.4
5.0 - 6.0
0.1 - 0.3
0.0
114.4 - 115.5
0.8 - 5.0
3.4
1.3 - 1.8
8.2 - 10.4
0.0
0.0
Remarks:
Chromium (Cr) (mg/i)
Tannin (mg/l)
* mg/i unless otherwise specified.
** None found
V — 104
2.6
Intake and Effluent Composition
at Plant 184*
TABLE 28
Total Solids
Organic Solids
Mineral Solids
Alkalinity as CaCO 3 (methyl—orange)
Alkalinity (phenolphthalein)
Free Carbon Dioxide
Total Hardness (as CaCO 3 )
Total Hardness (grains per gallon)
pH
DRAFT
-------
DRAFT
TABLE 29 GTC Analysis of River Water at the
Exemplary Chromote Facility 184
Parait ter SUr efltS ( UI Ufl1CSS other-
wise specified)
Color 270 APHA.. Units
Turbidity 5 F lU
Caiductivity 35 NaC1 eq.
Suspended Solids 5
6.59
Alkalinity (Total) - phen-0/2otal - 20 (as CaCO 3 )
Hardness: (Total) 23 (as CaCO 3 )
(Calcium) 15
Halogens: Chloride 11
Sulfate - C
Phosphates - D .38
Nitrate .0 .13 (as N)
Heavy Metals: Iron 1.5
chrartate 0
V — 105
DRAFT
-------
DRAFT
TABLE 30 GTC Analysis of Waste Treatnient Streams
at Plant 184
Parameter Before Treatment After Treatment
Flow Batch volume - 28,700 liters Batch volume - 30,400 liters
Temperature 49°C 61
Color >500 - (supernatant liquid) 70
Conductivity 5000 NaC1 14,500
! 5 issolvec1 Solids l0 ,700 18,000
Suspended Solids 170,00• Y 154,000
pH >10 (straight); 9.30 (1:100 9.10 (supernatant, fresh);
dilution) (filtered, 30 days
old)
Alkalinity (Total) pheri-0/total-1000 (as CaCO 3 ) 3/total - 23
Hardness: Tcital 600 (as CaCO 3 ) 6000
Calcium 520 (as CaCO 3 ) 6000
Halogens: Chloride 310 8700
Sulfate 3900 1900
Phosphate 0.7 0.7
Nitrate - 9.8 (as N)
Heavy Metals:
Chromate 1300 < 0.01
Iron 0.60
Oxygen (Dissolved) 10.4
V — 106
DRAFT
-------
DRAFT
concern the Solvay Process. Raw sodium chloride brine is
purified to remove calcium and magnesium compounds and is
reacted with ammonia and carbon dioxide produced from lime-
stone calcination to yield crude sodium bicarbonate which
is recovered from the solutions by filtration. The bicar-
bonate is calcined to yield soda ash and the spent brine-
ammonia solution is reacted with slaked lime and distilled
to recover ammonia values for process recycle. The calcium
chloride formed as a by—product during the distillation is
either discharged as a waste or recovered by evaporation.
Figure 55 shows a process flowsheet for the facility at
plant 166. Although all Solvay Process plants have high
dissolved solids effluents, this plant is exemplary in that -
it recovers a significant amount of an otherwise wasted by-
product.
3.4.1.1 Raw Waste
The raw waste loads for the 166 facility consist of brine
purification muds, unreacted sodium chloride and the calcium
chloride by-product, as follows:
Waste Products Process Source kg/kkg of Soda Ash
1. CaCO3 DS, B, P 84.5
2. Na2CO3 B 0.3
3. CaSO3 DS 31
4. NaC1 DS, B 510.5
5. CaC12 DS 1090
6. Na2SO4 B 0.8
7. Fe(OH)3 B 0.1
8. Mg(OH)2 DS, B, P 48.5
9. CaO (inactive) DS, B 109.5
10. NaOH B 0.05
11. Si02 DS, B 58.5
12. CaO (active) DS 24
13. NH3 DS 0.15
14. H2S DS 0.02
15. Ash & Cinders P 40
DS = Distillation, B = Brine, P = Power
V — 107
DRAFT
-------
FIGURE 55
SODA ASH PROCESS FLOW
DIAGRAM
AT PLANT
SOLVAY
-------
DRAFT
3.4.1 .2 Water Use in Plant 166
Water Inputs to Plant:
Type cu rn/day (MGD) Comments
River 9300(2.45) Sent to Power Section for
boiler feed water
Lake 119,000(31 .4) Treated prior to use with
chlorine
Municipal 5150(1 .36) Majority is sent to Power
Section for boil er feedwater
Water Flows:
Type cu rn/day (MGD) % Recycled
Cooling 133,000(35.05) 3—9
Process 11(0.003) 0
Sanitary Est. 190—380 0
(0.05-0.10)
Boiler Feed 13,500(3.65) 0
The maximum daily process water use s about 379 cu m (100,000 gallons), but the
average is only 11 CU m (3,000 gallons).
3.4.1.3 Treatment
Most of the water use is for cooling purposes and little stream recycling is employed.
Treatment methods in use are:
V-109
DRAFT
-------
DRAFT
Stream Source Treatment Disposal
Cooling water Various heat a. Internal recycle Discharge to cool—
effluent exchangers b. Segregation of ing water sewer
throughout waste system
plant c. Collection and
containment of
wastes
Settling pond Distiller wastes Settling out suspended Discharge to
effluent solids with coagula— source of cooling
tion and precipitation water
of metals and other
chemicals
Individual effluents from this plant are combined with other effluents.
Treatment consists of use of settling ponds and some pH control prior to discharge. The
performance of this treatment is detailed below:
Qualitative Waste Reduction
Method Rating Accomplished
Evaporation of Good Reduces CaCI by — 21 %;
distfller waste NaCI by 4%
Settling Ponds Excellent Suspended solids reduced
by 99%+
In addition, two other methods of treatment are used r planned:
(1) part of the wastes may be used for municipal waste treatment.
(2) part of the raw distiller waste stream is diverted to a small plant for
calcium chloride recovery. About 21% of the calcium chloride in
the raw waste s recovered on ths sidestream.
3.4.2.4 Effluent
The plant effluent after treatment contains about 100,000 ppm dissolved solids (mostly
NcCl and COCI2) in the process waste stream and is also fairly high in suspended solids.
This type of effluent is typical of a Solvay process plant. The only exemplary feature
of the 166 facility lies in its partial recovery and reuse of calcium chloride wastes.
V-i .10
DRAFT
-------
DRAFT
3.4.1 .5 Calcium Chloride Recovery
The flow diagram for the calcium chloride recovery process at plant 166 is shown in
Figure 56. The waste stream is first cycled through a number of partial evaporation
and filtration steps to concentraf the waste solutions. After this, further partial
evaporation is used to selectively remove the sodium chloride from solution and then
total evaporatkn s used to recover calcium chloride from the remaining solution.
Table 31 shows the row wastes produced in this recovery operation and some other data.
The principal waste is a contaminated sodium chloride co—product which is discarded,
as well as some calcium chloride from cor densotes and spills. Water use for this ie—
covery process is:
A. Water Inputs to Plant
Type cu ni/day (MCD) Commcnts
River 2210(0.585) Steam generation
Lake 67,000(17.7) Cooling
Municipal 246(0.065) Steam generation
B. Water Usage
Type cu rn/day (MGD) Recycle
Cooling 67,000(17.7) none
Process 2180(0.576)
The present recovery unit only reduces the effluent calcium chloride by about 21%.
This is because of the limited markel for calcium chloride. According to the manufac-
turer, if more of the material could be marketed, more would be recovered. Thus, the
major problem with soda ash wastes lies in findng a use or disposal for the by-product
calcium chloride. An evaporation process for its recovery, as can be seen from this dis-
cussion, iS already operative. This recovery step, as it is now practiced, also reduces
the sodium chloride effluent of the Solvay process by 4 percent.
3.4.2.6 Verification Measurements
Table 32 shows the GTC verification measurements on the water intake, the calcium
chloride cooling water, the final effluent and the soda ash cooling water.
v-ill
DRAFT
-------
DRAFT
WEAK LIQUOR
CLARIFIED LIQUOR STORAGE
NOTE: HP STEAM
o OCCURS DURING CO 2
UPSETS
OPERATIONAL LP STEAM 2nd EF CT
CONDENSATE TO BOILER
MILL MILL WATER SECONDARY 1 TO WASTE
WATER TO SEWER SETTLERS f ‘COLLECTION
______ _______ CONDENSATE
L BAROMETRIC
(USED AS HOT
FILTRATE
I __________
PR! MARY ___________ _____
CENTRIFUGE SALT SETTLER °OVERFLOW
> TO SEWER
-r
— HOT WATER
L_REPUDDLING_TAN k—HP STEAM I DRYER a COOLER I eOVERFLOW
K I— OVERFL0W SCRUBBERS >TO SEWER
TOSEWER
F SECONDARY J.. FILTRATE I SETTLERS eOVERFLOW
I CENTRIFUGE TO SEWER _____
________________ _______________ >TO SEWER
[ DRYER STRONG TANK
DUST rPREHEATERS AND HP STEAM
I ENTRATOR CONDENSATE TO
PRECONC BOILER HOUSE
TO SEWER ATINGJ_J
CONCENT
MILL WATER ______
NATURAL GAS ‘I MILL WATER NATURAL GAS
_______ ___ ______________ 1 ’
\L __ _________ _______
I 78% DRYERS _________
________ 1 94%
AND COOLEflS 1 FLAKERS I DRY -COOLER
FIGURE 56
CALCIUM CHLORIDE RECOVERY PROCESS
AT PLANT 166
-------
DRAFT
TABLE 31. Calcium Chloride Recovery Process
A. Raw Materials for Product
1. Soda ash distiller waste
2. Chlorine
3. Carbon dioxide 4O% CO 2
4. Captive steam and power
B. Rcsw Waste Loads
Waste Products
1. Ash and cinders
2. Water purification
sludge
3. NaCI co-produced
4. CoCl
Process Source
Steam and power
Steam
Evaporation
Condensates and
spills
kg/lckg (lb/ton) of
Product
42.5 (85)
0.75 (1.5)
235 (470)
35—50 (70-100)
C. Comments
Ratio of CoCI 2 to NaCl available in distiller waste is approximately 1.4.
Market demand at this location s at a ratio of 10.6 to 1.
V-113
DRAFT
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DRAFT
TABLE 32.
GTC Verification Measurements at Plant 166
Water Intake
Not Measured
CaC1 2
ing Water
Not Measured
23.2°C
Effluent
17,400
—
Cooling Water
Not
H
Measured
11.2°C
275
110
<20 Units (APHA)
35
15
0
5
<1OFTU
4000
67,000
21,000
2000 mg/i NaC1;
3800 1 imhos/cm
5 mg/i
7500
10
7.95
118,000
170
10.8
4,400
30
7.8
7.80
0
0
0
0 mg/i CaCO3
0 “ “
“ “
0
0
460
0
0
P
0
190
610
240
T
195 mg/i CaCO3
1300 mg/i CaCO3
1400
1350
45,000
45,000
1270
1120
Parameter
Flow, cu rn/day
Temperature
Color (Apparent)
T u rb i di ty
Conductivity
Suspended Solids
pH
Acidity: Total
Free
AlkalinitY (Total)
Hardness: Total
Calcium
Halogens:
Chl on ne
Chloride
Fluoride
Sulfate
Phosphates (Total)
Nitrogen (Total)
Heavy Metals:
Iron
Chromate
Oxygen (Di ssol ved)
COD
<0.1 mg/l
1525 mg/i
0.45 mg/i
170 mg/i
1.1 mg/i
0.55 mg/i
0.07
<0.01
4.7
175
50,000
1350
0.55
1.36
0.6
170
640
190
1.2
0.7
1.6
0.58
1.7
0.48
0.18
0
0.48
0
0.12
0
7.7
4
10
mg/i
mg/i
mg/i
mg/i
V-114
DRAFT
-------
DRAFT
3.5 Category 5 Raw Waste Loads and Plant Data
3.5.1 Titanium Dioxide (Sulfate Process )
For the sulfate process, we have examined information on all the exhting facililles in
the United Stales. None of these plants, based on data examined, can be consdered to
be exemplary. The following descripflon lists the raw wastes and waste segregation
practices normally used by the industry and describes planned improved treatments.
In the sulfate process, ground flmenite ore is d igested with concentrated sulfuric acid
at relatively high temperature. The acid used is normally about 150 percent of the
weght of the ore. In some cases, small amounts of antimony trioxide are also added.
The resulting sulfates of titanium and iron are then leached from the reaction mass with
water, and any ferric salts present are then reduced to ferrous by treatment with iron
scrap to prevent coloration of the final titanium dioxide product.
After these operations, the resulting solutions are clarified, cooled and sent to a vacuum
crystallizer. There, ferrous sulfate crystallizes out and is then separated from the mother
liquor by centrifugation. This material s either sold or disposed of as a solid waste.
The mother liquor is then clarified by filtration after addition of filter aid and is further
concentrated by vacuum evaporation. Seed crystals or other nucleating agents are
added, and the concentrated liquor is then treated with steam to hydrolyze the titanyl
sulfate present. The resulting precipitate s collected by filtraflon, washed several times
and then calcined to yield titanium dioxide. The calcined product is ground, quenched
and dispersed in water. The coarse products are separated in a thickener to which caus-
tic soda is added to maintain a constant pH. These coarse particles are reground and
further processed to yield a purer product.
3.5.1 .1 Raw Waste Loads
Table 33 gives a generalized listing of the raw wastes from titanium dioxide manufacture
by the sulfate process. Data in this table are in a form applicable to the effluent from
any of the five existing sulfate process plants. Each of these five facilities have slightly
different raw wastes due to differences in compositions of the raw ores.
3.5.1 .2 Water Use and Treatment
In this and the following sections, discussion will be based on one facility, chosen at
random from the five plants. The spedfic faciUty u d for these modelling discussions
is the plant 1 22 facility. A general waste treatment flowchart for this facility is pre-
sented in Figure 57 and generalized water usage is:
v-i 15
DRAFT
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DRAFT
TABLE 33. Sulfate Process Waste Streams ——
Titanium Dioxide Manufacture
Stream Constituent Approximate Quantity
1. Dissolving and Ore and scrap iron 0.07 x total ore and scrap iron
Filtration plus flocculants charged
H 2 S0 4 O.OOl 6 xore
Organic Carbon 0.0004 x ore plus 0.1 x C in ore
2. Copperas (if FeSO 4 7H 2 O (as Fe) (Fe 2 + 1 .50 Fe 3 ) in ore minus
produced) 0.33 x hO 2 in ore
Total sulfate (as H 2 S0 4 ) 1 .76 x iron in copperas
3. Strong Acid FeSO 4 (as Fe) 0.67 x (iron in ore minus iron
in copperas)
H 2 S0 4 1 .07 x ore
Other ore impurities 0.67 x impurities in ore
hO 2 0.03 x Ti0 2 in ore
Organic carbon 0.0022 x ore plus 0.81 x C in
ore
4. Weak Acid FeSO 4 (as Fe) 0.33 x (iron in ore minus iron in
copperas)
H 2 S0 4 (Total) 0.53 x ore plus 0.25 x T b 2 in ore
Other ore impurities 0.33 x impurities in ore
1102 0.02 x 1102 in ore
Organic Carbon 0.00025 x ore plus 0.09 x C in ore
5. Vent and Kiln H 2 S0 4 0.01 x ore
Scrubbing
6. 110 Losses 1102 0.OlóxTiO 2 inore
Na 2 SO 4 0.03 x 1102 in ore
Note: Effluents also contain traces of Pb andCu from process equipment. Silica
and zircon do not react and are discharged with the sludge.
V-lb
DRAFT
-------
DRAFT
FIGURE 57
PROCESS FLOW DIAGRAM
AT PLANT 122
SULFURIC
EXCESS TO
STOCKPILE
WET
COPPERAS
Ti0 2 PIGMENT PACKING
SULFATE
V-il 7
DRAFT
-------
DRAFT
Type Cu m/kkg of Product (gal/ton) Recycle
Cooling 284 (68,000) brackish 0%
Cooling 83.6 (20,000) fresh 90%
Process 100 (24,000) 2%
Boiler feed 16.7 (4,000) 30%
Currently, all of the process water used is fed to a settling pond to remove suspended
materials and is then discharged. The process water discharged is from two streams,
one from a solids separation part of theprocess which contains strong (18—22%) acid
and a second weak acid stream coming from other parts of the process. Both streams
are currently mixed before treatment.
In the treatment of wastes, the best approach would be to segregate these two streams
and attempt to recover acid values and/or ferrous sulfate from the more acidic stream,
while applying neutralization procedures ot the other. Considering the strong acid
stream first, a possible recovery treatment is first to partially evaporate the waste to
effect further precipitation of ferrous sulfate and other metal salts which could be
recovered by filtration after cooling. The remaining solution could be further con-
centrated for other use or recycled to the process.
The weak acid stream, which does not contain sufficient metal or acid values to justify
recovery, would be oxidized to convert ferrous salts to the ferric state and then treated
with lime to precipitate heavy metals and adjust for pH to neutral prior to discharge.
The effluent would be expected to contain about 2000 ppm dissolved CaSO 4 .
One advantage to this scheme is the possibility of further processing the heavy metal
salts recovered by acid concentration. These could possibly be further processed to
recover vanadium values, among others.
It may be noted that the above—mentioned scheme is a combination of two treatment
approaches. The method involving total neutralizationand settling is currently being
installed at the plant 122 to treat all of the waste streams. Table 34 lists some informa-
tion on this treatment process.
3.5.1.3 Effluent
Effluents from four titanium dioxide sulfate process facilities are listed in Table 35.
None of these have discharge pH’s in the 6—9 range for all streams, and all contain
3000 ppm dissolved solids. In some cases, strong acid streams are currently segregated
and this material, in one case, is disposed of by ocean dumpng. Thus, at present,
there is no titanium dioxide sulfate process plant with an acceptable effluent, although
the 166 plant after compleHon of installation of its total neutralization treatment facil-
ity may approach the exemplary status. The neutralization procedure, along with a
V-il 8
DRAFT
-------
DRAFT
TABLE 34. Future Treatment at Plant 122
Methods
Neutral ization of
acid to CaSO4
and oxidation of
iron, and remove
for sale or stock-
pile (as ferrous
sulfate) of pro-
cess wastes and
cooling water
Estimated
Installation
Time
22 mos
Estimated
Performance
Addi tional
ponds for
waters
setti ing
cooling
22 mos
v-i 19
Reduction of suspended
solids formed due to
neutralization by 95%
Reduce
Reduce
Reduce
Cr to
TDS 50
C.0.D. to Nil
acidity to Nil
Fe, Mn, V, and
Nil
ppm
DRAFT
-------
TABLE 35. Partial Discharge Data from 1102 Sulfate Plants 0 )
Plant 142 Streams( 2 ) Plant 046 Streams ( 3 ) Plant 122 Streams Plant 008
Parameter No. 1 No. 2 No. 1 No. 2 No. 3 No. 1 No. 2 No. 3 No. 1
BOD 10 3 6 3 -- -- 0.3 0.5
COD 71 145 -- -- 287 42 27 --
pH 8.0 1.2 6.5 5.6 1.0 2.6 5.0 5mm.
Alkalinity 220 —— —— —— —— —— ——
Total Dis-
solved Solids 1660 22,371 15,316 21,300 - 14,000 15,400 3,000 2,700 5,000
Iron 0.02 823 0.5 1.7 31,000 1,000 45 15 100
< Sulfate 1,170 12,377 1,617 1,378 131,000 6,800 187 125 ——
• - . Chloride 51 .5 105 6,394 7,900 -— 625 2,480 2,830
Acidity — — 11,435 36 -— -- 20,000 160 100 —-
Flow, cu m/d 10,200 Combined 20,800 123,400 6,100 20,800 40,900 30,300
(MGD) (2.7) (5.5) (32.6) (1.6) (5.5) (10.8) (8.0) -
-
(1) One plant of one manufacturer is not listed here. Data on titania and chromote concentrations were not provided.
(2) The corporationowning this facility iscurrently developing a process for recovery and recycle of the sulfuric acid used.
This process is still under testing on the pilot plant scale.
(3) This plant barges its strong acid wastes out to sea for disposal. This method of disposal of highly acid wastes containing
large amounts of dissolved heavy metals is not considered satisfactory. Effluent No. 3 is the available data on material
dumped at sea.
-------
DRAFT
possible scheme for some acid recovery, was discussed earlier in this section. More
details on possible treatment methods and their costs will be given in Sections VIII
and VIII.
3.5.2.4 Additional Treatment Details
For the sulfate process, an alternate treatment may consist of raw ore enrichment to
remove much of the irOn present before the raw material is used in the process. One
such potential process’ unzk r development at the U.S. Bureau of Mines Reno Research
Center involves the smelting of ilmenite (FeTiO3) with coal and sodium borate—titanate
slag which contains 40 weight percent titanium dioxide and 0.2 weight percent iron.
Over 99 percent of the titanium in the ore is recovered in the slog, while about 90 per-
cent of the iron present is converted to the elemental form. After separation of the iron
from the slag, air or oxygen is blown into the molten slog to oxidize the titanium to the
tetravalent form which is readily soluble in acid. The molten slag s water quenched
and leached in hot water to yield a sodium titanate residue (70-90 weight percent hO 2 )
in a sodium borate solution. The recovered sodium titanate can then be used in the
sulfate process.
Sodium borate in solution is recovered by crystallization and can be recycled to the
smelting step. Use of this procedure to provide a sodium Htanate feed for the sulfate
process eliminates the generation of large amounts of iron sulfate and the inherent
problems related to its disposal.
Othermethods of ore enrichment under development have been alluded to by the various
sulfate process titanium dioxide producers, but details have not been made available to
us.
Substitution of Sodium titonate for ilmenite as a sulfate process row material would lead
to a sulfate /bisulfate by—product which could be recovered by crystallization (as is
done with ferrous sulfate) for sale. This would eliminate much of the heavy metal salt
discharge problems with the sulfate process and also solve the problem of acidic dis-
charges via recovery of a low grade sodium bisulfate by-product for sale or other use.
This approach may prove to be a superior approach to either the neutralization scheme
or the acid recovery techniques mentioned earlier. The economics of the above men-
tioned possible sulfate process modification have not yet been reported. A more detailed
evaluation of this possible process must await such an economic presentation.
3.5.2 Titanium Dioxide (Chloride Process )
Virtually the same process is used at the two chloride process facilities studied (plants
009 and 160). The only process differences lie in Ihe types of ore used. Plant 160
V—121
DRAFT
-------
DRAFT
employs an ore containing 66 percent titanium dioxide, while plant 009 uses only
95 percent plus grades of rutile and upgraded ilmenite, and hence has a more exem-
plary effluent. Figure 58 and 59 show the process flows within the 009 facility.
3.5.2.1 Raw Waste Loads
The raw wastes from plant 009 consist of heavy metal salts, waste coke and hydrochloric
acid. In the row waste
stream, these are actually metal chlorides before waste treatment. In detail, the raw
wastes are:
kg/1kg of Product
Constituent ( Average )
Iron salts (equiv. Fe 2 0 3 ) 58
Other metal salts 58
(equiv. metal oxides)
Ore 138
Coke 23
Titanium hydroxide 29
hO 2 40.5
HCI 227
3.5.2.2 Plant Water Use
• Input Type cu rn/day (MGD )
Lake 11,500(0.025)
Municipal 76(0.020)
Use Type cu rn/day (MGD) % Recycled
Cooling 58,700(15.5) 93
Process 6,060(1.6) 0
Cleanup 284(0.075) 0
Sanitary 38(0.01) 0
Bc. ler Feed 834(0.22) 0
3.5.2.2 Treatmer’
Most of the cool nq water used is recycled. The waste treatment methods used on the
effluent stream, hich consists of neutralization and precipitation and settling of
heavy metal salts prior to discharge are shown below. Figures 60 and 61 show the
treatment processing at plant 009.
v—i 22
DRAFT
-------
WASTE SLUDGES
TuCI PURIFICATION COOLING
4 CHEMICALS WATER
COKE,ORE,C0 27 N 2 ,CO I ____________ _____________
TICI4, FOCI
02 QUENCH TiCI 4 TiCI 4 TiCI 4
COKE CHLORINATOR
- TOWER CONDENSATION PURIFICATION STORAGE
ORE
WATER >I I
COOLING WATER
Ti0 2 TICI 4
WASTE
PLANT SALES
SLURRY
r- — — EVERYTHING EXCEPT
__ LE
I WASTES I
FeCI, , ORE, I
COKE I ORE _____ WA
SOLID RECOVERED
— — RECOVERY TREATMENT
LIQUiD I
WASTES I -
I HCI ___________ ___________
L_ _j
ORE
FIGURE 58
TITANIUM TETRACHLORIDE PORTION OF TITANIUM DIOXIDE PLANT
-------
COOLING FUTURE ) FUTURE WASTE TO TiCI 4
WATER SCRUBBER
TICI 4 VAPOR PORTION
TiCI i ____ ci 2 —LIQUID CI 2 —?. TiCI 4 PROCESS
) RECOVERY WASTE
TREATMENT
COOLING WATER— ’ AT Ti02
_____________ OPERATION
VAPORIZER Cl 2 , 02, co21ç SYSTEM —
PURCHASED BY PIPELINE 02 \
VAR IOU S
OXIDATION
TREATMENT
REACTOR
WATER CHEMICALS
COOLING WATER
__?j J__) COLLECTION [ T102
CO ______________
SLURRY F T102
TREATMENT I ING
GENERATOR ‘ ____________ __________
WASTE WASTE WASTE
L SPENT COOLING WATER _____WASTE TREATMENT
>AT Ti0 2 OPERATION WASTE TREATMENT< FINISHED
AT TICI 4 OPERATION Ti0 2 , SPILLS, SALTS Tic 2
STORM DRAINAGE FROM Ti0 2 OPERATION
WASTE TREATMENT AT TiO 2 OPERATION
FIGURE 59
TITANIUM DIOXIDE PORTION OF PLANT (CHLORIDE PROCESS)
-------
DRAFT
STORM DRAINAGE
RETENTION
BASIN
Ii
SUMP PUMP SUMP PUMP
TiC4 ____ ____
CoO
WASTE ______
STREAM
____ POLISHING
Ti02 NEUTRALIZATION CLARIFIER
POND
-‘ ALSO SURGE FOR
PROCESS SYSTEM STORM WATER
TiCI 4
RUN-OFF
WASTE
STREAM ________________ _________________ ________________
I UNDERFLDW
I I OUTFALL
I I
j Ul
> 1
FLOCCULENTS LI POLISHING
THICKENER POND
IUNDERFLOW
Li
U
0
z
ROTARY _____ FILTER CAKE TO
FILTERS > LAND STOR E
“
FIGURE 60
TREATMENT, TITANIUM TETRACHLORIDE
OF PLANT 009
V- 125
DRAFT
-------
STORM
DRAINAGE
SYSTEM
OUTFALL
(SEPARATE
FROM T1CI 4
TREATMENT)
FIGURE 61
0
c - ) 1 .
‘-C ”
zo
w
K)
0
CO
-, U
W STE
MOSTLY COOLING WATER
ALL WATER GOES THRU
SUMP PUMPS
‘1
-I
TREATMENT,
TITANIUM DIOXIDE PORTION OF PLANT
009
-------
DRAFT
Treatment Final
Stream No. Source Methods Disposal
1 TICI 4 preparation Neutralization, Lake
settling
2 Cooling Neutralization, Lake
settling
3.5.2.3 Effluent
Table 36 shows the plant 009 effluents after neutralization and settling treatment. The
effluent consists of a neutral pH stream containing dissolved salts (mostly sodium chloride)
and low heavy metals concentrations. Table 37 shows GTC verification measurements
on this facility.
v-i 27
DRAFT
-------
DRAFT
TABLE 36. Composition of Plant 009 Effluent Streams
After Treatment
Constituents Stream No. 1 Stream No. 2
Present Avg. Range Avg. Range
Suspended Solids 18 1—50 15 0—40
Total Dissolved Solids 3300 1500-4500 300 180-900
COD 50 40-90 20 5-45
pH 7.8 6.0-9.0 6.8 6.0-9.0
Temperature 16°C 7-27°C 160 C 2- 32°C
(Ambient Temp.)
Organks None were found
Turbidity 20 <10—80 20 <10-50
(Jackson Units)
Color (APHA) 10 <10-20 10 <10-20
Chloride 1650 750-2050 50 70-100
Sulfate 1-2.5 —— 1—2.5
Sulfate 150 90-450
Iron 0.2 0-3.0 0.2 0.1—1.0
Copper 0.015 0.01-0.03 0.015 0.01-0.03
Chromate <0.01 <0.01
Total Chromium 0.05 <0.01 -0.15 0.05 <0.01-0.15
Arsenic <0.02 <0.02
Mercury <0.001 <0.001
Lead 0.14 0.1-0.19 0.02 0.02
*Units are mg/I unless otherwise noted.
v-i 28
DRAFT
-------
DRAFT
TABLE 37. GTC Verificati on Data of Plant 009
Parameter Lake Intake Water Effluent Stream #1 Effluent Stream 2
Flow, cu rn/day 3650(0.964) 6060(1 .60) 2240(0.590)
(MGD)
Temperature 9°C 16°C 26.5°C
Color (APHA) 100 Units 140 Units 90 Units
Turbidity (FTU) 35 35 30
Conducfivty (mg/I) 100 (NaCI) 2100 (NaCI) 170 (NaCI)
Suspended Solids
(mg)
pH 7.9 7.6 6.85
Acidity: Total (mg/I) N/A N/A 0 (CoCa 3 )
Free (mg/I) N/A N/A 0 (CaCO 3 )
Alkalinity (Total) P 0 (CaCO 3 ) 0 (CaCO 3 ) 0 (CoCO 3 )
(mg/I) 1 93 (CaCO 3 ) 22 (CaCO 3 ) 28 (CoCa 3 )
Hardness: Total 129 (CaCO 3 ) 2600 (CaCO 3 ) 185 (CaCO 3 )
(mg/I) Calcium 97 (CaCO 3 ) 1920 (CaCO 3 ) 139 (CaCO 3 )
Halogens:
Chlorine (mg/I) 0 0 0
Chloride (mg/I) 36.5 2250 49.5
Fluoride (mg/I) 0 0.3 0.25
Sulfate (mg/I) 32.0 240 175
Phosphates (Total) (mg/I) 1.4 0.025 0.225
Nitrogen(Total) 0.24 0.14 1.3
Heavy Metals:
Iron (mg/I) 0.225 1 .6 0.4
Chromate (mg/I) 0 (Cr 6 ) 0 (Cr 6 ) 0 (Cr 6 )
Oxygen (Dissolved) 10.8 9.0 6.2
(mg/I)
V-i 29
DRAFT
-------
DRAFT
4.0 VERIFICATION SAMPLING AND ANALYTICAL METHODS
4.1 Sampling Operations
Two teams of two men each were assigned to the field sampling
and measurements operations. Each of the teams was equipped
with a station wagon and a 4.7-meter trailer outfitted as a
mobile water testing laboratory. The visit of a team to each
facility was preceded by a visit to the plant by one of the
senior engineers on the project team. During this visit, efflu-
ent streams and potential sampling sites were determined and
approximate expected stream compositions were established.
The duties of the field team visiting the plant included mea-
surement of flow rate and collection of samples at each desig-
nated sampling site. Methods used to determine flow rates
varied from stream to stream, but included:
(1) Use of existing weirs or installed flow meters;
(2) Use of current meter plus dimensional measurements;
(3) Direct collection of small outfall streams, with volu-
metric measurement related to duration of collection;
(4) Use of dye tracer to give velocity measurement (plus
dimensional measurements).
Siiice many of the streams of interest could not be approached,
the waste: contained therein were sampled after having mixed
with one or moi other streams.
For most effluent sampling sites, four one—liter samples were
taken (one per hour) over a four—hour duration. These samples
were then mixed to give a four-liter composite sample. One
four-liter grab sample was taken of the water supply to the
plant. At the end of the day, a four-liter grab sample was
taken at each sampling site (and of the water supply) for backup.
One-half of the four—liter composite sample was used for analy-
ses and tests in the field laboratory. The remaining two liters
of composite sample were divided into several samples, some of
which were acid-stabilized, and were transported to our
Springfield, Virginia facilities for further analyses.
V — 130
DRAFT
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4.2 Basis of Analytical Method Selection
It was the philosophy of this program to adopt and to utilize
practical analytical methods which were reliable and easily
used in the field. This decision was dictated by several con-
siderations involving the necessity to accomplish sampling and
analysis in a large number of selected plants, plus the doubt-
ful nature of the conventional stabilization methods (such as
addition of nitric acid to metal solutions; sulfuric acid to
CO samples;- and mercuric chloride to nitrogen samples) when
applied to the often complex discharge streams encountered in
this study. Backup analyses were performed in the analytical
laboratory at the home office for those not practicable in the
field and to provide analyses conforming to the accepted stand-
ard techniques. (12)
The results obtained by the use of the field transportable
test methods were, in general, quite reliable. A a routine
matter, however, standard test samples were inserted into the
analytical program to allow some estimate of the validity of
the results reported from the field. The unlabeled standard
samples were made up from EPA Reference Samples and presented
to the analytical personnel without obvious identification.
The analysis of the samples from various process and discharge
streams has been a somewhat complex procedure. This is due
primarily to the extraordinary variation in flow rates, con-
centration of solutes and (in particular) the extremely wide
range of suspended solids which were encountered.
However, analytical techniques were utilized which were judged
to yield the maximum results within the time limitations of
the study.
Pretreatments in the field for the various types of samples were:
(1) Suspended and dissolved solids — none;
(2) Metal ion analysis — addition of 5 ml of concentrated
nitric acid per liter of sample;
(3) COD analysis — used immediately in the dichrornate re-
flux apparatus or treated with 1.0 N sulfuric acid;
(4) Nitrogen analysis - used immediately or treated with
mercuric chloride for stabilization;
V — 131
DRAFT
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DRAFT
(5) Phosphorus — addition of 40 mg. of mercuric chloride
per liter; and -
(6) Fluroide - none.
The analytical methods used in the field are described briefly
below:
4.3.1 Dissolved Oxygen, Temperature and pH
Dissolved oxygen and temperatures were measured in situ using
remote probes. The pH was measured immediately after sampling
with a Chemtrix type 40/40E pH meter (standardized to pH 7
before each measurement).
4.3.2 Color
Apparent color was determined by direct comparison of the sample
with platinum-cobalt standards. One unit of color is that pro-
duced by 1 mg/i of platinum in the form of the chioroplatinate
ion. To preclude changes during storage (biological activity,
for example), measurements were made in the field as soon as
possible after sampling.
4.3.3 Turbidity
The method was based on a comparison of the intensity of light
scattered by the sample under well-def!.ned conditions with the
intensity of light scattered by a standard (formazin) suspension
under identical conditions. Analysis was accomplished in the
field as soon after sampling as possible using a turbidimeter
calibrated with formazin polymer suspension.
4.3.4 Conductivity
The specific conductance of the sample was obtained by direct
measurement using a conductivity meter. Sample preparation
required protection from atmospheric gases and the adjustment
of pH using gal].ic acid (0.2 gm/50 ml sample). Results were
reported in mg NaCI/liter equivalent at 25°C.
4.3.5 Acidity
Acidity was determined by titration with Standard N/44 sodium
hydroxide to the carbonic acid equivalence point (pH 4 to 5)
V — 132
DRAFT
-------
DRAFT
using methyl orange as a coloriinetric indicator to determine
“free” acidity, and then further to the bicarbonate equiva-
lence point (pH 8.3 using phenolphthalein) for vtotaltI acidity.
These measurements were made in the field as soon as was prac-
tical after sampling.
4.3.6 Alkalinity (Phenolphthaiein and Total )
Phenolphthalein alkalinity was determined in the field as soon
as possible by titration of the unaltered sample with Standard
N/50 sulfuric acid to a phenolphthalein endpoint.
Total alkalinity was determined by addition of a Bromcresol
Green-Methyl Red Indicator solution at the phenolphthalein
endpoint and titrating with Standard N/50 sulfuric acid until
the color changed from green or blue-green to pink.
4.3.7 Hardness (Ca & Total )
Hardness was determined in the field using EDTA titration with
Chrom Black T as an indicator.
4.3.8 Chlorine
Total chlorine was determined in the field as soon as possible
after sampling by the orthotolodine method wherein the color
intensity is determined at 490 nanometers (nm).
4.3.9 Chloride
Chloride (expressed as mg/i chloride) was titrimetrically deter-
mined in the field using mercury nitrate with mixed diphenylcar-
bazone-bromphenol blue indicator. The endpoint of the titration
was the formation of the blue-violet mercury diphenylcarba zone
complex.
4.3.10 Sulfate
Sulfate determinations were made in the field using the barium
sulfate turbidimetric method with a spectrophotometer. A cal-
ibration curve for the spectrophotometer was prepared from
standard sulfate solutions.
V — 133
DRAFT
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DRAFT
4.3.11 Nitrogen
Nitrogen/nitrate determinations were made in the field using
the cadmium reduction method with l-naphthylamine sulfanilic
acid as the indicator. The resulting color was determined
spectrophotornetrically at 525 nm.
4.3.12 Hydrogen Sulfide
Hydrogen sulfide content was determined by stripping sulfide
from an acidified sample by lead acetate paper. Color com-
parison then allowed estimation of mg/i of hydrogen sulfide.
4.3.13 Chemical Oxygen Demand
COD was determined in the field as soon as possible after
sampling using the dichromate ref lux method with readout
accomplished spectrophotometrically at 600 nm.
4.3.14 Fluoride
Analyses for fluoride, total dissolved solids, total suspend-
ed solids, and e1enier tal phosphorus were performed in the
main analytical laboratory by the following procedures.
Fluoride ion determinations were carried out with an Orion
specific ion electrode (Model 94—09; a silver — silver
chloride — lanthanum fluoride crystal cell) used with an
Orion Model 801 meter. All samples and standards (made up
with reagent grade sodium fluoride) were diluted with a
Total Ionic Strength Adjustment Buffer to bring the sample
pH to between 5 and 6, to eliminate complexing with the
polyvalent ions Si+4, Al+3, and Fe+3 and finally to bring
the total ionic strength for sample and standards to a con-
stant level. A calibration curve of electrode potential in
voltage versus fluoride concentration was constructed, from
which the concentration of fluoride ion in the unknown was
determined. This method is also known as Storet 00950.
4.3.15 Solids
4.3.15.1 Total Dissolved Solids
A well-mixed sample is filtered through a standard glass fiber
filter, a Reeve Angel type 984 II. The filtrate is evaporated
on a steam bath and dried to constant weight at 180°C.
V — 134
DRAFT
-------
DRAFT
These analyses were carried out using the procedures outlined
as Storet No. 70300 and Storet No. 00530 in “Methods of Chemical
Analysis of Water and Wastes” (1971) pp. 275 ff. To determine
the precision of these methods, a standard solution of sodium
chloride was analyzed which contained 247 mg/i (dissolved solids
standard). The method showed a consistent error of less than
0.1%. On the other hand, an attempt to use a suspension of
Ti02 in water as a reference standard for suspended solids has
proved to be quite undependable; this observation is clearly in
line with the comment “the precision and accuracy data are not
available at this time” (for Storet 00500), from “Methods of
Chemical Analysis of Water and Wastes”, op. cit.
4.3.16 Elemental Phosphorus
The method for phosphorus consisted of oxidation to orthophos-
phate by nitric acid, followed by ascorbic acid addition and
colorimetric determination of orthophosphate.
4.3.17 Heavy Metals
Heavy metal concentrations were determined, as required, by
Penniman and Brown (Registered Analytical Chemists) Baltimore,
Maryland, using conventional atomic absorption methods.
V — 135
DRAFT
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5.0 EFFLUENT DATA ANALYSIS
5.1 Presentation of Available Day-to-Day Plant
Effuent Data
To convey the clearest possible picture of the effluent data ac-
quired from several plants, the presented data-samples (Figures
62 through 73) have been arranged in a dual format, as follows:
(a) Range of effluent-variation over the
time-domain of the sample; and
(b) Percentage frequency of readings over
the range of the effluent—variation.
Inspection of the time-domain plots (which were automatically
plotted by day from industry-supplied tables of raw data) indi-
cates the existence of higher frequencies of variation by the
“spiky” •appearance of the graph.
Of more significance is the magnitude of such variations. Observe
that, in Figure 62, the amplitude varies over an order of magni-
tude. In particular, the minimum value recorded was 727.3, while
th maximum was 7590.9. For this run, the standard deviation, a,
was calculated as 1441.9, and if we defined a normal 95% confidence-
interval for the mean, 11 = 3567.7, by
(where n = 182 is the number of data-points in the sample), this
would imply that the mean is 95% certain to lie between (approximately)
3363 and 3790. However, more than 65% of the readings fall below the
lower limit of this confidence interval, as can be seen by an inspec-
tion of Figure 63. Thus, it is obvious that neither the mean nor the
calculated confidence interval is completely meaningful.
The fact of the matter is that the variations in the effluent are
neither random, stationary, nor closely controlled. For example,
the week—long minimum early in 5-73 (due to a strike, in this case)
weights the data on the low side. But, over a sufficiently long
sample, such occasions could arise 5everal times and, if unaccounted
for, could bias the results heavily.
A better approach seems to be to regard the percentage-frequency
V - 136
DRAFT
-------
12/72 1/73 2/73 3/73 4/73 5/73
V)
I -
Plant 030
Cl-ion
12/72-5/73
10
9
8
7
6
5
4
mean:
3567.7
3
2
1
0
FIGURE 62. Time Variation of Effluent Chloride Ion Concentration at Plant 030
-------
20%
mean: 3567.7 kg/day
9 12 15 18 21 24 27 30
Plant 030
Cl- I on
12/72:5/73
102 kg/day
FIGURE 63.
Frequency Distribution of Effluent Chloride
Ion Concentration at Plant 030
In
C
•1
0 )
0
U
4- ,
C
U
U
S .-
U
‘-a
(A)
1 5%
10%
5%
0%
C
-------
10
9
8
7
6
5
.4
mean
3.271O • ‘
3
2
1
0
E
0
I-
Plant 144
Hg
8/72-1/73
8/72 9/72 10/72 11/72 12/72
1/73
FIGURE 64. Time Variation of Effluent Mercury Concentration at Plant 144
-------
30%
Plant 144
Hg
8/72-1/73
mean: 3.27•l0
Hg (l0 ppm)
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
FIGURE 65. Frequency Distribution of Effluent Mercury
Concentration at Plant 144
I n
C
-c
(ci
c i )
9-
0
ci )
(ci
.1 - 3
C
cu
U
S.-
a,
0
25%
20%
15%
10%
5%
I -J
0
C
0%
-------
5
4
3
2
mean:
1 .78.lO ’
1
0
(0
e4
I-
=
8/72 9/72
Plant 144
Hg
8/72—1/73
10/72
11/72 12/72 1/73
FIGURE 66. Time Variation of Effluent Mercury Daily
21
Discharge at Plant 144
-------
mean: 1.78!102
Plant 144
Hg
8/72-1 / 73
0 5 10
FIGURE 67.
15 20 25 30 35 40 45 50
Frequency Distribution of Effluent Mercury
Daily Dischar at Plant 144
Hg (lOs kg/day)
.,-
-
i0
a)
0
a)
0 )
(0
a)
U
20%
15%
10%
5%
0%
I-i
I
-------
3.0
2.5
2.0
1.5
1.0
mean: 0.64
0.5
E
0
0.
C
0
I-
C-)
Plant 144
Cl-ion
8/72-1/73
11/72 12/72 1/73
FIGURE 68. Time Variation of Effluent Chloride
0
8/72
9/72
10/72
Ion Concentration at Plant 144
-------
0 3 6 9 12
FIGURE 69.
Plant 144
Cl—ion
8/72-1/73
15 18 21 24 27 30
Frequency Distribution of Effluent Chloride
Ion Concr ‘ation at Plant 144
Cl—ion (102 ppm)
In
•1
cu
4-
0
U
ci
U
U
25%
20%
15%
10%
5%
0%
I -I
21
-------
c.u
15
10
5
mean:
3290.5
0
>,
- c i
0 ,
0
1
0
•1 •
( )
Plant 144
Cl—ion
8/72-1/73
8/72 9/72 10/72 11/72 12/72 1/73
FIGURE 70. Time Variation of Effluent Chloride Ion
Daily Discharge at Plant 144
-------
0 )
-C
l U
Cu
l x :
Cu
CJ
(C i
4 )
a,
LI
Cu
Plant 144
Cl-ion
8/72-1/73
mean: 3290.5
10
Cl—ion (10’ kg/day)
FIGURE 71.
Frequency
Ion Daily
t i-
c)
25%
20%
1 5%
10%
J,o
-l
0%
0
2
4
6
8
12
Distribution of Effluent Chloride
‘charge at Plant 144
-------
12
Plant 144
(discontinuities indicate absence of collected data)
8/72 9/72 10/72 11/72 12/72 1/73
pH
11
10
9
8
mean:
6.99
7
pH
8/72-1/73
6
5
4
3
2
1
0
FIGURE 72. Time Variation of Effluent pH at Plant 144
-------
30%
Plant 144
25% pH
8/72-1/73
20%
H
co
10%
5%
pH
0%
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
FIGURE 73. Frequency Distribution of Effluent H at Plant 144
I n
C
•1•
U
0
C,
4 )
C
ci
U
S.-
ci
-------
DRAFT
histogram as something akin to a “distribution pattern”. If,
over a sufficiently long sample (without strong biasing) a sub-
stantially greater percentage of readings are found to lie below
some particular value, it seems reasonable to assume that an
increase in control measures could substantially reduce the fre-
quency of readings above that level. Put another way, if a pro-
cess can be sufficiently well-controlled to limit a large majority
of its effluent readings to a relatively low (or even marginally
acceptable) level, there seems little reason not to demand that
all such readings remain below that level, except, perhaps, for
particular singular events which may be beyond control.
