EPA-660/2-73-036
January 1974
Environmental Protection Technology Series
Chemical/Physical and Biological
Treatment of Wool Processing Wastes
Office of Research and Development
U.S. Environmental Protection Agency
Washington, O.C. 20460
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Monitoring, 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.
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EPA-660/2-73-036
January 1974
CHEMICAL/PHYSICAL AND BIOLOGICAL
TREATMENT OF WOOL PROCESSING WASTES
By
L. T. Hatch
R. E. Sharpin
W. T. Wirtanen
Project 12130 HFX
Project Element 1BB036
Project Officer
Thomas N. Sargent
United States Environmental Protection Agency
Southeast Environmental Research Laboratory
College Station Road
Athens, Georgia 30601
U.S. EPA UBRARY REGION 10 MATERIALS
RXDDD0315TT
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20102 - Price $l.os
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ABSTRACT
Elevated temperature acid-cracking combined with pilot
activated sludge and lagoon treatment were utilized to treat
effluent wastewater from a woolen processing plant. Effluent
from woolen "top" (raw wool scouring) making is very high in
BOD, COD, and suspended solids (18,880 ppm, 60,600 ppm,
37,oOO ppm, respectively). The chemical/physical system con-
sisted of a hot acid-cracking process to reduce the grease con-.
tent in the influent to the biological system. Average grease
reductions were from 13,400 ppm to 120 ppm or 99 percent with
a BOD reduction of 70 percent and COD reduction of 80 percent.
The biological system consisted of a pilot extended aeration
activated sludge unit with clarification and retention in a
pilot facultative lagoon (53 days' retention). Typical BOD and
COD reductions in the activated sludge/clarification unit were
83 percent and 54 percent, respectively, and in the lagoon
56 percent and f>4 percent, respectively.
This report was submitted in fulfillment of Grant No. 12130 HFX
under the sponsorship of the Office of Research and
Development, United States Environmental Protection Agency.
ii
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CONTENTS
Page
Abstract 11
List of Figures iv
List of Tables v
Acknowledgments vil
Sections
I Conclusions 1
II Recommendations 2
III Introduction 3
IV Description of Pilot Plant 6
V Sampling and Analysis 10
VI Operation and Analysis 19
VII Special Studies 39
VIII Cost Estimate 52
IX References 54
X Abbreviations 56
ill
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FIGURES
No. Page
1 Schematic of Treatment System 8
2 Sampling Port of Biological Unit 11
3 Schematic of Apparatus for Alpha and Beta
Measurement 16
4 BOD vs. Time 22
5 Aerators and Supplemental Air Supply 23
6 Schematic of Proposed Treatment 26
7 BOD Concentration Thru System (Warm Weather) 27
8 BOD Concentration Thru System (Cold Weather) 27
9 Suspended Solids Thru System (Warm Weather) 28
10 Suspended Solids Thru System (Cold Weather) 28
11 Nitrogen Thru System (Warm Weather) 29
12 Nitrogen Thru System (Cold Weather) 29
13 Phosphorus Thru System (Warm Weather) 30
14 Phosphorus Thru System (Cold Weather) 30
15 Settling Curve 32
16 Schematic of Existing Treatment 35
17 Triton Apparatus 41
18 -Testing Stage of Triton Apparatus 41
iv
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TABLES
No. Page
1 Typical Barre Wool Scouring Waste Composition 3
2 Table Listing Units and Sizes 7
3 Design Parameters of Biological System 9
4 Sampling Points and Tests Plan 12
5 Characteristics of Aeration Tank Contents of
Startup 20
6 Typical Aeration Tank Influent Characteristics,
mg/L 24
7 Operating Conditions During Warm and Cold
Weather 25
8 Pilot Plant Settled Aeration Tank Effluent and
Lagoon Effluent Characteristics Under Warm and
Cold Temperature Effects 34
9 Comparison of Proposed and Existing Treatment in
Cold Weather 35
10 Comparison of Existing and Proposed Treatment to
EPA Guidelines Issued 9/22/72 36
11 Typical Hot and Cold Acid-Cracking Process
Effluent Characteristics, mg/L 37
12 Comparison of Wasted and Lagooned Sludges 40
13 Summary of Sludge Conditioning Tests 43
14 Chemical Agents Tested for Improvement of
Settled Aeration Tank Effluent 45
15 Summary of Alpha and Beta Determinations 45
16 Pollutant vs. Product ^6
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No,
TABLES (Continued)
17 Kilograms of Pollutant Before and After Hot
Acid Cracking *»7
18 Dissolved Solids Composition M8
19 Effluent Stream PNS Levels 49
20 Comparison of PNS Levels from Acid-Cracking
Processes 50
21 Arsenic Levels 50
22 Design Criteria 52
vi
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ACKNOWLEDGMENTS
This project was funded by United States Environmental Pro-
tection Agency Grant 12130 HFX, Commonwealth of Massachu-
setts Resources Commission Grant 71-15, and the Barre Wool
Combing Company.
The funding and assistance provided by the Environmental
Protection Agency and Mr. Thomas N. Sargent is deeply
appreciated.
The laboratory equipment, funds, and suggestions provided
by the Commonwealth of Massachusetts and Mr. Thomas C.
McMahon and Mr. Russell A. Isaac were most valuable in
setting up and conducting the study.
The process equipment, resourcefulness, and long hours of
side-by-side effort devoted to the project by staff members
at the Barre Wool Combing Company was of truly incalculable
value. The efforts of 'Mr. Richard Strauss, Plant Manager,
Mr. John Gould, Mr. Jon Holmes, and especially Mr. Fred
Gross, who ran the hot acid-cracking process, were a real
asset to the project.
Dr. James T. O'Rourke directed the project for Metcalf &
Eddy. Additional direction and supervision were provided
by Dr. Ronald Sharpin and Mr. Wayne Wirtanen. The design,
construction, operation, and evaluation were the responsi-
bility of Mr. Leslie T. Hatch.
vii
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SECTION I
CONCLUSIONS
1. Biological treatment of hot acid-cracked wool scour
wastewater will reduce BOD, COD and suspended solids by
96, 78 and 62 percent, respectively.
2. Based on a comparison between the pilot plant perfor-
mance and the draft proposed guidelines for waste dis-
charges of the textile industry, the effluent containing
6.2-8.2 kilograms (kg) of BODs/1,000 kg of product
(wool top) and 2.6-5.1 kg of total suspended solids/
1,000 kg of product would be acceptable for discharge.
3. Hot acid-cracking removes 99 percent of the,grease pre-
sent in the raw scour liquor.
4. Because of the wastefs high oxygen demand, low alpha
value, and the increased biological activity resulting
from warm water temperatures in the summer, very high
oxygen input must be made to maintain a dissolved oxygen
(DO) concentration of 1-2 mg/L in the aeration tank.
5. Because of the wastewater1s low oxygen transfer coeffi-
cient, 20 days1 detention time in the aeration tank is
required rather than the design time of 10 days.
6. Settling tanks used for grease separation after hot
acid cracking must operate on a batch basis rather than
in a continuous flow mode to provide adequate cooling
and settling.
7. Sludge drying beds are superior to lagooning, vacuum
filtration or centrifugation for dewatering waste
biological sludge.
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SECTION II
RECOMMENDATIONS
1. More effort should be made to limit the amount of acid
used in the cracking process, thereby reducing the
amount of lime required. This would lower operating
cost and lower the dissolved solids concentrations.
2. Further studies are recommended to investigate the
removal of phosphorus and, more importantly, nitrogen
using chemical and/or biological processes.
3. The secondary clarifier should be sized using a conser-
vative overflow rate of 8.14 mVnr/day (200 gpsf/day).
4. Additional study should be directed to determining ade-
quate methods of color removal using activated carbon,
chemical conditioning or possibly polymer adsorbents.
5. A reliable foam control system is needed to limit foam-
ing in the aeration basin; this is especially important
in cold weather when foaming is more of a problem.
6. Further research is needed to determine what coagulants
and/or coagulant aid(s) will satisfactorily reduce sus-
pended solids in the secondary clarifier effluent.
7. Softening or ion exchange studies are recommended to
lower the dissolved solids concentrations.
8. Methods of further BOD, COD, and suspended solids removal
such as multistage extended aeration, aeration of the
final lagoon, chemical/physical removal or treatment
with activated carbon should be considered for additional
study.
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SECTION III
INTRODUCTION
In the scouring of raw wool, there are two major wastewater
streams; the scour water and the rinse water. The scour
water is the stronger of the two wastewater streams since
it carries most of the dirt, grease, and excrement contained
in the raw wool. The rinse water, which serves to remove
the detergent from the wool, is considerably weaker (see
comparison Table 1).
Table 1. TYPICAL BARRE WOOL SCOURING
WASTE COMPOSITION
Biochemical oxygen demand, mg/L
Chemical oxygen demand, mg/L
Suspended solids, mg/L
Total Kjeldahl nitrogen, mg/L
Ammonia nitrogen, mg/L
Total phosphorus, mg/L
Grease, mg/L
PH
Scour
water
18,880
60,600
37,600
900
160
60
13,300
7.0-8.2
Rinse
water
390
1,560
780
50
5
4
130
6.0-8.7
Most efforts to treat the wastes from raw wool scouring pro-
cesses have been aimed at recovering the wool grease. The
grease is a source of lanolin as well as being a proprietary
source of base oils used in tanning preservative com-
pounds. ' In order to remove the grease, one of three
methods is commonly used:
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1. Chemical cracking, using acids or salts
2. Centrifuging
3. Solvent extraction.
With the increased use of nonionic detergents in the past
two decades, the acid or salt cracking processes have
become more attractive. The grease-water emulsion formed
by the nonionic detergents is more difficult to break than
the emulsion formed when a mixture of soda ash and soap is
used for scouring. The chemical cracking more satisfactorily
breaks this emulsion.3> ^
The need for further treatment has become more pressing with
the increasing concern for protecting our environment. Am-
bient, facultative lagoons have been used to treat the waste
prior to discharge to receiving streams.5> ° The tech-
nique of discharging to domestic sewerage systems for treat-
ment has been recommended.'* ° The trend of combining
industrial and domestic wastes for treatment has also been
adopted with the proposal of anaerobic digestion of the
wool scouring waste prior to treatment along with domestic
sewage at domestic trickling filter plants.9, 10» H
Progress, however, continues to center around grease recov-
ery more than trying to solve the overall pollution problem.
