DRAFT
Development Document
for Effluent Limitations
Guidelines and
Standards of Performance
SOAP
and
DETERGENT
INDUSTRY
PREPARED BY
COLIN A. HOUSTON & ASSOCIATES, INC.
FOR
\
o
T
/
United States Environmental Protection Agency
UNDER CONTRACT NUMBER 68-01-1517
JUNE 1973
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NOTICE
The attached document is a DRAFT CONTRACTOR'S REPORT. It
includes technical information and recommendations submitted
by the Contractor to the United States Environmental Protec-
tion Agency ("EPA") regarding the subject industry. It is
being distributed for review and comment only. The report
is not an official EPA publication and it has not been re-
viewed by the Agency.
The report, including the recommendations, will be undergoing
extensive review by EPA, Federal and State agencies, public
interest organizations and other interested groups and persons
during the coming weeks. The report and in particular the
contractor's recommended effluent limitations guidelines and
standards of performance is subject to change in any and all
respects.
The regulations to be published by EPA under Sections 304 (b)
and 306 of the Federal Water Pollution Control Act, as amended,
will be based to a large extent on the report and the comments
received on it. However, pursuant to Sections 304 (b) and
306 of the Act, EPA will also consider additional pertinent
technical and economic information which is developed in the
course of review of this report by the public and within EPA.
EPA is currently performing an economic impact analysis re-
garding the subject industry, which will be taken into account
as part of the review of the report. Upon completion of the
review process, and prior to final promulgation of regula-
tions, an EPA report will be issued setting forth EPA s con-
clusions concerning the subject industry, effluent limitations
guidelines and standards of performance applicable to such
industry. Judgments necessary to promulgation of regulations
under Sections 304 (b) and 306 of the Act, of course, remain
the responsibility of EPA. Subject to these limitations, EPA
is making this draft contractor s report available in order
to encourage the widest possible participation of interested
persons in the decision making process at the earliest
possible time.
The report shall have standing in any EPA proceeding or court
proceeding only to the extent that it represents the views of
the Contractor who studied the subject industry and prepared
the information and recommendations. It cannot be cited, ref-
erenced, or represented in any respect in any such proceedings
as a statement of EPA's views regarding the subject industry.
U.S. Environmental Protection Agency
Office of Air and Water Programs
Effluent Guidelines Division
Washington, D.C. 20460
DRAFT
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DRAFT
DEVELOPMENT DOCUMENT
for
EFFLUENT LIMITATIONS GUIDELINES
and
STANDARDS OF PERFORMANCE
SOAP AND DETERGENT INDUSTRY
AND ESTABLISHMENTS PRODUCING CRUDE
AND REFINED GLYCERINE FROM VEGETABLE
AND ANIMAL FATS AND OILS
June 1973
Colin A. Houston & Associates Inc.
1154 Old White Plains Road
Mamaroneck, New York 10543
DRAFT
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REVIEW NOTICE
This document presents conclusions and recommendations of
a study conducted for the Effluent Guidelines Division,
United States Environmental Protection Agency, in support
of proposed regulations providing effluent limitation guide-
lines and new source standards for the soap and detergent
industry.
The conclusions and recommendations of this document may
be subject to subsequent revisions during the document re-
view process, and as a result the proposed guidelines for
effluent limitations as contained within .this document may
be superceded by revisions prior to final promulgation of
the regulations in the Federal Register on or before
18 October 1973, as required by the Federal Water Pollution
Control Act Amendments of 1972 (P.L. 92-500).
DRAFT ii
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ABSTRACT
This document presents the findings of an extensive study
of the soap and detergent industry by Colin A. Houston &
Associates Inc. for.the Environmental Protection Agency
for the purpose of developing effluent limitations guide-
lineSj Federal standards of performance, and pretreatment
standards for the industry, to implement Sections 304, 306
and 307 of the "Act".
Effluent limitations guidelines contained herein set forth
the degree of effluent reduction attainable through the
application of the best practicable control technology cur-
rently available and the degree of effluent reduction attain-
able through the application of the best available technology
economically achievable which must be achieved by existing
point sources by July 1, 1977 and July 1, 1983 respectively.
The Standards of Performance for new sources contained herein
set forth the degree of effluent reduction which is achiev-
able through the application of the best available demonstrated
control technology processes, operating methods, or other
alternatives.
The proposed regulations for each level of technology set
forth above suggest guidelines for Levels I, II and III as
set forth in Section I of this report "Conclusions" and
amplified throughout the body of this report.
Supportive data and rationale for development of the pro-
posed effluent limitations guidelines and standards of
performance are contained in this report.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT iii
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CONTENTS
Section
II
III
IV
CONCLUSIONS
General
Categorization
Fatty Acids
Industrial Surfactants
History and Source of Data
Glycerine
Integrated Plants
Technology
Present Situation
Guidelines - Level I
Guidelines - Level II
Guidelines - Level III
RECOMMENDATIONS
INTRODUCTION
Purpose and Authority
Summary of Methods Used for
Development of the Effluent
Limitations Guidelines and
Standards of Performance
General Description
Historical
Companies and Markets
Industrial Cleaning Compounds
Sales and Production
Physical Plant
Trade Practices
Industry Problems
Future Trends
Basis of Soap and Detergent
Formulations
INDUSTRY CATEGORIZATION
Choice of Categories
Soap Manufacturing
Soap Process Descriptions
Process 101 - Soap Manufacturing
by Batch Kettle
Fat Refining and Bleaching
Soap Boiling
Continuous Soap Manufacture
1
3
4
4
4
5
7
7
8
9
11
13
15
17
17
18
19
19
20
22
23
23
23
24
24
26
33
33
35
35
35
35
37
40
DRAFT
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CONTENTS (Continued)
Section
IV INDUSTRY CATEGORIZATION (Continued)
Process 102 - Fatty Acid Manufactured
by Fat Splitting 41
Process 103 - Soap from Fatty Acid
Neutralization 43
Process 104 - Glycerine Recovery 46
Concentration 46
Distillation 46
Process 105 - Soap Flakes and Powders 48
Process 106 - Bar Soaps 49
Process 107 - Liquid Soap 53
Detergent Manufacturing Processes 55
Process 201 - Oleum Sulfonation and
Sulfation 56
Process 202 - Air-S03 Sulfation and
Sulfonation 56
Process 203 - SOo Solvent and Vacuum
Sulfonation 57
Process 204 - Sulfonic Acid Sulfation 60
Process 205 - Chlorosulfonic Acid
Sulfation 60
Process 206 - Neutralization of
Sulfuric Acid Esters and Sulfonic
Acids 60
Process 207 - Spray Dried Detergents 65
Process 208 - Liquid Detergents 66
Process 209 - Dry Detergent Blending 68
Process 210 - Drum Dried Detergents 71
Process 211 - Detergents - Bars and
Cakes 71
V WASTE CHARACTERIZATION 75
Introduction 75
Analytical Procedures 75
Acidity, Alkalinity and pH 75
Oxygen Demand 76
Surfactants, MBAS (Methylene Blue
Active Substances) 77
Phenols 78
Oil and Grease 78
Solids 78
Chemical Analyses 79
Standard Methods 79
Unit Processes 79
Process 101 80
Process 102 82
DRAFT
vi
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CONTENTS (Continued)
Section
VI
WASTE CHARACTERIZATION (Continued)
Process 103
Process 104
Process 105
Process 106
Process 107
Process 201
Process 202
Process 203
Process 204
Process 205
Process 206
Process 207
Process 208
Process 209
Process 210
Process 211
Analysis of Corps of Engineers
Permit Applications
SELECTION OF POLLUTION PARAMETERS
83
84
85
86
87
87
89
90
91
91
92
92
95
97
98
98
98
105
VII
Introduction 105
Biochemical Oxygen Demand 106
Chemical Oxygen Demand 106
Suspended Solids 107
Surfactant (MBAS) 107
Oil and Grease 107
pH 1U8
Parameters Omitted 108
Nitrogen 108
Phosphorus 108
Boron 110
Scope of Parameters Measured(101-211) 110-117
Industrial Cleaners 117
CONTROL AND TREATMENT TECHNOLOGY 119
Chemical and Physical Equilibrium 119
Soap and Detergent Industry
Process Control 119
Nature of Pollutants 125
Treatment Technology 127
DRAFT
vii
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CONTENTS (Continued)
Section
VII
VIII
IX
CONTROL AND TREATMENT TECHNOLOGY (cont'd.)
Discussion of Treatment Techniques 127
Oil and Grease Removal 127
Coagulation and Sedimentation 130
Bioconversion Systems 130
Carbon Adsorption Systems 130
Filtration for Removal of Suspended
Solids 131
Dissolved Solids Removal 131
Other Treatment Technique
Considerations 131
Special Operational Aspects of
Control Technology 132
Implementation of Treatment Plans 134
Solid Waste Generation Associated
with Treatment Techniques 142
COST, ENERGY AND NON-WATER QUALITY ASPECTS 149
The Technologies of In-Plant Control 149
Pre-Selection and Parity of Feed Stock 150
Physical Separation 151
Recycle of Unreacted Components 152
Cost and Energy Requirements of
Applicable Technology 153
Non-Water Quality Aspects 154
A Concordant Air-Water-Solid
Effluent Guideline 155
BEST PRACTICABLE CONTROL TECHNOLOGY
CURRENTLY AVAILABLE (LEVEL I) 159
Introduction 159
Process 101 160
Process 102 163
Process 103 165
Process 104 166
Process 105 170
Process 106 171
Process 107 172
Process 201 174
Process 202 175
Process 203 177
Process 204 178
DRAFT
viii
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Section
IX
XI
CONTENTS (Continued)
BEST PRACTICABLE CONTROL TECHNOLOGY
CURRENTLY AVAILABLE (LEVEL I) (cont'd)
Process 205
Process 206
Process 207
Process 208
Process 209
Process 210
Process 211
Process 102 - Fatty Acid Hydrogenation
Levels I, II and III
BEST AVAILABLE TECHNOLOGY ECONOMICALLY
ACHIEVABLE (LEVEL II)
Level II Guideline Recommendations
Process 101
Process 102
Process 103
Process 104
Process 106
Process 201
Process 202
Process 203
Process 204
Process 205
Process 208
NEW SOURCE PERFORMANCE STANDARDS AND
PRETREATMENT STANDARDS (LEVEL III)
Introduction
Level III Guideline Recommendations
Process 101
Process 108 - Continuous Counter
Current Process
Process 103
Process 106
Process 201
Process 202
Process 207
Potential New Technology
Process 202-N - Sulfonation Process
by Free Radical Reactions
Pretreatment Requirements
Level III Control and Treatment
Technology
180
181
183
188
190
191
193
195
199
200
202
205
209
210
213
214
219
224
224
224
225
227
227
228
230
230
233
233
238
239
244
246
246
250
253
DRAFT
ix
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CONTENTS (Continued)
Section Page
XII ACKNOWLEDGMENTS 255
XIII REFERENCES 257
XIV GLOSSARY 263
DRAFT
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TABLES
Number
2
3
4
5
6
7
8
9
10
11
Title
Summary Value of Shipments at
Manufacturers Level - Soaps and
Detergents SIC 2841 - After 1967
Census of Manufacturers (Adjusted)
Treatment Methods Used in the Elimi-
nation of Pollutants
Residual Pollutants 101 - Kettle
Boil Soap
Residual Pollutants 104 - Glycerine
Recovery
Residual Pollutants 106 - Bar Soap
Residual Pollutants 201 - Oleum
Sulfonation
Residual Pollutants 207 - Spray Dry
Detergents
Residual Pollutants 209 - Liquid
Detergents
Cost and Energy Requirements for
for Treatment Methods
Cost of Sludge Conditioning and
Disposal
Relative Efficiency of Several Methods
Used in Removing Pollutants
25
128
136
137
138
139
140
141
144-147
148
148a
DRAFT
xi
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FIGURES
Number Title Fagt
1 Soap Manufacture by Batch Kettle 36
2 Soap Making 39
3 Fatty Acid Manufacture by Fat Splitting 42
4 Soap from Fatty Acid Neutralization 44
5 Glycerine Recovery 47
6 Soap Flakes and Powders 50
7 Bar Soaps 52
8 Liquid Soap Processing 54
9 Oleum Sulfonation/Sulfation 58
10 Air-SO? Sulfation/Sulfonation 59
11 803 Solvent and Vacuum Sulfonation 61
12 Sulfamic Acid Sulfation 62
13 Chlorosulfonic Acid Sulfation 63
14 Neutralization of Sulfuric Acid Esters
and Sulfonic Acids 64
15 Spray Dried Detergents 67
16 Liquid Detergent Manufacture 69
17 Detergent Manufacture by Dry Blending 70
18 Drum Dried Detergent 72
19 Detergent Bars and Cakes 73
20 Composite Flow Sheet Waste Treatment
Soap and Detergent Industry 129
21 Sludge Solids Handling Soap and
Detergent Industry 135
22 Wastewater Sources in Soap Manufacture 161
23 Fat Splitting 163
24 Fats Recovery System 165
25 Glycerine Concentration 167
26 101-Soap Manufacture by Batch Kettle -
Modified 203
27 102-Fatty Acid Manufacture by Fat
Splitting - Modified 206
28 102-M Fatty Acid Manufacture: Hydrogena-
tion Step, if Carried Out 207
29 104-Glycerine Recovery 211
30 104-B Concentration of 80% Glycerine
to 99.5% 212
31 201 and 206-Continuous Detergent Slurry
Processing Plant 215
32 201 Modified 216
33 108-Soap Manufacture by Continuous
Saponification 231
34 103 Modified-Soap by Continuous Fatty
Acid Neutralization 234
DRAFT
xiii
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FIGURES (continued)
Number Title
35 Continuous 803 Sulfonation 240
36 Fatty Achohol Sulfation with 803 242
37 Alpha-Olefin Sulfonation with S03 243
DRAFT
xiv
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SECTION I
CONCLUSIONS
General
The manufacturing plants of the soap and synthetic deter-
gent industry represent a minor source of water pollution.
The industry is not a heavy user of water. Exclusive of
cooling and boiler water, it uses approximately 15,160
million liters a year (or 4 billion gallons a year) in its
processes. The pollutants emanating from its plants are
non-toxic and readily responsive to treatment. Some excep-
tions to this statement exist in the industrial surfactant
area and are discussed in this report.
More than 95% of plant effluents go to municipal treatment
plants with less than 5% classed as point sources. Since
virtually every kilogram (pound') of the 5.8 billion kilo-
grams (12.8 billion pounds) of product estimated to be pro-
duced in these plants in 1973 is destined for the nation's
treatment plants and waterways, the intricacies of the manu-
facturing processes of this industry warrant better under-
standing.
By dictionary definition a detergent is a cleaning agent
and includes ordinary bar soap, which is classically based
on natural fat. In popular usage, however, the term deter-
gent commonly excludes soap being restricted to the family
of cleaning compounds derived largely from petrochemicals.
This report follows popular usage.
?oaps and detergents are performance products. For example,
like paints, literally thousands of chemical compositions can
be formulated which clean or paint a surface. Detergents can
be formulated with entirely different organic and inorganic
chemicals to accomplish the same cleaning power or have the
same biodegradability. Detergents can also be formulated to
produce minimum solid waste and minimize air or water pollu-
tion in the manufacturing process. They can be formulated,
for example, to: (see following page)
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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1. Maximize cleaning power
2. Maximize biodegradability
3. Minimize eutrophication potential in a specific recei-
ving water.
4. Maximize cleaning power/unit cost
5. Minimize pollutants to:
a) Water
b) Air
c) folid waste
from the manufacturing process.
The guidelines recommended here have been designed to mini-
mize water pollution (5a above). Nonetheless, the report
takes account of items 1 through 4 and 5b and 5c above.
It is possible today to design formulas to satisfy criterion
5a above and give almost zero discharge of pollutants from
the manufacturing process to water. However, the imposition
of such low pollutant discharge limits on water from the
plants of the industry might result in forcing radical re-
formulations .
Study indicates, for example, that one formulation which would
enable a zero discharge from a manufacturing plant was volun-
tarily discarded by the industry 10 years ago because of its
poor biodegradability. Thus, hurried imposition of low dis-
charge regulations on the manufacturing plants might set
back progress in developing more environmentally sound for-
mulations for use by the nation's households.
Because of the great formulating flexibility possible in this
industry and the aforementioned often conflicting requirements
in items 1-5 above, attempts have been made to push 5a (mi-
nimization of pollutants to water from the manufacturing
plants) as far as possible in the recommended effluent guide-
lines recommendations without causing serious upset to items
1-4 and 5b and c.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON '
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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As more experience is gained it may well be possible to tighten
the guidelines recommended in this report or it might be
prudent to slightly relax a few of them.
Categorization
For the purpose of establishing effluent limitation guide-
lines and standards of performance the soap and detergent
industry has been divided into 18 categories or processes.
These units constitute building blocks to enable a permit
granting authority to evaluate and set standards for a plant
complex; the processes covered herein are:
SOAP MANUFACTURE
CODE PROCESS DESCRIPTION
101 Soap Manufacture - Batch Kettle and Continuous
102 Fatty Acid Manufacture By Fat Splitting
103 Soap From Fatty Acid Neutralization
104 Glycerine Recovery and Concentration
105 Soap Flakes & Powders
106 Bar Soaps
107 Liquid Soap
DETERGENT MANUFACTURE
CODE PROCESS DESCRIPTION
201 Oleum Pulfonation & Sulfation (Batch & Continuous)
202 Air S03 Sulfation and Sulfonation (Batch & Continu-
ous)
203 Solvent and Vacuum Sulfonation
204 fulfamic Acid Sulfation
205 Chlorosulfonic Acid Sulfation
206 Neutralization of Sulfuric Acid Esters & Sulfonic
Acids
207 Spray Dried Detergents
208 Liquid Detergent Manufacture
209 Detergent Manufacturing By Dry Blending
210 Drum Dried Detergents
211 Detergent Bars & Cakes
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT i
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EPA to prevent either natural or synthetically produced
glycerine from gaining an economic advantage here.
Fatty Acids
Guidelines for fatty acid production are set in this study
although in the Standard Industrial Classification, many
fatty acid plants are placed in the organic chemicals
industry rather than in the soap and detergent industry.
We believe the standards outlined in this report can be
applied fairly to all fatty acid production from natural
fats regardless of whether they are produced under the
heading of soaps and detergents or organic chemicals.
Synthetically produced fatty acids are not now a factor in
the U S. but they could become so in the near future. At
that time guideline standards for products derived from
natural oils will have to be re-evaluated with a view
toward providing fatty acids from natural products parity
with the guidelines applicable to synthetic fatty acid
production
Industrial Surfactants^
Since the treatability of many of the ingredient raw
materials of industrial surfactant formulas is expected to
be discussed in the guidelines for inorganic and organic
chemicals, it appeared premature to embark on a treatability
study on such compounds as chlorinated benzenes or hydro-
fluoric acid at the soap and detergent use level. Thus,
although industrial detergents are discussed in this report,
treatment studies of the raw materials involved are not
detailed and the study focuses on the bulk of dollar and
pound production, namely household cleaning products.
An in depth study of industrial detergents would be a desir-
able sequel to this report.
HISTORY AND SOURCE OF DATA
When contract awarded to contractor 1/16/73, there were no
detailed effluent studies available on this industry. A
literature search including previous EPA and state work
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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EPA to prevent either natural or synthetically produced
glycerine from gaining an economic advantage here.
Fatty Acids
Guidelines for fatty acid production are set in this study
although in the Standard Industrial Classification, many
fatty acid plants are placed in the organic chemicals
industry rather than in the soap and detergent industry.
We believe the standards outlined in this report can be
applied fairly to all fatty acid production from natural
fats regardless of whether they are produced under the
heading of soaps and detergents or organic chemicals.
Synthetically produced fatty acids are not now a factor in
the U S. but they could become so in the near future. At
that time guideline standards for products derived from
natural oils will have to be re-evaluated with a view
toward providing fatty acids from natural products parity
with the guidelines applicable to synthetic fatty acid
production,
Industrial Surfactants
Since the treatability of many of the ingredient raw
materials of industrial surfactant formulas is expected to
be discussed in the guidelines for inorganic and organic
chemicals, it appeared premature to embark on a treatability
study on such compounds as chlorinated benzenes or hydro-
fluoric acid at the soap and detergent use level. Thus,
although industrial detergents are discussed in this report,
treatment studies of the raw materials involved are not
detailed and the study focuses on the bulk of dollar and
pound production, namely household cleaning products.
An in depth study of industrial detergents would be a desir-
able sequel to this report.
HISTORY AND SOURCE OF DATA
When contract awarded to contractor 1/16/73, there were no
detailed effluent studies available on this industry. A
literature search including previous EPA and state work
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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yielded little useful data. The Corps of Engineers permit
applications were assembled and analyzed. The 30 permit
applications yielded little correlatable data since infor-
mation as to the products produced and any relationship of
product or processes to effluent flows was lacking. Without
a rational approach to the source of effluents from either
the literature or permit applications, a meeting was called
in Washington attended by EPA, Contractor, Trade Association
and industry personnel. As a result of this meeting, where
the problem was reviewed, it was agreed to take a building
block apprpach and the industry volunteered schematic flow
diagrams of each of their major processes. The flow diagrams
were assembled at a following New York meeting and a composite
schematic for each manufacturing process was drawn. Based
on these composite schematic drawings, the Contractor prepared
a detailed information audit request which the Trade Associations
circularized to their members. Another problem then arose when
it was found that the soap and detergent companies possessed
little or no detailed data regarding their effluent flows.
Most effluent data from the companies turned out to be on
combined sewers, combining the effluent of three to ten
process units and hence were of little value. Therefore,
the sample program originally conceived by the EPA and
Contractor as a program to verify literature and company-
provided information had to be enlarged and turned into a
major research project.
With the help of seven EPA laboratories, one state labora-
tory, plus two sub-contractor laboratories, one on the east
coast and one on the west, a major sampling program began.
The next problem encountered was the difficulty of sampling
the sewer lines of the various unit processes. Many were
under several feet of concrete. A number of ingenious schemes
were worked out to obtain the data needed. Great cooperation
was necessary from the companies, since in some cases lines
had to be broken into, processes started and stopped, and
special equipment washdowns arranged. A good data base
was thus obtained.
Ideally, such data should be obtained by composite sampling
over a period lasting from thirty days to a year. Because
of the great pressure to complete this work to enable the
EPA to publish guidelines October 18, 1973, as called for
in the Act, Public Law 92-500, it was impossible to run any
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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composite program longer than one week. As the scope of the
problem was realized the companies of the industry provided
increased assistance. A number of the sample programs ini-
tiated are being continued voluntarily by the companies.
More sophisticated information has begun to come in.
For publication of this report, it was necessary to foreclose
use of further data June 15, 1973. The data flow is expected
to continue and, after collation, is being turned over to
the EPA as received. A major conclusion stemming from this
work is the recognition of the necessity of arranging for a
long term EPA depository for industry effluent data so that
water handling problems can be fairly and inventively dealt
with.
Integrated Plants
An important conclusion reached in this study was that inte-
grated plants having a group of several unit processes at
the same plant site have a substantial advantage in their
ability to minimize pollution by cascading water and working
off the by-products from one process into another unit
process step. Although we have indicated many places where
we believe the permit writer should, for this reason, apply
more lenient standards to the small one or two unit process
plant, this is really an area needing case by case evalua-
tion.
It is recommended that the EPA maintain a soap and detergent
industry staff expert to be available to assist EPA regional
districts and state EPA's and thus help resolve such issues
when called on. The general force of guidelines is to make
the existence of the small company more tenuous and a con-
certed effort will be necessary to eliminate such an unfor-
tunate consequence.
Technology
Regarding levels II and III which make it necessary for the
industry to consider new technology and the application of
technology utilized in other industries to their own in-
dustry, this study recommends guidelines in levels II and
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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Ill at such a level that the industry is encouraged to evaluate
alternatives and supplements to barometric condensers in low
pressure distillation. Guideline levels could be met by the
addition of surface condensers and vacuum pumps or supplemental
liquid extraction as an aid in preventing light ends loss to
the water stream. The ultimate objective is the reduction of
the high BOD loadings of this industry when operating processes
highly dependent upon the barometric condensers for pressure re-
duction. If other industry guidelines do not have a similar ef-
fect, if the organic chemicals guidelines do not have the effect
of encouraging replacement of barometrics on a proposed new syn-
thetic fatty acid plant, this could alter the economics of ex-
pansion in the naturally derived fatty acid industry.
The conclusion is that it will require much coordination by EPA
to avoid having serious inequities arise.
Present Situation
This report is written around soaps and synthetic deter-
gents as they are being formulated in 1973. A considerable
effort has been made to avoid forcing major reformulations
on the manufacturers by setting water effluent standards at
the plant level so stringent as to necessitate such action
and thus upset the present good progress towards environ-
mentally sound formulations.
From a national treatment standpoint, and to lessen the
possible eutrophication impact of soap and detergent formu-
las, it may be necessary to change the 1973 formulas
considerably. Such changes will result in different
effluents from the production units. In the soap and
glycerine field, changes in formulation are not likely to
be very pronounced, but in detergent bars, powders and
liquids, substantial changes in effluents from unit pro-
cesses and hence detergent plants may be necessary to mini-
mize ecological impact of the end product in specific
receiving watersheds.
The guidelines according to the "Act" are to be updated
every year. Particularly in this industry, the guidelines
need to be reviewed annually to permit improvements in
formulas and to cover such possible conflicts as are outlined
above in regard to glycerine and fatty acids.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
8
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GUIDELINES
All values are given in terms of kilograms (kg) of pollutant
per 1000 kg of the anhydrous product produced in the numbered
process given. As all values express weight to weight ratios
the units are interchangeable and Ibs can be substituted for
kgs. For example, 0.6 kg BODc per 1000 kg of product is an
identical ratio to 0.6 Ibs 5005 per 1000 Ibs of product.
Level I Effluent Guideline Recommendations
101 - Soap Manufacture
Batch Kettle
102 - Fatty Acid Manu-
facture By Fat
Splitting
103 - Soap From Fatty
Acid Neutrali-
zation
104A- Glycerine Con-
centration
104B- Glycerine Dis-
tillation
105 - Soap Flakes &
Powders
106 - Bar Soaps
107 - Liquid Soap
BOD5
0.6
0.01
0.34
0.01
SOAP MANUFACTURE
COD
1.0
1.2 2.2
0.01 0.03
1.5 3.0
0.5 1.0
0.03
0.57
0.03
Susp.
Solids
0.4
2.2
0.02
0.2
0.2
0.01
0.58
0.01
Surf.
Oil
&
Grease
0.1
0.3
0.01
0.1
0.1
0.01
0.04
0.01
Note: All categories have pH of 6 - 9.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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Level I Effluent Guideline Recommendations
DETERGENT MANUFACTURE
Oil
Susp. &
BOD5 COD Solids Surf. Grease
201 - Oleum Sulfonation
& Sulfation (Batch
& Continuous) 0.02 0.06 0.03 0.03 0.07
202 - Air-S03 Sulfation
& Sulfonation
(Batch & Continu-
ous) 0.3 0.9 0.03 0.3 0.05
203 & 204 - 803 Solvent
& Vacuum Sulfona-
tion & Sulfamic
Acid Sulfation 0.3 0.9 0.03 0.3 0.05
205 - Chlorosulfonic
Acid Sulfation 0.3 0.9 0.03 0.3 0.05
206 - Neutralization of
Sulfuric Acid
Esters & Sulfonic
Acids 0.01 0.03 0.03 0.02 0.01
207A -(normal) Spray
Dried Detergents 0.01 0.03 0.01 0.02
207B -(air restric-
tions) Spray
Dried Detergents 0.08 0.25 0.10 0.15 0.03
207C -(fast turnaround)
Spray Dried Deter-
gents 0.20 0.60 0.20 0.40 0.03
208 - Liquid Detergent
Manufacture 0.2 0.4 0.13
209 - Detergent Manu-
facturing By Dry
Blending 0.01 0.05 0.01 0.01
210 - Drum Dried De-
tergents 0.01 0.03 0.01 0.01 0.01
211 - Detergent Bars &
Cakes 0.7 2.2 0.2 0.5 0.02
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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Level II Effluent Guideline Recommendations
101 - Soap Manufacture
Batch Kettle
102 - Fatty Acid Manu-
facture By Fat
Splitting
103 - Soap From Fatty
Acid Neutraliza-
tion
104A- Glycerine Con-
centration
104B- Glycerine Dis-
tillation
105 - Soap Flakes
& Powders
106 - Bar Soaps
107 - Liquid Soap
SOAP MANUFACTURE
Oil
Susp. &
BOD5 COD Solids Surf. Grease
0.40 0.70 0.40 — 0.05
0.25 0.60 0.20 — 0.15
0.01 0.03 0.02 — 0.01
0.40 0.80 0.10 — 0.04
0.30 0.60 0.04 --- 0.02
0.01 0.03 0.01 --- 0.01
0.20 0.40 0.34 --- 0.03
0.01 0.03 0.01 --- 0.01
Note: All Leveln categories have pH of 6 - 9.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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Level II Effluent Guideline Recommendations
DETERGENT MANUFACTURE
Oil
Susp. &
BOD5 COD Solids Surf. Grease
201 - Oleum Sulfonation
& Sulfation (Batch
& Continuous) 0.02 0.06 0.03 0.03 0.07
202 - Air-S03 Sul-
fation and
Sulfonation
(Batch & Con-
tinuous) 0.19 0.37 0.02 0.18 0.04
203 & 204 4 - S03 Sol-
vent and Vacuum
Sulfonation &
Sulfamic Acid
Sulfation 0.10 0.30 0.01 0.10 0.02
205 - Chlorosulfonic
Acid Sulfation 0.15 0.50 0.02 0.15 0.03
206 - Neutralization
of Sulfuric
Acid Esters &
Sulfonic Acids 0.01 0.03 0.03 0.02 0.01
207 - Spray Dried Det. 0.10 0.27 0.12 0.17 0.05
208 - Liquid Deter-
gent Manufac-
ture 0.05 0.15 --- 0.05
209 - Detergent Manu-
facturing By
Dry Blending 0.01 0.05 0.01 0.01
210 - Drum Dried
Detergents 0.01 0.03 0.01 0.01 0.01
211 - Detergent
Bars &
Cakes 0.30 0.90 0.10 0.20 0.02
NOTICE: • THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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Level III Effluent Guideline Recommendations
SOAP MANUFACTURE
Oil
Susp. &
BOD5 COD Solids Surf. Grease
101 - Soap Manufac-
ture - Batch
Kettle
102 - Fatty Acid
Manufacture
By Fat
Splitting
103 - Soap From
Fatty Acid
Neutraliza-
tion
104A- Glycerine Con-
centration
104B- Glycerine Dis-
tillation
105 - Soap Flakes &
Powders
106 - Bar Soaps
107 - Liquid Soap
0.2 0.4 0.02
0.25 0.60 0.20
0.01 0.03 0.02
0.40 0.80 0.10
0.30 0.60 0.04
0.01 0.03 0.01
0.20 0.40 0.34
0.01 0.03 0.01
0.05
0.15
0.01
0.04
0.02
0.01
0.03
0.01
Note: All Level III categories have pH of 6 - 9.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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Level III Effluent Guideline Recommendations
201 - Oleum Sulfona-
tion & Sulfation
(Batch & Continu-
ous)
202 - Air-S03 Sulfa-
tion & Sulfona-
tion (Batch &
Continuous)
203 & 204 - 803 Sol-
vent & Vacuum
Sulfonation &
Sulfamic Acid
Sulfation
205 - Chlorosulfonic
Acid Sulfation
206 - Neutralization
of Sulfuric Acid
Esters & Sulfo-
nic Acids
207 - Spray Dried Det.
208 - Liquid Detergent
Manufacture
209 - Detergent Manu-
facturing By
Dry Blending
210 - Drum Dried
Detergents
211 - Detergent Bars
& Cakes
DETERGENT MANUFACTURE
Oil
Susp. &
COD Solids Surf. Grease
0.01 0.02 0.02 0.01 0.04
0.09 0.27 0.09 0.09 0.02
0.10 0.30 0.01 0.10
0.15 0.50 0.02 0.15
0.01 0.03 0.03 0.02
0.10 0.27 0.12 0.17
0.05 0.15
0.05
0.01 0.05 0.01 0.01
0.01 0.03 0.01 0.01
0.30 0.90 0.10 0.20
0.03
0.03
0.01
0.05
0.01
0.02
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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14
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SECTION II
RECOMMENDATIONS
Tabulated here is a list of recommendations arrived at as
a result of working on this contract.
1. There is need of a better approach to the problem of
air versus water versus solid waste evaluations. Such a
problem was encountered in recommending a guideline on
this study and the contractor judged in the particular
circumstance that air quality took precedence over water
since there would be several chances downstream to improve
the water quality, but once effluent is in the air no treat-
ment is possible. Some such scheme as allowing a plant so
many effluent "points' to cover air, water, and solid wastes
as a total allowance might have merit.
2. There is need for a formula to take the quality and flow
of receiving waters into account in setting guidelines. If
a national effluent guideline is set on salt, NaCl, to cover
soap plants, in theory it would apply to a plant located
just upstream of the Gulf of Mexico or on a small freshwater
stream in New England. Such rigidity of approach places an
unnecessary financial burden on the economy.
3. A mechanism is required to resolve environmental choices
involving commercial alternatives in product design. In
the soap and detergent industry it is conceivable that a
product which is more environmentally attractive from a na-
tional use basis could be manufactured if the air restric-
tions on the plant source were reduced sufficiently to al-
low modest discharges. Quite possibly the entire nation
could gain materially by such a move. At present there is
no mechanism by which to resolve such a favorable trade off.
4. In examining the biochemical oxygen demand and chemical
oxygen demand values in various effluents, several instances
of high chemical oxygen demand/biochemical oxygen demand ra-
tios were noted. This indicates that some of the contami-
nants were biorefractory. An alternate explanation is that
unacclimated or poorly acclimated seed was used in the bio-
chemical oxygen demand tests.
It is recommended that the organic contaminants from the in-
dustry be studied individually to establish their treatability.
Seed acclimation should be studied. Use of Warburg, Bottle,
manometric and continuous or semi-continuous activated sludge
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT ..
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degradation techniques should be examined. Whenever pos-
sible the degradation of the organic substrate should be
followed with an analysis more specific than loss of oxygen
demand.
5. During the field work carried out by the contractor one
of the plants visited was observed to have demonstrated the
ability to achieve outstanding levels of water conservancy
and reduction in effluent contamination. It was learned
that this level of performance was the fruitage of ten years
of patient experimentation on the part of the engineering
staff.
This observation pointed out that with constant forceful
management persuasion and support,the effective improvement
of water use can be significantly improved. No amount of
hasty legislation or effort could have achieved such a goal.
It brought out forcefully to the contractor the need for
legislative and administrative patience in handling complex
water problems and is noted as a recommendation.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT ,,
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SECTION III
INTRODUCTION
Purpose and Authority
Section 301 (b) of the Act requires the achievement by not
later than July 1, 1977, of effluent limitations for point
sources, other than publicly owned treatment works, which
are based on the application of the best practicable con-
trol technology currently available as defined by the Ad-
ministrator pursuant to Section 304(b) of the Act. Section
301(b) also requires the achievement by not later than
July 1, 1983, of effluent limitations for point sources,
other than publicly owned treatment works, which are based
on the application of the best available technology eco-
nomically achievable which will result in reasonable fur-
ther progress toward the national goal of eliminating the
discharge of all pollutants, as determined in accordance
with regulations issued by the Administrator pursuant to
Section 304(b) to the Act. Section 306 of the Act re-
quires the achievement by new sources of a Federal stan-
dard of performance providing for the control of the dis-
charge of pollutants which reflects the greatest degree of
effluent reduction which the Administrator determines to
be achievable through the application of the best avail-
able demonstrated control technology, processes, operating
methods, or other alternatives, including, where practi-
cable, a standard permitting no discharge of pollutants.
Section 304(b) of the Act requires the Administrator to
publish within one year of enactment of the Act, regula-
tions providing guidelines for effluent limitations set-
ting forth the degree of effluent reduction attainable
through the application of the best practicable control
technology currently available and the degree of effluent
reduction attainable through the application of the best
control measures and practices achievable including treat-
ment techniques, process and procedure innovations, oper-
ation methods and other alternatives. The regulations pro-
posed herein set forth effluent limitations guidelines pur-
suant to Section 304(b) of the Act for the soap and deter-
gent industry.
Section 306 of the Act requires the Administrator, within
one year after a category of sources is included in a list
published pursuant to Section 306(b) (1) (A) of the Act, to
propose regulations establishing Federal standards of per-
formances for new sources within such categories. The Ad-
ministrator published in the Federal Register of January 16,
1973 (38 F.R. 1624), a list of 27 source categories. Pub-
DRAFT
17
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lication of the list constituted announcement of the Admin-
istrator's intention of establishing, under Section 306,
standards of performance applicable to new sources within
the soap and detergent category, which was included within
the list published January 16, 1973.
Summary of Methods Used for Development of the Effluent
Limitations Guidelines and Standards of Performance
The effluent limitations guidelines and standards of per-
formance proposed herein were developed in the following
manner. The point source category was first categorized
for the purpose of determining whether separate limitations
and standards are appropriate for different segments within
a point source category. Such subcategorization was based
upon raw material used, product produced, manufacturing
process employed, and other factors. The raw waste charac-
teristics for each subcategory were then identified. This
included an analyses of (1) the source and volume of water
used in the process employed and the sources of waste and
waste waters in the plant; and (2) the constituents (inclu-
ding thermal) of all waste waters including toxic constitu-
ents and other constituents which result in taste, odor,
and color in water or aquatic organisms. The constituents
of waste waters which should be subject to effluent limi-
tations guidelines and standards of performance were iden-
tified.
The full range of control and treatment technologies exist-
ing within each subcategory was identified. This included
an identification of each distinct control and treatment
technology, including both inplant and end-of-process tech-
nologies, which are existent or capable of being designed
for each subcategory. It also included an identification
in terms of the amount of constituents (including thermal)
and the chemical, physical, and biological characteristics
of pollutants, of the effluent level resulting from the ap-
plication of each of the treatment and control technologies.
The problems, limitations and reliability of each treatment
and control technology and the required implementation time
was also identified. In addition, the non-water quality en-
vironmental impact, such as the effects of the application
of such technologies upon other pollution problems, inclu-
ding air, solid waste, noise and radiation were also iden-
tified. The energy requirements of each of the control and
treatment technologies was identified as well as the cost of
the application of such technologies.
The information, as outlined above, was then evaluated in
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order to determine what levels of technology constituted
the "best practicable control technology currently avail-
able," "best available technology economically achievable"
and the "best available demonstrated control technology,
processes, operating methods, or other alternatives." In
identifying such technologies, various factors were con-
sidered. These included the total cost of application of
technology in relation to the effluent reduction benefits
to be achieved from such application, the age of equipment
and facilities involved, the process employed, the engineer-
ing aspects of the application of various types of control
techniques process changes, non-water quality environmental
impact (including energy requirements) and other factors.
The data for identification and analyses were derived from
a number of sources. These sources included EPA research
information, published literature, a voluntary industry-
wide audit, an extensive industry effluent plant sampling
program, qualified technical consultation, and on-site
visits and interviews at exemplary soap and detergent pro-
cessing plants throughout the United States. All references
used in developing the guidelines for effluent limitations
and standards of performance for new sources reported herein
are included in Section XIII of this document.
General Description of the Industry
This industrial category is covered under Standard Industrial
Code 2841 and includes establishments primarily engaged in
the manufacture of soap, synthetic organic detergents, inor-
fanic alkaline detergents, or any combination. Crude and re-
ined glycerine from vegetable and animal fats and oils are
also included. Excluded from this category are establish-
ments primarily engaged in manufacturing shampoos or shaving
products and synthetic glycerine. Also excluded are specialty
cleaners, polishing and sanitation preparations.
Historical
The industry which produces products for cleaning of fabrics,
dishes, and hard surfaces goes back to the earliest recorded
history. Clay tablets found in ancient Mesopotamia dating
back to the third millenium B.C., gave a soap recipe calling
for a mixture of potash and oil to be used in the making of
cloth. Modern soap and synthetic detergent formulations and
business practices were shaped by a series of events which
started in the 1930s. These include the introduction of
synthetic surface active ingredients in the mid 1930s.
There followed the war-induced shortage of the natural in-
gredients for soap making such as tallow and coconut oils
DRAFT
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and the consequent rapid increase then in the use of syn-
thetics.
The discovery of polyphosphate builders followed, which made
synthetic laundry products suitable replacements for soap.
The scramble of soap and detergent companies for the house-
wives' favor occurred during the 1950s and determined market
shares of companies in the household segment even today.
Finally, there began the formulation of detergent products
to meet environmental considerations.
The first environmental reformulation consisted of a vol-
untary industry switchover to more biodegradable linear
benzene sulfonate surfactants to replace the original highly
branched, poorly degradable benzene sulfonates in the 1960s.
Shortly thereafter the use of phosphate builders in deter-
gents came under attack from environmentalists. Of the 3
nutrients phosphorus, nitrogen and carbon,which cause eutro-
phication of lakes, phosphorus appears to be the only nutri-
ent amenable to control. A series of events led to today's
confusing and indeterminate situation vis-a-vis phosphate
builders. Nitrilotriacetic acid use was begun and then
stopped because of fears over teratogenicity. Detergents
built with carbonates and silicates were introduced and
then somewhat squelched because some of the products rep-
resented alkalinity hazards and there were also problems
such as interference with flame retardancy, and deposition
of hard water reaction products on clothes. Today the search
for a safe, effective builder to replace phosphate continues
in full swing with citrates and multifunctional compounds
such as carboxy methylene oxy succinate getting much research
effort. Other detergent ingredients have also been the sub-
ject of concern as to their safety and environmental impact.
Enzymes are an example, and sales of enzyme-containing de-
tergents suffered for a time as a result.
Companies and Markets
The household industry is dominated by three large companies.
The largest U. S. company has about one half of the U. S.
sales and production. The next two companies in size each
have about one sixth of the U. S. market. The remaining 1770
of the business is shared by over 500 companies. Very few
companies beyond the five largest producers produce and market
products across the country. The smaller companies captured
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an appreciable portion of the market share of the big three
with non-phosphate detergents before bad publicity put a
damper on sales of phosphate-free laundry detergents.
Laundry detergents are the largest category of products made
by the soap and detergent industry. The number one selling
brand has held about a 257» share of the U. S. market for
over two decades. This brand is the industry standard for
this category of product and the market leader fights hard
to maintain his level of sales of household detergents.
Other detergent companies constantly search for improved
products containing better ingredients so they can get a
bigger share of this market. The cost of the search for
new and improved products has increased greatly because of
the more sophisticated safety and environmental approaches
now needed.
In considering other household cleaning products, it will
be noted that the big three producers have a less dominant
position. Liquid hand dishwashing detergents are next to
laundry detergents in importance. Although the largest
companies do dominate this market there are many private
label products sold by supermarket chains and also quite a
number of brands marketed by smaller companies. The liquid
hand dishwashing detergent market is static in growth be-
cause of the constant shift toward home automatic dishwashers.
Automatic dishwashing detergents are produced in sizable
amounts by medium and small sized units as well as the bigger
detergent companies. This category of product has grown
very rapidly with the proliferation of the home automatic
dishwasher. With only a third of the nation's households
having automatic dishwashers great growth can be expected
to continue.
Household specialty cleaners of all types are produced by
hundreds of companies in successful competition with the
big three. This is possible because the specialties require
less capital investment than spray dried laundry detergents.
Also, specialties are amenable to smaller and localized
marketing and advertising programs.
As opposed to the production of detergents, the soap pro-
DRAFT
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ducing segment of the industry is now concerned primarily
with the production of toilet bars. A modest.amount of
soap is used in synthetic household detergent manufacture,
both in heavy duty solid formulations and in combination
detergent - soap bars. There is a possibility of a moderate
increase in the marketing of laundry soap if more local
ordinances prohibiting the use of detergents were to be
passed. For a number of economic reasons for example, the
doubling of the cost of natural fats and oils used in soap
manufacture within the last year alone would make it seem
unlikely that soap sales will increase significantly from
their present levels.
The largest sales of bar soaps are again made by the three
largest companies. In general, other soap companies special-
ize in private label, specialty soaps, and institutional
sales.
Glycerine is an important product of the industry. It is
made as a by-product of soap production, and synthetically
from petroleum-derived propylene. Glycerine is an important
cosmetic and food intermediate and many soap and detergent
companies are also in these businesses. Synthetic glycer-
ine competes with the naturally derived product. Its syn-
thesis bears no relationship to the fat-derived product,
but in composition it is essentially identical.
Glycerine is a mature chemical whose use is presently grow-
ing at the rate of 3% a year. The total 1972 estimated U. S.
production was 158 million kilograms (348 million Ibs) with
exceptionally high exports accounting for 29 million kilo-
grams (64 million Ibs). Synthetic glycerine (not included
in SIC 2841) is estimated to have accounted for approximately
91 million kilograms (200 million Ibs) of the total produc-
tion in 1972 with natural glycerine production accounting
for 68 million kilograms (150 million Ibs). There are 3 new
fat splitting plants under construction in the U. S. which
will give 3 new sources of by-product glycerine.
Industrial Cleaning Compounds
Industrial cleaning compounds are also an important part of
this industry. Compounds are made for metal cleaning, tex-
tile processing, food sanitation, and a host of other appli-
cations. Total dollar value of the non household cleaning
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market was $263 million in 1967 and is estimated at $373
million for 1973. There are a host of small companies and
divisions of large companies in this business area. Most
producers, though, serve a limited market and a limited
geographical area.
Sales and Production
Table I gives an estimate of dollar values and poundage
produced for the products comprising SIC 2841. It is inter-
esting that the oldest product, soap, still securely re-
tains an important market; that is, toilet and bath bars.
Automatic dishwashing detergents are growing rapidly and
these products are even more vitally effected by the phos-
phate controversy than are laundry detergents.
Physical Plant
In general, the soap and detergent industry has not inte-
grated backwards toward their raw materials. Basic raw
materials come from a host of supplier companies. Caustic,
fats, and oils for soap making come from chemical and agri-
cultural processors, although some companies do own coconut
plantations. Detergent alkylate, alcohols and non-ionic
surfactants usually come from large chemical and petrochem-
ical companies. Some anionic surfactant is also produced
by suppliers, but in general the soap and detergent companies
do most of their own sulfation and sulfonation. The in-
organic builders and other additives come exclusively from
supplier companies.
The three largest companies in the household market have
plants in major metropolitan areas across the country. Not
only are distribution costs important, but also the large
volume of products makes it possible for one company to
build economical sized plants in a number of locations.
There are about 30 major plants for production of heavy-
duty laundry detergents in the United States.
Trade Practices
It is fairly common for Ghe major companies to contract with
other companies for toll processing. In these arrangements
the soap and detergent company will buy synthetic detergent
bases, send them to a second company for reaction, and have
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the product returned for further compounding. For example,
detergent alcohols may be bought by a soap and detergent
company and then toll ethoxylated by a petrochemical com-
pany and returned to the soap and detergent company for
further processing.
Another business arrangement is the production of packaged
detergents by private label producers which are then sold
by the major food chains under their own brand names.
The capital requirements for a spray dried detergent bead
plant limit the number of these units. To be competitive,
these complexes produce volumes like 13,620 kgs per hour
(30,000 Ibs per hour) and cost up to 10 million dollars.
Soap making equipment can be fairly capital intensive, es-
pecially the newer fat splitting and fatty acid purification
processes. Production of light-duty liquid detergents and
dry blended products require less capital and consequently
many more producers are found. Freight is an important
consideration in shipping liquids.
