EPA-600/2-75-055
October 1:815
Environmental Protection Technology Series
TREATMENT OF TEXTILE WASTEWATER BY
ACTIVATED SLUDGE AND ALUM COAGULATION
PRO
Environmsntai lessarcrt Laboratory
Office of Research and Developont
U.S. Environmental Protectisn Agency
Rssearch Triangle Park, M.C. 27711
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development,
U.S. Environmental Protection Agency, have been grouped into
five series. These five broad categories were established to
facilitate further development and application of environmental
technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in
related fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed
to develop and demonstrate instrumentation, equipment and
methodology to repair or prevent environmental degradation from
point and non-point sources of pollution. This work provides the
new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
EPA REVIEW NOTICE
This report has been reviewed by the U. S. Environmental Protection
Agency, and approved for publication. Approval does not signify that
the contents necessarily reflect the views and policies of the Agency, nor
does mention of trade names or commercial products constitute endorse-
ment or recommendation for use.
This document is available to the public through the National
Technical Information Service, Springfield, Virginia 22161.
-------
EPA-600/2-75-055
TREATMENT OF TEXTILE WASTEWATER
BY ACTIVATED SLUDGE
AND ALUM COAGULATION
by
Thomas L. Rinker
Blue Ridge-Winkler Textiles
Division of Lehigh Valley Industries, Inc.
High and Kline Streets
Bangor, Pennsylvania 18013
Grant No. S801192
ROAPNo. 21AZT-006
Program Element No. 1BB036
EPA Project Officer: Thomas N. Sargent
Industrial Environmental Research Laboratory
Office of Energy, Minerals, and Industry
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
October 1975
-------
CONTENTS
SECTION PAGE
LIST OF FIGURES v
LIST OF TABLES viii
ACKNOWLEDGMENTS xi i
I. CONCLUSIONS 1
II. RECOMMENDATIONS 5
III. INTRODUCTION 6
IV. DESCRIPTION OF THE MANUFACTURING FACILITY
A. FABRICS PROCESSED 15
B. MANUFACTURING OPERATIONS 20
V. WASTEWATER CHARACTERIZATION
A. ANALYTICAL AND SAMPLING METHODS 30
B. SUMMARY OF WASTEWATER CHARACTERISTICS 33
VI. GENERAL DESCRIPTION OF THE TREATMENT SYSTEM 38
VII. PRE-TREATMENT STEPS
A. WASTE COLLECTION 48
B. HEAT RECLAMATION AND EQUALIZATION 50
VIII. ACTIVATED SLUDGE SYSTEM PERFORMANCE
A. EFFLUENT REMOVAL 53
B. OPERATING CHARACTERISTICS 58
IX. ALUM COAGULATION SYSTEM PERFORMANCE
A. EFFLUENT REMOVAL 70
B. OPERATING CHARACTERISTICS 77
X. COMBINED ACTIVATED SLUDGE AND ALUM COAGULATION
SYSTEM PERFORMANCE 94
-------
CONTENTS (CONT'D)
SECTION PAGE
XI. SLUDGE HANDLING SYSTEM PERFORMANCE
A. CHEMICAL AND BIOLOGICAL ANALYSES 105
B. VACUUM FILTER OPERATION 110
C. CENTRIFUGE OPERATION 112
XII. SUMMARY OF COST INFORMATION 116
XIII. OPERATIONAL AND MECHANICAL DIFFICULTIES
A. PROCESS 120
B. MECHANICAL 124
XIV. ANALYSES OF PRODUCTION CHEMICALS AND PROCESSES
A. CHARACTERIZATION OF CHEMICALS AND DYES 126
B. ACTIVATED SLUDGE TREATABILITY STUDIES 136
C. ALUM COAGULATION TREATABILITY STUDIES 140
D. CHARACTERIZATION OF PROCESS STREAMS 145
E. MANUFACTURING EFFECTS ON WASTEWATER
CHARACTERISTICS 153
XV. SUMMARY OF RESEARCH ACTIVITIES ON ALTERNATIVE TREATMENT
PROCESSES
A. INITIAL TREATABILITY STUDIES 156
B. BATCH TREATABILITY STUDIES 158
C. ALTERNATIVE COAGULANTS 160
D. POLYMER ADDITION TO ACTIVATED SLUDGE 163
E. TWO STEP ALUM COAGULATION 164
F. CHEMICAL OXIDATION 167
G. POWDERED ACTIVATED CARBON 175
H. GRANULAR CARBON ADSORPTION 177
I. RESIN ADSORPTION 181
J. MONITORING 184
XVI. CHARACTERISTICS OF THE RECEIVING STREAM 185
XVII. REFERENCES 187
XVIII. APPENDICES 189
iv
-------
LIST OF FIGURES
NUMBER PAGE
I U. S. Ffber Consumption 7
II Chronological Plot of Dally Production Values 18
III Chronological Plot of Dally Beam Production Values 18
IV Chronological Plot of Arnel/Nylon Production Values 18
V Correlation of Beam Production To Total Production 19
VI Manufacturing Process Flow Sheet 21
VII Chronological Plot of Daily Equalized Waste Flow 35
VIII Graph of Twenty Day BOD Data For Equalized Raw
Waste 35
IX Wastewater Color as a Function of pH 37
X Spectrophotometric Curves for Equalized Raw Waste 37
XI Site Plan-Wastewater Treatment Plant 39
XII Wastewater Treatment Plant Process Flow Sheet 40
XIII Fraction of BOD Remaining as a Function of the
F/M Ratio 61
XIV BOD Removal Rate 61
XV COD Removal Rate 61
XVI Ammonia Nitrogen Removal Rate 62
XVII Color Removal Rate 62
XVIII Oxygen Consumption Rate 64
XIX Aeration Basin Cooling 64
XX Sludge Production Rate Based on COD Removal 66
-------
NUMBER LIST OF FIGURES (CONT'D) PAGE
XXI Sludge Production Rate Based On BOD Removal 66
XXII Clarlfier Performance 68
XXIII Variation In Sludge Volume Index 68
XXIV Static Settling Curves For The Mixed Liquor 69
XXV Color Removal In The Treatment System 71
XXVI Spectrophotometrlc Curves For Alum Coagulation
Effluent 75
XXVII Solubility In Water of the Mixed Salt of
Aluminum, Sulfate, and Hydroxide 75
XXVIII Typical COD and BOD Removals By Alum Coagulation
At a pH = 6.0 79
XXIX Typical COD and BOD Removal Variation With pH
at an Alum Dose of 300 mg/l 79
XXX Typical Color Removal Variation With Alum Dose
and pH 81
XXXI Typical Orthophosphate Removal Variation With
Alum Dose and pH 81
XXXII Residual Chromium and Aluminum Variation with pH
at an Alum Dose = 400 mg/l 81
XXXIII Distribution of Hydrolyzed Aluminum (III) as a
Function of pH 83
XXXIV Schematic Representation of Coagulation 83
XXXV BOD Removal by Alum 86
XXXVI COD Removal by Alum 86
XXXVII Color Removal by Alum 87
XXXVIII Color Removal as a Function of pH 87
XXXIX Alum Coagulation Clarlfier Performance 89
vl
-------
NUMBER LIST OF FIGURES CCONT'D) PAGE
XL Alum Sludge Generation 89
XLI Static Settling Curves For Alum Sludge 90
XLII Suspended Solids Removal as a Function of pH 92
XLIII TItration of Activated Sludge Effluent 92
XLIV Survival Curve For One Month Leachate 109
XLV Survival Curve For Six Month Leachate 109
XLVI Survival Curve For Wet Sludge 109
XLVII Solids Recovery In Pilot Centrifuge 113
XLVIII APHA Color Values For Production Dyestuffs 130
XLIX Multiple Dilution BOD Data For Carrier NT 133
L Activated Sludge Treatabllity Data For Carrier NT 138
LI Dye Removal By Alum Coagulation 144
LII Correlation of Wastewater Flow With Beam Production 155
LIII Correlation of Wastewater COD With Beam Production 155
LIV Correlation of Wastewater Color With Production 155
LV Batch Activated Sludge Treatability Data 159
LVI Coagulation Equalized Raw Waste 161
LVII Residual Color Removal By Chi orI nation 168
LVIII Initial Color Removal By Ozonation 170
LIX Typical Color Removal By Ozonation 170
LX COD Removal By Ozonation As A Function of Contact
Time 171
LXI Activated Carbon Isotherms For Color 178
LXII Activated Carbon Isotherms For COD 178
LXIII Color Removal By Resin Adsorption 182
C-I Calibration Curve For Hach Colorimeter 193
vii
-------
LIST OF TABLfS
NUMBER PAGE
I Growth Rates of Textile Fibers 7
II Dyestuff Use and Growth 8
III Textile Industry Wastewater Treatment In 1972 10
IV Federal Effluent Guidelines Category E II
V Discharge Criteria For A Textile Mill In
Pennsylvania 12
VI Summary of Production Data By Fabric Construction 16
VII Summary of Production Data By Manufacturing Process 17
VIII Atmospheric Becks In Production 22
IX Sampling and Analysis Matrix 31
X Summary of Equalized Waste Characteristics 34
XI Summary of Major Treatment System Process Parameters 45
XII Analysis of Batch Wastewater Discharges From the
Mill One Dyehouse 49
XIII Analysis of Contaminant Equalization 52
XIV Summary of Activated Sludge Effluent Characteristics 54
XV Summary of Percentage Removals in Activated Sludge 55
XVI Activated Sludge Operating Characteristics 59
XVII Summary of Alum Coagulation Effluent Characteristics 72
XVIII Summary of Percentage Removals in Alum Coagulation 73
XIX Alum Coagulation Operating Characteristics 78
XX Predicted Removals By Alum Coagulation 85
viii
-------
NUMBER
XXI
XXII
XXIII
XXIV
XXV
XXVI
XXVII
XXVIII
XXIX
XXX
XXXI
XXXII
XXXIII
XXXIV
XXXV
XXXVI
XXXVII
XXXVIII
XXXIX
XL
LIST OF TABLES CCONT'D) PAGE
Summary of Total System Removal Rates 95
Effluent Contaminant To Production Weight Ratios
Based On Selected Data Analysis 96
Basis of Process Design Calculations 98
Process Design Calculations For Contaminant
RemovaI 99
Process Design Calculations For Sludge Production 101
Process Design Calculations For Operating
Characteristics 103
Treatment Process Material Balance 104
Chemical Analysis of Waste Sludge 106
Sludge Leachate Characteristics 107
Summary of Vacuum Filter Performance III
Summary of Centrifuge Performance 114
Summary of Centrate Characteristics 115
Summary of Cost Information 117
Basis of Estimated Operating Cost For Design
Treatment Level 119
Analysis of Ambient Air At The Aeration Lagoon
Surface
121
127
128
Chemical Oxygen Demand of Production Chemicals
Chemical Oxygen Demand of Production Dyes
Chemical Oxygen Demand From Various Fabric Washwater 129
Summary of Multiple Dilution BOD Data 132
Average Metal Concentration of Selected Dyes 134
Ix
-------
NUMBER
LIST OF TABLES (CONT'D)
PAGE
XLI Analysis of Foaming and Odor Characteristics
of Production Chemicals 135
XLII Summary of Batch Activated Sludge Treatablllty
Data For Chemicals and Dyes 137
XLIII COD Loss On Aeration of Production Chemicals 139
XLIV Alum Coagulation of Production Chemicals Using
Jar Test Procedures 141
XLV Alum Coagulation of Production Dyes For Color
Removal Using Jar Test Procedures 142
XLVI Alum Coagulation of Production Dyes For COD
Removal Using Jar Test Procedures 143
XLVII Characterization of Municipal Water 146
XLVIII Characterization of Wastewater From Apparel Fabric
Manufacturing 147
XLIX Characterization of Wastewater From Velour Fabric
Manufacturing 148
L Characterization of Wastewater From Uniform Fabric
Manufacturing 149
LI Characteristics of Finish Bath Discharges 150
LII Scrubber Water From Tenter Frame Air Pollution
ControI Equ i pment 151
LIII Characteristics of Slowdown Water 152
LIV Unit Water Rates For Production Processes 154
LV Pilot Scale Activated Sludge Performance 156
LVI Pilot Scale Alum Coagulation Performance 157
LVII Color Removal By Two Step Alum Coagulation 164
LVI 11 Solids Generation In Two Step Alum Coagulation 165
LVIX Estimated Effluent Characteristics From A Two Step
Alum Coagulation Process 166
-------
LIST OF TABLES CCONT'D) PAGE
Summary of Ozone and Filtration Process Design
Parameters 173
Summary of Ozone and Filtration Cost Data 174
Performance of a Powdered Activated Carbon Aided
Activated Sludge System 176
XIII Removal of Color By Activated Carbon 177
XIV Removal of COD By Activated Carbon 179
XV Cost Information For Granular Carbon Adsorption
Systems 179
XVI Performance of a Resin Adsorption Process 181
XVII Summary of Cost Information For A Resin Adsorption
Process 183
XVIII Analysis of Martins Creek Water Above BRW 186
i-I Tabulation of Production Chemical Use I9(D
(-1 Tabulation of Production Dye Use I9f
i-I Laboratory Qua Iity "Control Check Using Spiked
Samp I es 1:97
>-II Laboratory Quality Control Check Using Split
Samples 198
xi
-------
This report was prepared by Blue RIdge-Wlnkler Textiles, Division of
Lehlgh Valley Industries, Inc., for the National Environmental Research
Center, United States Environmental Protection Agency, Corvallls,
Oregon. The Project Director and report author was Thomas L. RInker,
Environmental Engineer for BRW.
Mr. Gerald Houck, Environmental Chemist at BRW, was responsible for the
analytical and laboratory research work for the project.
EPA Project Officer for the study was Mr. Thomas N. Sargent of the EPA
Southeast Environmental Research Laboratory'In Athens, Georgia.
The report Is submitted In fulfillment of commitments Incurred under
federal demonstration grant S80II92.
xll
-------
SECTION I
CONCLUSIONS
Blue Ridge-WFnkler Textiles, Bangor, Pennsylvania, conducted a one-
year demonstration project of its wastewater treatment plant for the
United States Environmental Protection Agency.
The demonstration project involved monitoring the performance of the
activated sludge-alum coagulation treatment system, collecting
production data for correlation with wastewater data, and conducting
basic research regarding treatment process improvement.
An analysis of the operating and research data gathered during the
course of the grant project has produced these following conclusions.
I. The wastewater was found to contain a significant
quantity of (a) degradable and refractory organic
chemicals, (b) soluble and colloidal dyestuffs,
(c) nitrogen and phosphorous and (d) certain heavy
metaIs.
Median values for wastewater flow, BOD, COD, and
color were 0.53 MGD, 448 mg/l, 1,553 mg/l, and
1,032 APHA units, respectively.
2. The treatment system, consisting of an activated
sludge process and an alum coagulation process
operating In series, was found to be capable of
producing a high quality effluent from a textile
mill producing knit synthetic fabric for the apparel
and automotive upholstery trades.
3. The activated sludge process was determined to be
an effective mechanism for removal of soluble,
degradable organic chemicals and ammonia nitrogen
when operated with a mixed liquor suspended solids
level of 2928 mg/l and a 14.4 hour residence time.
Removals of BOD, COD, color, and ammonia nitrogen
were 78 percent, 42 percent, 30 percent, and 73 percent,
respectively.
-------
4. The alum coagulation process was determined to be an
effective mechanism for removal of colloidal organic
chemicals (including dyes), suspended solids,
orthophosphate, chromium, copper, and zinc when
operated with an alum dosage of 262 mg/l and a pH of
6.2. Removals of BOD, COD, color, suspended solids,
and orthophosphate were 75 percent, 58 percent, 58
percent, 70 percent and 70 percent, respectively.
5. Removals of BOD, COD, color, and suspended solids by the
total treatment system were found to be 94 percent,
76 percent, 71 percent, and 40 percent, respectively.
Effluent concentrations of BOD, COD, color, and
suspended solids based on these removal percentages
were found to be 25 mg/l, 380 mg/l, 303 APHA units,
and 104 mg/l, respectively.
Effluent contaminant to production weight ratios for BOD,
COD, and suspended solids based on these removal
percentages were found to be 2.22 Ibs/IOOO Ibs (kg/kkg),
34.05 Ibs/IOOO Ibs (kg/kkg), and 9.31 Ibs/IOOO Ibs
(kg/kkg), respectively.
6. Mathematical models and graphical representations of the
performance data predicting performance of the total
system under a variety of influent wastewater and
operating conditions, was accomplished for both the
activated sludge and alum coagulation processes..
7. The activated sludge system was found to generate 943 pounds
(428 kilograms) of solids per day, and the alum coagulation
system was found to generate 1347 pounds (612 kilograms)
of solids per day. These solids were successfully
dewatered from a feed solids concentration of 1.50 -
1.75 percent to a discharge solids concentration
of 10.0 - 15.0 percent using a horizontal solid bowl
centrifuge with a cat ionic polymer additive.
8. Operating cost of the system was determined to be
$269,030 per year or $1.65 per thousand gallons
($0.43 per cubic meter) treated. Capital cost was
determined to be $1,150,000 for a 1.25 million gallon
(4731 cubic meter) per day capacity system. Operating
cost for a system operating at capacity was estimated to
be $1.20 per thousand gallons ($0.32 per cubic meter) treated,
and $0.014 per pound ($0.03 per kilogram) of product.
-------
9. Research Indicated that performance of the alum
coagulation system could be optimized if the process
were carried out using two step neutralization and
dual media final filtration. Effluent COD, suspended
solids, and color values would be 300 mg/l, 25 mg/l,
and 200 APHA units respectively. The increase in
operating cost for this modification would be
•$13,000 per year or $0.04 per design thousand gallons
($0.01 per cubic meter), and the increase in
capital cost was estimated at $200,000 for a 1.25
million gallon (4731 cubic meter per day) capacity
system.
10. The treatment system, even with a modification of the
alum coagulation system to a two-step process, would not
be capable of removing refractory organic material
or soluble dyestuffs to levels sufficient to meet
probable future discharge standards.
II. For removal of soluble color only, pilot investigation
Indicated that ozone oxidation following alum coagulation
was the least costly process available. This process would
yield a color level of 50 to 75 APHA units using a 10-15
mg/l dosage and a 5 to 10 minute reaction time when run
at a wastewater pH of 5.0. Operating cost of the process
would be an additional $37,000 per year or $0.10 per
design thousand gallons ($0.03 per cubic meter) treated,
and capital cost of the ozone system equipment would be
an additional $250,000 for a 1.25 million gallon (4731
cubic meter) per day system.
12. For an activated sludge/alum coagulation/ozonation/
filtration system designed for 1.25 million gallon
(4731 cubic meter) flow, the operating cost would be
$1.34 per thousand gallons treated ($0.36 per cubic
meter. Capital cost for the system was estimated to
be $1,600,000.
13. Chlorine or hydrogen peroxide oxidation were found not
to be effective for residual soluble color removal
except at high dosages or under special conditions.
14. For removal of refractory organic material and color,
a columnar adsorption process using either granular
activated carbon or polymeric and ion exchange resins would
be required as determined by bench scale investigations.
Capital costs for the carbon and resin systems were
estimated to be $636,000 and $836,000, respectively, for
a 1.25 million gallon (4731 cubic meter) per day facility.
-------
Operating cost of the systems was estimated to be
$0.44 per 1000 gallons ($0.12 per cubic meter)
treated for the carbon process and $0.48 per 1000
gallons ($0.13 per cubic meter) * - "ted for the
res i n.
15. The addition of powdered activated carbon to the
activated sludge system was found to appreciably
increase BOD removal capacity but did not result
in additional color reduction.
16. The total production level averaged 48,400 pounds
(22,000 kilograms) per day and wastewater was produced
at the rate of 12.05 gallons per pound of product
(0.10 cubic meter per kilogram). Pressure beam
dyed production of a nylon/arnel blend fabric was
found to account for 53.4 percent of total yearly
production. A graphical representation of the
effect of beam production on wastewater flow, COD,
and color was accomplished with the result that the
waste load to the treatment system could be predicted
based on beam production.
-------
SECTION II
[OTTENDATIONS
The following recommendations are in order following a review
of the results and conclusions of the study.
I. The performance of a full-scale two-step alum
coagulation process using dual media filtration
for final suspended solids removal, and a full-
scale ozonation system for residual, soluble
color removal should be demonstrated.
2. The potential for partial re-use of wastewater
from an activated sludge/alum coagulation/ozonation/
filtration system should be defined by a demonstration
project using laboratory and pilot-scale production
machinery.
3. The chemistry of the alum coagulation process should be
investigated in detail by a laboratory research project
to determine the factors affecting wastewater contaminant
removal in order that the process may be more
confidently applied for wastewater treatment in the
textile industry.
4. Cost projections of the alum coagulation process as
an addition to an activated sludge system should be
made.
5. A long-term research project should be initiated to
determine the cost and adverse environmental affects
of dewatering and disposing of sludge from an activated
sludge/alum coagulation system.
6. The residual chemicals remaining in textile wastewaters
after activated sludge and alum coagulation treatment
needs to be defined in order to allow for additional
waste reduction by consideration of in-plant changes.
7. Standard procedures need to be developed for evaluation
of the treatability of production chemicals by common
wastewater processes and for the assessment of the
potential Impact on the aquatic environment of the residual
amounts of these chemicals remaining 'after treatment.
-------
SECTION III
mnrajcnoN
PERSPECTIVE
The textile industry in the United States is one of the country's major
users of water as a basic raw material in the manufacturing processes.
This industry segment accounts for about one percent of all the aqueous
industrial discharge after the water has been used as a conveyor for the
chemicals and dyestuffs associated with converting raw fibers into
finished fabrics. The waste discharge is significant not only in volume
but also in the concentration and complexity of the contaminants that may
be present. Because the textile industry and Its effluents are so
diverse, it is helpful to view the industry not simply as a group of fiber
processors but as a large number of unique chemical processing plants
using a wide range of fibers, chemicals, dyestuffs, water, machinery, and
flow sheets to produce a final fabric. Each individual plant's discharge
can result in the addition to the nation's waterways of significant
quantity of degradable and non-degradable organics, nutrients, heavy metals,
toxic agents, and inorganic salts. The discharges contain both
conspicuous pollutants such as color and foam producing material and
insidious pollutants such as trace metals and organics.
One method that may be used to distinguish the segments of the textile
Industry is to analyze production in terms of fiber type. Historically
the natural fibers have constituted the bulk of yearly production in
this country, but recently the advent of man-made (synthetic) fibers
has resulted In an increasingly larger share of total production going
to production of new synthetic fibers and to production of knit fabric.
For example, there has been a 286 percent growth In knit synthetics, a
381 percent growth In woven synthetics, and a 12 percent decline in
cotton woven production since 1958.(9) Rayon was the first synthetic
and it was shortly followed by the cellulose acetates, nylon, polyester
and acrylic. In the last few years the list of synthetic fibers being
manufactured has dramatically increased. Figure I illustrates the sharp
increase in synthetic fiber consumption compared with the natural fibers,
and Table I projects the growth of synthetics for the next five years.
-------
FIBER CONSUMPTION-billlons of pouni
^ ->M(J^uiO>vlO>
ID
\^J
r ?-
/
— 0
60 »65 1970 1975
FIGURE I, U.S. fiber consumptfon(9)
TABLE I
GROWTH RATES OF TEXTILE FIBERS(6)
PERCENT INCREASE (DECREASE)
1970 BASE YEAR
FIBER 1972 197**
COTTON 13.9 (2.3)
WOOL (3.8) (4.0)
NYLON 49.2 20.1
ACETATE (11.6) 0
POLYESTER 39.5 26.0
ACRYLIC 21.7 14.2
RAYON (2.0) (6.2)
FROM PREVIOUS PERIOD
1976
(2.2)
0
14.6
2.6
22.3
12.5
(6.6)
1978
(2. ^)
(4.2)
17.2
2.6
18.1
11.4
(5.9)
-------
This growth in the synthetic fiber portion of the textile Industry
has resulted in significant changes in dye and chemical use and in
process flow sheets.
In the case of dyes, there has been a marked increase in the quantity
of dyes used in processing synthetics while the use of dyes
associated with natural fibers has declined. This data is
iIlustrated in Table II.
TABLE II
DYES7UF USE AND GROW
(6,7)
DYESTUFF
PERCENT PERCENT
FIBER OF TOTAL GROWTH
COTTON WOOL ACETATE POLYESTER NYLON RAYON USE 1975-1978
ACID
AZOIC
BASIC
DIRECT
DISPERSE
FIBER-
REACTIVE
SULFUR
VAT
X
X
X
X
X
X
X
X
X
X
X
10
3
6
17
15
1
10
26
6.3
7.2
2.8
9.7
8.2
(3.5)
With the development of polyester, a new group of auxilliary chemicals -
carriers - were introduced to allow the use of available dyes and equip-
ment. The trend to synthetics has also resulted in the increased use
of dyebath auxiliaries for leveling, penetration, fastness, softness,
and several other uses. An increased emphasis on durability has resulted
in the Increased use of finishes for softness, water repellency, soil
release, fire retardancy, and lubrication for mechanical finishing. These
new chemicals represent a broad range of organic/inorganic chemicals and
are a major reason for the diversity of wastewater characteristics in the
industry.
Smilarly, new equipment such as beam dyers, pressure becks, and jet
dyers have been developed as improvements on the basic atmospheric
beck in order to economically produce the new fibers using available
dyes.
8
-------
The United States Environmental Protection Agency (EPA) has segmented
the industry as follows for the purpose of developing industry
discharge guidelines as mandated by the 1972 Water Pollution Control
Act Amendments. °'
A. Wool scouring
B. Wool finishing
C. Dry processing
D. Woven fabric finishing
E. Knit fabric finishing
F. Carpet mills
G. Stock and yarn dyeing and finishing
Of the approximately 7100 textile plants in this county, approximately
1300 mills include wet processing operations and are part of the EPA
classifications. Approximately seventeen percent are in the knit
finishing segment, category "E" of the EPA effluent guideline
categories. ' This segment of the industry is relatively new, with
significant production beginning in the early I960's.
The textile industry over the last several decades has concentrated
its growth in the southeastern section of the country. For the knit
fabric finishing category, approximately twenty-eight percent of
the mills are now located in this geographical area with approximately
sixty percent of the goods for this category produced by these mills.
Given the demographic pattern of smaller communities in this area and
the likelihood that these communities have limited funds for wastewater
treatment facilities, it can be expected that industry owned treatment
facilities will be the available method of obtaining adequate treat-
ment of the wastewater prior to discharge.
Although no data are available, it is generally recognized that a
significant number of mills in the textile industry are not part of
large parent corporations but are part of small companies. If
the number of employees is used as a guide to illustrate this fact,
approximately thirty-six percent of the knit fabric finishing category
mills employee less than fifty people. ' These mills have limited
resources for supplying the capital for equipment or for retaining
expert advice for problems of environmental control. As a result,
these firms depend heavly on industry associations and governmental
agencies for direction in abating air and water pollution.
-------
TREATMENT REQUIREMENTS
Increasing public awareness of environmental issues has resulted in
increasing attention to water pollution control measures for all of
industry. In particular, environmental concern was sharply focused on
industry with the passage of the Federal Water Pollution Control Act
Amendments of 1972 (PL 92-500). Among the requirements of this
legislation is the mandate for implementation of the "best practicable
control technology currently available" by 1977, "best available control
technology economically achievable" by 1983, and the establishment of
a national goal of "zero discharge of pollutants" by 1985.
The historic method of textile wastewater treatment is by biological
processes in either public or private systems as illustrated in Table III
TABLE III
TEXTILE INDUSTRY WASTEWATER TREATTeT
IN 1972(7)
TO MUNICIAL TREATMENT SYSTEMS 35%
PRIMARY TREATMENT ONLY 5%
SECONDARY TREATMENT 45%
NO TREATMENT 15%
In January, 1974, when the EPA published the tentative discharge
guidelines for the industry, it chose activated sludge as the model
for best practicable treatment, currently available (BPTCA) technology.
For the best available treatment, economically achievable (BATEA)
technology, the EPA again seIected.activated sludge in combination
with a tertiary treatment process/7' Essentially, the criteria
proposed by the guidelines seek to limit only the gross organic
content of the wastewater as indicated by BOD, COD, and suspended
solids values. The American Textile Manufacturers Institute (ATMI),
while agreeing with the selection of the processes for the treatment
models, judged the tentative guidelines as too restrictive and proposed
an alternate set of values/3^ The final EPA industry guidelines
were published in the Federal Register on July 5, 1974. ^ These
several sets of guidelines for industry category "E" are summarized
in Table IV.
10
-------
TABLE IV
NT GUIDELINES CATEGORY E
PARAMETER
SUSPENDED
SOLIDS
EPA BPTCA EPA BATEA ATM I
PROPOSED FINAL PROPOSED FINAL BPTCA
CPOUNDS/1000 POUNDS OR K/KKG OF PRODUCT}
BOD
COD
1.8
24.0
2.5
40.0
1.2
6.4
1.7
13.3
4.0
40.0
8.0
10.9
5.3
1.7
6.0
Several states, particularly in the northeastern area of the country,
had adopted prior to the issuing of the federal guidelines either
effluent or stream criteria which limited discharges in the content
of nutrients, metals, color, or foam producing material. It can be
anticipated that the implementation of similar criteria will
continue to spread among the states and will become increasingly
important to the industry, particularly if stream limited (the
discharge is a significant portion of the design stream flow) criteria
apply. The latest Pennsylvania discharge criteria for a stream
limited textile discharge are presented in Table V. Regional agencies
such as the Delaware River Basin Commission (DRBC) have also been
increasingly active in setting criteria and have also adopted
restrictions limiting discharges.
AVAILABLE TECHNOLOGY
Wastewater treatment practice for the textile industry has been
concerned almost exclusively with the removal of degradable organic
material by biological treatment processes. However, wfth the changing
nature of textile wastewaters, considerable work needs to be done to
demonstrate through long term projects the efficiency of other
available treatment methods. The most critical need is to evaluate
those processes which could be added to an activated sludge treatment
system already in existence in order to minimize capital requirements
while providing for removal of additional contaminants.