Consider Figures 68 and 69 and Figures 70 and 71 as examples.
In Figure 68, variations in concentration range over two orders of
magnitude, while in Figure 70, the variation in total mass per day
varies over three orders of magnitude. In both cases, the standard—
deviations exceed the mean-values. However, inspection of Figures
69 and 70 indicates that,in both cases, better than 65% of the
readings lie below the mean value. Manifestly, we are not consider-
ing a process which could be described as well-controlled. Indeed,
if 65% of the daily readings over six months lie below the mean-
value of the six month sample, any limitation based upon a normal
standard deviation is little limitation at all. In fact, should we
again utilize the normal 95% confidence interval for the mean, as
previously, we find for the case of Figures 68 and 69 that the mean
(637.9) is 95% certain to lie between (approximately) 539 and 737;
whereas, for the case of Figures 70 and 71, the mean (3290.4) is
95% certain to lie between (approximately) 2770 and 3810. Inspec-
tion of the percentage frequency histograms indicates that over 50%
of the readings (in both cases) lie below the lower limit of the
95% confidence interval. As might be expected, comparison of
Figure 68 with Figure 70 serves to illustrate the accentuation of
the variations in concentrations by the variations in flow— :e.
A prime example of the deceptive nature of average-values is clearly
exhibited by Figures 72 and 73. Here, a six-month average of pH
readings provides us with a mean of 6.99 (highly favorable) and a
standard deviation of 1.44. Again taking the normal 95% confidence
interval for the mean, we find that the mean is 95% certain to lie
between 6.8 and 7.2. However, inspection of Figure 72 shows that
(midway through 8-72) in four successive days, the pH of the effluent
ranged from 3.9 to 11.0 to 2.7 to 10.8. This type of variation would
obviously conflict with any reasonable guideline which could be set.
Thus, when we finally come to analyze the raw data of a dangerous
pollutant (mercury), as illustrated by Figures 64 through 67, we are
V — 149
DRAFT
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DRAFT
inclined to be most careful about our conclusions. Concen-
tration is found to have a mean of approximately 3.3•l0- ppm,
with a standard deviation of about 2.03•l0- . Daily amount data
indicates a mean of 1.78.10-2 kg/day with a standard deviation
of 1.06.10-2. We observe, throughout, that we are continually
dealing with variations which have standard deviations on the
order of their mean-values. But the percentage-frequency histo-
grams yield a better indication of what is actually going on.
Figure 65, for example, shows that concentration is relatively
well-controlled. The spread of the readings about the mean is
reasonably limited, and one could reasonably conclude that some
care has been exercised with the process. Proceeding to Figure
67, however, it is clear that a much wider scatter of data points
is present in the mass per day sample. Clearly, such scatter
arises from variations in flow rate, which indicates that concen-
tration data, alone, are insufficient to provide an adequate assess-
ment of a potential effluent problem.
On the basis of the available data, it is hardly possible to arrive
at a satisfactory statistical justification for any “hard” limita-
tion placed on effluent outputs. On the other hand, if we can
assume that these data samples are not unrealistic over the industry
as a whole, inspection of the relevant percentage-frequency histo-
grams clearly indicates that “most” of the time the effluent outputs
are kept at generally lower levels than the sample-means, by them-
selves, would indicate. Consequently, it is not unrealistic to
assume that the actual “most probable population—value” would lie
considerably lower than the calculated means. If we can assume
this to be the case, it follows that calculated means would tend
to be “high” (at least over runs on the order of six months or
more) — and, therefore, limitations based upon such means should
certainly not be excessively restrictive.
5.2 Limitations of Statistical Treatment of Data
The intent of this program has been the construction of effluent limi-
tation guidelines for the inorganic chemicals industry. For such
guidelines to be defensible, they must be both realistic and realizable.
To be administratively useful and enforceable, they must afford a
standard basis F comparison between similar operational processes
and lend themselves to practical and economical monitoring operations.
Limitations, however, implies a bound to variation; consequently, it
is the degree to which such bounds satisfy the above criteria that
determines the effectiveness of the limitation. But, realistic bounds
V - 150
DRAFT
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DRAFT
can be constructed only when sufficient knowledge of the extent
and the apparent nature of existing effluent variations is accumu-
lated. For this reason, significant effort has been expended
throughout the program in attempts to acquire (whenever it existed)
records of monitoring data sufficiently complete to aid in the
characterization of these effluent variations as they actually occur
in practice. While this endeavor has not met with the success desired,
it seems clear from the samples obtained that, if they are represen-
tative of the industry as a whole, a high degree of caution should be
exercised in their analysis.
The ultimate value of conclusions based upon numerical results is
necessarily determined by the reliability of the data and the validity
of the methods by which these data are analyzed. Failure to realize
the importance of a continued appraisal of such factors can lead to
misdirected effort and expense, and, in extreme cases, may result in
unrealistic decisions.
A random (stochastic) process is distinguished by the fundamental in-
determinacy of its behavior. Over a run of measurements, a random
process exhibits variations from observation to observation which no
amount of effort or control exercised in the course of the run can
remove. Furthermore, knowledge of the past behavior of the system
over any particular run cannot be expected to y eld any precise indi-
cation of its future action. Any single output from a random process
is essentially an accident which is unlikely to occur again. With
such processes, the standard procedure is to replicate (to the limit
of practicality) whatever runs of measurements are of interest, and
to utilize the ensemble of collected records to characterize the
nature of the statistical variations involved. Once this has been
accomplished, reasonable statements concerning the probable spread
of future process—values (all salient process—parameters remaining
fixed) can be made.
Such well-defined systems are essentially non-existent in the chemical
process industries. That such a situation prevails can be appreciated
by noting that only in the most rigidly controlled processes should
we expect anything approaching random variations. As control diminishes,
nonrandom effects, nonstationary variations, and singularities begin
to appear in the output data. However, the population mean is the
“best,” or most probable output value only if the system variations
observed are the result of small, random, independent, and additive
effects. Once nonrandom or nonstationary variations are present, the
mean may differ significantly from the most probable value of the
V - 151
DRAFT
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DRAFT
population. Similarly, the standard deviation becomes useful in
establishing confidence-intervals only when the standard error of
a known statistic is known or can be estimated. Without such
knowledge, the data must be treated most carefully, and specific
conclusions must be cautiously constructed.
V — 152
DRAFT
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DRAFT
SECTION VI
SELECTION OF POLLUTANT PARAMETERS
1.0 PRIMARY WASTE WATER POLLUTION PARAMETERS OF SIGNIFICANCE
The primary or Group I parameters are those deemed significant
for the inorganic chemicals, alkali and chlorine industry in
terms of effluent volume, toxicity or other degrading impact
on receiving water quality. The Group I parameters of pollu-
tional significance for the industry include:
pH
Total Dissolved Solids (TDS)
Total Suspended Solids (TSS)
Chromates
Toxic Heavy Metals and
Arsenic
Cadmium
Chromium
Iron
Lead
Mercury
2.0 SECONDARY WASTE WATER POLLUTION PARAMETERS OF SIGNIFICANCE
The Group II parameters are those considered important due to
their impact on water quality, but which occur only in limited
quantities or only from a particular process. These parameters
include:
Alkali and Alkaline Earth Metals
Ammonia
Chloride
Chlorine
Chlorinated Hydrocarbons
Cyanides
Fluoride
Nitrate
Nitrite
Phosphates
Phenols and Cyclic Hydrocarbons
Chemical Oxygen Demand (COD)
Silicates
Sulfate
Sulfite
VI- ’
DRAFT
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DRAFT
Temperature
Other Toxic Metals:
Aluminum
Copper
Nickel
Manganese
Molybdenum
Tin
Titanium
Vanadium
z inc
3.0 SIGNIFICANCE OF POLLUTION PARAMETERS
In the inorganic chemical industry, the most significant pol-
lution parameters were determined to be total dissolved solids
(TDS), total suspended solids (TSS) and the presence or absence
of toxic quantities of heavy metals. These parameters are im-
portant for every chemical studied. Other specific parameters,
such as chloride, sulfate, phosphate, COD, etc. should be con-
sidered for individual chemical plants on a case-by-case basis.
Group I parameters are those which will have a large impact on
receiving water quality and should be monitored routinely and
with some degree of frequen cy.
Group II parameters are those occuring in waste waters from a
particular process or manufacturing operation. They need to
be routinely monitored less frequently except for those pro-
cesses where they are generated.
4.0 RATIONALE FOR SELECTION OF POLLUTION PARAMETERS
The justification for the selection of the Group I and Group II
parameters for the inorganic chemicals, alkali and chlorine in-
dustry is given below(14).
4.1 Chemical Oxygen Demand (COD )
Certain waste water components are subject to aerobic biochem-
ical degradation in the receiving stream. The chemical oxygen
demand is a gross measurement of organic and inorganic mater-
ial as well as other oxygen—demanding material which could be
detrimental to the oxygen content of the receiving water. It
is a Group I parameter.
VI-2
DRAFT
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DRAFT
4.2 Cyanides
These materials are of concern because of their toxicity, al-
though they are biodegradable in the receiving stream. The
approved analytical methods do not differentiate between com-
plex cyanides and simple cyanides, which may have different
toxicities. They are a Group II characteristic because they
were encountered in the waste water effluent from one process
in this study, that of the electrolytic method for the produc-
tion of hydrogen peroxide.
4.3 Ammonia
Ammonia is of concern, because it exerts an oxygen demand on
the receiving stream, as well as being toxic to fish and aqua-
tic organisms. It is a Group II parameter as it is encountered
in soda ash, calcium chloride, and nitric acid manufacture.
4.4 Nitrate
Nitrates are of importance in water supplies used for human
or •livestock consumption because high nitrate concentrations
can become toxic. From investigations of this toxicity, it
has been concluded that the nitrate content in terms of ni-
trogen should not exceed 20 mg/i in public water supplies(l5).
The U.S. Public Health Service(16)reconiniends that nitrate
concentrations in ground water supplies not exceed 10 mg/i
nitrate as nitrogen. It is a Group II parameter as it is
encountered primarily in nitric acid manufacture or use.
4.5 Nitrite
This parameter is reported as nitrite nitrogen. It occurs
between ammonia and nitrate with respect to the oxidation
status of nitrogen. In cases where the conditions exist,
for oxidation to nitrate it would impose an oxygen demand
on the receiving stream. It is considered a Group II para-
meter found mainly in boiler treating chemicals.
4.6 Total Dissolved Solids (TDS )
The total dissolved solids is a gross measure of the amounts
of soluble pollutants in the waste water. It is an important
parameter in drinking water supplies and water used for irri-
gation. A total dissolved solids content of less than 500 mg/i
is considered desirable. It is a Group I characteristic found
across the board in this industry.
VI-3
DRAFT
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DRAFT
4.7 Total Suspended Solids (TSS )
The measure of suspended solids as a parameter serves as an
important indicator of the efficiency of solid separation
devices such as clarifiers and settling ponds. The total
suspended solids are a source of sludge beds in receiving
streams. This is a Group I parameter found across the board
in the industry.
4.8 Fluoride
This parameter is of concern because of its toxicity to
aquatic organisms at certain concentrations and drinking
water standards which limit its content. It is a Group II
parameter found mainly in the manufacture of hydrofluoric
acid and its use.
4.9 Chloride
Chloride is important in water supplies used for drinkin 9
purposes or for irrigation. A total chloride content of
less than 500 mg/i is considered desirable by the U.S.
Public Health Service for drinking water purposes. It is
a Group II parameter found across the board in this industry.
4.10 Sulfate
Sulfate may be a large fraction of the TDS. It is a Group II
characteristic in this industry, found as a spent water treat-
ment chemical, in the manufacture of sulfuric acid and oper-
ations using sulfuric acid as well as titanium dioxide sul-
fate process and manufacture of sulfate compounds.
4.11 Sulfite
Sulfite is an intermediate oxidative state of sulfur, between
sulfides and sulfates. It exerts a chemical oxygen demand on
the receiving stream. It is a Group II parameter found in
sodium sulfite manufacture and in one of the sulfur dioxide
removal treatments.
4.12 Acidity/Alkalinity
Acidity and/or alkalinity, reported as calcium carbonate, are
quantitative measurements of the amount of neutralization to
VI-4
DRAFT
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DRAFT
be required in the receiving stream. There does not appear
to be any need for their determination in effluent waste waters
when the pH is between 6.0 and 9.0
4.13 pH
pH is a measure of the acidity or alkalinity of a solution,
with a pH of 7.0 defined as being neutral. The range of pH
of the effluents from this industry is generally between
6.0 to 9.0. This is a Group I parameter across the board
in this industry.
4.14 Phosphates
Phosphates, reported as total phosphorus(P), contributes to
eutrophication in receiving bodies of water. It is a Group II
characteristic for this industry found primarily in water
treatment chemicals.
4.15 Chromates
Chromates are reported as hexavalent chromium, which is a known
toxic material. It is a Group I parameter found primarily in
water treatment and conditioning, and as such is found across
the board in the industry.
4.16 Toxic Heavy Metals
The following heavy metals are frequently encountered in water
pollution control problems, particularly when they are used
in water conditioning applications. Although they are generally
encountered in relatively small amounts, they are all toxic to
some degree.
Arsenic Iron
Cadmium Lead
Chromium Mercury
They are all considered Group I parameters where they are used
as in water treatment or produced, in the case of the manufac-
turing process.
4.17 Other Toxic Metals
This class of toxic metals are much less frequently encountered
being primarily derived as by-products of mineral raw materials
vI-5
DRAFT
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DRAFT
or normal corrosion of process equipment. They include:
Aluminum Tin
Copper Titanium
Manganese Vanadium
Molybdenum Zinc
Nickel
They are considered to be Group II parameters.
4.18 Alkali and Alkaline Earth Metals
These metals, sodium, potassium, magnesium, calcium, and
barium, are Group II parameters for this industry. When
TDS is exceptionally high or the receiving stream is used
for irrigation water supply, these metals merit attention
as pollutants. Barium salts are of very low solubility,
but toxic.
4.19 Chlorine
Chlorine is of concern because of its known toxicity to fish,
bacterial organisms and aquatic organisms. It is a Group II
parameter encountered in chlor-alkali, aluminum chloride, and
hydrochloric acid manufacture.
4.20 Chlorinated Hydrocarbons
These materials are of concern because of toxicity under cer-
tain conditions to fish and aquatic organisms as well as taste
and odor problems in water supplies. They are a Group II para-
meter being found primarily in chlorine processes.
4.21 Phenols, and Cyclic Hydrocarbons
Although phenols are biodegradable, they sometimes persist in
the receiving stream and produce taste and odor problems in
water supplies and taint fish flesh. Phenols are a Group II
characteristic found primarily in operations producing coke as
a raw material. Cyclic hydrocarbons are found in hydrogen
peroxide manufacture.
4.22 Silicates
Silicates contribute to eutrophication in receiving bodies of
water. It is a Group II parameter for the industry found
VI - 6
DRAFT
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DRAFT
primarily in silicate manufacture or by—product of mineral
raw materials.
4.23 Temperature
Temperature is a sensitive indicator of unusual thermal loads
where waste heat is involved in the process. Excess thermal
load, even in non-contact cooling water in the inorganic chem-
ical industry has not been and is not expected to be a signi-
ficant problem. It is a Group II parameter.
VI-7
DRAFT
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DRAFT
SECTION VII
CONTROL AND TREATMENT TECHNOLOGY
1.0 INTRODUCTION
Control and treatment technology for water-borne wastes from
the inorganic chemicals industry needs to be approached from
a chemical and chemical engineering viewpoint rather than
classical sanitary engineering practices. Organic content
and biological oxygen demands of the effluents are usually
very low and not a significant factor. In fact, most of the
involved control and treatment technology is well known, es-
tablished and extensively practiced in the process of produc-
ing the inorganic chemicals of this study. Practices such
as chemical treatment (neutralization, pH control, precipita-
tion, and chemical reactions), filtration, centrifuging, ion
exchange, demineralization, evaporation and drying are all
standard unit operations for the industry. Process instru-
Inentation, monitoring and control for the chemical industry
is outstanding. Unfortunately, all too often, the engineering
and technological excellence used throughout the process does
not extend to waste treatment and control.
Another characteristic of the waste effluents from the inor-
ganic chemical plants of this study is that they differ widely
in both chemical nature and amount (see Table 38). Soda Ash
(Solvay) and titanium dioxide (sulfate process) have raw waste
loads ir excess of the amounts of chemicals produced. On the
other hand, chemicals such as the mineral acids, calcium car-
bide and aluminum chloride have almost no water-borne wastes.
Soda ash (Solvay) wastes are neutral salts while titanium di-
oxide (sulfate process) wastes are strongly acidic. Therefore,
control and treatment technology has to be applied differently
for each chemical.
Typical control and treatment technology in use on inorganic
water-borne wastes today includes neutralization and pH control
on effluent streams, ponds for settling of suspended solids,
emergency holding, and storage, and discharge of the neutralized
and clarified effluent to surface water.
VII — 1
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TABLE 38.
Typical Water-Borne Loads for
Inorganic Chemicals of this Study
Solids Basis
Chemical
Sodium Chloride
Soda Ash (Solvay)
Titanium Dioxide (Sulfate)
Chloride (Non-Rutile)
Chloride (Rutile)
Chlorine-Sodium Hydroxide
Sodium
Sulfuric Acid
(Sulfur Burning)
Sodium Dichroinate
Sodium Silicate
Aluminum Sulfate
Nitric Acid
Hydrogen Peroxide
Hydrofluoric Acid
Sodium Bicarbonate
Aluminum Chloride
Sodium Sulfite
Cc 1r!ium Carbide
Hydroch1 ric Acid
(Direct Burning)
Annual
Production
Metric Tons
39,000,000
3,630,000
374,000
186,000
64,000
8,600,000
150,000
27,200,000
136,000
601,000
1,020,000
6,300,000
64,000
281,000
186,000
31,000
209,000
834,000
200,000
Waste Load
Ki lograms/
Metric Ton
Product
150
1,500
5,000
400
75
150
150
0.5
58
•1 .5
3t5
0•d j
20
4
4.5
24
3
0.5
0.5
Total Waste
Metric Tons/
Year
5,850,000
5,440,000
1,870,000
744,000
4,800
1,300,000
22,500
13,600
13,600
4,500
3,570
1,590
1,270
1,120
840
725
625
415
100
1) Production figures were taken from Chem. & Eng. News,
May 7, 1973, pp. 8-9 and “The Economics of Clean Water”,
Vol. III, Inorganic Chemicals Industry Profile, U.S. Dept.
of the Interior, Federal Water Pollution Control Admin.,
March, 1970.
2) Typical waste loads were estimated from Final Technical
Report, Contract No. 68-01-0020, Industrial Waste Study
of Inorganic Chemicals, Alkalies and Chlorine, General
Technologies Corp., July 23, 1971 (for EPA).
3) Titanium dioxide industry production figures were esti-
mated from Chem. & Eng. News, February 19, 1973, pp. 8-9.
VII — 2
DRAFT
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DRAFT
Discharge of acidic or alkaline wastes to surface water is
uncommon and is becoming more so all the time. Toxic wastes
such as mercury, arsenic, cyanides, chromium and other heavy
metals are being removed with increasing efficiency. Tech-
nology has been developed for removal of these toxic materials
to very low levels. In exemplary plants, specified or accept-
able water quality levels are being met. Public outcry and/or
consensus agreement on the need to clean up these toxic wastes
has resulted in positive and effective action on the part of-
industry.
There were many instances, during this study of exemplary
plants, of conscientious and successful waste abatement pro-
grams. Profitable waste segregations and recoveries, closed
cycles, leak and spill containments, and in-process waste
reductions are commonplace. Some of these waste abatement
programs have not involved much money, but most have been
expensive. Numerous plants have reported program costs
ranging from several hundred thousand to several million
dollars. In many cases air pollution abatements involve
more capital outlay than water treatment costs.
2.0 GENERAL METHODS FOR CONTROL AND TREATMENT PRACTICES
WITHIN THE INDUSTRY
Waste abatement for the inorganic chemicals industry may be
accomplished by a variety of methods. These methods may be
divided into control and containment practices and treatment
techniques. In many cases the control and containment prac-
tices are more important than subsequent treatments as far
as feasibility and costs of waste abatement are concerned.
The reasons for this are discussed in the following sections.
2.1 In Process Controls
Control of the wastes includes in—process abatement measures,
monitoring techniques, safety practices, housekeeping, con- —
tainment provisions and segregation practices. Each of these
categories is discussed including the interactions with treat-
ment techniques.
VII — 3
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2.1.1 Raw Materials
Purity of the raw materials used in the manufacturing process
influences the waste load. Inert or unusable components com-
ing into the process are discharged as waste. Economics and
availability, however, necessitate use of impure ores and
technical grade reactants.
Control of these impurities can be exercised in many instances.
Ores can be washed, purified, separated, beneficiated or other-
wise treated to reduce the waste coming into the process. An
important facet of this approach is that this treatment can
often be done at the mining site where such operations can be
contained or handled on the premises without polluting effluents.
Reduction of shipping charges also favor beneficiation at the
mine. Sometimes, as for “synthetic rutile” used in the titanium
dioxide chloride process, beneficiated or high quality ore is
necessary for developed process technology. Economics of raw
material purity need to be balanced against the attendant waste
treatment and disposal costs. As waste costs change, it may be-
come more economical to use high quality materials.
Although pure raw materials reduce the inherent waste load,
there are instances where, aside from economic factors, it may
be desirable to use an impure material. In large manufacturing
complexes, wastes from one process may be used for useful pur-
pose in another. This procedure not only eliminates a bother-
some waste from one process, it also gives economic value in
the other. An example is the use of spent sulfuric acid in de-
comp plants. Recycled raw materials serve the same desirable
function.
2.1.2 Reactions
Except in rare cases such as the mining of salt or soda ash
(Trona), chemical reaction is involved in the manufacture of
inorganic chemicals. Sometimes the reactants are stoichiomet—
rically involved, but more often than not an excess of one or
more of the reactants is used. The purposes of the excess vary
but include:
1. certainty that the more expensive reactants are com-
pletely utilized;
2. yield improvement by driving the reaction in the de-
sired direction;
VII — 4
DRAFT
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DRAFT
3. safety concerns where it is imperative a given reac-
tant be eliminated;
4. shortening reaction time.
Excess reactants must be recovered for recycle or else they
becort e part of the waste load. Often when the cost of the
excess reactants was small, it had been more economical to
let them go into the waste load rather than recover them.
Sodium and calcium chlorides and sulfates are among the most
common materials so handled.
Reactions may often be made to operate at more nearly stoi—
chiometric conditions and thereby reduce waste loads. Also,
the waste load may be deliberately changed in many cases by
changing the reactant ratio. In the burning of hydrogen and
chloride to form hydrogen chloride, operating on the chlorine—
rich side provides more troublesome waste than operating on
the hydrogen—rich side. Similarly, aluminum chloride made on
the chlorine—rich side requires air scrubbing to remove excess
chlorine, while the aluminum-rich side does not.
Many chemical reactions are either faster and more complete
at high temperatures or are exothermic and generate high tem-
peratures. To produce, control and/or reduce these tempera-
tures, cooling water and steam are often used. If the water
or steam is used without contact (such as in a shell and tube
heat exchanger), it is not contaminated. If, however, the
water or steam contacts the reactants, then contamination of
the water results and the waste load increases. Therefore,
reaction heating and cooling should be non—contact whenever
feasible.
2.1.3 Separations, Purifications and Recoveries
After reaction, the products, by—products, impurities, inerts
and other materials present need to be separated, purified
and recovered. Separations are carried out exploiting differ-
ences in boiling points, freezing points, solubility and reac-
tivity to separate products from impurities, by-products and
wastes. The efficiency of these determines:
1. the fraction of product that is lost as waste or has
to be recycled;
2. the purity of the product;
VII — 5
DRAFT
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DRAFT
3. control of air pollutants;
4. the recovery and/or disposition of by-products and
wastes.
The more complete the separations into recovered product,
raw materials that can be recycled, and wastes, the smaller
the waste load from the process. The degree of separation
actually achieved in the process depends on physical, chem-
ical and economic considerations. These effects will be
discussed for the individual chemicals of this study as they
apply.
Cooling water and steam are also used in large quantities in
the separation and purification steps. The same concepts
apply as discussed in the reaction section. Indirect heating
and cooling may, in many instances, virtually eliminate water—
borne wastes.
2.1.4 Segregation
Probably the most important waste control technique, partic-
ularly for subsequent treatment feasibility and economics, is
segregation.
Incoming pure water picks up contaminants from various uses
and sources including:
1. non-contact cooling water
2. contact cooling water
3. process water
4. washings, leaks and spills
5. incoming water treatments
6. cooling tower blowdowns
7. boiler blowdowns
If wastes from these sources are segregated logically, their
treatment and disposal may sometimes be eliminated entirely
through use in other processes or recycle. In many instances,
the treatment costs, complexity and energy requirements may
be significantly reduced. Unfortunately, it is a corr rnon prac-
tice today to blend small, heavily contaminated streams into
large non—contaminated streams such as cooling water effluents.
Once this has been allowed to happefl, treatment costs, energy
requirements for these treatments, and the efficient use of
water resources have all been compromised .
VII — 6
DRAFT
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DRAFT
In general, plant effluents can be segregated into:
1. Non-contaminated cooling water. Except for leaks, non-
contact water has no waste pickup. It is usually high
volume.
2. Process Water. Usually contaminated but often small
volume.
3. Auxiliary Streams. Ion exchange regenerants, cooling
tower blowdowns, boiler blowdowns, leaks, washings -
low volume but often highly contaminated.
Although situations vary, the basic segregation principle is
don’t mix large uncontaminated cooling water streams with a
smaller contaminated process and auxiliary streams prior to
full treatment and/br disposal. It is almost always easier
and more economical to treat and dispose of the small volumes
of waste effluents - capital costs, energy requirements, and
operating costs are all lower .
The use of segregation will be discussed for individual chem-
ical processes.
2.1.5 Monitoring Techniques
Since the chemical process industry is among the leaders in
instrumentation practices and application of analytical tech-
niques to process monitoring and control, there is rarely any
problem in finding technology applicable to wastewater analysis.
Acidity and alkalinity are detected by pH meters, often install-
ed for continuous monitoring and control.
Dissolved solids may be estimated by conductivity measurements,
suspended solids from turbidity, and specific ions by wet chem-
istry and colorimetric measurements. Flow meters of numerous
varieties are available for measuring flow rates.
The pH meter is the most universal of the in-line monitoring
instruments. In acid plants, hydrochloric, sulfuric, phos-
phoric, nitric, hydrofluoric, and chromic acid leaks in cool-
ers, distillation columns, pumps and other equipment can be
picked up almost at once. Spills, washdowns and other con-
tributions also become quickly eviöent. Alarms set off by
sudden pH changes alert the operations and often lead to im-
mediate plant shutdowns or switching effluent to emergency
VII — 7
DRAFT
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DRAFT
ponds for neutralization and disposal. Use of in-line pH
meters will be given additional coverage in the control and
treatment sections for specific chemicals.
Monitoring and control of toxic materials such as chromates,
mercury, arsenic, and cyanides is often so critical that
batch techniques are used. Each batch is analyzed before
dumping. This approach provides absolute control of all
wastes passing through the system. Unless the process is
unusually critical, dissolved solids are not monitored con-
tinuously. This follows from the fact that most dissolved
solids are of rather low toxicity. Chemical analyses on
grab or composite effluent samples are commonly used to es-
tablish total dissolved solids, chlorides, sulfates and other
low ion concentrations.
2.1.6 Safety, Housekeeping and Containment
Many of the chemicals of this study or their wastes are either
toxic and/or corrosive. Examples are the acids, chromates,
chlorine, sodium hydroxide, sodium, phosphorus, and potassium.
Mercury from chior-alkali plants and arsenic from phosphoric
acid are examples of waste toxicity.
Containment and disposal requirements may be divided into sev-
eral categories:
1. minor product spills and leaks
2. major product spills and leaks
3. upsets and disposal failures
4. rain water runoff
5. pond failures
2.1.7 Minor Spills and Leaks
There are minor spills and leaks in all industrial inorganic
chemical manufacturing operations. Pump seals leak, hoses
drip, washdowns of equipment, pipes and equipment leak, valves
drip, tank leaksoccur, solids spill and so on. These are
not going to be eliminated. They can be minimized and con-
tained. In some cases the products are valuable (such as
hydrofluoric acid and titanium dioxide where every pound lost
is like throwing a quarter down the drain). In other cases,
where the financial loss may not be as great, personnel safety
VII — 8
DRAFT
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DRAFT
and cquipttent ccrro :ion play becorc oaramcur.t. T”hen a leak
develops n the heat exchanger of a sulfuric acid plant,
the plant shuts down before corrosion gets out of hand.
Also, phosphorus is nob handled carelessiy.
Reduction techni.ques are mainly good hous2keeping and
attention to sound engineering and i aintenance practices.
Pump seals or type of pumps are changed, Valves are e1ec-
ted for minimizing drips. Pipe and equipr ent leaks are
minimized by selection of corrosion-resistant materialc.
Containment techniques include drip pans under pumps,
valves, critical small tanks or equipment, and known leak
and drip areas such as loading or unloaäing stations. Sol-
ads can be c1eai ed up or washed down. All of these minor
leaks and spills shoujd then go to a containment system,
catch basin, sump porno or other area thdt collects and
isolates all of ti:eT1 fr m other water sysbems. They should
go from this systeir to suitable treatment facilities.
The above mentioned techniques are being used effectively
in a number of exemplary plants today, nd in many cases
with enhanced profitability.
2.1.8 Major Product Spills and Leaks
These are catastropic occurrences with major loss of pro-
duct —- tank and pipe ruptures, open valves, explosions,
fires, earthquakes.
No none can predict, plan for or totally avoid these
happenings; but they are extremely rare. Probably the
most common of these rare occurrences is tank or valve
failures. These can be handled by adequate dikes able
to contain the tank volume. All acid, caustic or toxic
material tanks should be diked to provide this protec-
tion. Other special precautions may be needed for
flammable or explosive substances.
2.1.9 Upsets and Disposal Failures
In many processes there are short term upsets. These may
occur during startup, shutdown or during normal operation.
VII — 9
DRAFT
-------
D f ’T
These upsets rep nt a very smafl oortion of overall pro-
duction but they nL’-ertheless ccr 1 trib ’te to waste loads.
Hopefully, the upse L-’loducts i ’av be treated, separated,
and largely recycicd. .‘ the event that this can not be
done, they must he dispcs of. Dis; osal failures recuire
emergency tanks and/or ponds : some other e :pediency for
temporary holding or disposition . r op wells should have
either a back-up well in case of original well failure or
an alternate method of disposal. Ocean barges for bad
weather interrup ons or barge damage or maintenance should
also have temporary stor ’cxe and/or treatment facilities.
Failur2 - co c ovide sufficient back-uo ten oo:cary_alterna-
tive ab oit a o. ispo i facilities was one o the
most t tsnor ccc 1i s o oian tsv Ito 0
2.1.10 Rainwater Runoff
Another area of concern is the pickup of suspended or diss-
olved wastes in rainwater runoff from the propercy.
There are a few areas whore concern is wacrented. Examples
are: the large gypsum piles at hydrofluoric acid plants,
chromate plants with poor housekeeping and some mercury
cell chlorine plants. Any potential problems, such as for
chromates, can usually be minimized by good housekeeping
and containment practices in the plant area (as discussed
in a previous section). Minimizing airborne wastes, which
settle as dusts and mists on buildings and grounds, also
reduces rainwater pickups and surface water contaminations.
2.1.11 Pond Failures
Ui ined ponds are the most common treatment. facility used
by the inorganic chemical industry. Failures of such ponds
occur because they are unlined and because they are impro-
perly constructed for containment in times of heavy rain-
fall.
Unlined ponds may give good effluent control if dug in
impervious clay areas or poor control if in porous, sandy
soil. The porous ponds will allow effluent to diffuse
into the surrounding earth and water streams. This may
or may not be detrimental to the area, but it is certainly
poor waste control. Lined ponds are the only answer in
these circumstances.
VII — 10
DRAFT
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DRAFT
Many ponds used today are large low-dyked basins. In times
of heavy rainfall, much of the pond content is released in-
to either the surrounding countryside or, more likely, into
the nearest body of water. Again, whether this discharge is
harmful or not depends on the effluent and the surrounding
area, but it does represent poor effluent control.
Good effluent control may be gained by a number of methods,
included:
1. Pond and diking should be designed to take any
anticipated rainfall - smaller and deeper ponds
should be used where feasible.
2. Control ponds should be constructed so that drain-
age from the surrounding area does not innundate
the pond and overwhelm it.
3. Substitution of smaller volume (arid surfaced)
treatment tanks, coagulators or clarifiers can
reduce rainfall influx and leakage problems.
2.2 Treatment and Disposal Methods
After the in-process control practices discussed in the
previous section have been utilized, treatment is usually
required for the contaminated streams. In general, these
streams may be divided into one of three categories:
cooling water, process water, and ancillary water.
Cooling water, either once-through or recycled by means of
a cooling tower, should be relatively free of wastes. Any
contaminants present would come from leaks (stream to be
sent to emergency pond as soon as control rnonotoring picks
it up) or recycle buildups (cooling tower) which are han-
dled as ancillary water blowdowne. In either event, cool-
ing waste contributions are small and treatment, except for
incoming water purification, should not normally be needed.
Process and ancillary waterborne wastes do require treat-
ment. The type, degree and costs involved will depend upon
specific circumstances unique for each chemical. Treatments
may be grouped with respect to general ranges of cost
involved:
Modest Costs :
Small settling ponds or vessels
Minor filtrations
Minor chemical treatments
Ion exchange (low TDS)
VII — 11
DRAFT
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DRAFT
i4edium-to-Hiah Costs :
Settling ponds or vessels
Major filtrations
Chemical treatments
Centrifuging
Drying
Carbon adsorption
Table 39. (Ref. 1) summarizes general treatment costs.
2.2.1 Modest Cost Treatments
Modest cost treatments apply to both incoming and waste
water streams. Incoming surface water from streams,
lakes, or ocean is often subjected to filtration to re-
move suspended objects and solid particles, minor chemical
treatments for clarification (small suspended solids parti-
cle removal), pH control, and chlorination for BOD control.
Ion exchange is used to replace undesirable calcium, mag-
nesium, carbonate and other ions which plate out on boiler,
water tower and process equipment as they are concentrated,
aerated or subjected to pH changes.
Waste water streams are often subjected to filtra ions to
remove minor suspended solids. Screens, cloths, cartridges,
bags, candles and other mechanisms are used. Driving force
may be gravity, pressure or vacuum. Usually the filters are
precoated with diatomaceous earth or other filter aids.
Minor chemical treatments on water waste streams include
neutralizations for pH control, equalization of streams in
a pond or tank to smooth out waste composition fluctuations,
and chemical reactions or precipitations to remove undesired
components.
Settling ponds or vessels are the major mechanism used for
reducing the suspended solids content of water waste streams
coming from the plant. Their performance and cost depends
on the amount of waste involved and the settling character-
istics of the solids suspended. In the modest cost category
they are small, reflecting either fast settling and/or small,
flow rates.
Costs for the above treatments may in sone cases be derived
in the following sections as extrapolations.
VII — 12
DRAFT
-------
TABLE 39. Approximate Treatment Efficiencies and Costs
Cost /1 cubic meter
- - - 1.3—5.3 5.3—10.6 >10.6
Waste-Water
Constituent
Treatment
Processes
Removal, %
0—1.3
Coarse solids
Screening
90
x
Grinding and
-
x
Suspended solids
comminuting
Sedimentation
60
•
x
removal
Flotation
Coagulation and
flocculation
Miscrostraining
60
80
60
x
x
x
Soluble organics
Stabilization
50
x
removal
basins
Activated sludge
Trickling filter
Aerated lagoon
Anaerobic contact
Activated carbon
60
60
50
50
70
x
x
x
x
x
Oil removal
Gravity separation
Dissolved air
flotation
Absorption
Filtration
95
90
30-80
90
x
x
x
x
Neutralization
Acid or base
treatment
99
x
-------
TABLE 39. Approximate Treatment Efficiencies and Costs (cont)
Cost ‘ /l cubic meter
- 3 1.3—5.3 5.3—10.6 >10.6
Waste-Water
Constituent
‘ Treatment
Processes
Removal,
%
0—1.
Disinfection
Chlorination
Irradiation
99
99
x
x
Ozonization
99
x
Ultimate
Marine
—
x
disposal
Land
Air
-
-
.
x
x
Fine suspended
Coagulation and
70
x
solids
flocculation
Filtration
Microstraining
70
60
x
Ammonia removal
Biological
nitrification
Ammonia stripping
Breakpoint
chlorination
Ion exchange
90
85
99
90
•
x
x
x
x
Biostimulant
Biological
85
x
removal
denitrification
nitrogen
Ion exchange
Algae ponds
90
50-8 0
x
x
Biostimulant
Chemical
95
x
removal
precipitation
phosphorus
Ion exchange
Biological uptake
90
30
x
x
-------
TABLE 39. Approximate Treatment Efficiencies and Costs (cont)
Dewatering Coagulation and
flocculation
F lotat ion
Thickening
_________________ Evaporation
*Removal efficiencies are dependent on
Cost /l cubic meter
1.3—5.3 5.3—.L0..6 >10.6
* x
x
x
x
origin and nature of the sludge.
Waste-Water
Constituent
‘Treatment
Processes
Removal, %
0—1.3
Trace organics
Activated carbon
95
x
removal
adsorption
Soluble inor-
Electrodialysis
90
x
ganics removal
Ion exchange
90
x
(heavy metals,
Distillation
95
x
radioactivity,
Reverse osmosis
90
x
salts)
Chemical
precipitation
Freezing
Liquid-liquid
extraction
20-95
80
80
x
x
Heat removal
Evaporative heat
exchange
Reservoir
Nonevaporative heat
exchange
70
70-
x
x
x
Ultimated
Marine
-
x
disposal
Land
Air
-
-
x
x
I .-
U.
4
Ct
*
*
*
the
-------
TABLE 39. Approximate Treatment Efficiencies and Costs (cont)
Cost /1 cubic meter
0—1.3 1.3—5.3 5.3—10.6
Rem
oval, %
>10.6
Dewatering(cont)
Centrifugation
Vacuum filtration
Irradiation
*
*
*
.
x
x
x
Reduction
Aerobic digestion
Anaerobic digestion
Wet oxidation
Incineration
Calcination
*
*
*
*
*
x
x
x
x
x
Ultimate
Marine
*
x
disposal
Land
*
x
Air
*Removal efficiencies are dependent on
*
the origin
x
and
nature of
the sludge.
Waste-Water
Constituent
Treatment
Processes
1’-
I L
__ 16
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DRAFT
2.2.2 Medium-to-High Cost Treatments
Higher cost treatments are rarely needed for incoming water
(except in cases where either only very poor quality water
is available or very low TDS is required). They are more
applicable for treating waste effluents.
2.2.2.1 Ion Exchange and Demineralizations
Ion exchange and demineralizations are usually restricted
in both practice and costs to total dissolved solids levels
of 1000 to 4000 mg/i or less. Table 40 gives water compo-
sitions as a function of water treatments, including ion
exchange and demineralization.
An ion exchanger may be simply defined as an insoluble
solid electrolyte which undergoes exchange reactions with
the ions in solution. An exchanger is composed of three
components: an inert matrix, a polar group carrying a
charge and an exchangeable ion carrying an opposite charge.
The inert matrix today is usually cross-linked polymeric
resin containing the needed polar groups.
There are two types of ion exchangers: cation and anion.
Cation exchangers contain a group such as sulfonic or
carboxylic acid. These can react with salts to give pro-
ducts such as the following:
RSO3H ÷ NaC1 = RSO3Na ÷ HC1
RCO2H + NaC1 = RCO2Na ÷ HC1
The above reactions are reversible and can be regenerated
with acid.
Anion exchangers use a basic group such as the amino family.
RNA3OH + NaC1 + RNA3C1 + NaOH
This is also a reversible reaction and can be regenerated
with alkalies. The conibination of water treatment with both
cation and anion exchangers removes the dissolved solids and
is known as demineralization (or deionization). The quality
of demineralized water is excellent. Table 41 gives the
level of total dissolved solids that is achieved. Membrane
and evaporation process water contain significantly higher
solids content and need final polishing in a demineralizer
if less than 3 mg/liter dissolved solids level is required
for the application. There are many combinations of ion
exchangers which can be used for demineralizations.
VII — 17
DRAFT
-------
TABLE 40.
Raw Water and Anticipated Analyses
After Treatment
Parts per million
( ppm )
6
as CaCO3
Substance Symbol
1
2
3
4
5
7
8
9
Cat ions
Calcium ......Ca++
100
35
58
1
1
—
—
100
100
Magnesium ..Mg++
100
58
7
1
—
—
—
100
100
Sodium Na++
100
100
85
298
164
—
—
100
100
Hydrogen Acidity..........H+
Total Cations.............
0
300
0
198
0
150
0
300
0
165
—
5
—
5
0
300
0
300
-
Anions
Bicarbonate) HCO3—
150
0
0
150
15
—
—
150
150
Carbonate ) Alkalinity C03—-
0
35
21
0
0
—
—
0
0
Hydroxide ) 0 1 1—
0
0
0
0
0
—
—
0
0
Phosphate ) P04---
0
0
0
0
0
-
—
0
0
Anions
Chloride Cl—
75
79
64
75
75
—
—
75
75
Sulfate S04——
75
79
63
75
75
—
—
75
75
Nibrate N03-
0
0
0
0
0
—
—
0
0
Total Anions
300
193
150
300
165
5
5
300
300
Total hardness. . ............
200
93
65
2
1
—
—
200
200
Alkalinity A (Methyl Orange)
150
35
23
150
15
—
—
150
150
Alkalinity 13 (Phenolphthalein).....
0
17
14
0
0
—
—
0
0
Non—Carbonate Hardness.............
50
58
55
0
0
—
—
50
50
SodiumAlkalinity..................
0
0
0
150
164
—
—
0
0
C
-1
Carbon dioxide.. as C02
S 1 ii ca . . . . . . . as S 102
Iron & Manganese as Mn & Fe
Turbict1.t , . . . . . .
Color . . . .
Total Solids(Cations + Si02).......
PPM
30
15
10
50
10
315
PPM
0
A
0.2b
0-2b
10
208
PPM
0
5
0 . 2b
0—2b
10
155
PPM
PPM
PPM
5—10
5—10
0
15
15
0.02
0.2
0.2
0.2
PPM
30
15
0.2
0-2c
10
315
0—2c
10
180
PPM
3 Od
15
0.2c
0—2c
10
315
0—2c
10
20
PPM
30d
15
0.3
0—2c
10
315
0-2c
10
5
-------
TABLE 40. Raw Water and Anticipated Analyses
After Treatment (cont)
1. Raw water
2. After cold lime softening and filtration
3. After hot process softening and filtration
4. Ion exchange softening
5. Sodium and hydrogen unit blend and degasification
6. Two-step demjneraljzatjon (weak base anion exchange) and degasification
7. Two-step deminera].izatjon (strong base anion resin) and degasification
8. Aeration and filtration C
9. Manganese zeolite filters
‘1
a. Some reduction will occur
b. Filtered effluent
c. With proper pretreatment
ci. Affected by pH adjustment
e. Iron only
Note: Ion exchange processes assume that the water was adequately pretreated.
zIt- 19
-------
DRAFT
TABLE 41. Water Quality Produced by Various
Ion Exchange Systems
Residual Specific
Residual Electro— Resistance
Silica lytes, ohm-cm
Exchanger Setup mg/i mg/i @ 25 C
Strong—acid No silica <3 <500,000
cation + weak— removal
base anion
Strong—acid <0.01—0.1 <3 <100,000
cation + weak-
base anion +
strong—base
anion
Strong—acid <0.01—0.1 0.15—1.5 <1,000,000
cation ÷ weak—
base anion +
strong—acid
cation + strong-
base anion
Mixed bed <0.01—0.1 <0.5 1—2,000,000
(strong-acid
cation + Strong
base anion)
Mixed bed <0.05 <0.1 3—12,000,000
+ first or second
setup above
Similar setup at <0.01 <0.05 18,000,000
immediately above
+ continuous re-
ci rcu 1 at ion
VII — 20
DRAFT
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DRAFT
Four types of demineralization units will be discussed in
the cost analysis development to follow:
1. Fixed bed - strong cation — strong anion
2. Fixed bed - strong cation — weak anion
3. Mixed bed demineralizers
4. Special ion exchange systems.
Special ion exchange systems have been developed for treat—
ing high dissolved solids content (more than 1000 mg/liter
total dissolved solids), minimizing regenerant chemicals
costs. Some of these special systems are listed in Table 42.
Ion exchange rarely used to treat dissolved solids in waste
streams unless some specific ion or ions need to be removed.
In fact, usually little overall is gained by this technique
since regenerations give wastes that are often as trouble-
some to dispose of as are the original dissolved materials.
Also, the cost of even 1000 ppm dissolved solids exchange is
not low. Demineralization can be used for many applications.
They will undoubtedly see increased use in the future.
2.2.2.2 Chemical Treatment
Chemical treatments for abatement of water— ,rne wastes are
widespread. Included in this overall category are such
important subdivisions as neutralization, pH control, pre—
cipitations and segregations, toxic and undesirable waste
modification and miscellaneous chemical reactions.
a. Neutralization
Most of the inorganic chemicals of this study are
either acidic, alkaline or react with water to give acidic
or alkaline solutions. Others have production wastes or by-
products of acidic or basic nature. Before disposal in
surface water or other medium this acidity or alkalinity
needs to be reduced and controlled. The most common method
is to treat acidic streams with alkaline materials such as
limestone, soda ash, sodium hydroxide, and lime. Alkaline
streams are treated with acids such as sulfuric. Whenever
possible, advantage is taken of the availability of acidic
waste streams to neutralize basic waste streams and vice
versa.