Industry Problems
Foremost in difficulty is the phosphate problem. Large
sums of money have been spent both by detergent companies
and by their suppliers to find phosphate replacements. To
date, no replacement has been found which is entirely safe,
effective, and economically feasible. Generally, companies
are reformulating with lower phosphate levels, substituting
nonionic for anionic organic surfactants, and using additional
amounts of alkaline builders like sodium carbonate and sodium
silicates.
New product development is not as frequent and fruitful as
in the past. It is much more difficult to produce new pro-
ducts which meet environmental requirements, so development
money leads to fewer products.
Future Trends
The industry is growing at a rate of 5% per year. It is
secure in the knowledge that its products are vitally nec-
essary. The relative standing of various industry members
depends upon how successfully they solve environmentally
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TABLE 1
SUflARY VALUE OF SHIPENIS AT MANUFACTURERS LEVEL
SOAPS AND DETERGENTS SIC 2841
AFTER 1967 CENSUS OF JIANUFACTURERS (ADJUSTED)
Cn
1963
(in millions)
1967
(in millions)
1973
(in millions)
All Soaps
Glycerine
Natural
Alkali
Detergents
Acid Type
Cleaners
Synthetic
Ore. Det.
Household
Kilograms
605.1
•63.6
519.0
156.1
2098.7
Pounds
1332.8
140.0
1143,2
343.8
4622.7
Dollars
355. U
26.0
200.2
35.2
1029.4
Kilogram
563.1
65.8
670.1
256.1
2513.5
; Pounds
12W.3
145.0
1476.0
564.0
5536.4
Dollars
383. y
36.0
279.6
61.7
1235.4
Kilograms Pounds
540.4
68.1
887.6
398.6
3169.9
1190.4
150.0
1955.0
878.0
6982.2
Dollars
415.1
35.0
384.5
100.7
1565.0
Synthetic Org.
Det. Non-
Household
Soap and Other
Det. NSK
Grand Total
Soaps and
Detergents
287.2 632.6 115.3
38.6 85.0 17.6
357.5 787.4 141.1 443.1 976.0 Ifi7.0
166.2 366.0 73.2 332.3 732.0 146.4
3768.3 8300.1 1778.7 4592.3 10115.1 2210.9 5840.1 12863.6 2813.7
MOTICE: THESE ARE TENTATIVE RECCNMENDATIONS BASED UPON rNFORMATIQN IN THIS REPORT AND ARE SUB-
JECT TO CHANGE BASED UPON CO>WENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
-------
actuated formulation problems.
Basis of Soap and Detergent Formulations
Soaps, detergents, and cleaning agents - some of the latter
containing specific ingredients for specified cleaning
purpose's - contain a wide variety of chemical compounds to
carry out the functions of the cleaning process involved.
In the case of soap, the sodium or potassium salts of a
range of fatty acids, having carbon numbers of 8 to 22,
constitute the principal surfactant or cleansing agent. In
addition, there is an amount of salt, NaCl, included in
soap to perform the function of having an electrolyte pres-
ent, which increases diffusion and surface orientation, by
ion reactions. Glycerine, itself, is often left in the
soap, or purposely added, for its general effect in promot-
ing a feeling of softness and slipperiness, the latter
feature being one that leads the user to thoroughly wash
off soap residue, especially in personal use.
In the case of a typical all-purpose household detergent,
a general average of approximately ten chemical components
are included in a typical formulation. All these compounds
have definite functions to produce a balanced detergent. .
The principal component, of course, is the surfactant itself,
typically, an alkyl-aryl sulfonate; a sulfate salt of lauryl
alcohol; and various types of sulfates or sulfonates derived
from ethoxylated alcohol or of other aromatic compound sul-
fonates. The surfactant itself is largely effective in re-
ducing interfacial tension between the surface to be cleansed
and the soil deposit itself. Typically, detergents contain
approximately 2JO - 3070 of such surfactant active-ingredient
material.
An important ingredient in detergents, at least up to the
present, is the radical phosphate, PO^, which is included
in a variety of forms, discussed later. The function
of the phosphate is that of a disperser, a suspender, an
emulsifier, and a buffer to reduce the general alkalinity
of the surfactants and produce a detergent in the pH range
of 7 - 9. The phosphate ion has been an important multiple-
functioning ingredient in detergents. If it is reduced by
DRAFT
26
-------
laws, these functions of a detergent will have to be made
up by other compounds that then need to be included in a
formulation. Another major constituent of most detergents
is an inorganic salt. Most typically, these are either in
the form of sodium sulfate and, occasionally, sodium chloride
or other added inorganic salts. In detergents they serve
the purpose of diminishing the interfacial tension, partic-
ularly that between water, carrying the detergent, and the
soil deposition to be removed. They also act for this reason
as a disperser of the soiling. Additionally, an important
function is to provide an electrolyte; i.e., an ion content
which enhances and accelerates the interchange and surface
orientation of wetting and organic solubilizing portions of
a molecule. These inorganics are usually present up to about
20% in the typical formulated detergent.
Methyl cellulose, in amounts of about 1%, are present in
many detergent formulations to reduce redeposition of the
soiling, once it has been removed from the soiled surface.
Silica, in various forms, but usually in the form of sodium
silicate, to an extent of 5% or less, is included in many
formulations to minimize the corrosion of metals, partic-
ularly those present in a drum liner or other washing con-
tainer surfaces. Fatty acids, such as are used in the soap
manufacturing process by neutralization, are added up to a
range of about 3%, largely to enhance foam stability and,
therefore, to prevent an over-use of the detergent in the
washing solution. The borates are also generally added,
often in the form of sodium perborate. These borate com-
pounds are added up to an extent of 10%, and serve the pur-
pose of bleaching a fabric and/or removing stain deposits of
soiling on textile surfaces. In addition to these compon-
ents there are often perfumes added, as well as anti-oxidants.
Dyes are often added as brighteners, and even fluorescent
dyes so that the reflectivity of the surface is enhanced so
that it looks brighter. Obviously, the perfumes are to give
a more pleasing odor and aroma. The anti-oxidants are added,
particularly when there are fatty acids in the composition,
to avoid a noticeably rancid odor.
In general, cleaning compounds contain far more of the in-
organic salts compounds, which are more efficacious in clean-
ing duties against surfaces such as dishware, flooring, and
DRAFT
27
-------
in the cleaning of machine parts, after oil has been used
during lathing operations. Thus, a typical floor cleaning
formulation contains as much as 60% of sodium silicate, as
much as 1070 of phosphates, in the form of tri-polyphosphate,
also, occasionally the tetravalent potassium pyro-phosphate.
The surfactant in such case is usually an alkyl-aryl sulfon-
ate to make up the balance of the composition. Dishwashing
detergents, on the other hand, often contain a good amount
of phenolic compounds such as sodium phenolate. Also, they
commonly contain alcohols, such as lauryl alcohol, sulfate,
or the lauryl alcohol in the form of its amide.
Sodium carbonate, present either as the normal divalent
carbonate, or as the sesqui-carbonate, in amounts ranging
up to 10%, is commonly used. Again, a tri-polyphosphate is
included to the extent of 4070 or up to the balance of the
detergent, if it is a powder.
Of all the functions, mentioned earlier with respect to the
compound, illustrating the functions, the main purpose of a
soap, detergent or cleaning agent must be to loosen occluded
soiling and to suspend it so that it does not redeposit.
Accordingly, the basic principle of the surfactant, even as
soap itself, is the lowering of the interfacial tension be-
tween the systems consisting of the fabric or surface to be
cleaned and the soiling on that surface. Frequently
the surfactant function is accomplished by components which
also reduce the interfacial tension between the water in
the system, and the air. This leads to high foaming compo-
sitions which are not useful in actually cleaning and re<-
moving the soiling depositions.
In the case of soap, now used mostly for personal body care,
the main function is that of interfacial separation, from
the epithelial or skin surface and the soiling, which can
be produced by the body itself, as well as from extraneous
particulate matter, oils and greases. The main components
of the body's own soiling are those of the fatty acid-esters,
which range in composition from carbon numbers 05 up to C^-j.
The compounds of lower molecular weight are generally the
fatty acid salts themselves or the fatty acid esters of these
salts. The other main soil components are the usual sebaceous
gland exudate, consisting largely of the esters of glycerine.
DRAFT
28
-------
These glyceryl esters are not unlike those found in fats
itself; however, they range in chemical structure and com-
position to a far greater extent than in the soap fatty
acids. Another component of sebatious soiling is the andro-
stanyl-sterols and squalenes. These have molecular weights
as high as €37 and range down to those in the order of C^g.
These esters are particularly difficult to remove, as the
sebum is itself a very complex physical-chemical inter-diffused
solid and semi-solid solution.
Surface tension reducing agents, such as inorganic salts,
are not very useful in the cleansing problem requiring the
use of a soap. Again, they serve mostly the function of
decreasing interfacial tension between air and water; and
roughly for each per cent of content in the cleansing sol-
ution they reduce the surface tension by approximately 2
dynes per centimeter. Their equivalency can be obtained
readily, without the foaming disadvantage, simply by raising
the temperature of cleaning about 10°C (50°F) which gives the
equivalent net effect.
As mentioned, there are a variety of inorganic salt compounds
which are found in detergents and serve to perform the func-
tions first illustrated. While normally, in soap, sodium
chloride is the usual electrolyte, the compounded detergents
have a far broader range of inorganic compounds to serve
functions illustrated earlier. In addition to the usual
salts of sulfuric acid, usually present as the sodium sulfate,
there are a variety of carbonates, silicates, phosphates and
borates. In the following, the alkaline metal ions, for the
sake of simplicity, were always considered to be sodium ion.
Several forms of the carbonate anion are present in detergents
as follows: Sodium carbonate - Na2C03; sodium bicarbonate -
NaHCO^; and the sesqui-carbonate - Na^.!^ (003)3 x 3 HoO. Among
the silicate compounds used, the common ones are as follows:
ortho silicate - Na^SiO^; neutral colloidal silicates, form-
ula approximate - Na20 x 3.3 SiOo; the basicity can be changed
by the addition of additional silicon dioxide, Si02, and the
basicity control achieved by this is readily measurable and
controllable.
Among the phosphate compounds used in detergents and cleaning
DRAFT
29
-------
agents are the following: Pyro-phosphate - Na/Pr^O^ x 10 HpO
- generally used in solid detergents; potassium pyro-phosphate
- K^P^y - generally appearing in liquid detergents; ortho
phosphate, di, tri, and the usual mono-phosphate: Na,jPO/ x
12 H20; Na2H x 12 H20; NaH2(H20); meta phosphate - Na^O^;
poly-phosphates, generally tri-poly phosphate, illustrated
as the single oxygen linkage of di-poly phosphate - PO
(ONa2-0-PO, (ONa)20. The common borate salts are the sodium
tetra-borate, then the anhydrous perborate and the sodium
perborate, containing more Na20. The formulas are as follows:
The tetra borate - Na2BAOy x H2Q; anydrous perborate - Na20
x 2 1*203; sodium perborate - (Na20) x 6203.
Soaps, detergents and cleaning compounds, for all purposes,
fall into three distinct chemical classes.relating to their
activity in interfacial tension reduction between the soiling
and the fabric or surface upon which the soiling is deposited.
These are described in terms of their activity due to the
ionic radical of a molecular compound. Anionic detergents
are typified by the sulfonated alkyl aryl benzenes and the
sulfated lauryl alcohol. Phosphate esters also fall in
this classification, along with soap itself. The cationic
active detergents largely are those in which the ionizing
radical that is effective -is of positive charge, such as the
fatty acids themselves, although the latter are used princi-
pally to enhance foam stability. The last category of chem-
ical classification are the non-ionics. These are typified
by the ethoxylates, propoxylates of fatty acids and of phen-
olic substituted compounds which have been ethoxylated.
Among the classes of compounds used for other functional
features of detergent performance requirements, outlined
earlier, they are as follows: The ether sulfates which are
used in modification of the cationic properties and where
anionic activity is desired. The amphoterics, such as car-
boxy compounds, sulfonates, amides, the cycloimidiniums,
and the imid-azolinium; also included as amphoterics are
the^ammonium salts of sultones, which are described in con-
nection with sulfonation products manufacture. These ampho-
terics seek to give an isotonic system when combined with
certain body fluids, such as those present in the eye.
As the redeposition preventers in a detergent formulation,
DRAFT
30
-------
cellulose and/or sucrose ethers are usually employed. A
useful component for both liquid and powder detergents are
the hydrotropes. Among such compounds are the sulfonates
of toluene and xylene; although medium molecular weight
alcohols, either primary or secondary, may also be employed
for this function. Hydrotropes contribute to a low point
in liquid detergents and serve the purpose of giving a low
viscosity slurry and in powders imparting free flow properties,
Other agents commonly found in detergents are the organic
sequesterants. These are essentially chelating agents.
The chelating agents serve to tie up metal ions in the
soiling or in the washing water itself so that they do not
precipitate the functional radical which performs the sur-
factant function. Among such compounds are gluconic acid,
ethylene di or tri amines; and a recently used one, now
essentially banned, nitrilo-tri-acetic acid. These organic
sequesterants are used with or without phosphates, in their
condensed form, such as the poly phosphates as described
earlier. Finally, detergent compositions often consist of
bleaching or whitening agents which are chlorine-liberating
or oxygen-liberating.
A review of some forty formulations of detergents and clean-
ing agents, formulated for all sorts of purposes, reveals
that some thirty generic chemical type of compounds are
used in the industry. It can be well understood then, par-
ticularly in the operations in which these are formulated
in liquid phase or in a solid dry powder phase, that the
constituents themselves may be lost by solubility into an
aqueous phase or by volatility into a vapor phase and thus
lost into water effluent and atmosphere as a result of the
processing required. Also, many constituents of a detergent
or cleaning formula react with metals ions in water and form
precipitates. Similarly, during the processing itself, un-
less extreme care is used, certain of the compounds can fur-
ther polymerize, grow to heavier molecular weight insoluble
chemical compounds and then must be eliminated in the form
of solid waste. Hence, an understanding of these require-
ments for performance is essential in setting guideline
recommendations or effluent standards for discharges from
the in-process units themselves.
DRAFT
31
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32
-------
SECTION IV
INDUSTRY CATEGORIZATION
CHOICE OF CATEGORIES
There are several ways in which the soap and detergent
industry could be categorized. Each has its own special
rationale, but only one way of categorizing was found to
be suitable for both identifying wastewater effluent
sources in an unambiguous manner, and providing a permit
granting authority an effective way to analyze a specific
plant regardless of its complexity. Some of the other
systems examined included categorization by raw material
used, plant size, degree of process integration, types
of markets served and degree of market integration.
As each of these bases for categorization was studied it
became apparent that the only way to build a usable sci-
entific data base was by first identifying the unit pro-
cess building blocks, the individual discrete units of
manufacture. Once such a division was made it was rela-
tively easy to locate the sources of wastewater loadings.
The other categorization systems did not afford such a
straightforward method of effluent identification.
In studying the raw materials as a basis for categoriza-
tion one finds quickly that little distinction can be made
between manufacturers, large or small, by an in depth
study of what they consume as raw materials.
For example, from the smallest to the largest toilet
bar soap manufacturers one finds those who kettle boil
all buy fats and process them in a similar manner. The same
problem occurs when you pursue the synthetic detergent pre-
cursors. Many, from very small (in gross proceeds) to very
large, purchase the appropriate hydrocarbon or alcohol and
then sulfonate/sulfate them. After going this far, there
is little left to pursue in major raw materials that could
lead to clear distinction between companies.
Utilizing plant size as a categorization method produced
similar complexities in seeking distinctions. One can
readily find among the small firms complete "replicas" of
the plants of the largest, at a reduced scale, but of great
DRAFT
33
-------
similarity in product and operating characteristics. Even
among the large firms there are significant variants in to-
tal plant size. This effort led to insignificant distinc-
tions .
Degree of process integration for categorization initially
offered some hope that significant, repeatable differences
could be found. The soap area seemed to be a hopeful place
to start since there are a number of firms which are exclu-
sively, or almost exclusively, in the toilet bar soap busi-
ness. Once one goes beyond these boundaries the combinations
of processes blur the distinction between companies since
there is frequently a greater difference between the various
plants of a given manufacturing firm than between one firm
and another.
Market types and degree of integration are not helpful as a
means of categorization. With few exceptions, mainly in the
industrial area, there is little distinction between the gene-
ral degree of integration, from manufacturing to marketing,
that can be found in firms of contrasting size. After the
distinction between industrial and consumer orientation is
made the distinctions again disappear. One finds the same
degree of integration back to raw materials and about the
same degree in processes from large to small size operations,
with some obvious exceptions. Yet the distinctions are not
clear enough to use as a means of categorization.
Our final choice then emerged: division of the industry in-
to two major process categories; soap manufacturing and deter-
gent manufacturing, followed by further subdivision of these
two categories into the individual manufacturing unit proces-
ses employed.
With this system, all soap and detergent plants, whether large
or small, can be completely segmented'and analyzed for the
purposes of detailed wastewater effluent analysis and permit
granting.
Reinforcement of this choice of categorization came out of de-
tailed study of the Corps of Engineers reports on wastewater
discharges into navigable waters. In attempting to utilize
this information it became quite clear that only by dividing
manufacturing facilities into their component manufacturing
processes could one adequately dissect the plant to find par-
ticularly troublesome wastewater flows. This methpdology is
of particular value to permit writing authorities in their
discussions with applicants.
DRAFT
34
-------
SOAP MANUFACTURING
This ancient product was made by our ancestors in a kettle
over a wood fire. They leached the alkali from wood ashes,
combined this solution with liquid fats and cooked the two
together. When the kettle contents developed the appropri-
ate "feel" the whole batch was poured into shallow contai-
ners to chill and complete the reaction. This was the pri-
mitive way to make what we now call cold frame soaps. Al-
though we now use much more sophisticated equipment, much of
the soap made today utilizes essentially the same process
steps.
The chemistry of soap making is simple. However, its physi-
cal chemistry is complex and will be explored to some extent
in the discussion of bar soaps.
The fundamental reaction of soap chemistry can be stated as
Fat + Caustic —V Soap + Glycerine
Fats and oils used in soap making are of both animal and vege-
table origin. Such animal-derived sources as tallow are most
common. Of the vegetable oils, coconut, palm.and tall are the
most popular.
Experience has shown that the optimum range of carbon chain
length of fatty acids used in soap manufacture ranges from
12 to 18. As a curiosity of nature, the acids occur naturally
only in even numbers of carbon atoms in the fats used commer-
cially.
SOAP PROCESS DESCRIPTIONS
Each of the process descriptions are associated with a pro-
cess flow sheet. All of the expected wastewater effluents
are identified in the flow sheet by name and code number for
quick reference.
101 - SOAP MANUFACTURE BY BATCH KETTLE
Most of the soap made by this process finds its way into toi-
let bar form for household usage. This use demands freedom
from offensive odors, and displeasing colors. In order to
meet this requirement, the starting fats and oils must be re-
fined. There is a direct relationship between quality of the
fats and the quality of the finished soap.
Fat Refining and Bleaching
There are several ways in which fats are refined. One of the
most frequently used methods employs activated clay as the ex-
traction agent. Activated clay, having a large ratio of sur-
DRAFT
35
-------
to
101 SOAP MANUFACTURE BY BATCH KETTLE
1011 RECEIVING
STORAGE-TRANSFER
W12 FAT REFINING
AND BLEACHING
1013 SOAP BOILING
CLAY
SALT
YOILS:
MIIT* TAI 1 nUU.
1
BOILING
M
r
MIXER
SETTLER
11
MIXER
. SETTLER
BAROMETRIC
CONDENSER
-»1
S
CLAY
BLEACHING
1
FILTER
. 1 1
«
^
•r
i
i
i
1
'
Ft
toLC
SO
O
c
WASHOUTS
101102
WASTEWATER
101231
I
J_
SOLID WASTE
101209
I
t
STEAM
STEAM
FATTY ACIDS
LOW GRADE
SOAP SALES
BAROMETRIC
CONDENSATE
101218
SEWER LYES
101319
BRINE AND ACID
WASTEWATER
101320
WASHOUTS
101202
NEAT SOAP TO
PROCESSING
AND SALE
GLYCERINE TO
RECOVERY
LOW GRADE SOAP
LOW GRADE
FATTY ACID
-------
face area to weight, is agitated with warm oil and filtered.
Color bodies, dirt, etc., are removed usually through a plate
and frame press. The clay is disposed of as solid waste. A
small amount of clay remains in the refined fat.
The clay is often "activated" by being given an acid treat-
ment itself by the clay supplier and is a source of sulfate
ion build-up in some soap recycling streams.
Other ways in which fats are refined include caustic extrac-
tion, steam stripping and proprietary aqueous chemicals.
When soap accounted for the major portion of the soap and
detergent market the Sol xol process of extraction found use
in refining of fats and oils. The design of this liquid pro-
pane extraction process is based on the diminishing solubili-
ty of fats in liquid propane with increasing temperature. The
fats are completely miscible at 48.84°C (120°F) but become
almost insoluble at 82.14°C (ISQop) . and most of the color
bodies precipitate.
Color bodies fall to the bottom of the treating tower while
decolorized oils dissolved in liquid propane sit on the sol-
vent (liquid propane) layer and are recovered from the top.
This process is not now used in the United States, but should
be reexamined since it offers a way to eliminate water use
and thus could again become economical as discharges must be
reduced.
Soap Boiling
Although a very .old process, kettle boiling still makes a
very satisfactory product and in several well integrated manu-
facturing plants this process has a very low discharge of
wastewater effluents.
Making a batch of neat soap (65 - 70% soap in water) can take
as long as four to six days to complete. A series of large
steel tanks are used in a counter current manner to "boil
soap. Their capacity can be as high as 54,480 kilograms
(120,000 pounds) of ingredients. Ever weakening caustic
streams are met by enriched fat so that the caustic is essen-
tially exhausted in the presence of fresh fat. In actual
practice the fat never leaves the tank in which it starts un-
til it is converted into neat soap. Just the aqueous caustic
stream flows from tank to tank.
A simplified process description follows for kettle boiling
soap:
DRAFT
37
-------
Step 1
weigh in
fats & oils
and alkali
Step 2
turn on
steam and saponify
Step 3
add salt and
boil for
graining
Step 4
turn off
steam and
settle
Step 5
drain off
spent lye
and send to
recovery
Step 6
add water to
kettle and
boil closing
Step 7
add strong
alkali to
closed soap
Step 8
settle
and run
off lye
to Step 1
Step 9
add water
and heat to
close soap
for filling
change
Step 10
settle and
draw off
neat soap
Step 11
recycle
bottom nigre
to Step 1
Neat Soap
,ctep 1 - Fats and oils are weighed in. The caustic stream
from the "extreme change" of step 7 is run in as well as
the nigre from step 11.
Ptep 2 - Live steam is customarily released into the kettle
where it not only heats up the materials but also performs
the stirring function. About three or four hours are con-
sumed in this step.
Step 3 - Graining is the act of separating the newly formed
soap from the exhausted lye solution. An operator adds salt
or salt solution until a sample withdrawn with a trowed sepa-
rates distinctly into soap and lye. About 10 - 1270 NaCl is
required.
Step 4 - About four hours are needed to completely settle
the contents into two layers.
Ptep 5 - The spent lye contains 7 - 8% glycerine and is
sent to the glycerine recovery unit.
DRAFT
38
-------
Step 6 - "Closed soap" is now made by adding fresh water
to the kettle and heating it to make a continuous creamy
material, dissolving the remaining glycerine and salt.
Step 7 - The "strong change" is carried out by adding fresh,
concentrated lye which saponifies the last remnants of fat.
The batch is brought to a boil again, water is added until
the soap is closed, then the lye is run in. Since the
soap in not soluble in the strong alkali it becomes grainy.
.ctep 8 - cteam is shut off and the batch allowed to settle
for three hours . The lye is run off and added to a begin-
ning batch in the "extreme kill".
9 - Heating is again begun and water run in until the
mass is closed and boiling is continued until the soap re-
moved on a trowel can be poured off in a transparent sheet.
Step 10 - Heat is turned off and the batch is allowed to
settle. Neat soap is drawn off the top and run off to be
processed into one of many forms of soap products. The
lower layer is the nigre which contains the color bodies,
dark soap, etc. It contains as much as 20 - 25% of the
kettle contents '30 -40% soap"* . When the nigre gets
particularly loaded with impurities it can itself be sal-
ted out, making a low grade soap for sale.
Step 11 - frequently the nigre is recirculated to the ket-
tle for the start of a new batch.
An overall schematic of the soap-making process is as fol-
lows:
t t
1 Kettle Boil| *
\
1 Spent
- L_^. r N1
f -^ • Nl
' yA
gre |
lye 1 '>~ Evaporator]
Dark soap ',
_ to market j
I - ~
— -^. . i Cone
glycerine
SOAP MAKING FIGURE 2
DRAFT 39
-------
The wastewater from kettle boiling is essentially from the
nigre stream. The nigre is the aqueous layer which con-
tains the color bodies generated in the soap making process,
mostly dark soaps. They are often marketed as industrial
lubricants or low grade special purpose soaps. Where such
a market can be established a kettle boil soap process is
slready at the zero discharge effluent level except for
the oil refining step.
A number of truly continuous soap making processes have
been developed which require only a fraction of the time
needed by kettle boiling to perform the saponification
and graining functions.
Continuous Soap Manufacture
Fat pretreatment is the same as that described in soap
manufacture by batch kettle.
As the title implies, soap is made in a continuous, unin-
terrupted manner with a minimum of fluid volume required.
One of the commercially used processes will make neat soap
from fatty oil in two hours at an operating temperature
not exceeding 104.34°C (220°F) and a working pressure
of under 2.72 atm (40 psig). In this process there are
four distinct changes:
1. Partial saponification.
2. Completion of saponification plus washing.
3. Boiling on strength plus washing.
4. neparation of the neat soap.
Reaction takes place in mixing units which, in each stage,
are followed by a centrifuge. The use of the latter em-
ploys a separation force which is 13,000 times that of gra-
vity, making separation a rapid process. No nigre is formed.
All of the impurities are found left in the centrifuge bowl
and are removed as part of the solid waste. The spent lye
coming from the first stage is free of alkali (lye1* and
contains the glycerine which is sent to recovery.
DRAFT
40
-------
Since this is a counter current process of ever weakening
lye coming into contact with ever stronger fats, the final
lye effluent is exhausted and has a high glycerine concen-
tration.
Salt Usage
In order to maintain suitable solubility for proper proces-
sing, salt is added to the soap making process to maintain
the required electrolytic balance. Most of the salt charged
into the .process is ultimately returned to it from the gly-
cerine concentration step, which will be discussed later.
Practically every kettle boiling soap manufacturer concen-
trates his glycerine stream although only a few go on to
the distillation of glycerine.
PROCESS 102 - FATTY ACID MANUFACTURE BY FAT SPLITTING
By means of fat splitting very low grade fats and oils are
upgraded to high value products by splitting the glycerides
into their two components, fatty acids and glycerine. Fat
splitting is an hydrolytic reaction which proceeds as fol-
lows :
Fat + Water > Fatty Acid + Glycerine
DRAFT
41
-------
102 FATTY ACID MANUFACTURE BY FAT SPLITTING
1021 RECEIVING
STORAGE-TRANSFER
1022 FAT PRETREATMENT
1023 FAT SPLITTING
1024 FATTY ACID DISTILLATION
OILS
NaOH
CLAY
ANDk
LYST-
»
»
x
v»nuuc
FAT AND
OIL
/
1 >VTO FAT
1 SPLITTING
f1
TREATING
VESSELS
*~
SPENT
CLAY
t
FOOTS
i
j RECOVERY L
1
1
REFINED FATS
AND OILS
STEAM
CATALYST —
FATTY ACIDS
"AND SOAPS
PRESSURE
REDUCTION
, REACTOR
4
L
J
PRESSURE
REDUCTION
\\
1
1
1
1
\
I 1
! i
FATTY
ACIDS
STEAM i
HYDROGEN i
CATALYST
CAUSTIC SODA — •
SULFURICACID-
hCBUDE
GLYCERINE
TO RECOVERY
La
, 1 BAROMETRIC
' STILL CONDENSER
1 FATTY ACIDS
''a ' » I
-1 1 f ' !
^^ HYDRO-
RFS, ^NATION
1 PU& EMULSION BREAKINC
=?
1
1
1
•?
•1
' '
1 1 1
STEAM
REFINED
FATTY ACIDS
FATTY ACID
PITCH AND
RESIDUES
O
G
WASTEWATER
102201
SOLID WASTE
102209
WASHINGS
102221
PROCESS CONDENSATE
102322
COOLING TOWER
BLOWDOWN
102404
BAROMETRIC
CONDENSATE
102418
SPENT CATALYST
AND WATER WASHINGS
102423
-------
Using a Twitchell catalyst (an aromatic sulfonic acid)
fats and a long residence time, fats can be split at near-
ly atmospheric pressures. Today, however, most fat split-
ting takes place in a high pressure, high temperature to-
wer operated at around 500 psig and at a temperature of
500°F. (500 psig = 34 atmospheres, 500°F = 260°C)
Heated fat, 254°C (490°F) and under pressure is fed into
the bottom of the tower and water, 204°C (400°F) and also
under pressure is fed into the top.
The two streams mix counter-currently and hydrolysis takes
place, often in the presence of a zinc or tin catalyst. At
the high temperatures employed the fat is soluble to the
extent of 12 - 25% of water, depending upon which fat is
used.
In about 90 minutes the splitting can be as high as 99%
complete. The glycerine by-product can be produced at a
variety of concentrations depending upon how complete a
fat hydrolysis is desired. More concentrated glycerine
can be provided at some expense of fatty acid yields.
The crude acids are flashed in a pressure reducer and then
distilled at 2 - 3 mm pressure. The resulting product is
subjected to a flash hydrogenation to reduce the amount
of linoleic and linolenic acids.
PROCESS 103 - SOAP FROM FATTY ACID NEUTRALIZATION
Soap making by fatty acid neutralization rivals the kettle
boil process in speed and minimization of wastewater efflu-
ent make. Although widely used by the large soap producers,
it is also very popular with the smaller manufacturer.
This route from the acids is faster, simpler (no by-product
dilute glycerine stream to handle) and "cleaner" than the
kettle boil process. Distilled, partially hydrogenated
acids are usually used.
The fatty acid neutralization process has several addi-
tional advantages over the kettle boiling process. It
does not have a large salt load to recycle, and has a free
DRAFT 43
-------
o
H
103 SOAP FROM FATTY ACID NEUTRALIZATION
1031 RECEIVING
STORAGE-TRANSFER
7032 SAPONIFICATION
1033 RECYCLE-REPROCESSING
STEAM
A pint
tSH
SHIM MvnRDYinF
.x"'
/^
I
1
MIXER
LEAKS. SPILLS, STORM
RUNOFFS, WASHOUTS.
103102
[J WASTEWATER BRINES
103224
SOAP TO
REACTOR
1
1
1
1
1 1
! 1
1
1
1
«
•^~-
1
1
1
- SCRAP SOAP
— CAUSTIC SODA
1
1
1
OFF QUALITY SOAP
TO LANDFILL 103325
VUASUni ITG
SEWER LYES
103326
FIGURE
-------
alkali concentration in the order of 0.1 - 0.27», contras-
ted with around 1% measured as Na20 in the kettle boiling
process.
The reaction that takes place is substantially:
Caustic + Fatty Acid t Soap
Often, sodium carbonate is used in place of caustic with
the attendant evolution of carbon dioxide. When liquid
soaps (at room temperature) are desired, the more soluble
potassium soaps are made by starting with potassium hy-
droxide. The potassium soaps are used in the familiar
liquid hand soap dispensers, in many industrial applica-
tions and often as lubricants.
As in kettle boiling soap manufacture, the most popular
mix of acids for bar soap is 20/80 coconut oil/tallow oil
derived acids. A number of distilled tall oil soaps (tall
oil is derived from the waste streams of paper manufacture)
are also made for industrial purposes.
In some cases, the soap making process is operated continu-
ously in tandem with a fat splitting process. The fatty
acids and caustic solution are proportionated into a reac-
tor continuously by pumps having a common variable speed
drive. The appropriate amount of salt is also programmed
in to maintain the correct electrolyte content.
The resulting neat soap will have about 307. moisture (if
going on to be processed into bar soap) and around 0.5%
salt.
To clarify the soap solution, the soap stream coming out
of the reactor is sometimes filtered with clay. The spent
clay creates a certain amount of solid waste and the fil-
ter press is washed out occasionally. Otherwise this is
a "clean" process.
The neat soap is further processed into bars or liquid
formulations in the same manner as the product from kettle
boiling.
DRAFT 45
-------
PROCESS 104 - GLYCERINE RECOVERY
Concentration
The kettle boiling soap process generates an aqueous stream
referred to as sweet water lyes. This stream will contain
8 - 10% glycerine, a heavy salt concentration and some fat-
ty materials. It is processed by first adding a mineral
acid (HC1) to reduce the alkalinity. This is followed by
the addition of alum which precipitates insoluble aluminum
soaps. The precipitate carries other impurities down with
it. If the stream were not treated with alum, there would
be severe foaming in the evaporators, and the contaminant
would be carried forward into the glycerine. The cleaned
up glycerine solution is sent to the evaporators.
The evaporators (in some smaller plants there will be only
one) are heated under reduced pressure. The partial vacuum
is generated by a barometric condenser. They frequently
operate at 66Omm-710mm (26-28"Hg) of vacuum.
As the glycerine is concentrated the salt comes out of
solution and is removed form the evaporation kettle, fil-
tered and returned to the soap making process. In many
plants this separating function is performed continuously
with a centrifuge with the filtrate being returned to the
evaporator.
The glycerine is usually concentrated to 80% by weight and
then either run to a still to be made into finished gly-
cerine, or stored and sold to glycerine refiners.
The barometric condenser used in concentrating will be
slightly rich in BOD due to the carryover of glycerine.
Distillation
The concentrated glycerine (80%) is run into a still which,
under reduced pressure, yields a finished product of 98+%
purity. Here again a barometric condenser is used to cre-
ate the partial vacuum.
At room temperature, the still bottoms (also called gly-
cerine foots) are a glassy dark brown amorphous solid rather
rich in salt. Water is mixed with the still bottoms and
DRAFT 46
-------
I
104 GLYCERINE RECOVERY
1041 RECEIVING
STORAGE-TRANSFER
7042 LYE TREATMENT
1043 GLYCERINE EVAPORATION
1044 GLYCERINE STILL
SWEET WATERS >.
AND LYES
ALUM .
HCL --•'
v^
— »•
MIXER
I
FILTER PRESS
i
I
4 i
TREATED
.GLYCER
LIQUOR
RECYCLE
SOLID WASTE
104209 -
D
INE
LE -
r
•*" EVAPO
A
\
SALT
BAROMETRIC
•CONDENSER
1
RATOR K
f
1
1
1
L
*
SEPARATOR r'
.
1 1
' i
i •
SALT BRINE
104327
STEAM
BAROMETRIC
CONDENSATE
104318
CRUDE
GLYCERINE
SALT RECYCLE
TO SOAP
MANUFACTURE
BAROMETRIC
CONDENSER
STILL
CHARCO/
"*" Fll TFR
1
1
1
1
1 1
1 1
\ 1 *
GLYCERINE | SOLID WASTE
FOOTS , ,04409
104428 '
1
1
.1
i
XL I.
1
1
1
1
*—
1
— STEAM
RE-
~ FINED
GLYCEI
INE
BAROMETRIC
CONDENSATE
104418 '
FIGURE
COOLING TOWER
SLOWDOWN
104404
-------
run into the wastewater stream. This particular stream
is very rich in BOD, and readily biodegradable. Many al-
ternative methods of disposal, including incineration,
have been evaluated, but none have proven to be more fea-
sible than disposal in a wastewater stream.
The other wastewater stream, the barometric condenser wa-
ter, will also contribute to the total BOD/COD load caused
by the glycerine foots.
The sweet water glycerine from fat splitting is flashed to
atmospheric pressure thereby releasing a considerable a-
mount of water very quickly. This can provide a glycerine
stream going to the evaporators of 2070 glycerine or more.
Since there is no salt used in fat splitting there will be
none in the sweet water.
Some glycerine refining is done by passing the dilute stream
over ion exchange resin beds, both cationic and anionic, and
then evaporating it to 98+% glycerine content as a bottoms
product. This method is suitable where there are copious
quantities of water available and the energy costs are
very high.
In the backwash of the ion exchange process the organic
suspended solids are stripped from the system. The re-
generation cycle of both types of beds will add a signi-
ficant dissolved solids load to the wastewater system.
There are frequently three sets, in series, of both cation
and anion exchange resins used in this process. Each step
is designed to reduce the input load by 90%. Some of the
fat splitting plants are equipped with this type of unit.
PROCESS 105 - SOAP FLAKES AND POWDERS
Neat soap '65 - 70% hot soap solution) may or may not be
blended with other products before flaking or powdering.
Neat soap is sometimes filtered to remove gel particles
and run into a crutcher for mixing with builders.
After thorough mixing, the finished formulation is run
into a flaker. This unit normally consists of a two roll
"mill" having two steel rolls. The small upper one is
steam heated while the larger lower one is chilled. The
DRAFT
-------
soap solidifies on the lower one and is slit into ribbons
as it sheets off the roller.
The ribbons are fed into a continuous oven heated by hot
air. The emerging flakes contain 1% moisture. As all of
the evaporated moisture goes to the atmosphere, there is
no wastewater effluent.
In spray drying, crutched, heated soap solution is sprayed
into a spray tower , or flash dried by heating the soap
solution under pressure and releasing the steam in the
spray dryer under reduced pressure. In either case the
final soap particle has a high ratio of surface area to
unit of weight, which makes it readily dissolvable in wa-
ter.
Some operations will include a scrap soap reboil to recover
reclaimed soap. The soap reboil is salted out for soap re-
covery and the salt water is recycled. After frequent re-
cycling the salt water becomes so contaminated that it must
be discharged to the sewer.
Occasional washdown of the crutcher may be needed. The
tower is usually cleaned down dry. There is also some
gland water which flows over the pump shaft picking up
any minor leaks. This will contribute a very small, but
finite, effluent loading.
PROCESS 106 - BAR SOAP
The procedure for bar soap manufacture will vary signi-
ficantly from plant to plant, depending upon the particular
clientele served. The following description typifies bar
soap manufacture.
In some processes additives are mixed with the neat soap
in a crutcher before any drying takes place. Another ap-
proach is to begin the drying process with the hot neat
soap going to an "atmospheric" flash dryer followed by a
vacuum drying operation in which the vacuum is drawn by a
barometric condenser. Soap is then double extruded into
short ribbons or curls and sent to plodders for further
blending or physical processing. At this point the soap
DRAFT
49
-------
105SOAP FLAKES AND POWDERS
1051 RECEIVING
STORAGE-TRANSFER
7052 FLAKING
CRUTCHING-DRYING
1053 SPRAY DRYING
7054 PACKAGING
FILTER BACKWASH
105129
PACKAGING
EQUIPMENT
^ FLAKES TO
PACKAGING
SCRUBBER
WASTEWATER
105201
LEAKS, SPILLS, STORM
RUNOFFS, WASHOUTS.
105202
WASTEWATER
105301
LEAKS. SPILLS. STORM
RUNOFFS. WASHOUTS.
105302
SCRUBBER
WASTEWATER
105401
SCRAP
TO SOAP
RECYCLE
PACKAGED
SOAP TO
WAREHOUSE
FIGURE
-------
will normally have 8 - 14% moisture depending upon the
previous course of processing.
Next, a milling operation affords the opportunity to blend
in additives as well as modify the physical properties of
the soap." This operation has much more significance than
just achieving uniformity in the mixing of further added
ingredients. The physical chemistry of soap is fairly com-
plex. Unless a bar of soap is almost predominately left
in the Beta phase, as distinct from the Omega phase, long
range solubility, warping resistance, and lathering pro-
perites are poor. Rapid chilling of the soap puts it pre-
dominantly in Omega but successive milling steps bring it
back into Beta - hence the importance of milling.
The mill consists of two polished rolls rotating at dif-
ferent speeds to maximize the shearing forces. After mil-
ling, the soap is cut into ribbons and sent to the plodder.
f
The plodder operates much like a sausage grinder. It thus
extrudes and cuts the soap into small chips, followed by
further mixing in which all of the individual pieces are
melted together into an homogeneous mass. The plodder is
often operated under reduced air pressure so that any oc-
cluded air is removed in the blending process. It has-a
powerful screw that forces the soap through minute holes
in a perforated plate.
Plodding completed, the soap is extruded continuously in
a cylindrical form, cut to size, molded into the desired
form, and wrapped for shipment. Most of the scrap in this
operation is returned to the plodder.
At times there will be soap scrap which has become too dry
to process properly in the plodder and it must be returned
to earlier steps in the soap making process.
The amount of water used in bar soap manufacture varies
greatly. In many cases the entire bar soap processing ope-
ration is done without generating a single wastewater stream.
The equipment is all cleaned dry, without any washups. In
other cases, due to housekeeping requirements associated
with the particular bar soap process there are one or more
DRAFT 51
-------
106 BAR SOAPS
1061 RECEIVING
STORAGE-TRANSFER
NEAT SOAP-
-•a-
ADDITIVES
••a-
FILTER BACKWASH
1 06129
In
NJ
1062 CRUTCHING AND DRYING
1063 SOAP MILLING
WATER
1064 PACKAGING
TO SOAP
MILLING
WATER
WASTEWATER
106201
WASHOUTS
106202
WASTEWATER
106301
FIGURE 7
SCRAP TO
-»>SOAP
RECYCLE
FINISHED SOAP
AND CAKES
TO WAREHOUSE
-------
wastewater streams from air scrubbers.
Since we are dealing with a consumer product with very
distinct (and important to the consumer) esthetic pro-
perties, all of these processes can claim significance
and essential character in the making of a particular bar.
Occupying a very minor position in the soap market, a bar
made from cold frame soap may be found. After the saponi-
fication reaction, this soap is poured directly from the
reactor into molds. Upon cooling and the completion of
saponification, the molded soap is cut into bars. The en-
tire operation is carried out without the generation of
any wastewater.
PROCESS 107 - LIQUID SOAP
Neat soap (often the potassium soap of fatty acids) is
blended in a mixing tank with other ingredients such as
alcohols or glycols to produce a product, or with pine
oil and kerosene for a product with greater solvency and
versatility. The final blended product may be, and often
is, filtered to achieve a sparkling clarity before being
drummed.
In making liquid soap, water is used to wash out the fil-
ter press and other equipment. Wastewater effluent is
minimal.
DETERGENTS
The first modern detergent introduced in the United States
in 1933 was an alkyl naphthalene sulfonate. The primary
reason for the success of detergents is their ability to
overcome the hard water behavior of soaps. Even though
the detergents also react with hard water minerals, the
resulting compounds are themselves soluble, or remain
colloidally dispersed in the water system. There are four
main groups of detergents:
Anionics
Cationics
Amphoterics
Nonionics
DRAFT
53
-------
I
707 LIQUID SOAP PROCESSING
707? RECEIVING
STORAGE-TRANSFER
7072 BLENDING
1073 PACKAGING
POTASSIUMSOAPS-
ADDITIVES-
SOLVENTS-
LEAKS, SPILLS, STORM
RUNOFFS. WASHOUTS.
107102
BLENDER
WASHDOWNS;
HEELS. 107212
PACKAGING
EQUIPMENT
LIQUID SOAPS
• TO WAREHOUSE
WASHOUTS
107302
FIGURE 8
-------
Anionics comprise the most important group of detergents.
They are usually the sodium salts of an organic sulfate or
sulfonate. Sulfates are made from long chain "fatty alco-
hols" (of animal or petroleum origin). Sulfonates generally
are made from alkyl aryl precursors.
By 1957 synthetic detergents took over 70% of the market
for soap-like products in the United States.
Cationic detergents are known as "inverted soaps" because
the long chain ion is of the opposite charge to that of
a true soap when dispersed in water.
This class of detergents is made in quite small volumes.
They are relatively expensive and somewhat harsh on the
skin. They make excellent bacteriostats and fabric sof-
teners and are used for this purpose.
Nonionic detergents are an increasingly popular active
ingredient of automatic washing machine formulations.
These products are unaffected by hard water (they do not
form ions) and are very low fearners (minimum foam when agi-
tated). They are made by the addition of ethylene oxide
to an alcohol.
Amphoterics are those surface active agents which can
either be anionic or cationic, depending upon the pH of
the system wherein they work. An important class chemi-
cally, they account for only a very small portion of the
detergent market.
DETERGENT MANUFACTURING PROCESSES
A finished, packaged detergent customarily consists of
two main components, the active ingredient (surfactant)
and the builder. The function of the surfactant is essen-
tially that of wetting the substrate to be cleaned. The
builder performs many functions including buffering the pH,
soil dispersion, and soil anti-redeposition. Both classes
of materials are required for proper detergent performance.
The processes described under this heading include the
manufacture of the surfactant as well as preparation of the
DRAFT 55
-------
finished detergent. The number preceding the title of
each process refers to the process flow chart.
PROCESS 201 - OLEUM SULFONATION/SULFATION
One of the most important active ingredients of detergents
is the alcohol sulfate or alkyl benzene sulfonate - and
particularly those products made via the oleum route.
In most cases the sulfonation/sulfation is carried out
continuously in a reactor where the oleum (a solution of
sulfur trioxide in sulfuric acid) is brought into intimate
contact with the hydrocarbon or alcohol. Reaction is rapid.
The stream is then mixed with water and sent to a settler.
Prior to the addition of water the stream is an homogen-
eous liquid. With the addition of water, two phases de-
velop and separate. The dilute sulfuric acid is drawn off
and usually returned to an oleum manufacturer for reproces-
sing up to the original strength. The sulfonated/sulfated
material is sent on to be neutralized with caustic.
This process is normally operated continuously and per-
forms indefinitely without need of periodic clean out.
Pump glands occasionally leak. Anticipating this problem,
a stream of water is normally played over pump shafts to
pick up such a leak if it occurs, as well as to cool the
pump. The flow of wastewater from this source is quite
modest but continual.
PROCESS 202 - AIR - S03 SULFATION/SULFONATION
This process for surfactant manufacture has numerous unique
advantages and is used extensively. In the oleum sulfation
of alcohols formation of water stops the reaction short
of completion because it reaches a state of equilibrium,
resulting in low yields.
With S03 sulfation, no water is generated, hydrolysis can-
not occur and the reaction proceeds in one direction only.
The absence of water in the 803 reaction is of a lesser
importance in sulfonation. What is particularly trouble-
DRAFT
56
-------
some in the use of oleum for alcohol sulfation is that
water cannot be used for oleum separation due to the poten-
tial hydrolysis that would take place. Even if this were
not a worry, no phase separation of the components takes
place with the addition of water to sulfated alcohols in
oleum.
803 sulfonation/sulfation is also quite amenable to
batch processing and in this manner can produce products
having a minimum of sodium sulfate (all of the excess of
803, or sulfuric acid in the case of oleum sulfonation,
will be converted into sodium sulfate in the neutraliza-
tion step with caustic).
Care must be exercised in the 803 process to control reac-
tion conditions - particularly temperature - to minimize
char formation and possible sulfonation of the hydrocarbon
chain of the alcohol.
Another advantage of the 863 process it its ability to
successively sulfate and sulfonate an alcohol and a hydro-
carbon respectively.
Because of this reaction's particular tendency to char the
product, the reactor system must be cleaned thoroughly on
a regular basis. In addition there are usually several
airborn sulfonic acid streams which must be scrubbed,
with the wastewater going to the sewer during sulfation.
863 can be generated at the plant by burning sulfur or
sulfur dioxide with air instead of obtaining it as a li-
quid. See the accompanying flow sheet for the process.
