United States
Environmental Protection
Agency
Municipal Environmental Research
Laboratory
Cincinnati OH 45268
EPA-600/2-78-164
September 1978
Research and Development
SEPA
Pilot Scale
of Septage Treatment
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6, Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental 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.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-78-164
September 1978
PILOT SCALE EVALUATIONS
OF
SEPTAGE TREATMENT ALTERNATIVES
by
Arthur J. Condren
Edward C. Jordan Co., Inc,
Portland, Maine 04112
Grant No. R804804-01
Project Officer
Robert P. G. Bowker
Wastewater Research Division
Municipal Environmental Research Laboratory
Cincinnati, Ohio 45268
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Municipal Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for publica-
tion. Approval does not signify that the contents necessarily reflect the
views and policies of the U.S. Environmental Protection Agency, nor does
mention of trade names or commercial products constitute endorsement or
recommendation for use.
ii
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FOREWORD
The Environmental Protection Agency was created because of increasing
public and government concern about the dangers of pollution to the health
and welfare of the American people. Noxious air, foul water, and spoiled
land are tragic testimony to the deterioration of our natural environment.
The complexity of that environment and the interplay between its components
require a concentrated and integrated attack on the problem.
Research and development is that necessary first step in problem solu-
tion and it involves defining the problem, measuring its impact, and
searching for solutions. The Municipal Environmental Research Laboratory
develops new and improved technology and systems for the prevention, treat-
ment and management of wastewater and solid and hazardous waste pollutant
discharges from municipal and community sources, for the preservation and
treatment of public drinking water supplies, and to minimize the adverse
economic, social, health, and aesthetic effects of pollution. This publica-
tion is one of the products of that research; a most vital communications
link between the researcher and the user community.
The research documented herein gives further definition to the pollu-
tant characteristics of septage, methods of physical, chemical and biological
treatment, and system designs and associated costs for effectively treating
this material at either municipal wastewater treatment plants or facilities
constructed exclusively for septage treatment.
Francis T. Mayo, Director
Municipal Environmental Research
Laboratory
iii
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ABSTRACT
This research program was undertaken to define technologies for the
treatment of septage. To facilitate this objective, a pilot plant capable
of treating up to 3.79 m /day (1,000 gpd) was constructed at the Falmouth,
Maine wastewater treatment plant.
Preliminary investigations revealed that approximately 75 percent TSS
removal could be achieved by screening raw septage. This operation yielded
a liquid fraction that could be consistently coagulated. If the septage
was not screened, effective coagulation was very difficult to realize.
Conditioning of screened septage with conventional chemicals such as
alum, ferric chloride and lime was possible. However, optimization of
chemical requirements proved to be involved. A two-stage acid/lime coagula-
tion process was developed which consistently yielded a clear supernatant
fraction approximating 70 percent of the total volume treated.
The supernatant fractions resulting from the various conditioning pro-
cesses contained mainly soluble BODc and ammonia as residual pollutants.
These acqueous fractions were ammenable to biological treatment by either
intermittent sand filtration or addition to the municipal wastewater treat-
ment plant influent.
The sludge fractions resulting from the various conditioning processes
were dewatered using various techniques. Sand bed and pressure filter
dewatering consistently yielded high TSS capture and dry sludge cakes.
Dewatering by solid bowl centrifuge or cloth belt vacuum filter led to less
desirable results. This may have been due, in part, to limitations of the
pilot scale equipment.
Combined fraction treatment was investigated by addition of screened,
neutralized septage to various components of the municipal contact stabili-
zation secondary treatment system. These included the aerobic digester,
the contact zone and the reaeration zone. Because of the current low
municipal loadings to the system no deliterious effect induced by septage
addition was noted. However, it must be pointed out that 3.79 nr (1,000
gal.) of screened septage has a BOD,- population equivalent of approximately
240 and a TSS population equivalent of about 360. The impact of introducing
such a concentrated waste stream to a given municipal facility should be
analyzed before this mode of treatment is employed.
iv
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Dewatered solids disposal by burial in a soil mantle was investigated
and it was found that the pollutant retention capabilities of different
soil mantles vary dramatically.
Septage may be effectively treated either by utilizing certain existing
equipment at municipal waatewater treatment plants or at facilities con-
structed exclusively for its treatment. Depending on the treatment process
selected and the size of the septage treatment facility installed, total
annual operating costs may range from $4 to $10/m3 ($14 to $37/ 1,000 gal.)
treated.
This report was submitted in fulfillment of Contract No. R804804-01 by
the Maine Municipal Association under the sponsorship of the U.S. Environ-
mental Protection Agency. This report covers the period October 1, 1976 to
March 31, 1978, and work was completed as of March 31, 1978.
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CONTENTS
Foreword iii
Abstract iv
Figures ix
Tables x
Acknowledgment xiii
1. Introduction 1
2. Conclusions 5
3. Description of Pilot Plant Facilities 7
4. Screening of Raw Septage 10
5. Screened Septage Conditioning 13
Sedimentation of Screened Septage 13
Aeration of Screened Septage 14
Ferric Chloride Addition 15
Ferric Chloride/Lime Addition 15
Alum Addition 18
Acid Addition 18
Acid/Lime Addition 22
Lime/Heat Addition 22
Lime/Magnesium Chloride Addition 24
6. Sludge Dewatering 26
Sand Drying Beds. 26
Centrifugation 30
Filter Pressing 31
Vacuum Filtration 32
7. Solids Fraction Disposal 35
8. Aqueous Fraction Treatment 38
Activated Carbon Adsorption 39
Chlorine Oxidation 40
Intermittent Sand Filtration 40
9. Septage Addition to Municipal Wastewater Treatment Plant . . 43
vii
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CONTENTS (Continued)
10. Discussion of Pilot Plant Results 47
Screening 47
Conditioning 47
Dewatering 49
Addition To Municipal Wastewater Treatment Plant. ... 49
Aqueous Fraction Treatment 50
Solids Fraction Disposal 51
11. System Design 52
Alternate 1: 9.48 m3/Day (2,500 gpd) Facility Exclu-
sively Designed For Septage Treatment 53
Alternate 2: Treatment of 9.48 m3/Day (2,500 gpd) Of
Septage At A Municipal Wastewater Facility 57
Alternate 3: 37.9 m3/Day (10,000 gpd) Facility Exclu-
sively Designed For Septage Treatment 60
Alternate 4: Treatment Of 37.9 m3/Day (10,000 gpd) Of
Septage At A Municipal Wastewater Facility 63
References 69
Appendix 70
viii
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FIGURES
Number Page
1 Comprehensive Septage Treatment Plan 4
2 Plan View Of Pilot Plant Facilities 8
3 Alternate 1 System Schematic 54
4 Alternate 2 System Schematic 58
5 Alternate 3 System Schematic 61
6 Alternate 4 System Schematic 65
ix
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TABLES
Number Page
1 Septage Characteristics Reported In The Literature
(1,2,3,4) 2
2 Impact of Screening On Raw Septage TSS Concentrations
Laboratory Data 10
3 Screened Septage Characteristics For This Study 11
4 Sedimentation Of Screened Raw Septage 14
5 Effect Of Aeration And Two Hours Of Settling On Screened
Septage Supernatant Characteristics .... 14
6 Ferric Chloride Addition To Raw Screened Septage (Average
Values From 12 Trials) 16
7 Lime Treatment Of Ferric Chloride Formed Supernatant
(Average Values From 10 Trials) 17
8 Ferric Chloride And Lime Treatment Of Raw Screened Septage
(Average Values From 3 Trials) 19
9 Alum Conditioning Of Raw Screened Septage (Average Values
From 18 Trials) 20
10 Acid Pretreatment Of Raw Screened Septage (Average Values
From 8 Trials) 21
11 Lime Treatment Of* Acid Formed Supernatant (Average Values
From 7 Trials) 23
12 Lime And Heat Treatment Of Raw Screened Septage 22
13 Lime And Magnesium Chloride Treatment Of Raw Screened
Septage 25
14 Sand Bed Dewatering Of Raw Screened Septage (Average Values
From 4 Trials) 26
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TABLES (Continued)
Number Page
15 Materials Balance On Sand Bed Dewatering Of Raw Screened
Septage 27
16 Sand Bed Dewatering Of Sludge From The Ferric Chloride/
Lime Conditioning Process 28
17 Materials Balance On Sand Bed Dewatering Of Sludge From
The Ferric Chloride/Lime Conditioning Process (Average
Value From 4 Trials) 28
18 Materials Balance On Sand Bed Dewatering Of Sludge From The
Alum Treatment Process (Average Values From 3 Trials) 29
19 Sand Bed Dewatering Of Sludge From The Acid/Lime Treatment
Process (Average Values From 4 Trials) 29
20 Materials Balance On Sand Bed Dewatering Of Sludge From
The Acid/Lime Treatment Process 30
21 Sludge Dewatering By Solid-Bowl Centrifugation 31
22 Sludge Dewatering With Filter Press 32
23 Vacuum Filter Dewatering Of Various Septage Conditioned
Sludges 32
24 Vacuum Filter Dewatering Of Combined Sludge 33
25 Metals In Leachate From Control Soil Columns . 35
26 Metals In Leachate From Soil/Sludge Columns 37
27 Anticipated Aqueous Fraction Quality ........... 38
28 Activated Carbon Adsorption Of Acid/Lime Supernatant ... 39
29 Activated Carbon Adsorption Of Alum Supernatant 39
30 Sodium Hypochlorite Destruction Of Ammonia 40
31 Intermittent Sand Filtration Treatment Of Neutralized Acid/
Lime Supernatant 42
32 Septage Introduced Into Contact Zone 43
xi
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TABLES (Continued)
Number Page
33 Loadings During Septage Addition To Contact Zone 44
34 Contact Zone Operational Parameters During Septage Addi-
tion 44
35 Secondary Clarifier Effluent Quality During Septage Addi-
tion To The Contact Zone 44
36 Septage Introduced Into Reaeration Zone 45
37 Reaeration Zone Operational Parameters During Septage Addi-
tion 45
38 Secondary Clarifier Effluent Quality During Septage Addi-
tion To The Rearation Zone 46
39 Estimated Chemical Costs For Conditioning 48
40 Alternate 1 Equipment List 55
41 Alternate 1 Activity Schedule 56
42 Alternate 1 Capital And Operating Costs 53
43 Alternate 2 Equipment List 59
44 Alternate 2 Capital And Operating Costs 60
45 Alternate 3 Equipment List 62
46 Alternage 3 Activity Schedule 64
47 Alternate 3 Capital And Operating Costs 63
46 Alternate 3 Activity Schedule 64
48 Alternate 4 Equipment List 66
49 Alternate 4 Activity Schedule 67
50 Alternate 4 Capital And Operating Costs 68
xii
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ACKNOWLEDGMENTS
The author wishes to acknowledge John L. Salisbury, Executive Director,
and his Maine Municipal Association staff for their project management
activities, including the formation and utilization of a project advisory
board. The role of the ten-member advisory board, which was composed of
state and local government officials and wastewater treatment plant opera-
tors, was to provide constructive criticism of the application of the
various septage treatment alternatives investigated.
Acknowledgment is also made to Mr. Frederick A. Keenan and Mr. Stephen
L. Wright, and their assistants of the Edward C. Jordan Co., Inc. for their
efforts in the conduct of, respectively, pilot plant operations and analyt-
ical services.
Special recognition is given to the Town of Falmouth, Maine for pro-
viding the site for the pilot plant studies, in-kind services, and project
assistance from Mr. David A. Whitlow, Town Manager, and Mr. Richard B.
Goodenow, Chief Treatment Plant Operator, and to the Portland Water District
of Portland, Maine for their in-kind services including supplemental sample
analyses and staff assistance from Mr. Thomas L. Lothrop, Director, Waste-
water Division, and Mr. R. Patrick Grady, Director, Quality Control.
Guidance from the Project Officer, Mr. Robert P. G. Bowker, Municipal
Environmental Research Laboratory, U.S. Environmental Protection Agency,
during the conduct of the research efforts and the preparation of this
report was greatly appreciated.
xiii
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SECTION 1
INTRODUCTION
Septage is defined as the sludge-type material which collects in on-
site wastewater disposal systems (septic tanks). The almost universal
generation and disposal of septage in rural areas has been responsible, in
part, for it not being recognized as a major pollutant source. However, it
has been estimated that the volume of this material generated annually
exceeds 15 million m3 (4 billion gal). On a dry solids basis, this is
equivalent to approximately one-third of the national secondary treatment
plant sludge production rate. Reported ranges of selected pollutant para-
meter concentrations are presented in Table 1.
Perhaps the main deterrent to the evolution of knowledge on septage
has been the rural nature of its origin. A limited amount of research on
septage treatment has been reported in the literature. Certain of these
studies have indicated positive results while others have been either
inconclusive or negative in outcome. Partially as a result of the above,
currently employed methods of septage disposal include, among others, (1)
spreading on the land; (2) lagooning; (3) discharge to municipal wastewater
treatment facilities; and/or (4) direct discharge to water courses.
The generation of septage in rural areas essentially dictates that the
treatment of this material be undertaken close to its point of origin to
minimize treatment costs. Two strategies exist for its proper treatment:
1. The utilization of local municipal wastewater treatment facilities as
a receiver for this waste, or
2. The construction of facilities exclusively for the handling of this
material.
Both of these approaches have their respective drawbacks, mainly due to
the limited state-of-the-art on septage treatment technology.
In the case of using smaller wastewater treatment plants, improperly
designed receiving facilities and/or inadequate operator knowledge can lead
to upset conditions in the entire system. For example, the discharge of
3.79 m3 (1,000 gal.) of raw septage to the influent of a 948 nT/day (250,000
gpd) extended aeration facility over a one-hour period would result in an
increased instantaneous BODij loading to the facility of about 200 percent
and an increased instantaneous TSS loading to the facility of approximately
900 percent. Such shock loadings cannot be readily absorbed by secondary
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TABLE 1. SEPTAGE CHARACTERISTICS REPORTED IN THE LITERATURE (1,2,3,4)
Parameter
TS
TVS, % of TS
SS
VSS, % of SS
BOD5
CODT
CODS
TOC
TKN
NH3-N
Total P
pH (units)
Grease
LAS
Fe
Zn
Al
Pb
Cu
Mn
Cr
Ni
Cd
Hg
As
Se
Mean
38,800
65.1
13,014
67.0
5,000
42,850
2,570(
9,930
677
157
253
6.9
9,090
157
205
49.0
48
8.4
6.4
5.02
1.07
0.90
0.71
0.28
0.16
0.076
Std. Dev.
23,700
11.3
6,020
9.3
4,570
36,950
.06 CODT)
6,990
427
120
178
(median)
6,530
45
184
40.2
61
12.7
8.3
6.25
0.64
0.59
2.17
0.79
0.18
0.074
Range
3,600-106,000
32-81
1,770-22,600
51-85
1,460-18,600
2,200-190,000
-
1,316-18,400
66-1,560
6-385
24-760
6.0-8.8
604-23,468
110-200
3-750
4.5-153
2-200
1.5-31
0.3-38
0.5-32
0.3-2.2
0.2-3.7
<.05-10.8
<. 0002-4.0
0.03-0.5
<0.02-0.3
No . Samples
25
22
15
15
13
37
21
9
37
25
37
25
17
3
37
38
9
5
19
38
12
34
24
35
12
13
All values in mg/1 unless otherwise indicated
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treatment facilities and no level of operator control can offset the delete-
rious impact resulting from such loadings.
In the case of constructing facilities exclusively for treating septage,
skepticism prevails since few systems are known to exist and to perform
consistently well.
Septage is composed of organic and inorganic pollutants, both dissolved
and suspended, in a water carrier. Total treatment of this waste can be
approached in a number of ways. A comprehensive plan for investigating
applicable septage treatment schemes either at existing wastewater treat-
ment plants or at facilities constructed exclusively for septage processing
is presented in Figure 1.
As shown on Figure 1, once septage is received at a facility, a number
of alternatives exist. The most direct, though not necessarily the most
effective alternative, is combined fraction treatment which could encompass
the addition of raw septage to the influent of a municipal wastewater
treatment plant. A more circuitous alternate could involve conditioning of
the raw septage with chemicals, allowing this conditioned septage to undergo
phase separation, and subjecting the thickened solids-bearing fraction to
further dewatering. To complete treatment, both the aqueous and the de-
watered solids-bearing fractions might have to be further treated to minimize
pollutant leaching when these fractions are ultimately disposed.
The following sections of this report define the function, approaches,
variables and problem areas associated with each of the unit operations
presented in Figure 1 as well as typical experimental results from the
conduct of various pilot plant studies. Raw data from all experimental
studies, if not presented in the text, are contained in the Appendix.
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AQUEOUS FRACTION
TREATMENT
RAW SEPTA6E
RECEIVING
STATION
PRETREATMENT
(SCREENING)
SEPTAGE
CONDITIONING
SLUDGE
DEWATERING
SLUDGE
DISPOSAL
COMBINED FRACTION
TREATMENT
FIGURE I. COMPREHENSIVE SEPTAGE TREATMENT PLAN
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SECTION 2
CONCLUSIONS
The results of laboratory and pilot scale studies on the treatment of
septage have indicated that a number of alternatives exist for effectively
reducing the gross pollution potential of this material.
Paramount to the effective application of any alternative is the
incorporation of a preliminary screening process. This process not only
provides for the continuous protection of equipment in the treatment system,
but also allows for the separation of septage into an aqueous and a sludge
fraction when coagulated by conventional chemicals. If screening is not
undertaken, consistent effective coagulation cannot be realized.
The pollutant characteristics of screened septage vary dramatically
from load to load. Average (maximum:minimum) values for 18 parameters
ranged from a low of 7:1 for iron and manganese to a high of 56:1 for
grease and oil. A mean (maximum:minimum) value of approximately 18:1 for
all parameters was noted.
Raw screened septage may be coagulated with conventional chemicals
such as ferric chloride, alum and lime. However, optimizing the chemical
dose to achieve effective phase separation is difficult. Effective phase
separation can be consistently achieved by the application of a two-stage
sulfuric acid/lime coagulation process.
The sludge fraction resulting from the coagulation of raw screened
septage can be dewatered, either alone or in combination with municipal
waste secondary sludge, by a number of processes. Sand drying bed and
filter press dewatering were found to be very effective. Vacuum filtration
and centrifugation were less effective, possibly because of limitations
associated with the equipment utilized. The application of specific de-
watering equipment at a given site should be carefully evaluated by supple-
mental testing.
The introduction of screened septage at a continuous rate to any com-
ponent of a municipal wastewater treatment facility^mav be considered if it
is recognized that 3.79 m3 (1,000 gal.) of this material has an average
BOD5 population equivalent of approximately 240 and an average TSS popula-
tion equivalent in the vicinity of 360.
The aqueous fractions resulting from the effective coagulation and
dewatering of septage contain essentially soluble BOD5 and ammonia nitrogen
-------
as residual pollutants. This aqueous fraction is ammenable to biological
treatment and may be processed by either controlled addition to a municipal
treatment plant influent or intermittent sand filtration treatment.
The ultimate disposal of dewatered septage solids may be accomplished
by, among others, burial in a soil mantle. Investigations should be under-
taken to insure the soil mantle has adequate pollutant retention capabil-
ities.
Depending on the quantity of septage processed and the mode of treat-
ment employed, total annual operating costs may range from $4 to $10/m-'
($14 to $37/1,000 gal.) of raw septage processed.
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SECTION 3
DESCRIPTION OF PILOT PLANT FACILITIES
To establish the most effective methods of septage treatment, the
physical, chemical, and/or biological transformations occurring across each
of the unit processes presented in Figure 1 should be established. To
facilitate the conduct of such measurements, a pilot scale facility capable
of processing up to 3.79 m3 (1,000 gal.) of raw septage per day was con-
structed. A schematic diagram of this facility is presented in Figure 2
and a description of each component is as follows:
1. A 30.5 cm (12-in.) diameter by 2.44 m (8 ft) high coarse screen made
of 0.64 cm (0.25 in.) opening wire mesh. The purpose of this screen
was to protect the pilot plant equipment by removing large objects
from the raw septage as it was discharged from the haulers' trucks.
2. A 4.73 m3 (1,250-gal.) raw septage receiving tank set approximately
2.44 m (8 ft) below grade to facilitate transfer of septage from the
haulers * trucks.
3. A 61.0 cm (24-in.) diameter vibrating screen equipped with a 40-mesh
screen. The purpose of this screen was to remove material which would
cause pump or pipeline plugging.
4. A 4.74 m3 (1,250 gal.) screened septage storage tank.
5. Septage conditioning tanks, each with a capacity of 1.04 m3 (275
gal.). A 186 J/sec (0.25 hp) mechanical mixer was installed in each
tank as well as air mixing equipment.
6. A 2.84 m (750 gal.) collection/storage tank for the aqueous fractions
resulting from various treatment investigations.
7. A 3.79 m3 (1,250 gal.) tank for the collection/storage of either the
solids-bearing fraction or the total volume subjected to pretreattnent
and/or other investigations.
8. A 38-190 1/min (10-50 gpm) diaphragm pump used for the transfer of
untreated and treated septage (and its fractions) throughout the
entire pilot plant.
