&EPA
United States
Environmental Protection
Agencv
Municipal Environmental Research
Laboratory
Cincinnati OH 45268
EPA-6QO/2-78-158
September 1978
Research and Development
Advanced Waste
Treatment for Housing
and Community
Developments
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development. U 3 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-600/2-78-168
September 1978
ADVANCED WASTE TREATMENT
FOR
HOUSING AND COMMUNITY DEVELOPMENTS
by
Russell Bodwell
Levitt arid Sons, Incorporated
Greenwich, Connecticut 06830
Contract No. 68-01-0077
Project Officer
Irwin J. Kugelman
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 publication. Approval does not signify that the
contents necessarily reflect the views and policies of the U.S.
Environmental Protection Agency, nor does mention of trade names
or commercial products constitute endorsement or recommendation
for use.
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FOREWORD
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 solution
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 hazardous water 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 publication is one of the
products of that research; a most vital communications link between the
researcher and the user community.
Provision of sewerage facilities for a dispersed population living in
semi-isolated subdivisions is a significant problem. Either the subdivision
must be connected to a central treatment plant, or a small scale plant must
be provided for treatment of the community wastewater. The former procedure
is often expensive because a long sewer run is required to serve only a few
homes. Small scale biological treatment plants are also relatively expen-
sive and exhibit poor performance when subjected to the wide fluctuations
of loading inherent in a small flow situation. In this study a treatment
plant for isolated subdivision wastes using wholly physical chemical treat-
ment technology was evaluated. Physical chemical treatment systems are
superior under fluctuatory loads, and are small enough to be placed in a
shell of a typical suburban house, thus reducing land costs.
Francis T. Mayo, Director
Municipal Environmental Research
Laboratory
m
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CONTENTS
Page
Foreword iii
ListofFigures V1-
List of Tables ix
Abbreviations xi
Acknowledgments x-j-j
I Introduction 1
II Conclusions 4
III Recommendations 7
IV Phase 1: Preconstruction Study
and Engineering Design 9
V Phase 2: Construction 36
VI Phase 3: Operation and Evaluation 44
A. Liquid Handling Process 44
1. Plant Startup and Break-In 44
October 1972 - June 1973
2. Steady State Operations 57
a. Normal Evaluation 65
b. Intensive Evaluation I 97
c. Intensive Evaluation II 102
B.SolidsDisposal 114
C. Plant Modifications 124
VII Financial Considerations 126
VIII Appendixes
A. Laboratory Procedures 132
B. Photographs 136
C. Conversion Table 140
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LIST OF FIGURES
Number Page
1. West Goshen Pa., Waste Treatment Plant
Flow Data for Fifty Day Period 10
2. West Goshen Pilot Plant Operation Schematic
Flow Diagram 11
3. Assumed Raw Sewage Flow Characteristics For
Surge Tank Design 16
4. Freehold Treatment Plant Furnace Sludge
Incineration Mode 23
5. Freehold Treatment Plant Furance Carbon
Regeneration Mode 24
6. Freehold Treatment Plant Regenerating Sludge
Dewatering Sand Filter 26
7. Sludge Dewatering Filter and Furnace Feed
Screw Chamber 27
8. Furnace Feed Screw Location in Sludge
Dewatering Filter 28
9. Vicinity Map Freehold Treatment Plant 37
10. Site Plan Freehold Treatment Plant 38
11. Equipment Layout, Main Floor Plan 40
12. Equipment Layout, Basement Plan 41
13. Plant Exterior 42
14. Process Flow Diagram 45
15. Flow and Occupancy During the Plant
Start-Up and Break-In Period 59
16. Monthly Variation of BOD of Sewage During
Break-In Period 63
vi
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LIST OF FIGURES
(continued)
Number Page
17. Suspended Solids Variation During Break-In
Period ................................... 64
18 Weekly Analysis Report ..................... 68
19. Average Monthly Flow During Original
Occupancy ............................... 70
20. Daily Effluent Flow July 1973-March 1974
Frequency Distribution .................. 71
21. Freehold Treatment Plant Dirunal Flow
Profile ................................. 73
22. Suspended Solids Frequency Distribution
In Raw Sewage and the Surge Tank ........ 75
23. Biochemical Oxygen Demand Frequency
Distribution In Raw Sewage and the Surge
Tank .................................... 76
24. Total Hydrolyzable Phosphorus Frequency
Distribution In Raw Sewage and the Surge
Tank .................................... 77
25. Removal of Pollutants Along the Flow Sheet
of the Freehold Treatment Plant ......... 82
26. Suspended Solids Weekly Averages .......... 84
27. Total Hydrolyzable Phosphorus Monthly
Average ................................. 85
28. Biochemical Oxygen Demand Monthly
Averages ................................ 86
29. Kjeldahl Nitrogen Monthly Averages ........ 87
30. Ammonia Nitrogen Monthly Averages ......... 88
31. Suspended Solids Frequency Distribution
Clarified and Filtered Effluent ......... 89
32. Suspended Solids Frequency Distribution
Plant Effluent .......................... 90
33. Biochemical Oxygen Demand Frequency
Distribution Ferrofilter Effluent ...... 92
vi i
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LIST OF FIGURES
(conti nued)
Number
34. Biochemical Oxygen Demand Frequency
Distribution Plant Effluent ............. 93
35. Intensive Analysis II
Daily Variation Suspended Solids 10 Day
Average, 2 Hour Frequency January 17, 1974-
April 7, 1974 ........................... 104
36. Intensive Analysis II
Daily Variation Biological Oxygen Demand
10 Day Average, 2 Hour Frequency
January 17, 1974-April 7, 1974 .......... 105
37. Intensive Analysis II
Daily Variation in Total Organic Carbon
10 Day Average, 2 Hour Frequency
January 17, 1974-April 7, 1974 .......... 106
38. Intensive Analysis II
Daily Variation in Total Oxygen Demand
10 Day Average, 2 Hour Frequency
January 17, 1974-April 7, 1974 .......... 107
39. Intenstive Analysis II
Daily Variation in Total Kjeldahl Nitrogen
10 Day Average, 2 Hour Frequency
January 17, 1974-April 7, 1974 .......... 108
40. Intensive Analysis II
Daily Variation in Phosphorus 10 Day
Average, 2 Hour Frequency January 17, 1974-
April 7, 1974 ........................... 109
41. Intensive Analysis II
Daily Variation in Ammonia-Nitrogen
10 Day Average, 2 Hour Frequency
January 17, 1974-April 7, 1974 .......... HO
42. Intensive Analysis II
Daily Variation in pH 10 Day Average,
2 Hour Frequency January 17, 1974-
April 7, 1974 ........................... '"'
43. Estimated Operating Cost vs. Plant Size... 130
vn i
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LIST OF TABLES
Number Page
1. West Goshen Pilot Plant Operation
Operating Conditions 13
2. West Goshen Pilot Plant Operation
Operating Results 14
3. Incinerator Design Parameters 31
4. Occupancy and Flow 58
5. Raw Sewage Characteristics 60
6. Surge Tank Characteristics 61
7. Plant Effluent Characteristics 62
8. Analytical & Sampling Schedule
During Normal Evaluation 66
9. Analytical & Sampling Schedule in Addition
to Normal Evaluation During Intensive
Evaluation 67
10. Occupancy and Flow 69
11. Liquid Treatment Performance Average Values 78
12. Liquid Treatment Performance Average Analysis 80
13. Liquid Treatment Performance Efficiencies 81
14. Chemical Consumption 94
15. Intensive Evaluation I
Average Values 99
16. Intensive Evaluation II
Average Values 103
17. Intensive Evaluation II
Three Period Average 112
ix
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LIST OF TABLES
(conti nued)
Number Page
18. Freehold Sludge Characteristics 116
19. Intensive Evaluation - Sludge Samples 118
20. Hydrasieve Solids Collected 119
21. Incinerator Operating Data 123
*• 22. Operating Costs 128
23. Projected Operating Costs 131
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ABBREVIATIONS
AC - Alternating Current
ALK _ Alkalinity
B°D _ Biochemical Oxygen Demand (Five-Day)
CFM - Cubic Feed Per Minute
COD _ Chemical Oxygen Demand
Col _ Coliform
DC _ Direct Current
D!A. - Diameter
00 - Dissolved Oxygen
FTU _ Formazin Turbidity Unit
GAL. - Gallon (United States Measure)
_ Gallons Per Hour
_ Gallons Per Minute
HP - Horsepower
Hr. . Hour
ID - Interval Diameter
JJU - Jackson Turbidity Unit (1FTU a 1JTU)
mg/1 - Milligrams Per Liter
MGD _ Million Gallons Per Day
NH3-N - Ammonia Nitrogen
P - Hydrolyzable Phosphorus
PSIG - Pounds Per Square Inch - Gauge
Res. C12 _ Residual Chlorine
RPM _ Revolutions Per Minute
SCFM _ Standard Cubic Feed Per Minute
SS _ Suspended Solids
TDH _ Total Discharge Head
TDS _ Total Dissolved Solids
TKN . Total Kjeldahl Nitrogen
TOD _ Total Oxygen Demand
TS _ Total Solids
xi
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ACKNOWLEDGMENTS
The authors wish to acknowledge the contributions of several
persons and organizations whose efforts were instrumental in
developing and completing this project.
Mr. Wallace B. Johnson of AWT Systems, Inc. for his efforts
and contributions in process research and development on this
plant and for preparing the greatest portion of this report.
Mr. Russell S. Bodwell, Vice President-Engineering, Levitt
and Sons, Inc., and the Engineering Department of Levitt and
Sons, Inc. for their interest and efforts in advancing the state-
of-the-art of waste water treatment plants relative to optimizing
effluent quality standards and incorporating treatment plants in
total compact community planning.
AWT Systems, Inc., for their efforts in research and design
of the treatment system and interest and contributions in the
construction and evaluation of the plant.
Appreciation is also expressed to Mr. Carl Birkhimer and Mr.
Henry J. Greenemeir of Winslow Sanitary Company. Both were plant
operators during the stead-state operation phase and whose
efforts in the collection of samples, smooth plant operations,
and general cooperation and assistance were invaluable.
Acknowledgment must also be made to Henderson and Bodwell
for modifications to the system, greatly instrumental in reducing
operating costs and increasing plant reliability; modifications
were largely implemented by Mr. Birkhimer. They also prepared
portions of the final draft and documents included herein.
xi
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SECTION I
INTRODUCTION
GENERAL
The home and community building industry, in order to meet
the housing requirements of today, has developed a concept of
total community planning. Such community planning includes
single-multi family housing, shopping centers, sites for industry,
schools, churches, etc. Consequently the building industry is
faced with a unique waste water disposal problem in that the
industry, not the municipality, is generally required to provide
adequate disposal facilities for new community developments.
This trend toward total community planning, in which domestic and
industrial wastes must be handled over a wide range of flow rates
and waste characteristics, requires that building firms in this
country have access to treatment facilities of types heretofore
seldom utilized.
A national commitment to manage water quality has been mani-
fested in the past decade in response to continual degradation of
water supplies for beneficial uses. Technical, legislative, and
financial moves have begun to zero in on the environmental prob-
lems. One of the first and most important needs in our national
priorities to meet existing water management goals is to develop
the minimum cost technology for removing contaminants from water
and permanently disposing of them in order to alleviate water
pollution problems. A further objective is to renovate waste
waters for agricultural, industrial, recreational, or even poten-
tially potable purposes. New advanced systems are now being
designed to meet the new objectives of total pollution control,
namely, the capability of treatment to extremely high levels of
quali ty.