II
-------
TABLE V
DISCHARGE CRITERIA FOR A TEXTILE
MILL IN PENNSYLVANIA
PARAMETER
AVERAGE VALUE
MAXIMUM VALUE
PENNSYLVANIA DEPARTMENT OF ENVIRONMENTAL RESOURCES
BOD CMG/L)
SUSPENDED SOLIDS CMG/L)
DISSOLVED SOLIDS CMG/L)
AMMONIA NITROGEN CMG/L)
TOTAL PHOSPHOROUS CMG/L)
COLOR CAPHA)
OIL AND GREASE CMG/L)
PHENOL CMG/L)
FOAM
CHROMIUM CMG/L)
ALUMINUM CMG/L)
IRON CMG/L)
ZINC CMG/L)
25
25
2.0
1.5
60
10
0.05
NO FOAM 50 YARDS
0.09
1.0
0.75
0.3
DELAWARE RIVER BASIN COMMISSION
BIOASSAY
50
50
1000
4.0
3.0
15
0.10
BELOW DISCHARGE
0.18
2.0
1.5
LESS THAN 50% MORTALITY
AFTER 96 HOURS AT A 1:1
DILUTION
BOD
SUSPENDED SOLIDS
DISSOLVED SOLIDS
95% REMOVAL
90% REMOVAL
33 1/3% INCREASE
STREAM LEVEL
IN
12
-------
Historically, most of the reported data for textile wastewater treatment
has considered effluents from textile plants producing primarily
natural fabrics. Clearly there is a need for data from a mi 11
producing widely used synthetic fabrics in order to better
characterize this particular type of wastewater. In order for such
single plant information to be effective in promoting the level of
knowledge in this industry segment, wastewater data needs to be
correlated with definitive production data.
Blue Ridge-Winkler Textiles, (BRW), A Divison of Lehigh Valley
Industries, Inc., was faced In the late 1960's with meeting new,
strict discharge criteria imposed by the Commonwealth of Pennsylvania's
Department of Environmental Resources on its Bangor Plant. This
plant produces simplex, tricot, and circular knit synthetic fabric
for the apparel and automotive upholstery trades. A research
program to evaluate alternate treatment processes was begun by BRW
in 1969.
Based on the performance characteristics of the then available and
demonstrated technology, BRW decided to use a system composed of an
activated sludge process and an alum coagulation process operating
in series. This system would result in the removal of degradable
organics and some nutrients by biological oxidation in the activated
sludge process, and in the removal of metals, colloidal organics,
and additional nutrients and soluble organics by coagulation or
precipitation in the alum coagulation process.
DEMONSTRATION GRANT
Realizing the importance of the demonstration of this new technology
to the textile industry, BRW sought and obtained an Environmental
Protection Agency Demonstration Grant (EPA Grant S80II92). The
grant would provide sufficient funding so that the treatment system
could be evaluated in detail over a one-year period of plant operation
in order to fully define the system capability. Also, production
data would be considered as a significant parameter in the evaluation
of system performance. The specific objectives of the grant project
were as follows:
13
-------
- Characterize the raw waste,
- Characterize the mill production in terms of fibers,
chemicals, and processes
- Determine the operating characteristics of each unit
treatment process,
- Establish the treatment capabilities of the total system
under various raw waste compositions,
- Correlate operating characteristics of the system with
the production characteristics,
- Determine the cost of treatment, and
- Determine what alternative processes would be available
to provide additional treatment, if required.
14
-------
SECTION IV
DESCRIPTION OF THE MANUFACTURING FACILI1Y
PART A - FABRICS PROCESSED
Present Mix And Volume
During the study period, daily records of production volume were
kept by fabric construction and by processing equipment type.
Tables XIII and XIV summarize this data and Figure II presents
part of the data graphically.
The data presented is in units of pounds of fabric dyed per day.
Since the production pipeline at BRW is relatively short and
continuous, this data is effectively the pounds and fabric dyed
and finished per day.
One of the variables in the production process is fabric yield -
the ratio of yards to pounds of fabric. For the present
mix this ratio varies from style to style within the range of 1.0
(automotive) to 4.25 (lingerie). Also, this ratio will vary
during production as the product is alternately shrunk (during
dyeing) and stretched (during drying). Therefore, it was decided
to use the pound method of reporting since dye and finish formulas,
as well as federal discharge limitations are based on fabric
weight.
As indicated by the data, the largest segment of the BRW product
line is velour fabric manufactured for the apparel trade. The
fabric is an arnel/nylon blend and represents 56.0 percent of the
total yearly production. It is dyed primarily on pressure beam
equipment which represents 53.8 percent of the total yearly production.
As illustrated in Figure V, it was possible to correlate total,
dally mill production with daily beam production. Other
significant fabrics include nylon (13.2 percent) for the automotive
and lingerie trades and polyester/nylon blends (13.0 percent) for
the uniform trade.
15
-------
TABLE VI
SUTT1ARY OF PRODUCTION DATA BY FABRIC CONSTRUCTION
FABRIC
CONSTRUCTION
ARNEL
NYLON
ARNEL/NYLON
NYLON/POLYESTER
QIANA
ACETATE/NYLON
ANTRON
DACRON
OTHER
NUMBER OF
DAYS
PROCESSED
DURING YEAR
153
276
278
228
269
53
223
151
_
YEARLY
AVERAGE
OF DAILY
PRODUCTION
CPOUNDS)
1,439
6,851
28,791
8,138
1,857
3,350
2,202
1,634
_
YEARLY
MEDIAN
OF DAILY
PRODUCTION
CPOUNDS)
960
6,720
29,600
7,680
1,800
.3,320
1,280
1,024
_
LOW
MONTHLY
AVERAGE
OF DAILY
CPOUNDS)
377
4,201
10,206
2,821
1,130
121
895
463
_
HIGH
MONTHLY
AVERAGE
OF DAILY
CPOUNDS)
3,259
8,750
41,761
13,764
2,857
9,587
3,900
3,071
-
FRACTION
OF
TOTAL
YEARLY PRODUCTION
CPERCENT)
1.6
13.2
56.0
13.0
3.5
1.2
3.4
1.7
6.4
-------
TABLE VII
SUWAKY OF PRODUCTION DATA BY MANUFACTURING PROCESS
PROCESS
PRESSURE BEAM
ATMOSPHERIC
BECK
PAD
YEARLY
AVERAGE
OF DAILY
PRODUCTION
(POUNDS)
25,829
1M37
9,03L
YEARLY
MEDIAN
OF DAILY
PRODUCTION
CPOUNDS)
27, CM)
iMoo
8,880
LOW
MONTHLY
AVERAGE .
OF DAILY
PRODUCTION
CPOUNDS)
7,88k
11,005
M99
HIGH
MONTHLY
AVERAGE
OF DAILY
PRODUCTION
CPOUNDS)
36,3*f8
19,97^
11,969
FRACTION
OF
TOTAL
YEARLY
PRODUCTION
CPERCENT)
53.8
28.5
17.7
TOTAL PRODUCTION
,127
56,560
100.0
-------
<
o
49.1
|
£39.3
2
§«
ui
m 100
X 8 8 m ™ •
spunod »o spuwnoin 'NOIiDnQOdd A11VQ 1VJ.Q1
FIGURE II, Chronological plot of
daily production
va I ues
1O-I-72
3-fr-73
5-18-73
7-3V73
UATC
FIGURE III, ChronoJoglcal plot of
dally beam production
va I ues
•763
052.8
26.8
8-1-72
n-t-73
Q-23-72 3-6-73
DATE
S-18-73
FIGURE IV, Chronological plot of dally arnel/nylon production values
18
-------
en
.9
••r 40
c
o
o
JC
"7
z
Q
j_
b
Q
o
UJ
m
30
20
1O
20 30 4O 50 60
TOTAL PRODUCTION-thousands of Ibs/day
FIGURE Vi Correlation of beam production to total production
19
-------
PART B-l - MANUFACTURING OPERATIONS: DYEING
Pressure (beam) dyeing is used at BRW for processing tricot knit
fabrics primarily of nylon/arnel blends in the velour product line.
In the first step of this operation (batching), a specific weight
of greige fabric is wound on a perforated stainless steel beam
using a predetermined tension. The beam is then placed in the
rectangular dyeing unit (Burlington Engineering Co., Inc.) and the
bath is forced through the hoi low beam and through the cloth.
During the dyeing part of the cycle the unit is closed and the
temperature raised to II6°C. Also, the flow may be reversed, and
the dye bath pulled through the fabric and into the beam. At the
conclusion of each segment of the production cycle, the bath is
dumped to the sewer and during rinsing segments, the rinse water
is pumped through the beam and overflows the unit to the sewer.
At the conclusion of the cycle the beam is withdrawn and additional
water is removed on a vacuum extractor.
The production complement of beam dyers at BRW consists of three,
2500 pound (1135 kg) and three, 1000 pound (454 kg) nominal fabric
capacity units. The larger units can hold approximately 3000
gallons (11.3 cubic meters) and the smaller units 1,200
gallons (4.5 cubic meters) not considering volume displacement by
the fabric.
A typical six to eight hour production sequence for the beam dyers
is as follows:
I. Load
2. Fill with water and steam
3. Overflow with water
4. Add carrier, dispersing agent and
Dyeing assistants and run
5. Add dye mix
6. Close lid and elevate temperature and run
7. Cool and dump dyebath
8. FiI I with water and steam
9. Add scour chemical and run
10. Overflow with water
11. Dump
12. Repeat steps 8 through II
13. Unload
The process flow for the pressure beam dyeing operation is illustrated
in Figure VI.
20
-------
RINSE
PAD
FINISH
FRAME
DRY
INSPECT
TO PAD FINISH
......rz
i ij i
• HI i
t=T-
I PRINTER r*"! SHIP I
'I I
I ----- J I ----- J
TO ATMOSPHERIC BECK
FIGURE VIi Manufacturing process flow sheet
-------
Atmospheric Beck Dyeing
Atmospheric beck (tub) dyeing is used at BRW for processing tricot,
simplex, and occasionally circular knits of nylon, arnel, and
polyester fibers in all product lines. In this operation a length
of greige fabric (piece) is threaded over an oval shaped reel at
the top of the beck, (Rodney Hunt Co.), and the ends of the piece
are sown together to form a continuous loop (rope). This rope is
then circulated through the bath as the reel turns with, at any
time, approximately 90% of the fabric in the bath and \Q% in the
atmosphere. The dye bath and other segments of the production cycle
are run at IOO°C. At the end of each segment, the bath is dumped
to the sewer, and during the rinsing segments, the rinse water
overflows the unit. At the conclusion of the cycle, the piece is
withdrawn and additional water is removed by a centrifugal extractor.
The production complement of atmospheric becks at BRW is presented
in Table VIII.
TABLE VIII
ATMOSPHERIC BECKS IN PRODUCTION
NUMBER LENGTH NOMINAL FABRIC NOMINAL WATER
OF UNITS CFEET) (METER) CAPACITY VOLUME
CPOUNDS) CKILOGRAMS) (GALLONS) CCUBIC METERS)
3 2 0.6 50 23 330 1.2
3 3 0.9 150 68 490 1.8
2 5 1.5 400 182 820 3.1
6 8 2.4 600 272 1,300 4.9
14 14 4.3 1,000 454 3,900 14.8
22
-------
Typical six to twelve hour production sequences for the atmospheric
becks are as follows:
I. Load
2. Fill with water and steam
3. Add scour chemicals
4. Elevate temperature and run
5. Overflow with water and steam
6. Dump
7. Fill with water and steam and run
8. Dump
9. Fill with water and steam
10. Add pH adjustment chemical and run
11. Dump
12. Fill with water and steam
13. Add carrier, dispersing agent, dyeing,
assistants, ph control chemicals, or
sequestering chemicals as appropriate and run
14 Add dye mix
15. Elevate temperature and run
16. Cool and dump dyebath
17. Fill with water and steam and run
18. Dump
19. Fill with water and steam and run
20. Dump
Alternate A (nylon;Iingerie)
2IB Fill with water and steam
22B Add fixing chemicals
23B Elevate temperature and run
24B Dump
25B FiI I with water and steam and run
26B Dump
27B FiI I with water and steam and run
28B Dump
Alternate B (nylonAutomotive)
Delete 5 through 12
5D Cool using cold water
6D Dump
7D FiI I with water and steam
8D Add pH control chemical
9D Elevate temperature and run
IOD Cool using cold water
11D Dump
I2D Fill with water and steam
21A Through 26A
The process flow for the atmospheric beck dyeing operation is
illustrated in Figure VI.
23
-------
Pad Dyeing
Pad dyeing is used at BRW for processing tricot and simplex knit
fabrics of nylon/polyester blends in the uniform product line.
The nature of the equipment limits dyeing to light shades on a
limited number of fabrics. In this production operation, the greige
fabric is continuously fed into the pad unit in a wide form from
a roll. The pad unit consists of a dye bath and a set of squeeze
rolls. As the fabric passes through the padder the dye is
applied to the surface on both sides of the material and the excess
removed by the rolls. The dye solution is maintained at a constant
level in the padder during processing in order to keep the dye
concentration constant. From the padder, it is fed through an
infrared drying chamber then to a chamber. In order to achieve dye
penetration, the chamber is set aside for two to four hours while
steam is applied. After this period, the roll is removed and
sent through the finishing step. The only water discharge from
this operation is the remaining full strength dye solution in the
padder and the equipment wash down.
BRW has one pad dyer (American Artos Inc.) in its production
complement. This unit has the capability of handling 1500 pounds
(681 kg) per hour of fabric and uses a 30 gallon (O.I I cubic meters)
pad bath.
The process flow for the pad dyeing operation is illustrated in
Figure VI.
Dye Kitchen
In Mill Number One all dyes and chemicals are hand carried from
the dye kitchen to the becks and beam dyers. A typical dye mix is
prepared in a portable, thirty gallon mix tank in the dye kitchen
by adding precisely weighed quantities of the dye powder or
concentrate to water. The mix tank is then wheeled to the
appropriate dye unit and the mix transferred. The mix tank is
then flushed clean with the flush water being directed into the
dye unit. This procedure Is typical of all operations in the dye
kitchen area and results in very little wastewater.
In Mill Number Two, the dye and chemical solutions are transported
by pipeline from the dye kitchen to the production units.
After each run, the mixers and pipelines must be cleaned by flushing
first with a solvent cleaner and then with water.
24
-------
PART B - 2 - MANUFACTURING OPERATIONS: FINISHING
Drying And Heat Setting
Drying and heat setting of fabric at BRW is accomplished using
four totally enclosed pin tenter frames of varying widths
(Kenyon Co., American Artos Inc.).
Two tenter frames are used almost exclusively for drying dyed
fabri-c. In this operation, the fabric is fed in an open form
through a padder, where a finish is applied, and then into the
drying oven. The pad bath volume is 215 gallons (0.81 cubic
meters). The solution is made in sufficient strength initially
to insure an adequate concentration at the end of a run or
is fed through a reservoir tank to insure a constant concentration.
As the cloth passes through the frame, the water evaporates
and some residual oils and chemicals are volatilized as the
air temperature is maintained at I50-I80°C. At the conclusion of
a run the pad bath is dumped and the equipment washed down.
One tenter frame is used exclusively for heat setting of dyed and
dryed goods. In this operation, the fabric is fed in an open
form into the drying oven. As the cloth passes through the frame,
with an air temperature at I75-200°C, significant amounts of
residual oils and chemicals are volatilized and the fabric is
partially plasticized to produce a particular texture or to
stabilize the width dimension.
One tenter frame is used for either drying or heat setting as
described above and also for frame scouring and dyeing. In this
operation the padder is preceded by a scour bath and a rinsing
chamber. Fabric is fed into the unit in a wide width form.
The scour bath consists of a constant water volume tank into
which scour chemicals are continuously fed. The rinsing chamber
consists of a spray washer to remove the scour products. The
padder bath may contain a solution of fluorescent dyes to
optically brighten the fabric. Goods going this route are
usually shipped as uniform fabric or sent to a commission
printer. Another alternate route is to pre-frame the fabric
before dyeing in the atmospheric becks by using only the scour
bath, rinsing chamber, and frame.
25
-------
The drying and heat setting operations are illustrated in Figure VI
The air exhausts from the tenter frames contain significant
amounts of pollutants in an aerosol form. At BRW, these exhausts
are cleaned using electrostatic precipitators after air stream
cooling. Water from the cooling step as well as equipment wash-
down water is sent to the process sewer system. Therefore, a
portion of the chemicals retained on the cloth from the dyeing
process may eventually find their way to the sewer.
Mechanical Processing
A number of mechanical processing steps are used at BRW to obtain
a variety of textures.
In the velour product line the fabric is napped (torn ) and
sheared (cut to a constant height) on the front face to give a
soft, resillient pile.
If-a suede texture is desired, the fabric is scoured, sueded
(rubbed with sand paper) and then dyed.
A third route that is available is to emboss a pattern into the
fabric after it is dyed and dryed by passing it under pressure
through a set of pattern roles. For certain fabrics, heat is
applied simultaneously with pressure, to partially placticize
the fiber and give a "wet" or shiny appearance.
In all cases, mechanical finishing processes are dry except for the
use of a small volume of cooling water for the machinery.
26
-------
PART B - 3 - MANUFACTURING OPERATIONS: DYE AND CHEMICAL USE
During the course of a production year, a textile firm may use
several hundred different dyes and chemicals in the manufacturing
processes. For BRW the total usually is in the range of 150-200
different dyes and chemicals, but a much smaller range accounts
for the greatest usage.
For the dyes category, three dyes (all disperse) account for
twenty-five percent of total use and 25 dyes account for fifty
percent of total use. A total of over 100 dyes were used
during the study year but the use of most of these was less
than 1.0 percent of total use. Approximately 30 percent of the
dyes used were of the acid class and accounted for 20 percent
of the total use. Approximately 70 percent were of the disperse
class and accounted for 80 percent of the total use.
Acid dyes are water soluble dyes which are used principally with
nylon, acrylic, and wool fibers. The chromogen is usually an azo
(-N=N-), anthroquinone (=C=0), or triarylmethane (=C=NH) structure
with the auxochromes being -N02, - S03H, or -COOH. The anionic
dyes attach to the cat ionic groups in the fiber. Quite often they
contain a metal as part of the organic structure to make the dye
more stable. At BRW, acid dyes are typically used at a water:
fabric:dye weight ratio of 1:35 to 70:0.02 to 0.08 in atmospheric
beck dyeing. Acetic acid is used to lower the dyebath pH to 4
to 5 in order to aid in exhaustion, and sodium sulfate may be
used to decrease the rate at which the dye is attached.
Disperse dyes are water insoluble dyes which are used principally
with acetate, polyester, nylon, and acrylic fibers. The chromogen
is usually an azo or anthraquinone structure and the dyes have a
neutral charge. The dyes are used in conjunction with a dispersing
agent which holds the dye in suspension, and a carrier to aid
the dye in penetrating the fiber. Disperse dye suspensions vary from
O.I to 3 microns in size depending on the dye and the dye
manufacturing process. The degree of solubility is very low with
anthraquinone types being soluble only to several parts per million.
Typically, from three to ten percent of the dye used in a bath
may go into solution. At BRW, disperse dyes are typically used
at a water:fabric:dye weight ratio of 1:5 to 10:0.04 to 0.08 in
beam dyeing and the dye cycle is carried out at an elevated
temperature to reduce the time required for migration and striking.
Also at BRW, the dyes are applied in a pad bath on a continuous
range for light shades.
27
-------
Because of their high costs, the exhaustion rate (percent of dye
removed from the dyebath solution) of dyes tend to be significant.
However, the exhaustion rate is a function of competing dyestuffs,
fiber type, auxiliary chemicals, temperature, and cycle time,.
Therefore, it is difficult to predict how much of a certain
dye is actually wasted to the sewer. A good example of this
variation in exhaustion at BRW is Acid Green 25. In some baths
it is the primary colorant and its exhaustion rate approaches
90 percent, but in other situations where it is used as a
secondary colorant (e.g. to give a green tint to a black shade)
its exhaustion rate may be as low as 50 percent.
For the chemical category, 8 chemicals account for 50 percent
of total use and 33 chemicals account for 97 percent of total
use. A total of approximately 100 chemicals were used during the
year with an average use of one to three percent for the
significant chemicals. These chemicals have a large variety of
uses and represent a very broad range of inorganic and organic
materials. However, they can be divided into the following
general categories:
Inorganic chemicals
Organic acids
Detergents
Carriers
Dyeing assistants
Finishes
Solvents
Fixing chemicals
Fluorescents
Inorganic chemicals account for approximately 15.0 percent of. the
total use. They are used principally in the fabric preparation
steps. It is probable that the greatest majority of these chemicals
go to the sewer and are not retained on the fabric.
Organic acids account for approximately 7.6 percent of the total
use. They are used primarily for pH control in the preparation and
dyebath steps. Again, virtually all the chemical is estimated
to go to the sewer.
Detergents account for approximately 13.8 percent of total use.
They are primarily weak anionic or non-ionic surfactants, and are
used in the scour baths to remove the small amount of dirt retained
during knitting and warehousing and to remove lubricants or other
residual materials associated with the yarn manufacturing. A
28
-------
high percentage of these chemicals is probably discharged to the
sewer along with the contaminants they remove.
Carriers account for approximately 22.2 percent of total use.
These chemicals are used as an auxiliary to disperse dyes. Their
functions are to (I) swell the fabric to allow the dye molecules
to enter and (2) to coat the fibers in order to serve as the
mechanism to allow transfer of the dye from the water suspension
to the fiber by the preferential solubility of the dye in the
carrier. The majority of a chemical in this category is probably
discharged to the sewer but a portion is retained on the fabric
and lost to the atmosphere during drying.
The broad classification of dyeing assistants account for 21.7
percent of total use and tend to be surfactants. These
chemicals are used for dye suspension, levelrng, penetration,
fastness, and to aid in obtaining a finished fabric texture.
Finishes account for approximately 8.0 percent of the total use.
The purpose of these chemicals is to impart a certain texture
or repellent property to the fabric. For this reason their
retention rate on the fabric is probably high.
Solvents account for approximately 8.6 percent of the total use.
In one case at BRW, a solvent is used in the scour bath to remove
grease and oil from particularly dirty fabric. In the other case,
a solvent is used to clean the padder rolls in the continuous
range and finishing areas. This latter material contains a high
concentration of an aromatic chemical. In both cases, virtually
all of the material is discharged to the sewer.
Fixing chemicals account for approximately 2.1 percent of total
use. The principle chemical is a surfactant and is used to insure
fastness of the dye to the fiber.
Fluorescents account for approximately 1.0 percent of total use.
These chemicals- are fluorocarbon compounds used to whiten fabric
in the uniform product line or to provide a background color for
print patterns.
29
-------
SECTION V
HASTWTER CHARACTERIZATION
PART A - ANALYTICAL AND SAMPLING METHODS
The methods of analyses and the sample preparation methods used
during the study are presented in Appendix C of this report.
The following automatic sample points were established at the
treatment plant for continuous monitoring wastewater
character i st i cs:
Equalized waste pump discharge
- Activated sludge clarifier overflow
Alum coagulation clarifier overflow
Sampling stations at these locations consisted of finger pumps
operated on a timed cycle (Sigmamotor model 7462). The pumps were
operated for five minutes every fifteen minutes at a flow rate
yielding about four liters every eight hours. Equal volumes from
each shift bottle were then mixed to give a single daily composite.
The tubing used for sampling was 1/4 inch (0.6 cm;I.D.) Tygon.
Several months into the study, a grab sampling station was
established for the incoming municipal water used in production.
These grab samples were obtained directly after the plant's water
softeners.
Samples of combined sludge were grab samples taken at the
inlet of the holding tank. Samples of the individual sludges were
taken at the pump discharges.
Sampling of wastewater from individual production process was done
by production personnel. The samples obtained were grab samples
selected to give a representation of the overall characteristics
of the discharge.
Periodic samples of receiving stream water above the BRW discharge
were obtained. These were grab samples obtained by
the use of wide mouth polyethylene jars. Sample points downstream
30
-------
TABLE IX
Sffl-ING AND ANALYSIS MATRIX
SAMPLE POINTS AND LOCATIONS
ANALYSES EQUALIZED ACTIVATED ALUM AERATED
RAW SLUDGE COAGULATION LAGOON
WASTE CLARIFIER CLARIFIER CONTENTS
EFFLUENT EFFLUENT
FLOW
TDS
TSS
VSS
SVI
BOD
COD
TOC
TEMPERATURE
DO
PH
COLOR
NH3N
OP£f
METALS
PHENOLICS
INORGANIC
SALTS
NOTES:
1.
2.
3.
if.
1
1 1
1 1
1 1
_ _
1 1
1 1
3 3
1 1
1 1
1 1
1 1
1 1
1 1
3 3
3 3
3 3
REGULAR ANALYSIS
REGULAR ANALYSIS
MONTHLY ANALYSIS
MONTHLY ANALYSIS
1
1 2
1 2
2
1
1
3
1 2
1 2
1 2
1
1
1
3
3
3
OF COMPOSITE SAMPLE
OF GRAB SAMPLE
OF COMPOSITE SAMPLE
OF GRAB SAMPLE
COMBINED
SLUDGE
1
_
2
2
_
_
_
_
_
_
if
_
if
if
if
if
if
31
-------
of the several dischargers were selected to allow for in-stream mixing
and were at a point of turbulence in the stream.
Dally samples were analyzed for routine contaminants at the BRW Water
Quality Laboratory In Bangor. Each month one set of daily samples
was shipped to Pollution Control Science, Inc. In Dayton, Ohio, for
analyses for heavy metals, salts, and particular organics. EPA
recommended preservation techniques were used for these monthly samples.
The sample and analysis matrix used during the study is presented In
Table IX.
A quality control check was made for metals analyses using split
samples spiked with EPA standard solutions, and the results of this check
were within acceptable tolerance limits.
Samples were always taken either in glass or polyethylene bottles. The
cleaning of the sample bottles was dependent on their use, with bottles
for routine analysis receiving only a wash with tap water and bottles
for metals analysis receiving a double acid/distilled water wash.
Distilled water In the BRW lab was prepared using a copper still. BOD
dilution water was prepared in a five gallon carboy on a routine basis
using the procedure In Standa rd Methods *'5 ^, and seed from the BRW
activated sludge process. Reagent standards were prepared In the BRW
laboratory In accordance with Standard Methods.
32
-------
PART B - SUMMARY'OF WASTEWATER CHARACTERISTICS
Table X presents a summary of the equalized wastewater
characteristics.
The median equalized flow value for the study period was
determined to be 520,000 gallons per day. As illustrated by
Figure VII, there was a significant variation in day-to-day and
month-to-month flow. The standard deviation was found to be
approximately 45 percent of the average.
The organic chemical concentration as measured by total BOD and
COD values (that is,'soluble plus insoluble) was determined to be
significant. The relatively few soluble BOD and COD determinations
that were made indicated that approximately 80 percent of the
total values result from soluble material (that is, material pass-
ing a glass fiber filter). Several 20 day BOD determinations were
made, and as the data in Figure VIII illustrates, BOC^Q for the
equalized waste was found to be approximately twice the BOD^.
The BOD and COD concentration values were found to be relatively
stable with the standard deviation being approximately 25 percent
of the average. However, the BOD and COD loading values were
found to vary significantly with the standard deviation being
approximately 50 percent of the average.
The suspended and dissolved sol i'ds concentrations were found not
to be significantly high.
The nutrient (nitrogen and phosphorous) content of the wastewater
was determined to be relatively high. Several analyses indicated
that ammonia nitrogen and orthophosphate were the only
significant forms of the major nutrients that were present.
Appreciable color was found to be present in the wastewater as a
result of less than total exhaustion of disperse and acid dyes
during production. Since the APHA color measurement method was
used, the color concentrations determined were only approximate.
However, since the pH and the hue of the BRW equalized water
was found to be relatively constant, the use of the method
was satisfactory to indicate variation in color concentration and
color removal through the treatment system.
33
-------
TABLE X
SUMMARY OF EQUALIZED WASTE CHARACTERISTICS
CONTAMINANT
FLOW (MGD)
TEMPERATURE (°C)
PH
COLOR (APHA)
DISSOLVED OXYGEN (MG/L)
BOD (MG/L)
COD (MG/L)
SUSPENDED SOLIDS (MG/L)
VOLATILE SUSPENDED SOLIDS (MG/L)
DISSOLVED SOLIDS CMG/L)
AMMONIA NITROGEN
CMG/L AS NI-^N)
ORTHOPHOSPHATE (MG/L AS PO^)
ALUMINUM (MG/L)
CALCIUM (MG/L)a
CHROMIUM (MG/L)
HEXAVALENT CHROMIUM (MG/L)3
COPPER (MG/L)
IRON (MG/L)
LEAD (MG/L)a
MAGNESIUM (MG/L)a
NICKEL (MG/L)a
POTASSIUM (MG/L)a
SODIUM (MG/L)a
ZINC (MG/L)
MERCURY (MG/L)a
PHENOL I CS (MG/L)
TOC (MG/L)
CHLORIDE (MG/L)a
SULFATE (MG/L)a
ALKALINITY
DETERGENT
MEDIAN
YEARLY
VALUE
0.520
34.6
6.7
1032
1.3
448
1,554
174
140
712
15.0
59.4
8.5
2.02
0.58
0.05
0.03
0.41
0.025
2.40
0.01
4.2
155
0.13
0.0016
0.10
360
43
154
103
15.4
YEARLY
STANDARD
DEVIATION
0.204
3.5
0.4
340
1.6
118
351
251
185
153
7.3
14.9
-
-
-
-
—
_
_
_
-
_
-
-
-
-
-
-
-
-
-
LOW
MONTHLY
AVERAGE
VALUE
0.200
25.3
6.1
806
0.2
386
1,158
46
90
542
11.1
43.2
0.2
0.004
0.11
0.25
0.005
0.05
0.006
0.32
0.005
1.97
78
0.08
0.0001
0.053
300
36
22
75
5.4
HIGH
MONTHLY
AVERAGE
VALUE
0.646
36.0
6.9
1,906
3.9
555
1,985
395
288
930
23.7
70.5
31.4
10.0
1.21
0.19
0.50
0.70
0.045
10.0
0.08
6.68
330
1.96
0.005
0.250
480
51
425
186
35.0
a AVERAGE VALUE NOT MEDIAN VALUE
34
-------
0781 r
O.669
T3
O>
I
0558
3 CU46
u_
0334
I
O.223
Q
HI
0.111
O
UJ O.OOO
_L
8-1-72 10-1-72 12-23-72 3-6-73
DATE
5-18-73
7-31-73
FIGURE VII• Chronological plot of daily equalized waste flow
m
80O
6OO
4OO
2OO
O
8OO
6OO
4OO
200
5OO
400
300
2OO
1OO
[-August, 1972
Soluble
-October, 1973
Total
Soluble
_L
5 10 15 20
DAYS
FIGURE VIIL Graph of twenty day BOD data for equalized raw waste
35
-------
Figure IX indicates the affect of pH on the APHA color of the BRW
wastewater.