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13d
a
I3b
00
8
18 feet
I. COARSE SCREEN
2. RAW SEPTAGE RECEIVING TANK
3. VIBRATING SCREEN
4. SCREENED SEPTAGE STORAGE TANK
5. PRETREATMENT TANKS (4)
6. AQUEOUS FRACTION STORAGE TANK
7. SLUDGE FRACTION STORAGE TANK
8. DIAPHRAGM PUMP
9. AIR BLOWER
10. INTERMITTENT SAND FILTER
II. SOIL COLUMNS (6)
12. SAND DRYING BEDS (3)
I3a. SOLID BOWL CENTRIFUGE
I3b. BASKET CENTRIFUGE
I3c. FILTER PRESS
13d. CLOTH BELT VACUUM FILTER
FIGURE 2. PLAN VIEW OF PILOT PLANT FACILITIES
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o
9. A 0.57 m /min (20 cfm) blower installed to provide air mixing, when
required, in any of the pilot plant tanks.
10. One 30.5 cm (12 in.) diameter by 91.5 cm (3 ft) deep sand column for
the investigation of intermittent sand filtration treatment of various
aqueous fractions.
11. Six 30.5 cm (12 in.) diameter by 122 cm (4 ft) deep soil columns for
the investigation of the leaching of heavy metals from dewatered
sludge solids buried in a soil mantle.
12. Three 0.93 m2 (10 ft2) by 30.5 cm (1 ft) deep sand drying beds for the
investigation of conditioned septage sludge solids dewatering.
13. A trailer equipped with the following pilot scale dewatering equipment:
a. Solid bowl centrifuge,
b. Basket centrifuge,
c. Filter press, and
d. Cloth belt vacuum filter.
The pilot plant facilities shown in Figure 2 were constructed at the
Falmouth, Maine municipal wastewater treatment plant. This plant was
designed as a dual train 6,690 m3/day (1.5 MGD) contact stabilization
plant. Each 2,840 m3/day (0.75 MGD) treatment train consists of a sludge
reaeration zone, a contact zone, a secondary clarifier and an aerobic
digester. Common facilities include the headworks, chlorine contact cham-
ber and centrifugal air blowers. The parallel treatment trains at this
location enabled the comparison of system performance when septage was
added to the individual components of one of the treatment train*.
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SECTION 4
SCREENING OF RAW SEPTAGE
Initial observations of raw septage in the laboratory showed a sub-
stantial content of large size particulate material. Included were sand,
gravel, solidified oil and grease, fruit and vegetable seeds, pieces of
plastic, rags, and hair.
A series of studies using a 20-mesh (0.84 mm opening) vibrating screen
was undertaken in the laboratory to measure the impact of preliminary
screening on the raw septage characteristics. TSS concentration was used
as the parameter for evaluation of this process and the results are pre-
sented in Table 2.
TABLE 2. IMPACT OF SCREENING ON RAW SEPTAGE TSS CONCENTRATIONS
(LABORATORY DATA)
Run No.
1
2
3
4
Average
TSS Concentration
, mg/1
Before Screening After Screening
27,300
25,000
49,200
27,200
32,200
3,280
6,860
8,930
10,400
7,370
Percent
TSS Removal
88
73
82
62
77
Screening with a 20-mesh screen in the laboratory had a pronounced
effect on the raw septage TSS concentration, resulting in an average re-
duction of 77 percent. The resultant screenings volume approximated 5 to
10 percent of the original volume and had a total solids content of 25 to
50 percent by weight.
Screening of raw septage in the field using a vibrating screen equipped
with 6-mesh (3.35 mm opening) screen led to non-functioning of the appa-
ratus. It was noted that hair would get interwoven in the screen, result-
ing in eventual complete blinding. Subsequent replacement of the screen
with one of 40-mesh size (0.42 mm opening) led to proper operation of the
vibrating screen with negligible blinding problems. Screenings volume
employing the 40-mesh (0.42 mm opening) screen approximately 7.5-37.4 1/nr
(1-5 ft->/l,000 gal-) of septage processed.
10
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The non-homogeneity of septage as received at the pilot plant facility
made it extremely difficult to obtain representative samples for accurate
analyses. Even with intense mixing (by air diffusion) in the raw septage
receiving tank, it was observed that the larger particulate matter such as
hair and solidified oil and grease had a tendency to concentrate on the
surface of the tank. As a result, thorough analyses were completed only on
raw septage that had been passed through a 40-mesh (0.42 mm opening) screen.
Table 3 presents the characteristics of screened septage encountered during
this study.
The data presented in Table 3 for the most part, are coincident with
values reported in the literature. Variations are interpreted as resulting
from the screening of the raw septage. Individual sample analyses data are
contained in the Appendix.
11
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TABLE 3. SCREENED SEPTAGE CHARACTERISTICS FOR THIS STUDY
Concentration, mg/1
Parameter
TS
TVS
TSS
VSS
pH, S.U.
BODc (total)
8005 (soluble)
COD
NH3-N, as N
Organic-N, as M
PO^ (total), as P
PO/> (ortho), as P
Alkalinity, as CaCO-j
Fe
Ni
Cd
Cu
Mn
Zn
Grease & Oil
Average
11,800
9,280
8,680
6,720
-
5,850
1,050
20,400
64
204
57
31
346
51
0.24
0.07
10.1
0.65
7.8
3,380
Minimum
2,560
1,830
2,140
1,820
2.8
1,040
315
4,530
3
64
20
8
0
18
0.05
<0.02
2.0
0.2
2.9
208
Maximum
42,100
32,600
40,200
20,700
9.8
50,000
5,450
132,000
102
549
135
100
910
120
0.42
0.2
30.0
1.4
18.0
11,600
No. of
Samples
30
30
39
39
39
39
39
30
30
30
30
30
39
11
3
5
11
11
11
15
12
-------
SECTION 5
SCREENED SEPTAGE CONDITIONING
The conditioning of septage by chemicals or other means is probably
the most important operation in an overall septage treatment program.
Physical, chemical, and/or biological transformations initiated in this
unit operation can greatly influence the results attainable from supple-
mental treatment operations.
The function of conditioning is to induce desired septage quality al-
terations including improved suspended solids settleability and sludge
dewaterability, complexation of metallic ions, precipitation of phosphorus,
initiation of biological kill, removal of ammonia and sulfide, and odor
inhibition. These alterations can be brought about by the addition of
gases, chemicals, or energy. The degree of alteration is a function of not
only the level of additives listed above, but also the type and degree of
mixing and the reaction time provided. Problem areas could include the
generation of odors or toxic compounds as well as the possibility of mutu-
ally exclusive desired quality alterations resulting from a given condition-
ing methodology. For example, the addition of chlorine could yield sub-
stantial bacterial kill, but could as well lead to the formation of toxic
chloramines.
Since most of the desired quality alterations sought were allied with
separation of the screened septage into an aqueous phase and a suspended
solids-bearing phase, the results of these as well as other conditioning
investigations are included in this section of the report.
An extensive series of studies were undertaken and the results of
these efforts are presented in the following subsections. All raw data1 are
presented in the Appendix.
SEDIMENTATION OF SCREENED SEPTAGE
Batch settling tests were undertaken to determine the degree of phase
separation achievable by plain sedimentation. Table 4 shows typical
supernatant quality following 24 and 48 hours of settling based on the
average characteristics of screened septage presented in Table 3. Indivi-
dual test data are presented in the Appendix.
13
-------
TABLE 4. SEDIMENTATION OF SCREENED RAW SEPTAGE
Supernatant Quality Following
Sedimentation For
Parameter 0 Hours 24 Hours 48 Hours
TS, mg/1
TVS, mg/1
SS, mg/1
VSS, mg/1
BOD5 (total) , mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
P04 (total), mg/1 as P
11,800
9,280
8,680
6,720
5,850
64
204
57
10,300
8,310
5,950
4,860
5,850
62
201
26
9,630
8,310
4,880
3,890
4,900
64
180
31
Plain sedimentation was partially effective in separating screened
septage into two phases. The phases, however, were not distinct because of
substantial residual turbidity remaining in the supernatant fraction.
Forty-eight hours of sedimentation resulted in the following average re-
movals: TSS - 44 percent; BOD^ - 16 percent; organic nitrogen - 12 per-
cent; and total phosphate - 45 percent.
AERATION OF SCREENED SEPTAGE
It is common practice at many municipal treatment facilities to aerate
septage for a designated period of time prior to metering it into the
plant. A series of runs were undertaken at the pilot plant level to in-
vestigate transformations induced by aeration alone. Aeration times ranged
from 16 to 96 hours. Following aeration, the septage was allowed to settle
for two hours and representative supernatant samples were collected and
analyzed. Table 5 presents the relative changes in selected parameters for
24 and 96 hours of aeration time based on average raw screened septage
characteristics.
TABLE 5. EFFECT OF AERATION AND TWO HOURS OF SETTLING
ON SCREENED SEPTAGE SUPERNATANT CHARACTERISTICS
Concentration Following Aeration For
Parameter 0 Hours 24 Hours 96 Hours
TSS, mg/1 8,680 9,550 1,480
BODs (total), mg/1 5,850 5,210 295
NH3-N, mg/1 as N 64 49 6
Organic-N, mg/1 as N 204 249 33
P04 (total), mg/1 as P 57 45 4
14
-------
Negligible changes occurred as a result of 24 hours of aeration. How-
ever, 96 hours of aeration induced a number of desired transformations
including: (1) the improvement of settling characteristics; (2) the
removal of BOD5 through biological activity and sedimentation; (3) the
removal of nitrogenous material by air stripping, bioassimilation, and
sedimentation; and (4) the removal of phosphates by bioassimilation and
sedimentation.
Although substantial partitioning was realized by four days of aera-
tion, complete phase separation was not achieved. The aqueous fraction
approximated 50 percent of the original volume treated and still contained
relatively high concentrations of, among others, TSS and 8005. However, a
distinct sludge layer could be noted in the bottom of the reaction tank.
FERRIC CHLORIDE ADDITION
Screened septage has the physical appearance of partially digested
domestic treatment plant primary sludge. Numerous chemicals can be em-
ployed to coagulate/condition such material, one of which is ferric chlo-
ride. Preliminary laboratory investigations were undertaken to define
applicable ferric chloride doses for screened septage and it was found that
400 to 600 mg/1 (as FeCl3) was required to achieve consistent desired
quality alterations. Table 6 summarizes the results of 12 studies where
400 to 600 mg/1 of ferric chloride was added to screened septage, a rapid/
slow mix reaction time of 30 minutes and 90 minutes, respectively, was
employed, and supernatant samples were collected and analyzed following 22
hours of sedimentation.
The addition of ferric chloride yielded effective coagulation of the
screened septage. However, optimization of the ferric chloride dose re-
quired that jar tests be run on each batch of raw screened septage.
Laboratory investigations indicated that if lime ,was added to the
supernatant decanted from the ferric chloride addition process the mixture
agitated for one hour and allowed to settle for 22 hours, additional pol-
lutant capture could be realized. In an attempt to obtain better phase
separation, ten pilot plant trials were undertaken to investigate this
process. Required lime dose had to be established by jar tests for each
run and ranged from 2,500 to 4,000 mg/1. Data from these trials are sum-
marized in Table 7.
The supplemental lime addition yielded a relatively high quality
supernatant. The only pollutants of concern remaining in the final super-
natant were noted as being moderate levels of TSS,,5005, and nitrogenous
compounds.
FERRIC CHLORIDE/LIME ADDITION
Following laboratory investigations, pilot plant trials using ferric
chloride and lime together were undertaken. Chemical requirements were
15
-------
TABLE 6. FERRIC CHLORIDE ADDITION TO RAW SCREENED SEPTAGE
(AVERAGE VALUES FROM 12 TRIALS)
Supernatant
Parameter
Volume , m-*
, gal
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 N
Organic-N, mg/1 N
P04 (total), mg/1 P
P04 (ortho), mg/1 P
Alkalinity, mg/1 CaCOg
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease & Oil, mg/1
Raw
Septage
0.758
200
9,790
7,990
6.0
7,980
1,080
26,100
58
233
47
29
293
54
-
-
11.0
0.66
8.9
5,000
Concen-
tration
0.455
120
271
240
5.3
664
616
1,300
53
81
<5.8
3.5
135
18
-
-
0.19
0.54
1.2
301
% of
Total
60.0
60.0
1.7
1.8
-
5.0
34.4
3.0
54.8
20.8
<7.4
7.2
-
20.0
-
-
1.0
49.1
8.1
4.4
Sludge
Concen-
tration
0.303
80
24,100
19,600
-
18,900
1,760
63,300
65.5
461
>109
67
-
-
-
-
27
0.84
20
9,800
% of
Total
40.0
40.0
98.3
98.2
-
95.0
65.6
97.0
45.2
79.2
>92.6
92.8
-
-
-
-
99.0
50.9
91.9
95.6
Experimental Conditions: FeClg dose
Rapid mix time
Slow mix time
Settling time
400 to 600 mg/1
30 minutes
90 minutes
22 hours
16
-------
TABLE 7. LIME TREATMENT OF FERRIC CHLORIDE FORMED SUPERNATANT
(AVERAGE VALUES FROM 10 TRIALS)
Parameter
Volume, nr
, gal
TSS, rng/1
VSS, mg/1
pH, S.U,
BOD5 (total), mg/1
BODs (soluble), mg/1
COD, mg/1
NH3-N, mg/1 N
Organic-N, mg/1 N
p°4 (total) mg/1 P
P04 (ortho) mg/1 P
Alkalinity, mg/1 CaCO.,
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease & Oil, mg/1
Experimental Conditions:
FeCl3
Treatment
Supernatant
0.455
120
245
215
5.3
738
712
1,310
52
112
6.6
3.8
145
18
-
-
0.19
0.54
1.2
302
Lime dose
Supernatant
Concen-
tration
0.409
108
81
28
11.8
475
432
716
41
111
1.9
1.5
1,479
0.28
-
-
<0.09
<0.1
<0.1
197
- 2,500
% of
Total
90.0
90.0
29.7
11.7
-
57.9
54.6
49.1
71.0
89.2
25.9
35.5
-
1.4
-
-
<42.6
<161.6
... <7.5
58.9
to 4,000
Sludge
Concen-
tration
0.045
12
1,720
1,900
-
3,110
3,230
6,680
513
121
49
25
-
177
-
-
>1.1
>4.5
>11
1,240
mg/1
% of
Total
10.0
10.0
70.3
88.3
-
42.1
45.4
50.9
29.0
10.8
74.1
64.5
-
98.6
-
-
>57.4
>83.4
>92.5
41.1
Rapid mix time
Slow mix time
Settling time
30 minutes
90 minutes
22 hours
17
-------
found, from jar testing, to approximate 400 mg/1 of ferric chloride and
4,000 mg/1 of lime to achieve effective coagulation of the screened sep-
tage. Three trials were conducted in the field and the average results are
presented in Table 8.
The average supernatant characteristics following 22 hours of sedi-
mentation indicated good phase separation. However, supplemental treatment
would have to be provided before final disposal of this fraction. Settling
column data for these trials are contained in the Appendix.
Once again, it was necessary to run jar tests on each batch of scre-
ened raw septage to establish the optimum chemical doses.
ALUM ADDITION
In a further attempt to coagulate screened raw septage, alum addition
was investigated. Laboratory investigations indicated that the optimum
alum dose (as A^tSO^^) was found to range from 2,250 to 8,250 mg/1,
depending on the initial septage characteristics. A total of 18 alum
addition studies were completed at the pilot scale level. The procedure
involved addition of the appropriate concentration of alum, mixing for two
hours, and allowing sedimentation to occur for 22 hours. A summary of the
average results is presented in Table 9.
As with other chemical addition studies, effective phase separation
was realized only when the optimum alum dose was applied. Adjustment of pH
seemed to have little effect on the supernatant quality. Supernatant
quality, however, was still not suitable for direct discharge and warranted
further treatment.
ACID ADDITION
Laboratory investigations indicated that when the pH of screened raw
septage was decreased to and held at a value of approximately 2.0, a
rather consistent phase separation occurred. As a result, eight pilot
scale studies were undertaken on pH adjustment. The procedure involved
adjusting and maintaining the pH of the septage at approximately 2.0 with
sulfuric acid, mixing for two hours, and allowing sedimentation to occur
for 22 hours. Table 10 summarizes the results of these studies.
Average sulfuric acid requirements ranged from 3,000 to 4,000 mg/1.
The benefit of the acid addition procedure was that a consistent phase
separation could be achieved by simple pH adjustment as opposed to running
extensive jar tests on each batch to find the optimum chemical dose to
achieve a given supernatant quality.
Column tests were undertaken to define settling times and it was found
that the minimum time for effective phase separation approximated six to
eight hours. These data are contained in the Appendix.
18
-------
TABLE 8. FERRIC CHLORIDE AND LIME TREATMENT OF RAW SCREENED SEPTAGE
(AVERAGE VALUES FROM 3 TRIALS)
Supernatant
Parameter
Volume, nr
> gal
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 N
Organic-N, mg/1 N
P04 (total), mg/1 P
P04 (ortho), mg/1 P
Alkalinity, mg/1 CaCO
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease & Oil, mg/1
Experimental Conditions:
Raw
Septage
0.758
200
9,220
7,960
5.9
4,290
897
11,300
55
172
41
25
743
47
-
-
11.7
0.3
7.6
1,550
Lime dose
Concen-
tration
0.512
135
108
88
12.1
610
495
5,480
51
85
<14
10
1,780
20
-
-
<4.9
<0.1
3.2
-
- 4,
Fed-} dose
Rapid Mix
Slow mix
Settling
time - 30
time - 90
time - 22
% of
Total
67.5
67.5
0.8
0.7
-
9.6
37.2
32.6
62.5
33.3
<23.0
27.0
-
28.7
-
-
<28.2
<22.5
28.4
'L
000 mg/1
400 mg/1
minutes
minutes
hours
Sludge
Concen-
tration
0.246
65
28,200
24,300
-
11,900
1,730
23,500
63
353
>97
56
-
-
-
-
>26
>0.7
17
-
% of
Total
32.5
32.5
99.2
99.3
-
90.4
62.8
67.4
37.5
66.7
>77.0
73.0
-
-
-
-
>71.8
>77.5
7|.6
-
19
-------
TABLE 9. ALUM CONDITIONING OF RAW SCREENED SEPTAGE
(AVERAGE VALUES FROM 18 TRIALS)
Supernatant
Parameter
3
Volume, m
, gal
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble) , mg/1
COD, mg/1
NH3-N, mg/1 N
Organic-N, mg/1 N
P04 (total), mg/1 P
P04 (ortho), mg/1 P
Alkalinity, mg/1 CaCO-j
Raw
Septage
0.694
183
13,400
10,600
6.5
5,250
1,240
13,500
61
165
51
28
217
Concen-
tration
0.474
125
183
139
4.5
293
233
407
47
22
<7
<4
161
% of
Total
68.3
68.3
0.9
0.9
-
3.8
12.8
2.1
52.6
9.1
<9.4
<9.8
-
Sludge
Concen-
tration
0.220
58
41,900
33,100
-
15,900
3,410
41,700
91
473
>146
>80
% of
Total
31.7
31.7
99.1
99.1
-
96.2
87.2
97.9
47.4
90.9
>90.6
>90.2
-
Experimental Conditions: Alum dose
Rapid mix time
Slow mix time
Settling time
2,250 to 8,250
30 minutes
90 minutes
22 hours
mg/1
20
-------
TABLE 10. ACID TREATMENT OF RAW SCREENED SEPTAGE
(AVERAGE VALUES FROM 8 TRIALS)
Supernatant
Parameter
o
Volume, m
, gal
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 N
Organic-N, mg/1 N
P04 (total), mg/1 P
P04 (ortho), mg/1 P
Alkalinity, mg/1 CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease & Oil, mg/1
Experimental Conditions:
Raw
Septage
0.758
200
8,690
7,720
6.0
5,530
1,230
10,900
68
232
43.8
22.6
302
59.7
0.17
0.08
11.9
0.87
8.5
4,720
Sulfuric
Mix time
Settling
Final pH
Concen-
tration
0.587
155
393
264
2.2
337
286
785
57
58
36
25
-
21.5
0.06
0.06
0.97
0.42
3.7
253
acid dose
time
% of
Total
77.5
77.5
3.5
2.6
-
4.7
18.1
5.6
-
19.4
63.7
85.7
-
27.9
27.3
58.2
6.3
37.4
33.7
4.1
- 3,000 to
- 2 hours
- 22 hours
- 2
Sludge
Concen-
tration
0.171
45
37,300
33,400
-
23,400
4,460
45 , 700
-
831
70.7
14.3
-
191
.55
.15
49.5
2.42
25.0
20,100
4,000 mg/1
% of
Total
22.5
22.5
96.5
97.4
-
95.3
81.9
94.4
-
80.6
36.3
14.2
-
72.1
72.6
41.8
93.7
62.6
66.3
95.9
21
-------
The impact of acid addition to screened septage on bacterial kill was
also of interest. It was found that the raw screened septage had a count
generally ranging from 4 to 6 million coliform colonies/100 ml. Upon
sulfuric acid addition to a pH of 2.0*, and allowing a reaction time of
four hours, the residual viable coliform count was consistently less than
30,000 colonies/100 ml. After 16 hours of reaction, the residual count was
less than 20 coliform colonies/100 ml.