Advanced waste treatment has made great progress in supply-
ing many tools to water resource management. Traditionally,
small scale treatment plants have had to be installed where
existing sewer lines were not available for hookup, or where
barriers existed making hookup impractical. Suburban developments
had to make use of so-called "package plants" to treat their
waste water flows. These plants are usually adaptations of the
conventional activated sludge process designed to meet special-
ized problems encountered in situations where flow is highly
variable.
1
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Two commonly used modifications are extended aeration and
contact stabilization. Contact stabilization aerates waste water
mixed with highly concentrated activated sludge to adsorb colloi-
dal organics. Sludge from a clarifier is then aerated to stabil-
ize the organic matter and renew the sludge surface for more
adsorption. Extended aeration handles waste without primary
settling. The aeration tank acts as an equalization basin to
smooth out variations in load and to dilute slugs of concentrated
or toxic impurities.
The most serious problems encountered with these package
plant units are related to the highly varying natures of waste
water flow together with waste strength or concentration. For
example, it is common to see flow patterns where peak flows of
2.5 to 3 times the average occur during the day and zero flow
occurs during hours of the night. Such flow and strength charac-
teristics are ill suited to the capabilities of secondary bio-
logical processes. Coupling these shock loadings with substandard
operation, maintenance, and reliability, it is not surprising that
these plants cannot be expected to achieve, on a consistent basis,
existing and projected water quality effluent requirements.
Physical-chemical treatment represents the first major inno-
vation in sewage treatment in several decades. Such systems,
while increasing the capability for handling a wide range of con-
tinuous and intermittent flow rates, offer added advantage in the
ability to handle toxic industrial wastes and to remove components
which cannot be treated biologically.
Advantages of a physical-chemical system include:
1. Smaller land area required (less than 1/2) of the
conventional biological plant.
2. Higher degrees of treatment efficiency than conventional
biological processes.
3. Lesser sensitivity to unusual loadings.
4. Lesser sensitivity to daily flow variations.
5. Greater design flexibility.
6. Greater operational flexibility and control.
Because these features make it possible to meet stringent effluent
criteria in remote sites, physical-chemical treatment technology
was chosen for a plant in a community in northern New Jersey. The
basic concept was to place the treatment plant within the frame of
a standard house on a standard lot in a subdivision. This pro-
cedure provides more land for ultimate development because a
buffer zone need not be established around the treatment plant as
it must if more conventional technology is used.
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LOCATION
An advanced waste treatment system based on physical-chemical
treatment technology was designed to serve approximately 127
single-family dwelling units, and a demonstration plant was con-
structed in a residential subdivision in Freehold Township, Mon-
mouth County, known as Woodgate Farms. The nominal average design
flow was 50,000 GPD.
PLANT DESCRIPTION
The plant design chosen provided for screening, flow equal-
ization, chemical coagulation, sedimentation, filtration, carbon
adsorbtion, and disinfection with chlorine. Sludge was to be de-
watered on site and incinerated on site in a fluidized bed furnace.
OBJECTIVE
The specific objective of this project was to demonstrate
the performance, economics, and applicability of a physical-
chemical domestic wastewater treatment system designed to provide
varying high quality discharges for isolated or developing com-
munities having an average wastewater flow in the 25,000 to
500,000 GPD range.
APPROACH
The total project was conducted in the following three phases
Phase I - Preconstruction Study and Engineering, during which
all necessary preliminary studies, subsystem designs, and engineer-
ing plans were completed.
Phase II - Construction, including purchase of all equipment,
subcontract work, construction of the building, and assembly of
the complete system.
Phase III - Operation and Evaluation, including a start-up
and break-in period while houses in the development were being
built and occupied (October 1972 through June 1973), and a period
of operation under steady state conditions (July 1973 through
March 1974) to obtain data on all aspects of plant performance.
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SECTION II
CONCLUSIONS
1) The physical-chemical wastewater treatment system provided
a high-quality discharge while processing all the sewage from an
isolated community of 127 single-family dwelling units over a
period of 18 months.
2) Average treatment performance showed removals of 99%
BODs, suspended solids and phosphorus; 37% Kjeldahl nitrogen.
The use of the ferric chloride coagulant caused reduction of 46%
alkalinity and a threefold increase in chlorides.
3) Unit operations performance shows:
a. Primary screen removed approximately 1/4 of the BOD,
suspended solids and phosphorus.
b. Chemical treatment and clarification removed approx-
imately 2/3 of the 8005, suspended solids and phosphorus.
c. Carbon adsorption removed about 16% of the BOD and
25% of the TKN.
d. Filtration was relatively ineffective.
4) Characteristics of raw sewage from the totally domestic
source were:
Flow - 206 gpd/unit
BOD - 207 mg/1
SS - 242 mg/1
TS - 628 mg/1
P - 10.8 mg/1
TKN - 44.7 mg/1
Coliforn - 1.1 x 106 MPN/100 ml
5) Twenty-four hour raw sewage profiles on flow and eight
analytical parameters showed substantial variation. For example:
Hourly peak flow (180% of average) occurred at 11 a.m.-noon, with
secondary peaks at 8 p.m. and 11:30 p.m. Minimum flow was reg-
istered between 4 and 5 a.m. at 14% of average. Analytical para-
meters showed similar variation but with peak and minimum concen-
trations occurring at different hours.
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6) The surge tank, provided to level out raw sewage varia-
tion, was very effective. It allowed constant flow rate process-
ing through the plant with only periodic adjustment. Also varia-
tions in the concentration of major constituents were smoothed
out and reduced to about half that in the instantaneous flow.
7) Chemical consumptions were higher than anticipated, aver-
aging 267 mg/1 for FeCls; 154 mg/1 for NaOH; 2.6 mg/1 for poly-
electrolyte; and 26.4 mg/1 for chlorine. They have been reduced
with plant modifications which include more automation, pH control
of FeCls, and greater mixing effectiveness and detention times.
8) Operating costs were higher than anticipated because:
a. Labor costs were excessive due to the experimental
nature of much of the equipment, due to the high level of analyt-
ical work carried out, and because more manual control was required
than anticipated.
b. Chemical, fuel and utility costs escalated signifi-
cantly during the trial period.
9) Soli ds disposal.
a. Sludge discharged from the clarifier averaged 6.8%
soli ds .
17%
b.
soli ds.
Sludge discharged from the primary screen averaged
c. An experimental continuously regenerating filter did
not perform satisfactorily for dewatering of the sludges.
d. Direct incineration of clarifier sludge was success-
fully conducted for short periods, but required significant
quanti ties of fuel .
e. Particulate emission was 0.011 grains/cu. ft. from
the incineration.
failure
use was
costs.
f. The incinerator was plagued with problems such as
of the distributor plate and hot spots in the shell. Its
discontinued due to above problems coupled with high fuel
10) An automated sludge removal system using an optical den-
sity probe has worked exceptionally well, and is a recommended
feature for future design considerations.
11) The magnetic filter used here has limited potential for
use if applied after a clarification process which functions
properly.
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12) The turbidimeter used to signal for recycle of poor
quality effluent to the head of the plant during periods of non-
operator attendance proved highly satisfactory. If possible,
however, the turbidimeter should have a continuously adjustable
set point in order to be used to full advantage by the operator.
13) The plant had an attractive appearance with no odors
or problems with close neighboring houses in four years of opera-
tion .
14) Liquid handling, chemical feed, mixing, and control
thereof, can be highly automated to minimize manpower require-
ments .
15) Disadvantages of this type of treatment plant are:
a. High electric and energy cost
b. Sludge disposal problem
c. Deficiency in nitrogen removal
d. Pumps and equipment are more prone to maintenance
problems than in large plants.
e. High cost of chemicals.
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SECTION III
RECOMMENDATIONS
Based on the experience gained from research, development,
construction and evaluation of this physical-chemical waste water
treatment plant, several positive steps are recommended to increase
plant efficiency and reduce operating costs.
Plant Efficiency: Positive head pumps in the lift station
would provide more dependable operation; solids cutting capability
in raw sewage pumps would improve settling process in the clari-
fier; air mixing provisions in surge tank would produce a better
mixture and a larger surge tank storage capacity would enhance
equalization of BOD loading.
Operational Cost Reduction: Manpower requirement can be min-
imized by highly automating liquid handling, chemical feed, and
mixing. Bulk storage provisions for chemicals would reduce chem-
ical costs significantly. In addition, spray washing the screens
with plant effluent would minimize water consumption costs.
Within the carbon column, biological regeneration of carbon
seemed to be evident. Investigation into this phenomenon could
result in development of a system which does not require thermal
regeneration of activated carbon. It is also recommended that the
volume of the carbon quench tank and the carbon spent tank be
enlarged to the equivalent volume of carbon within the column.
These tanks could then serve as carbon storage tanks when, the col-
umn must be emptied.
Carbon columns are in need of sophisticated design considera-
tions not previously highlighted in the literature. .Among these
are:
a. Adequacy of backwash
b. Proper distribution of support mechanisms
c. Proper design of take-off
d. Properly designed screens (stainless steel in screens
and support mechanisms may have limited life).
Sludge disposal methods specifically applicable to plants of
this type and size range are needed:
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a. Land fill facilities in the nearby vicinity is the most
logical and probably economical solution.
b. A large treatment plant nearby normally handling scaven-
ger and industrial wastes would be a good alternative.
c. Dewatering and land disposal is a current possibility
but has an uncertain future.
d. Dewatering and incineration is not economical unless the
plant is in the 500,000 gpd range.
Any dewatering system must recognize the difficulties of
accomplishing this on ferric sludges. The system tried at Free-
hold consisting of the coil vacuum filter had limited success pro-
bably due to lack of adequate pre-treatment and high chemical
levels at the time of experimentation.
The concept of putting a treatment facility in the shell of
a home in a subdivision should be tried again with a different
design in another location. Special attention should be given to
the physical arrangement in the shell, the need to use equipment
and construction features different from those in standard home
construction, and the method of sludge disposal. Treatment pro-
cesses which have not been proven at the scale to be used should
not be included. Special attention should be given to the pro-
blems which may result from the use of small site lines and small
capacity pumps.
8
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SECTION IV
PHASE 1. PRECONSTRUCTION STUDY AND ENGINEERING DESIGN
A. LIQUID HANDLING PROCESS
Predesign studies on all liquid process unit operation were
conducted in a transportable pilot plant, which for these studies
was installed at the Township of West Goshen, Pa., Sewage Treat-
ment Plant. The West Goshen treatment plant is a nominal 3 MGD
trickling filter plant, treating sewage from the bedroom commu-
nity of West Goshen along with a small percentage of commercial
wastes.
The sewage entering this plant is characterized as weak, with
BOD and suspended solids averaging about 100 mg/1. Infiltration
of ground water into the collection system is estimated to be 50-
60% of the total flow. The typical diurnal flow pattern entering
the plant is shown in Figure 1.
