EPA-670/2-74-030
March 1974
Environmental Protection Technology Series
WATERBORNE WASTES
OF THE PAINT AND INORGANIC PIGMENTS
INDUSTRIES
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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EPA-670/2-74-030
March 1974
WATERBORNE WASTES OF THE
PAINT AND INORGANIC PIGMENTS INDUSTRIES
By
William J. Barrett
George A. Morneau
John J. Roden, III
Southern Research Institute
Birmingham, Alabama 35205
Project R-800602
Program Element 1BB036
Project Officer
Dr. Herbert S. Skovronek
Industrial Waste Treatment Research Laboratory
Edison, New Jersey 08817
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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REVIEW NOTICE
The National Environmental Research Center—
Cincinnati has reviewed this report and approved its
publication. Approval does not signify that the
contents necessarily reflect the views and policies
of the U. S. Environmental Protection Agency, nor
does mention of trade names or commercial products
constitute endorsement or recommendation for use.
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FOREWORD
Man and his environment must be protected from the
adverse effects of pesticides, radiation, noise and other
forms of pollution, and the unwise management of solid
waste. Efforts to protect the environment require a
focus that recognizes the interplay between the components
of our physical environment—air, water, and land. The
National Environmental Research Centers provide this
multidisciplinary focus through programs engaged in
studies on the effects of environmental
° contaminants on man and the biosphere, and
a search for ways to prevent contamination
0 and to recycle valuable resources.
The studies for this report were undertaken to develop
the background needed to characterize pollution sources
within the subject industries, establish current levels
and methods of pollution control and identify specific
areas where the Agency's participation in the development
of new technology could have maximum effect on the
industry's efforts to protect our Nation's water resources.
A. W. Breidenbach, Ph.D.
Director
National Environmental
Research Center, Cincinnati
111
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ABSTRACT
This report describes a study of the wastewater management
practices in the paint and inorganic pigments industries.
Information was obtained from 153 plants manufacturing paints,
10 titanium dioxide plants, and 10 plants that produce other
inorganic pigments. The data were analyzed to identify the
sources and characteristics of wastewater from the manufactur-
ing processes of these plants, to determine the practices for
wastewater control and treatment that are presently employed,
and to identify deficiencies in technology that require
research and development to improve control and treatment
methods.
The major findings of the study indicate that although the
paint industry uses approximately 300 million liters (30 mil-
lion gal.) of water per day, only a small portion of this,
less than 5%, is necessarily contaminated by virtue of its
use. Suspended solids, consisting of pigments and resin
particles, are the major wastewater contaminants of the paint
industry. The wastewaters from plants that produce titanium
dioxide or other inorganic pigments generally contain a high
level of dissolved solids and acids for which no entirely
satisfactory control and treatment methods exist.1
The report includes conclusions and recommendations that may
be useful to the industries in meeting anticipated Environ-
mental Protection Agency regulations. In addition, the data
reported should be of value to the Environmental Protection
Agency in establishing effluent guidelines for the paint
industry.
This report was prepared by Southern Research Institute in
fulfillment of Project No. R-800602 under the sponsorship of
the Office of Research and Development, Environmental Protec-
tion Agency. The work was completed in July 1973.
IV
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TABLE OF CONTENTS
Page
ABSTRACT iv
LIST OF FIGURES vi
LIST OF TABLES vii
ACKNOWLEDGMENTS ix
SECTIONS
I. CONCLUSIONS 1
II. RECOMMENDATIONS 3
III. INTRODUCTION 5
IV. THE PAINT INDUSTRY 6
V. THE TITANIUM DIOXIDE INDUSTRY 30
VI. THE INORGANIC PIGMENTS INDUSTRY 43
VII. METHODOLOGY 50
VIII. REFERENCES 53
IX. APPENDIX 57
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FIGURES
No. Page
1. U. S. shipments of paint and allied products by 7
state, 1967
2. Historical and projected growth of coating pro- 9
ducts, 1955 to 1980
3. Flow diagram of paint manufacturing process 11
4. Sulfate process for producing titanium dioxide 32
5. Chloride process for producing titanium dioxide 34
6. Water data for typical titanium dioxide plant 35
7. Water data for typical inorganic pigment plant 46
VI
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TABLES
No. Page
1. DISTRIBUTION OF PAINT PLANTS (SIC 2851) BY SIZE 6
2. PAINT SHIPMENTS IN THE UNITED STATES, 1971 8
3. PRINCIPAL RAW MATERIALS USED IN THE MANUFACTURE 12
OF PAINTS, 1970
4. WATER USAGE BY SOURCE 13
5. WATER USES IN PAINT PLANTS BY PLANT SIZE 15
6. DISPOSITION OF WASTEWATER IN PAINT PLANTS 16
7. PAINT PLANTS REPORTING DISCHARGE OF CONTAMINATED 17
WASTEWATER
8. WASTEWATER GENERATED BY PROCESS EQUIPMENT IN THE 17
MANUFACTURE OF WATER-BASED PAINTS
9. AVERAGE VOLUME OF CLEANUP WATER DISCHARGED FOR 18
PLANTS OF VARIOUS SIZES
10. SUMMARY OF DISPOSITION OF WASTE MATERIALS FROM 19
FLOOR DRAINS, SPILLS, AND OFF-SPECIFICATION
BATCHES
11. MAJOR CONTAMINANTS IN WASTEWATER DISCHARGES 20
12. DAILY RAW WASTE LOADING FOR PAINT PLANTS 22
13. EXTENT OF CONTROL AND TREATMENT PRACTICED IN 23
PAINT PLANTS
14. WASTEWATER TREATMENT AND DISPOSAL METHODS 25
EMPLOYED IN THE PAINT INDUSTRY
15. SUMMARY OF PLANNED OR RECENTLY INITIATED WASTE- 26
WATER CONTROL AND TREATMENT PRACTICES
16. DOMESTIC PRODUCTION CAPACITY, TITANIUM DIOXIDE 31
17. PROCESS WASTEWATER INFORMATION FOR PLANTS PRO- 37
DUCING TITANIUM DIOXIDE BY THE SULFATE PROCESS 38
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TABLES (Concluded)
No. Page
18. PROCESS WASTEWATER INFORMATION FOR PLANTS PRODUC- 39
ING TITANIUM DIOXIDE BY THE CHLORIDE PROCESS
19. WASTE DISCHARGE DATA FOR TITANIUM DIOXIDE PLANTS 40
20. SUMMARY OF WASTE TREATMENT AND DISPOSAL COSTS 42
FOR THE TITANIUM DIOXIDE INDUSTRY
21. COMMON INORGANIC COLOR PIGMENTS 44
22. PROCESS WASTE LOADING FOR INORGANIC PIGMENT 47
PLANTS
23. SUMMARY OF WASTE TREATMENT AND DISPOSAL COSTS 48
FOR FIVE INORGANIC PIGMENT PLANTS
24. COVERAGE OF THE PAINT INDUSTRY BY SOUTHERN 51
RESEARCH INSTITUTE DATA BASE
viii
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ACKNOWLEDGMENTS
This project was conducted under the general supervision of
Dr. William J. Barrett, Project Director. George A. Morneau
served as Project Manager and was assisted by John J- Roden,
Associate Chemist, Robert E. Lacey, Senior Chemical Engineer,
Don Hooks, Assistant Chemist, and Gretchen Engquist, Statis-
tical Research Technician. All are members of the staff of
Southern Research Institute
Dr. Herbert S. Skovronek, Office of Research and Development,
Environmental Protection Agency, was the Project Officer.
His guidance and direction were especially helpful in plan-
ning and executing this program.
Appreciation is expressed to the members and staff of the
National Paint and Coatings Association (NPCA), especially to
Mr. Raymond J. Connor, Assistant Technical Director of NPCA,
and to Mr. Leslie E. Thompson of DeSoto, Inc., Chairman of
the Water Quality Task Force of the NPCA, and other industry
personnel who provided information for this study.
IX
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SECTION I
CONCLUSIONS
PAINT MANUFACTURING INDUSTRY
1. The major source of contaminated wastewater in the paint
manufacturing industry is water used in the cleaning of equip-
ment. This source represents a relatively small volume of
the total water discharged by the industry, probably less
than 2%. At typical plants that have fewer than 50 employ-
ees—about 80% of the industry's plants—the cleanup water
discharged amounts to less than 1,000 liters (250 gal.) per
day. At larger plants, the volume of cleanup water may
amount to as much as 40,000 liters (10,000 gal.) per day.
2. Other sources of contaminated wastewater at some of the
larger plants are air pollution control equipment and resin
manufacturing operations that use process water.
3. The largest use of water is for cooling purposes. This
use is exclusively non-contact; thus, the water is not contam-
inated with process wastes when discharged unless process and
cooling discharge streams are combined.
4. The major contaminant generated by the industry is sus-
pended solids, which can be reduced considerably by the effi-
cient application of conventional treatment methods practiced
in the industry.
5. Heavy metals, present in at least trace quantities in pig-
ments, drying agents, and fungicides, occur in the industry's
wastewater, but the effectiveness of treatment methods pres-
ently employed by the industry to control them could not be
determined from data obtained in this study.
6. The major portion of the industry consists of many small
plants with limited treatment capabilities. About 50% of the
plants with fewer than 50 employees discharge all of their
wastes to municipal sewers. Most other small plants are able
to dispose of their contaminated wastewaters by landfill,
evaporation, or other methods. About 10% of the small plants
have no wastewater discharges.
7. No advanced treatment technology was identified as being
practiced in' the industry, although advanced filtration proce-
dures and carbon adsorption have been reported to be used in
new installations.
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TITANIUM DIOXIDE MANUFACTURING INDUSTRY
1. The principal sources of contaminated water in the tita-
nium dioxide industry are process equipment, air pollution
control equipment, and some contact cooling.
2. Waste loadings at plants employing the sulfate process
are much higher than those at chloride-process plants.
3. The major contaminants are sulfate and chloride salts of
iron and other metals, waste acids, and lost titanium dioxide
fines.
4. Effective treatment to control pH and remove suspended
solids is practiced to some extent in the industry. Because
no effective alternatives or practical treatment methods
exist at present, wastes high in dissolved solids and acids
are disposed of by deep-well injection or barging to the
ocean.
5. Improved technology for reuse of acid wastes has not yet
progressed to the commercial stage.
MANUFACTURE OF OTHER INORGANIC PIGMENTS
1. The major use of water and the major source of contamina-
tion in the manufacture of other inorganic pigments is process
water from synthesis, filtration, washing, and grinding.
2. Contaminants consist of dissolved solids from reactants
or by-products formed in the synthesis of pigments. The dis-
solved solids include heavy metals derived from the raw mate-
rials and products. Wastewaters are generally acidic and
contain some suspended solids as well. The nature of the
suspended solids is such that conventional sedimentation tech-
niques are only partially effective.
3. Present treatment technology practiced in the industry is
limited to control of pH and removal of suspended solids by
conventional techniques.
4. One advanced treatment method, the use of ion-exchange
resins for the removal of chromium salts, was identified.
This method appears promising for controlling a portion of
the dissolved solids and heavy metal ions generated by the
industry.
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SECTION II
RECOMMENDATIONS
The following recommendations relate to problems that have
been identified in the industries and suggest activities that
may be undertaken by the industries—or in their behalf—to
alleviate these problems. The objectives of undertaking such
activities would be to reduce waste discharges from the manu-
facturing plants and to enable the plants to meet anticipated
Environmental Protection Agency effluent regulations in the
most effective manner.
PAINT INDUSTRY
1. Broader use of in-plant control measures in the industry,
including segregation of contaminated wastes from uncontami-
nated effluents, reduction of volume of water used for clean-
ing equipment such as through the use of high-pressure
sprayers, and reuse of cleanup water.
2. Broader dissemination to the industry of information on
applicable treatment practices currently available for removal
of suspended solids, including costs, design features, and
effectiveness levels.
3. Continued research and development on substitutes for
heavy metal compounds in fungicides and driers.
4. Determination of the effectiveness of treatment methods
presently available for the removal of heavy metals.
•
5. Determination of the effects of raw waste from paint
plants, especially heavy metals, on municipal treatment facil-
ities, which receive discharges from a large number of plants.
6. Estimation of cost versus effectiveness of various control
and treatment alternatives as a function of wastewater volume,
including drumming for landfill, evaporation, incineration,
pretreatment and direct discharge to municipal treatment
systems, and complete self-treatment for discharge to surface
waters.
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TITANIUM DIOXIDE INDUSTRY
1. A thorough evaluation of potential pollution reduction
benefits achievable through the upgrading of ilmenite ore for
use in the chloride process (since the chloride process is
inherently capable of generating lower waste loadings than
the sulfate process) and other methods of raw ore enrichment
that may be suitable for use in conjunction with the sulfate
process.
2. Identification of transferable technology used in other
industries that also generate large volumes of acidic wastes.
INORGANIC PIGMENTS INDUSTRY
1. Broader application of ion exchange technology for
recovery of chromium and investigation of its feasibility for
other heavy metals, particularly when it will allow reuse of
process water.
2. Development of more effective methods for removal of the
unique forms of suspended solids common to this industry.
3. Development of additional information concerning specific
major pigments and their individual manufacturing processes
and wastewater management problems.
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SECTION III
INTRODUCTION
This report describes a study of wastewater management prac-
tices of the paint manufacturing and inorganic pigments manu-
facturing industries. The purposes of the study were to
identify the sources and characteristics of wastewater in
these industries, to determine the wastewater control and
treatment practices that are presently employed, and to iden-
tify needed improvements in control and treatment technology
that would permit these industries to achieve the "best avail-
able" control as required by the Water Pollution Control Act
of 1972, including, if possible, zero discharge of pollutants.
Although the paint and pigments industries are closely allied
in terms of market dependence, the structure of the industries
and the manufacturing processes are quite different. In addi-
tion, within the inorganic pigments industry the processes
employed in the manufacture of titanium dioxide, the most
commonly used white pigment, are different from the processes
used to manufacture other inorganic pigments. Because of
these differences, paint, titanium dioxide, and other inor-
ganic pigments are covered in three separate discussion sec-
tions of this report.
Data for this study were obtained from individual manufactur-
ing plants, applications for permits to discharge under the
Refuse Act Permit Program, detailed in-plant studies con-
ducted by members of the project staff, and interviews and
discussions with industry personnel, trade association com-
mittees, and Environmental Protection Agency representatives.