ACID/LIME ADDITION
Neutralization of the previously discussed acid-formed supernatant
resulted in the formation of a minor precipitate. Further laboratory
investigations revealed that if lime was added to adjust the pH to approxi-
mately 11.0 and two hours of settling was provided, a very clear super-
natant evolved. Pilot scale studies were undertaken to confirm this find-
ing and the average supernatant quality from seven trials is presented in
Table 11.
Lime addition to pH 11.0* consistently yielded a very high quality
supernatant in approximately two hours.
LIME/HEAT ADDITION
Previous work on septage treatment indicated that conditioning with
lime not only enhanced dewaterability but also resulted in substantial bio-
logical kill. Laboratory studies were undertaken to expand upon this
concept by: (1) varying the screened raw septage pH with lime (and sul-
furic acid); (2) raising the temperature above ambient for a designated
period of time; and (3) measuring phase separation potential and biological
kill. Table 12 presents residual coliform counts and the phase separation
results for 16 hours of reaction time.
TABLE 12. LIME AND HEAT TREATMENT
OF RAW SCREENED SEPTAGE
Coliform Count, 10° Colonies/100 ml
Temperature, °C
PH
5
7
9
10
11
20
1.7
3.9
10.3
<0.05
35
1.6
>100
>100
X
50
0.8
<0.05
X
62
X
X
X
X
x = less the 20/100 ml
(Continued)
22
-------
TABLE 11. LIME TREATMENT OF ACID FORMED SUPERNATANT
(AVERAGE VALUES FROM 7 TRIALS)
Acid
Treatment
Parameter Supernatant
Volume , nr
» gal
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total) , mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 N
Organic-N, mg/1 N
PO^ (total), mg/1 P
POA (ortho), mg/1 P
Alkalinity, mg/1 CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease & Oil, mg/1
Experimental Conditions
0.587
155
393
264
2.2
337
286
785
57
58
36
25
-
21.5
0.06
0.06
0.97
0.42
3.7
253
s: Lime dose
Supernatant
Concen-
tration
0.523
138
69
39
11.7
419
303
650
48
30
3.1
2.1
-
0.34
0.03
0.02
0.19
0.18
0.22
219
- 3,500
% of
Total
89.0
89.0
15.6
13.2
-
-
-
73.7
75.0
46.0
7.7
7.5
1.4
44.5
29.6
17.4
38.2
5.3
77.1
to 4,500
Sludge
Concen-
tration
0.064
17
3,020
2,090
-
-
-
1,880
130
285
303
211
-
193
0.30
0.38
7.3
2.4
32
529
mg/1
% of
Total
11.0
11.0
84.4
86.8
-
-
-
26.3
25.0
54.0
92.3
92.5
-
98.6
55.5
70.4
82.6
61.8
94.7
22.9
Mix time T 30 minutes
Settling time - 2 hours
Final pH - 11.7
23
-------
TABLE 12. (Continued)
Sludge Volume, % of Total
Temperature, °C
pH 20 35 50 62
5
7
9
10
11
100
95
80
~
80
100
95
80
--
65
65
50
30
100
65
50
30
The pH-temperature interaction had an impact on biological population
as measured by total coliform count. Depending on pH and temperature,
coliform growth or kill could result. For example, at a pH of 9 and a
temperature of 35*C profound growth occurred while at a comparable pH and a
temperature of 62°C, residual total coliform count was less than 20 col-
onies/100 ml.
The pH-temperature interaction also had a definite impact on separa-
tion of the septage into two phases, with better separation being realized
with both elevated pH and temperature. Initial TSS was approximately 5,500
mg/1 and in those cases where a supernatant fraction developed, the super-
natant TSS concentration ranged from approximately 100 to 200 mg/1.
LIME/MAGNESIUM CHLORIDE ADDITION
It is known that lime, in conjunction with magnesium salts, can yield
effective coagulation of suspended material. Laboratory studies on this
combination were carried out and the results are presented in Table 13.
The above sludge volumes and supernatant qualities resulted following
six hours of quiescent'phase separation. Lime, in conjunction with mag-
nesium salts, yielded a high quality supernatant. However, the magnesium
salt concentration required to obtain such a quality was approximately
5,000 mg/1 of MgCl2'6H20.
-------
TABLE 13. LIME AND MAGNESIUM CHLORIDE TREATMENT
OF RAW SCREENED SEPTAGE
Temperature Chemical Dose, mg/1 Sludge Volume, Supernatant
C° Ca(OH)2 Mg++ % of Total TSSt mg/1
25 00 100 4,260
25 4,000 100 66 680
25 4,000 200 67 450
25 4,000 300 68 230
25 4,000 400 65 5
60 00 100 5,340
60 4,000 0 33 130
60 4,000 200 33 120
60 4,000 400 33 90
60 4,000 600 33 5
60 4,000 1,000 33 5
25
-------
SECTION 6
SLUDGE DEWATERING
Screened septage conditioning processes were shown to be capable of
separating 3.79 m3 (1,000 gal) of this material into approximately 2.27 to
2.65 ra3 (600-700 gal) of supernatant and 1.14 to 1.52 m3 (300-400 gal) of
sludge. Average total solids concentration of this sludge was in the
vicinity of 3.0 to 3.5 percent. At this consistency, further dewatering is
desirable to enable easier handling for ultimate disposal purposes. A
mathematical analysis has indicated that if this sludge fraction is further
dewatered to obtain a consistency of 25 percent, the final sludge volume
would approximate 0.15 to 0.19 m^ (40-50 gal).
In an attempt to achieve a solids cake of up to 25 percent, a number
of pilot scale studies were undertaken. Included were the utilization of
sand drying beds, a solid-bowl centrifuge, a filter press, and a cloth belt
vacuum filter. The following subsections present the results of these
dewatering studies.
SAND DRYING BEDS
Three sand drying beds, each with an area of 0.93 m2 (10 ft2) and a
sand depth of 30.5 cm (12 in) were constructed. The sand employed had an
effective size of 0.54 mm and a uniformity coefficient of 1.85. Septage
sludges resulting from the various conditioning processes were applied and
filtrate volumes and quality, with respect to drainage time, were noted.
As a preliminary study, 0.18 m3 (48 gal) batches raw screened septage
were placed on the beds in 20 cm (7.75 in) lifts. Table 14 presents the
average characteristics of the raw septage and the supernatant resulting
from one and two days of drainage time for four trials.
TABLE 14. SAND BED DEWATERING OF RAW SCREENED SEPTAGE
(AVERAGE VALUES FROM 4 TRIALS)
Parameter
Volume, m3
» gal
Raw
Septage
0.182
48.0
(Continued)
Average Filtrate On
Day 1
0.114
30.0
Day 2
0.045
12.0
26
-------
TABLE 14. (Continued)
Parameter
TS, mg/1
TVS, mg/1
SS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble),
mg/1
Alkalinity, mg/1
as CaC03
GST, sec
Raw
Septage
10,200
7,490
7,700
6,240
5.8
5,670
1,710
539
141
Average Filtrate On
Day 1
1,840
1,350
418
375
6.4
1,288
1,003
300
Day 2
1,080
750
70
70
6.9
650
615
331
A materials balance on the utilization of sand drying beds for dewater-
ing screened raw septage, employing a total drainage time of two days was
undertaken and the results are presented in Table 15.
TABLE 15. MATERIALS BALANCE ON SAND BED
DEWATERING OF RAW SCREENED SEPTAGE
Filtrate Fraction
Parameter
Volume, m^
, gal
TS, mg/1
TVS, mg/1
SS, mg/1
VSS, mg/1
BOD5 (total),
mg/1
BOD5 (soluble),
mg/1
CST, sec
Raw
Septage
0.182
48
10,200
7,490
7,700
6,240
5,670
1,710
141
Concen-
tration
0.159
42
1,630
1,180
319
288
1,110
892
% of
Total
87.5
87.5
13.9
13.7
3.6
4.0
17.1
45.6
Sludge Fraction
Concen-
tration
0.023
6
70,200
51,600
59,300
47,900
37,600
7,440
% of
Total
12.5
12.5
86.1
86.3
96.4
96.0
82.9
54.4
With a drainage time of two days, a 5.9 percent solids cake developed
(TSS basis). Filtrate quality was indicative of the passage of substantial
colloidal material through the sand drying bed.
27
-------
Sludge from the ferric chloride/lime conditioning process was next
investigated. Average sludge and filtrate characteristics based on four
trials, with respect to time, are given in Table 16.
TABLE 16. SAND BED DEWATERING OF SLUDGE FROM THE
FERRIC CHLORIDE/LIME CONDITIONING PROCESS
Parameter
Volume, m3
, gal
TSS, mg/1
VSS, mg/1
BODs (total), mg/1
BOD5 (soluble), mg/1
CST, sec
FeCl3
Sludge
0.182
48.0
21,000
11,000
9,250
2,410
23
Average
Day 1
0.109
28.8
39
19
931
886
Filtrate On
Day 2
0.036
9.6
66
33
1,230
920
A materials balance on the above ferric chloride/lime sludge was
undertaken and the results are presented in Table 17.
TABLE 17. MATERIALS BALANCE ON SAND BED DEWATERING OF SLUDGE FROM
THE FERRIC CHLORIDE/LIME CONDITIONING PROCESS
(AVERAGE VALUE FROM 4 TRIALS)
Filtrate
Parameter
Volume, m^
, gal
TSS, mg/1
VSS, mg/1
BODs (total),
mg/1
BODs (soluble),
mg/1
FeC 13
Sludge
0.182
48.0
21,000
11,000
9,250
2,410
Concen-
tration
0.146
38.4
46
23
1,010
895
% of
Total
80.0
80.0
0.2
0.2
8.7
29.7
Sludge
Concen-
tration
0.036
9.6
105,000
54,900
42,200
8,490
% of
Total
20.0
20.0
99.8
99.8
91.3
70.3
Ferric chloride/lime conditioning substantially improved the filtrate
quality over that resulting by sand drying bed treatment of raw screened
septage alone. In addition, the cake solids increased from 5.9 for the raw
screened septage to 10.5 percent for the ferric chloride/lime sludge.
28
-------
Application of alum treated septage solids to the sand drying beds
yielded a high quality supernatant and a 15.3 percent cake after only one
day of drainage. The materials balance for alum sludge is presented in
Table 18.
TABLE 18. MATERIALS BALANCE ON SAND BED DEWATERING OF
SLUDGE FROM THE ALUM TREATMENT PROCESS
(AVERAGE VALUES FROM 3 TRIALS)
Filtrate
Parameter
Volume, m3
» gal
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble),
mg/1
CST, sec.
Alum
Sludge
0.182
48.0
30,600
25,500
4.0
10,200
1,180
12
Concen-
tration
0.146
38.4
79
29
5.1
240
220
% of
Total
80.0
80.0
0.2
0.1
-
1.9
14.9
Sludge
Concen-
tration
0.036
9.6
153,000
127,000
-
50,200
5,020
% of
Total
20.0
20.0
99.8
99.9
_
98.1
85.1
Sand drying bed treatment of sludge resulting from the acid/lime
treatment process also led to very positive results. Table 19 presents
average sludge and filtrate characteristics, with respect to time, for the
acid/lime produced sludge from four trials.
TABLE 19. SAND BED DEWATERING OF SLUDGE FROM
THE ACID/LIME TREATMENT PROCESS *
(AVERAGE VALUES FROM 4 TRIALS)
Parameter
Acid/Lime
Sludge
Average Filtrate On
Day 1
Day 2
Volume, m3 0.182
, gal 48.0
SS, mg/1 21,100
VSS, mg/1 13,400
pH, S.U. 8.2
BOD5 (total), mg/1 19,600
BOD5 (soluble), mg/1 1,750
P04 (total), mg/1 as P 59
0.109
28.8
54
51
6.8
695
647
2
0.057
15.0
51
27
6.7
484
442
2
29
-------
A materials balance following two day's drainage yielded the data pre-
sented in Table 20.
TABLE 20. MATERIALS BALANCE ON SAND BED DEWATERING OF
SLUDGE FROM THE ACID/LIME TREATMENT PROCESS
Filtrate
Parameter
Volume, m3
, gal
TSS, mg/1
VSS, mg/1
BOD5 (total) ,
mg/1
BOD5 (soluble),
mg/1
P04 (total),
mg/1 as P
Acid/Lime
Sludge
0.182
48.0
21,100
13,400
19,600
1,750
59
Concen-
tration
0.166
43.8
53
43
622
576
2
% of
Total
91.0
91.0
0.2
0.2
2.9
30.0
3.1
Sludge
Concen-
tration
0.016
4.2
241,000
153,000
217,000
14,000
653
% of
Total
9.0
9.0
99.8
99.8
97.1
70.0
96.9
Average filtrate quality was excellent, except for residual 8005, and
a cake solids of 24.1 percent was realized.
Subsequent studies involving the three different sludges from the
chemical conditioning processes were undertaken and involved multiple
applications of these sludges to the same drying beds. Following the
application of 0.18 m3 (48 gal) of sludge to a given bed, two days of
drainage was given before the application of an additional 0.18 m^ (48 gal)
of chemical sludge on top of the existing cake. Two more days of drainage
were allowed before the application of a third 0.18 m3 (48 gal) batch of
sludge. Following three days of supplemental drainage, cake consistencies
approximated those listed in Tables 17, 18, and 20. In all cases, a ter-
minal drainage time of five days yielded cakes that had dried to the extent
that natural cracking of the mat occurred.
CENTRIFUGATION
Included in the sludge dewatering trailer loaned to the research
project by the U. S. Environmental Protection Agency were a solid bowl and
a basket centrifuge. The basket centrifuge was inoperative during the
entire conduct of the studies and, therefore, efforts were exclusively on
the solid bowl centrifuge.
In total, approximately 60 trials were undertaken on the solid bowl
centrifuge. Pond depth was varied during the course of the studies and it
30
-------
was found ,that optimum results were achieved at a median pool depth setting
(#3). Design flow rate to this unit was in the range of 4 to 11 1/min (1
to 3 gpm), and most studies were conducted at the minimum feed rate. Feed
to this unit was sludge resulting from ferric chloride/lime conditioning,
alum conditioning, acid/lime conditioning, and a 90/10 (volume percent)
mixture of aerobically digested secondary sludge from the Falmouth treat-
ment plant and acid/lime conditioned septage sludge. Supplemental condi-
tioning, established by laboratory evaluations, included the utilization of
cationic or anionic polymers depending on the feed material to the centri-
fuge. In most cases, the dewatering performance of the centrifuge using no
supplemental conditioning was not acceptable, even at an influent flow rate
of 3.8 1/min (1.0 gpm). Table 21 presents the results of the most positive
runs achieved at the minimum possible flow rate of 3.8 1/min (1.0 gpm)
using no polymer addition.
TABLE 21. SLUDGE DEWATERING BY SOLID-BOWL CENTRIFUGATION
TSS,
Feed Source Influent
Ferric Chloride/Lime
Septage Sludge 31,000
Alum Septage Sludge 33,000
Acid/Lime Septage Sludge 30,700
90/10 Mixture Sludge 23,400
rnp/1
Centrate
3,970
14,000
17,600
18,400
Cake,
% Solids
16.5
20.6
23.0
20.0
% Capture
of TSS
90.5
62.4
45.0
25.7
The centrifuge was so constructed that polymer addition could only be
to the influent flow and not part way down the bowl. Addition of polymer
at this point in the system led to equivalent or less desirable results
than those presented in Table 21. It is felt that if polymer could have
been introduced part way down the bowl, enhanced solids capture would have
been realized.
FILTER PRESSING
The EPA sludge dewatering trailer was also equipped with a 0.046 m2
(0.5 ft2) filter press. Sludge is introduced to the press using a pro-
gressive cavity pump. When pump pressure reaches 10.5 kg/cm2 (150 psi),
the pump is shut off and air pressure incrementally applied to 10.5 kg/cm2
(150 psi). The air pressure is employed to decrease the moisture content
of the filter cake.
As in the centrifugation studies, ferric chloride/lime, alum, and
acid/lime septage sludges from their respective conditioning processes as
well as a 90/10 (volume percent) mixture of aerobically digested secondary
sludge and septage sludge from the acid/lime conditioning process were
investigated.
31
-------
Initial trials indicated no supplemental conditioning of these sludges
was required. Table 22 presents the experimental results derived from the
filter press studies.
TABLE 22. SLUDGE DEWATERING WITH FILTER PRESS
Feed
Source
TSS,
Influent
mg/1
Filtrate
%
Solids
Cake
Thickness,
mm (in)
%
Capture
of TSS
Ferric Chloride/Lime
Septage Sludge
Alum Septage Sludge
Acid/Lime Septage Sludge
90/10 Mixture Sludge
31,
33,
30,
27,
000
000
700
000
38
14
3
6
50.
55.
26.
45.
1
0
0
7
6.
12.
12.
6.
35
70
70
35
(0.
(0.
(0.
(0.
25)
50)
50)
25)
99
99
99
99
.91
.99+
.99+
.99+
In all cases, filter press dewatering worked very well, yielding a
high filter cake solids content and a filtrate low in TSS. Run times
approximated 45 minutes, 12 to 15 minutes required for sludge pumping and
25 to 30 minutes required for drying with air pressurization.
VACUUM FILTRATION
The pilot scale cloth belt vacuum filter in the EPA sludge dewatering
trailer had a diameter of 0.92 m (3.0 ft) and a drum length of 0.46 m (1.5
ft). Drum speed could be varied from 1.5 to 16 minutes/revolution and
vacuum could be varied between 127-559 mm (5-22 in) of mercury.
Septage sludges from the various conditioning processes were subjected
to dewatering. Preliminary laboratory investigations utilizing capillary
suction time measurements as well as filter leaf testing revealed that: 1)
polymer addition generally would not assist dewaterability; 2) applied
vacuum should be 381 mm (15 in) mercury; and 3) a drum speed of 16 minutes
per revolution should be employed. Five runs were made on each sludge and
typical results are presented in Table 23.
TABLE 23. VACUUM FILTER DEWATERING OF VARIOUS
SEPTAGE CONDITIONED SLUDGES
TSS. mg/1Cake Yield
% Thickness, kg/mz/hr
Feed Source Influent Filtrate Solids mm (in) Ib/ft2/hr)
Ferric Chloride/
Lime Septage Sludge 22,200 117 35.0 1.59 (0.06) 2.44 (0.5)
(Continued)
32
-------
TABLE 23. (Continued)
~TSS, mg/1 Cake Yield
% Thickness, kg/nr/hr
Feed Source Influent Filtrate Solids mm (in) (Ib/ft2/hr)
Alum Septage Sludge 33,000 80 28.0 1.59 (0.06) 1.95 (0.4)
Alum Septage Sludge
(1) 33,000 56 27.0 6.35 (0.25) 7.33 (1.5)
Acid/Lime Septage
Sludge 30,700 44 27.0 3.18 (0.13) 3.91 (0.8)
(1) Conditioned with 2,000 mg/1 lime and 25 mg/1 of anionic polymer.
In general, cake release from the filter cloth was good for both the
ferric chloride/lime and the acid/lime septage sludges. Alum septage
sludge would release only if it was conditioned with both lime and polymer.
Vacuum filtration of a 90/10 (volume percent) mixture of aerobically
digested secondary sludge and septage sludge from the acid/lime condi-
tioning process was also investigated. Preliminary laboratory investiga-
tions were undertaken to establish supplemental conditioning requirements.
Approximately twenty trial runs were undertaken on the pilot scale vacuum
filter and typical results are presented in Table 24.
TABLE 24. VACUUM FILTER DEWATERING OF COMBINED SLUDGE
Trial
A
C
E
H
Conditioning*
None
15 mg/1 anionic
polymer
800 mg/1 FeClo
4,000 mg/1 Ca(OH)2
10 mg/1 anionic
polymer
2,000 mg/1 FeCl3
8,000 mg/1 Ca(OH)2
160 mg/1 cationic
polymer
TSS, mg/1 Cake
Influent Filtrate % Solids
29,000 49 13.9
46,000 20 24.0
24,000 87 17.8
26,000 200 13.0
(Continued)
33
Yield
kg/m2/hr
(Ib/ft2/hr)
1.95 (0.4)
3.42 (0.7)
2.44 (0.5)
1.47 (0.3)
-------
TABLE 24. (Continued)
Yield
TSS. me/1 Cake kg/m*7hr
Trial Conditioning* Influent Filtrate % Solids (Ib/ft2/hr)
I 2,000 mg/1 alum 17,000 190 9.3 0.98 (0.2)
pH adjusted to 6.3
M 2,000 mg/1 alum 28,000 84 16.0 1.95 (0.4)
15 mg/1 anionic
polymer
*Conc. of condition^ chemical x 2,000 » conditioning dose, Ib/ton
Influent TSS Concentration
*lb/ton x 0.501 - kg/t
Cake thickness for all runs was approximately 3.17 mm (0.13 in) and in
essentially all trials, the release of the cake from the cloth was not
complete. Combinations of supplemental conditioning agents could not be
found to either enhance cake release or filter yield.