PROCESS 203 - 80^ SOLVENT AND VACUUM SULFONATION
Undiluted SO, and organic reactant are fed into the vacuum
reactor through a mixing nozzle (vacuum maintained at 0.06
atm (5" Hg). Recycle is accomplished by running the
flashed product through a heat exchanger back into the re-
actor. The main advantage of the system is that under
vacuum the 803 concentration and operating temperature is
kept low, thereby assuring high product quality. Offset-
ting this is the high operating cost of maintaining the
vacuum.
DRAFT 57
-------
201 OLEUM SULFATION AND SULFONATION (BATCH AND CONTINUOUS)
2011 RECEIVING
STORAGE-TRANSFER
2012 SULFONATION
2013 SPENT ACID
SEPARATION
WATER CAUSTIC
I I
OLEUM
FUME
SCRUBBER
I
! t
i
i
i
1
WASTE-
WATER
201101
T
4
LEAKS. SPI LLS, STORM
RUNOFFS, WASHOUTS.
201102
T
COOLING"
WATER
-WATER
r
t t
RPAPTOR
*
1
L_^
* SCRUBBER
\
t
I
I *
COOLING
WATER
207200
WASTE-
WATER
201201
WATER*
MIXER
•»
1
1
1
1
1
\
LEAKS, SPILLS, STORM
RUNOFFS. WASHOUTS.
207202
WASHOUTS
201302
SETTLER
\
SPENT ACID
201305
SULFONICACID
ANDSULFURIC
ACID ESTER TO
NEUTRALIZATION
Oi
00
FIGURE
9
-------
o
H
202 AIR-S03 SULFATION AND SULFONATION (BATCH AND CONTINUOUS)
2021 RECEIVING
STORAGE-TRANSFER
2022 SULFUR BURNING
2023 SULFONATION-SULFATION
SULFURf
SO3 LIQUID
ALKYL BENZENE
ALCOHOLS
ETHOXYLATES
CONDENSATE
202106
LEAKS. SPILLS, STORM
RUNOFFS, WASHOUTS.
202/02
WATER
CAUSTIC
SULFONIC ACID AND
SULFURIC ACID ESTER
TO NEUTRALIZATION
AND SALES
SULFUR 1C ACID
202309
1
1
VENTG
202308
WASHOUTS
202302
vO
FIGURE 10
-------
PROCESS 204 - SULFAMIC ACID SULFATION
Sulfamic acid is a mild sulfating agent and is used only
in very specialized quality ar.eas because of the high re-
agent price. The system is of particular value in the
sulfonation of ethoxylates.
The small specialty manufacturer may use this route to
making high quality alcohol sulfates, equivalent to that
from the chlorosulfonic acid route, substituting high rea-
gent cost for high capital costs of the chlorosulfonic route.
PROCESS 205 - CHLOROSULFONIC ACID SULFATION
For products requiring high quality sulfates, chlorosul-
fonic acid is an excellent agent. It is a mild sulfating
agent, yields no water of sulfation and generates practical-
ly no side reactions. It is a corrosive agent and generates
HC1 as a by-product.
An excess of about 5% chlorosulfonic acid is often used.
It will yield an inorganic salt upon neutralization which
is undesirable in some applications as it can result in
salt precipitation in liquid formulations, etc.
PROCESS 206 - NEUTRALIZATION OF SULFONIC ACID ESTERS AND
SULFONIC ACIDS
This step is essential in the manufacture of detergent
active ingredients; it converts the acidic hydrophylic por-
tion of the molecule to a neutral salt.
Alcohol sulfates are somewhat more difficult to neu-
tralize than the alkylbenzene sulfonic acids due to the
sensitivity to hydrolysis of the alcohol derivative. For
this reason, neutralization is usually carried out at a
pH above 7 and as rapidly as possible.
This is not a difficult feat for those who neutralize con-
tinuously, but it is more of a problem for the batch pro-
cessor unless he has excellent stirring.
60
DRAFT
-------
0
H
203 - SO3 SOLVENT AND VACUUM SULFONATION
2031 RECEIVING
STORAGE - TRANSFER
2032 SULFONATION
2033 SULFONATION
ALKYL BENZENE —
ALCOHOLS
ETHOXYLATES
sn
OJ2 .- -
qr\ i IDI nn
OU, I_IUUILI
^
V
/
\
A \
\
VACUUM
so3
REACTOR
STEAM JET €-
N
S
^
s
1
X
V
->
VAPORIZER
BLOWER |
1
i
/ ^.
i
i
1
i
1 i
_ STEAM
ACID
FEED
STOCK
>•
S
H*
REFRIGERATION
o
2 -> S02 TO
STORAGE
V
LIQUID
REACTOR
f
SCRUBBER
T
.5, DEGASSER
I
V.
r
_ i_
^
S
WATER
CAUSTIC
SULFONIC
ACID
LEAKS. SPILLS,
STORM RUNOFFS,
WASHOUTS
203102
CONDENSATE
203206
CONDENSATE
2032/7
WASHOUTS 20J202
I
I
±-
vl/
WASTEWATER
203301
WASHOUTS 203302
CJN
FIGURE 11
-------
204 SULFAMIC ACID SULFATION
2041 RECEIVING
STORAGE-TRANSFER
2042 SULFATION
A i pnHni c
1
LEAKS, SPILLS, STORM
RUNOFFS, WASHOUTS.
204102
^^
WATER
SOLVENTS —
>fc.
-^
*•
r
SCRUBBER
REACTOR
^_
I
I
I
I
I
I
I
I
I
I
I
I
<>
f
I
I
.«
•*•
WASTEWATER
204207
WASHOUTS
204202
—-WATER
— CAUSTIC
AMMONIUM ALKYL
- SULFATES
FIGURE 12
ON
NO
-------
I
205 CHLOROSULFONIC ACID SULFATION
2051 RECEIVING
STORAGE-TRANSFER
2052 SULFATION
CHLOROSULFONIC ACID
ALCOHOLS
ETHOXYLATES
LEAKS. SPILLS, STORM
RUNOFFS, WASHOUTS.
205102
SCRUBBER
REACTOR
-------
NEUTRALIZATION OF SULFURIC ACID ESTERS AND SULFONIC ACIDS
2061 RECEIVING
STORAGE-TRANSFER
2062 LIQUID NEUTRALIZATION
2063 DRY NEUTRALIZATION
ACIDS:
SULFURIC ACID ESTERS*"
SULFONIC ACIDS
OTHER INGREDIENTS:
WATER; SOLVENTS;
ADDITIVES
N~
TO DRY NEUTRAL
TO DRY NEUTRAL
TO DRY NEUTRAL
SCRUBBER JC
1
NEU
IZA1
REA
1
TRAL- !
DON f
CTOR |
1
1
1
I
1
1
WASTEWATER
2062O1
- WATER ACIDS -
- CAUSTIC
LIQUID PRODUCTS
AND SLURRIES TO
SALE, BLENDING,
OR CRUTCHING
BASES: '
OTHER
INGREDIENTS: x
WASHOUTS
206202
Rl
•. BL
it
/
\
1
1
1
1
1
1
'
BBON
ENDER
~1
SCRUBBER *
1
1
t
f
WASTEWATER
206301
WASHOUTS
206302
DRY PRODUCTS
TO STORAGE
.WATER
FIGURE 14
-------
As a result of hydrolysis occurring in the neutraliza-
tion step, there will be some free alcohol generated which
would be picked up in the oil and grease analysis. As a
product this is not all bad since the free alcohol can ac-
tually be considered a foam stabilizer in some situations.
If used in heavy duty products, the alcohol tends to be
lost in the spray tower.
PROCESS 207 - SPRAY DRIED DETERGENTS
Here is another critical area of detergent manufacture.
In this segment of processing, the neutralized sulfonates
and/or sulfates are brought to the crutcher where they are
blended with requisite builders and additives. From here
the slurry is pumped to the top of a spray tower of about
4.5 - 6.1 m (15 - 20 ft) in diameter by 45 - 61 m (150 -
200 ft) high where nozzles around the top spray out deter-
gent slurry of approximately 70% concentration.
A large volume of hot air enters the bottom of the to-
wer rising to meet the falling detergent. For low density
products, hot gas and powder flow concurrently downward.
This step is critical in that the detergent particles'
shape, size and density are determined by all of the design
preparation made previously, and the shape and size in turn
will largely determine dusting and the solubility rate of
the detergent itself in the washing process.
The air coming from the tower will be carrying dust par-
ticles which must be essentially eliminated to meet air
quality standards.
Due to product change and buildup of combustible deposits,
the spray towers are periodically shut down and cleaned.
This practice varies from two or three times a week to
once in two weeks or longer. One thing that all tower
operations share is the cleaning process. First, the
easily available material sticking to the tower walls is
scraped to be recycled if at all possible, or sent on to
solid waste.
65
DRAFT
-------
Men are sent into the tower with abrading equipment to
continue the dry cleaning process. Here again, the product
is usually preserved for reuse or disposed of as solid waste.
Finally, the tower is thoroughly washed down by spraying
streams all over the inside surface. The final step is
mandatory since the detergent manufacturers must be very
careful to avoid any mixing of any phosphate-nonphosphate
formulations, white with colored systems or anionic with
nonionic formulations.
The mixing problem is compounded somewhat by the fact
that some detergent manufacturers custom process for a
variety of marketers which requires more frequent spray
tower "turnaround".
Wastewater streams are rather numerous (see accompanying
flow sheet for process). They include many washouts of
equipment from the crutchers to the spray tower itself.
One wastewater flow which has one of the highest loadings
is that of the air scrubber which cleans and cools the
hot gases exiting from this tower. This is only one of the
several units in series utilized to minimize the particulate
matter being sent into the atmosphere.
All of the plants recycle some of the wastewater genera-
ted. Some of the plants recycle all of the flows generated.
Due to increasingly stringent air quality requirements,
we can expect that fewer plants will be able to maintain
a complete recycle system of all water flows in the spray
tower area. In the case of the fast "turnaround" tower,
they, too, are unable to utilize all of their scrubber and
other washwaters.
After the powder comes from the spray tower it is further
blended and then packaged. Solid wastes from this area
are usually recycled.
PROCESS 208 - LIQUID DETERGENTS
Sulfonated and sulfated products as produced in processes
described in categories 201 - 206 are pumped into mixing
DRAFT 66
-------
207SPRAY DRIED DETERGENTS
207J RECEIVING
STORAGE TRANSFER
2072 CRUTCH ING
2O73 SPRAY DRVING
2074 BLENDING AND PACKAGING
ACTIVES
LAS SLURRY. ALCOHOL
SULFATE SLURRY.
ETHOXYLATES
BUILDERS
PHOSPHATES. SILICATES.
CARBONATES. SULFATES.
BORATES
ADDITIVES
AMIDES. SOAPS. FLOUR-
ESCENT WHITENERS.
PERFUMES. OVES. PER-
BORATE. CMC. ANTICAKING
AGENTS. ENZYMES
WASHOUTS
207102
WATER
ADDITIVES.
BUILDERS.
AND ACTIVES
FROM
STORAGE
WASTEWATER
2072M
WASTEWATER
207201
WASH DOWN WATER
TO WASTE OR
RECYCLE TO
CRUTCHER
107311
WATER
FINISHED
DETERGENTS
TO WAREHOUSE
WASTEWATER
2073OI
SCRAP TO RECYCLE
OR SOLID WASTE
207416
FIGURE 15
-------
tanks where they are blended with numerous ingredients.
They range from perfumes to dyes. From here, the fully
formulated liquid detergent is run down to the filling
line.
The filling line usually consists of a long conveyor
which passes many stations. Each station performs a given
task such as filling, capping, checking weight, labeling,
etc. Often, soap solutions are used to lubricate the
conveyor so that the bottles flow smoothly past the vari-
ous stations.
Whenever the container being filled is to change to a
different product, the filling system must be thoroughly
cleaned out. This is equally true of the filling equip-
ment. Properties of differing products are often so con-
trasting that there must be no cross contamination, other-
wise the performance and other specifications cannot be met.
To avoid this problem the mixing equipment and all fil-
ling plumbing is thoroughly flushed with water until it
runs clear.
PROCESS 209 - DRY DETERGENT BLENDING
Fully dried "active" (surfactant) materials are blended
with additives, including builders, in dry mixers. In
the more sophisticated plants mixing time is utilized to
the maximum by metering components into weighing bins
prior to loading into mixers. When properly mixed, the
homogeneous dry product is packed for shipment.
Normal operation will see many succeeding batches of de-
tergent mixed in the same equipment without anything but
dry cleaning. This procedure is followed until the next
formulation to be blended must not be contaminated with
even an almost negligible amount of the previously pre-
pared product. At this time the equipment must be complete-
ly washed down.
For this reason, a modest amount of wastewater is required
for the blender to maintain specification requirements.
68
DRAFT
-------
208 LIQUID DETERGENT MANUFACTURE
ACTIVES:
LAS; SULFONIC ACID;
ETHER SULFATES;
OLEFINSULFONATES;
ETHER SULFONATES;
AMINE OXIDES; AMIDES
BUILDERS:
PHOSPHATES; SILICATES
ADDITIVES:
HYDROTROPES;
SOLVENTS; COLOR;
PERFUME
vO
2081 RECEIVING
STORAGE-TRANSFER
WATER- -».
FIGURE 16
2082 BLENDING
MIXERS
WATER
TREATMENT
BULK
DETERGENT
SALES
WASHDOWN
208212
WASHOUTS
208202
2083 PACKAGING
PACKAGING
EQUIPMENT
CONTAINER
WASHINGS
208310
_CASE GOODS
TO WAREHOUSE
SOLID WASTE
2083O9
LEAKS, SPILLS,
WASHOUTS
208302
-------
209 DETERGENT MANUFACTURE BY DRY BLENDING
209;
RECEIVING
STORAGE-TRANSFER
2092 DRY BLENDING
2093 PACKAGING
ACTIVES:
LAS SLURRY; FLAKES;
BEADS; SULFONIC ACID;'
AMIDES; ETHOXYLATES
BUILDERS:
SILICATES; CARBONATES;
PHOSPHATES; BORATES
ADDITIVES:
CMC; ANTICAKING AGENTS;
COLORS; PER FUMES;
ABRASIVES; DIATOMACEOUS
EARTH; PUMICE
BLENDER
BULK
DETERGENT
SALES
SOLIpJWASTE
209209
PACKAGING
EQUIPMENT
CASE GOODS
TO WAREHOUSE
I
_L
SOLID WASTE
209309
WASHOUTS
209202
WASHOUTS
209302
FIGURE 17
-------
The products fulfill a wide variety of industrial cleaning
uses from dairy cleaning to box car washing. They are also
used to some extent in household products.
PROCESS 210 - DRUM DRIED DETERGENTS
Drum drying of detergents is an old process. Much of the
equipment still in use is well over thirty years old. The
process yields a fairly friable product which can become
quite dusty with any extensive handling.
There are several types of drum driers; those which have
double rotating heated drums with liquid feed coming onto
the space above and between the rolls, and a twin-drum
dryer with dip or flash feed. The dip feed is a pan into
which the "bottom" of the roll or drum picks up material
to be dried.
The thin layer is removed continuously be a knife blade
onto conveyors. The powder is substantially anhydrous.
The vapors coming off are often collected and removed
through a vapor head between the drums.
The rolls of a drum dryer are often 0.6 - 1.8m (2 - 6
ft) in diameter and 0.9 - 4.5 m (3 - 15 ft) long with re-
volution speeds of 5 - 10 rpm. About 6-15 seconds resi-
dence time is provided the slurry on hot metal surface which
is short enough to avoid degradation of heat sensitive pro-
ducts.
As an example of the limitations of drying capacity, the
capacity of the drum varies between 4.5 - 48.8 kg of finished
product per sq meter of drying surface per hour (between
1-10 Ibs per sq ft per hour).
This operation should be essentially free of generation
of wastewater discharge other than an occasional washdown.
PROCESS 211 - DETERGENT BARS AND CAKES
In answer to the need for a bar soap which performs satis-
factorily in hard water, the detergent industry manufac-
DRAFT 71
-------
o
H
270 DRUM DRIED DETERGENT
2101 RECEIVING
STORAGE-TRANSFER
2702 DRUM DRYING
2103 PACKAGING
APTIWF1 _
AnniTivpr _
a
|-»-| SCRUBBER |*-j
CRUTCHER
1
i
I
1
1
JL
1
I
I
J
DRUM
DRIER
— *•
STOR-
AGE
BULK
DETERGENT
SALES
PACKAGING
EQUIPMENT
^^^H
i j ;
1 1
PACKAGED
— *• GOODS TO
WAREHOUSE
WASTEWATER
270207
WASHOUTS
210202
WASHOUTS
210302
FIGURE 18
ro
-------
o
H
27 7 DETERGENT BARS AND CAKES
2111 RECEIVING 2/72 MIXING
STORAGE-TRANSFER WORKING-CONDITIONING
2113 STAMPING-PACKAGING
ACTIVE INGREDIENTS
BUILDERS
ADDITIVES
SOLID WASTE
211209
WASTEWATER
211201
WASHOUTS
211202
STAMPER
WRAPPER
PACKAGER
WASHOUTS
211302
BAR
DETERGENTS
TO
WAREHOUSE
DETERGENT
CAKES
SCRAP SOAP
TO RECYCLE
FIGURE 19
-------
tures and markets detergent bars. They constitute about
20% of the toilet bar market.
There are two types of "detergent" bars, those made of
10070 synthetic surfactant and those blending synthetic
surfactant with soap.
Once the active ingredients have been manufacture they
are blended in essentially the same manner and in similar
type of equipment used for conventional soap.
Due to the sensitive nature of the surfactant portion of
the detergent bar, fairly frequent cleanups, including
equipment washdowns are required. Otherwise thermally de-
graded surfactant will contaminate the bar leading to such
undesirable properties as stickiness and off-color.
DRAFT
-------
SECTION V
WASTE CHARACTERIZATION
INTRODUCTION
In this section the results of investigation of the quanti-
ties and concentrations of contaminants in effluents from
the industry are discussed. The various analytical proce-
dures and their significance are briefly treated. Analy-
sis of samples taken by project personnel and information
submitted by industry companies is the source of data for
this commentary. Wastewaters from each individual process
are described from the standpoints of their origin and con-
stituents. The final part of this section is an analysis
of data contained in Corp of Engineers Permits for plants
of the industry.
Numerous organic and inorganic chemical compounds are used
in the manufacture of soaps and detergents. As the reac-
tions are carried out some of these products and their de-
rivatives enter the wastewaters from the processing steps.
These materials are then treated as contaminants and pro-
cessed as wastewater in conventional waste treatment units.
In the discussions of the individual unit processes the
various constituents are considered in detail. The fol-
lowing paragraphs will briefly relate the significance
of the analytical procedures to pollutants generated by
the industry.
ANALYTICAL PROCEDURES
Acidity, Alkalinity and pH
These are interrelated parameters. The accepted tests
for acidity and alkalinity are measures of how much alka-
li or acid must be used to bring the wastewater to a neu-
tral point. The test method will be found in Standard
Methods for the Examination of Water and Wastewater pub-
lished by the American Public Health Association Inc.
Hereafter this publication will be referred to as Stan-
dard Methods.
DRAFT
75
-------
pH, on the other hand, will determine how far from neu-
trality the water is. When the pH gets much outside the
range of 6 - 9, microorganisms present in sewage treatment
plants or receiving waters can be endangered. Alkaline pHs
up to 10 and 11 are acceptable under certain conditions.
Highly acid and alkaline conditions can cause corrosion
of facilities and upsets in the physiochemical characteris-
tics of waters.
Oxygen Demand
Oxygen is a necessary ingredient for a healthy body of wa-
ter. Therefore, pollutants that react directly with oxy-
gen or act as fuel and food for microorganisms cause de-
pletion of the oxygen in the receiving water. The degree
of this depletion by a pollutant is a very important fac-
tor in determining its impact.
There are several methods to determine oxygen demand of
wastes. We will discuss the three used in data evalua-
tion for this report; BOD,COD,TOC. There are other pro-
cedures used in special circumstances.
The Chemical Oxygen Demand (COD) procedure most often
used is based on oxidation by potassium dichronate in
sulfuric acid (of the wastewater constituents). Because
it is a standardized chemical procedure results are repeat-
able.and precise. Almost all organic carbon compounds,
as well as oxidizable sulfur and nitrogen compounds, re-
act quantitatively. A few compounds, notably acetic acid,
do not react completely.
Biochemical Oxygen Demand (BOD) is usually determined by
the dilution technique (Standard Methods) although -other
procedures such as Warburg respirometery are also used.
There is no fixed relationship between BOD and COD of soap
and detergent contaminants because microorganisms utilize
organic compounds not only to generate energy but also to
synthesize cellular matter. Furthermore, some organic
compounds are incompletely degraded to relatively stable
intermediates.
76
DRAFT
-------
The BOD test gives variable results because the reac-
tion of oxygen with the substrate is carried out with
living organisms. Microorganisms differ in their abili-
ty to utilize the many organic compounds which find their
way into soap and detergent wastewater streams. Unless
a culture has time to acclimate to an organic, it will
show a variable ability to use the compound. In extreme
cases, the compound under study will be toxic to an
unacclimated culture. Quite often a substrate, especially
synthetic soap and detergent ingredients, will exert an
inhibition effect and low results will be obtained.
LAS (linear alkylate sulfonate) is an excellent example
of the need for acclimation. In high concentrations these
compounds are toxic to microorganisms. Until the micro-
organisms develop the ability to use LAS, no degradation
results. After acclimation the organisms metabolize LAS
as rapidly and completely as the average domestic sewage.
To determine biodegradability and oxygen demand, a thorough
study is needed with acclimated cultures.
Final conclusions about oxygen demand of wastes should not
be based on screening type BOD measurements.
The Total Organic Carbon (TOG) procedure depends on
oxidation of organic carbon to C02 in a high temperature
furnace. On a given organic compound, precise and re-
producible results are obtained. Being an instrumental
procedure, results can be easily and rapidly obtained.
As with the COD procedure there is not a fixed relationship
with BOD. However, where a ratio for the particular waste
has been established, the TOG and COD procedures give ra-
pid results for monitoring and control.
Surfactants. NBAS CMethylene Blue Active Substances^
This colorimetric procedure is specific for anionic sur-
factants. Soap is not determined. Neither are the non-
ionic surfactants which make up an increased portion of
nonphosphate formulations. There are some interferences.
Non-surfactant sulfonates, such as the hydrotropes and
DRAFT 77
-------
LAS degradation products, are not determined. However,
the procedure is well known and is very useful for deter-
mining the raw waste loads of MBAS. Also, it is widely
used to trace the biological degradation of MBAS. Un-
fortunately, equivalent methods for the nonionic surfac-
tants are not available.
Phenols
Phenol and the low molecular weight phenolics are used
in a few specialty household cleaners. Phenols are are
constituents of soap and detergent wastes, (industrial
cleaners sometimes contain phenols. Study is needed to
define the treatability of wastes of phenols and other
such ingredients and it is expected this work would be
a part of the organic chemical guidelines. (Standard
Methods techniques for phenolics are suitable for their
detection and estimation).
Oil and Grease
This procedure (Standard Methods) consists of solvent
extracting the wastewater with hexane to recover hydro-
carbon, fats and oils. Chloroform and Freon solvents
are also used. The method does not distinguish between
petroleum oils which may be relatively non-degradable
and natural fats and oils which degrade readily in bio-
logical treatment processes. Application of data from
this analytical procedure should always be related to
the actual constituents and their treatabilities of prob-
lem causing potentials.
Solids
There are several types of determinations (Standard Met-
hods) of solid compounds dissolved or suspended in waste-
waters. Total Solids includes all categories. Suspended
solids are those that can be removed by filtration - dis-
solved solids are those which cannot, including some col-
loids. Volatile solids, both dissolved and suspended, in
general are organics which can be vaporized or burned.
As in other procedures a knowledge of the chemistry of
the solids in the wastes is most helpful in interpreting
the test results.
78
DRAFT
-------
CHEMICAL ANALYSES
Standard Methods are available for determination of
almost every common compound and element found in wa-
ter. In this study data was sought on chloride, sulfate,
sulfite, arsenic, boron, phosphorus, copper, mercury,
and the various forms of nitrogen. Some elements are
toxic if the concentration is high enough, e.g., Zn, Ba,
Cu, Hg, As, B. Some are nutrients and of interest in
eutrophication, e.g., P, N, S. Others, i.e. sulfate
and chloride are innocuous in small amounts, but can be
important if the receiving water is close to the limits
for the various uses.
UNIT PROCESSES
In this section the qualitative and quantitative aspects
of soap and detergent wastewatersare discussed. The ini-
tial section lists the constituents which are found and
their relationship to analyses and tests for pollution
potential. A very brief discussion of the significance
of the various analyses and tests is presented, but the
user of the report should familiarize himself in depth
with the tests used for the plant to be regulated. The
test methods used are found in Standard Methods.
The bulk of this section then treats the wastewaters of
each unit process individually. The source and disposal
of water is considered in all water balances. Recycle and
reuse or the lack thereof are discussed. The split be-
tween cooling and contact of process water is brought out.
Wherever possible, flows related to production of product
is detailed.
The specific constituents in the individual unit process
wastewaters are discussed both in pounds per 1000 pounds
of product and by concentration. Their effect on pollu-
tion parameters is indicated.
The data assembled in this section is used in the follow-
ing section - Selection of Pollution Parameters VI.
DRAFT 7g
-------
In the following section reference is made by number of
the specific wastewater flows identified in previously
described industry categories. Please refer to the
Schematic Flow Sheets for the individual processes lo-
cated in the chapter on Categorization.
PROCESS 101 - SOAP MANUFACTURE BY BATCH KETTLE
Introduction
Effluents of this process arise from three sources. Hand-
ling of fats and oils results in leaks and spills (streams
101102 and 101202). These are usually collected with water
and the fats skimmed. Pretreatment of the fats or oils re-
sults in process wastewaters 101321 and 101218. Soap making
results in two by-products, 101319 and 101320, which gene-
rally are disposed of as wastewaters. These streams are:
discussed in detail in the following sections.
Water and Wastewater Balance
Water for this process will usually come from municipal
systems since the plants are old and somewhat isolated.
For the barometric condenser '101218) surface water or
cooling tower water will be used. Since steam is used
for heating the fat in both pretreatment and saponifica-
tion, some process water is introduced in this manner.
Kettle boiling soap is a batch process and water use will
be intermittent. Instantaneous flows of 0.12-18.9 I/sec
(2-300 gpm) will be experienced. Over-all water use can
be limited to 623 1/1000 kg (15 gal./lOOO Ibs) of soap,
but as much as 2080 1/1000 kg (250 gal./lOOO Ibs)is used.
Water reuse and recycle is not common in kettle boil
soap plants for process water. Where a barometric con-
denser is used for the steaming pretreatment step, recy-
cle through a cooling tower is sometimes used, but even
here use of surface water is more common. Except for
the barometric condenser, all water use can be considered
process water.
Specific wastewater sources and constituents are discussed
generally and specifically tabulated in the next section.
80
DRAFT
-------
Wastewater Constituents
Leaks, spills and storm runoff or floor washing (streams
101102 and 101202) are invariably collected for recovery
of fats and oils by settling and skimming in fat traps.
The wastewater will contain some emulsified fats, since
the skimmers and settlers do not operate at 10070 efficiency,
The fat pretreatment is carried out to remove impurities
which would cause color and odor in the finished soap.
Acid and/or caustic washing may be used. This results
in sodium soaps or sulfuric acid solutions of fatty acids
(10123D. Other pretreatment steps make use of proprie-
tary chemical formulas which result in water containing
the treatment chemicals, fatty impurities and emulsified
fats. Clay and carbon treatments give solid wastes and
do not directly result in aqueous effluents, but steam is
used for heating and the condensate must be removed. Of-
ten a barometric condenser is used, and there is carryover
of low molecular weight fatty acids (101218).
Wastewaters from the fat skimmer and from the pretreat-
ment steps each contribute about 1.5 kg of BOD per 1000
kg of soap (1.5 lbs/1000 Ibs). Concentrations typically
are 3600 mg/1 BOD, 300 mg/1 COD, 250 mg/1 of oil and
grease with a pH of 5.
Saponification of the fats and oils by sodium hydroxide
and salting out of the soaps (graining) with salt does
not necessarily lead to any effluent. The nigre which
comes from washing excess salt and impurities from the
neat soap with aqueous caustic is always recycled to
some extent. The organic portion consists of low grade
soap. In some plants, the nigre is acidified to revert
the soaps to fatty acids which are recovered for sale.
Although acidification removes much of the organic con-
taminant, some is still discharged (101320^. Some manu-
facturers' third alternative for the nigre is the sewer
(101319).
The stream called sewer lyes f101319) arises most often
from the reclaiming of scrap soap. The lye and salt wa-
ter added to separate the soap must be discarded because
it contains paper and other dirt.
DRAFT
81
-------
Sewer lyes and nigre are concentrated wastewaters (alka-
linity up to 32,000, BOD as high as 45,000, COD up to
64,000, chlorides of 47,000 and a pH of 13.5. Volumes,
however, are small - 249 1/1000 kg of soap (30 gal./lOOO
PROCESS 102 - FATTY ACIDS BY FAT SPLITTING
Introduction
In this process, fats and oils are converted to fatty
acids and glycerine by hydrolysis with water. In sec-
tion 103 conversion of fatty acids to soap is considered
and section 104 deals with glycerine recovery. There are
two process condensates which contain organic contaminants
- 102322 and 102418. Also, treatment of the fatty acid
still bottoms results in contaminated water (102423>.
Since streams from fat pretreatment (102203 and 102221)
and leaks and spills (102102, 102202, 102302, 102402)
are essentially the same as analogous streams (101102
and 101202) in Process 101, the discussion will not be
repeated.
Water and Wastewater Balance
In general fatty acid plants are relatively new and con-
tain a water recycle system. The small amount of clean
water required will come from surface water, municipal
systems, or wells. Although operation of surface conden-
sers and barometric condensers requires thousands of gal-
lons per minute, blowdown from fatty acid plants ranges
from 3.2-1.26 I/sec (50-200 gpm)(102204, 102304 and 102-
404).
The other main contaminated stream is from treating still
bottoms ^102423). It is smaller, but highly contaminated.
Wastewater Constituents
See process section 101 for discussion of 102102, 102202,
and 102402 which are wastewaters from leaks, spills and
storm runoff. Also, fat pretreatment wastes 102205 and
102224 are covered under Process 101 for the analogous
streams.
DRAFT 82
-------
Process condensate 102322 from fat splitting will be con-
taminated with volatile low molecular weight fatty acids
as well as entrained fatty acids and glycerine streams.
The barometric condensate 102418 will also contain vola-
tile fatty acids. These streams will be settled and skimmed
to remove the insoluble fatty acids which are processed for
sale. The water will typically circulate through a cooling
tower and be reused. To keep emulsified and soluble fat-
ty material at a reasonable level, part of the stream is
purged to the sewer. This blowdown (102204, 102304, 102-
404> contributes about 10 kg of BOD and 18 kg of COD per
1000 kg (10 Ib BOD and 18 Ib COD/1000 Ibs) of fatty acids
produced plus some oil and grease.
Treatment of stream 102423 consists of acidification to
break the emulsion and skimming of insoluble fatty acid
pitch. The wastewater is neutralized and sent to the se-
wer. This wastewater will contain salt from the neutrali-
zation, zinc and alkaline earth metal salts from the fat
splitting catalyst and emulsified fatty acids and fatty
acid polymers. One plant had about 0.6 kg of BOD and
0.9 kg of COD/1000 kg(0.6 Ib BOD and 0.9 Ib COD/1000 Ibs)
of fatty acids from this source.
PROCESS 103 - SOAP BY FATTY ACID NEUTRALIZATION
Introduction
This process is relatively simple and high purity raw ma-
terials are converted to soap with essentially no by-pro-
ducts. Leaks, spills, storm runoff and washouts are ab-
sent. There is only one wastewater of consequence. It
is 103326, the sewer lyes from reclaiming of scrap.
Stream 103224 is almost nonexistent since there is a net
consumption of brine in the process.
Water and Wastewater Balance
Except for the small amount of water (258 1/1000 kg; 31 gal.
/1000 Ibs of soap) used for reclaiming scrap and resulting
in the sewer lyes, the process produces no other aqueous
effluent. Potable water is fed into the process.
83
DRAFT
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Wastewater Constituents
The sewer lyes (103326) will contain the excess caustic
soda and the salt added to grain out the soap. Also,
they will contain some dirt and paper not removed by the
strainer. Typically 3 kg of BOD and 5.5 kg of COD/1000
kg (3 Ibs of BOD and 5.5 Ibs of COD/1000 Ibs) of soap
will be discharged.
PROCESS 104 - GLYCERINE RECOVERY
Introduction
The feedstock for this unit process comes from soap boil-
ing and fat splitting processes 101 and 102. Both crude
glycerines will contain about 90% water, but that from
soap kettle boiling will contain a fair amount of salt
and some NaOH. Both streams will contain soap or fatty
acids which must be removed in the pretreatment section
by precipitation with alum and filtration.
There are three wastewaters of consequence from this pro-
cess; two barometric condensates from evaporation of water
(104318) and from distillation of glycerine (104418) plus
the glycerine foots or still bottoms (104428). Contaminant
of the barometric condensates is essentially glycerine
with a little entrained salt. The glycerine foots contain
glycerine, glycerine polymers and salt. The foots are wa-
ter soluble and are removed by dissolving in water.
Glycerine can also be purified by use of ion exchange re-
sins to remove the sodium chloride followed by evaporation
of the water. This process puts additional salts into the
wastewater but results in less organic contamination.
Water and Wastewater Balance
Compared with the amount of water used in the barometric
condensers, water used for other purposes is negligible.
Installations not recirculating cooling water through a
cooling tower use from 698,000-1,540,000 1 of water per
1000 kg (84,000-185,000 gal. of water per 1000 Ibs) of
glycerine produced. With a cooling tower, blowdown con-
sumes 9975 1/1000 kg (1200 gal./lOOO Ibs) glycerine.
84
DRAFT
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The ion exchange process is reported to use 449 1/1000 Ibs
C54 gal./lOOO Ibs) of glycerine for both backwashing and
regeneration.
The source of water for glycerine recovery is usually sur-
face water. Since it is used mainly for condensing steam,
quality is unimportant. Typically, a plant will withdraw
water from a river, put it through the barometric condensers,
and discharge it into the river with no treatment.
As mentioned above, water used for washout of the still, for
steam generation and the ion exchange process is relatively
small. These water uses require treated water, usually
from municipal supplies. No water is produced or consumed
in the process.
Wastewater Constituents
The two barometric condensers streams (104318 and 104408)
become contaminated with glycerine and salt due to entrain-
ment. Stream 104428 is a water soluble by-product which
is disposed of by washing into the sewer. It contains gly-
cerine, glyerine polymers and salt. The organics will
contribute to BOD, COD and dissolved solids. The sodium
chloride will also contribute to dissolved solids. Little
or no suspended solids, oil and grease or pH effect should
be seen.
From the glycerine evaporator barometric condenser about
30 kg of COD and 15 kg of BOD per 1000 kg (30 Ibs of COD
and 15 Ibs of BOD per 1000 Ibs) of product will be dis-
charged. The foots and glycerine still contribute about
equal amounts of BOD (2.5 kg)(2.5 Ibs) and COD (5 kg)
(5 Ibs). Because the barometric condensers use large
amounts of water, concentrations are low. The foots are
diluted only enough to remove them from the still, and
concentrations of organics and salts are about 30,000
mg/1.
PROCESS 105 - SOAP FLAKES AND POWDERS
Introduction
In this process the neat soaps from processes 101 or 104
DRAFT 85
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are converted to flakes or powders for packaging and sale.
The unit processes use the soap dry in the physical form
desired. There are a number of possible effluents shown
on the flow sheet for process 105. However, survey of the
industry showed that most operating plants either recycled
any wastewater to extinction, or used dry cleanup proces-
ses. Occasionally water will be used for equipment clean-
up.
In converting neat soap to flakes, powder or bars, some
scrap results. The flow sheets show scrap reclaim in pro-
cesses 101 and 103. There is an aqueous effluent - sewer
lyes - from this reclaim operation (streams 101319 and 103-
326). All existing soap plants both make and process soap;
therefore, the given categorization will handle the efflu-
ent sewer lyes under process 103. Should a plant start
with neat soap, the sewer lye guideline should be applied
to 105.
PROCESS 106 - BAR SOAPS
Introduction
To produce soap bars, neat soap is dried and physically
worked prior to extrusion and stamping. Some plants have
filter backwash (106129), scrubber waters or condensate
from a vacuum drier (106201) and water from equipment wash-
down (106202 and 106302).
Wastewater Balance
Water from drying neat soap is vented to the atmosphere.
Water use by plants producing dry soap varies from none
to 6230 1/1000 Ibs (750 gal./lOOO Ibs) of soap made. The
largest quantity is required when a barometric condenser
is used on the drier.
Wastewater Constituents
The contaminant of all wastewaters is soap which will con-
tribute primarily to BOD and COD. Concentrations of BOD
and COD are typically 1600 mg/1 and 2850 mg/1 respectively
in the scrubber (106201), which is the major source of
86
DRAFT
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contamination. Driers contribute from 0.3 - 0.7 kg/1000 kg
(0.3 - 0.7 lbs/1000 Ibs) of soap to wastewaters. Washouts
of the filter and of equipment account for the remainder to
give an average process total of 2 kg of BOD per 1000 kg
(2 lbs/1000 Ibs) of dry soap.
PROCESS 107 - LIQUID SOAPS
Introduction
Production of liquid soaps consists of a simple blending
operation followed by filling of rather large containers
(drums) for sale. According to manufacturers interviewed,
there is very little aqueous .effluent. Leaks and spills
can be recycled or handled dry. Washout between batches
is usually unnecessary or can be recycled to extinction.
Water Balance
Some water is used as a part of the liquid soap formula,
and small amounts (16.6 1/1000 kg of dry soap)(2 gal.
/1000 Ibs) are occasionally used for cleanup.
Wastiewater Constituents
The liquid soaps will contribute to BOD,COD, and dissolved
solids. However, amounts are very small fQ.l kg BOD and
0.3 kg COD per 1000 kg of product) (0.1 Ib BOD and 0.3 Ib
COD /1000 Ibs).
PROCESS 201 - OLEUM SULFONATION AND SULFATION
Introduction
The principle raw materials for synthetic detergent manu-
facture are alkylbenzenes, fatty alcohols and alcohol etho-
xylates. These are converted to surface active agents by
sulfonation or sulfation and neutralization with sodium hy-
droxide or other bases. There are no process wastewaters
from this reaction, but leaks, spills and washouts result
in some highly acidic wastes (streams 201102, 201202 and
201302"! . The oleum tank breathing scrubber which collects
S03 vapors during filling of the tank also contributes
sulfuric acid to the wastewaters (201101). Although cool-
87
DRAFT
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ing water is used for the sulfonation, it is indirectly
used to cool Freon or brine systems and doesn't become
contaminated.
Although the amount of acids released are small, both
the sulfuric and sulfonic acids are strong acids and small
amounts can give a pH of 1 - 2; therefore, neutralization
of spills is imperative. Also, the sulfonic and sulfuric
acid esters are surface active (MBAS) and contribute to
BOD and COD. Some oil and grease can be expected from
spills of organic raw materials. The pH will be very low.
Water and Wastewater Balance
Usually leaks from pump packing glands will be flushed
away continuously with small streams of water. Little
water is used. Because the water use is small, 100 -
2740 1/1000 kg (12-330 gal./lOOO Ibs) of surfactant,
potable water is generally used. Since the oleum tank
scrubber will only be used when the tank is being filled,
little water is used here.
Since sulfonation is highly exothermic and temperatures
must be kept low to avoid charring, the cooling water for
sulfonation is a large stream. Well water, or municipal
water is preferred because of their low temperatures,
making the refrigeration cycle more economical.
Wastewater Constituents
Since the source of contaminants in this process is
leaks and spills, all the raw materials and product will
be present. These are fatty alcohols, dodecylbenzene,
sulfuric acid, dodecylbenzene sulfonic acid and the ester
of the sulfuric acid and alcohol. These chemicals will
contribute acidity, eulfate ion, MBAS, oil, BOD and COD
to the wastewater streams.
Concentrations of contaminants will depend on the amount
of water used for washdown. Amounts of contaminants ave-
rage 0.2 kg (0.2 Ib) BOD, 0.6 kg (0.6 Ib) COD and 0.3 kg
(0.3 Ib) MBAS per 1000 kg (1000 Ibs) of sulfonated pro-
duct produced. The pH will usually be very low (1-2)
unless the sulfonation wastes are commingled with neu-
DRAFT
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tralization wastes.
PROCESS 202 - AIR SO SULFONATION & SULFATION
Introduction
Anhydrous SOo is used to sulfonate alkylbenzenes and to
sulfate alcohols and alcohol ethoxylates converting them
to surface active agents. The acids produced are neu-
tralized with NaOH, ammonia and other bases as described
in process 206.
Because of the hazardous nature of anhydrous 803, the sys-
tems designed for its use are essentially leak-free. How-
ever, any leaks and spills will end up in the wastewaters.
The main source of contaminated wastewaters are by-products.
The incoming air-S03 stream will be scrubbed with H2S04 and
the spent acid purged,(202309). The effluent gas contains
entrained sulfonic acid, sulfuric acid and SOo (202301).
These two streams are often disposed of by flushing into
the sewer with large quantities of water.
Another sizable source (202302) of contamination comes
from'startup and shutdown. Plants that run 7 days per
week, 24 hours per day will obviously have much less con-
tamination from this source than plants that shut down
more frequently.
Water Balance
A considerable amount of water is used for cooling the
sulfonation reactor. This is usually a clean water stream.
Approximately 249 1/1000 kg (30 gal./lOOO Ibs) of water
is used for disposing of by-products. All of this water
usually goes to the sewer.
Wastewater Constituents
Stream 202302 which receives startup slop will contain
unreacted alcohols, alcohol ethoxylates, and alkylbenzenes.
These will show up as oil and grease as well as BOD and
COD. The other contaminated streams (202102, 202202, 202-
309 and 202301) as well as 202303 will contain sulfonic
89
DRAFT
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and sulfuric acids. These will analyze as MBAS, acidity,
SO^, dissolved solids, BOD and COD.
Concentrations from the process were observed to range
from 380-520 mg/1 of BOD and 920-1589 mg/1 of COD. The
pH ranged from 2-7. Source of the contamination comes
from three streams; leaks and spills - 157», scrubbers -
50% and startup slop - 35%.
PROCESS 203 - SOLVENT AND VACUUM SULFONATION
Introduction
Compared to the Air-S03 process, these techniques are
used infrequently. Usually they will be batch operations
and relatively small. Leaks, spills and washouts will be
the main source of contamination. No data specific to
these processes was obtained or submitted, but it is be-
lieved that effluents and contaminants will be essentially
the same as for Air-SO., sulfonation, Process 202.
Water and Wastewater Balance
No direct process water will be used, but a small stream
will be used for cleanup of leaks and spills. Cooling wa-
ter will be indirect. It is possible that operators will
use barometric condensers to maintain the vacuum and to
strip solvent, which is usually S02- If barometrics are
used, there could be a large volume effluent with low con-
centrations of MBAS, oil and sulfite.
Wastewater Constituents
Leaks and spills will consist of raw materials and pro-
ducts. These will include alkylbenzenes, alcohols and
ethoxylated alcohols; sulfonic acids and sulfuric acid
esters. These constituents will contribute BOD, COD,
acidity, dissolved solids, sulfate, sulfite oil, and
MBAS to effluent wastewaters.
90
DRAFT
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PROCESS 204 - SULFAMIC ACID SULFATION
Introduction
Sulfamic acid is used to sulfate alcohol and alkylphenol
ethoxylates, but seldom for other raw materials. The re-
action is run batchwise and requires relatively simple
equipment. The ammonium salt of the other sulfate is ob-
tained directly, so it is only necessary to dilute the
product with the chosen solvent.
Water and Wastewater Balance
No process water is used and cooling or heating water
will be non-contact.
Wastewater Constituents
A small amount of contamination will come from leaks and
spills, but a major effluent comes from washing out the
reactor between batches. This is necessary since the sol-
vent (water or alcohol') will react with the sulfamic acid.
Data submitted by industry indicates that 30 kg (30 Ibs)
of BOD and 60 kg (60 Ibs) of COD is added to wastewaters
per 1000 kg (1000 Ibs) of ammonium ether sulfate produced.
This is understandable since the product is viscous and
surface to volume ratio of the reactor is high.
PROCESS 205 - CHLOROSULFONIC ACID SULFATION
Introduction
This process is used to produce high quality alcohol and
ether sulfates for specialty surfactant use. Leaks, spills,
and reactor washout will be the main source of organic con-
taminants. Since HC1 is a by-product it may be absorbed in
water or caustic and sent to the sewer.
Water and Wastewater Balance
The only process water used is for absorbing HC1. Cooling
water is non-contact and should remain uncontaminated.
91
DRAFT
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Wastewater Constituents
Contaminants found in leaks and spills will be the alco-
hols or alkylphenol and alcohol ethoxylates used for
feedstocks. Also, chlorosulfonic acid hydrolysis pro-
ducts (HC1 and I^SO^) can be expected, plus the sulfated
surfactants. The same materials will be in the other
wastewaters.
Since it is not necessary to clean out the reactor be-
tween batches, raw waste loads will be similar to other
sulfonation processes, i.e.; SOo-Air. An average of 3 kg
(3 Ibs) of BOD and 9 kg (9 Ibs) of COD per 1000 kg (1000
Ibs) of sulfated product was found. Sizable amounts of
acidity and chloride (5 kg/1000 kg) (8 lbs/1000 Ibs) can
also be expected if the HC1 is sent to the sewer, but
many plants recover it and sell it as muriatic acid.
PROCESS 206 - NEUTRALIZATION OF SULFURIC ACID ESTERS
AND SULFONIC ACIDS
Introduction
This' process is used to convert the sulfated and sul-
fonated alkylbenzenes and alcohols to neutral salts.
Various bases are used depending on the required charac-
teristics of the final surface active agent. The dry
neutralization process (2063^) is infrequently used in the
United States to make consumer products falling within
SIC 2841. However, some industrial products will be made.
Most salts are made by liquid neutralization (2062).
Plants making neutralized products range from a small
batch kettle of a few thousand kilograms to several mil-
lion kilograms per day continuous unit processes.
Water and Wastewater Balance
Wastewaters from these plants come almost entirely from
leaks and spills, with washouts occasionally contributing
(206102 and 206202). Indirect cooling water is used since
the neutralization is exothermic, but contamination should
be very rare. No process water is involved.
92
DRAFT
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Wastewater Constituents
All of the anionic surface active agents used in soaps
and detergents will be found in these wastewaters. Also
the inorganic salts, such as sodium sulfate, from neu-
tralization of excess sulfuric acid will be found. Alkyl-
benzene sulfonates, ether sulfates, alcohol sulfates, ole-
fin sulfonates, with the ammonium, potassium, sodium, mag-
nesium and triethanol ammonium cations will be represented.
These constituents will contribute to BOD and COD, MBAS,
dissolved solids, Kjeldahl ammonium nitrogen, sulfate
acidity and alkalinity.
The total amount of contaminants contributed from *~his
process is quite small. The equipment used has stood the
tests of time. Of course there will always be occasional
leaks and spills. Depending on whether a plant recycles
or discharges to a sewer determines the concentration of
contaminants and water usage. When recycle is practiced,
as little as 10.4 1/1000 kg (1.25 gal./lOOO Ibs) of water
is used. Concentrations in this case were high - 6000
mg/1 of BOD and 21,000 mg/1 of COD. The other extreme
was 4170 1 (1100 gal.) of water - a BOD of 85 mg/1 and
a COD of 245 mg/1.