In December 1969, Metcalf & Eddy submitted a report to the
Town of Barre, Massachusetts, suggesting that a sewage
treatment plant be constructed which would handle a combi-
nation of domestic and very strong wool-scouring waste. In
leading to this conclusion, bench scale activated-sludge
units had been used to determine that the effluent from a
new grease recovery system developed at the Barre Wool
Combing Company could be treated biologically.
Based on the pilot studies, it was felt that operation of a
larger pilot plant would clarify more fully the following
issues:
1. Sustained treatment reliability.
2. Cold weather reliability of the biological system.
3. Possible nutrient deficiencies.
4. Any unforeseeable toxicity.
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5. Design and operating parameters for a full-scale
plant.
PROPOSED TREATMENT
The treatment of the wool-scouring wastewaters was to be
conducted in two phases; a physical/chemical phase which
would remove most of the grease and solids, and a biologi-
cal phase to treat the remaining pollutants. The first
phase of treatment was to be concerned primarily with
treating the raw scour liquor to separate the grease. The
biological process would treat the combined effluent from
the grease removal operation and the raw rinse water.
Primary settling of the raw scour liquor would remove the
coarser grit and solids. The supernatant would then be
acidified using industrial grade (66 degrees Baume) sulfuric
acid to a pH of 2-3. The acidified liquor would then be
hot cracked by heating to a boil and being maintained at
that temperature for one hour; after the boiling has broken
the emulsion, cooling and settling would separate the grease
and solids from the cracked scour liquor.
The decanted cracked scour liquor would be mixed with rinse
water in a 60:40 ratio (essentially the same ratio as the
present plant flow streams), and the resulting mixture
would be neutralized to a pH of 4.5-5.5 using lime. In
operating the pilot plant, the neutralized mixture would be
stored prior to feeding to the biological system thus main-
taining sufficient feed material during periods of low plant
flow (weekends when Barre Wool plant production was down).
The biological process would consist of an extended aeration
lagoon with 10 days' detention. Following aeration, the
settled effluent would be further lagooned for 53 days.
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SECTION IV
DESCRIPTION OF PILOT PLANT
CONSTRUCTION PHASE
Construction occurred in three phases:
1. Outdoor construction of concrete tanks and necessary
earthwork.
2. Installation of motors, pumps, galleries, and elec-
trical controls.
3. Installation of acid-cracking tank, heat exchangers,
and all connecting plumbing for all units.
The completion of Phases 1 and 2 occurred on time. Phase 3
took longer than expected due to problems encountered when
installing heat exchangers and the delay caused by late
material delivery. Total construction for all three phases
consumed 12 weeks.
Particular care was taken in designing and constructing the
aeration tank, lagoon, and secondary settling tank. Prelim-
inary site investigation indicated a high-groundwater table
within 1.83 meters (m) (6 ft) of the surface during the
spring. For this reason, the units were installed partially
above ground to reduce the danger of floating in the spring.
To simplify construction, Schedule 80 Plastic Pipe Chlori-
nated Poly vinyl Chloride (CPVC) was used for all small feed,
effluent, and sludge lines. The process piping for the acid-
cracking portion of the plant was black iron in both Sched-
ules 40 and 80, depending upon the application. Cor-Ten
Steel was used for the two settling tanks. Reinforced-fiber-
glass tanks were used for mixing, neutralizing, and storing
the feed. Type 316 stainless steel was used for the acid-
cracking tank.
The major components of the pilot plant consisted of a 3.03
cubic meters (m3) (800 gal.) cracking tank, a 9.08 m3 (2,400
gal.) grease settling tank, four 7.57 m^ (2,000 gal.) rein-
forced fiberglass plastic (RFP) storage tanks, a 75•7 nP
(20,000 gal.) aeration tank, a 2.08 m-3 (550 gal.) secondary
clarifler, a 45.^2 nn (12,000^gal.) ambient lagoon, and a
7.57 nP (2,000 gal.) sludge lagoon. A complete inventory
of units is Included in Table 2.
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Table 2. TABLE LISTING UNITS AND SIZES
316 stainless-steel cracking tank
Grease settling tank
Mixing tank (RFP)
Storage tanks (RFP % 7.57 m3
(2,000 gal.)
Total storage
Mixer
Transfer pump
Feed pump
Aeration tank
Aerators
Secondary settling tank
Return sludge/waste sludge pump
Storage lagoon
Storage lagoon feed pump
Sludge lagoon
3.03
9.08
7.57
75
(800 gal.)
(2,400 gal.)
(2,000 gal.)
22.71 m3 (6,000 gal.)
30.28 m3 (8,000 gal.)
2.24 kw
1.9 L/sec
0-0.13 L/sec
,7
(3 hp)
(30 gpm)
(0-2 gpm)
(20,000 gal.)
fi 0.56 kw (26 3/4 hp)
2.08 m3 (550 gal.)
0-0.13 L/sec (0-2 gpm)
45.42 m3 (12,000 gal.)
0-0.03 L/sec (0-0.5 gpm)
7.57 m3 (2,000 gal.)
The system was located in two separate areas of the Barre
Wool Combing Company plant. The primary portion, consisting
of the acid-cracking tank, grease settling tank, neutralizing
and storage tanks was located inside the existing grease
works facility. The biological part was located out-of-doors
in an empty plot 180 m (600 ft) from the grease works. A
schematic of the system is shown on Figure 1.
The wool scour waste was drawn out of the existing cold acid-
cracking tank and passed through a preheater before being
fed into the stainless-steel cracking tank. The hot acid
cracking was accomplished by using stainless-steel steam
coils within the tank and heating the scour waste to a boil.
Steam resulting from this boiling was exhausted into a con-
denser located above the cracking tank which permitted con-
densate to return to the cracking tank. This prevented any
reduction in waste volume and resultant increase in waste
strength, and also prevented air pollution.
Following hot acid cracking, the waste flow was cooled in
a heat exchanger before being dumped into the grease set-
tling tank. After settling, an adjustable drain permitted
the supernatant, the cracked scour liquor, to be drawn off
for mixing with rinse water and neutralizing. The grease
sludge produced was pumped out the bottom of the settling
-------
tank and discharged into one of the existing Barre Wool
grease plant settling tanks for treatment in their existing
grease extraction facility.
RAW SCOUR
EXISTING
SETTLING
CONE
\y
t
ACIDIFICATION
& MIXING
HOT
CRACKING
^-
SETTLING
o
CRACKED
^. SCOUR
LIQUOR
SCOUR
GREASE
RINSE
WATER
O
.890
O-
.no
e
AERATION
TANK
LIME
MIXING
& STORAGE
FEED
RS
O
LAGOON
SLUDGE
LAGOON
NOTE: CIRCLED NUMBERS INDICATE SAMPLING POINTS
PIG. 1 SCHEMATIC OF TREATMENT SYSTEM
Supernatant from the grease settling tank was dumped into.
one of the 7.57 m3 (2,000 gal.) reinforced-fiberglass storage
tanks where it was mixed with the rinse water. This mix-
ture's pH was then adjusted to 4.5-5.5 by adding lime while
mixing. Upon completion of neutralization, the waste was
then transferred to one of the other three tanks for storage
until being fed to the aeration tank.
f
The aeration tank was designed to provide equal mixing zones
of 4.27 m by 4.27 m x 2.29 m (14 ft by 14 ft by 7.5 ft)
deep around each of the two aerators. This optimized the
mixing zones according to the manufacturer's data. The
aerators used were submersible motors with impellers which
pumped the mixed liquor up a draft tube to a sparger plate.
A total of 1.12 kilowatt (kw) (1.5 hp) of aerator capacity
was used.
8
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Overflow from the aeration tank proceeded into the secondary
clarifier. No scraper mechanism was provided since the tank
was designed with steep conical walls (1:1 slope) at its
base. This provided for good transport of the settled
solids to the center sludge withdrawal pipe. The weir plate
had four equally spaced 60-degree V-notches. Underflow from
this clarifier could either be returned to the influent end
of the aeration tank or pumped to the sludge lagoon. The
clarifier overflow passed into a flow splitter designated
as a sump.
Eighty-nine percent of the clarifier overflow passed through
the sump and out of the system. The remaining 11 percent
was pumped into the storage lagoon. Following ambient
lagooning for 53 days, this flow was also discharged from
the system.
Waste sludge was lagooned prior to disposal in the sludge
lagoon. Only if the lagoon's capacity was exceeded would
sludge be disposed of on land. If this were necessary, the
sludge would be trucked to a land disposal site presently
used by Barre Wool for sludge disposal.
The basic design parameters for the biological system were
determined in two ways. The completely mixed aeration tank
design was based on the results of the bench units tested
in 1969 as previously mentioned. The lagoon design was
based solely on lagoon volumes which Barre Wool presently
has available. These design values are listed in Table 3.
Table 3. DESIGN PARAMETERS OF BIOLOGICAL SYSTEM
F/M 0.03-0.05
BOD loading 7**-83 grams/mVday (15-17 lb/1,000
cf/day)
Aeration detention time 10 days
Return sludge 100-200 percent of the influent flow
Alpha 0.75
Beta 0.95
Lagoon detention time 53 days
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SECTION V
SAMPLING AND ANALYSIS
Since the pilot plant was operated in two different modes,
batch in the acid-cracking operation, and continuous in the
biological operation, separate sampling techniques were
applied. During the preparation of feed for the pilot plant,
samples were taken at points 1, 2, 3, and 4 (see Figure 1).
These were grab samples taken as the various steps in the
batch process hot acid cracking were performed.
The biological units, being fed continuously, were sampled
continuously at points 5, 6, 8, and 9 using an arrangement
as shown on Figure 2.
Samples from points 5,6 and 8 were taken from lines under
pressure due to pumping. The rate of sample collection was
controlled by pinchcocks on the tygon tubing. Sample loca-
tion No. 9 was under only a very slight hydrostatic pressure
but still required a pinchcock to control the sampling rate.