VII — 21
DRAFT
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DRAFT
TABLE 42. Special Ion Exchange Systems
System : Desal (Rohm & Haas)
Application : Feedwater with high solids contents (above
1000 ppm TDS)
There are two variations of this system —- two-bed or three-
bed setup. Two—bed system consists of weak-base (HCO3)
anion + weak-acid (H) cation exchangers followed by a
decarbonator unit. NH4OH and C02 are used to regenerate
the anion exchanger and sulfuric acid to regenerate the
cation exchanger. In place of decarbonate a second weak—
base (OH) anion exchanger is used in the three—bed Desal
system.
System advantages: high flow rates; carbon dioxide re-
covery, good regenerant efficiency. Limitations: solids
content of water must be less than 2000 ppm; highly alka-
line feedwater needed for best performance; iron in feed-
water cannot be tolerated.
System : Sul—bisul (Nalco-Elgin)
Application : Feedwater with high solids content.
Also employs two- or three-bed setup. Two-bed system con-
sists of strong-acid (H) cation + strong—base (S04) anion
exchangers followed by decarbonator. Sulfuric acid used to
regenerate cation exchanger, raw water the anion exchanger.
In three-bed system a weak-acid (H) cation exchanger pre-
cedes the strong-acid cation exchanger.
Advantages: raw water can be used to regenerate the strong-
base anion exchanger; high quality rinse-water not required.
Limitations: ratio of S04 to Cl in feedwater must be high;
requires high volume of rinse water; low capacity.
System : Mori-Tavani (Resindion-Sybron)
Application : Feedwater with high solids content.
Four-bed systems consisting of: strong-base anion (HCO3)
+ weak-acid cation (H) + strong-acid cation (H) + weak-
base anion (OH) exchangers. NaHCO3 is us6d to regenerate
anion exchangers; sulfuric acid to regenerate cation
exchangers.
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TABLE 42. Special Ion Exchange Systems
(continued)
System : Mori-Tavani (Resindion-sybron) (continued)
Application : (continued)
Advantages: may be used on feedwater containing up to
3000 ppm solids, content; high capacity and regenerant
efficiency. Limitations: number of columns required;
low service flow rates; high cost of regenerants.
System : AlnTnonex (Cochrane)
Application : Condensate desalination
Mixed-bed ion exchangers have been plagued by the fact that
complete resin separation is difficult to achieve -— some
cation resin remains mixed with anion resin after back-
washing, with the result that sodium is released sooner
(lower capacity); some leakage occurs (affecting water
quality) since ammonia is usually present in condensate.
This is overcome in Alnmonex process by regenerating cation
exchanger with acid and first regenerating anion exchanger
with caustic and then with ammonia to remove the sodium
present in anion exchanger.
System : Calex (Permutit)
pp1ication : Condensate desalination
Water quality and run length improved similarly as in
Axnmonex process except that anion exchanger is regenerated
with caustic and lime rather than caustic and ammonia.
System : Seprex (Graver)
Application : Condensate desalination
Water quality and run length improved by separating mixed-
bed with strong caustic solution then regenerating beds in
customary procedure; i.e., with acid for cation exchanger
and caustic for anion exchanger.
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b. pH Control
The control of pH may be equivalent to neutraliza-
tion if the pH control point is at or close to 7. As dis-
cussed in the earlier control section, acidity or alkalinity
is best accomplished by pH meter monitoring. The usual ac-
ceptable range for pH control is 6.0 to 9.0 for discharge
water.
c. Precipitations and Segregations
The reaction of two soluble chemicals to produce
insoluble or precipitated products is the basis for remov-
ing many undesired waterborne (and airborne) wastes. The
use of this technique varies from lime treatments to preci-
pitate common sulfates, fluorides and carbonates to sodium
sulfide precipitations of mercury, copper, lead and other
toxic heavy metals.
d. Modifications
Chemical reactions can also be used to change or
destruct undesirable wastes. Among the more common are
the oxidation-reduction mechanisms. Cyanides can be ox-
idized to cyanates; hexavalent chromium reduced to the
less toxic trivalent form; hypochiorites changed to chlor-
ides; sulfites oxidized to sulfates. These examples and
many others are basic to the modification of inorganic
chemicals waterborne wastes to make them less troublesome.
2.2.2.3 Settling Ponds and Vessels
The chemical treatments described in the previous section
produced, in many instances, suspended solids. These solids
need to be removed but in the moving, agitated, often tur-
bulent waste steams flowing through pipes, tanks, and chan-
nels, there is little opportunity to do this. In fact, it
would usually be undesirable to do so in any event —- pipes
and flow channels are not easy or economical to clean.
To facilitate settling of suspended solids, large quiet set-
tling ponds and vessels are needed. Settling ponds are the
foremost industrial treatment for removing suspended solids.
The size and number of settling ponds differ widely depending
on the settling functions required. Waste streams with small
suspended solids loads and fast settling characteristics can
be cleared up in one or two small ponds (surface area less than
O.l-.2 hectare (1/4—1/2 acre)]. Other ponds with heavier sus-
pended solids loads and/or slower settling rate may require
5 to 10 ponds and up to 405 hectares (1000 acres) total surface area.
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Most of the settling ponds are unlined. Costs and control
characteristics of settling ponds are the same as discussed
in the previous section on control and disposal techniques
for unlined settling ponds.
Although not nearly as widely used as settling ponds, tanks
and vessels are also employed for reduction of suspended
solids loads in inorganic chernica]. production waste streams.
Commercially these units are listed as clarifiers or thick-
eners depending on whether they are light or heavy duty.
They also have internal baffles, compartments, sweeps and
other directing and segregating mechanisms to provide more
efficient performance. This feature plus the positive con-
tainment and control and reduced rainfall influence (smaller
area compared to ponds) should lead to increasing use of
vessels and tanks in the future.
2.2.2.4 Filtration (Major )
Major filtration equipment includes pressure and vacuum units
of various designs, including plate—and-frame leaf and rotary
constructions. Although it is entirely feasible that filtra-
tion equipment be used for removing suspended solids from
waste streams, most of these are not filtered. The preferred
treatment for removing suspended solids is the settling ponds.
Filtrations are common for collection of solid wastes from
toxic chemical treatments where complete removal is imperative.
Sludges containing heavy metal sulfides (mercury, arsenic, etc.)
are good examples of materials handled in this way.
2.2.2.5 Centrifuging
When the force of gravity is not sufficient to separate solids
and liquids to the desired degree or in the desired time more
powerful centrifugal force can be utilized. Although there
are many types of centrifuges most industrial units can be
broken down into two major categories -- solid bowl and per-
forated bowl. The solid bowl centrifuge as its name indicates
consists of a rapidly rotating bowl into which the stream with
suspended solids is introduced. Centrifugal action of the
spinning bowl separates the solids from the liquid phase and
the two are removed in separate take of fs.
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The perforated bowl centrifuge has holes in the bowl through
which the filtrate escapes by centrifugal force. The solids
are retained on the filter inside the bowl and removed either
continuously (such as for the pusher types) or in batch fashion.
Centrifuges are not widely used for inorganic chemical waste
streams, since it is rare that settling ponds or filters are
not adequate for the same suspended solids removal job.
2.2.2.6 Carbon Adsorption
In the rare occasions that inorganic chemicals waste streams
contain organic materials one of the appropriate treatments
to remove these organic components is carbon adsorption. When
waste streams containing organic contaminants are passed
through activated carbon beds the organic material is adsorbed.
When the carbon bed is saturated with this organic substance
the bed may be regenerated by burning off the adsorbed organic
and returning the carbon to service.
2.2.2.7 Reverse Osmosis
The phenomenon of osmosis has its explanation in thermodyna-
mic equilibrium and free energy concepts. Essentially, when
a semi-permeable membrane separates a pure liquid and solu-
tion of dissolved material in the same liquid there is a net
migration of the pure liquid to the solution, driven by the
free energy difference between the two sides of the membrane.
Equilibrium is reached only when the liquids on each side of
the membrane are of the same composition or sufficient addi-
tional pressure is applied on the solution side of the membrane
to counterbalance the osmotic driving force. Application of
additional pressure on the solution side reverses the direction
of osmotic flow through the membrane and results in concentra-
tion of the solution and migration of additional pure liquid to
the pure liquid side. This is reverse osmosis. It may also
be looked at. as pressure filtration through a molecular pore—
sized filter.
The small pore size of the reverse osmosis membrane is both
its strength and its weakness. It strength comes from the
molecular separations that it can achieve. Its weakness comes
from the criticalness it has to blinding, plugging, and chemi-
cal attack. Acidity, suspended solids, precipitations, coat-
ings, dirt, organics and other substances can make it inopera-
tive. Membrane life is critical and unknown in many mediums.
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With these restrictions there is little wonder that its indus-
trial applications are few. Fortunately, the inorganic chem-
istry industry water purification needs are similar to those
of the areas where reverse osmosis has been shown to be appli-
cable -- treatment of brackish water and low (500 ppm to 20,000
ppm) dissolved solids removal. Organics are usually absent,
suspended solids are low and can be made low rather easily,
acidity is easily adjusted, and most of the dissolved solids
are similar to those in brackish water -- sodium chlorides,
sulfates and their calcium counterparts.
The reverse osmosis membranes used coimnercially are generally
one to two types -- flat sheet or hollow fiber. For maximum
membrane area in the smallest space, various sheet configura-
tions have been devised including tubes, spiral winding, and
sandwich-type structures. Sheet membranes have been largely
cellulose acetate, while hollow fibers have been largely poly-
amides. Costs for the different membrane construction are
roughly comparable. The type selected depends upon the speci-
fic application.
Regardless of membrane type or material, the basic unit of
construction is the module (or package of membrane materials).
The module is usually integral and of the plug—in type, where
a faulty module can be easily (but not inexpensively) replaced.
The modules are the heart of the reverse osmosis process, with
ancillary equipment such as pumps, tanks, piping, pretreatment
facilities and other hardware performing peripheral functions.
Module cost alone comprises one—third to one-half of the in-
stalled capital investment.
Detailed cost figures, both capital and operating, are given
in the next section.
2.2.2.8 Evaporation Processes
Evaporation is the only method of general usefulness for the
separation and recovery of dissolved solids in water . All
others either involve mere concentrations (reverse osmosis)
or introduce contaminations for subsequent operations (deinin—
eralizer regenerants and chemical precipitations).
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The evaporation process is well known and well established
i the inorganic chemical industry. Separations, product
purifications, solution concentrations are commonly accom-
plished by evaporative techniques. In-depth technology for
handling the common dissolved solids in water waste streams
has been developed in the soda ash, salt, calcium chloride,
and sea water chemical industries. In addition, numerous
desalination plants producing fresh water from brackish or
sea water are scattered all over the world and have been in
operation for a number of years. Seawater generally has
approximately 35,000 ppm dissolved solids (3.5 percent by
weight) while brackish water has 2,000 to 25,000 ppm depend-
ing on location. Some southwestern U.S. water supplies con-
tain dissolved solids above 2,000 ppm and have to be treated
similar to brackish water.
On the other hand evaporation is a relatively expensive oper-
ation. To evaporate one kilogram of water, approximately 550
kilogram-calories of energy is required and the capital cost
for the evaporating equipment is not low. For these reasons
ind ustrial use of evaporation in treating waste water has been
minimal. As the cost of pure water has increased in portions
of the United States and the world, however, it has become in-
creasingly attractive to follow this approach.
Almost always the treatment of water waste streams by evapor-
ation has utilized the principle of multi-effects to reduce
the amount of steam or energy required. Thus the theoretical
difficulty of carrying out the separation of a solute from its
solvent is•the minimum amount of work necessary to effect the
particular change, that is the free energy change involved. A
process can be made to operate with a real energy consumption
not greatly exceeding this value. The greater the concentra-
tion of soluble salts, the greater is the free energy change
for separation, but even for concentrated solutions the value
is much lower than the 550 kg-cal per kilogram value to evapor-
ate water. Multi-effect evaporators use the heat content of the
evaporated vapor stream from each preceding stage to efficiently
(at low temperature difference) evaporate more vapor at the
succeeding stages. Thus the work available is used in a nearly
reversible manner, and low energy requirement results. However,
a large capital investment in heat transfer surface and pumps
is required. The interaction of the capital equipment costs
versus energy or operating costs will be discussed in detail in
the treatment costs section.
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2.2.2.9 Drying
After evaporative techniques have concentrated the dissolved
solids to high levels, the residual water content must usually
still be removed for either recover, sale or disposal. Water
content will range from virtually zero up to 90 percent by
weight. Gas or oil fired dryers, steam heated drum dryers or
other final moisture-removing equipment can be used for this
purpose. Since this drying operation is a conunon one in the
production of inorganic chemicals themselves, technology is
well known and developed. Costs are mainly those for fuel or
steam.
2.2.3 Disposal Practices
Disposal of the waterborne wastes from inorganic chemicals man-
ufacture represents the final control exercised by the waste
producer. A number of options are available, some at zero or
low cost, others at high cost.
Low-cost options include discharge to surf . ce water —— river,
lake, bay or ocean —— and where applicable, land disposal by
running effluent out on land and letting it soak in or evap-
orate.
At somewhat higher costs, wastes may be disposed of into the
municipal sanitary system or an industrial waste treatment
plant. Treatment and reuse of the waste stream can also be
practiced. In dry climates unlined evaporation ponds, if
allowed, would involve moderate costs.
High—cost disposal systems include lined evaporation ponds,
deep well disposal, ocean barging, and high-cost treatment
prior to disposal or recovery. Such methods are used for
wastes which cannot be disposed of otherwise. These wastes
contain strong acids or alkalies, toxic substances, or high
dissolved solids content.
Feasibility, use, and cost figures can be discussed for:
1. unlined evaporation ponds
2. -lined evaporation ponds
3. deep wells
4. ocean barging.
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2.2.3.1 Unlined Evaporation Ponds
Two requirements must be met for an unlined evaporation pond
to be successfully utilized. First it must be located in an
area in which unlined ponds are allowed, and secondly, the
rainfall in that area must not exceed the evaporation rate.
This second requirement eliminates most of the heavily indus-
trialized area. For the low rainfall areas, evaporation
ponds are feasible with definite restrictions. Ponds must
be large in area for surface exposure. The volume of water
evaporated per year can be determined by the following formula:
Volume = 0.00274 x A x Area
Where A = difference between meters of water evaporated/year
and meters of rainfall per year.
The area of the pond is given in square meters and the volume is
given in cubic meters per day. For example, if one wanted to dis-
pose of 3785 cubic meters per day of waste water in an area that
gained 0.61 meters of evaporated water per year the required area
would be:
Area = 3785 = 2.26 x l06m2 or 226 hectares or 560 acres
0.61 x 0.00274
Evaporation of large amounts of waste water requires large
ponds. The availability and costs of sufficient land place
another possible restriction on this approach.
2.2.3.2 Lined Evaporation Ponds
The lined evaporation ponds now required in some sections of
the country have the same characteristics as developed for
the unlined ponds -- large acreage requirements and a favor-
able evaporation rate to rainfall balance. They are signifi-
cantly higher in cost than an unlined pond. Such costs are
developed in a later section. Reduction of the evaporation
load is a significant advantage. For this reason, plus the
short supply and high cost of water in much of southwestern
United States, distillation and membrane processes are begin-
ning to be used in these regions.
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2.2.3.3 Deep Wells
Deep well disposal is becoming an increasingly popular tech-
nique for industrial wastes. While used for brine disposal
in the petroleum and salt industries, deep wells are usually
reserved for the “dirtiest” wastes such as strong acids,
chromates, pickle liquor, and corrosive metallic salt solu-
tions for which no low or medium cost disposal system is avail-
able.
There are several reasons for this specialization, including:
1. Costs — A single well costs $40,000 to $1,500,000 de-
pending on depth, drilling ease and criticalness, casing,
exploration and monitoring involved.
2. Geological — The geological structure in the area is
of utmost importance. In many parts of the country deep wells
are not possible. Even in those sections where the geological
structure permits their use, deep wells must be carefully
planned and coordinated using the best geological information
and expertise available.
3. Drillin Considerations — Deep wells are drilled by
specialists using oil well technology. While this technology
is well developed, there is always the possibility that some-
thing expensive will go wrong -— cracks, lost drills, imper-
meable formations, etc.
4. Reliability - Deep wells often plug or develop operating
difficulties even after several years of good performance.
5. Extensive Pretreatment may be necessary to remove or—
ganics, suspended solids and other undesirable waste components.
6. The risk of contamination, of underground potable water
or seismic effects.
Most wells are approximately the same size and range in flow
rate from 12.6 liters per second to 56.8 liters per second with
the average being about 18.9 liters per second to 25.2 liters
per second. This corresponds to approximately 1890 cubic meters
per day capacity.
Since wells fail at unknown times and cannot be drilled in
short periods of time a spare well or an acceptable disposal
alternative always has to be available . In addition to the
initial and recurring capital cost, operating and maintenance
costs are also involved.
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2.2.3.4 Ocean Barging
The ultimate disposal sinks for aqueous wastes are the oceans.
As with deep wells, barging wastes out to sea for disposal is
reserved for the “dirtiest” of effluents.
3.0 SPECIFIC CONTROL AND TREATMENT PRACTICES IN THE INDUSTRY
3.1 Category 1
3.1.1 Aluminum Chloride
3.1.1.1 General -
Direct chlorination of aluminum to produce aluminum chloride
is a relatively simple process. Plants are small (9 to 18 metric
tons/day). Since the process is so simple, plant age is not
an important factor. There is no process water involved,
nor usually any cooling water. The only source of water
wastes is from equipment used to treat air-borne wastes such
as aluminum chloride dust around the packing station and
aluminum chloride and chlorine from the air-c.,oled condensers.
3.1.1.2 Typical Control and Treatment Techno. gy
In some plants, run on the aluminum-rich side (white or gray
aluminum chloride), there is very little chlorine in the dis-
charge from the air-cooled condenser. Also, the gas volume
from the condenser is such that only a very small quantity
of aluminum chloride is discharged. In such plants there
may be no air pollution control provision. One of the exem-
plary plants of this study operates in this fashion. In
plants operating on the chlorine-rich side (yellow aluminum
chloride), water scrubbing of the air condenser discharge
gases is needed. Provisions for this treatment vary from
none to exemplary, depending on the plant involved.
3.1.1.3 Best Practicable Control and Treatment Technology
At least three practicable, economically feasible, and low
energy air pollution control approaches are available:
(1) No air or gas treatment for gray or white aluminum
chloride.
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(2) Gas scrubbing and sale of scrubber wastes. This
approach is taken by an exemplary plant of this
study.
(3) Gas scrubbing followed by chemical treatment to
precipitate aluminum hydroxide and convert chlorine
to sodium chloride. Technology available from the
chior-alkali and titanium dioxide chloride process
may be applied. Costs for this treatment process
are developed in Section VIII to demonstrate its
economic reasonableness.
Best available control and treatment technology is the same
as for the best practicable level.
3.1.2 Aluminum Sulfate
3.1.2.1 Typical Control and Treatment Technology
Current typical treatment involves use of a settling pond to
remove muds followed by neutralization of residual sulfuric
acid prior to discharge.
3.1.2.2 Best Practicable Control and Treat. nt Technology
Two exemplary plants (049 and 063) of this study have closed
loop waste-water systems. Suspended solids are dropped out
in the settling vessels and ponds and the clear overflow re-
turned to the treatment process.
Best available technology is the same as best practicable.
3.1.3 Calcium Carbide
3.1.3.1 General
There is no process water involved in the production of cal-
cium carbide. Ancillary water wastes such as cooling tower
blowdowns and ion exchange regenerants are often present.
There may also be water—borne wastes from air pollution con-
trol equipment.
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3.1.3.2 Typical Control and Treatment Technology
Practices evidently vary from one plant to another as far as
air pollution control practices are concerned. Some plants
have no facilities for air-borne wastes; other use water scrub-
bers.
3.1.3.3 Best Practicable Control and Treatment Technology
Water—borne wastes from air—borne waste control equipment may
be avoided by use of dry bag collector systems. Unlike alum-
inum chloride, the air—borne wastes from the calcium carbide
process are all dusts -- coke and coal fines, limestone powder
and calcium carbide from the packing station. Coke, coal and
limestone fines, which constitute a significant fraction of
the feed materials, may be profitably returned to the system.
The exemplary plant of this study uses only dry bag collectors
and recycle of collected fines to the furnace.
Dry bag collection of air-borne fines not only eliminates water-
borne wastes and makes it possible to reuse these fines but it
also significantly reduces energy requirements by avoiding high
energy drying costs needed for recovery of water wastes. There-
fore, only dr r dust collection systems should be considered for
calcium carbide air—borne fines control and recovery .
Best available treatment and control technology is the same as
discussed above.
3.1.4 Hydrochloric Acid
3.1.4.1 General
The only process considered in this study is chlorine burning.
Only about ten percent of the U.S. production comes from this
process. Most hydrochloric acid is produced as a by—product
of other processes. The chlorine—burning process is a simple
one and capital equipment is relatively inexpensive. The pro-
cess fits well with chior—alkali complexes where low-cost or
waste chlorine (and possibly hydrogen from mercury cells) is
readily available.
There is no water—borne process waste during normal operation.
A small amount of chlorine and hydrochloric acid wastes are
developed during startup.
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3.1.4.2 Typical Control and Treatment Technology
Since there are no process wastes, spills, leaks, contributions
from air-borne hydrogen chloride waste treatment equipment,
and startup and upset wastes are the only Concerns. Base
treatment and control of these small miscellaneous wastes con-
sists of neutralization with available sodium hydroxide follow—
ed by discharge to surface water.
3.1.4.3 Best Practicable Control and Treatment Technology
To reduce water-borne wastes, containment and isolation tech-
niques need to be followed. Dikes, drip pans and other devices
are used for leaks and spills. Centralized collection and neu-
tralization with sodium hydroxide can be followed by forwarding
the neutralized stream to other chior—alkali complex u es such
as make—up water for brine solutions used in mercury of dia-
phragm cells. The size of the waste load, excluding that from
the air-borne hydrogen chloride treatment, is small — 0.5 to
one kilogram per metric ton.
If waste water streams are kept small, as is certainly feasible,
control and treatment costs are minimal.
Best available technology is the same as best practicable.
3.1.5 Hydrofluoric Acid
3.1.5.1 General
Hydrofluoric acid sells for approximately 550 dollars per
metric ton. Therefore, the incentive for containment and recov-
ery of leaks, spills and other product losses is understandably
greater than for the other mineral acids. By the nature of the
process, large quantities of cooling water are needed, but this
is in the non—Contact category. Water—borne process waste loads
are sniall and can be reduced by control and treatment to zero
effluent by closed loop systems.
3.1.5.2 Typical Control and Treatment Technology
Neutralization of sulfuric and hydrofluoric acid wastes with
lime, followed by removal of precipitated calcium sulfate and
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calcium fluoride in settling ponds, reduces fluorides to 5-10
mg/liter and calcium sulfate to approximately 2000 mg/liter in
treated water streams.
3.1.5.3 Best Practicable Control and Treatment Technology
Segregation of the leaks, spills and sulfuric acid-containing
wastes from the cooling water is the first requirement. This
segregation reduces the quantity of water which has to be
treated. Also by in-process changes, such as using stoichio-
metric quantities of sulfuric acid in the process reactor, the
sulfuric acid may be eliminated from the water—borne wastes.
Lime treatment of the isolated wastes and settling pond removal
of the precipitate reduces the fluoride content of this small
stream to approximately 10 mg/liter. This procedure gives
waste with less than 0.5 kilogram total dissolved solids per
metric ton of hydrofluoric acid, and makes closed cycle oper-
ation possible. Two exemplary plants, one using once—through
cooling water, and the other (plant 152) a closed cycle system
(zero effluent), were found in this study.
There are no air pollution problems for this process, but mass-
ive calcium sulfate solid wastes (3400-4250 kilograms per metric
ton of hydrofluoric acid) from the process reactor give both
land disposal and rainwater runoff problems. Storage piles of
this calcium sulfate should be located and contained so that mater-
ials such as calcium sulfate and residual lime or sulfuric acid
are not conveyed by rainwater runoff to surface or underground
fresh water streams.
Best available control and treatment technology is the same as
best practicable.
3.1.6 Lime
3.1.6.1 General
The process for producing lime involves no water—borne wastes.
The only wastes result from plants that use wet scrubbing of
the gaseous effluent to remove entrained dust.
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3.1.6.2 Typical Control and Treatment Technology
Air-borne particulates control practices vary. Some use wet
scrubbing. Others use dry collection methods.
3.1.6.3 Best Practicable Control and Treatment Technology
The choice between water scrubbing and dry collection of air—
borne wastes should in general be determined on the basis of
the type of wastes involved. Reactive gaseous wastes such as
chlorine, hydrochloric acid, and sulfur dioxide respond to
aqueous scrubbing or chemical reaction. Air-borne, relative-
ly inert dusts and particulates such as limestone, fly ash,
coal dust, and lime can usually be handled by dry collection
methods with less energy, better chance of reuse and recovery,
and with the avoidance of water-borne wastes.
Dry bag collection systems are used in some lime plants today
(e.g., exemplary plant 007). It is recommended that lime
plants have no water-borne wastes . Plants that either current-
ly use water scrubbing or plan to for future installations
should be restricted to closed cycle water systems or reduce
suspended solids to 15 mg/liter and negligible dissolved solids
by ponding, chemical treatment and filtration.
Best available treatment and control technology is the same as
best practicable.
3.1.7 Nitric Acid
3.1.7.1 General
There are no water—borne process wastes. There are usually no
water-borne wastes from air pollution abatement practices.
Cooling water requirertlents are high. Minor water—borne wastes
are due to leaks, spills and washdowns and ancillary systems
such as cooling towers.
3.1.7.2 Typical Control and Treatment Technology
Provisions are made for handling and neutralizing spills and
leaks. Neutralization can be done with limestone, oyster or
clam shells, lime or sodium hydroxide. Sometimes collected
leaks, spills and washdowns are returned to the process.
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3.1.7.2 Best Practicable Control and Treatment Technology
Diking of tanks, pump areas, loading and washing areas should
be combined with isolation and return of leaks, spills and
waphdowns whenever possible. Diking of large tanks should be
sufficient for complete containment. Emergency ponds should
be provided for major upsets. Limestone or seashell pond
linings and ground coverings are used fo neutralizations.
Best available treatment and control technology is the same
as best practicable.
3.1.8 Potassium Metal
There are no water—borne wastes from this process.
3.1.9 Potassium Chromates
Potassium dichromate is made from the reaction of sodium di-
chromate with potassium chloride. There is none of the mass-
ive ore waste present as in the sodium dichromate process.
The only water—borne wastes from the major U.S. production
facility emanate from contamination of once—through cooling
water used in the barometric condensers. These are scheduled
for replacement in 1974 by heat exchangers using non-contact
cooling water. This will result in no discharge of water-
borne wastes.
3.1.10 Potassium Sulfate
The exemplary plant for production of potassium sulfate is
plant 118. It is a closed cycle plant where water recovery
is accomplished by distillation of 1,500 cubic meters per
day (somewhat larger than the sodium dichromate evaporation
modelled in Section VIII).
3.1.11 Sodium Bicarbonate
3.1.11.1 Typical Control and Treatment Technology
Typical practices involve the settling of suspended solids in
ponds followed by discharge to surface water.
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3.1.11.2 Best Practicable Control and Treatment Technology
The effluent from this process is essentially sodium carbonate
in solution. In a complex, use for this solution could be
made, probably at lower cost than for recovery. Present water-
borne wastes are a relatively low 6.5 kilograms per metric ton
of product.
3.1.11.3 Best Available Control and Treatment Technology
By keeping the waste stream small and the solids level high,
evaporative techniques are feasible without undue expense.
The evaporation process give demineralized water for boilers
plus recovered product worth S36/metric ton. An alternative
approach would involve total recycle.
3.1.12 Sodium Chloride
In spite of the fact that the sodium chloride industry has
very heavy wastes, disposal is usually accomplished by pumping
the brine wastes back into the well or mine, by storage of
solar salt wastes in large ponds or by sale of salt wastes.
Pond storage is feasible because large land areas are already
available arid evaporation—rainfall balances are favorable in
the pertinent areas. Pond storage of bitterns is not a desir-
able or economical long range solution for solar salt producers.
The use of the magnesium-rich bitterns for magnesium chemicals
roductjon would conserve major quantities of energy over start-
ing with natural brines or seawater.
3.1.13 Sodium Silicate
3.1.13.1 Typical Control and Treatment Technology
Contaminated waste streams containing sodium hydroxide, sodium
Silicate and filter aids are sent to settling ponds to remove
suspended solids. Waste water is then neutralized and discharged
to surface water.
3.1.13.2 Best Practicable Control and Treatment Technology
The wastes from sodium silicate plants are so minor that closed
loop zero discharge operation is feasible.
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Best available technology is the same as best practicable.
3.1.14 Sulfuric Acid (Sulfur—Burning and Regen Plants)
3.1.14.1 General
There are no process wastes from the sulfur—burning sulfuric
acid plants. The only water-borne wastes are spills, leaks,
washdowns, and those from air—borne sulfur dioxide scrubbers.
Regen plants which start with waste sulfuric acid of 30-90 per-
cent strength in addition to sulfur have an additional waste
of weak sulfuric acid which must be removed before regular
high strength sulfuric acid can be produced. Once this weak
acid waste has been removed from the system, the remaining
wastes are typical of the sulfur-burning process.
3.1.14.2 Typical Control and Treatment Technology
Leaks, spills and washdowns are detected by monitoring pH in-
struinentation. In—process leaks give serious corrosion pro-
blems so that shutdown and repair is in order as soon as these
leaks are detected. Neutralization with lime or sodium hydrox-
ide is used to control the pH level of the effluent. Regen
plants dispose of the weak sulfuric acid wastes in various ways
including neutralization, sales, and use in making some grades
of acid.
3.1.14.3 Best Practicable Control and Treatment Technology
Monitoring is needed with pH instrumentation for in-process
leaks and spills and emergency ponds are required for contain-
ing contaminated cooling water for neutralization.
Containment, isolation, and reuse or neutralization of minor
leaks, spills and washdowns may be obtained with dikes, catch
pans, sumps and drain systems. Major storage tanks should be
sufficiently dikea for complete storage tank capacity contain-
merit. Pond linings and pertinent plant grounds coverings of
limestone or seashells can provide automatic neutralization.
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Regen plant weak acid wastes should be used for good purpose.
Included uses are feed to a sulfur-burning unit, neutraliza-
tion of alkaline solution in other processes, addition to
strong acid to make weaker grades, and sales for miscellaneous
uses. As a last resort, the weak acid can be distilled to
greater strength or chemically neutralized with lime. Air-
pollution devices to remove sulfur dioxide sometimes contri-
bute to the water-borne waste load. This should be avoided.
Sulfur dioxide removal processes which do not involve water
wastes are now available. They should be used for all future
installations . These non—water waste processes include
double-absorption add-ons (for existing plants), and molecular
sieve processes. Several other processes are either in com-
mercial or developmental status.
3.1.14.4 Best Available Control and Treatment Technology
Existing sulfur dioxide control equipment which involves water-.
borne waste can be converted to a waste-free basis by concen-
tration and recovery of dissolved solids. Since the recovered
solid is sodium sulfate for which there is a market, this
approach will be analyzed in Section VIII.
3.2 Category 2
3.2.1 Sodium Metal
3.2.1.1 General
Sodium metal is produced in a Downs Cell Process. Chlorine,
produced simultaneously with the sodium, is covered in this
Section VII under chlorine. The treatment and control pro-
blems for chlorine once it leaves the cell are the same for
the Downs Cell product as for the mercury and diaphragm cells
chlorine. Therefore, no discussion of chlorine treatment and
control will be made in this subsection.
3.2.1.2 Typ.ical Control and Treatment Technology
The non-chlorine based wastes consist of brine purification
muds, cell wastes such as bricks, graphite, sodium chloride
and calcium chloride, and sodium-calcium sludge from the
sodium cooling and purification step. Settling ponds are
used for mud removal. Bricks, graphite and other solids are
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landfilled. Sodium chloride and calcium chloride are washed
down and allowed to flow to surface water.
3.2.1.3 Best Practi cable Control and Treatment Technology
1n the exemplary plant of this study, (no. 096), the only cell-
based wastes not land dumped are the sodium and calcium chlor-
ides. These salts, lost to the extent of an estimated 88 kilo-
grams per metric ton of sodium produced, are developed from cell
dumpings, wash tanks, and run of fs, and are not currently con-
trolled, but rather allowed to run off over the land into sur-
face water. Isolation and collection of these wastes would
make it possible to recover and reuse the sodium and calcium
chlorides in the incoming brine system. The simplest procedure
would be to recycle this weak brine into the brine purification
system. If this procedure is not satisfactory, then the fairly
small stream can be concentrated to recover, first any calcium
sulfate or sodium sulfate, secondly sodium chloride, and finally,
calcium chloride. Sodium chloride and calcium chloride can be
dumped. Sodium sulfate can be sold if there is enough to war—
ant it. If not, it may be containerized and disposed of to
landfill.
3.2.1.4 Best Available Control and Treatment Technology
Like the chlor-alkali facilities discussed under chlorine of
Section VII, the sodium production process should have no water-
borne waste. It should be even easier to achieve for the sodium
process than for chior-alkali plants, since only dry salts,
chlorine and solid sodium are involved in the heart of the pro-
cess. Ancillary water—borne wastes such as cooling tower blow-
downs, ion exchange regenerants and other such contaminants
will still be present.
3.2.2 Sodium Chloride (Brine Mining )
See Section 3.1.12 Sodium Chloride (Solar).
3.2.3 Sodium Sulfite
3.2.3.1 Typical Control and Treatment Technology
The wastes from this process are primarily sodium sulfite and
sodium sulfate. The sulfites constitute a heavy chemical oxygen
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demand (COD). Typical treatment, at least until recently,
has consisted of mixture with large quantities of cooling
water to dilute the waste load.
3.2.3.2 Best Practicable Control and Treatment Technology
Best practicable treatment consists of air oxidation of the
sodium sulfite in the waste stream to sodium sulfate. Treat-
ment results in approximately ninety-five percent conversion
of sulfite to sulfate.
3.2.3.3 Best Available Control and Treatment Technology
Recovery of the sodium sulfate from the effluent eliminates
process waste. This technologically and economically feasi-
ble recovery reduces the sulfite process waste to virtually
zero and provides both a saleable product and a supply of
high quality demineralized water for boiler, cooling tower,
or process use.
3.2.4 Calcium Chloride
3.2.4.1 General
This chemical is obtained both from soda ash wastes and from
natural salt deposits. The soda ash produces large amounts
of calcium chloride as a by—product. Unreacted sodium chlor-
ide and other dissolved solids are also present in this waste
stream. After calcium chloride is extracted from this waste
stream, the remaining calcium chloride, sodium chloride and
other dissolved solids are returned to the waste stream of
soda ash manufacture. Extraction of calcium chloride from
natural salt deposits is carried out in a major chemical com-
plex and is scheduled within the next six months to be brought
to virtually zero waste discharge. Since both processes are
abnormal, interpretation must be developed for each.
3.2.4.2 Typical Control and Treatment Technology
There are no typical practices. The two major producers dif-
fer widely in their approach.
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3.2.4.3 Best Practicable Control and Treatment Technology
From the soda ash process, recovery of calcium chloride is con-
sidered as a zero discharge process similar to sodium sulfate
from the sodium dichromate process. There are no additional
wdstes generated as a result of this recovery.
The natural salt process, on the other hand, utilizes the in-
tegrated nature of the complex where it is produced to take
advantage of every normal waste. Sodium chloride goes to chior-
alkali facilities. Magnesium chloride, which is often difficult
to dispose of, is isolated and used for other processes. Con-
sequently this process for making calcium chloride is also zero
effluent in the particular complex where it is made. This is
a good example of the previously discussed principle that wastes
from a complex should never be greater than the sum of the indi-
vidual plants and should be significantly less. Best available
technology is the same as best practicable in this unusual case.
3.2.5 Hydrogen Peroxide (Organic Process)
3.2.5.1 General
The organic process effluent generally contains waste hydrogen
peroxide plus organic solvent used in the process. The nature
of this solvent is considered a trade secret.
3.2.5.2 Typical Control and Treatment Technology
The hydrogen peroxide waste is decomposed with scrap iron and
the organic solvent is removed by skimming the insoluble layer
off the top of the water stream. The effluent is then passed
into a settling pond for removal of suspended solids or organ-
ic solvent interaction with suspended solids from other pro-
cesses.
3.2.5.3 Best Practicable Control and Treatment Technology
The only difference between typical and best practicable treat-
ment and control technology is the efficiency of the treatment
methods themselves. Additional isolation, containment and
treatment of wastes with scrap iron for peroxides and skimming
separation for organics further reduces the waste loads.
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3.2.5.4 Best Available Control and Treatnent Technology
Organics may be removed from this waste water stream by bio-
logical digestion as commonly used in sanitary sewage treat-
ment. The waste water could be sent directly to a municipal
sewer without problem.
An alternate technique is to remove the organics by carbon
absorption.
Neither of the above treatment processes is considered nec-
essary, should the levels recommended in Sections IX, X,
and XI be unobtainable by current practices treatment
methods, however, these relatively expensive but still fea-
sible approaches need to be applied.
3.3 Category 3
3.3.1 Chlorine
3.3.1.1 General
Chlorine is produced by three major processes: mercury cells,
diaphragm cells and Downs Cells. The other chemicals produced
are sodium (Downs Cell only), sodium hydroxide and potassium
hydroxide, variously. There is also quite often a direct burn-
ing hydrochloric acid plant in the complex.
The following chlorine discussion include mercury and diaphragm
cell productions. Downs Cell operation will be discussed under
sodium, but the chlorine—based wastes are the same as for the
mercury and diaphragm cells.
The chior—alkali industry is based on salt (sodium chloride or
potassium chloride). Transformations of all sodium and chlorine
chemicals can and have been made in chior-alkali plants. This
is a fortunate situation from the standpoint of waste reduction
and zero discharge. In contrast, for example, are the soda ash
process which produces large quantities of calcium chloride for
which no use can be made and the potassium dichromate process
which produces large quantities of sodium chloride with no use
for t in the process. Examples of how waste conversions can
be made in the chior-alkali process are given in the following
equations:
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(1) 2NaC1 2Na + C12
(2) 2Na + 2H20 2NaOH + H2
(3) 2NaOH + C12 + NaOC1 + NaC1 + H20
(4) 2NaOC1 2NaC1 + 02
(5) C12 ÷ “ 2HC1
(6) HC1 + NaOH NaC1 + H20
Equations (1) and (2) show the product formations. Equation
(3) represents tail gas scrubbing operations to remove chlorine
gas from air effluents from the plants. Equation (4) shows
conversion of sodium hypochiorite back to salt raw reactant
materials. Equation (5) eliminates waste chlorine gas by
direct burning of chlorine to produce hydrochloric acid.
Equation (6) uses hydrochloric acid to neutralize waste
sodium hydroxide, thereby producing salt for return to the
system. Provided the water-borne waste streams are kept iso-
lated from much larger cooling water streams, control and
treatment techniques are entirely feasible.
3.3.1.2 Typical Control and Treatment Technology
Salt impurities have to be removed by precipitations before
the brine solutions can be used in the cells. Treatment
with soda ash, sodium hydroxide, and sometimes barium chlor-
ide, removes calcium, magnesium and sulfate ions as calcium
carbonate, magnesium hydroxides and barium sulfates, respec-
tively. The precipitated muds are removed in ponds or clari-
fication tanks and the muds disposed of by land dumping or
fill.
Brine and sulfuric acid wastes are neutralized with lime or
sodium hydroxide, ponded for reduction of suspended solids,
and discharged to surface water.
Water—borne mercury in the mercury cell process is treated
and removed by a variety of processes, usually employing
precipitation of mercury sulfide, followed by mercury recov-
ery by roasting or chemical treatment processes. Plants with
typical recovery systems probably reduce mercury in the plant
effluent to 0.11 to 0.22 kilogram/day.
3.3.1.3 Best Practicable Control and Treatment Technology
Reduction of wastes depends on in—process control, isolation,
treatment and reuse. There is no known problem which has not
been solved by at least one plant of this survey.
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Mercury cells give inherently “cleaner” processes than the
diaphragm cells. Diaphragm cells have asbestos diaphragm
deteriorations with suspended asbestos wastes. These have
to be filtered out or allowed to settle in ponds. Sodium
hydroxide produced in diaphragm cells has sodium chloride
and other wastes and has to be purified for many uses.
A sodium sulfate purge, made by back-washing the precipita-
ted salt slurry on the filter during the evaporation concen-
tration of sodium hydroxide, is also needed to ensure satis-
factory diaphragm cell operation. This sulfate purge can
be handled by removing it from the system and using it
elsewhere (as is done by exemplary diaphragm cell plant 057),
by returning it for sulfate removal in the brine purification,
or by recovery of sodium sulfate for sale.
Another waste for the diaphragm process, but not the mercury
cell, is organic waste from the graphite anode. These are
currently land disposed by the exemplary diaphragm cell plant,
but are allowed to go out in waste streams at others.
Waste sulfuric acid from the chlorine-drying step is handled
by its use for neutralizations in other processes, sale,
shipment to a regen sulfuric acid plant, concentration, or
at worst it can be neutralized with lime or sodium hydroxide.
Collected chlorine gas for abatement of air—borne wastes can
be burned to produce hydrochloric acid or converted to sodium
chloride as discussed earlier.
Diaphragm cells are also prone to develop cracks around their
anode protective resin seals and lead salts from the underly-
ing lead mountings can get into the effluents. Dimensionally
stable anodes can eliminate this problem and at a reported
significant reduction in required cell electrical energy load.
The mercury cell, although “cleaner” than the diaphragm pro-
cess, has a major waste problem in the form of mercury in the
water-borne wastes. Major expenditures (discussed more quan-
titatively in Section VIII) and in-process modifications have
been made to alleviate this problem. The best plants today
are capable of mercury levels of 0.045 to 0.11 kg/day of water—
borne mercury content. These low levels are accomplished by
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isolation of mercury—containing waste streams and chemical
treatment of these streams. Costs have been high for this
cleanup.
Although no specific mention has been made of potassium hy-
drbxide production, the same principles hold except that
potassium is substituted for sodium.
Since the exemplary diaphragm plant (057) has very little
water—borne waste, and mercury cell plants inherently have
less waste loads than diaphragm plants, both processes can
feasibly and economically be expected to have little water—
borne waste.
3.3.1.3 Best Available Control and Treatment Technology
This is similar to best practicable except that there is no
waste effluent from the process. All wastes are treated,
controlled, sold or reused.
3.3.2 Hydrochloric Acid (in Complexes )
The only difference between isolated hydrochloric acid plants
and ones in chior—alkali complexes is that flexibility of
treatment, control and disposal of wastes is enhanced. There-
fore, waste loads which should be the same in both situations,
are lower in the complex. The principle followed throughout
treatment and control sections, particularly Section VIII on
costs, is that each chemical process has inherent wastes iso-
latable from other processes. This approach makes it simple
to calculate maximum waste loads from complexes merely by add-
ing individual plant wastes per tori of production. Expected
loads for each complex may be determined specifically from
interactions possible.
3.3.3 Sodium Hydroxide
Discussed under c’hlorine.
3.-3.4 Potassium Hydroxide
Discussed under chlorine.
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3.3.5 Hydrogen Peroxide (Electrolytic )
The electrolytic process for making hydrogen peroxide is re-
presented by a single U.S. plant (100). Its effluent has
practically the same composition as the incoming water,
because the relatively very small amount of process water
discharged is combined with the very large cooling water
stream. Present levels were accomplished by in—process con-
trols. The total water flow into the plant is about 41,600
cubic meters per day (3.47 x 106 liters/metric ton). 75.7
cu rn/day (6300 liters/k kg) is treated by ion exchange and
used for boiler feed and process water. Discharges of this
treated water includes 3.8 cu rn/day (316 1/k kg) of ion ex-
change blow-down, 26.5 cu rn/day (2200 1/k kg) of boiler blow-
down, and 1.1 cu rn/day (95 1/k kg) of process water effluent.
This latter stream can be reduced to zero discharge by simple
procedures such as total evaporation and still be inexpensive
because of the small quantity.
3.3.6 Sodium Dichromate
3.3.6.1 Typical Control and Treatment Technology
Typical treatment is to reduce the hexavalent chromium ion
(toxic) in the waste to trivalent chromium (non—toxic), re-
move the suspended solids in a settling pond, and discharge
the clear solution to surface water. Ferrous chloride is
often used as a reducing agent.
3.3.6.2 Best Practicable Control and Treatment Technology
An exemplary chromium treatment and control plant (184) in-
cludes isolation of all chromium-containing, water—borne
wastes from cooling water, collection of these wastes in
tanks, batchwise treatment f or hexavalent chromium reduc-
tion, and pond settling of suspended solids. The hexavalent
chromium content remaining after treatment is very low. Pro-
vision is even made in this plant for collection and treatment
of rainwater (important in toxic chemical plants). Batchwise
treatment and analysis before discharging provides good control.