The transportable pilot plant contained the following unit
process equipment:
1 . Primary Screen
2. Surge Tank
3. Chemical Addition System
4. Magnetic Filter
5. Carbon Adsorption System
Figure 2 is a schematic drawing of the arrangement of these
components in the process excluding the carbon adsorp.tion system
which followed the magnetic filter.
The primary screen was a Bauer Hydrasieve. It was operated
with a number of different screen openings ranging from 10 to 40
mils. A 20 mil opening was found to be optimum to give acceptable
solids removal with a minimum of blinding.
The liquid from the screen flowed by gravity into the surge
tank which was a portable 4,000 gallon vinyl-lined swimming pool.
The screened sewage was pumped through a flow control valve
and flow meter into the treatment system where inorganic floccu-
lant was added continuously. Previous work had established ferric
chloride as the most cost effective inorganic flocculant. Kenics
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FIGURE I
WESTGOSHEN.PA.
WASTE TREATMENT PLANT
FLOW DATA
FOR FIFTY DAY PERIOD
AVERAGE FLOW
10 MAXIMUM DAYS
50 DAY COMPOSITE
\MEAN FLOW
10 NORMAL DAYS
50 DAY PERIOD
MEAN FLOW
s 1,800 MOD
NAVERAGE FLOW
10 MINIMUM DAYS
12 I 2 3 4 5 6 7 8 9 10 II I2W I 2 3 4 5 6 7 8 9 10 II C
TIME OF DAY
10
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FIGURE 2
WEST GOSHEN PILOT PLANT OPERATION
SCHEMATIC FLOW DIAGRAM
Raw Sewage^ ^ J^
A S A ^ A
*l Pump ) *l Hydrasievel • "\ burge lany n Hump J
_i
_i
\
Slu
NaOH
r
dge
FeCl3
f Static A^ v r RetentionV. C Static A- ir f Flow A^
V Mixer J' \^ Loop J^ V Mixer y" ^Control ^/"
Polyelectrolyte
^Rptpntinn A ir ^ <;ta
Fe 0 M
3 * Turbidimeter
u
tip A *T .. ... A v /" MaanPticA
'V LOOD J X Mixer J V,ar,.,e»V V Filter J „*
T
Siudge
Sludge
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Corporation Static Mixers were used to achieve satisfactory mixing
with minimum energy, followed by a variable retention loop to
attain optimum contact time for ferric phosphate precipitation and
hydroxide floe formation. Study of flocculation process estab-
lished the desirability of controlling the pH of the stream after
primary coagulation, and a pH control section was added to the
system.
Following primary floe formation and pH control a polyelec-
trolyte was added, and the stream flowed through another Static
Mixer and retention loop into the clarifier. The clarifier was
constructed of plexiglass sheet to enable visual observation of
the effects of chemical and flow variations on the clarification
process. The action of the sludge blanket under varying operat-
ing conditions was also observed.
The filtration device was a magnetic filter, "Ferrofi1ter",
supplied by the S. G. Frantz Co. Its use required the addition
of finely divided magnetic iron oxide to the clarified stream.
Contact with the magnetic field in the filter removed these iron
oxide particles as well as occluded residual suspended solids
from the clarification step. Several variables were studied with
this device:
1 . Field Strength
2. Amount and type of iron oxide
3. Through-put
4. Filter loading
5. Backwash mode and cycle time
Effluent turbidity from the magnetic filter was continuously re-
corded.
Following filtration a portion of the clarified stream was
contacted with granular activated carbon in 2-inch ID adsorption
columns. An upflow expanded bed mode of operation was utilized.
Carbon capacity, shape of the column exhaustion curve, and op-
timum contact time were studied in these columns.
Table 1 summarizes the range of operating conditions used in
the West Goshen pilot plant to obtain design information for the
Freehold plant. Table 2 presents a summary of typical operating
results from the pilot plant.
B. DESIGN PARAMETERS AND EQUIPMENT SELECTION
Following the pre-design research at the West Goshen plant,
the following design parameters were selected for the plant at
Freehold, based on anticipated population, State regulations and
pilot plant analytical data.
!• Design Capacity - 50,000 GPD (35 gom)
12
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TABLE 1
WEST GOSHEN PILOT PLANT OPERATION
OPERATING CONDITIONS
Range Typical
Flow Rate from Surge Tank, gpm 10-27 20
Fe111 Addition, mg/1 19-71 45
Polyelectrolyte Addition, mg/1 0.75-2.0 1.0
Fe-jO, Addition, mg/1 5-28 10
p
Carbon Column Feed Rate, gpm/ft. 3-9 5
Carbon Contact Time, min. 20-60 40
Hydrasieve Screen Opening, mils 10 to 40 20
13
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TABLE 2
Analysis, mg/1
Surge Tank
Clarifier Effluent
Magnetic Filter Effluent
Carbon Column Effluent
Clarifier
Filter
Carbon Columns
WEST GOSHEN PILOT
OPERATING
Suspended
Solids
98
14. 9
7. 5
3. 2
PER CENT
85
92
97
PLANT OPERATION
RESULTS
Soluble
Ortho-
Phosphate
18. 5
1. 0
0. 8
0. 5
REMOVAL
94
96
97
Total
Organic
Carbon
44
18. 1
16.3
1. 5
59
63
97
Biochemical
Oxygen
Demand
95
-
23.4
4.6
75
95
-------
2. Lift Station
Dual pump system with automatic level controls. A
vacuum-primed unit was selected with dual centrifugal pumps,
each with capacity of 75 gpm.
3. Primary Screen
Bauer Hydrasieye - 36" wide x .020" openings. Since it
was possible for both lift station pumps to operate simultane-
ously, the Hydrasieve was sized for a flow of 150 gpm. In order
to avoid corrosion problems, the screen was constructed of 316
stainless steel and the frame of fiberglass reinforced polyester.
4. Hydrasieve Enclosure
Because of the possibility of generating odors around
the Hydrasieve and the necessity for frequent cleaning in the
area it was decided to enclose this unit. A room was built with
Transite paneling around the Hydrasieve on three sides and a 6
ft. glass sliding door on one side. This enclosed area was ven-
tilated by a small exhaust fan (1/8 HP, 195 CFM) discharging to
the atmosphere.
5. Surge Tank
15,680 gallons, reinforced concrete, 13.5' x 13.5' x
11.5' deep. The design capacity of the surge tank was 11,500
gallons. This was based on operation at constant withdrawal of
36 gpm with the flow profile as shown by Figure 3. This profile
was derived from flow data of a Levitt and Sons' Stony Brook,
Long Island, New York, treatment plant processing domestic sewage
which contained essentially no infiltration. Under these con-
ditions maximum calculated accumulation is 11,500 gallons. Thus,
the surge tank has excess capacity of 4,180 gallons or 36% of
normal requirements.
6. Surge Tank Agitator
The agitator was selected to provide sufficient agitation
to suspend any particles passing through the Hydrasieve screen.
The agitator selected was a 2 HP unit. The impeller operates at
68 RPM with a four blade single agitator 36" in diameter with
stabilizer fins on a 24" diameter. The center of the agitator
paddle is 24" from the bottom of the tank.
7. Primary Feed Pumps
50 gpm at 120 ft. TDH, 3 HP, 2450 rpm. The design
throughput of the plant is 35 gpm. To provide for overload con-
ditions and recycle water the pumps were specified at 50 gpm.
15
-------
FIGURE 3
200
ASSUMED RAW SEWAGE FLOW CHARACTERISTICS FOR SURGE
TANK DESIGN
\
\
LJ
tr
LJ
LJ
O
tr.
LJ
Q_
O
LJ
_l
U_
100
12
100
o
§
Z>
Z>
o
3
X
50
INFLUENT
>
LU
*
I
LJ
tE
13
cn
SURGE TANK
12 NOON
TIME
12
-------
Although the head requirement for the primary feed pumps was
approximately 50 TDK, the pumps were specified to have a 120 ft.
TDH so that they would be interchangeable with the adsorber feed
pumps.
8. Chemical Treatment System
Chemical preparation and pumping equipment, mixers, and
retention loop. This system included dual 50 gallon polyethylene
tanks for FeCla and polyelectrolyte and one tank each for NaOH
and magnetic iron oxide. Each tank was provided with an agitator.
Chemical feed pumps were electronic drive diaphragm pumps by
Precision Chemical Pump Company. Electronic controllers were
provided for the FeCls and NaOH pumps. Kenics Corporation Static
Mixers, PVC-2" pipe size by 8 elements, were installed after each
chemical injection point. The retention loop was designed for
one minute detention at design flow, and consisted of 55 feet of
4" PVC pipe mounted horizontally.
Calculation of loop length:
1 min. x 35 gallons/minute = 35 gallons = 4.68 ft.3
Retention pipe loop at 0.085 ft.* for 4 in.
PVC pipe = 4.68 ft.3 * 0.085 ft.2 = 55 ft. long
9. Chemical Requirements
Based on raw sewage composition at design flow: based on
selected design criteria agreed upon by all agencies in the
approval process
mg/1
BODs 275
Suspended Solids 275
Phosphorus 12
FeCls: two mole ratio to phosphorus
2 x 12 x 162/31 = 125 mg/1 FeCl3 = 48 Ibs./day
NaOH: to neutralize half of FeC^
FeCl3 + 3 NaOh + 3 Nad + Fe (OH)3
125/2 x 3(40)/162= 46 mg/1 NaOH = 19 Ibs./day
Hercofloc: 1 to 2 mg/1
1 to 2 x 10-6 x 0.050 x 106 x 8.35 = 0.42 to 0.83 Ibs./day
Chlorine: 10 mg/1
10 x 10-6 x 0.050 x 106 x 8.35 = 4.2 Ibs./day
17
-------
10 mg/1
10 x 10'6 x 0.050 x 106 x 8.35 = 4.2 Ibs./day
10
C 1 a r i f i e r
1.5 gpm/ft. upflow rate and 30 minutes retention time
at design flow rate. Actual fabrication:
1 '6" dia. center well
= 26.5 ft.2
6' dia. x 6' side -wall depth wit!
Upflow area = 28.3 ft.2 - 1.8 ft.'
Volume = 1270 gallons
Upflow Rate = 1-32 gpm/ft.2
Retention Time = 36 minutes
Several commercially available clarifiers were investi-
gated for utilization in the Freehold plant. The size required
was below the normal size of most clarifier manufacturers and
consequently the cost of commercial units was very high. It was
then decided that it was more economical to design a special
clarifier for this plant and have it fabricated. As originally
designed the clarifier had a conical bottom sloping down to the
center line. Equipment arrangement studies showed, however, that
there was not enough elevation to locate the clarifier above the
control panel and still have access room to the rake drive. The
slope of the bottom was, therefore, changed to the outside
instead of to the center line. This change allowed the control
panel equipment to fit beneath the clarifier. Because of the
limited ability to lift tanks in the building the clarifier was
made in two sections and the center seam welded in the field.
The main tank was fabricated from steel. The inlet well and
overflow weir were constructed of 304 stainless steel.
11. Clarifier Rake
Tip speed: 1.1 in./sec. The clarifier rake was driven
by a gear reducer with an output of 0.67 rpm. The rake was con-
structed of steel pipe and angle iron. Because of the limited
headroom, it was necessary to use a gear drive with as low a pro-
file as possible.