The sampling from point 7 was a daily grab sample. It was
taken between the two aerators at a point of good mixing.
Sampling point 10 was not used until the end of the study
when lagooned sludge was sampled for grease and solids.
A list of tests conducted on each flow stream is shown in
Table 4. Testing frequency was initially set at 1-3 times
weekly; however, during the study, most tests were performed
3-5 times weekly.
TESTING PROCEDURES
Total Solids, Total Volatile Solids, Suspended Solids, and
Volatile Suspended Solids
The procedures suggested by "Standard Methods"12 were
followed: The only deviation occurred when determining
total solids for samples having a pH less than 4.3. "Stan-
dard Methods" recommends that when samples have a pH below
4.3, a solution of IN sodium hydroxide, NaOH, be added to
the sample to maintain a pH greater than 4.3 during evapora-
tion. This procedure would have applied to Samples 2 and 3,
10
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FIG. 2 SAMPLING PORT OF BIOLOGICAL UNIT
-------
Table 4. SAMPLING POINTS AND TESTS PLAN
Stream
name
Sampling
point
No.
•a
8
o
>
rH
«S
S
•O
§ -
m
*J
i
s
•A
3
£
Raw
scour
1
Plow
TS
TVS
SS
VSS
Set. sol.
BOD
COO
TOC
PH
ALK
Acid
TKN
NH3-N
N03-N
N02-N
Total P
Grease
PNS
_
-
Acid
cracked
scour
liquor
2
Flow
TS
TVS
SS
VSS
Set. sol.
BOD
COD
TOC
pH
ALK
Acid
TKW
NHo-N
NOo-N
N02-N
Total P
Grease
PNS
_
-
Scour
grease
1
Flow
TS
TVS
-
_
_
-
_
«
PH
-
-
-
-
Grease
—
_
-
Rinse
water
^
Plow
TS
TVS
SS
VSS
Set. sol.
BOD
COD
TOC
PH
ALK
Acid
TKN
NJI3-N
N03-N
N02-N
Total P
Grease
PNS
«,
-
Aeration
tank
influent
5
Plow
TS
TVS
SS
VSS
Set. sol.
BOD
COD
TOC
pH
ALK
Acid
TKN
NH3-N
NOo-N
NOp-N
Total P
_
_
_
-
Aeration
tank
settled
effluent
6
TS
TVS
SS
VSS
Set. sol.
BOD
COD
TOC
PH
ALK
Acid
TKN
NH3-N
NO-j-N
NOp-N
Total P
_.
_
,^
_
Aeration
tank
mixed
liquor
7
TS
TVS
SS
VSS
Set. sol.
_
_
_
pit
_
—
-
„
—
DO
Temp.
Return
sludge
8
Plow
TS
TVS
-
—
-
-
_
_
-
-
-
-
-
-
-
_
-
Lagoon
effluent
9
^
TS
TVS
SS
VSS
Set. sol.
BOD
COD
TOC
-
-
-
TKN
NH3-N
N03-N
N02-N
Total P
-
-
DO
Temp.
Lagoon
sludge
10
Plow
-
-
-
-
-
- .
«•
_
-
-
-
-
-
-
-
-
-
-------
the Acid Cracked Scour Liquor and Scour Grease. The poten-
tial loss of volatile material at the low pH during evapo-
ration was insignificant compared to the total solids con-
centration of the samples, so the recommended procedure was
not followed.
Because of the high volatile organics concentrations present
as grease and fatty acids, there was an Inherent error in
all of the solids determinations. It is safe to say that
the samples do not dry to constant weight at the desired
test temperatures because of the different evaporation
rates of the various volatile compounds present. This
applies to Samples 1 and 4, the Raw Scour and Rinse Water,
as well as Samples 2 and 3. During the study, the error
in solids determinations was assumed to be negligible for
all samples and no corrections were made.
BOD
The membrane electrode modification as suggested in "Stan-
dard Methods" was used for the BOD. A Yellow Springs Instru-
ment Model 54 Portable Dissolved Oxygen Analyzer was used
with a self-stirring probe. An acclimated seed.of mixed
liquor was used in the dilution water. Because of manpower
requirements, a 7-day test was used instead of the normal
5-day test. A factor of 0.8? related the 7-day BOD to the
5-day BOD. All data in this report are reported as 5-day
BOD.
COD
The Dichromate Reflux Method of determining COD as outlined
in "Standard Methods" was followed.
TOG
Tests were run using a Beckman Total Organic Carbon Analyzer
as "Standard Methods" suggests. The samples were filtered
through Whatman No. 40 paper to remove large particles.
Because of the high-grease content, filter binding occurred
and some loss of accuracy resulted. Sample 1, The Raw
Scour Liquor, was most susceptible to binding.
pH. Alkalinity. Acidity
The same procedures as outlined in "Standard Methods" were
utilized using a Beckman pH meter. Deviation from "Standard
13
-------
Methods" was made in determining the pH of Samples 1 and 3,
The Raw Scour Liquor and Cracked Scour Grease. Instead of
using the pH meter, pH indicating paper was used. This
limited pH results to an accuracy of not better than +1 pH
unit. This action was necessary because of repeated pH
electrode failures after taking pH measurements in these
two high-grease content streams. Efforts to thoroughly
clean the electrode as suggested by the manufacturer were
not successful and contributed to shorter electrode life.
For these reasons, the pH indicating paper'was used.
Nutrients
Total Kjeldahl nitrogen, ammonia nitrogen, nitrate nitrogen,
nitrite nitrogen, and total phosphorus levels were deter-
mined using tests outlined in "Standard Methods." A Bausch
and Lomb nSpectronlc-20" spectrophotometer was used for the
colorimetric analysis and the Beckman pH meter was used for
titrations. To eliminate interfering color in the tests
for nitrate, nitrite, and phosphorus, samples were treated
using "Darco KB" activated carbon.
Grease
The approaches suggested in "Standard Methods," Sections
209A and 209C were followed. The solvent used was petroleum
ether rather than n-Hexane or trichlorotrifluoroethane. The
petroleum ether was used because of its lower boiling point
which allowed refluxing to begin quicker and also shorten
evaporation time at the end of the test. In addition, oil
and grease are extracted to the same extent by either petro-
leum ether or trichlorotrifluoroethane.
Surfactants
Since the Barre Wool Combing Company uses a nonionic deter-
gent, the tests suggested in "Standard Methods" which is
specific for anlonic surfactants could not be used. How-
ever, the procedure developed by Crabb and Persinger13
for polyoxyethylene nonionic surfactants was applicable.
The following is an outline of the procedure used:
1. Place sample in 500-milliliter (ml) separatory
funnel.
2. Add 25 ml of dlethyl ether and shake. If ether-
layer does not separate, add 1 gram potassium
chloride and shake again.
14
-------
3. Draw water layer into a clean beaker and filter
other layer through Whatman No. IPS paper into a
125-ml separatory funnel.
4. Repeat steps 2 and 3 until 100 ml of diethyl ether
is used.
5. Evaporate ether in hot water bath.
6. Add 5 ml ammonium cobalt thiocyanate solution and
shake.
7. Add 15 ml chloroform and shake.
8. Draw off chloroform layer through Whatman No. IPS
paper into a 25-ml graduated cylinder.
9. Repeat chloroform extraction with 5 ml and 6 ml of
chloroform. Add enough carbon tetrachloride
to make up 25 nil.
10. Read at 620 millimicrons (my).
Color
The color procedure as outlined in "Standard Methods" was
used. Also a stream dilution study was run. The pilot
plant lagoon effluent was diluted to the point at which no
color difference could be detected between existing river
water and the dilutions.
Alpha Value
Alpha, or the relative oxygen transfer coefficient, was
determined using an adaptation of a procedure suggested by
Sawyer.1^ The equipment used is shown on Figure 3. The
procedure which follows was used for both distilled water
and wastewater.
1. Aerate sample at a constant temperature to point of
dissovled oxygen saturation; record saturation,
DO and temperature.
2. Draw a 700-ml sample of water into a 1,500-ml flask.
3. Add 0.75 ml of cobalt chloride solution (1 ml * 5 mg
CoCl2).
15
-------
THERMOMETER
COMPRESSED AIR
RUBBER
STOPPER
ROTOMETER
1,500 ml
ERLENMEYER
FLASK
AIR
DIFFUSER
STONE
DISSOLVED
OXYGEN
PROBE
1
DISSOLVED
OXYGEN
METER
O
o
O
MAGNETIC STIRRER
THERMOMETER
AIR
SUPPLY
DISSOLVED OXYGEN PROBE
STOPPER
(TOP VIEW)
FIG. 3 SCHEMATIC OF APPARATUS FOR ALPHA AND BETA
MEASUREMENT
16
-------
4. Add 0.06 grains sodium sulfite powder.
Note: Amounts indicated in 3 and 4 may be adjusted
up or down to achieve zero DO.
5. Place flask on magnetic stirrer and mix until all
powder and solution are thoroughly dispersed. DO
should now be zero.
6. Turn off mixer and insert stopper with metered air
supply, DO probe, and thermometer.
7. Begin aerating at a constant rate, start timer when
first air bubbles reach liquid surface.
8. Continue aerating and record DO concentration and
temperature at 3-minute intervals.
9. Continue aerating and collecting data until DO level
approaches saturation.
Calculation of Kw and Kww rate coefficients of oxygen absorp-
tion for tap water and wastewater, respectively, can be
done using the following formula:
Kw = (log D! - log D2) 2.3/(t2 - t)
where :
KW = Rate of oxygen absorption in mg/L per hour per
mg/L DO deficiency.
t^ = Elapsed time hours to first DO deficiency reading
used in calculation.
t2 = Elapsed time in hours to second DO deficiency
reading used in calculation.
= Oxygen deficiency at time t^.
D2 - Oxygen deficiency at time t2.
Similarly, K^^ can be calculated.
Prom this, alpha can be determined using the following
relationship:
a= KWW/KW
17
-------
A word of caution, all values should be corrected to some
standard temperature, preferably 20 deg C.