Supplemental trials on 90/10 (volume percent) mixtures of aerobically
digested waste secondary sludge and screened raw septage were also under-
taken. Even under massive chemical conditioning, cake release was poor and
vacuum filter yield was mediocre, approximating those values presented in
Table 24.
34
-------
SECTION 7
SOLIDS FRACTION DISPOSAL
Once septage solids have been dewatered, they must be ultimately dis-
posed. The most common practice is burial in a soil mantle. Questions
have existed on the release of pollutants from dewatered septage solids
disposed of in this manner. To investigate this potential problem, 30.5 cm
(12 in) diameter by 1.07 m (3.5 ft) deep soil columns were constructed,
dewatered sludge solids buried in them, and the equivalent of 2.54 cm (1.0
in) of rain deposited on the soil surface each day. Leachate was collected
and analyzed for selected heavy metals.
Three typical soil mantles found in the State of Maine were used in
these studies. Paxton soil is a well-drained, fine sandy loam glacial
till. This soil, when found in situ, has a compacted layer of material at
a depth of about 0.61 m (2.0 ft) below ground elevation which hinders the
downward movement of water through the soil mantle. Windsor soil is very
well drained outwash derived loamy sand. The texture of this soil is
coarser than a convential glacial till. The third soil used was a Canton
soil. Canton soils are a well drained glacial till usually found on hills
and ridges.
Control columns were set up with no sludge in them. Leachate was col-
lected from the three control columns and the average concentrations of
various heavy metals found over a nine-week period were as presented in
Table 25.
TABLE 25. METALS IN LEACHATE FROM CONTROL SOIL COLUMNS
Soil Type
Paxton
Windsor
Canton
pH, S.U.
7.8
7.4
7.4
Fe, mg/1
<0.01
<0.01
<0.01
PARAMETER
Cu, mg/1
<0.01
<0.01
0.02
Mn, rag/I
0.05
0.03
0.07
Zn, mg/1
0.03
0.03
0.01
35
-------
In general, very low concentrations of metals leached from the three control
soil columns.
Dewatered septage solids from the acid conditioning process was the
material placed in the three soil columns under investigation. The de-
watered solids were approximately 25 percent solids by weight and had a pH
of 2.5. These solids were selected to measure metals retention by the soil
as opposed to metals retention by insoluble matrix formations at elevated
pH's. Approximately 76 cm (30 in) of soil was placed in the bottom of each
column, followed by a 15 cm (6 in) thick layer of dewatered sludge, and
capped with 31 cm (12 in) more of soil.
Leachate from each soil column was collected and analyzed. The re-
sults of the analyses are presented in Table 26. Values presented in this
table reflect changes in concentrations that occurred over a nine-week
period and the values are corrected for the leachate concentrations found
in the control columns.
The Paxton soil effectively retained all metals measured except man-
ganese. Average pH of the leachate from this column was 7.7 compared to
the control value of 7.8. The Windsor soil retained only copper, with
iron, manganese, and zinc concentrations in the leachate substantially
above the control. Average leachate pH from this column was 7.3 or 0.1
S.U. less than the control. The Canton soil similarly retained only
copper well. The pH of the leachate from this column decreased to 7.0
compared to 7.4 for the control.
36
-------
TABLE 26. METALS IN LEACHATE FROM
SOIL/SLUDGE COLUMNS
Paxton Soil
Concentration, mg/1
Week
2
3
4
5
6
7
8
9
Fe
0.01
0.01
0.01
0.01
0.01
0.01
0.10
0.07
Cu
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
Windsor
Mn
0.01
0.01
0.01
0.03
0.65
0.59
0.33
0.23
Soil
Zn
0.01
0.01
0.01
<0.01
<0.01
<0.01
<0.01
<0.01
Concentration, mg/1
Week
2
3
4
5
6
7
8
9
Fe
0.28
3.6
13.5
21
26
20
22
18
Cu
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
Canton
Mn
0.20
0.01
0.01
35
28
-
20
13
Soil
Zn
0.01
0.01
0.01
0.07
0.11
0.18
0.17
0.12
Concentration, mg/1
Week
2
3
4
5
6
7
8
9
Fe
0.01
0.01
0.01
0.7
0.6
0.5
0.7
0.7
Cu
0.01
0.01
0.01
<0.01
<0.01
0.01
<0.01
<0.01
Mn
0.17
0.09
0.15
6.5
3.2
2.8
2.1
1.9
Zn
0.01
0.01
0.01
0.26
0.34
0.33
0.67
0.91
37
-------
SECTION 8
AQUEOUS FRACTION TREATMENT
With proper conditioning and/or dewatering of screened septage, a
relatively good quality aqueous fraction should result. Typical charac-
teristics of such an aqueous fraction have been estimated and are presented
in Table 27.
TABLE 27. ANTICIPATED AQUEOUS FRACTION QUALITY
Parameter
Range of Concentrations
TSS, mg/1
BOD5 (total), mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
P04 (total), mg/1 as P
Metals, mg/1
pH, S.U.
25
300
50
25
0
5
- 100
- 500
- 100
- 50
- 2
1.0
- 11
Wastewater of such quality is not suitable for direct discharge and
thus must receive supplemental treatment. Possible treatment alternatives
include: (1) addition to the influent of a municipal treatment plant; (2)
chemical oxidation by ozone or chlorine; (3) activated carbon adsorbtion;
(4) spray irrigation/land disposal; (5) intermittent sand filtration;
and/or (6) combinations of the above.
Influent addition of the aqueous fraction was not investigated because
resultant pilot plant volumes available were insignificant compared to the
Falmouth treatment plant flow. Chemical oxidation by ozone was not under-
taken because no ozone generator was available. Spray irrigation/ land
disposal was not pursued because of the complexity in monitoring the per-
formance of such systems.
Several alternatives were investigated at the laboratory/pilot plant
level: activated carbon adsorption, chemical oxidation with chlorine, and
intermittent sand filtration. The following subsections summarize the
results of these investigations.
38
-------
ACTIVATED CARBON ADSORPTION
In an attempt to achieve supplemental pollutant removal from aqueous
fractions, several activated carbon adsorption studies were conducted in
the laboratory.
The first study was run on filtered supernatant from the acid/lime
addition process which had been neutrailized to a pH of 7 with sulfuric
acid. Powdered activated carbon and a contact time of 24 hours was used in
this study. The results are presented in Table 28.
TABLE 28. ACTIVATED CARBON ADSORPTION
OF ACID/LIME SUPERNATANT
Activated Carbon TOC,
Dose, mg/1
0 930
600 920
800 900
2,000 850
20,000 830
Because of the very low levels of organic carbon adsorbed per gram of
activated carbon added, further studies were discontinued.
A similar study using neutralized filtered supernatant from the alum
addition conditioning process was undertaken. The results are presented in
Table 29
TABLE 29. ACTIVATED CARBON ADSORPTION
OF ALUM SUPERNATANT
Activated CarbonTOC,
Dose, mg/1 mg/1
0 730
1,000 720
2,000 660
5,000 620
50,000 520
39
-------
Once again, calculations yielded extremely low adsorption values and thus
further investigative efforts were discontinued.
CHLORINE OXIDATION
As previously noted, one of the pollutants remaining in the aqueous
fraction following coagulation was ammonia. In the case of the supernatant
from the acid addition process, the pH was in the vicinity of 2 and thus
presented a case for destruction of ammonia via acidic chlorination.
A series of laboratory studies was undertaken to define the chlorine
dose required for ammonia destruction. Table 30 presents typical results
of these ammonia destruction studies using sodium hypochlorite.
TABLE 30. SODIUM HYPOCHLORITE DESTRUCTION
OF AMMONIA
NaOCl Dose, Residual
mg/1 Ammonia, mg/1 as N
0 90
2,500 51
5,000 5.8
7,500 <0.2
10,000 <0.2
The data indicate that ammonia, as measured by a specific ion
probe, is readily destroyed by the addition of sodium hypochlorite under
acidic conditions. However, the required sodium hypochlorite dose was
relatively high. In the example cited above, the requirement approximated
6.59 kg/m3 (55 lb/1,000 gal).
INTERMITTENT SAND FILTRATION
In cold climates, the pumping of septic tanks is usually a seasonal
activity, with most tanks being pumped in either the spring, summer or
early fall. In addition, most haulers do not pump seven days a week
during this period. This makes consistent treatment of the aqueous frac-
tion of septage difficult If a biological process is to be employed at a
facility designed exclusively for the treatment of septage.
One biological treatment process held potential for application under
such potentially erratic organic loading conditions. This process is
intermittent sand filtration. A 30.5 cm (12 in) diameter intermittent sand
40
-------
filter column was constructed and filled with 91.4 cm (3.0 ft) of sand.
Characteristics of the sand included a uniformity coefficient of 1.85 and
an effective size of 0.54 mm.
To establish a biopopulation in the columns, 18.9 1 (5.0 gal)of un-
chlorinated secondary effluent from the Falmouth treatment plant was passed
through the columns. Following this irinoculation, the columns were dosed
at a rate of 1,400 m3/ha (150,000 gal/acre) approximately every other day.
Feed to the columns was supernatant from the acid/lime addition process
which had been neutralized to a pH in the range of 6 to 8. The results of
intermittent sand filtration studies are presented in Table 31.
Average BOD^ loading to the intermittent sand filter was 650 kg/ha
(580 Ib/acre) per loading cycle. At this loading, a 53 percent BOD5
removal was achieved. Of interest is the high level of ammonia destruction
achieved by the process, averaging 76 percent removal.
The effluent quality from the intermittent sand filtration process,
though not truly acceptable for direct discharge, was of relatively high
quality. It is felt that an effluent suitable for direct discharge could
be realized if the organic loading to such a system were decreased. This
should be confirmed by supplemental testing.
41
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TABLE 31. INTERMITTENT SAND FILTRATION TREATMENT OF
NEUTRALIZED ACID/LIME SUPERNATANT
Day
1
3
5
7
10
13
18
20
22
28
32
34
37
39
44
46
48
51
53
58
AVG.
pH,
Inf
7.0
7.0
7.2
6.8
6.4
7.2
6.2
5.0
6.8
6.5
11.4
6.5
5.7
6.3
6.4
6.8
5.1
6.9
5.3
5.2
6.6
S.U.
Eff
7.0
7.4
7.5
7.0
7.4
6.8
7.0
7.0
7.6
7.3
7.9
7.5
7.5
7.2
7.4
7.3
7.3
7.3
7.0
7.4
7.3
Total BOD^
Inf
400
400
950
720
840
630
390
510
310
300
390
460
480
690
135
375
465
420
270
180
465
. rag/1
EFF
230
370
420
360
470
330
180
180
140
140
90
140
230
330
115
160
230
170
130
30
220
TSS,
Inf
56
56
7
9
10
20
61
66
103
18
25
41
53
28
84
38
31
72
65
58
45
mg/1
Eff
70
34
33
18
31
26
30
38
45
21
46
22
21
23
30
40
32
24
19
20
31
NHo-N.mK/l as N
Inf
100
100
100
76
82
86
72
28
48
52
48
50
64
73
62
74
64
99
88
66
72
Eff
15
39
46
24
31
27
34
1
10
3
2
2
2
12
13
13
9
16
19
18
17
42
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SECTION 9
SEPTAGE ADDITION TO MUNICIPAL WASTEWATER TREATMENT PLANT
Each of the two treatment trains at the Falmouth water pollution
control facility is composed of a 246 nr (65,000 gal) contact zone, a 108
m2 (1,160 ft2) secondary clarifier, a 625 m3 (165,000 gal) reaeration zone,
and a 246 m3 (65,000 gal) aerobic digester. At the design flow of 5,690
m3/day (1.5 mgd), each treatment train should have a 8005 loading of
approximately 590 kg/day (1,300 Ib/day). Currently, the dry weather flow
to each treatment unit approximates 569-758 mj/day (0.15-0.20 mgd), the
BOD5 loading, 79.5 kg/day (175 Ib/day), and the TSS loading 56.8 kg/day
(125 Ib/day).
For a one-week period, 5.69 m3/day (1,500 gpd) of raw screened septage
was introduced into the contact zone of one of the treatment trains. The
average characteristics of the septage are presented in Table 32.
TABLE 32. SEPTAGE INTRODUCED INTO CONTACT ZONE
Parameter Concentration
Volume 5.69 m3/d
1,500 gpd
TSS 3,965 mg/1
VSS 3,285 mg/1
v Wfc* f ~^y* ^
BOD5 (total) 2,657 mg/1
BOD5 (soluble) 547 mg/1
pH 6.5 S.U.
NH3-N, as N 65 mg/1
The above septage was introduced to treatment train number 1 and
treatment train number 2 acted as a control. The respective loading on the
units is presented in Table 33.
43
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TABLE 33. LOADINGS DURING SEPTAGE ADDITION TO CONTACT ZONE
Parameter
TSS
VSS
BODr
BOD5
(total)
(soluble)
Unit
kg/day
79.5
57.2
99.0
39.5
1
Ib/day
175
126
218
87
Unit
kg /day
56.8
38.6
79.5
36.3
2
Ib/day
125
85
175
80
The impact of the septage loading on the effluent from the contact
zone is presented in Table 34.
TABLE 34. CONTACT ZONE OPERATIONAL PARAMETERS
DURING SEPTAGE ADDITION
Parameter
PH, S.U.
TSS, mg/1
VSS, mg/1
02-Uptake Rate, mg/l/hr
Unit 1
6.2
4,754
3,700
16.7
Unit 2
6.3
3,757
2,763
16.0
Secondary clarifier effluent quality during this same period is pre-
sented in Table 35. These data are derived from 24-hour composite sample
analyses.
TABLE 35. SECONDARY CLARIFIER EFFLUENT QUALITY
DURING SEPTAGE ADDITION TO THE CONTACT ZONE
Parameter
pH, S.U.
TSS, mg/1
BOD5 (total), mg/1
NH3-N, mg/1 as N
TOC (soluble), mg/1
Unit 1
6.9
8
7
4
12
Unit 2
6.9
11
8
3
7
The above data indicated that the impact of 5.69 m3/day (1,500 gpd) of
screened septage had a negligible effect on final effluent quality. It was
44
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visually noted, however, that more grease had accumulated in the treatment
unit receiving septage. Supplemental data are presented in the Appendix.
Similarly, 5.69 m3/day (1,500 gpd) of raw screened septage was intro-
duced to the reaeration zone of treatment unit number one for a one-week
period. The supplemental loadings to unit number 1 during this period are
presented in Table 36.
TABLE 36. SEPTAGE INTRODUCED INTO REAERATION ZONE
Parameter
Volume
TSS
VSS
BOD5 (total)
BOD- (soluble)
PH
NH3-N, as N
Quantity
5.69 m3/day (1,500 gpd)
18.6 kg/day (41 Ib/day)
15.0 kg/day (33 Ib/day)
15.9 kg/day (35 Ib/day)
2.3 kg/day ( 5 Ib/day)
6.7 S.U.
0.3 kg/day (0.7 Ib/day)
The impact of this loading was measured at the mid-point of the re-
aeration zone and these data are presented in Table 37.
TABLE 37. REAERATION ZONE OPERATIONAL PARAMETERS
DURING SEPTAGE ADDITION
Parameter
pH, S.U.
TSS, mg/1
VSS, mg/1
02-Uptake Rate, mg/l/hr
Secondary clarifier effluent quality
L J 4 » 1*^1*1 «. OD Tli Aaa /I at- a at"a Aavl *M
Unit 1
6.5
4,566
3,256
12.4
during
Unit 2
6.4
3,964
2,732
'10.6
this same period is pre-
analyses.
45
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TABLE 38. SECONDARY CLARIFIER EFFLUENT QUALITY
DURING SEPTAGE ADDITION TO THE REARATION ZONE
Parameter
pH, S.U.
TSS, mg/1
BOD5 (total), mg/1
NHo-N, mg/1 as N
TOC (soluble), mg/1
Unit 1
7.1
33
11
2.6
13
Unit 2
6.9
20
5
2.8
9
The above data indicate that the addition of 5.69 m3/day (1,500 gpd)
of screened septage had a slight effect on final effluent quality. How-
ever, during this study there was a break in the wastewater collection
system which allowed measurable quantities of sea water infiltration to
occur. Thus, the actual cause of the decrease in final effluent quality
could not be totally attributed to the addition of screened septage to the
reaeration zone of the treatment plant. It was visually noted, once
again, that more grease had accumulated in the unit receiving septage than
in the control unit. Supplemental data are presented in the Appendix.
In summary, the addition of septage to the Falmouth treatment plant
resulted in minor changes in final effluent quality. This was felt to be
mainly because the BODg and TSS loadings to the plant were approximately 20
percent of design capacity. Operational control measurements such as
oxygen uptake rate and sludge volume index increased slightly. Of concern
was the noticeable increase in MLSS which eventually end up as waste second-
ary sludge solids which must be dewatered.
46
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SECTION 10
DISCUSSION OF PILOT PLANT RESULTS
The previous sections of this report presented summaries of the results
from the pilot plant studies. The purpose of this section is to provide an
interpretation of the data and the application of various unit processes to
either: (1) utilization of local municipal wastewater treatment facilities
as a receiver for septage, or (2) the construction of facilities exclusive-
ly for the treatment of this material.
SCREENING
Septage, as pumped from septic tanks, varies dramatically in physical
and chemical character. In addition, it contains a substantial quantity of
readily screenable material which, if not removed, can lead to the plugging
of piping and valving as well as impaired pump operation. It was found
that screening raw septage through a 40-mesh (0.42 mm opening) vibrating
screen at a rate of 244-293 1 (5-6 gpm/ftz) yielded effective removal of
this undesirable material and resulted in screenings in the vicinity of 25
to 50 percent solids. It is recommended that any facility receiving septage
install a preliminary screening system.
Even following preliminary screening, the characteristics of septage
were noted to vary markedly from load to load. Independent of the sub-
sequent septage treatment process to be employed, an equalization tank
equal in volume to the anticipated maximum day treatment requirements
should be installed. This volume should afford a more consistent quan-
titative and qualitative character to any subsequent treatment processes.
The pilot plant studies indicated that air diffusion at a rate of 20 m3/
min/1,000 m3 (20 cfm/1,000 ft3) ensured adequate mixing to obtain homo-
genity of the tank contents. Equivalent mixing should be installed in any
screened septage storage/equalization facility.
CONDITIONING
Screened raw septage has associated with it a relatively high,per-
centage of very fine/colloidal suspended organic and inorganic solids.
Effective treatment of septage can be realized only if these solids can be
consistently captured.
47
-------
It should be emphatically noted that chemical coagulation of raw
unscreened septage yielded poor results. Consistent, positive results
could be achieved only if the raw septage was first subjected to the above
described screening operation.
Chemical conditioning of raw screened septage is possible with a
number of chemicals including ferric chloride, lime, alum, acid and combi-
nations of the above. Utilization of ferric chloride, lime, and/or alum
necessitated the conduct of extensive jar testing to optimize chemical dose
requirements. On the other hand, utilization of the acid/lime conditioning
process required only that: (1) the pH of the raw screened septage be
adjusted to and maintained at approximately 2 with sulfuric acid; (2) batch
settling occur for six to eight hours or longer, if desired; (3) the
sludge fraction be separated from the supernatant fraction; (4) the pH of
the supernatant fraction be adjusted to approximately 11 with lime; and (5)
gravity settling occur for an additional two hours. The acid and lime
produced sludges could then be combined and subjected to further treatment
as could the high quality supernatant.
Chemical requirements and associated costs for the various condition-
ing alternatives investigated are summarized in Table 39.
TABLE 39. ESTIMATED CHEMICAL COSTS FOR CONDITIONING
Alternate
A
B
C
D
Used
FeCl3
FeCl3+
Ca(OH)2
Al2(Sb4)'3*l4H20
H2S04+
Ca(OH)2
kg/m3
0.50
0.40
4.00
9.12
3.58
2.99
Chemical
Dose
lb/103 Kal
4.2
3.3
33.4
76.1
29.9
25.0
$/mJ
0.06
0.21
1.39
0.33
Cost
$/103 gal
0.23
0.78
5.25
1.26
The ferric chloride alternate is the least expensive based on chemical
costs listed in the January 30, 1978 issue of the Chemical Marketing Re-
porter. However, the acid/lime conditioning achieves consistent results
and therefore should be highly considered.
Settling column tests on all of the above alternates indicated effec-
tive separation in six to eight hours. Consideration was given to utiliz-
ing continuous flow equipment. Average flow rates at such a facility
would, in all probability, be less than 37.9 1/min (10 gpm). The commer-
cial availability of such continuous flow equipment was felt to discourage
this approach. The above, coupled with the inconsistent delivery rates of
septage to a treatment facility, encourages the utilization of batch sedi-
mentation in the selected conditioning process to be employed.
48
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DEWATERING'
The dewatering of septage solids to a consistency of at least 15
percent can be accomplished by a number of processes. However, essentially
all processes require conditioning of the raw screened septage prior to the
actual dewatering process to be employed.
Sand drying beds proved to be practical for dewatering sludges from
the various conditioning processes. Using the multiple application tech-
nique for dewatering sludge from the acid/lime pretreatment-process, sand
drying bed area requirements would approximate 3.6-4.9 m /m (15-20 ft /
1,000 gal) of raw screened septage processed. This technique holds sub-
stantial promise for application.