Because of the variety of products made we observed quite
a range of waste loadings: BOD - 0.07 kg - 0.8 kg/1000 kg
(0.07 Ib - 0.8 lb/1000 Ibs) of product, COD - 0.2 kg -
2.3 kg (0.2 Ib - 2.3 Ib), MBAS - 0.1 kg - 3.1 kg (0.1 Ib -
3.1 Ibs).
PROCESS 207 - SPRAY DRIED DETERGENTS
Introduction
This is probably the single largest volume unit process
utilized by the soap and detergent industry. There is
great variation in the operation of spray towers insofar
as water use and reuse is concerned. These variations
result from different processing characteristics of pro-
duct formulas containing the different air pollution
standards and frequency of product changeovers and plant
DRAFT 93
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integration.
The principal sources of contaminated water are washdown
of the tower - 207312; scrubber waters - 207301 and 207-
330; and leaks and spills - 207202 and 207302.
Water and Wastewater Balance
No cooling water is used in this process. All process
water which is added to the crutcher leaves the process
as water vapor from the spray tower (207308). Therefore,
all water used is for various types of cleanup. Some
plants employ total recycle of cleanup waters and there-
fore have a very low rate of discharge. Some plants dis-
charge all wastewaters to the municipal sewer. Most plants
are intermediate and specific problems must be recognized
to be able to understand water disposal practices.
To be able to meet air quality standards it may be neces-
sary to use very large quantities of water for scrubbing
organics from spray tower vent gases. This problem is
still under study. Frequent product changeovers for smal-
ler plants make it economically and physically impossible
to collect and recycle all tower washouts. Highly inte-
grated plants have more opportunities to recycle or use
detergent laden wastewaters.
Wastewater Constituents
All of the streams will be contaminated with the deter-
gent being produced in the plant at the time. The various
surfactants,builders and additives are listed on the flow
diagram entering 2071 Receiving Storage And Transfer.
These constituents will contribute to BOD, COD, MBAS,
dissolved and suspended solids, oil and grease and alka-
linity.
Average Raw Waste Loads for the three types of operation
of spray towers are tabulated on the following page
(kg/1000 kg dry detergent) (lb/1000 Ib).
94
DRAFT
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Suspended Oil and
BOD5 COD Solids MBAS Grease
Few turnarounds &
no air quality
problem 0.1 0.3 0.1 0.2 nil
Air quality
problems 0.8 2.5 1.0 1.5 0.3
Fast turn-
around 2.0 4.0 2.0 4.0 0.3
PROCESS 208 - LIQUID DETERGENT MANUFACTURE
Introduction
Manufacture of liquid light duty hand dishwashing and
heavy duty laundry detergents requires relatively simple
equipment for blending the various ingredients. Usually
this is done batchwise with the several surfactants added
by weight, and then thoroughly blended.
Filling of the bottles is done on sophisticated high
speed filling lines. This is a most critical and dif-
ficult operation because of machine complexity, speed,
and cost.
From the filling line leaks, spills and overflows are
sources of water contamination (208302). From both the
blending and filling operations, purging the lines be-
tween products produce slugs of detergent contaminated
water (208212, 208213 and 208302). Also, filled deter-
gent bottles are sometimes washed (208310).
Contaminants from light duty liquid detergents are very
high in surface active agents. Heavy duty liquid deter-
gents are also produced in much lower volume and can re-
sult in some contamination with builders (phosphates,
carbonates).
Water and Wastewater Balance
Liquid detergents consume water as the major solvent for
DRAFT 95
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the product. Little or no water is used for heating and
cooling. But, large amounts of water are used for washing
equipment and packages. Because very small amounts of
liquid detergents can cause extraordinary amounts of foam,
it is necessary to use very large volumes of water; and
recycle or reuse of water becomes impractible. Reported
water usage was in the range of 625-6250 1/1000 kg (75-
750 gal./lOOO Ibs) of detergent.
Wastewater Constituents
All of the effluent streams will contain the starting in-
gredients of the products. These are mainly:
ammonium, potassium & sodium alkylbenzene sulfonates (LAS)
11 " " alcohol ethoxy sulfates (AES)
11 " " alkylphenol ethoxy sulfates
" " " olefin sulfonates (OS)
11 " " toluene and xylene sulfonates
(hydrotropes)
" " " alcohol sulfates
Fatty acid alkanol amine condensates (amides)
Urea (hydrotrope)
Ethanol (hydrotrope)
Polyacrylates and polystyrene (opacifiers)
Dyes & perfume
Phosphate & citrate builders
Silicate builders
These constituents will contribute to alkalinity, BOD,
COD, nitrogen MBAS (and undetected surfactants) and dis-
solved solids.
Raw waste loadings vary more in concentration than total
amount between plants. The following were observed:
(see following page)
DRAFT
96
-------
kg/1000 kg of detergent mg/1
BOD5 0.5 - 1.8 65 - 3400
COD 1.0 - 3.1 120 - 7000
MBAS 0.4-1.1 60 - 2000
As much as 90% of the detergent can come from washout of
tanks and lines when changing products. With fewer chan-
ges waste loads will decrease,- but the lower levels in
the above table represent minima with current practice.
PROCESS 209 - DETERGENT MANUFACTURE BY DRY BLENDING
Introduction
Production of detergents by this process requires no water
for processing and can be operated without using water for
washdown. Dry builders and surfactants are simply mixed,
or liquid surfactants are sprayed into dry powders so that
the entire mass stays free flowing. Some water may also
be sprayed onto the dry powders to produce more stable
hydrates.
Water and Wastewater Balance
Since no process or cooling water is used, water used for
cleaning equipment or for taking care of spills is the only
source of effluent (209202 and 209302). J'ome plants claim
to use no water and handle all cleanup dry.
Wastewater Constituents
Wastewaters will be contaminated with the entire deter-
gent formula. They will be similar to effluent from spray
dried detergents. Some plants do profess to have efflu-
ents 209202 and 209302, but it is more likely that contami-
nants are very small and guidelines allow for this minimum
amount.
97
DRAFT
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PROCESS 210 - DRUM DRIED DETERGENTS
Introduction
In this detergent drying process, the aqueous slurry of
detergent is dried on steam heated rolls and recovered as
flakes. Little or no formulated household detergent is
made by this process now-a-days. Most of the products
are high active LAS products for dry blending of industrial
detergent products.
Water and Wastewater Balance
The detergent slurry contains water added in the neutrali-
zation process no. 206. This water is removed as steam
and vented to the atmosphere or scrubbed (201201). T team
condensate is generated also, but this should be free of
contamination (210203).
Wastewater Constituents
The only appreciable effluent will be similar to, and less
in concentration,than the scrubber from spray drying (207-
301). Surfactants, builders, and free oils can be expected
These will contribute to BOD, COD, alkalinity, MBAS, dis-
solved solids and oil and grease.
PROCESS 211 - DETERGENT BARS AND CAKES
This process is similar in operation to Process 106 Bar
Soaps. The significant difference arises in the more fre-
quent washouts required because of the heat sensitivity of
the detergent active ingredient. Washwaters will be simi-
lar in character to those of spray dried det-ergents.
In some instances soap will also be found in the wastewater
since it is a part of the blend comprising some toilet bar
soaps.
DRAFT
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ANALYSIS OF CORPS OF ENGINEERS EFFLUENT PERMIT APPLICATIONS
INTRODUCTION
The contractor received 30 permit applications from the
contracting officer and the EPA. Several of the permits
were for complexes which contained operations covering more
than just the standard industrial classification 2841 and
were not useful for further study. Also, several of the
applications contained so few data that they could not be
used. As a result, 22 separate applications were analyzed.
These applications have been garnered under four separate
Acts of Congress: 1) The Refuse Act of 1899; 2) The Fish and
Wildlife Coordination Act of 1956; 3) The National Environ-
mental Policy Act of 1069; and 4) The Water Quality Improve-
ment Act of 1970.
The Corps of Engineers' permit form covers point source
discharges and, is in two sections. Depending upon the
character of the given industry, but applying to all indus-
tries, Section A is required to be filled out totally in
supplying information of the applicant. In the case of
certain industries, including the soap and detergent industry,
standard industrial classification 2841, all plants operating
under this classification are required also to submit part B.
of The Corps of Engineers form in order to present a broader
and more comprehensive notion of the types of effluents and
their character.
Biochemical Oxygen Demand and Chemical Oxygen Demand
For process stream effluents, the range of BOD in the efflu-
ent ranged from about 15-5,000 milligrams per liter. In some
cases where low BODc is reported, the effluent is usually
only comprised of water discharge from cooling water towers,
boiler drain-off and the like. If one struck a balance of
average of best plant operations, it could be concluded that
somewhere in the range of 40 to 50 mg./l. represents the con-
centration of BODc in the average of the best performing
plants.
Referring now to the BODc, in pounds per day, the plant contri-
bution ranged from less than one pound per day to almost 2,000
pounds per day. However, it must be realized that in these
DRAFT 99
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cases we must take into account the increase in concentra-
tion and the absolute volume of the water, in turn related
to plant size.
It should also be noted that a factor of maximum concen-
tration and, therefore, maximum pounds per day to average
pounds per day reaches sometimes as much as sevenfold.
This points up the fact that the discharge is far from
uniform and that, in particular, plant upsets causing
this to happen do occur, perhaps infrequently.
Referring to Chemical Oxygen Demand, the average of the
concentration ranges from a nominal 100 to almost 5,000
milligrams per liter in the effluent. The ratio of BOD^
to COD gives evidence of the biologically refractory na-
ture of some of the chemical compounds which are still
subject to oxidation. In terms of average amounts per
day of chemical oxygen demand these range from a nominal
amount about equivalent to the BOD all the way up to 25,000
pounds per day. Here again, however, we must take into
account the size of the installation as well as the in-
crease in concentration of 6005. In this case an "average
of 'best1'1 is not easily discernible since there is a con-
siderable variance in the nature of the intake material
and the degree of its conversion in the detergent and
soap making processes.
The impression one obtains in studying the effluent BODj.
compared to the COD is that normally efficient soap and
detergent plants would not be expected to produce more than
two or three times as many pounds of COD as BOD^. This
emphasizes that the COD should, in general, be not more than
two or three times as much as the BOD unless refractory bio-
logically degradable materials are present.
The average pounds increase in surfactant from influent to
effluent might also be expected to reflect a measure of
loss of product. If so, these variances are too small to
be significant. In fact, except for three installations,
the surfactant is surprisingly low, not exceeding a modi-
cum of about 50 pounds per day. These 3 plants ranged
from 250 to approximately 275 pounds per day.
DRAFT 10Q
-------
Anions in the Effluent
Content of the chloride ion in the intake stream is often
high when sea water of estuarial waters are used in the
process, even after any water pretreatment. More impor-
tantly, the increase of the chloride ion in the water ef-
fluent can be generally expected from any soap manufac-
turing operation or any neutralization reaction where
caustic is used to neutralize the effluent from chlorina-
ted hydrocarbon plants. Similarly, in the case of the sul-
fate ion, this is often the result of the balancing of
the electrolyte in the detergent where sulfonation or sul-
fation processes are the principal methods of manufacture.
Significant decreases are shown in both the chloride and
sulfate ion content of the effluent over that of the intake
stream in the case of two plants. This can hardly be re-
garded as natural removal and is more obviously the result
of inaccuracies in the analysis because these relate to
large quantities of intake and great variances on the com-
position of the intake.
Other anions considered are borates, phosphates, sulfides
and sulfite ions. There are few instances where there are
any data on boron compounds and, in all cases tabulated,
they show minimal quantities and minimal changes between
the intake waters and the effluent stream. The data,
where given on phosphate, silicate, sulfide, and sulfite,
also show minimal changes and very low poundages reported
for these ions, and appear of no very great significance
in this study.
A total phosphate content measured in terms of elemental
phosphorus was tabulated in our plant analysis. Without
respect to plant size or detergent or soap manufacturer,
the maximum increase in pounds of phosphorus per day was
33 pounds, with the exception of the plant mentioned ear-
lier, which makes a variety of other chemicals besides
those of soaps and detergents.
Cations in Effluent
Changes in concentration of calcium, potassium, magnesium,
manganese, and zinc as shown in these tabulations are both
low in actual quantity and low in actual change. They,
101
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therefore, seem to be of little significance in judging the
quality of the effluent. In only one case are there signi-
ficant increases, which are in both calcium and magnesium
and this applies to a plant which makes a variety of pro-
ducts besides that which is strictly defined as a soap and
detergent. In all other cases, calcium actually shows a
decrease in the effluent from that in the intake waters,
probably as a result of treatment or as precipitation of
a calcium soap if used in a soap making process.
In regard to the sodium ion, it is almost surprising to
see the low actual poundages of sodium shown in all the
effluent streams. While in all cases they show an increase
in the effluent over that in the intake waters, it is still
extremely low in relation to the quantities of water pro-
cessed, and in consideration of the great variation in
processes employed in manufacture, it is indicated that
any sodium ion introduced in the form of caustic soda
finds its. way into the soap or detergent product as a
result of saponification or sulfonate neutralization.
It is noteworthy to mention that several attempts were
made to close the material balance on the cations and ani-
ons and also in relation to the soluble components of the
intake and effluent. In few cases were these balances
sufficiently accurate to put substantial faith in all the
various analyses and a stoichiometric closure. In fact,
in only one of the material balances attempted was the data
well enough coordinated so that, indeed, a balance could
be made.
Other Components
In general no significant or consistent contributions of
other contaminants were discernible. Alkalinity was lower
in the effluent than in the influent in some cases but pH
showed no marked increase or decrease. Suspended solids
were lower in the effluent than in the influent in some
cases which reflects in-plant treatment. The total oxy-
gen content procedure (TOG) was not reported sufficiently
to develop a correlation with COD5 or COD. No nitrogen
increase of significance could be found.
DRAFT 102
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CONCLUSIONS
It should be realized that all of the permit applications
cover, in general, commingled effluents from a number of
process units. Therefore, they cannot be considered as
data relevant to the unit processes used in the plants.
It should also be realized that the bulk of the effluent,
which contains process wastes, are generally sent by the
soap and detergent industry to a municipal treatment plant
and are not reported as such in their own effluent permit.
Here again the data is not sufficient, therefore, to judge
point source effluents. Where the data covered only cooling
water, boiler blowdown water, or water from surface drain-
age, this can have little significance with respect to the
actual processing involved.
Our analysis led to the conclusion that although good gene-
ral background data is available from study of the Corps
applications, the information is not useable for building
a data base necessary to establish effluent guidelines.
In particular the lack of any volume information related
to either product or process output rendered these reports
unuseable for guideline establishment.
103
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104
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SECTION VI
SELECTION OF POLLUTANT PARAMETERS
INTRODUCTION
This section contains a discussion of the specific contami-
nants which were selected for guideline recommendations,
and those which were omitted. Rationales for the decisions
are given for each pollution parameter.
The source of the various wastewaters and contaminants can
be understood by referring to Industry Categorization -
Section IV. The significance, both qualitative and quan-
titative, together with discussion of appropriate analy-
tical methods is treated in Section V - Waste Characteri-
zation. Guidelines and procedures for achieving the re-
ductions of pollutants are found in Sections VII, IX, X
and XI.
Production of soaps and detergents results in numerous
wastewater streams and several types of contaminants which
are of special concern. Synthetic surface active agents
not only create a BOD and COD, but also cause water to
foam and in high concentrations can be toxic to fish and
other organisms. Nutrients, particularly phosphate, are
of concern because of their contribution to eutrophication
of lakes. Soap production leads to wastewaters with high
alkalinity, high salt, and high oxygen demand. Spills of
raw materials contribute to oil and grease levels. Most
of the suspended solids come from organics, i.e., calcium
soaps, and many are of the volatile rather than non-vola-
tile type. Since strong acids and strong alkalies are used,
pH can be very high or very low in wastewaters.
PARAMETER RECOMMENDATIONS
To monitor the quality of the treated wastewater flows
coming from soap and detergent plants as point source dis-
charges, the key parameters recommended for sampling and
analysis and structure of guidelines are:
105
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Biochemical Oxygen Demand
All of the organic active materials found in soap and
detergent formulations are biodegradable in varying de-
grees. Most are totally and rapidly assimilated. Al-
though highly criticized for its lack of reliability,
the analytical method for BOD is still the only generally
accepted method for grossly measuring the potential impact
on the environment. Unfortunately, not all of the organic
materials found in these wastewater flows contribute to
the oxygen demand at the same rate. Some may inhibit
the microorganisms which degrade these contaminants, and
others are incorporated into the cell tissue of the micro-
organisms at different rates. This leads to varying ra-
tios of BOD values when compared to the companion COD
test.
There are a number of factors which tend to reduce relia-
bility of the BOD5 in actual practice. One difficulty
stems from the frequent need for long term acclimation
of the biota to the special unique organic substrates en-
countered in the waste streams from the manufacture of
detergents. Too often biota are employed in the 8005
tests which are totally unacclimated, or at best only par-
tially acclimated. When data derived from such testing
are viewed in isolation they tend to indicate that a large
quantity of such organics are resistant to biodegradation
or are only slowly degraded. However, detailed studies
carried out with thoroughly acclimated microbial systems
do not support this casual observation. In fact, the vast
bulk of the materials now employed as synthetic detergents
are subject to rapid and complete assimilation by accli-
mated saprophytic microorganisms. Industrial surfactants
production does lead to a higher refractory component than
the household surfactants.
The use of the BOD5 test is recommended. However, it is es-
sential that acclimated biota be maintained especially where
the concerned effluent originates from a plant producing
industrial cleaners.
Chemical Oxygen Demand
The COD or chemical oxygen demand is a companion test and
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106
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internal check on the biochemical oxygen demand. COD/BOD
ratios of 2 - 3/1 indicate complete or virtually complete
biochemical assimilation. Ratios greater than 3 indicate
that the material being tested is toxic to the bacteria,
inhibitory or resistant to biochemical attack.
Because of the difficulty discussed in the preceding sec-
tion concerning the reliability of the BOD test, it is
recommended that the COD be used as a primary parameter
where acclimated biota cannot be readily obtained.
The COD test, however, is not without some special prob-
lems of its own. Volatile substances such as low molecu-
lar weight hydrocarbons can escape before oxidation. Also,
long chain fatty acids which are commonly found in the
waste streams from soap manufacture, are slowly oxidized
in the COD test. Special attention must be given to in-
sure the complete oxidation of these materials.
Suspended bolids
Although the wastewater sources of the soap and detergent
industry are not notably heavy in suspended solids, sus-
pended solids should be monitored to insure that stream
clarity is not unduly affected, particularly by some up-
set in the processing train.
Surfactants (MBAS)
Because of the possible contribution to foaming in streams
and biological upset, measurement of the organic active in-
gredient in formulations is necessary. Not all organic
active materials are measured by this method. 'Soaps are
not detected, nor are non-ionics. However, both of the
latter are measured by the BOD5 and COD methods.
Oil and Grease
As the name implies, those materials which would contribute
to esthetic problems as well as to oxygen demand need to
be controlled. The analytical method picks up not only
the fatty oils and greases used in the soap making pro-
cess, but any hydrocarbon bodies which are generated from
DRAFT 107
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the synthetic detergent portion of the plant processes.
The test method does not distinguish between the two
sources, therefore the results must be interpreted with
discretion.
£H
This is important for control since there are occasional
upsets in those portions of the processes which could po-
tentially lead to highly acidic - or alkaline spills.
Parameters Omitted
The most prominent parameter omitted is dissolved solids.
While there will be times of high concentrations of salts
in some of the wastewater flows within the plant, by the
time they are commingled with the total plant effluent they
will be quite dilute. In addition, the salts themselves
are not in a toxicity range of concern. Most of them are
found as deliberate additions to food in other manufactu-
ring processes. If the contamination of the waters by
dissolved solids could be damaging, the permit granting
authority should then issue specific guidelines covering
that particular situation.
Nitrogen
Nitrogen, although important in the general concern over
the quality of the receiving waters, is omitted since
there is at this time very little use of products derived
from nitrogen. 3pot checks of industrial effluents and
contractor's analysis of Corps of Engineers permit applica-
tions confirmed this observation.
Phosphorus
The effluents from many of the plants manufacturing soaps
and detergents contain small quantities of phosphates or
borates or both. These materials are employed in large
quantities in the manufacture of detergents and appear as
such in the final product. With the foregoing in mind and
the knowledge gained from our analysis of discharge permit
applications and in view of the low discharge of these two
ions from detergent plants, the contractor decided against
including these two ions in specific guideline recommenda-
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108
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tions. The reason for limiting phosphorus and boron
relates most importantly to the receiving waters destina-
tion and use.
In the case of phosphorus, the matter of concern is eutro-
phication the accelerated ageing of lakes due to over
fertilization. There are a number of essential nutrients
necessary for eutrophication to occur such as carbon,
nitrogen and phosphorus. Phosphorus is believed to be the
most controllable, thus the most likely way of controlling
eutrophication is believed to be to control phosphorus. A
program to control eutrophication requires a highly sophis-
ticated study of the watershed as well as the lake or lakes
involved. If phosphorus is declared to be the limiting
nutrient, then phosphorus must be controlled to a concentra-
tion of say 25 micrograms per liter in the lake. Working
back up stream to attain this level, appropriate standards
must be set throughout the watershed. All the treatment
plant effluent, agricultural runoff and background phosphate
must be quantified as to their contribution of phosphorus
and stern control measures taken applicable to all the
controllable contributors of phosphorus. Implementation
of these measures is a costly affair which in some areas
may require the limitation or banning of the use of
phosphorus compounds. If a point source soap and deter-
gent plant is located within such a watershed the regional
authorities will have to impose whatever standards are
necessary to make their regional program an effective one.
The detergent plant itself can go to any level required
including no discharge of phosphorus by installing treat-
ment facilities if fairly low levels are required, or by
ceasing production of phosphorus based detergents at that
plant if no discharge is permissible.
Another important consideration, again regional, is that if
there is no eutrophication problem one of the best ways of
disposing of sewage effluent is to irrigation waters by
spray and other methods. Probably no soap or detergent can
be as advantageous as a phosphorus based product in this
application. Thus the contractor is of the opinion that
any guidelines set on point sources for phosphorus compounds
should be resolved and implemented on a local basis.
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BORON
The problems surrounding the use of boron are primarily
regional but separate from phosphorus. Boron compounds
are not a measurable factor in the eutrophication problem.
Although boron compounds are micronutrients for plants
they are well-known to be phyototoxic to certain plants
such as lemon and blackberry at levels over one part per
million concentration. The mechanism of boron toxicity
is unknown. For example, the boron compounds are relatively
non-toxic to fish. Where there is a possibility of using
the effluent for irrigation, and it is known the irriga-
tion waters will come in contact with such plants as
citrus, regional standards should be set.
Additionally, the boron compounds can upset sewage treat-
ment bacteria at higher concentration. It appears that
boron at higher concentrations, that is over ten parts
per million, can affect the endogeneous respiration rate
of activated sludge. The exact level at which such
interference becomes significant is the subject of current
study and the contractor feels that there is insufficient
data on hand to be able to make a sound judgment.
In any case, the entire problem regarding the use of boron
does not at this time appear to be susceptible to a national
generalization such as would be involved in a national
effluent guideline.
Scope of Parameter Measurements - By Processes
Each of the individual processes of the soap and deter-
gent industry are reviewed in the following paragraphs
in order to relate the significance of the parameters
chosen for guidelines to the measurement of the contami-
nants contained in wastewater flows originating in each
unit process.
The ways in which effluent discharge can be monitored are
suggested.
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110
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PROCESS 101 - SOAP MANUFACTURE BY BATCH KETTLE
Significant contaminants from this process are the fats and
oils used as raw material; unrecovered sodium chloride,
sodium sulfate and sodium hydroxide; soaps that are spilled
or lost and dark colored by-product soaps. Limits are pro-
posed for BOD and COD, suspended solids, oil and grease and
a range of 6 - 9 for pH. The soaps, fats and oils will be
controlled by the first four tests. A pH in the 6-9 range
will insure against discharge of sodium hydroxide or strong
acids.
Since soap plant wastes can cause depletion of dissolved
oxygen, limitation is necessary. Oils and suspended solids
cause esthetic problems. A very high or very low pH is
detrimental to almost all organisms.
No recommendation has been made for specific limitations of
the two inorganic salts, NaCl and NaoSO/. These are rela-
tively non-toxic (NaCl 10-20,000 mg/1 MLD; Na2S04 11-17,
600 mg/1 MLD, and most receiving waters are below the limits
of dissolved salts set by the United States Public Health
Service.
PROCESS 102 - FATTY ACIDS BY FAT SPLITTING
The organic compounds from this process are primarily fatty
acids although some unreacted fat and glycerine from spills
and leaks will also be found. The total of the inorganics
will be low compared to the organics. Sodium hydroxide and
sodium sulfate from fat pretreatment and from treatment of
still bottoms are expected.
Total organics should be controlled by setting BOD and COD
limits. Free fatty acids and fats should be controlled by
setting oil and grease and suspended solids limits. The pH
should be controlled.
Contaminants not limited are the generally innocuous sodium
sulfate plus small amounts of zinc and alkaline earth metals
used as the fat splitting catalyst. These metals ions are
below harmful concentration in commingled plant wastes and
are removed in secondary treatment processes which must be
used on the organic contaminants.
PROCESS 103 - SOAP BY FATTY ACID NEUTRALIZATION
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Except for fats and oils the contaminants from this process
will be the same as from the kettle boil soap process. Con-
centrations and loadings are much lower, however.
Control of discharge is established by setting limits on BOD,
COD, pH, suspended solids and oil and grease.
The small amount of sodium chloride relative to the produc-
tion of soap should not require regulation unless the re-
ceiving stream is at a critical chloride level.
PROCESS 104 - GLYCERINE RECOVERY
Contaminants in wastewaters from this process are water sol-
uble organics and two inorganic salts. The organics are
glycerine and glycerine polymers. The salts are NaCl and
Organics discharge is controlled by setting BOD and COD limits,
Although contaminants affecting pH, suspended solids, and oil
and grease are minimal, limits have been set to guard against
carryover from previous processing steps.
Sodium chloride and sodium sulfate should not be restricted
unless the receiving stream is close to the specification
limit for chloride and sulfate ions.
PROCESS 105 - SOAP FLAKES AND POWDERS
Effluents from this process are minimal. Since almost pure
soap is processed, the contaminants will be primarily soap
with only small amounts of free fatty matter, alkali and salt,
BOD and COD are used to limit discharge of soaps, and pH is
to be kept to the 6-9 range. Suspended solids and oil and
grease should be measured to guard against unusual contamina-
tion.
Although sodium chloride is not limited, its concentration
should be negligible.
PROCESS 106 - BAR SOAPS
As with soap flakes and powders, wastewater contaminants from
this process will be mainly soap. Small amounts of salt and
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alkali which are in the soap will also be found. Some free
fatty matter and additives can be expected in the waste-
waters .
Assignment of BOD and COD limits will control the discharge
of soap. Specifying limits for pH, oil and grease, and
suspended solids will handle unusual spills.
Inorganic contaminants should be low and control should be
unnecessary.
PROCESS 107 - LIQUID SOAP
Liquid soaps are formulated products and will contain solvents,
builder, dyes and perfumes in addition to potassium soaps.
Almost all contamination will come from spills so the waste-
water will be contaminated with all constituents of the
formula.
BOD and COD limits will control overall discharge of organ-
ics. Control of pH to the 6-9 level should present no
problem since the product will be in that range. The sus-
pended solids and oil and grease tests will be more important
here than with other soaps since the formulated soaps often
contain hydrocarbon solvents.
Inorganic salts should be negligible from this process and
thus require no control. Potassium ion will be found here
but the level should be low enough to require no limitations.
PROCESS 201 - OLEUM SULFONATION AND SULFATION
In effluents from this process, one can expect to find the
oily raw materials, sulfuric acid and surfactant sulfonic
acids. All of these contaminants need to be treated before
discharge.
Raw material spills should be limited by setting specifica-
tions for the oil and grease and suspended solids. The MBAS
test can measure surface active sulfuric acids and be used
to limit their concentration. Total organic contamination
can be monitored and controlled by running the oxygen demand
procedures, BOD and COD. Sulfuric acid and sulfonic acids
are very strong acids and must be neutralized before dis-
charge. This can be assured by specifying a pH of 6 - 9.
The only contaminant not limited is sulfate. Most effluent
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streams can absorb current„quantities of this ion, but if
necessary the regional permit officer can restrict discharge
of sulfate.
PROCESS 202 - AIR 803 SULFATION - SULFONATION
This process is identical to process 201 with respect to con-
taminant composition. However, the levels of contamination
are higher.
Limitations have been set for BOD, COD, pH, oil and grease,
MBAS and suspended solids. Sulfate need not be limited for
the usual receiving water.
See the discussion under section 201 for the rationale.
PROCESS 203 - VACUUM AND SOLVENT SULFONATION
This process is identical to process 201 insofar as contami-
nation is concerned. One exception is the possible presence
of sulfate in the wastewater. Levels should be similar to
process 201.
Limits have been set for BOD, COD, pH, oil and grease and sus-
pended solids. Sulfate should generally be exempted.
For rationale see section 201.
PROCESS 204 - SULFAMIC ACID SULFATION
This reaction is rather limited in scope, but can have a high
discharge because of washdown after each batch. Contaminants
will be unsulfated ethoxy alcohols, sulfamic acid and ammon-
ium ether sulfates.
The MBAS test and a limitation for the process will be most
useful for control. Because the MBAS test does not pick up
nonionic surfactants, BOD and COD are needed to control the
'overall organic load. As usual, pH control will be needed
since sulfamic acid is a strong acid.
Sulfamic acid hydrolyzes to ammonium acid sulfate in water so
that no control is needed unless the receiving water is close
to its limit for nitrogen and sulfate.
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PROCESS 205 - CHLOROSULFONIC ACID SULFATION
The organic contaminants from this process will be feed-
stock, fatty alcohols, alcohol ethoxylates and alkyl phenol
ethoxylates. Also, the sulfated products and the final
annomium, sodium and triethanol amine salts will be found.
Inorganics will be hydrochloric and sulfuric acids plus
ammonium and sodium ions.
Limitations have been established for total organics by
specifying BOD and COD values, MBAS should be measured and
controlled. Raw material spills can be controlled by speci-
fying suitable values for oil and grease and suspended
solids. As usual, pH needs adjustment to the 6-9 level.
PROCESS 206 - NEUTRALIZATION OF SULFURIC ACID ESTERS AND
SULFONIC ACIDS
In this process the organic acids produced by sulfation and
sulfonation are reacted with bases to produce the desired
salts. Therefore, contaminants will be the products of
processes 201, 202 and 203. In addition, the neutralized
products and the various cations will be present.
The MBAS test, and a limitation thereon, will be important
in controlling contamination from this process. BOD and
COD allowances will determine overall organic contamination.
To assure a neutral wastewater, pH adjustment will be neces-
sary. Oil and grease and suspended solids should be minimal
but specifications are needed for unusual spills.
Control of inorganic sulfate, potassium, sodium and ammonium
ions is believed unnecessary for most receiving streams.
PROCESS 207 - SPRAY DRIED DETERGENTS
Effluents from this process will contain all of the many in-
gredients used in dry detergent powders: LAS, amide, nonionic
and alcohol surfactants; sodium phosphate, carbonate and sili-
cate builders; carboxymethyl cellulose, brighteners, perborate,
dyes, fillers and perfumes.
An MBAS limit will handle anionic surfactants, but COD and
BOD tests are needed to estimate other surfactants. Careful
attention needs to be paid to BOD/COD ratios since the
various surfactants can inhibit or react slowly with unaccli-
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mated BOD cultures. The suspended solids test will serve to
limit insolubes and the oil and grease limit is needed for
fill oils from the spray tower.
Specific limits have not been recommended for carbonate,
silicate, phosphate and sodium ions. The condition of the
receiving stream should be determined by the permit officer
before limiting these contaminants.
PROCESS 208 - LIQUID DETERGENTS
These products are made by simple blending so effluents will
contain the starting ingredients. High levels of organic
surface active agents can be expected from washdown and
cleanup. Heavy duty liquid detergents will also contain
potassium phosphate, silicate and citrate builders, solvents
(ethanol), and hydrotropes (sodium xylene sulfonate and urea),
will also be found.
To control total organics the BOD and COD levels have been
specified. MBAS limits have been set to control the impor-
tant anonic surfactant. Limits on pH, oil and grease, and
suspended solids have been set but control measures should be
unnecessary.
Except for the generally innocuous inorganic salts, levels
for all contaminants have been specified.
PROCESS 209 - DRY DETERGENT BLENDING
This process usually has a very low effluent level. Any
contaminants will be the same as those discussed in section
207 - spray dried detergents. Our rationale for limiting
BOD, COD, pH, suspended solids, MBAS and oil and grease are
the same also.
PROCESS 210 - DRUM DRIED DETERGENTS
Almost exclusively devoted to the manufacture of industrial
detergent powders, this process uses a wide variety of raw
materials. They find their way into wastewater flows through
spills and washouts. BOD, COD and surfactant (MBAS) limits
will govern these sources, coupled with pH.
There should be no oil and grease appearing in any wastewater
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116
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from this process.
PROCESS 211 - DETERGENT BARS
Processing of detergent bars is almost identical with soap
bars. However, the wastes will contain synthetic surfac-
tants. Therefore, in addition to setting limits on BOD,
COD, pH, suspended solids and oil and grease, it is necessary
to specify a limit on MBAS.
The rationale for the limits and parameters will be found
under process 106.
Industrial Cleaners
Industrial cleaning compounds are also manufactured in plants
of the soap and detergent industry. Insufficient data was
obtained to make specific recommendations on the multitude of
compounds employed but some guidance can be given. Industrial
cleaners make up about 1070 of the industry output. The stud-
ies of the Organic and Inorganic Chemicals Industries are
expected to provide much useful treatment data on some of the
more exotic chemicals. The phosphates, silicates, carbonates
and caustic alkalis which are employed will create the same
basic situations as are discussed in Sections 207, 208 and
209. Similar treatment procedures and guidelines also apply.
Other materials not sufficiently characterized but expected
to be in the industrial wastewaters are hydrogen fluoride,
sulfamic acid, phenols and cresol, chlorinated hydrocarbons,
complex organic and inorganic corrosion inhibitors, and exotic
surfactants. Flourides can be easily precipitated with lime.
Sulfamic acid should behave like sulfuric acid and ammonia.
Phenol and cresol are readily biodegradable if concentrations
are kept low. The chlorinated hydrocarbons may have to be re-
moved by solvent extraction or carbon absorption. Some cor-
rosion inhibitors used in acids for industrial cleaning are
complex organics which will require individual study. The
exotic surfactants will include phosphoro, fluoro and silico
organo compounds which have unknown treatability. Nonionic,
amphoteric, and low molecular weight wetting agents with
different treatability can also be expected.
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118
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SECTION VII
CONTROL AND TREATMENT TECHNOLOGY
Chemical and Physical Equilibrium
All processes involving chemical reactions and the attendant
physical equilibria, relating to the separation of various
products and various unreacted components, are subject to the
immutable laws of chemistry and physical-chemical equilibria.
The equilibria of a reaction, in both a chemical and physical
totality sense, is related in a complex manner to the total
energetics of the system. The energetics involve some twenty
forms of energy. At times they may all be involved. However,
a reaction, in a physical or a chemical sense, can never be
complete, but is in each instance subjected to restraints of
the energetic balance of a system or envelope.
The manner in which the highest degree of reaction completion
and recovery of finished products can be obtained is by the
application of the optimum conditions relating to temperature,
pressure, concentration, phase relationships, phase ratios,
the application of catalysts and the application of precise
flow of raw materials and products. The latter is accom-
plished by the use of instruments for control of all the
environmental factors including temperatures, pressures,
amount of feed material, close attention to the analytical
contents of the feed material, close attention to the process
product withdrawal rate and close attention to concentra-
tions. Also, the use of ancillary extraction agents or
agents which alter phase relationships and solubilities and
phase partitioning effects must be brought into play for
optimum product production.
In most chemical reactions, one or the other of the raw feed
materials is employed in excess in order to force the
chemical equilibrium to completion, at least with respect to
one of the feed raw materials. This immediately requires
that the other uncompletely reacted feed materials must be
withdrawn from the process in a high degree of efficiency
and recycled back into the system. Thus, in the case of
general water phase reactions, characteristic of the soap
and detergent industry though not exclusively so, the maxi-
mum recycle of water phase streams containing unreacted
excess of feed raw materials should be recycled back to the
reaction step. This requires, then, the use of such water
phase recycle in the makeup of the solution chemicals fed
to a process reactor step.
SOAP AND DETERGENT INDUSTRY PROCESS CONTROL
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In reviewing the soap and detergent industry manufacturing
operations, it can be observed that there is not a uniformly
high attainment of a closed-in water system. Barometric
condensers are generally employed throughout the industry,
which occasions the use of additional water; first, by the
general- use of steam jet deck ejectors in the production of
a vacuum, and by the general use of barometric condensers
where the water for cooling is additionally put into and
added into the process stream. This diminishes the amount
of the stream of water phase which can be recycled back to
the reactor system for makeup purposes in introducing the
feed material, if fed in the water phase. Analogically, a
full advantage does not appear to have been taken in
present practices, of the use of a partial condensing
system, which would be capable of removing heavy molecular
weight unreacted materials and removing them from the sys-
tem, since they are generally not useful in recycling back
to the reactor system, although such is not uniformly so.
These heavy products from a partial condenser can be re-
moved from the system if not recyclable and disposed of by
burning, to carbon dioxide and water, since they are
generally hydrocarbon or oxygenated hydrocarbon compounds.
Another useful device, effective in the reduction of non-
product components and which are not necessarily usefully
recycled to the reaction system, can be removed by scrubbing
operations or in washing operations as defined. These
operations can be either at atmospheric, super-atmospheric
pressure, or even effectively used in vacuum systems by the
employment of the proper apparati. The removal of such
components can be accomplished, if soluble in water, by a
recycle water stream fed back to the reaction makeup system;
or they can be removed, if more soluble in a liquid organic
or oil phase, by employing a feed reactant itself for washing
action before condensation.
The fact that these systems are not in general and total use
in the soap and detergent industry, can be best ascribed to
their added cost and to the added requirement for close
operating control, either achieved by instrumental flow de-
vices or metering devices, or alternatively by close atten-
tion when manually controlled by human operators.
In a review of the cost of such installation, the recommenda-
tions of using such equipment have not appeared to greatly
increase the cost, at least not to an unreasonable extent
compared to the value of the product produced and with respect
to the capital requirement as it impinges on profitability
occasioned by additional fixed long term depreciable assets.
The utility requirements of such a system, and the related
DRAFT
120
-------
energy requirements, are not exceptionally high. Generally,
the use of an indirect surface condenser in the place of a
barometric condenser would only approximately double the
requirement of cooling water on an average basis throughout
the United States. The requirement of electrical energy
for mechanical equipment including washers, pumps for re-
circulation, and evacuators, is also not excessive as com-
pared to product value and other costs of operation with a
plant.
If these apparati are well instrumented and flow controlled,
the elimination or diminution of human operators often can
effect a savings. In some cases, the capital costs of these
systems for a new installation at least, is less than re-
placement by the kind of equipment presently used, taking
into account all costs and features of the installation and
operation.
It is not possible to give a precise prediction of the de-
crease in effluent levels when employing the above sugges-
tions of process change and equipment change. The reason
for this is that each reaction is unique, even as affected
by a variety of different process raw materials and as
affected by the availability of cooling water streams, their
temperature and the humidity conditions in the surrounding
atmosphere relating to cooling tower efficiency. A further
variable is that relating to the quality of plant engineer-
ing maintenance particularly in seeing that vessel closures
minimize the leaks of air into a system where vacuum is
employed and the minimization of leaks from pump glands,
etc., or from any rotating or reciprocal motive power unit.
The utilization of partial condensers, for knocking out a
heavy end material not desired for recycle, is common in the
art and any reliable heat exchanger manufacturer is able to
estimate the requirements within reasonable limits, both as
to performance and cost. The use of a washer or a scrubber
for the removal of sticky or gelatinous materials, or solid
unreactants or even reacted products, can be accomplished in
a variety of equipment; however, it is not necessarily re-
quired in many situations.
When above-atmospheric pressure is used in the final dis-
tillation system, there is no problem in the design of a
suitable washer. For example, sieve trays, Paulson cone
trays and many other systems can be usefully employed and are
well-known within the art to the various and many equipment
manufacturers of these washers. In the case of vacuum
operation, where a minimization of pressure drop is desired,
then several vacuum-type washers are also readily available.
The Bartlett-Hayward washer is a well-known design that has
DRAFT
121
-------
been employed for several decades. Another washer of this
type, which can be employed in vacuum operations, is that
manufactured by the Croll-Reynolds Company.
The use of booster jets, generally employing steam as the
ejector prime mover, are readily available from almost any
manufacturer of steam apparati. In non-vacuum operations,
and if the temperature and oxidation susceptibility is not
high, compressed air can often be usefully employed for
pressure boosting before going to a high volume evacuator.
The design of surface condensers, especially when used in a
vacuum system, needs to cover a wide variety of considerations.
Accordingly, the choice of a manufacturer for the design of a
surface condenser to be used in various systems needs to be
explored and designed in proper conformance to the con-
straints and variabilities of the system in which it is being
used.
With respect to evacuators or vacuum pumps, there are a
variety in use and which may be readily obtained from many
manufacturers. However, where the surface is likely to
consist of a sticky, gelatinous or solid clinging residue,
then the Nash-Hytor evacuator might be considered. This
uses a liquid piston system and is very effective for the
handling of particularly sticky materials, but is recommended
for use after a jet ejector boost. Another type of evacua-
tor of the cycloidal type is that of the Roots evacuator
which has been used in many industries for almost half a
century. If a jet ejector is required as a booster, as for
instance with a Nash-Hytor evacuator, this is readily accom-
plished, when water is the fluid, by the use of a steam jet
which by an addition of no more than 5 - 107. of steam con-
densate to the process water, can still permit essentially
a complete recycle back to the process unit. The steam
ejector boost should therefore add no more than 10% to the
water load of the ideally closed system and therefore we have,
in considering acceptable loadings, allowed only a 107.
makeup and a concommitant 10% allowance of the waste effluent
of that in the water phase.
In this brief study, it was not possible to ascertain each
and every possibility where the science of chemistry and/or
the art of engineering, chemical engineering, mechanical
engineering, or otherwise could be employed to enhance the
quality of products or to diminish effluent streams, whether
liquid, solid or gaseous. Neither is this study meant to
imply that all of the concepts proposed will be totally
applicable. However, they are offered with the hope they would
stimulate thinking towards innovative approaches of process
improvement.
DRAFT
122
-------
The application of all or a combination of some of the
above described apparati, are shown in the schematic sket-
ches for the various sub-categories of the soap and deter-
gent manufacturing processes. These may be-seen, in the
form as each is recommended and as each is used as a basis
for a guideline recommendation or as a standard for in-
process performance, as follows: Schematic diagram 101 -
modified: Soap manufacture by batch kettle. Here the pro-
cess of the above is shown in relation to the vacuum dis-
tillation system in the step 1012 of fat refining and
bleaching. It is also depicted on Schematic 102 - modi-
fied: Fatty acid manufacture by fat splitting, for the
step of fat splitting 1023 and for the step of hydrogena-
tion and fatty acid distillation step 1024. It is also
shown for Schematic 103: Soap from fatty acid neutrali-
zation, including drying, where it is shown as applied
to the drying of the neat soap to the essentially anhy-
drous product. In Schematic 104: Glycerine recovery:
Sections A and B: the application of it to glycerine eva-
poration to 80%, Section 1043 and to the glycerine dis-
tillation, Section 1044 are depicted. The application
of the above described equipment in the case of Schema-
tic 108: Soap manufacture by continuous processing, inclu-
ding drying. In this instance, the application is shown
with respect to the drying operation of neat soap to the
finished soap.
Another very useful method in which reactions may be
brought to fullest possible Completion, and the minimiza-
tion of effluents thereby accomplished, is that of continuous
processing all of purely counter-current staged batch or
continuous processing. In this system essentially the flow
of reactants are counter-current to each other so that both
reactant feed materials are finally reacted in their most
favorable environment for their highest equilibria of reac-
tion. This is depicted under flow diagram, Schematic 108 -
Soap manufacture by continuous processing; and with res-
pect to the Sulfonation and Sulfation processes depicted
in Schematics 201 - modified, 206 - modified; and in 202 -
modified and in 206 - modified.
One of the other points applicable to control technology is
that relating to distillation equipment and entrainment se-
123
DRAFT
-------
parators. Wherever a distillation is carried out, whether
on a batch basis or by multi-component continuous fraction-
ation, there is an entrainment of liquid droplets from one
tray of a tower to the tray above. This is essential in
order to accomplish good vapor-liquid contacting and to
make the efficiency of the physical transfer of the high-
est possible order. However, it does result in carrying
droplets of liquid by the vapor from the stage below to
the stage above. By the use of one or two additional spe-
cial trays in a distillation column, whether used in con-
centration as in glycerine manufacture, or as used for the
separation of components, such as in fatty acid manufacture,
the use of additional plates and fractionation will not only
eliminate carryover in the form of entrainment but lead to
a more complete separation and a higher purity of each com-
ponent of a multi-component distillation feed.
124
DRAFT
-------
NATURE OF POLLUTANTS
The soap and detergent industry produces wastewaters con-
taining both conservative and nonconservative pollutants
which must be treated, removed from the waste stream, and
ultimately disposed of under controlled conditions. The
important conservative pollutants consist of organic raw
materials, fats and oils and lost portions of finished
product, soap and/or synthetic detergent. Mineral solids,
catalysts and builder materials such as borate and phos-
phate also appear in the effluents in moderate concentra-
tions. Some of these substances reach polluting concen-
trations in plant effluents which then have to be treated.
The pollutants of primary concern, together with the con-
centration ranges within which they are generally found
in plant effluents are as follows:
1. Oils and greases (0-3500 mg/1)
2. Suspended organic material other than oils and
greases (0-30,000 mg/1)
3. Dissolved or finely dispersed colloidal organic
substances which contribute to the chemical and
biochemical oxygen demands. (100-12,000 mg/1)
4. Certain organics with surfactant properties.
(0-1700 mg/1)
In addition to pollutants per se, the alkalinity or
acidity of wastes is also a primary concern and may man-
date the treating of a plant effluent.
Of secondary concern are the following pollutants:
1. Boron or borates (less than 1 mg/1)
2. Phosphates (25-1000 mg/1)
3. Dissolved mineral solids (0-250,000 mg/1)
4. Zinc and barium (less than 1 mg/1)
Since phosphate compounds are used in the manufacture of
several types of detergent, some of them inevitably find
their way into the process waste streams. The concentra-
tions actually measured vary widely and the data are not
sufficiently complete to make absolute judgments concern-
ing typical levels for many of the operations carried out
in the industry. However, some generalizations can be
made.
DRAFT 125
-------
1. In the closely controlled, well operated, integrated
manufacturing facilities examined as a part of the
present study, where phosphoric acid type cleaners
were not being produced, the concentrations of
phosphorus contained in the combined effluent waste-
water was generally under 25 mg/1 as phosphorus.
2. In those same facilities the average concentrations
in the combined effluent were typically 5-10 mg/1
as phosphorus, i.e., of the same order as is con-
tained in domestic sewage.
It must be concluded, even if only in a tentative fashion,
that the discharge of phosphorus from plants producing
either soaps or detergents does not represent a primary
pollution problem requiring extraordinary control
measures. In fact, if the phosphorus involved in the manu-
facture of detergents is to be controlled in a meaningful
fashion, it must be done through a limitation on the use
of that substance or by requiring a high degree of phos-
phorus removal at all U.S. domestic wastewater treatment
facilities. That is, the phosphorus used by the industry
ends up in domestic sewage rather than in production ef-
fluents .
With regard to borates, it is recognized that boron is
phytotoxic at concentrations of over 2.0-5.0 mg/1. How-
ever, the discharge of boron from the manufacture of
detergents is miniscule compared to that derived from
household use. Therefore, borate discharges also are
primarily a domestic sewage problem rather than one attri-
butable to the industry under study.