Beta Value
The beta value is the ratio of the DO concentrations in
the wastewater at saturation to the DO concentration in
distilled water at saturation. Both values used should be
corrected to some constant temperature.
18
-------
SECTION VI
OPERATION AND ANALYSIS
OPERATION
The operation and evaluation of the pilot plant was divided
into three phases:
1. Startup and acclimation, March 8-August 28, 1973
2. Warm weather, August 29-November 16, 1972
3. Cold weather, November 17, 1972-January 5, 1973.
STARTUP
The comparatively long startup period of 6 months should be
explained. Attempts to start a biological system in very
cold weather are normally unsuccessful. Since cold weather
evaluation was a prime purpose of this project, a study was
made of the efforts to develop the biological system under
adverse temperature conditions. The cold weather startup
period ran from early March to early July, a period of 4
months. The warm weather startup phase, the 2 months from
July to September, was more productive than the previous 4
months1 efforts as far as producing a growing microbiologi-
cal population. However, the efforts expended in the first
4 months should be discussed.
COLD WEATHER STARTUP
During early March 1972, rinse water was pumped into the
aeration tank and the aerators were placed in operation.
During this period, a composite of four 1-liter samples
was taken at different locations along the length of the
aeration tank. The results of the analysis of this sample
are shown in Table 5.
Icing conditions existed in the aeration tank, with large
blocks of ice forming on the aerator tethering ropes. The
secondary clarifier was often .inoperative due to a thick
layer of surface ice.
Initially, an attempt was made to start the plant without
seeding. Following three weeks' aeration and feeding with
19
-------
rinse water, suspended solids data indicated no increase in
the mixed liquor suspended solids level over the initial
200 mg/L.
Table 5. CHARACTERISTICS OP AERATION TANK
CONTENTS OP STARTUP
PH 7.8
Total alkalinity 145 mg/L as CaCo3
SS 194 mg/L
VSS 140 rag/L
TKN 24 mg/L
Total phosphorus 3*76 mg/L
BOD 260 mg/L
Temp. 0.4 deg C
At this point, late March 1972, a 3.8 m^ (1,000 gal.) seed
of domestic septic tank pumpIngs was fed into the aeration
tank. The suspended solids level was near 1,000 mg/L
immediately following the seeding. The feeding of rinse
water was maintained following this seeding. This mode of
operation continued into mid-April, with no increase in
suspended solids. There was no sludge returned during this
period due to a lack of settleable solids.
With no Increase in mixed liquor suspended solids, a change
in feed was initiated in an effort to provide more food for
the system. Cracked wool scour liquor was mixed with rinse
water and neutralized to pH 7+ in the ratio of 95 percent
rinse water to 5 percent craclced scour liquor. Over a two-
week period, this ratio was increased until in early May,
the feed was 60 percent cracked scour liquor and 40 percent
rinse water.
The mixed liquor suspended solids continued to hover near
1,000 mg/L even after feeding the higher BOD mixture. A
second seeding was attempted again using domestic septic
20
-------
tank pumpings. Following this, two weeks* feeding produced
no measureable increase in mixed liquor suspended solids
concentration.
In an attempt to conserve suspended solids and achieve
growth, the feeding schedule was changed from continuous
feed to a batch feed operation in mid-May. This was accom-
plished by shutting down the aerators each second morning
for one hour to allow settling in the aeration tank. Then,
from 0.8 to 1.6 m3 (200-400 gal.) of feed was pumped into
the aeration tank displacing only the supernatant. Follow-
ing feeding, the aerators were again turned on. This method
did not Increase mixed liquor suspended solids concentration.
After two weeks, continuous feeding was resumed. This opera-
tion continued through June 1972.
WARM WEATHER STARTUP
As expected, with warmer water temperatures in early July,
the system began to develop. Prior to July, the water
temperature had risen steadily to 15 deg C, the mixed liquor
had 7-8 mg/L dissolved oxygen. However, the mixed liquor
suspended solids had only climbed to 1,200 mg/L. In July,
the water temperature was 20-24 deg C, the mixed liquor
dissolved oxygen dropped to 0.5 mg/L, and the mixed liquor
suspended solids increased steadily from 1,200 mg/L to
3,900 mg/L. Although the BOD loading remained constant at
42.5 grams/m3/day (9 lb/1,000 cf/day), the F/M ratio
decreased steadily from 0.1 to the design ratio of 0.03-0.05
as the mixed liquor suspended solids concentration increased.
During the startup period, two specific subjects were con-
sidered. First, a study was conducted to determine how the
BOD was exerted, and secondly, attempts were made to increase
the mixed liquor dissolved oxygen level. Twenty-one day
BOD tests were performed. As shown on Figure 4, 80 percent
of the 20-day BOD was exerted within the first 5 days, an
indication that the waste as prepared and fed to the biolo-
gical system was readily biodegradable. Since most of the
nitrogen was in the organic form and the septic tank seed
that was used was low in nitrifying organisms, no discern-
able nitrogenous oxygen demand appeared over the 21-day
test period.
Efforts were begun to correct the low dissolved oxygen level
as soon as the problem arose. The feed rate was reduced
and even stopped for one 24-hour period without showing any
increase in the mixed liquor dissolved oxygen level. This
21
-------
5.000
4,000
3,000
2,000
1,000
0 5 10 15 20 25
TIME (DAYS)
FIG. 4 BOD VS. TIME
condition of low dissolved oxygen was aggravated further
by aerator failures which cut the system's oxygenating and
mixing capacity by 50 percent. To supplement the aerators,
compressed air was introduced below the draft-tube of the
mechanical aerators using low-pressure air lines as shown
on Figure 5. This arrangement introduced an additional
*6 kg (100 Ib) of oxygen to the aeration tank each day.
While using this "Hybrid" system of mechanical and diffused
aeration, the system continued to operate at a dissolved
oxygen level of 0.5 mg/L. This condition of low dissolved
oxygen was very noticeable during the latter part of -tart-
up when septic odors and a black mixed liquor were predomi-
nant at the aeration tank.
22
-------
INF
LOW PRESSURE
AIR LINE
EFF
FIG. 5 AERATORS AND SUPPLEMENTAL AIR SUPPLY
The startup phase did reveal three facts about the waste
which differed considerably from the original bench-scale
pilot testing conducted in Metcalf & Eddy's laboratory in
1969.
1. The waste had a much lower alpha coefficient than
originally assumed which required much larger
aerators and $2 supply.
2. The oxygen requirements were much higher than anti-
cipated due to this higher oxygen requirement.
3. Chemical treatment created a very high level of
fixed dissolved solids.
The combination of lower alpha and beta and high fixed
dissolved solids concentration contributed significantly
to the inability to maintain a 1-2 mg/L dissolved oxyeren
concentration in the mixed liquor.
WARM AND COLD WEATHER OPERATION
For ease of comparison, the warm and cold weather phases
will be discussed simultaneously.
23
-------
. Table 6. TYPICAL AERATION TANK INFLUENT CHARACTERISTICS, mg/L
Entire study period
TS
rv> S3
Jr
BOD
COD
TKN
NH3
Total P
Wax.
27,600
1,720
3,830
10,1*50
623
220
50
Min.
13,500
130
1,740
5,600
204
106
8.7
Ave .
18,260
380
2,840
7,560
420
160
27.4
Warm study period
Max.
27,600
880
3,830
10,450
623
220
50
Min.
14,500
130
1,890
5,600
306
106
12.8
Ave.
18,910
340
2,930
7,750
420
160
28.3
Cold study- period
Max.
17,800
1,720
3,010
8,100
376
183
28.
Min.
13,500
190 -
1,740
5,600
204
138
8 8.7
Ave.
15,610
300
2,420
6,560
310
150
18.5
-------
Due to the approaching cold weather, it was necessary to
begin collecting the warm weather data even though the
oxygen deficiency still existed. It is preferable to oper-
ate an activated-sludge system with a mixed liquor dissolved
oxygen level of 1-2 mg/L. At the start of the warm weather
period, the mixed liquor dissolved oxygen level was 0-0.5
mg/L. If higher oxygen concentrations could have been main-
tained during the entire warm study period, it is reasonable
to assume that performance would have been better.
During the warm weather period, influent to the aeration
tank was slightly higher in BOD, COD, nitrogen, etc. than
occurred during the cold weather period. This is shown by
the data of influent waste characteristics in Table 6. A
possible explanation for this change in waste characteris-
tics is a change in the quality of wool processed.
The operating conditions for the warm and cold weather
periods are listed in Table 7. It would have been desirable
to operate the pilot plant under similar conditions of
loading, detention time, and F/H ratio. However, severe
freezing conditions prevented continuous feeding on two
occasions in December. As a result, the cold weather
period had a lower BOD loading and longer detention time.
There was also a drop in mixed liquor volatile suspended
solids; however, the loading was sufficiently lower to cause
the F/M ratio to decrease.
Table 7. OPERATING CONDITIONS DURING
WARM AND COLD WEATHER
Warm Cold
BOD loading (grams/m3/day) 48.0 25.9
F/M 0.05 0.03
Mixed liquor DO (mg/L) 1.0 6.0
Mixed liquor temp, (deg C) 13 3.0
Detention time (days) 19 25
25
-------
LIME
1
RAW
SCOUR
HOT
ACID
CRACK
MIXING AND
NEUTRALIZATION
RINSE
WATER
TO
GREASE
EXTRACTION
I
EXTENDED
AERATION
RIVER
W/O LAGOON
RIVER
WITH LAGOON
PIG. 6 SCHEMATIC OF PROPOSED TREATMENT
Performance of the biological pilot plant can be evaluated
using the two options shown on Figure 6:
1. Aeration and settling without stabilization lagoon.
2. Aeration and settling with stabilization lagoon.
The levels of BOD, suspended solids, nitrogen, and phos-
phorus during warm and cold weather at various points in
the treatment system including with and without the stabi-
lization lagoon are shown on Figures 7 through 1*4.