13.6.3 Best Available Control and Treatment Technology
Although the best available treatment and control technology
described above is excellent for chromium treatment and control,
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two environmental problems remain —— disposal of large quan-
tities of solids which gradually fill the settling ponds and
discharge of large quantities of dissolved sodium chloride into
surface water. The settled solids can be landfilled and the
sodium chloride can be recovered by evaporation techniques and
sold. The evaporative approach is economically and technically
feasible but both money and energy costs are greater than
should be necessary for this process. There are other technol-
ogies available for chromium reduction and it is recommended
that future plants not be built until this available technology
is explored and the overall optimum process selected.
3.3.7 Sodium Sulfate (By-Product )
Sodium sulfate is a relatively pure by-product from the manu-
facture of sodium dichromate and other processes. As such, it
has no water—borne wastes and there is no treatment and control
technology applicable, except as applied to the sodium dichro—
mate process itself.
3.4 Category 4
3.4.1 Sodium Carbonate
3.4.1.1 General
The Solvay Process for making sodium carbonate (soda ash) is an
old one dating back to the late 1800’s. The Solvay plants are
also old, the last U.S. plant being built in the 1930’s. In
view of the discovery and development of natural soda ash depo-
sits in the western United States, it is doubtful if a new
Solvay Process plant will ever be built in this country. This
follows both from the high capital and maintenance costs for
the Solvay Process and the present almost even tradeoff between
lower production costs for natural sodium carbonate and lower
freight rates for Solvay Process sodium carbonate made closer
to the users. With this competitive situation, Solvay Process
soda ash producers can not realistically pass on the cost of
expensive waste abatement practices by price increases on their
product.
The Solvay Process discharges more poundage of waste into sur-
face water (solid basis -- see Table Vu-i.) than any other
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chemical of this study (sodium chloride producers deep-well
or store most of their effluent). The only redeeming feature
is the relatively low toxicity of the waste.
3.4.1.2 Typical Control and Treatment Technology
Present treatment of water-borne wastes consists of removing
most of the suspended calcium carbonate and other solids in
unlined settling ponds followed by discharge to surface
water. Adjustment for pH may or may not be done prior to this
discharge.
3.4.1.3 Best Practicable Control and Treatment Technology
The water—borne wastes from the Solvay Process are suspended
and dissolved solids. The suspended solids are removed effec-
tively by settling ponds and polish filtering can be done if
necessary to reduce total suspended solids levels to 25 mgI
liter.
Dissolved solids are another matter. There are extensive
treatment technologies available which can be used to elimi-
nate the dissolved solids from the water effluent but most
of them are not economically practical for the Solvay Process.
Also, the geographical location of the plant has a major
bearing on the treatment and disposal feasibility and costs.
Ocean barging, conventional evaporation and land disposal of
solids, membrane processes, demineralizations, and drying are
too high in cost to be considered. Solar evaporation is not
practical in areas where the plants are located. Major pro-
cess revisions are also not believed to be economical at this
time.
Approaches considered feasible are:
1. Recovery and sale of a portion of the calcium chloride-—
The degree to which this may be practiced depends on
the market for calcium chloride and the geographic lo-
cation of the plant. Only 10-15 percent of the calcium
chloride potentially available from soda ash waste can
currently be absorbed by the market. Also, since the
major usage is for snow removal from the roads, the
southern plants can not use this approach.
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2. Deep Welling -— The soda ash industry has traditionally
located close to major supplies of salt. Just as tradi-
tionally, salt manufacturers have disposed of mining
wastes by well injection. Also, pumping calcium and
sodium chloride wastes into areas already containing
massive quantities of such materials should be less ob-
jectionable than in other locations. Costs for the
various approaches are developed in Section VIII.
A combination of recovery and sale of calcium chloride plus
deep welling of the excess effluent could be economically fea-
sible for northern plants where deep welling is practical.
However, there is no generally applicable waste abatement re-
commendation available for sodium carbonate.
3.4.1.4 Best Available Control and Treatment Technology
A new plant of the Solvay Process is very unlikely to be con-
sidered. If a new Solvay Process plant were to be built, the
process itself would likely be revised. Process modifications
now in the laboratory or pilot plant stages would have to be
investigated and developed for commercial feasibility. The
major area of revision would be in the recovery of ammonia
from ammonium chloride. Use and recovery of magnesium hydrox-
ide or decomposition of ammonium chloride to ammonia and chlor-
ine are two such modifications that have been proposed. Recov-
ery and reuse of the excess sodium chloride in the waste efflu-
ent could be accomplished by evaporation and crystallization
techniques similar to those for the salt industry.
3.4.2 Sodium Bicarbonate (aspart of the Soda Ash Complex )
Sodium bicarbonate is made by a simple, low—waste process. Its
effect is similar to isolated plants in this case since there
is no effective general way to reduce Solvay Process wastes.
3.5 Category 5
3.5.1 Titanium Dioxide (Sulfate Process)
3.5.l.l General
The sulfate process for producing titanium dioxide has the
worst raw waste load of all the processes of this study.
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Approximately 2,000 kilograms of sulfuric acid and 1,000 kilo-
grams of metallic sulfates per metric ton of product have to
be discarded. Low grade ores used in the process contribute
major quantities of heavy metals which may someday be profit-
ably extracted.
Waste streams generated by the sulfate process include: (1)
sludge from the dissolving step and .filtration, (2) copperas,
(3) strong acid cuts, (4) weak acid cuts and (5) titanium
dioxide losses.
3.5.1.2 Typical Control and Treatment Technology
Wastes are collected, sent to a settling pond for suspended
solids removal, and discharged to surface water.
3.5.1.3 Best Practicable Control and Treatment Technology
The sulfate process for titanium dioxide was one of the few
for which no exemplary plant was found. This is not because
control and treatment technology is lacking, but rather be-
cause it is more economical not to apply it. The exemplary
treatment and control process involves filtration and disposal
of the sludge from the dissolving step by land dumping, neu-
tralization of both strong and weak acid cuts with limestone,
followed by lime treatment to raise pH to approximately 8 and
precipitate iron and other metallic oxides and hydroxides.
The conventional chemical treatment system of neutralization
tanks, clarifiers, thickeners, filters or centrifuges and
ponds may be employed for this purpose. This treatment reduces
the waste load discharge to solubility limits of calcium
sulfate.
Ocean barging of the strong acid wastes, sludges and metallic
sulfates is now used for disposal. Uncertainty about the fu-
ture of this disposal method currently clouds its general
application. Also, the weak acid and other wastes are still
in many cases being discharged to surface water without sig-
nificant treatment.
3.5.1.4 Best Available Control and Treatment Technology
Recovery of the strong sulfuric acid in the sulfate process
waste load has been used in the past and, whether for techni-
cal or economic reasons is not known, abandoned. A pilot
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plant process has also recently been developed by New Jersey
Zinc Company with contract assistance from EPA.
Acid recovery is accompanied by treatment of the weak acid,
metallic sulfates and titanium dioxide losses in the same type
of chemical treatment system as discussed for complete neu-
tralization. Acid recovery reduces the solid waste load in-
herent with complete neutralization approximately two-to-three
fold and also decreases the amount of water-borne wastes.
Costs likewise favor this approach over complete neutraliza-
tion. The shortcoming for acid recovery processes is that
they are either still in the development stage or are captive
technology not being used currently.
If ocean barging is allowed to continue, it is recommended that:
1. All water-borne wastes be barged to sea, not just strong
acids and sludges, or
2. Strong acids and sludges be barged and the weak acids
and other wastes be given complete neutralization and
land disposal treatment similar to acid recovery pro-
cesses. Water effluent from the plant would contain
<25 ppm suspended solids and 2000 mg/i or less of diss-
olved calcium sulfate.
3.5.2 Titanium Dioxide (Chloride Process)
3.5.2.1 General
The titanium dioxide industry is in a state of flux. Rutile
is in a very short supply and most chloride process producers
need this ore or a synthetic version of it. “Synthetic Rutiles”,
or beneficiated low grade ores, are bring offered by various
foreign and a few domestic suppliers. Ishihara of Japan has
operated a 27,000 metric ton plant since 1971 and is expanding
to 40,000 metric tons by October 1973. Sherwin Williams has
announced a proposed 45,000 metric ton/year plant using Australian
technology. A comprehensive discussion of ore deposits, their
composition, and beneficiation techniques may be found in
Dr. Thomas S. Mackey’s article “Alteration and Recovery of
Ilmenite and Rutile”, Australian Mining, Nov. 1972, pp. 18—94.
“Synthetic Rutiles” offer the opportunity to eliminate most of
the ore dross and undesired metallic oxides in sites more
suited for this purpose than most present titanium dioxide
plants.
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Chloride process plants, by the nature of the process and the
ore used (90—96 percent titanium dioxide), usually have less
waste than the sulfate process plants which use ilmenjte or
other low grade ores. Some chloride process plants can use
many of the lower grade ores and have a corresponding heavier
waste load than the rutile—using chloride process plants.
Waste streams for the chloride process fall into two categories:
1. Chlorination wastes composed of sludge from titanium
tetrachioride losses and
2. Wastes incurred during the oxidation process and treat-
ment of titanium dioxide product.
3.5.2.2 Typical Control and Treatment Technology
There is no typical treatment and control procedure. ase
level treatment usually includes ponding to remove titanium
dioxide, ore, coke and other settleable solids.
3.5.2.3 Best Practicable Control and Treatment Technology
Three techniques for treatment and disposal of chloride process
wastes are available; neutralization of acids and conversion
of metallic chlorides to insoluble oxides, ocean barging and
deep welling.
A full chemical treatment system similar to that described
earlier in this section is used in exemplary plant 009.
Chemical neutralization tanks, a clarifier, a thickener, and
filters followed by a pond system are used for full acid neu-
tralization, conversion and precipitation of metallic oxides,
and concentration of suspended solids into a sludge. The
sludge is disposed of as land dump. Both of the main chloride
process waste streams, chlorination solids and oxidation pro-
cess and titanium dioxide product-treatment wastes, are put
through the chemical treatment system. The water-borne wastes
from the system consist primarily of dissolved calcium chloride.
Deep welling of the chlorinated wastes is practiced by a second
exemplary plant (160). The oxidation and titanium dioxide
product treatment wastes are sent through a settling pond system
and discharged to surface water. Such deep well disposal is
not a general solution to waste abatement practices, since it
is not geologically feasible in many sections of the country.
VII — 55
DRAFT
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DRAFT
Ocean barging is also used to dispose of chloride process
wastes. This disposal technique also can not be used general—
ly since some of the chloride process plants are not accessible
to the oceans.
3. .2.4 Best Available Control and Treatment Technology
The major chloride process wastes, particularly when low grade
ore is used, are ferrous and ferric chlorides. Various propo-
sals have been made for disposing of these chlorides. Included
in these proposals are processes for decomposing the iron chlor-
ides to iron oxide and hydrochloric acid (favored for pickle
liquor recovery), a process for oxidation of iron chlorides to
iron oxides and chlorine, and sale of the iron chlorides as such.
Beneficiation of ore by chlorination, separation of iron chlor-
ides, and dechlorination of the iron chlorides is another p±o—
cedure. All of the above are still in the exploratory, labora-
tory, pilot plant or other preliminary stage at this time. It
is recommended, however, that both government and industry de-
vote research and development attention to this problem. Bureau
of Mines research is already being carried out. Undoubtedly
there are industrial efforts along similar lines. Further dis-
cussion of these and other waste abatement practices may be
found in Section VIII where rough cost estimates are included.
VII — 56
DRAFT
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SECTION VIII
COST, ENERGY AND NON-WATER QUALITY ASPECTS
1 .0 COST AND REDUCTION BENEFITS OF TREATMENT
AND CONTROL TECHNOLOGIES
1.1 Summary
The inorganic chemical industry has large energy requirements for gas furnaces, kilns,
calciners, electric furnaces, reactors, dstillotion columns, and evaporators and other
common equipment. In contrast, treatment practices consume less than one tenth of
one percent of this amount. Chemical reactions and pond settUng, the most commonly
used treatments, required almost no energy. Filtrations, centrifuging, and other
Separation techniques are still relatively low energy processes. The only two high
energy treatments, evaporation and drying, are now rarely used. Utilizing these treat-
ment techniques to the extent covered in the cost effectiveness discussions later in this
section will still maintain treatment energy at a tiny fraction of the total energy for the
industry. Total energy estimated from reference 85.
Table 38 (Section II) presented the approximate costs for the different methods of treat-
ment. These together with the specific costs discussed in the body of Section VIII
provide a generalized approach to cost estimates. Note that removal of dissolved solids
is expensive.
Table 43 summarizes cost and energy requirements for the inorganic chemicals of this
study. To bring the processes to zero water-borne waste effluent through total recycle
of process water, rough estimates for additional capital expenditures are 295 million
dollars. Of this amount, three industries contribute almost eighty percent. These in-
dustries —— soda ash (Solvay Process), chlor-alkali, and titanium dioxide —— have vastly
different situations. For soda ash (Solvay) there is no general economic solution for
total water—borne waste elimination. Also, the western frona deposits provide an alter-
native source for soda ash at similar costs. Solvay soda ash can be expected, therefore,
to play a decreasing role in the future.
Titanium dioxide has no satisfactory replacement. It can absorb and pass on the
large capital and operating costs needed for warer-borne waste cleanup. This major
clean—up is also long overdue. Development and application of existing treatment
technology con save the titaniur dioxide industry an estimated 100 million dollars
over the full neutalization costs given in Table 43. -
It is recommended that whenever possible the
VllI-1
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TABLE 43. Summary of Cost and Energy Information For Att&nment of Zero Discharge
Ad&tional Energy
Percent of June, 1973
Additional 10 10 Cost/Fon Selling Setting Price
Chemkal - Capital, $ BTU/yr kg caVyr English Metric Price 71on $/MetricTon
Aluminum Chloride 0 0 0 0 0 0 >255 280
Aluminum Sulfate 4,700,000 17,000 4300 0.90 1 .0 1 .4 62.80 69
Calcium Carbide 0 0 0 0 0 0 171.40 188
Hydrochloric Acid 250,000 0 0 0.05 0.06 0.04 110 (100°, ) 121 (100%)
Hydrofluoric Acid 1,180,000 3300 8350 13-16 14-18 2.5 560 (100%) 617(100%)
Lime 0 0 0 0 0 0 19.50- 21 ,50-
21.75 24.00
Nitric Acid 11,000,000 0 0 0.22 0.24 0.18 113 (100%) 124 (100%)
Potassium Metal 0 0 0 0 0 0 --
Potassium Chromates 90,000 210 53 4.65 5.15 0.97 480 528
Sodium Bicarbonate 0 0 0 0 0 0 88 97
Potassium Sulfate 1,570,000 680,000 162,000 1 .60 1 .16 3.7 42.50 47.50
Sodium Chloride (Solar) 0 0 0 2.20 2.42 11 .‘- ‘20 --.22
Sodium Silicate 850,000 332,000 84,000 0.90 1 .0 0.95 95 102
Sulfuric Acid 20,000,000 0 0 0.10 0.11 0.11 0.3 30.75-35.00
Hydrogen Peroxide 350,000 0 0 I .00 1 .10 0.2 460 505
(Organic) (70% Sot’ n) (70% Sot ‘n)
Sodium Metal 4,700,000 0 0 2.25 2.48 0.6 375 412
Sodium Sulfite 3,730,000 116,000 29,300 2.50 2.75 2.1 117 129
Calcium Chloride 1,040,000 0 0 0.20 0.22 0.5 42 46
Sodum Chloride 7,750,000* 0 0 1 .00 1 .10 5 “ -20 --22
Chior-alkali 40,000,000**800,000 202,000 0.50 0.45 Cl 2 $75 Cl 2 $83
(combined product basis) NaOH $110 NaOH $121
(75%) (75%)
Hydrogen Peroxide 15,000 870 220 0.25-.75 0.27—.83 0.1 460 507
(Electrolytic) (70% Sol n) (70% Sol’n)
(continued on next page)
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TABLE 43. Summary of Cost and Energy Information For Attainment of Zero Dscharge (continued)
Additional Energy Percent of June, 1973
Additional 106 lO Costflon SelUng Selling Price
Chemical Capital, $ BTU/yr kg cal/yr English Metric Price $/Ton $/Metric Ton
Sodium Dichromate 4,100,000 240,000 60,700 16 18 4.6 345 380
Sodium Sulfate 0 0 0 0 0 0 24-33 26-36
Soda Ash ****25,000,000 200,000 50,200 1 .60 1 .76 4.5 35.50 39
Titanium Dioxide ***74,000,000 675,000 170,000 64 70 11.4 550-570 605-615
(Chloride)
Titanhim Dioxide ***96,000,000 535,000 135,000 96 103 17.1 550-570 605-615
(Sulfate)
< D
Totals 294,895,000 3,590,000 905,000 --
-
*Based on 3 million tons/year vacuum pan salt production fromSalt, Bureau of Mines Minerals Yearbook, 1969.
**Based on $2.00/ton chlor—alkali production —— estimated from cost effectiveness data of subsections VIII,
1.5.3.1 and 1.5.3.2.
***Based on full neutralization plus demineralization costs as given in subsections VIII, 1.5.5.1 and 1.5.5.2.
****Based on deep—welling costs as in subsection VIII 1.5.4.1.
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industry should be encouraged and allowed to do so over the next two to three years.
The chior—olkali industry differs from both soda ash (Solvay) and titanium dioxide in
that mainly in—process changes and more efficient use of raw materials are required
to attain zero water—borne waste. There are many ways to accomplish this, some of
which are suggested in sections VII and VIII of this report.
Solar evaporation sodium chloride production presents a problem in that the magnesium—
rich bitterns have to be stored. Before storage space and costs become a major problem,
use of these natural resources should be encouraged.
Other industries that have major capital expenditures in Table 43, sulfuric acid, nitric
acid, sodium metal (which is similar in process wastes to chlor—alkoli plants), aluminum
sulfate, potassium dichromate, and sodium chloride (brine/mining) have these costs
primarily because of the large size of the industry or toxic wastes. Except for sodium
chloride (brine mining)
and potassium dichromate all waste abatement costs are
below 1.5 percent of the selling price.
For all other chemicals, the yearly cost for total water—borne waste abatement is less
than 4 percent of the current selling priceq
Energy requirements of 905 X 1O 9 kg cdl/y.r ( 3.6 X iol2 BTU/yr) or the energy
equivalent to burning 10,220 cubic meters (3.6 million gallons) of fuel oil for the
elimination of water—borne wastes for the chemicals of this study are less than that
currently consumed by one large Solvay soda ash plant.
Thermal pollution was not encountered in this study nor was n&se or other types of pol—
lutions. Air pollution abatement costs as encountered are presented in this section for
information purposes only.
In general, plant size itself does not appear to be a signiflcant factor influencing waste
effluents on a metric tons waste/metric ton of product basis. Multichemical complexes
have an advantage over single isolated facilities on costs and options for
waste utilizatiori , P lant age does have some influence 1 with the new plants having the
edge.
These are by no means the controlling criteria, however. For example, nineteen ex—
emplary plants used in the cost effectiveness development given later in this section
have an average age of 21 years, with 5 plants of 30 years or greater age and 6 of
10 years or less age.
Vlll-4
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Geographical location is often a critical factor for waste disposal costs. Availability
of deep welling, ocean barging, or solar evaporation options is an advantage. Also,
the western United States has more incentive to recover and reuse scarce water than
the east.
Company attitude is probably more importani today in waste abatement efforts and ex-
penditures than any other single factor. A number of companies of this study have
excellent overall corporate commitments to minimizing waste effluents. They have
spent large sums of money and devoted research, development and engineering efforts
to problem solutions. They are to be commended. Others are avoiding any real atten-
tion unless it is clearly profitable. Both small and large companies are found in each
category.
New plants being built can avoid major future waste abatement costs by inclusion of:
(1) Dikes, emergency holding ponds, catch basins, and other containment
facilities for leaks, spills and washdowns.
(2) Piping, trenches, sewer, sumps and other isolation facilities to keep leaks,
spills and process water separate from coling and sanitary water.
(3) Non—contact condensers for cooling water. Barometric condensers should be
avoided.
(4) A full water treatment system, including demineralization, reverse osmosis,
evaporative and solids waste handling equipment when needed.
(5) Efficient reuse, recycling and recovery of all possible raw materials and by-
products regardless of inherent value. Sodium chloride and sodium sulfate
are two that cause most frequent trouble.
(6) Closed cycle water utilization whenever possble. Closed cycle operation
automatically eliminales all water-borne wastes. Generally, if water is
pure enough for discharge, it is pure enough for reuse.
1 . 2 Cost References and Rationales
Detailed cost developments, calculations, references and rationales for treatment and
disposal techniques pertinent to the inorganic chemicals industry are given in Supple-
ment A. A summary of these costs is given in subsection 1 .4 of this section. In addi-
tion to the costs developed in Supplement A, costs for specific plant treatment systems
are given in Supplement B. The combination of these two costs sources and engineering
judgment extrapolations from them are used in subsection 1 .5 of this section for cost
effectiveness developments.
VIlI-5
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1 .3 Definition of Levels of Control and Treatment
For each chemical of this study, there is technology available for reduction to zero
effluent or closed loop status. Using the general models as given in Figures 74 and 75,
cost and energy effectiveness values are developed in subsection 1 .5. Four levels of
treatment and control are considered:
1.3.1 Level A— — Base level practices followed by most of the industry and exceeded
by exemplary plants.
1 .3.2 Level B -— Treatment and control practices at the overage exemplary plant.
1.3.3 Level C —— Based upon the best technically and economically feasible treatment
and control technology.
1 .3.4 Level D — — Complete water—borne waste elimination. This level may or may not
be ecoi micalIy feasible for the specific chemical.
1 .4 Cost of Control ond Treatment Systems
Segregation of contaminated water streams from non—contaminated streams is the first
and most important step in water-borne waste abatement. Since the treatment costs
normally depend on the volume of wafer to be treated more than the amount of waste,
keeping the wastewater volume small reduces costs and energy requirements . Spills,
le Ts and washdowns ore smafl, but need to be contained and isolated.
Cost for segregation and containment vary over a wide range depending on the size and
complexity of the plant, volume and nature of the wastes, and the equipment
employed.
Rough estimates of these costs based on information oblained from exemplary plant visits
are given in Table 44. In general, small chemical plants produce 50 tons per day or less
of product. However, this may vary significantly with the particular chemical.
Isolation for toxic wastes containing mercury and chromium usually costs approximately
$200,000 to $300,000. Large salt, acid and chlor—alkaU plants also fall in a similar
price range for isolation and containment costs. Older plants may be more difficult
and expensive to modify than the cost of similar features in new facilities.
VII 1-6
DRAFT
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I-
Zcs) E
Li.Jj- 02 I-•O-•
W I— O W° j w _i
-zO Z 0 c ozo
WATER
AREA
WASTES REMOVAL DISCHARGE
4 ’
SOLID MAKEUP
WASTES WATER
FIGURE 74
MODEL FOR WATER TREATM T AND CONTROL SYSTEM
OIF GA C C CCI\LS DUSTRY
-------
SOLID
INCINERATION, WASTE
I FINAL TO REUSE,
SALE OR
FILTRATION • I EVAPORATION LANDFILL
LOW
DISSOLVED >1 SOLIDS —I OTHER
HIGH SUSPENDED I pH ADJUST ] EVAPORATION
ENERGY
SOLIDS
STREAMS [ REMOVAL I CONDITIONING
___________ L HIGH
SOLIDS
I STREAM I > PURE BOILER
REVERSE REGENERANTS ____ WATER TOWERS AND
OSMOSIS - “OTHER REQUIREMEN T 3
UN ITS
MAKEUP WATER
POLISHING
FOR
LOW SUSPENDED 1 I pH ADJUST I F SOFTENERS
DISSOLVED >1 SOLIDS I ‘I OTHER - [ I ION EXCHANGERS
STREAMS [ I REMOVAL J I CONDITIONING I [ DEMU : .ZERS I
SOLIDS
PROCESS WATER
— OF
DESIRED PURITY
FIGURE 75
MODEL FOR WATER TREATMENT SYSTEM
INORGANIC CHEMICALS INDUSTRY
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TABLE 44. Isolation and Containment Costs
Installations Small Plants Large Plants
Isolation Trenches and sewers $ 10,000- $100,000—
pipelines, sumps, 100,000 300,000
catch basins, tanks
and pumps
.Cantainment Dikes and curbing ‘1 5,000- $ 50,000-
50,000 200,000
Isolation Non-contact heat- $ 50,000 $100,000—
exchangers 500,000
Barometric condensers are the most common source of cooling water cont&nation. They
change cooling water to process water and increase both cost and energy treatment re-
quirements. No new plant thould be built with barometric condensers unless they do not
contribute to waste loads. Barometric condensers are now being replaced by non-contact
heat exchangers in various inorganic chemical plants. Installing barometric condensers -
and later replacing them is expensive . Initial installation of non—contact heat exchang-
:.Ø fl place of barometric condensers in new plants is not a large additional cost item.
1 .4.2 Oiemical Treatment Systems (21 — 26)
1.4.2.1 Equipment Costs
These systems, consisting of chemical reactors, clarifiers, thickeners, and filters or
centrifuges, are designed as integral units for complete waste treatment. Installed
equipment costs for chemical treatment systems as a function of capacity are summarized
below,
Clarifiers Filters or Total*
Capacity Reaction and Centrifuges, Costs
cu.m./day(GPD) Tanks, $ Thickeners, $ $ $
38(10,000) 15,000 15,000 25,000 60,000
379(100,000) 25,000 40,000 25,000 150,000
3785(1,000,000) 37,500 75,000 200,000 500,000
37850(10,000,000) 50,000 200,000 750,000 2,000,000
includes engineering, land preparation, and installation. Does not include land cost,
storage tanks and disposal facilities, or other auxiliary equipment.
VII 1—9
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These costs are for light slurry loads. For heavy slurry loads, such as for titanium
dioxide wastes, overall costs are several times greater. -
L4.22 Chimical Costs -
The-costs for chemical treatments cannot be generalized. Most of the chemicals used,
however, are for neufralizaflons. Chemical treatments costs depend on the chemical
used and the amount required which varies with the particular situation. The unit cost
of the chemical is usually known. Whenever feasible, neutralization of alkaline -
wastes is done with sulfuric acid. As shown in Table 45, sulfuric acid costs only 30 to
40 percent as much as hydrochloric and nitric acid. In other words, a dollars worth of
-sulfuric acid will neutralize 2.5 to 3.5 times as much alkalinity as a dollar 1 s worth of
the other two acids. Costs for sulfuric acid is approximately. $33/kkg ($30/ton).
For acid wastes, the preferred neutralization materials are limestone and lime. Lime-
stone is the lower cost material $7—i 1/ickg ($6-10/ton);but suffers the disadvantages of
slower reaction, high Impurities, and lower obtainable pH. Lime costs are approxi’-
mately $22 per kkg. Ammonia and sodium hydroxide are far more expensive than lime
or limestone, with 50 percent sodium hydroxide at $1 21/kkg ($110/ton) (100% basis),
it can be seen why lime is preferable in most cases.
For smallusage or where solubility or character of precipitate is important, caustic soda
may still be employed.
Neufrali ations with waste acids or bases can change the whole cost structure. Waste
sulfuric acid is often available at either no cost or the cost of freight. Waste lime,
caustic soda or ammonia can sometimes be obtainedat similar low costs. -
Costs for neutralizations and other chemical -reactions are simply determined for special-
applications by multiplying the cost/weight of the neutralizing or reacting chemical by
the weight stoichfometrically required. Where specific experience is available, it may
have been found that 10 to 20 percent excess over stoichiometric quantifies may be’
needed. In rare cases, several—fold excesses may be used to ensure complete reaction.
1.4.3 S ttling Ponds and Vessels
Ponds, for storage, emergency discharge or holding, settling of suspended solids, or
solar evaporation, are the most commonly employed treatment and control facility in
the inorganic chemical industry. Two categories, (1-) unlined ponds and (2) lined ponds
are summarized in the tables and figures of this section.
A third category, tanks and vessels such as thickeners and clariflers, are not widely
used at present in the inorganic chemical industry as contrasted to other chemical in-
dustries and sanitary treatment facilities. As land becomes more costly and unavailable
VIll—lO
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TABLE 45. Comparison of Chemicals for Waste
Neutralization
Alkaline Wastes Relative
Chemical kg* Req’d/lckg Alkali**
Neufrdizing Material Cost*,$ CaCO 3 Ca(OH) NaOH
Sulfuric Acid (50° Be) 1.00 1260 1700 1580
Hydrochloric Acid (20° Be) 2.57 2320 3140 2500
Nitric Acid - (39.5° Be) 3.51 2100 2840 2630
Acid Wastes Relative
Chemical g*** Req’d/kkg Acid**
Neutralizing Material Cost*,$ H2S04 HCI HNO3
Lumplimestone,highCa 1.16 1100 1480 860
Lun limestone, dolomitic 1 .00 940 1270 730
Pulv. limestone, high Ca 1 .59 1100 1480 860
Pulv. limestone, dolomitic 1.37 940 1270 730
Hydrated lime, high Ca 3.06 790 1070 620
Hydrgted lime, dolomitic 2.50 650 870 510
Pebble lime, high Ca 2.07 600 800 460
Pebble lime, dolomitic 1 .87 540 730 420
Pulv. quicklime, high Ca 2.18 600 800 460
Pulv. quicklime, dolomitic 1 .97 540 730 420
Sodium bicarbonate 20.65 1730 2330 1350
Sodaash 13.08 1190 1600 930
Caustic soda (50%) 9.96 1640 2200 1270
Ammonia (anhyd.) 5.90 350 470 270
Magnesium oxide 3.90 420 560 330
*Del;vered cost including freight.
**Cam ity weight.
***To convert numbers to lbs. req’d/lOO lbs alkali or acid, multiply x 0.1.
Vlll—1 1
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and treatment and control requirements change, open tanks and vessels may see increased
use. Cost information on equipment of this type has already been given in the chemical
treatment section.
1’4.3.1 linlined Ponds
The costs of constructing unlined ponds differ widely depending on the circumstances.
Since they cover large areas, the cost of the land itself is a factor. Building a 200
hectare (500 acre) pond on prime industrial land may cost 1 to 5 million dollars lust for
the land itself. No provision s made in this analysis, however, for such costs. It is
assumed that the land value is not a large portion of the cost. For small ponds of less
than 4 to 20 hectares (10 to 50 acres) and land values of $250 to $625 per hectare
($100 to $250 per acre), this assumption is good, as will be seen from the magnitude of
the other costs.
Construction costs vary widely depending on the circumstances. Use is often made of
natural pits, valleys, ponds, lakes, etc., for minor alternations, such as damming,
dike building and leveling. Excavation is easier in some localities than others.
Size of the pond is also a malor Factor in costs. Small ponds may be dug and the exca-
vated dirt used For dikes. Large ponds are usually diked or dammed.
Assuming equal depths-of two ponds, one large and one small, the volume increases as
- the square while the dike length (and earth moving) s increasing only -linearly. There-
fore, costs will be developed for small-ponds and then for large-ones-—-
Small pond capital costs are given in Figure 76 (Ref. 28,29 and 30).
Large pond costs developed from reference (27) dre given in Figure 77. Undoubtedly,
many of these instal lotions made use of natural topography (lakes, basins, etc.) to avoid
as much excavation as possible. Nevertheless, the general cost levels and trends may
be seen. A would be expected from the dikng costs varying by the square root of the
the area, the pond costs per hectare above 200 hectares (500 acres) change very slowly.- - -
1.4.3.2 Lined Ponds
To avoid excessive liquid seepage, ponds are often lined with clay, concrete or other
substances. Recently, however, a new class of lining materials have come into use —
rubber and plastic sheeting.
Essentially, costs for pond construction are the same as for unlined ponds except for the
sheefing material and installation. Therefore, the costs may be estimated by adding the
installed liner costs to the previously determined costs For unlined ponds. The material
Vlll-12
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4
I:
II .
F
I
DRAFT
I 5 5
P W - -
. 4 S 1 7
AREA
FIGURE 76
CAPITAL COSTS FOR SMALL UNLiNED PONDS
(REFERENCE (28), (29), AND (30))
CAPITAL
FIGURE 77
COSTS FOR LARGE UNLINED PONDS
(REFERENCE (27))
DRA
VIII- ’
C
0
I
I
0
F
I
0
0
0
0
0
0
0
0
? A C )
A ( S)
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DRAFT
cost for the lining ranges from $1 .00 to $6.00 per square meter (10 to 60 per square
foot), depending on the material seJftcted and the thickness of the sheei(9
Although thicknesses as low as 250 microns (10 mils) have been discussed’ “,
the most used thickness appears to be 750 microns (30 mils). For 750 micron
(30 mils) PVC liners, the installed cost per square meter is approximately $2.00.
The construction costs for small lined ponds are given in Figure 78. These values may
be conservative as far as film costs are concerned. For large ponds, lined costs have
been estimated by adding $2.00 per square meter (20 per square foot) to the-unlined
costs. The results are shown in Figure 79.
Since a two hundred hectare (five hundred acre) lined pond costs 4 to 6 million dollars,
this approach for large scale waste treatment and/or storage will require careful inves-
tigation before proceeding.
1.4.3.3 Solar Evaporation Ponds
Lined solar evaporation ponds have been discussed in Section VII. Table 46 gives the
costs for solar ponds as a function-of evaporative capacity. Table 47 gives costs per
3785 liters (1000 gallons) calculated from Table 46 for comparision with treatment costs
for other processes. A pond and liner life of 20 years was assumed.
1.4.4 Carbon Adsoiption
There are a few instances where organic materials are present in-the-inorganic chemi-
cals industry water wastes. These organic materials-may-be-handled-in-many-cases by- -
conventional biological digestion sanitarywaste processesr or they-may be treated by
methods such as carbon adsorption.
Installation costs from References (32) and(33) range-from 5 to 20 /3785 liters -
-(1000 gal Ions) treated. A cost of 1 5 was chosen as representative. This cost in-
cludes 5 percent loss of effici cy upon carbon regeneration.
Combining capital costs from Figures 80 and operating costs fronrabove,overal I costs
are shown in Figure 81.
1 .4.5 Ion Exchange and Dernineralization ( 36’ 42,44—48 )
Ion—exchange and demineralization water treatments are widely used, particularly for
pretreatment of boiler, cooling tower, and process feeds.
Vll l—14
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o I S $ 4 4 S V I S 12 II 12
S &A 1
FIGURE 78
CONSTRUCTION COST OF SMALL LINED PONDS
(REFERENCE (30))
1500
pas * (
FIGURE 79
CAPITAL COSTS FOR LARGE LINED PONDS
DRAFT
JIII 1 6
a
a
a
U
I1
• a a 4
A ( MES)
U
I’
II
I
0
A ( Th )
120
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TABLE 46. Capital Costs for Lined Solar Evaporation
Ponds as a Function of Capacity*
Evaporaflon—Rainfal I Differential
2Ff. 4Ft. 6Ft .
Capacity Hectare Capital Hectare Capital Hectare Capi T
cu • m . /doy(G PD) ( Acres) Costs ( Acres) Costs ( Acres) Costs
38(10,000) 2.2(5.6) 150,000 1.1(2.8) 95,000 0.8(1.9) 80,000
189(50,000) 11.2(28) 420,000 5.6(14) 212,000* 3.7(9.3) 220,000*
378(100,000) 22(56) 820,000 11 .2(28) 470,000 7.5(18.7) 282,000
945(250,000) 56(140) 1,960,000 28(70) 1,010,000 18.7(46.7) 690,000
1890(500,000) .112(280) 3,700,000 56(140) 1,960,000 37.3(93.3) 1,350,000
3785(1,000,000) 220(560) 6,650,000 112(280) 3,700,000 74.8(187) 2,570,000
t Ponds of 10 acres and under taken from Figure 74; those over 10 acres taken -
from Figure 75.
• TABLE 47. Costs for Solar Evaporative Pond Disposal
20-Year Pond Life
Evaporative Cost, /3785 liters ( /1,000 Gal.)
• Evaporation—Rainfall Differential
Capacity
Cu • m . /day ( GPD) 2 ft/yr 4 ft/yr 6 ft/yr
38(10,000) 213 136 114
379(100,000) 117 67 40
3785(1,000,000) 95 53 37
Vlll-16
DRAFT
-------
DRAFT
0
__
CAWØTY 1W M )
, ff
C ?Y ITO)
FIGURE 80
INSTALLED CAPITAL
CARBON ADSORPTION
COST FOR
EQUIPMENT
r
I
0
0
0
I
§
000
00o
2000 3000 5000
CAPACITY (CU M/DAY)
10,000
a ooo 30,00040,000
1,000,000
CA TY (GPO)
FIGURE 81
OVERALL COSTS FOR CARBON ADSORPTION
DRAFT
VIII-17
-------
DRAFT
Ion exchange, as its name impfles, replaces undesired loris with less oblectionable
ones. Some of the ions removed in this way include magnesium, calcium, iron, man-
ganese, carbonate, nitrate, and sulfate. Usually these ions are replaced by sodium
or chloride ions. Total amount of dissolved solids remains almost the same.
Demineralizations, on the other hand, by a combination of ion—exchange operations,
actually remove almost all the dissolved soUds.
1 .4.5.2 Ion Exchange Costs
Since total dissolved solids of greater than 500—750 mg/liter, regardless of ion type,
usually cause problems for potable, boiler, cooling tower, process or other water use,
ion exchanges are generally restricted to treating low—total—dissolved—solids water.
Two common treatment methods are:
(1) Sodium—hydrogen zeolite dealkalizers
(2) Zeolite softeners
Estimated costs of ion-exchange operations as a function of dissolved solids are shown
below:
Sodium
Total Zeolite Hydrogen
Dissolved Softening, Dealkalizer,
Solids, /3785 liters /3785 liters
mg/liter ( 1000 gals) ( 1000 gals )
200 5.7 6.4
500 10.8 9.5
750 15.0 12.2
While these values are only approximations, they do show that zeolile “softening” or
ion exchange with sodium chloride or sodium chloride plus sulfuric acid is fairly low in
cost even at the 750 mg/liter total dissolved solids level. Ion exchange does not re-
move dissolved solids from waste water . Therefore, ion exchange is rarely used for
industrial waste treatment. Ion exchange units produce regenerant wastes that have
to be disposed of. With these considerations, ion exchange can be virtually written
off for waste treatment technology except for certain specific toxic ion situations.
1.4.5.2 Demineralization Costs
1.4.5.2.1 Capitol Costs
The cost of dernneralization equipment itself is fairly consistent for the low solids
fixed bed units used for most applications. For the specialty systems described in
VIII -18
DRAFT
-------
DRAFT
Section VII, particularly at high solids, above 1000 mg/liter, the costs are signifi-
cantly higher for a given capacity. Both the special nature of these units and the
influence of the higher resin volumes required to take the increased loading increase
capital costs. Installed capital costs can also differ greatly depending on land avail-
ability, pretreatment facilities needed, buildings, storage tanks, and engineering
and contractor costs. The installed capital costs developed in this section have been
adjusted using 33 percent of equipment costs for installation and 6 percent increase
per year in equipment costs. All values are in 1973 dollars. They do not include
resin costs which are covered in operating costs. Values for capital costs were taken
from references (34), (35), (37), (38), (39), (40), (41) and (43). Average values are
plotted in Figure 82.
A rule—of—thumb is that installed capital costs for conventional demineralization units
are about one-half those for reverse osmosis install at ions for similar capacity.
1 .4.5.2.2 Operating and Overall Costs
The operating costs for demineralizations are made up of the costs of:
(1) Resin; (2) Chemicals; (3) Labor and Maintenance.
For the higher dissolved solids levels, chemical costs are the primary concern. These
costs are shown in Figure 83. Overall costs are given at Tables 48 and 49.
1 .4.6 Reverse Osmosis Treatment Costs
The costs involved with waste treatment using reverse osmosis are given comprehensive
coverage in reference (49). Most of the costs for this section were derived from this
reference. References (50) through (56) provided additional information concerning
reverse osmosis costs and performance.
The costs for reverse osmosis treatment include: capital eqUipment, membrane replace-
ment, pretreatment, power and labor plus maintenance materials.
1 .4.6.1 Installation Costs
The capital costs for reverse osmosis installations change significantly with plant size.
Small units cost $1 .00 to $1 .50 per 3.78 liters per day (GPD) while large units lower
this cost to $0.50 or less per 3.78 liters per day as shown in Figures 84 and 85. These
costs do not include either extensive pretreatment or dsposal facilities.
Vlll—19
DRAFT
-------
II
INSTALLED
____ FOR
r
2o
DRAFT
OO O
CAPITAL COST vs. CAPi4CITY
DEMINERALIZATION
CHEMICAL
FIGURE 83
COSTS FOR DEMINERALIZATION
• B-STEP ST BASE
.2-STEP WEAK BASE
,
/
/
/
/
LE S E1i
- i TOTAL ssa w
( 1000-4000 110/Li
— L TOTAL SS W E2J
(0-ASO MG/Li
CAPAQTY (OJ M/ Y TREATED)
IP0O / CO
CA .C1TY (GPO TREATED)
FIGURE 82
I 4 .VITEA E. CEM ALIZEA5 ARE REOD RATED WITH
LN HTD VE .WO 5ULFU C £C0
2 MOM £FrC’E. v LMTS EPE E EO WITH I.JIC
10 2LFU C I0 Y. STE C BY-PRO CT5 ARE
1010 W EI.E’.ER POSS.ALE
I
VIII-20 DRAFT
-------
TABLE 48. Overall Costs for Demineralizatfon
FIXED BED 2—STEP DEMINERALIZATION
Installed Labor and
Capital Resin Chemical Maintenance Overall
Capacity Amortization Costs Costs Costs Costs
Treated /1000 gallons /1000 gallons /1000 gallons /1000 gallons /1000 gallons
cu nVday(GPD) or 3785 liters or 3785 liters or 3785 liters or 3785 liters or 3785 liters
100 mg/liter, Total Dissolved Solids
38(10,000) 26.3 3.2 10 1.8 41.3
378(100,000) 16.3 3.2 10 1.1 30.6
37850,000,000) 8.2 3.2 10 0.5 21.9
500 mg/liter, Total Dissolved Solids
9: 38(10,000) 26.3 . 3.2 50 1.8 81.3
378(100,000) 16.3 3.2 50 1.1 70.6
3785(1,000,000) 8.2 3.2 50 0.5 61.9
1000 mg/Uter, Total Discri d Solids
38(10,000) 26.3 3.2 100 1.8 131.3
378(100,000) 16.3 3.2 100 1.1 120.6
3785(1,000,000) 8.2 3.2 100 0.5 111.9
2000 mg/liter, Total Dissolved Solids
38(10,000) 26.3 6.4* 200 1 .8 234.5
378(100,000) 16.3 6.4* 200 1.1 223.8
3785(1,000,000) 8.2 6.4* 200 05 215.1
*Doub le resin cost assumed for Increased loading.
-------
TABLE 49. Overall Costs for Demineralization
SPECIALTY PROCESSES —— High EFFIciency—Low Cost Regeneration Units
Labor
Capital Resin Chemical Maintenance Overall
Capacity Amortization Costs Costs Costs Costs
Treated /1000 gallons /1000 gallons /1000 gallons /1000 gallons /100O gallons
cu nv’day(GPD ) - or 3785 liters or 3785 liters or 3785 liters or 3785 liters or 3785 liters
l 000 itig/s , Total Dissolved Solids
38(10,000) 43 3.2 17 2.9 66.1
379(100,000) 21.4 3.2 17 1.4 43.0
37 5(1,000,0OO) 12.5 32 17 0.8 33.5
2000 n /i , Total Dissolved Solids
38(10,000) 43 6.4* 33 2.9 85.3
37Y(100,000) 21.4 6.4* 33 1.4 62.2
37 5(1,0O0,0O0) 12.5 6.4* 33 0.8 52.7
3500pt9/ft , Total Dissolved Solids
38(10,000) 43 12.8** 60 2.9 118.7
37q(100,000) 21.4 12.8** 60 1.4 95.6
37 5(1,000,000) 12.5 12.8** 60 0.8 86.1
*Double resin cost asMJmed for increased loading.
**Four times low solids resin costs assumed for this very heavy loadng.
-------
DRAFT
C TY ( O T ATED)
FIGURE 84
INSTALLED CAPITAL COSTS FOR
REVERSE OSMOSIS EQUIPMENT
K
I
I
§1
I
4
I
__ qw W
C 1TV ( D I NI T ATED)
CI Y (GPO T )
FIGURE 85
COSTS FOR REVERSE OSMOSIS TREATMENT
-
I
C TY (DI U D T1 AT )
-------
DRAFT
1.4.6.2 Membrane Selection and Life
The selection of the membrane material, either sheet or hot low fiber, depends primarily
on the nature of the waste to be treated and the product water quality desired. In
general, tighter (small pore size) membranes have lower flux rates (liters per day per -
square meter of membrane surface) than more open—structured ones. Therefore, to ob-
tain low-total—dissolved-solids product water, the area required for treatment of a
given liters—per—day flow rate will be significantly higher-than for an allowable high—
total—dissolved—solids product water. In turn, the increased membrane surface area
will increase the capital and membrane replacement costs. Thisinfluence is shown in
Figure 86 as it affects overall costs.-
1.4.6.3 Operating Costs
Membrane life is one of the major factors of operating coits. Currently membrane life-
appears to be one to three years, with the average shifted- toward- the one to two year
interval for replacement. This short and variable life has restricted use of reverse
osmosis in many otherwise logical applications.
• Since modules constitute one—third to one—half of ‘the capital equipment costs, the life
of the--modules is critical. Unfortunately, module performancethul life are ako the
most difficult features of the unit -to predict and control. For- this-reason, --cost develop—
jnents in. thiLsection are based on a two (2) year—lfe--. -As appl t on experience in—
- creases , improved membrane -life will significantly reduce øper i tô ti-Tôble 50
summarizes membrane--replacement costs for-two and three yeariife
Various chemical pretreatments are required to prepare feedwater for passage: through
- the membrane units. Included in these pretreatments are pH adjustment,- such-as- -acid
addition to eliminate carbonate scaling, sulfate scaling control through- addition of
sodium hexametaphosphate, and chlorination for organics. -
_j.owenergy requirement- is one of the majOr advantages-of the reverse -osmosis=process .