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SECTION IV
THE PAINT INDUSTRY
The paint Industry (SIC Group 2851) consists of about 1,500
companies with about 1,700 plants. In 1971, total industry
employment was about 63,000 and the total number of produc-
tion workers was about 35,000.33 Because of the relatively
simple technology and low capital investment required, the
industry contains many small companies. The distribution of
plants by size is given in Table 1.
Table 1. DISTRIBUTION OF PAINT PLANTS (SIC 2851) BY SIZEa
Size of plant
(total number
of employees)
Fewer than 10
10 to 19
20 to 49
50 to 99
100 to 249
250 or more
Totals
Number
of
plants
710
311
350
171
113
46
1,701
Total number
of production
workers
1,700
2,500
6,100
6,700
9,200
10,100
36,300
Value of
shipments ,
millions of dollars
104.9
180.3
441.9
512.6
813.4
858.4
2,911.5
Reference 4 (1967 data).
About 42% of the plants have fewer than 10 employees. In
1967, these small companies accounted for less than 5% of the
industry sales, whereas the four largest companies accounted
for about 22% of sales.1*
Although the industry is spread over a wide geographical area,
it is concentrated in heavily industrialized areas. Ten
states accounted for about 80% of the value of shipments in
1967.l2 A map illustrating the geographical distribution of
the industry is given in Figure 1.
The major products of the industry consist of trade-sales
paints, which are primarily off-the-shelf exterior and inte-
rior paints for houses and buildings, and industrial finishes
sold as custom products to manufacturers of such products as
automobiles, aircraft, appliances, furniture, machinery, and
metal containers.
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1
2
3
4
LESS THAN $15 MILLION
$15 TO $99 MILLION
$100 to $199 MILLION
OVER $200 MILLION
Figure 1. U. S. shipments of paint and allied products by state, 1967*
1967 Census.
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In 1971, the value of trade-sales paints amounted to $1,563
million and that of industrial finishes was $1,268 million.12
Between now and 1980 the value of these products is expected
to increase at an average annual rate of 7.5%.33 The histori-
cal and projected growth of these products is illustrated in
Figure 2.
PRODUCTS AND RAW MATERIALS
The major products of the paint industry are paints, var-
nishes, and lacquers, all of which consist of film-forming
binders (resins or drying oils) dissolved in volatile organic
solvents or dispersed in water. In addition, all paints and
most lacquers contain pigments and extenders. The industry
also produces putty, caulking compounds, sealants, paint and
varnish removers, and thinners, which have been excluded from
this study. Some plants produce resins for their internal
consumption. The quantity and value of shipments of trade-
sales paints in 1971 are shown in Table 2. A breakdown of
industrial finishes by type of product is not available.
Table 2. SHIPMENTS OF TRADE-SALES PAINTS, 1971a
Type of product
Water-based paint pro-
ducts
Solvent-based paint
products
Stains, varnishes, and
other coatings
Other trade sales pro-
ducts
Primers and sealers
Enamels
Totals
Volume
Millions of
liters
833
303
132
231
76
57
1631
Millions of
gallons
220
80
35
61
20
15
431
Value ,
millions of
dollars
730
340
145
223
65
60
1563
Reference 12.
8
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co
3.0
2.0
M J
§ O
ft Q
H
33 fe , «
CO O 1.0
fo co
o a
o
W H
D J
d ^
«
0.1
TRADE
SALES
INDUSTRIAL
FINISHES
1955
1960
1965
1970
1975
1980
H
M
CO
0
CO
a
O
700
600
500
400
300
200
TRADE
SALES
INDUSTRIAL
FINISHES
I
1955
1960
1965
1970
1975
1980
Figure 2. Historical and projected growth
of coating products, 1955 to 1980a
Reference 12.
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The principal raw materials consumed by, the industry are oils,
resins, pigments, and solvents. Drying oils, such as linseed
oil, are used as the film-forming binder in some oil-based
paints. Semi-drying oils, such as soybean oil, are used in
the manufacture of alkyd resins, which are the principal
binders in all oil-based paints. Acrylic resins are used in
the manufacture of water-base (latex) paints. Some industrial
water-base paints contain a third type of resin, the water-
soluble alkyd resins. Pigments are used to impart opacity
and color to the coatings. The pigment particles must be
finely divided to provide good dispersibility in the oil or
water medium and to provide opacity. The four basic types of
pigments are prime white pigments, colored inorganic and
organic pigments, filler and extender pigments, and metallic
powders. Not surprisingly, the paint industry is the largest
consumer of titanium dioxide (55% of total production in 1970)
and inorganic pigments (60%).
The paint industry is also a large consumer of solvents,
which are used as the volatile vehicles in all coatings
except water-base paints. The major solvents used are min-
eral spirits, toluene, xylene, naphtha, ketones, esters, alco-
hols, and glycols.
Consumption of the principal raw materials used by the indus-
try is shown in Table 3. In addition, the industry consumes
a wide variety of other additives such as driers, bactericides
and fungicides, defearners, antisettling agents, and thick-
eners.
MANUFACTURING PROCESSES
Paint is manufactured by a batch process in quantities up to
23,000 liters (6,000 gal.) per batch. Most plants manufac-
ture too many different formulations to make continuous pro-
cesses feasible. There are three major steps in the paint
manufacturing process: mixing and grinding of raw materials,
tinting and thinning, and filling operations. The flow dia-
gram in Figure 3 illustrates these steps.
At most plants, the mixing and grinding of raw materials is
accomplished in one production step. The pigments and a por-
tion of the binder and liquid base or wetting agent are mixed
into a paste of a specified consistency. This paste is fed
to a grinder or high-speed mixer which disperses the pigments
(by breaking down particle aggregates, rather than by reducing
the particle size). The pebble or steel-ball mills, or roll-
type mills traditionally used for this purpose are generally
being replaced by more modern equipment.
10
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PIGMENTS;
WETTING
AGENTS
OILS
I
RESINS
TINTS AND
THINNERS;
LATEX AND
OTHER
INGREDIENTS
MIXING
TANK
STONE
OR
ROLLER MILL]
PEBBLE
OR
BALL MILL
HIGH-SPEED
MIXER
THINNING
AND
TINTING
TANK
FILLING,
PACKAGING,
AND
SHIPMENT
Figure 3. Flow diagram of paint manufacturing process
11
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Table 3. PRINCIPAL RAW MATERIALS USED IN THE
MANUFACTURE OF PAINTS, 1970a
Raw material
Pigments
Prime white
Titanium dioxide
Zinc oxide
White lead
Extenders and fillers
Red lead
Carbon black
Oils in paint
Oils in paint resins
Natural resins
Total selected solvents*3
Volume
Thousands of
tons
360.8
27.0
4.0
333.0
8.0
7.1
133.9
76.5
21.0
482.2
Thousands of
metric tons
327.4
24.5
3.6
302.0
7.3
6.4
121.5
69.4
19.0
437.6
Reference 12.
Includes glycol esters, alcohols, ketones, and esters,
but omits mineral spirits (probably the major solvent
used), for which data are not available.
In the next stage of production the paint premix is trans-
ferred to tinting and thinning tanks, occasionally by means
of portable transfer tanks, but more commonly by gravity feed
or pump. Here the remaining binder and liquid are added, as
well as various additives and tinting colors. The paint is
analyzed and the composition is adjusted as necessary to
obtain the correct formulation for the type of paint being
produced. The finished product is then transferred to a fill-
ing operation where it is packaged and labeled.
Some of the larger paint plants manufacture the resins used,
either the usual alkyd types or a water-soluble alkyd resin.
The manufacture of either type involves the reaction of poly-
basic acids and polyhydric alcohols to form a condensation
product, which may be modified by the addition of various
oils or fatty acids. The raw materials are fed into a large
reactor (kettle) equipped with an agitator. The kettle is
then heated to the specified reaction temperature. Most
alkyd resins are manufactured at around 200°C. When the
reaction is complete, the resins are filtered and stored for
use in paint production or for sale.
12
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WATER USAGE AND WASTE CHARACTERIZATION
The methodology used in obtaining the data on water usage and
waste characterization and the significance of the industry
sample from which the data were obtained are discussed in
Section VII. In most instances, the data were adjusted to
reflect differences in coverage of the various size groups in
the industry sample. It is recognized, however, that the
data may not reflect with complete accuracy the input from
plants of different sizes.
On the basis of data sheets on plants representing 26% of the
total industry's paint production and 38% of the total indus-
try's production employees, the water usage for the entire
industry is estimated at 284 to 310 million liters (75 to 82
million gal.) per day. The principal uses and sources of
water are presented in Table 4. For this table, percentages
were calculated from the actual data provided in the data
sheets representing the sample of the industry described
above. As shown in the table, cooling is the largest single
use of water, accounting for about 83% of the total usage.
Table 4. WATER USAGE BY SOURCE
Use
Boiler feed
Cooling
Sanitary
Cleanup
Consumed in product
Air pollution control
Other
Unaccounted for
Totals
Percent of total water used,
by source
Municipal
or public
supply
1.9
30.5
5.2
1.1
1.1
1.2
0.3
1.3
42.7
Surface
water
0.03
21.3
0
0.15
0
0
0
0.15
21.5
Well
water
1.3
28.6
0.3
0.2
0.1
0.8
1.0
0
32.3
Recycle
0.5
2.6
0
0
0.01
0.5
0
0
3.6
Total
3.7
83.0
5.6
1.4
1.2
2.5
1.3
1.4
100.1
The major source of water is municipal or public supply,
which accounts for about 43% of the total intake. Well water
and surface water account for about 21% and 32%, respectively,
Only about 4% of the total water used is recycled; however,
the reported figures are probably somewhat low because some
plants did not include the water used in recirculating cool-
ing systems.
13
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Table 5 shows the distribution of water uses for plants in
various size groups. Small plants appear to use much less
water per production employee than large plants. For example,
plants with fewer than 50 employees have 28.'4% of the total
industry employees and account for 25% of sales, but use only
4.1% of the total water; plants with 250 or more employees
have nearly the same proportion (27.8%) of total industry
employees and 30% of sales, but use nearly 70% of the total
water. The larger plants use a higher portion of their total
water for cooling purposes than do the smaller plants, while
the smaller plants use a higher portion for sanitary purposes
and for formulation of product.
Disposition of wastewater from the various uses in the paint
industry is shown in Table 6. The relative proportions for
each use are about the same as shown in Table 4 for uses by
source, which indicates consistency in the reported data.
Since cooling water normally does not contact the product or
raw material, it should not become contaminated if properly
handled. On the other hand, water used for cleanup and air
pollution control, which accounts for about 4% of the total
discharge, necessarily becomes contaminated in use and its
use can result in the discharge of pollutants. Thus, although
Table 6 shows that about 70% of the total wastewater is dis-
charged untreated, only about 2% (from cleanup and air pollu-
tion control, excluding sanitary use) is likely to be contam-
inated and most of this goes to municipal treatment systems.
A somewhat higher level of recycling is shown in Table 6 than
in Table 4, and, as discussed above, is probably more consis-
tent with actual industry practice. It is also worth noting
that approximately 25% of the industry's wastewater is not
discharged, but is disposed of by evaporation, recycling, or
by some other method.
The number of plants reporting the discharge of contaminated
wastewater is shown in Table 7, which gives the source of con-
tamination for plants of various sizes. Nearly all plants
report cleanup water as a source of contamination while only
larger plants show other sources, such as air pollution con-
trol or process water from resin manufacturing.
Most cleanup waste results from cleaning the equipment used
to manufacture water-based paints. The specific kinds of
equipment and the amounts of water used are shown in Table 8.
The types of equipment most frequently cleaned are filling
machines, tinting and thinning tanks, and mixers.
Other sources of wastewater generated in cleanup operations
include the washing of equipment used in the preparation of
solvent-based paints, resins, and other products. The equip-
ment used to prepare these products is frequently cleaned
14
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Table 5. WATER USES IN PAINT PLANTS BY PLANT SIZE
«
Production employees in
size group, % of total
Total use, % of total
industry usage
Uses, % of total for
size group :
Boiler
Cooling
Sanitary
Cleanup
Consumed in product
Air pollution control
Other
Unspecified
Percent, by size of plant
(number of employees)
Fewer
than 10
4.7
0.3
0
25
58
3
11
0
0.6
2.3
10 to
19
6.9
0.6
0.7
48
16
4
14
2
12
3.3
20 to
49
16.8
3.2
5
74
6
1.2
2
1.6
0.8
9.4
50 to
99
18.5
6.7
2
75
6
1.7
4
1.1
0.5
9.7
100 to
249
25.3
20.4
8.4
72
7.0
1.5
1.2
3.2
5.2
1.6
250 or
more
27.8
68.7
2.5
87
6.2
1.4
0.7
2.4
0.01
••
Use, % of
total for
all size
groups
^
100
3.7
83
5.6
1.5
1.2
2.5
1.3
1.2
-------
Table 6. DISPOSITION OF WASTEWATER IN PAINT PLANTS
Use
Boiler feed
Cooling
Sanitary
Cleanup
Air pollution
control
Other
Unaccounted
for
Total dispo-
sition as
% of total
wastewater
Total use,
ao 9;
do o
of total
wastewater
3.4
79.0
6.5
1.5
2.5
1.4
5.7
100.0
Disposition, percent of use
Discharged
Untreated | Treated
To
sanitary
sewer
34.2
20.5
95.0
47.2
39.1
0.3
0.7
26.9
To
surface
receiving
body
39.4
56.7
0
0.3
3.7
2.3
0
46.1
To
sanitary
sewer
0.8
0.1
0
30.7
19.2
17.0
0
1.3
Other
0
0.4
0
0.3
0
0
0
0.3
Not discharged
Evaporated
8.6
0.3
2.9
12.3
0.6
2.6
1.3
4.2
Recycled
14.2
4.1
0
2.5
14.4
0
3.2
11.8
Other3
2.8
17.9
2.1
6.7
23.1
77.7
0
9.4
Includes landfill, hauling, incineration, septic tanks, etc
-------
Table 7. PAINT PLANTS REPORTING DISCHARGE
OF CONTAMINATED WASTEWATER
Number of
plants
reporting
Source of
contamination :
Cleanup
Air pollution
control
Resin manu-
facturing
Intake water
treatment
backwash
Number of plants, by size
(number of employees)
Fewer
than 10
12
12
-
^
10 to
19
15
15
1
—
M.