26
-------
2O.OOO —
18,000—
/
5.OOO —
BOD
mg/L
3,000-
2,OOO —
l.OOO —
19.9OO
WARM WEATHER
r "
4,780
RAW CRACKED
SCOUR SCOUR
LIQUOR LtQUOR
440 |
2,930
d70 I
1 1 280 |
RINSE MIXED SETTLED LAGOON
WATER NEUTRALIZED AERATION EFFLUENT
FEED TANK
EFFLUENT
FIG. 7 BOD CONCENTRATION THRU SYSTEM (WARM WEATHER)
18.OOO-
16.OOO -
/
/
5,OOO-
BOD 4,OOO-
mg/L
3,000 -
2OOO -
1.OOO-
I7,37O
3,920
390
2.42O
COLD WEATHER
19O
_L
1
RAW CRACKED RINSE MIXED SETTLED
SCOUR SCOUR WATER NEUTRALIZED AERATION
LIQUOR LIQUOR FEED TANK
EFFLUENT
LAGOON
EFFLUENT
PIG. 8 BOD CONCENTRATION THRU SYSTEM (COLD WEATHER)
27
-------
45.OOO —1
SS
mg/L
4O.OOO—
/*••
42.540
WARM WEATHER
1OOO-
5OO
— v —
RAW
SCOUR
LIQUOR
28O
CRACKED
SCOUR
LIQUOR
900
340
1.O9O
9O J^
RINSE MIXED SETTLED LAGOON
WATER NEUTRALIZED AERATION EFFLUENT
FEED TANK
EFFLUENT
FIG. 9 SUSPENDED SOLIDS THRU SY3TE.1 (WARM WEATHER)
3O.OOO—i
SS
mg/L
1,000-
5OO-
2921O
COLD WEATHER
310
64O
30 o
86O
170
RAW
SCOUR
LIQUOR
CRACKED
SCOUR
LIQUOR
RINSE
WATER
MIXED
NEUTRALIZED
FEED
SETTLED
AERATION
TANK
EFFLUENT
LAGOON .
EFFLUENT
FIG. 10 SUSPENDED SOLIDS THRU SYSTEM (COLD WEATHER)
28
-------
1 UUU —
N
mg/L
5OO-
AS N
927
TKN
174
NH3
RAW
SCOUR
LIQUOR
_
720
r 1
220
CRACKED
SCOUR
LIQUOR
WARM WEATHER
424
1
1 1 ~l
1 1 199 1
ISO I | 1 14,
1 99 i
RINSE MIXED SETTLED LAGOON
WATER NEUTRALIZED AERATION EFFLUENT
FEED TANK
EFFLUENT
FIG. 11 NITROGEN THRU SYSTEM (WARM WEATHER)
lOOO-i
787
COLD WEATHER
N
mg/L
AS N
5OO -i
TKN
117
NH3
RAW
SCOUR
LIQUOR
456
r 1
_^n__
177 1 150 1 r~T7"0~~'
41 '125
1 7
CRACKED RINSE MIXED SETTLED LAGOON
SCOUR WATER NEUTRALIZED AERATION EFFLUENT
LIQUOR FEED TANK
EFFLUENT
FIG. 12 NITROGEN THRU SYSTEM (COLD WEATHER)
29
-------
oo —
TOTAl f
mg/L 4G-
AS P
20-
61.O
45.9
WARM WEATHER
1 4.7 |
28.3
8.5
1 3* I
RAW CRACKED RINSE MIXED SETTLED LAGOON
SCOUR SCOUR WATER NEUTRALIZED AERATION EFFLUENT
LIQUOR LIQUOR FEED TANK
EFFLUENT
FIG. 13 PHOSPHORUS THRU SYSTEM (WARM WEATHER)
60-i
COLD WEATHER
TOTAL P
mg/L 4O -
AS P
2O —
48.6
29.S
18.5
T>
\ w I 1 47
RAW CRACKED RINSE MIXED SETTLED LAGOON
SCOUR SCOUR WATER NEUTRALIZED AERATION EFFLUEN
LIQUOR LIQUOR FEED TANK
EFFLUENT
FIG.
PHOSPHORUS THRU SYSTEM (COLD WEATHER)
30
-------
By comparing the raw scour liquor, cracked scour liquor,
rinse water, and mixed neutralized feed for the warm and
cold periods, the difference in influent waste characteris-
tics as shown in Table 6 is clearly seen. With respect to
the hot acid-cracking process, note the substantial drops
in BOD and suspended solids resulting from the process as
shown on Figures 7 through 10. A similar reduction in nitro-
gen and phosphorus can be seen on Figures 11 through 14;
however, the decreases are not as significant. The fact
that the nitrogen and phosphorus reductions are of lesser
magnitudes than the BOD and suspended solids indicates the
more soluble nature of the nitrogen and phosphorus.
The removal of BOD and phosphorus in the biological processes
in warm and cold weather are very good. This is seen by
comparing the mixed neutralized feed, settled aeration tank
effluent, and lagoon effluent BOD and phosphorus levels as
shown on Figures 7, 8, 13, and 14.
The settled aeration tank effluent suspended solids levels
shown on Figures 9 and 10 indicate either a poor settling
sludge or improper settling tank selection. Settling tests
were run on the mixed liquor. A typical settling, curve is
shown on Figure 15. Based on an analysis of the settling
velocity as outlined by Rich,1-* a maximum overflow rate
of 8 m3/mVday (200 gpsf/day) was calculated.
Since the pilot clarifier operated at 3.5-4.1 m3/m2/day
(85-100 gpsf/day) and settling was rather rapid once agglo-
meration occurred, the poor settling could have been a
result of clarifier design. Metcalf & Eddy has determined
through experience that the clarifier side water depth (swd)
should be 3.6 m (12 feet) minimum. The pilot plant settling
tank had a 1.5 m (5 feet) swd. This rather shallow depth
was dictated because of groundwater conditions which pre-
vented deep tank installations. Also, construction costs
prevented building the tanks at levels far enough above the
existing grade to install a clarifier with a 3.o m swd. If
a 3.6 m swd had been provided, it is safe to assume that the
aeration tank settled effluent suspended solids level would
have been much lower.
The unit was not operated at or near 10 days' detention time
as suggested by the 1969 Metcalf & Eddy report for two
reasons:
31
-------
o
1,000
900
800
700
600
500
400
300
200
100
1,000
Mixed Liquor)
15 20
TIME (MINUTES)
FIG. 15 SETTLING CURVE
:
1. A higher rate of oxygen uptake than anticipated due
;he low alpha and beta limited BOD loadings in
order to maintain a mixed liquor dissolved oxygen
level of 1 mg/L.
2. The low residual dissolved oxygen levels during
warm weather forced lower BOD loadings in an effort
to maintain aerobic conditions. Since loadings
and detention were related by flow, the lower
loading increased detention times.
With respect to the biological plant, a few operating guide
lines should be emphasized.
32
-------
1. During warm weather, the ability to maintain a
residual dissolved oxygen level was very difficult.
This can be attributed to low alpha and beta values.
2. The use of surface aerators in areas of extreme
cold should be cautiously considered (mixed liquor
temperature fluctuations lagged behind air tempera-
ture changes by only one day, resulting in rapid
lowering of water temperatures which increased
icing problems).
3. Foaming in the aeration tank during cold weather
was excessive with 0.6-1.2 m of foam on the water
surface when water temperature dropped to 0-2 deg C.
The effluent characteristics and removal efficiencies for
the biological process options previously shown on Figure 6
are shown in Table 8.
A comparison between the warm and cold weather performance
with and without the stabilization lagoon as previously
described and the existing lagoon treatment system will now
be made. Data was gathered on the performance of the exist-
ing lagoons during only cold weather. For purposes of this
comparison, a flow of 8,500 mVday (225,000 gpd) was used
(consisting of 60 percent scour water and 40 percent rinse
water to duplicate present plant conditions). Based on the
performance of the existing lagoon system, shown on Figure 16,
and the removals demonstrated by the two options shown on
Figure 6, the river loadings shown in Table 9 can be devel-
oped. This clearly indicates the superiority of the pro-
posed treatment, especially with the lagoon, over the
existing method of treatment.
Based on the performance of the existing lagoons and the
pilot plant system, another comparison of particular con-
cern can be made, i.e., how do the two treatment systems
compare with the Draft Proposed Effluent Limitations for
the Refuse Act Permit Program^" released on September 22,
1972 by the Environmental Protection Agency. The results
of this comparison are shown in Table 10. This table rein-
forces the need for the stabilization lagoon in both warm
and cold weather. It can be hypothesized from the previously
mentioned settling tests that if a properly designed secon-
dary settling tank were used, the solids levels in the
effluent without using the lagoon would be much lower, in
the range of 3.6-4.5 kg (8-10 Ib) of solids per 453 kg
(1,000 Ib) of product.
33
-------
u>
Table 8. PILOT PLANT SETTLED AERATION TANK EFFLUENT AND LAGOON EFFLUENT
CHARACTERISTICS UNDER WARM AND COLD TEMPERATURE EFFECTS
Without
warm
TS
S3
BOD
COD
TKN
NH3-N
Total P
mg/L
15,000
1,090
470
3,350
320
200
8.5
7*
Removal
20
-290
84
56
17
-24
69
lagoon
Oola
mg/L
13,040
860
190
2,400
230
170
7.2
%
Removal
17
-210
92
64
27
-13
59
With
Warm
mg/L
8,580
90
280
1,620
140
100
3.4
%
Removal
57
74
91
80
62
50
89
lagoon
Cold
mg/L
8,780
170
210
1,580
140
125
4.7
%
Removal
43
41
92
76
54
26
77
-------
RAW ^
SCOUR
COLD
ACID
CRACK
ACID
LAGOON
RIVER
TO
GREASE
EXTRACTION
RINSE
WATER
RINSE
WATER
LAGOON
-DRIVER
PIG. 16 SCHEMATIC OF EXISTING TREATMENT
Table 9. COMPARISON OP PROPOSED AND EXISTING
TREATMENT IN COLD WEATHER
(Kilograms of discharge to river based on
plant flow of 8,520 m3/day)
Proposed system
Pollutant
to
stream
TS
SS
BOD
COD
TKN
NH3
Total P
Grease
Existing
system
kg
12,188
734
2,849
8,965
254
59
14
498
Without
kg
11,334
747
165
2,084
199
149
6
28
lagoon
Decrease
from
existing
7
2
94
77
21
153
56
94
With
kg
7,633
149
181
1,373
122
109
4
10
lagoon
Decrease
from
existing
37
80
94
85
52
85
71
98
35
-------
Table 10. COMPARISON OP EXISTING AND PROPOSED TREATMENT
TO EPA GUIDELINES ISSUED 9/22/72
(Kilograms of pollutant/1,000 kg of product)
TSS
BOD
EPA
propo'se
"A"
8
8
da
B"
10
20
Existing
lagoons
(Cold)
24.9
96.8
Without
(Cold)
25.4
5.6
Proposed
lagoon
(Warm)
32.2
13.9
system
With
(Cold)
5.1
6.2
lagoon
(Warm)
2.6
8.2
maximum allowable discharge under circumstances.