The primary energy requirement is for high pressure pumps. Power for this-pumping-
operation may be-calculated by-the following formula . -
Power/i 000 gallons or 3785 liters treated water = Pumping--pressure , c—-7. 28
0.85
Where 7.28 x io- is a-conversion factor and 0 ..85Jslthe pump/motor efficiency,
power is in kilowatt—hours and pumping pressure is-in atmospheres. E cpetieii e-has-
shown that 10 percent allowance for-auxiliaries gives the approximate overall energy
needed.
V I 11-24-
DRAFT
-------
FEED COMPOSITION (ppm )
DASHED LINES DENOTE
MEMBRANE PERMEABI LITI ES. GFD/1 00 PSI
• INDICATES STATE-OF-THE-ART MOOULES
• INDICATES DEPLOYMENT OF LOW PRESSURE MEMBRANES
CURRENTLY UNDER DEVELOPMENT
PRODUCT WATER QUALITY, TDS . ppm
FIGURE 86. TRADE-OFF BETWEEN MEMBRANE PERMEABILITY (FLUX)
AND SELECTIVITY (REJECTION AND PRODUCT WATER
QUALITY) FOR CELLULOSE ACETATE BASE MEMBRANES
(10 MCD PLANT 055% RECOVERY, 3100 ppm TDS FEED)
20
15
LP-HFF 250 PSI
N.
C.
U,
2
U)
xz
0
I -
Ow
U
C,
—w
-ii ..
-------
TABLE50. - Re ,erse Osmosis —Membmne
Replacement Costs
- vr;ooo ‘Gal or 378 Utèi Treat d _ -
Vó lumj Treated 2Yr. Life 3Yr. Life
Cu np’ -day GPD Present Futuri Present Future
38 10,000 45 22 30 15
9 25,000 45’ 22 30 15
189 50,000 45 22 30 -15
100,000, 38 2O- -25 13
945 250,000 38, 20 25 13
1890 500,000 30 15 20 10
.1,000,000 30 15 20 10
18,90Q 5,000,000’ ‘2Z. 12 ‘15 8
10,000,000 i5 8 10 5
Taken from Reference (49 , p. i08 -. , . Conveitedto c ’ iy’day .and GPD treated,
basis plus:two (2). year.life adjustmónt.-
Labor an naintenarice casts Shown -in ‘Table 51. are taken f àrn reference (49). The
other cited 50) ’4h ugh 56) ive Iue :ifrreàsOnàbJe agreernenf. -T-able
Si mmarizer4he - perafl’ng costs; ‘-.Fi ure 85 :combined all the1nf rmation.4eveloped.
into overall revetseosmosistreatment Qsts-: Thesevalue dJ e -based on conservative
engineeriyig and.industrial -coIculaflot s and a tump1 ons. Membrané1ife-of two years
h assumed.’ straight line 1Oyeqr depreciation -ahd ’ -4Lpercent ri ne ’ -areused in the
calculations.
1.4.7 Evc oiàflon Costs
Although there are many ‘different designs’änd variations of-evaporative -equipmeiit,
Ibur basic types can be-used- to coyer the needsiof -th inorganic-chemical field:
(1) single-effect evaporators;; (2) ulti-effectevapc*ators; :(3) ‘hIgh efficiency
vertical tube and multi—effect flash evaporators; and (4) low energy specialty
evaporators. Costs for these types-of equipment and their operation are given in the-
fbi lowing-subsections. Descriptions of these units:were. given in- Section VI.
VIII - 26
-------
DRAFT
TABLE 51. Reverse Osmosis —— Operating Costs
/1000 Gal, or 3785 Liters Treated
Labor Plus
Volume Treated Maintenance Total
ai ,rVdoy GPD Power* Chemicals** Materials Cost
38 10,000 6 4 28 38
95 25,000 6 4 20 30
189 50,000 6 4 15 25
37q 100,000 6 4 10 20
945 250,000 6 4 7 17
1)890 500,000 6 4 5 15
785 1,000,000 6 4 4 14
18900 5,000,000 6 4 2 12
3 850 10,000,000 6 4 15 11.5
*At 1 per kwhr.
**w;ll vary depending on pretreatment required.
***Mditional breakdowns in reference cited abo
1 .4.7.1 Equipment Selection
Each of these types of evaporators has its own performance area, as discussed in
Table 52. Figure 87 gives the energy requirements of each as well as other treatment
techniques as a function of dissolved solids content.
The selection of evaporative equipment depends on the job requirements. For high
volume, low solids stream concentrations the VTE, multi—flash or Resources Conserva-
tion Company (RCC) type units should be used. Ninety percent or more of the water
can be recovered as high purity product with relatively low energy requirements. The
remaining five to ten percent can be more economically removed by recirculating
evaporators or dryers. Although energy requirements are high per kilogram of water
removed for single effect evaporators and dryers, the total energy requirement and
capital costs for this step are relatively low. High—volume, high—solids—content
streams may be handled similarly except that conventional multi—effect evaporators
should be used for the first concentration.
1 .4.7.2 Low Energy Specialty Evaporator Costs (References (57), (58), and (59))
Capital costs for a specialty low energy unit, the flat plate vapor compression evapo-
rator (RCC unit), are given on page Vlll—30 (Reference (58)).
Vlll—27
DRAFT
-------
DRAFT
TABLE 52. Evaporator Characteristics
High
Efficiency Low
Re— Vertical Energy
Character— circulative Multi— Tube Specialty
i sti cs Evaporator ‘effect Evaporator Evaporator
Effects 1—3 2-6 10—20 15—30
Evaporative (400—1000) (j80-6o0 (75 -1oo (35 - looj
energy, 222- S55 ’ a OO 33 - jq -5 ’
(Btu/l b)
k c ’aJ/ 9
Opti mun 20 to max. 10—50 1-10 1—10
concentration
range, % by
weight of
solids
Ability to Excellent Good, Poor, Good,
handle heavy can be not for calcium
crystallizing easily operable sulfate and
or suspended equipped other slurrie5
solids load for re-
drculation
Optimum Best,for Good over Mainly for Mainly for
capacity small capa- wide capa— high capo— high capa—
range city below city range city more city more
5000 GPD 10,000— than than
2,000,000 1,000,000 1001000
GPD GPD GPD
General Relatively Inter— High Highest
costs low mediate
VIll—28
DRAFT
-------
TOTAL DISSOLVED SOLIDS (ppm of concentrate)
FIGURE 87. ENERGY COMPARISON FOR DISSOLVED SOLIDS REMOVAL
‘9
55.5
kg cal/kg
5.6
11000 0OO
1,000
5
-ø
-Q
LU
0
LU
‘ Ii
z
LU
10
1,000
10,000 1O0 0O0
-------
DRAFT
Capacity Installed Capitol
rn/day (GPD) Costs, $
379(100,000) 635,000
850(225, 000) 1,350,000
1890(500,000) 2,500,000
Larger capacities would currently be made up of multiple smaller units. Operating
costs for the RCC unit arise from eleciri power, pretreatment chemicals, and labor.
Unlke most evaporators, the RCC unit depends on on electrically driven compressor
insteod of steam for its energy, therefore, operating cost’ is directly influenced by the
electrical power costs in the area. This cost may range from $0.003/kwhr to over
$0.01/kwhr. For industrial applications, operating power costs for this study are taken
as $0.01/kwhr. The amount of power requh-ed depends on the evaporative situation.
The Following table gives estimated power as a functon of total dissolved solids in ppm
in the concentrate.
kwhr/1,000 gal
Concentrate TDS*Lpp v or 3785 liters Treated
10,000 60
50,000 65
100,000 100
200,000 250
*Total solids, including those suspended in the slurry,
may be several times greater than the dissolved solids.
The above correlations are approximations -— useful for operating cost calculations.
Operating and overall costs in /3785 Uters (1000 gallons) for an 850 cu rn/day
(225,000 GPD) RCC unif are given below:
Operation
Concentrate Power and
TDS*, ppm ( kwhr/l000gal) Chemicals Main on ice Total
10,000 60 3 52 115
50,000 65 3 52 120
100,000 100 3 52 155
200,000 250 3 52 305
*Since sparingly soluble water contaminants such as calcium sulfate and silica
precipitate with concentration, total solids are usually much higher.
VIII -30
DRAFT
-------
DRAFT
Capital Operation Total
Concentrate /1 ,000 Gal. /1 ,000 Gal. /1 ,000 Gal.
TDS or 3785 liters or 3785 liters or 3785 liters
10,000 257 115 327
50,000 257 120 377
100,000 257 155 412
200,000 257 305 562
These RCC unit overall cost values are admittedly conservative, but are consistent
with the basis used for other calculations of this report —— industrial 10 year depre-
ciations and higher cost electric power than would be available to many current users.
Low cost power and 35 year capital writeoffs would bring the overall costs down to
approximately $2.00/i ,000 gallon or 3785 liters treated.
It should also be emphasized that the power requirem!nt correlation with total dissolved
solids neglects the suspended solids portion of the recirculated slurry. Since many dis-
solved solids such as calcium sulfate are only sparng t v soluble in water, concentration
causes them to precipitate and form slurries. The RC( unit is designed to handle such
slurries up to total solids contents of 35 to 50 percent F which point the total dis-
solved soRds might be one percent or 10,000 ppm). The critical difference here is
that cflssolved solids raise the boiling point of the solution while suspended solids do
not appreciably affect it. The ability to handle slurries is one of the key RCC technol-
ogy advantages over multi—flash and vertical tube evaporators which are discussed next.
1 .4.7.3 High Efficiency Wulti-Flash and Vertical Tube Evaporators (60-70 )
Vertical tube, multi—stage flash and other high efficiency evaporators, as discussed in
Section VII, have been used extensively in units designed to recover pure water from
either salt or brackish sources.
Installed capital costs are shown in Figure 88 and operating and overall costs are given
in Figure 89.
1 .4.7.4 Conventional Multi—Effect Evaporators
For the heavy—duty, very high—solids evaporations, industrial type multi—effect eva-
porators are indicated. The inorganic salts in seawater and inorganic chemical indusr
try are very corrosive. Even cupro—nickel and stainless steel alloys may not be suffi-
cient for many of the solutions involved. Therefore, for this section, costs ore given
for solid nickel, titanium and tantalum materials, as well as stainless steel. Nickel
construction raises the cost signflcantly, J,ut will provide reliable service demanded
for industrial applications.
Vlll—31
DRAFT
-------
DRAFT
a
— 40 I-’
!0O0
I0
01 400 1000 4000 40000
PLANT SIZE (CU M/QEf TREATED)
PLANT SIZE (GPO TREATED)
FIGURE 88
I iSTALLED CAPITAL COSTS vs. CAPACITY FOR HIGH
EFFICIENCY VTE OR MULTI-STAGE FLASH EVAPORATORS
— __ E1 00575 REP (II)
n20I
400 l 00 4. 0 )0 -- 400)0
CAPOCITY (CU M/D )
100 .000 I 000)0
CA CITY (GPO)
FIGURE 89
OVERALL AND TOTAL OPERATING COSTS
FOR VIE AND MULTI-FLASH EVAPORATORS
DRAFT
V 1 11—32
-------
DRAFT
In selecting the optimum number of effects, a balance has to be made between equip-
ment costs and operating costs. If the oddilion of an effect will not pay for itself in
lower steam costs within approximately three years, the effect will probably not be
added. It is rare that more than six or seven effects con be lustified in this manner.
(This is particularly true because of the high dissolved solid solutions or wastes in-
volved.) Figures 90 and 91 show the interrelationships between number of effects and
capital cost and steam usage, respectively.
Capital costs may be calculated rather quickly and directly from Figure 92 (supplied
courtesy of Goslin—Birmingham Corporation and used by them for such calculations).
Calculations for installed capital costs for a 378 cu rn/day (100,000 GPD) 6-effect
all—nickel evaporator show the evaporation load 31,300 pounds per hour or 14,000
kg per hour. The heating surface/effect = 31,300 = 1.040 ft 2 = 14,200= 97ni 2
30 146
Miere 146 kg,4ir/m 2 (30 pounds/li r/avg. fp 2 ) is the design evaporation flux from em-
pirical experience (Reference (60)).
For six effects, total surface area = 97 x 6 = 582m 2 (1040 x 6 = 6240 ft 2 ). Using
Figure 92, equipment capital costs = $500,000, adding 33 percent for installation
(taken from Reference (60)). Total installed capital costs = $667,000. The 33 percent
addition for installation should be conservative, since the equipment cost is three times
that of stainless steel construction. Using the above procedure, values for other capa-
cities are given below:
Treated Total Installed
cu m/day (GPD) Capital Cost, $
378(100,000) 667,000
945(250,000) 1,530,000
1ft90(500,000) 2,800,000
785(1 ,000,000) 5,470,000
Analogous values for stainless steel and other construction material capital costs may
be similarly derived.
Operating costs are made up of steam value, labor and m&ntenance. Chemkol pre-
treatment costs are usually minimal. Operating costs are summarized below for 6-
effect evaporators.
Overall costs for all—nickel and stainless—steel 6—effect evaporators are given in
Figure 93.
Vlll-3
DRAFT
-------
0 2 4 6 8
Number of Effects
EVAPORATION
Capital Costs Vs. Effects
for Conventional t’t.ilti-
Effect Evaporatc rs.
0
U-
I-
‘F)
0
U
5
4
3
2
0’
a
-I
Figure 90.
-------
6000
GPM
5000
%lJ
II
4000 ,-.
c v )
w O
I- 0
.
3000
20C’ O
1000
200,000 */hr
400,000 /hr
EVAPORATION
600.000
(X 0.454 = kgAw)
j
0
Figure 91.
Steam Usage Vs. Effects for C nventicxta1 Milti-Effect Evaporators
-------
‘I ,
DRAFT
RJ. W I
tOTAL l€AI1NG SO Fr)
FIGURE 92
CORRELATIONS OF EQUIPMENT COST WITH
EVAPORATOR HEATING SURFACE
o 701
‘a
500
40
3C
I-
101
CAMcITY (GPD TPEATED)
FIGURE 93
OVEflALL COSTS FOR 6-EFFECT EVAPORATOR
TREATMENT OF WASTE WATER
1000
CAPACITY (C l i M/OAY ‘rPEATEW
DRAFT
VUI—36
TOTAL I€ATIM3 &JR I SO Mt
300
a
‘a
I d
I-
s, SOC
Li
I- .
-j
0
8
I—
U,
0
L i
9C
w8
7C
SC
400 500
-------
DRAFT
Steam Labor and Total
Costs in Maintenance Costs
Treated Treated /3785 liters /3785 liters /3785 liters
cu rn/day GPD ( 1000 gal) ( 1000 gal) ( 1000 gal )
378 100,000 95 91 186
945 250,000 95 80 175
1890 500,000 95 71 166
3785 1,000,000 95 68 163
1 .4.7.5 Single Effect Evaporators
When evaporation loads are small as for Final concentrations or minor waste streams,
evaporative energy costs are secondary. In these cases, equipment costs and reliability
of operation are the controlling considerations. Various designs are available for hand-
ling crystallizing solids or slurries and design and industrial technology is widely
available.
Using Figure 92 and following the same procedures anc osts For energy, installation,
maintenance and labor as for multi—effect evaporators, costs can be developed. Ess h-
folly, single—effect evaporators costs are treated as an extrapolation of the multi—effect
cost values. A summary of the costs involved is shown below for single—effect evapor-
ators —— all stainless steel construction.
Total
Installed Capital Operating Overall
Capital Writeoff Costs Costs
Treated Treated Costs /3785 liters /3785 liters /3785 liters
cu rn/day GPD $ ( 1000 gal) (1000 gal) ( 1000 gal )
38 - 10,000 8,000 34 564 598
189 50,000 28,000 24 551 575
379 100,000 45,000 19 545 564
945 250,000 80,000 14 539 553
1 890 500,000 146,000 12 536 548
3785 1,000,000 267,000 11 533 544
Basis: Installation Costs —— 100% of equipment capital for 38 and 189 cu rn/day
(10,000 and 50,000 GPD) size, 50% for 379 cu m/doy (100,000 GPD),
33% above 37 9 cu rn/day (100,000 GPD).
15% Capital writeoff/yr.
_ 4% Capital cost/yr for maintenance materials.
(continued on next page)
VllI-31
DRAFT
-------
DRAFT
GPD — 3O (38 cm/d)
GPD — 20 (189 cm/d)
GPD — 15 (379 cnVd)
GPD — 1O (945 cm/d)
GPD — 8 (1,890 cm/d)
GPD - 5 (3785 cm/d)
Similar values for all nickel, titanium, tantalum construction are:
Basis: Same as previously shown except 33% of capital costs used for installation
estimates for all capacities. -
These figures show that single—effect evaporation costs are largely steam. Also, mate-
rials of construction are not very important in their influence on overall costs. All
nickel, titanium, tantalum or other high cost materials of construction are often needed
and can be used without undue penalty.
The high overall costs per liter treated also indicate that single—stage evaporators are
restricted to small capacities. For example, at the 3785 cm/d (1,000,000 GPD) capa-
city, yearly overall cost for stainless steel equipment is $1,910,000. Comparable
multi—effect and VTE costs are $583,000 to $1 ,400,000 yearly, obviously the higher
efficiency units would be used whenever possible. At the 379 cm/d (100,000 GPD)
level, comparable costs are $198,000 per year for single effect, $72,200 per year for
six—effect, and S78,500 per year for 14—effect. For this case, there is sf 11 approxi—
rr.ately 51 20,000 per year savings in going to multi-effect evaporators. Single—effect
evaporators would normally be used in the capacity range of 48 cm/d (10,000 GPD).
Vlll-38
90% evaporation.
Steam cost -- $0.70/bOO lbs or $0.70/454 kg
Labor cost/1000 gal or 3785 liters treated: 10,000
(350 day/yr operation) 50,000
100,000
250,000
500,000
1 ,030,000
Total
Overall
Costs
Capital
Operating
Installed
Writeoff
Costs
/3785 liters
rn/day
GPD
Capital
/3785 liters
/3785 liters
(1000 gal)
Treated
38
Treated
10,000
Costs,1
16,000
(1000 gal)
(1000 gal)
Treated
69
574
643
189
5t,000
68,000
58
561
619
378
100,000
133,000
57
555
612
945
250,000
300,000
52
549
601
1890
500,000
532,000
46
545
591
3785
1,000,000
1,060,000
45
542
587
DRAFT
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DRAFT
1 .4.8 Mechanical Drying Costs
The crystallized, suspended or dissolved solids in the previous evaporation section can
either be recycled, sold, or disposed of in their concentrated form, or, they may re-
quire further treatment. Whenever possible, suspended solids should be dewatered by
centrifuging or filtration. These relatively low cost treatments may be all that is
needed, or reduction to full dryness may be required. When full dryness is required,
the filter cakes, centrifuged solids, and concentrated dissolved solids may be subjected
to conventional thermal drying. Heating may be by gas, oil, or steam. Types of dryers
include rotary drum dryers, screw type mechanical dryers, scraped surface tunnel dryers
and heated evaporation pans. -
Capital costs and labor costs are minimal (labor and materials are estimated to be at
$0.11 to $0.33 per kkg ($0.10 to $0.30 per ton) of product for small dryers (Reference
(71)) as compared to the energy cost.
Taking energy costs as $0.50 per 252,000 kg cal (million Bfu) (gas or oil combustion)
and an energy utilization efficiency of 50 percent, dr”ing costs are $1 .00/454 kilo-
grams (thousand pounds) of water evaporated.
The average deep well capital and operating costs determined from a recent compre-
hensive survey (reference (77)) are: capital cost —— $305,000; operating costs ——
30 /3785 liters (1000 gallons).
Operating costs for deep well disposal, taken from references (74), (76), and (77),
range from 4 /3785 liters (1000 gallons) to $2.20/3785 liters (1000 gallons). The lower
costs are for shallow wells, low injection pressures, minimum pretreatment, relatively
low corrosiveness, and a minimum of monitoring and instrumentation. The higher oper-
ating costs involve deep wells with high injettion pressures, extensive pretreatment,
high maintenance costs, extensive monitoring and instrumentation, and corrosion resist-
ant equipment. In any cost calculations involving deep wells, as discussed in Section
Vil, either a backup well or alternate disposal facility is necessary . This will increase
the average capital cost to approximately $500,000 (for a single-well operation).
Calculating overall costs for deep well disposal at a 1890 cu rn/day (500,000 GPD)
rate and using the 15 percent capital amortization used for other treatment and control
methods gives an overall cost of 73 /3785 liters (1000 gallons).
Economic land disposal of soluble solids is one of the more difficult environmental
problems facing the inorganic chemicals industry. If it is not solved, a number of
chemicals may have to be produced in favorable geographical areas (for solar pan
or land storage) or wastes will have to be shipped to those areas .
Vlll-3
DRAFT
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DRAFT
1 .4.10 Deep Welling Costs (References (75), (79) and (80 )
The capital costs for injection wells vary over a very wide range —— from $40,000 to
more than $1,000,000 (references (74) and (77)). The costs depend on factors such as
well depth, geology, well hole size, care in drilling, well construction, geographical
I ocati on, pre—treatme nt requirements, instrumentation and monitoring, corrosion prob-
lems, injecflon pressure, and maintenance.
The principal cost factors in well construction are drilling contractor costs and casing
and tubing costs. These two factors comprise approximately two—thirds of the total
construction costs. The larger and deeper the hole, the higher the contractor costs
will be.
Surface equipment such as pumps, fitters, tank, piping, and instrumentation can vary
from 50 percent of well construction costs to 100 percent or more
Injection pressures above 27 atmospheres (400 psi) require more expensive pumps.
Corrosive liquids require more expensive materials in the liquid handling equipment.
Drying costs as a function of solids content are given below:
% Solids Drying Costs, Drying Costs,
in Feed /454 kgCIc 1A) c /3785 UtersOocoy*/)
( by weight) Feed Feed
90 10 Dry Basis
80 20 Dry Basis
70 30 Dry Basis
60 40 Dry Basis
50 50 420
40 60 ‘- 500
30 70 580
20 80 660
Aside from the energy costs involved, there are practical drying problems with common
dissolved salts such as calcium chloride, potassium chloride, and magnesium chloride.
These can be dried but they hold tenaciously to residual water and musr be given
special treatment. They can be and are dried, however, by high tem roture and
special handling techniques involving drum flakers, pan evaporations, arid other pro-
cesses well known to industry.
VIll—40
DRAFT
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DRAFT
1 .- Solid Wastes Disposal Costs
The slurries, water soluble solids and water insoluble solids obtained from control and
treatment of inorganic chemicals industry water—borne wastes have to be contained, or
disposed of, in a safe and economical manner.
There are two key considerations:
(1) Are the solids soluble or insoluble in water?
(2) What is the net evaporation—rainfall situation for the area?
1 .4.9.1 Insoluble Solids
Provided that the solids are insoluble in water, most solid wastes from the inorganic
chemicals industry may be land dumped or land—filled. Slightly soluble materials such
as calcium sulfate may be handled this way (although not necessarily with complete
justification). Costs are $0.22 to $0.66/kkg ($0.20 to $0.60/ton) of solids (Reference
(71)) —- for simple dumping or landfilling. Figure 94 gives a breakdown of complete
londfilling costs. Large scale operations without cover cost less than $1 .11/kkg
($1 .00/ton). If cover is involved for appearance or zoning requirements, the costs may
increase to $1 .05 to $2.20/kkg ($1 .50 to $2.00/ton).
1 .4.9.2 Soluble Solids
If the evaporation—rainfall situation for the disposal area is fa orable (as is the case
for much of the southwestern U.S. and some other areas of the country), then landfill
in an impervious, lined pan is feasible Costs for this operation are similar to landfill
with no cover (reference (71)) —— $0.22 to $0.66/kkg ($0.20 to $0.60/ton).
If, as is the case for most of the U.S., the evaporation—rainfall balance is unfavorable•
(more inches of ran than evaporation per year) then ocean dumping or waterproof con-
tainment must be practiced.
Ocean dumping of industrial wastes in 1968 involved 4,200,000 kkg (4,690,500 tons)
at an average disposal cost of $187/kkg ($1 .70/ton) for bulk wastes and $26.40/kkg
($2 4 /ton) for containerized wastes (Reference (73)). Since soluble solid wastes for the
inorganic chemicals industry are mainly sodium chloride, sodium sulfate or other com-
mon salts, the solid wastes would not have to be containerized.
Landfilling-of -containerized soluble solids in plastic drums or sealed envelopes is prac-
ticable but expensive. Blow-molded plastic drums, made from scrap plastic (which is
one of the present major problems in solid waste disposal) could be produced for
$11—22/kkg ($lO—20/ton) capacity at 227 kg (500 pounds) solids/drum and a rough
estimate of $2.50-$5.00 cost/drum. A more economical method, particularly for large
volumes, would be sealed plastic envelopes, 750 microns (30 mils) thick.
VIIl-4 1
DRAFT
-------
LrnArT
0
is
liE
.4
3
2
1
0
P 1
Solid wastes, ton/wk. (six-day operation)
(XO..907 kkg/week)
Figure 94. Disposal Costs for Sanitar ’L-andfi11s
600 900 1,200
I
I
VI
-------
DRAFT
At $1 .10/kg (50 /tb.) of film, low density polyethylene costs about 1O per 0.0929
square meter (1 square foot). Using the film as trench liner in a 1 .8 meters (6—foot)
deep trench, 1 .8 meters (6 feet) wide, the perimeter (allowing for overlap) would be
approximately 7.5 meters (25 feet). At a density of 1.6 grams/cc (100 pounds/cubic
foot) for the solid, costs of plastic sheet per metric ton would be $2.00 ($1 .75/ton).
With sealing, the plastic envelope cost would be approximately $2.20/kkg $2/ton).
With landfill costs of $2.20/kkg ($2/ton) additional, the total landfill disposal costs
would be about $4.40/kkg ($4/ton).
The above figures for solubles disposal using plastic containers, bags or envelopes are
only rough estimates. Also, the technology would not be suitable for toxic solids or
in situations vhere leaching contamination is critical.
1.4.11 Ocean Barging Costs
References (81) through (84) have been used to establish capital operating and overall
costs for barging of difficult or expensive—to—treat, water—borne industrial wastes.
The cost of a 4500 kkg (5,000—ton) capacity barge in 1973 dollars is approximately
two million dollars. New docking, storage tanks, pui. is, piping and other shore
facilities may be 50 to 100 percent of the barge cost, but are not included in these
cost developments, because in many plants these auxiliary facilities are already
available. In a new plant, or a major conversion, these costs could add $1 .00 to
$2.00 per 3785 liters (1,000 gallons) to waste disposal costs.
Overall costs for a 4500 kkg (5,000 ton) barge are approximately $4.50 per 3785 liters
(1,000 gallons) of waste disposed (updated References (81) and (84). A rough break—
down of these overall costs is tug rental, 50%) labor and maintenance, 20%,
and amortizations (l5%/yr), 30%. Using th above breakdown of overall costs, opera-
ting costs for other disposal and treatment techniques would be $3.15/3785 liters
(1000 gallons).
1.4.12 Treatment Costs for Ancillary Water—Borne Wastes
In many plants of this study ancillary wastes such as boiler btowdowns, cooling tower
blowdowns, ion exchange regenerants, and contributions from air purification equip-
ment, are either the sole or dominant contributors to water—borne wastes coming from
the plant. Rarely is removing these wastes from plant effluent water considered part
of the treatment or waste abatement process costs.
1 .4.12.1 Air—Borne Waste Abatement Costs
Five chemicals of this study have been selected for specific cost analysis. The circum-
stances for each are explored.
VIII-43
DRAFT
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DRAFT
L412.1.1 ‘ulfuric Acid
Reduction of sulfur dioxide in the stack gas of sulfur-burning and regen sulfuric acid
plants to specified limits is expensive for most existing plants. In each of two plants
of this study (113 and 023) over 2,500,000 has been spent for this purpose alone. As
regulations tighten, other plants will have to be modified similarly. The nature of
these modifications should be determined by the overall costs and perforrnunce of the
sulfur dioxide unit considered. For the $2,500,000 installations mentioned above,
reduction of the water—borne wastes without such on installation would require approxi—
motely $80,000 additional capital investment ($20,000 for evaporation; $20,000 for
filter or centrifuge plus 100 percent addition for pumps, piping, auxiliaries, engineer-
ing and installation) and a roughly estimated overall cost of $25,000 per year. Recov-
ered sodium sulfate at $38.50/kkg (535/ton) would return approximately $lOO,000/yeor
product value. A profit could be realized, therefore, on the installation of the addi-
tional equipment and instead of having a water-borne wasteload, useful product would
be available for sale.
If a sulfuric acid producer does not choose to follow the path of scrubbing sulfur dioxide
from the stack gases, producing water—borne wastes and then eliminating them, it will
undoubtedly be more profitable to recycle sulfur dioxide which should have a recovered
sales value of approximately $50/kkg ($45/ton) and eliminate the expense of sodium
hydroxide or other chemicals.
Both add—on double adsorption systems and other processes which have no water—borne
wastes exist. New plants all use the double absorption process.
Existing plants should be free to use any sulfur dioxide abatement process provided that
rhere is no final water—borne waste contribution. Those that produce these wastes
should ciso provide for their removal as part of the process and process costs.
1.4.12 . 1.2 Lime
The lime process has no waste water. The only contribution is from stack scrubbers
which collect the lime dust in water.
Current practice is to settle out solids from the scrubber water in ponds and possibly
neutralize this effluent before discharge to surface water. A large lime plant which
currently follows this general type of procedure (057) plans to install a cyclone re-
covery and calcining unit on the waste stream at a cost of $750,000. Cost of instal—
lotion will be covered by product value obtained. This will remove almost 100% of
the suspended solids. Some dissolved solids remain. Calcium oxide is soluble to the
extent of about 1000 mg/I. The water should be recycled for closed loop scrubbing
and would therefore be zero discharge.
VIll-44-
DRAFT
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DRAFT
A second approach, which escapes water-borne waste and waste recovery problems, is
dry bag collection. The exemplary plant of this study has no water effluent and uses
bag collection systems. Installation’ cost was $675,000 with annual operating costs of
$37,500. Just as for sulfur dioxide wastes from the sulfuric acid process, lime process
dusts should be collected by any effective abatement process provided that there is no
final water—borne waste contribution. Those processes that produce these wastes should
also provide for their removal as part of the process.
1 .4.12.13 Calcium Carbide
There is no water—borne process waste from the calcium carbide manufacturing process.
The only contributions are ancillary wastes —— cooling tower blowdowns, ion exchange
regenerants and gas stream scrubbings.
For water scrubbers, the water effluent needs to be isolated, suspended solids removed
by ponding or chemical treatment, alkalinity neutralized and a closed loop recycle
instituted to avoid dissolved solids discharge. Capital costs for a large plant adjusted
to 1973 prices are approximately $750,000 for the scrubber system, Si 1 2,000 for
improvements, pius a thickener and settling ponds that will bring the total cost up to
$1 ,000,000. No wastes are recovered and recylce is possible but would require
equipment modification. Therefore, over $1 ,000,000 investment is needed to water—
scrub without water—borne waste with both capital and operating costs being losses.
In contrast, the exemplary plant of ths study uses dry bag collecHon techniques
throughout. Collection and reuse of 10 percent of the raw materials from these dust
collectors makes installation profitable, and there are no water—borne wastes involved.
1 .4.12.l4Chlorine
The options of what to do with chlorine coming from the tail gas of a chlor—alkali or
Downs cell sodium plant are numerous, but dry bag collection is not one of them. In
contrast to the dusts from the first three processes discussed, chlorine is a reactive and
noxious gas. It is soluble in water and forms hypochiorites with water or basic mate-
rials present such as sodium hydroxide or calcium hydroxide.
The hypochlorites are bleaches and may be sold. They are also reactive and can be
used in the treatment of other chemical wastes such as cyanides. This is done in
exemplary plant 096. Sodium hypochiorite may also be catalytically decomposed to
sodium chloride and reused as a raw material in the process. Costs are low for the
decomposItion and reuse, but many plants simply discharge this reusable material as
waste effluent. This should not be allowed. It must be avoided if the zero discharge
limits recommended for Level II are to be met. Removal later from the waste stream
will be expensive .
VllI-4c
DRAFT
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DRAFT
Another method for direct utilization of tail gas chlorine is direct burning with hydrogen
to produce hydrochloric acid. Exemplary plant 057 is planning this approach at an esti-
mated capital investment of $430,000. Return on investment looks good from the stand-
point of product value and decreased sodium hydroxide usage.
With all of the above low cost options, there is no reason for ever finding chlorine tail
gas wastes in water effluents from the plant.
1 .4.12J. Aluminum Chloride
The aluminum chloride process has no water—borne wastes, but condenser gas scrubbing
removes residual chlorine gas and entrained aluminum chloride fumes. T vo exemplary
plants (152 and 125) of this study avoid any water—borne wastes as discussed in Sect ion
VII. Costs for a generalized treatment process are shown below to illustrate the dollar
values involved. For discharge of 4.5 kg (10 pounds) of aluminum chloride and 2.25 kg
(5 pounds) of chlorine per 0.907 metric ton (ton) of product in a 18 metric ton/day
(20 ton/day) plant, treatment costs are developed below for neutralization with sodium
hydroxide. Sodium hydroxide costs are estimated to be 70,000 per year. Also, 195 kg
(430 pounds) per day of sodium chloride and 53 kg (117 pounds) per day of aluminum
hydroxide are formed. The volume of neutralized solution s approximately 946 liters/
day (250 gallons/day). Installed cost for a 379 liter (1000 gallon) neutralizing, set-
tling and hypochlorite decomposition system plus a small recirculating single—effect
concentrator and crystallization system would be approximately S25,000. Operating
costs including steam, electricity, disposal of solid wastes, labor and maintenance,
arid chemical costs would be approximately $l2,000/yr. Overall costs of capital
writeoff plus operating costs would be approximately $16,000/yr or slightly more than
$2.20/kkg ($2/ton) of product.
1.4.12.2 Boiler Blowdowns, Cooling Tower Blowdowns, and Ion—Exchange
Regeneronts Treatm nt Systems and Their Costs
In many chemical plants., blowdowns, and water treatment wastes are larger in quantity
than process wastes. This occurs for sulfuric acid, nitric acid, electrolytic hydrogen
peroxide, calcium carbide, phosphoric acid, and sodium tripolyphosphate. As process
wastes are reduced, more chemicals will join the list. Therefore, these wastes should
not be ignored.
Present water treatment facilities in existing plants are usually not designed for zero
discharge of water—borne wastes, nor are they designed for complete closed cycle
operation. Dissolved solid5 are the only water contaminants which involve apprecable
treatment problems, costs and energy and if is in this area that present water treatment
facilities are inadequate.
VIlI-4 ’
DRAFT
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DRAFT
The generalized wafer treatment facflites given in Figure 75 earlier in this section
provide three treatment techniques for removing dissolved solids from makeup and re-
cycle water—demirieralization, reverse osmosis and evaporation. It s assumed from the
overall treatment model given in Figure 74 (of Which Figure 75 is a detailed portion)
that suspended solids and toxic materials have already been removed. Figure 95 gives
the dissolved solids concentration range over which each type of treatment technique
is economically feasible. Costs for different flow rates and dissolved solids contents
are given in Table 53. This table shows that if all the incoming and recycle water
and blowdowns ore less than 1000 mg/liter total dissolved solids then demineralizations
can be used economically from 1000 mg/liter to 3500 mg/liter. Specialty deminerali—
zation systems are favored, if available. Most blowdowns are in the 750 mg/liter to
3500/liter range. If specialty systems are available, they can be economically used.
Regenerants disposal adds to the overall demineraflzafion costs. With these costs-added,
the specialty demineralization and reverse osmosis plus evaporation treatment costs are
nearly equal in the 1000 mg/liter to 3500 mg/liter range. If any of the streams coming
into the treatment area have greater than 3500 mg/liter total dissolved solids, then
reverse osmosis and/or evaporation are usually the only treatment approaches.
New plants should have a central integrated water treatment area with all the necessary
equipment to eliminate water—borne discharges, including blowdowns and ion exchange
regenerants .
A model plant example is shown in Table 54 to illustrate needed equipment and costs for
treatment.
In ciddition to the cost of treating the waste streams, approximately 36—45 kkg (4—5
tons) per day of solids must be disposed of. Disposal costs for these could range from
1 .10 to $11 .00 per kkg ($1 to $10 per ton). A centralized treatment system as
described gives not only zero water—borne waste but also supplies all the demineralized
water needed for boilers, operation of cooling water towers at 95 to 98 percent recycle,
and reduces process water wastes. Since the treatment equipment is all highly automated,
labor costs are also low.
1.4.13 Geographic Influences on Treatment and Control Costs
Treatment and control practices and costs for the inorganic chemicals industry depend
largely on plant location.
Ocean dumping is economically feasible only for plants with easy access to the ocean.
Even a difference of being located directly on ocean shores as contrasted to being
80 to 160 km (50 to 100 miles) up a bay or river can charge barging costs by a fact or
two. Ocean barging for titanium dioxide wastes may be as little as S5.50 per kkg
($5 per ton) of product for well—situated plants. Costs may rise to $22—$44 per kkg
($20440 per ton) for others requiring more capital expenditures and longer barging
distances.
VIII —47
DRAFT
-------
I I
20 30
Pcrcan1 To Dissolved
Solids
J I
10 20
Percent
1 .1
30 40
To al Dissolved
Solids
‘1’: tn n L
T- ”
xc’h i: gc
Srnnil Wa’ Le S1:rc tni
day
Lc s then iCCO PPM
.
Ltrcjo W Qe Strc irn.’
GPDJ r>379 cu Wday
‘ L s s U i in 1000 PPM
Conv tionci1
Dcmincral-
izaLi’ n
j Up In 1000 PPM
Up to 1000 PPM
::a
1
De thiecal-
LZ LCiO1i
Up to 4000 PPM
.I
] Up to 4000 PPM
-
T1 ver
O.L. I
E1n 0 !o
1 -,J-
X I?JrC Lc.r
-
5 ) bo 10 ,CO0 PPM
500 bo 10 ,(X)0 PPM
I J
//7/t V/ j10,ooo PPM to M x Conc. [ ? //// ‘
l 3 Muibi-
1000 PPM Lo 100,000 PPM
1000 PPM to 100,000 PPM
L p ro Lio i
L Olxonc -
boo PPM to Max Conc,
C’ cmica1
Prcc Lpi r tior
0
< 5 Percent Tobal Dissolved Solids
7
10
40 50
< 1 Percent Tobal Dissolved Solids
0
50
Figure 95.
TreaLmont 7\pplicabiliby to Dissolved Solids Rzu-ige in Waste Streams.
-------
DRAFT
TABLE 53. Cost Estimates for Different Treatment
Reverse Osmosis
Flow Demineralzation + Evaporation
,/d (GPD) Costs, $/day Costs, $/day
100 mg/liter Total Dissolved Solids
Conventional Fixed—Bed
38(10,000) 4 20
37q0 00,000) 31 142
3785(’l,OOO,OOO) 220 1005
3 50O0,000,000) 2000 6000
1000 mg/liter Total Dissolved Solids
Conventional Specialty
Fixed-Bed Systems
38(10,000) 13 7 20
379(100,000) 121 43 142
3785(1,000,000) 1120 335 1013
3 850(10,00O,000) 10,000 ‘ -3000 6275
3500 mg/liter Total Dissolved Solids
Specialty Systems
38(10,000) 12 20
379(100,000) 96 142
3785(1,000,000) 861 1013
3 850(10,000,000) 8000 6275
10,000 mg/lifer Total Dissolved Solids
38(10,000) Costs are very high. This 20
37q( loo,000) is above the appflcation 154
785(1,000,000) level. 1115
3?850(1 0,000,000) 7600
VIll-4q
DRAFT
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DRAFT
TABLE 54. Model Treatment Plant Calculations
Design and Cost Basis
Total
Waste Dissolved
Category cL /d (GPD) SoUds, mg/I
Process Wc er 37q(100,000) 10,000
Cooling Tower Blowdown 38(10,000) 1 1000
B&ler alowdowns 19(5,000) 500
Air Pollution Control 38(10,000) 10,000 (Recoverable at $33/kkg
or $30/ton.)
Makeup Water 189(50,000) 300
Equipment Capital
Needed c ja ç/d (GPD) Cost, S
Demineralizer 37 (1 00,000) 60,000
Reverse Osmosis Unit 379(100,000) 80,000
Multi -Effect Evaporator 94(25,000) 60,000
2—Single-Effect Evaporators 38(10,000) 32,000
Rotary DrumFilter —- 25,000
Centrifuge 25,000 Iota I S 282,000
Waste Treated Overall Costs/Day
Process Water $ 142
Cooling Tower Blowdown $ 45
Bo r Blowdown $ 45
Make-Up Water $ 45
Air Pollution Control ( $100 credit )
Net Cost $ 85 or $ 3 0,000/yr.
VllI-50
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DRAFT
Deep—well disposal is geologically feasible in some ports of the United States but not
in others. Since deep—welling is sometimes the lowest cost, f not the only, feasible
disposal method practicable, ability to deep well can save millions of dollars. Brine
well salt producers have traditionally deep-welled their wastes. Any other disposal
method would raise the disposal costs significantly and perhaps close down some plants.
An economkally feasible method for disposal of wastes from the Solvay soda ash plants
is deep—welling. Uri fortunately, at least some of the plants are located where deep—
welling is not geologically feasible.
Treatment and disposal situations and costs for eastern and western United States differ
widely. Water is scarce in most of the west and, therefore, is worf more for recovery
and reuse. Pure water maybe worth 5.3 to 1 3.2ç per thousand liters (2Oç to 50ç
per thousand gallons). Therefore, it is not surprising to find evaporation foci pities used
for treatment of water wastes. Evaporation is rarely used on waste water in the East.
It can also be expected that the West will lead the East in treatment technology for
water reuse closed systems, and dry air cleaning equipment.
Another difference between eastern and western U.S. is the West has less rainfall.
Except for some coastal and isolated areas, western United States has a positive
evaporation—rainfall differential. This positive differential makes if possible ro ds—
pose of water—borne wastes by solar evaporation. Disposal costs as low as ?‘.9ç per
thousand liters (3U per thousand gallons) were given earlier in this section. Comoara—
ble deep welling costs are 19.3 per thousand liters (T3c per thousand gallons). A
Solvay plant could operate very well in many parts of the West using solar evaporation.
The location, character, and size of the company—owned land around the plant is be-
coming increasingly important. Mziny of the older plants in the inorganic chemical
industry are built on small plots, surroundec 1 by industrial and residential neighbors.
Industries such as hydrofluoric acid, titanium dioxide and sodium dichromate have
heavy solid waste loads but often limited storage capacity. Even where wastes can be
successfully disposed of outside the premises, costs are higher than for plant site stor-
age. Location of i eavy wasle load plants, such as Solvay process facilities, on small
fresh water streams has been fatal thus far for a number of such plants.
A number of the exemplary plants of this study had poor containment and control prac-
tices, but since they owned the land all around or were located in isolated areas, there
was no problem with pollution. Closed loop systems can be run with heavy contami-
nation in the loop, but, if the loop is all inside the plant, there is no pollution problem.
Design and location of any new plant should include consideration for treatment methods
and space required, solid waste disposal space and neighborhood compatibility, and
political and ecological factors for the localt
Vlll—5 1
DRAFT
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1 .5 Cost Effectiveness Information by Category
The general cost information developed in the previous subsections can now be applied
to specific categories and chemicals of this study. Jn the following water effluent
treatment cost sheets the costs for each of the four levels of waste abatement described
in Subsection 1 .3 are developed.
1.5.1 Category 1
1 .5.1 .1 Aluminum Chloride
There are no water—borne process wastes. The only ancillary waste would result from
air pollution control. Two exemplary plants of this study have no wastes from this source.
As discussed in subsection 1 .4, air pollution abatement contributions to water effluents
are costed as zero cost and energy. All such costs are credited to air pollution costs.
Exemplary plant number 125 has been chosen for cost effectiveness development (see
Table 55). This is a 30 year—old plant of nominal 22.5 kkg/day (25 ton/day) capacity.
Treatment facilities are newly installed.
Energy requirements are very low (small pumps and stirrers) and are taken as 0.75 kwh
0 horse power—hr.). Converting this to common units
6 gives 5.3 x 106 kg c cl
(21 x 10 Btu ) or 79.5 liters/yr (21 gal,”yr) of fuel oil energy equivalent.
For the entire industry, the energy requirement would be 17.1 x 106 kg c cl (68 x io6
Btu) or 257 liters/yr (68 gal lons/yr) of fuel oil energy.
Tieatment costs for air pollution control are Si .88/metric ton ($1 .70/ton) of product.
Treatment costs and energy requirements for water pollution control are zero.
1.5.1.2 Aluminum Sulfate
Two exemplary closed-cycle plants, numbers 049 and 063, were visited during this
study. Exemplary plant 063 is chosen for cost effectiveness analysis. This 46 —year—
old plant has an average production of 36 metric tons/day (40 tons/day). Cost effec-
tiveness information is given in Table 56.
Energy requirements for pumps, clarifier, drives, etc., are taken as 7.5 kwhr (10 hp—
hr) or 53 x io6 kg—cal (210 x 106 Btu) or 795 liters/yr (210 gal/yr) of fuel oil energy.