Centrifugation of septage sludge solids, alone or mixed with aerobic-
ally digested secondary sludge led to acceptable cake solids consistencies
but poor solids capture. With a more advantageous point of polymer appli-
cation than that available on the pilot scale solid bowl centrifuge, en-
hanced solids capture would, in all probability, be achieved. However,
centrifugation, as undertaken in the pilot plant studies, should not be
considered as a method for dewatering septage solids.
The use of a filter press for dewatering septage sludge solids derived
from the various conditioning processes, either alone or admixed with
aerobically digested secondary sludge, yielded excellent filtrate clarity
as well as high cake solids consistencies. To dewater 3.79 m3 (1,000 gal)
of pretreated raw screened septage, it has been estimated that the chamber
volume of a filter press should approximate 0.113 m3 (4.0 ft3). Filter
presses as small as this are commercially available and thus this dewater-
ing process is a viable alternative.
The vacuum filter dewatering of septage solids yielded good solids
capture and cake solids consistencies. However, achieving consistent
release of the cake from the filter cloth was difficult and the filter
yield was consistently low, usually in the range of 0.18-0.36 kg/m2/hr
(0.4-0.8 Ib/ft2/hr). The dewatering of mixed septage/aerobically digested
secondary sludges by vacuum filtration yielded comparably poor cake release
and filter yield. In addition, extensive efforts were required to define
the levels of supplemental conditioning agents required for these mixtures
to obtain optimum results. As a result of the above, utilization of vacuum
filters for dewatering screened septage solids should be carefully scruti-
nized.
ADDITION TO MUNICIPAL WASTEWATER TREATMENT PLANT
Because of the current municipally derived influent loadings at the
Falmouth water pollution control facility, the impact of septage addition
on the plant's performance could not be realistically assessed. The only
truely apparent impact was a substantial increase in the MLSS and MLVSS
concentrations during the period of screened septage addition.
49
-------
Raw screened septage, based on a volume of 3.79 m3 (1,000 gal), has an
average BOD- population equivalent of 240 and an average TSS population
equivalent of 360. General knowledge of secondary treatment plant opera-
tions indicates that random increases in influent organic loadings of up to
about 50 percent (above normally anticipated variations) may be absorbed by
treatment plants before effluent quality deterioration becomes readily
discernable. On this basis, not more than 3.79 m3 (1,000 gal) of raw
screened septage should be randomly introduced on any given 24-hour day to
secondary facilities with influent flows of less than 5.68-974 m3/day
(0.15-0.25 mgd) if they are operating at design capacity. If a given
secondary facility of this size is operating at less than design capacity,
facilities should be installed to introduce raw screened septage at a low,
controlled rate.
The introduction of raw screened septage to a secondary treatment
facility at a controlled rate leads to, among others, BOD5 and ammonia
nitrogen removal. Research by others has shown that approximately 40
percent of the TSS in septage are degradable by aerobic bio-oxidation (5).
On this basis, net accumulation of MLSS could amount to at least 4.78-5.37
kg/day/m3 (40-45 lb/day/1,000 gal) of raw screened septage introduced to a
secondary treatment plant. At a concentration of 1.0 percent TSS, this
would amount to a minimum supplemental secondary sludge wasting and de-
watering volume of approximately 0.5 m3/m3 (0.5 gal/gal) of septage treated
by this technique. This is in contrast to a sludge volume resulting from,
for example, the acid/lime conditioning process of about 0.3 m3/m3 (0.3
gal/gal) of septage treated by this technique.
AQUEOUS FRACTION TREATMENT
The aqueous fraction evolving from conditioning and/or dewatering pro-
cesses contains mainly BODg and ammonia nitrogen and minor levels of TSS as
pollutants. This wastewater, though more concentrated in BOD5 and ammonia
than domestic wastewater, is ammenable to biological treatment. If septage
is being treated at a municipal wastewater treatment facility, the aqueous
fraction could be metered into the treatment plant influent since each 3.79
m3 (1,000 gal) of this liquid contains roughly only 2.27 kg (5 Ib) BODs,
0.23 kg (0.5 Ib) TSS, and 0.23 kg (0.5 Ib) NH3-N. At a remote facility
constructed exclusively for the treatment of septage, a viable aqueous
fraction treatment process could be intermittent sand filtration. Because
of the waste's strength, organic loading would be the controlling para-
meter. Previous work by others (6) in the area of intermittent sand fil-
tration has indicated that if the BOD5 loading is kept to less than 168
kg/ha (150 Ib/acre), approximately 90 percent 8005 removal can be consis-
tently achieved. To treat 3.79 m3/day (1,000 gpd) of aqueous fraction by
this technique would thus require an intermittent sand filter approximately
204 m2 (2,200 ft2) in area.
50
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SOLIDS FRACTION DISPOSAL
One of the practices to be considered for the ultimate disposal of
dewatered septage solids is burial in a soil mantle. Pilot scale studies
were set up to evaluate soil retention capabilities under extreme condi-
tions. These conditions included the utilization of an acidic sludge as
well as an average rainfall intensity of 2.54 cm/day (1.0 in/day). Under
these conditions, it was shown that soil type influenced leachate quality.
If septage solids disposal is to be by burial, the dewatered sludge
should have an alkaline pH to optimize insoluble metallic matrix forma-
tions, water flow through the soil/sludge mass should be minimized, and a
soil mantle with desired retention capabilities utilized.
51
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SECTION 11
SYSTEM DESIGN
The incorporation of the pilot scale results presented in this report
can lead to numerous approaches to the treatment of septage, either at a
municipal wastewater treatment plant or at facilities designed exclusively
for the treatment of septage. Four of these possible alternatives are
presented in the following subsections; two are capable of treating 9.48
m3/day (2,500 gpd) and the other two, 37.9 m3/day (10,000 gpd). One of
each size is designed for the exclusive treatment of septage; the other two
are for the treatment of this material at municipal wastewater treatment
plants.
The four alternatives presented do not necessarily reflect optimum
combinations of the substantial number of unit operations and processes
that may be employed. Rather, they reflect possible combinations that were
shown to yield positive results during the conduct of the pilot plant
studies. In the actual design of a treatment facility, supplemental test-
ing should be undertaken to confirm the application of the specific method-
ologies selected.
Each of the four facilities has been set up to operate in the batch
treatment mode. The main reasons for taking this approach are: (1) the
continuous delivery of finite quantities of septage to a given facility
cannot necessarily be guaranteed, and (2) continuous flow equipment capable
of operating in the range of 7.6 to 26.5 1/min (2 to 7 gpm) are not readily
available.
The installed costs of the systems presented in this section were
established as follows:
1. Purchase prices on all equipment and materials were obtained from
various suppliers and an 18 percent contractor mark-up added to cover
shipping charges and taxes (5 percent), electrical wiring (3 percent)
and profit (10 percent).
2. Installation costs were developed from the 1978-1979 Edition of the
Richardson Process Plant Construction Estimating Standards.
3. A 15 percent contingency was added to the sum of 1 and 2, above, to
obtain the total installed cost.
52
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Total installed cost was then amortized over ten years using an
interest rate of 7.0 percent.
Maintenance costs were assumed to be one percent of the total installed
cost of the facility per year. Chemical costs were obtained from the
January 30, 1978 issue of the Chemical Marketing Reporter. Electrical
costs were based on a rate of $0.03/kwh and water on a rate of $0.17/m3
($0.47/100 cu ft). The labor rate was based on a total cost of $15,000/
year per person or $7.21/hr and included salary and fringe benefits. The
cost for hawling and ultimate disposal of the dewatered septage solids have
not been included in any of the four alternates.
ALTERNATE 1: 9.48 M3/DAY (2,500 GPD) FACILITY EXCLUSIVELY DESIGNED FOR
SEPTAGE TREATMENT
A series of processes have been selected for a facility exclusively
designed for the treatment of 9.48 m3/day (2,500 gpd) of septage. The
processes involve: (1) the screening and equalization of the raw septage,
(2) the application of the acid/lime addition process, (3) aqueous fraction
treatment by intermittent sand filtration, and (4) sludge dewatering by
sand drying beds. Figure 3 presents a schematic of this system as well as
the associated flow, BOD5, and TSS balances based on the average perfor-
mances of each operation noted in this study. Calculated intermittent sand
filter effluent quality indicates less than 50 mg/1 of both BOD5 and TSS.
Dewatered sludge after three days of drainage, is estimated to be approxi-
mately 30 percent solids and to occupy a volume of 0.035 m3/m3 (4.65 cu
ft/1,000 gal.) treated.
A list of the required equipment and installed cost estimates is given
in Table 40. Estimated total installed cost is $88,275.
Table 41 gives a tentative scheduling of events at the 9.48 m3 (2,500
gal.) capacity septage facility. It has been estimated that approximately
five person-hours would be required to process 9.48 m3 (2,500 gal.) of raw
septage and perform required maintenance duties at this facility.
Assuming a maximum of 47.4 m3 (12,500 gal.) of raw septage is pro-
cessed per week and facility life is ten years, estimated minimum treatment
costs have been calculated and are presented in Table 42.
TABLE 42. ALTERNATE 1 CAPITAL AND OPERATING COSTS
Cost
Category $/mJ $/1.000 Gal.
Amortization of Capital 5.10 19.34
Maintenance 0.36 1.36
Chemicals 0.41 1.57
(Continued)
53
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LEGEND
A 8000 gal receiving tank
B 30" <(> vibrating screen
C 3000 gal acid addition tank
D 2000 gal lime addition tank
E 3000 gal neutralization tank
F 2- 1800 sq ft intermittent tond filters
6 1000 gal neutralization tank
H 3 - 50 sq ft sand drying beds
25 Ib Ca(OH)2
NEUTRALIZED SLUDGE
0 = 770 gal
BOD5= llSIb
TSS = 222lb
ACID SLUDGE
0 = SeOgal'
BOD5 = I ISIb
TSS s|74lb
LIME SLUDGE
H
DEWATERED SLUDGE
Vol II.Scuff
B00e* 112 Ib
TSS 221 Ib
Q = 2IOgal
BOD5 = Olb
TSS *36lb
FILTRATE
0 =TOOgor
BODB < 3lb
TSS « 9 Ib
TSS i <2lb
AQUEOUS EFFLUENT
0 = 2410 gal
BOD,= < lib
TSS = < lib
FIGURE 3. ALTERNATE I SYSTEM SCHEMATIC
54
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TABLE 40. ALTERNATE 1 EQUIPMENT LIST
Component Installed Cost, $
3.03 m3 (8,000 gal) raw septage receiving tank* $ 6,500
11.4 m3 (3,000 gal) acid addition tank 3,385
7.6 m3 (2,000 gal) lime addition tank 2,845
11.4 m3 (3,000 gal) supernatant/filtrate neutralization
tank* 2,950
3.8 m3 (1,000 gal) sludge neutralization tank* 95Q
0.76 m (30 in) diameter 40-mesh vibrating screen 5,080
95-190 1/min (25-50 gpm) positive displacement sludge
transfer pump 4,000
95 1/min (25 gpm) supernatant/filtrate transfer pump 215
0.28 m3/min (10 cfm) air blower for mixing 860
0.57 m3 (150 gal) sulfuric acid storage tank 910
3.8 1/min (1 gpm) sulfuric acid metering pump 1,730
0.76 m3 (200 gal) lime slurry tank 755
57 1/min (15 gpm) lime slurry pump 170
Two 167 m2 (1,800 ft2) intermittent sand filters 22,000
Three 4.6 m2 (50 ft2) sand drying beds 2,000
Sand drying bed covers 340
5.6 m2 (600 ft2) building for housing equipment 12,600
Piping and valving 2,970
Pickup truck 5,000
Electrical 1,500
Subtotal $76,760
Contingency (15 percent) 11,515
Total $88,275
*Installed below grade " ~~ ~~~
55
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TABLE 41. ALTERNATE 1 ACTIVITY SCHEDULE
Time Activity
6:45 - 8:00* Transfer lime supernatant to supernatant filtrate tank
using centrifugal pump
8:00 - 8:15 Drain lime sludge to sludge neutralization tank
8:15 - 9:30 Transfer acid supernatant to lime addition tank using
centrifugal pump
8:30 - 9:30 Clean one sand drying bed
9:30 - 9:45 Drain acid sludge to sludge neutralization tank and
make up lime slurry
9:45 - 10:45 Screen 2,500 gal of raw septage using positive displace-
ment pump and place in acid addition tank
10:00 - 10:15 Adjust pH of supernatant-filtrate to 6.5 to 8.5
10:15 - 10:30 Adjust pH of acid supernatant to 11.0+
10:30 - 10:45 Adjust pH of combined acid and lime sludges to 9 to 10
10:45 - 11:00 Adjust pH of screened septage to 2.0+
11:00 - 12:30** Transfer neutralized supernatant-filtrate to inter-
mittent sand filter using centrifugal pump
11:15 - 11:45 Transfer neutralized sludge to sand drying bed using
positive displacement pump
11:30 - 12:30 Perform required maintenance and/or dewatered solids
and screenings disposal
*Initiated with automatic timer.
**Automatic shutoff.
56
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TABLE 42. (Continued)
Cost
Category $/mJ $71.000 Gal.
Electricity and Water 0.05 0.18
Labor 3.81 14.42
Total $9.73 $36.87
ALTERNATE 2: TREATMENT OF 9.48 M3/DAY (2,500 GPD) OF SEPTAGE AT A MUNI-
CIPAL WASTEWATER FACILITY
A series of processes have been selected for the treatment of 9.48
m3/day (2,500 gpd) of septage at a municipal wastewater treatment facility.
The processes involve: (1) screening, pH adjustment and equalization of
the raw septage, (2) aerobic digestion of the neutralized material with the
treatment plant's waste secondary sludge, and (3) dewatering of the mixed
aerobically digested sludge utilizing the treatment plant's existing equip-
ment. Figure 4 presents a schematic of this system as well as the asso-
ciated flow, BOD5 and TSS balances.
Aerobic digestion of septage for ten days has been noted to yield a 20
percent reduction in TSS (6). Based on this factor and the average charac-
teristics of raw screened septage, supplemental aerobic digestion volu-
metric capacity of approximately 114 m3 (30,000 gal.) should be installed
if the treatment plant is at or near design capacity. As a result, approx-
imately 66 kg (145 Ib) of TSS must be dewatered per 9.48 m3 (2,500 gal.) of
raw septage processed. It has been calculated that the treatment of 9.48
m3/day (2,500 gpd) of septage at a 948 m3/day (250,000 gpd) municipal
treatment plant, using the above outlined process, could result in in-
creased dewatering requirements of 30 to 40 percent including chemicals,
labor, electric power, and dewatering equipment running time.
The pilot plant studies indicated that the utilization of centrifuga-
tion or vacuum filtration equipment for dewatering,should be carefully
scrutinized. However, it must be recalled that centrifuge performance was
limited because of the point of application of the appropriate polymer.
Similarly, only one cloth was available for use on the cloth belt vacuum
filter and this particular media may have led to the marginal results
reported.
A list of the required equipment and installed cost estimates is given
in Table 43. Estimated total installed cost is $61,075. If adequate
aerobic digester capacity exists at the treatment plant, the total in-
stalled cost of appropriate equipment would approximate $30,000.
57
-------
LEGEND
A 8000 gal receiving tank
B 30" $ vibrating screen
C 3000 gal neutralization tank
0 Expanded municipal aerobic digester (30,000 gal)
E Existing municipal dewatering equipment
CONVERSION FACTORS
gal. X 0.00379 m3
in. X 2,54 * cm
tq. ft. X 0.0929 ' m2
cu. ft. X 0.0283 = m3
NOTE'
36 Ib TSS destroyed by the
aerobic digestion process
DIGESTER DECANT
0 1240 gal
BOD8a 5lb
TSS * 24 Ib
DEWATERING FILTRATE
0 *
BOD,* S Ib
TSS : 6 Ib
RAW SEPTAGE
0 = 2500 gal
SCREENINGS
0: 20gal
SCREENED SEPTAGE
0 * 2480 gal
BOD, -121 Ib
TSS *!60lb
5LB Ca(OH)8
NEUTRALIZED SEPTAGE
Q 2480 gal
BOD5= 121 ib
TSS s 180 Ib
AEROBICALLY DIGESTED SEPTAGE
Q * 1240 gal
BOD,' 92 Ib
TSS °!20lb
DEWATERED SEPTAGE SOLIDS
0 *
BOD9=87lb
TSS * M4lb
FIGURE 4. ALTERNATE 2 SYSTEM SCHEMATIC
58
-------
TABLE 43. ALTERNATE 2 EQUIPMENT LIST
Component Installed Cost, $
30.3 m3 (8,000 gal) raw septage receiving tank* $ 6,500
11.4 m3 (3,000 gal) screened septage neutralization
tank* 3,000
0.76 m (30 in) diameter 40-mesh vibrating screen 5,080
19-190 1/min (5-50 gpm) positive displacement sludge
transfer pump 4,000
0.76 m3 (200 gal) lime slurry tank 755
57 1/min (15 gpm) lime slurry pump 170
3.4 m3/min (120 cfm) air blower 1,200
114 m3 (30,000 gal) aerobic digester 19,000
Piping and valving 6,305
27 m2 (270 ft2) building for housing equipment 6,090
Electrical 1.010
Subtotal $53,110
Contingency (15 percent) 7,965
Total $61,075
*Installed below grade
59
-------
Approximately one and one-half person-hours would be required to
screen and neutralize the raw septage, and maintain the equipment for each
9.48 mj (2,500 gal.) processed. Time commitments for dewatering would be
30 to 40 percent above that currently being expended at a given municipal
facility. A time for septage sludge dewatering has been estimated to be
one hour/9.48 nr (2,500 gal) of septage processed.
Assuming a maximum of 47.4 m3 (12,500 gal.) of raw septage is pro-
cessed per week and facility life is ten years, estimated minimum treatment
costs, including those associated with dewatering, are presented in Table
44.
TABLE 44. ALTERNATE 2 CAPITAL AND OPERATING COSTS
Category
Amortization of Capital
Maintenance
Chemicals*
Electricity and Water
Labor
Total
$/mJ
3.53
0.25
0.33
0.36
1.90
$6.37
Cost
5/1.000 Gal.
13.38
0.94
1.24
1.36
7.21
$24.13
*Includes 5 kg/t (10 Ib/ton) of polymer for dewatering on
municipal equipment at a cost of $4.4l/kg ($2.00/lb)
ALTERNATE 3: 37.9 M3/DAY (10,000 GPD) FACILITY EXCLUSIVELY DESIGNED FOR
SEPTAGE TREATMENT
Processes selected for this alternate include: (1) screening and
equalization of the raw septage, (2) acid/lime conditioning process, (3)
sludge dewatering by filter press, and (4) aqueous fraction treatment by
intermittent sand filtration. Figure 5 presents a schematic of this system
as well as flow, BOD^ and TSS balances based on the average performances of
each operation noted in the study.
Essentially, the system is the same as that presented in Alternate 1
except that sludge dewatering is accomplished with a filter press. De-
watered sludge volume has been estimated to be approximately 0.03 ra3/m"* (4
cu ft/1,000 gal.) of raw septage processed. Two 650 m2 (7,000 sq ft)
intermittent sand filters are required for the aqueous fraction treatment.
A list of the required equipment and installed cost estimates is given
in Table 45. Estimated total capital cost is $452,615.
60
-------
LEGEND
A 20,000 gol receiving tank
B 60" 0 vibrating screen
C 10,000 gal add addition tank
0 BOOOgal lime addition tank
E 10,000gal neutralization tank
F 2-7000 sq ft intermittent sand filters
G 4000 gal neutralization tank
H Filter press
RAW SEPTAGE
Q *IO,OOOgal
SCREENINGS
QsSOgal
SCREENED SEPTAGE
Q * 9920 gal
BODB = 484 Ib
TSS * 720lb
ACID SLUDGE
ib Co(OH)g »*i 6
NEUTRALIZED SLUDGE
0 s 3080 gol
BODB* 460 Ib
TSS = 805 Ib
i
DEWATERED SLUDGE
Vol - 44.5CU ft
BODB» 448lb
TSS - 793 Ib
i
r*
JL 0 s2240gor
^» BODB «460lb
TSS »696lb
LIME SLUDGE
0 a 840gol
BODB =0lb
TSS M59lb
I
, FILTRATE _
0 = 2780gol
BODB* I2lb
TSS «
-------
TABLE 45. ALTERNATE 3 EQUIPMENT LIST
Component Installed Cost. $
76 m3 (20,000 gal) raw septage receiving tank* $ 12,000
38 m3 (10,000 gal) acid addition tank 7,750
30 m3 (8,000 gal) lime addition tank 6,560
38 m3 (10,000 gal) supernatant/filtrate neutralization
tank* 6,300
15 m3 (4,000 gal) sludge neutralization tank* 3,825
1.53 m (60 in) diameter 40-mesh vibrating screen 10,000
Two 38-380 1/min (10-100 gpm) positive displacement
sludge transfer pump 13,000
Two 380 1/min (100 gpm) supernatant/filtrate transfer
pump 1,400
0.17 m3/min (25 cfm) air blower for mixing 950
1.9 m3 (500 gal) sulfuric acid storage tank 1,000
3.8 1/min (4 gpm) sulfuric acid metering pump 1,730
1.9 m3 (500 gal) lime slurry tank 1,000
227 1/min (60 gpm) lime slurry pump 230
Filter press 220,500
Two 650 m2 (7,000 ft2) intermittent sand filters 48,000
Piping and valving 4,640
178 m2 (1,920 ft2) building for housing equipment 40,320
Pickup truck 5,000
Electrical 9.375
Subtotal $393,580
Contingency (15 percent) 59.035
Total $"452,615
*Installed below grade~~~
62
-------
o
Table 46 gives a tentative scheduling of events at this 37.9 m
(10,000 gal.) capacity septage facility. It has been estimated that appro-
ximately 0.75 person-hours would be required to process 3.79 m3 (1,000
gal.) of raw septage and perform required maintenance at this facility.