Several spectrophotmetric plots were made of the equalized waste and
representative data is presented in Figure X.
A number of metals were present in the wastewater in significant
concentrations. The aluminum concentration was found to be
approximately 50 percent soluble and was estimated to result
prinarily from the presence of recycled a I urn sludge as described in
Section XII. However, some aluminum appears to have been added
during the production operation. The zinc concentration was 65
percent soluble and was due solely to the presence of zinc in the
municipal water purchased for production use.
The chromium concentration was 80 percent soluble and resulted
primarily from the dyes used in manufacturng, primarily the acid
class of dyes. The iron concentration was 80 percent soluble,
and the mill piping system was thought to be the primary source
of this contaminant.
On Iy a trace concentration of phenol was found in the wastewater.
The source of the contaminant was not investigated.
The pH of the equalized wastewater was constant and slightly
acidic. The average temperature was 35°C, and the average dissolved
oxygen content was 1.3 mg/l.
36
-------
8
7
6
to 5
i
i
i
100 200 300 ' 6OO 700 8OO
COLOR, APHA Units
90O
Z 0-4
O
Q 0.3
in
u
O 0-2
m
O
£ O-1
FIGURE IXi Wastewater color as a function of pH
30O
40O 500 60O
WAVELENGTH ,m;j
70O
FIGURE Xi Spectrophotometric curves for equalized raw waste
37
-------
SECTION VI
GENERAL DESCRIPTION OF TIE
TREATT'BIT SYSTEfi
The wastewater treatment facility at BRW consists of the following
unit operations:
Heat reclamation
EquaIization
Activated-sludge treatment
Ch tori nation
Sludge dewatering by centrifugation
A layout of the facility is presented in Figure XI and ~t~ne process
flow is presented in Figure XII.
In reviewing the system it is important to realize that significant
changes and additions were made to the initial facility during the
course of the project in order to improve treatment levels. These
modifications are discussed in this report, and the drawings of the
system indicate the facility as it existed at the completion of the
data col lection phase.
HEAT RECLAMATION
The raw waste at BRW is collected in a common wastewater sump
in Mills One and Two. The wastewater temperature ranges from 38°C
to 50°C, and is a candidate for heat recovery. During the study,
a shelI and u-tube exchanger was used to preheat water for the hot
water feed system in Mill Number Two.
In this exchanger, wastewater flowed on the tube side and to
prevent plugging, the wastewater was screened twice before being
pumped to the exchanger. The first screening consisted of a series
of three screens mounted in the trench system at several locations.
These screens were successively coarse to fine mesh (1.27, 0.64, 0.32
centimeter openings), and were manually cleaned. The second
screening consisted of a medium screen (0.64 centimeter openings)
concentric to and running the full length of the vertical suction
pipe of each raw waste pump.
38
-------
CHLORINATION BASIN
VO
ACTIVATED
SLUDGE
CLARIFIER
CHLORINE 8. STORAGE
BUILDING
ALUM
COAGULATION
CLARIFIER
AMMONIA STORAGE
ACTIVATED SLUDGE LAGOON
FLOCCULATION
BASIN
MAIN PUMP AND
CONTROL BUILDI
EQUALIZATION TANK
CENTRIFUGE
BUILDING,. '
ALUM STORAGE
FIGURE XI. s'te Plan ~ wastewater treatment plant
-------
HYDROGEN PEROXIDE
LIQUID ALUM
CAUSTIC SODA
ANIONIC POLYMER
HYDROGEN PEROXIDE
-CHLORINE
PRODUCTION
DISPOSAL SITE
FIGURE XIIi Wastewater treatment plant process flow sheet
-------
EQUALIZATION
The production week at BRW may vary from five and one third days to
seven days during normal production periods. Also there are a
number of three day holiday shutdowns and two, ten day vacation
period shutdowns during the course of a production year. Because
wastewater is required for the activated sludge system on a
continuous basis, an equalization tank was provided for storage
and for contaminant equalization. This tank was an open top steel
vessel, 70 feet (21.3 meters) in diameter and 36 feet (I 1.0 meters)
high with a nominal capacity of one million gallons (3785 cubic
meters).
Influent to the tank was pumped from the wastewater collection sumps
in Mills One and Two through a discharge header running the diameter
of the vessel. A circulation pump was provided to withdraw waste
from the tank and pump it back through the header with the
incoming raw waste.
No other mixing was provided in the tank, and as a result some
sedimentation did occur. The combination of this sedimentation,
the ready biodegradabiIity of a portion of the waste, and the low
dissolved oxygen content of the raw waste resulted in the
generation of septic odors. A hydrogen peroxide feed system to the
equalization tank was installed late in the study and successfully
abated the problem.
ACTIVATED SLUDGE TREATMENT
The activated sludge process consisted primarily of an aerated
lagoon and a clarifier. Equalized waste was pumped to the lagoon
through a flow control instrumentation loop.
The aerated lagoon was a lined, earthen basin with a capacity of
336,000 gallons (1272 cubic meters). Aeration and mixing was
proved by a single, 125 horsepower (93 kilowatts), platform
mounted aerator of the vaned, inverted cone type. Capacity of
this unit was 415 pounds (188 kilograms) of oxygen per hour at
standard conditions (tap water at 20°C with a dissolved oxygen
level of 0.0 mg/l and an a and 3 of 1.0 each) or 136 pounds
(62 kilograms) of oxygen per hour at design conditions
(a = 0.51, B = 0.9, D.O. = 2.0 mg/l, and temperature = 25°C).
The clarifier was an above grade steel vessel 50 feet (15.2 meters)
in diameter with a side water depth of 8 feet (2.4 meters) and
contained a rotating, suction type sludge collection mechanism with
41
-------
a peripheral discharge weir. Settled sludge in the clarifier was returned
back to the aeration basin on a continuous basis, but was limited
to a rate of 150-200 gallons per minute (0.57-0.76 cubic meters
per ni nute).
Return sludge and equalized raw waste were pumped to the same
header which discharged the mixture in the lagoon at the
bottom directly under the aerator.
Initial studies on the waste indicated possible nutrient defici-
encies, and therefore provisions were made for adding phosphoric
acid and anhydrous ammonia (industrial grade) to the equalized
waste pump discharge. The phosphorous content of the wastewater
was found to be adequate for the activated sludge system and the
phosphoric acid equipment was removed before the start of the
project. Ammonia was added, however, to determine if supplemental
nitrogen was required for biological oxidation.
Because foaming in the aeration basin was expected, provisions
were made to add a chemical defoamer directly to the equalized waste
pump discharge. This did not prove to be effective and the
addition point was moved to the lagoon surface. While this was
satisfactory for warm weather operation, winter operation
necessitated moving the feed equipment indoors and injecting the
defoamer into a dilution water line for transport to the lagoon
at a 0.I percent concentration. Also a block foam baffle was
constructed around the perimeter of the lagoon after start-up to
prevent wash-out of solids due to excessive foaming.
ALUM COAGULATION TREATMENT
The alum coagulation process consisted primarily of mixing and
flocculation basins and a clarifier.
Initially, liquid alum (commercial grade, 17$ ALjO,) was added to
the discharge pipe of the activated sludge clarifier without
mixing. This arrangement did not prove totally satisfactory, and
as a result, a rapid mix basin and a flocculation basin were put
into service in May, 1973. The mixing facility consisted of a
1,500 gallon (5.6 cubic meter) concrete basin with two, 5 horse-
power (3.7 kilowatt), turbine mixers (mixing speeds
of 168 and 84 rpm are possible using interchangeable gears). The
flocculation facility consisted of a 15,000 gallon (56.8 cubic
meter) concrete basin with two, 1.5 horsepower (I.I kilowat),
vertical paddle turbine mixers (mixing speeds of 12 to 37 rpm
are possible by variable speed drives).
42
-------
Initially caustic soda (50% strength) was added to the clarifier
effluent for final pH control, but this arrangement was changed
in May, 1973, to caustic soda addition at the rapid mix basin
simultaneously with the alum.
Polymer addition was not begun until May, 1973 when a polymer feed
system was put into service. A dry anionic polymer (Magnifloc 837A)
is mixed to a 0.2 percent concentration in a 300-gallon (I.I cubic
meter) tank and then pumped into a water line for dilution and
transport to the flocculation basin at a 0.05 percent concentration.
The a I urn sludge is settled out in a 44 foot (13.4 meter) diameter,
12 foot (3.6 meter) side water depth, below grade concrete clarifier.
Sludge was collected by a plow type mechanism and the supernatant
overflowed a peripheral weir. The clarifier mechanism included
a 14 (4.3 meter) foot flocculation section with a vertical paddle
mixer but provided no solids circulation.
Collected sludge was removed periodically from the clarifier and
further processed.
During the project, a problem developed from septic odors
in the final clarifier due to oxygen depletion in the sludge blanket.
As a solution, a hydrogen peroxide feed system was installed to in-
ject the chemical into the flocculation basin discharge. Peroxide
addition eliminated the septicity problem with no peroxide carryover
in the final effluent.
CHLORI NAT ION
Overflow from the alum coagulation clarifier discharged into an
8000 gallon (30.3 cubic meter) below grade concrete chlorination basin,
Mixing in the basin was provided by around-the-end baffles. A
side stream of effluent was pumped back to the chlorine building,
gaseous chlorine injected from 150 pound (68 kilograms) cylinders,
and the mixture returned to the head of the basin. Overflow from
the basin was discharged down a 25 foot (7.6 meter) long rock
spillway to a storm sewer for eventual discharge into Martins Creek,
a tributary of the Delaware River.
43
-------
SLUDGE HANDLING FACILITIES
Originally, the excess activated sludge and the chemical (alum)
sludge from the treatment facility were combined before further
processing.
The combined sludge was sent to an open top, steel storage tank
and then processed on a precoat vacuum filter. The filter had a
surface area of 200 square feet (18.6 square meters), used
diatamaceous earth on cotton cloth as the filter base, and had
a rated capacity of 10 gallons per minute (0.03 cubic meter per
minute) with a one percent sludge. This filter had been part of
the first treatment facility at BRW, and eventually proved to be
inadequate to handle the sludge load.
Filtrate from the unit was discharged back to the wastewater sump
in Mill Number One. The sludge cake containing the sludge and
pre-coat was discharged into a dump truck for transportation to a
landfill for disposal using conventional practice. Overflow from
the storage tank was discharged back to the Mill Number One sump.
Late in the study, operation of the filter was discontinued, and
the sludge slurry was hauled directly from the storage tank to
ocean disposal. During this period of time evaluations were made •
of sludge dewatering on a horizontal scroll centrifuge, and in
March, 1974, a centrifuge of this type was put into service.
The unit was a Sharpies P-3400 capable of dewatering up to 35
gallons per minute (0.15 cubic feet per minute) of a two percent
sludge. A highly charged cationic polymer (Magnifloc 335) was
applied at a concentration of five percent to aid cake dryness
and solids recover. The alum sludge and excess activated sludge
were normally dewatered separately, although, at times, they were
successfully combined and dewatered.
Centrate from the centrifuge was discharged back to the floccuL'tion
basin. The sludge cake was discharged into a screw conveyor and
transported to a closed top dumpster. This dumpster was removed by
a contract hauler for eventual disposal of the sludge cake in the
ocean outside the 116 mile (186.7 kilometer) limit (in late 1974
the disposal site is expected to change to a permitted landfill
for burial using a lime encapsulation method).
A summary of major treatment system process parameters is presented
in Table XI.
44
-------
TABLE XI
SUPMARY OF NUOR TREATTHIT SYSTEM
PROCESS PARAMETERS
COLLECTION SUMP CAPACITY
MILL NUMBER ONE
MILL NUMBER TWO
MILL NUMBER TWO HEAT EXCHANGER
WASTEWATER INLET/OUTLET TEMPERATURE
CAPACITY
EQUALIZATION TANK
DIAMETER
HEIGHT
WORKING HEIGHT
WORKING VOLUME
CIRCULATION PUMP CAPACITY
HYDROGEN PEROXIDE FEED CAPACITY
AERATION BASIN
BOTTOM DIMENSION
SIDE SLOPE
WATER DEPTH
CAPACITY
ANHYDROUS AMMONIA EED CAPACITY
DEFOAMER FEED CAPACITY
AERATOR
HORSEPOWER
HORSEPOWER:NOLUME RATIO
AERATION CAPACITY
TEMP = 20°C a 13=1 D.O. = 0 MG/L
TEMP = 25°C a = 0.75 B = 0.9 D.O. ~ 2 MG/L
AERATION CAPACITY:VOLUME RATIO
TEMP 20°C a = 1 B = 1 D.O. = 0 MG/L
TEMP 25°C a ^ 0.75 B = 0.9 D.O. = 2 MG/L
45
11,300 GALLONS (42.8 CUBIC METERS)
3,000 GALLONS (11.4 CUBIC METERS)
100° F/80° F(38°C/27°C)
1 X 10& BTU/HR. (290 KILOWATTS)
70 FEET (21.4 METERS)
36 FEET (11.0 METERS)
34.5 FEET (10.5 METERS)
990,000 GALLONS (3740 CUBIC METERS)
500 GALLONS/MINUTE (31.5 LITER/SEC)
1 GALLON/HOUR (1.05 ML/SEC)
47 FEET X 47 FEET (14.3M X 14.3M)
2:1
10 FEET (3.048 METERS)
336,000 GALLONS (1270 CUBIC METERS)
2 POUNDS/HOUR (0.91 KILOGRAM/HR)
2 GALLONS/HOUR (2.1 LITERS/SEC)
125 HP (93 KILOWATTS)
0.37HP/1000 GALLONS (74 WATTS/CUBIC
METER)
415 POUNDS 02/HOUR (188 KG/HR.)
136 POUNDS 02/HOUR (61.6 KG/HR.)
1.24 POUNDS 02/HOUR/ (149G/HR/CUBIC
1000 GALLONS METER)
0.40 POUNDS 02/HOUR/ (48 G/HR/
1000 GALLONS CUBIC METER
-------
TABLE xi (corn)
ACTIVATED SLUDGE CLARIFIER
DIAMETER
SIDE WATER DEPTH
BOTTOM SLOPE
SURFACE AREA
CAPACITY
RETURN SLUDGE RATE
RAPID MIX BASIN
CAPACITY
NUMBER OF MIXERS
MIXER HORSEPOWER
WATER DEPTH
HORSEPOWER: \OLUME
SPEED RANGE
ALUM EED CAPACITY
CAUSTIC SODA EED CAPACITY
FLOCCULATION BASIN
CAPACITY
NUMBER OF MIXERS
MIXER HORSEPOWER
WATER DEPTH
HORSEPOWER: VOLUME
SPEED RANGE
POLYMER FEED CAPACITY
HYDROGEN PEROXIDE EED CAPACITY
ALUM COAGULATION CLARIFIER
DIAMETER
SIDE WATER DEPTH
BOTTOM SLOPE
SURFACE AREA
CAPACITY
SLUDGE WITHDRAWAL RATE
CHLORINATION BASIN
CAPACITY
WATER DEPTH
CHLORINATION CAPACITY
CONTACT TIME
50 FEET (15.2 METERS)
8 FEET (2.44 METERS)
1/4 INCH PER FOOT (0.25 MM/CM)
1960 SQUARE FEET (182 SQUARE METERS)
117,500 GALLONS (445 CUBIC METERS)
200-250 GALLONS/MINUTE CONTINUOUS
(12.6 15.8 L/SEC.)
1500 GALLONS (56.7 CUBIC METERS)
2
5 HP EACH (3.7 KILOWATTS)
5 FEET (1.52 METERS)
6.67 HP/1000 GALLONS (1.3 KILOWATTS/CUB1C
METER)
84 OR 168 RPM
18 GALLONS/HOUR (18.9 ML/SEC.)
6 GALLONS/HOUR (6.3 ML/SEC.)
15,000 GALLONS (56.5 CUBIC METERS)
2
1.5 HP EACH (1.1 KILOWATTS)
12 FEET (3.7 METERS)
0.20 HP/1000 GALLONS (40 WATTS/CUBIC METER)
12 TO 37 RPM
50 GALLONS/HOUR (52.6 ML/SEC.)
1 GALLON/HOUR (1.05 ML/SEC.)
44 FEET (13.4 METERS)
12 FEET 9 INCHES (3.9 METERS)
1/2 INCH PER FOOT (0.4 MM/CM)
1520 SQUARE FEET (141 SQUARE METERS)
145,000 GALLONS (550 CUBIC METERS)
75 GALLONS/MINUTE (4.6 L/SEC)
0-60 MINUTES/HOUR
8000 GALLONS-(30.2 CUBIC METERS)
5 FEET (1.52 METERS)
25 MG/L
20 MINUTES
46
-------
TABLE XI (COfJT'D)
VACUUM FILTER
STORAGE TANK CAPACITY
FILTER SURFACE AREA
MAXIMUM FEED RATE
AVERAGE FEED CONCENTRATION
SOLIDS CAPACITY
FILTER CAKE LIFE
PRE-COAT TIME'
PRE-COAT USAGE
CENTRIFUGE
MAXIMUM FEED RATE
AVERAGE FEED CONCENTRATION
BOWL SPEED
CONVEYOR DIFFERENTIAL
POLYMER DOSE
SOLIDS CAPACITY
75,000 GALLON (284 CUBIC METERS)
200 SQUARE FEET (18.6 SQUARE METERS)
10 GALLONS/MINUTE (0.63 L/SEC)
1.0 PERCENT
50 POUNDS DRY SOLIDS/
HOUR (23 KG/HR)
2-3 DAYS
8-16 HOURS
1,000 POUNDS/COAT (454 KG)
40 GALLONS/MINUTE (2.5 L/SEC.)
2.0 PERCENT
3,000 RPM
10-20 RPM
5-15 POUNDS/TON DRY SOLIDS
(2.5 - 7.5 KG)
400 POUNDS DRY SOLIDS/HOUR
(182 KG/HR)
47
-------
SECTION VII
STEPS
PART A - WASTE COLLECTION
The raw wastewater from the batch manufacturing operations was
collected In a single sump In each mill. Table XII and presents an
analysis of discharges from the Individual production machinery Into the
Mill One sump. For the single day analyzed, there was a total calculated
discharge of 425,180 gallons (1609 cubic meters), a peak flow of 36,690
gallons (139 cubic meters) per hour or 8.6 percent of the total, a
median flow of 17,000 gallons (64 cubic meters) per hour, and a standard
deviation of 11,500 gallons per hour. Instantaneous flows Into the
sump of as high as 2500 gallons per minute (9.5 cubic meters per minute)
were possible when the large beam dyers were being dumped.
The trench screens were effective In removing a variety of trash that
entered the trench system, and these screens were manually cleaned
once each day. During the course of a year however, solid matter did
pass through the screens and settle out in the sump necessitating an
annual cleaning.
48
-------
TABLE XII
ANALYSIS OF BATCH
WASTWTER DISCHARGES
FROM THE MILL ONE DYEHOUSE
TINE
TOTAL GALLONS
DISCHARGED
PERCENT OF
TOTAL
AVERAGE GALLONS
PER MINUTE
AM
7-8
8-9
9-10
10-11
11-12
PM
12.-1
1-2
2-3
3-4
4-5
5-6
6-7
7-8
8-9
9-10
10-11
11-12
AM
12-1
1-2
2-3
3-4
4-5
5-6
6-7
TOTAL
MEDIAN
NOTE:
0
2,120
11,540
10,600
12,800
30,720
2,170
26,750
11,540
25,680
14,340
35,700
36,690
25,850
18,500
25,450
11,350
19,500
15,770
20,400
11,700
15,000
17,130
4,880
425,180
17,000
100 GALLONS EQU
0.00
0.50
2.71
2.49
3.00
7.22
4.97
6.29
2.71
6.03
3.40
8.39
8.62
6.01
4.34
5.98
2.67
4.
3.
3,
4.
1,
.58
.70
4.79
2.75
.52
.02
,15
100.00
0
36
192
177
214
512
353
445
192
428
239
585
612
431
308
424
189
325
263
340
195
250
286
81
258
49
-------
PART B - HEAT RECLAMATION AND EQUALIZATION
Heat Reclamation
The shell and u-tube exchanger in Mill Two was able to reclaim
approximately one million BTU (0.25 million kilocalories)
per hour for use in pre-heating feed to the hot water system.
Equali zation
The principle use of the equalization tank was for water storage
to insure relatively constant flow to the treatment processes during
low production periods or Mill shutdowns. The wastewater tended
to be self-equalizing in regard to contaminant concentration despite
the, wide variations that were anticipated after examining the
characteristics of the various baths that are part of a production
cycle. Apparently, the random nature of the discharges from the
35 available dyeing units over a 24 hour period results in a
self-equalizing affect. Table XIII presents the COD of the
equalized waste over a 24 hour period, and the data illustrates the
relative stability of the contaminant concentration with a one
day equalization tank retention time.
The raw waste pumped to the equalization tank contained a low
concentration (1.0 mg/l) of dissolved oxygen. At times, a
significant level of solids was present in the waste which settled
out in the relatively quiescent conditions of the tank. This
situation was particularly acute when the vacuum filter system was
not operating and there was an appreciable recircuI ation of
solids from the sludge storage tank. The net result of these
conditions was a depletion of available oxygen and the development
of an anaerobic environment with consequent septic odors.
To overcome this condition, hydrogen peroxide addition to the
raw waste was begun in mid-1973. It was determined that a dosage
rate of 15-25 mg/l of hydrogen peroxide in the raw waste flow
would be satisfactory to maintain an aerobic environment and
yield an equalized waste dissolved oxygen level of at least
2.0 mg/l in the tank discharge.
50
-------
In the late 1973, the tank was drained and cleaned after being in
service since late 1971, and as evidence of the lack of n-ixing,
approximately two feet of accumulated sludge was removed from the
tank bottom.
51
-------
TABLf XIII
ANALYSIS OF OWTAFIINANT EQUALIZATION
HOUR
0
2
4
6
8
10
12
14
16
18
20
22
COD
(MG/L)
1249
1218
1222
1284
1238
1270
1249
1168
1189
1157
1083
1150
MEDIAN:
STANDARD DEVIATION:
AVERAGE WASTEWATER
VOLUME IN TANK:
AVERAGE RAW FLOW
TO TANK:
AVERAGE EQUALIZED
FLOW FROM TANK:
1215 MG/L
60 MG/L
772,000 GALLONS (2922 CUBIC METERS)
674,000 GALLONS (2551 CUBIC METERS)
792,000 GALLONS (2998 CUBIC METERS)
52
-------
SECTION VIII
ACTIVATED SLUDGE SYSTEM PERFORMANCE
PART A EFFLUENT CHARACTERISTICS
Table XIV presents a summary of the activated sludge effluent
characteristics. Table XV presents a summary of the percentage
removals for the process, calculated from the influent and effluent
median values. The first column of this table indicates the
removal based on a statistical analysis of all the data collected
during the study. However, it was the author's opinion that this
data is not truly representative of the process performance
because of the number of mechanical problems encountered during
the study as discussed in Section XVI of this report. Therefore,
the second and third columns of Table XV present the
percentage removals and effluent concentrations resulting from an
analysis of the data during periods free of unusual problems.
This latter data is intended to indicate the expected median
performance levels (but not necessarily the best performance levels)
for a well designed and operated facility.
The BOD removal through the process was determined to be 73
percent for the total data analysis and 78 percent for the
selective data analysis, indicating that a significant portion
of the waste loading consists of bio-degradable organic material.
This removal rate is somewhat less than obtained by other activated
sludge systems treating textile wastes, as reported in the general
literature. The probable reason for this is the significant
carryover of biological solids from the clarifier. While the poor
influent design of the clarifier was primarily the cause of this
situation, an examination of the data indicates that even with
better designed inlet conditions, there would still be a net
increase in suspended solids across the process. The available
soluble BOD data across the system indicated an 88 percent removal.
53
-------
TABLE XIV
SUTWW OF ACTIVATED SLUDGE
USTICS
CONTAMINANT
TEMPERATURE C°C)
PH
COLOR CAPHA)
DISSOLVED OXYGEN CMG/L)
BOD CMG/L)
COD CMG/L)
SUSPENDED SOLIDS CMG/L)
VOLATILE SUSPENDED SOLIDS
CMG/L)
DISSOLVED SOLIDS
AMMONIA NITROGEN
CMG/L AS NO^H)
ORTHOPHOSPHATE
CMG/L AS PO^)
ALUMINUM CMG/L)3
CALCIUM CMG/L)
CHROMIUM CMG/L)
HEXAVALENT CHROMIUM3
CMG/L)
COPPER CMG/L)
IRON CMG/L)
LEAD CMG/L)3
MAGNESIUM CMG/L) a
NICKEL CMG/L)3
POTASSIUM CMG/L)3
SODIUM CMG/L)3
ZINC CMG/L)
MERCURY CMG/L)3
PHENOLICS CMG/L)
TOC CMG/L)
CHLORIDE CMG/L)3
SULFATE CMG/L)3
ALKALINITY CMG/L)
MEDIAN
YEARLY
VALUE
25.1
6.8
804
1.7
122
1,056
368
316
619
4.8
65.1
12.5
1.48
0.36
N.D.
0.03
0.57
0.028
1.57
0.01
2.82
154
0.22
0.0018
0.03
200
46
144
66
YEARLY
STANDARD
DEVIATION
6.0
0.2
348
2.7
83
359
236
200
170
3.4
65.1
—
-
—
—
—
—
_
—
—
_
-
_
-
-
—
—
-
LOW
MONTHLY
AVERAGE
VALUE
9.3
6.4
381
1.0
34
509
103
52
408
3.8
40.0
0.69
1.06
N.D.
—
N.D.
0.14
N.D.
0.36
N.D.
1.40
76
0.02
0.0001
N.D.
64
40
24
50
HIGH
MONTHLY
AVERAGE
VALUE
29.3
6.8
1,441
5.3
225
1,508
539
435
790
11.4
82.0
23.4
2.22
0.05
—
0.05
0.86
0.070
4.00
0.10
3.96
352
0.49
0.0040
0.08
378
56
330
94
Average Values
54
-------
TABLE XV
SHT1ARY OF PERCOTAGE REMOVALS Ifl ACTIVATED SLUDGE
CONTAMINANT
BOD
COD
COLOR
SUSPENDED SOLIDS
DISSOLVED SOLIDS
AMMONIA NITROGEN
ORTHOPHOSPHATE
ALUMINUM
CALCIUM
CHROMIUM
HEXAVALENT CHROMIUM
COPPER
IRON
LEAD
MAGNESIUM
NICKEL
POTASSIUM
SODIUM
ZINC
MERCURY
PHENOLICS
TOC
CHLORIDE
SULFATE
ALKALINITY
REMOVAL
BASED ON
TOTAL DATA
ANALYSIS
(PERCENT)
73
32
22
Cm)
13
68
CIO)
C47)
27
38
100
0
C28)
C12)
34
0
33
1
C69)
C12)
73
45
C7)
9
36
REMOVAL
BASED ON
SELECTIVE DATA
ANALYSIS
CPERCENT)
78
42
30
Cioo)
13
73
0
0
27
38
100
0
C28)
C12)
34
0
33
1
C69)
C12)
73
45
C7)
9
36
EFFLUENT CONCENTRATION
BASED ON SELECTIVE
DATA
ANALYSIS
CMG/L)
96
901
722 APHA
348
619
4.0
59.4
8.5
1.48
0.36
N.D.
0.03
0.57
0.028
1.57
0.01
2.82
154
0.22
0.0018
0.03
200
46
144
66
55
-------
The COD removal through the process was determined to be 32
percent for the total data analysis and 42 percent for the
selective data analysis. This lower removal rate for COD compared
to BOD indicates a significant portion of the waste loading
consists of non-biodegradable organic material. The COD. removal
percentage is also influenced by the high suspended solids levels
in the effluent, but to a lesser degree than the BOD values. In
comparing soluble COD data across the system, 45 percent removal
was indicated.
Color removal across the process was 22 percent for the total data
analysis and 30 percent for the selective data analysis. The
mechanism for this removal may be primarily by flocculation or
adsorption of dyes by the microorganisms since the available
literature indicates little degradation of most dyes by biological
systems'^', in addition to adsorption, some precipitation of
disperse dyes could have occurred if the associated dispersing
chemicals were biologically oxidized since these dyes are
generally water insoluble.
Ammonia nitrogen removal through the system was good and was
determined to be 68 percent for the total data analysis and 73
percent for the selective data analysis. This removal "resulted
from both utilization of the nitrogen by the biomass during
synthesis and by conversion to nitrate nitrogen by nitrifying
bacteria. The ratio of BOD removal to nitrogen removal was
found to be 100:3.1 not considering the addition of supplemental
ammonia or 100:4.0 when the addition is considered.
Orthophosphate was found to increase slightly through the system.
This was attributed to sampling and analysis error, and it was
then estimated that there was no measureable utilization of
phosphorous by the biomass.
Dissolved solids removal across the process was determined to be
13 percent.
Of the heavy metals measured during the study period, only chromium
was found to be removed by the activated sludge process. This
removal was thought to be associated with the removal of dyes by
the mechanisms proposed above since chromium is present as a
constituent of the acid class of water soluble dyes used at the
plant. Similarly, it was felt that the removal of hexavalent
chromium below the detectable limit of the test method used
during the study (0.02 mg/l) was due to dye removal rather than
oxidation to the trivalent form.
56
-------
The wastewater contained a detectable amount of phenolic
compounds at about the concentration that would result in taste
and odor problems in a water source. The process reduced this
concentration by 73 percent to a level acceptable for discharge.
The process also removed a significant percentage of a number
of trace inorganics such as calcium, magnesium, and potassium.
For the study period, the temperature difference across the
system was 9.5°C or a heat loss rate of 3.1 million BTU per hour
(0.78 million kilocalories per hour).
The dissolved oxygen level in the process discharge was determined
to be 1.7 mg/l compared with an aeration basin level of 4.1 mg/l.
The discharge level however was determined on a sample after the
clarifier overflow weir and after some re-aeration had occurred.
The data from several oxygen profile studies of the plant indicated
a level of approximately 1.0 mg/l in the clarifier.
57
-------
PART B - OPERATING CHARACTERISTICS
Table XVI presents a summary of the activated sludge process
operating characteristics.