With reference to Table 10, if the previously mentioned
settling data is considered, it would be possible for the
system without the lagoon to meet the proposed Class B dis-
charge standards in either summer or winter. With the use
of the lagoon, proposed Class A discharge standards could be
met throughout the year.
In general, the biological treatment systems tested more
adequately removed the pollutants than the existing lagoon
system. Activated-sludge treatment followed by lagooning
provides the more satisfactory alternative of the two options
studied.
GREASE REMOVAL
The original concept in operating the hot acid-cracking
system was to crack two or three batches of raw scour liquor,
dump them into the settling tank, let the liquor cool, the
grease settle, and then decant the cracked scour liquor for
mixing and neutralization. It was found that a better qual-
ity of cracked scour liquor (much clearer, therefore le.ss
grease and solids) could be obtained if the cracked scour
liquor from the first batch dropped each day was drawn off
before the dumping of any more cracked material into the
same settling tank.
Comparing the hot and cold acid-cracking processes, the
major difference between the two systems is the one hour
of boiling following acidification. This more completely
breaks the grease-water emulsion formed by the nonionic
detergent during scouring. The effluent characteristics of
the two processes are shown in Table 11. From the point of
36
-------
biological treatment, the hot acid cracking provides a more
desirable waste because of much lower grease, BOD, and COD
levels since unit loadings are reduced substantially.
Table 11. TYPICAL HOT AND COLD ACID-CRACKING
PROCESS EFFLUENT CHARACTERISTICS, mg/L
BOD
COD
SS
TS
Ore as e
PNS
NH3-N
TKN
Total P
Cold acid cracking
6,400
24,000
4,500
24,800
3,200
120
130
590
40
Hot acid cracking
3,930
12,500
280
27,100
110
<40
210
700
40
SUMMARY
After evaluating the grease extraction process and biologi-
cal system individually and collectively, the results of
the project should be reviewed:
1. The biological plant should be designed using these
parameters:
a. 20 days' detention time
b. F/M ratio of 0.03-0.05
c. Aeration tank loading of 49.3 grams/mVday
(10 lb/1,000 cf/day)
d. a* 0.54, 0 - 0.86
37
-------
e. Clarifier overflow of 8.2 m3/m2/day (200 gpsf/day)
f. Stabilization lagoon detention time of 50-60
days.
2. Cold weather does affect both aeration tank and
stabilization lagoon performance adversely, but
adequate treatment is provided when unit loadings
are properly controlled and sufficient oxygen is
provided.
3. The waste biological sludge produced is difficult
to dewater, but can be disposed of using either
lagoons or properly drained filter beds.
*l. Hot acid cracking is superior to cold acid cracking
with respect to loads exerted on subsequent treat-
ment facilities and with respect to grease quantities
made available for grease extraction processes.
38
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SECTION VII
SPECIAL STUDIES
WASTE SLUDGE
Extended aeration processes do not normally produce large
amounts of waste sludge. This is because most solids are
consumed during residence in the aeration tank. For the
study period, August 29, 1972 through January 5, 1973, waste
biological sludge amounted to 906 kg (2,000 Ib). The plant
flow was 454 m3 (120,000 gal.) during this time. Of this
906 kg (2,000 Ib), 453 kg (1,000 Ib) was in the settled
aeration tank effluent and 453 kg was wasted to the sludge
lagoon. Wasting to the sludge lagoon occurred during one
3-week period, October 24 to November 14, 1972. This
period coincides with a trend to moderating water tempera-
tures and decreasing DO levels in the aeration tank. There
was a decrease in the influent nutrient and food levels
immediately before and during the early part of this 3-week
period. Reflecting these conditions was a drop in the
mixed liquor volatile suspended solids in the first of the
3 weeks.
The sludge blanket in the secondary settling tank rose to
the weir and increasing the return sludge rate did not lower
the blanket. In an effort to drop the sludge blanket and
improve the quality of the settling tank, periodic wasting
was initiated. This did lower the effluent suspended solids
concentration. This wasting was discontinued once an
equilibrium condition was reached.
SLUDGE DISPOSAL
Two methods of sludge disposal were considered - lagooning
and landfill. To facilitate land disposal, two methods of
solids concentration were considered; vacuum filtration and
centrifugation.
During the three weeks of sludge wasting, the waste sludge
was tested for total solids and total volatile solids.
After the sludge had been in the lagoon for 9 weeks from
the date of the last wasting, the sludge was analyzed for
total solids, total volatile solids, and grease. The com-
parison of the sludge composition is shown in Table 12.
The data indicates that lagooning does not satisfactorily
dewater the sludge.
39
-------
Table 12. COMPARISON OP WASTED AND
LAGOONED SLUDGES
Average ofLagooned sludge
wasted sludge after 2 months
Total solids, mg/L 73,000 106,000
Total volatile solids, mg/L 41,000 65,000
Grease, as percent of total
solids NDa 4.72
aND - Not Determined.
The return sludge sampling connection ruptured on one occa-
sion creating a substantial pool of sludge on the sandy
embankment around the aeration tank. This pool was 5 centi-
meters (cm) (2 in.) thick and covered 4.6 square meters (m2)
(50 sq ft). With the excellent drainage provided by the
sand, the sludge dried into a firm, dry cake in 3 to 4
weeks.
The second means of sludge disposal studied was vacuum fil-
tration. Prior to filtration, the sludge is normally
treated with a coagulant and/or a coagulant aid. This
treatment aids the filtration process by chemically causing
the solids to agglomerate into larger masses, thereby ren-
dering the liquid and solid portions more distinct.
Prior to launching a full series of Buchner Funnel Tests
and Filter Leaf Tests, a Triton apparatus was used to
screen coagulants and coagulant aids. This instrument,
produced by Electronics Limited, Essex, England, measures
the capillary suction time (C.S.T.), a relative measure of
the rate at which water is released from a sludge under
the force of gravity. A photograph of the instrument is
shown on Figure 17 and a schematic of the testing stage is
shown on Figure 18.
A sample of sludge, treated with the desired coagulant
dosage, is poured into the stainless-steel tube. The water
in the sludge drains into the filter pad. As the water
spreads outward from the tube, it contacts two electrical
sensors on the inner concentric circle, labeled 1. This
starts the timer. As the water continues to spread through
the filter pad, it contacts another sensor on the outer
40
-------
FIG. 17 TRITOIJ APPARATUS
GUIDE PLATE
FILTER PAD
SLUDGE CYLINDER
STAGE
CONTACT (2
CONTACTS (7)
FIG. 13 TESTING STAGE OF TRITON APPARATUS
-------
concentric circle, labeled 2. This stops the timer. The
time taken by the water to travel from Contact 1 to Con-
tact 2 is the C.S.T. Using this comparison of C.S.T.'s,
the coagulants, coagulant aids, and combinations thereof
which produce the lowest C.S.T.*s can be more readily
selected for use in the filter leaf test.
Table 13 compares the various coagulants and coagulant aids
used, dosages applied, and resultant C.S.T.'s. A "good"
C.S.T. is usually on the order of 10 seconds or less. The
normal dosage for most organic polymers is in the range of
0-20 mg/L, but inorganic coagulants can often be used in
the range of 1,000-20,000 mg/L or more. Often, a moderate
dosage of the inorganic coagulant plus a small dose of poly-
mer will give superior results to either type of treatment
used separately. Because of the chemical costs represented
by the dosages listed in Table 13 and the respective C.S.T.s,
further studies such as Buchner Funnel and Leaf Tests were
not conducted.
Samples of the waste sludge were also given to a major manu-
facturer of centrifuges to determine the effect of this
concentrating method prior to land disposal. Sludge cakes
were on the order of 12-1*1 percent solids with only 50 per-
cent capture efficiency. The effluent was of very poor
quality. Based on chemical costs for conditioning, it was
felt that centrifuging would not be a practical means of
dewatering the sludge.
Based on the results of the previously described tests and*
observations, sludge drying beds appear to be the most
feasible solution. Economics rule out the sludge condi-
tioning and vacuum filtration approach. Solids production
and general performance preclude centrifugatlon. Sludge
lagoons did not improve the solids content significantly.
The sludge drying on the sand did work satisfactorily,
however.
COAGULATION TESTS
With the rising effluent suspended solids concentrations in
the settled aeration tank effluent, a program of Jar tests
was initiated. It was hoped that a satisfactory coagulant
and/or coagulant aid would be found which could be added to
the mixed liquor between the aeration tank and the settling
tank to aid in removing the suspended solids.