Assuming a maximum of 190 m3 (50,000 gal.) of raw septage is processed
per week and facility life is ten years, minimum estimated treatment costs
have been calculated and are presented in Table 47.
TABLE 47. ALTERNATE 3 CAPITAL AND OPERATING COSTS
Category
Amortization of Capital
Maintenance
Chemicals
Electricity and Water
Labor
Total
- ' " " '
v/u.
6.54
0.46
0.41
0.18
1.43
$9.02
Cost
$/l,000 Gal.
24.79
1.74
1.57
0.69
5.41
$34.20
ALTERNATE 4: TREATMENT OF 37.9 M3/DAY (10,000 GPD) OF SEPTAGE AT A MUNI-
CIPAL WASTEWATER FACILITY
Processes selected for the treatment of 37.9 m3/day (1.0,000 gpd) of
septage at a municipal wastewater facility include: (1) screening and
equalization, (2) ferric chloride and lime conditioning, (3) aqueous
fraction treatment by controlled rate addition to the treatment plant
influent, and (4) sludge fraction dewatering using the plant's existing
equipment. An example of such equipment is a vacuum filter. Figure 6
presents a schematic of this system as well as the associated flow, BODc
and TSS balances.
A list of the required equipment and installed cost estimates is pre-
sented in Table 48. Estimated total cost is $110,705.
Table 49 gives a tentative scheduling.of events at this facility. It
has been estimated that approximately 0.75 person-hours would be required
to process 3.79 m3 (1,000 gal.) of raw septage and perform required main-
tenance at this facility.
O
Assuming a maximum of 190 nr (50,000 gal.) of raw septage is processed
per week and facility life is ten years, minimum treatment costs have been
calculated and are presented in Table 50.
63
-------
TABLE 46. ALTERNATE 3 ACTIVITY SCHEDULE
Time Activity
6:45 - 8:00* Transfer lime supernatant to supernatant filtrate tank
using centrifugal pump
8:00 - 8:15 Drain lime sludge to sludge neutralization tank
8:15 - 9:30 Transfer acid supernatant to lime addition tank using
centrifugal pump
9:30 - 9:45 Drain acid sludge to sludge neutralization tank and
make up lime slurry
9:45 - 12:15 Screen 10,000 gal of raw septage using positive dis-
placement pump
10:00 - 10:15 Adjust pH of supernatant-filtrate to 6.5 to 8.5
10:15 - 10:30 Adjust pH of acid supernatant to 11.0+
10:30 - 10:45 Adjust pH of sludge to 9 to 10
10:45 - 11:00 Adjust pH of screened septage to 2.0+
11:00 - 1:00 Transfer neutralized supernatant-filtrate to inter-
mittent sand filter using centrifugal pump
1:00 - 3:00 Perform required maintenance and/or dispose of de-
watered solids and screenings
7 1/2 hrs/day Filter press operation
*Initiated with automatic timer.
64
-------
LEGEND
A 20,000 gal receiving tank
8 60" vibrating screen
C 10,000 gal chemical addition tank
0 8000 gal supernatant collection tank
E 17,000 gal sludge holding tank
F Municipal treatment plant vacuum filter
o
POLYMER
4 Ib
FeCI3/Ca{OH)8 SLUDGE
0 = 3220 gal
BOOS =438 Ib
TSS =965 Ib
0
FILTRATE
Q = 2720 gal
B005 = 21 Ib
TSS =36lb
DEWATERED SLUDGE
Vol =65.2 cu. ft.
BOD8 -417 Ib
TSS =929Ib
RAW SEPTAGE
Q - 10,000 gal
SCREENINGS
j
Q - 80 gal
SCREENED SEPTAGE
Q = 2920 gal
BOD5 =484 Ib
TSS *720lb
33 Ib FeCls
335 Ib Ca(OH)z
FeCI3/Ca(OH)8 SUPERNATANT
0 * 6700 go I
BOD5 =46 Ib
TSS =6lb
SUPERNATANT - FILTRATE
Q *9420gal
BOD8 ' 67 Ib
TSS :42lb
CONVERSION FACTORS
gal. X 0.00379: m3
in. X 2.54 = cm
iq. ft. X 0.0929: m2
cu. ft. X 0.0283 = m3
FIGURES. ALTERNATE 4 SYSTEM SCHEMATIC
65
-------
TABLE 48. ALTERNATE 4 EQUIPMENT LIST
Component Installed Cost, $
76 m3 (20,000 gal) raw septage receiving tank* $ 12,000
38 m3 (10,000 gal) chemical addition tank 7,750
30 m3 (8,000 gal) supernatant holding tank* 6,560
64 m3 (17,000 gal) sludge holding tank* 8,300
1.53 m (60 in) diameter 40-mesh vibrating screen 10,000
Two 38-380 1/min (10-100 gpm) positive displacement
sludge transfer pumps 13,000
Two 380 1/min (100 gpm) supernatant transfer pumps 1,400
0.71 m3/min (25 cfm) air blower for mixing 950
0.57 m3 (150 gal) ferric chloride storage tank 910
3.8 1/min (1 gpm) ferric chloride metering pump 1,730
1.9 m3 (500 gal) lime slurry tank 230
227 1/min (60 gpm) lime slurry pump 1,000
Piping and valving 3,990
117 m2 (1,260 ft ) building for housing equipment 26,460
Electrical 1.985
Subtotal $ 96,265
Contingency (15 percent) 14.440
Total $110,705
*Installed below grade ~""~~
66
-------
TABLE 49. ALTERNATE 4 ACTIVITY SCHEDULE
Time Activity
7:00 - 8:30 Transfer FeClg/CaCOH^ supernatant to supernatant-
filtrate tank using centrifugal pump.
7:30 - 8:00 Mix polymer for dewatering
8:30 - 9:30 Transfer FeCl3/Ca(OH)2 sludge to sludge holding tank
using positive displacement pump.
*9:45 - 1:45 Dewater FeCl2/Ca(OH)2 sludge using municipal treatment
plant gravity dewatering device
10:00 - 1:00 Screen 10,000 gal of raw septage using positive dis-
placement pump
10:15 - 11:15 Make up FeCl3 solution and lime slurry
2:00 - 3:00 Clean up dewatering equipment and perform maintenance
*Time required to dewater 929 Ibs of sludge (not necessarily done every
day).
67
-------
TABLE 50. ALTERNATE 4 CAPITAL AND OPERATING COSTS
Category
Amortization of Capital
Maintenance
Chemicals*
Electricity and Water
Labor
Total
$/m3
1.60
0.11
0.42
0.06
1.43
$3.62
Cost
$/l,000 Gal.
6.06
0.43
1.59
0.24
5.41
$13.73
*Includes 5 kg/t (10 Ib/ton) of polymer for dewatering on
municipal equipment at a cost of $4.41/kg ($2.00/lb).
68
-------
REFERENCES
1. Feige, W. A., Oppelt, E. T., Kreissl, J. F., "An Alternative Septage
Treatment Method: Lime Stabilization/Sand-Bed Dewatering," Environ-
mental Protection Technology Series, EPA-600/2-75-036, September 1975.
2. Bennett, S. M., Heidman, J. A., Kreissl, J. F., "Feasibility of
Treating Septic Tank Waste by Activated Sludge," Environmental Protec-
tion Technology Series, EPA-600/2-77-141, August 1977.
3. Kreissl, J. F., "Septage Analysis," U. S. EPA Memorandum, February 2,
1976.
4. Perrin, D. R., "Physical and Chemical Treatment of Septic Tank Sludge,"
M. S. Thesis, University of Vermont, February 1974.
5. Rowley, J. B., "Biological Treatment of Septic Tank Sludge," M. S.
Thesis, University of Vermont, October 1973.
6. Llewellyn, L. A., "A Tertiary Wastewater Treatment System for Seasonal
Resort Areas," M. S. Thesis, University of Vermont, October 1972.
69
-------
APPENDIX
SUPPLEMENTAL PILOT PLANT DATA
70
-------
TABLE A-l. RAW SCREENED SEPTAGE CHARACTERISTICS
Parameter
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
PO^ (total), mg/1 as P
PO^ (ortho), mg/1 as P
Alkalinity, mg/1 as CaCO
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
001
3,000
2,380
2,250
1,940
6.7
1,360
315
3,270
62
71
50
27
3 390
18
-
0.04
2.0
0.20
3.7
-
002
5,560
3,670
5,060
4,440
6.2
3,550
780
20,500
98
91
135
100
440
39
-
0.06
3.5
0.52
3,4
-
003
5,090
4,040
4,370
3,810
6.0
2,280
700
10,200
75
75
70
20
320
35
-
0.03
2.4
0.40
2.9
Batch
004
2,560
1,830
2,140
1,820
7.0
1,380
560
4,120
92
108
25
25
475
47
0.05
<0.02
2.8
0.60
3.7
-
005
29,700
26,400
22,600
22,200
5.3
24,000
5,450
37,000
82
558
54
8
500
85
0.42
0.2
30.0
1.4
18.0
-
006
13,100
10,900
11,600
10,000
5.9
4,700
775
12,400
44
226
40
28
910
57
-
-
14
0.2
9.3
~
(Continued)
71
-------
TABLE A-l. (Continued)
Batch
Parameter
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
PC<4 (total), mg/1 as P
PO^ (ortho), mg/1 as P
Alkalinity, mg/1 as CaCO
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
007
5,320
4,200
4,470
3,900
6.0
3,480
1,140
9,200
76
64
42.5
19
3 41°
26
-
-
7.2
0.6
4.2
-
008
9,400
7,500
9,300
7,700
5.0
>5,000
1,200
14,400
70
170
42
11
430
120
-
-
16
1.0
11
-
009
7,900
6,300
10,700
8,900
4.8
>5,000
1,360
14,100
70
258
27
21
410
51
-
-
11.6
0.6
7.2
-
010
12,950
10,750
8,592
6,935
4.8
>5,000
1,440
12,500
68
177
50
36
550
62
-
-
12
1.2
9.2
- -
Oil
14,200
11,000
13,800
11,000
6.0
6,600
780
18,600
69
191
54
54
340
-
-
-
-
-
-
-
012
14,200
11,000
13,800
11,000
6.0
6,600
780
18,600
69
191
53.5
53.5
340
19.7
-
-"
8.6
0.42
13.2
; -
(Continued)
72
-------
TABLE A-l. (Continued;
Parameter
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
PC>4 (total), mg/1 as
PO^ (ortho), mg/1 as
Alkalinity, mg/1 as
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease & Oil, mg/1
013
26,400
20,010
20,190
14,970
9.8
4,395
555
15,500
3
242
P 40.5
P 22
CaC03 370
-
-
-
-
-
-
014
9,950
6,540
6,420
4,320
6.1
50,000
4,650
132,000
73
549
60
42
520
-
-
-
-
-
-
Batch
015
27,740
15,730
18,940
11,500
6.1
7,500
750
34,900
76
454
44
35
420
-
-
-
-
-
-
-
016
2,720
1,920
2,510
2,090
7.0
990
390
18,430
37
165
20
20
110
-
-
-
-
-
-
.' -
017
25,860
24,900
18,850
17,560
6.3
3,900
435
28,400
80
470
60
27
280
-
-
-
-
-
-
11,600
018
5,760
4,670
5,180
4,540
5.4
2,690
495
10,600
74
316
46
35
70
-
. -
-
-
. -
-
1,660
(Continued)
73
-------
TABLE A-l. (Continued)
Parameter
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH-j-N, mg/1 as N
Organic-N, mg/1 as N
FO^ (total), mg/1 as
PO^ (ortho), mg/1 as
Alkalinity, mg/1 as
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mh, mg/1
Zn, mg/1
Grease and Oil, mg/1
019
5,970
5,130
5,570
3,990
5.4
10,900
900
28,500
74
111
P 60
P 35
CaC03 250
-
-
-
-
-
-
7,600
020
3,300
2,480
2,750
2,430
5.3
10,000
780
12,120
73
112
66
8
190
-
-
-
-
-
-
4,350
Batch
021
9,240
7,190
8,870
6,870
6.5
4,900
720
28,400
54
98
72
30
240
_
-
-
-
-
-
1,710
022
6,845
5,340
6,440
5,260
6.6
2,560
630
4,525
37
113
35
28
212
-
-
-
-
-
-
1,192
023
4,050
3,180
3,950
3,280
6.9
2,380
1,330
7,750
67
113
30
24
290
-
-
-
-
-
-
1,140
024
4,050
3,180
3,920
3,280
6.9
2,380
1,830
7,750
67
113
30
24
290
-
-
-
-
-
-
1,140
(Continued)
74
-------
TABLE A-l. (Continued)
Parameter
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
P04 (total), mg/1 as P
P04 (ortho), mg/1 as P
Alkalinity, me/1 as CaCO<
025
9,850
7,920
5,860
4,900
6.3
3,030
1,860
9,050
71
154
64
35
, 300
026
42,100
32,600
40,200
30,700
6.8
11,700
1,175
35,100
102
253
130
25
640
Batch
027
17,290
14,315
16,630
13,330
6.6
8,550
1,200
10,700
50
261
65
33
240
028
4,680
3,890
3,440
3,000
2.8
2,175
390
4,850
26
80
50
14
0
029
9,140
8,080
6,300
3,975
7.6
3,840
1,200
6,700
47
120
18
17
375
030
-
-
4,880
3,820
6.3
3,820
750
-
95
-
-
-
330
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1 208
2,350 1,420 1,312
(Continued)
75
-------
TABLE A-l. (Continued)
Batch
Parameter
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BODr (soluble), mg/1
031
-
-
3,150
2,480
5.8
2,610
500
032
-
-
3,690
3,190
7.2
1,410
340
033
-
-
4,140
3,650
6.8
2,430
600
034
-
-
3,810
3,270
7.0
3,420
500
035
-
-
2,400
2,070
6.7
2,280
540
036
-
-
2,400
2,070
6.5
1,740
420
COD, rog/1
NH3-N, mg/1 as N 52
Organic-N, mg/1 as N
PO^ (total), mg/1 as P
PO^ (ortho), mg/1 as P
Alkalinity, mg/1 as CaCO^ 360
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
51
60
280
290
62
52
54
330
285
310
(Continued)
76
-------
TABLE A-l. (Continued)
Batch
Parameter 037 038
TS, mg/1
TVS, mg/1
TSS, mg/1 2,400 3,840
VSS, mg/1 2,070 2,600
pH, S.U. 6-5 6.9
BOD5 (total), mg/1 A, 200 1,035
BOD5 (soluble), mg/1 360 400
COD, mg/1
NH3-N, mg/1 as N 54 44
Organic-N, mg/1 as N - - '
PO^ (total), mg/1 as P
PO^ (ortho), mg/1 as P - -
Alkalinity, mg/1 as CaC03 310 340
Fe, mg/1
Ni, mg/1
Cd, mg/1 ~ -
Cu, mg/1
Mn, mg/1 ~ -
Grease and Oil, mg/1 ' - .
039
9,850
7,920
5,860
4,900
6.3
3,030
1,860
9,050
71
225
64
35
300
-
-
-
-
. , _
208
77
-------
TABLE A-2. PLAIN SEDIMENTATION OF RAW SCREENED SEPTAGE
Run Number 1
Corresponding Feed
Parameter
TS, mg/1
TVS, mg/1
SS, mg/1
VSS, mg/1
BOD5 (total), mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as
PO, (total), mg/1
Run Number 2
Corresponding Feed
tS, mg/1
TVS, n»g/l
SS, mg/1
VSS, mg/1
BOD5 (total), mg/1
NtL-N, mg/1 as N
Organic-N, mg/1 as
PO, (total), mg/1
Material - 016
Supernatant
0 Hr
2,720
1,920
2,510
2,090
990
37
N 128
as P 20
Material - 021
9,240
7,190
8,870
6,870
4,900
54
N 98
as P 72
Quality Following^
24 Hr
2,370
1,720
1,720
1,510
990
36
126
9
8,780
6,820
7,230
5,520
4,700
54
96
42
Sedimentation For
48 Hr
2,220
1,720
1,410
1,210
830
37
113
11
8,620
6,740
6,920
5,350
4,600
52
87
40
(Continued)
78
-------
TABLE A-2. (Continued)
Run Number 3
Corresponding Feed Material
Parameter
TS, mg/1
TVS, mg/1
SS, mg/1
VSS, mg/1
BOD5 (total), mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
P04 (total), mg/1 as P
Run Number 4
Corresponding Feed Material
TS, mg/1
TVS, mg/1
SS, mg/1
VSS, mg/1
BOD5 (total), mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
PO/ (total), mg/1 as P
- 027
Supernatant
0 Hr
17,290
14,315
16,630
13,330
8,550
50
261
65
- 039
9,850
7,920
5,860
4,900
3,030
71
225
64
Quality Following
24 Hr
13,700
11,330
12,650
10,050
8,240
50
230
57
7,230
5,740
5,220
4,240
2,980
70
195
58
Sedimentation For
48 Hr
13,520
11,100
12,500
9,840
8,030
50
230
53
6,840
5,330
5,130
4,120
2,640
68
190
52
79
-------
TABLE A-3. SUPERNATANT CHARACTERISTICS FOLLOWING AERATION
AND TWO HOURS SETTLING
Parameter
Corresponding Feed Material*
Aeration Period, Hours
3
Supernatant Volume, m
, gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
P04 (total), mg/1 as P
P04 (ortho) mg/1 as P
Alkalinity, mg/1 as CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease & Oil, mg/1
101
001
16
0.57 C
150
2,460 4,
1,960 3,
1,910 3,
1,700 3,
5.9
1,190 2,
240
2,460 10,
4.3
67
10
<5
106
15
-
0.04 0
2.0
0.20 0
3.0
(Continued)
80
Treai
102
002
16
1.30
80
400
560
930
410
6.4
920
510
400
19
123
30
15
100
38
-
.04
2.9
.45
2.9
-
tment Number
103
004
16
0.76
200
9,320
8,410
7,570
6,900
6.1
3,660
1,020
12,600
32
438
31
1
460
-
-
-
-
-
4,140
104
017
16
0.76
200
18,570
15,600
12,300
10,600
6.7
2,540
390
16,200
58
332
56
19
258
-
-
-
mm
mm
6,970
-------
TABLE A-3. (Continued)
Treatment Number
Parameter
Corresponding Feed Material*
Aeration Period, Hours
o
Supernatant Volume, mj
, gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
PO^ (total), mg/1 as P
PO^ (ortho) mg/1 as P
Alkalinity, mg/1 as CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
^Initial Volume 0.76 m^ (200
105
001
20
0.53
140
1,540
1,150
810
760
5.5
710
280
820
17
34
<10
<5
98
4.3
-
0.04
0.47
0.07
0.90
gal)
106
Oil
24
0.76
200
13,100
11,000
10,800
9,540
6.6
5,910
262
17,300
58
212
25
18
340
-
-
-
-
-
-
107
021
24
0.76
200
15,800
11,175
10,200
7,850
6.3
3,840
780
29,500
36
229
66
30
240
_
-
-
-
-
1,710
108
002
96
0.42
110
1,800
1,150
875
790
6.4
180
150
2,390
10
15
<10
<5
47
26
-
0.04
1.8
0.32
2.1
81
-------
TABLE A-4. SUPERNATANT CHARACTERISTICS FOLLOWING
FERRIC CHLORIDE ADDITION TO RAW SCREENED SEPTAGE
Treatment Number
Parameter
Corresponding Feed Material*
FeCl3 Dose, mg/1 as FeCl3
o
Supernatant Volume, m
» gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
P04 (total), mg/1 as P
PO^ (ortho) mg/1 as P
Alkalinity, mg/1 as CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
109
007
400
0.45
120
960
360
64
58
5.0
700
680
670
72
31
<2
<2
16
18
-
-
0.05
0.60
0.8
110
008
400
111
009
600
0.49 0.45
130 120
1,400 1
630
88
74
4.8
1,380 1
1,140 1
1,320 1
60
40
10.5
5.5
220
10
-
-
0.13
0.50
0.43
(Continued)
82
,430
510
68
52
3.3
,200
,080
,050
62
24
<1
-------
TABLE A-4. (Continued)
Parameter
115
Corresponding Feed Material* 014
FeCl^ Dose mg/1 as Fed-
Supernatant Volume, m3
t gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
PO^ (total), mg/1 as P
PO^ (ortho) mg/1 as P
Alkalinity, mg/1 as CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
*Initial Volume - 0.76 m3
400
0.53
140
2,920
1,680
200
150
5.8
1,165
1,055
1,495
78
29
2
<2
320
-
-
-
-
-
-
-
(200 gal)
Treatment Number
116
016
400
0.42
110
1,060
580
20
20
6.2
175
-
350
28
10
<2
<2
50
-
-
-
-
-
-
204
117
017
400
0.38
100
2,340
1,790
800
730
6.1
480
190
2,530
59
81
3.5
<2
50
-
-
-
-
-
328
118
018
400
0.42
110
2,150 1
1,650
780
670
6.2
810
-
3,200
91
139
14
14
190
-
-
-
-
-
440
119
028
600
0.42
110
,560
765
90
85
4.2
100
84
200
24
8
<2
<2
-
-
-
_
-
-
-
120
021
500
0.57
150
2,275
1,120
45
40
4.3
120
84
235
33
4
<2
<2
-
-
-
»
_
232
83
-------
TABLE A-5. SUPERNATANT CHARACTERISTICS FOLLOWING LIME TREATMENT
OF FERRIC CHLORIDE FORMED SUPERNATANT
Treatment Number
Parameter
Corresponding Feed Material*
Lime Dose, mg/1 as Ca(OH)2
o
Supernatant Volume, nr
, gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BODc (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
P04 (total) , mg/1 as P
P04 (ortho) mg/1 as P
Alkalinity, mg/1 as CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
121
109
4,000
0.42
110
33,160
29,210
<1
<1
12.6
750
730
750
54
<1
<2
<2
-
0.10
-
-
0.04
<0.10
0.01
122
110
4,000
0.44
115
5,130
1,720
370
25
11.5
1,200
1,200
860
52
68
<1
<1
1,380
0.30
-
-
0.09
<0.10
0.22
123
111
4,000
0.40
105
2,500
600
70
5
11.3
990
900
1,120
56
29
<1
<1
1,070
0.50
-
-
0.11
<0.10
0.14
124
112
4,000
0.42
110
7,900
2,585
15
10
11.8
250
245
550
51
229
5
1
1,800
-
-
-
-
-
-'-* _
125
113
4,000
0.38
100
3,720
1,285
34
24
11.7
465
450
700
56
214
1
<1
1,460
-
-
-
-
-
-
(Continued)
84
-------
TABLE A-5. (Continued)
Treatment Number
Parameter
Corresponding Feed Material*
Lime Dose, mg/1 as CaCOH)^
s
Supernatant Volume, mj
» gal
TS, tng/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
PO^ (total), mg/1 as P
PO, (ortho) mg/1 as P
Alkalinity, mg/1 as CaCO-j
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
126
114
3,000
0.38
100
5,710
1,980
52
48
11.4
50
20
220
2
238
2
<2
1,200
0.02
-
-
<0.1
<0.1
<0.1
-
127
115
2,000
0.38
100
4,140
1,600
50
48
11.3
25
20
280
1
249
1
<1
1,000
-
_
-
-
-
-
-
128
116
2,500
0.47
125
12,770
4,225
20
10
11.7
325
310
1,200
64
15
<2
<2
2,420
-
-
-
-
-
-
-
129
117
2,000
0.44
115
5,750
1,230
130
68
12.2
650
410
1,275
56
64
<2
<2
130
-
-
-
-
-
-
190
130
118
2,500
0.42
110
7,260
2,150
65
41
12.1
46
31
200
21
7
<2
<2
2,850
-
-
-
-
-
-
204
*Initial volumes equal to those presented as supernatant volumes in Table A-4.