20 to
49
11
11
2
—
_
50 to
99
13
8
7
2
1
100 to
249
19
17
9
1
1
250 or
more
18
16
11
5
_
Total
89
80
30
8
2
Table 8. WASTEWATER GENERATED BY PROCESS EQUIPMENT
IN THE MANUFACTURE OF WATER-BASED PAINTS
Type of equipment
Feed tanks
Mixers
Mills
Tinting and thinning tanks
Transfer tanks
Filling machines
Average unit volume of
wastewater per unit
volume of product
0.22
0.09
0.06
0.31
0.16
0.06
Number of
plants
reporting
7
21
13
28
4
35
with solvent. When water is used, it is often as a caustic
solution, which requires further treatment (neutralization)
prior to discharge.
The total volume of cleanup water discharged for plants of
various sizes is shown in Table 9. For small plants—those
with fewer than 50 employees—the volume discharged is rela-
tively small, less than 1000 liters (260 gal.) per day. At
plants with more than 250 employees, the average volume of
cleanup water is about 40,000 liters/day (11,000 gal./day).
17
-------
Table 9. AVERAGE VOLUME OF CLEANUP WATER DISCHARGED
FOR PLANTS OF VARIOUS SIZES
Size of plant
(total number
of employees)
Fewer than 10
10 to 19
20 to 49
50 to 99
100 to 249
250 or more
Number of
plants
reporting
24
30
34
21
22
20
Cleanup water
discharged
Liter/day
292
769
983
4,679
11,957
40,490
Gal. /day
77
200
260
1,200
3,200
11,000
Relatively concentrated wastewaters are generated through
general plant cleanup (housekeeping), spills, and disposal of
off-specification batches, as well as through routine equip-
ment cleanup. It is not possible to estimate accurately the
volumes of wastewater arising from these operations.
Table 10, however, shows how these wastes are handled in
terms of the number of plants reporting the use of a specific
disposal method. About half of the plants reported that
floor drains do not exist or have been sealed or plugged. In
about one-third of the plants that have floor drains the
wastes pass to settling tanks prior to discharge, and in
about two-thirds of these plants the wastes are discharged
directly to sewers without any treatment. Some plants indi-
cated that they have no .disposal problems resulting from
spills or off-specification batches; some of these plants
manufacture no water-based paints. Most other plants dispose
of spills and off-specification batches by hauling the wastes
to an off-site landfill or, in a few instances, to an inciner-
ator. The hauling is usually done by a contractor. Many
plants recover off-specification batches for reuse or sale.
The major contaminants of wastewater reported by 71 plants of
various sizes are listed in Table 11. As would be expected,
these contaminants, except for caustics used in cleaning, are
components of paint. The materials listed most frequently by
plants as major contaminants are pigments and latex. The
presence of one or both of these materials in the wastewater
was reported by about 90% of the 71 plants. Over half of the
plants also reported the presence of such materials as oils,
resins, driers, and dispersing agents. Only four plants
listed solvents as a major contaminant of the wastewater.
Eleven plants reported heavy metals and fungicides. However,
the presence of heavy metals is probably more extensive than
indicated in the table because of varying interpretations of
what constitutes a "major" contaminant, and because most pig-
ments and drying agents are likely to contain heavy metals.
18
-------
Table 10. SUMMARY OF DISPOSITION OF WASTE MATERIALS FROM
FLOOR DRAINS, SPILLS, AND OFF-SPECIFICATION BATCHES
Disposition of wastes
Plants reporting no wastes
from these sources
Direct to municipal sewer
without treatment
Direct to storm sewer without
treatment
Use of settling tanks for
preliminary treatment
Use of treatment methods
other than or in addition
to settling
Direct to septic tanks or
evaporation ponds
Off-site disposal to landfill
or incinerator
Wastes recovered, reused, or
sold
Number of plants reporting the
indicated disposition of wastes
Floor
drains
78
34
10
22
6
4
2
0
Spills
24
10
3
15
2
3
80
9
Off-
specification
batches
24
3
0
2
0
0
81
43
The amount and quality of the waste parameter data reported
were so limited that interpretation was difficult. Although
48 (about 30%) plants reported that routine effluent analyses
were conducted by plant staff or outside laboratories, only
33 (about 20%) reported any data on the results of the analy-
ses. Of these 33 plants, two gave mercury data only; two
gave oil and grease only; and six gave total suspended solids,
BOD or COD, and oil and grease. Thirteen plants listed only
five or fewer parameters. Only 12 plants listed 10 or more
parameters. Several of the analyses reported were on single
samples only, and some plants did not indicate either the
source of the sample or the frequency of sampling. Of the
33 plants providing some waste parameter data, 19 gave values
for total dissolved solids, 23 for total suspended solids,
19
-------
Table 11. MAJOR CONTAMINANTS IN WASTEWATER DISCHARGES
Number of
plants
reporting
Major
contaminants :
Pigments
Latex
Driers and
wetting
agents
Oils
Resins
Caustics
Fungicides
(including
mercury)
Heavy metals
(excluding
mercury)
Solvents
Other
Number of plants, by size
(number of employees)
Fewer
than 10
12
6
6
2
1
3
0
2
0
0
3
10 to
19
14
9
6
1
2
4
1
0
0
0
2
20 to
49
16
6
5
2
2
2
0
1
0
1
1
50 to
99
7
4
3
2
1
1
0
1
1
2
6
100 to
249
12
8
5
5
3
0
3
1
1
1
5
250 or
more
10
3
1
3
3
1
4
1
3
0
5
Total
71
36
26
15
12
11
8
6
5
4
22
22 for BOD, 21 for COD, 21 for oil and grease, 25 for one or
more of the heavy metals, and lesser numbers gave values for
other parameters.
The more complete waste parameter data were supplied gener-
ally by the larger plants. Of the 48 plants stating that
effluent analyses were conducted routinely, 19 had fewer than
100 employees; nine of these plants supplied some data and
10 supplied no data. Thirteen plants had 100 to 249 employ-
ees; ten of these supplied some data and three supplied no
data. Sixteen plants had more than 250 employees; 14 supplied
data and two did not.
Approximately 100 plants stated that effluent analyses were
not conducted routinely. Many of these plants stated that
they have no wastewater effluent. Typical reasons given for
the absence of effluent discharges were: "consumed in pro-
duct"; "incinerated and hauled to landfill"; "drummed for
commercial disposal"; or, simply, "no wastewater". Comments
20
-------
from other plants that have discharges but conduct no analy-
ses included these: "analyzed by city"; "cooling (or sani-
tary, or boiler) water only"; "never requested"; "not contami-
nated"; and "no contaminants other thah pigments". Several
plants stated that they were planning, or had just begun, a
systematic program of analysis.
The waste parameter data acquired in this project are insuf-
ficient for making any accurate estimates of the paint indus-
try's total waste loadings. The best estimates that can be
made with the data available are given in Table 12. These
data were taken from information supplied by nine plants.
Most of the data represent the raw waste characteristics of
combined effluents; thus, calculations of the waste loadings
in relation to production of particular products—such as
water-based paints or resins, for example—were not possible.
The loadings are therefore expressed in kg/day or g/day,
rather than in the preferred units of weight per unit of pro-
duct. Although 68 plants (see Table 13) reported that all or
part of their wastewater was subjected to some degree of
treatment in the plant, only about 20 plants reported data on
treated effluents. Most of these effluents were from cleanup
operations. However, no meaningful conclusions could be
drawn from the analyses of treated effluents because of the
limited amount of data presented and because too few plants
used the same treatment methods.
As indicated in Table 12, suspended solids, primarily from
pigments and resin particles, is the most significant param-
eter. The next highest parameter is dissolved solids. How-
ever, the high loading .of dissolved solids is not readily
explainable in terms of the ingredients used in paint or the
soluble constituents shown in the table that would constitute
the dissolved solids. A substantial portion of the dissolved
solids may, however, be derived from once-through cooling
water. Loadings of BOD and COD, principally from biodegrad-
able oils, resins, and solvents, are not as high as those of
suspended and dissolved solids. While oil and grease contents
appear high, it should be noted that the standard test gives
erroneously high results for oil and grease in the effluents
from this industry because resin particles that are present
are at least partially extracted by the solvent used in the
test. The relatively high loadings of metals are due princi-
pally to the pigments, drying agents, and preservatives.
Mercury is still present in some preservatives, although the
industry is attempting to replace mercury biocides when pos-
sible. In addition to lead and zinc, shown in the table,
some drying agents also contain cobalt and manganese. All of
the heavy metals shown in the table, and a number of others,
are commonly present in at least trace quantities in inorganic
21
-------
Table 12. DAILY RAW WASTE LOADING FOR PAINT PLANTS
Parameter
Total dissolved solids
Total suspended solids
Volatile suspended
solids
Acidity/Alkalinity
BOD 5 (acclimated seed)
Chemical oxygen demand
Total organic carbon
Chloride
Oil and grease
Sulfate
Sulfide
Organic nitrogen
Nitrogen, as N
Ammonia
Phosphorus
Mercury
Lead
Cadmium
Chromium
Zinc
Iron
Titanium
Waste loading,
kg/da^
Average
220
377
40
17
20
28
15
43
224
14
0.12
0.4
6
2
0.2
0.2
77
8
112
4,713
2,919
933
r (or g/day)a
Low
9
3
15
2
4
13
6
0.4
0.8
0.4
<0.02
—
0.4
0.02
<0.02
<0.2
24
2
10
28
426
52
High
483
3,233
61
47
77
44
23
125
1,327
40
0.4
—
18
10
0.5
0.4
120
120
217
10,840
9,636
1,205
Number of
plants
reporting
7
9
3
5
9
6
2
3
6
3
3
1
4
5
4
5
7
6
3
5
4
4
The waste loading is in g/day for the seven metals
listed.
pigments. The averages shown in the table are not necessar-
ily representative of the industry because of the small num-
ber of samples and the wide range of concentrations.
CONTROL AND TREATMENT TECHNOLOGY
The extent of control and treatment technology reported by
plants of various sizes is shown in Table 13. About 20% of
all plants reported that they generate no wastewater on a
routine, daily basis, other than sanitary, non-contact cool-
ing, and boiler blowdown water. Most of the plants gener-
ating no wastewater manufacture little or no water-based
paint; however, the few of those that do manufacture some
water-based products are able to recycle and reuse virtually
all cleanup water generated. Most of the plants that either
22
-------
Table 13. EXTENT OF CONTROL AND TREATMENT
PRACTICED IN PAINT PLANTS
to
Plants in group
Plants generating no
wastewater
Plants controlling
all wastewater
Plants self-treating
all wastewater
Plants partially self-
treating or control-
ling wastewater
Plants not treating
or controlling
wastewater
Number and percentage of plants in group
reporting, by size (number of employees)
Fewer
than 10
No.
25
7
6
5
2
5
%
16
28
24
20
8
20
10 to
19
No.
29
5
9
10
2
3
%
19
17
30
33
7
10
20 to
49
No.
34
11
12
5
4
2
%
22
33
35
15
11
6
50 to
99
No.
22
5
4
5
5
3
%
15
23
18
23
18
14
100 to
249
No.
22
2
1
10
6
3
%
15
9
5
45
27
14
250 or
more
No.
20
1
1
10
4
4
%
13
5
5
50
20
20
Total
No.
152
31
33
45
23
20
%
100
20
22
30
15
13
-------
do not generate wastewater or control all wastewater have
fewer than 50 employees. About half of the plants in this
size group discharge all of their wastes to municipal sewers.
An additional 22% of the plants, while generating some waste-
water, do not discharge wastewater, but control or dispose of
it by some nondischarge method.
Of the remaining 58% of the plants that discharge wastewater,
30% treat all wastewater, including spills, 15% control or
treat some of their wastewater, and 13% discharge without
using any control or treatment. Thus, about 87% of the
plants either do not generate any wastewater or are treating
or controlling at least some of it.
Table 14 summarizes the treatment and disposal methods
employed in plants of various sizes. Sedimentation is the
most common treatment method employed, which is to be expected
in view of the high level of suspended solids characteristic
of the wastewater of this industry. In about half of the
plants employing sedimentation, flocculation is also used to
increase the effectiveness of removing suspended and some
dissolved solids. Neutralization, principally of caustic
cleaning solutions, is reported at eight plants. Of the
remaining treatment methods, none is widely employed. Off-
site disposal, such as landfill, is the most common disposal
(nontreatment) method, and is practiced at 32 plants. Reuse
of cleanup water in products is practiced at 26 plants. Ten
plants evaporate wastewater and three plants use incineration
to dispose of specific wastes.
Table 15 is a summary of practices reported as planned or
recently initiated for the control or treatment of wastewater.
About a third of the plants report reduction of wastewater
volume by recycling, or by conservation of water)by the use
of high-pressure nozzles for cleaning or other conservation
methods. Twenty plants reported current or planned enlarge-
ment or improvement of existing treatment facilities, and
seven plants reported installation of new treatment facili-
ties where none existed previously. Sedimentation and floccu-
lation continue to be the most common treatment practices
being installed, although increased use of chemical treatment
and filtration are also reported.
A total of 87- plants reported on the adequacy of treatment
facilities. This number is larger than the number of plants
reporting treatment facilities, because some respondents
interpreted the question as applying to their wastewater
management practices. Of these 87, 56 consider their prac-
tices adequate, while 14 consider them inadequate. At the
remaining 17 plants, the adequacy is unknown, probably because
of uncertainties regarding local effluent requirements.
24
-------
Table 14.