An analysis of all the data collected during the study indicates
a median aeration residence time of 14.4 hours, a median volatile
mixed liquor suspended solids concentration of 2510 mg/l, a
median biological loading rate of 0.30 pounds of BOD per pound of
volatile mixed liquor solids, and a median volumetric loading
rate of 43.2 pounds of BOD per thousand cubic feet (692 kg per
1000 cubic meters) of aeration basin volume.
The relationship between the biological loading to the process
(F/M ratio) and the fraction of BOD remaining in the process
effluent is presented in Figure XIII.
The data presented in this Figure and subsequent Figures is from
selective monthly averages. Assuming an F/M ratio of 0.30,
and an influent BOD of 448 mg/l, a BOD of 96 mg/l is obtained
for the process discharge using Figure XIII.
Removal rates for BOD and COD were calculated using the
mathematical model for activated sludge proposed by Eckenfelder
and others^' )'•
(S°-S*) . KS (I)
V
where SQ = Influent substrate (mg/l)
Se = Effluent substrate (mg/l)
Xv = VMLSS (mg/l)
T = Aeration basin residence time (hr.)
K = Rate constant
58
-------
TABLE XVI
ACTIVATED SLUDGE OPERATING CHARACTERISTICS
PARAMETER
YEARLY YEARLY
MEDIAN STANDARD
VALUE DEVIATION
LOW
MONTHLY
AVERAGE
VALUE
HIGH
MONTHLY
AVERAGE
VALUE
AERATION RESIDENCE TIME 14.4
(HOURS)
MIXED LIQUOR:
SUSPENDED SOLIDS
CMG/L) 2,928
VOLATILE SUSPENDED SOLIDS 2,510
CMG/L)
DISSOLVED OXYGEN 4.1
CMG/L)
TEMPERATURE C°C) 24.9
SVI CML/GM) 125
CLARIFIER OVERFLOW RATE
CGAL/SQ.FT./DAY)
APPLIED F/M RATIO
CMG/L PER MG/L VMLSS)
BOD
COD
280
0.30
1.03
19.4
814'
691
3.2
6.2
54.8
112
0.19
0.67
REMOVAL RATE3
CMG/L PER MG/L VMLSS PER HOUR
AERATION)
BOD 0.008 0.005
COD 0.013 0.013
OXYGEN UP-TAKE RATE" 28.9
CMG/L/HR)
a AVERAGE VALUES ONLY AVAILABLE
12.8
2,285
2,172
2.2
11.8
68
127
0.07
0.23
0.002
0.002
12.9
48.4
4,508
3,906
10.9
29.1
243
364
0.45
1.59
0.014
0.024
44.4
59
-------
This relationship is illustrated in Figures XIV and XV. In the
case of BOD the rate was determined to be 0.0925 hr above a
Se of 75 mg/l. Below that value the process is indicated to be severely
substrate limited and the mathematical model is no longer
applicable. For COD, the rate constant was found to be 0.086
hr'1 above a Se of 900 mg/l.
Ammonia nitrogen removal is illustrated in Figure XVI in which
the fraction of nitrogen remaining is plotted against the
product of mixed liquor solids and aeration time and also the
F/M ratio for BOD. The following nomenclature is used in this
analysis:
NQ = Influent ammonia nitrogen (mg/l)
Me = Effluent ammonia nitrogen (mg/l)
Xy = VMLSS (mg/l)
T = Aeration basin residence time (days)
F/M = VV
S0 = Influent BOD (mg/l)
The data in this Figure indicates that removal of ammonia nitrogen
by synthesis of carbonaceous bacteria and by nitrification
becomes substrate limited above a X^T of 1750 mg-day/l, and
that the minimum value for the fracrion of nitrogen remaining
that can be obtained by the process is 0.175 mg/mg. Also,
Figure XVI illustrates that the lack of carbonaceous
material at a F/M ratio of less than 0.25 prevents nitrification.
Assuming \ = 2510 mg/l, T = 14.4 hours, and 1^, = 15.0 mg/l,
a N^ of 4.0 mg/l is calculated using the indicated relationship.
Color removal is illustrated in Figure XVII in which the
fraction of color remaining is ploted against XyT. The following
nomenclature is used:
C0 = Influent color (APHA units)
C = Effluent color (APHA units)
60
-------
of
E
O
O
CD
CC
e
o
s
ce
0.45
O.40
0.35
O.30
0.25
0.2O
0.15
0.10
O.O5
O)
E
>
x
o
•^s
o
o 0.10 0.20 0.30
FRACTION OF BOD REMAINING
'0 2O 4O 6O 8O 1OO 12O
BOD REMAINING, S^-mg/i
FIGURE XIII, Fraction BOD remaining FIGURE XIV, BOD removal rate
or
£
in
i
o
60
55
50
45
4O
35
3O
25
2O
15
10
5
20O 6OO 1OOO MOO
COD REMAINING, S8-mc/l
FIGURE XV, COD removal rate
61
-------
O)
E
\
en
O.4O
0.30
0.20
0.1O
1OOO 2OOO 3OOO 4OOO 5OOO
XyT, mg-day/I
O.1 O.2 0.3 0.4 05
Fv/M,mg/mg-day
FIGURE XVI• Ammonia nitrogen removal rate
O.8
0.7
O.6
05
0.4
03
0.2
0.1
0 1OOO 2000 3000 4OOO 5OOO
Xv T, mg-day/l
FIGURE XVII, Color removal rate
62
-------
This Figure indicates that color removal by the activated sludge
process is limited to a value of 52.5 percent of the initial
color. Assuming ^ = 2510 mg/l, T = 14.4 hours, and Co = 1032,
Ce is 722 APHA is calculated using the indicated relationship.
During the course of the study, the oxygen consumption (up-take)
rate for the mixed liquor was measured. A sample was taken
from the lagoon and a dissolved oxygen probe was immediately
inserted in the container. Dissolved oxygen concentration was
measured at one minute intervals over a fifteen minute period
of time, and the consumption rate calculated. Oxygen
consumption as a function of substrate removal was determined
for the process using the mathematical model proposed by
Eckenfelder and others^'^:
(Rr) (V) - A(SQ - Se)(Q) + B(XV)(V) (2)
or
Rr/\ = A (So - Se)/XvT + B (3)
where:
Rr = Oxygen consumed (mg/l/day)
SQ = Influent substrate (mg/l)
Se = Effluent substrate (mg/l)
T = V/Q = Aeration basin residence time
(days)
A = Oxygen consumption rate due to
synthesis
B = Oxygen consumption rate due to
autoxidation
Figure XVIII presents this data and indicates values of A = 0.64
and B = 0.13 using BOD as the substrate. Very similar results
were obtained using COD. Assuming So = 448 mg/l, Se = 96 mg/l,
Xv = 2510, and T = 14.4 hours, an oxygen consumption rate of 29.3
mg/1/hr is obtained.
In addition to providing the required oxygen and mixing for the
process, the aerator also serves as an air/water heat exchanger.
Figure XIV illustrates the cooling affect of the aeration basin.
The temperature change is shown to increase with aeration basin
residence time, but the rate of cooling is shown to decrease
with residence time. Assuming an aeration time of 14.4 hours
and an initial temperature of 34.6°C, yields an effluent
temperature of 25.5°C, and a heat loss rate of 1.9 million BTU
per hour (0.48 million kilocalories per hour).
63
-------
O
z
<
I
u
liJ
o:
oe
111
o.
2
UJ
0 0.1 0.2 0.3 0.4 0.5 0.6
FIGURE XVIII• Oxygen consumption rate
20
18
16
14
12
1O
8
6
4
2
BTU
TEMP
2D
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
o
.c
3
CD
(0
•o
I
o
V)
Q
UJ
I
0 5 1O 15 2O 25 30 35 40 45 50
HOURS OF AERATION
FIGURE XIX• Aeration basin cooling
64
-------
The generation rate of excess biological solids as measured by waste
sludge and net effluent solids was investigated using the following
mathematical model:
XaV = (Xe) (Q) + (X^) (QT) = A'(S0 - Se) (Q) + B'(XV)(V) (4)
or
(Q) + (Xe') (Q»)
where:
VXv
A'(S0 - Se)/XvT + B'
(5)
V
Q
Q'
A'
B1
V =
Influent substrate (mg/l)
Effluent substrate (mg/l)
V/Q = Aeration basin residence time (days)
Aeration basin volume (millions of gallons)
Influent flow (millions of gallons)
Sludge flow (millions of gallons)
Sludge production rate due to synthesis
Sludge production rate due to autoxidation
VMLSS (mg/l)
Effluent biological suspended solids
CActual effluent solids minus influent solidsU
(mg/l)
Underflow suspended solids (mg/l)
B i oiogIcaI so Ii ds accumuI at I on (mg/1)
The data using BOD and COD as the substrate is presented in Figures XX
and XXI respectively. Values of A' = 0.625 and B' = 0.012 were obtained
for BOD removal. Values of A' = 0.46 and B' = 0.12 were obtained
Xv =
for COD removal. Assuming So = 448 mg/l BOD, Se = 96 mg/l,
mg/l and T = 14.4 hours, a sludge production rate of 943 pounds
(428 kilograms) per day is calculated using Figure XXI.
2510
An examination of the data indicated that there were was no removal of
influent suspended solids through the process, and that there was a
substantial carryover of biological solids in the clarifier. The
performance of the clarifier in removing biological solids Is Illustrated
In Figure XXII which plots effluent solids against total solids load.
Biological solids were calculated as effluent minus influent TSS and MLSS
minus influent TSS. The solids load was calculated based on the flow
rate plus an assumed constant recycle rate of 0.20 MGD to the aeration
lagoon. Assuming flow = 0.52 MGD (1968 cubic meters per day),
X = 2928 mg/l, and Influent TSS = 174 mg/l, and effluent TSS level =
324 mg/l Is calculated.
65
-------
o
TJ
I
0)
O.24
0.20
0.16
of
£ O.12
> 0.08
« 0.04
0 0.1 O.2 0.3 0.4 05 0.6
(S0-Se)/XvT, day'1
FIGURE XXi Sludge production rate based on COD removal
O.24
-
i
O.20
0.16
i_
> 0.12
OJ08
O.O4
O
O O.1 O.2 0.3
(S0-SC)/XVT, day"1
FIGURE XXL Sludge production rate based on BOD removal
66
-------
The variation In sludge volume index (SVI) with XVT is illustrated in
Figure XXIII. The data indicates an optimum SVI of 90 ml/gr at a
XyT of 2250 mg-day/l. A similar dependency of settling characteristics
on MLSS concentration is illustrated in the static settling test results
presented In Figure XXIV.
The underflow solids concentration of the biological sludge during the
base study period averaged approximately 0.5 percent. However, it was
judged that poor Influent conditions to the clarifier adversely affected
sludge thickening. After the completion of the study, modifications
were made to the clarifier and as a result the average underflow
concentration was Increased to 1.5 percent solids.
Foaming in the aeration basin was a constant operational problem and
as a result a chemical defoamer (Drew ED7IO) was added to the lagoon.
The median dosage rate for this chemical was 24 mg/l. The defoamer
used was an oil based chemical with a COD of 2.55 gm/gm and an oil
content of O.I I gm/gm.
67
-------
in
.D
O
U)
Q
GO
I-
LJ
U.
u.
LJ
1200
1OOO
800
600
400
200
6£>00 1O,OOO 14.OOO 18.0OO 22.0OO
BIOLOGICAL SOLIDS LOADING.Ibs/day
FIGURE XXII, Clarlfier performance
u
8
UJ
I
U)
2OO
175
15O
125
1OO
75
50
25
0
1OOO 20OO 3OOO 4000 50OO
*VT, mg-day/l
FIGURE XXIII, Variation In sludge volumn Index
68
-------
CURVE
MIXED LIQUOR
SUSPENDED SOLIDS (mg 1 1 )
AERATION TIME (hours)
MIXED LIQUOR
DISSOLVED OXYGEN(mg ll)
XvT(mg-day 1)
A
3400
14
4
1983
B
36OO
13
2
1950
C
2600
14
4
1517
D
2600
12
2
1350
E
1500
15
1
938
F
2600
71
2
7692
1000
0 4
8 12 16 20 24 28 32
TIME - minutes
FIGURE XXIV, Static settling curves for the mixed Ifquor
69
-------
SECTION IX
ALUF1 COAGULATION SYSTBI PERFORMANCE
PART A - EFFLUENT CHARACTERISTICS
Table XVII presents a summary of the alum coagulation effluent
characteristics. Table XVIII presents a summary of the percentage
removals for the process calculated from the influent and effluent
median values. As in the previous section, both a total data and
selective data analysis are presented.
The BOD removal through the process was determined to be 73
percent for the total data analysis and 75 percent for the
selective data analysis. This removal was due primarily to the
coagulation of suspended solids and to the destabiIization and
precipitation of colloidal material. The removal of soluble
(less than 0.5 micron) BOD by the process was estimated to be 47
percent. Several analyses indicated that effluent BOD2Q was
approximately twice the BODt value.
The COD removal through the process was determined to be 61
percent for the total data analysis and 58 percent for the
selective data analysis. The significantly higher removal rate
by this process in comparison with the activated sludge process
indicates that the majority of wastewater COD is due to
colloidal material removed by precipation and destabiIization.
The removal of soluble COD (less than 0.5 micron) by the
process was estimated to be 51 percent.
Color removal by the process was found to be a substantial 60
percent based on total data analysis and 58 percent based on a
selective data analysis. This color reduction was determined
to be due primarily to the destabiIization and agglomeration of
dispersed dyes, although some precipitation of water soluble
acid dyes was also indicated. A beaker scale dyeing procedure
using the wastewater and a multiple fiber test fabric were used
to qualitatively indicate the presence of the dispersed
and acid types. Figure XXV is a photograph of a typical series of
samples indicating slight removal of both acid and disperse dyes
by the activated sludge process and the essentially complete
removal of the disperse dyes and some removal of the acid dyes by
the alum coagulation process. This result agrees with results of
dyestuff removal by coagulation reported in the Iiterature^'^.
Two representative spectrophotometric plots of the process
effluent are presented in Figure XXVI.
70
-------
A. Multiple fiber fabric
before dyeing
B. Fabric dyed with
equalized raw waste
(Color = 1290 APHA units)
C. Fabric dyed with
activated sludge effluent
(Color = 1050 APHA units)
D. Fabric dyed with alum
coagulation effluent
(Color = 220 APHA units)
FIGURE X)0/i Color removal in the treatment system.
-------
TABLE XVII
SUNW OF ALUM COAGULATION EFFLUENT CHARACTERISTICS
CONTAMINANT
TEMPERATURE C°C)
PH
COLOR CAPHA)
DISSOLVED OXYGEN CMG/L)
BOD CMG/L)
COD CMG/L)
SUSPENDED SOLIDS CMG/L)
VOLATILE SUSPENDED
SOLIDS CMG/L)
DISSOLVED SOLIDS CMG/L)
AMMONIA NITROGEN
CMG/L AS NH^N)
ORTHOPHOSPHATE
CMG/L AS P04)
ALUMINUM CMG/L)
CALCIUM CMG/L)a
CHROMIUM CMG/L)
HEXAVALENT CHROMIUM
CMG/L)a
COPPER CMG/L)
IRON CMG/L)
LEAD CMG/L)a
MAGNESIUM CMG/L)a
NICKEL CMG/L)a
POTASSIUM CMG/L)a
SODIUM CMG/L)a
ZINC CMG/L)
MERCURY CMG/L)a
PHENOLICS CMG/L)
TOC CMG/L)
CHLORIDE CMG/L)a
SULFATE CMG/L)a
ALKALINITY
MEDIAN
YEARLY
VALUE
25.7
6.2
320
4.8
33
416
122
80
600
3.4
22.0
16.0
—
0.28
N.D.
N.D.
0.68
0.023
1.47
0.01
2.83
1.48
0.11
0.0017
0.04
105
46
283
30
YEARLY
STANDARD
DEVIATION
5.9
1.3
281
3.2
87
268
141
82
145
3.0
15.6
—
-
—
-
-
-
-
-
-
-
-
-
-
-
-
-
—
LOW
MONTHLY
AVERAGE
VALUE
5.0
4.4
116
2.5
14.5
249
64
44
485
2.6
12.7
5.8
0.17
0.10
—
N.D.
0.35
0.003
0.84
N.D.
2.19
71
0.01
0.0001
N.D.
54
42
40
6
HIGH
MONTHLY
AVERAGE
VALUE
29.7
6.7
601
7.1
98.0
751
262
211
792
8.0
65.0
35.4
1.06
0.54
-
0.03
2.18
0.050
3.40
0.02
4.05
333
0.74
0.003
0.11
240
56
490
65
a AVERAGE VALUES
72
-------
TABLE XVIII
SUIflARY OF PERCENTAGE REMOVALS IN ALUM COAGULATION
CONTAMINANT
BOD
COD
COLOR
SUSPENDED SOLIDS
DISSOLVED SOLIDS
AMMONIA NITROGEN
ORTHOPHOSPHATE
ALUMINUM
CALCIUM
CHROMIUM
HEXAVALENT CHROMIUM
COPPER
IRON
LEAD
MAGNESIUM
NICKEL
POTASSIUM
SODIUM
ZINC
MERCURY
PHENOLICS
TOC
CHLORIDE
SULFATE
ALKALINITY
REMOVAL
BASED ON
TOTAL DATA
ANALYSIS
(PERCENT)
73
61
60
67
3
29
66
C28)
42
22
-
100
C19)
18
6
0
0
4
50
6
(33)
48
0
(96)
54
REMOVAL
BASED ON
SELECTIVE DATA
ANALYSIS
(PERCENT)
75
58
58
70
3
30
70
(18)
42
44
-
100
(5)
18
6
0
0
4
50
6
0
48
0
(96)
54
EFFLUENT
CONCENTRATION
BASED ON SELECTIVE
DATA ANALYSIS
(MG/L)
25
380
303 APHA
104
600
2.8
18.0
10.0
0.86
0.20
N.D.
N.D.
0.60
0.023
1.47
0.01
2.83
148
0.05
0.0017
0.03
105
46
283
30
73
-------
Orthophosphate removal, by precipitation as an aluminum salt, was
determined to be a substantial 66 percent based on a total data
analysis and 70 percent based on a selected data analysis.
Ammonia nitrogen removal was determined to be 29 percent, based on
the total data anaylsis and was due to the removal of nitrogen
containing colloidal organic matter.
Net dissolved solids removal across the process was determined
to be 3 percent. However, considering the contribution of
inorganic dissolved solids by the alum, the removal of process
influent dissolved solids was estimated to be between 15 and 20
percent.
Chromium, copper, and zinc were found to be removed effectively
by the alum coagulation process. The residual concentrations of
copper and zinc were estimated to approach their solubility
limits. Additional removal of chromium to a level of approximately
0.20 mg/l could be achieved, however, with an additional removal
of dyes since the remaining dyes were most likely of the chromium
metalized acid type. Mercury concentration was increased
slightly probably as a result of the use of mercury contaminated
liquid caustic soda for neutralization. Aluminum was increased
3.5 mg/l during the study as a result of the alum addition.
This value is significantly higher than projected from the
solubility data presented in Figure XXVII. Approximately 68 percent
of the effluent aluminum was in the soluble form and the
estimated increase in soluble aluminum through the process was
3.0 mg/l. The iron content of the waste was increased
slightly as a result of the iron present as a contaminant in the
a I urn.
There was an increase in phenol concentration across the process, as
indicated by the data. This increase was due to sampling
and analytical error considering the low concentration being
measured.
The sulfate concentration of the wastewater was increased
significantly as a result of non-compIexed sulfate from the alum.
Calcium, of the trace inorganics measured, was significantly
reduced.
The pH was controlled to a-level of 6.2 by caustic soda addition
following alum addition, but there was a wide variation in effluent
pH as indicated by a 2.3 pH unit standard deviation.
Alkalinity, primarily calcium alkalinity, was reduced 54 percent by
the precipitation process.
74
-------
0.28
300
4OO
50O
6OO
Wavelength, m>i
FIGURE XXVL Spectrophotometric curves for alum coagulation effluent
1.0
or
E
10"1
<
>
m
3
o
10
1O
Reference: Source No-1O
6 7
PH
FIGURE XXVII, Solubility in water of the mixed salt
of aluminum, sulfate, and hydroxide
15
-------
The dissolved oxygen in the process discharge was determined to be
4.8 mg/l. This measurement was at the final plant discharge after
several weir overflow points. The data from several oxygen
profile studies of the plant indicated a dissolved oxygen level of
approximately 3.5 mg/l in the clarifier overflow. The
increase in dissolved oxygen between the activated sludge and alum
coagulation clarifiers was attributed to re-aeration in the
wastewater free fall line connecting the two units.
76
-------
PART B - OPERATING CHARACTERISTICS
Table XIX presents a summary of the alum coagulation operat'ng
characteristics.
An analysis of all the data indicated a median alum dosage of 263 mg/l.
After the polymer feed system was placed in operation, the median
dosage of the an ionic polymer was 3.9 mg/l.
The coagulation process (that is the formation of colloidal particles
and the aggregation of existing and newly formed particles) is dependent
on two principle events:
- particle transport to effect interparticle contact
- particle destabiIization to permit attachment when contact
occurs
The first event involves the selection of structures and mixing equipment
and the second event involves the selection of a coagu.lant and the
process conditions ('*'.
In evaluating the performance of the acrivated sludge system, two
separate analyses were made. The first analysis was to determine the
optimum coagulant dose range as indicated by beaker scale ("Jar") +ests
that approximate the full-scale treatment method. The second analysis
was to determine the removal rate characteristics in the full-scale
system to predict performance based on the use of the effective range
of coagulant dose.
Figure XXVIII presents the data for a typical series of jar tests in
which supernatant BOD and COD was measured at various alum dosage levels.
This data indicates an alum dosage of 200 - 300 mg/l was required in
order to achieve maximum removal. At a dosage of over 300 mg/l the
additional alum provided no further significant removal. At a dosage
of under 200 mg/l contaminant removal decreased rapidly and a turbid
supernatant was produced.
Contaminant removal was also found to be dependent on supernatant pH.
Figure XXIX illustrates this for BOD and COD values and indicates an
optimum pH of 5.0 for an alum dose of 300 mg/l (the pH resulting from
an alum dose of 300 mg/l without the pH adjustment would be 3.8 - 4.0).
77
-------
TABLE XIX
ALJUM COAGULATION OPERATING CHARACTERISTICS
PARAMETER
ALUM DOSAGE (MG/L)
AN I ON 1C POLYMER DOSAGE^3 ^
CMG/L)
CLARIFIER OVERFLOW RATE
(GAL/ SQ.FT. /DAY)
YEARLY
MEDIAN
VALUE
263
3.9
364
YEARLY
STANDARD
DEVIATION
103
2.3
141
LOW
MONTHLY
AVERAGE
VALUE
206
2.94
198
HIGH
MONTHLY
AVERAGE
VALUE
358
4.72
485
REMOVAL RATE
CMG/L PER MG/L OF ALUM)
COD5
COLOR
0.34
2.18
1.4
2.4
0.27
1.23
0.92
0.76
6.93
2.4
NOTE:
a AFTER MAY 1, 1973 ONLY
b AVERAGE VALUES
78
-------
100
2OO
3OO
ALUM DOSAGE
mg/l
FIGURE XXVIII, Typical COD and BOD removals by alum
coagulation at a pH = 6.0
350-
567
SUPERNATANT pH
8
FIGURE XXIX, Typical COD and BOD removals with
pH at an alum dose of 300 mg/l
79
-------
Similar data is presented in Figures XXX through XXXII for color,
orthophosphate, aluminum, and chromium. For color an optinum alum
dosage of over 225 mg/l was indicated with a maximum insolubility
at 5.0 pH. For orthophosphate an optimum alum dose of 300 mg/l
was indicated with a maximum insolubility at 5.0 - 6.5 pH. For
aluminum and chromium, maximum insolubility was indicated at 6.0 pH.
The data presented in these graphs are typical of the results obtained
during the study and indicate an alum dosage of 200-300 mg/l
is required to obtain effective coagulation. The data also indicates
that there are two separate pH points (5.0 and 6.0) for maximum
insolubility of the contaminants (this is further discussed in
Section XVII of this report).
In order to insure that the proper coagulant dose is applied to the
wastewater in a chemical treatment process, periodic jar test
analyses are required. During the course of the study, these tests
were made periodically and the results tended to substantiate the
200 - 300 mg/l dose as the optimum.
Before proceeding further, it may be helpful to review several
general concepts of coagulation that have been discussed in the
literature in recent years. O'Melia indicates the following four
methods o.f metal salt coagulation. '^'
- compression of the diffuse charge layer surrounding
colloidal particles by attraction of counter ions
- adsorption of metal ions into the colloid to
produce charge neutralization
- enmeshment of the colloid in a precipitate
- adsorption of a polymeric species by the colloid
to permit interparticle bridging
For wastewater treatment, only the latter two methods may be
signi ficant.
When a metal salt is used as a coagulant in sufficient concentration
to cause rapid precipitation, colloidal particles can be enmeshed
in the precipitate as it is formed. The rate of colloid removal by
this method is influenced by the degree of over-saturation of the
solution, the presence of multivalent anions, and the concentration
of the colloid. That is, the higher the degree of saturation or
the concentration of the anion or the concentration of the colloid,
the lower the amount of coagulant required to affect removal^'3)>
80
-------
SUPERNATANT pH
34567
5OO
4OO
I
g
d
u
K
uj
Q»
^
I/)
300
200
100
Alum @ pH 5.7
pH @ 30O mg/l Alum
100 200 300 400
ALUM DOSAGE-mg/l
100 2OO 300 400
ALUM DOS AGE-mg/l
FIGURE XXXi TypJcal cofor removal
variations with alum
dose at pH
FIGURE XXXI, Typical orfhophosphate
removal variation with
alum dose at pH
34 5678
SUPERNATANT pH
FIGURE XXXIL Residual aluminum and chromium variation with pH at an
alum dose of 400 mg/l.
81
-------
Coagulation by interparticle bridging occurs when a colloid
contacts a polymer species and absorbs some of the chemical
groups of the polymer "hile leaving other groups available for
adsorption by remain!, _ colloids.
The water chemistry of aluminum (III) is a complex subject even
when the solute is pure water. Hayden mentions the following
concepts, however, as the major factors whicb. sign! f icantly
affect- the understanding of the
The species and state of aluminum (III) that
can be formed during coagulation are pH
dependent as indicated by Figure XXXIII, and
these species affect the method of coagulation
experienced
For pure water, the pH point of precipitation (pHp)
varies between 4.2 and 4.9 depending on concentration
Simarily the pH point of dissolution (pH
-------
Ale OH) zo
AI(OH)3(c)
I
AI(OH)4
7 8
PH
1O
11
FIGURE XXXIII, Distribution of hydrolyzed aluminum (III) as a function
of pH and a I.0 x \Q~* molar concentration of aluminum
(III)
o
u
UJ
O
<
to
COLLOID CONCENTRATION
FIGURE XXXIVi Schematic representation of coagulation
83
-------
coagulant has been added to obtain oversaturation and enmeshment
of the colloid in the hydroxide precipitate. For concentration $2,
destabiIization can occur either at the oversaturation level, or
at a much lower concentration by the adsorption of hydrometal
polymers. For 83, the colloid concentration is sufficiently high
that destabiIization can only occur by adsorption of hydrometal
polymers.
Based on the voluminous sludge produced by the coagulation process,
in comparison with the small fraction of colloidal chemicals and
dyes in the BRW wastewater, it is estimated that the mechanism
observed in the full-scale coagulation process is primarily due
to oversaturation and generation of aluminum hydroxide solids.
This agrees with the data presented by Hayden, in that a settleable
floe rather than a suspension will be produced because the sulfate
concentration experienced in the BRW wastewater depresses the
pHc point to the pHp point.
However, since the optimum pH point for organic chemical and
color removal is in the range of 5.0, it may be possible that
additional destabiIization occurs through the adsorption of the
cat ionic, polymeric species of aluminum that exist in "this pH
range. Also, it may be possible that these cationic polymers
chemical interact with the anionic acid dyestuffs and form an
insoluble basic.salt. This latter method has been observed in the
removal of naturally occuring organic color from water ^.
The data in Figure XXXI indicates that a ratio of 1.6 moles of
AI (III) per mole of phosphorous is required to remove phosphate
below a level of 1.0 mg/l -(as PO/). This ratio is similar to
that reported in the literature Til). The pH effect indicated
generally agrees with published information that the range for
destabiIization of aluminum/phosphate precipitates is
pH 4.5 - 7.0 (IO).
Figure XXXII indicates a residual aluminum of 1.0 mg/l at the
optimum pH of 6.0 although the literature indicates that a residual
of O.I mg/l should be obtained at this pH(l°j*. The solubility
of chromium as indicated by the literature ('^ is substantially
higher than the values illustrated in Figure XXXII and suggest that
the measured chromium is complexed with the acid dyes rather than
present in a free ion state.
After establishing that sufficient alum was present to cause
coagulation, it was possible to examine contaminant removal
characteristics in the full system for periods when the alum dose
was within the effective range.
84
-------
An analysis of the data for the coagulation process determined that for
BOD, COD, and color the only significant correlation was between the
removal rate per mg/l of alum and the influent concentration of
contaminant. Figures XXXV through XXXVII illustrate this relationship
and indicate the generally increasing rate of removal with higher
initial concentration of contaminant. This relationship is in
agreement with the theory previously presented. Figures XXXV through
XXXVII have been projected to a zero removal rate to indicate estimate
minimum obtainable effluent values for the coagulation process.
Using these graphs and assuming alum dose and influent values, effluent
concentrations are calculated as presented in Table XX.
TABLE XX
REMOVALS BY ALUT1 COAGULATION
ALUM DOSE CONTAMINANT INFLUENT VALUE EFFLUENT VALUE
CMG/L)
275 BOD (MG/L) 100 26
275 COD CMG/L) 900 ws
275 COLOR (APHA) 725 340
The removal of orthophosphate was found to be relatively constant
(0.14 gr phosphate per gr of alum or 0.44 moles of phosphorous per mole
of aluminum) and no correlation was found between alum dosage, removal
rate, or influent or effluent phosphate values.
Assuming an influent orthophosphate concentration of 60 mg/l, an
alum dosage of 275 mg/l, the calculated effluent orthophosphate
concentration would be 21 mg/l.