Mineral solids are considered only in the Level III anal-
ysis inasmuch as most plants report effluent concentra-
tions of from 500 to 2000 mg/1 which is satisfactory for
the immediate future.
Employed as catalysts in fat splitting, small amounts of
zinc and barium find their way into effluent streams.
Zinc is considered for pretreatment in this study because
a major spill could result in toxic levels entering the
biological treatment plant. A pretreatment scheme to
prevent this possibility is needed.
In addition to the pollutants earlier shown to be associ-
ated with each unit process, an additional pollutant of
importance appears in the waste streams of some soap and
detergent manufacturing plants. Residual methylene blue
DRAFT 126
-------
Active substances are found in the effluents of plants
manufacturing synthetic detergents and are removed along
with other organic substances.
TREATMENT TECHNOLOGY
The waste components of effluent streams associated with
the several unit processes involved in soap and detergent
manufacture have been identified. The pollutants associated
with the manufacturing unit processes, see Section V, have
been listed in Table 2.
In the second column are listed the corresponding waste
treatments applicable to each pollutant. The unit processes
are:
1. Kettle Boil Soap
2. Glycerine Recovery
3. Fat Splitting
4. Bar Soap Manufacture
5. Oleum Sulfonation
6. Spray Dried Detergent Manufacture
7. Liquid Detergent Manufacture
Discussion Of Treatment Techniques
The treatment technology proposed is standard and in routine
use. Operating and design techniques are well established
and have been reported upon extensively in the literature.
Therefore, only a brief discussion of such operations and
processes is included in this report.
Oil and Grease Removal - This may be accomplished by the ap-
plication of any one, or a combination of three basic separa-
tion methods - gravity separation, physical filtration, or
adsorption. The gravity separators are designed to handle
loads of 20,500-41,000 liters per day per square meter
(.500-1,000 gpd/sf) of surface. The filters are normally
operated at 205-615 liters per minute per square meter
(5-15 gpm/sf).
Carbon and other related solid phase adsorption operations
require approximately 0.45-0.68 kg (1.0-1.5 ibs) of
adsorbent per 0.45 kg (1 Ib) ot oil removed. Flotation
operates very much the same as the sedimentation operation
in terms of over-all efficiency. Air rates are usually
maintained around 0.004-0.011 cum/min/100 1 (0.5-1.5 cu ft/
min/100 gal.) of recycled flow. Chemical doses of FeCl3,
alum, or lime vary from 50-150 mg/1.
DRAFT
127
-------
TABLE 2
TREATMENT METHODS USED IN THE ELIMINATION OF POLLUTANTS
Pollutants
Free and emulsified
oils and greases
Suspended Solids
Dispersed Organics
Dissolved Solids
(Inorganic)
Unacceptable Acidity
or Alkalinity
Sludge obtained from
or produced in
process
Treatments
1. Gravity separation
2. Coagulation and sedimentation
3. Carbon adsorption
4. Mixed media filtration
5. Flotation
1. -Plain sedimentation
2. Coagulation-sedimentation
3. Mixed media filtration
1. Bioconversion
2. Carbon adsorption
1. Reverse osmosis
2. Ion exchange
3. Sedimentation
4. Evaporation
1. Neutralization
1. Digestion
2. Incineration
3. Lagooning
4. Thickening
5. Centrifuging
6. Wet oxidation
7. Vacuum filtration
DRAFT
128
-------
o
H
COMPOSITE FLOWSHEET
WASTE TREATMENT
SOAP & DETERGENT INDUSTRY
TO REGENERATION
<
cc
RAW
WASTE'
EQUALIZA-
TION
OIL & GREASE
REMOVAL
COAGULATION
SEDIMENTATION
SLUDGE &
OIL OUT
Q
D
CO
GREASE & OIL RECOVERY
11
FROM
REGENERATION
CARBON
ADSORPTION
BYCONVERSION
SLUDGE-RECYCLE
EFFLUENT
SLUDGE CONDITIONING
AND
DISPOSAL
BRINE
1
REVERSE
OSMOSIS
ION
EXCHANGE
FINAL
EFFLUENT
SAND OR
MIXED MEDIA
FILTRATION
\o
FIGURE 20
-------
Coagulation and Sedimentation - These units are designed
to provide between 30 and 60 minutes of coagulation time
and are normally designed for surface loading rates
of 16,400-61,500 liters per day per square meter
(400-1500 gpd/sf) depending on the nature of the waste.
Bioconversion Systems - Bioconversion is a biological
method of removing pollutants from wastewater. Its use
involves one or more of the following:
1. Aerated lagoons
2. Extended aeration
3. Activated sludge
4. Contact stabilization
5. Trickling filters
While both aerobic and anaerobic digestion are bio-
conversion processes, they are not used to remove pol-
lutants directly from the waste stream, but rather to fur-
ther treat materials already removed or currently being
generated as a part of the treatment operation. Bioconver-
sion units based on the use of activated sludge or one of
the basic modifications thereof are designed on the basis
of 90-363 mg (0.2-0.8 Ib) of COD per 0.45 kg (1 Ib) of dry
biomass. Depending on the nature of the organics, this
loading will provide removals in excess of 80-90%.
Trickling filter systems are designed in a more empirical
fashion using one of the many formulae in the literature
relating efficiency to areal loading, depth, recycle
rate and hydraulic load.
Carbon Adsorption Systems - These are of two general types -
those which use a more or less fixed carbon bed, and those
which use powdered carbon and recover the spent carbon in
an accompanying clarifier. The carbon is usually loaded at
rates of 45-227 gm (0.1-0.5 Ib) of pollutant per 0.45 kg
(1 Ib) of carbon. At conventional surface loadings, spent
powdered carbon is easily recovered in a clarifier after
coagulation with inorganic salts or organic polyelectrolytes
Carbon regeneration is a comparatively new art. While
some regenerative type systems do exist, they are neither
common nor completely satisfactory. In carbon regeneration,
there are a number of technological questions still to be
answered. For example, movement of the carbon to the fur-
nace; attrition rates; control of oxygen to prevent explos-
ion. All of these questions should be carefully examined
prior to entering upon a major program utilizing the carbon
adsorption waste treatment process. However, if the
nature of the wastes to be treated clearly indicate the de-
sirability of using the process, the above considerations
should not be viewed as absolute deterrents.
DRAFT 130
-------
Filtration for Removal of Suspended Solids - See discus-
sion of oil removal.
Dissolved Solids Removal - The design of systems for this
purpose varies widely with the manufacturer. They are
evaluated on the basis of efficiency, water recovery, and
the tendency to foul in the presence of suspended material.
Most systems require the removal of most of the solids
prior to treatment. Some require virtually complete re-
moval. Over-all water recovery tends to vary from 65-9078
depending on the particular system employed and the nature
of the waste.
Other Treatment Technique Considerations - In a good part
of the soap and detergent industry, the conversion of raw
materials and the recovery of reaction by-products is car-
ried on on a batch rather than a continuous basis. This
results in effluent streams which flow sporadically and
vary greatly in content and volume. Because of this, most
soap and detergent plants have devised ways of offsetting
such irregular performance and obtaining effluent streams
of a more constant nature, usually by providing some system
capacitance.
While it is not recommended that provision be made speci-
fically for the control of phosphorus, it is recognized
that a certain amount of phosphorus is normally degraded
in the normal course of waste treatment. The following
discussion is presented to indicate how this occurs.
When in the coagulation and sedimentation unit waste treat-
ment process lime, alum or a combination of iron salts is
used as the primary coagulant for the removal of suspended
or colloidal material, the removal of phosphorus may be car-
ried out concomitantly by making minor adjustments in the
mode of operation and the handling of the sludge. In many
cases, a high degree of removal will be obtained with no
change in the standard operating practices. It depends upon
the pH levels employed in lime coagulation and the level of
aluminum or iron salts employed in polyelectrolyte coagula-
tion. In general, this procedure will produce phosphorus
levels well under 1 mg/1 and under 0.5 mg/1 where an extremely
high level of sedimentation performance is obtained.
In the above mentioned waste treatment process, some phos-
phorus is removed as the phosphate salt of the metal cation
employed in the coagulation step. In the case of lime pre-
cipitation, pH values in excess of 9.5 are generally re-
quired for a high level of removal. The actual value de-
pends on the background calcium in the waste stream and the
DRAFT l
-------
level of removal required. In the case of ferric or
aluminum phosphate precipitation, 1-3 times the stochio-
metric quantity will be required for a high degree of re-
moval. As can be seen, these quantities of material do
not represent a major addition to the chemical requirements
and indeed a high level of phosphate removal may be incident-
al to suspended and colloidal solids removal. Where phos-
phorus removal is practiced as a part of an over-all waste
treatment operation which includes bioconversion, a suffici-
ent level of phosphorus must remain in the stream flowing to
thebiological system to support microbial action. On a
weight basis, this is generally of the order of 200 units of
COD for each unit of phosphorus.
To facilitate an understanding of the relationship between
the various unit processes involved in the over-all waste
treatment process, the former have been arranged in the
approximate order in which they might occur in a composite
waste treatment flow chart, Figure 20. The chart should
also be a useful adjunct used in correlating information
given in other self-explanatory charts linking pollutants
with appropriate treatments and showing the relative ef-
ficiency of several waste treatment unit processes.
SPECIAL OPERATIONAL ASPECTS OF CONTROL TECHNOLOGY
The nature of the treatment scheme proposed herein, coupled
with certain basic characteristics of the industry itself,
calls for special design and operating techniques in order
to achieve satisfactory waste control. The factors involved
are discussed briefly in the following paragraphs.
The industry employs many batch operations which tend to
produce waste of variable character and quantity. As a
consequence, there is often a need for some way of obtain-
ing a more uniform waste stream from the standpoints of
both composition and flow. Traditionally this has.been done
by installing mixed equalization tanks through which the
wastes pass prior to being subjected to the principal
treatment. However, these units often present operating
problems of their own. For example:
1. If the waste is not at biostatic concentrations
when it reaches the treatment plant, some bacter-
ial growth will occur in the equalization unit pro-
ducing solids and tending to reduce the oxidation
potential of the system to ineffective levels with
accompanying odors and nuisance status.
132
-------
2. It is.necessary to provide a minimum of
40 hp/3.8 thousand 1 (40 hp/thousand gal.) to be sure
that the wastes in the equalization tank are com-
pletely mixed and that sedimentation will not occur.
On the other hand, if an equalization unit is not provided,
unit operations and processes which are regulated by flow
and concentration will be adversely affected. In minimiz-
ing or eliminating the adverse effects of influent surges,
the following should be considered:
1. Installation of clarification units which can be
kept uniformly over 12 feet side water depth. Deep
units are much less subject to upsets by variations
in surface loading than are shallower units of 3 m
(10 ft) or less.
2. If a completely mixed first stage activated sludge
bioconversion system is to be employed it should be
understood that the effluent quality will vary with
the influent strength surges. Effluent quality vari-
ations can be handled either by equalization, or by
providing a second activated sludge stage of the plug
flow type. Since the hp/volume requirements for
either option are roughly comparable, the latter pro-
cedure is generally the most cost effective means of
dealing with this problem.
If carbon adsorption is to be employed instead of biocon-
version, an equalized feed stream will be necessary.
Regardless of other considerations, an upstream system
capacitance must be provided if maximum efficiency is to
be obtained from the treatment.
Whenever the waste entering a coagulation and sedimentation
unit tends to be highly biodegradable, troubles with gasi-
fication in high solids systems may be anticipated if
neutral pH values are employed for coagulation. Therefore,
it is necessary to evaluate the residence or holdup of
solids that can be employed, prior to deciding upon a
treatment system.
Plant shutdown for turnaround or under emergency condi-
tions particularly if operations cease for more than two
to three days, can result in a diminution in the effective-
ness of bioconversion systems on startup. Under such cir-
cumstances, the advantages of having an equalization unit
of substantial size ahead of the bioconversion unit become
apparent. During turnaround, the equalization unit may be
drained and cleaned, thereby providing the food materials
necessary to sustain the resident biota in the bioconversion
DRAFT 133
-------
portion of the system. If this is not possible, provis-
ion should be made for the discharge of stored concentrated
waste to the bioconversion unit during plant shutdown.
The equipment associated with the treatment steps proposed
herein does not have extraordinary maintenance require-
ments. Normal once per year examination, along with
routine maintenance, is the standard requirement. Considera-
tion should be given to providing unit by-passes or the
utilization of design concepts which will permit routine
maintenance without taking the unit out of service. It
should be generally possible to by-pass each individual
unit without taking the plant off the line or markedly
changing the over-all operational efficiency.
Waste treatment works must be well managed to avoid their
becoming public nuisances. If not handled properly, lagoons,
the incineration of sludge or the regeneration of carbon
may generate objectionable odors. This problem may be
eliminated or controlled by proper location of the units
and the use of gas emission control equipment. In the
case of lagoons, proper operation of the preceding waste
treatment units is essential.
IMPLEMENTATION OF TREATMENT PLANS
The equipment required for implementing the waste treat-
ments discussed in the preceding sections of this report is
available as off-the-shelf items or it may be found in manu-
facturers' catalogs. In the present economy the construction
manpower is generally available, although short term local
variations in availability are to be expected. However,
virtually all of the work required would be carried out by
the general contractor normally involved in the construction
of sewage and industrial waste treatment works.
Depending on the waste treatment employed and the precise
unit process under consideration, the land requirements will
vary from as little as one-half acre to as much as three or
four acres. It is likely that, for the industry as a whole,
a good mean land requirement would be of the order of
0.4 to 0.8 ha (one to two acres).
DRAFT
-------
SLUDGE SOLIDS HANDLING
SOAP & DETERGENT INDUSTRY
SLUDGE FROM OILY
WATER TREATER
SLUDGE FROM
COAGULATION & SEDIMENTATION
OVERFLOW TO
PROCESS
WASTE SLUDGE
FROM BYCONVERSION
SYSTEM
THICKENING
OVERFLOW TO
PROCESS
THICKENING
\r
DEWATERING
VACUUM FILTER
OR CENTRIFUGE
TO LAGOON
OVERFLOW TO
PROCESS
HEAT
TREATMENT
LAGOON
DISPOSAL
CAKE TO INCINERATION
OR GROUND DISPOSAL
GROUND
i
DISPOSAL
ASH TO LANDFILL
OR GROUND DISPOSAL
INCINERATION
DRAFT
FIGURE 21
135
-------
Table 3
Residual Pollutants
101 Kettle Boil Soap
Operation or Process In ng/1 Out ng/1
Oil OOP SS. Oil OOP SS_
Oil and Grease Removal
Plant fl 46 315 14 5 182
Plant #2 - 288,000 30,000 5 288,000 30,000
Coagulation-Sedimenta-
tion 5 182 - 1 170
288,000 30,000 - 239,000 3,000
Bioconversion 1 170 - - 30-50 5
239,000 3,000 - 29,000 300
Carbon Adsorption
Plant Flow - Plant #1 - 444 klpd (117,000 gpd)
Plant #2 - 947 Ipd (250 gpd)
ON
-------
o
H
Operation or Process
Table 4
Residual Pollutants
104 Glycerine Recovery
In tqg/1
Out ng/1
Oil and Grease Removal
Plant #1
Plant #2
Coagulation -Sedimentation
Plant #1
Plant #2
Bioconversion or Carbon
Adsorption
Plant fl
Plant #2
Oil
0
0
0
0
0
0
COD
585
657
585
657
539
595
SS
28
36
28
36
5
5
Oil
0
0
0
0
0
0
COD
585
657
539
595
60
70
§§.
28
36
5
5
5
5
Plant Flow - Plant #L - 2050 klpd (540,000 gpd)
Plant #2 - 1590 klpd (420.000 gpd)
-------
Table 5
Residual Pollutants
106 Bar Soap
Operation or Process
Oil & Grease Removal
Plant #1
Plant #2
Coagulation-Sedimentation
Plant #1
Plant #2
Bioconversion or
Carbon Adsorption
Plant #1
Plant n
Inmg/1
Out tra/1
Oil
104
4
10
0
COD
1.040 2,800
38 281
300
177
92
85
ss
850
85
104
51
10
5
Oil
104
4
10
0
0
0
COD
300*
177
92
85
30-50
30-50
SS
104*
51
10
5
c
J
5
-''Estimated now - Plant #1 - 4500 gpd (17.1 klpd)
Plant #2 - 7500 gpd (28.4 klpd)
00
-------
o
H
Operation or Process
Oil & Grease Removal
Plant fl
Plant #2
Coagulation-Sedimentation
Plant #1
Plant #2
Bioconversion or Carbon
Adsorption
Plant #1
Plant #2
Table 6
Residual Pollutants
201 Oleum Sulfonation
lnmg/1
Oil COD SS
4000C2)20,400 200
3405 4026 149
(15,000)
400
341
40
34
9600
5808
5520
2406
0
0
0
0
Plant Flow - Plant #1 - 26.5 klpd (7,000 gpd)
Plant- #2 - (12,000 gpd)
SURF
2000
1657
2000
1657
1000
830
(2)
Cut IIR/1
Oil
400
341
40
34
10
10
COD
9600
5808
5520
2416
2040
1500
SS
0
0
0
0
5
5
SURF
2000
1657
1000
830
200
166
(2) Estimated
(1) Based on the oil, grease and surfactant values, the COD values of plant 2 must be
low by a factor of approximately 4. The suspended solids data are alos susoect.
The COD value will be taken at 15,000 mg/1 for present purposes.
VO
-------
o
H
Table 7
Residual Pollutants
207 Spray Dry Detergents
Operation or Process
Oil and Grease Removal
Plant #1
Plant #2
Coagulation-Sedimentation
Plant #1
Plant #2
Bioconversion or Carbon
Adsorption
Plant #1
Plant #2
In mg/1
Out TtlR/1
Oil
ND*
ND
-
-
COD
1,940
2.480
1.940
2,430
1.490
2,241
SS
ND
4
•»
4
-
SURF
300
127
300
127
150
64
Oil OOP
-
- 1.490
- 2,241
200
250
SS
-
-
5
5
SURF
-
150
64
30
13
Plant Flow - Plant #1 - 557 klpd (147.000
Plant #2 - ' 716 klpd (189.000 gpfc)
•P-
o
-------
Operation or Process
Oil & Grease Removal
Coagulation-Sedimentation
Bioconversion or Carbon
Adsorption
Table 8
Residual Pollutants
209 Liquid Detergents
In mg/1
Oil
ND*
COD SS
1748 66
1798 66
1082 7
SURF
444
444
222
Oat me/1
OIL COD SS SURF
1082 7 222
175 5 44
Plant Flow - 28.5 klpd (7530 gpd)
*No Data.
-------
Solid Waste Generation Associated With Treatment Technology
Depending on the precise nature of the over-all waste stream,
solid waste may originate at any one of several points in the
waste treatment process. Please refer to the composite waste
treatment flow sheet. The principal sources of solid waste
are :
1. Sludge from the under flow of a gravity type oily water
treater. This sludge would normally be combined with other
waste solids from the process.
2. Sludge is withdrawn from the coagulation and sedimentation
unit and combined with other waste sludges or processed sepa-
rately.
3. Some waste sludge is normally generated in a bioconver-
sion facility although the units can be designed to approach
virtual steady state between new sludge production and the
loss of resident sludge over the weir and through endogenous
respiration.
Process sludges are treated by one or more of the methods
outlined in Figure 21 on page 135. In rough chronological
order, steps leading to the ultimate disposal of sludge in-
clude the following:
1. As a first step, the sludge is thickened in a gravity
thickener or a centrifugal device. In either case, ef-
fluent solid concentrations varying from 370 to 10% may
be anticipated. The difference arises from the substan-
tial differences in the characteristics of the sludges.
1. After thickening, biological sludges may be treated to
reduce moisture content of the ultimate cake. The sludge
is then subjected to heat and pressure to reduce the size
and complexity of the protein and carbohydrate cellular
material. This, in turn, releases bound water. In some
cases the sludge is discharged to a lagoon after this step.
3. In the next step, the sludges are dewatered, either on
a vacuum filter or in a solid bowl centrifuge. In some
instances sludges will have to be conditioned with either
organic polymers or inorganic polyelectrolytes prior to
dewatering.
4. Following the dewatering step the sludge may be disposed
of directly or incinerated for the removal of virtually all
of the residual organic matter.
5. Following incineration, the ash, which constitutes from
5% to 107o of the initial mass, is disposed of as land fill.
DRAFT
142
-------
Sludge conditioning and disposal costs are highly variable,
depending on the nature of the sludge and the procedures
followed. The cost brackets for the sequences outlined in
Figure 20 are shown in Table 10 • It is assumed that land
is available for lagoon and landfill disposal of sludge and
ash.
The basic costs and relative efficiencies of the waste treatment
processes outlined in the composite waste treatment flew
chart have been summarized in Table 9 The data in the table
were obtainedfrom several sources in the literature and
adjusted upward and expressed in terms of 1972 dollars.
The energy requirements are based on manufacturer's data
for the size of motors and other energy refining systems
normally used in each waste treatment unit process.
The cost of treating the brine stream from a reverse osmosis
or an ion exchange system is highly variable. Depending
on the flow and solids concentration the cost to take this
stream to dryness will vary from $0.50to $2.50 per 3785 liters
(1000 gallons). Disposal may still be a problem that must
be viewed on an effluent by effluent basis.
Regarding operational costs, the figures cited are direct
costs only. They do not include any administrative, over-
head, fringe benefits or directly charged laboratory support.
If these costs were to be included, the total would be
roughly double.
DRAFT
143
-------
Table 9
Cost and Energy Requirements Associated
With Various Treatment Methods
Treatment Procedure
Costs
Power Requirements
'Capital
Operational
Oil & Grease
Removal
Hand skimmed
tanks $26-79/1000 1
($100-300/1000 gal.)
Mechanically
cleaned tanks $13-18/1000 1
($50-70/1000 gal.)
Mixed media
filtration $21-66/1000 1
($80-250/1000 gal.)
Flotation
Carbon
adsorption
$11-37/1000 1
($49-140/1000 gal.)
$26-210/1000 1
($100-800/1000 gal.)
$5.00/day
$0.008-0.026/1000 1
($0.03-0.10/1000 gal.)
$0.032-0.105/1000 1
(0.12-0.25/1000 gal.)
$0.03-0.11/1000 1
($0.12-0.40/1000 gal.)
$0.22-0.66/kg oil
($0.10-0.30/lb
None
0.19-0.57 kw/1000 cu m/day
1-3 hp mgd
1.52-2.85 kw/1000 cu m/day
8-15 hp/mgd
1.14-2.85 kw/1000 cu m/day
6-15 hp/mgd
0.95-1.9 kw/1000 cu m/day
5-10 hp/mgd
-------
I
Ln
Table 9
(cont'd)
Treatment Procedure
Costs
Power Requirements
Capital
Operational
Carbon Adsorption
System
Fixed carbon
in column $26-79/1000 1 $0.04-0.132/1000 1
($100-300/1000 gal.) ($0.15-0.50/1000 gal.
Powdered car-
bon fed prior
to coagulation
& sedimentation
void
$6-26/1000 1
0.95-1.9 kw/1000 cu m/day
) 5-10 hp/mgd
?0.04-0.132/1000 1
($25-100/1000 gal.) ($0.15-0.50/1000 gal
Final
Clarification $13-40/1000 1
$0.008-0.019/1000 1
'($50-150/1000 gal.) ($0.03-0.07/1000 gal
Effluent
Filtration $21-69/1000 1
$0.013-0.040/1000 1
($80-260/1000 gal.) ($0.05-0.15/1000 gal.
Reverse Osmosis
Systems
579-158/1000 1
$0.079-0.269/1000 1
($300-600/1000 gal.) ($0.30-1.00/1000 gal
0.95-2.85 kw/1000 cu m/day
) 5-15 hp/mgd
0.19-0.57 kw/1000 cu m/day
) 1-3 hp/mgd
0.95-1.9 kw/1000 cu m/day
5-10hp/mgd
190 kw/1000 cu m/day
) 1000 hp/mgd
-------
Table 9 (cont'd)
Treatment Procedure Costs ^ Power Requirements
Capital Operational
Suspended Solids
Removal
Coagulation &
sedimentation $13-40/1000 1 $0.013-0.024/1000 1 0.19-0.57 kw/cu m/day
($50-150/1000 gal.) ($0.05-0.09/1QQO)gal.) 1-3 hp/mgd
Chemical
addition $0.003-0.013/1000 1
($0.01-0.05/1000 gal.) Fractional mgd
Mixed Media
Filtration & Flotation - See Oil & Grease Removal
Bioconversion-:
Systems
Activated
sludge $29-73/1000 1 $0.013-0.039/1000 1 19-95 kw/1000 cu m/day
($110-275/1000 gal.) ($0.05-0.15/1000 gal.) 100-500 hp/mgd
Aerated Lagoons
$28-53/1000 1 $0.016-0.029/1000 1 19-95 kw/1000 cu m/day
($70-2000/1000 gal.) ($0.04-0.12/1000 gal.) 100-500 hp/mgd
Extended
aeration $21-79/1000 1 $0.013-0.053/1000 1 19-95 kwAOOO cu m/day
($80-300/1000 gal.) ($0.05-0.20/1000 gal.) 100-500 hp/mgd
-------
--Power cost taken at $0.01 KWH
--Attendance @ $5.00/hour
--Manufacturer data used for power requirements
--Plant sizes are generally across 0.01-0.19 kw/1000 cu m/day (0.1-1.0 HGD) to show
cost variation and economy of scale.
-------
o
H
Procedure
Table 10
Cost of Sludge Conditioning and Disposal Operations
Costs
Power Requirements
1. Thickening-
influent at
5000 mg
2. Lagooning
3. Heat Treatment
Capital
Operational
$1800-6400/metric ton
($2000-7000/ton)
$1.60-6.40/metric ton
($1.80-7.00/ton)
Depends upon land cost entirely
$13,640-45,400/metric
($15,000-50,000/ton)
ton $4.50-13.60/metric ton
($5-15/ton)
Fractional/tpd
181-454 hp/mtpd
200-500 hp/tpd
00
Dewatering
4.
Vacuum Filtration $103-297/m2
(95-275/sq ft)
5. Centrifugation
6. Incineration
$455-909/mtpd
($500-1000/tpd)
$136,400-681,800/mtpd
($150,000-750,000/tpd)
$7.30-31.80/metric ton
($8-35/ton)
$4.55-22.70/metric ton
($5-25/toh)
$4.55-22.70/metric ton
($15-50/ton)
22.7-68.2 hp/mtpd
22-75 hp/tpd
45.5-90.9 hp/mtpd
50-100 hp/tpd
182-273 hp/mtpd
200-300 hp/tpd
17.2-68.9 1 of
fuel oil/metric
ton (5-20 gal.
fuel oil/ton)
-------
-P-
00
to
Table 11
Relative Efficiency of Several Methods Used in Removing Pollutants
Pollutant and Method
Oil and Grease
API type separation
Carbon adsorption
Flotation
Mixed media filtration
Coagulation-sedimentation
with iron, alum or solid
phase (bentonite, etc.)
Suspended Solids
Mixed.media filtration
Coagulation-sedimentation
_Effic_ie_ncy_ (Percentage of Pollutant Removed)
Up to 90% of free oils and greases. Varia-
ble on emulsified oil.
Up to 95% of both free and emulsified oils.
Without the addition of solid phase, alum or
iron, 70-80% of both free and emulsified oil.
With the addition of chemicals, 90%
Up to 95% of free oils. Efficiency in remov-
ing emulsified oils unknown.
Up to 95% of free oil. Up to 90% of emulsi-
fied oil.
70%-80%
50%-80%
-------
Pollutant and Method Efficiency (Percentage of Pollutant Removed)
Chemical Oxygen Demand
Bio-conversions (with final
clarifier) 60%-95% or more
Carbon adsorption Up to 90%
Residual Suspended Solids
Sand or mixed media filtration 50%-95%
Dissolved Solids
Ion exchange or reverse osmosis Up to 99%
00
cr
-------
SECTION VIII
COST, ENERGY AND NON-WATER QUALITY ASPECTS
The Technologies of In-Plant Control
Since all components used in soaps and detergents require the
carrying out of chemical and/or physical reactions for their
manufacture, there are limitations imposed by the laws of
reaction equilibria and phase equilibria which must be ob-
served.
The completion of a chemical reaction, from feed reactant(s)
to desired product(s), is related to restraints of energy
balance and to stoichiometry, or the molecular ratios of each
reactant species in a final product species.
The rate of a chemical reaction and attainment of a phase
equilibrium, are intrinsic properties of an overall system
and, while influencable in rate by catalysts and promoters,
are still subject to the same equilibria restraints.
A reaction can be best pushed toward its unique equilibrium
by 1) an excess of one reactant in relation to another, 2)
selection of operating environments (temperature, pressure,
concentration) most favorable to the optimum equilibrium in
the minimum of time, but at the optimum energy environment for
the reaction equilibrium.
However, there are restraints on the above suggestions due
to cost (including capital costs), complexity and contain-
ment materials, and vessels structure. The relation of in-
cremental costs to incremental production is exponential,
i.e., it can absolutely cost just as much to increase reac-
tion completeness from 80% to 90%. Therefore, no general-
ization is accurate and such reaction or physical system will
have its own optimum, relating costs of accomplishment to a
feed stock saving or an additional amount of product made.
The most practical way of always having an excess of one
reactant in relation to another, is by the employment of a
counter-current feed of the separate reactants. This is
even further enhanced by employing truly continuous flow of
each reactant and in the proper desired stoich iometrical
proportions. If phase separations of products and reactants
DRAFT 149
-------
is possible, then product withdrawal can be from one or the
other end of the continuous counter-current flow system. If
phase separation is not possible, then product withdrawal is
optimally done at an intermediate stage and from which, sep-
aration of the desired product can be accomplished, with
recycle back to one of the reactant streams, the excess of
that reactant. From this description, it may be realized
that no generalizations can be made. The specific reaction
and/or the specific phase equilibrium must be specifically
considered. For that reason, we have treated each applica-
tion of this technology separately, under the sub-categoriza-
tion of the soap and detergent industry processes.
Pre-Selection and Purity of Feed Stock
Many reactant streams, such as fats and oils and petroleum
hydrocarbons, employed for making soaps and detergents, con-
tain components which, when reacted produce product components
which are not permissible or at least not desired.
One way of minimizing such undesired products is to select
and use only those feed reactants, the product of which is
desirable in the final soap or detergent. This can also be
accomplished by a prior physical and/or chemical treatment to
remove these selectively, in advance of feeding the remainder
of the raw material into the reaction system. In addition to
undesired components from feed raw materials, there may be
components which have a truly adverse effect. They may inter-
fere with the reaction itself, slow it down, alter it from
the desired equilibria, or otherwise generally interfere in
optimization of the reaction system. These too, can often be
treated and removed by chemical and/or physical methods.
Again, each of the fee streams and each of the reaction sys-
tems of the sub-category must be treated individually, to
optimize benefit vs. cost.
Chemical Side Reactions
In addition to the desired reactions from a given raw material
to make the desired product(s), there are side-reactions.
These may lead to totally different products or to products
which interfere in the sequence of reaction steps. As an
example, in the sulfation of a fatty alcohol with sulfur tri-
oxide, it is also possible chemically to replace a hydrogen
atom of a methylene group with an S0-j group leading to an
undesirable di-sulfonic acid. This side-reaction is minimized
by an optimum concentration of sulfur trioxide - air, and by
DRAFT 150
-------
having an excess of the fatty alcohol.
Physical Separations
An important source of waste effluent loadings arises from
the incomplete separation of two mutually insoluble liquid-
liquid phases; gas-liquid phases; and liquid-solid phases.
An important technological application which can serve to
minimize this is the use of phase separation enhancers.
Thus, minor amounts of a surface-active agent can serve to
reduce foam, consisting of mixtures of vapor and liquid, and
of reducing liquid droplets carryover from phase to phase.
Another technological advantage is the application of good
engineering design; first, in creating the correct droplet
surface area and second, in the design of the phase separa-
tion equipment itself.
Distillation processes are much used to accomplish physical
separations in contrast to chemical reactions. In any distil-
lation column there is a necessity for a high degree of vapor-
liquid contacting and this automatically creates a high level
of entrainment. The entrainment results from a vapor carry-
over of liquid from a tray or stage below to a tray or stage
above. The use of mist separators and good engineering design
of fractionation trays serves to minimize these carryovers and
inter-contamination.
In any physical separation process, there are again certain
phase equilibria which control the limits of complete separa-
tion. This partitioning limitation is inherent to every
chemical species and to the system in which it is contained
in solution. Thus, again, one cannot generalize or advance
a precise system for optimization of all the pertinent environ-
mental and concentration conditions. Instead, each physical
separation system must be treated uniquely. This was done for
each of the unit processes for each of the categories involved
in this study.
Utilization of Non-Desirable Components
Many of product species are encountered which are neither use-
ful nor desirable in soap or detergent formulations. Typical
of these, are low molecular weight fatty acids, found in the
form of their esters and high molecular weight unsaponifiables
in the original fat or oil. They are often valuable for other
industrial uses or as reactants in another chemical system
DRAFT 15
-------
and can therefore often find their outlet in a pure form, or
sold as such. Lacking any such utilization, these kinds of
materials can be incinerated, thus being burnt to carbon
dioxide and water vapor, harmless to the atmosphere.
Recycle of Unreacted Components
In the application of all of the principles outlined above,
there is almost a deliberate excess of one or the other of
reactant components. Naturally, these unreacted components
need to be returned as recycle feeds to the original point of
entry into the system. However, these are often limited in
the extent to which they can be recycled and not discharged
as a water effluent, because there is a limitation on the
amount of water which can be fed to the process. In the case
of the soap and detergent industry, where the reactions are
generally carried out in the presence of water, this has be-
come more limited than necessary by employing barometric
condensers to achieve a degree of vacuum. In using baro-
metrics, cooling water is added to the processwater stream
and thus cannot be fully recycled.
This limitation can be overcome by employing a fully closed
water circuit, or at least almost so. In order to accomplish
this, it is necessary to employ indirect condensation and cool-
ing systems. In this case, surface heat exchangers are employ-
ed for condensation of vapors and for cooling of process
streams. This cooling water, never in contact with the process,
can then be re-cooled by the use of a cooling tower or return-
ed to a flowing water source.
In the application of surface condensers and coolers, a limita-
tion is often imposed due to the solid properties of a process
component or due to their stickiness to exchange surfaces. By
the use of washers, scrubbers, and re-absorbers such compon-
ents can be recovered and returned to the appropriate place in
the process flow. The use of a process feed reactant is it-
self the best possible washing fluid. Another way of minimiz-
ing the surface tenacity of components on heat exchange
surfaces is to have a recirculation of the process stream so
that it moves at high velocities through the tubes of the ex-
changer and thus, concomitantly, removes it.
The employment of these systems is also useful in reducing
unwanted or side-reaction products, since by partial condensa-
tion they can be removed and sold or otherwise disposed of.
DRAFT
152
-------
Furthermore, the complete reuse of water, to the maximum ex-
tent possible, avoids dilution of feed reactants in the
chemical reaction system, thus minimizing equipment size and
resultant higher capital costs. The use of vacuum systems,
particularly in fractionation or evaporation, accomplishes
a reduction in the temperature of operation, thus also
minimizing side-reactions and product/feed decomposition.
Cost and Energy Requirements of Applicable Technology
It is obvious from the previous discussion that no generaliza-
tion of cost vis-a-vis benefits is possible. For this reason,
each application was separately covered, where possible, of
the above described principles under each of the eighteen
process categories and for each of the separate unite opera-
tions within such category. This is covered, particularly
for level II and level III technology; first, in a general
description and, second, in the section entitled rationale
and assumptions. In each case, the effect on the energy
costs has been stated, whether an increase or a reduction on
a marginal basis. Capital costs of the relevant physical in-
stallation have also been included as if it were always a
new piece of equipment essentially located in place of, or
adjacent to, the replaced equipment. The operating costs, in
labor, material, utilities, and plant level overhead have
been included in the statement of operating costs as marginal
increases or decreases.
The cost and energy impact have been discussed and the method
of minimizing them, in the specific sense related to all of
these unit operations of the categories. In each case, there
was a selection of a feed, product, and by-product components
and their different chemical and physical properties. For
each unit process and each unit operation within the process,
of each of the sub-categories, we have chosen an optimum
process environment such as reaction time, temperature,
pressure, concentrations, phase relationships and many other
factors.
In each case, the size of the column, vessel or exchanger,
and its location was envisaged in dimensional terms. This
allowed a calculation of pressure head and energy require-
ments for the relevant fluid flows. The differences in heat
capacity of components in a process or ancillary stream were
taken into account as well as their individual rates of heat
transfer through indirect cooling or heating equipment. Also
DRAFT 153
-------
taken into account were the expected losses to the atmos-
phere as a result of the high volatility of some of the low
molecular weight components rejected in obtaining a product
of appropriate purity.
In considering level III technology, in calculation of costs
and in consideration of the related energy and utility re-
quirements, a new point source has been considered as a new
"Battery Limit Installation". The definition of the Battery
Limit is well understood throughout the chemical-process
construction industry.
Non-Water Quality Aspects
General
Some very special considerations need to be made for the soap
and detergent industry in respect to the requiring of an out-
let for feed/products in water, air, solid waste or in prod-
ucts as they are sold. This stems from the fact that feed
materials used in the manufacture of soap, whether they are
converted to ionic substituted products, unreacted or recov-
ered and burned and not disposed of for use by another
chemical manufacturer are themselves highly biodegradable or
chemically oxidizable and thus high in biological and chemical
oxygen demand. As an example, a typical feed material compon-
ent for soap making is the tri-palmitate of glycerol. This
has a COD of 2,680 lbs/1000 Ibs of the ester. Should this
component not be completely saponified, and wherever it may be
discharged as an effluent as to the air, water or as solid
waste or as it is in soap itself, it then still requires 2.68
Ibs of oxygen from the atmosphere to convert a pound of it
completely to carbon dioxide and water and so re-enter the
biological life-cycle.
A typical fatty oil obtained as a by-product from vacuum
treatment of feed stock fats and oils, however disposed of,
requires circa 2,000 Ibs of oxygen for the conversion of
1,000 Ibs of it back to carbon dioxide and water and to the
biological life-cycle. If this component is converted, as
part of a fatty acid production step, or in whatever form it
may finally leave a plant or a user, it still requires the
same amount of oxygen from the biological life support system.
The same is true of heavy components, not taken into the soap
making process, but removed as either solid or liquid waste
154
DRAFT
-------
or separated and used by other chemical manufacturers.
Still, in the end, that molecular species will require the
same 2 Ibs of oxygen for every pound of it, obtained from
the air, thus reintroducing it into the biological life
cycle.
The situation is not much different with respect to the feed
materials for detergents, for the by-products of unreacted
feed in making detergents, and for the detergent products
themselves. Detergents are also produced from petroleum re-
finery processing, in forms such as alkyl benzene, normal
paraffins, and normal olefins. Whether these are burned in
somebody's automobile or whether they are converted into
detergents, they too have a comparable biological/chemical
oxygen demand as in the case for soap feed materials des-
cribed earlier. There is just really one substantial differ-
ence and that is that many of the hydrocarbons used as feed
in detergent manufacture are themselves not readily bio-
degradable. However, they are slowly oxidized in the atmos-
phere, if not burned directly as a fuel source in home heating
or moving vehicle usage. The same can be said for every
portion of an organic compound which finally appears as a
detergent component, as a recovered by-product sold to another
chemical manufacturer, or as a volatile product vented direct-
ly to the atmosphere.
In the manufacture or compounding of detergents, many
inorganic chemicals are employed as well. These inorganic
chemicals are generally in an already oxidized state, and re-
quire no oxidative processes to convert them. Originally,
these salts of metal ions were taken from the earth and are
returned to the earth in the same or slightly altered form,
but generally have an eventual fate, in all cases, in the sea
water itself.
A Concordant Air - Water - Solid Effluent Guideline
Considering the restraints imposed by the immutable laws of
the physical sciences, the restraints on the attainment of
true equilibria in chemical/physical systems and the infinite
costs involved in substitute approaches, an enduring industry
average would permit 1% of a feed stream to remain unreacted,
or not worth recovering, and needed to be disposed of as an
effluent waste stream from reaction systems. Comparably, a
total industry physical loss could be placed in the order of
0.57o. Transferring these to the measurement of oxygen demand,
DRAFT
-------
to re-enter the biological life cycle, permissible effluents
in all forms to the air, to the water, and in the form of
solid waste would be as follows:
25 Ibs of BOD per 1000 Ibs of feed raw materials for
chemical losses; additionally, 10 Ibs per 1000 Ibs of feed
for physical losses as relating to BOD; thus making a total
of 35 Ibs of BOD per 1000 Ibs of feed processed. That total,
corresponds to the level of a permissive 70 Ibs per 1000 Ibs
of chemical oxygen deficiency.
This total level of effluents is proposed in sum, to be per-
mitted to be discharged in the gaseous, liquid, and solid
phase. It is presumed here that any liquid effluent would
be discharged in the form of water to a navigable stream, in
its ultimate sense. An upper limit would then be applied on
any one of the effluent nhases of say no more than 1/2 of the
total and for two such phases, such as water and air, no more
than 75% of the total allowed.
Such an approach is believed to be far more logical than the
approaches now inflicted upon this industry by the lack of
concordance in some seven Congressional legislation public
laws relating to the environment.
It should be fully realized that, if these fats and oils ob-
tained from the vegetable and animal sources, are not utilized
for the purpose of soap manufacture as it pertains to personal
and apparel hygiene, they would instead be utilized by man
and/or animals. And, in turn, the products of their utiliza-
tion would in turn relate to a total effluent load of circa
2800 Ibs of biological oxygen demand for each 1000 Ibs of
vegetable or animal fats consumed by man and animals. Fur-
thermore, the effluent streams to the bio-life cycle, will
also be in the form of a gaseous, liquid, or solid waste
effluent. In the case of detergents, the demand for organic
feed materials, again finds its source in previously living
plant or animal organisms, but now in the form of accumulat-
ed capital resources of petroleum oils and gas, or even of
solid fuels such as coal. The biological oxygen demand for
these components are analogical to and in the same order as
for feed as for soap making purposes. If they are not utiliz-
ed for detergent manufacture, their alternate use is as fuel
or as feed to other chemical processes for the manufacture of
products for human desire, if not needs. Therefore, in prin-
ciple, a concordant application of the same levels of efflu-
ent discharges, as for soaps, would be a far more coherent
approach.
156
DRAFT
-------
All this adds up to the interpretation of the pressure for
legislation. It is simply said, analogically; we all want
to use airplanes, but we want the airport far away from our
home or where we work. Again, analogically: we all want
the power plant, the chemical plant, and we want the products
from such industry; however, we want them to be located other
than where we work, eat, or live. It is no different for the
soap and detergent industry. In the sense of noise effects,
land use, thermal effects or other undesirable events, such
as traffic congestion for personnel for carrying out manu-
facturing operations, this is one of the less demanding
industries.
157
DRAFT
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158
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SECTION IX
BEST PRACTICABLE CONTROL TECHNOLOGY
CURRENTLY AVAILABLE
Introduction
One of the first steps in the development of guidelines was
the determination of raw waste loadings in the wastewater
flows for each category in terms of kg/1000 kg (Ibs of con-
taminant/1000 Ibs) of anhydrous product produced in that
category. The raw waste loading to be expected from the
best practicable technology was established and the guide-
line values defined as a 90% reduction of the raw waste
load, a reasonable expectancy of any treatment plant having
a biological secondary treatment process.
Wherever appropriate, attention was given to in-plant controls
to minimize the raw waste load.
Several soap and detergent processes have almost a negligi-
ble discharge in a number of manufacturing plants practicing
those processes. Level I guidelines give each of these
processes a very small but finite effluent allowance because
of one or more of the following reasons:
1. The product in the effluent stream is so degraded
it would be unsuitable for incorporation in the
final product and must thus be disposed of.
2. The wastewater source is so dilute as to require
undue amounts of heat energy to recover the dis-
solved solids content.
3. The material in the wastewater is quite biodegrad-
able; therefore, is readily handled by the re-
ceiving treatment plant.
In those categories where the guidelines have been set parti-
cularly low, the permit writer should be alert to the
occasional need to make spot increases in these limits.
Upsets and mechanical problems requiring cleanouts may crop
up, rare though they may be. This will be particularly
critical for small plants (under $500,000 in gross proceeds).
The larger integrated plants have sufficient flexibility in
their ability to recycle the contents of waste streams, to
minimize their need for spot increases.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 159
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In a few processes there are some relatively heavy discharges
of salt and sodium sulfate. No limit has been established
for these very low toxicity materials since 1) they will be
highly diluted by other process effluents before becoming a
point discharge and 2) the permit writer will undoubtedly
want to evaluate the background levels in the receiving waters
and determine what levels, if any, should be established.
No maximum delta temperature was established since the dif-
ferential between inlet and outlet process water temperatures
is quite modest, around 17°C (30°F) and much of the heat
would be dissipated in the waste treatment process.
The interrelationship of air and water pollution problems
became quite apparent in this study. Increasingly stringent
air emission standards have set performance requirements
beyond the ability of dry recovery systems available on det-
ergent spray towers. Wet scrubbers have been employed which
now allow the air effluent to meet those standards, resulting
in a substantial water flow and a correspondingly high BODc
loading.
In every instance in the following guidelines, the pH of the
point source discharge is required to be between 6 and 9.
SOAP MANUFACTURING
101 - SOAP MANUFACTURE BY KETTLE BOILING
General
This ancient art has been carefully scrutinized by all of its
practitioners to minimize cost and the avoidable loss of
marketable products where the installed capital permits.
Even in the area of very high quality soaps there still
appears to be a preference for this well established process.
There are essentially two main streams carrying away waste
from this source (in actual practice there may be more
subsidiary sources). They are typified by the blocks in-
dicated in the simplified flow diagram given below:
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 160
-------
Fats &
; Pre
J. CL L> O Ul i L ( A JL C i &x^ L> l>
Oils ['^^''iTreatmentr^-iBoll
T
I
teat Soap
Kettle
Recycle j
Solid
Waste
Refining
t
Soap Scrap
Recycle
Dark Soaps
to Market
t
Liquid Waste
WASTEWATER SOURCES IN SOAP MANUFACTURE
FIGURE 22
The liquid waste from fat pretreatment will normally be a fat
in water emulsion of modest BOD, perhaps some clay and other
organics. However, the stream from nigre processing, often
just a purge, will be very rich in BOD and contain some sodium
chloride and sodium sulfate. Some soap manufacturers do not,
at present, completely process their nigre but run it dir-
ectly to sewer. This is a point, for some, to improve in
effluent control.
Raw Waste Loading
The following are the expected thirty day average raw waste
loadings which would be entering a waste treatment plant:
BOD5 - 6 kg /1000 kg (6 lbs/1000 Ibs) anhydrous soap
COD - 10 kg /1000 kg (10 lbs/1000 Ibs) anhydrous soap
Suspended Solids - 4 kg /1000 kg (4 lbs/1000 Ibs) anhydrous
soap
Oil and Grease - 0.9 kg /1000 kg (0.9 lbs/1000 Ibs)
anhydrous soap
pH 5-14
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
161
-------
Level I Effluent Guideline Recommendations
On a thirty day average basis the following parameter values
are recommended:
BOD5 - 0.6 kg/1000 kg (0.6 lbs/1000 Ibs) anhydrous soap
COD - 1.0 kg /1000 kg (1.0 lbs/1000 Ibs) anhydrous soap
Suspended Solids - 0.4 kg /1000 kg. (0.4 lbs/1000 Ibs)
anhydrous soap
Oil and Grease - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs)
anhydrous soap
pH 6-9
In the event of upset, startup or shutdown procedure, a value
of three times that indicated above should be considered, pro-
vided that over any given thirty day period the recommended
average is maintained.