10
en
WASTEWATER TREATMENT AND DISPOSAL METHODS
EMPLOYED IN THE PAINT INDUSTRY
Treatment method:
Sedimentation
Flocculation
Neutralization
Flotation
Aerated lagoon
Filtration
Equalization
Odor control
Activated sludge
Chemical treatment
Unspecified or other
Disposal method:
Off-site disposal
Reused in product
Evaporation
Incineration
Number of plants reporting, by size
(number of employees)
Fewer
than 10
5
0
0
0
1
0
0
0
0
0
0
3
1
4
0
10 to
19
9
3
1
1
, 0
1
0
0
0
1
1
5
8
3
0
20 to
49
5
3
0
0
0
0
0
1
0
0
1
7
4
2
2
50 to
99
3
1
2
1
0
0
1
0
0
0
3
9
6
0
0
100 to
249
9
5
3
1
0
1
0
0
0
0
2
5
1
1
0
250 or
more
8
5
2
0
1
0
0
0
1
0
2
3
6
0
1
Total
39
17
8
3
2
2
1
1
1
1
9
32
26
10
3
-------
Table 15. SUMMARY OF PLANNED OR RECENTLY INITIATED
WASTEWATER CONTROL AND TREATMENT PRACTICES
Control practice
10
a\
Recycling of water, includ-
ing reuse of cleanup water
Reduction of volume of
wastewater
Use of high-pressure nozzles
for cleaning
Elimination of use of mer-
cury compounds
Segregation of contaminated
streams
Removal of floor drains
Off-site disposal
Elimination of wet scrubbers
Number of
plants
reporting
34
12
6
4
4
2
2
Treatment practice
Number of
plants
reporting
Improvement or enlargement 20
of existing facility
Treatment methods added or
enlarged:
Sedimentation 11
Flocculation 7
Chemical treatment 5
Filtration 4
Cooling tower 3
Improved automation 2
Aeration 1
Carbon sorption 1
Installations by plants hav-
ing no previous facility
-------
For those plants that reported data on the costs of treatment
facilities, the variations are large. A small proportion of
the plants account for most of the expenditure. At 27 plants,
the capital cost to 1972 ranges from $250 to $800,000, for a
total investment of $1,848,650. The projected additional
capital cost through 1977 ranges from $300 to $1,500,000 for
17 plants for a total of $1,895,300. Thus, the plants
studied will about double their investment in treatment facil-
ities over the next five years. The cost of operating treat-
ment facilities also varies widely, from $75 to $150,000 per
year. The operating cost at 27 plants ranges from $0.001 to
$4.49 per 1000 liters of wastewater treated. The reported
age of treatment facilities indicates that most of the facil-
ities were installed or modified within the last three years,
probably to comply with recent local interest in pollution
abatement.
The effectiveness of the treatment facilities employed by the
paint industry is difficult to judge on the basis of avail-
able data. However, the most significant parameter, suspended
solids, is amenable to treatment by the conventional sedimen-
tation methods used—if effectively operated. As in other
industries, dissolved solids are not treated and no practical
treatment methods exist. This probably constitutes the major
area that will require development of new technology before
"zero discharge" of pollutants can be effected in the paint
industry.
EXAMPLES OF PAINT PLANTS. EMPLOYING CONTROL AND TREATMENT
TECHNOLOGY
In the following section, four plants are discussed to illus-
trate examples of control and treatment technology employed
in the paint industry.
Plant A—Small Plant with No Wastewater Discharge
This plant employs fewer than 50 production workers. The
principal products are solvent-based coatings, with water-
based products representing only a small portion of the total
production.
Only sanitary effluent and non-contact cooling water are dis-
charged to the municipal sewer. Floor drains have been sealed
at this plant, and solvents used for cleaning are recovered
for reuse. No caustic cleaning is used, and the small amount
of wastewater generated in cleanup of equipment used for mak-
ing water-based paint is drummed and hauled away.
27
-------
Plant B—Medium-Size Plant Employing Sedimentation for Pre-
Treatment of Cleanup Water
This plant employs fewer than 100 production workers and manu-
factures about 23,000 liters (6,000 gal.) of paint per day,
of which about 65% is water-based product.
Non-contact cooling water is discharged directly to surface
water bodies without reuse. Wastewater from cleanup opera-
tions is pumped from a holding sump to an 11,000 liter (3,000
gal.) tank (formerly used for production), where lime, sodium
sulfite, alum, and a polyelectrolyte are added. The waste-
water from the tank is pumped to a 53,000 liter (14,000 gal.)
two-stage settling pond with about 4 days' retention time
before discharge to the sanitary sewer. Sludge is pumped
from the pond to an adjacent landfill about every 2 months.
This system was designed to precipitate mercury compounds and
is reported to be effective. Plans are underway for routing
floor drains and runoff from the latex storage area into the
tre atment sy s tern.
Plant C—Large Plant Employing Reuse and Pretreatment of
Wastewater in Tank-Form Facilities
This plant employs about 250 production workers, manufactures
alkyd and latex resins, and produces a wide range of solvent-
based and water-rbased products. Non-contact cooling water,
boiler blowdown, and surface runoff are discharged to surface
waters without treatment. Floor drains have been sealed and
precautions taken to prevent spills from entering storm
drains. Other non-contaminated wastewater is segregated and
discharged directly to sanitary sewers.
Wastewater from the paint and resin plants and a tank clean-
ing station is pumped to an in-plant treatment facility.
Sumps are located in each of these areas and collected sludge
is removed weekly by a private contractor. Portable collec-
tors are located near each sump to contain overflow in the
event of pump failure. Waste from the resin plant consists
of spent caustic cleaning solution and wastewater fron con-
densers. Paint plant waste consists of cleanup water and,
occasionally, waste from caustic cleaning of mills. The
first wash of filling machines is drummed and reused as make-
up water in later batches of similar paint; although mercuri-
als are no longer used, this practice, adopted to eliminate
the discharge of mercury compounds, is still used.
The treatment facility consists of a series of tanks sur-
rounded by a dike to contain any spills. Wastewater is
pumped to a 19,000 liter (5,000 gal.) tank where it is agi-
tated by a continuous pumping until the volume reaches a
28
-------
specified level. It is then fed to a smaller tank where sul-
furic acid and a flocculating agent (FeSCK) are added. Addi-
tion of sulfuric acid is controlled by a pH probe. Following
these additions, the mixture is pressurized in a smaller tank
to dissolve a quantity of air, which is subsequently released
in another 19,000 liter (5,000 gal.) tank. In this tank, the
resulting froth is skimmed off and the solids settle out.
The remaining liquid is discharged into the sanitary sewer
after pH measurement and analysis. The system meets the
requirements of the local control agency.
Plant D—Large Plant Employing Pretreatment of Wastewater in
an Aerated Lagoon System
This plant has more than 250 employees and manufactures
resins and water-based paints. Non-contact cooling water,
boiler blowdown, and sanitary wastes are discharged directly
to the municipal sewer. Wastewater from cleanup operations
in the paint plant amounts to 23,000 to 45,000 liters (6,000
to 12,000 gal.) per day. Wastewater from wet scrubbers, tank
washing, filtering, and decanter wastes in the resin plant
amounts to 38,000 to 113,000 liters (10,000 to 30,000 gal.)
per day. The total wastewater from these two sources con-
tains about 900 kg (2,000 Ib) per day of suspended solids and
has a COD of about 1,800 to 1,700 kg/day (4,000 to 6,000
Ib/day).
Paint plant wastes are collected in large tanks where a poly-
electrolyte is added. Once the polyelectrolyte is thoroughly
mixed with the waste based on the volume needed to flocculate
the solids, the mixture is pumped to one of two clarifiers
for settling. After settling, the underflow is pumped to a
3,800,000 liter (1,000,000 gal.) sludge drying lagoon. The
overflow is sent to a 11,400,000 liter (3,000,000 gal.) three-
stage, aerated lagoon where it is mixed with the wastes from
the resin plant and the run-off from the yard. The yard is
equipped with collection sumps to prevent the run-off from
going into the stream. The aerated lagoon is equipped with
aerators that reduce the influent COD by approximately 90%
during a 20-day retention time. At this plant the influent
and effluent are monitored daily.
Effluent discharge to the municipal sewer contains about
45 kg (100 Ib) per day of suspended solids and has a COD of
about 180 to 230 kg (400 to 500 Ib) per day. This system is
considered exemplary by the local control agency.
29
-------
SECTION V
THE TITANIUM DIOXIDE INDUSTRY
There are seven companies with eleven plants currently produc-
ing titanium dioxide (TiO2) in the United States. Total
annual capacity in 1972 was 756,000 metric tons (833,000 tons)
with planned expansions at three plants expected to bring the
annual capacity to 929,000 metric tons (1,024,000 tons) by
1975.32 The eleven plants and their capacities are listed in
Table 16.
The principal market for TiOa is in the manufacture of paints
and lacquers, which accounts for more than half of consump-
tion. Other markets include paper and paper board, plastics
and fibers, rubber, floor coverings, printing inks, and
ceramics. Together, these uses accounted for a consumption'
of about 700,000 metric tons (780,000 tons) in 1972. About
11% of this amount was imported.32 Thus, production in 1972
is estimated at about 623,000 metric tons (687,000 tons).
PRODUCTS
Titanium dioxide may be made in two crystalline forms—
anatase and rutile. Because its index of refraction is
higher, the rutile form is preferred in paints where it
offers advantages in hiding power and opacity. The anatase
form is generally whiter, although advances in the production
techniques for making the rutile form have led to improve-
ments in color, which, combined with superior brightness and
hiding power, make rutile the preferred form. Anatase is
used principally in paper manufacturing where whiteness is
important.
MANUFACTURING PROCESSES
There are two basic processes for the manufacture of titanium
dioxide—the sulfate process and the chloride process. In
the sulfate process, which is outlined in Figure 4, finely
ground ore, usually ilmenite (which contains 40 to 65% Ti02
and 30 to 50% FeO and FezOa and smaller amounts of other
metal oxides), is digested with concentrated sulfuric acid to
convert the ore to the soluble sulfates. Excess iron is
30
-------
Table 16. DOMESTIC PRODUCTION CAPACITY, TITANIUM DIOXIDE*
Company
American Cyanamid
Savannah, Georgia
E. I. du Pont de Nemours
Antioch, California
E. I. du Pont de Nemours
Edgemoor, Delaware
E. I. du Pont de Nemours
New Johnsonville, Tennessee
Glidden-Durkee
Baltimore, Maryland
Kerr-McGee
Hamilton, Mississippi
NL Industries
St. Louis, Missouri
NL Industries
Sayreville, New Jersey
New Jersey Zinc
Gloucester City, New Jersey
New Jersey Zinc
Ashtabula, Ohio
Sherwin Williams
Ashtabula , Ohio
Totals
Capacity, thousands of metric tons
(thousands of tons)
1972
Sulfate
65
(72)
0
(0)
45
(50)
0
(0)
50
(55)
0
(0)
104
(115)
113
(124)
39
(43)
0
(0)
0
(0)
416
(459)
Chloride
36
(40)
25
(27)
45
(50)
128
(141)
23
(25)
34
(37)
0
(0)
0
(0)
0
(0)
25
(27)
25
(27)
340
(374)
Total
102
(112)
25
(27)
91
(100)
128
(141)
73
(80)
34
(37)
104
(115)
113
(124)
39
(43)
25
(27)
25
(27)
756
(833)
1975
Sulfate
65
(72)
0
(0)
0
(0)
0
(0)
50
(55)
0
(0)
104
115
113
(124)
39
(43)
0
(0)
0
(0)
371
(409)
Chloride
36
(40)
25
(27)
136
(150)
207
(228)
23
(25)
50
(55)
0
(0)
33
(36)
0
(0)
25
(27)
25
(27)
558
(615)
Total
102
(112)
25
(27)
136
(150)
207
(228)
73
(80)
50
(55)
104
(115)
145
(160)
39
(43)
25
(27)
25
(27)
929
(1024)
aReference 32.
-------
GROUND
ILMENITE ORE
SULFURIC . .
ACID • M DIGESTION }«-
MAKE-UP f ' '
WASTE
ACID
WASTE
WATER
EVAPORATION
SETTLING
I IRON REMOVAL}-
[CLARIFICATIONj
PRECIPITATION
AND SOLIDS
SEPARATION
I CALCINATION |
GRINDING
WASHING
DRYING
FINISH
GRINDING
BAGGINGt
SHIPPING AND
STORAGE
WATER
FERROUS
SULFATE
WATER
WATER
Figure 4. Sulfate process for producing titanium dioxide
32
-------
introduced to convert a small amount of titanium to the tri-
valent state and thus prevent later reoxidation of the fer-
rous iron. The iron salts are removed by vacuum crystalliza-
tion and the Ti02 is precipitated after hydrolysis of the
Ti(SOi»)2 at an elevated temperature. The precipitate, in the
hydrous oxide form, is filtered, washed, dried, and calcined
in a rotary kiln where it is converted from the amorphous
state to the desired crystalline form.
The chloride process, outlined in Figure 5, requires a raw
material of higher TiO2 content; rutile ore, slag, or bene-
ficiated ilmenite may be used. In this process, liquid tita-
nium tetrachloride, produced by the reaction of ore with
gaseous chlorine in the presence of coke, is purified by dis-
tillation and oxidized in a flame to TiO2 which condenses as
a fume with the evolution of chlorine.
The TiO2 that is formed in either process may be given a chem-
ical surface treatment to impart wettability or other proper-
ties. This additional treatment involves further filtration,
washing, and drying.
The choice of process is dictated by the technology of the
company and the availability of raw materials. Although the
chloride process is preferred because of its simplicity rela-
tive to the sulfate process and the purer, more uniform pro-
duct, it requires higher-grade ore. Wastewater problems are
much greater in the sulfate process, which generates large
quantities of ferrous sulfate and spent sulfuric acid. Pro-
cesses for the beneficiation of ilmenite ore result in a
suitable raw material for the chloride process, but the waste-
water problems may only be shifted to the beneficiation plant.
Presently, the industry is divided on the question of process
preference; Du Pont is planning to switch its production to
the chloride process, while NL Industries has closed down the
chloride process operation at its Sayreville, New Jersey,
plant.