12. Sludge Level Controller
Ultrasonic sensors with adjustable depth. During the
development stages at the West Goshen pilot plant the sludge
level was normally controlled manually. An ultrasonic level
detector was tested for use on the sludge level control mecha-
nism, and this equipment was installed at Freehold.
18
-------
13. Sludge Pumps
Jabsco positive displacement pumps had been used success-
fully at West Goshen for handling sludge from the clarifier. These
same pumps were utilized in the design of the Freehold plant.
14. Magnetic Filter
Upflow rate 50 gpm/ft.2 at design flow. Flush Cycle:
Adjustable with timer control. Typical operating cycle: 1 hr.
interval; 20 sec. flush; 20 sec. rinse. A Model 473 Ferrofilter
(S.G. Frantz Company) with 12" ID was used for this application.
15. Adsorber Feed Tank
7 ft. dia. x 7 ft. deep; operating capacity 1800 gal.
This tank was constructed of carbon steel.
16 . Adsorber Feed Pumps
Identical to Item 7.
17. Carbon Adsorption System
After considering various proposals by potential suppliers,
it was decided to purchase a carbon adsorption system from Chemec
Process Systems Inc. This unit consisted of the carbon adsorber,
the quench tank, the blow case, interconnecting piping, pneumat-
ically operated control valves, and a panel for activating the
control valves. In order to avoid corrosion from the activated
carbon, all piping was made of type 304 stainless steel.
18. Activated Carbon Adsorption Column
Empty bed contact time: 40 minutes; Upflow rate: 2.2 gpm/
ft.2; Actual fabrication: 4.5 ft. dia. x 14 ft. straight side x
90° top cone x 60° bottom cone. Total volume 253 ft.3 = 1890 gal-
lons; contact time = 1890/35 = 54 minutes.
The original adsorption system concept consisted of three
downflow pressure columns in series. A study of other systems,
coupled with theoretical considerations and physical constraints,
indicated that a single upflow packed-bed column using pulse trans-
fer would have several advantages. These included more efficient
overall operation, substantially less space requirements, a simpler
piping system, and significantly lower total cost. Off-setting
these advantages were concern about suspended solids penetration
into the column, the risks involved with only a single contact unit,
and difficulties experienced with upflow packed-bed operation at
other locations.
A compromise solution was reached retaining the single
19
-------
column concept but increasing the straight side of the column
from 12 to 14 feet to allow operation in an upflow expanded-bed
mode if desired.
The column was constructed of steel, lined with Plasite
No. 7155 with a minimum dry thickness of 8 to 10 mils. The bottom
cone included a Neva-Clog underdrain constructed of stainless
steel. Design pressure was 50 psig.
19. Spent Carbon Blow Case
30 ft.3 to contain approximately 5% of carbon column
charge per transfer (assuming blow case to be half full of carbon).
Actual fabrication: 3'-6" dia. x 3' straight side, dished heads;
Total volume-36 ft.3. The blow case was constructed of steel with
Plasite No. 7155 lining. Design pressure was 50 psig.
20. Carbon Quench Tank
5 ft. dia. x 5 ft. x 60° cone bottom; volume-930 gallons.
The quench tank was constructed of type 304 stainless steel with
an internal launder at the top to allow backwashing of the carbon.
21 . Spent Carbon Tank
4.5 ft. dia. x 6 ft. x 60° cone bottom; volume-850 gal-
lons. The spent tank was built of carbon steel and lined in the
field with two coats of Ceilcote Flakeline No. 252 and a top coat
of clear resin. It was also equipped with an internal launder at
the top to allow for excess water overflow and for backwashing of
the carbon.
22. Sludge Holding Tank
Capacity for approximately 2 days sludge storage at 3%
solids. 5 ft. dia. x 8 ft.=1150 gallons. The sludge hold tank
was designed to have a working capacity of 1100 gallons and con-
structed of carbon steel. The original concept was to sluice the
sludge out of the bottom of the sludge hold tank. A special
bottom was therefore designed with a water inlet and sludge outlet
nozzle 180° apart. This concept was later abandoned but the tank
specifications had already been prepared and since the additional
nozzle was not detrimental, it was left in.
23. Chlorine Feeder
In order to avoid having chlorine under pressure in the
building, a Wallace and Tiernan chlorine injection system was used
The driving force for the injection unit was a 10 gpm rotary pump.*
The chlorine cylinders, chlorine scales, and feed rotometers were"
located in a separate room in the building as required by New
Jersey law. This room was located behind the laboratory and office
space so that the operator could observe the consumption of chlo-
rine, as shown on the scales, through a window.
20
-------
2 4 . Chlorine Contact Tank
30 minutes at design rate =30x3b= 1050 gallons. Actual
Fabrication: 5 ft. dia. x 9.5 ft.=1200 gallons. In order to
encourage plug flow the tank was baffled, with flow entering the
top of the tank on one side of the baffle, then down under the
baffle, up, and out the overflow nozzle. It was constructed of
carbon steel. There was some concern about overchlorinating in
case the flow stopped. Consequently, a weir was put in the over-
flow nozzle so that when the flow stopped the level in the weir
would drop. This in turn would close a switch which would shut
off the circulating water pump and thus stop the input of chlo-
rine into the chlorine contact tank.
25. Instrumentation
Economical operation of the plant required that operator
attention be at a minimum. Consequently, the extensive intrumen-
tation supplied was approximately 12% of capital cost. The major
instrument systems for the liquid handling process were as follows:
a. Level alarm showing high level in the wet well
b. Level recorder alarm on the surge tank
c. Process flow recorder controller alarm
d. pH recorder controller alarm for NaOH addition ahead
of the clarifier.
e. Level alarm showing high level in the sump
f. Level controller adding make-up water to the adsorber
feed tank.
g. Turbidity recorder controller alarm, setting the
ferric chloride flow as determined by the turbidity leaving the
clarifier, and also diverting flow from the clarifier to the surge
tank in case of high turbidity.
h. Timers on the magnetic filter to set the time and
frequency of backwash.
i. Effluent flow recorder and totalizer.
j. Sludge level controller in the clarifier to automati-
cally control discharge of sludge to the holding tank.
k. Telephone connection to transmit any alarm condition
to a remote location.
B. SOLIDS DISPOSAL
The solids disposal segment of the process was in a consider-
ably less advanced state than the liquid handling process. It was
based upon concepts developed by Procedyne Corporation, New Bruns-
wick, New Jersey. This concept was based upon the use of a fluid-
ized bed reactor in both incineration and carbon regeneration modes
In addition, the raw sludge would be mixed with sand from the fluid
bed reactor and the mixture dewatered in a continuous sludge de-
watering filter of novel design. After dewatering the mixture of
sand and sludge would be fed to the incinerator. The combustible
21
-------
portion of the sludge would be burned off and the sand recycled to
the filter. This process is shown schematically in Figure 4. The
Carbon Regeneration mode of operation is shown schematically in
Figure 5.
The sludge dewatering concept shown in Figure 4 consisted of
continuously pumping sludge from the Sludge Holding Tank into the
top of a filter (6) where the sludge would mix with hot sand re-
cycling from the Incinerator. Make-up sand could be added as re-
quired from a bin (8). The sand-sludge mixture would move down
the filter screen where the liquid would be removed under vacuum
to a filtrate receiver (9) by a vacuum pump (11) and returned to
the head of the plant by a transfer pump (10). The dewatered sand-
sludge mixture would be discharged to a feed screw (7) which would
convey it into the fluid bed of the Incinerator (1). Fluidizing
and combustion air would be supplied by a blower (5). Fuel oil
would be injected automatically via gun burners as required to hoi
-------
GAS DISCHARGE
ro
CO
TO
TREATMENT
PLANT
SLUDGE FEED
-------
REGENERATED CARBON
16
16
rr rr
,SPENT
I CARBON
—M
«.
V
GAS DISCHARGE
t
TO THE
TREATMENT PLANT
EQUIPMENT LIST:
13. After Burner
14. Start-Up Burner
15. Plenum Burner System
16. Carbon Bins (Mobile)
FIGURE 5
FREEHOLD TREATMENT PLANT FURNACE
CARBON REGENERATION MODE
-------
a. Vacuum is a more effective driving force than exter-
nal pressure in the filtration of these slurries.
p
b. Filtration rates average between 0.2 gpm/ft. and 0.6
gpm/ft.2.
c. The filtration device should be constructed to provide
a contact and mixing section, a filtration section, and a cake
removal section.
d. The filtration section should be truncated in shape
for smooth and continuous downward motion of the slurry. The angle
of truncation should be 65°-750 to prevent bridging of the wet sand/
sludge mixture.
e. A multi-screw live bottom should be provided for dry
cake removal.
These considerations in combination with material and heat
balance calculations involved in the dewatering process led to the
design and specifications shown in Figure 6 and as described herein,
In this design, evaporation occurs in the mixing zone above the
distribution screw. Filtration takes place through the inner sides
of the unit. This false side is constructed of stainless steel
wedgewire screen with 10 mil openings. Compression dewatering
occurs beneath the three feed screws through a false bottom screw
which is also constructed of 10 mil wedgewire.
Initial demonstration tests with this concept showed that
the volume of dewatered sand-sludge mixture was too small for con-
trollable discharge with the three-screw live-bottom-bin configura-
tion. This led to a further refinement in the design. The three
removal screws were replaced by a single screw placed in a drop
section in the bottom of the unit. This was fed by two counter
rotating paddles to prevent bridging of the wet sand. This modi-
fication is shown in Figures 7 and 8. The unit was built in this
manner. Prior to installation of the filter at the Freehold Plant,
the unit was subjected to intensive testing. Several mechanical
and operational problems were encountered and corrected:
a. Sand Sludge Distribution
Tests on the filter as originally delivered showed
that sand-sludge distribution into the top of the filter was not
uniform and resulted in piling up of the sand toward one end of
the filter. This problem was resolved by replacing the top ribbon
distributor with a variable pitch paddle arrangement. The lower
paddles were also replaced with an adjustable unit so that the
proper arrangement could be determined experimentally.
b. Sand Leakage
In the original experiments sand leaked past the
25
-------
PARTS IDENTIFICATION:
1 . Screens
2. Filtrate Collector
3. Filtrate Outlet Nozzle
4. Short Pitch Screw (Feed Screw)
5. Distribution Screw
6. Sand Inlet Nozzle
7. Sludge Inlet Nozzle
8. Vent & Insp. Nozzles
9 . SIudge Mixing Zone
10. Paddle Screws
DIMENSIONS:
A Screen Width - -18
B Screen Height 12
C Mixing Zone Height - 9
r\i D Bed Leveling Zone 6
E Trough Diameter 4
F Filter Width--- 21
G Filter Depth - 13
H Mixing Zone Depth 4"
I Short Pitch Screw Size 3"
J Sand Inlet Nozzle Dia. 3"
K Sludge Inlet Nozzle Dia. 1"
L Vent Size 2"
M Bottom Screen Size 18"xl2"
N Filtrate Outlet Nozzle Dia 2"
0 Feed Length To Be Spec
AREAS:
Total Filtration Area Provided - 5 Sq.Ft.