85
-------
O.6
^2S 0.5
O)
2 0.4
< 0.3
o 0.2
0,
I I i_
0 50 1OO 150 2OO
INFLUENT BOD, So-mg/l
FIGURE XXXV, BOD removal by alum
en
JP
5
4
3
2
1
0 400 800 1200 1600
INFLUENT COD, So-mg/l
FIGURE XXXVI, COD removal by alum
86
-------
L-
tfl
c
ID
Z
CL
ID
^
-------
Jar tests of the a I urn coagulation process indicated increased
color removal at a pH in the 4.75 - 5.25 range. Figure XXXVIII
illustrates a similar result using treatment plant performance
data. In this presentation, the effluent color values were
mathematically adjusted to a value representing color at a pH
of 6.5 by the use of Figure IX in Section V of this report.
This data indicates that by lowering the pH of the coagulation
process from 6.5 to 5.0, the fraction of color remaining will
be reduced to 65.0 percent of the 6.5 pH color value. Therefore,
based on the previous example, an effluent color of 340
APHA units at a 6.5 pH would be reduced to 200 APHA units at
a 5.0 pH.
Figure XXXIX illustrates the performance of the alum coagulation
clarifier in removing suspended solids.
For this presentation, solids loading to the clarifier was
calculated as pounds of influent suspended solids. Effluent
solids was calculated as pounds of suspended solids in the
clarifier overflow. The data indicates a substantially lower
removal rate at wastewater pH values below 4.5.
Assuming an influent suspended solids concentration of 330 mg/l
and a flow rate of 0.52 MGD (1968 cubic meters per day), the
calculated effluent suspended solids concentration would be
90 mg/l according to Figure XXXIX.
The alum sludge generation rate is presented in Figure XL where
solids added are plotted against solids lost from the clarifier.
For this presentation, solids added was calculated as the total of
influent suspended solids and alum dose in pounds, and the solids
lost was calculated as the suspended solids lost over the weir plus
the suspended solids in the sludge underflow in pounds.
Assuming an influent suspended solids concentration of 330 mg/l,
a flow rate of 0.52 MGD (1968 cubic meters per day), an alum
dosage of 275 mg/l, a solids underflow concentration of 20,000 mg/l,
the calculated sludge flow would be 8,200 gallons (31.0 cubic
meters) per day.
Typical settling curves for the alum generated sludge are
presented in Figure XLI. The effects of rapid mixing and polymer
addition are illustrated in this Figure. Without rapid mixing of
the alum and wastewater or without polymer addition, the initial
settling rate was 38.5 mis per minute after five minutes of
non-settling. With rapid mixing, the settling rate was increased
to 125 mis per minute, the non-settling time reduced to three
minutes. With rapid mixing and anionic polymer addition, the
settling rate was increased to 400 mis per minute, and the non-settling
period eliminated.
88
-------
J3
- 1000
(/>
j 800
«" 600
g 400
3
u! 200
U.
it) o
pH <5.0
PH >6.O
0 1OOO 200O 3000
SOLIDS LOADING, Ibs/day
FIGURE XXXIX, Alum coagulation clarlfler performance
V)
450O
4000
3500
3OOO
250O
2000
15OO
1OOO
500
0
O 1OOO 2OOO 30OO.
EFFLUENT PLUS WASTE SOLIDS-Ibs/day
FIGURE XL A'um sludge generation
89
-------
SLOW MIX
RAPID MIX
POLYMER ADDITION
A
YES
NO
NO
B
YES
NO
NO
C
YES
YES
NO
D
NO
YES
YES
E
NO
YES
YES
TIME
OMIN
2 MIN
15 MIN
60MIN
SUPERNATANT
SUSPENDED SOLIDS
DURING TEST"E"
510 mq 1 1
15 mg l|
14 mq 1 1
11 mq 1 1
0
8
12 16 20 24 28 32
TIME-MINUTES
FIGURE XLL Static settling curves for alum sludge
90
-------
The adverse effect of pH In suspended solids removal in the alum
coagulation clarifier is illustrated in the treatment plant performance
data presented in Figure XLII. This data indicates that by lowering the
wastewater pH from 6.5 to 5.0, the fraction of solids remaining will be
increased from 0.21 to 0.45.
The neutralization requirement for the coagulation process is illustrated
in Figure XLIII, which presents titration data for activated sludge
effluent using alum to titrate downward and sodium hydroxide to titrate
upward. In this example, an alum dosage of 275 mg/l would lower the
wastewater pH to 4.5 and would require 40 mg/l of sodium hydroxide to
adjust the wastewater to 6.5 pH.
In Section VI of this report, the new rapid mix, slow mix, and polymer
injection additions to the alum coagulation process were discussed.
While an analysis of the data indicates a barely detectable increase in
contaminant removal, a major change that occurred was in the thickening
of solids in the clarifier and an order of magnitude increase in under-
flow solids concentration. Prior to the modification an average under-
flow solids concentration of 2317 mg/l required an average underflow
pumping rate of twelve percent of through-put flow. After the modification,
an average underflow concentration of 19,584 mg/l required only an average
underflow rate of three percent of through-put flow.
The turbidity values for the ^lum coagulation clarifier effluent for the
month prior to the mixing and polymer modifications and for the two
months after the modifications were examined. This data indicates that
turbidity in the effluent was reduced from a median of 110 JTU to a
median of 55 JTU by installation of rapid mix and polymer addition
faciIities.
The effluent from the activated sludge clarifier typically contained
a dissolved oxygen residual of 0.5 - 2.0 mg/l. Prior to the
installation of the new mixing and polymer addition equipment to the
alum coagulation system, this concentration was increased to a 4.0 -
5.0 mg/l level due to the piping arrangement between the activated
sludge and alum coagulation clarifiers. The difference In elevation
between the clarifier water surfaces exceeded eight feet (2.4 meters),
and a large volume of air was entrained in the wastewater as it flowed
down a vertical section of pipe at the activated sludge clarifier exit.
When the new mixing equipment was installed, the hydraulics were
improved but at the expense of the dissolved oxygen concentration.
As a result, dissolved oxygen was depleted in the wastewater as
degradation of organic matter continued In the clarification step.
91
-------
I
a.
z
UJ
u.
u_
UJ
7
6
5
4
3
0 0.2 QA O.6
FRACTION SOLIDS REMAINING, X/XQ -gr/gr
FIGURE XLIL Suspended solids removal as a function of pH
100 200 3OO 400
ALUM DOSE-mg 11
0 10 2O 30 40 5O 6O 70 80 90 100
CAUSTIC SODA DOSE-mg 11
FIGURE XLIII, Tltration of activated sludge system effluent with alum
and caustic soda
92
-------
To correct this situation, hydrogen peroxide was added to the
discharge end of the flocculation basin. A dosage rate of 15 mg/l
was found to provide a sufficient residual to prevent septic odor
formation without a detectable peroxide residual in the effluent.
93
-------
SECTION X
COMBINED ACTIVATED SLUDGE AND ALUM
COAGULATION SYSTEM PERFORMANCE
A summary of overall removal rates for the combined activated
sludge and alum coagulation system is presented in Table XXI
for both a total data analysis and a selective data analysis.
Also, effluent contaminant to production weight ratios for
the contaminants listed in the July 5, 1974, EPA textile
industry guidelines have been calculated and are presented in
Table XXII.
Observation of the performance of the combined system resulted
in the following conclusions regarding total system capabilities:
- Soluble and colloidal biodegradable organic chemicals,
expressed as BOD, were removed to a high degree
Colloidal, refractory organic chemicals, expressed as
total COD, were removed to a high degree. There was
only partial removal of soluble, refractory organic
chemicals, expressed as soluble COD
- Dispersed dyes were effectively removed by the system
but only partial removal of acid dyes was accomplished
as indicated by color measurement and qualitive dye
analysis
- Only minimal removal of dissolved solids was
accomplished
- Ammonia nitrogen was removed to a high degree by the
system, primarily by the activated sludge process
- Orthophosphate was removed by the a Turn coagulation
process, but the high influent concentration resulted
in significant, phosphate in the effluent
- Total chromium, hexavalent chromium, copper, and zinc
were effectively reduced by the system. However, aluminum,
iron, and mercury were increased by the system.
94
-------
TABLE XXI
SUWRY OF TOTAL SYSTEM
REMOVAL RATES
CONTAMINANT
BASED ON TOTAL
DATA ANALYSIS
CPERCENT)
BASED ON SELECTIVE
DATA ANALYSIS
(PERCENT)
BOD
COD
COLOR
SUSPENDED SOLIDS
DISSOLVED SOLIDS
AMMONIA NITROGEN
ORTHOPHOSPHATE
ALUMINUM
CALCIUM
CHROMIUM
HEXAVALENT CHROMIUM
COPPER
IRON
LEAD
MAGNESIUM
NICKEL
POTASSIUM
SODIUM
ZINC
MERCURY
PHENOLICS
TOC
CHLORIDE
SULFATE
ALKALINITY
DETERGENT
FOAMING
HEIGHT
DURATION
92
73
69
30
16
77
63
C88)
57
52
100
100
0*5)
8
39
0
33
4
15
C6)
60
72
C6)
C79)
71
88
(42)
32
94
76
71
40
16
84
70
NOT PREDICTED
51
65
100
100
C45)
8
39
0
33
4
C60)
C6)
60
72
C6)
C79)
71
90
NOT PREDICTED
NOT PREDICTED
95
-------
TABLE XXII
EFFLUENT CONTAMINANT TO PRODUCTION
WEIGHT RATIOS BASED ON SELECIH) DATA ANALYSIS
CONTAMINANT CONCENTRATION RATIO
(MG/O CLBS/1000 LBS OR
KG/KKG)
BOD
COD
SUSPENDED SOLIDS
TOTAL CHROMIUM
PHENOL
25
380
104
0.20
0.03
2.24
3^.05
9.26
0.018
0.003
BASIS:
FLOW = 0.520 MILLION GALLONS C1968 CUBIC METERS) PER DAY
PRODUCTION = 48,400 POUNDS C21,950 KILOGRAMS) PER DAY
96
-------
Phenolic chemicals were reduced to an acceptable
discharge primarily by the activated sludge process
Calcium, magnesium, and potassium were significantly
reduced but sulfate was increased by the system
The alkalinity of the discharge was reduced significantly
by the system
Detergent concentration, measured as MBAS, was very
effectively reduced by the system. However, there
was essentially no change in the characteristic
of the wastewater to produce a noticeable amount of
long duration foam when agitated.
Based on the waste characteristics and operating characteristics
presented in Table XXIII and using the performance models for
the treatment processes previously presented, the effluent
characteristics and operating parameters for the system have been
predicted. The calculations for this process design are
presented in Tables XXIV through XXVI. A process material
balance using the data from this process design is presented
in Table XXVIII.
97
-------
TABLE XXIII
BASIS OF PROCESS DESIGN
CALCULATIONS
FLOW CMGD) 0.52
EQUALIZED WASTE CONTAMINANTS
BOD CMG/L)
COD CMG/L) 1550
COLOR CAPHA) 1030
AMMONIA NITROGEN CMG/L) 15
ORTHOPHOSPHATE CMG/L) 60
SUSPENDED SOLIDS CMG/L) 175
TEMPERATURE C°C) 35
OPERATING CHARACTERISTICS
MLSS CMG/L) 2950
VMLSS CMG/L) 2500
RETURN SLUDGE RECYCLE RATE CMGD) 0.17
ACTIVATED SLUDGE CLARIFIER
UNDERFLOW SOLIDS CONCENTRATION C%) 1.5
ALUM COAGULATION CLARIFIER
UNDERFLOW SOLIDS CONCENTRATION C%) 2.0
ALUM DOSE CMG/L) 300
98
-------
TABLE XXIV
PROCESS DESIGN CALCULATIONS
FOR OMMNANT REMOVAL
:tivated Sludge Process (see Section VIII for development of
slationships) .
A. BOD Removal
S0
-------
TABLE XXIV PROCESS DESIGN CALCULATIONS FOR
CONTAMINANT REMOVAL (CONT'O)
F. Cooli ng
Hours of aeration 15.5
Temperature change = IO°C (See Figure XIV)
Effluent temperature - influent - change =
35-10 = 25°C
Alum Coagulation Process (see Section IX for development of relationships)
A. BOD Removal
Influent BOD = 85 mg/l
(S0 - Se)/Alum = 0.205 (See Figure XXX)
(87 Se)/300 = 0.205
Se = 25 mg/l
B. COD Removal
Influent COD = 968 mg/l
(S0 - Se)/Alum = 1.95 (See Figure XXXI)
(968 - Se)/300 = 1.95
Se = 380 mg/l
C. Color Removal
At pH 6.5 At pH = 5.0
Influent color = 700 APHA Cg1 = 0.65 (Ce)
-------
TABLE XXV
PROCESS DESIGN CALCULATIONS
FOR SLUDGE PRODUCTION
Excess Activated Sludge (see Section VIII for development of relationships)
Y A' (Q - S )
Xg A li>0 3e> + B,
VXVT XVT
0.625 (450-87) (24) (8.34)
(2500) (8.34M.336) (2500) (8.34) (15.5)
Xa = (0.140 - 0.012) (7006)
Total Solids Generated =
Xg = 897 pounds/day = 407 ki lograms/day
Solids Loss in Effluent = ( 155) (8.34) ( .52)
= 672 pounds/day = 305 kilograms/day
Solids to Centrifuge = 897 - 672
= 225 pounds/day = 102 kilograms/day
Flow = (225)(I06)/(8.34)(IO,000)
= 2700 gallons/day = 10.2 cubic meters/day
Alum Coagulation Sludge (see Section IX for development of relationships)
Influent Solids Plus Alum Dose
= (330 + 300) (8.34) (.52)
= 2732 pounds/day = 1240 kilograms/day
Effluent Solids Plus Waste Solids (See Figure XXXV)
= (0.67)
= 1830 pounds/day = 831 kilograms/day
101
-------
TABLE XXV PROCESS DESIGN CALCULATION FOR
SLUDGE PRODUCTION (CONT'D)
Effluent Solids = (90) (8.34) (.52) (see Figure XXXIV)
= 390 pounds/day = 177 kilograms/day
Solids to Centrifuge = total waste - effluent solids
= 1830 - 390
= 1440 pounds/day 654 kilograms/day
Sludge Flow = (1440) M06)/(8.34) (20,000)
= 8600 gallons/day =32.6 cubic meters/day
102
-------
TABLE XXVI
PROCESS DESIGN CALCULATIOMS
FOR OPERATING CHARACTERISTICS
Oxygen Consumption (see Section VIII for development of relationships)
R/Xy = A
-------
TABLE XXVII
TREATFBfT PROCESS WTERIAL RAL/VJCE
CONTAMINANT
VOLUME
TEMPERATURE C°O
PH
DISSOLVED OXYGEN CMG/L)
BOD CMG/L)
COD CMG/L)
COLOR CAPHA)
SUSPENDED SOLIDS CMG/L)
DISSOLVED SOLIDS CMG/L)
AMMONIA NITROGEN CMG/L)
ORTHOPHOSPHATE CMG/L)
ALUMINUM CMG/L)
CHROMIUM CMG/L)
COPPER CMG/L)
IRON CMG/L)
MERCURY CMG/L)
ZINC CMG/L)
PHENOL CMG/L)
SULFATE CMG/L)
ALKALINITY CMG/L)
EQUALIZED
WASTE
0.520 Ca)
35
6.7
2.0
1*50
1550
1030
175
715
15.0
60.0
8.5
0.60
0.03
O.MJ
0.0015
0.13
0.10
150
105
NOTES
Ca) MGD C3785 CUBIC METERS/DAY)
Cb) TONS WET SLUDGE/DAY
ACTIVATED
SLUDGE
0.520 (a)
25
6.7
1.5
87
968
700
330
620
3.8
60.0
8.5
0.37
0.03
0.50
0.0017
0.22
0.025
135
65
Cc)
Cd)
SLUDGE
ALUM EXCESS
COAGULATION ACTIVATED ALUM CENTRATE
0.520 ^a) 0.0027^a) 0.0086(a)o.010 ^a-
25 -
6.5 - - 7.3
2.0 - - -
25 -
380 - - 750
295 - - 250
90 10,000 20,000 200
600 - - 600
2.8 - - 35.0
18.0 - - 10.0
10 -
0.20 - - -
N.D. - -
0.60 - - -
0.0016 - -
0.11 - -
0.03 - - -
265 - -
30 -
PERCENT
MG/GR
SLUDGE
CAKE
> -.60C
—
-
-
1<*(C)
100(d
0.9 ('
0.0021
0.30 <
-
-
-------
SECTION XI
SLUDGE HANDLING
PART A - CHEMICAL AND BIOLOGICAL ANALYSIS
A number of tests were made during the course of the study to
determine the chemical characteristics of the waste sludge
produced by the treatment system. Table XXVIII presents the
results of several separate analyses that were made of the
combined biological and chemical sludges. These analyses
indicate that a significant part of the sludge was inorganic
chemicals such as aluminum, iron, chromium, zinc, lead, phosphate,
sulfate, and chloride salts. Ammonia nitrogen and COD were
also present in a significant concentration indicating that
organic material was a major constituent of the sludge. It
should be noted, in considering the wastewater removal values for
iron, mercury, phosphate, ammonia nitrogen, and aluminum, the
concentration values reported for the sludge are higher than
anticipated.
The ultimate disposal route for the dewatered sludge from the
BRW treatment plant will be by landfill ing. In order to determine
the possible constituents in the leachate at the landfill site, a
laboratory study was conducted. In the study a four-inch
(IO.I centimeter) diameter column was packed with five inches
(12.7 centimeter) of dewatered sludge on top of a two-inch
(5.1 centimeter) layer of sand and gravel. Distilled water was
then applied continuously to the surface of the packed sludge
at the rate of 220 mililiters per day. The leachate was
collected and analyzed periodically. A summary of the results
of the chemical analyses are presented in Table XXIX. The BOD,
COD, and total solids data indicate that there was substantial
leaching of organic and inorganic material during the first ten
days following application of water, and after one month these
values had stabalized. The iron content in the leachate
remained constant over the test period. The chromium content in
the leachate was low in comparison with the cake content indicating
the chromium was not readily leached. In comparison, the copper
105
-------
TABLE XXVIII
CHEMICAL ANALYSIS OF WASH SLUDGE
SLUDGE
SLURRY
CMG/L)
IRON
TOTAL CHROMIUM
HEXAVALENT CHROMIUM
COPPER
NICKEL
LEAD
CADMIUM
MANGANESE
ZINC
ARSENIC
CALCIUM
ALUMINUM
SODIUM
POTASSIUM
MERCURY
BERYLLIUM
SELENIUM
PHOSPHATE CAS P)
SULFATE
CHLORIDE
AMMONIA NITROGEN
CYANIDE
PESTICIDES
CHLOROFORM EXTRAC-
TABLES
ACID INSOLUBLES
TOTAL SOLIDS
TOTAL SUSPENDED
SOLIDS
PHENOL
COD
ALKALINITY
ACIDITY
14.0
0.62
0.12
1.11
N.D.
t _
1.98
0.155
—
_
_
0.008
0.025
0.035
6.7
520
-
__
.^
NEGATIVE
NEGATIVE
-
19,950
18,900
_
26,760
430
230
LAB
SLUDGE
CAKE
CMG/G)
1.46
1.406
0.040
0.008
0.036
0.0022
0.040
0.136
0.0015
3.20
200
2.2
2.9
0.0052
_
N.D.
1.07
520
9.6
10.0
N.D.
_
_
445
—
_
-
—
_
-
LAB
SLUDGE
CAKE
CMG/G)
8.04
0.796
0
0.042
0.048
0.145
N.D.
0.304
_
100
m_m
0.0002
__
-
0
1.04
0
o
0
0
_
0
0
0
_
—
CENTRIFUGE
SLUDGE
CAKE
CMG/G)
5.20
0.55
0.025
0.027
N.D.
0.30
0.008
0.41
_
166
_
0.0010
-
900
6.0
47.5
N.D.
16.80
NEGATIVE
_
—
_
0.0049
_
_
_
106
-------
TABLE XXIX
SLUDGE LEAD1ATE CHARACTERISTICS
TIME FROM START OF STUDY
CONTAMINANT
PH
BOD CMG/L)
COD CMG/L)
TOTAL SOLIDS
CMG/L)
TSS CMG/L)
IRON CMG/L)
CHROMIUM CMG/L)
TOTAL COPPER
CMG/L)
SOLUBLE COPPER
CMG/L)
LEAD CMG/L)
TOTAL ZINC CMG/L)
SOLUBLE ZINC
TWO
DAYS
7.3
252
1027
1128
56
1.39
0.05
0.26
-
0.06
0.38
_
FIVE
DAYS
7.3
402
1244
1130
80
2.45
0.035
0.21
-
0.04
0.23
_
TEN
DAYS
7.3
480
1170
784
-
2.53
0.08
N.D.
-
0.06
0.11
_
TWENTY-
NINE DAYS
6.9
240
531
322
60
2.35
N.D.
N.D.
-
0.06
0.14
_
SIX
MONTHS
7.0
141
504
484
83
2.48
-
0.12
0.02
N.D.
0.18
0.05
CMG/L)
TOTAL ALUMINUM 0.06
CMG/L)
SOLUBLE ALUMINUM
CMG/L)
CALCIUM CMG/L) 32
.COLOR CAPHA)
0.4
19
COMPOSITE = 400
1.0
11
0.50
0.12
250
107
-------
in the cake was leached in the first five days. Zinc which was present
was readily leached in the first five days, and then remained at a
constant low level. The aluminum content in the leachate was suprising-
ly low considering that twenty percent by weight of the sludge cake
was aluminum. Color in the leachate was relatively constant for the
first 30 days but slowly reduced with time.
Static bioassays using the leachate were also conducted to determine
relative toxicity. Common gold fish was the test organism. The results
of the test are presented in Figures XLIV and XLV and indicate a 96
hour Tl_50 of 12.0 percent after 30 days and 25.0 percent after 6 months
of leaching.
During a portion of the study, waste wet sludge from the treatment system
was sent to the ocean for disposal. As part of the US EPA permit
program for ocean disposal, a static bioassay of the wet sludge was run
using brine shrimp, Artemia Salina, as the test organism. Figure XLVI
illustrates the results of this test, and indicates a 96 hour TLjQ of
2.7 percent.
108
-------
1OO-O -
o
z
UJ
8 10.0
u
uj
CONCENTRATION
(PERCENT)
TIME OF DEATH
FOR FIRST FISH
(HOURS)
TEST ORGANISM: COMMON GOLDFISH
20
4O 60 80
SURVIVAL- percent
10O
O
Z
llJ
O
z
X
u
UJ
1OO.O
1O.O
1.0
24 hour
48TL =37%
50
96TL =25°/.
50
TEST ORGANISM: COMMON GOLDFISH
2O 40 6O 80
SURVIVAL- percent
1OO
FIGURE XLIV, Survival curve for one
month leachate
FIGURE XLV, Survival curve for six
month leachate
z
UJ
u
8
10O
1.O
TEST ORGANISM: ARTEMIA SALINA
2O 40 60 8O 1OO
SURVIVAL - percent
FIGURE XLVL Survival curve for wet sludge
109
-------
PART B - VACUUM FILTER OPERATION
Because of the poor performance of the original pre-coat vacuum filter
system in handling the treatment plant sludge, very little data was
gathered to define its operating characteristics during the grant period.
The information that was obtained is summarized in Table XXX.
The primary reason for the filter system not performing satisfactorily
was the extended periods of down-time between filter runs. Typically
approximately one shift was required to wash down the filter and apply
a new four inch pre-coat layer. However, it was seldom possible to
begin the pre-coat operation immediately after the filter shutdown,
so that the average downtime between runs was approximately twenty-four
hours. As a result, solids accumulated in the storage tank prior to
the filter and an anaeraobic condition quickly developed. The partially
digested sludge was extremely difficult to dewater because of the tend-
ency to blind to filter surface. The storage problem was compounded by
a sludge flow rate that exceeded the design expectations and resulted
in increased retention time in the storage tank.
A review of these operational problems shortly after the treatment
system was functional determined that vacuum filtration was not a
feasible method of dewatering.
10
-------
TABLE XXX
SUWRY OF VACUUM FILTER PERFORMANCE
SOLIDS FEED TO STORAGE TANK
SOLIDS FEED TO FILTER FROM STORAGE
TOTAL FEED RATE
RECYCLE RATE
CAKE MOISTURE (INCLUDES PRE-COAT)
FILTER RUN TIME
TIME TO PRE-COAT
TOTAL DOWN TIME
PRE-COAT TYPE
PRE-COAT USE PER FILTER RUN
FILTER BACK
if, 100 MG/L
23,600 MG/L
30 GALLONS
(0.11 CUBIC METERS) PER MINUTE
15 GALLONS
(0.05 CUBIC METERS) PER MINUTE
65 PERCENT
60 HOURS
8 HOURS
24 HOURS
DICALITE 436
900 POUNDS (409 KILOGRAMS)
COTTON CLOTH
III
-------
PART C - CENTRIFUGE OPERATION
Prior to the purchase of full-scale centrifuge equipment for
sludge dewaterlng, performance evaluation testing was conducted
using pilot-scale equipment at the customer demonstration laboratory
of Sharpies Centrifuge Division of the Pennwalt Corp. Both solid
bowl (basket) and horizontal scroll units were evaluated using a
combined biological and chemical sludge.
The solid bowl unit was able to produce a sludge cake of II
percent solids without a polymer but with only a 85 percent
sol ids recovery.
The horizontal scroll unit was able to produce a sludge cake of
15 percent solids with over 95 percent solids recovery. The
performance of this unit was found to be dependent on polymer dose
and differential conveyor speed, and the requirements for each
of these operational characteristics was found to vary widely
between sludge samples. It was estimated that considerable
flexibility was required In order to handle the various sludges
from the treatment system and that the horizontal scroll type
provided this flexability. It was projected that the model
selected would handle 35 gallons (0.13 cubic meters) per minute
of a two percent sludge at a polymer dose of 10-20 pounds/ton
(0.005 gr/kllogram) and with a 95 percent solids recovery.
Typical test data from the horizontal scroll trial is
presented In Figure XWII.
The full-scale horizontal scroll centrifuge was placed In operation
at BRW in March, 1974. Table XXXI presents a summary of the
operating charactdrlstics of this unit, and although the data
used was gathered after the end of the base study period, the sludge
characteristics experienced were felt to be similar to those
previously reported. Excess activated sludge was found to
dewater very easily upon centrifugation with only a low polymer dose
required for good solids recovery and cake dryness. Alum sludge was
found to dewater to a sufficient cake dryness only at a higher
polymer dose. Initially the sludges were dewatered together but It
was determined that the operators could better control the centrifuge's
performance if the sludges were dewatered separately. Although the
cake dryness indicated by the data for activated sludge Is lower
than for alum sludge, both sludges had the same consistency
("truckable") and performance was determined to be satisfactory in
both cases.
112
-------
The centrate from the unit was returned to the flocculation basin,
and Table XXXII presents a summary of the chemical characteristics
of the centrate. For the-; excess activated sludge, the centrate
was found to be similar to the activated sludge clarffier overflow
except for a much lower color value. For the alum sludge the high
polymer dose (using a polyamine catlonic polymer) significantly
increased the centrate COD and ammonia nitrogen values. Grab
samples of centrate were used In these evaluations.
UJ
§
oc.
9
O
2
UJ
UJ
Q.
100
9O
80
70
60
50
40
3OJ
2O
1O
CURVE
SYMBOL
DIFFERENTIAL(RPM)
FEED RATE (GPM)
A
•
7
2.6
B
A
20
3.7
C
o
20
2.6
Polymer was Atlesep lAI(Anionic)
Maximum cake solids of 15% in all cases
4 8 12 16 2O 24 28 32
POLYMER DOSE - pounds per ton
FIGURE XLVII, Solids recovery fn pilot centrifuge
II3
-------
TABLE XXXI
SUMWY OF CENTRIFUGE PERFORMANCE
PARAMETER
EXCESS
ACTIVATED
SLUDGE
ALUM
SLUDGE
COMBINED
SLUDGE
FEED RATE (GPM) 7.6
FEED SOLIDS (PERCENT) 1.74
SOLIDS RECOVERY 95
CPERCENT)
CAKE SOLIDS (PERCENT) 10.5
DIFFERENTIAL SPEED 12
CRPM)
POND SETTING 3.5
1.95
99
15.7
10
3.5
11.0
1.42
98
13.6
16
3.5
114
-------
TABLE XXXII
SLWAKY OF CENTCATE CHARAOERISTICS
CHARACTERISTIC
EXCESS
ACTIVATED
SLUDGE
CENTRATE
ALUM
COAGULATION
SLUDGE
CENTRATE
PH
TOTAL SUSPENDED SOLIDS
CMG/L)
TOTAL DISSOLVED SOLIDS
CMG/L)
COLOR CAPHA)
AMMONIA NITROGEN
CMG/L AS N)
ORTHOPHOSPHATE
CMG/L AS PC«P
COD CMG/L)
7.1
68
450
180
15
20
485
7.5
91
640
260
46
5
940
115
-------
SECTION XII
SUWARY OF COST INFORMATION
Capital and operating cost data for the treatment system is
summarized in Tables XXXIII and XXXIV. To develop the actual
unit costs indicated, the total water volume processed -
163,050,000 gallons (617,144 cubic meters) - and the total
goods produced - 13,523,774 pounds (6,139,793 kilograms) -
during the study year were used. To develop the design unit costs
indicated, a water volume of 360 million (1.36 million cubic
meters) gallons and a production level of 30 million pounds
(13.62 million kilograms) were used.
The capital expenditure required to build a combined activated
sludge, alum coagulation system for a yearly wastewater volume
of 360 million gallons (13.62 million cubic meters) was
estimated at $1,150,000 or $3.19 per thousand gallons ($0.84
per cubic meter) of design capacity. Based on the projected
profit level for the 30 million pounds (13.62 million kilograms)
of product per year generating this wastewater volume, the
capital expenditure would be approximately 20 percent of net
yearly profit. The operating cost for the treatment system
was estimated at $430,420 per year. The unit costs were estimated
to be $1.20 per design thousand gallons treated ($0.32 per cubic
meter), $0.014 per design pound of product ($0.031 per kilogram),
and 8 percent of yearly net profit at the design production level.
AM costs are in 1973 dollars.
The labor costs Indicated for the actual grant period include
3.5 operators, I superintendent/chemist, and I part-time
technician. The projected labor cost include 4 operators,
I superintendent, I chemist, and I full-time technician.