WATER USE AND WASTE CHARACTERIZATION
A composite flow sheet of water sources, uses, and waste dis-
posal for a titanium dioxide manufacturing plant representing
the overall industry is shown in Figure 6. This composite is
based on averages of data reported by seven plants that use a
total of 870 million liters (230 million gal.) of water per
day. Both sulfate and chloride process plants are included
in the seven plants'. The data available were not sufficient
to prepare separate flow sheets for each process. By far the
largest source of water is surface water, which accounts for
about 63% of the total water used. Less than 6% of the water
33
-------
WASTE
WATER
CHLORINE
MAKE-UP ~" i
CHLORINE
WASTE
WATER
GROUND
RUTILE ORE
1
JCHLORINATION \» CARBON
TiCli,
CONDENSATION
AND SEPARATION
1
(DISTILLATION |
OXIDATION
J*
102 SEPARATION|
4 1 SETTLING}* { WASHING f*
FILTRATION
EVAPORATION 4 \ DRYING |
FINISH
GRINDING
BAGGING,
SHIPPING AND
STORAGE
•OXYGEN
WATER
WATER
Figure 5. Chloride process for producing titanium dioxide
34
-------
SOURCES
USES
DISPOSAL
PUBLIC
SUPPLY
1.9%
SURFACE
63.2%
PROCESS
BOILER
COOLING
CLEANUP
SANITARY
11.9%
2.5%
70.6%
0.4%
0.2%
AIR POLLUTION CONTROL 14.4%
TREATED
BEFORE
DISCHARGE
11.8%
88.2%
UNTREATED
RECYCLED
31.1%
0.1%
0.2% 54.1%
MUNICIPAL
SEWER
0.3%
10.5%
0.9%
SURFACE
64.6%
WELL
0.2%
0.7%
OCEAN
BARGE
1.6%
2.2%
EVAPORATION
2.2%
Figure 6. Water data for typical titanium dioxide plant*
Composite based on average of seven plants reporting
information on data sheets.
35
-------
used is from wells or public water supplies. The remaining
31% is recycled and is mostly used for cooling, which accounts
for 70% of the total water used. Process water accounts for
12%, and 14% is used for air pollution control equipment.
The remaining 3% is used for boiler feed, cleanup, and sani-
tary purposes. In addition to the 31% of the water that is
recycled, 4% is disposed of by evaporation, ocean barging,
and subsurface disposal. Virtually all of the remaining 65%
is presently discharged to surface waters. A total of only
12% of the wastewater is treated prior to discharge.
Although some contamination of water occurs through cleanup,
use of air pollution control devices, and some contact cool-
ing, most of the contamination results from process uses. A
summary of the volume of process wastewater generated in
various operations, the major contaminants introduced in
these operations, and the disposition of process wastewater
is shown in Table 17 for the sulfate process and Table 18 for
the chloride process. As shown in these tables, fewer con-
taminants and smaller volumes of wastewater are generated
in the chloride process than in the sulfate process.
Table 19 summarizes waste discharge data for nine titanium
dioxide plants. These data were obtained from both discharge
permit applications and data sheets. Four of the plants use
the chloride process only, three use the sulfate process only,
and two use both processes. It is not feasible to tabulate
data for the industry as a whole because of variations in the
manner in which data are presented by the different plants
and variations in their methods of handling wastes. Three of
the plants in this group dispose of part of their wastes in
landfills, two discharge part in the ocean by barge transport,
and one uses deep-well injection. For six of the plants the
data in Table 19 represent the total discharge of plant efflu-
ents to streams and to landfill, deep well, or ocean. Param-
eter data on discharge other than that to streams were lacking
for the other three plants; for these three plants, therefore,
the data given in the table represent only a part of the
total wastes. The treatment of wastes discharged to streams
varies considerably, but all of the nine plants use sedimenta-
tion methods and some use several other treatment methods in
addition to sedimentation. Most of these plants reported
that their waste disposal systems were in the process of being
modified or improved. The parameter loadings in Table 19 were
calculated from reported daily average concentrations, dis-
charge flow rates, and annual production rates. It was
assumed for the purposes of computation that each plant oper-
ated for 350 days during the year.
36
-------
Table 17.
PROCESS WASTEWATER INFORMATION FOR PLANTS PRODUCING
TITANIUM DIOXIDE BY THE SULFATE PROCESS
Digeston/
reduction
Thickening
Separation
of iron salts
Concentrating
Discharge, liters/metric ton
of product (gal./ton):
Average
Maximum
Minimum
Number of plants
reporting
Major contaminants:
H2SOi»
FeSO>»
Other SO4 salts
SO 2
Ti02
Ore/gangue
Method of disposal of waste:
Surface
Ocean barging
Evaporation
Landfill
Number of plants treating
wastes prior to discharge
18,000 (4,500)
67,000 (16,000)
500 (120)
4
2,200 (520)
3,000 (720)
1,350 (325)
3
1,900 (450)
2,700 (650)
1,000 (250)
2
10,800 (2,600)
40,000 (9,700)
1,200 (300)
4
+a
a"+" indicates presence of indicated major contaminant or use of indicated method of
disposal.
(Continued)
-------
Table 17(Continued). PROCESS WASTEWATER INFORMATION FOR PLANTS PRODUCING
TITANIUM DIOXIDE BY THE SULFATE PROCESS
Filtering
Washing
Kiln
Thickening/
filtering
u>
oo
Discharge, liters/metric ton
of product (gal./ton):
Average
Maximum
Minimum
Number of plants
reporting
Major contaminants:
H2SO<»
FeSOi*
Other S0i» salts
SO2
Ti02
Ore/gangue
Method of disposal of waste:
Surface
Ocean barging
Evaporation
Sewer
Number of plants treating
wastes prior to discharge
5,000 (1,200)
7,400 (1,800)
1,900 (455)
4
34,000 (8,300)
70,000 (17,000)
18,000 (4,300)
4
6,200 (1,500)
13,000 (3,200)
1,700 (410)
4
13,000 (3,300)
27,000 (6,500)
8,100 (1,950)
4
a"+" indicates presence of indicated major contaminant or use of indicated method of
disposal.
-------
Table 18.
U)
V£>
PROCESS WASTEWATER INFORMATION FOR PLANTS PRODUCING
TITANIUM DIOXIDE BY THE CHLORIDE PROCESS
Discharge, liters/metric ton
of product (gal./ton):
Average
Maximum
Minimum
Number of plants
reporting
Major contaminants:
HC1
FeClx
Other chloride salts
Other salts
TiO2
Method Of disposal of waste:
Surface
Ocean barging
Evaporation
Landfill
Number of plants treating
wastes prior to discharge
Chlorination
4,200 (1,000)
5,000 (1,200)
2,800 (675)
4
+a
+
+
+a
+
+
+
Filtering/
washing
12,500 (3,000)
27,000 (6,480)
5,800 (1,400)
4
+
4
Drying
3,300 (800)
5,000 (1,200)
1,500 (360)
2
"+" indicates presence of indicated major contaminant or use of indicated
method of disposal.
-------
Table 19. WASTE DISCHARGE DATA FOR TITANIUM DIOXIDE PLANTS3
•£».
O
Parameter
Average wastewater
discharge, millions
of liters/day
Total dissolved solids
Total suspended solids
Total volatile solids
Acidity/alkalinity
BOD 5
COD
Oil and grease
Total organic carbon
Total organic nitrogen
Ammonia, as N
Chloride
Fluoride
Nitrate
Sulfate
Sulfide
Phosphorus, total
Iron
Titanium
Antimony
Arsenic
Cadmium
Chromium
Lead
Manganese
Mercury
Nickel
Selenium
Zinc
Waste loading, kg/metric ton of product", c
Plant A
Cl, SOi.
112
2,650
46
1,043
1,652
4.6
40
3.3
1.5
1.0
0.4
316
-
-
484
-
0.2
449
26
300
-
3
440
150
14,000
0.04
-
500
600
Plant B
SOH
35.2
2,274
24
-
-
0.6
26
0
-
1.3
7.7
13
-
-
980
-
0.5
656
19
-
-
0
1,100
0
-
0
-
-
1,100
Plant Cd
Cl, SO*
135
3,720
53
-
-
0
28
0
-
0
0
35
-
-
3,170
1.0
0.06
192
40
_
-
-
1,900
200
-
0
-
-
600
Plant Dd
SO.,
146
7,240
595
1,060
20
2.1
-
-
2.2
1.4
<0.1
3,540
-
-
205
<0.08
0.05
7
0.9
_
-
<1
30
<0.3
-
<0.3
_
—
40
Plant Ed
Cl
11.0
601
7.1
-
15
0.6
9.1
<0.1
3.5
0.3
0.7
453
0.2
V"
32
0.008
0.2
0.05
9.8
_.
-
<0.6
50
3
-
<0.1
10
<0.6
3
Plant F
Cl
J34
1,330
15
-
-
-
-
-
-
-
-
877
-
-
26
-
-
330
-
_
—
_
-
-
-
-
_
_
—
Plant G
Cl
2.8
175
-
-
-
-
-
-
-
-
-
181
-
-
35
-
-
27
1.4
^
_
_
0.2
—
-
0.02
1
_
—
Plant H
Cl
2.6
169
0.2
4.4
2.2
<0.4
1.1
—
0.6
0.01
<0.01
47
0.05
0.05
16
<0.02
0.002
11
<0.02
20
10
<2
1,800
<0.4
0.4
<0.02
_
_
2,100
Plant I
Cl, SO.,
109
_
-
—
-
-
-
1.0
2.0
0.6
-
853
0.2
—
486
0
-
144
25
—
20
0
800
0
4,000
0
90
700
a_. .- _ f T> s J • v. -A. i • a- jj *_
rData from Corps of Engineers discharge permit applications and data sheets.
A zero indicates that the constituent was reported as "absent" or "not detected"; a dash indicates
Ithat no information was reported on the concentration of the constituent.
TJaste loadings for the ten metals listed in the lower part of the table are in g/metric ton of pro-
oduct.
T>lants C, D, and E dispose of part of their wastes by methods other than discharge to streams, but
did not provide data on these disposal methods. The data given for these plants represent only dis-
charges to streams.
-------
Total solids, almost all in the form of dissolved solids, is
the most significant parameter for both processes. The pH of
discharged process water ranges from 3 to 7.5. Since the raw
materials used in the sulfate process contain up to 50% of
impurities that are removed in the digestion with sulfuric
acid, all of the other parameters are explainable as by-
products of these impurities and sulfuric acid. In the chlo-
ride process higher-grade raw materials are used, and this
fact is reflected by lower loadings. In addition to process
waste, the industry discharges a large volume of cooling water
at an elevated temperature that must be considered as part of
the overall environmental problem. Some cooling water is also
used for contact cooling and therefore becomes contaminated.
CONTROL AND TREATMENT TECHNOLOGY
Waste abatement practices currently employed in the industry
include disposal of some process wastes, particularly iron
sulfate and sulfuric acid, by ocean barging, deep-well dis-
posal, and landfill. In-plant control measures consist of
recycling and reuse of wastewater, reuse of sulfuric acid,
segregation and concentration of waste streams, and, more
recently, process and raw material changes designed to reduce
the waste loading. Reuse of sulfuric acid appears to be
limited to one plant, which recovers "some of the dilute sul-
furic acid".
All seven plants reporting information on wastewater treat-
ment facilities employ sedimentation to reduce suspended
solids. Three of these plants use flocculation to increase
the effectiveness of sedimentation, and two also employ fil-
tration. In view of the relatively low level of suspended
solids in the discharge reported by the industry (Table 19),
these methods appear to be effective for removal of suspended
solids.
Neutralization of acidic wastes is practiced at four of the
seven plants and planned at one other, and one plant employs
an additional, unspecified chemical treatment before final
discharge. The treatment methods employed by these plants
are considered adequate by three, inadequate by three, and
unknown by one plant.
The reported investment and operating costs of the treatment
facilities, including cost of sludge disposal, ocean barging,
and deep-well injection, are summarized in Table 20. Signifi-
cantly, the anticipated investment in treatment facilities
through 1977 reported by these seven plants is nearly equal
to the total investment to date. Five of the seven plants
41
-------
Table 20. SUMMARY OF WASTE TREATMENT AND DISPOSAL COSTS
FOR THE TITANIUM DIOXIDE INDUSTRY
Capital cost to 1973
Capital cost 1973-
1977
Annual operating cost
Cost,
millions of dollars
Total
21.6
18.0
5.9
Average
3.1
3.0
0.8
Low
0.3
0.7
0.2
High
9.0
7.0
2.0
Number of
plants
reporting
7
6
6
installed treatment facilities when the plants were con-
structed; all have been enlarged or modified since 1966, six
of them within the last three years.
A number of problems related to the control and treatment of
plant effluents are reported by six of the seven plants.
These range from unique problems at individual plants, such
as difficulty in segregating individual waste streams and
controlling spills and runoff, to universal agreement that
practical methods for treatment of dissolved solids are not
available. Practical alternatives are needed for disposal of
wastes currently being ocean barged or deep-well injected.
These wastes are especially high in dissolved solids. Con-
siderable development of technology to resolve the problem of
dissolved solids, including heavy metals, will be required
before "no discharge" of pollutants will be feasible.
One plant is reported to be considering an arrangement with
another company for the manufacture of gypsum (CaSOi») from
limestone (CaCOa) and waste sulfuric acid. The economics of
the process appear to be attractive; however, the process
has not yet been commercialized. Operating experience will
be required before any judgement may be made as to the prac-
ticality of this process. In any case, such an arrangement
is dependent on minimum shipping costs for one or both mate-
rials. At another plant the recovery of sulfuric acid is
being evaluated on a pilot scale with EPA assistance (Project
No. S801349). Also, the Bureau of Mines has proposed an
alternate beneficiation route that uses coal and sodium
borate. No data on commercial feasibility is available for
any of these procedures at this time.
42
-------
SECTION VI
THE INORGANIC PIGMENTS INDUSTRY
The manufacture of inorganic pigments is classified by the
Department of Commerce as SIC 2816. The products include
titanium-, lead-, and zinc-based white pigments, and colored
pigments, mostly chrome- and iron-based. There are about 98
manufacturing establishments in the United States in SIC 2816.
This number includes the manufacturers of TiOz (11 plants,
considered separately in this report); manufacturers of pearl
essence and carbon blacks, which are not covered in this study
since these pigments are considered organic pigments; and
manufacturers of extender pigments, which also are excluded
from consideration. In the course of this study, about 30
companies having about 35 plants were identified as manufac-
turers of prime inorganic pigments. The value of total ship-
ments of all inorganic pigments in SIC 2816 have been esti-
mated at 732 million dollars in 1972, compared to 564 million
dollars in 1967.33 For the inorganic pigments that are
included in this study, 1967 shipments were 184 million
dollars. Assuming that the ratio of these pigments to the
total is the same as for 1967, the 1972 shipments are esti-
mated to have a value of about 240 million dollars.