Vlll-5Z
DRAFT
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DRAFT
TABLE 55. Water Effluent Trea!ment Costs
Inorganic Chemicals —— Aluminum Chloride
(22.5 kkg/day (25 tons/day) Capa city)
Treatment or Control Technologies A B C D
Identified under Item Ill of the
Scope of Work:
Investment 0 100,000 100,000 100,000
Annual Costs:
Interest + laxes and Insurance 0 5,000 5,000 5,000
Depreciation 0 10,000 10,000 10,000
Operating and Maintenance 0 0 0
Costs (excluding energy
and power costs)
Energy and Power Costs 0 -.- 0 0
Total Annual Cost 0 15,000 ***15,000*** 15,000***
Effluent Quality:
Effluent Constituents Raw Resulting
Parameters (Units) kg/kkg (lbs/ton) Waste Load Effluent Levels
A B,CandD
Aluminum Chloride ± Chlorine (Airborne) 75(1 50) 75(1 50) 25(5*)
No water—borne effluent from process.
*Residual air—borne wastes.
**Operating costs of S18,000/yr balanced by sale of product as aqueous aluminum
chloride solution.
***Credited to air pollution control water pollution control cost is zero.
Vlll-53
DRAFT
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TABLE 56. Water Effluent Treatment Costs
Inorganic Chemicals -— Aluminum Sulfate
(36 kkg/day (40 tons/day) Capadty)
Treatment or Control Technologies A B C D
Identified under Item Ill of the
Scope of Work:
Investment 40,000 100,000
Annual Costs:
Interest + Taxes and Insurance 2,000 5,000
Depreciation 4,000 10,000
Operating and Maintenance 5,000 8,OCO
Costs (excluding energy
and power costs)
Energy and Power Costs —— 1 1000
Total Annual Cost ii ,000 24,000
Effluent Quality:
Effluent Constitutents Raw Resulting
Parameters (Units) kg.kkg (lbs/ton) Waste Load Effluent Levels
A B,CandD
Sflicon Dioxide 20(40) 1(2) 0
Titanium Dioxide 20(40) 1(2) 0
Aluminum Oxide 10(20) 1(2) 0
Aluminum Sulfate 0.25(0.5) 0.05(0.1) 0
A —— Typical treatment taken as pond settling -— total pond area of 0.4 hectare (one
acre)(un lined).
B —— Best average treatment level involves clarifiers plus additional ponds + level A
ponds and closed cycle operation.
Vlll—54-
DRAFT
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Entire industry energy for treatment s roughly estimated as 4300 x 106 kg cal
(17,000 x 100 Btu) or 64,345 liters (17,000 gallons) of fuel oil per year.
Treatment costs for closed cycle zero effluent are $1 .87/metric ton ($1 .70/ton) of which
$100/metric ton ($0.90/ton) of product represents additional cost above typical opera-
tion in all plants.
1 .5.1 .3 Calcium Carbide
The calcium carbide process, per Se, has no water—borne waste. The only possible
contribuHons are scrubbers to remove dusts and particulates from the gas streams. As
discussed in earUer subsection 1 .4 costs for cleaning up air pollution abatement con—
tributions to water effluents are credited to air pollution costs. Therefore, energy and
costs for water—waste abatement for calcium carbide are zero.
For information purposes a cost—effectiveness sheet, Table 57 has been prepared for air
pollution abatement costs for exemplary plant 190 of this study. In this case air pol-
lution control costs are zero since recovered raw materials pay for total annual costs.
1.5.1.4 Hydrochloric Acid (Chlorine—Burning )
During normal operation the chlorine—burning hydrochloric acid process has no water—
borne wastes. Startup wastes are less than one pound per ton and are typically neu-
tralized in sodium hydroxide solutions. Cost effectiveness information is given in
Table 58 using exemplary plant 121 as a model. Addition of a small sodium hypochlo—
rite destruction vessel plus a pump and transfer line to chlor—alkali brine for reuse gives
zero effluent from the process. Total cost for zero effluent attainment is $0.33 per
metric ton ($0.30 per ton) of product, while the incremental cost for goirg from typical.
to zero effluent treatment levels is $0.055 er metric ton ($0.05 per ton). Energy costs
are negligible.
1.5.1.5 Hydrofluoric Acid
Hydrofluork acid, like the other mineral adds, has a very low water—borne waste load.
Good engineering, maintenance and housekeeping bring the waste effluent down to
0.5 kg/kkg (one pound per ton) or less. A complete recycle zero discharge plant number
152 of 36 metric tons/day (40 tons/day) capacity and 15 years age, is chosen for cost
effectiveness calculations as given in Table 59.
The large cost differential between Level C and D show that two different approaches
make a substantial difference in the costs involved. Plant 011 follows stoichiometric
use of sulfuric acid, thereby eliminating $30,000 neutralization chemical costs per
VlIl—55
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TABLE 57.
Water Effluent Treatn ent Costs
Inorganic Chemicals
chervical: Cal cium Carbide (127 kkg/day (140 tons/day) Capacity)
Theath rt of Control Tedinalo-
gies Identified under Item
III of the Scxjpe of Work: A B C D
Irivesft ent 0 Not known
Annual Costs:
Interest ± Taxes and Not known
L suran
I eDreciation - Not known
Operating and 4aintenance 0 Not known
Costs (excluding energy
and pc er cx sts)
Enery and P er Costs 0 Not known
Total Annual Cost 0 0 0 0
Effluent Quality:
Ef Elu nt Constituents
Para ters (Units) Raw
Kg/kg (Pounds/Ton) Weste Resulting Effluent
Load Levels
Coke Dust 50(100) 50(100) 0 0 0
Furnace Dust 85(1 70) 85(1 70) 0 0 0
Packing Dust 10(20) 10(20) 0 0 0
Level A —— In many plants there cre no dust collectors.
Level B —— Plant 190 installations are expected to pay for themselves in recovered raw
material value. Therefore, annual air polluron control cost i- zero.
VI t I-5
DRAFT
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BLE 58.
Water Effluent Treatrrent Costs
Inorganic th nicals
theinical: Hydrochloric Acid (36 kkg/day (40 tons/day) Capacity)
Tieatrrent of Control thno1o-
gies Identified under Item
III of the Scope of Work: A B C D
Invest nent 10,000 10,000 15,000 15,000
P nnual Costs:
Interest + Taxes and 500 500 750 750
Insurance
i preciation 1,000 1,000 1,500 1,500
Operating and Maintenance 2,000 2,000 2,000 2,000
Costs (excluding energy
and p er costs)
Energy and Pcx zer Costs ‘-‘0
Total .lthnual Cost 3,500 3,500 4,250 4,250
Effluent Quality:
Effluent Constituents
Pararreters (Units) Raw
kg/kkg (Pounds/Fon) Waste Resulting Effluent
Load Levels
Chlorine & Hydrogen 0.5(1) 0.75(1.5) 0.75(1.5) 0 0
Chloride
Levels A and B —— Neutralization in sodium hydroxide solution followed by discharge to
surface water.
Levels C and D—— Destruction of sodium hypochiorite in small pond or vessel and use of
sodhim chloride solution in chlor—alkoli system. Chlorine-burning -
hypockloric acid units are always located in chlor—alkali complexes.
VIII -57
DRAFT
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TABLE 59.
Water Effluent Treatnent Costs
Ir organic th nicals
theinical: Hydrofluoric Acid (36 kkg/day (40 tons/day) Capacity)
Ti:eatxrent of Contiol ¶Iècthnolo-
gies Identified under Item
III of the Scxpe of Work: A B C D
Investment 0 30,000 50,000 75,000
nrnial Costs:
Interest + Taxes and 0 1,500 2,500 3,750
I rancE
Depreciation 0 3,000 5,000 7,500
Operating and Naintenance 50,000 52,000 60,000 165,000
Costs (ex&iirl ng energy -
and p er cxists)
ergy and Po ’ier Costs 1,000 5,000
Total 1 nnua3. Cost 50,000 56,500 68,500 181,250
Effluent Quality:
Effluent Constituents
Pai aeters (Units) Raw
tcg/kkg (Pounds/Fon) Waste Resulting Effluent
Load levels
Calcium Sulfate 3650(7300) 0 0 0 0
Sulfuric Acid 110(220) 0 0 0 0
Calcium Fluoride 62.5(125) 0.5(1) 0.25(0.5) 0 0
Hydrogen Fluoride 2.5(5) 2.5(5) 0.25(0.5) 0 0
Hydrofluorosilicic Acid 12.5(25) 12.5(25) 0 0 0
Silicon Dioxide 12.5(25) 12.5(25) 0 0 0
Level A —— Land dumping of calcium sulfate, minimizing acid by operating near stoichio—
metry requirements. Costs are all for trucking of calcium sulfate, calcium fluoride
and contained sulfuric acid to land dump.
Level B —— Similar to Exemplary Plant 011 of this study.
Level C -— Closed loop extension of oil.
Level D —— Exemplary closed loop Plant 152.
Vlll-5S
DRAFT
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year. They handle coldum sulfate and calcium Fluoride dry by h iuUng to Land dump,
thereby eliminating pond settling and dredging costs for another $70,000 per year
differential. In—process changes account, therefore, for $7.70 per metric ton ($7 per
ton) difference in treatment costs.
Total cost for zero water waste effluent achievement forplantOllis$1 7.60/metric ton
($16 per ton) and for plant 152 is $l4.30/metric ton ($13 per ton). By far the greatest
portion of this cost is for handling and disposal of solid calcium sulfate, which has to
be done in all plants.
Additional energy required For going from base level treatment to closed cycle operation
iS negligible.- An additional 7.5 kilowatts (10 horsepower) is allowed for pumping from
collection ponds back to the system. This gives 53 x 106 kg cal (210 x 106 Btu ) or
795 liters (210 gallons) of fuel oil energy per year. Total industry addtonal energy
requirements are 830 x 106 kg cal (3300 x 100 Btu ) or 12,490 liters (3300 gallons) of
fuel oil.
1.5.1.6 Lime
There is no water—borne woste from the process. There re, no cost or energy is
involved.
For informational purposes cost effecfivness Table 60 is given for eliminating air pollu-
tion. Cost is $1 .45 per metric ton ($1 .32 per ton) for dry bag collection installations.
If, as discussed earlier in this section, water scrubbing plus elimination of water—borne
wastes is more economical than $1 .45 per metrkTon ($1 .32 per ton) of lime produced,
then water scrubbing should be used.
1 .5.1 .7 Nitric Acid
There is no water—borne waste from the nitric acid process, nor is there usually any
contribution from air pollution treatment equipment. Only leaks, spills, monitoring
and containment costs are involved.
For 7 year old 281 kkg/day (310 ton/day) Exemplary Plant 114 there are no effluents
except boiler and cooling tower blowdowns. These ore over 378,500 liters/day
(100,000 GPD) in volume and illustrate comments made earlier in this section regard-
ing ancillary streams. Ancillary streams are disregarded as far as guide—
line specifications are concerned, however, so Exemplary Plant 114 has zero guide-
lines defined effluent. Since no cost figures are available for nitric add, they are
taken as the same as For sulfuric acid isolation and containment costs of $160,000.
Vlll-&9
DRAFT
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BLE 60.
Water Effluent Treatiient Costs
Inorganic thernicals
thernical: Lime — Air Pollution Costs Only (281 klcg/day (310 tons/day) Capacity)
reath nt of Control Tediriolo-
gies Identified under Item
III of the Scxpe of Work: A B C D
Irwestinent 0 675,000 675,000 675,000
annual Costs:
Interest + Taxes and 0 33,750 33,750 33,750
Insurance
Depreciation 0 67,500 67,500 67,500
Operating and Maintenance 0 35,000 35,000 35,000
Costs (excliiñi i ig energy
and p er c sts)
Energy and Pager Costs 0 2,500 2,500 2,500
Total Annual Cost 0 138,750 138,750 138,750
Effluent Qtv l it y:
Effluent Constituents
Paraneters (Units) Raw
kg/kkg (Pouncli/Fon) Waste Resulting Effluent
Load Levels
Kiln Dusts 67(134) 67(134) ‘-0
Level B —— Dry bag collectors installed.
v i ii -60
DRAFT
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Applying this cost to the 288 metric ton/day (320 ton/day) plant gives $0.24 per metric
ton ($0.22 per ton) cost for isolation and containment of leaks and spills. No energy
addition is involved.
1 .5.1 .8 Potassium (Metal )
There are no process, air pollution or ancillary water wastes involved for this chemical.
1 . 5.1 . 9 Potassium Chromates
Since potassium dichromate is made from the reaction of sodium dichromate withpotas—
sium chloride, there is none of the massive ore waste present as in the sodium dichro—
mate process. The only water—borne waste from the exemplary 25—year—old 13.5 metric
ton/day (15 ton/day) plant 002 of this study is from once—through cooling water used on
the barometric condensers. Replacement of these condensers with non—contact heat
exchangers, as planned for l974 will make this a zero water—borne waste plant. Cost
for this .onversion is estimated at $60,000. See Table 61.
The treatment differential in going from base level A to zero discharge costs $5.12 per
metric ton ($4.65 per ton) of potassium dichromate. Here is a case where initial in-
stallation of a non—contact condenser would have saved $60,000 and reduced treatment
costs to $3.25 per metric ton ($2.95 per ton).
Energy requirements for pumps, filters, centrifuge , and other equipment is taken as
7.5 kilowatts (10 horsepower) overall, or 53 x 10 kg cal/yr or (210 x 106 Btu / yr).
Entire industry additional energy is estimated at the same value.
1.5.1.10 Potassium Sulfate
The treatment and c ’ rol cost effectiveness values for potassium sulfate using xemplary
plant 118 as a mod& are developed in Table 62.
Costs for going fro base treatment level to ro effluent is $2. 8 per metric ton ($2. I
per ton) of potassium sulfate.
There is a relatively high energy recovery process with 67,000 x io 6 kg cal (265,000
x 106 Btu ) or 1,000,000 liters (265,000 gallons) of fuel oil energy per year. For the
entire industry the additional energy requirement is 172,000 x 106 kg-cal (680,000 x
106 Btu).
1.5.1 .11 Sodium Bicarbonate
Water—borne wastes from sodium bicarbonate facilities are small. Using Exemplary Plant
166 as a model, cost effectiveness values ore developed in Table 63.
Vlll-61
DRAFT
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¶I? BLE 61.
Water Effluent Treatnent Costs
Iro]ganic thernicals
themical: Potassium Chromate (13.5 kkg/day (15 tons/day) capacity)
eabrent of Contiol Tethriolo-
gies Identified under Item
III of the Scope of Work: A B C D
Investment 20,000 50,000 110,000 110,000
Annual Costs:
Interest + Taxes and 1,000 2,500 5,500 5,500
Insuran
Depreciation 2,000 5,000 11,000 11,000
Operating and Naintenance 0 10,000 10,000 10,000
Costs (excluding energy
and p er costs)
Energy and Pcwer Costs 0 1,000 1,000 1,000
Total Annual Cost 3,000 18,500 27,500 27,500
Effluent Qu li ty:
Effluent Cbnstithents
Paicaui ters (Units) Raw
kg/kkg (Poundsflon) Waste Resulting Effluent
Load Levels
Sodium Chloride 400(800) 400(800) 0 0 0
Filter Aid 0.85(1.7) 0.05(’ 0.1) 0 0 0
Potassium Dichromate “0.5(—1) ‘0.5( 1) —0.5(’’l) ‘-0 —‘0
Level A —— Discharge of all water to settling pond to remove filter aid.
Level B —— Centrifuge, filter, pumps, piping and installation for sodium chloride and filter
aid removal. Salt value has been assumed zero.
Level C —— Non—contact heat exchangers installed.
VllI-62
DRAFT
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¶j 3LE 62
Water Effluent Treatirent Costs
Ir rganic c’neinicais
c herdcal: Potassum Sulfate (454 kkg (500 tons) per day Capacity)
Treatzrent of Control TedLnolo-
gies Identified under Item
III of the Scx pe of Work: A B C D
Investi ent 40,000 700,000 700,000 700,000
2 rinua1 Costs:
Interest + Taxes and 2,000 35,000 35,000 35,000
L xanca
Depreciation 4,000 70,000 70,000 70,000
Operating and Maintenance 10,000 124,000 124,000 124,000
Costs (excluding energy
and poser costs)
Energy and Pcwer Costs 0 166,000 166,000 166,000
Total .nrr ia1 Cost 16,000 395, 000 395,000 395,000
Effluent aality:
Effluent Constithents
Paraireters (Units) Raw
kg/kkg (Pounds/ron) Waste Resulting Effluent
Load Levels
Ore Muds 15(30) 0 0 0 0
Waste Uquor 2000(4000) 2000(4000) 0 0 0
Level A —— Pond settUng of muds. Discharge of dissolved soflds to surface water.
Level B —— Evaporation to recover liquor chemkals and water + Level A value of recovered
chemicals not deducted from costs. Water value is also not deducted.
‘/111-63
DRAFT
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DRAFT
BLE 63.
Water Effluent Treatirent Costs
Irorganic Ch icals
chemical: Sodium Bicarbonate (272 kkg/day (300 ton/day) Capacity)
Tr atirent of Control Technolo-
gies Identified under Iten
III of the Scope of Work: A B C D
Investment 10,000 15,000 15,000 15,000
Annual Costs:
Interest + Taxes and 500 750 750 750
Insurance
preciation 1,000 1,500 1,500 1,500
Operating anal ainthnance 1,000 2,000 2,000 2,000
Costs (excluding energy
and po ier sts)
Energy and Pcwer Costs -.0 ‘ 0 ‘-O 0
Total Annual Cost 2,500 4,250 4,250 4,250
Effluent Quality:
Effluent Constituents
Parameters (Units)
kg/kkg (Pounds/ron) Waste Resulting Effluent
Load Levels
Sodium Carbonate 30(76) 38(76) 38(76) 0 0
Sodium Bicarbonate 10(20) 10(20) 0 0 0
Rubbish <2.5(<5) 0 0 0 0
Level A —— Se.. .Iing pond, landfill for rubbish, discharge to surface water.
Level B —— Redissolve broken bags and waste sodium bicarbonate + Level A. -
Level C —— Recycle sodium carbonate to Solvay Process system. Value obtained equal cost.
VlIl-64
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Reducing the bicarbonate wastes to zero should be virtually cost free since current pro-
duct losses should cover expenses.
There are no significant new energy requirements.
1 .5.1 .12 Sodium Chloride (Solar )
It has been recommended that concentrated magnesium-rich residual brines or bitterns
from solar salt manufacture be stored and eventually used for their chemical value.
Solar energy of great magnitude has been used to concentrate these brines and it would
be wasteful of both the country’s energy as well as raw materials not to utilize them.
Taking exemplary plant 059 as a model, cost effectiveness values are developed in
Table 64.
One 146 hectare (360 acre) pond is needed ec. i year. While this storage capacity is
available for the next 5 to 10 years, obviously it cannot go on indefinitely. Use of
these valuable mineral deposits should be made in the near future.
Storage costs for solar salt bitterns for exemplaryplant O59are $2.42 per metric ton
($2.20 per ton).
Additional energy requirements are negligible.
1.5.1.13 Sodium Silicate
The wastes from the sodium silicate process are relatively small and closed loop zero
effluent operation has been achieved in exemplary plant 072.
For the purpose of cost effectiveness, development plant 34 has been selected for
Table 65 calculations. This plant is a ten—year-old, 72 metric ton-per—day (80 ton—
per—day) facility. Costs are approximately $1 .00 per metric ton ( i.90 per ton) of
product.
Additional energy costs using this approach are 3530 x 106 kg cal (14,6000 x 106 Btu).
For the total igdustr 1 additional energy requirements are 84,000 x 10 kg cal
(332,000 x 10 Btu).
A second approach using onl’ level A treatment and closing the loop for zero effluent
bypasses both the energy requirements and most of the cost. This approach s used in our
exemplary plant 072. Treatment costs for this approach would be approximately $0.22
per metric ton ($0.20 per ton) of product.
VllI—65
DRAFT
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¶ [ BLE 64.
Water Effluent Treatcent Costs
IrOrgaZiJC Ch tiicals
Ccieirical: Solar Salt (2540 kkg/day (28 tons/day) Capacfly)
Treatit nt of Control Tethnolo-
gies Identified under Item
III of the Scope of Work: A B C D
Investrne.nt 14,400,000 14,400,000 14,400,000 14,400,000
Annual Costs:
Interest + Taxes and 720,000 720,000 720,000 720,000
L surance
] preciation ‘ 1,440,000 1,440,000 1,440,000 1,440,000
Operating and Maintenance 0 ‘ ‘0 -0
Costs (exclu rtg energy
and p ier oc sts)
Energy and Pa ie.r Costs 0
Total 2 nnual Cost 2,160,000 2,160,000 2,160,000 2,160,000
Effluent Quality:
Effluent Cans tithents
Parar e hers (Units) P
k9/kkg (Pounds/ron) Waste I esulti-tg Effluent
Load levels
Bittems 70,000(1 40,000) 0 0 0 0
Level A —— 1 new 360 acre unlined pond per year is needed. Costs are taken from
Section VIII for unlined ponds.
VIIl-66
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‘] BLE 65.
Water Effluent Treatrrent Costs
Lrorganic th iicals
chemical: Sodium Silicate (72 kkg/day (80 tons/day) Capacity)
Treatir nt of Control Tethnolo-
gies Identified under Item
III of the Scrape of tcork: A B C D
Inves nent 26,000 42,000 62,000 62,000
nnua]. Costs:
Intarest ÷ Taxes and 1,300 2,106 3,100 3,100
L suranca
Depreciation 2,600 4,200 6,200 - 6,200
Operating and Maintenance 1,000 9,000 10,000 10,000
Costs (exc1u 3ing energy
and pci ;er sts)
Energy and Pacer Costs 10,000 10,000
Total 2 nruial Cost 4,900 15,300 29,300 29,300
Effluent Qn 1ity:
Effluent Cons titiients
Pararrs hers (Units) Raw
kg/kkg (Pounds,tFon) Waste Resulting Effluent
Load Levels
Sodium Silicate 2(4) 2(4) 2(4) 0 0
Sodium Sulfate 2.5(5) 2.5(5) 2.5(5) 0 0
Filter Aids 2(4) 0 0 0 0
Sand 0.5(1) 0 0 0 0
Sodium Hydroxide 0.5(1) 0.5(1) 0 0 0
Level A —— Settling pond only.
Level B —— Settling pond plus neutralization.
Level C —— Evaporation to remove and recover dissolved solids + Levels A and B treatment.
Sodium silicate recovered.
‘ 1 11 1 -67
DRAFT
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Costs for both approaches are reasonoble. In view of the energy advantage for
p lant 072’s approach, this recycle method should be favored.
1 .5.1 .14 Sulfuric Acid
The sulfuric acid (sulfur—burning) process has no process wastes. The only water—
borne wastes are from leaks, spills, air pollution control equipment, and ancillary
operations such as cooling tower blowdowns and ion—exchange regenerants. Since
cooling tower and ion—exchange regenerants are not considered waste for the guide-
lines, they are not included here. Air pollution control equipment contributions are
also discussed only for informational purposes since they are costed in this study as
zero effluent at zero cost.
Regen plants for making sulfuric acid from waste or spent acid are not specifically
covered in this study but are included in cost effectiveness development for infor-
mational purposes.
Exemplary sulfur—burning plant 141, a three—year-old 360 kkg-per-day (400 ton-per
day) plant, was used as the model.
Costs are less than’*0.1O per kkg ($0.lO/ton) of product. Additional energy is negli-
gible. See Table 66.
Regen plant 023 is given similar development in Table 67 using plant 023, 675 metric
ton/day (750 ton/day) fourteen-year—old facility with extensive pollution control
expenditures. Regen plants have to get rid of a stream of weak sulfuric acid, after
which they behave much as a sulfur—burning facility.
The differential costs in this case from level A treatment to essentially zero waste
discharge status of level D is approximately $2.40 per metric ton (S2.Z0 per ton) of
sulfuric acid produced for overall air plus water pollution abatem nt, and $0.55 per
metric ton ($0.50 per ton) of sulfuric acid produced, for water pollution abatement
alone.
Additional energy requirements for water pollution abatement are negligble. Air
pollution contributions for the abatement equi rnent us%d are relatively high for
sodium sulfate recovery 25,200 kg cal (“100,000 x 10 Btu ) or 378,500 liters
(100,000 gallons) of fuel oil energy.
Regen Plant 023, having spent almost four million dollars for water and air pollution
control is a model for regen sulfuric acid waste abatement practices and is recommended
for technology and costs for specific problem solutions.
Vlll-68
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‘L BLE 66.
Water Effluent Treatrent Costs
Inorganic Ch Lcals
chemical: Sulfuric Acid (SulFur Burnng)(360 kkg/day (400 tons/day) Capacity)
Tieatr nt of Coritiol Tec±inolo-
gies Identified under Item
III of the Scope of Work: A B C D
Iiweslinent 50,000 100,000 160,000 160,000
2 nnua]. Costs: 2,500 5,000 8,000 8,000
Interest + Taxes and 5,000 10,000 16,000 16,000
It s3rancs
Depreciation —0 —0 —0 —0
Operating and Maintenance 0 —0 0 —0
Costs (excluding energy
and p ier costs)
Energy and P er Costs 7,500 15,000 24,000 24,000
Total .Annual Cost
Effluent Qnality:
Effluent Cons tithents
Paraire ters (tJrLi±s) Raw
kg/kkg(Poundsflon) Waste Resulting Effluent.
I ad Levels
Spills, Leaks 1(2) 0.5(1) 0 0 0
Closed Cycle System
Level A —— Typical di king and containment.
Level B —— Good isolation and containment + Level A.
Level C —— Lined containment emergency pond —— 0.4 hectare (1 acre) + Level A and B.
Vlll-69
DRAFT
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¶I?IBLE 67.
Water Effluent Treatnent Costs
Irio_rgarnc the ’icals
che. ical: Sulfuric Acid (Regen Plant) (675 kkg/day (750 tons/day) Capacity )
Treatnent of Control Technolo— -
gies Identified under ItEn
III of the S pe of Work: A B C D
Investment 100,000 1,250,000 3,750,000 3,750,000
2thnual Costs:
Interest + Taxes and 5,000 62,500 187,500 187,500
Insurance
preciation 10,000 125,000 375,000 375,000
Operating and ?.!aintenance 50,000 10,000 15,000 15,000
Costs (excluding energy
and pc er costs)
Energy and Pa. er Costs 76,000
Total Annual Cost 65,000 197,500 577,500 ($3 1 S00
Effluent Qua] 1 ty :
Effluent Constituents
Paraxre ters (Units)
kg/kkg (Pcunds/ron) Waste Resulting Effluent.
Load Levels
Spills & Leaks 1(2) 0.5(1) ‘‘0 ‘ 0 —‘0
Weak Sulfuric Acid 82 .5(1 65) 0 0 0 0
Sodium Sulfate 23.5(47) 0
Level A —— Typical diking and containment plus neutralization of weak acid + 1 acre settling
pond.
Level B —— Level A + improved diking, isolation and containment, lined emergency pond, all
indirect cooling, surge basins, rainfall decanter, final disposition of weak acid,
recycle of strong acid streams.
Level C —— Full air pollution system added.
Level D —— Removal of air pollution wastes at no cost. In this case raw material value recovered
equals cost.
Vlll-70
DRAFT
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DRAFT
1.5.2 Category 2
1 .5.2.1 Hydrogen Peroxide (Organic )
The organic process effluent contains waste hydrogen peroxide pius organic solvent used
in the process. The nature of this solvent is regarded as a trade secret.
Cos-t-effeeflveness- inforrnoHon 15 developed- in Table 68 for exemplary plant 069, a
twenty—year—old 85 metric ton/day (94 ton per day) facility.
Esfimated additional cost to attain zero waste discharge level is approximately $1 .10
per metric ton ($1 .00 per ton) of hydrogen peroxide produced.
Additional energy requirement should be negligible.
There are a number of alternative procedures which could be implemented, starting
with isolation and containment of waste streams from cooling water, to reduce waste
discharge to essentially zero at feasible cost levels.
1.5.2.2 Sodium Metal
Sodium metal is produced as coproduct with chlorine in the Downs Cell process. Since
the chlorine produced is handled similarly and has the same wastes as the mercury and
diaphragm cell processes to be discussed later only wastes specific to the Downs Cell
and sodium production are included here. Table 69 gives the estimated cost effective-
ness values for a 58 mefric-ton-.per...day (65-fon.per —day) fourteen-year—old plant (096).
Costs for plant 096 for essentially zero water—borne waste effluent are $2.47 per metric
ton ($2.25 per ton) of sodium above initial expenditures of $3.30 to $4.40 per kkg
($3 to $4 per ton) of sodium, which is currently seli 9 for $412 per metric ton ($375
per ton).
Additional energy costs should be negligible.
1 .5.2.3 Sodium Sulfite
The wastes from the sodium sulfite process are essentially .z dium sulfite. Table 70
gives the cost effectiveness values for exemplary plant 1 a fifteen—year—old
installation.
Costs for reducing exemplary plant 168 to essentially zero wcter—borne waste status
are approximately $2.75 per metric ton ($2.50 per ton) of product. If recovery o’
sodium sulfite is directed at the same stream as now converted to sodium sulfate and
VlIl-71
DRAFT
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BLE 68. -
Water Effluent Treatirent Costs
Irorganic c iet ’icais
cheTical: Hydrogen Peroxide (Organic Process) (85 kkg/day (94 tons/day) Capacity)
Treatirent of Contiol Tedinolo-
gies Identified under Item
11101 theScxpeof Work: A B C
Investi exit 23,000 53,000 200,000 0-
P nnua]. Costs:
Interest ÷ Taxes and 1,150 2,650 10,000 10,000
Insurance
t preciation - 2,300 5,300 20,000 - 20,000
Operating and Maintenance 3,000 3,000 5,000 5,000
Costs (exclui ing energy
and pa?Ier cx sts)
Erer y arid Pa.jer Costs —0 -‘0 - 0 -‘0
Total Arinnal Cost 6,450 10,950 35,000 35,Ot)0
Effluent Qia] tty:
Effluent Cons tithents
Para rre hers (Units) Raw
kg/kkg (Pow dsfFon) WaSte Resulting Effluent
Load Levels
Organics 0.25(0.5) 0.1(0.2) 0.025(0.05) 0 0
Hydrogen Peroxide 20(40) 5(10) 5(10) 0 0
Level A —— Reduction of hydrogen peroxide with scrap iron, organics removal by mechanical
separation.
Level B —— Level A + improved organics removal and spill containment.
Level C —— Closed loop process water, non—contact cooling water only effluent.
VIIl—72
DRAFT
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DRAFT
BLE 69.
Water Effluent Treatirent Costs
Iro ganic c’ne icals
chemical: Sodium Metal (58 kkg/day (6Stons/day) Capacity)
Treat nt of Control Tec±iriolo-
gies Identified under Item
III of the Scope of Work: A B C D
Inves rent 0 400,000 700,000 0
Annual Costs:
Interest + Taxes and 0 20,000 35,000 35,000
In irance
t preciation 0 40,000 70,000 70,000
Operating and Maintenance 4,000 4,000 10,000 10,000
Costs (excluding energy
and power sts)
Energy and Po er Costs ‘ 0 - ‘0
Total Annual Cost 4,000 64,000 115,000 115,000
Effluent Qual ty ;
Effluent Cons tithents
Parazreters (Units)
kg/kkg (Pu ndsflon) Waste Resulting Effluent.
Load levels
Sodium Chlorde 57.5(115) 57.5(115) 57.5(115) -‘0
Misc. Alkaline Salts 30(60) 30(60) 30(60) —‘0
Bricks, Anodes, Other (2.5 Z5) 0 0 0 —0
Solids
Level A—— Disposal of salts plus solids.
Level B —— Facflities for separating salts from solids.
Level C —— Containment, solaton and return of salts to brine system.
VllI—73
DRAFT
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DRAFT
TABLE 70.
Water Effluent Treatirent Costs
Ir rganic ch nicals
c ernical: Sodium Sulfite (45 kkg/day (50 ton/day) Capacity)
Treatrrent of Contiol Technolo-
gies Identified under It n
III of the Scope of Work: A B C D
Iir restment 250,000 275,000 150,000
2 rinual Costs:
Interest + Taxes and 0 12,500 13,750 7,500
Insurance
J preciation 0 25,000 27,500 15,000
Operating and Maintenance 0 10,000 12,000 5,000
Costs (excluding energy
and pc er costs)
Energy end Pcwer Costs 0 2,000 7,000 6,000
Total Annual Cost 0 49,500 47,750 (25,000) Profit
Effluent Qi; 1
Effluent Constituents
Pararre hers (Units) Raw
kg/kkg (Pc ds/Fon) Waste Resulting Effluent
Load Levels
Sodium Sulfate — — 29(58) 0 0
Sodium Sulfite 30.5(61) 30.5(61) 1.5(3) 0 0
Level A —— No treatment —— typical for industry.
Level B —— Full treatment system, but dissolved solids still discharged.
Level C —— Level B + evaporation recovery and sales of recovered product. Product value
$12,500.
Level D —— Isolation and containment parts of complete system of Level B + evaporation to
recover sodium sulfite. Product value is $58,500.
VlIl-74
DRAFT
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DRAFT
directly discharged, there is a potential for $25,000 per year profit. Plants not now
treating or recovering sodium sulfite should explore this approach.
Additional energy required is approximately 1620 x 106 kg cal/yr (6400 x i0 6 BIt,/
yr or 24,200 liters (6400 gallons) of fuel oil energy/yr. For the entire industry this
would be 29,200 x 106 kg cal (116,000 x 106 Btu ) or 439,000 liters (116,000 gallons)
of fuel oil energy per year.
1 .5.2.4 Calcium Chloride
Calcium chloride comes from two major sources, Solvay soda ash by-product and brine
chemicals by-product. A forty—five—year-old (450 metric ton—per-day (500 ton—per—
day) brine reclamation plant 185 is used for cost effectiveness development, as shown
in Table 71. Solvay process plant wastes are obscured by the overall process discharges.
Cost for elimination of present wastes is roughly estimated as $0.22 per kkg ($0.20 per
ton) of product.
No additional energy requirements are involved.
1 .5.2.5 Sodium Chloride (Brine/Mining )
Unlike the solar salt industry where all wastes are stored or disposed of in surface ponds,
the other salt producers get their salt from underground and return most wastes to
underground disposal.
Exemplary Plant 030, a forty—nine—year old (1,000 metric ton—per—day (1,100 ton—
per—day) facility is used for cost effectiveness developments in Table 72. Complete
elimination of salt wastes in plant effluent surface water would cost for a new plant,
approximately $0.28 per kkg ($0.25 per ton) of product. This assumes plant 030
technology plus initial installation of non—contact final condensers and conveying and
packing losses being recovered dry and either reused or land (or well) disposed.
Elimination of all but 1 kg/day (2 lbs/ton) waste from plant 030 would cost approxi-
mately $0.55 per metric ton ($0.50 per ton) of product.
Negligible additional energy would be required.
Vlll—75
DRAFT
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¶I BLE 71.
Water Effluent Treatirent Costs
Irorganic CnezttLcals
chemical: Calcium Chloride (450 kkg/day (500 tons/day) Capacity)
Treatzrent of Contzol Tedinolo-
gies Identified under Item
III of the S pe of Work: A B C D
200,000 200,00() 200,000
lthnual Costs:
Interes ÷ Taxes and 0 10,000 10,000 10,0CC
Insurar
Depreciation 0 20,000 20,000 20,000
Operating and Maintenance 0 0 0 0
Costs (excluaing energy
and pacer crsts)
Energy and Pacer Costs 0 0 0 0
Total 2&.nruaal Cost 0 30,000 30,000 30,000
Effluent a1 thj
Effluent Constituents
Parazre iers (Units)
kg/kkg (PoundsfFon) Waste Resulting Effluent
Load Levels
Calcium Chloride 30(60) 30(60) 0.5(1) —0
Sodium Chloride 0.5(1) 0.5(1) 0 —‘0 —‘0
Ammonia 0.5(1) 0.5(1) 0 ‘ 0
Level A —— Normally these wastes, as dissolved solids are discharged to surface water in
non—exemplary of soda ash plants.
Level B —— Replacement of barometric condensers with non—contact heat exchangers.
Level C —— Elimination of packing station water-waste contributions.
VllI-76
DRAFT
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L1BLE 72.
Water Effluent Treatn .nt Costs
Irorganic Che rnicals
aiernical: Sodum Chloride (Brine/Mining) (1000 kkg/day (1100 ton/d y) Capacity
T reatri rtt of Control Technolo—
gies Identifisd under It n
III of the Scxpe of Wo±: A B C D
Ltwestsent - 500,000 1 ,000L000 600,000
.Arinual costs:
Intarest + Taxes and 25,000 50,000 30,000
I nsurance
Depreciation 50,000 100,000 60,000
Operating and Naintenance 10,000 10,000 10,000
Costs (excluding energy
and pci 1er o sts)
Enery and Pacer Costs
Total 1\nriual cost 85,000 160,000 100,000
Effluent Qnal i ty
Effluent Cons tituents
Paran eters (Units)
kg/lkg (Pounds/Fon) Waste Resulting Effluent
toad Levels
Sodium Chlorine 50(100) 6(12) 1(2)
Brine Sludge 2.5(5) 0 0
Level A —— No information.
Level B -— Plant 030 technology, sludge returned to wells. Control system developed including
$425,000 damming, curbing, collection and pumping to wells, and $63,000 instru-
mentation and miscellaneous pumps and piping.
Level C —— Level B + non—contact heat exchangers for barometric condensers.
Level D —— For new plants. Elimination of conveying and packing station losses peculiar
to Plant 030.
Vlll-77
DRAFT
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1.5.3 Category 3
1.5.3.1 Mercury—Cell, Chlor—Alkali
Both chlorine and sodium hydroxide are produced by the i ercury cell process. Potas-
sium hydroxide s produced similarly by starting with potassium chloride brine instead;
of the usual sodium chloride.
Cost effectiveness values are developed in Table 73 using two—year—old 158 metric
ton—per—day (175 ton—per-day) (chlorine basis) plant 098.
For zero water—borne wastes the cost above levels A and B mercury removal is approxi-
mately $1.00 per metric ton ($O,90 per ton) of chlorine produced. Spreading these
costs to chlorine and sodium hydroxide co—products reduces the value to approximately
$0.55 per metric ton ($0.50 per ton) of products.
Roughly 2,520 x i06 kg cal/yr (10,000 x io6 Btu /yr) additional energy is required for
this plant.
Plants have now reduced water effluent mercury discharges to approximately 0.045-
0.225 kg per day (0.1-0.5 lb per day) by spending level Aand B money. Some exem-
plary plants have spent Level C money (Plant 098 is at this level). Level D money, in
many cases, may not be needed. The particular plant modelled happens to have a
negative water balance from rainfall into open tanks and vessels.
1 .5.3.2 Diaphragm Cell)Chlor—Alkoli
Diaphragm cells also produce both chlorine and sodium hydroxide (or potassium hydrox-
ide if potassium chloride brine is used).
Table 74 gives the progressive cost effectiveness development for one—year--old 2070
metric ton—per—day (2300 ton er—doy) (combined chlorine and sodium hydroxide basis)
exemplary plant 057. Costs for essentially zero water—borne effluent are approximately
$0.55 per metric ton ($0.50 per ton) of product. For new facilities the cost would be
considerably less since non-contact condensers should be used in place of barometric
condensers.
Additional energy requirements are negligible.
1 .5.3.3 Hydrogen Peroxide (Electrolytic )
Electrolytic process hydrogen peroxide is produced in twenty—year old exemplary plant
100. Table 75 gives cost effectiveness information.
Vlll-78
DRAFT
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DRAFT
Treatrent of Control Tediriolo-
gies Identified under It n
III of the Scope of Work: B C
.$___ ,- .2-
J.fl l
Annual. Costs:
Interest + Taxes and
L surance
Depreciation
Operating and Maintenance
Costs (excluding energy
and pcwer costs)
Erielgy and Pacer Costs
Total Annual Cost
Effluent Qii l i ty:
500,000
1 1 ,000
500,000 700,000 750,000
1 1,000 168,000
183,500
Sodhim Chloride
Sodium Hypochlorite
Mercury
Raw
Waste
Load
50(100)
20(40)
<0.05(0.1)
Resulting Effluent
t vels
50(1 00) 70(1 40)
20(40)
<7x10 4 <7x10 4
(<3.5x10 4 ) (<3.5x10 4 )
Reduction of mercury to less than 0.225 kg/day (0.5 lb/day).
Reduction of mercury to less than 0.07 kg/day (0.15 lb/day).
Level B + catalytic conversion of sodium hypo chlorite to sodium chloride.
Plant 098 is at this level.
Level C ÷ evaporation and reuse of sodium chloride. No effluent except cooling
water from system. Drying sulfuric acid to other use c concentration.
¶ [ L E 73.
Watar Effluent Treatrrent Costs
Lrorganic thet iicals
ernical: Mercury Cell Chlor—Alkali (158 kkg/day (175 tons/day) Capacity)
D
25,000
25,000
35,000
37,500
50,000
50,000
70,000
75,000
55,000
55,000
61,000
64,000
1,000
1,000
2,000
7,000
Effluent Constituents
Paraireiers (Units)
kg/kkg (Pounds/Ton)
50(100)
20(40)
<1 1o
(<2 x 1o )
Level
Level
Level
A--
B——
C--
-‘0
- 0
Level D ——
VIII -79
DRAFT
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DRAFT
‘I?LBLE 74.
WaLer Effluent Treatirent Costs
Irorganic thernicals
chemical: Diaphragm Cell, Chlor—Alkali (2070 kkg/day (2300 ton/day) Capacity)
Treatrrent of Control Technolo-
gies Identified under It€ n
III of the Sape of Work: A B - C D
Invesbt’ erit 45,000 65,000 495,000* 1,500,000
nnua1. Costs:
Interest ÷ Taxes arid 2,250 3,250 3,250 75,000
Insurance
Depreciation 4,500 6,500 6,500 150,000
Operating and Nainteriance 24,000 224,000 224,000 224,000
Costs (excluding energy
arid pcwer sts)
Erergy and Pa. er Costs 1,000 1,000 1,000
Total Annual Cost 30,750 234,750 234,750 450,000
Effluent Guality
Effluent Constituents
Paraire hers (Units)
kg/kkg (Pounds/ton) Waste Resulting Effluent
Load Levels
Calcium Carbonate sludge 12.25(24.5) 0 0 0 0
Sodium Hypochlorite 7.5(15) 7.5(15) 7.5(15) 0 0
Spent Sulfuric Acid 4(8) 4(8) 0 0 0
Chlorinated Hydrocarbons 0.7(1 .4) 0.7(1 .4) 0 0 0
Sodium Chloride 25.5(51) 25.5(51) 5(10) 5(10) 0
Sodium Hydroxide 22(44) 22(44) 4.5(9) 4.5(9) 0
Level A —— Settling Pond.
Level B —— Chlorinated hydrocarbons to disposal pit + sulfuric acid to sales, neutralization of
sodium hydroxide and brine returned to system.
Level C —— Installation of chlorine burning hydrochloric acid plant for chlorine tail gas.
Hydrochloric add value equal to cost.
Level D —- Non-contact cooling substituted for barometric condensers — rough estimate.
*Cost of installation —— 0 contribution to cost —— see Level C note.
Vlll-80
DRAFT
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DRAFT
¶1 BLE 75.
Water Effluent Treat rent Costs
Inorganic Cnerziicais
chemical: Hydrogen Peroxide — Electrolytic (12 kkg/day (13.2 ton/day)_Ccpadty)
Treatjz ent of Control Tediriolo-
gies Identified under Item
IIIofteScxpeof ork: A B C D.
L .vestiient 12,500 1 5, 000
2 rinual Costs:
Inthrest + Taxes and 625 750
Insurance
Depreciation 1,250 1,500
Operating and Maintenance 1,600 2,000
Costs (excluding energy
and pa ier costs)
Energy and Pcwer Costs — ‘0 1,000
Total Annual Cost 3,475 5,250
Effluent Qi ]j1y:
Effluent Constituents
Paraireters (Units) Raw
kg/kkg (Pounds/Fon) Waste Resulting Effluent
load levels
Sodilum Sulfate 0.75(1.5) 0.75(1.5) 0.75(1.5)
Ammonium Sulfate 0.75(1 .5) 0.75(1 .5) 0.75(1 .5)
Level A —— There is no typical plant.
Level B —— Present plant operation
Level C —— Distillation to dryness 1136 liters/day (300 GPD)
Vlll—81
DRAFT
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DRAFT
Reduction of this plant to zero discharge of process waste would cost approximately
$0.28 to $0.8 per metric ton ($0.25 to $0.75 per ton) of product produced.
Additional energy required would be 220 x 106 kg cal (870 x io6 Btu).
1 .5.3.4 Sodium Dichromafe
The sodium dichromate process has heavy suspended and dissolved solids levels primarily
because of the chromium treatment process used. Two—year—old 149 metric ton—per—day
(164 ton-per—day) exemplary plant 184 is used as the model for cost effectiveness devel-
opment as shown in Table 76.
Additional cost above typical treatment level A is $17.60 per metric ton ($16 per ton)
of product, of which $13.20 per metric ton ($12 per ton) is already being spent in
exemplary plant 184. Evaporation to recover dissolved salt costs $4.40 per metric ton
($4 per ton) of product. Selling price of sodium dichromate is $380 per metric ton
($345 per ton).
These Figures illustrate the expensiveness of isolating, containing, treating and dispos-
ing of toxic wastes as discussed in Sections VII nd VIII. They also show that if the
effluent streams can be kept smalljl,3l7 cu rn/day (348,000 GPD in this case) removal
of dissolved salts by evoporation is expensive but not prohibitively so.
It s believed that, while the isolation, containment and treatment fadlities of exem-
plary plant 184 are exceptional, there are more economical ways of achieving the
same level of chromium toxicity in the effluent.