Level I Technology
In many soap making plants there are no access points in the
floor to the sewer. This makes good housekeeping unavoidable.
All leaks and spills are promptly attended to and recycled
within the process.
The guideline limitations can be attained by the production
(and marketing) of low grade soaps from the nigre, recovery
of fats from acidulated sewer lyes and nigre followed by
secondary treatment of the resulting waste.
Rationale and Assumptions
Fat saponification is carried out counter-currently where the
aqueous caustic stream is exhausted in a final reaction with
fresh fat. At the other end of the process the nearly fully
saponified fat is completely reacted by coming into contact
with fresh caustic. Salt recycle becomes automatic in that
energy required to concentrate the glycerine stream automati-
cally concentrates the salt. Filtration of the evaporator
product provides the recycle salt. There is still a sub-
stantial amount of salt that goes to the sewer via the bleed
of the nigre.
Phase relationships of electrolyte, soap and caustic content
largely govern their concentration and use so that proper
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FATHER INTERNAL REVIEW BY EPA.
DRAFT 162
-------
soap solubility is maintained. Within these constraints good
manufacturing management will minimize the total constituents
going to sewer.
This process can be brought close to no discharge only, at
present, at the expense of the smaller soap manufacturers
who do not exhaust their nigre. The recommended settling and
acidulation tank will go a long way toward attaining this
goal.
Most soap making equipment is several decades old and repre-
sents fully amortized capital, in a market not noted for its
dynamic expansion.
102 - FATTY ACID MANUFACTURE BY FAT SPLITTING
General
The wastewater effluents for disposal come from essentially
three sources; pretreatment of the fat, light ends emitted
from the fat splitter and the fat still, and the water sol-
ubles left in the acidulated still bottom after the recycle-
able fats are removed and recovered.
The light ends mentioned above are found in the condensate
from the barometric condenser and include short chain fatty
acids and unsaponifiables. One of the major contaminants
in the stream coming from the still bottoms is the catalyst.
It can be the sulfate salt of zinc, or other alkaline earth
metals.
A simplified schematic is given for the process to indicate
the approximate location of wastewater streams.
[Fats_
Fat
Glycerine
to
Recovery
: Light j
Ends 1
-f Still i- ->
i *
1 Bottoms—)
.....>
Fatty Acid ',
to Market i
Acidulation
To. i
Receiving
Stream
A
1
JWater Solubles
&_Settling H& Metals Salts,
[Fats Recoveryj
FAT SPLITTING
FIGURE 23
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FARTHER INTERNAL REVIEW BY EPA.
DRAFT
163
-------
Raw Waste Loadings
The following raw waste loading can be expected:
BOD5 - 12 kg /1000 kg (12 lbs/1000 Ibs) anhydrous acid
COD - 22 kg /1000 kg (22 lbs/1000 Ibs) anhydrous acid
Suspended Solids - 22 kg /1000 kg (22 lbs/1000 Ibs) anhydrous
acid
Oil and Grease - 2.5 kg /1000 kg (22 lbs/1000 Ibs) anhydrous
acid
Included in this loading are wastewater flows from: fats
treatment, fats splitting, acid distillation and still bottoms
disposal.
Level I Effluent Guideline Recommendations
On a thirty day average, the following parameter levels are
recommended:
BOD5 - 1.2 kg /1000 kg (1.2 lbs/1000 Ibs) anhydrous acid
COD - 2.2 kg /1000 kg (2.2 lbs/1000 Ibs) anhydrous acid
Suspended Solids - 2.2 kg /1000 kg (2.2 lbs/1000 Ibs)
anhydrous acid
Oil and Grease - 0.3 kg /100 kg (0.3 lbs/1000 Ibs) anhydrous
acid
pH 6 - 9
No additional provision need be made for startup, shutdown
or upsets. Allowance should be made for a threefold load-
ing over a 24 hour period, providing that during a thirty day
period, which includes this day of high loading, the recom-
mended average is maintained.
Level I Technology
Essential to the proper performance of the plant is the
incorporation of appropriate fat traps. Indicative of the
technology involved is the flow chart of a condenser/recovery
unit which could handle the load. Note that the only eff-
luent is blowdown of the fat settler which handles cooling
tower waters.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 164
-------
Still! ) | Fatty Acid L v| Barometric „ \ j Cooling,
1 "" JVapors j i Condenser iTower
! (Light Ends)j I " " " j
.Recycle! : Fat Settler
i Water ! "~ ~~
Recovered ; Slowdown to
Fat j :Stream
FATS RECOVERY SYSTEM
FIGURE 24
Due to the high temperatures maintained in the fat splitter
fat solubility and reaction rate are high so that 99% hydro-
lysis can be expected. This makes separation of the
condensates a relatively simple problem, well within the
engineering capabilities of the industry. As noted in the
above discussion, it is reasonable to expect that the only
materials to be disposed of are light ends and bottoms.
Rationale and Assumptions
A fats recovery unit for treating fatty acid still bottoms
will help minimize loadings of effluent. This equipment
plus the biological secondary treater will bring the loadings
down to the guideline level.
103 - SOAP FROM FATTY ACID NEUTRALIZATION
General
This method of neat soap manufacture is a clean process. The
major starting material, fatty acid, has already been sub-
jected to a severe refining step. During the oil splitting
process the volatile acids and color bodies have been re-
moved .
Neutralization is frequently carried out with soda ash,
which results in the evolution of carbon dioxide. In large
installations, the neutralization is continuous following
the fat splitter.
Raw Waste Loading
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA
DRAFT
165
-------
The following raw waste loading can be expected:
BOD5 - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs) anhydrous soap
COD - 0.25 kg /1000 kg (0.25 lbs/1000 Ibs) anhydrous soap
Suspended Solids - 0.2 kg /1000 kg (0.2 lbs/1000 Ibs)
anhydrous soap
Oil and Grease - 0.05 kg /1000 kg (0.05 lbs/1000 Ibs)
anhydrous soap
Level I Effluent Guideline Recommendations
On a thirty day average basis the following parameter limits
are recommended:
BOD5 - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs) anhydrous soap
COD - 0.03 kg /1000 kg (0.03 lbs/1000 Ibs) anhydrous soap
Suspended Solids - 0.02 kg /1000 kg (0.02 lbs/1000 Ibs)
anhydrous soap
Oil and Grease - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs)
anhydrous soap
pH 6 - 9
Level I Technology
Secondary biological treatment will very adequately handle
the effluent from this process.
Rationale and Assumptions
This process is carried out using stoichometric quantities of
all reactants so that the entire content of the reactor is
sent in total to the next processing step; bar soap, soap
flakes/chips, or liquid soap. The product is neat soap at
approximately 70% concentration.
Leaks from pump and other packing glands should be gathered
and returned to the process.
104 - GLYCERINE RECOVERY
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 166
-------
General
The character of the wastewater streams from glycerine re-
covery will be determined by the source of the dilute streams
which are concentrated. There are two sources of dilute
glycerine; one from the processing of sweet water lyes of
kettle boiling soap and the other from fat splitting.
In the case of the soap making source, a stream which contains
8 - 15% glycerine, salt and miscellaneous organic matter is
run to a batch evaporator and concentrated to 60 - 807.. In
glycerine concentration the 80% product is removed as a
bottoms product and therefore contains all of the original
impurities (less a lot of the original salt) , but in a much
more concentrated form. At this point the stream is either
sold to a glycerine refiner or again batch handled in a
glycerine still where the product is taken overhead.
The dilute glycerine stream from fat splitting can be varied
significantly in concentration. It all depends upon how the
fat splitter is operated. Glycerine is a bottoms product
from the splitter. A fairly concentrated glycerine can be
obtained if the yield of fatty acid is sacrificed or the
production rate is diminished.
As the glycerine stream comes from the fat splitter, it is
normally flashed to atmospheric pressure, thereby gaining
an immediately increased concentration of product.
A simplified flow chart of the concentrating and distillation
process is as follows:
JGondensate to Waste!
"~ '~"
Glycerine
1 .Concentrated Glycerine { Glycerine
Evaporator: r~ Glycerine * Still >j to Market
60 - 80%
V
[salt filtered \
I or centrifuged:
""
Glycerine.
Foots to
Wastewater
To Soap ^
Manufacture
GLYCERINE CONCENTRATION
FIGURE
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
167
-------
Raw Waste Loading
The glycerine concentration and glycerine distillation should
be handled separately. Quite often the glycerine which is
concentrated to 60 or 80% is sold to another firm for further
distillation to an assay of 98+% glycerine.
Raw waste characteristics are expected to average as follows:
Glycerine Concentration
BOD5 - 15 kg /1000 kg (15 lbsf/1000 Ibs) anhydrous glycerine
COD - 30 kg /1000 kg (30 lbs/1000 Ibs) anhydrous glycerine
Suspended Solids - 2 kg /1000 kg (2 lbs/1000) Ibs) anhydrous
glycerine
Oil and Grease - 1 kg/1000 kg (1 lb/1000 Ibs) anhydrous
glycerine
Glycerine Distillation
BOD5 - 5 kg /1000 kg (5 lbs/1000 Ibs) anhydrous glycerine
COD - 10 kg /1000 kg (10 lbs/1000 Ibs) anhydrous glycerine
Suspended Solids - 2 kg /1000 kg (2 lbs/1000 Ibs)
anhydrous glycerine
Oil and Grease - 1 kg/1000 kg (1 lb/1000 Ibs) anhydrous
glycerine
Level I Effluent Guideline Recommendations
Separate guidelines should be established for the wastewater
effluents for the glycerine concentration step and the final
glycerine distillation since, in many cases, these two opera-
tions are not carried out at the same geographical location
nor by the same manufacturer. In the event both concentration
and distillation are conducted at the same location, the
parameter values of each operation should be combined for a
final effluent allowance.
On a thirty day average basis, the following effluent guide-
lines are recommended:
NOTICE- THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 168
-------
Glycerine Concentration
BOD5 - 1.5 kg /1000 kg (1.5 lbs/1000 Ibs) anhydrous glycerine
COD - 3.0 kg /1000 kg (3.0 lbs/1000 Ibs) anhydrous glycerine
Suspended Solids - 0.2 kg /1000 kg (0.2 lbs/1000 Ibs)
anhydrous glycerine
Oil and Grease - 0.1 kg/1000 kg (0.1 lbs/1000 Ibs) anhydrous
glycerine
pH 6 - 9
Glycerine Distillation
BODj - 0.5 kg /1000 kg (0.5 lbs/1000 Ibs) anhydrous glycerine
COD - 1.0 kg /1000 kg (1.0 lbs/1000 Ibs) anhydrous glycerine
Suspended Solids - 0.2 kg /1000 kg (0.2 lbs/1000 Ibs)
anhydrous glycerine
Oil and Grease - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs) anhydrous
glycerine
pH 6 - 9
A startup allowance of three times the average should be
allowed as long as the thirty day average is maintained.
Level I Technology
Much of the glycerine concentrating equipment in soap plants
is fairly old. It is operated in a batch manner and apparently
the vapors carry a fair amount of entrainment, as is evidenced
by the amount of salt carryover in the condensate. The long
residence time in the concentrators helps to build up glycerine
polymers and degrades other heavy ends leading to high BOD
loadings in the resulting wastewater stream.
Where the barometric condenser is continued in use, the in-
stallation of a biological cooling tower with the attendant
recycle of barometric water can materially reduce the raw
wasteload.
Rationale and Assumptions
In almost all cases observed there has been a significant
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
-------
BODc loading in the barometric condenser water, which is due
to the glycerine escaping the condensing system. Apparently
this is not now regarded as a worrisome economic loss; it
does constitute a high biochemical loading. The employment
of more efficient condensers, eliminating the barometric leg,
is one way in which effluent loadings can be reduced.
Another method is the employment of column reflux in the
glycerine evaporators to reduce glycerine loss.
105 - SOAP FLAKES AND POWDERS
General
Neat soap is either chill rolled and air dried or spray dried.
In either case, the wastewater loading is minimal. There are
occasional washdowns and cleanups required, though rare.
Raw Waste Loading
The leaks, spills and pump gland cooling water will contribute
the following loadings:
BOD5- 0.1 kg /1000 kg (0.1 lbs/1000 Ibs) anhydrous soap
COD - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) anhydrous soap
Suspended Solids - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs)
anhydrous soap
Oil and Grease - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs)
anhydrous soap
Level I Effluent Guideline Recommendations
On a thirty day average basis, the parameter levels are rec-
ommended to be:
BOD5 - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs) anhydrous soap
COD - 0.03 kg /1000 kg (0.03 lbs/1000 Ibs) anhydrous soap
Suspended Solids - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs)
anhydrous soap
Oil and Grease - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs)
anhydrous soap
pH 6 - 9
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 17Q
-------
The permit authority may find an occasional situation meriting
a spot increase above these values for unforeseen equipment
washouts.
Level I Technology
Manufacture of flakes and powders has been optimized well to
minimize losses. The systems are maintained dry in normal
practice, thereby no continuous wastewater is generated.
Only where there is associated soap reboil (to recover scrap
soap) is there any appreciable amount of effluent generated.
Incineration of scrap soap is one way in which effluents
could be reduced, where applicable and economically feasible.
In any event, biological secondary treatment will appropri-
ately reduce the waste loadings to acceptable levels.
106 - BAR SOAPS
General
Starting with neat soap (approximately 70% soap solution in
water) the processes for making bar soaps are quite varied.
The major differences occur in the drying technique. Soaps
in bar form will have a final moisture content varying from
8% to over 15%, depending upon the particular properties
desired.
One can encounter situations where there are no wastewater
effluents generated of any kind, to those having several
scrubber water effluents, depending upon the particular
product' made. Washouts as such are minimal in terms of water
use and effluent loadings.
Raw Waste Loading
The following wastewater effluent concentrations are regarded
as an average expectation:
BOD_- 3.4 kg /1000 kg (3.4 lbs/1000 Ibs) anhydrous soap
COD - '5.7 kg /1000 kg (5.7 lbs/1000 Ibs) anhydrous soap
Suspended Solids -. 5.8kg /1000 kg (5.8 lbs/1000 Ibs)
anhydrous soap
Oil and Grease - 0.4 kg /1000 kg (0.4 lbs/1000 Ibs)
anhydrous soap
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 171
-------
Level I Effluent Guideline Recommendations
On a thirty day average basis the following parameter values
are recommended:
BOD5 - 0.34 kg /1000 kg (0.34 lbs/1000 Ibs) anhydrous soap
COD - 0.57 kg /1000 kg (0.5?" lbs/1000 Ibs) anhydrous soap
Suspended Solids - 0.58 kg /1000 kg (0.58 lbs/1000 Ibs)
anhydrous soap
Oil and Grease - 0.04 kg /1000 kg (0.04 lbs/1000 Ibs)
anhydrous soap
pH 6 - 9
Level I Technology
There is a concerted effort within the industry to minimize
water use in this particular operation. One of the un-
resolved questions is whether air quality restrictions will
force other "dry" operators to incorporate scrubber systems
for picking up elusive soap dust.
The levels specified in the guidelines are readily achiev-
able by the collection and recycle of soap dust (via dust
collectors or scrubbers) or in secondary biological treat-
ment.
Rationale and Assumptions
Without much more detailed analysis of the bar soap making
operation it is very difficult to discern just how close to
zero discharge all processes could come without seriously
jeopardizing the product performance, hence the relatively
broad allowances.
107 - LIQUID SOAP
General
Neat soap (approximately 70% soap and 30% water) is run into
a mixing tank to be blended with other ingredients, filtered
if required and drummed. There may be need for an occasional
equipment washout and a frequent filter cleanout.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 172
-------
Constituents going into these blends are quite varied since
their functions range widely. This kind of business is
close to custom blending due to the high performance nature
of many of their products.
Raw Waste Loading
On the basis of a thirty day average the following raw waste
loadings can be expected:
BOD5 - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs) anhydrous soap
COD - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) anhydrous soap
Suspended Solids - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs)
anhydrous soap
Oil and Grease - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs)
anhydrous soap
Level I Effluent Guideline Recommendations
As a thirty day average the following effluent parameter
values are recommended:
BOD5 - 0.01 kg/1000 kg (0.01 lbs/1000 Ibs) anhydrous soap
COD - 0.03 kg /1000 kg ( 0.03/1000 Ibs) anhydrous soap
Suspended Solids - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs)
anhydrous soap
Oil and Grease - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs)
anhydrous soap
pH 6 - 9
There may be an occasional need on the part of some manu-
facturers to exceed these limits due to a highly varied
product mix requiring washouts more frequently than allowed
above.
Level I Technology
Secondary biological treatment is adequate to meet the levels
proposed.
Rationale and Assumptions
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 173
-------
This processing step is essentially clean, requiring only
rare washouts to prevent cross contamination of widely
varied performance products. Many of these same processors
blend dry detergents requiring comparable frequency of wash-
outs. A biological secondary treatment is expected to be
adequate to handle the effluents.
201 - OLEUM SULFONATION/SULFATION
General
This chemical process has been optimized in that it is close
to a "push button" operation. It is practically trouble-
free and requires washdowns only when there is to be mainte-
nance of the operating equipment. The leaking pump glands
are a problem typical of this kind of equipment, although
modest in nature. Normally an operator can quickly observe
a significant leak and repair it promptly.
Raw Waste Loading
An average expected raw waste loading is:
BOD5 - 0.2 kg /1000 kg (0.2 lbs/1000 Ibs) anhydrous product
COD - 0.6 kg /1000 kg (0.6 lbs/1000 Ibs) anhydrous product
Suspended Solids - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs)
anhydrous product
Oil and Grease - 03 kg /1000 kg (03 lbs/1000 Ibs)
anhydrous product
Surfactant - 0.7 kg /1000 kg (0.7 lbs/1000 Ibs) anhydrous
product
Level I Guideline Recommendations
The following thirty day average recommendations for effluent
loadings are made with the understanding that there may be
some firms on some occasions requiring additional loadings for
washouts of equipment. Further, during any 24 hour period
the limits could be allowed to approach 4 times the average
as long as the thirty day average meets the guidelines.
BOD- - 0.02 kg /1000 kg (0.02 lbs/1000 Ibs) anhydrous product
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
TUF55MATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FATHER INTERNAL REVIEW BY EPA.
DRAFT 174
-------
COD - 0.06 kg /1000 kg (0.06 lbs/1000 Ibs) anhydrous product
Suspended Solids - 0.03 kg /1000 kg (0.03 lbs/1000 Ibs)
anhydrous product
Oil and Grease - 0.03 kg /1000 kg (0.03 lbs/1000 Ibs)
anhydrous product
Surfactant - 0.07 kg /1000 kg (0.07 lbs/1000 Ibs) anhydrous
product
pH 6 - 9
Some small scale batch operated plants may have great diffi-
culty in reaching these levels. Consideration should be
given by the permit writing authority to modest relaxation
of these levels where circumstances clearly warrant them.
Level I Technology
As indicated in the General discussion this process can be
operated continuously in essentially a trouble-free manner.
There is little room for improvement.
Other than the gland leakage and very occasional washouts
this process has no effluent. Gland leakage around pump
shafts is a universal problem wherever liquids are handled,
particularly corrosive liquids. Because of the corrosive
nature of the oleum, thorough washouts are mandatory prior
to maintenance work being carried out on the equipment.
Integrated plants will have little difficulty meeting the
levels of the guidelines. The washwater can be recycled and
the leaks and spills run to the neutralization unit.
Biological secondary treatment will handle the residual wastes
where they occur.
202 - AIR-S03 SULFATION/SULFONATION
General
This process is in as widespread use as the oleum sulfonation
(201), particularly for the sulfation of alcohols and ethoxy-
lates. Although continuous and. automatic, the Air - 503
process is much more inclined to cause product degradation
than the oleum unit.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 175
-------
Whenever the process is started up some material must be
discarded due to low sulfonation, making the material below
specification. Promptly upon shutdown a thorough washdown
is required to keep char formation to a minimum. There are
mist knockdown scrubbers which will also contribute to
wastewater loadings.
Raw Waste Loading
Average expected raw waste loadings are:
BODij - 3 kg /1000 kg (3 lbs/1000 Ibs) anhydrous product
COD - 9 kg /.1000 kg, (9 lbs/1000 Ibs) anhydrous product
Suspended Solids - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs)
anhydrous product
Surfactant - 3 kg /J.OOO kg (3 lbs/1000 Ibs) anhydrous
product
Oil and Grease - 0.5 kg /100 kg (0.5 lbs/1000 Ibs)
anhydrous product
Level I Guideline Recommendations
Thirty day average recommendations are made on a similar basis
as those for Category 201 - Oleum Sulfonations. Because of
product changes or mechanical failures some plants may, at
times, have to exceed established effluent limits. Such
cases have not been provided for in our suggested guide-
lines. Therefore, regulatory agencies may wish to extend
special consideration in such cases and write appropriate
limitations into any permits they issue.
BODg - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) anhydrous product
COD - 0.9 kg /1000 kg (0.9'Ibs/1000 ibs) anhydrous product
Suspended Solids - 0.03 kg /1000 kg (0.03 lbs/1000 Ibs)
anhydrous product
Surfactant - 0.3 kg /10QO kg (0.3 lbs/1000 Ibs) anhydrous
product
Oil and Grease - 0.05 kg /1000 kg (0.05 lbs/1000 Ibs) anhydrous
product
pH 6 - 9
NOTICE- THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 176
-------
During any 24 hour period up to A times the thirty day
average should be allowed for special upsets.
Level I Technology
This process too has received much research and development
attention leaving little to be expected in the short term
in the form of process improvement.
In-plant practices can significantly aid in reducing raw
waste loads by handling much of the cleanup dry, or blending
off the material into industrial cleaners, provided the firm
is sufficiently integrated.
Rationale and Assumptions
In small plants particularly, there must be accommodation
made for.the disposal of these rather minimal wastes, in
that the off specification product could seriously impact
the product quality if incorporated in that stream.
The raw waste loading has been structured higher than that
for oleum sulfonation to acknowledge the product degrada-
tion which takes place when sulfonated material remains in
the reaction area, requiring thorough washouts.
203 - S03 SOLVENT AND VACUUM SULFONATION
General
Other than an occasional washout, this process is essentially
free of wastewater generation.
Raw Waste Loading
The following raw waste loading is expected:
BOD5 - 3 kg /1000 kg (3 lbs/1000 Ibs) anhydrous product
COD - 9 kg /1000 kg (9 lbs/1000 Ibs) anhydrous product
Suspended Solids - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs)
anhydrous product
Surfactant - 3 kg-/1000 kgs. (3 lbs/1000 Ibs) anhydrous
product
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 177
-------
Oil and Grease - 0.5 kg /1000 kg (0.5 lbs/1000 Ibs) an-
hydrous product
Level I Effluent Guideline Recommendations
On a thirty day average basis, the following parameter
levels are recommended:
BODs - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) anhydrous pro-
duct
COD - 0.9 kg /1000 kg (0.9 lbs/1000 Ibs) anhydrous pro-
duct
Suspended Solids - 0.03 kg /1000 kg (0.03 lbs/1000 Ibs)
anhydrous product
Surfactant - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) anhydrous
product
Oil and Grease - 0.05 kg /1000 kg (0.05 lbs/1000 Ibs) anhydrous
drous product
pH - 6 - 9
No additional allowance need be made for startup, shutdown
or upset conditions.
Level I Technology
Secondary biological treatment will adequately handle the
wastes from this process.
Rationale
As in other categories, there will be some occasions when
washouts will be required.
204 - SULFAMIC ACID SULFATION
General
Washouts are the only wastewater effluents from this pro-
cess.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 178
-------
Raw Waste Loading
The following raw waste loading is expected:
BODs - 3 kg /1000 kg (3 lbs/1000 Ibs) anhydrous product
COD - 9 kg /1000 kg (9 lbs/1000 Ibs) anhydrous product
Suspended Solids - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs)
anhydrous product
Surfactant - 3 kg /1000 kg (3 lbs/1000 Ibs) anhydrous
product
Oil and Grease - 0.5 kg /1000 kg (0.5 lbs/1000 Ibs) an-
hydrous product
Level I Effluent Guideline Recommendations
On a thirty day average basis, the following parameter
levels are recommended:
BODs - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) anhydrous pro-
duct
COD - 0.9 kg /1000 kg (0.9 lbs/1000 Ibs) anhydrous pro-
duct
Suspended Solids - 0.03 kg /1000 kg (0.03 lbs/1000 Ibs)
anhydrous product
Surfactant - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) anhydrous
product
Oil and Grease - 0.05 kg /1000 kg (0.05 lbs/1000 Ibs) an-
hydrous product
pH - 6 - 9
No startup, shutdown or upset allowance is recommended.
Level I Technology
In order to comply with these guidelines the operator would
be obliged to recycle the washwater rather than sewer it.
If the washwater can't be used, perhaps ethanol can be used
as the solvent, if it is also a part of the ultimate formu-
lation.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 179
-------
Rationale
This reaction is normally carried out in batches. Reason-
able housekeeping would permit the recycle via a holding
tank for most of the washwater. As in other processes,
this one can either accumulate unusable amounts of dilute
washwater or occasionally have off-specification material
to be disposed of. Unlike a large integrated plant, the
firm using this process is unlikely to have anywhere to
put it other than disposal.
205 - CHLOROSULFONIC ACID SULFATION
General
This specialized process is another route to a high qual-
ity surfactant produced uniquely under mild reaction con-
ditions. The by-product HC1 is a significant distinction
from other sulfonation processes. It is usually scrubbed
out in a caustic solution with the formation of salt or
dissolved in water for sale as muriatic acid.
Raw Waste Loading
The following values can be expected on a thirty day basis:
BODs - 3 kg /1000 kg (3 lbs/1000 Ibs) anhydrous product
COD - 9 kg /1000 kg (9 lbs/1000 Ibs) anhydrous product
Suspended Solids - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) an-
hydrous product
Surfactant - 3 kg /1000 kg (31bs/1000 Ibs) anhydrous pro-
duct
Oil and Grease - 0.5 kg /1000 kg (0.5 lbs/1000 Ibs) anhy-
drous product
Level I Effluent Guideline Recommendations
As a thirty day average the following parameter levels are
recommended:
BODs - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) anhydrous product
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
-------
COD - 0.90 kg /1000kg . (0.90 lbs/1000 Ibs) anhydrous product
Suspended Solids - 0.03 kg /1000 kg (0.03 lbs/1000 Ibs)
anhydrous product
Surfactant - 0.30 kg /1000 kg (0.30 lbs/1000 Ibs) anhysrous
product
Oil and Grease - O.OS kg /1000 kg (0.05 lbs/1000 Ibs) an-
hydrous product
pH - 6 - 9
No upsets, startup or shutdown allowances are recommended.
Level I Technology
This important, moderately used process is optimized to
the extent reasonably expected.
Rationale
The effluent washouts are minimal and the required loadings
reasonable in relationship to the other processes. Recycling
washouts can materially aid in meeting these guidelines.
Biological secondary treatment is adequate to handle the ex-
pected raw wasteload.
206 - NEUTRALIZATION OF SULFURIC ACID ESTERS AND SULFONIC ACIDS
General
Neutralization is the essential step which converts the sul-
fonic or sulfuric acids into neutral surfactants. It is a
potential source of some oil and grease generation due to
the possible hydrolysis of the sulfates. Occasional leaks
and spills around the pump, valves, etc., are the only ex-
pected source of wastewater contamination.
Raw Waste Loading
The following loadings can be expected:
BODs - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs) anhydrous product
COD - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) anhydrous product
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 181
-------
Suspended Solids - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) an-
hydrous product
Surfactant - 0.2 kg /1000 kg (0.2 lbs/1000 Ibs) anhydrous
product
Oil and Grease - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs) anhy-
drous product
Level I Effluent Guideline Recommendations
On a thirty day average basis the following parameter values
are recommended:
BOD5 - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs) anhydrous pro-
duct
COD - 0.03 kg./1000 kg (0.03 lbs/1000 Ibs) anhydrous pro-
duct
Suspended Solids - 0.03 kg /1000 kg (0.03 lbs/1000 Ibs)
anhydrous product
Surfactant - 0.02 kg /1000 kg (0.02 lbs/1000 Ibs) anhydrous
product
Oil and Grease - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs) anhy-
drous product
pH - 6 - 9
No startup, shutdown or upset allowances are recommended.
Level I Technology
This process step is quite simple and usually continuous
when in tandem with a continuous sulfonator. The biotreater
in secondary treatment processing can accommodate the load.
Recycle is probably the best way to eliminate waste loads.
Rationale
In a large volume operation of this type there will be oc-
casional inadvertent leaks of valve and pump packing, spills
due to maintenance disruption of piping, and occasional clean-
up to repair the equipment, all necessitating the generation
of dilute wastewater streams. These streams are usually too
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 182
-------
dilute for recycle back into the process, but by use of
small amounts of water, recycle is practical. By storage
and recycle some of this washout water could diminish the
problem and lead to product recovery later in the finish-
ing process.
207 - SPRAY DRIED DETERGENTS
General
This unit operation is one of the most critical - and the
largest - as well as the most important of the detergent
industry. Here, the final detergent particles are formed
which must have the appropriate physical characteristics
for solubility, packaging and storage.
Tower cleanliness is essential so that degradation pro-
ducts or material significantly different, made in an
earlier run, do not contaminate the currently processed
product. In such a case, the spray tower is put through
a multi-stage, thorough cleaning process.
After the large dry "chunks" of adhering detergent are
knocked down by hand, the tower walls are abraded. Fi-
nally, water is played over the surface to finish the
cleaning process. The frequency of tower "turnaround"
varies considerably in practice. Some towers operate
for many weeks before shutdown and washing. Others may
have a tower changeover sixteen times in a given month.
In many cases there are product changeovers made on-the-
fly requiring neither stoppage of spray tower operation
nor cleanout.
Among many of the towers which have extended runs on one
product, there is minimal discharge as wastewater effluent.
All of the dry product is recycled or sent to solid waste
disposal. The washwater and scrubber water is all sent
back into the process and recycled to extinction.
There are numerous possible sources of water containing
contaminants originating in this process. They encompass
crutcher cleanouts, packaging equipment cleanouts, storage
area washouts, vent scrubbers, etc.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 183
-------
Characteristics of the exit air coming out of the spray
tower are largely determined by the composition of the
detergent formulation being dried. The increasing use of
alcohol sulfates and ethoxylated alcohols as active in-
gredients has increased plume generation in this air stream
which is not effectively eliminated by mechanical and elec-
trostatic methods without a significant volume of scrubber
water being employed.
The total volume of scrubber water and washouts becomes
too great to be recycled to extinction in some spray tower
operations when they have to meet source air standards.
Consequently, some wastewater is expected to be sent to the
sewer under these conditions.
A similar problem is faced by those who operate spray towers
on a fast turnaround basis. They end up with much more wash-
out wastewater than they can handle via recycle.
In both cases cited above, the other immediately apparent al-
ternative is to reuse all of the water, forcing the solids
concentration of the tower slurry from around 70% to some
lower value. This is not a suitable alternative, particu-
larly from an environmental viewpoint, since excessive energy
consumption would be required to drive off the additional
water.
Raw Waste Loading
Under normal spray tower operation, a thirty day average raw
waste loading can be expected to reach:
BOD5 - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs) anhydrous product
COD - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) anhydrous product
Suspended Solids - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs) anhy-
drous product
Surfactant - 0.2 kg /1000 kg (0.2 lbs/1000 Ibs) anhydrous
product
In towers facing particularly stringent air quality standards,
the following wastewater loadings can be expected:
- 0.8 kg /1000 kg (0.8 lbs/1000 Ibs) anhydrous deter-
gent
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 184
-------
COD - 2.5 kg /1000 kg (2.5 lbs/1000 Ibs) anhydrous deter-
gent
Suspended Solids - 1.0 kg /1000 kg (1.0 lbs/1000 Ibs) an-
hydrous detergent
Surfactant - 1.5 kg /1000 kg (1.5 lbs/1000 Ibs) anhydrous
detergent
Oil and Grease - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) anhy-
drous detergent
In spray towers having fast turnarounds, as well as strin-
gent air quality standards, the following wastewater load-
ings can be expected:
BOD5 - 2.0 kg /1000 kg (2.0 lbs/1000 Ibs) anhydrous deter-
gent
COD - 6.0 kg /1000 kg (6.0 lbs/1000 Ibs) anhydrous deter-
gent
Suspended Solids - 2.0 kg /1000 kg (2.0 lbs/1000 Ibs) an-
hydrous detergent
Surfactant - 4.0 kg /1000 kg (4.0 lbs/1000 Ibs) anhydrous
detergent
Oil and Grease - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) anhy-
drous detergent
Level I Effluent Guideline Recommendations
For normal spray tower operation the following thirty day
average parameter values are recommended:
BOD5 - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs) anhydrous pro-
duct
COD - 0.03 kg /1000 kg (0.03 lbs/1000 Ibs) anhydrous pro-
duct
Suspended Solids - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs)
anhydrous product
Surfactant - 0.02 kg /1000 kg (0.02 lbs/1000 Ibs) anhydrous
product
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 185
-------
pH - 6 - 9
No special startup, shutdown or upset allowances are recom-
mended .
For spray towers operating under stringent air quality stan-
dards » the thirty day average parameter loading guideline
recommendations are:
BOD5 - 0.08 kg /1000 kg (0.08 lbs/1000 Ibs) anhydrous de-
tergent
COD - 0.25 kg /1000 kg (0.25 lbs/1000 Ibs) anhydrous deter-
gent
Suspended Solids - 0.10 kg /1000 kg (0.10 lbs/1000 Ibs) an-
hydrous detergent
Surfactant - 0.15 kg /1000 kg (0.15 lbs/1000 Ibs) anhydrous
detergent
Oil and Grease - 0.03 kg. /1000 kg (0.03 lbs/1000 Ibs) anhy-
drous detergent
pH - 6 - 9
And, for spray tower operation with fast turnaround (an
average of twelve turnarounds per month):
BOD5 - 0.20 kg /1000 kg (0.20 lbs/1000 Ibs) anhydrous sur-
factant
COD - 0.60 kg /1000 kg (0.60 lbs/1000 Ibs) anhydrous surfac-
tant
Suspended Solids - 0.20 kg /1000 kg (0.20 lbs/1000 Ibs) an-
hydrous surfactant
Surfactant - 0.40 kg /1000 kg (0.40 lbs/1000 Ibs) anhydrous
surfactant
Oil and Grease - 0.03 kg /1000 kg (0.03 lbs/1000 Ibs) anhy-
drous surfactant
pH - 6 - 9
No special startup, shutdown or upset allowances are recom-
mended. None of these guideline recommendations are to be
construed as being additive.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 186
-------
Level I Technology
It is expected that the levels of effluent constituents
can be met readily if the equivalent of cyclone scrubbers
are used before electrostatic precipitators in the air
stream exiting from the spray tower. Since the function
of the water scrubbing is to chill the air as well as re-
move particulate matter, a significant step toward re-
duced effluent loading can be taken by substituting re-
turned cooled recycle water for that used on a once through
basis.
With the water recycled, a sufficient concentration can be
built up in the water flow to make return to the detergent
making process possible. Foaming is avoided by maintain-
ing the surfactant concentration at a sufficiently high
level in the recycled scrubber water.
Ultimately, the secondary biotreater will have no diffi-
culty processing the waste load from the spray tower area.
Rationale
The demands for clean air and clean water come into con-
flict in spray tower operation. In order to meet the in-
creasingly tighter air pollution regulations while produ-
cing products which are more environmentally compatible,
tower operation problems develop. These newer formula-
tions contain increasing amounts of nonionic surfactants
which are prone to produce an aerosol plume that persists
in the exit tower gas.
A system of dry cyclone dust collectors followed by an e-
lectrostatic precipitator is suitable for removing the par-
ticulate matter present, but it does not influence the
plume since it is a vapor.
By inserting a wet scrubber in between the cyclone dust col-
lector and the electrostatic precipitator the particulate
matter is further reduced and the organic aerosol vapors
are condensed so that they can then be removed by the elec-
trostatic preceipitator.
Introduction of this scrubber water flow now converts a po-
tential air contamination into a contaminated wastewater
problem. Since the materials removed in the scrubber are
biodegradable and essentially the same product as that which
is put into our sanitary sewers throughout the country, this
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 187
-------
is a satisfactory method of minimizing the environmental
impact.
Additional study is needed in this area, particularly con-
cerning the economics of installing sufficient tankage to
enable the fast turnaround towers to approach total recycle
must be explored.
208 - LIQUID DETERGENT MANUFACTURE
General
There are numerous liquid detergent products made and it is
likely that they are going to become more abundant as more
emphasis is placed upon non-phosphate products. Many pro-
ducts, including heavy duty detergents, are more amenable
to convenient use and manufacture in the liquid form than
as a dry powder.
The title 'liquid detergents' embraces a large variety of
formulations which fulfill an equally large spectrum of
uses. The ingredients used to formulate the products have
a wide response to such tests as BOD5. Consequently, the
statement of any single raw waste loading could cause a
significant problem to a given manufacturer.
In the process of preparing the liquid detergent, there
are two main sources of wastewater effluent; from mixing
equipment and distribution system washouts, and filling e-
quipment cleanup. Most operators recycle as much diluted
product as possible, but, as in the case of spray tower
operation, the total water volume cannot be economically
recycled to extinction.
Raw Waste Loading
On a thirty day average basis, the following raw waste
loadings will be experienced:
BOD5 - 2 kg /1000 kg (2 lbs/1000 Ibs) anhydrous detergent
COD - 4 kg /1000 kg (4 lbs/1000 Ibs) anhydrous detergent
Surfactant - 1.3 kg-/1000 kg (1.3 lbs/1000 Ibs) anhydrous
detergent
However, when observing smaller firms, the raw waste load-
ings may get to:
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 188
-------
BODs - 5 kg /1000 kg (5 lbs/1000 Ibs) anhydrous product
COD - 7 kg /1000 kg (7 lbs/1000 Ibs) anhydrous product
Surfactant - 3.3 kg /1000 kg (3.3 lbs/1000 Ibs) anhydrous
product
This latter case is associated with the high use of common
transfer lines for moving the product to filling lines,
losses resulting from breaking hose connections and rela-
tively short filling runs.
Level I Effluent Guideline Recommendations
On a thirty day average basis, the following parameter
levels are recommended:
BOD5 - 0.2 kg /1000 kg (0.2 lbs/1000 Ibs) anhydrous deter-
gent
COD - 0.4 kg /1000 kg (0.4 lbs/1000 Ibs) anhydrous deter-
gent
Surfactant - 0.13 kg /1000 kg (0.13 lbs/1000 Ibs) anhy-
drous detergent
pH - 6 - 9
There should be some accommodations made for the smaller
operator where his loadings are marginally greater than
those shown. Another exception which should be noted is
that the COD/BOD5 ratio may rise to 5:1 or more due to
the use of some relatively bio-hard industrial cleaner
ingredients such as orthodichlorobenzene, hydrochloric
acid, or chromic acid. Such compounds can upset the biota
in BOD5 tests, as well as giving a refractory residue. No
allowance need be made for the suspended solids or oil and
grease since the products marketed are normally clear, fil-
tered fluids, devoid of suspended particles.
Level I Technology
Secondary biological treatment will adequately handle the
wastewater effluents from this process.
Rationale
With an industry very much aware of market demands, there
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 189
-------
will be a continually changing array of formulations to
meet new consumer preferences and environmental perfor-
mance demands. There are generally two different markets
for liquid detergents; household and industrial. In this
latter market, many moderately sized operators supply a
wide variety of special purpose detergents to meet very
specialized needs. Often fairly "exotic" materials are
used.
Being relatively small, these operators do not have the
flexibility of operation of the large manufacturers. This,
coupled with numerous small batches of product, creates
special wastewater problems, since there is no place to
hold or recycle numerous, varied spills, leaks and wash-
outs. The cut-off point in allowances becomes critical,
then, since it could have severe economic consequences
for some manufacturers. There are other special problems
relating to analytical results of effluent evaluations.
Due to the wide variety of products used in liquid for-
mulations , fully acclimated cultures may net be available
for gaining results which reflect the actual technical
conditions.
209 - DRY DETERGENT BLENDING
General
Many different dry detergent blends are made for a multi-
plicity of industrial uses. The product is usually mar-
keted in drums.
The customary practice is for many successive batches to
be made in a given mixer before a wet washdown is required.
Raw Waste Loading
An average thirty day wastewater loading would be:
BODs - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs) anhydrous pro-
duct
COD - C.5 kg ./10CO kg (0.5 lbs/1000 Ibs) anhydrous product
Suspended Solids - C.I kg /10CO kg (0.1 lbs/1000 lus) an-
hydrous product
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 19Q
-------
Surfactant - 0.1 kg /1000 kg (0.1 lbs/1000 ibs) anhydrous
product
Level I Effluent Guideline Recommendations
Based upon a ttiircy day average, the recommendations of
parameter loadings are:
BODs - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs) anhydrous pro-
duct
COD - 0.05 kg /1000 kg (0.05 lbs/1000 Ibs) anhydrous pro-
duct
Suspended Solids - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs)
anhydrous product
Surfactant - 0.01 kg-/1000 kg- (0.01 lbs/1000 Ibs) anhy-
drous product
pH - 6 - 9
No additional allowance need be made for startup, shutdown,
or upsets.
Level I Technology
Biological secondary treatment is adequate for the efflu-
ent involved.
Rationale
A wide variety of materials are formulated dry. Although
little water is used, that which is required for the in-
frequent washings is critical. It will be very dilute and
diverse in content, unsuitable for recycling.
210 - DRUM DRIED DETERGENTS
General
This well established process produces no effluent, but
some provision must be made for those periods of mandatory
washdown due to equipment failure or critical formulation
change.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
191
-------
Raw Waste Loading
The average raw waste load which could be expected is:
BOD5 - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs) anhydrous pro-
duct
COD - 0.3 kg /1000 kg (0.3 lbs/1000 Ibs) anhydrous pro-
duct
Suspended Solids - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs)
anhydrous product
Surfactant - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs) anhy-
drous product
Oil and Grease - 0.1 kg /1000 kg (0.1 lbs/1000 Ibs) an-
hydrous product
Level I Effluent Guideline Recommendations
On a thirty day average basis, the following parameter
levels are recommended:
BODs - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs) anhydrous
product
COD - 0.03 kg /1000 kg (0.03 lbs/1000 Ibs) anhydrous
product
Suspended Solids - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs)
anhydrous product
Surfactant - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs) anhy-
drous product
Oil and Grease - 0.01 kg /1000 kg (0.01 lbs/1000 Ibs) an-
hydrous product
pH - 6 - 9
No startup, shutdown or upset allowances are required.
Due to the low values recommended, a total of three times
the average should be allowed over any 24 hour period as
long as over any thirty day period the guidelines are main-
tained.
Level I Technology
Secondary biological treatment can adequately handle the
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
192
-------
constituents.
Rationale
Even though the process is essentially dry, the slurry pans
and other equipment will require an infrequent but necessary
and thorough washout.
211 - DETERGENT BARS AND CAKES
General
In the manufacture of detergent bars there is need for me-
ticulous cleaning of equipment to insure that any product
which may have been degraded due to adhering to hot process
equipment is removed and disposed of.
The approximately 160 million pounds of synthetic toilet bar
soap used in the U.S. is significant, yet modest when com-
pared to the 600 million pounds of 'natural' soap used in
toilet bars.
Raw Waste Loading
The following raw waste load can be expected:
BODs - 7 kg /1000 kg (7 lbs/1000 Ibs) anhydrous product
COD - 22 kg /1000 kg (22 lbs/1000 Ibs) anhydrous product
Suspended Solids - 2 kg /1000 kg (2 lbs/1000 Ibs) anhy-
drous product
Surfactant - 5 kg /1000 kg (5 lbs/1000 Ibs) anhydrous
product
Oil and Grease - 0.2 kg /1000 kg (0.2 lbs/1000 Ibs) anhy-
drous product
Level I Effluent Guideline Recommendations
On the basis of a thirty day average, the following para-
meter levels are recommended:
BOD5 - 0.7 kg /1000 kg (0.7 lbs/1000 Ibs) anhydrous pro-
duct
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 193
-------
COD - 2.2 kg /1000 kg (2.2 lbs/1000 Ibs) anhydrous product
Suspended Solids - 0.2 kg /1000 kg (0.2 lbs/1000 Ibs) an-
hydrous product
Oil and Grease - 0.02 kg /1000 kg
hydrous product
pH - 7 - 9
(0.02 lbs/1000 Ibs) an-
No additional allowance is recommended for startup, shut-
down or upsets. During any thirty day period an allowance
of three times the average should be allowed over a 24 hour
duration, provided that throughout the entire thirty day
period the thirty day average is not exceeded.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
194
-------
102 - FATTY ACID HYDROGENATION
General
As an example of the depth to which some technological stud-
ies have been conducted, the details of fatty acid hydrogen-
ation processing are presented. Due to the advanced state of
the art, guidelines recommended are to cover levels I, II
and III.
Technology for Levels I. II, III
Hydrogenation of fatty acids intended for soap manufacture
is regarded as an additive effluent loading to the fat
splitting operation.
The principal raw materials for the manufacture of fatty
acids used in soap making are coco and tallow fats. These
are generally used in the ratio of about 80% tallow fatty
acids to 207o coco fatty acids in soap making.
This blend contains in the order of 157, of the mono-unsaturated
oleic acid and around 3 - 4% of the doubly unsaturated linoleic
acid. There is very little of the triply unsaturated lino-
lenic acid. 20% unsaturated fatty acids in soap is often
excessive, consequently the tallow portion of the fatty acids
going into soap manufacture are partially hydrogenated. This
is particularly necessary since tallow contains up to 50%
oleic acid esters and as much as 3% linoleic esters.
The usual process of making fatty acids and the hydrogenation
of them is given in the schematic flow diagram 102. The
hydrogenation process is usually carried out batch wise parti-
cularly for fatty acids destined for soap making.
The hydrogen source for this process depends upon plant loca-
tion. When near a petroleum refinery the hydrogen is often
available from cracking operations and subsequently requires
purification. Hydrogen is also available from electrolytic
cells dedicated to electrolysis of salt for sodium and
chlorine.
Another common source of hydrogen is that from the de-
hydrogenation of isopropyl alcohol to make acetone. What-
ever the source of hydrogen there will usually be some
alkane impurities that will build up in the recycle use of
hydrogen, consequently, a bleed is necessary which is usually
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 195
-------
disposed of by burning. This disposition carries no water
effluent and consequently is disregarded in the guidelines.
The hydrogenation process requires a catalyst. There are
two v^e 11-known catalyst systems. One involves the deposi-
tion of nickel as nickel formate onto a pumice or kiesselguhr
or a synthetic product such as Celite. The other commonly
used catalyst is Raney-nickel. Both catalysts are usually
suspended in the liquid to be hydrogenated and subsequently
filtered out. When Raney-nickel is used, the spent catalyst
is often recovered and returned to the manufacturer for
reprocessing.
Complete saturation of the fatty acids is not desirable since
a modest amount of cross linking by oxidation helps to make
a firm soap and gives the bar good feel or hand. Though not
strictly true, the hydrogenation of coco and tallow fatty
acids is described as if the same in nature.
Hydrogenation is usually carried out with the catalyst sus-
pended in the liquid fatty acids in a batch process heated
to a temperature of approximately 175 - 200°C (347 - 392°F)
as the hydrogen passes through the reactor. When the degree
of saturation desired is achieved (as measured by Iodine
number) the reaction is terminated. Recovered hydrogen is
removed and sent back to storage via a booster system.