PRODUCTS AND RAW MATERIALS
Colored inorganic pigments consist of a wide variety of inor-
ganic compounds, principally metal oxides and salts. The
principal metals are iron, chromium, cadmium, zinc, copper,
antimony, and lead. Restrictions on the use of lead have
decreased its use in recent years. Table 21 shows a list of
common colored pigments and their chemical composition. Raw
materials for the manufacture of colored inorganic pigments
include naturally-occurring ores, acids, salts, and oxides,
as well as metal-organic compounds such as lead acetate.
MANUFACTURING PROCESSES
Each pigment is made by a slightly different process. A
detailed discussion of the processes involved is beyond the
scope of this report. However, the following five major
operations are common in the industry: precipitation, filtra-
tion and washing, calcining or roasting, quenching, and grind-
ing and milling. These operations are not necessarily all
43
-------
Table 21. COMMON INORGANIC COLOR PIGMENTS
Red, Maroon, and Brown Pigments
Natural red iron oxide Fe203
Synthetic iron oxide Fe203
Burnt sienna Fe2O3/SiO2/Al2O3
Red lead Pb30i»
Cadmium red CdS/CdSe
Cuprous oxide Cu20
Raw and burnt umber Fe203/MnO2
Metallic brown Fe2O3/Si02/Al203
Yellow and Orange Pigments
Ocher Fe203/SiO2/Al2O3
Raw sienna Fe2O3/SiO2/Al2O3
Synthetic hydrated yellow Fe203»H2O
iron oxide
Chrome yellow PbCrOi»
Chrome orange PbO-PbCrOit
Molybdenum orange PbCrO^/PbMoOi*
Zinc yellow ZnCrOi*
Basic zinc chromate 4Zn(OH) 2»ZnCrOi*
Cadmium yellow CdS/BaSO^
Green Pigments
Chrome green PbCrO^/FefNH,,) [Fe(CN) 61
Chromium oxide green Cr2O3
Hydrated chromium oxide Cr203»2H2O
Blue Pigments
Iron blue Fe(NH^)[Fe(CN)6]
Ultramarine blue Si02/Al203/Na2O/S
Blue basic lead sulfate PbO/PbSO^/PbS/PbS03/C
used for any one pigment; for example, red lead (Pb3Oi») is
made by calcining finely-ground litharge (PbO) at 482-509°C
(900-950°F) for about 24 hr. Further, other pigments may
require operations in addition to those listed above.
Precipitation is the operation most commonly involved in the
manufacture of synthetic pigments. Usually, the reactants
are dissolved in water and the product is precipitated under
carefully controlled conditions of temperature and pH. Care-
ful control is necessary to ensure that the desired
44
-------
crystalline form is obtained in maximum yield. Following
precipitation, the product is washed to remove excess reac-
tants and soluble by-products.
Calcining may be done for several reasons, including oxida-
tion, dehydration, modification of crystal structure, and
chemical reaction. This operation may involve the use of
rotary kilns or furnaces, in either the presence or absence
of oxygen. Quenching pigments after they are calcined may be
done to cool them under controlled conditions and thus to pro-
duce the desired crystalline state.
Before packaging and shipment, pigments may be ground to
reduce their particle size as required for use. In addition,
surface treatments may be given to impart specific properties.
WATER USE AND WASTE CHARACTERIZATION
A flow sheet of water sources, uses, and disposal for inor-
ganic pigment manufacturing plants is shown in Figure 7.
This flow sheet is a composite, based on averages of data
reported by only six plants. The principal source of water
is public supplies, which accounts for 77% of the water used.
Surface water and well water account for 19%, and 4% of the
water is recycled.
In contrast to titanium dioxide manufacturing, cooling is a
relatively minor use of water in this industry, while process
uses account for over 50% of the water used. One industry
source noted that about 42 liters (11 gal.) of water are used
in the precipitation and washing processes to make 1 kg
(2.2 Ib) of pigment.
About 80% of the wastewater reported by these six plants is
treated in some manner before discharge and most of the waste-
water discharged, 60%, goes to surface water bodies. Of the
20% that is not treated after use, nearly half, 8.5%, is
either recycled or evaporated.
Table 22 shows some of the more significant waste parameter
data reported by six plants. The loading of individual waste
constituents varies considerably from plant to plant because
of the variety of types of pigments manufactured and differ-
ences in the methods and extent of treatment used. Some
uncertainties are undoubtedly due to the quality and quantity
of the analytical data provided. Most of these plants are
expanding and improving their waste treatment facilities.
45
-------
SOURCES
USES
DISPOSAL
16.5%
MUNICIPAL
SEWER
21.0%
PUBLIC
SUPPLY
76.8%
WELL
OR
SURFACE
19.0%
PROCESS
BOILER
COOLING
CLEANUP
SANITARY
TREATED
BEFORE
DISCHARGE
90%
20%
UNTREATED
RECYCLED
OR
REUSED
52.3%
17.5%
13.6%
4.8%
2.6%
AIR POLLUTION CONTROL 9.2%
4.5% 63.5%
7.7%
SURFACE
70.5%
4.2%
EVAPORATION
4.2%
4.2%
0.1%
SEPTIC
TANK
0.1%
Figure 7. Water data for typical inorganic pigment planta
Composite based on average of six plants reporting
information on data sheets.
46
-------
Table 22. PROCESS WASTE LOADING FOR INORGANIC PIGMENT PLANTS'
Parameter
Average wastewater
discharge, millions
of liters/day
Total solids
Total dissolved solids
Total suspended solids
Total volatile solids
Acidity
Alkalinity
BOD 5
COD
Sulfate
Nitrate
Ammonia, as N
Phosphorus , total
Chloride
Mercury
Lead
Cadmium
Chromium
Zinc
Iron
Cobalt
Copper
Waste loading, kg/metric ton
of product for Plants A-Fb
A
Treated
0.076
1.72
1.69
0.026
0.92
-
0.69
0.98
1.95
-
0.0002
0.15
0.0
0.042
—
-
-
-
1.27
-
-
**
B
Combined
0.048
5.42
5.02
0.39
0%.0
-*
-
-
0.029
0.12
-
-
-
0.0
—
11.2
0.0
3.5
-'
3.6
0.5
^
C
Treated
1.31
204
204
-
-
-
3.44
-
-
49.6
-
-
-
2.46
—
-
-
-
3.11
105
-
"•
D
Treated
4.09
0.90
1.80
-
-
—
0.79
-
-
4.32
-
-
-
—
_
-
-
-
-
0.007
—
~
E
Untreated
12.1
985
920
73
221
123
0.0
66
118
144
33
16
0.5
44
3.6
15,000
625
8,500
2,100
6,700
_
1.08
F
Treated
1.13
820
820
3
7.2
0.09
-
5.6
5.0
215
112
0.0
0.0
89
—
112
—
67
0.0
_
_
—
These data were taken from Corps of Engineers Discharge Permit Applica-
tions.
Waste loadings for the eight metals listed are in g/metric ton of pro-
duct.
-------
Dissolved solids constitute the most significant parameter in
this industry. Since one of the principal production pro-
cesses is precipitation from solution, a high level of dis-
solved solids is to be expected because of excess reactants
and by-products that are present in filtrate and washwaters.
Metals of all kinds, including some of the more toxic ones,
are present in significant quantities in process waters.
CONTROL AND TREATMENT TECHNOLOGY
There are three principal problems that must be dealt with in
this industry. The most serious is the presence of heavy
metals such as chromium and lead. These metals are present
both as finely divided suspended solids from filtration and
washing operations and as dissolved solids in spent mother
liquor. The second problem is the high level of dissolved
solids present as by-products from precipitation reactions.
These are generally sodium and potassium salts, such as
nitrates, chlorides, sulfates, and acetates. The third prob-
lem is the presence of suspended solids so finely divided
that they pass through the filters used in the process. The
varied combinations of finely divided solids and gelatinous
metal hydroxides that are sometimes present result in greatly
differing settling rates, which make normal sedimentation
processes difficult to control.
The treatment technology employed at the five plants listed
in Table 22 that treat their wastes consists of neutralization
at all five plants; sedimentation at four, combined with
flocculation at one; and filtration and chemical treatment at
three. These methods are generally used for reduction of
suspended solids, control of pH and elimination of heavy
metals. The costs of treatment facilities for these five
plants are summarized in Table 23.
Table 23.
SUMMARY OF WASTE TREATMENT AND DISPOSAL COSTS
FOR FIVE INORGANIC PIGMENT PLANTS
Capital cost to 1973
Capital cost 1973-1977
Annual operating cost
Cost, millions of dollars
Total
8.1
3.4
0.91
Average
1.6
0.68
0.18
Low
0.1
0.25
0.012
High
5.6
2.0
0.5
48
-------
One of the more significant heavy metals is Cr(VI). A common
approach to its elimination is the segregation of Cr(VI)-
containing solutions, followed by reduction to Cr(III) and
precipitation as the hydroxide. Although there are a number
of problems associated with this procedure, it is the best
one in common use.
One plant is successfully using an ion-exchange process for
the recovery of chromates (EPA Project 12020ERM). About
454 kg (1,000 Ib) of chromate, formed by regenerating the ion-
exchange resins at high pH, is being recovered per day.
Eventually, the process is expected to pay for itself on the
basis of recovered chromates. This technique should be appli-
cable to other metals, as well.
The removal of suspended solids is accomplished by standard
sedimentation processes. The problems of differential and
ineffective settling must be resolved before these methods
are as effective as in other industries.
At present, as in other industries, effective methods for
treating dissolved solids are needed.
49
-------
SECTION VII
METHODOLOGY
Sources of information used in this study included the follow-
ing:
• Copies of applications to the Corps of Engineers
for permits to discharge under the Refuse Act Per-
mit Program (RAPP) were obtained for 25 paint
plants, seven titanium dioxide plants, and ten
plants manufacturing other inorganic pigments.
These applications provided information on the
characteristics of intake and effluent waters,
water usage (including flow diagrams in many cases),
wastewater treatment and control practices
employed, products produced, daily production, and
raw materials consumed.
• Data sheets were obtained during the first quarter
of 1973 for 153 paint plants, seven titanium diox-
ide plants, and seven plants manufacturing other
inorganic pigments. The nature of the information
sought is indicated by the data forms in the Appen-
dix. This information was obtained with the coop-
eration of the National Paint and Coatings Associa-
tion and the Dry Color Manufacturers1 Association.
• Visits were made to four paint plants, a titanium
dioxide plant employing both the sulfate and chlo-
ride processes, and two plants manufacturing other
inorganic pigments. These visits provided detailed
information on water usage, waste characteristics,
and control and treatment practices and costs.
• Other sources of information included Environmental
Protection Agency technical reports, trade litera-
ture, personal and telephone interviews, and meet-
ings with industry personnel and trade association
committees.
Coverage of the paint industry from data reported by 153
plants is summarized in Table 24. Indices of industry cover-
age in different size groups are based on number of plants,
number of production workers, and production of coating pro-
ducts. In general, coverage was proportionally higher for
plants of increasing size as characterized by number of
50
-------
Table 24. COVERAGE OF THE PAINT INDUSTRY BY
SOUTHERN RESEARCH INSTITUTE DATA BASE
Total number of plants in size
' group3
Number of plants covered
Industry coverage, %
Total number of production
employees3
Number of production employees
covered
Industry coverage, %
Production of coating products,
millions of gallons per yeara
Industry coverage, %
Size of plant (number of employees)
Fewer
than 10
710
25
3.5
1,700
149
8.8
2.8
6.4
10 to
19
311
30
9.6
2,500
433
17.3
17.0
22.6
20 to
49
350
34
9.7
6,100
1,018
16.7
26.4
14.3
50 to
99
171
22
12.9
6,700
1,580
23.6
43.4
20.4
100 to
249
113
22
19.9
9,200
3,371
36.6
84.8
25.0
250 or
more
46
20
43.5
10,100
6,962
68.9
139.7
39.0
Total
1,701
153
9.0
36,300
13,513
37.2
314.1
26.0
aBased on data reported in 1967 Census of Manufactures, U. S. Department of Commerce.
Production reported in census adjusted to 1972.
-------
employees. In tabulating data for the paint industry in this
report, adjustments were made to take into account the differ-
ences in extent of coverage of the several size groups. The
adjustments were made on the basis of the percentage of the
industry's plants in each size group that supplied data. The
data in Table 24 indicate that the production of coating pro-
ducts was approximately proportional to the percentage of
plants covered in each group.
Information was obtained for ten of the eleven titanium diox-
ide plants to give a coverage of 90% of the plants in that
industry.
Of the 35 plants manufacturing other inorganic pigments, RAPP
applications were obtained for ten and data sheets for seven
plants.
52
-------
SECTION VIII
REFERENCES
1. Air Resources, Inc. Air Pollution Control Engineering
and Cost Study of Paint and Varnish Industry. Contract
Number 68-02-0259. Environmental Protection Agency.
1972.
2. Bridge, D. P., and Hummell, J. D. Incinerator Designed
Specifically to Burn Waste Liquids and Sludges. In:
1972 National Incinerator Conference Proceedings. New
York, American Society of Mechanical Engineers, 1972.
p. 55.
3. Bruhns, Frank. The Paint Industry versus Water Pollu-
tion. Paint and Varn. Prod. 6_1:35, May 1971.
4. Bureau of the Census, U. S. Department of Commerce.
Census of Manufactures. 1967.
5. Cecil, Lawrence K. Water Reuse and Disposal. Chem. Eng.
1£:92. 1969.
6. Datagraphics, Inc. Inorganic Chemicals Industry Profile.
Publication Number 12020 EJI 07/71. Environmental Pro-
tection Agency. Washington, D. C. July 1971.
7. Ficek, Kenneth J. Potassium Permanganate for Cleaner
Air and Water. Paint and Varn. Prod. 63^:45. 1973.
8. Hall, S. Douglas. How to Control Chemical Waste. Paint
and Varn. Prod. 6,2:41. 1972.
9. Hine, Willard R. Disposal of Waste Solvents. (Presented
at 48th Annual Meeting of the Federation of Societies
for Paint Technology. Boston. October 27, 1973.)
10. Kataoka, S., and Yamada, S. Acid Leaching Upgrades
Ilmenite to Synthetic Rutile. Chem. Eng. 8_0_:92. 1973.
11. Kirk-Othmer. Encyclopedia of Chemical Technology. New
York, John Wiley & Sons. 1967. Volume 14.
12. Marketing Guide to the Paint Industry. Fairfield, New
Jersey. Charles H. Kline & Co., Inc. 1972.