-------
Table 13. SUMMARY OP SLUDGE CONDITIONING TESTS
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
Conditioning agent
Atlas 2A2
Atlas 2A2
Atlas 2A2
Rohm & Haas C-7
Rohm & Haas C-7
Rohm & Haas C-7
American Cyanamid Magnifloc 905N
American Cyanamid Magnifloc 905N
Magnifloc 52 1C
Magnifloc 573C
Magnifloc 575C
Magnifloc 577C
Calgon Cat-Floe B
Calgon Cat-Floe B
Calgon WT 2,660
Calgon WT 2,660
Calgon WT 2,870
Calgon WT 2,870
Fe 013
Fe 013
Fe Cl3
Alum
Alum
Alum
Lime
Lime
Lime
Lime
Lime
Fe 013
Lime
Fe 013
Lime
WT 2,870
Lime
WT 2,870
Lime
WT 2,870
Fe C13
WT 2,870
Fe C13
WT 2,870
Dos age ,
mg/L
0.2
0.6
1.0
0.2
0.6
1.0
0.6
1.0
10.0
10.0
10.0
10.0
20.0
100.0
20,0
100.0
20.0
100.0
1,000
5,000
10,000
1,000
6,000
12,000
5,000
10,000
20,000
40,000
20,000
10,000
40,000
5,000
20,000
20.0
20,000
40.0
20,000
60.0
10,000
20.0
10,000
40.0
C.S.T.,
sec
>120
>120
>120
>120
>120
>120
>120
>120
>120
>120
>120
>120
>120
>120
>120
>120
>120
>120
>120
77.6
30.4
>120
92.1
44.1
99.0
51.7
34.1
27.4
29.4
25.3
55.5
49.0
46.0
58.1
75.6
-------
Table 13 (Continued). SUMMARY OP SLUDGE
CONDITIONING TESTS
Dosage, C.S.T.,"
Conditioning agent mg/L sec
36.
37.
38.
39.
40.
41.
42.
43.
44.
Lime
Magnifloc 5 770
Lime
Magnifloc 577C
Lime
Magnifloc 577C
Lime
Hercules 814.2
Lime
Hercules 8l4.2
Lime
Magnifloc 905N
Lime
Magnifloc 905N
Lime
Rohm & Haas C-7
Lime
Rohm & Haas C-7
20,000
20.0
20,000
40.0
20,000
60.0
20,000
20.0
20,000
40.0
20,000
20.0
20,000
40.0
20,000
20.0
20,000
40.0
43.6
35.2
35.3
51.4
66.0
49.0
66.1
58.0
58.3
Using a Phipps and Bird Multiple Stirrer, mixed liquor sam-
ples were treated with various coagulants and coagulant
aids, flash mixed for 1 minute at 90 revolutions per minute
(rpm), slow mixed for 15 minutes at 20 rpm, and then allowed
to settle for 15 minutes. Table 14 lists the chemicals
tested and concentrations used.
Based on a visual comparison of floe formation, rapidity of
settling, and clarity of supernatant produced, only alum
used at a concentration of 2,000 mg/L showed any substantial
improvement over the untreated mixed liquor. It was noted
that the mixing procedures used in the testing did produce
some flocculation without the addition of any coagulant.
The zinc sulfate was used along with sodium hydroxide to
test the effectiveness of zinc hydroxide, but this also
proved unsuccessful.17 The results of the testing did not
provide any basis for adding a coagulant so this course was
not pursued further.
44
-------
Table 14. CHEMICAL AGENTS TESTED FOR IMPROVEMENT
OP SETTLED AERATION TANK EFFLUENT
Chemical Concentration, mg/L
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Alum, A12( 304)3 " l8 H2°
Calcium hydroxide, Ca (OH)2
Ferric chloride, Fe 013
Zinc sulfate, Zn SQi\ • 7 H20
Atlas, 2A2
Hercules, 814.2
Calgon, Cat -Floe B
Rohm and Haas , C-7
American cyanamid, Magnifloc 905N
Cat- Floe B
Alum
Cat-Floe B
Alum
Cat-Floe B
Alum
Cat-Floe B
Alum
0-2,000
0-500
0-400
0-500 as Zn
0-10
10
5-50
10
10
10
50
10
100
10
200
10
250
ALPHA DETERMINATIONS
In the design of an aerobic biological treatment system,
the amount of oxygen input required to maintain satisfac-
tory aerobic conditions is very important. During the
operation of the pilot plant, alpha and beta values were
determined several times. The results are summarized in
Table 15.
Table 15. SUMMARY OF ALPHA AND BETA DETERMINATIONS
Range
Alpha
Beta
0.405 -
0.814 -
0.638
0.943
Average
0.543
0.861
Since the amount of oxygen which must be supplied to an
aerobic system is inversely proportional to alpha, it can
45
-------
be seen that for decreasing values of alpha, the amount of
oxygen supplied must increase.
Normally, alpha values are in the range of 0.8 to 0.9. For
the design of our pilot plant, an alpha value of 0.75 was
considered good. Since, in actuality, the value was much
lower, it is understandable that the BOD loading had to be
decreased and the oxygen supply increased.
PRODUCTION OP POLLUTANT VS. PRODUCT
The new discharge guidelines being considered by The Envi-
ronmental Protection Agency consider the quantities of water
consumed and waste produced per unit of product. Therefore,
Table 16 was compiled to indicate the pollution load exerted
on the river following biological treatment with and without
the stabilization lagoon.
Table 16. POLLUTANT VS. PRODUCT
Kilograms of pollutant discharged
to river/1,000 kg of wool
top produceda
Pollutant
BOD
TSS
COD
Grease
TKN
NH3-N
Total P
Without
Warm
13.9
32.2
96.8
0.9
9.2
5.8
0.2
lagoon
Cold
5.6
25.4
69.3
0.9
6.6
4.9
0.2
With
Warm
8.2
2.6
46.8
0.3
4.0
2.9
0.1
lagoon
Cold
6.2
5.1
45.6
0.3
4.0
3.6
0.1
aBased on
and wool
plant wastewater flow of 852 raVday (225,000 gpd)
top production of 29,500 kg (65,000 Ib/day).
Table 17 is presented to show how hot acid cracking affects
the flow stream contributions which are biologically treated,
Prom Table 17, it can be seen that the hot acid-cracking
46
-------
process substantially reduces the load on the biological
treatment process. The reduction in suspended solids and
grease is the most significant reduction. These tables
also indicate that although the hot acid-cracking process
removes a considerable amount of the BOD, COD, suspended
solids, and grease, the nitrogen and phosphorus present in
the waste are essentially unaffected. As stated in Section
VI, however, the hot acid cracking and biological treatment
with lagooning produces a much higher quality effluent for
discharge into the river.
Table 17. KILOGRAMS OP POLLUTANT BEFORE AND AFTER
HOT ACID CRACKING
(Based on scour liquor flow = 510 m^/day
and average stream concentrations for
entire study period)
Pollutant
BOD
SS
COD
TKN
NH3-N
Total P
Grease
Raw scour
9,655
19,171
30,908
471
82
32
6,772
Hot acid-cracked scour
2,306
145
6,383
358
109
23
54
COLOR, COLIFORM AND CHLORINE DEMAND
In addition to characterizing the waste treatment effective-
ness, a major goal of the pilot plant study was to determine
guides for the design and operation of a prototype plant.
Wool-scouring waste is normally a very rich brown and requires
considerable dilution to limit the effect of this color on
the receiving body of water. The Ware River was considered
as the receiving stream. To maintain a color of 30 (American
Public Health Association (APHA) units), it was necessary to
provide a dilution factor of 800 to 1, river water to lagoon
effluent.
-------
The membrane filter test indicated that both biological
effluent streams, with and without benefit of the stabili-
zation lagoon, had total coliform levels from 10-3^0/100 ml.
These levels are from unchlorinated streams.
The chlorine demand was determined by dosing samples of the
effluent streams with 100 or 200 mg/L of chlorine and mea-
suring the residual after 20 minutes. The difference between
the dosage and residual was the chlorine demand. Both
streams produced chlorine demands from 36-158 mg/L. Based
on this wide range of demands, it would be wise to evaluate
the demand frequently. Also, since the chlorine demand is
so variable, each similar treatment system should be con-
sidered an individual and evaluated separately.
DISSOLVED SOLIDS
Because of the high dissolved solids present, the three
major flow streams in the biological treatment system were
analyzed. The results of this testing are shown in Table 18.
Notice that the sulfates comprise a major portion of the
dissolved solids. Also, the calcium is present in substan-
tial amounts. This indicates that the acidification and
neutralization contributes much of the dissolved solids.
Table 18. DISSOLVED SOLIDS COMPOSITION
Total dissolved solids, mg/L
Chloride, mg/L
Iron, mg/L
Manganese, mg/L
Sulfate, mg/L
Calcium, mg/L
Magnesium, mg/L
Aeration
tank
influent
16,330
206
78.0
3.6
7,300
950
60
Settled
aeration
tank
effluent
11,500
35.5
15.5
2.0
6,400
800
56
Lagoon
e f fluent
4,370
84.5
2.2
1.3
2,220
270
20
-------
In looking at Table 18, the question which must be answered
is how are the dissolved solids removed, not only in the
aeration process but also in the stabilization lagoon.
With respect to the aeration tank, it is possible that the
cations combine with the sulfate ion forming insoluble com-
pounds which would precipitate out in the settling tank.
In the lagoon, anaerobic conditions would allow the sul-
fate to be reduced to sulfide. In the sulfide state, the
calcium and manganese compounds of sulfide would be rela-
tively insoluble, thus precipitating out in the lagoon.
Another possibility is that during the synthesis of cell
material that occurs in the lagoon, both soluble and insolu-
ble forms are adsorbed and/or adsorbed by the cells which
then could settle in the lagoon.
SURFACTANTS
As mentioned in Section V, the nonionic detergent required
the use of the polyoxyethylene nonionic surfactants (PNS)
procedure rather than the more conventional "Methylene Blue
Active Substance" determination. A comparison of PNS dis-
charges for the various existing and proposed effluent
streams is shown in Table 19. The degree of treatment
supplied by the pilot plants approach proved superior to
the existing system with respect to the removal of nonionic
surfactants. The hot acid-cracking process performance also
is better than the present cold acid-cracking process with
respect to reducing the PNS load on the biological system.
The comparison is shown in Table 20.
Table 19. EFFLUENT STREAM PNS LEVELS
Existing acid lagoon effluent 27.0
Existing rinse lagoon effluent 6.0
Settled pilot plant aeration tank effluent 7-0
Pilot plant lagoon effluent <5-°
-------
Table 20. COMPARISON OP PNS LEVELS PROM
ACID-CRACKING PROCESSES
PNS. mg/L
Raw scour 445
Cold acid-cracked liquor 128
Hot acid-cracked liquor 71
ARSENIC
During the pilot plant study, the Commonwealth of Massachu-
setts Water Resources Commission was conducting a survey of
heavy metals in the bottom deposits of various streams.