ified
DROCEDYNE CORPORATION
NEW BRUNSWICK. NEW JERSEY
joe NQ 1431 - FIGURE 6
FREEHOLD TREATMENT PLANT
REGENERATING SLUDGE
DE WATERING SAND FILTER
DATE
-2-71
DRAWING No
B-05552
-------
SLUDGE
SAND
SLUDGE 8 SAND
INTO
MIXING CHAMBER
FEED AND MIXING
SCREWS ON BULKHEAD
ATTACHED HERE
TO REACTOR
SPRAY NOZZLE
TO CLEAN
•WATER DRAIN
SCREENS
VACUUM DEWATERING SPACE
FIGURE 7
SLUDGE DEWATERING
FILTER 6 FURNACE FEED SCREW CHAMBER
FREEHOLD TREATMENT PLANT
27
-------
MIXING CHAMBER-
SAND 8 SLUDGE
SCREENS
OUTER SHELL
SAND a SLUDGE
DISTRIBUTION
SCREW
PADDLE SCREW
REACTOR
FEED SCREW
FIGURE 8
FURNACE FEED SCREW LOCATION
IN SLUDGE DEWATERING FILTER
FREEHOLD TREATMENT PLANT
28
-------
screen in considerable quantity into the filtrate area. Dis-
mantling of the filter showed that the gasket has been improperly
piaced.
c • Drive Chain S1 •[ pj) a g e
In early tests considerable difficulty was encoun-
tered with the drive chain jumping or slipping on some of the
sprockets. This was attributed to the excessive loads caused
largely by piling up of sand because of the improper arrangement
of the mixing paddles. This condition was corrected by the adjust-
able paddle arrangement and also by installing larger sprockets on
the lower mixing paddles, allowing operation at slower speeds with
a greater wrap of chain around the sprockets.
d. SIudge Bypass ing
In early tests considerable solids werefound in the
filtrate from the sand filter. This was believed to be caused by
sludge bypassing sand at the top of the filter. In order to mini-
mize this problem part of the filter screen was temporarily blanked
off by tape in approximately the top six inches of filter area.
Tests showed that it might be desirable to blank off the entire
side area section of the screens. The unit was subsequently modi-
fied with an adjustable gasket arrangement so that any portion of
the side screen could be blanked off.
These mechanical modifications consumed much of the
time available for testing. Consequently, only very limited per-
formance data was developed. Two primary observations evolved:
(1) Filtrate quality was very poor with suspended
solids in the range of 0.3 to 1.5% when feeding sludge at concen-
trations of 1.2 to 3.0% solids.
(2) At high sludge feed concentrations, an almost
impervious layer of sand and dewatered sludge mixture tended to
built up against the side screens, preventing further filtration
and also inhibiting downward movement of sand within the filter.
This eventually caused a cavity to develop in the center of the
filter, followed by discontinuation of discharge from the dis-
charge screw, bridging above the screens, and inability to con-
tinue feed of sand and sludge to the top of the filter.
These difficulties were felt to be due to a combina-
tion of the mechanical problems outlined above and limited facil-
ities at the test location. The unit was, therefore, installed at
the Freehold Plant. It was believed that the modifications out-
lined above would permit satisfactory mechanical operation of the
unit, and that more appropriate testing could be accomplished
where the complete facilities and components of the filtration
concept were available.
29
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2. Incinerator
Early discussions on incinerator design revolved around
the relative merits of insultated high temperature alloy construc-
tion versus refractory lined steel. It was decided that the most
conservative design would be with refractory lining, and this ap-
proach was chosen. This choice dictated that the inside diameter
of the unit be no less than two feet in order to allow access for
a bricklayer into the unit.
The incinerator was designed with a superficial vapor
velocity of approximately 2 ft./sec. For this velocity, the de-
sired disengaging height is 8 ft. Because of space limitations
the disengaging space provided was only 7 ft. above the expanded
bed height of 4.9 ft. This causes a slightly greater loss of sand
because of sand being carried over in the exit gas. The inciner-
ator design was completed after the building and most of the equip.
ment had been designed and laid out. It was therefore necessary
to make much of the incinerator equipment fit the available space
and to provide the capability of placing the reactor in the field,
moving it around equipment already in place. This limitation dic-
tated that the reactor be built and installed in three flanged
sections. Installation of the incinerator required that the top
section be suspended in place prior to setting and refractory
lining the base and middle sections. This added to the reactor
design, fabrication and installation time and cost.
Basic performance parameters for sludge incineration are
shown in Table 3.
3. FJuidizing Blowe^
The blower to feed the incinerator was designed for 150
scfm with a discharge pressure of 10 psig.
4. Cyclone
The cyclone for separating solids from the incinerator
offgas was specially designed for this service. It was fabricated
of high temperature resistant alloy (RA 330). The design specifi-
cations were:
Incoming gas flow:
Rate - Max. 250 scfm
Temperature - 1600°F.
Pressure - Approx. 6" Water
Pressure Drop - 5" to 8" Water
Collection Efficiency - 99% above 5 micron
30
-------
TABLE 3
Incinerator Design Parameters
Parameters
Bone Dry Sludge
Water
Ash
Air
Fuel Oil
Operating Temp, (exit gas)
Diameter
Static Bed Height
Expanded Bed Height
Sand Loss
Maximum Flue Gas Generation
Minimum Fluidization Velocity
Quantity
13.65 #/hr.
62.2 #/hr.
4.78 #/hr.
77.6 scfm
2. 36 gal/hr.
160QOF.
2'
3.5'
4.9'
ca. 1 #/hr.
110 scfm
0. 255 ft. /sec.
FREEHOLD TREATMENT PLANT
31
-------
Dimensions:
Diameter - 22"
Height of Straight Side - 33"
Height of Conical Side - 55"
Nozzles: Gas Inlet 11" x 4.4"
Gas Outlet 11" dia.
Solids Outlet 6" dia.
5. Scrubber
The scrubber was designed to handle a maximum of 400 scfm
of gases at 400°F. A Crol1-Reynolds No. 8x8 Fume Scrubber with
24" Circulation Tank and Pump was selected.
6. Suction Blower
Incorporation of the Continuously Rengenerating Filter in
the solids handling design required a suction blower to overcome
the pressure drop from the incinerator through the cyclone and
scrubber system in order to create a slightly negative pressure at
the inlet to the filter. The blower was designed for 300-500 scfm
at 3" mercury.
7. Carbon Rengeneration
The carbon regeneration concept in the overall design was
based on interruption of the sludge incineration mode in the fluid-
ized bed reactor for a period of about two days once each thirty
days. During this two-day period, the accumulated spent carbon
would be regenerated. The regeneration system was designed to
interface with the treatment system on the following basis:
mg/1 Ib./day
BOD to Carbon Adsorber 40 16.7
BOD Residual 5 2.1
BOD Removed 35 14.6
Carbon Exhausted 29.2
29.2 Ib/day x 30 days * 48 hr. regeneration cycle = 18.25 Ib/hr.
Preliminary carbon regeneration work was carried out using
a 6" diameter laboratory fluidized bed reactor. General observa-
tions made as a result of this work are as follows:
a. Carbon recovery during steady state operations ranged
from 85% to 100%.
b. Regenerated carbon quality as determined by relative
capacity and iodine value was equivalent to virgin carbon.
c. The ratio of carbon to sand in the bed overflow in-
creased with time.
32
-------
d. For a given fluidization velocity, low initial static
sand bed height reduced the percentage of sand in the overflow.
Initial design specifications for the carbon regeneration
process were:
Carbon 18.25 #/hr.
Volatiles 9.125 #/hr.
Water 18.25 #/hr.
Fuel 3.05 gph
Air 64.6 scfm
Flue Gas 115.9 scfm
Temperature in Reactor 1400°F.
Later work showed that the water to carbon ratio in the spent car-
bon would be nearer 1.5:1 rather than the 1:1 originally assumed.
This condition required more heat during the regeneration cycle
than had been previously calculated; requiring several design
changes.
a. The plenum temperature capability was increased from
1600°F. to 2000°F. to effect greater heat utilization.
b. The incinerator would be operated with limited air and
with fuel injected directly into the bed.
c. A carbon feed screw was designed with a special drain-
age section to try to bring the water in the carbon feed to as low
a value as possible.
8. Instrumentation
Major instrumentation in the fluidized bed reactor system
included the following:
a. Plenum temperature recorder controller
b. Bed temperature recorder with high-low shut-off and
alarm.
c. Upper bed temperature indicator.
d. Freeboard temperature indicator with high temperature
shut-off and alarm.
e. Off gas temperature indicator with high temperature
shut-off and alarm.
f. Scrubber inlet gas temperature indicator alarm.
g. Scrubber water temperature indicator alarm.
h. Scrubber water level control alarm.
33
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C. AUXILIARY FACILITIES
Certain facilities in the plant were common to both the
liquid handling and solids disposal processes.
1 . Oil Tank
2,000 gallon capacity, steel: Fuel was needed for three
purposes: incinerator, emergency generator, and space heaters. It
was originally thought that natural gas could be used for the space
heater and the emergency generator, but it developed that no natu-
ral gas would be available in the community. Since fuel oil was to
be used for the fluid bed incinerator, the generator and heater were
changed to fuel oil. A 2,000-gallon tank size was selected. This
was located outside, underground with a level indicator showing
inside the building.
2. Oil Pump
A gear pump with a capacity of 0.23 gpm against a head of
276 ft. of fluid was selected.
3. Air Compressor and Receiver
10.8 cfm, 100 psig, 3 HP; with 240 gallon receiver. The
air compressor was sized to handle instrument and other require-
ments, with the largest instantaneous use being flushing of the
magnetic filter. The oversize receiver was specified to handle
this large but infrequent load.
4. Emergency Generator
A 50 kilowatt emergency generator was selected. This
would supply power to the liquid handling equipment in the plant
in case of any loss of power. Because of the large size of the
blower motors on the incinerator, and because sludge storage
capacity was provided, it was decided that it was not economical
to supply emergency power for the incinerator section. In order
to avoid overloading the emergency generator by the high starting
current on motors, a timer was installed to sequence the startup
of some motors.
5. Instrument Air Drier
A refrigeration type air drier was provided to insure a
source of dry air for instrumentation.
Inlet Flow: 25 scfm
Inlet Pressure: 100 psig
Outlet Moisture: -IQOF. dewpoint at atmospheric prssure
34
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6 . Sump _P um£
One-half HP open impeller, with pressure switch actua-
tion; 50 gpm at 20 ft. head.
35
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SECTION V
PHASE 2. CONSTRUCTION
A. INTRODUCTION
One objective of this project was to locate the treatment
plant within the housing development subdivision which it would
serve. Since a portion of the development plot bordered on the
Manasquan River the plant site was selected for convenient dis-
charge into this receiving stream. Figure 9 is a vicinity map
showing the location of the treatment plant within the subdivision.
A more detailed view of the plant site is depicted in Figure 10,
showing the adjacent playground area, location of the lift station
which delivers raw sewage to the plant, and the point of effluent
discharge into the Manasquan River.
Construction of the treatment plant was carried out under a
number of contracts and subcontracts for equipment and construction
services. Coordination of this phase with other aspects of the
total project was essential in order to meet the schedule objectives
As a result some overlap of work was necessary, leading to a few
problems and inefficiencies which would not have been encountered
otherwise.
For example, the treatment plant was scheduled to be the only
route for disposing of sewage from the housing development. It was
necessary, therefore, that the plant be operational, at least in
the liquid handling process, before the first house in the develop-
ment was completed and occupied. This requirement in turn dictated
early completion of construction design before part of the process
engineering design was completed.