53
-------
13. Kobliska, J. J., Kodama, S. P., Eckhart, C. G., Gaydosh,
R. U., McMeckin, L. J., Santacana, F., and Prescott,
W. B. Determining Trace Elements. Paint and Varn. Prod.
£2:27. 1972.
14. Kunin, Robert. Pollution Abatement Control. J. Paint
Technol. 4J3:69. 1971.
15. Larkman, David. Physical/Chemical Treatment. Chem. Eng.
£0(14):87- 1973.
16. Larsen, Douglas K. DeSoto, Inc. (Presented at 84th
Annual Meeting of the National Paint, Varnish and Lacquer
Association. San Francisco. November 8, 1971.)
17. Larsen, Douglas K., and Kuncl, Karen L. COD, Solids
Removal Exceeds 90% in Effluent from Coatings Plant.
Chem. Process. 2_1:17. 1971.
18. Maass, Walter B. Solid Waste Disposal and Organic
Finishing. Metal Finish. 70^:44. 1972.
19. Mann, Abraham. Mercurial Biocides: Paint's Problem
Material. Paint and Varn. Prod. 61.:26. 1971.
20. Mann, Abraham. Special PVP Report/1972 Review/1973 Fore-
cast. Paint and Varn. Prod. 63_:23. 1973.
21. McGovern, Joseph G. Inplant Wastewater Control. Chem.
Eng. 8£:137. 1973»
22. Paint Red Book. New York, Palmerton Publishing Co.
1971.
23. Peschiera, Lincoln, and Freiherr, Frank H. Disposal of
Titanium Pigment Process Wastes. (Presented at 40th
Annual Conference of the Water Pollution Control Federa-
tion. New York. October 1967.)
24. Project Cope. Industry-wide Conference, Federation of
Societies for Paint Technology. Cleveland. May 1972.
25. Putting the Closed Loop into Practice. Environ. Sci.
Technol. 6_(13):1072. 1972.
26. Reiter, W. M., and Sobel, R. Waste Control Management.
Chem. Eng. 8£(14):59. 1973.
27. Rhodes, W. H., and Webb, R. J. Replacing Leaded Pig-
ments. Paint and Varn. Prod. 62:34. 1962.
54
-------
28. Roland, Robert A., and Ruckelshaus, William D. Industry
Forum. Paint and Varn. Prod. 6_2:36. 1972.
29. Rosenstein, Irwin. Three Industrial Waste Case Histo-
ries: Apple Processing, Paint Production, and Metal
Plating. (Presented at Industrial Water and Pollution
Conference and Exposition. New York. 1973.)
30. Sales Survey for the Year 1972. Washington, National
Paint and Coatings Association, Inc. January 1973.
31. Seels, Frank H. Industrial Water Pretreatment. Chem.
Eng. £0:27. 1973.
32. Titanium Dioxide Supplies Tighten as Demand Surges.
Chem. Eng. News. 5_1:8. 1973.
33. U. S. Department of Commerce. U. S. Industrial Outlook
1972 with Projections to 1980. 1972.
34. Walden Research Corp. Background Information for the
Establishment of National Standards of Performance for
New Sources. Paint and Varnish Manufacture. Contract
Number CPA 70-165. Environmental Protection Agency.
Research Triangle Park, N. C. October 1971.
35. Wellman, Glenn L. Mechanized Cleaning for Production
Equipment. Paint and Varn. Prod. 5:9:67- 1969.
36. Roy F. Weston, Inc. Pretreatment Guidelines for the
Discharge of Industrial Wastes to Municipal Treatment
Works. Environmental Protection Agency, Washington.
1972.
55
-------
SECTION IX
APPENDIX
FORMS FOR TABULATION OF DATA FROM INDIVIDUAL PLANTS
57
-------
Plant Identification Ho.
HASTEWATER SURVEY OF THE PAINT
AND INORGANIC PIGMENTS INDUSTRIES
Data Sheet for Paint Industry
1. Number of production and supervisory employees at this plant.
2. Average production man-hours per week
3. Year plant constructed
4. Year of most recent expansion or major modification of production
facilities
5. Products produced at this plant (specify Ib, gal, etc.)
Annual production
Hater-based paint products
Solvent-based paint products •
Clear coatings •
Lacquers ____^____^______
Putty, caulking compounds, wood fillers, and sealers
Resins and emulsions
Paint and varnish removers
Other (specify) __^
6. Principal raw materials consumed at this plant
(specify Ib, gal, etc.)
Annual consumption
Produced in plant Purchased
Resins and oils
Solvents _
Titanium dioxide
Other inorganic pigments
Organic pigments
Latexes
Fillers, extenders, dryers....
Other
(specify)
7. Has a Corps of Engineers' permit to discharge into navigable waters been applied for at this plant?
Q Ye. Q No
8. Have any other water-discharge permits been applied for in compliance with state or local regulations?
[n Yes Q No
9. Are the wastewater effluents from this plant routinely analysed?
Q] Yes, by plant staff
Q Yes, by outside laboratory
[| No, not required by disposal method
I""! No (specify reason)
58
-------
10. Indicate the amount of water consumed in this plant for each major uae by source.
Amount consumed, qpd ^__
MunicipalSurfaceRecycledother sources
Use or public water body Private well from plant Amount Sou
Boiler feed
Cooling water
Sanitary
Cleanup
Consumed in product
Air pollution control
Other
(specify)
Total
11. Indicate the amount of untreated wastewater only that is recycled to plant, lost, discharged, or
otherwise disposed of for each major use.Specify methods of disposition, if not listed below, i.e.,
storm sewers, deep well, surface dumping, ocean barging, etc.
Amount discharged, qpd
Municipal
sanitary Surface Recycled Other disposal methods
Use sewer water body Evaporation to plant Amount Method
Boiler feed
Cooling water
Sanitary
Cleanup
Air pollution control
Other
(specify)
Total
12. Indicate for each major use the amount of wastewater treated in-plant prior to discharge. Also indi-
cate amount discharged after treatment, where treated water is discharged (see headings in Question
11) , and whether wastewater is analysed before treatment or discharge.
Amount Amount Wastewater analyzed
treated, discharged, Before Before
_ Use _ gpd _ qpd Specify where discharged treatment discharge
Boiler feed
Cooling water _ _ _ _ I I Q
Sanitary _ _ __ I I Q
Cleanup ________ _ _ | _ | | ]
Air pollution control _ _ _ I I Q]
Other _ _ _ n I"]
tspecity) ___ n n
Total
13 If wastewaters are not treated or not routinely analysed, liat below the major contaminants known to
be present and their source (i.e., cleanup, air pollution control, etc.).
59
-------
14. For each type'of process equipment used, indicate the average size and number of batches produced per
day and the total quantity of wastewater, including cleanup or other process water, that becomes con-
taminated and is discharged. (Do not include water consumed in product.) If different types of
products are produced that vary in batch size or in quantity of water used, please use extra spaces
provided.
Description of products_
Typical Average no. Wastewater, Check if treated
Equipment batch size batches/day gal/batch Ultimate disposition before discharge
Feed/weigh tanks I—I
Mixers I—I
Mills LJ
Tinting/thinning tanks I—I
Transfer tanks ^^_^_^^^^^ I—J
D
Filling machines
Other
D
(specify)
B. Description of products
Typical Average no. Wastewater, Check if treated
Equipment . batch size batches/day gal/batch Ultimate disposition before discharge
Feed/weigh tanks 1—1
Mixers I—I
Mills LJ
Tinting/thinning tanks LJ
Transfer tanks I—I
D
Filling machines
Other
D
(specify)
C. Description of products
Typical Average no. Wastewater, Check if treated
Equipment batch size batches/day gal/batch Ultimate disposition before discharge
Feed/weigh tanks I—I
Mixers I—'
Mills I—I
Tinting/thinning tanks I—I
Transfer tanks I—J
D
Filling machines
Other
D
(specify)
v. Description of products
Typical Average no. Wastewater, Check if treated
Equipment batch size batches/day gal/batch Ultimate disposition before discharge
Feed/weigh tanks I—I
Mixers '—'
Mills LJ
Tinting/thinning tanks '—'
Transfer tanks *—'
Filling machines I—I
Other I—I
(specify)
60
-------
15. Please describe any special arrangements or agreements with waste acceptance firms, or public, munic-
ipal, or cooperative systems for the disposal or treatment of wastewaters. Describe nature and
source of contaminants, and fees and other costs arising from such services.
16. If this plant is equipped with floor drains that receive water from cleanup, spills, leaks, etc.,
water goes to:
17. Describe the disposition of accidental spills, leaks, contaminated runoff, and off-spec batches of
material.
18. Describe any special problems related to the treatment of waterborne wastes generated at this plant
that make it difficult to comply with existing or anticipated water-effluent regulations.
19. Other than treatment facilities, describe any modifications of operating processes or equipment
recently initiated or planned to reduce volume ot extent of contamination of wastewater.
20. Provide the following information for any in-plant water-treatment facilities.
Date initial facility installed.
Date of last major addition or modification
Capital cost to date
Additional capital investment projected through 1977
Annual operating costs
Design volume, gpd
Average volume of wastes treated, gpd
Method of disposal of sludge, if any
Adequacy of present facility in light of existing operations and regulations
Q Adequate Q Not adequate Q] Unknown
21. Describe plans for the addition or improvement of treatment facilities
61
-------
22. Describe below the waste treatment sequence for wastewaters which are treated prior to discharge by
using block diagrams similar to the example.
b.
c.
d.
Sources
Identify source from Questions 12 and 14.
Identify treatment with code number as given below.
Identify points at which samples are taken for analysis as 1, 2, 3, etc. Do not repeat number.
Identify ultimate disposition of treated wastewaters.
Treatment methods
and sampling points
^
Ultimate
disposition
/ — . II J.
Filtrate.
C/e iQf, + "V 5- P ' •""• ^
— # /t'O ^ I t/7 x\ ^
Treatment method codes
104. Neutralization 108. Chemical coagulation or flocculation
105. Odor control 109. Sedimentation or settling
106. Trickling filter 110. Digestion of solids
107. Activated sludge 111. Chemical treatment
100.. Equalization
101. Filtration
102. Flotation
103. Incineration
112. Aerated lagoon (specify retention time)
113. Anaerobic lagoon (specify retention time),
114. Other (specify)
115. Other (specify)
62
-------
23. For each point in the plant at which water is analyzed, provide the following information on any
parameters for which data are available. If sampling point is identified in Question 22, use its
identification number, otherwise please describe. Please make facsimile copies, if more are
required.
Sampling point_
Sampling point
Sampling point
Average flowi_
Maximum flow:
Average flow:
Maximum flow:
Parameter
pH
Total dissolved solids
Total suspended solids
Volatile suspended solids
Acidity/Alkalinity
BOD 5 — acclimated seed
Chemical oxygen demand
Total organic carbon
Total oxygen demand
Oil and grease
Sulfate
Sulfide
Organic nitrogen
Nitrogen, as N
Ammonia, as N
Phosphorus , total
Chlorides
Mercury
Lead
Cadmium
Chromium
Zinc
Iron
Titanium
Other (specify)
Max.
concn ,
mcj/1
Daily
avg
concn
mg/1
Sampling
frequency
Max.
concn,
mg/1
Daily
avg
concn,
mg/1
Sampling
frequency
Average flow: gpd
Maximum flow: gpd
Max.
concn,
mg/1
Daily
avg
concn ,
mg/1
Sampling
frequency
63
-------
Plant Identification No.
WASTEWATER SURVEY OF THE PAINT
AND INORGANIC PIGMENTS INDUSTRIES
Data Sheet for Inorganic Pigment Manufacturers
1. Number of production and supervisory employees at this plant.
2. Average total production man-hours per week
3. Year plant constructed
4. Year of most recent expansion or major modification of production
facilities
5. Products produced at this plant
Annual Annual
production, Ib production, Ib
White lead pigments.. Cadmium-based pigments
White zinc pigments.. Iron oxide pigments
Other white pigments. Organic pigments
Colored lead pigments Other inorganic pigments (specify)
Colored zinc pigments
Chrome-based pigments
6. Estimated consumption of products produced at this plant
For paint manufacturing % For ink manufacturing % For all other purposes
7. Principal raw materials consumed at this plant
Annual consumption, Ib
Unrefined minerals, ores
Processed minerals, pigments
Acids
Other (specify)
8. Has a Corps of Engineers' permit to discharge into navigable waters been applied for at this plant?
[n Yes Q No
9. Have any other water-discharge permits been applied for in compliance with state or local regulations?
Q Yes Q No
10. Are the wastewater effluents from this plant routinely analyzed?
P] Yes, by plant staff
II Yes, by outside laboratory
| | No, not required by disposal method
r~] No (specify reason) ,
-------
11. Indicate the amount of water consumed in this plant for each major use by source.
Amount consumed,
Municipal Surface Recycled Other sources
Use or public water body Private well from plant Amount Source
Boiler feed
Cooling water
Process water
Sanitary
Cleanup
Air pollution control
Other
(specify)
Total
12. Indicate the amount of untreated wastewater only that is recycled to plant, lost, discharged, or
otherwise disposed of for each major use.Specify methods of disposition, if not listed below, i.e.,
storm sewers, deep well, surface dumping, ocean barging, etc. ~
Amount discharged, gpd
Municipal
sanitary Surface Recycled Other disposal methods
Use sewer water body Evaporation to plant Amount Method
Boiler feed
Cooling water
Process water
Sanitary
Cleanup .
Air pollution control
Other
(specify)
Total
13. Indicate for each major use the amount of wastewater treated in-plant prior to discharge. Also indi-
cate amount discharged after treatment, where treated water is discharged (see headings in Question
13), and whether wastewater is analyzed before treatment or discharge.
Amount Amount Wastewater analyzed
treated, discharged, BeforeBefore
Use gpd gpd Specify where discharged treatment discharge
Boiler feed | | |~~|
Cooling water I I I I
Process water I I PH
Sanitary Q Q
Cleanup I I Q
Air pollution control | 1 Q
Other Q HI
tspeci£y) n n
Total
65
-------
14.
A.
For each type of process operation used, indicate the average size and number of batches produced per
day and the total quantity of wastewater, including cleanup or other process water, that becomes con-
tamined and is discharged. If different types of products are produced that vary in batch size or in
quantity of water used, please use extra spaces provided. If typical batch size and average number
of batches per day are not appropriate, report water usage in gal/lb of product.