The discharge channel from the existing acid lagoon and the
sludge from the bottom of the existing acid lagoon indicated
arsenic levels of 7.6 mg/L and 11.4 rag/L, respectively.
Based on these results, they asked for an indication of
arsenic levels in the raw wastewater. Table 21 summarizes
the results of a brief sampling program conducted at the
end of the pilot plant study. The acidified wastewater
arsenic was in a soluble form. The rinse water arsenic
was from 60-100 percent soluble.
Table 21. ARSENIC LEVELS
Arsenic, mg/L
Raw wool scour 0.5
Rinse water 0.1
Cold acid-cracked scour liquor 2.0
Effluent from existing acid lagoon 1.2
Effluent from existing rinse water
lagoon 0.04
Pilot plant mixed liquor 0.27
50
-------
Arsenic has been found to be toxic to rotifers at concen-
trations of 4 mg/L.l° Since the arsenic is in a highly
soluble state, it is most likely the result of a highly
soluble arsenic compound such as NaAs02 or Na2HAsOij being
used in a sheep-dip mixture. Although not an apparent
source of trouble, the arsenic levels should be checked
periodically in at all points in the wastewater treatment
process. Also, the groundwater arsenic levels near the
landfill sites receiving the sludge from the grease pro-
cessing should be checked since most drinking water in the
area is derived from wells.
51
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SECTION VIII
COST ESTIMATE
Based on the criteria listed in Table 22, the full-scale
hot acid-cracking plant and biological treatment facilities'
capital costs can be estimated. The cost estimate for the
hot acid-cracking plant was adjusted based on ENR Construc-
tion Index19 changes since the initial figures were done in
1969-1970. The biological facility costs were arrived at
using an estimating manual published for the Technology
Transfer Program of the United States Environmental Protec-
tion Agency^O with proper ENR adjustment.
Table 22. DESIGN CRITERIA
1. Plow 950 m3/day (250,000 gpd) (510 m3/day) to hot acid
cracking)
2. Aerators supply 1.8 kg of oxygen/kilowatt-hour (kwh)
(3 lb of oxygen/hp/hr)
3. Biological unit designed on:
a. BOD loading to aeration tank
48,8 grams/m3/day (10 lb/1,000 cf/day)
b. a = 0.51* b = 0.86
c. 20 days* aeration time
d. Clarifier overflow of 8.2 m3/m2/day (200 gpsf/day)
e. Stabilization lagoon detention 50-60 days
4. ENR Construction Index - 1900
5. Capital costs amortized over 20 years at an interest
rate of 6-3/4 percent
6. No engineering fees considered
52
-------
With conditions as previously mentioned, the capital costs
are as follows:
Hot acid-cracking plant $ 400,000
Biological plant (including aeration,
settling, stabilization, chlorination,
influent pumping, sludge pumping,
necessary appurtenances, and sludge
drying beds) 968,600
Total $1,368,600
The annual operating and maintenance (O&M) costs include
manpower, chemicals, repairs, power, fuel for steam genera-
tion, etc. For each portion of the facility, the costs are:
Hot acid cracking, O&M $ 2?4,600/yr
Biological plant, O&M l60.800/yr
Total $
Amortizing the above capital costs and adding O&M costs,
the annual expenditures can be determined:
Hot acid-cracking plant annual capital
cost $ 31,500
Hot acid-cracking annual O&M 27^,600
Subtotal $ 306,100
Biological plant annual capital cost 76,200
Biological plant annual O&M 160,800
Subtotal $ 237,000
Total $ 5^3,100
-------
SECTION IX
REFERENCES
1. Masselli, N. W. , and Burford, M. G., A Simplification
of Textile Waste Survey and Treatment, New England
Interstate Water Pollution Control Commission, Boston
(1959).
2. Esholt Sewage Works and North Bierley Sewage Works,
Sewage Department, Bradford, England (1965;.
3. Pong, W., "Nonionic Detergents in Raw-Wool Scouring
Including Studies of Waste Clarification," Proceedings
of the American Association of Textile Chemists and
Colorists (January 2b, 1959).
4. Slade, P. H., "Process Water and Textile Effluent Pro-
blems (Part 3)," The Textile Manufacturer (June 1968).
5. Wilroy, Robert D., "Industrial Wastes from Scouring
Rug Wools and the Removal of Dieldrin," Proceedings of
the llth Industrial Waste Conference, Purdue University
U95b).
6. Coburn, Stuart E., "Comparison of Methods for Treatment
of Wool Scouring Wastes," Sewage Works Journal (1949).
7. Hoare, J. L., et al., "New Zealand Wool Scouring
Liquor Treatment and Potassium Recovery," Textile
Technology Digest. 26, 12245 (1969).
8. Anonymous, "Investigation of Wool-Scouring Wastes for
the Fred Whitaker Company," Metcalf & Eddy, Inc.,
Boston.
9. Singleton, M. T., "Experiments on Anaerobic Digestion
of Wool Scouring Wastes," Sewage Works Journal (1949).
10. Latham, James K., Lyne, James A., and Miles, Charles P.,
"The Anaerobic Digestion of Wool Scouring Wastes,"
Proceedings of the 7th Industrial Waste Conference,
Purdue University (1952).
11. Buswell, A. M., and Muller, H. P., "Treatment of Wool
Wastes," Proceedings of the llth Industrial Waste
Conference, Purdue University (1956).
54
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12. Standard Methods for the Examination of Water and
Was tew at er, Thirteenth Edition American Public Health
Association, Inc., New York (1965).
13. Crabb, N. T. , and Persinger, H. E. , "The Determination
of Polyoxyethylene Nonionic Surfactants in Water at
the Parts Per Million Level," The Journal of the
American Oil Chemists' Society (November
14. Sawyer, C. N. , "Procedure for the Determination of
Oxygen Transfer Coefficients and Alpha Values,"
unpublished Metcalf & Eddy Office Memorandum.
15. Rich, L. G. , Unit Operations of Sanitary Engineering,
John Wiley and Sons, Inc., New York (19bl).
16. "Proposed Effluent Limitation Guidance for the Refuse
Act Permit Program," United States Environmental
Protection Agency (1972).
17. Saito, M. , "Treatment of Waste Waters from Washing
Wool," Kagaku Sochi. 13(1) Japan (1971).
18. McKee, J. E. , and Wolf, H. W. , Water Quality Criteria.
California State Water Quality Board, Second Edition,
Sacramento (1963).
19. Engineering News-Record, published weekly, McGraw-Hill,
New York.
20. "Estimating Costs and Manpower Requirements for Conven-
tional Wastewater Treatment Facilities," United States
Environmental Protection Agency, 17090 Dan 10/71 (1971),
55
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SECTION X
ABBREVIATIONS
ALK alkalinity
APHA American Public Health Association
BOD biochemical oxygen demand
cf cubic feet
COD chemical oxygen demand
CPVC chlorinated polyvinylchloride
GST Capillary Suction Time
deg degrees
DO dissolved oxygen
ENR Engineering News Record
F/M food-to-microorganisms ratio
ft feet
gpsf gallons per square foot
hp_ horsepower
hr hour
kg ki Hi grams
kw kilowatt
khw kilowatt-hour
m meter
mg/L milligrams per liter
mji millimicrons
O&M Operation and Maintenance
56
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NHy-N ammonia as nitrogen
NQ2-N nitrite as nitrogen
NOq-N nitrate as nitrogen
PNS polyoxyethylene nonionic surfactants
RFP reinforced fiberglass plastic
3,3 suspended solids
swd side water depth
TKN Total KJeldahl Nitrogen
TOG total organic carbon
TS total solids
VSS volatile suspended solids
4U.S. GOVERNMENT PRINTING OFFICE:1973 546-316/261 1-3
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SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
1.
w
This
Chemical/Physical and Biological
Treatment of Wool Processing Wastes
5. Ac port tiA^.e
October 1973
8.
Hatchj Lester T., Sharpin, Ronald E.,
and Wirtanen, W. T. " ,
Organization
Metcalf & Eddy, Inc.
1200. Statler Office Building
Boston, Massachusetts 02116
form .. £?rg«. . at/on
' fio.
12130 HFX
Typ- Rep- and
12*
isori:
twn
EPA
Sapp!cr& "--••; > ' :.
Environmental Protection Agency report number,
EPA-660/2-73-036, January 1974.
16.
.
Elevated temperature acid cracking combined with pilot activated
sludge and lagoon treatment were utilized to treat effluent waste-
water from a woolen processing plant. Effluent from woolen "top"
(raw wool scouring) making is very high in biochemical oxygen demand
(BOD), chemical oxygen demand (GOD), and suspended solids (SS)
(18,880 ppm, 60,600ppm,. and 37,600 ppm, respectively). The
chemical/physical system consisted of a hot acid-cracking process to
reduce the grease content in the influent to the biological system.
Average grease reductions were from 13,400 milligrams per liter (mg/L)
to 120 mg/L or 99 percent with a BOD reduction of 70 percent and
COD reduction of 80 percent. The biological system consisted of a
pilot extended aeration activated sludge unit with clarification and
retention in a pilot facultative lagoon (53 days' retention).
Typical BOD and COD reductions in the activated sludge/clarification
unit were 83 percent and 5^ percent, respectively, and in the lagoon
56 percent and 54 percent, respectively.
This report was submitted in fulfillment of Grant No. 12130HPX by
Metcalf & Eddy, Inc. under the sponsorship of the Water Quality Office
, .
PrntgGtion Agency. Wnrtf
nn f)f Onfr .
17a, Descriptors
Wastewater Treatment, Wastewater Quality Control Pollution Abatement,
Pilot Treatment Facility, Industrial Wastewater Treatment
17b. Identifiers
Wool Scouring Wastewater, Chemically/Physically Treated Grease
Removal, Biological Organic Removal, Temperature Effects.
J7c. COWRR Field & Group
IS. Availability
19. Security Class.
'Repo. 1
'). So ,-ityCi s.
(Pass)
2t, tfo. of
, 'r
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. D. C. 2O24O
Ahst^ctor Sharp-in,, TJnnalrf E.
Institution
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