During the hydrogenation process a number of side reactions
occur, some of which cause significant wastewater effluent
contamination. Isomerization of the double bond along the
chain does not cause any difficulty, however, occasional
chain scission occurs resulting in the formation of short
chain length olefins and short chain fatty acids not desirable
in the soap making process. As a result of the fatty acid
pre-heating prior to hydrogenation there is a tendency for
some oxidative cross linking to occur resulting in a modest
amount of polimerized fatty acids. Storage of the fatty acids
at high temperatures also accelerate this polymerization
reaction. None of these undesirable reactions result in
added wastewater contamination.
The same raw waste loadings can be expected for Levels I,
II and III technology.
Raw Waste Loadings - Levels I, II and III
The following raw waste loadings are expected:
BOD5 - 1.5 kg /1000 kg (1.5 lbs/1000 Ibs) anhydrous acid
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 196
-------
COD - 2.5 kg /1000 kg (2.5 lbs/1000 Ibs) anhydrous acid
Suspended Solids - 1.0 kg /1000 kg (1.0 lbs/1000 Ibs)
anhydrous acid
Oil and Grease - 1.0 kg /1000 kg (1.0 lbs/1000 Ibs)
anhydrous acid
Levels I. II and III Effluent Guidline Recommendations
On a thirty day average basis, the following guidelines are
recommended:
BOD5 - 0.15 kg /1000 kg (0.15 lbs/1000 Ibs) anhydrous acid
COD - 0.25 kg /1000 kg (0.25 lbs/1000 Ibs) anhydrous acid
Suspended Solids - 0.10 kg /1000 kg (0.10 lbs/1000 Ibs)
anhydrous acid
Oil and Grease - 0.10 kg /1000 kg (0.10 lbs/1000 Ibs)
anhydrous acid
pH 6 - 9
Rationale and Assumptions
It may be noted that hydrogenation steps in the manufacture
of fatty acids from fats is considered as a supplemental
allowance in view of the occasional use of this process in
the general manufacturing system for soap manufacture. The
levels of effluents suggested and their nature have been
outlined above, based upon a reasonable allowance by careful
practice of the art of hydrogenation and by careful control
and maximum recovery of effluent streams. There is no parti-
cular discernible additional investment or anything signifi-
cant in the way of capital requirements or of utility and
power requirements that would be more than marginal for this
entire Level I, II and III guideline addition.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
197
-------
198
-------
SECTION X
BEST AVAILABLE TECHNOLOGY
ECONOMICALLY ACHIEVABLE
INTRODUCTION
Level II technology is expected to involve both improvement
in the manufacturing process as well as adoption of the best
available treatment technology that is within reason econom-
ically.
Not all of the processes identified in Level I are expected
to perform with less effluent by 1983. Those which are
anticipated to have lower effluent loadings have an explan-
ation given in this Section.
A quick glance at the following tables of Level II Guidelines
will inform the reader which values have changed.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
199
-------
o
H
Level II Guideline Recommendations
Note: All values reported are in kgs/1000 kgs (lbs/1000 Ibs) of anhydrous product made
in that category. For all categories the guideline pH is 6 - 9.
101* Batch Kettle Soap
BOD5 COD Suspended Solids
0.40 0.70 0.40
Surfactant
Oil & Grease
0.05
o
o
102* Fatty Acid By Fat
Splitting
103@ Soap From Fatty
Acid Neutrali-
zation
104* Glycerine Recovery
A. Concentration
B. Distillation
105@ Soap Flakes And
Powders
106* Bar Soaps
107@ Liquid Soap
0.25 0.60
0.01 0.03
0.40
0.30
0.01
0.20
0.01
0.80
0.60
0.03
0.40
0.03
0.20
0.02
0.10
0.04
0.01
0.34
0.01
0.15
0.01
0.04
0.02
0.01
0.03
0.01
@ Denotes guidelines are identical with those established in Level I. Same conditions
and limits apply.
* Denotes a change in guidelines from Level I and are treated at length in this section.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION IN THIS REPORT AND ARE
SUBJECT TO CHANGE BASED UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
-------
ro
o
201@ Oleum Sulfation/
Sulfonation
202* Air-S03 Sulfation/
Sulfonation
Level II Guideline Recommendations (cont.)
BOD_ COD Suspended Solids Surfactant Oil & Grease
0.02 0.06
0.19 0.37
203@ S03 Solvent and
Vacuum Sulfonation 0.10 0.30
204* Sulfamic Acid
Sulfation
205* Chlorosulfonic
Acid Sulfation
206@ Neutralization
Of Acids
207* Spray Dried
Detergents
208* Liquid Detergents
209@ Detergent Dry
Blending
210@ Drum Dried
Detergents
211* Detergent Bars
and Cakes
0.10 0.30
0.15 0.50
0.01 0.03
0.10 0.27
0.05 0.15
0.01 0.05
0.01 0.03
0.30 0.90
0.03
0.02
0.01
0.01
0.02
0.03
0.12
0.01
0.01
0.03
0.18
0.10
0.10
0.15
0.02
0.17
0.05
0.01
0.01
0.07
0.04
0.02
0.02
0.03
0.01
0.05
0.01
0.10
0.20
0.02
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION IN THIS REPORT AND ARE
SUBJECT TO CHANGE BASED UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
-------
101 - MODIFIED SOAP MANUFACTURE BY BATCH KETTLE
Level II Technology and Rationale
A significant reduction of wastewater contamination volume
can be made in the fat pretreatment step of kettle boiling
soap manufacture by replacing the barometric condenser used
in vacuum bleaching by a surface condenser.
Prior to being fed into the soap boiling operation, fats
are frequently refined, which generally consists of two
successive operations. The first step involves treating
the fats lightly with caustic soda to remove low molecular
weight fatty acids present in the crude fat.
Upon neutralization with acid the nonsaponifiables and high
molecular weight, highly unsaturated fatty acids are removed
by clay treatment. The unsaturated acids are prone to form
color bodies during soap manufacture. After this treatment
the fats are often vacuum bleached, thus removing very high
boiling unsaponifiables.
The vacuum flashing also serves to remove some very high
boiling unsaturated fatty acids, as well as the phyto or
chole sterols, especially those in tallow.
The best already available technology, which appears eco-
nomically achievable, suggests that an important elimination
of water effluent waste streams could be accomplished by the
substitution of a barometric condenser used in the vacuum
bleaching of the fats and oils, by replacement with a sur-
face condenser. This modification allows the fats, oils,
and the hydrolyzed fatty acids of low molecular weight, and
those containing color bodies, to be removed without con-
taminating much process feed water. These impurities could
be burned or further refined and disposed of for other uses.
While a one stages-vacuum surface condenser could be used, a
two stage condenser is preperred or at least a two pass con-
denser of an indirect feed exchange variety so that high
boiling materials could be eliminated from a leg in the
first or partial condenser.
It has been estimated that the capital cost of such a sur-
face condenser replacing the normally used barometric con-
denser would be about $2.12/1000 kg ($1.00/1000 Ibs) of soap
product. It is further estimated that this would increase the
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 2Q2
-------
SECTION X
LEVEL II TECHNOLOGY
101 - SOAP MANUFACTURE BY BATCH KETTLE : MODIFIED
mil RECEIVING
STORAGE-TRANSFER
ion FAT REFINING
AND BLEACHING
1013 SOAP BOILING
FATTY OILS
COCONUT. TALLOW
CAUSTIC SOD,
H,SO.
SALT
WATER
CAUSTIC
NEAT SOAP TO
PROCESSING
AND SALE
GLYCERINE TO
RECOVERY
,,». LOW GRADE SOAP
LOW GRADE
FATTY ACID
FIGURE 26
-------
utility cost, particularly in the form of cooling water
for the surface condenser (approximately doubling the
volume) and electricity for the vacuum pump to remove
fixed gases. At the standard utility values described
at the outset, this would cost no more than approximately
O.lc per pound or less of soap product, or approximately
$2.12/1000 kg ($1.00/1000 Ibs) of neat soap for these in-
creased utility requirements.
Raw Waste Loading
The expected raw waste load is:
BOD5 - 4 kg /1000 kg (4 Ibs/1000 Ibs) anhydrous soap
COD - 7 kg /1000 kg (7 lbs/1000 Ibs) anhydrous soap
Suspended Solids - 4 kg /1000 kg (4 lbs/1000 Ibs) anhy-
drous soap
Oil and Grease - 0.5 kg /1000 kg (0.5 lbs/1000 Ibs) an-
hydrous soap
Level TI Effluent Guideline Recommendations
BOD5 - 0.4 kg /1000 kg (0.4 lbs/1000 Ibs) anhydrous soap
COD - 0.7 kg /1000 kg (0.7 lbs/1000 Ibs) anhydrous soap
Suspended Solids - 0.4 kg /1000 kg (0.4 lbs/1000 Ibs) an-
hydrous soap
Oil and Grease - 0.05 kg /1000 kg (0.05 lbs/1000 Ibs) an-
hydrous soap
pH - 6 - 9
No special startup, shutdown or upset values are recommended.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 204
-------
102 - M - FATTY ACID MANUFACTURE BY FAT SPLITTING
- MODIFIED
Level II Technology and Rationale
Typical of the best operation is a plant utilizing high
temperatures and high pressures hydrolysis catalytically,
countercurrently. A continous countercurrent hydrolysis
at high temperatures is conducted in a tall column under
substantial pressure. Fresh water enters the top of the
column, which keeps the glycerine concentration low and
forces the remaining dilute upwelling fats to split. At
the same time the acqueous phase falling downward in the
column progressively increases in glycerine content, which
it extracts from the fat-rich upward moving stream.
This modern process achieves some 97 to 99% completion of
fats hydrolysis. The concentration of glycerine in the
acqueous phase flowing out the bottom of the column is in
the range of 18%. This high temperature operation enjoys
the advantage of high water solubility in the fatty phase
- much greater than it is at lower temperatures. As a
consequence the hydrolysis-hydration withinr.the fatty phase
is greatly facilitated. It should be remembered that this
is a reaction between two separate phases and a high degree
of agitation is important in achieving good boundary-layer
reactant diffusion and high yields.
Re f e'er ing to the schematic flow diagram 102, there is some
possibility of diminishing further the effluent streams from
this unit. This can be accomplished by in-process recycle
of the process condensate to the maximum extent possible
shown as 102322 stream on the flow diagram. Similarly, the
barometric condenser of the fatty acid distillation process
can be replaced with a surface condenser so that this stream
also can be totally recycled after fats recovery and fatty
acid separation.
There are two effluent streams from this process. One is
the very light volatile fatty acids which are not desired
in the process for fatty acid neutralization to make soaps
including small amounts of butyric, valeric and caproic acids
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 205
-------
SECTION X and SECTION XI
LEVEL] I TECHNOLOGY
and
LEVEL III TECHNOLOGY
102 Modified: FATTY ACID MANUFACTURE BY FAT SPLITTING
FATTY ACIDS
TO SALES.
NEUTRALIZATION
OR HVDROGENATION
ro
o
FIGURE 27
-------
SECTION t and XI
LEVEL II TECHNOLOGY
and
LEVEL III TECHNOLOGY
SCHEMATIC - 102-H: FATTY ACIDS MANUFACTURE : HYDROGENATION STEP, IF CARRIED OUT.
RECYCLE -<
TO:
DISTILLATION
OF FATTY ACIDS
Iss
O
FATTY ACIDS
FEED TO
HYDROGENATION
FROM:
102-M
PUMP
FROM
STORAGE
CATALYST
BED
OR
SUSPENDED
CATALYST
WITH
TRAYS
DEMISTER
COMPRESSOR
HYDROGEN:
FROM SUPPLIER
BLEED
IMPURITIES
TO SUPPLIER
OR VENT:
TO STACK
HYDROGENATED
FATTY ACIDS TO:
SALES OR
NEUTRALIZATION
HYDROGENATED
FATTY ACIDS
FILTER OR
CATALYST
PHASED
REMOVAL
SPENT
CATALYST
AND
POLYMERS
FIGURE 28
-------
This is an irreducible effluent unless these light fatty
acids can be sold or Otherwise burned or disposed of, other
than to a. water stream.
The other major process effluent is that of the spent catalyst.
If a zinc of tin soap is used as a catalyst, the distillation
column bottoms contains these ions, usually as their soluble
sulfate salts, if still bottoms are acidulated with the usftal
sulfuric acid. After fats separation and recovery, this acqueous
effluent constitutes an irreducible waste stream.
The principal source of BOD and COD wastes arises during the
fatty acid distillation where the unutilizable lower fatty
acids are produced and where in the current practice of
Level I, barometric condensers are usually employed. By
replacement of this barometric condenser with a surface
condenser, as described in other applications, it is estimated
that 80% if the useable fatty acids which would normally go
into a waste stream can be recovered and recycled along with
other process condensates back to the original fat splitting
reactor system. For this reason the deduction of biodegradables
is estimated to be achievable economically to the extent of
80%.
This replacement requires a vacuum pump and a surface
condenser. As a result, it is estimated that a capital cost
of approximately $2.12/1000 kg($1.00/1000 lbs)of fatty acids pro-
duced.is required. Steam use will be approximately the same as in
fatty'acid distillation by'the normal process; however,
cooling water will increase twofold. This is over that shown
in Level I technology. The electrical requirement for the
vacuum pump and/or steam for a jet ejector will increase the
total electrical or steam and electrical demands for this
process by no more than 207. over that for Level I.
It is expected that any unhydrolyzed fats will remain with
the fa$£y acids, sold or converted, in further steps to soap
by fatty acid neutralization and will not appear in an
effluent stream at this stage. However, as mentioned earlier,
the light unutilizable fatty acids, such as caproic, will have
to be either burned or discharged. An allowance has been made
for this in the above reccomendations.
For the 45 M kg/yr(100 M Ibs/yr)fatty acid plant optimum
size estdonated for process Schematic 102, the increased
cooling water cost will amount to approximately $10,000
per yearaand the increased electrical (and/or steam) usage
to approximately $7,000 per year.
NOTICE; THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 208
-------
Raw Waste Loadings
The following raw waste loadings can be expected.
BOD5 - 2.5kg /1,000kg (2.51bs/10001bs) ahydrous fatty acid
COD - 6.0kg /1000kg (6.01bs/100Qlibfr) ahydrous fatty acid
Suspended Solids - 2.0kg /1000kg (2.01bs/10001bs) ahydrous
fatty acid
Oil and Grease - 1.5kg /1000kg (1.51bs/10001bs) ahydrous
fatty acid
Level II Effluent Guideline Recommendation
The following 30 Day average parametric values are recommended.
BODs - 0.25kg /1000kg (6.25ifes/10001bs) ahydrous
COD - 0.60kg /1000kg (0.601bs/10001bs) ahydrous
Suspended Solids - 0.20kg /1000kg (0.201bs/10001bs) ahydrous
Oil and Grease - 0.15kg /1000kg (O.lSlbs/lOOOlbs) ahydrous
pH 6 - 9
No special allowances are recommended for startup shutdown
or upset.
103 - SOAP FROM FATTY ACID NEUTRALIZATION
This process has already achieved a point of minimum dis-
charge in level I so that the recommended guidelines are
the same as those in level I.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 209
-------
Level II Effluent Guideline Recommendations
On a thirty day average basis, the following parameter values
are recommended:
BOD5 - 0.01 kgs/1000 kgs (0.01 lbs/1000 Ibs) anhydrous soap
COD - 0.03 kgs/1000 kgs (0.03 lbs/1000 Ibs) anhydrous soap
Suspended Solids - 0.02 kgs/1000 kgs (0.02 lbs/1000 Ibs)
anhydrous soap
Oil and Grease - 0.01 kgs/1000 kgs (0.01 lbs/1000 Ibs)
anhydrous soap
pH 6 - 9
No special startup, shutdown or upset allowances are recom-
mended.
PROCESS 104 - GLYCERINE RECOVERY
Level II Technology and Rationale
With the modification of the barometric leg on both the gly-
cerine evaporation and glycerine distillation, an improve-
ment in the raw waste loading is expected.
Raw Waste Load
The following average raw waste load is expected:
Glycerine Evaporation
BOD5 - 4.0 kg/1000 kg (4.0 lbs/1000 Ibs) anhydrous glycerine
COD - 8.0 kg/1000 kg (8.0 lbs/1000 Ibs) anhydrous glycerine
Suspended Solids - 0.0 kg/1000 kg (IvO lbs/1000 Ibs) anhydrous
glycerine
Oil and Grease - 0.4 kg/1000 kg (0.4 lbs/1000 Ibs) anhydrous
glycerine
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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o
H
104 GLYCERINE RECOVERY
1041 RECEIVING
STORAGE TRANSFER
HU2 LYE TREATMENT
100 GLYCERINE EVAPORATION TO 80% CONCENTRATION
TREATED
,GLVCERINE
LIQUOR
« I . RECYCLE
80% GLYCERINE TO CONCENTRATOR
HEAVY ENDS TO FOOTS STILL
SOAP MAKING
SOLUTION MAKE-UP
FIGURE 29
-------
104-B: CONCENTRATION OF 80% GLYCERINE TO 99.5%
1044 GLYCERINE STILL
80SGLYCERINE
from 104 A
ro
STILL
HEAVY ENDS
from 104 A
GLYCERINE
FOOTS
104423
\
i
SOLID WASTE
t044O9
FOOTS STILL
FOOTS TO FLARE
OR WASH TO SEWER
REFINED GLYCERINE
995XGLVCERINE
TO SALES
HEAVY ENDS TO
FOOTS STILL
WASH I LIQUID
BLEED: TO FLARE
FIGURE 30
RECYCLE SALT TO.
SOAP MAKING
RECYCLE CAUSTIC
TO: SOAP MAKING
-------
Glycerine Distillation
BOD5 - 3.0 kg/1000 kg (3.0 lbs/1000 Ibs) anhydrous glycerine
COD - 6.0 kg/1000 kg (6.0 lbs/1000 Ibs) anhydrous glycerine
Suspended Solids - 0.4 kg/1000 kg (0.4 lbs/1000 Ibs) anhydrous
glycerine
Oil and Grease - 0.2 kg/1000 kg (0.2 lbs/1000 Ibs) anhydrous
glycerine
Level II Effluent Guideline Recommendations
Please refer to Guidelines Table at beginning of Section.
PROCESS 106 - BAR SOAPS
Level II Technology and Rationale
By 1983 there is an expectancy that the current relatively
high BOD processes will more closely match those operations
which now are enjoying very low discharge.
Raw Waste Load
The following average raw waste load is expected:
BOD5 - 2.0 kg/1000 kg (2.0 lbs/1000 Ibs) anhydrous soap
COD - 4.0 kg/1000 kg (4.0 lbs/1000 Ibs) anhydrous soap
Suspended Solids - 3.4 kg/1000 kg (3.4 lbs/1000 Ibs) anhydrous
soap
Oil and Grease - 0.3 kg/1000 kg (0.3 lbs/1000 Ibs) anhydrous
soap
Level II Effluent Guideline Recommendations
Please refer to Guidelines Table at beginning of Section.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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201 - OLEUM SULFATION AND SULFONATION
Level II Technology
The following analysis of the use of oleum is outlined to
give stimulus to thought and action toward incremental im-
provement by reduction of effluent wastes. The subject is
treated by discussing first sulfonation, then sulfation.
Guidelines established in Level I are reasonably low. In
existing plants they may not be lowered practicably, con-
sequently the Level I guidelines are repeated for Level II.
Sulfonation
This reaction can best be carried out in three stages for
Level II technology in order to minimize non-reacted and
to minimize the reversion of the sulfonic acids produced.
Whether batch or a continuous reactor system is used, it is
important to have counter-current flow of the oleum feed and
of the alkyl benzene feed streams, withdrawing the product
sulfonic acid stream from a stage, or position in a continu-
ous reactor, one removed from the oleum inlet stage.
The purpose of this system is achieved by distributing the
heat of reaction and resultant temperature rise uniformly
throughout the film surface for heat transfer to the cooling
water side.
The first step of this reaction is the sulfonation reaction
itself to produce the sulfonic acid of an alkyl-benzene with
the concommitant production of sulfuric acid of circa 96%
concentration.
This can be neutralized directly in a second step; however,
generally, a preferred method of reaction is to first dilute,
with water, the product of the reaction from the first re-
action step, to an approximately 75-8070 sulfuric acid con-
centration. At this concentration the inter-solubility of
the sulfonic acids and the sulfuric acids phases are minimal.
Therefore, a phase separation can be achieved to produce a
sulfonic acid concentration of an alkyl-aromatic in the or-
der of 88% sulfonic acid and 1270 sulfuric acid; whereas the
sulfuric acid phase will have a concentration averaging about
77.5% sulfuric acid.
The value of this optional step is to reduce the amount of
sodium sulfate, inorganic salts, that would otherwise occur
on direct neutralization of the sulfonic acids. Moreover,
the sulfonic acid concentration is increased so that a more
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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o
H
SECTION X and XI
LEVEL II TECHNOLOGY
and
LEVEL III TECHNOLOGY
SCHEMATIC FLOW DIAGRAM - 201 and 206
CONTINUOUS DETERGENT SLURRY PROCESSING PLANT
HIGH-ACTIVE ALKYLATE SULFONATION WITH OLEUM : FEED A_
LOWNa2SO4 CONTENT
REACTION
COIL
Modified 201-A" SULFONATION
ALKYL BENZENE
FROM STORAGE
Cooling
Water
I
SULFONATION
COOLER
PROPORTIONING
PUMP
WATER-
COOLED
MIXING
PUMP
Cooling f
Water —"'
SETTLER
DILUTION
COOLER
OLEUM
FROM
STORAGE
WATER
I
I
SPENT
ACID
MIXING
PUMP
206-A: Neutralization
NEUTRALIZED
DETERGENT
SLURRY
Cooling
Water
NEUTRALIZATION
.COOLER
Water Cooled
MIXING
PUMP
ALKALI
FIGURE 31
-------
SCHEMATIC FLOW DIAGRAM— 201 MODIFIED
CONTINUOUS DETERGENT SLURRY PROCESSING PLANT
FATTY ALCOHOL SULFATION WITH OLEUM : FEEDS B and C
FATTY ALCOHOL
FROM STORAGE
OLEUM
FROM
STORAGE
PROPORTIONING
PUMP
MIXING
PUMP
T
NEUTRALIZED
->• DETERGENT
SLURRY
NEUTRALIZATION
COOLER
MIXING
PUMP
Cooling
Water
ALKALI
Modified: 201-B and C : SULFATION
201-B and C : NEUTRALIZATION
to
FIGURE 32
-------
concentrated product can be produced, with less sodium sul-
fate, therefore giving the detergent manufacturer an added
flexibility. This also permits a reduction of the sulfuric
acid concentration levels and its better utilization in
this reaction; and, consequently, a lower acid loading to
a concentrator or an oleum makeup facility.
The third step of the reaction is the neutralization of the
sulfonic acid separated phase, in the optional system, or
the neutralization of the entire product from the first re-
action stage. This is accomplished either with caustic soda,
potassium hydroxide or other alkali cations desired or ac-
ceptable in the finished detergent.
The above three reactions are carried out separately. The
first reaction, of the sulfonation proper, can be carried
out at a temperature range of 104°F up to 140°F (40°C up to
60°C) and with a residence time of from 30 minutes to three
hours, the latter particularly with counter-current flow of
reactants, even in a batch system arrangement. The second
reaction step, optional, requires a dilution which can be
essentially a pump system for mixing - dilution. Then ap-
proximately 10 to fifteen minutes is required for total sep-
aration of the sulfonic acid layer from the sulfuric acid
layer. In step two, the neutralization with an alkali, this
can be done in a mixing pump and requires fewer than 2 or 3
minutes. However,again, cooling must be adequate and is ac-
complished by a cooler in the circuit and a recycle stream
through the water-cooled mixing pump.
Since the sulfonic acid produced is in equilibrium with the
feed reactants, it is truly a reversible reaction, so that
quick neutralization is required. This also has the advan-
tage of minimizing the disproportionation of the alkyl group
on the aromatic and also the isomerization from the usual
para position to considerably more of the ortho and meta sub-
stitution products.
Sulfation
The reaction of 803, whether from oleum or 863 as a gas or
liquid, with alcohols or ethoxylated alcohols or ethoxylated
phenols, results in a sulfation reaction rather than the for-
mation of a sulfonic acid. The sulfation reaction, in the
case of fatty alcohols, produces sulfate esters, or, in the
case of the ethoxylated fatty alcohols, the ethoxylated sul-
fate ester.
The quality of the final product in this reaction can be con-
siderably enhanced by first treating the feed alcohols by
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
217
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solvent extraction to remove impurities, or to carry out a
stripping reaction to remove low boiling point impurities;
or, a combination of these pretreatment steps can be usefully
employed to obtain higher quality and higher yield.
This reaction too, like the sulfonic acid reaction described
for step one, is also reversible; but, because the concen-
tration of the spent sulfuric acid in sulfation can be
brought to a lower level, there is less loss from reversion
of the equilibrium attained in the reaction. Further, im-
mediate neutralization is carried out to minimize reversion
losses, but this does result in a high concentration of so-
dium sulfate, inorganic salt, in the detergent product. Li-
quid NH40H, KOH, or alkyl amine may be optionally used as
neutralizing reactants, to minimize sodium ions. For this
reason, an improvement, whether batch or continuous operation
is employed, is to have a staged reaction, in which the feed
of the alcohol or ethoxylated alcohol, and the oleum sulfa-
tion reactant are introduced at opposite stages of a train
or system.
One of the other ways to minimize the amount of sodium sul-
fate salt produced in the neutralization step, is to use so-
dium bi-carbonate or in company with solid carbon dioxide
(dry ice) as the neutralizing agent. This is claimed to re-
sult in a detergent product which is almost of a white color.
The reaction conditions in the sulfation process are similar
to that in sulfonation except that they are less severe in
temperature rise and control and in time requirements. How-
everv since these two different products are generally made
in the same unit, this has no important effect on capital or
operating cost savings per se.
For Level II technology, we are not assuming that a great im-
provement is possible over those suggested for Level I ef-
fluent waste loadings. Principally, better purification of
feed products and a counter-current system of either a batch
or a continuous reaction process does give a minimization of
effluent, particularly in the way of unreacted feed reactants
going to an effluent. A further improvement, requiring the
use of 803 rather than oleum, is covered by Schematic 202.
Level II effluent guideline recommendations remain the same
as Level I.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
218
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202 - AIR - SOq SULFATION AND SULFONATION
With the expectation that intensive dialogue will aid in
incorporating improvements to currently practiced proces-
ses, the following detailed analysis is offered.
When vapor phase sulfur trioxide is used in sulfonation
and sulration processes, regardless of whether or not the
vapor S03 is diluted with nitrogen or air , three distinct
tyjpes of feed and reactions for the application of sulfur
trioxide need to be considered. The three feed stocks in-
volved are 1) alkyl benzenes; 2) alpha or branched chain,
olefins; and 3) the sulfation of lauryl alcohol or other
fatty alcohols to produce a lauryl fatty and/or ethoxylated
alcohol sulfuric acid. A sulfonic acid is the product of
the reaction of sulfur trioxide with feed stocks 1) and 2).
The sulfur trioxide used in these three processes using dif-
ferent reactants may be prepared in three different ways.
Although other methods of preparation are also possible,
the following are those used commercially. The first pro-
cess for producing sulfur trioxide is that of sulfur burn-
ing. In this process a liquid sulfur is vaporized and burned,
usually in two stages, with air to form a sulfur trioxide-
air mixture which can be fed directly in vapor form to the
sulfonation/sulfation unit.
Another source of sulfur trioxide is that derived from high
strength oleum. In this process, 2), 65 - 7070 oleum is the
purchased feed component. It is heated in a reboiler opera-
tion to produce anhydrous vapor SO^, as the concentration of
the oleum is reduced to a 20% or even a lower level. The
863 vapor is then diluted with air or nitrogen as the feed
stream to the reactor. The sulfuric acid remaining is then
sold or transferred to a sulfuric acid manufacturer for re-
constitution to the higher 65 - 70% oleum level.
A third way of obtaining sulfur trioxide is by purchasing
stabilized liquid sulfur trioxide. This source of sulfur
trioxide, 3), can be brought in by tank cars or by an over-
the-fence arrangement. It is of 99% or higher purity and
in a stabilized form of one of its phases. It is stored
over an inert gas, usually nitrogen, in order to preserve
its stability in storage while in the liquid state.
For the purposes of both illustrating and costing Levels
II and III technology as applied to schematic 202 plus 206,
and for all three of the reactions with different feed ma-
terials described earlier, we have assumed the production
of 803 from sulfur burning. We have further assumed that
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
219
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this does not add to the water effluent waste loading, since
most of the losses from carrying out the preparation of 863
would be in the vapor phase and therefore concerned only
with problems of waste blowing into the atmosphere, if any.
In a sense, the purchase of sulfur trioxide in its stabili-
zed form would lead to no different degree of .air or water
effluent waste. In the case of sulfur trioxide production
from high concentrations of oleum, then a reboiler reactor,
which produces the SOo vapor, does lead to a liquid stream
of sulfuric acid. However, as stated earlier, this is gen-
erally sent over the fence or even shipped for reconcentra-
tion to the original strength oleum. It thus presents no
added water effluent flow except for spills and accidental
incidents.
When an alkyl-benzene is employed as the raw material for
reaction with sulfur trioxide (feed reactant 1), as well as
in the other reactants mentioned above (2,3), there are side
reactions which occur if sufficient heat removal and close
temperature control is not attained. Therefore, generally
useful, is the recycle of the cooled intermediate stage al-
kyl-benzene sulfonic acid or the alkene sulfonic acid or the
lauryl alcohol sulfuric acid back into the staged reaction
loop, after cooling. In this way and with good temperature
control, preferably in the range of 60-80°C (140°-176°F),
high yield of the desired products may be obtained.
In the case of alkyl-benzene as a feed stock,1), it is de-
sired principally to obtain the para-substituted product
rather than those in other positions on the benzene ring.
If high temperatures at the surface of contact is unfortun-
ately reached, there is a strong tendency for both dispro-
portionation and ring isomerization in the case of alkyl-
benzene feed stock, 1). In addition to the desired mono-
substituted alkyl-benzene sulfonic acid, a fair amount of
anhydrides of sulfonic acid are also obtained. These are
essentially the anhydride of two alkyl-benzene sulfonic acid
molecules. These anhydrides must be hydrated with water or
otherwise reacted, in order to produce alkyl-benzene sulfonic
acid of good quality. This reaction to produce the anhydrides
is the result of the affinity for sulfur trioxide in the li-
quid phase to react with water, extracting it from combined
hydrogen and hydroxyl groups, to form sulfuric acid. The sul-
furic acid in the water phase cannot be reverted but must in-
stead be decomposed by the dilution or hydration with added
water in a separate step.
When either an alpha olefin or a branched chain olefin is to
be sulfonated (reactant feed 2), then several side reactions
occur which diminish the product quality and result in by-
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
220
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products which must be dealt with. The principal reaction
besides that of the sulfonation of the olefin to produce
an alkene-sulfonic acid in the terminal bond position of
the olefin, is that of bond migration where the sulfur tri-
oxide reacts and moves along the chain, so that no longer
does one obtain a terminal sulfonic acid product but one
which is branched chained at the position of the sulfur tri-
oxide addition.
Another reaction, forming undesirable by-products, that oc-
curs with sulfur trioxide and an olefin is that of the for-
mation of sultones, which are a cyclyzed form of the thiolone.
These appear generally in three of their most stable forms;
that is, alkyl-propane sultone, alkyl-butane sultone and also
octane-alkyl sultone, all of which must first be destroyed
before a useful product can be obtained.
The conversion of sultones is accomplished by direct reaction
with caustic soda or sodium hydroxide, which produces the so-
dium hydroxy-sulfonate of the alkene product together with a
sodium alkene sulfonate in stoichiometrical proportions.
The normal reaction product, alkene sulfonic acid, simultan-
eously neutralized with caustic soda to form the desired so-
dium alkene sulfonate and water.
In the case of sulfation reactions from the reactant feed
type 3), in which an alcohol or an ethoxylated alcohol or
an ethoxylated phenol is used for sulfation with sulfur tri-
oxide, the product formed is lauryl/fatty alcohol sulfuric
acid. In this case, the same by-products can occur as with
sulfation using oleum, as described under 201 schematic tech-
nology.
The reaction products from the alpha olefin or branched ole-
fin described as reactant feed 2), must first be neutralized
to produce the desired sodium alkene sulfonates before further
hydration processes, whereas in the case of the direct reac-
tion of sulfur trioxide with alky1-benzene, reactant 1), the
neutralization can follow hydration steps. Of course, lauryl
alcohol sulfuric acid requires no hydration.
In all cases, of these three reactions, there is usually a
holding tank after a cyclone separation of Vapor 803 that is
unreacted,1 and the liquid streams of product and sulfuric acid.
For this reason the holding tank provides not only additional
residence time for the completion of the formation of sulfonic
acids or alkyl alcohol sulfuric acid, but completes the re-
action so that a recycle stream can be returned to the sulfo-
nator or sulfator stage in order to get increased heat trans-
fer and diminish the possibility of double substitution of a
sulfonic acid group.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
221
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Some of these reactions are carried out simultaneously in
certain instances. This is for the reason that the alkyl
benzene sulfonate and the fatty alcohol sulfates are both
often blended for a better balanced detergent. This blend-
ing can best be done after the reaction loop but before the
hydration and neutralization steps, and leads to superior
blended products.
The neutralization of the reaction can be carried out with
any agent that does not generate carbon dioxide, which would
otherwise be preferred, in order to reduce sodium sulfate
content of the inorganic ions. All other varieties of al-
kaline neutralizing agents can be used depending upon the
product desired. For example, caustic soda, as earlier des-
cribed, aqua amonia, which will lead to the formation of an
ammonium salt; potassium, or even ethanol amines can be used.
In addition, when liquid detergents are being made, substances
such as low molecular weight alcohol, urea, toluene and/or
xylene sulfonates for hydrotropic agents can be also simul-
taneously made in tandem operations and blended before hy-
dration and neutralization.
The most feasible means of decreasing water effluent contam-
inants and simultaneously of increasing the quality of the
product, as it applies either to a batch or a continuous
system assumed in Level I technology, is the addition of di-
lution in the reaction step, increased agitation to diminish
temperature elevations as a result of the exo-thermal nature
of the reaction, or better contact between the vapor sulfur
trioxide and the liquid reactant phases. Additionally, a
batch counter-current process can be installed by utilizing
two or more reaction loops, in which the fresh sulfonic acid,
in the form of sulfur trioxide, is introduced into the stream
to the completion stage or holding stage of the reaction in
counter-current to the feed of the alkyl-benzene, the olefin,
or a fatty acid alcohol as represented by reactions 1), 2),
and 3). Such a batch counter-current arrangement is easily
feasible and should be economically viable by the addition
of one or more small reaction loops for a second and even
third stage of the process.
Raw Waste Loadings
The following average raw waste loadings can be expected:
BODs - 1.9 kg /1000 kg (1.9 lbs/1000 Ibs) anhydrous product
COD - 3.7 kg /1000 kg (3.7 lbs/1000 Ibs) anhydrous product
Suspended Solids - 0.2 kg /1000 kg (0.2 lbs/1000 Ibs) anhy-
drous product
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
222
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Surfactant -1.8 kg,/1000 kg (1.8 lbs/1000 Ibs) anhydrous
product
Oil and Grease - 0.4 kg /1000 kg. (0.4 lbs/1000 Ibs) anhy-
drous product
Level II Effluent Guideline Recommendations
On a thirty day average basis the following parameter load-
ings are recommended:
BODs - 0.19 kg /1000 kg (0.19 lbs/1000 Ibs) anhydrous pro-
duct
COD - 0.37 kg /1000 kg (0.37 lbs/1000 Ibs) anhydrous pro-
duct
Suspended Solids - 0.02 kg /1000 kg (0.02 lbs/1000 Ibs)
anhydrous product
Surfactant - 0.18 kg ,/1000 kg (0.18 lbs/1000 Ibs) anhydrous
product
Oil and Grease - 0.04 kg /1000 kg (0.04 lbs/1000 Ibs) anhy-
drous product
pH - 6 - 9
During any 24 hour period up to 4 times the thirty day
average should be allowed for special upsets.
Rationale
In citing the above Level II guidelines, which includes the
neutralization step after the reaction of sulfonation, or of
sulfation in the case of alcohol feeds, the recommendation
of one or additional counter-current reaction loops, if the
batch process is practiced now, with increased recycling from
that stage of un-neutralized sulfonic acids to the reaction
step should provide better heat transfer, better contacting
and lower elevation in instantaneous temperature at the film
surface. This should give improvements at .almost undiscern-
ible added cost. In this case the added cost in capital
should be a nominal $2.2/Mkg($l/Mlbs)annual capacity. Utili-
ties will increase less than 10%, required for the recycling
of the un-neutralized sulfonic acid product back to each re-
action loop, and the reaction step itself need not be in-
creased in size since only additional flow rates (not pro-
duct) are required in this instance.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
223
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203
204
205
Level
BODs
1.0
1.0
1.5
II Effluent
COD
3.0
3.0
5.0
Guideline
Suspended
Solids
0.1
0.1
0.2
Surfactant
0.1
0.1
1.5
Recommendations
PROCESS 203 - S03 SOLVENT AND VACUUM SULFONATION
PROCESS 204 - SULFAMIC ACID SULFATION
PROCESS 205 - CHLOROSULFONIC ACID SULFATION
Level II Technology
In the expectancy of experiencing better control of wastewater
use the Level II recommendations have been reduced over Level I,
Raw Waste Load
The following average raw waste loads are expected (all values
given in kg/1000 kg, lbs/1000 Ibs of product produced).
Oil &
Grease
0.2
0.2
0.3
Please see table at beginning of Section.
PROCESS 207 - SPRAY DRIED DETERGENTS
Level II Technology
By 1983 the proficiency of wastewater control is assumed to
match that projected for Level III. Please refer to Category
207 under Section XI for rationale.
Raw Waste Load
The following average raw waste load is expected:
BOD5 - 1.0 kg/1000 kg (1.0 lb/1000 Ibs) anhydrous product
COD - 2.7 kg/1000 kg (2.7 lbs/1000 Ibs) anhydrous product
Suspended Solids -1.2 kg/1000 kg (1.2 lbs/1000 Ibs) anhydrous
product
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
224
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Surfactant - 1.7 kg/1000 kg (1.7 lbs/1000 Ibs) anhydrous product
Oil and Grease - 0.5 kg/1000 kg (0.5 lb/1000 Ibs) anhydrous
product
Level II Effluent Guideline Recommendations
Please refer to table at beginning of Section.
PROCESS 208 - LIQUID DETERGENTS
PROCESS 211 - DETERGENT BARS AND CAKES
Level II Technology
Guideline recommendations for both processes were reduced on
the basis of expected greater control over product losses in
washups and general manufacturing.
Raw Waste Load
The following raw waste loads are expected (all values given in
kg/1000 kg, lbs/1000 Ibs of anhydrous product.)
BOD5 COD Suspended Surfactant Oil &
Grease
0.2
208
211
Level
0.5
3.0
II Effluent
1.5
9.0
Guideline
Sol
ids
1.0
Recommendations
0
2
.5
.0
Please refer to table at beginning of Section.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
225
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226
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SECTION XI
NEW SOURCE PERFORMANCE STANDARDS
AND PRETREATMENT STANDARDS
Introduction
Level III technology, being that which would be employed
in a new source of manufacture, offers an opportunity to
start afresh in the design of production facilities. Re-
viewing candidate processes for minimized effluent has
produced no great surprises. Soap and detergent making
is an old art. Still, a number of relevant, substantive
concepts for improvement have emerged as well as a few
fairly far from commercial realization.
Bearing in mind the necessity of being very practical, in
the discussion of all newer developments for Level III,
particular note has been made of the degree to which each
technique has been reduced to acceptable commercial prac-
tice.
Level III technology, in most categories, reflects the im-
provements developed in Level II. The guidelines for many
of these categories will be the same in Level III as in
Level II.
To simplify study of the recommendations, the Level III
Guidelines are reported in tabular form with the processes
given special consideration in the Level III text noted by
an asterisk in the Guidelines table. The sign @ in the table
means Levels II and III guidelines are identical. Please
refer to the corresponding Level II guidelines discussion
in SECTION X for extensions and exceptions recommended for
the guidelines. These exceptions are applicable to both
Levels II and III. See Table
Following the discussion of specific process improvements
for Level III is a review of process chemistry developments
which deserve further continuing study for ultimate improve-
ments in low effluent level products. As with all such "far
out" developments, some of the concepts have greater proba-
bility for success than others. They are offered for the
different perspectives they offer to this sophisticated art
of soap and detergent manufacturing and formulating.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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00
Level III Guideline Recommendations
Note: All values reported are in kgs/1000 kgs (lbs/1000 Ibs) of anhydrous product made
in that category. For all categories the guideline pH is 6 - 9.
101* (108) Batch Kettle
Soap
102* Fatty Acid By Fat
Splitting
103* Soap From Fatty
Acid Neutrali-
zation
104@ Glycerine Recovery
A. Concentration
B. Distillation
105@ Soap Flakes And
Powders
106* Bar Soaps
107@ Liquid Soap
BOD5
0.20
0.25
0.01
0.40
0.30
0.01
0.20
0.01
COD Suspended Solids
0.40
0.60
0.03
0.80
0.60
0.03
0.40
0.03
0.20
0.20
0.02
0.10
0.04
0.01
0.34
0.01
Surfactant
Oil & Grease
0.05
0.15
0.01
0.04
0.02
0.01
0.03
0.01
@ Denotes guidelines are identical with those established in Level I. Same conditions
and limits apply.
* Denotes a change in guidelines from Level I and are treated at length in this section.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION IN THIS REPORT
AND ARE SUBJECT TO CHANGE BASED UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW
BY EPA.
DRAFT
-------
Level III Guideline Recommendations (cont.)
BOD5 COD Suspended Solids Surfactant Oil & Grease
N>
N>
\O
201* Oleum Sulfation/
Sulfonation
202* Air-S03 Sulfation/
Sulfonation
203(§ 803 Solvent and
Vacuum Sulfonation
204(§ Sulfamic Acid
Sulfation
205(§ Chlorosulfonic
Acid Sulfation
206@ Neutralization
Of Acids
207* Spray Dried
Detergents
208@ Liquid Detergents
209@ Detergent Dry
Blending
210@ Drum Dried
Detergents
211(3 Detergent Bars
and Cakes
0.01
0.09
0.10
0.10
0.15
0.01
0.10
0.05
0.02
0.27
0.30
0.30
0.50
0.03
0.27
0.15
0.02
0.09
0.01
0.01
0.02
0.03
0.12
0.0
0.01
0.09
0.10
0.10
0.15
0.02
0.17
0.05
0.04
0.02
0.02
0.02
0.03
0.01
0.05
0.0
0.01 0.05
0.01 0.03
0.30 0.90
0.01
0.01
0.10
0.01
0.01
0.20
0.0
0.01
0.02
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON INFORMATION IN THIS REPORT AND
ARE SUBJECT TO CHANGE BASED UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA
DRAFT
-------
PROCESS DISCUSSION
101 - SOAP MANUFACTURE BY BATCH KETTLE
(108) - SOAP MANUFACTURE BY CONTINUOUS COUNTER-CURRENT PROCESS
General
There appears to be no incentive for another batch kettle
processing soap plant to be built in a brand new installation.
The reasons for this are manifold. There is a constant de-
crease in per capita use of soap for personal cleansing.
Soap in bar form is being replaced by detergent bar formula-
tions, particularly in hard water areas, and by other liquid
cleansing formulations in commercial applications. As a re-
sult, it is reasonable to expect that a soap manufacturer
who has a considerable investment in a soap boiling plant
will merely replace a kettle or some other piece of equip-
ment as is necessary to maintain economical production in
that plant.
However, any brand new installation will be a small marginal
unit that will probably consist of a continuous counter-cur-
rent soap processing plant, as envisaged by category 108
schematic diagram.
The principal technical accomplishment of a truly counter-
current continuous soap making operation is the substantial
reduction in nigre which cannot be fully worked off in the
kettle boiling plant except into very inferior soaps and
then, at some point, can no longer be used at all. Nigre
reduction in continuous processing is due to the shortened
residence time in contrast with the batch kettle operation
where residence time is as high as nine to ten days. During
this period there is a continuous degradation of both the
soap feed raw materials as well as the soap itself. This
oxidative deterioration is multiplied many times due to the
combination of high residence time and high temperatures in
the soap boiling kettles. By the use of continuous proces-
sing the time can be reduced to two to five'hours, with a
consequent important reduction in buildup of by-products.
Manufacturing operations still require preliminary fat re-
fining and bleaching, as shown in section 1012 of the sche-
matic diagram for soap manufacture by batch kettle, 101.
Therefore, the waste streams from this operation can only
be minimized in the same manner as that described in Level II
technology and accomplishes the reduction to the
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
230
-------
o
£
"i
H
SECTION XI
LEVEL III TECHNOLOGY
108: SOAP MANUFACTURE BY CONTINUOUS SAPONIFICATION
mi RECEIVING
STORAGE TRANSFER
1017 FAT REFINING
AND BLEACHING
to
U)
WASHOUTS
101102
*1
t-t
o
I
WASTE WAT EJ1 1
JOi73i 1
SOLID WASTE
IOI3O9
4th STAGE
FITTING
WEAK
CHANGE
1
TURBO
DISPER
,SER
<*
'
—
V '
I
1
ELECTROLYTE •%
BALANCE
I
«EATSOA*
FROM
REACTION
CENTRIFUGE
NEAT SOAP
TO DRYING
LYE GLYCERINE.
SALT and WATER
LEAKS SPILLS. DRAINS
CONDENSATES. STEAM
-------
extent of about 807. from that currently used in the batch kettle
process. Thus, utilities are expected to run no more than
0.440 to 0.66o/1000kg (0.2$ to 0.3c/10001bs) of neat soap.
Electric use is somewhat increased by the requirements of the
turbo-disperser motors and those for the centrifuge operations.
This added cost would be approximately 0.22C/1000kg (O.lc
/lOOOlbs) of soap product according to our best estimates.
A significant reduction in operating cost is expected by the
substitution of the continuous processing over a batch kettle
by reduction of labor requirements. Instead of labor in the
range of eight to ten men per shift for a kettle plant of
circa 9 to 13.6Mkg (20 to SOMlbs) capacity per year or higher,
it should be possible to reduce this to no more than two or
possibly three men per shift for a continuous unit, with a
striking reduction in labor costs. This labor saving appears
to pay out a continuous soap processing plant at the present
time, and on an internal economic basis alone, in about ten
years, not considering any other advantages of the process or
the need for a new capital installation anyway.
Realizing that the clay treatment and vacuum bleaching of the
feed oils and fats are limited in improvement for Level II
to only the replacement of a barometric condenser by a two-
stage surface condenser, and that only good operating
cleanliness can reduce this further, Level III recommendations
allow only additional contaminants coming from the fat and
oils pretreatment operation and essentially none for the
continuous saponification process itself..
It may be noted that both the BOD and COD levels have been
considerably reduced because of the elimination of oxidizable,
biodegradable or refractory materials from such a process.
This is largely accomplished by the time reduction in the
continuous processing as against the batch processing.
Similarly, because of the good separation of salt and lye
stream from the soap or fat phased by the use of centrifugation,
and their reprocessing is appears that the level recommended
should be easily achieved in the continuous saponification
plant.
Raw Waste Load
The following average raw waste load can be expected.
BOD5 - 2kg /1000kg ( 21bs/10001bs) anhydrous soap
COD - 4kg./1000kg (41bs/10001bs) anhydrous soap
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 232
-------
Suspended Solids - 2.0kg /1000kg (2 .Olbs/lOOOlbs) anhydrous
soap
Oil and Grease - 0.5kg /1000kg (O.Slbs/lOOOlbs) anhydrous soap
/
103 - M SOAPS BY CONTINUOUS ACID NEUTRALIZATION
106 - M BAR SOAP
General
In Level III technology the manufacture of soap by fatty
acid neutralization is regarded as the norm for the
preparation of neat soap. It is depicted in schematic
diagram 103 - M. Data reported here is a combination of
field visits and contractor's engineering design parameters.