85
-------
TABLE A-6. SUPERNATANT CHARACTERISTICS FOLLOWING FERRIC CHLORIDE
AND LIME TREATMENT OF RAW SCREENED SEPTAGE
Parameter
Corresponding Feed Material*
FeCl3 Dose, mg/1 as FeCl3
Lime Dose, mg/1 as Ca(OH)2
0
Supernatant Volume, m
, gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BODj (soluble) , mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
PO^ (total), mg/1 as P
PO^ (ortho) mg/1 as P
Alkalinity, mg/1 as CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
*Initial Volume - 0.76 m3 (200
131
006
400
4,000
0.53
140
5,000
2,160
168
136
12.2
740
585
12,400
44
226
40
28
910
57
-
-
14
0.2
9.3
-
gal)
Treatment
132
006
400
4,000
0.53
140
6,700
2,710
125
110
12.1
190
50
3,200
38
9
<1
<1
1,900
0.6
-
-
<0.1
<0.1
0.1
-
Number
133
007
400
4,000
0.49
130
7,400
2,500
31
19
12.2
900
850
850
72
21
<1
<1
2,540
1.0
-
-
0.7
<0.1
0.1
-
86
-------
TABLE A-7. SUPERNATANT CHARACTERISTICS FOLLOWING
ALUM CONDITIONING OF RAW SCREENED SEPTAGE
Treatment Number
Parameter
Corresponding Feed Material*
Alum Dose, mg/1 as Al2 (80^)3
Supernatant Volume, nr
, gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total) , mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
P04 (total), mg/1 as P
PO^ (ortho) mg/1 as P
Alkalinity, mg/1 as CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
134
021
4,000
0.57
150
5,900
3,000
200
160
4.1
78
60
630
32
14
8
6
_
32
-
-
.28
.05
.47
135
022
3,800
0.53
140
5,815
2,630
85
70
4.0
300
230
362
38
17
7
5
-
-
-
-
-
-
-
136
022
4,700
0.38
100
6,560
3,140
250
195
3.9
300
240
400
38
16
10
7
-..,,
-
-
-
-
-
-
137
022
5,700
0.44
115
6,850
2,330
208
172
3.9
310
280
424
38
33
9
7
-
-
-
-
-
-
-
138
023
2,250
0.42
110
2,540
1,340
60
50
4.2
380
100
242
61
5
3.5
4
-
-
-
-
-
-
-
176 236 -
(Continued)
139
024
3,750
0.44
115
4,480
1,850
150
115
4.0
260
160
222
60
22
9
6
-
-
-
-
-
-
-
280
87
-------
TABLE A-7. (Continued)
Treatment Number
Parameter
Corresponding Feed Material*
Alum Dose, mg/1 as A12(SO^)3
Supernatant Volume, m3
» gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
PO^ (total), mg/1 as P
PO^ (ortho) mg/1 as P
Alkalinity, mg/1 as CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
140
024
6,000
0.44
115
5,850
2,350
100
90
4.0
315
180
283
61
<1
11
9
-
-
-
-
-
-
-
-
141
025
2,250
0.42
110
2,500
690
300
70
6.6
465
405
582
62
12
<2
<2
156
-
-
-
-
-
-
-
142
025
3,750
0.40
105
3,380
720
200
145
6.6
400
370
606
62
10
<2
<2
186
-
-
-
-
-
-
-
143
025
6,000
0.38
100
3,740
550
70
40
6.6
280
275
364
100
77
<2
<2
142
-
-
-
-
-
-
"228
144
026
3,750
0.45
120
2,810
1,060
120
90
4.2
315
315
510
29
32
8.5
2
-
_
-
-
-
-
-
-
145
026
6,000
0.44
115
2,690
1,965
510
375
4.0
400
295
1,415
31
34
9
7
-
-
-
-
-
-
-
-
(Continued)
88
-------
TABLE A-7. (Continued)
Treatment Number
Parameter
Corresponding Feed Material*
Alum Dose, mg/1 as A12(S04)3
3
Supernatant Volume, m
» gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
P04 (total), mg/1 as P
P04 (ortho) mg/1 as P
Alkalinity, mg/1 as CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
*Initial Volume - 0.76 mj (200
146
026
8,250
0.49
130
5,760
2,500
240
240
4.0
375
340
860
39
23
17
10
-
-
-
-
-
-
-
248
gal)
147
027
4,700
0.63
165
2,260
940
130
130
4.2
330
280
410
45
-------
TABLE A-8. SUPERNATANT CHARACTERISTICS FOLLOWING
ACID CONDITIONING OF RAW SCREENED SEPTAGE
Treatment Number
Parameter
Corresponding Feed Material*
o
Supernatant Volume, nr
» gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
P04 (total), mg/1 as P
PO^ (ortho) mg/1 as P
Alkalinity, mg/1 as CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
153
004
0.61
160
3,145
625
345
170
<2
350
320
600
92
108
25
25
-
10.1
-
<0.02
0.90
0.15
1.1
_
154
004
0.64
170
3,850
550
410
220
<2
420
-
485
38
52
25
23
-
34.0
0.07
<0.02
0.70
0.48
2.8
-
155
005
0.45
120
7,800
4,200
1,900
1,400
<2
1,400
1,100
3,000
82
58
52
50
-
19.0
0.05
0.16
1.5
0.70
8.5
<.*.
156
017
0.45
120
4,370
1,510
250
20
2.3
200
130
1,150
58
30
9
2
-
-
-
-
-
-
340
(Continued)
90
-------
TABLE A-8. (Continued)
Parameter
Corresponding Feed Material*
Supernatant Volume, nr
» gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
NH3-N, mg/1 as N
Organic-N, mg/1 as N
PC-4 (total), mg/1 as P
P04 (ortho) mg/1 as P
Alkalinity, mg/1 as CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
- _ - __~~i " " ^ * A ~^. ._.
157
018
0.61
160
4,970
1,620
83
74
2.8
560
400
800
94
51
60
59
-
-
-
-
-
-
_
160
Treatment
158
021
0.57
150
3,520
800
175
150
2.4
200
140
630
38
10
58
14
-
-
_
-
-
-
-
196
Number
159
028
0.70
185
4,105
2,230
120
115
2.0
92
72
303
25
40
21
9
-
-
-
-
-
-
-
-
160
029
0.66
175
4,320
2,170
250
210
2.2
60
53
404
40
62
29
23
-
-
mm
-
-
-
-
238
*Initial Volume - 0.76 mj (200 gal)
91
-------
TABLE A-9. SUPERNATANT CHARACTERISTICS FOLLOWING
LIME TREATMENT OF ACID FORMED SUPERNATANT
Treatment Number
Parameter
Corresponding Feed Material*
o
Supernatant Volume, nr
, gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
Organic-N, mg/1 as N
PO^ (total), mg/1 as P
P04 (ortho) mg/1 as P
0-P04, mg/1 as P
Alkalinity, mg/1 as CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
161
153
0.57
150
3,300
445
nil
nil
11.2
120
120
120
62
37
2
<1
-
0.30
0.03
<0.02
0.02
0.01
0.06
-
162
154
0.57
150
3,150
230
nil
nil
>11
88
88
89
38
27
2
2
-
0.36
<0.02
<0.02
0.15
0.46
0.15
-
163
155
0.38
100
9,050
1,420
200
140
>11.5
1,400
1,050
1,310
58
20
2
<1
930
0.36
0.03
<0.01
0.52
<0.01
0.57
-
164
156
0.53
140
6,200
1,140
103
60
12.0
350
330
1,330
38
45
10
1
1,820
-
-
-
-
-
-
260
(Continued)
92
-------
TABLE A-9. (Continued)
Treatment Number
Parameter
Corresponding Feed Material*
o
Supernatant Volume, mj
» gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble), mg/1
COD, mg/1
Organic-N mg/1 as N
P04 (total), mg/1 as P
PO^ (ortho) mg/1 as P
0-P04, mg/1 as.P
Alkalinity, mg/1 as CaC03
Fe, mg/1
Ni, mg/1
Cd, mg/1
Cu, mg/1
Mn, mg/1
Zn, mg/1
Grease and Oil, mg/1
165
158
0.42
110
5,160
1,170
23
10
12.2
240
75
400
40
0
<2
<2
1,410
-
-
-
-
-
-
208
166
159
0.57
150
5,200
1,230
130
68
12.2
650
410
1,275
59
61
<2
<2
1,130
-
-
-
-
-
-
190
167
160
0.63
165
6,820
1,470
60
25
12.0
83
45
200
37
14
<2
<2
2,420
-
-
-
-
-
-
-
*Initial volumes indicated as supernatant volumes in Table A-8.
93
-------
TABLE A-10. SAND DRYING BED TREATMENT OF RAW SCREENED SEPTAGE
Parameter
Trial No. 1 Volume, m
» gal
TS, mg/1
TVS, rag/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5, (total), mg/1
BOD5, (soluble), mg/1
Trial No. 2 Volume, m3
, gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total) , mg/1
BOD5 (soluble), mg/1
Raw Sept age
0.18
48.0
10,340
7,700
7,240
5,800
6.2
5,650
1,100
0,18
48.0
10,060
7,270
8,150
6,680
5.3
5,690
2,320
Filtrate
Day 1
0.09
24.0
1,790
1,280
310
300
6.6
755
662
0.14
36.0
1,880
1,390
490
425
6.2
1,630
1,230
On
Day 2
0.05
12.0
1,080
750
70
70
6.9
650
615
-
-
-
-
-
-
-
-
(Continued)
94
-------
TABLE A-10. (Continued)
Parameter
Trial No. 3 Volume, m3
, gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BODs (soluble), mg/1
Trial No. 4 Volume, m3
, gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total), mg/1
BOD5 (soluble) , mg/1
Raw Septage
0.18
48.0
16,280
12,350
14,560
7,280
6.3
7,450
2,580
0.18
48.0
14,320
10,130
8,550
5,200
5.4
9,560
2,550
Filtrate
Day 1
0.10
27.0
1,400
950
200
180
6.7
750
640
0.13
33.0
1,450
1,080
240
220
6.8
1,090
895
On
Day 2
»»
-
-
-
-
-
-
-
-
-
-
-
-
-
-
_
95
-------
TABLE A-ll. SAND DRYING BED TREATMENT OF THE COMBINED SLUDGE FRACTIONS
FROM FeCl3 ADDITION FOLLOWED BY LIME ADDITION
Parameter
Trial No. 1 Volume, m3
» gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total) mg/1
BOD5 (soluble) mg/1
3
Trial No. 2 Volume, m
» gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH,, S.U.
BOD5 (total) mg/1
BOD5 (soluble) mg/1
Ferric Chloride/
Lime Sludge
0.18
48.0
-
-
11,220
3,903
11.9
7,350
2,180
0.18
48. 0
-
-
29,250
17,500
12.2
10,200
2,530
Filtrate
Day 1
0.10
25.2
-
-
9
4
12.1
1,020
1,000
0.10
25.2
-
-
9
4
12.1
1,020
1,000
On
Day 2
0.04
9.6
-
-
66
33
12.1
1,230
920
-
-
-
-
-
-
-
-
(Continued)
96
-------
TABLE A-11. (Continued)
Parameter
Trial No. 3 Volume, m3
, gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5, (total) mg/1
BOD^ (soluble) mg/1
Trial No. 4 Volume, m3
» gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total) mg/1
BOD^ (soluble) mg/1
Ferric Chloride/
Lime Sludge
0.18
48.0
-
-
14,460
5,040
11.3
-
-
0.18
48.0
-
29,250
17,520
12.2
10,200
2,530
Filtrate On
Day 1 Day 2
0.11
30.0
-
- -
49
14
11.4
860
- -
0.14
36.0
- -
66
33
12.1
1,020
890
97
-------
TABLE A-12. SAND DRYING BED TREATMENT OF ALUM CONDITIONING SLUDGE
Parameter
Trial No. 1 Volume, m3
, gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (fotal) mg/1
BOD5 (soluble) mg/1
Trial No. 2 Volume, m3
, gal
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total) mg/1
BOD5 (soluble) mg/1
Trial No. 3 Volume, m3
, gal
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total) mg/1
BOD5 (soluble) mg/1
Alum Sludge
0.18
48
41,180
32,560
30,600
25,500
4.0
10,240
1,180
0.18
48.0
26,470
22,060
4.1
8,850
1,190
.18
48
34,730
28,940
3.9
11,630
1,170
Filtrate On
Day 1 Day 2
0.15
38.4
1,130
950
79
29
5.1
240
220
0.14
38.2
81
46
5.0
320
320
0.15
38.6
77
12
5.2
160
120
98
-------
TABLE A-13. SAND DRYING BED TREATMENT OF COMBINED SLUDGES FROM THE
ACID/LIME CONDITIONING PROCESS
Parameter
Trial No. 1 Volume, m3
, gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total) mg/1
BODij (soluble) mg/1
Trial No. 2 Volume, m3
» gal
TS, mg/1
TVS, mg/1
TSS, rag/1
VSS, mg/1
pH, S.U.
BOD5 (total) mg/1
BOD5 (soluble) mg/1
Acid /Lime
Sludge
0.18
48.0
-
-
15,170
6,023
8.9
10,350
1,660
0.18
48.0
34,387
13,900
22,140
12,920
10.4
11,700
2,110
Filtrate On
Day 1
0.11
28.8
-
-
140
140
6.8
360
330
0.09
24.0
3,720
1,290
96
96
7.5
420
360
Day 2
0.05
13.2
-
-
58
16
7.3
360
330
0.05
14.3
3,520
1,130
72
38
7.0
340
330
(Continued)
99
-------
TABLE A-13. (Continued)
Parameter
Trial No. 3 Volume, m3
, gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total) mg/1
BODc (soluble) mg/1
Trial No. 4 Volume, m3
, gal
TS, mg/1
TVS, mg/1
TSS, mg/1
VSS, mg/1
pH, S.U.
BOD5 (total) mg/1
BOD5 (soluble) mg/1
Ac id /Lime
Sludge
0.18
48.0
31,500
27,000
30,700
24,300
3.0
36,400
1,125
0.18
48.0
31,500
27,000
30,700
24,300
3.0
36,400
1,125
Filtrate
Day 1
0.11
28.8
3,560 3
1,050 1
11
8
6.9
840
840
0.14
36.0
2,050 1
570
45
40
6.0
585
600
On
Day 2
0.05
12.0
,635
,150
15
11
6.2
930
880
0.04
10.8
,270
378
35
35
6.1
460
410
100
-------
TABLE A-14. SLUDGE DEWATERING BY SOLID BOWL CENTRIFUGE
Run
Number
2
3
4
6
12
13
15
16
18
20
24
27
29
31
42
46
50
53
54
56
58
Sludge
Type
FeCl3/Lime
FeCl3/Lime
FeCl3/Lime
FeCl./Lime
FeCl3/Lime
FeCl3/Lime
Alum
Alum
Alum
Alum
Alum
Acid/Lime
Acid/Lime
Acid/Lime
Ac id /Lime
Acid/Lime
90/10*
90/10*
90/10*
90/10*
90/10*
Influent
TSS, mg/1
31,000
42,140
28,560
26,510
22,580
30,930
33,000
28,400
36,800
22,450
31,900
29,400
24,580
30,700
32,600
38,500
31,590
23,350
18,420
23,790
29,470
Centrate
TSS, mg/1
3,695
6,928
4,754
3,720
3,280
3,686
13,973
13,120
18,260
10,140
18,500
18,800
15,490
17,550
20,120
24,000
25,100
18,420
14,580
18,920
23,540
Cake,
% Solids
16.5
16.0
14.3
15.8
15.9
16.3
20.6
20.1
18.4
17.6
17.2
19.1
20.0
20.0
19.8
21.9
16.4
20.0
18.2
19.1
16.4
% Capture
Of TSS
90.5
87.3
85.1
88.2
87.3
89.5
62.4
56.6
55.0
58.7
48.5
39.9
40.6
40.6
42.6
42.2
24.2
25.7
22.6
22.7
23.5
*90% aerobically digested secondary sludge + 10% acid/lime sludge (v/v)
101
-------
TABLE A-15. SLUDGE DEWATERING BY FILTER PRESS
Run
Number
1
2
12
15
16
18
27
28
30
31
50
53
55
Sludge
Type
FeCl3/Lime
FeCl3/Lime
FeCl3/Lime
Alum
Alum
Alum
Acid/Lime
Ac id /Lime
Ac id /Lime
Acid/Lime
90/10*
90/10*
90/10*
TSS,
Influent
29,600
31,000
22,580
33,000
28,400
36,800
29,400
24,650
32,940
30,700
31,590
23,350
27,000
mg/1
Filtrate
42
38
34
14
16
21
2
6
4
3
12
9
6
Cake
% Solids
50.0
50.1
47.2
55.0
51.3
49.8
24.9
25.3
24.8
26.0
44.6
42.8
45.7
Thickness
mm (in)
6.35 (0.25)
3.18 (0.13)
6.35 (0.25)
12.70 (0.50)
12.70 (0.50)
6.35 (0.25)
6.35 (0.25)
9.53 (0.38)
12.70 (0.50)
12.70 (0.50)
6.35 (0.25)
6.35 (0.25)
6.35 (0.25)
*90% aerobically digested^ secondary sludge + 10% acid/lime sludge (v/v)
102
-------
TABLE A-16. SLUDGE DEWATERING BY CLOTH BELT VACUUM FILTRATION
Sludge
Run #
1
2
5
7
9
14
15
16
19
22
25
27
28
36
41
Sludge
Type
FeCl3/Lime
FeClo/Lime
Fed 3/ Lime
FeCl3/Lime
FeCl,/Lime
j
Alum*
Alum
Alum
Alum
Alum
Ac id /Lime
Acid/Lime
Acid/Lime
Ac id /Lime
Acid/Lime
TSS,
Influent
29,600
31,000
20,170
20,170
24,128
33,000
33,000
28,400
26,400
29,280
31,580
24,900
24,650
30,700
33,280
mg/1
Filtrate
67
87
117
97
121
56
80
62
97
103
52
64
23
44
37
%
Solids
29.3
24.5
35.0
22.8
26.7
27.0
28.0
26.5
24.8
26.4
25.4
26.9
28.3
27.0
23.2
Cake
Thickness ,
mm (in)
1.59
(0.06)
3.18
(0.13)
1.59
(0.06)
1.59
(0.06)
1.59
(0.06)
6.35
(0.25)
1.59
(0.06)
1.59
(0.06)
1.59
(0.06)
3.18
(0.13)
3.18
(0.13)
3.18
(0.13)
3.18
(0.13)
3.18
(0.13)
3.18
(0.13)
Cake Yield
kg/m2/hr
(Ib/ft2/hr)
2.0
(0.4)
3.4
(0.7)
2.4
(0.5)
1.5
(0.3)
2.0
(0.4)
7.3
(1.5)
2.0
(0.4)
2.0
(0.4)
1.5
(0.3)
2.0
(0.4)
3.4
0.7
3.4
(0.7)
3.9
(0.8).