116
-------
TABLE XXXIII
SUMWY OF COST INFORMATION
CAPITAL COST
ACTUAL COST FOR INITIAL TREATMENT PLANT
AND MODIFICATIONS
ESTIMATED COST FOR SINGLE PHASE
CONSTRUCTION
- TOTAL
- PER ACTUAL THOUSAND GALLONS
PER YEAR
- PER DESIGN THOUSAND GALLONS
TREATED PER YEAR
- PER DESIGN CUBIC METERS
TREATED PER YEAR
OPERATING COST
$1,328,000
$1,150,000
$7.05
$3.19
$0.8«f
DEPRECIATION
OPERATING LABOR
SUPPLIES
SLUDGE DISPOSAL
UTILITIES
REPAIRS
LABORATORY
INDIRECTS
TOTAL
ACTUAL
$88,530
50,310
38,880
25,000
10,310
13,770
ll,ifOO
30.830
$269,030
ESTIMATED FOR DESIGN VOLUME
AND SINGLE PHASE CONSTRUCTION
$76,670
58,^50
137,000
52,500
15,000
11,500
32,000
tt7.300
117
-------
TABLE XXXIII SUMMARY OF COST INFORMATION (CONT'D)
ACTUAL
PER THOUSAND
GALLONS TREATED
PER YEAR
$1.65
PER CUBIC METER
TREATED PER YEAR $0.43
PER POUND OF
PRODUCT PER YEAR $0.020
PER KILOGRAM
OF PRODUCT PER
YEAR
$0.043
ESTIMATED FOR DESIGN VOLUME
AND SINGLE PHASE CONSTRUCTION
$1.20
$0.32
$0.014
$0.031
118
-------
TABL£ XXXIV
BASIS OF ESTIMATED OPERATING COST
FOR DESIGN TREATOJT LEVEL
CHEMICALS
ALUM
CAUSTIC
ANIONIC POLYMER
CATIONIC POLYMER
DEFOAMER
HYDROGEN PEROXIDE
COST (DRY BASIS)
PER POUND PER KILOGRAM
$0.036
0.217
1.617
1.930
0.526
0.411
$0.079
0.478
3.562
4.251
1.158
0.905
OPERATORS C4)
SUPERINTENDENT
CHEMIST
LAB TECHNICIAN
INDIRECT CFRINGE BENEFITS,
MANAGEMENT, SECRETARY,
SAFETY, ETC.)
MAINTENANCE AND REPAIRS
MATERIAL AND LABOR
SLUDGE DISPOSAL
HAULING AND BURIAL
USE
275 MG/L
40 MG/L
5 MG/L
20 POUNDS/TON
CIO KG/KKG)
20 MG/L
35 MG/L
$0.29/1000 GALLONS
C$0.08/CUBIC METER)
$0.01/KWH
$4.25/HOUR
$6.00/HOUR
$5.25/HOUR
$4.00/HOUR
55% OF LABOR
1% OF CAPITAL COST
$15.00 PER CUBIC YARD
C$19.4 PER CUBIC METER)
19
-------
SECTION XIII
OPERATIONAL AND MECHANICAL DIFICULTIES
PART A - OPERATIONAL
One of the more troublesome problems encountered with the
treatment system was odor generation. Since the system was
located in a residential neighborhood, any odors were immediately
detected and resulted in numerous complaints. The septic odor
problems in the equalization tank and chemical clarifier have
been mentioned previously and were found to be controllable by
the use of hydrogen peroxide. However, a "chemical" odor was
found to persist at the aeration lagoon, and a sampling program
was instituted to define this problem. A small vacuum pump was
used to pull a 2.0 liter per minute ambient air sample through a
carbon tube. The sampling apparatus was suspended on the aerator
access bridge two feet (0.6 meters) above the lagoon surface.
Each carbon tube was desorbed with carbon disulfide for 24 hours.
The resulting samples were injected into a gas chromatographic
column at I50°C and detected using flame ionization . The aromatic
chemicals, toluene and xylene, were found to compromise 50 percent
of the hydrocarbon emission with the balance being five or six
hydrocarbons in the Cg to CJQ range. Total hydrocarbon concentrations
ranged from 0.378 mg/cubic meter to 1.60 mg/cubic meter with an
average of 1.12 mg/cubic meter. The data collected is presented in
Table XXXV. The presence of these chemicals in the ambient air
at the lagoon was thought to be due to air stripping as a result of
the severe agitation of the mixed liquor by the aeration device.
As previously mentioned in Section VIII, foaming in the aeration
basin was a continual problem during the study period. Immediately
after the system was put into operation, a foam baffle was erected
around the aeration lagoon parameter to prevent solids loss by
foaming. Several attempts were made at defoamer addition. A
system of metering the defoamer into a dilution water line and
the spraying of the dilute defoamer water on the lagoon surface
was found to be the most effective method of preventing excess
foam build-up in the lagoon. The most successful change that effect-
ively reduced the foam to a level requiring only periodic defoamer
use, was a lowering of the water level in the lagoon. A new
outlet structure resulted in a drop of submergence of the aerator
(measured when the aerator unit was not operating) from five
inches (12.7 cm) to three inches (7.6 cm).
120
-------
TABLE XXXV
ANALYSIS OF AMBIENT
AIR AT THE AERATION LAGOON SURFACE
SAMPLE
SAMPLE
TOTAL HYDROCARBON 1.43 MG/M3
1.0 yG TOLUENE
24 yG XYLENE
60 yG Cg - C1Q HYDROCARBONS
TOTAL HYDROCARBONS 1.10 MG/M3
2.2 yG TOLUENE
30 yG XYLENE
100 yG Cg - C10 HYDROCARBONS
SAMPLE #3
SAMPLE #f
TOTAL HYDROCARBONS 1.60 MG/M3
4.0 yG TOLUENE
60 yG XYLENE
320 yG Cg - C1Q
HYDROCARBONS
TOTAL HYDROCARBONS l'.14 MG/M3
2.4 yG TOLUENE
36 yG XYLENE
30 yG Cg - C1Q HYDROCARBONS
SAMPLE
TOTAL HYDROCARBONS 1.05 MG/M3
3.0 yG TOLUENE
44 yG XYLENE
80 yG C8 - C10 HYDROCARBONS
SAMPLE fl6
TOTAL HYDROCARBON 0.378 MG/M3
2.8 yG TOLUENE
38 yG XYLENE
50 yG Cg - C10 HYDROCARBONS
121
-------
Foam in the final effluent continued to persist throughout the study
and was particularly severe when the effluent pH dropped below 5.5 as
a result of a problem with the neutralization system. The tendency to
foam was apparent even during periods of extremely high performance,
and as Indicated in Section X, this foaming was apparently due to
surface active chemicals not measured by the Standard Methods test
for anionic detergents^15). A significant reduction of this foaming
tendency was found to be provided only by a tertiary adsorption
process.
As previously described in Section VIII, sludge was returned from the
activated sludge clarifier to the lagoon at a constant rate and there
was no instrumentation available to indicate or regulate this rate.
Similarly, there was no instrumentation available for either the alum or
activated-sludge waste lines to indicate or regulate flow rate, and
flows were estimated from pump performance'curves and checked crudely
with a bucket and stop watch. As a result, the activated sludge system
could not be tightl'y regulated and controlled by determination of
optimum return and waste rates, and the sludge production rates for
both the activated sludge and alum process may not be as accurate as
desirable.
The rapid mix, flocculatlon, and polymer feed equipment described in
Section IX was not placed in service until late In the study period.
The major benefit from the installation of this equipment was the
reduction In alum sludge volume which, considering the capital and
operating cost of sludge dewatering and disposal, was of major
significance. A corollary benefit was that the alum sludge settled with
zone settling rather than discrete settling characteristics with the
result that it was much easier for the operators to control solids loss
from the clarifier.
A number of sources in the literature report on the mixing requirements
for rapid mixing and flocculation using the mean velocity gradient, G,
as the measure of mixing required. For rapid mixing values of over 300
sec"' are reported^'^ and for flocculation values of 30-100 sec"' are
reported (5,11,13) por -f^e BRW system, the 6 values for the rapid mix
and flocculation basins were 200 sec and 35 sec"' respectively.
The alum coagulation clarifier was not designed as a "reactor clarifier"
or "sludge blanket" clarifier. That is, the center baffle of the unit
extended below the water surface only one-third of the total water depth.
In "sludge blanket" clarifiers, this baffle typically extends to
two-thirds or three-quarters of the total depth so that a solid layer of
a depth higher than the bottom of the baffle results In a feedwater flow
through the settled solids. This flow pattern typically results In better
solids removal by contacting the freshly generated solids with settled
122
-------
sludge to increase floe size and floe density. The alum sludge
generated at BRW was felt to be amenable to this sedimentation
process. However, because of the fragile nature of the floe, a
"solids recirculating" clarifier would not be applicable to the
alum coagulation process.
In flowing from the flocculation basin to the clarifier there was an
apparent breaking of some of the floe. Experiments in the laboratory
attempted to duplicate this situation and indicated that the fine
solids resulting from this turbulence would not readily flocculate
again without the addition of more polymer. It was felt that the
addition of a small concentration of polymer into the center baffle
of the clarifier would aid in capturing a significant portion of
effluent suspended solids which result from floe breakage during
transport.
123
-------
PART B - MECHANICAL
The major mechanical difficulty experienced with the treatment
system was the lack of back-up equipment to prevent degradation of
performance in the event of equipment failure. This was
particularly true in the case of chemical metering pumps. A
major modification program underway at BRW will result in the
duplication of all major process equipment (except tankage) and
this policy of installed spare equipment has already demonstrated
its useful I ness.
The metering pumps used in the treatment system came equipped with a
calibrated stroke adjustment. Daily dosages were calculated based
on a single calibration curve obtained when the system was first
placed in operation. Recently these pumps were replaced and the
new feed systems now include in-line graduated cylinders for
calibration. Weekly checks on calibration has indicated a significant
variation as a result of changing chemical storage tank or
treatment vessel liquid level.
Liquid caustic soda was chosen for pH adjustment rather than lime
because of anticipated ease of operation and lower control cost.
However, because of the high crystallization point of 50 percent
caustic soda (approximately 7°C) numerous problems were encountered
with plugging of feed lines. It was very apparent that in
designing a caustic system extreme care must be exercised to insure
that all caustic lines, tanks, and pumps, are properly heated and
insulated and that as much of the equipment as possible is located
i ndoors.
The gravity flow line between the aeration lagoon and activated
sludge clarifier in the initial treatment plant was sized for a
maximum flow of 400 gallons (1.5 cubic meters) per minute and
any flow in excess of this value caused a rise in the water level
of the lagoon and a consequent strain on the aerator electrical
componets. To overcome this problem, a new line was Installed,
but because of mechanical restraints, this line discharged
at the clarifier surface just outside the center baffle. This
arrangement allowed for a higher flow but also resulted in a
point loading of solids In the clarifier. Late In the study,
the center baffle was enlarged, and near normal inlet distribution
of solids were restored.
124
-------
One of the most important concepts In the design of a treatment plant,
is the allowance for flexibility of operation under varying load and
treatability conditions. Unfortunately the Initial design of the BRW
treatment plant did not Include a reasonable allowance for changes
in process characteristics such as flow or chemical dosage or for
mechanical problems such as pump failure. This lack of flexibility was
undoubtedly reflected In the total performance characteristics of the
system, and the selective data evaluation attempted to remove periods of
mechanically caused low performance from the analysis of system
capablIity.
125
-------
SECTION XIV
ANALYSES OF PRODUCTION CHEMICALS AND PROCESSES
PART A - CHARACTERIZATION OF PRODUCTION CHEMICALS, DYES AND FABRICS
As indicated in Section IV, the manufacturing operation at BRW
involved the use of a wide variety of chemicals, dyes, and fabrics
in a constantly changing product mix. Several studies were
undertaken in an attempt to develop an environmental characterization
of the production processes. The first of these studies to be
reviewed in this section involved the characterization of chemicals,
dyes, and fabrics.
Tables XXXVI through XXXVIII present total and soluble COD data for
major dyes, chemicals, and fabric as they are received at BRW
(soluble indicates material passing Whatman number 5 filter paper).
A wide variation was obtained in repetitive samples for the fabric
COD values, and, as a result, the data presented be useful only
for a qualitative analysis.
Not all of the COD indicated by these tests is discharged to the
sewer system since there may be some loss of the chemical to the
atmosphere or some retention on the fabric. Several analyses were
attempted to determine the portion of major chemicals entering the
sewer system and the portion retained on the fabric or lost to the
atmosphere, but no meaning'ful data was obtained because of the
wide variation in the results of repetitive analyses.
A number of dyes were analyzed for color values at various
concentrations using the APHA method on un-filtered, un-neutralized
solutions, and this data is presented in Figure XLVIII. Considering
the nature of the test method, this information can be interpreted
only as a method of qualitatively indicating 'the potentially
significant colorants.
126
-------
TABLE XXXVI
CHEMICAL OXYGEN BETOND OF PRODUCTION CHEMICALS
CHEMICAL TOTAL COD SOLUBLE COD
CARRIER NT
AEROTEX WATER
REPELLENT
SOLVECREST RB
CAP LEV ME
OAK SCOUR SO-50
ACETIC ACID
AVITONE F
<»
ROLLER CLEANER
CAP LUBE LSP
HERRITON SWD
SANDOPAN DTC
CAP CARRIER BB
FORMIC ACID
RACOFIX NY
SOAP OFF 60
ANTIFUME GFD
OAKAPON X-70
WINKLER FINISH NO.l
DISPERSING AGENT
INTRAWITE EBF
RESIN CP
CUNIT
1.590
0.760
1.430
0.930
2.010
0.630
2.730
1.620
0.975
1.390
2.790
1.700
0.410
0.695
0.380
1.800
1.145
0.250
0.385
0.245
1.120
OF COD/UNIT OF CHEMICAL)
1.475
0.295
0.460
0.390
0.385
0.630
0.920
0.975
0.620
1.260
1.280
0.710
0.340
0.650
0.380
0.800
1.090
0.240
-
0.185
0.424
PERCENT
SOLUBLE COD
93
39
32
42
19
100
34
40
64
91
46
42
83
94
100
44
95
96
-
76
38
127
-------
TABLE XXXVII
CHEMICAL OXYGEN DEMAND
OF PRODUCTION
DYES
DYESTUFF 1
CUNl
EASTMAN BLACK T
LATYL BRILLIANT BLUE
BGN
AMACEL BLUE GP
AMACRON BRILLIANT
BLUE G
TERASIL MAW BLUE SGL
INTRALAN BLACK BGL
RESOLIN BRILLIANT
YELLOW 76L
CALCOSPERSE RED 5G
ALIZARINE FAST GREEN
'OTAL COD SOLUBLE COD
.T OF COD/UNIT
0.685
1.475
1.320
1.400
1.210
1.830
1.405
0.870
1.510
OF CHEMICAL;
0.365
0.830
0.660
1.380
1.075
0.530
1.375
0.699
0.655
PERCENT
SOLUBLE COD
53
56
50
98
89
29
98
80
43
CGN
CALCOSPERSE BLUE BGLK 1.005
1.005
100
128
-------
TABLE XXXVIII
CHEMICAL OXYGEN DEMAND FROM
VARIOUS FABRIC VJASHWATER
FABRIC
WASH TEMPERATURE
C°F)
WATER:FABRIC
RATIO
(UNIT OF WATER/
UNIT OF CLOTHl
COD
CMG/L) CGRl
COD:FABRIC
RATIO
(UNIT OF COD/
UNIT OF CLOTH)
100% ARNEL
fsj
VO
100%
100%
100%
ARNEL
NYLON
POLYESTER
204
240
208
208
70:1
40: 1
40:1
70:1
2550
530
2400
5700
1
0
1
2
.34
.21
.14
.00
0
0
0
0
.134
.021
.114
.200
-------
5OO -
1,5
2O 4O 60 8O 100
DYE CONCENTRATION, mg/l
Key Number
2
3-
4
5
6
7
8
9
[0
Dye
Amacel Blue GP
Eastman Black T
Latyl Brilliant Blue BGN
Amacron Brilliant Blue G
Calcosperse Red 5G
Resolin Brilliant Yellow 76L
Intralan Black BGL
TerasiI Navy Blue SGL
AIizarine Green CGN
Foron Ye I low - Brown S-2RFL
FIGURE XLVIII, APHA color values for production dyes
130
-------
A number of reports on textile wastewater treatment that have
appeared in the literature have reported the biochemical oxygen demand
of production chemicals. Similar work was attempted at BRW, but
in all cases there was a non-linear relationship indicated between
BOD and chemical concentration. Therefore the test method was
determined to be applicable only when a chemical were known to
consistently appear at a constant concentration in the wastewater.
An adaptation of the BOD test was used, however, to determine the
relative toxicity of a chemical at varying concentrations. In
these tests, BOD bottles were prepared using constant concentrations
of equalized raw waste to create a decrease in dissolved oxygen.
Various concentrations of the chemical were then added to the
bottles. An observed decreasing dissolved oxygen depletion with
concentration would indicate a retarding of biological activity.
A depletion of oxygen less than the depletion caused by the raw
waste would Indicate toxicity to the seed microorganisms that had
been acclimated to the raw waste. A summary of the data obtained
Is presented In Table XXXIX, and a typical data plot is shown in
Figure XLIX- No chemicals or dyes were found which exhibited
toxic effects at the concentration expected in the wastewater.
The typical metal content of the classes of dyes used at BRW as
reported by the dyestuff industry, is presented in Table XL. ^
An analysis of foaming characteristics is presented in Table XLI
for various chemicals. Data is reported as foam height, and
foam duration. This data indicates that a large number of chemicals
used contain surface active chemicals that have a high foaming
potential. This Table also lists the percent aromatics and
Tnd-tcetes that only three chemicals contain this potentially
odorous cHass of organic chemicals.
131
-------
TABLE XXXIX
SUMWY OF MULTIPLE DILUTION BOD DATA
CHEMICAL CRITICAL CONCENTRATIONS
START OF RETARDING START OF TOXICITY
(PERCENT) (PERCENT)
CARRIER NT
AEROTEX WATER REPELLENT
OAK SCOUR SO-50
AVITONE F
ROLLER CLEANER
CAP LUBE LSP
SANDOPAN DTC
RACOFIX NY
OAKAPON X-70
DISPERSING AGENT
LYOSEN MS
0.01
0.1
>0.02
13
>0.02
0.01 2.2
NO D. 0. DEPLETION DIFFERENT FROM CONTROL
132
-------
O)
E
z
LU
O
X
O
Q
UJ
O
O
10
9
8
7
6
5
4
3
2
1
0
. CONTROL RESIDUAL
OO01
0.01
PERCENT BY VOLUME OF CARRIER NT
FIGURE XLIX, Multiple dilution BOD data for Carrier NT
-------
METAL
TABLE XL
AVERAGE lETAL OHHTRATION
OF SELECTED DYES
AVERAGE METAL CONCENTRATION
CMG/L)
ACID DYES DISPERSE DYES
ARSENIC
CADMIUM
CHROMIUM
COBALT
COPPER
LEAD
MERCURY
ZINC
<1
<1
9.0
3.2
79
37
<1
13
<1
<1
3.0
<1
f5
37
<1
3.0
134
-------
TABLE XLI
ANALYSIS OF FOAMING
AND ODOR CHARACIERISTICS
OF PRODUCTION CH01ICALS
CARRIER NT
SOLVECREST RB
CAP LEV ME
OAK SCOUR 50-50
ACETIC ACID
MONOSODIUM PHOSPHATE
AVI TONE F
CAUSTIC SODA
CALGON
NEUTROL #9
ROLLER CLEANER
CAP LUBE LSP
HERRI TON SWD
OAKSPERSE AD-40
SANOPAN DTC
CAP CARRIER BB
RACOFIX NY
ANTIFUME GFD
OAKAPON X-70
FANAPON X-70
WINKLER FINISH NO. 1
OAK LEV NU 9
NEOPORT D86
LYOGEN P
PERCENT
AROMATICS
CPERCENT)
0
0
0
0
0
0
0
0
0
0
75
0
0
0
0
0
0
40
0
0
0
0
80
0
FOAM
HEIGHT
CINCHES)
3.50
6.00
5.62
0.29
4.40
-
0.02
6.00
0.50
5.88
1.43
0.06
8.26
4.38
4.73
2.2
19.64
3.00
3.19
19.64
7.25
5.7
TIME FOR
FOAM TO
DISAPPEAR
(MINUTES)
136
15
135
100
±37.5
-
5
+7.5
<1.0
143
+9.5
90
+11.7
31
+5.2
+5.3
240
+5.5
+22.3
120
+8.8
+7.25
135
-------
PART B - ACTIVATED SLUDGE TREATABILITY STUDIES
A series of tests were performed usfng production chemicals and dyes to
determine treatablllty characteristics In an activated sludge process.
The test method used was to measure COD, oxygen up-take, and mixed
liquor solids during a 24 hour batch reactor study. A two-liter graduate
cylinder was used as the reactor vessel. Waste was fed to the mixed liquor
only at the beginning of the test and mixed liquor solids were used from a
batch reactor acclamated to BRW raw wastewater- Table XLII presents a
summary of the results of the tests and Figure L Illustrates a typical
plot of the results.
Only three of the materials tested (Carrier NT, Solvecrest RB, and
Avltone F) exhibited a COD removal rate (SQ - Se/XT) within the range
determined as typical for the full-scale system. All others exhibited
a low or zero rate of degradation at the concentration tested. In all
except two cases (Solvecrest RB and Roller Cleaner) the oxygen consump-
tion rate was below that anticipated from the full-scale system (In
Figure XVIII of Section VIII, the value of constant B, the oxygen
consumption rate due to biological synthesis, was determined to be 0.13
mg/mg-day or 0.005 mg/mg-hr for the full-scale system). A number of the
materials (Aerotex and the dyes) exhibited oxygen consumption rates
less than this synthesis value with little or no removal of COD, indicating
possible retarding or toxic affects. For Aerotex, a retarding effect
was also detected for a low concentration (100 mg/l) In the multiple
dilution BOD test previously described In Part A of the Section.
The treatabillty test Indicated COD removal due to biological activity
and to aeration. If the chemical under study were volatile, an
incorrect rate of degradation would be assumed. Several tests were made
to determine the loss of COD on aeration without gross biological
activity. Results from these tests is presented in Table XLIII.
This data Indicates that for Oak Scour SO-50, Roller Cleaner, and Antlfume
GFD, there Is a significant loss due to the volatility of the chemical
at room temperatures. For the latter two chemicals, this Is explained
by the significant aromatic content as previously Indicated in
Table XLI.
136
-------
TABLEXLII
CHEMICAL
AVERAGE
MLSS
CMG/O
INITIAL
COD
CMG/L)
SUNWtf OF BATCH ACTIVATED SLUDGE
TREATABILOY DATA FOR CHEMICALS
AflDDYES
PERCENT COD REMOVED COD REMOVED
8 HRS 12 HRb Ti HKb
PER MLSS PER HOUR
8 HRS 12 HRS 22 HRS
OXYGEN CONSUMED
PER MLSb KtR HUUK
8 HRS 12 HRS 22 HRS
Ui
-J
CARRIER NT 1440
AEROTEX 96 3825
SOLVECREST RB 2705
ROLLER CLEANER 2470
CAP LEV ME 2555
OAK SCOUR SO-50 2325
AVITONE F 1770
ACETIC ACID 2380
EASTMAN BLAC"K T 4365
LATYL BRILLIANT
BLUE BGN 3360
INTRALAN BLACK BGL 2530
ALIZERINE GREEN CGN 3520
870
55
370
305
455
200
565
385
625
930
650
18 30 49 0.013 0.015 0.014
COD INCREASE DURING TEST
50 56 72 0.008 0.006 0.004
5 11 30 0.001 0.001 0.002
22 35 54 0.005 0.005 0.0004
NO COD DECREASE DURING TEST
23 29 34 0.009 0.008 0.005
- - 47 - - 0.003
COD INCREASE DURING TEST
0.009 0.008 0.006
0.002 0.002 0.002
0.010 0.010 0.008
0.009 0.009 0.008
0.009 0.008 0.006
0.007 0.006 0.004
0.006 0.006 0.005
0.010
0.004 0.004 0.004
678
& 8 10
COD INCREASE DURING TEST
0.002 0.002 0.001 0.002 0.002 0.002
0.003 0.002 0.001 0.002 0.001 0.001
0.002 0.002 0.002
-------
O)
E
i
o
O
u
UJ
_i
CO
1>
O
Q
UJ
O
u
CD
X
O
100
8 10 12 14 16 18 20 22
AERATION TIME-Hours
FIGURE L- Activated sludge treatablllty data for Carrier NT
138
-------
VO
TABLE XLIII
COD UOSS ON AERATION
OF PRODUCTION CHEMICALS
CHEMICAL
CARRIER NT
AEROTEX
AVI TONE F
OAK SCOUR SO-50
ROLLER CLEANER
ANTIFUME GFD
INITIAL
CONCENTRATION
(PERCENT)
0.10
0.15
0.05
0.10
0.10
0.05
TIME
(HOURS)
0
2
23
0
2
24
0
3
23
0
23
0
3
23
0
4
23
TOTAL COD
CONCENTRATION
(MG/L)
962
992
869
1050
1050
1070
517
521
490
550
410
1010
760
425
660
628
379
LOSS
(PERCENT)
(3)
10
_
0
(2)
_
(1)
5
_
25
_
25
60
_
5
42
SOLUBLE
CONCENTRATION
(MG/L)
867
867
807
290
290
310
478
485
450
430
386
683
644
431
364
386
310
COD
LOSS
(PERCENT)
0
7
_
0
(7)
_
(1)
6
_
10
6
37
_
(6)
15
-------
PART C - ALUM COAGULATION TREATABILITY STUDIES
A series of tests were performed using production chemicals and
dyes to determine the treatability characteristics in an alum
coagulation process. The test method used was to measure COD
and color removal with constant alum and polymer dose and
supernatant pH. Tables XLIV through XLVI present a summary of
the results of these tests.
The data indicates excellent color removal of the disperse dyes
and significantly less removal of the acid dyes (Intralan Black
BGL and Alizarine Fast Green CGN). The developed disperse dye
also exhibited a lower level of removal. Among the disperse
class, the COD removal percentage is much more widely scattered
than the color removal percentages indicating that the dispersing
agents that are part of the dyes mix may tend to remain in
solution.
Figure XLV is a photograph illustrating the removal of disperse
and acid dyes by alum coagulation using a synthetic dye bath
and a multiple fiber test fabric.
140
-------
TABLf XLIV
ALJUM COAGULATION OF PRODUCTION
QWCALS USING JAR TCST PROCEDURES
CHEMICAL
CARRIER NT
AEROTEX WATER REPELLENT
SOLVECREST RB
CAP LEV ME
OAK SCOUR SO-50
AVI TONE F
ROLLER CLEANER
CAP LUBE LSP
HERRI TON SWD
SANDOPAN DTC
CAP CARRIER BB
FORMIC ACID
RACOFIX NY
SOAP OFF 60
ANTIFUME GFD
OAKAPON X-70
WINKLER FINISH NO. 1
DISPERSING AGENT
INITIAL COD
(MG/L)
1590
760
1,^30
930
2,010
2,730
1,620
975
1,390
2,790
280
1,700
410
6,930
1410
1,800
1,800
940
385
FINAL COD
CMG/L)
950
54
240
300
430
220
670
320
810
1,215
160
585
365
415
590
440
440
570
255
PERCENT COD
REMOVAL
40
93
83
68
79
92
59
67
42
56
46
66
11
93
58
76
76
39
34
141
-------
TABLE XLV
ALUM COAGULATION OF PRODUCTION DYESTUFFS
FOR COLOR REMOVAL USING JAR TEST PROCEDURES
DYESTUFF CLASS INITIAL CONDITIONS FINAL CONDITIONS PERCENT
EASTMAN BLACK T DEVELOPED DISPERSE
LATYL BRILLIANT BLUE BGN
AMACEL BLUE GP
AMACRON BRILLIANT BLUE G
TERASIL NAVY BLUE 5GL
INTRALAN BLACK BGL
RESOLIN BRILLIANT YELLOW 76L
CALCOSPERSE RED 5G
ALIZARINE FAST GREEN CGN
CALCOSPERSE BLUE BGLK
DISPERSE
DISPERSE
DISPERSE
DISPERSE
ACID
DISPERSE
DISPERSE
ACID
DISPERSE
PH
6.5
8.5
6.7
6.4
6.0
6.2
6.1
6.2
6.5
COLOR
2240
1220
1050
345
765
810
158
585
1500
810
PH
6.9
7.4
6.5
6.5
6.8
6.4
6.5
6.7
7.4
6.8
COLOR
740
50
60
5
45
250
15
20
600
35
COLOR REMOVAL
67
96
94
98
94
69
90
96
60
96
-------
TABLE XLVI
ALUM COAGULATION OF PRODUCTION DYES
FOR COD REMOVAL USING JAR TEST
DYESTUFF
EASTMAN BLACK T
LATYL BRILLIANT BLUE BGN
AMACEL BLUE GP
AMACRON BRILLIANT BLUE G
TERASIL NAVY BLUE SGL
INTRALAN BLACK BGL
RESOLIN BRILLIANT YELLOW
CALCOSPERSE RED SG
ALIZARINE FAST GREEN CGN
CALCOSPERSE BLUE BGLR
INITIAL COD
CMG/L)
68
148
335
142
148
46
76L 141
92
140
103
FINAL COD
CMG/D
4
22
26
61
54
31
40
19
55
19
PERCENT COD
REMOVAL
94
85
92
57
64
33
72
79
61
82
143
-------
A. Disperse Blue 60
(10 gr/liter)
Acid Yellow 49
(10 gr/liter)
,,»1r
C. Combined Disperse Blue
60 and Acid Yellow 49
D. Dyebath mixture after
a I urn coagulation
FIGURE LIi Dye removal by coagulation.
I44
-------
PART D - CHARACTERIZATION OF PROCESS STREAMS
A number of process streams were sampled In the manufacturing
area to provide an environmental characterization.
Table XLVII presents a summary of the results of repetitive
sampling of the incoming municipal water used during
manufacturing. This data indicates that the majority of the
copper, mercury, and zinc contained in the untreated wastewater
results from concentrations in the purchased plant water.
Tables XLVIII through L present typical wastewater characterization
data for the major product lines at BRW obtained from several
samples of actual production runs in the dyehouse. This information
is only a very general approximation of the contribution of the
various sources because of the wide variation possible in water
volume, fabric weight, type and concentration of process chemicals.