A critical path schedule was developed for Phase 1 and 2 of
the project as a guide to the most efficient route to completion.
In general, the construction phase was carried out with no major
insurmountable problems although some annoyances and delays did
develop.
B. CONSTRUCTION DETAILS, PROBLEMS AND SOLUTIONS
The balance of this section deals principally with difficul-
ties which were encountered during construction, solutions to these
problems, and recommendations, where appropriate, for avoiding
similar pitfalls in other projects of this type.
36
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FIGURE 9
VICINITY MAP
FREEHOLD TREATMENT PLANT
TOWNSHIP OF FREEHOLD,MONMOUTH CO..N.J.
37
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MtOFOK) OWO
FIGURE 10
SITE PLAN
FREEHOLD TREATMENT PLANT
TOWNSHIP OF FREEHOLD, MONMOUTH CO..N.J.
38
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1• Building Selection
It was originally planned to enclose the treatment plant
in one of the four housing models offered in the development. The
first choice was a so-called high ranch style, a two-story house,
chosen primarily because it offered the largest envelop. It was
later decided, however, to change to a single-story Cape Cod style,
the Phoenix, for a lower profile and to blend into the neighborhood.
This house had external dimensions of 24'8" x 50'. In order to
utilize the Phoenix house a basement 13 feet deep had to be incor-
porated in the design. Since economics dictated that no rock exca-
vation would be done, the floor of the basement was built on bed
rock. This put the ground floor of the house several feet above
the existing grade, thereby requiring extensive grading around the
house.
Although the building selection proved generally satisfac-
tory some improvements in cost and equipment arrangement would
likely have resulted from a slightly larger (10-20%) envelop and
construction on a single floor layout.
2. Arrangement and Layout
As noted above, it was necessary to proceed with the build-
ing design and construction while development work and equipment
engineering design were still in progress. As a result, the size
and optimum arrangement of several major pieces of equipment,
primarily in the sludge dewatering and incineration sections, had
not been established when the final building configuration was
selected. This situation, compounded by space limitations, made
the physical dimensions of equipment a very important consideration.
In several cases extensive engineering effort was expended to
satisfy the simultaneous requirements of field installation, access-
ability for operation and future maintenance, relationship to other
equipment, and available space. The principal problems involved
carbon transfer piping layout, clarifier location and design, carbon
configuration and arrangement, and provision for a small office-
laboratory space.
Final arrangement of major equipment in the plant is shown
in Figures 11 and 12. Figure 13 is a photograph of the completed
building.
3. Access and Services
The treatment plant was the first structure to be built in
the development, and initial construction work preceded the building
of the permanent road to the plant. A temporary acess from a nearby
road was bulldozed to the plant site. This was not an all-weather-
road, however, and there were many days during the Winter and Spring
when access was very difficult or impossible, particularly for large
trucks and cranes, needed for placing heavy equipment. An unusually
mild winter contributed to the difficulty, as the ground did not
39
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D
012 345
o
o
outfit
MM*
TANK-
fllUWOfc
TtolKft
•
\
(/^\
00 1
WOIA
MAIN FLOOR PLAN
K)
}\
FIGURE II
EQUIPMENT LAYOUT
FREEHOLD TREATMENT PLANT
TOWNSHIP OF FREEHOLO,MONMOUTHCa,N.J.
-------
Ooo
FWM^g-V
FLED
CD
FULL OIL
RJMP
BASEMENT PLAN
O I 2 3 4
FIGURE 12
EQUIPMENT LAYOUT
FREEHOLD TREATMENT PLANT
TOWNSHIP OF FREEHOLD,MONMOUTH Co.,N.J.
-------
FIGURE 13
PLANT EXTERIOR
r
FREEHOLD
-------
freeze in the area. This problem was finally solved by hauling in
sufficient rock to stabilize the access road.
No permanent electric service was provided during the con-
struction phase, and a portable generator was required to furnish
power for hand tools and other equipment.
The driveway to the treatment pi ant, completed in the latter
stage of the development, was of the same type as in the adjacent
home construction. It was not heavy enough for the large trucks
delivering equipment and materials to the plant. In addition, the
driveway was designed with an "S" curve which made it very diffi-
cult for a truck to back into the area. The net result was con-
siderable damage to the lawn area and driveway. The driveway was
ultimately straightened and strengthened.
4. Mi seel 1aneous
The surge tank was constructed of reinforced concrete.
Leaks were encountered when the tank was initially filled with
water for testing. Two patching attempts, requiring draining and
refilling the tank, were needed to completely eliminate the leaks.
The building contractor misplaced the Hydrasieve dis-
charge opening in the poured concrete floor. It was then necessary
to cut out and repour part of the floor.
During the electrical check out phase an electrician
inadvertently connected 100 volt AC power to the low voltage DC
circuits in the instrument panel. This accident damaged a number
of alarm systems which had to be replaced.
Several delays caused a number of problems in other phases
of the construction. The most serious of these were:
a. The access problem referred to above.
b. Overlap of development and design of the solids dis-
posal system with plant design and construction as
discussed earlier.
c. Slow completion of the building, requiring double
handling of delivered equipment.
d. Late delivery of the carbon adsorption system, inter-
fering with the scheduling of piping and electrical
work .
43
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SECTION VI
PHASE 3. OPERATION AND EVALUATION
A. LIQUID HANDLING PROCESS
1. Plant Startup and Break-In: October 1972-June 1973
a • General Description
The Woodgate Farms wastewater treatment plant uses
physical-chemical technology, patterned after the pilot system de
scribed in Section IV. ""
Large solids are removed by screening; fine suspended
solids and some dissolved solids are removed by chemical floccu-
lation, settling, and filtration; and dissolved organic matter 1S
removed by adsorption on granular activated carbon. The effluent
is disinfected and discharged to the river. The settled sludges
are converted to an inert ash by incineration in a fluidized bed
reactor. The plant is automated for operation with minimum
attention. A schematic Process Flow Diagram is shown in Figure IA
b• Process Description
(1) Lift Station
Gravity mains in the community deliver raw do-
mestic sewage to the lift station which is near the treatment
plant. This station is a vacuum lift type unit with two centri-
fugal sewage pumps, check valves, a vacuum chamber and pump, level
control floats, and electric starters and controls. The vacuum
pump and chamber keep the centrifugal pumps primed by not allowlno
sewage to drain back to the well when a pump shuts down. The
electrical switching gear alternates pump operation, thus equally
ing wear. The pumps can be operated automatically or manually.
The station is equipped with an automatic temperature-controlled
heater to prevent freezing during cold weather.
When the sewage level in the wet well rises to a
predetermined point set by float No. 1, one of the lift pumps will
start and run until the level is pumped down to the low set point
of the float, then it will shut off. If for some reason, such as
a very high inflow or a defective pump, the level continues to in-
crease, float control No. 2 will start the second pump. If the
44
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HYDRASEIVE
en
SURGE
TANK
i
T
COARSE SOL'CS
TC DISPOSAL
T
CARBON
COLUMN
CLARIFIER
MIXING
J
SLUDGE
HOLDING
TANK
EFFLUENT
TO
STREAM
FERRO
FILTER
ii
\ Pv^^^
- SEWAGE
- SLUDGE
CARBON
CHLORINE
CONTACT
TANK
SPENT
CARBON
! TANK
FIGURE 14
PROCESS FLOW DIAGRAM
FREEHOLD TREATMENT PLANT
TOWNSHIP OF FREEHOLD, VONMOUTH CO..N.J.
CAR30N
COLUMN
FEED
TANK
-------
level increases above this point, float No. 3 will activate a
"High Wet Well Level" light on the process control panel and an
alarmwill sound.
(2) Pr i m a r y S cr e e_n_ i ni £
Raw sewage from the lift station is pumped to the
distribution box of a Bauer "Hydrasieve", a 3 ft. wide sloping
wedge wire screen with 0.020 inch openings between the wedge wires
As the sewage flows down the screen, solids greater than 0.020
inches in size are separated from the liquid and slide into a col-
lection hopper for further processing. The liquid flows through
the screen to a collection pan and then by gravity to the Surge
Tank. The screen can handle flows of 150 GPM.
(3) Surge Storage
The Surge Tank serves as a storage and equalizing
vessel between the highly variable raw sewage influent flow and the
subsequent operations which are carried out at a constant rate.
The capacity of the tank is 15,680 gallons. It is constructed'of
reinforced concrete and is equipped with an agitator.
(4) Process Flow Control
The screened liquid from the Surge Tank is pumped
through a chemical mixing-retention loop to the clarifier by one
of two Process Feed Pumps rated at 50 GPM each. The flow rate is
controlled by an automatic valve in the process line actuated by
the Process Flow Recorder-Controller on the control panel. This
instrument will automatically maintain a present flow when the
switch on the front of the controller case is in "Auto" position,
and the switch on the side is in the "Local" position. It will
increase the flow as the surge level increases and decreases the
flow as the surge level descreases when the switch on the side is
moved to the "Remote" position; however, this method of control
was not used.
(5) Chemical Treatment
As the screened liquid is pumped through the
mixing loop enroute to the Clarifier, three chemicals are added
continuously.
(a) Ferric Chloride is added to react with the
phosphorus to form insoluble ferric phosphate. It also forms
ferric hydroxide, a gel-like material which acts as a coagulant.
The ferric chloride is continuously injected into the process line
downstream of the process flow control valve at a tee by an elec-
tronically operated chemical metering pump. This pump can be
controlled automatically by a turbidity sensor, or it can be con-
trolled manually. Ferric chloride is received in 50 gallon drums
46
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as a 40% solution by weight of FeCl3 in water. When it is trans-
ferred to the feed tank, one gallon of 40% ferric chloride is
diluted with one gallon of water for greater accuracy of metering
into the system.
(b) Sodium Hydroxide, added for pH control, is
continuously injected into the process stream halfway through the
retention loop, at a 180 bend, by an electronically controlled
chemical metering pump similar to the ferric chloride pump. The
pump is regulated by a pH Recorder-Controller which is set to con-
trol the pH of the process stream at the desired value; usually
about 7.0. Sodium Hydroxide (caustic soda) is received in 50 gal-
lon drums as a 50% solution by weight. When it is transferred to
the feed tank, one gallon of 50% caustic is diluted with one gallon
of water.
(r) Flocculant is added downstream from the
caustic addition point at the end of the retention loop. A 0.2%
solution of Hercofloc 836.2, a polyelectrolyte, is used. It in-
duces efficient f1occulation, incorporating the suspended sewage
solids and ferric precipitates into large, rapidly settling floes.
The flocculant is injected by a chemical metering pump, manually
controlled but otherwise similar to the ferric pump. Hercofloc
836.2 is received in 50 Ib. bags as a white powder. The 0.2%
solution is prepared by dissolving the calculated amount of powder
in hot water using an eductor and agitator.
Kenics mixers were originally installed
in the pipelines downstream of each chemical feed point but were
later removed because of excessive plugging.
(6) Clarification
The flocculated sewage enters the clarifier via
a central downflow feed well, then flows up through a sludge blan-
ket. The clarified liquid leaves the clarifier peripherally
through "V notch slots to a collection trough. A continuous slip
stream of the clarifier effluent runs through a turbidity meter.