Adg;tional energy requirements are estimated to be 25,200 x 106 kg cal (100,000 x
10 Btu.) per year for plant 184. For the industry, using similar treatment (which is
doubtful) to zero water—bcrne waste discharge, the additionat energy requirements
would be 60,500 x 106 kg cal (240,000 x 106 Btu).
1 .5.3.5 Sodium Sulfate
Sodium sulfate is a by—product of the sodium dichromate and other processes. As such,
it has no water—borne wastes of its own. Therefore, it is a zero effluent—zero treatment
and control chemical with zero additional energy requirements.
1.5.4 Category 4
1.5.4.1 Soda Ash (Solvay Proces )
The Solvay process produces approximately 1370 kg (3000 Ibs) dissolved solid wastes
for every ton of product. These solids consist of slightly over 0.91 kkg (one ton) of
VllI—82
DRAFT
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DRAFT
BLE 76.
Water Ef eluent Treatrr rtt Costs
Ir rgariic ther’icals
c iernical: Sodium Dichromate (149 kkg/day (164 tons/day) Capacity)
reatrrent of Control Tedinolo—
gies Identified under Item
III of the S pe of Work: A B C D
Invest ment 100L000 1L000,000 1,800 000 l,800 000
2thnual Costs:
Interest + Taxes and 5,000 5,000 90,000 90,000
Insurance
Depreciation 10,000 100,000 180,000 - 180,000
Operating and Maintenance 0 560,000 610,000 610,000
Costs (excluding energy
and pc7 er cxsts)
Energy and Pa er Casts 4,000 64,000 64,000
Total Annual Cost 15,000 669,000 944,000 944,000
Effluent Qntl ty
Effluent Cons tituents
Parazreters (Units) -
kg/kkg (Pounds,tFon) Waste Resulting Effluent
Load Levels
Total Suspended Solids 900(1800) 0.1 25(0.25) 0.125(0.25)
Total Dissolved Solids 88.5(177) 88.5(177) 88.5(177) —‘0
Chromium 6 - 0.0001(0.0002)
Level A —— Settling pond.
Level B —— Segregation and chemical treatment for chromium—6. Pond settling and discharge
of clear effluent to surface water.
Level C —— Level B ÷ evaporation to recover dissolved sodium chloride. Recovered sodium
- chloride costed as zero value. Closed loop operation.
Vlll-83
DRAFT
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DRAFT
calcium chloride, which has high water solubility, is difficult to obtain in anhydrous
Form and spontaneously picks up moisture from the air when land dumped, and about
0.45 kkg (one—half ton) of unreacted sodium chloride, also of high wafer solubility.
Although there is a market for calcium chloride, the total volume of this market can
be supplied with 10 to 15 percent of the calcium chloride available from Solvay plants
alone. Therefore, most of the available calcium chloride must be disposed 0 F at zero
value or iCSS (disposal costs). The sodkim chiorde can be reused if it can be separated
from the calcium chloride and other wastes, but the value of this raw material is so low
that it is uneconomical to recover it. Therefore, half a dozen Solvay plants discharge
more waste to surface water than any other inorganic chemicals industry and there is no
general economically feasible way for them to avoid it .
Costs are given below for Solvay Process plant 166. This 2520 metric ton—per—day
(2800 ton—per-day) over seventy—five—year—old faciUty is used for cost developments.
Values are plant 166 estimates.
Treatment and Control Capital Annual
Method Costs Cost $
1. Coproduction of ammonium chloride 34,000,000 26,000,000
wth soda ash
2. Ammonia and hydrogen chloride from 133,000,000 45,000,000
ammonium chloride
3. Ammonia and chlorine from ammonium 80,000,000 34,000,000
chloride
4. Deep well disposal 6,000,000 1,600,000
5. Total evaporat ion plus ocean barging 51,000,000 31,000,000
of solid wastes
Options 1, 2, and 3 are process changes or additions with monstrous capital investments.
The quantities of ammonium chloride, hydrogen chloride and chlorine produced either
exceed present total market or would be such major contributors that the market struc-
ture would be drastically altered.
Total evaporation and ocean barging of solid wastes also involves major cost and energy
additions.
Vlll-84
DRAFT
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The only economically feasible disposal options for Solvay process soda ash wastes
today are: (1) partial recovery of calcium chloride for sales and (2) deep welling.
Since the Solvay soda ash wastes are similar to those for brine salts and oil well
salts, which are extensively deep-welled, a good case can be made for such disposal,
if geologically feasible at the plant location (or close by).
Cost effecflveness values are developed using these two technologies in Table 77.
Additional costs for zero discharge of wastes to surface water are approximately
$0.55 permetric ton ($0.50 per ton) of product. For deep-.we ling disposal alone,
costs for zero waste effluent are $1 .76 per metric ton ($1 .60 per ton) produced. Addi-
tional energy requirements, primarily for calcium chloride recovery 1 are high. Estimated
requirements for plant 166 are 315,000 x 106 kg cal/yr (1,250,000 x 106 Btujyr) or
for the entire industry 1,260,000 x 106 kg cal/yr 5,O00,000 x 106 Btu/yr . Without
calcium chloride recover> 6 about 12,500 x 10 kg 6 cal/yr (50,000 x 10 Btu /yr)
for plant 166 or 50,000 x 10 kg cal/yr (200,000 x 10 Btu /yr) for the industry 1 would
be needed for deep welling.
1.5.5 Category 5
1 .5.5.1 Titanium Dioxide (Chloride Process )
Most chloride processes for titanium dioxide production use either ruffle or “synthetic
rutile” ore. DuPont is able in its process to use lower—grade ores but for the purposes
of this cost effectiveness discussion, the DuPont process is considered to be on—site
benefkiation pks a “synthetic rutile” process.
Currently chloride process wastes are treated or disposed or by complete neutralization,
deep—welling and ocean barging.
For companies already ocean barging, costs run $5.50—$1 1 per metric ton ($5 to $10
per ton) of titanium dioxide product. For ose starr : barging, oca iri further from
the ocean, or requiring extensive shore foc, ities the costs may range from $1 1 to $22
per metric ton ($10 to $20 per ton).
Deep—welling costs run from $2.20 to $5.50 per metric ton ($2 to $5 per ton) of titanium
dioxide product. Complete neutralization, on the other hand, is much more expensive.
Table 78 shows the cost effectiveness development for this approach using ten—year-old
67 metric ton-per—day (74 ton—per—day) exemplary plant 009 as the model.
Complete neutralization which is now done by plant 009 costs $40 per metric ton ($36
per ton) differential over base treatment Level A.
VII 1-85
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¶ [ 2,BLP. 77.
Water Effluent Treatirent Costs
Inorganic U ie icals
themical: Soda Ash (2520 kkg/day (2800 tons/day) Copacity)
Treatrent of Contiol Tedmolo-
gies Identified under It n
III of the Scope of Work: A B C D
Inve .nt 500,000 21,500,000 27,500,000 27,500,000.
Jthnual Costs:
Interest + Taxes and 25,000 1,075,000 1 ,375,000 1,375,000
Insurance
Depreciation 50,000 2,150,000 2,750,000 2,750,000
Operating and ‘!aintenance 375,000 3,175,000 3,675,000 3,675,000
Costs (excluding energy
and p er costs)
Energy and P ier Costs 800,000 1 ,000,OCO 1,000,000
Total Annual Cost 450,000 (1,080,000) 520,000 520,000
Profit
Effluent Qti ]ity:
Effluent Constithents
Paraireters (Units) Raw
kg/kkg (Pouflds/Ton) Waste Resulting Effluent
Load Levels
Calcium Chloride 1100(2200) 1100(2200) 900(1800) 0* 0*
Sodium Chloride 500(1000) 500(1000) 500(1000) 0* 0*
Calcium Carbonate 85(170) -. .0 O 0* 0*
Calcium Oxide 135(270) 25(50) 25(50) 0* 0*
Calcium Sulfate 31(62) 2.5(5) 2.5(5) 0* 0*
Ash and cinders 40(80) 0 ..O 0* 0*
Silicon Dioxide 58 5(117) “ 0 “ 0 0* 0*
Level A —— Settling ponds
Level B —— Level A + evaporation of 20% of stream to recover calcium chloride for sole at
$44/kkg ($40/ton) -— 8 280,000 value.
Level C —— Level B + deep well disposal.
*No surface water effluent.
Vlll—86
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‘L BLE 78.
Water Effluent Treatrrent Costs
Inorganic C ’icals
cher icai: Titanium Dioxide (Chloride Process),67 kkg (74 ton) per day basis
Treatrr ent of Control Techriolo-
gies Identified under It n
III of the Sa pe of Work: A B C D
L iest ’.ent 300,000 4,000,000 4,000,000 5,300,000
Annual Costs:
Interest + Taxes and 15,000 200,000 200,000 265,GC0
Insurance
I preciation 30,000 400,000 400,000 530,000
Operating and Maintenance 10,000 390,000 390,000 890,000
Costs (excluding energy
and paner s ts)
Energy and Po r : Costs 10,000 10,000. 45,000
Total .Anniial Cost 55,000 1 1000, 000 1,000,000 1 ,730, 000
Effluent Quality:
Effluent Cons tithents
Pararr ters (Units) Raw
kg/kkg (Pounds/ton) Waste Resulting Effluent
Load Levels
Iron Hydroxides 65(130) 65(1 30) 0 — .0 0
Other metal oxides 65(130) 65(130) .,0 — ‘0 “0
Ore 138(276) —.0 -‘0 --‘0 - . - .0
Titanium hydroxides 25(50) 29(58) —‘0 ‘O “-0
Hydrochloric Add 227(454) 227(454) ‘-0 “‘O “0
Titanium Dioxide 40.5(81) —‘0 -‘0 “‘0 — .0
Coke 23(46) -‘0 -‘0 —‘0 —‘0
Soluble Chlorides and — 315(630) 315(630)
sulfates
Leval A —— Pond settling.
Level B —— Complete chemical treatment facility + land dumping of solid waste.
Level C —— Same as Level B.
Level D —— Level C + specialty unit demineralizatiori + evaporation of regenerant solution.
VIll-87
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Reduction to virtually zero discharge of wastes costs $71 /per metric ion ($64 per
ton) of product. Titanium dioxide sells for $605 to 627 per metric ton ($550 to $570
per ton).
Addiflonal energy costs are roughly estimated to be 13,000 x iO6 kg-cal (50,000 x
io6 Btu) for plant 009 and 170,000 i0 6 kg-cal (675,000 x io6 Btu) for the entire
industry using the same treatment.
The chlorine process, disregarding ocean barging and deep-welling disposals, for
current technology has more waste than the sulfate process. The lower grade ore pro-
cess is particularly bad, and may be considered an on—site beneficiation with all the
waste attendant.
Both Government and Industry should strive to improve on current technology following
the paths of:
1. Beneficktkn of ore gtmine site or other remote locations to reduce waste loads in
current plants which are often not located in areas compatible with large mining-
type disposal. There ore various processes —— some in commercial status, others in
research or development stages. Research and development should be encouraged.
2. Improved utilization of present ore and process wastes. Ferric chloride, one of the
malor wastes, has been researched and is being researched by various people — —
the steel industry particularly. Valuable metals such as vanadium are also being
wasted.
If the above programs are folj 9 wed, then chloride process wastes will be reduced signi-
ficantly. In the absence of’ lternative plan , the total neutralization approach is
feasible, available, and reliable.
1 .5.5.2 Titanium Dioxide (Sulfate Process )
The sulfate process For producing titanium dioxide has the heaviest water—borne waste
load per ton of product of all the processes of this study. Of the approxmctTely three
metric tons of waste per metric ton of product, two metric tons are sulfuric acid.
There is no present exemplary plant. Plant 122 of this study has publicly announced,
however, plans for complete cleanup of wastes and it is essentially this model which
will be followed in cost effectiveness development. The model plant used, however,
is non-exemplary plant 142, a twenty-seven-year old 108 metric ton-per—day (120 ton-
per-day) facility. Cost effectiveness is developed in Table 79.
Additional costs in going from typical Level A to virtually complete elimrnation of
water—borne wastes are $106 per metric ton ($96 per ton) or 10.5c /kg (4.8c /Ib) of
VI 11—88
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BLE 79.
WaLer Effluent Trea1 rent Costs
IrxDrganc chemicals
chemical: Titanium Dioxide (Sulfate Process), 108 kkg (120 ton) per day basis
Treatirent of Control Technolo—
gies Identified under Item
III of the Scope of Work: A B C 1)
T- t. -r ,r .4- 1 d O 150 AnA 10 AflA AflA 1 AA
. I • • I
. r1nual Costs:
Interest + Taxes and 5,000 7,500 500,000 575,000
Insurance
r preciation 10,000 15,000 1,000,000 1,150,000
Operating and !aintenance 65,000 400,000 2,000,000 2,350,000
Costs (excluding energy
and pa’ier s1s)
Energy and Pacer Costs 10,000 45,000
Total . nnual Cost 80,000 422,500 3,510,000 4,120,000
Effluent Qu . 1ity
Effluent Constituents -
Para te rs (Units) Raw
k’g/kkg (Pounds/Fon) Waste Resulting Effluent
Load Levels
Sulfuric Acid 2025(4050) 2025(4050) 145(3490)
Iron Sulfate 387(774) 387(774) 370(740)
Aluminum Sulfate 270(540) 270(540) 260(520) — ‘0
Magnesium Sulfate 220(440) 220(440) 210(420)
Other metal suflates 35(70) 35(70) 35(70)
Solid Wastes 21 0(420) 20(40) 20(40)
Soluble Calcium Sulfate — 265(530)
Level A —— Settling Pond
Level B —— Level A + neutralization of weak acid stream.
Level C —- Full neutralization.
Level D —— Level C + specialty system demineralization + evaporation of regenerant solution.
VI 11-89
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titanium dioxide produced. Going to Level C costs $90 per metric ton ($82 per ton)
or 9.0 / kg (4.1 /lb).
This is compared to $8.80 to $1 1 .00 per metric ton ($8 to $10 per ton) for ocean barging
of strong acid wastes. Adding Level B costs of approximately $ll/metric ton ($10/ton)
to this gives about $22/lckg ($20/ton) for removal of acidity and the largest portion of
the wastes. Ocean barging as mentioned for the chloride process 1 can range for new
plants (or oki plants not now using this disposal means) up to $33/kkg ($40/ton) or
$44/kkg ($40/ton) overall waste costs. Therefore, ocean barging costs about one—
fourth to one—half that of complete neutralization.
Acid recovery is another att, ctive approach. Using a current EPA—support pilot plant
as model for acid recovery, cost effectivness is developed in Table 80. Additional costs
for this approach are $53 per metric ton ($48 per ton) of titanium dioxide produced for
practically zero water—borne waste eliminating Level D. Without demineralizatfon,
additional costs above Level A are $37.50 per metric ton ($34 per ton) or about one-
half that for complete neutralization.
Required additional energy for complete neutralization plus demineralization and evap-
oration of regenerant is 41,500 x 106 kg cal/yr (4000 x 106 Btu /yr) for plant 142 and
135,000 x io6 kg cal/yr (535,000 x 106 Btujyr) for the industry (sulfate process).
Similar values for acid recove y are 160,000 x 10 kg cal (630,000 x 10 ) for
plant 142 and 1,320,000 x 10° kg cal (5,200,000 x 106 Btu),
Summarizing the costs for rough comparison purposes gives:
Cost/lckg (Cost/Ton)
Method Titanium Dioxide
Ocean barging and weak acid $22($20)
neutralization
Acid recovery $44($4 0)
Total neutralization $88($80) -
Overlaps in costs can occur depending on specific circumstances. Since most of the
neutralization products are insoluble calcium sulfate and metallic oxides and hydroxides,
the complete neutralization of sulfate process wastes is a relatively “clean” process.
Also, its s ; ple tested technology reliab ility is attractive. Acid recovery is still in
the devek -ment stage for the process described. Corrosion problems are the biggest
current u ‘:rtainty. The cost of this approach is one—half that of complete neutrali..
zation, however, and there is no reason why technology know—how can not be brought
to bear on this process.
Vlll—90
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¶J BLE 80.
Watx r Effluent TreatErent Costs (Acid Recovery Option)
Inorganc Chemicals -
cheinicai: Titanium Dioxide (Sulfate Process) 1O8kk (1 20/ton) per day basis
Treatirent of Control Technolo-
gies Identified under It n
III of the Scope of Work: A B C D
I zestment 100,000 150,000 4,000,000 5,500,000
Annual Costs:
Interest + Taxes and 5,000 7,500 200,000 275,000
Insuzanos
Depreciation 1,000 15,000 400,000 550,000
Operating and Maintenance 65,000 400,000 500,000 850,000
Costs (exc1ii ing energy
and po 1er sts)
Energy and P ;er Costs .0 0 400,000 445,000
Total lthnual Cost IL 1000 422,500 1,500,000 2, t 20,000
Effluent Qi l t i :
Effluent Oonstibients
Parazte hers (Units) P i
lcg/kkg (Pounds/Ion) Resulting Effluent
Load Levels
Sulfuric Acid 2025(4050) 2025(4050) 1745(3490)
Iron Sulfate 387(774) 387(774) 370(740) —‘0
Aluminum Sulfate 270(540) 270(540) 260(520) “0
Magnesium Sulfate 220(440) 220(440) 210(420) “-‘0
Titanium Sulfate 180(360) 180(360) 130(260) —‘0
Other metal sulfates 35(70) 35(70) 35(70) — ‘0 “-‘0
Solid Wastes 210(420) 20(40) 20(40) “ ‘0 “0
Soluble Calcium Sulfate — —‘200(-- ’400) .... ,O
Level A —— Settling Ponds
Level B —— Level A + weak acid stream neutralization.
Level C —— Level B + acid recovery facilities.
Level D —— Level C + specialty system demineralization + evaporation of regenerant solution.
VIIl-91
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SECTION IX
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION
OF THE BEST PRACTICABLE CONTROL TECHNOLOGY
CURRENTLY AVAILABLE,
LEVEL I EFFLUENT GUIDELINES AND LIMITATIONS
1.0 INTRODUCTION
The effluent limitations which must be achieved by July 1, 1977
are based on the degree of effluent reduction attainable through
the application of the best practicable control technology cur-
rently available. For the inorganic chemical industry, this
level of technology was based on the best existing performance
by exemplary plants of various sizes, ages and chemical pro-
cesses within each of the industry’s categories. In Section IV,
the inorganic chemicals industry was divided into five major
categories based on the characteristics of the effluents emerg-
ing from the various facilities under study. The twenty—five
inorganic chemicals investigated were grouped into these five
categories.
Best practicable control technology currently available, empha-
sizes treatment facilities at the end of a manufacturing pro-
cess but also includes the control technology within the pro-
cess itself when it is considered to be normal practice within
an industry. Examples of waste management techniques which
were considered normal practice within the inorganic chemicals
industry are:
manufacturing process controls
recycle and alternative uses of water
recovery and/or reuse of wastewater constituents.
Consideration was also given to:
a. The total cost of application of technology in relation
to the effluent reduction benefits to be achieved from
such application;
b. The size and age of equipment and facilities involved;
c. The process employed;
d. The engineering aspects of the application of various
types of control techniques;
e. Process changes;
f. Non—water quality environmental impact (including energy
requirements).
IX — 1
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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The following is a discussion of the best practicable cur-
rently available treatment methods for each of the chemicals
in these categories, and the proposed limitations on the
parameters in their effluents.
2.0 EFFLUENT REDUCTION ATTAINABLE USING LEVEL I TREATMENT
TECHNOLOGY -
Based upon the information contained in Sections III through
VIII of this report, the following determinations were made
on the degree of effluent reduction attainable with the ap-
plication of the best practicable control technology current-
ly available in the various categories of the inorganic chem-
icals industry. -
2.1 General Water Guidelines
2.1.1 Process Water
Process water is defined as any water contacting the reactants
of a process including contact cooling water. All values of
guidelines and limitations presented below for total dissolved
solids (TDS), total suspended solids (TSS), heavy metals and
toxic pollutants and other parameters are expressed as monthly
averages in units of pounds of parameter per ton and kilogra’ms
of parameter per metric ton of product produced except wh re
expressed as a concentration. The daily maximum limitation is
double the monthly average, except as noted. Where a zero ap-
pears for a parameter applicable to a discharge of process
wastewater, the zero signifies no increase in the parameter
above the level of the intake water or receiving water, which-
ever is lower. Zero discharge of process wastewater means that
no process water be discharged from the plant into surrounding
waterways.
2.1.1.1 pH Guidelines
Unless otherwise specified all process water effluents are
limited to the pH range of 6 to 9. Exceptions to this range
must be considered on an individual case basis. The pH limi-
tation range is both daily and monthly average.
2.1.2 Non Contact Cooling Waters and Blowdowns
In the chemical industry, at present, cooling and process wa-
ters are mixed in some cases prior to treatment and discharge
and in other situations, only cooling water is discharged.
Recommended Level I limitations on the discharge of such cool-
ing water are as follows:
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE S E T 2 CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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(a) An allowed discharge of all non-contact cooling waters
provided that the following conditions are met:
(1) No toxic or hazardous pollutants are added. Cooling
waters discharged must not have levels of chromate or
other toxic pollutants higher than that of the intake
water or receiving water, whichever is lower.
(2) Thermal pollution be in accordance with local stand-
ards. Excessive thermal rise in once—through non-
contact cooling water in the inorganic chemical indus-
try has not been and is not expected to be a signifi-
cant problem.
(3) No process waters be added to the cooling waters prior
to discharge. -
(4) All non-contact cooling waters should be monitored to
detect leaks from the process and provisions should be
made for emergency treatment prior to release.
(b) An allowed discharge of water treatment, cooling tower and
boiler blowdowns provided these do not contain toxic or
otherwise hazardous materials such as chromium or cadmium
and are within the required pH range. -
2.2 Category 1 Chemicals
Aluminum chloride, aluminum sulfate (alum), calcium carlicle,
hydrochloric acid, hydrofluoric acid, calcium oxide (lime),
nitric acid, potassium dichromate, potassium metal, potassium
sulfate, sodium bicarbonate, sodium chloride (Solar), sodium
silicate and sulfuric acid were placed in this category.
Category 1 chemical plants, utilizing the best existing treat-
ment technologies, have process effluents free of heavy metals
and low in dissolved and suspended solids.
2.2.1 Aluminum Chloride
The process used for the manufacture of anhydrous aluminum
chloride uses no water except in cas’es where a scrubber is
employed to eliminate the discharge to the atmosphere of un-
reacted chlorine gas. There are essentially three different
grades of anhydrous aluminum chloride product made using the
process of reacting chlorine gas with molten aluminum. The
grey product is aluminum-rich; the white product is made from
stoichiometric quantities of aluminum and chlorine; and the
yellow product is chlorine-rich. The grey and white product
IX - 3
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT 10 CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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manufacture has little or no chlorine evolving from the reac-
tor and, therefore, dry collection methods can be employed to
minimize process dust. The manufacture of yellow product re-
quires wet scrubbing to trap the excess chlorine gas as well
as the process dust.
The exemplary aluminum chloride plant 125 uses a wet scrub-
ber to produce a 28 percent aluminum chloride solution as a
product for sale and has no water discharge. In cases where
wet scrubbing is required and a market for aluminum chloride
solutions does not exist, these plants could treat their scrub-
ber effluent to precipitate the aluminum salts from solution
and recycle the supernatant liquid to the scrubber. Since the
volume of water used for scrubbing per day in plant 125 is
only 2720 liters (720 gallons), another treatment approach
could consist of concentrating the scrubbing water contain—:
ing aluminum chloride by recycling and then evaporate to
dryness to recover additional product.
The Level I guidelines and limitations recommended for aluminum
chloride plants is zero discharge of process water.
2.2.2 Aluminum Sulfate (Alum )
Aluminum sulfate is made by digesting bauxite ore in sulfuric
acid. The wastes emanating from this process consist of in—
solubles such as iron and silicon oxides present in the bauxite.
These wastes are removed during settling and filtration of the
product alum solution and also during washdown of tanks. In
both exemplary plants (049 and 063), the waste muds are
ponded to settle the solids and the clear water is recycled
to the process. No process water is discharged. The Level I
guidelines and limitations recommended for aluminum sulfate
plants is zero discharge of process waters.
Zero discharge is also recommended for plants producing iron-
free alum when refining of the bauxite ore is not done on the
plant site. The production of iron-free alum requires pure
raw metals: that is, iron—free sulfuric acid and iron-free
hydrated alumina. The refining of the bauxite to produce the
iron—free hydrated alumina yields wastes that must be segre-
gated from the alum production process waters. The refining
of bauxite to alumina is not included in this phase of effort
and, therefore, no effluent guidelines for this process are
presented in this report.
IX - 4
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN ThIS REPORT AND ARE SUBJECT 10 CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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2.2.3 Calcium Carbide
The data cited from exemplary plant 190 shows that the only
manufacturing wastes involved are dusts emerging in tail
gases from the furnaces. These are collected by dry bag fil-
tration methods and are reused in the process or disposed of
as solid wastes by landfilling. The only water-borne efflu-
ent leaving plant 190 is cooling tower blowdown water amount-
ing to about 13,200 liters per day (3500 GPD) which contains
some added water treatment chemicals. Presently, 80—90 per-
cent of the cooling water used at this plant is recycled.
Dry bag collection of solid waste and complete recycle of
cooling water, or the use of once-through non—contact cooling
water, constitute the best practicable control technology
currently available. The Level I guidelines and limitations
recommended for calcium carbide plants is zero dischar e of
process waters.
2.2.4 Hydrochloric Acid
As indicated in Section III of this report, the manufacture
of hydrochloric acid by the chlorine burning process comprises
a minor part of the total U.S. production. All of the chlor-
ine burning facilities are located within chior—alkali com-
plexes. Exemplary plant 121 is one such facility. The only
waste generated from this process consists of weak h rdroch1oric
acid, and it is generated only during startup of the operation.
No waste emanates from the process during normal operation.
The startup weak acid waste is normally neutralized with sodium
hydroxide which yields a dissolved solids (sodium chloride)
waste amounting to about 0.5 kg/kkg (1 pound per ton) of pro-
duct acid.
It is recommended that the weak brine startup waste from the
hydrochloric acid plant be utilized in the brine make-up opera-
tion at the chior-alkali portion of the complex and that zero
discharge of process waste waters be allowed from the hydrochlor-
ic acid plant.
2.2.5 Hydrofluoric Acid
The manufacture of hydrofluoric acid at exemplary plant 152 by
the reaction of fluospar (about 97% calcium fluoride) with sul-
furic acid generates about 3.1—3.6 Jckg (3.5 to 4.0 tons) of solid
waste per metric ton of product acid. All wastes from the process
are water slurried to settling ponds, and the clear liquid is
IX - 5
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUB JECT 10 CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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recycled for the same purpose. All process water is segregated
from non-contact cooling water. Also, the process is conducted
at a reduced pressure so that if a leak occurs, the cooling
water enters the system and the product is contaminated and not
the discharged cooling water.
The recommended Level I guidelines and limitations for the
production of hydrofluoric acid is zero discharge of process
waste waters.
2.2.6 Calcium Oxide (Lime )
The manufacture of lime by the calcination of limestone is a
dry process and uses only non—contact cooling water, and, in
some cases, contact scrubber water. Exemplary plant 007 uses
dry bag dust collectors and, therefore, discharges no process
water. The use of dry bag collection methods is not contin-
gent on the use of specific fuels for the calcination kilns
nor is it geographically dependent and constitutes the best
practicable treatment technology currently available to elim-
inate water wastes and minimize air pollution from calcium
oxide plants. Based on plant 007, the recommended Level I
guidelines and limitations for lime plants is zero discharge
of process waste water.
2.2.7 Nitric Acid
Commercial grade nitric acid (up to 70% concentration) is made
by the oxidation of ammonia and, at exemplary plant 114, all
process waters are recycled with no discharge. Of the 30,280
cu.m (8 million gallons) of water per day used for cooling,
about 95% is recycled. An additional 757 cu.m (0.2 million
gallons) of water per day are used to make steam for the pro-
cess, and 75% of this quantity is recycled. About 87 cu.m
(23,000 gallons) per day of steam condensate is used for acid
make-up water. The discharge from the plant consists of non-
contact cooling water which contains blowdowns from boilers,
cooling towers and water treatment with a total non—toxic
waste load amounting to about 2 kg/kkg (4 pounds per ton) of
product produced. The best practicable treatment technology
availbie for commercial grade nitric acid plants is the re-
cycle of all process waters and the segregation of process
waters from cooling water. Extensive amounts of suspended
solids generated from water treatment can be controlled by
settling ponds.
IX - 6
NOTICE : THESE ARE TENTATIVE RECOMMENDATiONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT 10 CHANGE BASED UPON COMMENTS
RECEiVED AND FURTHER INTERNAL REVIEW BY EPA.
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The Level I guidelines and limitations recommended for plants
producing nitric acid up to 70% concentration is zero discharge
of process waste waters.
2.2.8 Potassium Dichromate
The process for the production of potassium dichromate involves
the reaction of potassium chloride with sodium dichromate. At
exemplary plant 002, all process water is recycled and sodium
chloride (400 kilograms per metric ton of product) is removed
as a solid waste. The only water—borne waste source is con-
tamination of cooling water by hexavalent chromium in a baro-
metric condenser presently in use on the product crystallizer.
The plant has plans to replace the barometric condenser with
a non—contact type heat exchanger which will eliminate .cooling
water contamination.
The Level I guidelines and limitations recommended for potassium
dichromate plants is zero discharge of process waste waters.
2.2.9 Potassium Metal
Exemplary plant 045 produces most of the potassium metal man-
ufactured in the U.S. by a completely dry process. No water
is used, not even for cooling purposes. Therefore, zero dis-
charge of process waste water is recommended as Level I guide-
lines and limitations for the production of potassium metal.
2.2.10 Potassium Sulfate
All of the potassium sulfate manufacturers in the U.S. are
located in the arid southwest close to deposits of langbein—
ite ore (K2S04.2MgSO4). The reaction of this ore with a
potassium chloride solution and the subsequent crystalliza-
tion and separation of potassium sulfate from magnesium
chloride brine constitutes the proce’ss for the production of
potassium sulfate. A large amount (about 2000 kg. per kkg
of product) of magnesium chloride brine is a co-product of
this process. Exemplary plant 118 sells most of this
brine when the sodium content of the ore is low and ponds the
brine for evaporation when it can’t be sold. Evaporation
ponds in this area of the country are no problem. The cost
of water is a problem and most of the liquor in the brine is
recycled back to the process for reuse before the magnesium
IX - 7
NOTiCE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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chloride is sold or dumped. The percolation of the dumped
soluble chloride and contamination of ground water apparent-
ly has not been a problem to date. Other insoluble wastes
from the process muds amount to about 15 kilograms per metric -
ton of product, and they are landfilled.
Because of the geographical dependence of plants manufac-
turing potassium sulfate to the arid southwest, the Level I
guidelines and limitations recommended is for zero dis-
charge of process waste water into navigable waters. The
impact of dumping or landfilling soluble chlorides will
have to be considered on a case—to—case basis as to the
probability of contaminating ground waters.
2.2.11 Sodium Bicarbonate
Sodium bicarbonate is manufactured by the carbonation of a
sodium carbonate (soda ash) solution. Most plants are loca-
ted in or near complexes manufacturing soda ash by the Solvay
Process. There is one isolated facility which uses mined
soda ash as a raw material. Exemplary sodium bicarbonate
plant 166 is located within a Solvay Process complex. The
major wastes from this process are about 10 kilograms of Un—
dissolved sodium bicarbonate per metric ton of product and an
average of about 38 kilograms of dissolved sodium bicarbonate
per ton of product. Some of the undissolved sodium bicarbo—
nate is reusable and it is redissolved and recycled to the
process. The remainder is landfilled along with sand from
the filters and other non-process type solid waste. The
present discharge of approximately 76 cu.m per day (20,000 GPD)
contains an average of 20,000 ppm of dissolved solids and little
or no suspended solids which are removed in a settling pond.
Plant 166 has plans to use the weak slurry thickener over-
flow, which constitutes their present major source of waste,
as a source of liquid for the product dryer scrubber and
recycle this liquid to concentrate it with respect to sodium
carbonate and reuse it in the process. These process changes
will eliminate tbe discharge of process waste waters.
The Level I guidelines and limitations recommended for sodium
bicarbonate plants is zero discharge of process waste waters.
IX - 8
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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2.2.12 Sodium Chloride (Solar )
Solar salt is produced by the long-term solar evaporation of
sea water to precipitate sodium chloride. This process gen-
erates a bittern waste solution consisting mainly of sodium,
potassium and magnesium salts. Many solar salt plants in the
U.S. are located in California, and this state prohibits the
discharge of bitterns to the ocean. Exemplary plant 059 re-
claims some of the waste salts from the bitterns and stores
the rest for future reclamation. The process is highly geo-
graphically dependent. There is no discharge of process waste
water from plant 059.
The Level I guidelines and limitations recommended for solar
process sodium chloride plants is zero discharge of process
waste water.
2.2.13 Sodium Silicate
Sodium silicate is produced by the reaction of soda ash and
silica in a furnace to form a sodium silicate glass. The
material is sold either as a solid glass product or is pres-
sure dissolved in water and sold as a solution with various
ratios of silica to sodium oxide. The water-borne waste
generated consists of unreacted silica, sodium hydroxide and
sodium silicate from tank washdowris, product shock cooling
with water and scrubber effluent. At exemplary plant 072,
these wastes are ponded to settle the solids and the clear
liquid is partially recycled and partially pond evaporated,
resulting in no discharge of process waste water.
The Level I guidelines and limitations recommended for sodium
silicate plants is zero discharge of process waste water.
2.2.14 Sulfuric Acid
Sulfuric acid is manufactured using the sulfur-burning Contact
Process by three different types of plants. These are single
absorption plants, double absorption plants and spent acids
plants. The guidelines presented herein do not apply to spent
acid plants.
Exemplary plant 141 is a single absorption plant and exem-
plary plant 086 is a double absorption plant. The double
I X - 9
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absorption plant has no process waste and uses only non—
contact cooling water. The single absorption plant requires
the use of wet scrubbing to minimize air pollution, and the
scrubber water is recycled. This plant also uses non-contact
cooling water. The only process waste from these plants
emanate from the cooling system if leaks occur contaminating
the cooling water. These leaks should be controlled in ac-
cordance with paragraph 2.1 of this section of the report.
There is no discharge of process waste water from these exem-
plary plants. Therefore, the Level I guidelines and limita-
tions recommended for single and double absorption sulfur
burning sulfuric acid plants is zero discharge of process
waste waters.
2.3 Category 2 Chemicals
Calcium chloride, hydrogen peroxide (organic), sodium chloride
(brine mining), sodium metal and sodium sulfite were placed
in this category. Category 2 chemical plants, utilizing the
best existing treatment technologies, have process effluents
with no heavy metals present and low in suspended solids, and
contain medium quantities o dissolved solids.
2.3.1 Calcium Chloride
Calcium chloride is produced by extraction from natural brine
and as a by—product of soda ash manufacture by the Solvay’
Process. The guidelines presented herein apply only to the
brine extraction process.
The process wastes are weak brine solutions, and they emanate
from the blowdown of various brine purification steps and
from several evaporation steps used in the process. The
currently available practicable treatment technology used
at exemplary plant 185 is to pass the waste brine streams
through activated sludge to remove organics, pond to settle
suspended solids and adjust pH and final pond to remove addi-
tional suspended so1ids before discharge.
The Level I guidelines and limitations recommended for pro-
cess waste water discharge from calcium chloride plants using
the brine extraction process are:
TDS 30.7 kg/kkg (61.4 lbs/ton)
TSS Not to exceed the level in the incoming
water or 25 ppm, whichever is lower.
Heavy metals and 0
Toxic pollutants
Other 0
NOTICE : THESE ARE TENTATI\ C REC MENDAT!ONS BASED UPON INFORMAT1ON
IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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2.3.2 Hydrogen Peroxide (Organic )
The organic process for the manufacture of hydrogen peroxide
at exemplary plant 069 generates a waste stream containing
0.17-0.35 kg/kkg (0.34-0.70 lbs/ton) of organics. The treat-
ment methods currently used at this plant include an 80% reduc-
tion of hydrogen peroxide to water and oxygen, a recovery sys—
tern which recovers 60-70 percent of lost organics, and tank
dikirig and process curbing to retain waste spills. The
12.5—15 kg of sulfuric acid per metric ton of product cur-
rently discharged comes from water treatment ion exchange
regeneration and therefore is allowed as a discharge, pro-
vided this water treatment blowdown conforms to the pH range
allowable.
The Level I guidelines and limitations recommended for-process
waste water discharge from organic process hydrogen peroxide
plants are:
TDS 21.5 kg/kkg (43 lbs/ton) monthly average
23 kg/kkg (46 lbs/ton) daily maximum
TSS 0.28 kg/kkg (0.56 lb/ton) monthly average
0.32 kg/kkg (0.64 lb/ton) daily maximum
Heavy metals 0
and toxic
pollutants
Organics 0.26 kg/kkg (0.52 lb/ton) monthly average
0.35 kg/kkg (0.64 lb/ton) daily maximum
2.3.3 Sodium Chloride (Brine Mining )
Sodium chloride manufacture by this process involves pumping
of water into an underground salt deposit (solution mining)
and returning brine for treatment to remove impurities and
then to multiple effect evaporators to crystallize and collect
the pure sodium chloride for sale. At exemplary plant 030,
the brine sludges from the brine purification step are dis-
posed of by returning them to the mine. Other sources of
waste water are the purges from the evaporators, spills and
the barometric condenser. All of the concentrated brine
wastes are recycled to the process. The current plant ef flu-
ent is neutral in pH, low in suspended solids and contains an
average of 5—6 kg per kkg of product of total dissolved solids.
Ix — 11
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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The Level I guidelines and limitations recommended for dis-
charge of process waste water from solution mining .2vapora—
tive process sodium chloride plants are:
TDS 6 kg/kkg (12 lbs/ton)
TSS 0.125 kg/kkg (0.25 lb/ton)
Heavy metals and 0
toxic pollutants
Other 0
2.3.4 Sodium Metal
The process for the manufacture of sodium metal, commonly
called the Downs Cell Process, is essentially dry. However,
water—borne wastes are generated during cleanout and- wash—
down of cells when the electrolyte is replenished, from
scrubbing chlorine tail gases and from drying the chlorine -
with sulfuric acid. At exemplary plant 096, the spent
drying acid is not discharged but used elsewhere in the
works complex. The calcium hypochlorite waste from the
tail gas scrubber is also used to advantage elsewhere in
the complex. The wastes from cell wash—downs, runoff
water and residual chlorine containing water from the tail
gas scrubber are ponded to settle suspended solids and then
discharged. At plants where the utilization of the spent
drying acid and calcium hypochiorite solution is not possibl-e,
it is recommended that the spent acid be sold to a “decomp’ t
sulfuric acid plant and the calcium hypochiorite solution’
be recovered and marketed as a bleach product.
In accordance with the above available technologies, the
following Level I discharge of process waste water guide-
lines and limitations are recommended for sodium metal
manufacture plants:
TDS 51.5 kg/kkg (103 lbs/ton)
TSS 0.25 kg/kkg (0.50 lb/ton)
Heavy metals and 0
toxic pollutants
Other 0
2.3.5 Sodium Sulfite
Sodium sulfite is manufactured by the reaction of sulfur di-
oxide with soda ash. The process wastes are mainly sulfides
from product purification and sodium sulfite/sodium sulfate
Ix — 12
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IN This REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
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solutions from the product dryer ejector, filter washings and
vessel cleanouts. Exemplary plant 168 is the only sodium sul—
fite plant currently treating the waste sulfite-containing
solutions to oxidize sulfite to sulfate. The efficiency of
this aeration treatment is about 94 percent. An additional
filtration treatment is given to the process waste water which
removes 98 percent of the suspende& solids.
The Level I guidelines and limitations recommended for dis-
charge of process waste water from sodium sulfite plants are:
TDS 30 kg/kkg (60 lbs/ton) monthly average
36.5 kg/kkg (73 lbs/ton) daily maximum
TSS 0.05 kg/kkg (0.10 lb/ton) monthly average
0.125 kg/kkg (0.25 lb/ton) daily maximum
Heavy metals 0
and toxic
pollutants
Sodium 3.0 kg/kkg (6.0 lbs/ton) monthly average
sulfite 3.65 kg/kkg (7.3 lbs/ton) daily maximum
2.4 Category 3 Chemicals
Chlorine-alkali (diaphragm cell), chlorine-alkali (mercury
cell), hydrogen peroxide (electrolytic), sodium dichromate
and sodium sulfate were placed in this category. Category 3
chemical plants, utilizing the best existing treatment tech-
nologies, have process effluents with heavy metals present,
are low in suspended solids and have medium concentrations
of dissolved solids.
2.4.1 Chlorine-Alkali (Diaphragm Cell ) -
The diaphragm cell process for the manufacture of chlorine and
caustic soda or caustic potash usually have the following raw
wastes emanating from the process:
a. a solution of sodium hypochiorite and sodium bicarbo-
nate from the scrubbing of chlorine tail gases (about
7.5 kilograms of dissolved solids per metric ton of
chlorine produced)
b. chlorinated organics from the liquifaction of chlorine
gas (about 0.7 kilograms per metric ton of chlorine
produced)
c. brine wastes from the brine purification system (about
12.2 kilograms of dissolved solids per metric ton of
chlorine produced)
d. spent sulfuric acid from the chlorine drying process
(about 4.2 kilograms per metric ton of chlorine produced)
NOTICE : THESE ARE TENTATIVE RE MMEND TI0NS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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e. weak caustic and brine solution from the caustic
evaporators using barometric condensers (about 9.5
kilograms of dissolved solids per metric ton of chlor-
ine produced)
f. weak caustic and brine solution from the caustic
filter washdown (about 37.5 kilograms of dissolved
solids per metric ton of chlorine’produced).
At exemplary plant 157, the tail gas scrubber wastes are pres-
ently discharged, but the plant intends to install a chlorine
burning hydrochloric acid plant in the near future which will
eliminate the scrubber wastes. This, however, constitutes
Level II technology. The chlorinated organics are disposed
of by incineration. The brine wastes from brine purification
are ponded to settle out suspended solids and the brine liquor
is recycled to brine make-up. The spent sulfuric acid at this
plant is utilized elsewhere in the complex or sent back to a
spent sulfuric acid plant for regeneration. Some plants pre-
sently use this acid to partially neutralize caustic wastes
in the plant which aides in controlling the effluent pH but
adds to the total dissolved solids present. The weak caustic/
brine solution from the caustic evaporators can be eliminated
by replacing the barometric condensers with non-contact surface
condensers or by recycling the discharge from the barometric
condenser back to brine make—up. The weak caustic/brine solu-
tion from the caustic filters is presently pH adjusted ançl
discharged.
The Level I guidelines and limitations recommended for process
waste water discharge from diaphragm cell chior-alkali plants
are based on the dissolved solids loading from tail gas scrub-
bing, partial neutralization of caustic wastes with spent sul-
furic acid and recycle of the remainder of weak caustic/brine
solutions to the process. These guidelines are:
TDS 19.25 kg/kkg (38.5 lbs/ton) of chlorine
TSS 0.10 kg/kkg (0.20 lb/ton) of chlorine
Heavy metals 0.0025 kg/kkg (0.005 lb/ton) lead
and toxic
pollutants
Other 0
2.4.2 Chlorine—Alkali (Mercury Cell )
The mercury cell process for the manufacture of chlorine and
caustic soda or caustic potash usually has similar wastes to
the diaphragm cell process which was discussed in paragraph
Ix — 14
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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2.4.1 of this section. The major exception is the loss of
mercury from the process. Exemplary plants 144, 098 and 130
have excellent mercury control systems to minimize the incor—
poration of mercury into discharge streams. These contro1
consist of curbing the cell area to retain mercury lost in
spills or leaks, collecting all mercury contaminated streams
for treatment to remove the mercury before ponding and dis-
charge and/or recycling mercury—containing waste water back
to the cells for reuse after treatment to remove any impur-
ities. These plants have continuous mercury monitors on
streams possibly contaminated that are meant for ponding to
settle suspended solids before discharge.
The following Level I guidelines and limitations for process
water discharge from mercury cell chior-alkali plants are
based on the same technologies cited in paragraph 2.4.1 above
for diaphragm cell plants.
TDS 19.25 kg/kkg (38.5 lbs/ton) of chlorine
TSS 0.32 kg/kkg (0.65 lb/ton) of chlorine
Heavy metals 0.00007 kg/kkg (0.00014 lb/ton) mercury
and toxic
pollutants
Other 0
2.4.3 Hydrogen Peroxide (Electrolytic )
There is only one plant in the U.S. that makes hydrogen per-
oxide by the electrolytic process. Plant 100 recovers all
of the solids present in the process wastes and ion exchange
treats to recover 98 percent of the cyanides present in the
waste stream before discharge. The current process water
discharge is low in suspended solids and marginally low to
medium in dissolved solids. The ion exchange regenerant is
pH controlled prior to discharge.
The Level I guidelines and limitatidns recommended for pro-
cess waste water discharge from the electrolytic process
hydrogen peroxide plant are:
TDS 1.0 kg/kkg (2.0 lbs/ton)
TSS 0.0025 kg/kkg (0.005 lb/ton)
Heavy metals 0.0002 kg/kkg (0.0004 lb/ton) cyanide ion
and toxic 0.0002 kg/kkg (0.0004 lb/ton) heavy metal
pollutants ion
Other 0
IX — 15
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
iN This REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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2.4.4 Sodium Dichromate and Sodium Sulfate
These two chemicals are manufactured as co-produces by the
calcination of a mixture of chrome ore, soda ash and lime
followed by water leaching and acidification of the soluble
chromates. The sodium sulfate product is crystallized out
after acidification. The bulk of the waste originates from
the undigested portions of the ore and are mostly solid
wastes. Water—borne wastes arising from spills and wash—
downs contain most of the hexavalent chromium. Plant 184
was chosen as exemplary because of its excellent treatment
to minimize the discharge of hexavalent chromium. The
treatment consists of good containment of spills, leaks and
rain water runoff in chrornate areas of the plant followed
by treating the chromium-containing wastewater with pickle
liquor to affect reduction of the chromates and then lagoon—
ing to settle out suspended solids before discharge. This -
treatment removes 99 percent of the hexavalent chromium.