3.9
(0.8)
2.9
(0.6)
Conditioned with lime at 2,000 mg/1 and anionic polymer 25 mg/1.
103
-------
TABLE A-17. VACUUM FILTRATION OF A MIXTURE OF 10% ACID/LIME SLUDGE AND
90% AEROBICALLY DIGESTED SECONDARY SLUDGE (v/v%)
Feed Sludge Condi
Run # % TSS Type
A 2.2 None
B 2.6 None
C 4.6 Anionic
D 4.9 None
E 2.4 FeCl3
Lime
Anionic
F 3.7 FeCl3
Lime
Anionic
G 2.6 FeCl3
Lime
Cationic
Cake
tioner CSTT %
Dose, mg/1 Sec. Solids
121 20.4
132 5.2
15 29 24.0
57 23.0
800
4,000
10 20 17.8
600
4,000
30 29 18.4
500
4,000
160 38 12.6
Thickness, Filtrate
mm (in) TSS, mg/1
1.59 64
(0.06)
3.18 74
(0.13)
1.59 20
(0.06)
3.18 20
(0.13)
3.18 87
(0.13)
1.59 52
(0.06)
1.59 59
(0.06)
Cake Yield
kg/m2/hr
(Ibs/ft2/hr)
1.5
(0.3)
0.5
(0.1)
1.5
(0.3)
2.9
(0.6)
2.4
(0.5)
2.4
(0.5)
1.0
(0.2)
(Continued)
-------
TABLE A-17. (Continued)
o
Oi
Cake
Feed Sludge Conditioner CST, %
Run # % TSS Type Dose, mg/1 Sec. Solids
H 2.6 FeC13
Lime
Cationic
I 1.7 Alum
Lime
J 1.7 Alum
Lime
K 1.9 Alum
Cationic
L 3.4 Alum
Anionic
M Alum
Anionic
2,000
8,000
160 16 13.0
2,000 21 9.3
to pH 6.3
2,000 29 8.4
2,000
160 20 7.2
2,000
200 39 15.0
2,000
15 34 16.0
Thickness , Filtrate
mm (in) TSS, mg/1
3.18 200
(0.13)
3.18 190
(0.13)
1.59 210
(0.06)
1.59 1,200
(0.06)
1.59 3,120
(0.06)
3.18 84
(0.13)
Cake Yield
kg/m2/hr
(Ibs/ft2/hr)
1.0
(0.2)
1.0
(0.2)
0.5
(0.1)
0.5
(0.1)
1.0
(0.2)
2.0
(0.4)
-------
TABLE A-18. VACUUM FILTRATION OF A MIXTURE OF 10% RAW SCREENED SEPTAGE AND
90Z AEROBICALLY DIGESTED SECONDARY SLUDGE (v/vZ)
Run #
N
0
P
Q
R
S
Feed Sludge
Z Solids
3.7
2.9
3.1
2.8
3.7
3.7
Conditioners
Type
None
None
FeCl3
Lime
FeCl,
Lime
Anionic
Alum
Lime
Anionic
Dose, mg/1
_
-
200
6,000
2,000
6,000
25
5,000
to pH 6.5
160
GST,
Sec.
128
187
42
28
39
47
Cake
% Thickness, Filtrate
Solids mm (in) TSS, mg/1
18.2 <1.59
(<0.06)
<1.59
(<0.06)
<1.59
7.8 (<0.06)
3.58
11.5 (0.13)
1.59
8.7 (0.06)
9.2 1.59
(0.06)
290
210
110
87
76
120
Cake Yield
kg/m2/hr
(Ibs/ft2/hr)
1.0
(0.2)
_
0.5
(0.1)
1.5
(0.3)
0.5
(0.1)
0.5
(0.1)
Cake Release
Did not
release
Did not
release
Did not
release
Poor
release
Poor
release
Poor
release
-------
TABLE A-19. SEPTAGE INTRODUCED TO CONTACT ZONE OF UNIT # 1
Screened Sept age Characteristics
BOD5
(Total) ,
Date mg/1
11-18-77 3,820
11-19-77 2,610
11-20-77 1,410
11-21-77 2,430
Average 2 , 657
BODc
(Soluble),
mg/1
750
500
340
600
547
pH, S.U.
6.3
5.8
7.2
6.8
6.5
Parameters Measured
pH, S.U.
Date /Unit 1 2
11-18-77
11-19-77 6.2 6.3
11-20-77 6.2 6.3
11-21-77 6.2 6.2
11-22-77 6.3 6.3
Average 6.2 6.3
NH3-N,
mg/1 as N
1 2
._ _
6.4 4.4
6.2 4.8
i. 6 1.4
1.7 1.4
4.0 3.0
Alkalinity,
mg/1 as
CaC00
1 32
-
70 70
82 68
81 69
71 69
76 69
NHo-N, Alkalinity,
mg/1 mg/1 as
as N CaC03
95 330
52 360
51 280
60 290
64.5 315
in Contact Zone
TSS, mg/1 VSS,
121
_ - -
5,220 4,270
5,550 4,000 4,230
4,060 3,120 3,180
4,189 3.640 3,690
4,754 3,757 3,700
TSS,
mg/1
4,880
3,150
3,690
4,140
3,965
mg/1
2
-
-
2,900
2,450
2,940
2,763
VSS,
mg/1
3,820
2,480
3,190
3,650
3,285
Oj Uptake,
mg/l/hr
1 2
15.0 18.0
15.6 12.0
18.6 15.6
16.2 19.0
18.0 15.6
16.7 16.0
(Continued)
-------
TABLE A-19. (Continued)
o
CO
Parameters Measured
Date /Unit
11-18-77
11-19-77
11-20-77
11-21-77
11-22-77
Average
Date/Unit
11-18-77
11-19-77
11-20-77
11-21-77
11-22-77
Average
PH,
1
-
6.3
6.3
5.8
6.2
6.2
BOD5,
1
6
8
7
7
7
7
S.U.
2
-
6.3
6.3
6.3
6.3
6.3
mg/1
2
13
10
10
9
9
8.2
Alkalinity,
NH3-N, mg/1 as
mg/1 as N CaC00
1
-
5.6
6.4
3.0
3.0
4.5
2 1
- -
4.2 68
5.8 58
2.6 78
2.6 83
3.8 72
Secondary
"2
-
60
68
68
67
66
in Re-Aeration Zone
TSS,
1
-
4,270
5,050
2,980
1,200
3,375
mg/1
2
-
2,525
3,950
2,300
2,300
2,768
02 Uptake,
VSS, mg/1 mg/l/hr
121
15.0
14.4
4,230 2,920 18.6
17.4
1,000 1,740 15.6
16.2
2
21
10.8
12.6
10.8
25.8
16.2
Clarifier Effluent
NH3-N,
pH, S.U. mg/1 as N
1
6.9
7.0
7.0
6.9
6.9
6.9
2 1
6.5 3.3
6.5 3.1
6.8 2.2
6.8 2.3
2.4
6.6 2.7
2
1.9
1.2
1.5
1.9
1.5
1.6
Alkalinity,
mg/1 as CaCO-j
1
56
54
52
54
54
54
2 "
39
40
38
44
46
41
TSS, mg/1 TOG,
121
13 15 12
14 17 12
10 10 11
- 6 14
8 5 11
11.2 10.6 12
mg/1
2
-
7
8
6
6
6.8
(Continued)
-------
TABLE A-19. (Continued)
o
VD
Date
11-18-77
11-19-77
11-20-77
11-21-77
Falmouth
Flow,
nr/Day (mgd)
2,480
(0.655)
3,180
(0.839)
3,490
(0.920)
2,780
(0.734)
Treatment Plant - Operational
Plant
BOD5, mg/1
48
61
39
52
Influent*
TSS, mg/1
52.3
34.8
51.9
47.2
Parameters
Plant
BODs, mg/1
8
9
9
9
Effluent
TSS, mg/1
14
15
10
7
*Does not include contributions from screened septage added to plant.
-------
TABLE A-20. SCREENED SEPTAGE INTRODUCED IN RE-AERATION ZONE OF UNIT #1
Influent Septage Material
Date
12-5-77
12-6-77
12-7-77
12-8-77
12-9-77
Average
Date /Unit
12-5-77
12-6-77
12-7-77
12-8-77
12-9-77
Average
BOD5 BOD5 Alkalinity
(Total), (Soluble), NH3-N mg/1 as
mg/1 mg/1 pH, S.U. mg/1 as N CaCOi
2,280
1,740
4,200
4,200
1.035
2,810
PH,
1
6.6
6.7
6.5
6.4
6.5
6.5
540
420
360
360
400
430
S.U.
2
6.5
6.7
6.8
6.5
6.6
6.6
7.0
6.7
6.5
6.5
6.9
6.7
NH3-N
mg/1 as N
1 2
3.2 3.0
3.3 3.1
3.6 3.1
2.8 2.9
2.4 2.1
2.5 2.8
62
52
54
54
44
53.2
Contact Zone
Alkalinity
mg/1 as
CaC03
1 2
82 68
78 68
84 70
78 74
76 74
79.6 70.8
330
285
310
310
340
255
Values
TSS, mg/1
1 2
3,310 2,320
3,110 2,460
3,670 3,030
3,712 2,880
3,300 3,170
3,420 2,772
TSS, mg/1 VSS, ma/1
3,810
3,800
2,400
2,400
3,840
3,252
VSS,
1
2,410
2,170
2,650
2,590
2,238
2,412
3,270
3,270
2,070
2,070
2,600
2,656
02 Uptake
mg/1 mg/l/hr
212
1,694 11.4 11.
1,700 12.0 11.
2,160 15.0 9.
2,080
1,902 11.4 10.
1,907 12.4 10.
4
2
0
8
6
(Continued)
-------
TABLE A-20. (Continued)
Re-Aeration Zone Values
Date/Unit
12-5-77
12-6-77
12-7-77
12-8-77
12-9-77
Average
Date/Unit
12-5-77
12-6-77
12-7-77
12-8-77
12-9-77
Average
pH, S.U.
1 2
6.5 6.3
6.5 6.4
6.5 6.5
6.4 6.5
6.7 6.5
6.5 6.4
BODs mg/1
112
10.5 5.4
8.6 3.5
_ _
11 7,5
12.3 4.8
10.6 5.3
Alkalinity,
NH3-N, mg/1 as
mg/1 as N CaCOq
1 2
2.0 1.0
4.3 3.2
2.5 2.3
2.0 2.0
1.1 1.0
2.4 1.9
PH,
1
6.9
7.8
-
7.1
6.8
7.1
1 2
66 64
70 86
86 76
88 78
94 70
81 75
Secondary Clarifier
NH3-N,
S.U. mg/1 as N
21 2
6.8 2.8 2.6
7.2 2.2 2.2
_ - _
6.9 3.1 3.5
6.7 2.5 3.0
6.9 2.6 2.8
TSS, mg/1
1 2
4,280 3,800
3,800 4,100
5,200 4,100
5,550 4,600
4,000 3,220
4,566 3,964
Effluent Values
Alkalinity,
as CaCOr?
1 2
52 50
56 58
- -
56 62
62 62
56 57
02 Uptake
VSS, mg/1 mg/l/hr
1 21 2
3,100 2,710 9.0 10.2
2,760 2,400 9.6 8.4
3,800 2,900 14.0 9.6
3,860 3,260
2,760 2,390 13.8 9.0
3,256 2,732 11.6 9.3
TSS, mg/1 TOC, mg/1
12 12
5.1 3.7 13 9
46 22 97
_ _ _ _
56 34 18 12
27 19 12 9
33.5 19.7 13 9
(Continued)
-------
TABLE A-20. (Continued)
Falmouth Treatment Plant - Operational Parameters
.Flow Total Plant Influent* Total Plant Effluent
Date
12-5-77
12-6-77
12-7-77
12-8-77
12-9-77
mj/day mgd BOD^jng/1
3,440 39
(0.907)
3,140 48
(0.828)
3,140 51
(0.829)
2,670 37
(0.704)
5,190 42
(1.37)
TSS^ mg/1 BOD5 mg/1 TSS, mg/1
54.3 8 4.2
39.7 6 12.1
52.8
47.8 9 9.2
65.6 8 11.8
*Does not include contributions from screened septage added to plant
-------
TABLE A-21. SETTLING RATE DATA FOR SEPTAGE CONDITIONED WITH ACID
mg/1, TSS
Depth,
Inches
0
7
15
22
30
36
Time, Hours
0
4,340
4,500
5,050
4,600
5,970
6,120
1
250
520
7,040
7,100
11,800
12,580
2
82
86
200
8,400
15,400
16,290
3
80
80
130
210
16,500
18,340
4
80
80
148
157
18,200
21,280
5
80
76
123
100
17,600
22,940
6
67
62
76
74
20,900
23,750
22
45
65
62
62
310
26,280
Final pH - 2.0
Total Tank Depth - 106.7 cm (42 in)
113
-------
TABLE A-22. SETTLING RATE DATA FOR LIMED ACID SUPERNATANT
mg/1, TSS
Sampling Depth,
cm (in)
0.0
17.8
38.1
55.9
76.2
91.4
(0)
(7)
(15)
(22)
(30)
(36)
Settling Time, Hours
0
640
640
750
750
750
750
1
30
52
46
45
950
2,210
1.5
30
30
30
30
30
4,010
2.0
30
30
30
30
30
5,260
Final pH - 11.5
Total Tank Depth - 106.7 cm (42 in)
114
-------
TABLE A-23. SETTLING RATE DATA FOR FERRIC CHLORIDE AND LIME
CONDITIONED SLUDGE
Depth,
Inches
0
7
15
22
30
36
mg/1, TSS
Time, Hours
0 1 2 3 4 56
6,800 75 40 40 40 30 30
6,800 75 50 40 40 30 30
7,200 5,800 75 50 42 33 33
6,700 13,600 14,200 6,400 75 40 40
6,800 11,570 16,900 19,390 25,900 18,600 23,120
6,950 12,200 16,900 21,290 26,480 19,230 24,280
22
30
30
30
40
750
26,590
FeCl3 - 400 mg/1
Ca(OH)2 - 4,000 mg/1
Total Tank Depth - 106.7 cm (42 in)
115
-------
TABLE A-24. SETTLING RATE DATA FOR ALUM CONDITIONED SEPTAGE
mg/i, TSS
Depth,
Inches 0
0 6,400
7 6,410
15 6,600
22 6,800
30 6,790
36 7,240
Time, Hours
1
138
194
6,590
8,920
10,600
11,200
2
72
74
185
11,400
17,700
18,400
3
74
70
80
2,350
23,700
25,280
4
70
68
74
170
16,600
26,570
5
68
70
80
80
20,500
27,290
6
70
70
75
80
26,300
29,380
22
60
64
72
72
278
29,560
Alum - 4,000 mg/1
No pH adjustment
Total Tank Depth - 106.7 cm (42 in)
116
-------
TABLE A-25. COLIFORM KILL BY ACID ADDITION
Contact
Time, Hr
0
4
S
16
pH, S.U.
TSS, mg/1
T, °C
Trial 1
4.5 x 106
1,200
<20
<20
1.6
13,280
20
Coliform Colonies/100 ml
Trial 2
5.8 x 106
910
200
<20
1.9
9,840
20
Trial 3
6.3 x 106
1,100
<20
<20
2.0
6,840
20
117
-------
TABLE A-26. LIME AND HEAT TREATMENT OF
RAW SCREENED SEPTAGE
Trial
//I
Coliform
Count, 10 6
Colonies/ 100
ml
Temperature, *C
pH
5
7
9
10
11
Trial
5
7
9
10
11
Trial
5
7
9
10
11
20
2.1
4.2
10.6
0.036
#2
1.3
4.1
11.5
0.058
#3
^ 1.7
3.4
8.8
0.056
35
2.1
110
110
x
1.3
95
95
x
1.4
95
95
x
50
__
0.75
0.058
x
^^
0.83
0.036
x
__
0.83
0.056
x
62
x
x
X
X
X
X
X
X
X
X
X
X
X
X
X
x « less than 20/100 ml
(Continued)
118
-------
TABLE A-26. (Continued)
Trial #1
Sludge Volume, % of Total
Temperature °C
PH
5
7
9
10
11
20
100
95
80
SO
35
100
95
80
60
50
__
65
50
30
62
100
65
50
__
30
Trial #2
5
7
9
10
11
100
95
80
80
100
95
80
65
65
50
30
100
65
50
__
30
Trial #3
5 100 100 100
7 95 95 65
9 80 80 65 50
10 50
11 80 70 30 30
119
-------
TABLE A-27. PILOT SCALE EQUIPMENT IN U.S. EPA
SLUDGE DEATERING TRAILER
Description
Manufacturer
Solid Bowl Centrifuge
Basket Centrifuge
Cloth Belt Vacuum Filter
Filter Press
Sharpies, Model P-600E
DeLaval, Model 12
Eimco, 0.92 m (3 ft) drum
diameter by 0.46 m (1.5 ft)
drum length
Dart-Hoesch, Model MP-300
120
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-78-164
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
PILOT SCALE EVALUATIONS OF SEPTAGE TREATMENT
ALTERNATIVES
5. REPORT DATE
September 1978 (Issuing Date
6. PERFORMING ORGANIZATION CODE
17. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
Arthur J. Condren
;
PERFORMING ORGANIZATION NAME AND ADDRESS
Edward C. Jordan Maine Municipal Association
Co., Inc. for Local Government Center
Portland, ME 04112 the Community Drive
Augusta, ME 04330
10. PROGRAM ELEMENT NO,
1BC611.AP C611B,SGS #6, Task OS
11. CONTRACT/GRANT NO.
R804804-01
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research LaboratoryCin.,OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final 10/76-3/78
14. SPONSORING AGENCY CODE
EPA/600/14
15. SUPPLEMENTARY NOTES
Project Officer:
Robert P. B. Bowker (513) 684-7620
16. ABSTRACT ' ~ ~ ~~~~~" "
Pilot scale studies at a 3.79 m^/day (1,000 gpd) facility on septage treatment have
indicated a number of alternatives exist. Screening with a 40-mesh (0.42 mm opening)
vibrating screen yielded approximately 75 percent TSS removal as well as a resulting
liquid that could be conditioned with conventional chemicals. Conditioning of screenec
septage with lime, ferric chloride, and/or alum yielded positive results but required
extensive jar testing to optimize chemical dose(s). A two-stage acid/lime process
was developed for conditioning which yielded consistent positive results with no jar
testing required. The sludge fraction from various conditioning studies was dewatered
by centrifugation, vacuum filtration, filter pressing and sand bed drying with the
latter two techniques affording more positive results. The aqueous fraction from
various conditioning studies was subjected to chlorination, activated carbon adsorp-
tion, intermittent sand filtration and conventional biological treatment at a munici-
pal treatment plant with the latter two techniques yielding more positive results.
Studies on leachate from dewatered septage solids buried in soil indicated soil type
had a pronounced impact on leachate quality. Treatment of screened septage in a
municipal secondary treatment plant was also investigated. Selected system designs
ana associated capital ana operating coses xur sepcage treauueui. OLC pxcaejueu aim
discussed.
17. KEY WORDS AND DOCUMENT ANALYSJS |
3. DESCRIPTORS
Sludges
Septic tanks
Screenings
Treatment
Settling
Dewatering
Disposal
18. DISTRIBUTION STATEMENT
Release to Public
b.lDENTIFIERS/OPEN ENDED TERMS
Septic tank sludge
(septage) treatment
Septage treatment
system design
19. SECURITY CLASS (This Report)
Unclassified
20. SECURITY CLASS (This page)
Unclassified
c. COSATI Field/Group 1
13B
21. NO. OF PAGES
135
22. PRICE
EPA Form 2220-1 (9-73)
.,;T U.S. GOVERNMENT PRINTING OFFICE: 1978-457-060/1478 Region No. 5-11
------- |