The results are continuously recorded as JTU by the Turbidity
Recorder on the control panel. If the turbidity rises above a pre-
set level (8.4 JTU) the clarifier effluent is automatically re-
cycled to the Surge Tank and the High Turbidity alarm sounds.
Sludge discharge is assisted by a slow moving
rake (0.3RPM). Ultrasonic type fixed probe sludge level detectors
monitor the sludge level and automatically start or stop the Clari-
fier Sludge Pump, as required to maintain the predetermined sludge
level desired in the clarifier. The sludge is pumped to the
Sludge Holding Tank.
47
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(7) Fi1tratlon
The Clarifier effluent flows by gravity
through a magnetic filter to the Carbon Adsorber Feed Tank.
Magnetic iron oxide slurry is injected into the effluent stream
enroute to the filter. The magnetic iron oxide is received in
50 Ib. bags. It is slurried in water at a concentration of 0.5%
by weight and pumped by a chemical feed pump similar to the
flocculant pump.
The magnetic filter (Ferrofi1ter) consists
essentially of a water cooled shell with copper coils which,
when electrically energized, produce a strong magnetic field.
The center of the shell through which the liquid flows is pack-
ed with iron grids. The iron oxide added to the clarifier
effluent stream attaches to or associates with any floe particles
leaving the clarifier, then is trapped and holds the floe in the
magnetic field of the filter. The magnetic field is turned off,
and the filter washed via an automatic valve arrangement to
the Surge Tank at regular intervals as determined by timers in
the control panel. These timers can be set to obtain the
desired frequency as well as duration of air scour and wash.
(8) Carbon Adsorptjon
The Ferrofilter effluent flows by gravity
to the Carbon Adsorber Feed Tank which has a capacity of 2,000
gallons. The tank is normally nearly full, the level controlled
by a float operated valve, because water from this tank is used
tccool the Ferrofilter jacket and as the supply for the incinera-
tor off gas spray nozzles and scrubber. Should the level in the
Feed Tank get too high it will overflow to the basement sump and
be pumped to the Wet Well. Should the level drop too low, a
pressure switch opens an automatic valve to add city water. An
approved backflow preventer valve was in the water line.
The Adsorber Feed Pumps, rated at 50 GPM
each, pump effluent from the Feed Tank through the Carbon Ad-
sorber to the Chlorine Contact Tank. The float operated valve,
described under Item 8, in the discharge line from the Adsorber
will open or close as required to maintain the proper level in
the Feed Tank.
The Carbon Adsorber utilizes granular
activated carbon to adsorb the dissolved organic material in
the effluent stream. The water enters the bottom through a
screen, moves up through the carbon and leaves at the top via
four Johnson well point wedge wire screens. Part of the water
returns to the Feed Tank as required to maintain the proper
level. The remainder passes through a flow meter and enters
the Chlorine Contact Tank. Periodically, a small amount of car-
bon is removed from the base of the column. The carbon in the
48
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column is washed with water and an air scour, and then the car-
bon is put back into the top of the column.
C9) Disi nfection
The effluent stream is disinfected with
chlorine in the Chlorine Contact Tank. The chlorine is supplied
from a cylinder in the Chlorine Room and is added via an eductor
driven by a circulating pump. The chlorinated effluent is dis-
charged to the Manasquan River.
(10) Sludge Storage
As described in the Clarification section,
sludge is pumped from the Clarifier and stored in the Sludge
Holding Tank. The sludge pump is controlled by the sludge level
detectors in the Clarifier which are set to turn the pump on at
a predetermined upper level and turn it off at a lower level so
as to maintain a sludge blanket. This is designed to produce a
sludge ranging from 5 to 8% total solids. The speed of the pump
can be manually changed to vary the pumping rate as may be
requi red.
The sludge is pumped to the Sludge Holding
Tank where it is stored. Hydrasieve solids are also pumped to
this tank from the Hydrasieve Hopper via the grinder pump. This
is a manual operation performed daily. The sludge in the Hold-
ing Tank thickens by settling. Periodically, clear liquid can
be decanted from the tank via the decant nozzles. The original
design provided for sludge to go through the sand filter into
the Incinerator.
Sludge is pumped to the Incinerator by the
Incinerator Sludge Feed Pump. This pump is controlled by an in-
dicator-controller on the Incinerator panel which shuts the
pump off if the bed temperature drops below the set point and
restarts the pump when the temperature rises above the set point
provided the pump switch is on "Auto".
(11) Inci nerati on
The sludge is destroyed by fluid bed in-
cineration at 1400-1500 F. which produces a sterile ash and odor-
less flu gases. The details of the operation of the fluid bed
reactor system are contained in the Solids Disposal section.
c. Problems, Solutions, Modifications
(1) Equipment Checkout
During August and September, 1972, as plant
construction was nearly complete and prior to start up, the pipe
49
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lines were flushed out and checked for leaks, all electric
motors tested for proper rotation, and the tanks and vessels
washed out and calibrated. The reinforced concrete Surge Tank
leaks were repaired.
The four chemical feed pumps were tested and
calibrated with water. The control instruments were tested and
adjusted. The Clarifier effluent turbidity meter was calibrated
and the recorder-controller set point set to divert the effluent
flow back to the Surge Tank when the turbidity exceeded 8.4 JTU.
The Clarifier weir was leveled while the unit
was full of water so as to obtain a uniform overflow distribu-
tion. The Carbon Adsorber was loaded with granular activated
carbon by preparing a carbon-water slurry in the Quench Tank and
educting it to the Adsorber.
The laboratory was cleaned. Major laboratory
equipment was installed and calibrated as needed. Analytical
procedures were checked using blanks and known standards.
(2) Startup Activi ties
On September 27, 1972, sewage from an adjacent
community was pumped to the Lift Station via a force main connec-
tion. The Lift Station automatically pumped this sewage to the
Surge Tank and treatment was begun. During the first three
months sewage from this force main was admitted as needed to
maintain plant operations for tests and adjustments. The use of
force main sewage was discontinued in December 1972. At a later
date the valve in the connecting line was removed and the line
was plugged.
From the initial startup until late December
1972, the plant was operated intermittently as required to treat
the effluent sewage. Starting in late December, the flow in-
creased so that continuous, around-the-clock operations could
be sustained. Initially, the plant was checked several times
during the night. As start-up problems described in the follow-
ing sections were solved, the frequency of operator attendance
was reduced. By the latter part of the start-up period, the
plant was running unattended about sixteen hours a day during
the week and about twenty-one hours a day during weekends and
hoiidays.
(3) Problems
The problems encountered during the start-up
period, together with changes in equipment or procedures to
solve the problems, are described according to the unit opera-
tions involved and not chronologically.
50
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(a ) Li ft Station
The lift station failed at irregular inter-
vals during the start-up period. The cause of the failures and
the solutions were as follows:
[1] The level control float would swing over
and hang up on carbon and other solids accumulated at one side
of the wet well, allowing the liquid to be pumped down to the
level of the priming tank suction pipe. Air would enter the pipe
and the priming tank thus would lose the vacuum lift which keeps
the sewage pumps primed. The surge of air into the vacuum prim-
ing tank would jam the vacuum pump surge float closed so the
vacuum could not evacuate air from the priming tank to return
the vacuum lift to normal operation.
The carbon and other solids were removed
from the wet well and the floats and float guides readjusted.
In addition, screen baskets were installed on the carbon column
and Quench Tank drains to catch any carbon so it can be reused.
A longer surge chamber supplied by the manufacturer was install-
ed on the vacuum pump.
[2] After about six months of operation,
the high humidity of the lift station caused corrosion of the
switching gear contacts so that arcing occurred and the pumps
would sometimes fail to start. The contacts were cleaned and a
regular maintenance and inspection procedure was initiated.
[3] Small sticks, rags, and similar objects
hung in the check valves, preventing them from closing when the
pumps stopped. Thus, air flows back through the line and the
pump prime was lost. Changing the check valve spring tension
did not solve the problem. Submersible pumps were installed at
a later date which solved the problem.
(b) Hydrasieve
The initial openings between the wedge wires
were 0.020 inches. The screen had to be cleaned several times
a day because of blinding with grease. The screen was exchanged
for one with 0.040 inch openings. Performance of this screen
was better, but it still blinded during the unattended periods,
especially during late evening hours. A hot water spray wash
was installed complete with timers to control the duration and
frequency of the wash. Experience has proven that satisfactory
operation is obtained with a spray frequency of 1 1/2 to 2 hours
and a spray duration of 2 minutes. In addition, the Hydrasieve
is manually cleaned with a brush and cleanser each morning.
This hot spray wash and cleaning procedure has resulted in good
Hydrasieve performance.
51
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(c) Surge Tank
The Surge Tank is vented to the Hydrasieve
enclosure via the influent line from the Hydrasieve and to the
Chlorine Contact Tank via the emergency overflow line from the
Surge Tank. There is also an access manhole from the Storage
Room above the tank. The tank is agitated, but not aerated.
Odor has never been a problem.
Periodically, during the nine-month starting
period, problems were encountered with floe floating in the
Clarifier. After considerable study, it was noted that this
problem occurred when the Surge Tank level was below the 21%
mark. It was determined that at levels below about 21% the agi-
tation was such that air became entrained and dissolved in the
liquid, which was then pumped through the chemical treatment
loop to the Clarifier. The air, disengaging in the Clarifier,
caused some flocculated solids to float instead of settling.
The Surge Tank Level sensing system was
modified to control the agitator. When the Surge Tank level
drops to 25%, the controller stops the agitator. When the level
increases to 30%, the controller restarts the agitator. This
procedure solved the problems of air entrained floating solids
in the Clarifier. No problem was encountered with solids that
settle in the Surge Tank during periods when the agitator is off.
(d) Chemical Treatment
The ferric chloride, sodium hydroxide,
flocculant, and magnetic iron oxide were each added to the
process flow stream by Precision Control Products electronic
pulser, diaphragm type, chemical metering pumps. Just down-
stream from each injection point, two-inch diameter Kenics static
mixers were used to rapidly and completely mix each chemical with
the process stream. To avoid a pulsed flow of chemical, small
diameter tubing and an accumulator were installed between each
pump and the process line. Early in the start-up period, fifty
foot lengths of capiliary tubing were inserted between the
accumulators and the injection points. This resulted in a
fairly uniform flow of chemical.
The static mixers seemed to be very effec-
tive in mixing the chemicals with the process stream; however,
plugging of the elements with fiberous material from the process
sewage stream was a serious problem. Once a week the plant had
to be shut down to remove and clean the three mixers (ferric
chloride, sodium hydroxide, and flocculant) upstream from the
Clarifier. This required three to four hours of operator time.
A strainer was installed upstream from the mixers. The mixer
cleaning frequency was reduced from once a week to once every
two weeks; however, the strainer had to be cleaned daily, a
52
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simple task requiring about ten minutes of operator time. The
two-week cleaning frequency was unacceptable; therefore, the
static mixers were removed and the chemicals introduced at tees
in the process line. Clarification and effluent quality were
satisfactory, but chemical consumption increased.