Level III Technology - Soap Manufacture
For Level III technology a continuous neutralization plant
is recommended which utilizes coco and tallow fatty acids.
The process is shown in schematic diagram 103 - M.- Soap
from fatty acid neutralization.
Data from two installations has been integrated with
additional information found in the literature. The combined
process is designated S. A Second engineering design offered
by a contractor was seen and studied in operation, but no data
was forthcoming directly from the vendor.
One of the continuous processes observed is based upon the
sodium carbonate neutralization of the fatty acids rather
than sodium hydroxide or potassium hydroxide. This principally
benefits the manufacturer in that he can reduce residual
sodium chloride content in his soap and make a higher quality
product without loss of overall efficiency of recovery. He
may need to add sodium chloride to the soap to give a proper
electrolyte balance in use. In this case the continuous process
makes use of proportioning pumps with interlocks and main
control-interlocks for absolute rate of feeds flow, very
similar to that outlined in the continuous saponification
process - 101 Schematic - Amended. In this process turbo-
dispersers are used which greatly enhance the contacting
efficiency between the water and fatty acid or oil phases
of the reactants. The reaction time is reduced to a matter
of 10 to 15 minutes total within the reactor and separation
systems.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 233
-------
SECTION XI
LEVEL III TECHNOLOGY
103 Modified: SOAP BY CONTINUOUS FATTY ACID NEUTRALIZATION
Section 1062-Modified:
NEAT SOAP DRYING: FOR BAR SOAPS
ro
w
•P-
a
LO
-------
Claims of a reduction have been as much as fivefold. A
conservative reduction of 50% has been chosen; that is,
to 0.5% salt content in soap product. Similarly, the
glycerine contained in the average soap batch process
manufacture is in the order of about 0.6% to 1.0%. Here
again, a reduction in the glycerine content of the soap
product by continuous operation should result in a product
with a glycerol content in the range of 0.30% to 0.40%.
More importantly, with respect to waste product, the spent
lye sweet water from such a continuous process operation
is reduced considerably over that in the batch process.
For example, free alkali in the lye phase runs in the order
of 1.0%* in current batch operations and can certainly be
reduced to the order of 0.1% by continuous processing,
which more effectively used caustic soda. The salt content,
of course, is fixed by the stoichiometry of the reaction, but
nevertheless can be concentrated in the spent lye due to the
elimination of high fresh process water requirements in the
normal operation of the batch process.
Thus, salt content running in the order of 10% to 15% in the
batch process and sometimes considerably higher, can certainly
be reduced to the order of 10.0% by continuous processing, thus
reducing the chloride ion significantly in a residual effluent.
Furthermore, more of this salt will be recovered anyway in
the glycerine recovery operation (Schematic flow sheet 104)
and is of no great consequence except as it appears in the
final spent lye. Currant batch operations have a spent lye
running in the order of 9 to 10% glycerine. By means of the
continuous process, limited by the complete solubility of gly-
cerine in water streams and thus requiring a reduction in
the water stream, the glycerine concentration can be increased
from two to threefold, that is, in the order of 20 to 25%.
The capital cost of such a continuous soap process, at least
certified by the installed plants of the subject process, is
nominally in the same order as that required for a batch kettle
installation. The capital cost estimate of a continuous
saponification plant including fat refining and bleaching per
Level II, forty million pounds a year will be less than $10.00
per thousand pounds of annual product and is considered
competitive or even less costly than any complete replacement.
of a soap plant by the batch kettle process. This cost benefit
is without considering both the improvement in the product
quality and in the minimization of effluent streams.
Reduction in utilities from current usage will also be
signigicant. The steam consumption, will be reduced to the
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 235
-------
levels as specified.
Rationale
Five processes have been studied for the manufacture of
soap by a continuous counter-current technique. Much of
the data was obtained from the literature and represents
claims by the manufacturer. They are unconfirmed because
the contractor offering the processes was unwilling to
disclose relevant details. One process was selected for
detailed study. Capital cost estimates were obtained from
the contractor for the construction of such plants and op-
erating data from one of the operating installations out
of some seventeen or eighteen constructed to date through-
out the world.
This process is about average with respect to quality of
soap and contaminants appearing in final effluent streams.
Thus, it is justified from the point of what really could
be available and therefore the guideline will be less se-
vere than it might have been, had full data been available.
As previously mentioned, the reduction in contact time,
the faster reaction due to the use of turbo-dispersers,
and high gravity centrifugal separations of fatty oil ver-
sus water phases permits not only a substantial reduction
in contact time but also a minimization of waste effluent
streams. It should be remembered that soap itself, being
a solid, even in neat form, and the fact that the fats and
oils initially fed are high in molecular weight and are
slow to react, again emphasizes the importance of good
dispersal of one phase into another during the reaction
sequence. Once a particle of soap has been formed it tends
to entrap oils and fats which still need to be reacted. By
a high degree of dispersion of these soaps already formed,
much more of an area for heterogeneous phase reaction with
the caustic soda is obtained and the faster and more com-
plete reaction results.
The quality of the soap product made from such a continuous
operation is equivalent to or an improvement over that from
the batch kettle. For example, the batch kettle process
will result in an average content of free alkali, measured
as Na20 of the order of 0.57. to 0.75%. In the case of the
continuous manufacturing operation, and representing an
average range of all contractors' claims, the free alkali
is reduced by a tenfold factor in the product to approxi-
mately that of 0.05% to 0.075%. Similarly, the salt content
from the batch operation runs roughly in the area of 1.0%.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 236
-------
When sodium carbonate is used for neutralization, C02
is generated. It must be separated from the soap
solution and vented to the atmosphere. Entrainment is
lowered by use of knock-down plate5 in a column and
this vapor can be further cooled to remove any possible
unreacted fatty acids or other volatiles.
The neat soap produced from this reaction needs to be
dried from approximately 357. water content to the level of
1 to 3%. The drying process is considered separately.
Battery limit capital investment, including appropriate
tankage for the reactants, will cost in the order of
$500,000 for a 20 million pound per year plant. Operating
labor will cost in the order of $60,000 per year using our
standard labor costs and the appropriate maintenance
figures and administration costs would be identical in
relation to hourly labor as given in other processes
described. It is estimated that, at the prescribed costs,
steam consumption will amount to approximately $6,000
per year; electricity to approximately $10,000 per year
and cooling water approximately $2,000 per year for this
20 million pound per year installation, again emphasizing
that this covers the neutralization step only to neat soap.
BAR SOAP - DRYING
The drying operation from neat soap is no different than in
current facilities and as in Level II guidelines for the case
of solid bar soap manufacture from coco and tallow acids. A
surface condenser is indicated to be used in place of the
normal barometric condenser now utilized for soap drying, and
especially when vacuum drying operations are carried out for
clear soaps.
The cost for the above drying operation, for the production of
a bar soap extrudate, is estimated at $200,000 of capital for
9Mkg (20Mlbs) per year of anhydrous soap products. Operating
steam, electric and cooling water costs will be in correspondence
to the Level II recommendations and entails no additional cost
over that outlined.
SOLVENT PROCESS FOR SOAP MANUFACTURE
A fascinating process developed in the 1940s requires no water
to make anhydrous soap and dynamite glycerine.
In the Kokatnur process, fats or oils are dissolved in kerosene
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 237
-------
260 - 290C (500 - 554F) and then mixed, under pressure, with
anhydrous caustic soda. The reaction takes place in ten
minutes producing dynamite grade glycerine . After drawing
off the glycerine, the remaining mixture is released into
an expansion chamber yielding anhydrous soap. The process
has the following advantages:
1. Very short reaction time.
2. Use of kerosene prevents charring.
3. Absence of water reduces heat requirement.
4. Dynamite grade glycerine is obtained directly.
One major defect of the process is that there is no refining
stage and traces of kerosene are left in the soap making
it impossible to market the product for toilet bar use.
The soap is suitable only for limited industrial uses.
201 - OLEUM SULFATION AND SULFONATION
Level III Technology
The guideline recommendations and economics are based on
a new plant (battery limits) of around 2.3 million kg (51! Ibs)
per year of surfactant capacity made in a continous process.
Extensive contractor data indicated that by good engineering
design of the reactor and a minimum residence time prior to
neutralization, the levels indicated for raw waste load can
be readily met.
The estimates indicate that for a new battery limit in-
stallation, the use of a continuous process plant design
can save capital over that of a batch system of roughly
$66/1000kg. ($30/10001bs) per year of detergent active
product capacity. Yields are higher. This suggests that
there is a further saving achievable by continuous operation
of the order of 0.8 to 1.07» of the feed.
An additional saving is possible in the form of labor costs
when the continuous processing system is utilized. Utilities
are all minimized and will be lower, if only slightly, than
that required in a batch or semi-batch reverse feed system.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
238
-------
The continuous process reviewed is capable of meeting
the raw waste loadings indicated for Level III. The
process is adaptable to almost any size installation from
900 thousand kgs (2 million Ibs) per year upward.
Raw Waste Loadings
The following average raw waste load can be expected:
BOD5 - 0.1 kg. /1000 kg. (0.1 lbs/1000 Ibs) anhydrous product
COD - 0.2 kg. /1000 kg $0.2 lbs/1000 Ibs) anhydrous product
Suspended Solids - 0.2 kg./1000 kg (0.2 lbs/1000 Ibs) an-
hydrous product
Surfactant - 0.1 kg. /1000 kg, (0.1 lbs/1000 Ibs anhydrous
product
Oil and Grease - 0.4 kg. /1000 kg. (0.4 lbs/1000 Ibs) an-
hydrous product
202 AIR S03 SULFATION AND SULFONATION
Level III Technology
Level III guideline recommendations are based upon technology
depicted in schematic flow diagram 202 - M. The process
involves the reaction, hydration, neutralization and finishing
steps for reaction of alkylated aromatics. In the case of
using an olefin feed stock, the only difference is the
addition of a neutralization step before the indicated
hydrator shown on the flow diagram. In the case of the
sulfation of an alcohol by this same feed, liquid SOg, which
is vaporized and diluted with air, there is no difference in
the main flow diagram. However, a tandem operation duplicating
the reaction steps and the gas cyclone separator followed by
independent stream recycle and then concommittant carrying
out of the second step of the reaction, i.e., the completion of
reaction in the digester, followed by a hydrator, is identical
with the schematic 202 Modified.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
239
-------
SECTION XI
LEVEL III TECHNOLOGY
COMBINED PROCESSES
Modified 202 • SOg - SULFONATION / SULFATION PROCESSES - CONTINUOUS
AND
Modified 206 : NEUTRALIZATION OF SULFONIC OR ALKYL SULFURIC ACID PROCESSES - CONTINUOUS
TO SCRUBBERS
M
8
Ln
202A and 206A : SCHEMATIC FLOW DIAGRAM
Modified ALKYL BENZENE SULFONATION
Reaction: 202 A Section
ALKYL
BENZENE
SO3-AIR
SULFONATION
NEUTRALIZATION: 206 A Section
DIGESTOR
HYDRATOR
PRODUCT
PUMP
WATER
DIGESTION
HYDRATION
CAUSTIC SODA
NEUTRALIZATION
-------
Raw Waste Load
The following raw waste load can be expected.
BOD5 - 0.9 kg. /1000 kg (0.9 lbs/1000 Ibs) anhydrous product
COD - 2.7 kg. /1000 kg (2.7 lbs/1000 Ibs) anhydrous product
Suspended Solids - 0.9 kg ./1000 kg. (0.9 lbs/1000 Ibs)
anhydrous product
Surfactant - 0.9 kg./1000 kg. (0.9 lbs/1000 Ibs) anhydrous
product
Oil and Grease - 0.2 kg ./1000 kg. (0.3 lbs/1000 Ibs)
anhydrous product
Rationale
The use of a continuous unit embracing all the steps
recommended for Level II applied to batch, batch counter
current or continuous systems already in place can be moderately
improved in a new installation with the continuous sulfonation/
sulfation reaction. This is regardless of whether the process
unit includes sulfur burning, oleum reboiling, or the use of
stabilized liquid sulfur trioxide as the feed stream. This is
because the effluent water loads are not changed regardless of
how sulfur trioxide is introduced to the reaction system.
The cost depicted and guaranteed by a manufacturer shows utility
demands as follows; electricity 0.9 to l.lc/kg (0.4 - 0.5c/lb)
of active material from the reaction; cooling water require-
ments of 0.1 - 0.2c/kg (0-05 - O.lOc/lb) of active product.
The initial capital cost for this installation relates of course
to plant size with economic benefits being obtained the larger
the plant size.
For plants in the size range of 13.6Mkg per year (30M Ibs per
year) of active ingredient, and based upon a 92% stream factor,
capital amounts to $88-110/1000 kg ($40 - $50/1000 Ibs) annually
of active material made. This assumes the use of stabilized
liquid sulfur trioxide. If sulfur trioxide is produced by
sulfur burning, this is considered to be a separate unit,
and the economics and the justification for that unit is inde-
pendent of the nature and principles covered in the water efflu-
ent.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
241
-------
o
H
SECTION XI
LEVEL III TECHNOLOGY
SCHEMATIC FLOW DIAGRAM
202 C and 206 C: Modified - Combined
FATTY ALCOHOL SULFATION : WITH SO,
Reaction : 202 C Section
Neutralization : 206-C Section
FATTY
ALCOHOL
TO SCRUBBER
S03-AIR
O
U)
CAUSTIC
SODA
PRODUCT
HEAT
EXCHANGER
PUMP
Cooling
Water
-------
SECTION XI
LEVEL III TECHNOLOGY
SCHEMATIC FLOW DIAGRAM - COMBINED 202B and 206B
ALPHA - OLEFIN SULFONATION WITH SO,
Reaction: 202 B Section
Neutralization : 206 B Section
ALPHA
OLEFIN
ro
J>
LO
SO3-AIR
s
PRODUCT
CAUSTIC
SODA
-------
guideline recommendations for the schematic 102 modified
plus 106 modified.
207 SPRAYED DRIED DETERGENTS
Level III Technology
The struggle between clean air and clean water comes to a
sharp focus when one evaluated the contribution to
wastewater streams made by detergent spray tower operations.
Moving in the direction of continually changing product
formulations which are increasingly more compatible with
the environment after their use has aggravated air
pollution problems at the point of manufacture. Detergent
manufacturers have been increasing their use of surfactant
components which are not readily removed by dust recovery
systems which were satisfactory for earlier products.
In order to cope with the problems, wet scrubbers are now
being employed in many plants in order to meet stringent
air standards and simultaneously knock out a substantial
amount of solids in exiting gas. Thus, the problem is
transferred from air management to water management.
Tower scrubber water now becomes a major source of BOD/COD
in an integrated plant effluent. Guidelines have been
established on the basis that if the scrubber water were
cooled and remained more concentrated, water consumption
would diminish and could potentially be consumed via the
crutcher.
The problem of potentially shorting out the electrostatic
precipitator by entrainment of concentrated scrubber water
could be met by installing a second more dilute scrubber
downstream from the first. The concept deserves further study
to firm up the economics and evaluate other alternatives.
Level III raw waste loading has been established at one set
of values on the presumption that essentially the same constraints
of air quality and product formulation will confront all spray
tower operators shortly and a single set of technical guidelines
will prevail.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
244
-------
Raw Waste Loadings
On a average the following raw waste loads are expected.
BOD5 - 1.0 kg/1000 kg (1.0 lbs/1000 Ibs) anhydrous product
COD - 2.7 kg/1000 kg (2.7 lbs/1000 Ibs) anhydrous product
Suspended Solids - 1.2 kg/1000 kg (1.2 lbs/1000 Ibs)
anhydrous product
Surfactant -1.7 kg/1000 kg (1.7 lbs/1000 Ibs) anhydrous
product
Oil and Grease - 0.5 kg/1000 kg (0.5 lbs/1000 Ibs)
anhydrous product
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
245
-------
POTENTIAL NEW TECHNOLOGY
202 - N: SULFONATION PROCESS BY FREE RADICAL REACTIONS:
SULFONATES FROM NORMAL PARAFFIN HYDROCARBONS
General Description
This reaction may be characterized as arfree radical -
chain reaction. The only feed material is the paraffin
hydrocarbon of proper chain length, together with sulfur
dioxide and oxygen, either pure or taken from air. The
sequence of steps leading to the over-all reaction are
given at the end of this section, in the series of equa-
tions numbered one to ten.
The hydrocarbon introduced can range from normal CIQ paraf-
fin to normal C2Q paraffin. Naturally, the composition of
the desired final detergent sulfonate controls the feed
choice; however, they may range as required by the detergent
manufacturer. A considerable proportion of isoparaffins,
i.e., up to 5%, may be included in the feed stock paraffins.
Desirably, aromatic hydrocarbons are kept as low as possible,
certainly in the range below 2%.
Similarly, though not as critical, mono-olefins should not
range higher than 7% and, preferably, in the region of about
2%. Cycloparaffins are not as deleterious in the final pro-
duct and hence may range as high as 20%. However, a more
desirable range of cyclic paraffins is about 5 - 1070.
The sulfur dioxide reactant may be obtained from the usual
burning of sulfur with air, but it must be high in purity
so that it does not cause cessation of the chain reaction
carried out. The oxygen can be used in the form of pure
oxygen or may be in the form of air. In all cases, however,
it must be anhydrous, or containing no more than a few hun-
dreths of a percent of water.
The ranges of the reactant ratios are quite flexible. How-
ever, the ranges for oxygen content to hydrocarbon content
should be no higher than 2:1. Similarly, the sulfur dioxide
to hydrocarbon ratio should be no more than 4:1. The ratio
02/S02 can be over quite a broad range but must remain gen-
erally within the limits of 1:1 to 10:1. The other prefer-
able ranges for this reaction are approximately the following
62/Cn = 1:1; S02/Cn = 2:1.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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The temperature at which this reaction should be carried
out may range from about 77°F to 140°F (25°C to 60°C).
However, a preferred operating range is in the order of
104°F (40°C). Similarly, the pressure for the reaction
may range from 3-14 atm (30 - 200 psig). However, a
preferable range is around 4-8 atm (50 - 100 psig).
The reaction time is in the order of 10 to 40 minutes,
depending upon the ratio of reactants chosen. The reaction
is carried out in the liquid phase, with oxygen or air be-
ing bubbled through the paraffin hydrocarbon.
This free radical - chain reaction is catalyzed by the pro-
duction of free radicals from ionizing radiation, as shown
in the equation A following:
Reaction A - Initiation reaction: Over-all
H H
u (gamma radiation) + H-C^—Cn-H + S02 + %02
0 H H
H H -i
H-Ci---Cn - S - OH
H1 Hn g
The ionizing radiation for this free radical reaction can
be produced by a low energy source of approximately 30 elec-
tron volts. The wave length of this radiation can vary from
that of 10~3 to 1Q2 angstroms of wave length. Gamma radia-
tion, such as may be used from a cobalt 60 source, or a beta
ray, that is an electron beam, may be employed. However,
neutron bombardment cannot be used, though it would be quite
effective, because it would lead to the production of radio-
active sulfur. The electronic radiation, if it is desired
to choose beta radiation, cannot be produced from a Van der
Graff accelerator, since the beta radiation from this source
is too warm.
The product from this reaction is unreacted normal paraffins
and other feed hydrocarbon compounds, the desired normal paraf-
fin sulfonic acid, and paraffins which have been double sulfo-
nated to have become disulfonic acid of the paraffin hydro-
carbon feed.
The sulfonic acid can be extracted from the reaction mixture
using water, or preferably, an alcohol such as methanol. The
non-water phase, consisting of unreacted hydrocarbons, can be
recycled back to the reactor if water is used, or the methanol
or alcohol can be distilled from the solution, before recy-
cling the paraffin stream back to the reactor.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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Neutralization of the sulfonic acid can be carried out in
any manner as depicted under the Schematic 206. A range
of neutralization agents can be used including caustic soda,
sodium carbonate, and either.lime, calcium oxide, or calcium
hydroxide, by choice of appropriate equipment. The schema-
tic for this reaction is shown at the end of this section.
It should be realized that the knowledge of this reaction
derives from literature and patent sources. The actual
knowledge of the reaction, as carried out in private plants,
and on a commercial basis at Hoechst in Germany is not known.
In particular, the efficiency of the radiation as it relates
to the cost of carrying out this reaction is not generally
known. For this to be commercially feasible, that is, eco-
nomically so, it is necessary that the G ratio, which
measures efficiency in an ionizing reaction, is at least a
multiple in the order of thousands.
Since it is known that this reaction is being carried out
commercially in Germany, it may be assumed that a high ef-
ficiency has been obtained in the ionizing radiation use.
However, it is possible that other chain initiation reactions
have been found which employ very common chain reaction rad-
ical producers.
As a result of complete lack of knowledge about the pilot
phase and the commercial application of this reaction waste
levels cannot be specified in accordance with the standards
required for Level III.
SULFONATES FRON ALPHA OLEFINS BY RADICAL - CHAIN REACTION
General Description
A free radical-chain reaction, similar to that described
above, can be carried out on alpha olefins, i.e., a term-
inal 1 - normal olefin. The other reactant is an alkali
metal bisulfite. The feed hydrocarbon stream, in the form
of terminal olefins, can range in carbon number from 1-30.
Thus, a desirable detergent range is readily accommodated.
The sequence of this reaction is shown below, as reactions
11 and 12:
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT
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Reaction 11;
S0§ + RCH=CH2^RCH-CH«SO~
- ^ • *O-
Reaction 12:
RCH-CH2SO§+HS03 >RCH2CH2803+803, etc.
The radical sulfur trioxide is reacted with the radical
1 - olefins which are produced by ionizing radiation.
The sulfonic ion produced from this reaction is then reacted
with the bisulfite ion to restore the ionized radical 803*
and to produce, as the other product, the desired sulfonic
radicals as the sulfonic acid. This can be immediately neu-
tralized, and is in effect accomplished by using a metal icn
salt of the bisulfite as the reactant. Otherwise, neutrali-
zation must be accomplished immediately following the com-
pletion of the reaction.
The temperature and pressure requirements for this reaction
are in the same range as that described above for the radi-
cal chain reaction with paraffins. The time requirement,
however, is somewhat longer, being in the order of 2 to 72
hours with 24 hours as a good average. The medium in which
this reaction is carried out is sodium bisulfite dissolved
in acetone or an acetone-hexane mixture which is a solvent
for one of the reactants. Since this is a two phase system,
it is desirable to use an alkylaryl sulfonate from a final
detergent product of the usual system, to improve mixing
and inter-phase reactions.
The catalyst is the same as previously described above;
that is, radiation of the proper wave length and energy con-
tent .
Product recovery is accomplished by extraction, filtration
and precipitation, depending upon the sulfonate and the
chain length of the hydrocarbon feed. The unreacted sodium
bisulfite plus the solvent used for carrying out the reac-
tion can be separated from the product and recycled back
into the reactor.
As in the case described above for the sulfonation of paraf-
fins, little is known about the practical application of this
reaction and its commercialization and experience in pilot
plant operations. Hence, it is impossible to assign any
waste effluent level or to recommend this as a definitely
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 249
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available Level III technology. Attached is a diagram rep-
resenting the reaction for the production of the olefin-
sulfonates as depicted in the equation first shown. The
schematic shows a source of ionizing radiation as coming
from a reactor of the nuclear type. As before, this radia-
tion is to some extent limited, and the same conditions
apply as described earlier.
RADICAL CHAIN REACTIONS
Ionizing Radiation
1) RH .................. ^ R* + H*
2) R* + S02 ............ *
3) RS02 + 02 ----------- *
4) RS020*. + RH - -------- * RS0202H + R*
5) RS0202H + H20 + S02 -^ RS03H + H2S04
6) RS0202H -— ......... » RS020* + OH*
7) OH* + RH ............ > H20 + R*
8) RS020* + RH ......... > RS03H + R*
9) H2S04 + MH20 ...... --* H2S04 + (H20)m
s
10) Overall Reaction:
RH + S02 + 1/2 02 — > RS03H
PRETREATMENT REQUIREMENTS
In this section of the report those pollutants capable of dis-
rupting, or likely to disrupt, the operation of a publicly owned
wastewater treatment plant are cited. However, it should be
fully understood that it is not the intent to provide limits or
other standards which would in effect supplant any sewer use
ordinance developed and now being enforced by a central authority,
In fact, every authority that owns a collection and treatment
system should have an up-to-date sewer use ordinance which would
enable it to regulate the types and quantity of industrial wastes
NOTICE : THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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admitted to its system. The purpose of this section is to point
out possible problem areas and indicate applicable control
measures.
With the exception of dissolved mineral salts there is essentially
no pollutant in the wastes from soap and detergent manufacturers
that cannot be removed at high levels of efficiency in a central
plant. However, oils, fats, greases, and the heavy metal zinc
could have serious adverse effects on both the collection and
the treatment systems even if only moderately uncontrolled
at their source.
Fats and Oils - Soap Plants
Fats and oils from soap plants are readily degradable. Whenever
excessive fat, oils or greases are discharged, or whenever a
safeguard against such a discharge is required, the waste should
be passed through a gravity type separator prior to discharge to
the central system. This type of pretreatment serves to remove
up to 907o of the free oils which are the primary source of
problems in both the sewers and the treatment plant.
As previously discussed the well-designed fat trap is similar
to a primary clarifier in a municipal plant. An appropriate
size for a large soap plant would be rated 2078 I/day/I sq m
(600 gallons/day/square foot). Residence time should be about
1 hour. Such a fat trap, equipped with a radial flow to the
trough around the perimeter overflow weir and a rotating scraper
arm which moves the fat layer in front of the arm and thence
into a well, will do an excellent job and provide essentially
complete removal.
The underflow from such a fat trap will have a high treatable
BOD. In one of the soap plants observed in this study a reser-
voir of the underflow is retained in tanks to use as a feed for
the biological treater which requires a source of food for the
bacteria when only a few units of the plant are operating.
If the pollutant is a low molecular weight mineral solvent which
has a low water solubility the same treatment mechanism can be
employed. The captured material should be burned or processed
for reuse. The non-flotables and the liquid phase should be
passed on to the central treatment plant.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 251
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The efficiency of the fat trap must be maintained and routine
inspections should be nade by the proper authorities.
Fats and Oils - Detergent Plants
Detergent plants will have oil and grease effluents more
like the hydrocarbons encountered in the organic chemical
industry, namely, they will be of fossil or petroleum ori-
gin rather than from natural fats. These hydrocarbons are
not so fast-degrading, then, as those originating from the
soap plant. The only analytical method generally accepted,
namely the hexane extractable method, as described in Stan-
dard Methods, makes no differentiation between the two types
of hydrocarbons. Until such a test can be devised it would
be unfair to set a standard based on the least degradable
product and make the more degradable product conform to it.
Additionally, from an economic standpoint it is most impor-
tant to make a differentiation in treatability. Therefore,
it is urgently recommended that a test and procedure be
developed to make such a differentiation. The problem is
accentuated in that the industrial detergents will probab-
ly contain hydrocarbons extracted in the hexane extractable
test that are more difficult to degrade than the household
detergent plant.
The contractor believes that setting up rational pretreat-
ment standards for detergent plants must await development
of improved analytical procedures. This is covered in Sec-
tion II, Recommendations.
Zinc
Concentrations of zinc which could lead to problems at the
central facility have not been found in the waste water
examined or in the data analyzed. The best information
available would indicate that zinc concentrations of between
5 and 100 mg/1 in the biological portion of the central plant
could slow the rate of assimilation. Therefore, any concentration
of not more than 5 mg/1 would appear to be a satisfactory process
effluent level. The observed values have been less than 4 ng/1.
The relationship of zinc to the activity of nitrifying bacteria
is under study in EPA. The results could have an effect on this
standard.
Should a zinc problem arise, pretreatment employing alkaline
precipitation is the most cost effective means of reducing zinc
levels to satisfactory concentrations in process effluent. This
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
TNTOBHATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 252
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should be carried out at pH values in excess of 8.5 and less
than 9.5 in the coagulation step and at surface loadings of
16297 1 - 20377 1/sq n (400-500 gpd/sf) in the sedimentation
step. The sludge should be dewatered and incinerated or dried
prior to ground disposal.
Phosphorus
Since high levels of phosphorus compounds are not hazardous to
either a waste water collection or treatment system, it does not
seem appropriate here to categorically require pretreatraent for
the removal of phosphorus or reduction of phosphorus levels
in effluents being discharged 'to a central collection and
treatment facility. This is a matter which should ?sore
properly be handled through the proper application of a sewer
use ordinance. By this it is intended that the central authority
has the power to recover the cost of special treatment for
phosphorus removal if such steps are indeed necessary. At the
same time the central authority could also require a reduction
in the industrial effluent if this was deemed the most appropriate
means of controlling the effluent from the central waste water
treatment plant.
Also, it cannot be said that phosphorus moves through a plant
without interaction which involves the removal of that species.
Phosphate is involved in biological incorporation, in inter-
actions with metals which bring about its precipitation and
adsorptive process, and that can and do reduce its concentra-
tion in a waste stream. If these naturally occurring phenomena
do not reduce phosphorus to satisfactory levels a conventional
secondary waste water treatment plant can easily be modified if
necessary to reduce the concentration of phosphorus contained in
the effluent to virtually any value desired down to 0.5 mg/1 as
phosphorus. This is the place to deal with phosphorus if it
is to be controlled and not as a pretreatrnent step processing
only the industrial effluent unless specifically required by
the central authority. In some instances the phosphorus may
be useful as a nutrient to a central facility which is treating
a high strength low phosphorus-containing industrial waste. For
appropriate pretreatment processes see the discussion on phosphorus
rembva.1. in Section VII. This is another example as to why the
sewer use ordinance should be the primary mechanism for the control
of phosphorus in industrial effluents.
Industrial Cleaners
A number of soap and detergent manufacturers studied produce
industrial cleaners which contain such products as phosphoric
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT ' 253
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and .hydrofluoric acids; and organics such as chlorinated
benzenes. The implication of the first two substances is clear
and whenever they are used, strict in-house control steps should
be exercised to control their discharge. The problem of chlorin-
ated organic discharge is more serious, however. These materials
used in such applications as acid cleaners are moderately to
highly toxic to man and have a deleterious effect on waste
treatment plants and on receiving waters. It is expected that
treatability of these compounds is being studied by the industries
manufacturing them. It is suggested that further definition of
their impact, and discussions of in-house and pretreatment control
measures await the completion of those studies.
Definition of New Source
The definition of "New source" appears as follows in the "Act":
Section 306 (a) (2) . . . the term "new source" means
any source, the construction of which is commenced
after the publication of proposed regulations ore-
scribing a standard of performance under this section.
which will be applicable to such source if such
standsrd is thereafter promulgated in accordance with
this section.
In this report standards for performance in the Soap and
Detergent Industry are recommended for each of 18 unit processes
which cover the principal unit processes of this industry. Thus
it is recommended that a new source in soap and detergent manu-
facture be the installation of new equipment or chdlngcs in the
use of existing equipment employed in one of the 13 processes
described herein. A new source is further described as a
new "battery limits" of construction as the term is commonly
used in the chemical construction industry related to the IS
processes herein described. We have based our Level III
on the.battery limits definition tied to our 18 unit processes.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE EASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
DRAFT 254
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SECTION XII
ACKNOWLEDGMENTS
The guideline recommendations report for the soap and
detergent industry was prepared by a team consisting
of Mr. Colin A. Houston, Project Manager; Mr. Frederick
C. Herot, Chief Engineer; Mr. Charles H. Daniels, Biolo-
gist; and Ms. Susan M. Weisman.
In several specialized fields, a knowledge of which was
essential to a proper handling of the study, much appre-
ciated consultative services were rendered by Mr. G. C.
Feighner in the field of analytical chemistry; by Dr.
A. W. Fleer in chemical engineering; and by Mr. R. W.
Okey in sanitary engineering.
As the work progressed the technical competence of our
two subcontractor laboratories, Cook Research Laboratories,
Inc. in Palo Alto, California and Scientific Services in
Franklin Lakes, New Jersey proved invaluable.
Because of the wide-ranging scope of this study, its au-
thors had occasion to call upon many individuals and or-
ganizations for assistance in the course of bringing it
to completion. Many people, both as individuals and as
members of various organizations, responded with the ut-
most courtesy and generosity. The debt owed to each and
every one of them is gratefully acknowledged.
For their unflagging enthusiasm, long hours of field work,
and constructive criticisms throughout, we would like to
thank EPA's Dr. Richard Gregg, our untiring Project Officer
who, with his able consultant Mr. William Cloward, Chief,
Industrial Waste Section, Region IV, contributed so much
at all stages of the project and whose assistance is espe-
cially appreciated. Mr. John Ciancia, Chief, Industrial
Waste Technology Branch, Water Quality Research Laboratory,
was most helpful in the startup of the project.
Valuable counsel was received from Mr. Allen Cywin, Direc-
tor, Effluent Guidelines Division; Mr. Ronald McSwiney,
Program Advisor, Effluent Guidelines Division; Mr. George
Webster, Chief, Technical Analysis and Information Branch,
Effluent Guidelines Division; and Mr. David Mears, Contract
Officer.
Special help was received from EPA's staff at Regions II,
IV, V, VI, and VII. Generous assistance was provided by
DRAFT
255
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the Laboratory of the Division of Water Pollution and Con-
trol, Louisiana Wildlife and Fisheries Commission, Baton
Rouge, Louisiana and the following EPA laboratories.
Analytical Quality Control Laboratory, Cincinnati, Ohio,
Robert S. Kerr Water Research Center, Ada, Oklahoma and
the EPA Regional Laboratories in Athens, Georgia, Evans-
ville, Indiana and Kansas City, Kansas.
Three trade associations performed valuable liaison func-
tions in making the project a truly cooperative uhe; TKe
Soap and Detergent Association, the Chemical Specialties
Manufacturers Association, and the International Sanitary
Supply Association.
Throughout the country, soap, detergent, and fatty acid
producers, large and small, graciously assisted in pro-
viding process information and opening up their plants
to detailed study and sampling.
DRAFT
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SECTION XIII
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3. Air Pollution Control District, County of Los Angeles,
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DRAFT
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11. Bell, Doug. Report of Office of Air Programs.
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DRAFT
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Concentration Ratios in Manufacturing, Part 3: Employ-
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DRAFT
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34. Dreger, E. E. Low Temperature Catalytic Alcoholysis.
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59. Morris, R. L. Process Plant for Sulfation of Alpha
Olefins. Proctor and Gamble Company. U. j. Patent
3,234,258. ^1966)
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60. National Technical Advisory Commission. Water Quality
Criteria. Secretary of the Interior, Federal Water
Pollution Control Administration, Washington, D.C.
Government Printing Office. April (1968)
61. Pattison, E. Scott. Fatty Acids and Their Industrial
Application. Marcel Dekker, Inc., New York (1968)
62. Potts, R. H. and Me Bride, G. W. Continuous Hydroly-
sis Process of Colgate - Emery Companies. Chemical
Engineering. (1950)
63. Projected Wastewater Treatment Costs in the Organic
Chemicals Industry (updated). Datagraphics, Inc.,
Pittsburgh, Pennsylvania. July (1971)
64. Industrial Wastes: Their Disposal and Treatment.
Reinhold Publishing Corp, New York. (1953)
65. Sharpies Division of Pennwalt Company. Sharpies
Continuous Soap Process. Brochure. Pennwalt Company,
Warminster, Pennsylvania. April (1972)
66. Smith, Curtis W. Acrolein: Derivatives of Glyceral-
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67. Tashen, Edward S. and Booman, Keith A. Biodegrada-
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Class of Nonionic Surfactants. Proceedings of the
22nd Industrial Waste Conference, pp 211. Purdue
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68. Todd, David Keith. The Water Encyclopedia. Water
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69. Texas Division, The Dow Chemical Company. Treatment
of Wastewater from the Production of Polyhydric Organics,
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(1971)
70. Tyschbinek, G. Alcohol Estenification with Chlor-
sulfonic Acid. U.S. Patent 2,931,822. (1960)
262
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SECTION XIV
GLOSSARY
ABS - An abbreviation applied to a family of closely related
branched side-chain benzene compounds formerly used as sur-
factants in household detergents. ABS is an acronym for al-
kyl benzene sulfonate.
Act - The Federal Water Pollution Control Act Amendments
6T~1972, Public Law 92-500.
Aerobic - Growing only in air or free oxygen.
Aerobic Bacteria - Bacteria which require the presence of
free (dissolved or molecular) oxygen for their metabolic
processes. Oxygen in chemical combination will not support
aerobic organisms.
Alkalinity - A quantitative measure of fhe capacity of li-
quids or suspensions to neutralize strong acids or to re-
sist the establishment of acidic conditions. Alkalinity
results from the presence of bicarbonates, carbonates,
hydroxides, volatile acids, salts and occasionally borates,
silicates and phosphates. Numerically, it is expressed in
terms of the concentration of calcium carbonate that would
have an equivalent capacity to neutralize strong acids.
Amalgamator - A large horizontal mixer used to blend per-
fumeT dyes, fillers (titanium dioxide for whitening), and
other materials in the manufacture of soap.
Anaerobic Bacteria - Bacteria that do not require the pres-
ence of free or dissolved oxygen for metabolism. Strict
anaerobes are hindered or completely blocked by the presence
of dissolved oxygen and in some cases by the presence of
highly oxidized substances such as sodium nitrate , nitrites,
and perhaps sulfates. Facultative anaerobes can be active in
the presence of dissolved oxygen but do not require its
presence. See also aerobic bacteria.
Anaerobic Decomposition - Reduction of the net energy level
and change in chemical composition of organic matter caused
by microorganisms in an anaerobic environment.
Antioxidants - Phenolic and amino compounds which inhibit
oxidation of organic compounds.
Atmosphere - Unit of pressure. One atmosphere is normal
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atmosphere pressure.
Barometric ^Condenser - A system of both chilling vapors
into the liquid state from a gaseous state and reducing
the pressure in a vessel by means of a long column of water
flowing down a vertical pipe with considerable velocity.
Identical to the laboratory aspirator, which depends upon
the Venturi effect to create a vacuum.
Battery Limits - In considering plant construction and
costs, an arbitrary boundary between essential process
units and supporting facilities. Customarily within bat-
tery limits are reactors, stills, mixers, driers, and
fabricators. Usually outside battery limits are power
plants, cooling towers, sewage and water treatment, raw
material and product storage, laboratory and office buildings
and roads.
Best Available Demonstrated Control Technology (BADCT) -
Treatment required for new sources as defined by Section
306 (a) (2) of the Act. Level III.
Best Available Technology Economically Achievable (BATEA) -
Treatment required by July 1, 1983 for industrial discharges
to surface waters as defined by Section 301 (b) (2) (A) of
the Act. Level II.
Best Practicable Control Technology Currently Available
(BPCTCA) - Treatment required by July 1. 1977 for industrial
discharges to surface waters as defined by Section 301 (b)
(1) (A) of the Act.
Biological Cooling Tower - A cooling tower which is seeded
with microorganisms and fed with nutrients in which biological
degradation of organics occurs.
Biological Oxidation - The process whereby, through the
activity of living organisms in an aerobic environment,
organic matter is converted to more biologically stable
matter.
Biological Stabilization - Reduction in the net energy level
of organic matter as a result of the metabolic activity of
organisms.
Biological Treatment - Organic waste treatment in which bac-
teria and/or biochemical action is intensified under con-
trolled conditions.
Blowing Tower - See spray tower.
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BOD - Biochemical oxygen demand. An indirect measure of the
concentration of biologically degradable material present in
organic wastes. It is the amount of free oxygen utilized by
aerobic organisms when allowed to attack the organic matter
in an aerobically maintained environment at a specified
temperature (20°C) for a specific time period (five days).
It is expressed in milligrams of oxygen utilized per liter
of liquid waste volume (mg/1) or in milligrams of oxygen per
kilogram of solids present (mg/kg=ppm=parts per million parts)
Builders - Inorganic salts (usually) which augment the
cleansing or dirt-suspending power of a soap or detergent;
i.e., sodium silicate, sodium carbonate, carboxy methyl
cellulose, phosphates, etc.
Capital Costs - Financial charges which are computed as the
cost of capital times the capital expenditures for pollution
control. The cost of capital is based upon a weighted aver-
age of the separate costs of debt and equity.
Caustic - Sodium hydroxide, caustic soda.
Changes - Those separate and identifiable steps taken in the
manufacture of kettle boiling soap.
Chemical Oxidation - Oxidation of organic substances without
benefit of living organisms. Examples are by thermal combus-
tion or by oxidizing agents such as chlorine.
Clay - Alumino silicate minerals.
Closed Soap - That single phase of soap and water having a
creamy consistency while in the hot, agitated state.
COD - Chemical Oxygen Demand. An indirect measure of the
biochemical load exerted on the oxygen assets of a body of
water when organic wastes are introduced into the water.
Cold Frame Soap - A type of soap produced by solidification
by cooling and slicing into bars.
Condensate - The product resulting from a vapor condensing
into a liquid.
Cooling Water Slowdown - Whenever cooling water is reused
and run over atmospheric contactors (in turn cooled by am-
bient air) there is a buildup of contaminants. Periodically
it is necessary to dilute them or treat the cooling water to
"blow down" or rid the system of the concentrated contaminants
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Crutcher - A cylindrical vessel of 681 - 2270 kgs (1500 -
5000 Ibs) capacity in which soap or synthetic surfactants
are mixed with builders prior to drying. It is often steam
jacketed.
Deaerator - A piece of equipment for removing air dissolved
or suspended in a fluid.
Detergent - Technically, any cleaning agent, including ordi-
nary soap, the new "synthetic" granules and liquids, many
alkaline materials, solvent, or even sand when used for
scrubbing, whether used in the home or in industry. In
popular speech, the term "detergent" is generally applied
to packaged cleaning products based on a surface active
ingredient such as ABS or LAS. Its cleaning power is re-
tained in hard water, contrary to the performance of soap.
Dissolved Oxygen - The oxygen dissolved in sewage, water,
or other liquid, usually expressed as milligrams per liter
or as per cent of saturation.
Effluent - The outflow of a sewer; a wastewater stream from
a manufacturing process or plant.
Evaporator - A unit in which liquids are converted to gas.
Fat - Glycerol esters of long chain fatty acids of animal
or vegetable origin.
Fat Refining - Purification of fats by treatment with clay,
caustic, etc.
Fat Splitting - Various processes for hydrolysis of fatty
triglycerides to fatty acids and glycerine.
Fatty Acid - Naturally occurring straight chain carboxylic
acids which usually occur as triglyceride esters (fats).
Fatty Oil - Triglycerides which are liquid at room tempera-
ture.
Fitting Change - Also called pitching or finishing change,
is the final step in soap making in which clear water is
mixed with the soap to separate the neat soap from the
nigre.
Foots - The residue of refining fats or oils which contain
color bodies, insolubles, suspended matter, etc.
Full Boil Process - Soap making where the neat soap is com-
pleted in the kettle and the by-product glycerine drawn off.
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Heels - The residue remaining from any processing unit
after drawing.
Killing Change - The first step in soap manufacture where
fresh fat is brought into contact with a lye solution.
The start of the saponification process.
LAS - A new surfactant in which a straight chain hydro-
carbon has been joined to the benzene ring. It has a high
rate of biodegradability.
Low Grade Fatty Acids - These are contaminated fatty acids
derived from recovery of scrap, acidification of nigre, and
contaminated fatty acid raw materials.
Mazzoni Process - A proprietary process for manufacture of
soap.
mg/1 - Milligrams per liter.
Neat Soap - An intermediate, completely saponified and puri-
fied soap containing about 20 - 30% water, ready for final
formulation into finished product.
New Source - Any building, structure, facility or installa-
tion from which there is or may be a discharge of pollutants
and whose construction is commenced after the publication of
the guidelines.
Nigre - The bottom layer which separates out in the last wash-
ing step of kettle boiling soap which contains the impurities
leading to poor color, odor, etc. Often contains 20 - 25% of
the kettle contents at that stage of the soap making and
possesses a soap content of 30 - 40%. The nigre can be
concentrated and salted out to yield a low grade colored
soap for sale.
No Discharge of Pollutants - No net increase (or detectable
gross concentration if the situation dictates) of any para-
meter designated as a pollutant to the accuracy that can be
determined from the designated analytical methods.
Oil - Fats found in liquid form at room temperature. Gly-
cerol esters of long chain fatty acids.
Oleum - A solution of 803 in sulfuric acid.
Operations and Maintenance Costs - Those required to operate
and maintain pollution abatement equipment. They include
labor, material, insurance, taxes, solid waste disposal, etc.
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p_H - A measure of the relative acidity or alkalinity of
water. A pH of 7.0 indicates a neutral condition. A
greater pH indicates alkalinity and a lower pH indicates
acidity. A one unit change in pH indicates a tenfold change
in acidity and alkalinity.
Phenol - Class of cyclic organic derivatives with the basic
formula CgH5OH.
Plodder - A powerful homogenizer which resembles a sausage
grinder in design; used for the final processing of bar
soap wherein the occluded air is removed (under partial
vacuum) and the individual soap particles melded into one
continuous homogenous whole prior to being cut up into bar
stock.
Pollution - The presence in a body of water (or soil or air)
of substances of such character and in such quantities that
the natural quality of the body of water (or soil or air) is
degraded to a point where the water is rendered useless or
offensive to the senses of sight, taste or smell. Contami-
nation may accompany pollution. In general, a public health
hazard is created, but in some cases only economy or esthetics
are involved as when waste salt brines contaminate surface
waters or when foul odors pollute the air.
Pretreatment - Treatment provided prior to discharge to a
publicly owned treatment works.
Process Water - In the manufacture of soap and detergent,
all waters that come into direct contact with the raw mater-
ials , intermediate products, final products or contaminated
waters or air.
Refractory BOD - Organic substances which are slowly or
incompletely degraded by microorganisms.
Saponification - The hydrolysis of an ester into its
corresponding alcohol and soap.
Secondary Treatment - Biological treatment provided beyond
primary clarification, usually aerobic activated sludge,
trickling filters or lagoon systems.
Semi-boil Process - That soap making process wherein the
exact (stoichiometric) amount of caustic is added to fat
for saponification, and the soap is then run off into frames
or further processed without the benefit of removal of by-
product glycerine.
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Sewage - Water after it has been fouled by various uses.
From the standpoint of source it may be a combination of
the liquid or water-carried wastes from residences, office
buildings and institutions together with those from indus-
trial and agricultural establishments, and with such ground-
water, surface water and storm water as may be present.
Sewer Lyes - Waste sodium hydroxide from reclaiming of scrap
soap.
Silicates - A chemical compound containing silicon, oxygen,
and one or more metals. In soaps and detergents, sodium
silicates are added to provide alkalinity and corrosion
protection.
Soap Boiling - The process of heating a mixture of fats/oils
with caustic solution until the fatty ester is split and
the alkaline metal salt formed, glycerine being released in
the process. The step where saponification takes place.
Soda Ash - Sodium carbonate.
Spray Drying Tower - A large vessel in which solids in
solution or suspension are dried by falling through hot gas.
Stabilizers - An additive which gives physical and/or
chemical stability to a formulation.
Still - A distillation apparatus.
Strong Change - That step in the soap making process where
virgin, strong lye is added to the already saponified fat
to finally complete saponification of remnants of fat.
Surface Waters - Navigable waters; the waters of the U.S.
including the territorial seas.
Sweet Water - By-product aqueous glycerine from soap manu-
facture"!
Synthetic Detergent - Chemically tailored cleaning agents
soluble in water or other solvents. Originally developed
as soap substitutes. Because they do not form insoluble
precipitates, they are especially valuable in hard water.
They are generally combinations of surface active agents
and complex phosphates to enhance detergency.
TDS - Total dissolved solids.
TSS - Total suspended solids.
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