The Level I guidelines and limitations recornniended for pro-
cess waste water discharge from sodium dichromate/sodiura
sulfate co—product plants are:
TDS 88.5 kg/kkg (177 lbs/ton) monthly average
115 kg/kkg (230 lbs/ton) daily maximum
TSS 0.125 kg/kkg (0.25 lb/ton) monthly average
0.215 kg/kkg (0.43 lb/ton) daily maximum
Heavy metals 0.0001 kg/kkg (0.0002 lb/ton) hexavalent
and toxic chromium
pollutants
Other 0.00125 kg/kkg (0.0025 lb/ton) total
chromium
2.5 Category 4 Chemicals
Category 4 chemicals, utilizing the best existing treatment
technologies, have process waste water effluents with no
heavy metals, that are low in suspended solids and high in
dissolved solids. Of the chemicals studied in this phase of
the program, sodium carbonate (soda ash) by the Solvay Process
is the only one in this category.
2.5.1 Sodium Carbonabe (Soda Ash - Solvay )
The Solvay Process for the manufacture of sodium carbonate
(soda ash) involves the reaction of sodium chloride brine,
ammonia and carbon dioxide to yield crude soda ash. The
IX — 16
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ammonia is recovered for the process by reacting the spent
brine solution with lime followed by distillation. This
process produces about 1500 kilograms of dissolved solids -
waste per metric ton of soda ash manufactured. Calcium chlor-
ide comprises the majority of this waste, amounting to about
1050 kilograms for every metric ton, of soda ash. There are
no true exemplary plants manufacturing soda ash by the Solvay
Process but plant 166 recovers about 21 percent of the waste
calcium chloride for sale. The total recovery of calcium
chloride is not practical because of the limited market value.
The only treatment used at this plant is a settling pond to
reduce the concentration of suspended solids in the effluent.
The Level I guidelines and limitations recommended for pro-
cess waste water discharge from Solvay Process soda ash
plants are:
TDS 1535 kg/kkg (3070 lbs/ton) monthly average
1650 kg/kkg (3300 lbs/ton) daily maximum
TSS 0.125 kg/kkg (0.25 lb/ton) monthly average
0.205 kg/kkg (0.41 lb/ton) daily maximum
Heavy metals 0
and toxic
pollutants
Other 0
2.6 Category 5 Chemicals
Category 5 chemicals, utilizing the best existing treatment
technologies, have process waste water effluents with heavy
metals present and high concentrations of both suspended and
dissolved solids. Titanium dioxide (titania) prepared by
both the chloride process and the sulfate process falls in
this category.
2.6.1 Titania (Chloride Process )
The amount of wastes generated by the manufacture of titania
by either th chloride or sulfate process is heavily depen-
dent on the purity of raw material used. The exemplary chlor-
ide process plant 009 uses neutralization, clarification and
ponding to settle suspended solids and to precipitate heavy metals
as treatment methods. The relatively large amounts of suspended
and dissolved solids, expressed as kilograms per metric ton
or as pounds per ton of product titania, is due mainly to the
IX — 17
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IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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relative impurity of the ores used in the process. About 93
percent of the cooling water is recycled but there appears
to be no practical approach for recycling process water. Deep
well disposal is utilized by another company (plant 160). The
plant effluent is neutral pH and contains mostly sodium chlor-
ide as the dissolved solid.
The Level I guidelines and limitations recommended for process
waste water discharge from chloride process titania plants are:
TDS 315 kg/kkg (630 lbs/ton) monthly average
430 kg/kkg (860 lbs/ton) daily maximum
TSS 1.75 kg/kkg (3.5 lbs/ton) monthly average
4.8 kg/kkg (9.6 lbs/ton) daily maximum
Heavy metals 0.019 kg/kkg (0.038 lb/ton) iron monthly
and toxic average
pollutants 0.29 kg/kkg (0.58 lb/ton) iron daily maxinthm
0.05 kg/kkg (0.1 lb/ton) titanium monthly
average
0.0025 kg/kkg (0.005 lb/ton) other heavy
metals monthly average
Other 0
2.6.2 Titania (Sulfate Process )
Of the five sulfate process titania plants in the U.S., non
are considered exemplary. The high iron content in the ilmen—
ite ore raw material is a major source of the wastes generated
by this process. Another major contributor to the process
waste is the large amount of spent sulfuric acid from digestion
of the ore. Very little treatment is presently being used and
the effluents from these plants are highly acidic and contain
high concentrations of suspended and dissolved solids including
heavy metal ions. Ocean barging is used by some to dispose of
the process waste waters. Plant 122 is presently installing
treatment facilities to neutralize and oxidize the process
wasie to remove the acid as calcium sulfate, to reduce the chem-
ical oxygen demand and reduce the concentration of heavy metal
ions. They also .plan additional settling ponds to reduce the
suspended solids formed during the neutralization treatment.
Considerable research is being done to improve treatment tech-
nologies for this process and they are discussed in detail in
Section VII of this report.
The Level I guidelines and limitations recommended for discharge
of process waste water from sulfate process titania plants are:
TDS 265 kg/kkg (530 lbs/ton)
TSS 25 ppm
Heavy metals and 25 ppm expressed as oxides
toxic pollutants
Other 0
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN This REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INT ’JAL 1 VIEW BY EPA.
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SECTION X
EFFLUENT REDUCTION ATTAINABLE THROUGH THE
APPLICATION OF THE BEST AVAILABLE
TECHNOLOGY ECONOMICALLY ACHIEVABLE,
LEVEL II EFFLUENT GUIDELINES AND LIMITATIONS
1.0 INTRODUCTION
The effluent limitations which must be achieved by July 1,
1983 are based on the degree of effluent reduction attainable
through the application of the best available technology
economically achievable. For the inorganic chemical industry,
this level of technology was based on the very best control
and treatment technology employed by a specific point source
within the industrial category or subcategory, or where it is
readily transferable from one industry process to another.
In Section IV, the inorganic chemicals industry was divided
into five major categories based on the characteristics in
the effluents emerging from the various facilities under study.
The twenty—five inorganic chemicals investigated were grouped
into these five categories.
The following factors were taken into consideration in deter-
mining Level II technology:
a. the age of equipment and facilities involved;
b. the process employed;
c. the engineering aspects of the application of various
types of control techniques;
d. process changes;
e. cost of achieving the effluent reduction resulting
from application of Level II technology; and
f. non-water quality environmental impact (including
energy requirements).
In contrast to Level I technology, Level II assesses the
availabilityin all cases of in—process controls as well as
control or additional treatment techniques er ployed at the
end of a production process. In-process control options
available which were considered in establishing Level II con-
trol and treatment technology include the following:
x- 1
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a. alternative water uses
b. water conservation
c. waste stream segregation
d. water reuse
e. cascading water uses
f. by—product recovery
g. reuse of wastewater constituent
h. waste treatment
i. good housekeeping
j. preventive maintenance
k. quality control (raw material, product, effluent)
1. monitoring and alarm systems.
Those plant processes and control technologies which at the
pilot plant, semi—works, or other level, have demonstrated
both technological performances and economic viability at a
level sufficient to reasonably justify investing in such
facilities were also considered in assessing Level II tech-
nology. Level II is the highest degree of control technology
that has been achieved and has been demonstrated to be capa-
ble of being designed for plant scale operation up to and
including “no discharge” of pollutants. Although economic
factors are considered in this development, the costs for
this level of control are intended to be for the top-of-the—
line of current technology subject to limitations imposed by
economic and engineering feasibility. However, Level II
may necessitate some industrially sponsored development work
prior to its application.
2.0 EFFLUENT REDUCTION ATTAINABLE USING LEVEL II
TREATMENT TECHNOLOGY
Based upon the information contained in Sections III through
IX of this report, the following determinations were made
on the degree of effluent reduction attainable with the ap-
plication of the best available cont ol technology economi-
cally achievable in the various categories of the inorganic
chemical industry.
X- 2
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IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
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2.1 General Water Guidelines
2.1.1 Process Water
Process water is defined as any water contacting the react-
ants of a process including contact cooling water. All values
of guidelines and limitations presented below for total dis-
solved solids (TDS), total suspended solids (TSS), heavy
and toxic pollutants and other parameters are expressed as
monthly averages in units of kilograms of parameter per metric
ton (lbs/ton) of product produced except where expressed as
a concentration. The daily maximum limitation is double the
monthly average, except as noted. Where zeros appear for a
parameter when there is discharge of process wastewater, the
zero means no increase above that of the intake or receiving
water, whichever is lower. Zero discharge of process waste—
water means that no process water be discharged from the
plant into surrounding waterways.
2.1.1.1 pH Guidelines
Unless otherwise specified all process water effluents are
limited to the pH range of 6 to 9. Exceptions to this range
must be considered on an individual case basis. The pHlimi-
tation applies to both daily and monthly averages.
2.1.2 Non-Contact Cooling Waters and Blowdowns
The same as Level I except that monitoring shall be required
for process leaks and provisions shall be made for emer-
gency holding facilities for cooling water contaminated by
leaks until such time as they can be treated.
2.2 Category 1 Chemicals
All Category 1 chemical plants were recommended for zero
discharge of process wastewater at Level I.
2.3 Category 2 Chemicals
The chemicals in this category are calcium chloride, hydro-
gen peroxide (organic),sodium chloride (brine mining),
sodium metal and sodium sulfite.
X- 3
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2.3.1 Calcium Chloride
Exemplary plant 185 has plans to replace their evaporator
and recycle the packaging area washdown, which will
eliminate the discharge of calcium chloride and ammonia.
Therefore, Level II guidelines and limitations recommended
are for zero discharge of process wastewater.
2.3.2 Hydrogen Peroxide (Organic )
The Level II technology recommended for organic process
hydrogen peroxide plants is to recycle all process water.
The discharged processed water presently contains hydrogen
peroxide and organic solvent which should not be detrimental
to the process. Zero discharge of process wastewater is
recommended as Level II guidelines and limitations.
2.3.3 Sodium Chloride (Brine Mining )
The major source of the discharged sodium chloride dissolved
solids waste generated at plant 030 emanates from carryover
in the barometric condensers. The Level II technology re-
commended for brine mining evaporative process sodium chlo-
ride plants is to replace the barometric condensers with
non-contact heat exchangers and recycle the steam condensate
to the evaporators. The Level II guidelines and limita—
tions recommended for evaporative process sodium chloride
plants are zero discharge of process wastewater.
2.3.4 Sodium Metal
The Level II technology recommended for sodium metal-
chlorine plants is:
a. Recycle of the wastes from cell washdowns to brine
purification after removal of suspended solids.
b. Recovery of the calcium hypchlorite waste from the
tail gas scrubber as a product and recycle of water
to the scrubber, or replace the scrubber with a
chlorine—burning hydrochloric acid facility.
c. Recycle the spent sulfuric acid used for drying
the chlorine to a “decomnp” sulfuric acid plant or
sell to a possible user of weak acid. The Level
X- 4
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN This REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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DRAFT
II guidelines and limitations recommended for sodium
metal—chlorine plants are zero discharge of process
wastewaters.
2.3.5 Sodium Sulfite
The Level II technology reconimendedto eliminate waste dis-
charge from sodium sulfite plants is recovery of the sodium
sulfate from the waste discharge by evaporation and sale as
a by-product. This should not be too costly since the vol-
ume of effluent from exemplary plant 168 averages only 14-
26.5 cu m per day (3700-7000 gallons per day), and the dis-
solved solids in this stream are mostly sodium sulfate.
The Level II guidelines and limitations recornmened for sodium
sulfite plants is zero discharge of process wastewater;
2.4 Category 3 Chemicals
Chior-alkali (diaphragm cell), chlor-alkali (mercury cell),
hydrogen peroxide (electrolytic), sodium dichromate and
sodium sulfate are included in this category.
2.4.1. Chlor—alkali (Diaphragm Cell )
Level I technology for the manufacture of chlorine/caustic
soda or caustic potash by the diaphragm cell process allows
the discharge of treated wastes from the tail gas scrubber
and of neutralized spent acid from chlorine drying. Level
II technology recommended for this subcategory is elimina-
tion of the discharge entirely by:
a. Catalytic treatment of the hypochiorite waste from
the scrubber to convert to a brine and recycle to
brine purification, recovery of the hypochiorite
as a bleach product or elimination of the scrubber
and utilization of the chlorine gas elsewhere in
the plant, such as in a chlorine—burning hydro-
chloric acid plant;
b. Recovery of the spent acid from chlorine drying
and sale, utilization elsewhere in the plant or
return to spent sulfuric acid plant for regenera-
tion; and
X- 5
NOTICE : THESE ARE TENTATIVE RECOMMENDATiONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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DRAFT
c. Recycle of all weak brine/caustic solutions to
the process after extraction/elimination of
heavy metals and impurities.
Level II guidelines and limitations recommended for diaphragm
cell chior—alkali plants are zero discharge of process waste-
waters.
2.4.2 Chior—alkali (Mercury Cell )
See the preceding paragraph 2.4.1 for the Level II techno-
logy recommended for diaphragm cell plants. The same
technology applies to mercury cell plants.
The Level II guidelines and limitations recommended for mer-
cury cell chior—alkali plants are zero discharge of process
wastewaters.
2.4.3 Hydrogen Peroxide CElectrolytic )
The Level II technology recommended for this process is
to segregate the process wastewater from the cooling water
discharge and treat the relatively small amount (4.15 cu in!
day; 1100 GPD) of process wastewater by distillation and
recycle the distillate to the process. The solid wastes
from the distillation could be land-filled.
The Level II guidelines and limitations recommended for
this process are zero discharge of process wastewater.
2.4.4 Sodium Dichromate and Sodium Sulfate
At exemplary plant 184, a total of approximately 113,000 kkg
of product and by—product are manufactured per year. As in-
dicated in Supplement A, Cost Information, of this report,
the additional treatment costs to this plant for the evapor-
ation of the effluent to effect zero discharge would amount
to about $250,000 per year. This would mean an approximate
cost increase pef kkg of sodium dichromate and sodium sulfate
of $2.20. Therefore, the Level II guidelines and limitations
recommended for plants producing sodium dichroxnate and by-
product sodium sulfate is zero discharge of process wastewater.
X- 6
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT 10 CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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DRAFT
2.5 Category 4 Chemicals
Sodium carbonate (soda ash) manufactured by Solvay Process
is the only chemical under study that falls in this category.
2.5.1 Sodium Carbonate (soda ash-Solvay )
Because of the extremely large amount of dissolved solid
wastes generated by this process, the lack of market for
the waste product and the lack of economically available
technology to eliminate it, the Level II technology recom-
mended for this chemical is elimination of the Solvay Process
in favor of the alternate process for its manufacture, i.e.,
mining of soda ash. This recommendation, of course, presup-
poses the availability of soda ash deposits sufficient for
and amenable to exploitation. Extensive deposits appa±ently
exist in the Green River, Wyoming, area.
2.6 Category 5 Chemicals
Titanium dioxide ( itania) prepared by both the chloride pro-
cess and the sulfate process is the only chemical studied that
is in this category. The Level I guidelines and limitations
recomm’ nded for these processes were based on the intended
near future treatments planned by the titania industry. As
indicated in Section VIII of this report, the additional
treatment costs projected to bring each of these processes
cioWfl to zero discharge of process waste water by demineral-
ization and evaporation of regenerant solutions are as
follows:
a. Chloride orocess — an additional S730,000 per year for a
plant with a 24,300 kkg (27,000 tons) per year capacity or
an increase of approximately 5% per rretric or shcrt ton pro-
duced over the technology costs for Level I.
b. Sulfate process - an additional $620,000 per year for a
plant with a 39,600 kkg (43,000 tons) per year capacity or
an increase of approximately 3% per metric or short ton pro-
duced over the technology costs for Level I.
Based on these modest product cost increases over Level I
required treatment technology, the Level II guidelines and
limitations recommended for both the chloride and sulfate
processes for the manufacture of titanium dioxide are zero
discharge of process waste water.
X- 7
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBIJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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DRAFT
SECTION XI
NEW SOURCE PERFORMANCE STANDARDS
AND PRETREATMENT STANDARDS,
LEVEL III GUIDELINES AND LIMITATIONS
1.0 INTRODUCTION
This level of technology is to be achieved by new sources.
The term “new source” is defined in the Act to mean “any
source, the construction of which is commenced after the
publication of proposed regulations prescribing a stand-
ard of performance”. Level III technology evaluated by add-
ing to the consideration underlying the identification of
Level II technology a determination of what higher levels of
pollution control are available through the use of improved
production processes and/or treatment techniques. Thus, in
addition to considering the best in-plant and end-of—process
control technology, identified in Level II, Level III tech-
nology was based upon an analysis of how the level of efflu-
ent may be reduced by changing the production process itself.
Alternative processes, operating methods or other alterna-
tives were considered. However, the end result of the
analysis identifies effluent standards which reflect levels
of control achievable through the use of improved produc-
tion processes (as well as control technology), rather than
prescribing a particular type of process or technology which
must be employed. A further determination which was made
for Level III technology is whether a standard permitting
no discharge of pollutants is practicable.
The following factors were considered with respect to pro-
duction process which were analyzed in assessing Level III
technology:
(a) the type of process employe 1 and process changes;
(b) operating methods;
(c) batch as opposed to continuous operations;
Cd) use of alternative raw materials and mixes of raw
materials;
Ce) use of dry rather than wet processes (including
substitution of recoverable solvents for water);
and
(f) recovery of pollutants as by-products.
XI - 1
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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DRAFT
In addition to the recommendation of Level III technology
and related effluent limitations covering discharges direct-
ly into waterways, the constituents of the effluent discharge
from a plant within the industrial category which would in-
terfere with, pass through, or otherwise be incompatible with
a well designed and operated publicly owned activated sludge
or trickling filter wastewater treatment plant was identi-
fied. A determination was made of whether the introduction
of such pollutants into the treatment plant should be com-
pletely prohibited.
2.0 EFFLUENT REDUCTION ATTAINABLE USING LEVEL III
TREATMENT TECHNOLOGY
Based upon the information contained in Sections III through
X of this report, the following determinations were made on
the degree of effluent reduction attainable with the applica-
tion of new source standards for the various categories of
the inorganic chemicals industry.
2.1 General Water Guidelines
The process water, cooling water and blowdown guidelines for
Level III are identical to those recommended for Level II.
See paragraphs 2.1.1 and 2.1.2 of Section X.
2.2 Category 1 Chemicals
The Level I recommended guidelines and limitations for plants
manufacturing the fourteen chemicals in Category 1 were zero
discharge of process wastewater.
2.3 Category 2 Chemicals
The Level II recommended guidelines and limitations for plants
using the five processes in Category 2 were zero discharge
of process wastewater.
2.4 Category 3 Chemicals
The Level II recommended guidelines and limitations for plants
manufacturing the six chemicals in Category 3 were zero
XI - 2
NG1ICE : THESE ARE TENTATI\/E RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT TO CHt NGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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DRAFT
discharge of process wastewater.
2.5 Category 4 Cher ica1s
An alternate process (mining) was recommended in Level II
for the manufacture of sodium carbonate (soda ash) by the
Solvay Process. -
2.6 Category 5 Chemicals
The Level II guidelines and limitations recommended for both
the chloride and sulfate processes for the manufacture of ti-
tanium dioxide were zero discharge of process wastewater.
3.0 PRETREATMENT STANDARDS
Plants whose wastewater discharges are characterized by inor-
ganic materials or by presence of toxic materials that inter-
fere with operation of biological systems are not suited to
use of conventional secondary waste treatment. Extreme segre-
gation (that is, limiting the sewered discharge to sanitary
and other organic wastes) or pretreatment are required by such
manufacturing plants.
The pretreatment standards recommended for the various cate-
gories of the inorganic chemical industry are the same as
those recommended for Level III (new sources standards) tech-
nology. All of the processes in Category 1 are recommended
for zero discharge of process wastewater. The two processes
in Category 5, the chloride and sulfate processes for the
manufacture of titanium dioxide, have wastes which could not
be handled by a conventional municipal waste treatment plant,
even with the recommended control and treatment technology.
XI-3
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION
IN THIS REPORT AND ARE SUBJECT 1D CHANGE BASED UPON COMMENTS
RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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DRAFT
SECTION XII
ACKNOWLEDGEMENTS
The preparation of this report was accomplished through the
efforts of the staff of General Technologies Corporation,
a subsidiary of Versar, Inc., Springfield, Va., under the
direction of Dr. R.G. Shaver.
Mr. Elwood E. Martin, Project Officer, Effluent Guidelines
Division, through his assistance, leadership, and advice has
made an invaluable contribution to the preparation of this
report. Mr. Martin provided a careful review of the draft
report and suggested organizational, technical and editorial
changes. He was also most helpful in making arrangements for
the drafting, presenting, and distribution of the completed
report.
Mr. Allen Cywin, Director, Effluent Guidelines Division and
Mr. Walter Hunt, Branch Chief, Effluent Guidelines Division,
offered many helpful suggestions during the program.
Acknowledgement and appreciation is also given to the secre-
tarial staffs of both the Effluent Guidelines Division and
General Technologies Corporation for their efforts in the
typing of drafts, necessary revisions, and final preparation
of the effluent guideline document.
Appreciation is also extended to th following trade associa-
tions and corporations for assistance and cooperation rendered
to us in this program:
Chlorine Institute
Manufacturing Chemists Association
Salt Institute
Water Pollution Control Federation
Airco Corporation
Alcoa
Allied Chemical Corporation
American Cyanamid Corporation
Aqua-Chem
BASF Wyandotte
Bird Machine Company
Cabot Corporation
Calgon Corporation
Chemical Separations Corporation
XII — 1
DRAFT
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DRAFT
Diamond Shamrock
Dorr Oliver
Dow Chemical
E.I. DuPont de Nemours & Company
Duval Corporation -
Eimco
Envirogenics Company
Essex Chemical
Ethyl Corporation
FMC
Freeport Sulfur
Goslin Birmingham, Inc.
Gulf Environmental Systems Company
Harshaw Chemical
Hooker Chemical
International Mineral & Chemical Corp.
International Salt
Kaiser Chemical
Leslie Salt
Midwest Carbide
Monsanto
Morton Salt Company
4SA Research, Inc.
National Lead Industries
New Jersey Zinc
Occidental Petroleum
Office of Saline Water, U.S. Department of Interior
Olin Corporation
Pearsall Chemical
Potash Institute of America
PPG Corporation
Resources Coffservation Company
Rice Engineering and Operating, Inc.
PMI Corporation
Rohm and Haas Corporation
Sherwin Williams
Stauffer Chemical
Union Carbide
U.S. Borax Corporation
U.S. 3ureau of Mines, Reno Research Center
U.S. Lime, Division Flintkote Company
Van de Mark Chemical
Vicksburg Chemical
Water Services Corporation
Weliman Power Gas, Inc.
XII — 2
DRAFT
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DRAFT
Also, our appreciation is extended 1o the individuals of the
Staff of General Technologies Corporation for their assistance
during this program. Specifically, our thanks to:
Mr. E.F. Abrams, Chief Engineer
Dr. R.L. Durfee, Senior Chemical Engineer
Mr. L.C. McCandless, Senior Chemical Engineer
Dr. C.L. Parker, Senior Chemical Engineer
Mr. R.C. Smith, Jr., Senior Chemical Engineer
Mr. E.F. Rissmann, Environmental Scientist
Mr. J.R. Vaill, Senior Statistical Analyst
Dr. F.C. Whitmore, Senior Analytical Chemist
Mr. A.J. Whitman, Analytical Chemist
Mr. H.M. Armstrong, Field Engineer
Mr. F.A. Bialas, Field Engineer
Mr. M.C. Calhoun, Field Engineer
Mr. S.A. Hicks, Field Engineer
We wish to extend our thanks to personnel in the EPA Regional
Offices of regions II, III, IV, V , and vi for many helpful sug-
gestions and advice offered to us on this program.
XII - 3
DRAFT
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SECTION XIII
REFERENCES
[ References 1-11 and 13 were used to characterize the industry
and develop its profile and statistics in Sections III and IV]
1. Popper, H., “Modern Cost Engineering Techniques”, McGraw-Hill
Book Co., 1970.
2. Shreve, R. N., “Chemical Process Industries,” 3rd Ed., McGraw-
Hill Book Co., 1967.
3. Perry, J. N., “Chemical Engineer’s Handbook” 4th Edition,
McGraw-Hill Book Co., 1962.
4. Kirk, R. E. and Othmer, D. F., “Encyclopedia of Chemical Tech-
nology,” 2nd Ed., Wiley-Interscience, 1963.
5. Faith, W. L., Keyes, 0. B., and Clark, R. L., “Industrial
Chemicals”, 3rd Ed., John Wiley & Sons, Inc. (1965).
6. Keyes, D. B. and Deem, L. G., “Chemical Engineer’s Manual,”
Prof. Ed., John Wiley & Sons, Inc. (1942).
7. Davidson, R. L., “Successful Process Plant Practices,” McGraw-
Hill Book Co. (1958).
8. U. S. Brueau of Mines, “Producers of Salt in the United States-
1965”.
9. Hicks, T. G. “Standard Handbook of Engineering Calculations,”
McGraw-HilT Book Co. (1972).
10. Chemical and Engineering News, June 4, 1973, pp. 12-13.
11. “Study of the Economic Impact of the Cost of Alternative Federal
Water Quality Standards on Ten Inorganic Chemicals,” Borz-Allen
Public Administration Services, Inc., Washington, D. C. (1973).
12. ‘Methods of Chemical Analysis for Water and Wastes,” FWPCA, p. 72
(1971).
13. Cheniical Marketing Reporter, June 4, 1973.
14. Fairall, J. M., Marshall, L. S., Rhines, C. E., “Guide for Con-
ducting an Industrial Waste Survey,” Draft only, U. S. Enviror.-
mental Protection Agency, Cincinnati, Ohio (1972).
E3 kk ’FT 1
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DRAFT
15. Sawyer, Clair N.,”Chemistry for Sanitary Engineers,” McGraw—
Hill Book Co., New York, N. V. (1960).
16. “Public Health Service Drinking Water Standards,” Revised 1963,
U. S. Department of Health, Education and Welfare, U. S. Public
Health Service Publication No. 956, U. S. Government Printing
Office, (‘Jashington, D. C. (1962).
17. “Chemical and Engineering News”, May 7, 1973, pp. 8-9.
18. “The Economics of Clean Water,” Vol. III, Inorganic Chemicals
Industry Profile, U.S. Dept. of the Interior, Federal Water
Pollution Control Admin. (March 1970).
19. Final Technical Report, Contract No. 68-01-0020, Industrial
Waste Study of Inorganic Chemicals, Alkalies and Chlorine,
General Technologies Corp., July 23, 1971 (EPA).
20. Chemical and Engineering News, February 19, 1973, pp. 8-9.
21. Besseljevre, Edward B., “The Treatment of Industrial Wastes”,
McGraw-Hill Book Co., p. 56 (1968).
22. Personal Communications, EIMCO Division, Enviro—Tech Corp.,
Salt Lake City, Utah.
23. Personal Communications, Dorr-Oliver Co., Sta iford, Conn.
24. “The Economics of Clean Water”, Vol. III, Inorganic Chemicals
Industry Profile, Contract No. 14-12-592, U. S. Department of
the Interior, Federal Water Pollution Control Administration
(March, 1970).
25. “Sludge Dewa ering: The Hardest Phase of Waste Treatment,”
Environmental Science and Technology, Vol. 5, No. 8, August
1971, pp. 670-671.
26. Jacobs, H. L., “In Waste Treatment - — Know Your Chemicals, Save
Money,” Chemical Engineering, May 30, 1960, pp. 87—91.
27. Sonnichsew, J. C., Jr., Engstrom, S. L., Kolesar, IL C. and
Bailey, G. C., “Cooliiig Ponds - A Survey of the State of the
Art,” Hanford Engineering Development Laboratory, Report HEDL—
TME—72-101 (Sept. 1972).
28. Unpublished Information,E.I. DuPont Letter (May 3, 1973).
29. Unpublished Information, E. I. DuPont Letter (May 16, 1973).
X 2
1 AFT
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DRAFT
30. Kumar, J., “Selecting and Installing Synthetic Pond-Linings”,
Chemical Engineering, Feb. 5, 1973, Pp. 67-68.
31. Rapier, P.M., “Ultimate Disposal of Brines from Municipal Waste-
water Renovation”, Water-1970, Chemical Engineering Progress Sym-
posium Series 107, Vol. 67, p. 340-351.
32. Browning, Jon E., “Activated Carbon Bids for Wastewater Treatment
Jobs”, Chemical Engineering, Sept. 7, 1970, pp. 32—34.
33. “New Treatment Cuts Water Bill”, Chem. Week, June 10, 1970, p. 40.
34. Ahigren, Richard M., “Membrane vs. Resinous Ion-Exchange Demiperal-
ization”, Industrial Water Engineering, Jan. 1971, pp. 12-15.
35. Crits, George J., “Economic Factors in Water Treatment,” Industrial
Water Engineering, Oct. 1971, pp. 22-29.
36. “Applications of Ion Exchange”, 111, Rohm & Haas Bulletin No. 94,
July 16-18, 1969.
37. Higgins, I. R. and Chopra, R. C., “Chem-Seps Continuous Ion—Exchange
Contactor and its Application to De-mineralization Processes,” Pre-
sentation, Conf. of Ion Exchange in the Process md., Imperial Coil.
of Sci. & Tech., London, July 16—18, 1969.
38. Kunin, Robert and Downing, Donald G., “New Ion Exchange Systems for
Treating Municipal and Domestic Waste Effluents”, Water-1970, Chem.
Eng. Prog. Sym. Series 107, Vol. 67, pp. 575—580 (1971).
39. Downing, D. G., Kunin R., and Polliot, F. X., “Desal Process -
Economic Ion Exchange System for Treating Brackish and Acid Mine
Drainage Waters and Sewage Waste Effluents”, Water-1968, Chem. Eng.
Prog. Sym. Series 90, Vol. 64 (1968).
40. Parlante, R., “Comparing Water Treatment Costs”, Plant Engineering
(May 15, 1969).
41. Bingham, E. C. and Chopra, R. C., “A Closed Cycle Water System for
rnmonium Nitrate Producers”, presented, Tnt. Water Conf., The Eng.
Soc. of Western Penn., 32nd Annual Meeting, Pittsburgh, Pa. (Nov.
4, 1971).
42. Holzmacher, Robert G., “Nitrate Removal from a Ground Water Supply”,
Water and Sewage Workd (reprint).
43. “Ion Exch- ngers Sweeten Acid Water”, Envir. Sci. & Tech., Vol. 5,
No. 1, pp. 24—25 (Jan. 1971).
XIII — 3
DRAFT
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DRAFT
44. Sawyer, George A., “New Trends in Wastewater Treatment and Recycle,”
Chemical Engineering, pp. 120-128 (July 24, 1972).
45. Dryden, Franklin 0., “Demineralization of Reclaimed Water”, md.
Water Eng., pp. 24-26 (Aug./Sept., 1971).
46. Seels, Frank H., “Industrial Water Pretreatment”, Chem. Eng.,
Deskbook Issue (Feb. 26, 1973).
47. Calmon, Calvin, “Modern Ion Exchange Technology”, md. Water Eng.,
pp. 12-15 (April/May 1972).
48. “Deniineralizing, Dealkalization, Softening,” Chemical Separations
Corporation Bulletin.
49. “Reverse Osmosis Principles and Applications,” text by Roga Systems
Division Staff, Gulf Environmental Systems Company, P.O. Box 608,
San Diego, Calif. 92112.
50. Kremen, S.S., “The Capabilities of Reverse Osmosis for Volume Pro-
duction of High-Purity Water and Reclamation of Industrial Wastes”
for Thirty-Second Annual Meeting of the American Power Conference,
Chicago, Ill (April 21-23, 1970).
51. Cruver, J. E. and Nusbaum, I., “Application of Reverse Osmosis to
Wastewater Treatment”, presented at Water Pollution Control Federa-
tion Meeting, Atlanta, Georgia (October 8-13, 1972).
52. Kaup, Edgar C.,, “Design Factors in Reverse Osmosis”, Chemical Engi-
neering, Vol. 80, No. 8, Pp. 46-55 (April 2, 1973).
53. Myers, J.H., “Reverse Osmosis Can Cut Cost of Water Treatment,”
Industrial Water Engineering, pp. 25-30 (March 1970).
54. Rowland, H., Nusbaurn, I. and Jester, F.J., “Consider RU for Producing
Feedwater”, Power, pp. 47-48 (December 1971).
55. Witmer, F. E., “Low Pressure RU Systems - Their Potential in Water
Reuse Applications,” paper presentation at Joint EPA-AICHE Water
Reuse Meeting, Washington, D. C. (April 23—27, 1973).
56. Channabasappa, K. C. and Harris, F. L., “Economics of Large-Scale
Reverse Osmosis Plants”, md. Water Eng., pp. 40—44 (October 1970).
57. Resources Conservation Co., unpublished data and engineering design
and cost information.
XI II - ‘1.
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58. Herrigel, H., Fosberg, 1., Stickney, W. and Perry, C., Final
Report, “Operating Data of a Vertical Plane Surface, Falling
Film Evaporator Using Slurry and High Concentration Feeds”,
OSW Contract No. 14-30-2939.
59. “El Paso Natural Participates in Promising Process for Water Re-
covery”, The Pipeliner (Dec. 1971).
60. Casten, James, Goslin-Birmingham Corp., unpublished data and en-
gineering design and cost information.
61. Prescott, J.H., “New Evaporation-Step Entry”, Chemical Engineering,
pp. 30—32 (Dec. 27, 1971).
62. “Industrial Wastewater Reclamation with a 400,000 Gallon-Per-Day
Vertical Tube Evaporator, Design, Construction, and Initial
Operation,” EPA Program No. 12020 GUT.
63. “Evaporator Tackles Wastewater Treatment”, Chemical Engineering,
p. 68 (March 20, 1972).
64. Cosgrove, J., “Desalting: Future Looks Bright”, Water and Wastes
Engineering, Vol. 9, No. 8, p. 43.
65. Houle, J. F. and Challis, J. A., “Industrial Use of Desalting in
Southern Puerto Rico”, Water-1970 , Chem. Eng. Prog. Sym. Series
107, Vol. 67 (1971).
66. Patterson, J. and Minear, Roger A., “Wastewater Treatment Technology”,
2nd Edition, Report to Inst. of Envir. Cont., State of Illinois, pp.
321-343 (Jan. 1973).
67. “The Economics of Clean Water”, Vol. III Inorganic Chemicals In-
dustry Profile, Contract No. 14-12-592, U.S. Dept. of the Interior,
Fed. Water Poll. Cont. Admin., pp. 445-447 (March 1970).
68. Okey, Robert W., Envirogenics Company, Letter (May 14, 1973).
69. Gavelin, Gunnar, “Is Evaporation the Ultimate Solution to Effluent
Problems?” paper Trade Journal, pp. 102-103 (June 10, 1968).
70. Ahlgren, Richard M., “A New Look at Distillation,” md. Water Eng.,
pp. 24-27 (October 1968).
71. Young, K. G., “Summary of Design and Economic Considerations for
Complete Drying and Disposal of the Inorganic Salt Slurry Produced
by the RCC M225B Brine Concentrator”, Resources Conservation Company,
Unpuilished Analysis. (Using Ref. 72).
XIII — 5
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72. W. L. Badger Associates, “Conversion of Desalination Plant Brines
to Solids”, OSW Contract Report #636 (October 1970).
73. Witt, Phillip A., Jr., “Disposal of Solid Wastes”, Chemical Engineer-
ing, pp. 67—77 (Oct. 4, 1971).
74. Unpublished Data, E. I. DuPont Co.
75. Goodheart, L. B., Rice Engineering & Operating, Inc., General Cost
Letter (May 4, 1973).
76. “Well-Disposal Is No Panacea”, Chem. Eng., pp. 26—28 (May 1972).
77. Wright, J. L., “Disposal Wells are a Worthwhile Risk”, Mining
Engineering, pp. &3-72 (Aug. 1970).
78. Ramey, B. J., “Deep-Down Waste Disposal,” Mech. Eng., pp. 28—31
(Aug. 1968).
79. “Injection Wells Pose a Potential Threat”, Envir. Sci. & Tech.,
Vol. 6, No. 2, pp. 120-122 (Feb. 1972).
80. “The Economics of Clean Water”, Vol. III, Inorganic Chemicals In-
dustry Profile, Contract No. 14—12—592, Fed. Water Poll. Contr.
Admin., U. S. Department of Interior (March 1970).
81. Fader, Samuel W., “Barging Industrial Liquid Wastes to Sea”, J.
Water Poll. Contr. Fed., Vol. 44, No. 2, pp. 314-318 (Feb. 1972).
82. “At Sea About Chemical Wastes”, Chem. Week, pp. 133-136 (Oct. 14,
1967).
83. “Tide May be Going Out for Waste Disposal at Sea”, Cheni. Week, pp.
49-53 (Oct. 28, 1970).
84. Unpublished Data, E. I. DuPont Co. Letter and verbal communications
(May 16, 1973).
XIII — 6
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SECTION XIV
GLOSSARY
Ac i di ty
The total titratable hydrogen ion content of the solution is de-
fined as the acidity. Acidity is expressed in ppm of free hydro-
gen ion.
Adsorption
Condensation of the atoms, ions or molecules of a gas, liquid or
dissolved substance on the surface of a solid called the adsorbent.
The best known examples are gas/solid and liquid/solid systems.
Air Pollution
The presence in the atmosphere of one or more air contaminants in
quantities injurious to human, plant, animal life, or property, or
which unreasonably interferes with the comfortable enjoyment thereof.
Alkalinity
Total titratable hydroxyl ion concentration of a solution. In water
analysis, alkalinity is expressed in ppm (parts per million) of cal-
cium carbonate.
Ash
The solid residue left after incineration in the presence of oxygen.
Bag Filter
A dry collection device for recovery of particulate matter from gas
streams.
Barometric Condenser
Device, operating at barometric pressure, used to change vapor into
liquid by cooling.
XIV - 1
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Biochemical Oxygen Demand, BOD5
The BOD test is an empirical bioassay-type procedure which measures
the dissolved oxygen consumed by microbial life while assimilating
and oxidizing the organic matter present. Standard test conditions
include dark incubation at 20°C for a specified time period (usually
5 days).
Blowdown
A discharge from a system, designed to prevent a buildup of some
materials, as in a boiler to control dissolved solids.
Brine
An aqueous salt solution.
Calci nati on
The roasting or burning of any substance to bring about physical or
chemical changes; e.g., the conversion of limestone to quicklime.
Carbonation
Treatment with carbon dioxide gas.
Catalytic Converter
A unit containing a packed or fluidized bed of catalyst.
Caustic
Capable of destroying or eating away by chemical action. Applied to
strong bases and characterized by the presence of hydroxyl ions in
solution.
Centrifuge
A device having a rotating container in which centrifugal force
separates substances of differing densities.
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Chemical Oxygen Demand, COD
Its determination provides a measure of the quantity of oxygen re-
quired to oxidize the organic matter (or other oxidizable matter)
in a waste sample, under specific conditions of oxidizing agents,
temperature and time. The general method is applied to waste samples
having an organic carbon concentration greater than 15 mg/i.
Coke
The carbonaceous residue of the destructive distillation (carboni-
zation) of coal or petroleum.
Conditioning
A physical and/or chemical treatment given to water used in the plant
or discharged.
Conductivity, Electrical
The ability of a material to conduct a quantity of electricity trans-
ferred across a unit area, per unit potential gradient per unit time.
In practical terms, it is used for approximating the salinity or total
dissolved solids content of water.
Cooling Water
Water which is used to absorb waste heat generated in the process.
Cooling water can be either contact or non-contact.
Copperas
Ferrous sulfate.
cyclone Separator
A mechanical device which removes suspended solids from gas streams.
Demineral ization
The removal from water of mineral contaminants usually present in
ionized form. The methods used include ion—exchange techniques, flash
distillation or electrodialysis.
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Electrostatic Precipitator
A gas cleaning device using the principle of placing an electrical
charge on a solid particle which is then attracted to an oppositely-
charged collector plate.
Filtrate
Liquid after passing through a filter.
Filtration
Removal of solid particles from liquid or particles from air or gas
stream through a permeable membrane.
Flocculation
The combination or aggregation of suspended solid particles in such a
way that they form small clumps. The term is used as a synonym for
coagulation.
Fluidizeci Bed Reactor
A reactor in which finely divided solids are caused to behave like
fluids due to their suspension in a moving gas or liquid stream.
Gas Washer (or Wet Scrubber )
Apparatus used to remove entrained solids and other substances from a
gas stream.
Hardness (Total )
The characteristic of water generally accepted to represent the total
concentration of calcium and magnesium ions, usually expressed as ppm
of calcium carbonate.
Heavy Metal
One of the metal elements not belonging to the alkali or alkaline earth
group. In this study, the classification includes titanium, vanadium,
iron, nickel, copper, mercury, lead, cadmium, and chromium.
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Ion Exchange
A reversible chemical reaction between a solid and a
of which ions may be interchanged from one substance
The customary procedure is to pass the fluid through
solid, which is granular and porous and has a limited
exchange. The process is essentially a batch type in
ion exchanger, upon nearing depletion, is regenerated
salts or acid.
Kiln (Rotary )
fluid by means
to another.
a bed of the
capacity for
which the
by inexpensive
A large cylindrical mechanized type of furnace used for calcination.
Membrane
A thin sheet of synthetic polymer, through the apertures of which
small molecules can pass, while larger ones are retained.
Mother Liquor
The solution from which crystals are formed.
Multi-Effect Evaporator
In chemical processing installations, requiring a series of evaporations
and condensations, the individual units are set up in series and the
latent heat of vaporization from one unit is used to supply energy for
the next. Such units are called “effects” in engineering parlance as,
e.g., a triple-effect evaporator.
Oleum or Fuming Sulfuric Acid
A solution of sulfur trioxide in sulfuric acid.
Is a measure of the relative acidity or alkalinity of water. A pH value
of 7.0 indicates a neutral condition; less than 7 indicates a predomi-
nance of acids, and greater than 7, a predominance of alkalis. There is
a 10—fold increase (or decrease) from one pH unit level to the next, e.g.,
10-fold increase in alkalinity from pH 8 to pH 9.
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Plant Effluent or Discharge after Treatment
The waste water discharged from the industrial plant. In this defi-
nition, any waste treatment device (pond, trickling filter, etc.) is
considered part of the industrial plant.
Pretreatment
The necessary processing given materials before they can be properly
utilized in a process or treatment facility.
Process Effluent or Discharge
The volume of waste water emerging from a particular use in the plant.
Process Water
Water which is used in the internal plant streams from which products
are ultimately recovered, or water which contacts either the raw
materials or product at any time.
Reverse Osmosis
A method involving application of pressure to the surface of a saline
solution forcing water from the solution to pass from the solution
through a membrane which is too dense to permit passage of salt ions.
Hollow nylon fibers or cellulose acetate sheets are used as membranes
since their large surface areas offer more efficient separation.
Sedimentati on
The falling or settling of solid particles in a liquid, as a sediment.
Settling Pond
A large shallow body of water into which iidustrial waste waters are
discharged. Suspended solids settle from the waste waters due to the
large retention time of water in the pond.
Sinteri ng
The agglomeration of powders at temperatures below their melting
points. Sintering increases strength and density of the powders.
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Slaking
The process of reacting lime with water to yield a hydrated product.
Sludge
The settled mud from a thickener clarifier. Generally, almost any
flocculated, settled mass.
Slurry
A watery suspension of solid materials.
Sni ff Gas
The exhaust or tail gas effluent from the chlorine liquefaction and
compression portion of a chior-alkali facility.
Solute
A dissolved substance.
Solvent
A liquid used to dissolve materials.
Thickener
A device or system wherein the solid contents of slurries or sus-
pensions are increased by evaporation of part of the liquid phase,
or by gravity settling and mechanical separation of the phases.
Total Dissolved Solids (TDS )
The total amount of dissolved solid materials present in an aqueous
solution.
Total Organic Carbon, TOC
A measurement of the total organic carbon content of surface waters,
domestic and industrial wastes, and saline waters.
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Total Suspended Solids (TSS )
Solid particulate matter found in waste water streams which, in
most cases, can be minimized by filtration or settling ponds.
Turbidity
A measure of the opacity or transparency of a sediment-containing
waste stream. Usually expressed in Jackson units or Forniazin units
which are essentially equivalent in the range below 100 units.
Wet Scrubbing
A gas cleaning system using water or some suitable liquid to entrap
particulate matter, fumes, and absorbable gases.
Waste Discharged
The amount (usually expressed as weight) of some residual substance
which is suspended or dissolved in the plant effluent.
Waste Generated (Raw Waste )
The amount (usually expressed as weight) of some residual substance
generated by a plant process or the plant as a whole. This quantity
is measured before treatment.
Water Recirculation or Recycling
The volume of water already used for some purpose in the plant which is
returned with or without treatment to be used again in the same or
another process.
Water Use
The total volume of water applied to various uses in the plant. It is
the sum of water recirculation and water withdrawal.
Water Withdrawal or Intake
The volume of fresh water removed from a surface or underground water
source by plant facilities or obtained from some source external to
the plant.
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