Table LI presents a summary of the characteristics of finishing bath
discharges and illustrates the low contribution of these chemicals
to the wastewater pollutant level with the possible exemption of
Aerotex due to a high volume of use (145,265 pounds; 65,880
kilograms per year).
A part of the finishing room operation is the air pollution control
equipment or the tenter frame exhausts. An analysis of
scrubber water from this equipment is presented in Table LII.
In addition to the discharge from isolated restrooms, the process
water also contains blowdown water from the plant's water
softeners and boilers. The results of analyses of these discharges
is presented in Table LIII.
145
-------
TABLE XLVII
CHARACTERIZATION OF MUNICIPAL WATER
CONTAMINANT
AVERAGE VALUE
CMG/D
PERCENT OF
EQUALIZED WASTEWATER
VALUE
ALUMINUM a
CALCIUM
TOTAL CHROMIUM
HEXAVALENT CHROMIUM
COPPER a
IRON9
LEAD
MAGNESIUM
NICKEL
POTASSIUM
SODIUM
ZINCa
MERCURY
CHLORIDE
SULFATE
0.05
0.26
N.D.
N.D.
0.02
0.05
N.D.
0.11
N.D.
0.66
8.97
0.15
0.0015
5.1
8.^
0.5
12.9
0
0
66.7
12.0
0
*t.6
0
15.7
5.8
100.0
93.8
11.9
5.3
TOTAL DISSOLVED SOLIDS 100
19.6
a MEDIAN CONCENTRATION VALUE USED
146
-------
TABLE XLVIII
CHARACTERIZATIQN OF WASTBIATER FROM
APPAREL FABRIC MANUFACTURING
FABRIC:
100% NYLON
APPAREL STYLE
EQUIPMENT: ATMOSPHERIC BECK
LOT SIZE: 1100 POUNDS (499 KILOGRAMS)
PROCESS:
LOAD ->• SCOUR + RINSE ->• RINSE -> DYE ->• RINSE -»• RINSE -»• FIX -»- RINSE
RINSE -> UNLOAD
CHEMICAL USE:
SCOUR BATH
FANAPON-X-70
SODA ASH
HYDRO
CALGON
DYE BATH
ALKANOL ND
MERPOL OJS
MSP
CAP LUBE LSP
ACETIC ACID
CALGON
SULFER YELLOW PR
PURPLE MED. YELLOW SG
FIXING BATH
RACOFIX NY
ACETIC ACID
WASTEWATER CHARACTERISTICS:
SAMPLE
SCOUR BATH
DYE BATH
FIRST POST
DYE RINSE
FIXING BATH
WATER VOLUME
(GALLONS) (CUBIC
1,300 4.
1,300 4.
UNKNOWN
1,300 4.
METERS)
9
9
9
PH
9.8
5.0
5.9
3.4
COLOR
(APHA)
1,000
2,800
200
200
BOD
(MG/L)
356
38
284
COD
(MG/L)
3,680
4,500
389
1,135
147
-------
TABLE XLIX
CHARACTERIZATION OF WASTEMATER FROM
VELJOUR FABRIC MAfJUFACTURING
FABRIC:
100% ARNEL
VELOUR STYLE
EQUIPMENT: PRESSURE BEAM
LOT SIZE: 2700 POUNDS (1226 KILOGRAMS)
PROCESS: LOAD -*• RINSE •+ DYE ->• SCOUR -»• RINSE
CHEMICAL USE:
DYE BATH
CARRIER NT
NEUTROL 9
GLUCONIC ACID
HERRITON SWD
ANTI FUME GFD
CALGON
RESOLYN YELLOW 7GL
AMACEL BLUE GP
INTROLAN BLUE GREEN C
AFTER DYE SCOUR
OAK SCOUR SO-50
SCOUR ->- RINSE -> UNLOAD
DISPERSE II
WASTEWATER CHARACTERISTICS:
SAMPLE
WATER VOLUME
(GALLONS) CCUBIC METERS)
PH COLOR BOD COD
CAPHA) CM6/L) CMG/L)
INITIAL RINSE
DYE BATH
BEFORE PRESSURE
DYE BATH
BEFORE DUMP
FIRST POST
DYE SCOUR
FINAL POST
DYE RINSE
UNKNOWN
3,000 11.4
3,000 11.4
UNKNOWN
UNKNOWN
5.
5.
4.
5.
6.
2
3
9
2
2
5,
!<*,
12,
5,
2,
000
000
000
000
000
<*,
21,
19,
<*,
6,
500
400
100
200
500
2,940
7,300
6,300
700
15
148
-------
TABlf L
CHARACTERIZATION OF WASTEWATER FROM
UNIFORM FABRIC MANUFACTURING
FABRIC: 80% POLYESTER/20% NYLON UNIFORM STYLE EQUIPMENT: CHAMBER
LOT SIZE: 1278 POUNDS
PROCESS: LOAD -> PAD DYE -»• CHAMBER SET -»• ROTAMAT RINSE ->
PAD FINISH ->- DRY -> UNLOAD
CHEMICAL USAGE:
DYE BATH
MERPACYL ORANGE R
ALIZERINE ASTROL B
PALANIL BRILLIANT YELLOW
LATYL CERISE NSN
LATYL BRILLIANT BLUE BGN
SUPERCLEAR 10ON
ACETIC ACID
MONO-SODIUM PHOSPHATE
3G
FINISH BATH
RESIN CP
RAYSTAT B
CLEAN-UP
ROLLER CLEANER
WATER CHARACTERISTICS:
SAMPLE POINT
ACID DYE
ACID DYE
DISPERSE DYE
DISPERSE DYE
DISPERSE DYE
THICKENER
POLYVINYL ACETATE
ANTI-STAT
AROMATIC CHEMICAL
WATER VOLUME
(GALLONS) CCUBIC METERS)
PH COLOR
CAPHA)
BOD COD
CMG/L) CMG/L)
DYE BATH 60
RINSE 500
FINISH BATH 80
INITIAL EQUIPMENT WASH 50
FINAL EQUIPMENT WASH 250
0.25
1.89
0.30
0.19
0.95
^. 9
6.6
5.4
8.5
6.6
24,000
5
15
2,300
500
160
2
0
810
18
225
29
1540
3970
57
149
-------
TABLE LI
CHARACTERISTICS OF FINISH BATH DISCHARGES
Ul
o
FINISH
WINKLER NO. 1
VIVA
AEROTEX
SOLVOSOFT 115
RESIN CP
FABRIC USED
WITH
APPAREL-NYLON
ARNEL
ARNEL
POLYESTER
NYLON-POLYESTER
CONCENTRATION
IN BATH
CPERCENT)
1.0
0.5
2.0
2.5
1.5
USE RATE
1 BATCH/ 2- 3 LOTS
1 BATCH/2-3 LOTS
1 BATCH/HOUR
1 BATCH/ LOT
1 BATCH/ LOT
BOD
CMG/L)
71
2
56
4
0
COD
CMG/L)
2,750
H2
127
217
165
PH
5.0
k.k
3.9
8.6
5.f
NOTE: BATH VOLUME = 215 GALLONS (o.si CUBIC METERS)
-------
TABLE LI I
SCRUBBER WATER FROM TENTER
FRAPE AIR POLLUTION CONTROL EQUIFTBJT
BOD: 6,400 MG/L
COD: 10,400 MG/L
SUSPENDED SOLIDS: 100 MG/L
VOLATILE SUSPENDED SOLIDS: 100 MG/L
TOTAL SOLIDS: 5,560 MG/L
TOTAL VOLATILE SOLIDS: 2,060 MG/L
PH BEFORE NEUTRALIZATION: 4.2
WEEKLY WATER VOLUME: 5,000 GALLONS
CIS.9 CUBIC METERS)
151
-------
TABLE LIII
CHARACTERISTICS OF BLOWDOWN WATER
SOURCE PH SS DISSOLVED SOLIDS ORTHOPHOSPHATE
CMG/L) CMG/L) CMG/D
WATER SOFTENER 6.3 52 15
BACK WASH BRINE 6.1 - 25
RINSE 6.2 - 60
BOILER SLOWDOWN 11.2 - 2050 68
152
-------
PART E - MANUFACTURING EFFECTS ON WASTEWATER CHARACTERISTICS
Data on major production and wastewater parameters collected during the
study period was examined to determine the significant correlations
between the two sets of Information. Table LIV presents a list of the
approximate unit water rates for the major product lines at the plant.
The overall unit water rate was determined to be 12 gallons/pound (O.I
cubic meters/kilogram) of product and the typical dally range was found
to hange between 10 and 15 gallons/pound (0.8 and 1.2 cubic meters/kilo-
grams) of product. This data was developed by estimating the rate
from formula cards and refining the estimate by comparison of calculated
and actual total flow values.
Of the correlations attempted between equalized raw waste characteristics
and production volume by product style, only velour style (beam)
production demonstrated any significant correlation. This result could
be expected considering that velour production by pressure beam dyeing
accounts for 54 percent of the total yearly mill volume. Figures LII
through LIV Illustrate the effect of beam production volume on wastewater
flow, Influent COD concentration and Influent color concentration
respectively. Accordingly to Figure LII, the water use rate for beam
production was 9 gallons per pound (75.1 liters per kg) or slightly
higher than the 8 gallons per pound (66.8 liters per kg) determined by
the data presented in Table LIV.
Using Figure V of Section IV of which correlates total and beam production,
and the data presented In this Section, It Is possible to predict the
major Influent waste characteristics for a given mill production level.
It was anticipated that a correlation would be possible between
effluent color concentration and automotive production, since the acid
dyes used in manufacturing this fabric were found to be the major dye-
stuffs remaining after alum coagulation. However, because of the
number of variables encountered in the treatment system no correlation
was possible.
153
-------
EQUIPMENT
TABLE LIV
UNIT WATER RATES FOR PRODUCTION PROCESSES
FABRIC
UNIT WATER RATE
CGALLONS/POUND) CLITERS/KILOGRAMS)
BEAM
CHAMBER
ATMOSPHERIC BECK
ARNEL/NYLON
NYLON/POLYESTER
AND OTHER
AUTOMOTIVE NYLON
ALL OTHER
PLANT AVERAGE
8
2.5
28
15
12
66
21
232
100
154
-------
•u
o>
E
a:
u
P
i
a?
-------
SECTION XV
SUm\RY OF RESEARCH ACTIVITIES ON
ALTERNATIVE TREATTtNT PROCESSES
PART A - INITIAL TREATABILITY STUDIES
The design of the full-scale BRW treatment plant was based on the data
gathered during a three-month bench-scale treatablllty study using
continuous feed reactors to define the activated sludge process. This
Investigation, conducted In early 1970, determined that the process would
perform as Indicated In Table LV when operated at a 10.8 hour aeration
time and a 2820 mg/l mixed liquor suspended solfds concentration.
TABLE LV
PILOT SCALE ACTIVATED SLUDGE PERFORIWE
CONTAMINANT INFLUENT VALUE PERCENT REMOVAL EFFLUENT VALUE
CMG/L) CMG/L)
BOD
COD
SUSPENDED SOLIDS
350
1060
k7
90.6
60.0
C55.3)
33
f35
73
Insufficient data was available from this Initial study to develop a
mathematical model. The summary data presented above does Indicate that
a much higher percentage of biological oxidation was obtained by the
pilot and full-scale performance Is only partially explained by the
insoluble BOD and COD contributed by the full-scale effluent suspended
solids.
156
-------
The estimated soluble BOD and COD removal percentages were
88 and 45 respectively for the full-scale system as described
in Section VIII of this report. In comparing these values to
those in Table LV, there Is a significant difference in the
soluble COD removal percentage. This difference is
attributed to a change in production chemical use between the
early 1970 and the 1972 - 1973 periods.
During the pilot scale studies, effluent from the activated
sludge system was alum coagulated on a daily batch basis.
Table LVI presents the summary of data gathered during this
study when the alum dose was 200 mg/l. These removal
percentages are in general agreement with those obtained by the
full-scale equipment.
TABLE LVI
PIUOT SCALE ALUM COAGULATIOfJ PERR3RMANCE
CONTAMINANT INFLUENT VALUE EFFLUENT VALUE PERCENT REMOVAL
CMG/L) CMG/L)
BOD 33 7 78.8
COD 435 174 60.0
157
-------
PART B - BATCH ACTIVATED SLUDGE TREATABILITY STUDIES FOR THE TOTAL
PROCESS STREAM
During the course of the grant project, a number of batch activated
sludge treatabl'l ity evaluations were made. A wide variation in
data was obtained-by these evaluations when equalized raw waste
was used as the substrate. Figure LV presents the data from
one such test, and while there was a significant variation in
removal rates In these evaluations, the general shape of the
substrate COD, oxygen consumption and mixed liquor solids curves
were very similar. The most unusual part of these graphs Is the
apparent Increase in soluble COD after between 5 and 10 hours
of aeration and after a significant decrease In COD had occurred.
This observation was repeated In each test and was felt to Indicate
either a change in the microorganism population or a partial
conversion of insoluble COD material to soluble COD material.
The VMLSS curve was also repeated during the ten evaluations that
were made. Several evaluations were made with a very low initial'
mixed liquor solids concentration In order to detect solids
growth. However there was no detectable growth even at these
Iow I eve Is.
158
-------
ui
VO
o>
E
1200
1000
800
600
UJ
10
U
z
U
^400 800
O)
300 6OO -
2OO 400-
1OO 2OO -
Oxygen Consumed
10 15 2O
HOURS OF AERATION
25
FIGURE LV, Batch activated sludge treata&IIIty data
-------
PART C - ALTERNATIVE COAGULANTS
At various times since the start of research activities on the
present BRW treatment system, investigations have been conducted
to determine the most effecitve and economical primary coagulant.
Figure LVI indicates the results of a typical analysis in which
equalized raw waste was coagulated with alum, ferric chloride,
and lime. These data indicate that lime at a dosage of up to
600 mg/l provides very little COD removal and that alum and
ferric chloride provides substantial COD removal. Alum was found
to give slightly better performance (removal of COD, color,
and suspended solids) than the ferric chloride and was judged to
be the easier raw material to handle. Ferric chloride was found
to yield better performance than alum, however, if the pH of the
wastewater was lowered to the 2.5 to 3.0 range during the rapid
mixing. A cost comparison between this proposed system
and"the alum system indicated that the costs associated with acid
addition and increased caustic soda addition required for
neutralization would far exceed the anticipated benefits for this
process alternate.
In the last several years there has been a significant advance in
the application of polymer chemistry to wastewater treatment, and
as a result there is an increasing number of cationic polymers
introduced that have the potential for replacing the an ionic
metal salts that have historically been used for coagulation of colloidal
material in water and wastewater. A number of these polymers were
investigated, and the results produced by two deserve comment.
First, a highly charged, and high molecular weight liquid cationic
polymer of a melamine construction manufactured by American Cyanamid Co.
(Cyanamid 509C) was found to provide excellent treatment of the
activated sludge effluent. At a dosage of 2500 mg/l (approximately
250 mg/l on a dry basis) the polymer consistently produced a jar
test supernatant of less than 100 APHA color units and on several
occassions produced a colorless supernatant. Use of the polymer
at this dosage was not economically feasible, but the results
justified additional polymer evaluations. Another liquid cationic
(Cyanamid 573C) of a polyamine construction and with similar
physical properties, was found to produce good results at a dosage
of 100 mg/l when alum was also added at a dosage of 50 mg/l with
160
-------
1600
12OO
or
E
Q
o
U
9OO
400
FERRIC CHLORIDE
ALUM
Note : No pH Correction
O
10O 20O 3OO 4OO 5OO 6OO
CHEMICAL DOSE mg/i
FIGURE LVL Coagulation of equalized raw waste
I6I
-------
an anionic polymer (Cyangmid 837A) at a dose level of 3.0 mg/l.
This polymer produced a slightly better jar test supernatant
than the alum alone and as an additional benefit depressed the
pH to only 6.4, compared to 4.0 for the alum alone. Th'is latter
point is significant in that bulk supplies of liquid caustic
soda for neutralization were in scarce supply at the time this
report was being written.
162
-------
PART D - POLYMER ADDITION TO THE ACTIVATED SLUDGE SYSTEM
During the settling phase of the activated sludge process,
aggregation of the biological floe is brought about by naturally
occurring enzymes and polymers. However, there is a wide variation
in the effectiveness of the flocculation step that affects the
effluent suspended solids level and the waste sludge concentration.
Two full-scale trials were made to investigate the possible
benefits of the addition of a polymer chemical to the activated
sludge influent to aid the flocculation process. A Nalco Chemical
Co. cationic polymer (73C32) was chosen for this experiment based
on previously favorable thickening experiments.
During the first trial, the polymer was added at an average
dosage of 12 mg/l but a bulking situation rapidly developed. This
situation was determined to be a result of an unusually high
mixed liquor solids concentration without a compensating Iy higher
recycle rate.
During the second trial, the polymer was added at an average dosage
of 15 mg/l. There was no detectable decrease in effluent
suspended solids or decrease in the sludge volume index, but there
did seem to be an increase in effluent turbidity during the trial.
As a result, it was judged that cationic polymer addition did not
exhibit any positive influence on the activated sludge
clarification process.
163
-------
PART E - TWO STEP ALUM COAGULATION
During the course of the study, observation of the alum coagulation
process indicated improved color and COD removal during periods when
a failure in the caustic soda feed system resulted in a low pH in
the clarifier. This observation prompted an investigation of the
pH effect on contaminant removal and typical results from this
investigation have previously been illustrated in Figures XXIX
through XXXII of Section IX of this report.
For color, Figure XXX indicates maximum removal at a pH of 4.5 -
5.0 and this result has been consistently confirmed. A partial cause
of the apparent lower color value at a lower pH was due to the
dependency on pH of the color measurement method. However, experimental
data indicates that the primary cause of the increased color
removal was due to decreased solubility of the dye precipitates
or the coagulant/dye complexes at the lower pH as illustrated by
the data in Table LVII.
TABLE LVII
COLOR R010VAL BY TWO STEP
ALUM COAGULATION
PRIMARY PRIMARY SECONDARY SECONDARY
PH COLOR COLOR AT 6.5 COLOR AT 7.5
PH PH
3.9 120 100 120
4.7 90 90 90
5.9 95 100 120
6.5 140 140 150
7.4 200 - 200
164
-------
The data in Table LVII indicates the following:
- The point of minimum color during primary coagulation
occurs at a pH of 4.7
- The color level during the primary coagulation was found
to vary significantly primarily as a result of changing
solubility wjfh PH
The point of maximum insolubility for aluminum and chromium was
found to be at a pH above 6.0, and as a result there was additional
precipitation of solids when the primary supernatant from a two
step process was neutralized as illustrated by the data in
Table LVIII.
TABLE LVIII
SOLIDS GENERATION IN TWO STEP ALUM COAGULATION
PRIMARY SUSPENDED SOLIDS
PH (MG/L)
SECONDARY PH VALUE
PH = 6.5
3.9 138
4.8 22
PH = 7.5
116
52
5.7 4 4
6.5 2 2
7.6 - 6
Solids generated during the second stage neutralization could be
removed by either clarification on filtration. The experience of
BRW in operating the present alum coagulation clarifier indicated"
that filtration was the only way to insure a continual low solids
effluent. The expected solids load to the filtration step
(50 - 75 mg/l) would permit the design of a filtration system
with acceptable backwash requirements. The literature suggests
the use of a dual media filter (anthracite and sand) in handling
the expected metal hydroxide solids at a 10 gallon/minute/squre
foot (0.41 cubic meters/min/square meter) filtration rate to produce
an effluent with essentially no suspended solids.
165
-------
The two-step alum coagulation experiments conducted during the study
Indicated that an Improved process consisting of (I) primary
coagulation and clarification at a 4.5 - 5.0 pH (2) neutralization of
the clarlfier overflow to a pH of 6.5 - 7.0 and (3) filtration of the
neutralized waste would yield an effluent with the characteristics
presented In Table LVIX.
TABLE LVIX
ESTIMATE) EFFLUENT CHARACTERISTICS FROM
A TWD-SIEP ALUM COAGULATION PROCESS
CONTAMINANT CONCENTRATION EFFLUENT
WEIGHT RATIO
BOD <25 CMG/O 2.2 LB/LB PRODUCT
COD 300 CMG/O 26.9 LB/LB PRODUCT
SUSPENDED SOLIDS 15 (MG/L) 1.3 LB/LB PRODUCT
COLOR 200 CAPHA)
166
-------
PART F - CHEMICAL OXIDATION
The original treatment system at BRW included a chI orination
step, but the unit was designed primarily for disinfection rather
than for additional color removal. As a result, chlorine dosage
was limited to a maximum of 10-15 mg/l, contact time was limited
to 20 minutes, and no appreciable color removal was achieved.
The results of a brief laboratory study to remove color from a
low initial color stream is presented in Figure LVIII and indicate
a chlorine dosage of 20-30 mg/l was required to produce an
effluent color of 50 APHA units.
Similar experiments were conducted using hydrogen peroxide as the
oxidizing chemical, but color removal was not achieved unless the
wastewater pH was reduced below a 4.0 value.. At this pH level,
color removals to 50 APHA units were obtained without the color
returning after neutralization.
Since the residual color left after alum coagulation was determined
to be due to a low concentration of soluble dyes, it was felt
that a chemical oxidation process would provide the most economical
method of color removal. When readily available oxidants such
as chlorine and hydrogen peroxide did not achieve the desired
results, several bench scale tests were made using ozone. The
oxidation potential of ozone is approximately twice that of
chlorine and is the highest of any practical oxidizing chemical.
These tests proved successful, and it was decided to proceed with
a pilot plant evaluation. A mobile facility with the capability of
processing a 15 gallon (0.06 cubic meter) per minute side stream
of alum coagulation effluent was installed at the BRW plant and
operated for a period of two months.
This mobile unit consisted of two, 15 foot (4.6 meter) high, 0.75
foot (0.23 meter) diameter plexiglass columns with intermediate
holding tanks to allow multiple contacting of the effluent.
Ozone was generated on-site in an ozone in oxygen stream. The
unit was run in a continuous mode at various flow rates and ozone
dosages with samples being taken after the contact unit reached
equiIibrium.
167
-------
1O 2O 3O 40
CHLORINE DOSE, mgH
5O
FIGURE LVIL Residual color removal by chlorlnatlon
168
-------
The major conclusions resulting from this work are listed below
and are illustrated in Figures LVIII through LX.
- Color removal was found to proceed very rapidly, with
the majority of the removal occurring in the first
contact step
- Color removal was found to be dependent on the feedwater
pH value, with an acidic waste (pH less tnan 5.0)
reaching a lower color level much more rapid!ly than a
neutral waste
For a waste at a pH less than 5.0, approximately 75
percent of the color was removed in the initial contact
step at a contact time of 3.5 minutes, and if the
initial contact time were increased to 10.0 minutes
approximately 90 percent of the color would be removed.
- The system was operated with an excess of applied ozone
in most experiments, but experiments at reduced
dosage levels indicated a critical initial color to
ozone ratio of 40 to 50 APHA units per mg/l of ozone
in water for the initial contact step. At a
ratio higher than this range, color removal was
substant 5 a 11y reduced.
- For the initial contacting step, the color removal rate
occurred in two distinct patterns. First, the majority
of the color removal obtained appeared to be mass transfer
rather than time dependent. Second, additional color
removal appeared to be contact time dependent.
- Color removal in the secondary contacting steps was
found to range between 40 and 60 percent at all pH
values and was found to occur almost Instantaneously.
The critical ozone in water concentration was determined
to be between 3 and 5 mg/l for the secondary steps.
- A feedwater COD value of 300 mg/l was found to be critical
to the successful performance of the process, and
feedwater COD values in excess of this value resulted
in greatly reduced color removal in all contacting steps
- COD removal was found to be dependent on both contact
time and ozone dosage level. For a total ozone
dosage of 15.0 mg/l through two stages and a total
contact time of 10.0 minutes, the COD removal would be
approximately 8.5 percent.
169
-------
o
2
O.6
Ill
cc
2
8
05
0.4
0.3
2 0.2
u
< 0.1
pH>6.5
pH<5.O
0.2 4 6 8 1O 12 14 16 18 20 22
CONTACT TIME - minutes
FIGURE LVIIL Initial color removal by ozonation
U)
J—
z
I
a.
^
^
cc
g
o
u
35O
30O
25O
2OO
15O
1OO
50
n
J PH>6.5
I
i
•_ |
•«•» ^ ln«i^w«il~^
^
PH<5.O 1 ,
O1 2345
CONTACT STEPS
FIGURE LIX, Typical color removal by ozonation
170
-------
0
z
z
u
* 1.0
o
8 °-9
Z 0.8
O
O °'7
? 0-6
0.5
SYMBOL
A
a
OZONE DOSE (mgli)
> 20
15-20
< 15
6 8 1O 12 14 16 18 20 22 24
CONTACT TIME, minutes
FIGURE LXi COD removal by ozonation
-------
- An increase In BOD across the process was estimated
to be due to the conversion of refractory dyes to
degradable products by the oxidation of the color
producing bonds of the dye molecules. BOD
generation was found to range between 0.01 and 0.03 mg/l
per APHA unit of color removed when the total ozone
dosage in two contact stages was less than 25 mg/l
and the total contact time was less than 20 minutes.
This generation rate increased to 0.04 to 0.06 mg/l
per APHA unit when the total ozone dose or detention
time exceed 25 mg/l or 20 minutes.
- The turbidity of the alum coagulation effluent was
reduced from a range of 25 - 75 JTU to a range of
5-10 JTU by the process
- The median reactor ozone utilization efficiency was
determined to be 55 percent.
Based on the results of this pilot plant work, a process design
was developed for the ozone process combined with two-step alum
coagulation and filtration processes to provide a complete color
removal system. In this process scheme, the coagulation and
settling portion of the first step of the alum process would be
conducted with the feedwater pH controlled to a 4.5 - 5.0 range.
Clarifier overflow would be pumped through an ozonation process
using three contact vessels in series. Two parrallel trains of
contactors would be used to maintain a resonable range of contact
time with variable flow. The ozone would be generated at a one
percent concentration from air. Flow in the contactors would be
alternately co-current/counter-current to the gas flow. High
shear mixing would be provided to increase design gas transfer
efficiency in the first two contactors but porous diffusers could
be used in the third contactor to minimize feedwater pumping
requirements. Ozonated effluent would then be neutralized and
sent to a train of anthracite and sand filters. Design parameters
for this process series is presented in Table LX.
The process would be fully Instrumented to control ozone
generation (based on effluent color) wastewater pH, and
filtration pressure loss.
For the total system, it was estimated that there would be no
net BOD increase since the soluble BOD generated by the ozone
system would be compensated for by the Insoluble BOD removed
by fiItration.
Cost data for the process is presented in Table LXI.
172
-------
TABLED
SUN1ARY OF OZONE AND FILTRATION
PROCESS DESIGN PARAFETERS
FIRST STEP
COAGULATION EFFLUENT
PH 4.5 - 5.0
COD 300 MG/L
BOD 25 MG/L
COLOR 200 APHA
SUSPENDED SOLIDS 50-75 MG/L
DISSOLVED OXYGEN 2.0 MG/L
OZONE SYSTEM
FIRST STAGE
DETENTION TIME
OZONE DOSE
SECOND STAGE
DETENTION TIME
OZONE DOSE
THIRD STAGE
DETENTION TIME
OZONE DOSE
OZONE TRANSFER EFFICIENCY
OZONE REQUIREMENT FOR 1.25
MGD
FILTRATION SYSTEM
FILTRATION RATE
FILTER RUN TIME
BACKWASH RATE
BACKWASH RUN TIME
AIR SCOUR RATE
FINAL EFFLUENT
4.0 MINUTES
7.5 MG/L
3.0 MINUTES
3.0 MG/L
2.0 MINUTES
2.0 MG/L
75.0 PERCENT
175 POUNDS/DAY
12 GAL/MIN/SQ.FT.
8 HOURS
20 GAL/MIN/SQ.FT.
5 MINUTES
10 SCFM/SQ.FT.
PH 6.5 MG/L
COD 275 MG/L
BOD <25 MG/L
COLOR 50 APHA
SUSPENDED SOLIDS 15 MG/L
DISSOLVED OXYGEN 5.0 MG/L
24.6 LB/LB PRODUCT
< 2.2 LB/LB PRODUCT
1.3 LB/LB PRODUCT
173
-------
TABLE LXI
SIH1APY OF OZONE AND FILTRATION
COST DATA
CAPITAL COST C1973 DOLLARS)
TWO STEP ALUM COAGULATION $25,000
OZONATION $250,000
FILTRATI.ON $175,000
TOTAL $450,000
OPERATING COST C1973 DOLLARS)
TOTAL $50,000
PER DESIGN THOUSAND GALLONS
TREATED PER YEAR $0.14
PER DESIGN CUBIC METERS
TREATED PER YEAR $0.03
174
-------
PART 6 - POWDERED ACTIVATED CARBON AIDED ACTIVATED SLUDGE
Powdered activated carbon addition to the aeration basin of an
activated sludge process has been suggested as a method of increasing
organic chemical removal including a reduction of dyes by adsorption
of the chemicals on the carbon particle. By adsorbing the chemicals,
the carbon apparently provides a site for additional biological
action not obtainable by a simple dispersion of biofloc in a dilute
solution. Once a critical mixed liquor carbon concentration is
obtained, then daily addition of the carbon is required only
make-up loss by sludge wasting and loss over the clarifier weir.
During the course of the study, two full-scale tests were made of
the process modification were made using Darco XPH as manufactured
by ICI America, Inc., and data from these tests are presented in
Table XVII.
The first trial occurred just as the system was recovering from an
upset condition and dispersed growth conditions probably resulted
in heavy carbon loss from this system. The data for this period
Indicates removals below predicted levels and can be attributed
to this condition. For the second trial, the system was operating
well and there was probably a high build-up of carbon in the
system, approaching the calculated level of 515 mg/l. For this
period, the COD, color, and ammonia nitrogen removals were
significantly better than predicted from the mathematical models
presented in Section VIII which indicates that the carbon was
having a beneficial effect on the process.
Data presented In Part H of this Section indicates that a carbon
concentration of approximately 1500 mg/l is necessary in order to
achieve a high color removal level. It is estimated, that a mixed
liquor carbon concentration of this magnitude would be required in
order to achieve an increase in COD and color removals that would
significantly affect the total treatment system discharge
I eve Is.