Description of products
Operation
Precipitation
Filtration and washing
Calcining
Quenching
Wet grinding
Hilling
Other
Typical
batch size
(specify)
B. Description of products_
Average no.
batches/day
Hastewater,
gal/batch
Ultimate disposition
Check if treated
before discharge
D
D
D
D
D
D
D
Operation
Typical
batch size
Average no.
batches/day
Wastewater,
gal/batch
Ultimate disposition
Precipitation
Filtration and washing
Calcining
Quenching
Wet grinding
Milling
Other
(specify)
C. Description of products_
Check if treated
before discharge
D
D
D
D
D
D
D
Operation
Typical
batch size
Average no.
batches/day
Hastewater,
gal/batch
Ultimate disposition
Check if treated
before discharge
Precipitation
Filtration and washing
Calcining
Quenching
Wet grinding
Milling
Other
(specify)
D. Description of products_
D
D
D
D
D
D
D
Operation
Precipitation
Filtration and washing
Calcining
Quenching
Wet grinding
Milling
Other
(specify)
Typical
batch size
Average no.
batches/day
Wastewater,
gal/batch
Ultimate disposition
Check if treated
before discharge
D
D
D
D
D
D
D
66
-------
15. Please describe any special arrangements or agreements with waste acceptance firms, or public, munic-
ipal, or cooperative systems for the disposal or treatment of wastewaters. Describe nature and
source of contaminants, and fees and other costs arising from such services.
16. If this plant is equipped with floor drains that receive water from cleanup, spills, leaks, etc.,
water goes to:
17 If wastewaters are not treated or not routinely analyzed, list below the major contaminants known to
be present and their source U.e., cleanup, air pollution control, etc.).
18. Describe any special problems related to the treatment of waterborne wastes generated at this plant
that make it difficult to comply with existing or anticipated water-effluent regulations.
19. Other than treatment facilities, describe any modifications of operating processes or equipment
recently initiated or planned to reduce volume or extent of contamination of wastewater.
20. Provide the following information for any in-plant water-treatment facilities.
Date initial facility installed
Date of last major addition or modification
Capital cost to date
Additional capital investment projected through 1977
Annual operating costs
Design volume, gpd
Average volume of wastes treated, gpd
Method of disposal of sludge, if any^
21. Indicate adequacy of present wastewater management practices in light of existing operations and
regulations.
Q Adequate Q Hot adequate Q Unknown
22. Describe plans for the addition or improvement of treatment facilities
67
-------
23. Describe below the waste treatment sequence for wastewaters which are treated prior to discharge by
using block diagrams similar to the example.
a. Identify source from Questions 13 and 14.
b. Identify treatment with code number as given below.
c. Identify points at which samples are taken for analysis as 1, 2, 3, etc. Do not repeat number.
d. Identify ultimate disposition of treated wastewaters.
Sources
Treatment methods
and sampling points
1 — 4-
r i It rate-
C, \S-0- <*• I* p
1 i ~ * 3
t ° • f
\ 1
rnf IH«J
Z i
_- , , M
/ X
i ^ i -. a .. .-s/n*?
— ' lOQ ? / o 7
• v
_\y
O v
JK^
*1^
4- ~\>. ^
6/
Ultimate
disposition
> r\\ V& r-
Treatment method codes
104. Neutralization 108. Chemical coagulation or flocculation
105. Odor control 109. Sedimentation or settling
106. Trickling filter 110. Digestion of solids
107. Activated sludge 111. Chemical treatment
100. Equalization
101. Filtration
102. Flotation
103. Incineration
112. Aerated lagoon (specify retention time)
113. Anaerobic lagoon (specify retention time)
114. Other (specify)
115. Other (specify)
68
-------
24. For each point in the plant at which water is analyzed, provide the following information on any
parameters for which data are available. If sampling point is identified in Question 23, use its
identification number, otherwise please describe. Please make facsimile copies, if more are
required.
Sampling point_
Sampling point
Sampling point_
Average flow:_
Maximum flow:
Average flow:
gpd Maximum flow:
pd
Parameter
DH
Total dissolved solids
Total suspended solids
Volatile suspended solids
Acidity/Alkalinity
BOD s — acclimated seed
Chemical oxygen demand
Total organic carbon
Total oxygen demand
Oil and grease
Sulfate
Sulfide
Organic nitrogen
Nitrogen, as N
Ammonia, as N
Phosphorus , total
Chlorides
Mercury
Lead
Cadmium
Chromium
Zinc
Iron
Titanium
Other (specify)
Max.
concn ,
rag/1
Daily
avg
concn,
mg/1
Sampling
frequency
Max.
concn ,
mg/1
Daily
avg
concn ,
mg/1
Sampling
frequency
Average flow: gpd
Maximum flow: gpd
Max.
concn ,
mg/1
Daily
avg
concn ,
mg/1
Sampling
frequency
69
-------
Plant Identification No.
WASTEWATER SURVEY OF THE PAINT •
AND INORGANIC PIGMENTS INDUSTRIES
Data Sheet for Titanium Dioxide Manufacturers
1. Number of production and supervisory employees at this plant.
2. Average production man-hours per week
3. Year plant constructed
4. Year of most recent expansion or major modification of production
facilities
5. Products produced at this plant
Annual production, tons
Titanium dioxide ,
Other (specify)
6. Estimated consumption of products produced at this plant
For paint manufacturing % For paper manufacturing % For all other purposes %
7. Principal raw materials consumed at this plant
Annual consumption, tons
Produced in plantPurchased
Ore
Acids (specify type)
Chlorine
Mineral additives.
Other (specify)
8. Type of ore and typical assay (if more convenient, attach ore specification or analysis sheet)
9. Has a Corps of Engineers' permit to discharge into navigable waters been applied for at this plant?
D Yes D No
10. Have any other water-discharge permits been applied for in compliance with state or local regulations?
D Yes [^ No
11. Are the wastewater effluents from this plant routinely analyzed?
[~] Yes, by plant staff
r~] Yes, by outside laboratory
r~| No, not required by disposal method
|"~[ No (specify reason)
70
-------
12. Indicate the amount of water consumed in this plant for each major use by source.
Amount consumed, god
clei
Municipal Surface Recycled Other sources
Use or public water body Private well from plant Amount Source
Boiler feed
Cooling water
Process water
Sanitary
Cleanup
Air pollution control
Other
(specify)
Total
13. Indicate the amount of untreated wastewater only that is recycled to plant, lost, discharged, or
otherwise disposed of for each major use.Specify methods of disposition, if not listed below, i-e.,
storm sewers, deep well, surface dumping, ocean barging, etc.
Amount discharged, gpd
Municipal
sanitary Surface Recycled Other disposal methods
Use sewer water body Evaporation to plant Amount Method
Boiler feed
Cooling water ,
Process water
Sanitary
Cleanup
Air pollution control
Other
(specify)
Total
14. Indicate for each major use the amount of wastewater treated in-plant prior to discharge. Also indi-
cate amount discharged after treatment, where treated water is discharged (see headings in Question
13), and whether wastewater is analyzed before treatment or discharge.
Amount Amount Wastewater analyzed
treated, discharged, BeforeBefore
Ose gpd gpd Specify where discharged treatment discharge
Boiler feed | | PH
Cooling water ______^___ __^__^____ I I [ [
Process water | | FH
Sanitary | | FH
Cleanup • | | [ f
Air pollution control | | fH
Other Q [""I
t8pecity) : n n
Total
71
-------
IS. Refer to the appropriate diagram below and indicate the quantity, composition, and ultimate disposi-
tion of process wastewater at Points A through C for chloride process or Points A through I for sul-
fate process. Please modify diagram, if necessary.
Flow, gal/ton
Point of product
Major contaminants
Ultimate disposition
Check if treated
before discharge
A
B
C
D
E
F
G
H
I
CHLORIDE PROCESS
Rutile
ore
Pui
Carbon
4
Lorination ]
TiCl.,
\
rification |
A
Oz *j oxidation |
1 = Pi<
steam f Hc
t PU
Oversize
1 se
later in -
Water B —£
Dr
Pu
Ba
naent collection 1
A
itralization j^apor^. ^
1
Lping |
ttling
i
ating 1
Itering, washing | '"««i- £
4
/i"9 1 if '"".I- C
1 removal
Iverizing, air separation |
i
aging , storing 1
SULFATE PROCESS
Ilmenite
ore
1
>l Grinding
1
™^n^ *{ Digestion, reduction
.1
1 Thicken ing
1 Crystallizing
| Separation of iron salts
[
1 Concentrating
i
| Hydrolysis
1
Hater ^j Filtering
1
| Kiln
|
water i Kepulping
i
I Milling
J
Hater ^ Thickening
D
a
a
a
a
a
a
a
a
Vaoors __ <
Residue r
Iron /
salts l
1 Vapors T
— E2 -I
recovery
to TiO» ~ '
recovery
to dust l
separation
Overflow I
to waste '
72
-------
16. Please describe any special arrangements or agreements with waste acceptance firms, or public, munic-
ipal, or cooperative systems for the disposal or treatment of wastewaters. Describe nature and
source of contaminants, and fees and other costs arising from such services.
17. If this plant is equipped with floor drains that receive water from cleanup, spills, leaks, etc.
water goes to:
18. Describe the disposition of accidental spills, leaks, contaminated runoff, and off-spec batches of
material.
19. Describe any special problems related to the treatnerit of waterborne wastes generated at this plant
that make it difficult to comply with existing or anticipated water-effluent regulations.
20. Other than treatment facilities, describe any modifications of operating processes or equipment
recently initiated or planned to reduce volume or extent of contamination of wastewater.
21. Provide the following information for any in-plant water-treatment facilities.
Date initial facility installed
Date of last major addition or modification
Capital cost to date
Additional capital investment projected through 1977
Annual operating costs
Design volume, gpd
Average volume of wastes treated, gpd
Method of disposal of sludge, if any
Adequacy of present facility in light of existing operations and regulations
Q Adequate Q Not adequate Q Unknown
22. Describe plans for the addition or improvement of treatment facilities
73
-------
23. Describe below the waste treatment sequence for wastewaters which are treated prior to discharge by
using block diagrams similar to the example.
a. Identify source from Questions 14 and 15.
b. Identify treatment with code number as given below.
c. Identify points at which samples are taken for analysis as 1, 2, 3, etc. Do not repeat number.
d. Identify ultimate disposition of treated wastewaters.
Sources
Treatment methods
and sampling points
—
r ill fsTe-
Qf |C.
"/"xj ; ' v
^" "r*- *r
> lo& &
Ultimate
disposition
vc r
Treatment method codes
104. Neutralization 108. Chemical coagulation or flocculation
105. Odor control 109. Sedimentation or settling
106. Trickling filter 110. Digestion of solids
107. Activated sludge 111. Chemical treatment
100. Equalization
101. Filtration
102. Flotation
103. Incineration
112. Aerated lagoon (specify retention time)
113. Anaerobic lagoon (specify retention time)_
114. Other (specify)
115. Other (specify)
-------
24. For each point in the plant at which water is analyzed, provide the following information on any
parameters for which data are available. If sampling point is identified in Question 23, use its
identification number, otherwise please describe. Please make facsimile copies, if more are
required.
Sampling point_
Sampling point
Sampling point_
Average flow:_
Maximum flowi
pd Average flow:
gpd Maximum flow:
gpd
Parameter
PH
Total dissolved solids
Total suspended solids
Volatile suspended solids
Acidity /Alkalinity
BOD; — acclimated seed
Chemical oxygen demand
Total organic carbon
Total oxygen demand
Oil and grease
Sulfate
Sulfide
Organic nitrogen
Nitrogen, as N
Ammonia, as N
Phosphorus, total
Chlorides
Mercury
Lead
Cadmium
Chromium
Zinc
Iron
Titanium
Other (specify)
Max.
concn,
mg/1
Daily
avg
concn ,
mg/1
Sampling
frequency
Max.
concn ,
mg/1
Daily
avg
concn,
mg/1
-
Sampling
frequency
Average flow: gpd
Maximum flow: gpd
Max.
concn ,
mg/1
Daily
avg
concn ,
mg/1
Sampling
frequency
75
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA-670/2-74-030
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
WATERBORNE WASTES OF THE PAINT AND
INORGANIC PIGMENTS INDUSTRIES
5. REPORT DATE
March 197H^Issuing Date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
William J. Barrett, George A. Morneau,
and John J. Roden, III
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORG-\NIZATION NAME AND ADDRESS
Southern Research Institute
2000 Ninth Avenue South
Birmingham, Alabama 35205
10. PROGRAM ELEMENT NO.
1BB036;ROAP21AZQ;TASK01
R-800602
12. SPONSORING AGENCY NAME AND ADDRESS
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 4526-8
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This report describes a study of the wastewater management practices in
the paint and inorganic pigments industries. Information was obtained
from 153 plants manufacturing paints, 10 titanium dioxide plants, and
10 plants that produce other inorganic pigments. The data were analyzed
to identify the sources and characteristics of wastewater from the manu-
facturing processes of these plants, to determine the practices for
wastewater control and treatment that are presently employed, and to
identify deficiencies in technology that may require research and
development to improve control and treatment methods. The major find-
ings of the study indicate that although the paint industry uses approx-
imately 300 million liters (80 million gal.) of water per day, only a
small portion of this, less than 5%, is necessarily contaminated by
virtue of its use. Suspended solids, consisting of pigments and resin
particles, are the major wastewater contaminants of the paint industry.
The wastewaters from plants that produce titanium dioxide or other
inorganic pigments generally contain a high level of dissolved solids
and acids for which no entirely satisfactory control and treatment
methods exist.
17.
KEY WORDS AND DOCUMENT ANALYSIS
a.
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
*Water pollution
sources, Waste water
disposal, Chemical
wastes, Waste water
treatment, *Heavy
metals, ^Colored
pigments , ^Inorganic
pigments, Water
c. COS AT I Field/Group
*Paints, ""Pigments, ""Titanium
dioxide, ''Industrial wastes,
Waste water, *Waste treatment,
Titanium
13B
rments ,
.lution
control
pollution control
f9. SECURITY CLASS (ThisReport)
UNCLASSIFIED
13. DISTRIBUTION STATEMENT
21. NO. OF PAGES
86
Release to public
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
76
.S. Government Printing Office: 757-582/5316
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