175
-------
TABLE LXII
PERTORWE OF A PCWDERED ACTIVATED CARBON
AILED ACTIVATE) SLUDGE SYSTEM
PARAMETER
TRIAL I
TRIAL II
INFLUENT CONDITIONS
FLOW CMGD)
BOD CMG/L)
COD CMG/L)
COLOR CAPHA)
DETERGENT CMG/L)
AMMONIA NITROGEN CMG/L)
AERATION BASIN
RETENTION TIME
MLSS
VMLSS
CALCULATED CARBON IN
AERATION BASIN
CARBON FEED RATE
ACTUAL REMOVALS
BOD CMG/L)
COD CMG/L)
COLOR CAPHA)
DETERGENT CMG/L)
AMMONIA NITROGEN CMG/L)
PREDICTED REMOVALS
BOD CMG/L)
COD CMG/L)
COLOR CAPHA)
DETERGENT CMG/L)
AMMONIA NITROGEN CMG/L)
0.573
1910
1620
26
14.1 HOURS
3530 MG/L
2910 MG/L
90 MG/L
72
25
18
76
82
41
35
80
PERCENT
PERCENT
PERCENT
PERCENT
PERCENT
PERCENT
PERCENT
PERCENT
0.712
463
1320
1020
10.7
11.2 HOURS
3160 MG/L
2530 MG/L CESTIMATED)
515 MG/L
55 MG/L
76 PERCENT
46 PERCENT
39 PERCENT
76 PERCENT
78 PERCENT
30 PERCENT
23 PERCENT
65 PERCENT
176
-------
PART H - GRANULAR CARBON ADSORPTION
The removal of dissolved organic chemicals Including dyes by granular
carbon adsorption has been widely reported In the literature in recent
years. The process has been found to be an excellent method of treat-
ment In a tertiary mode, but the regeneration costs of the carbon after
exhaustion have generally been too high for acceptance in full-scale
systems except on unusually high strength wastes.
Several Investigations of the BRW effluent were made to determine what
the probable removal rates were for residual COD and color from the
present treatment system. It was felt that the removal rates could be
sufficiently high to consider disposal rather than regeneration of the
exhausted carbon. Typical Isotherms derived from the addition of
granular carbon (Darco 8X35) to various effluents are presented In
Figures LXI and LXII and the data from these graphs are summarized In
Tables LXIII and LXIV.
TABLE LXIII
REMOVAL OF COLOR BY ACTIVATED CARBON
EFFLUENT
ACTIVATED
SLUDGE
CARBON CAPACITY
C% APHA UNITS
REMOVED PER %
CARBON IN
SOLUTION
5000
DESIGN
INFLUENT
COLOR
(APHA)
800
DESIGN
EFFLUENT
COLOR
CAPHA)
50
CARBON USAGE
CLBS/ CKG/CU
GAL) METER)
1.6 320
ALUM
COAGULATION 4000
200
50
280
177
-------
UJ
£1.000
I
tr.
<
O
S 100
UJ
cc
o:'
^ACTIVATE SLUDGE EFFLUENT
oALUM COAGULATION EFFLUENT
101-
10
1OO 1.OOO 10.OOO
COLOR REMAINING-APHA Units
FIGURE LXI, Activated carbon Isotherms for color
1.0
S
z
o
m
cc
<
u
o
UJ
111
oc
Q
8
io2
ACTIVATED SLUDGE EFFLUENT
• ALUM COAGULATION EFFLUENT
" EQUALIZED RAW WASTE
10 10.0
COD REMAINING - mg/l
1000
FIGURE LXIIi Activated carbon Isotherms for COD
178
-------
TABLE LXIV
REMOVAL OF COD BY ACTIVATE) CARBON
EFFLUENT
ALUM
COAGULATION
CARBON CAPACITY
CWT. OF COD
REMOVED PER WT.
OF CARBON IS
SOLUTION
DESIGN DESIGN
INFLUENT EFFLUENT CARBON USAGE
COD COD CLBS/ CKG/CU
(MG/L) (MG/L) GAL) METER)
ACTIVATED
SLUDGE
0.75
1000
200
8.9
1780
0.42
300
150
3,0
600
Based on this Isotherm data, preliminary estimates were made of capital
and operating costs by ICI America, Inc., and this cost information Is
presented in Table LXV.
These costs are based on the use of Hydrodarco 3000 in a fixed bed mode
with a 217 square foot (20.2 cubic meter) cross sectional area and a
16 foot (4.9 meter) bed depth. Weight of the Initial carbon fill was
76,000 pounds (34,776 ktograms) with a 7 percent regeneration af a
carbon cost of $0.28 per pound ($0.62 per kilogram). The cost of a
filtration system proceeding the adsorption process Is not Included.
TABLE LXV
COST INFORMATION FOR GRANULAR CARBON ADSORPTION SYSTEMS
CAPITAL COST FOR A 1.25 MGD SYSTEM (1973 DOLLARS)
CARBON DOSE COST
CLBS/GALST (KGMS/CU. METER)
2.0
3.5
4.0
9.5
400
700
800
1900
$636,000
$676,000
$681,500
$761,000
179
-------
TABLE LXV. COST INFORMATION FOR GRANULAR CARBON
ADSORPTION SYSTEMS (CONT'D)
YEARLY OPERATING COST FOR 360 MILLION GALLONS (1.7 MILLION CUBIC METERS)
PER YEAR (1973 DOLLARS)
CARBON DOSE
(IBS? CKG/CU
COST PER
C1000 (CU.
COST PER UNIT OF PRODUCT
GAL)
2.0
3.5
«f.O
9.5
METER)
400
700
800
1900
TOTAL COST
$160,000
$180,000
$185,000
$250,000
GALLONS)
$0.¥f
$0.50
$0.51
$0.69
METER)
$0.12
$0.13
$0.14
$0.18
CPOUND)
$0.005
$0.006
$0.006
$0.008
CKG)
$0.011
$0.013
$0.013
$0.018
These costs are for process equipment purchased, Installed and owned
by BRW. The yearly operating cost for leasing similar equipment
including off-site carbon regeneration was estimated at $301,700
by Calgon Corp. using a carbon dose level of 3.0 pounds per thousand
gallons. Capital cost was estimated at $25,000 for this approach for
non-leasable mechanical and foundation Items.
Dosage requirements to achieve the necessary decolonization were
found to be too high to permit disposal of the spent carbon. For the
2.0 pounds/1000 gallons (400 kilograms/cu. meter) case, the capital cost
would be reduced to a $45,000 but the yearly operating expense would
be Increased to $310,000 per year or $0.86 per 1000 gallons treated
($227/cubic meter) If the carbon were wasted after exhaustion.
In both cases, carbon was found to provide a method for removing both
residual, soluble color and COD but only at a substantial capital and
operating investment.
180
-------
FART I - RESIN ADSORPTION
An alternative adsorption process for removal of dissolved
organics and some inorganics is by the use of a series of resins
as the absorbent, and application of the process to textile
and dyestuff wastes have been reported in the general literature.
A study to evaluate the cost and performance characteristics of
this process was undertaken by Rohm and Haas Co and BRW. This
study evaluated the process using bench-scale continuous flow
equipment to determine the major process parameters.
The studies indicated that the best system for decolorization of
the effluent from the activated sludge-alum coagulation system
would be a column of a polymeric adsorbent resin (Amberlite XAD-7)
followed in series by a column of a weakly basic an ion exchange
resin amberlite XE-275). The major process parameters were a
XAD-7/XE-275 ratio of 2:1, 150 bed volumes of effluent treated
per cycle at an influent color level of 200 APHA units,
and a flow rate of 16 bed volumes (2 GPM per .cubic foot) of resin
on line. Performance of the process is summarized in
Table LXVI and Figure LXIII.
TABLE LXVI
PERFORMANCE OF A RESIN ADSORPTION PROCESS
INFLUENT COLOR
COLOR REMOVAL
INFLUENT BOD
BOD REDUCTION
INFLUENT COD
COD REDUCTION
INFLUENT FOAM DURATION
FOAM DURATION REDUCTION
187 APHA
79 PERCENT
22 MG/L
64 PERCENT
196 MG/L
69 PERCENT
360 SECONDS
98 PERCENT
181
-------
00
N)
INTIAL COLOR, APHA
235 20O 175 150
50
10O
150
2OO
BED VOLUMES TREATED
FIGURE LXIIL Color removal by resin adsorption
-------
The results of the study indicate that the process provides excellent
removal of residual color, BOD, COD, and foam producing chemicals. If
the process were placed In service treating the 200 APHA color units
from a two-step alum coagulation process, the 150 bed volumes would be
treated before a break through as indicated in Figure LVII.
Spent adsorbent and exchange resins could be regenerated in place as
determined by the study. The absorbent would be regenerated by an 80
percent methanol solution, and the colored methanol used to elute the
dye from the exchange resin. Additional regeneration of the exchange
resin by acid and caustic treatment would also be required.
The methanol-dye mixture would be sent to a small still for recovery
of the methanol, and the still "bottoms" would be evaporated prior to
incineration and land disposal by others.
Cost information for the process is presented in Table LXVII. These
costs do not Include a filtration step prior to the adsorption process,
TABLE LXVII
SUIflARY OF COST INFORMATION FOR
A RESIN ADSORPTION PROCESS
CAPITAL COST FOR 1.25 MGD PROCESS (1973 DOLLARS) $836,000
YEARLY OPERATING COST FOR A PROCESS
TREATING 360 MILLION GALLONS (1.14 MILLION CUBIC METERS)
PER YEAR (1973 DOLLARS)
TOTAL $171,700
TOTAL PER THOUSAND GALLONS TREATED $0.48
TOTAL PER CUBIC METER TREATED $0.13
TOTAL PER KILOGRAM OF PRODUCT $0.013
TOTAL PER POUND OF PRODUCT $0.006
183
-------
PART J - MONITORING
Several experiments were made during the course of the study
to evaluate quick response methods of wastewater analyses.
First, TOC measurements were made once a month of the various
plant effluents -and compared with BOD and COD values. For
BOD, no correlation was found, but for COD a reasonable correlation
of TOC =0.25 COD was determined.
Second, over a two month period, optical density (0. D.) was compared
to alum coagulation effluent suspended solids and a reasonable
correlation of TSS = C(O.D.) (650) - IOH was determined.
184
-------
SECTION XVI
CHARACIERISTICS OF THE RECEIVING STREAM
During the study, samples were regularly taken from Martins Creek
above the BRW discharge for analysis. This data is presented in
Table LXVIII.
185
-------
TABLE LXVIII
ANALYSIS OF MARTINS CF
ABOVE BRW
WATER
PARAMETER
AVERAGE VALUE
CRITICAL FLOWS
7 DAY, 10 YEAR
SPRING AVERAGE
SUMMER AVERAGE
FALL AVERAGE
WINTER AVERAGE
0.5 CFS (0.01 CMS)
27.7 CFS CO. 78 CMS)
5.4 CFS (0.15 CMS)
5.3 CFS (Q.15 CMS)
14.2 CFS CO UQ CMS^)
CONTAMINANTS
TEMPERATURE
HIGH
LOW
PH
DISSOLVED OXYGEN
ALUMINUM
CALCIUM
CHROMIUM
COPPER
IRON
MAGNESIUM
NICKEL
POTASSIUM
SODIUM
ZINC
MERCURY
PHOSPHATE
BOD
COD
COLOR
TURBIDITY
20°C
2°C
7.4
9.4
0.13
32.8
.005
N.D,
0.125
5.15
N.D,
1.375
6.67
0.004
0.2718
0.5
10
7
19
2
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
APHA
JTU
186
-------
SECTION XVII
I. Adams, C. E. "Treatment of a High Strength Phenolic and Ammonia
Wastestream By Single and Multi-Stage Activated Sludge Processes."
A paper presented at 29th Purdue Industrial Waste Conference:
Lafayette, Indiana. May, 1974.
2. American Dye Manufacturer's Institute. "Contribution of Dyes to the
Metal Content of Textile Mill Effluents." Dyes and the Environment,
VoIume I. New York, N.Y., September, 1973.
3. American Textile Manufacturer's Institute and the Carpet and Rug
Institute. Recommendations and Comments For The Establishment of
Best Practicable Wastewater Control Technology Currently for the
Text!le Industry. Charlotte, N.C., January, 1973.
4. American Water Works Association. "Coagulation and Flocculation."
In: Water Quality and Treatment, Third Edition. McGraw-Hill Book
Co. New York, NY.
5. Gulp, R. L. and G. L. Gulp "Chemical Coagulation and Flocculation. "
In: Advanced Wastewater Treatment. Van Nostrand Reinhold Co.
New York, N.Y. 1971.
6. Deiecluse, C. "Dyestuffs, Five Year Outlook". American Dyestuff
Reporter. £(l):68-72. January, 1972.
7. Environmental Protection Agency. Development Document for Proposed
Effluent Limitations Guidelines and New Source Performance
Standards for the Textile Mills Point Source Category. Washington,
D. C. January, 1974.
8. Federal Register. "Textile Point Source Category Effluent Guideline;
and Standards." 39_( 130): 24736-52. July 5, 1974.
9. Environmental Protection Agency. Economic Analysis of Proposed
Effluent Guidelines, Textile Industry. Washington, D. C.
March, 1974.
10. Hayden, P. L. Aqueous Chemistry of Aluminum III. DIssertion for
The Ohio State University Graduate School. Columbus, Ohio. 1971.
II. Metcalf and Eddy, Inc. "Chemical Unit Processes." In: Wastewater
Engineering; Collection, Treatment, Disposal. McGraw Hill Book Co.
New York, N.Y. 1972.
187
-------
12.
13.
14.
15.
National Lime Association. "Chemical Precipitation." In:
Chemical Treatment of Sewage and Industrial Wastes. Garamond/Pridemark
Press. Baltimore, Md. 1965.
O'Mella, C. R. "Coagulation and Flocculation." In:
Process For Water Quality Control. Weber, Walter J
Wi ley-lnterscience, New York, N. Y. 1972.
Physicochemical
, Jr. (ed).
Rodman, C. A. "Removal of Color From Textile Dye Waste." JournaI
of the American Association of Textile Chemists and Colorists.
3_( I I):239-247. November, 1971 .
American Public Health Association. Standard Methods For The
Examination of Water and Waste, Thirtenth Editloo. APHA. New
York, N. Y. 1971.
188
-------
SECTION XVIII
APPENDICES
A. TABULATION OF PRODUCTION CHEMICAL USAGE
B. TABULATION OF PRODUCTION DYE USAGE
C. SUMMARY OF ANALYTICAL METHODS
D. LABORATORY QUALITY CONTROL DATA
E. PROCEDURE FOR BATCH ACTIVATED SLUDGE TREATABILITY
STUDIES
F. PROCEDURE FOR BATCH ALUM COAGULATION TREATABILITY
STUDIES
G. PROCEDURE FOR LEACHATE STUDY
H. PROCEDURE FOR STATIC BIOASSAY
I. PROCEDURE FOR MULTIPLE DILUTION BOD
J. CONVERSION TABLE
189
-------
APPENDIX A
TABLE A-I
TABULATION OF PRODUCTION CHEMICAL USAE
CHEMICAL PERCENT OF
YEARLY TOTAL
CARRIER NT 18.4
AEROTEX WATER REPELLENT 5.7
SOLVECREST RB 5.4
CAP LEV ME 4.9
OAK-SCOUR SO-50 4.3
ACETIC ACID 4.2
MONOSODIUM PHOSPHATE 4.1
SUB-TOTAL 47.0
AVITONE F 3.5
CAUSTIC SODA 3.3
CALGCM 3.2
NEUTROL #9 3.1
ROLLER CLEANER 2.9
CAP LUBE LSP 2.7
SODIUM HYDROSULPHITE 2.3
HERRITON SWD 2.3
OAKSPERSE AD-40 2.3
SANDOPAN DTC 2.2
CAP CARRIER BB 2.2
FORMIC ACID 2.2
RACOFIX NY 2.1
SOAP OFF 60 2.0
AMMONIUM CHLORIDE 1.6
ANTIFUME GFD 1.5
OAKAPON X-70 1.4
FANTAPON X-70 1.2
WINKLER FINISH NO. 1 1.2
OAK LEV NU9 1.1
DISPERSING AGENT 1.0
GLUCONIC ACID 1.0
INTRAWITE EBF 1.0
NEOPORT DB6 0.9
LYOGEN P 0.9
RESIN CP 0.8
SUB-TOTAL 96.9
OTHER 3.1
TOTAL 100.0
TOTAL USAGE: 2,500,000 POUNDS Ci,i35,poo KILOGRAMS) PER YEAR
190
-------
APPENDIX B
TABLE B-I
TABULATION OF PRODUCTION DYE USAGE
DYESTUFF CLASS
EASTMAN BLACK T D
LATYL BRILLIANT BLUE BGN D
AMACEL BLUE GP D
SUB-TOTAL
AMACRON BRILLIANT BLUE G D
TERASIL NAVY BLUE SGL D
INTRALAN BLACK BGL A
PALACET RED GFL D
RESOLIN BRILLIANT YELLOW 76L D
CALCOSPERSE RED 5G D
ALIZARINE FAST GREEN CGN A
CALCOSPERSE BLUE D
SUB-TOTAL
FORON YELLOW-BROWN S-2RFT D
LANASYN YELLOW 24L A
LANASYN BLACK BGL A
AMACEL VIOLET 34-GLF D
LANASYN RED 2GL A
ALIZARINE LIGHT BLUE 3FR A
AMACEL FAST YELLOW 24-GLF D
POLYSPERSE YELLOW WGLW D
LANASYN ORANGE RL A
TE.RASIL BLACK PR D
NYLON FAST BLACK BRW A
AMACRON DIAZOIC BLACK JB D
VITROLAN BLACK WA A
INTRASPERSE DARK BLUE RB D
CALCOSPERSE RED 4GR D
INTRASPERSE BLUE GREEN C D
PALANIL RUBIN FL D
SODYECRON BRILLIANT VIOLET B5R D
CALCOSPERSE RED GF D
RESOLYN BR YELLOW P8 GUM D
IRGALAN YELLOW 2GL A
SUB-TOTAL
OTHER
PERCENT OF
YEARLY TOTAL
10.2
7.8
7.5
25.3
3V 1
2.8
2.4
2.1
2.2
2.2
2.1
2.0
1.5
1.6
1.6
1.6
1.4
1.3
1.2
1.1
1.0
1.0
1.0
1.0
1.0
1.0
0.9
0.9
0.8
0.8
0.8
0.7
0.7
67.1
32.9
TOTAL 100.0
TOTAL USAGE: 295/000 POUNDS Ci34,ooo KILOGRAMS) PER YEAR
NOTE: D = DISPERSE A = ACID
191
-------
APPENDIX C
SUWARY OF ANALYTICAL fETODS
Routine Analyses in the BRW Laboratory
I. Alkalinity and Acidity
Potentiometric method as described in Standard Methods
For the Examination of Water and Wastewater
(13th Edition)
2. Biochemical Oxygen Demand
Five day incubation method as described In
Standard Methods
3. Chemical Oxygen Demand
Dichromate Reflux method as described In Standard
Methods
4. Color
Absorbtion measurement using a filter photometer
(Hach AC-DR) to give results in terms of the
Standard Methods cobalt-platinum scale. Samples
were filtered through Whatman Number Five paper or
Reeve Angel 934AH glass fiber filter discs and
compared with distilled water. A calibration
curve for the Instrument is presented in
Figure C-I. This curve shows a substantial
divergence from standard beginning at a value of
250, and for this reason samples were diluted to
give readings in the 0-250 range.
5. Dissolved Oxygen
Membrane electrode method as described in Methods
for Chemical Analysis of Water and Wastes (1971
Edition)
192
-------
cr
3
8 500
4OO
a:
UJ
I-
UJ
5
2
8
300
200
100
I I I- 1- I
100 20O 300 4OO 500
STANDARD APHA COLOR
FIGURE C~Ii Calibration curve for Hach Colorimeter
193
-------
6. Nitrogen
Measurement of soluble ammonia nitrogen using
the direct nezzlerization method with absorbance
measurement using a filter photometer. Samples
were filtered through Whatman Number Five paper
or Reeve Angel 934AH glass fiber filter discs.
7. Phosphorous
Measurement of soluble orthophosphate using the
single reagent method with absorbance measurement
using a filter photometer samples were filtered
t-hrough Whatman Number Five paper or Reeve Angel
934AH glass fiber filter discs.
8. pH
Electrometric method as described in Standard Methods
9. Solids, Dissolved and Suspended
Glass fiber filter (Reeve Angel 934AH) methods as
described in Methods For Chemical Analysis
10. Surfactants
Measurement of soluble an ionic surfactants using the
methylene blue method with absorbance measurement
using a filter photometer. Samples were filtered
through Whatman Number Five paper or Reeve Angel 934AH
glass fiber filter discs.
II. Turbidity
Measurement of turbidy using absorbance measurement
with a filter photometer. Samples of waste were
compared with a standard prepared by filtering
the waste through filter paper of filter discs.
194
-------
Monthly Analyses By Pollution Control Science, Inc.
I. MetaIs
Atomic absorption spectrophotometric method as
described in Methods For Chemical Analysis using
a Perkin-Elmer #305 with a carbon rod attachment
2. Total Organic Carbon
TOC method as described in Methods For Chemical
Analysis using a Beckman 915 Analyzer.
3. Hexavalent Chromium
S-DyphenyIcarbazide method as described in
Standard Methods
4. Sulfate
Turbimetric method as described in Standard Methods
5. Chloride
Mercuric nitrate method with potentiometric
titration as described in Standard Methods
6. Nitrate
PhenoldisuIfonic method as described in
Standard Methods
7. Nitrite
Dfazotization method as described in Standard Methods
8. Cyanide
Distillation followed by colorimetric analysis
as described in Standard Methods
9. Phenol
Distillation followed by colorimetric analysis as
described In Standard Methods
195
-------
10. Oil and Grease
Sokhlet extraction method as described in
Standard Methods
II. Total Hydrocarbon
EPA procedure proposed by Region I I Laboratory
using an infrared scan (2600 cm"' to 3200 cm"')
of a carbon tetrachloride extraction of the sludge
12. Digestion of sludges and sediment
Samples of sludge and sediment were digested
using warm nitric and hydrochloric acids
196
-------
APPENDIX D
TABLE D-I - LABORATORY QUALITY CONTROL CHECK USING SPIKED SAPPLES
SAMPLE NUMBER
CONTAMINANT
CMG/O
ALUMINUM
CHROMIUM
CQPPER
IRON
LEAD
ZINC
1
ANALYSIS
5
0
2
-
30
10
ACTUAL
25
9.2
9.0
18
28
20
2
ANALYSIS
585
45
53
295
80
95
ACTUAL
575
83
67
402
92
79
3
ANALYSIS
1185
300
302
640
300
395
ACTUAL
1100
406
314
769
350
367
197
-------
TABLE D-2
LABORATORY QUALITY CONTROL CHECK
USING SPLIT SAMPLES
CONTAMINANT
CMG/O -
CHROMIUM
COPPER
IRON
LEAD
MERCURY
NICKEL
ZINC
BRW
RAW WASTE
110
5
400
<1
1
<20
150
ANALYSIS
FINAL EFFLUENT
150
20
410
30
<0.5
<50
155
EPA
RAW WASTE
100
10
610
1
10
<20
80
ANALYSIS
FINAL EFFLUENT
150
20
620
30
<0.5
<50
70
198
-------
APPENDIX E
PROCEDURE FOR BATCH ACTIVATED SLUDGE
TREATABILITY STUDIES
I. Preparation of Initial Batch Mixture
A. Dewatered Sludge
I. The sludge used was obtained from either the acclamated
mixed liquor of the lab scale bio-oxidation unit or
from the full-scale activated sludge system.
2. The sludge was filtered through a Buchner funne-l
with a cloth filter until the sludge was concentrated
enough to be scraped and collected with a spatula.
3. Approximately 75 grams was needed to yield a suspended
solids concentration of 3000 mg/l in the two liter volume
of the graduate cylinder used as the reaction vessel.
B. Chemical Solution
I. The concentration of solution needed to obtain an
initial COD of about 1000 mg/l was estimated from
preliminary COD data.
2. Two liters of solution at the strength determined above
were prepared and adjusted to final pH (6.0 - 8.0)
if necessary.
3. The dewatered sludge was diluted with the prepared
chemical solution to the two liter mark.
II. Reactor Operations
A. Mixing using a magnetic stirring apparatus and aeration with
compressed air and an air diffuser were used to produce a
uniform mixture.
B. Sampling was done at near mid-height of the reaction
vessel at timed intervals of 0 hour (initial), 2 hr.,
4 hr., and 22 hrs.
C. Surface sludge and foam build-up was periodically scraped
back into the solution.
D. Aeration rates were decreased if foaming persisted.
199
-------
APPBOIXF
PROCEDURE FOR BATCH ALUM COAGULATION
TREATABILI1Y STUDIES
Jar tests were performed using paddle stirring equipment for
mixing and a pH meter to measure pH during the coagulation process.
Stock solutions of alum, caustic, and polymer were prepared at
\%, 5%, and 0.\% respectively.
For the single coagulation process, the "Standard Jar Test"
procedure was used:
I. Add 400 ppm alum during rapid mix at 80-100 rpm
for I - 3 minutes
2. Adjust pH during rapid mix with caustic soda
3. Add 5 ppm polymer during slow mix at 40 - 45 rpm
for 5-10 minutes
4. Settle
5. Decant and Analyze
For the two-step coagulation process the "Two-Step Jar Test"
procedure was used:
Step One
I. Add 400 ppm alum during rapid mix at 80 - 100 rpm
for I - 3 minutes
2. Adjust pH during rapid mix with caustic soda
3. Add 5 ppm polymer during slow mix at 40 - 45 rpm
for 5-10 minutes
4. Settle
5. Decant and Use in Step Two
Step Two
I. Adjust pH of decanted supernatant of Step One to
pH = 6.5 or pH = 7.5 during rapid mix at 80-100 rpm
for I - 3 minutes
2. Settle
3. Decant and Analyze
200
-------
APPENDIX G
PROCEDURE FOR LEACHATE STUDY
In order to determine leachate characteristics under
approximate landfill conditions, a column leaching study was
conducted. Dewatered sludge was placed in a 4 inch (10 cm)
diameter PVC column to a depth of 5 inches (13 cm). The sludge
was supported by a 2 Inch (5 cm) layer of sand and gravel.
Distilled water was then applied to the surface of the
sludge at the rate of 220 mis per day. The leachate was collected
daily and analyzed periodically.
Initially, the sludge would not percolate the applied
water. As a result, the sludge was removed and put through a
single freeze/thaw cycle. This treatment resulted in satisfactory
percolation.
201
-------
APPENDIX H
PROCEDURE FOR STATIC BIOASSAY
For the purpose of determining relative toxiclty of sludge
cake leachate, brief static bioassays were conducted. The
leachate was diluted to the appropriate concentration using
tap water. One gallon was used as the test volume, and
five gold fish obtained from a local pet store were placed
in each test vessel. The solutions were aerated throughout
the test and the dissolved oxygen concentration maintained
at 8 mg/l or greater. Temperature was maintained at 70°F +_
2°F. Fisti were removed from each container as soon as
immobilization or death was noted.
202
-------
APPENDIX I
PROCEDURE FOR lUTLIPLE DILUTION BOD
The multiple dilution BOD procedure was performed to determine
the threshold toxic Ity level of a substance. The threshold toxlclty
level Is the concentration of the substance at which a depressed
biological oxidation rate Is flr$t detected. The toxlclty observation
reflects acute effects on the seed organism.
The procedure was as follows:
I. Prepare a series of BOD bottles with Increasing
concentration of test material.
2. Add about 3.0 ml of equalized raw wastewater to
each bottle as a control. One bottle should
contain the same amount of seed.
3. Prepare at least three blank samples for each test
series
4. Neutra11ze the samp Ie before f1111ng each bottIe
with dilution water-
5. Incubate at 20°C for three days.
6, Record initial and residual D. 0. readings.
7. Plot data by percent volume of test material
versus D. 0. mg/l.
203
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-75-055
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Treatment of Textile Wastewater by Activated Sludge
and Alum Coagulation
5. REPORT DATE
October 1975
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Thomas L. Rinker
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING OR6ANIZATION NAME AND ADDRESS
Blue Ridge - Winkle r Textiles
Division of Lehigh Valley Industries, Inc.
High and Kline Streets
Bangor. Pennsylvania 18013
10. PROGRAM ELEMENT NO.
1BB036; ROAP 21AZT-006
11. CONTRACT/GRANT NO.
S 801192
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final; 8/22/72-5/31/75
14. SPONSORING AGENCY CODE
is. SUPPLEMENTARY NOTEsproject officer fe TnOmas N. Sargent, EPA, Environmental
Research Laboratory, College Station Road, Athens, GA 30601.
s. ABSTRACT Tne repOr£ gjves results of B. study of the treatment of wastewater, from a
textile mill producing synthetic knit fabric for the apparel and automotive markets,
with a system combining biological (activated sludge) and chemical (alum coagulation)
processes. The treatment consisted of: heat recovery; equalization; completely
mixed activated sludge with sedimentation and nutrient supplement; and alum coag-
ulation with sedimentation, polymer addition, and pH adjustment. The activated
sludge process effectively removed degradable organics and ammonia nitrogen. The
alum coagulation process effectively removed colloidal organics, suspended solids,
orthophosphate, and certain metals. Total treatment system removals for BOD,
COD, and color were 92, 73, and 69 percent, respectively. Capital cost of the sys-
tem was $1.15 million with a yearly operating expense of $269,030, including capi-
tal cost depreciation. Additional treatment was required to meet anticipated
discharge limitations. Appropriate research studies were conducted using carbon
adsorption, resin adsorption, and ozonation for residual, soluble color removal.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
*Water Pollution, *Sliidge, *Industrial
Wastes, *Coagulation, *Textile Proces-
ses, Waste Water, Waste Treatment,
Heat Exchangers, Equalizing, Aerobic
Processes, Alums, Neutralizing,
Polyelectrolytes, Color, Decoloring
*Activated Sludge
*Sludge Treatment
Textile Wastewater
Treatment
*Phys ical/Chemical
Treatment
Secondary Treatment
13B, 07A
07D
13H
ISA
06C, 07B
20F
18. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (This Report}
Unclassified
21. NO. OF PAGES
216
20. SECURITY CLASS (Thispage}
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
204
OU.S. G.P.O.: 1975 647-013
EPA - RTP LIBRARY
------- |