The original ferric chloride, flocculation
and magnetic iron oxide feed tank agitators were stainless steel
powered by 1/20 HP motors. They were used to dilute and mix the
chemicals. These agitators were too small and lacked sufficient
power to adequately mix the chemicals in a reasonable time. The
ferric chloride agitators were removed. An air sparge was used
to mix the 40% as received solution with water prior to feeding
to the process stream. A portable 1/4 HP mixer was used to pre-
pare the flocculant solution. An air sparge was installed and
ran continuously to improve the agitation of the magnetic iron
oxide slurry to keep it in suspension.
(e) Clarifier
The original design of the Clarifier pro-
vided for the process flow to enter the center well in a down-
ward direction parallel to the rake shaft, and to discharge
laterally against the inside wall of the center well through a
tee installed at the end of the inlet pipe about one foot below
the surface. During the initial start-up period, it was found
that at flows of about 20 GPM and higher the Clarifier was plagu-
ed with erratic operation and periods of high clarifier effluent
turbitidy. This problem appeared to be aggrevated by operation
of the clarifier rake, which had a speed of 0.67 rpm. It was
soon discovered that the tee had not been installed on the inlet
line, and that the influent flow was producing a jet-like dis-
turbance of the sludge blanket. Installation of the tee and re-
duction of the rake speed to 0.3 rpm eliminated this type of
clarifier sludge problem.
In the fabrication of the clarifier a conical
wooden block was installed at the bottom just below the rake hub.
Its purpose was to minimize the accumulation of sludge in what
might be a dead spot. This cone began to disintegrate after
about six months of operation, and pieces of wood occasionally
plugged the sludge discharge nozzle. The remains of the cone
were finally removed. Sludge accumulation, if it occurs, on the
flat center section under the rake hub has not been determined
to be a problem.
The Clarifier effluent leaves via a circular
V-notch weir and collection trough to a float chamber and from
there by gravity through the Magnetic Filter to the Adsorber
Feed Tank. A slipstream of about two liters per minute flows by
gravity from the float chamber to a continuous turbidity meter.
53
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The turbidity controller is normally set to divert the flow h*r^
to the Surge Tank if the Clarifier effluent is higher than 8 4
JTU. The float was designed to regulate a valve down-streamof
the magnetic filter so as to maintain a constant level in the
float chamber, thus assuring a representative slipsteam flow tn
the turbidimeter. Despite frequent adjustments to the float
control system, the water level fluctuated to the extent that
periodically air bubbles would be drawn into the turbidimeter
slipstream giving erroneous readings and control. The float
control system was removed and a short standpipe inserted in the
discharge line. This eliminated the air bubbles, yet provided
a slipstream typical of the Clarifier effluent.
. Erratic sludge level control was a reoccurr-
ing problem during the first six months of operation. Frequent
ly, the ultrasonic sludge level controller would fail to start
or stop the sludge pump as required to control the sludqe level
in the Clarifier. Thus, the sludge level would get too hiqh
resulting in solids carryover; or too low, resulting in loss of
the sludge blanket leading to less efficient clarification and
low sludge solids in the sludge hold tank. Representatives of
the manufacturer, working with plant operating personnel de-
termined that the erratic operation was caused by misalignment
of the Sensall probes, which had been supplied on an adjustable
mount during the development phase. Factory aligned probes in
rigid assembly were then installed and the controls adjusted
Sludge level control has been good since this change was made
' • i V> I ts I iiui.*/ fc* %, *» iI ^ v V* V* <^iii\*x»
(f) Clarifier Sludqe Pump
Tl-*^i r*lav»-i-P-iAw* c* "I i i /"I /i « r
The Clarifier sludge pump was originally
located on the basement floor under the Sludge Tank. The pump
was a positive displacement type with an eccentric rotor and a
rubbecrlined stator. This pump soon failed because of wear be-
tween the sides of the rotor and the stator. It was replaced
with a stainless pump with a flexible gear-like rotor made of
rubber. The rubber rotor failed after a few weeks of service
A Moyno, type FS, progressing cavity pump with a chrome plated
stainless rotor and synthetic rubber stator was installed. The
high head, about 23 feet, on the suction caused frequent col-
lapse of the synthetic rubber stator. The pump was moved to the
Hydrasieve room reducing the suction head to about 7 feet. The
operation and maintenance history of this pump has been good
The stator needs to be replaced at three-month intervals. The
rotor lasts about nine months.
Considerable difficulty was encountered in
handling sludge containing five to eight weight percent solids
in small diameter lines, i.e. lines less than 1.0" diameter
Steel pipe was replaced with reinforced synthetic rubber hose
using the minimum number of valves and fittings to avoid points
where plugging might occur. In addition, a procedure was estab-
lished to flush the sludge line with water each day. These
54
-------
changes reduced plugging problems to infrequent intervals.
(g) Carbon Adsorption System
In the initial loading operation of the car-
bon adsorption column, some difficulty was experienced in moving
the carbon slurry from the quench tank into the carbon transfer
line. This condition also occurred periodically during the sub-
sequent plant evaluation. This condition was inevitably traced
to the presence of some foreign material in the quench tank,
causing blockage of the quench tank discharge line, the lower
valve, or the transfer line eductor. It was necessary on several
occasions to drain water from the tank, remove the lower toot-
tings, and clean out the problem material. The foreign material
ranged from 1" diameter rubber balls, which entered with the
granular carbon, to pieces of paper, plastic, wrenches, pens,
bolts, and nuts. This problem was caused primarily by the open
top quench tank being located below an opening in the floor.
The original design of the Carbon Adsorber
provided for about five percent of the carbon to be removed each
week from the bottom of the Adsorber and stored in the Spent
Tank. Regenerated, or fresh carbon, from the Quench Tank was to
be added to the top of the Adsorber. Approximately once a month
the spent carbon was to be thermally regenerated in the fluid
bed reactor then stored in the Quench Tank until needed to refill
the Adsorber. Several problems developed during the start-up
period which led to changes in the design operation.
[1] The four effluent screens at the top
of the Adsorber each consisted of a cylindrical backing screen
covered with a 60 mesh twill woven wire screen. They were
flanged on one end and inserted into the Adsorber via four
nozzles. These screens gradually plugged with carbon fines and
biogrowth, and had to be cleaned every two weeks, a four-hour
job. To facilitate cleaning, the rigid pipe on the discharge
manifold was replaced with pressure hose with quick disconnects
mating with quick disconnects welded to the flanged end of the
screens. «This reduced cleaning time to about one hour. Finally,
the screens were replaced with wedge wire well points with 0.010
inch openings. These screens require cleaning every four to six
months.
[2] In April of 1973, after approximately
six months of operation, pressure drop began to be evident
throughout the entire column rather than only across the effluent
screens. High levels of iron and turbidity in the plant effluent
were also observed periodically, in addition to the presence of
hydrogen sulfide in the carbon column effluent. These symptoms
appeared to result from bacteriological growth and anaerobic
activity within the carbon column. The first attempt to correct
this problem was to employ recirculation through the column back
55
-------
to the adsorber feed tank. This tended to reduce, but not elim-
inate, the anaerobic frequency; however, the pressure drop in-
creased. The addition of chlorine at a rate of 8 to 14 mg/1
to the Adsorber Feed Tank was then initiated. This reduced the
rate at which the pressure drop increased, especially the pres-
sure differential across the lower third of the Adsorber. The
dissolved oxygen content of adsorber effluent was still very low,
at 0 to 3 mg/1, and the presence of H2S in the adsorber effluent"
persisted. A compressed air line and rotometer were installed,
and air was introduced into the Adsorber with the feed water at
a rate of about 1.5 SCFM. The dissolved oxygen content of the
adsorber effluent increased to about 8 to 10 mg/1 and the
anaerobic condition was eliminated.
The Standard Operating Procedure was
modified to require continuous addition of chlorine at about 8
to 14 mg/1 to the Adsorber Feed Tank, and air at a rate of about
2 SCFM to the base of the Adsorber. In addition, once a week
about half a blow case of carbon was moved from the Adsorber to
the Spent Tank, the Adsorber flushed for two hours with water
and an air scour, then reloaded with carbon which had been pre-
viously washed in the Quench Tank. This procedure has produced
good Adsorber operation. The BOD of the plant effluent has con-
sistently averaged less than 5 mg/1 each month; thus it has not
been necessary to thermally regenerate the carbon.
(h) Chlorination
It was noted near the end of the start-up
period that sludge was accumulating in the bottom of the Chlorine
Contact Tank. Two nozzles 180° apart were welded on the side of
the tank, flush with the bottom, and equipped with valves so the
tank could be washed as needed. The chlorinated water circu-
lating pump used to educt chlorine into the water failed. A new
pump was supplied by the manufacturer. During the interval when
the pump was out of service city water was used as the motive
force to educt the chlorine.
(i ) Emergency Generator
Power failures occurred frequently during
the last four months of the start-up period. On each failure
the emergency generator started and supplied power to continue
wastewater treatment operations automatically without requiring
operator attention. This generator starts fifteen seconds after
a power failure. All wastewater processing equipment and con-
trollers then start in sequence. The generator continues to
operate until the power has been restored then shuts down auto-
mati cally.
The Incinerator and related equipment do not
restart automatically after a power failure, manual restart was
used to assure safety.
56
-------
(j) Mi seel 1aneous
The temperature in the building would fre-
quently exceed 38° C on warm days in the early summer. A two-
speed ventilating fan was installed in the roof above the
Incinerator. This reduced the building temperature to accept-
able levels.
The original sump pump in the basement had
inadequate capacity, and frequently plugged with fibrous and
solid materials. A higher capacity open impeller submersible
type pump was installed which performed satisfactorily.
The magnetic filter would start its pro-
grammed air and water wash cycle before the relatively slow mov-
ing automatic valve in the effluent line to the Adsorber Feed
Tank had fully closed. This would send a slug of dirty water to
the feed tank, and the force of the air caused splashing. A
limit switch was installed on the automatic effluent valve to
delay the wash until the valve was fully closed. The air-water
wash also caused a surge of water to flow back up the line to the
Clarifier. A fast-action check valve was installed in the line
to stop this backflow.
d. Wastewater Characteristics
(1) The occupancy rate and flow data are contain-
ed in Table 4 and are plotted in Figure 15. The high average
daily flows per house for October and November 1972 were due
partly to use of sewage from the force main and partly to infil-
tration. The flows from December 1972 through May 1973 show a
steadily decreasing infiltration rate as the result of intensive
efforts by the developer to locate and repair breaks in the
sewerage system. The flow per house for the final seven months
of 1973 was 216 gallons per day.
(2) Raw sewage, surge tank, and plant effluent
analysis are contained in Tables 5, 6 and 7 respectively. The
BODc and suspended solids values are plotted in Figures 16 and 17
The influent, typical of domestic sewage, became stronger as the
infiltration decreased and the occupancy rate increased. Despite
various start-up problems, the quality of plant effluent was con-
sistently high, with all parameters well below design limits.
These data are the average of daily composites.
2 . Steady State Operations
By June, 1973, most of the houses in the development
were occupied, influent sewage flow had stabilized at about
26,000 GPD, and a number of problems in the liquid handling
process had been encountered and corrected. A 36-week period of
"steady-state" operation was designated to begin on July 1, 1973.
57
-------
TABLE 4
OCCUPANCY AND FLOW
WOODGATE FARMS - FREEHOLD, N. J.
October '72
November '72
December '72
January '73
February '73
March '73
April '73
May '73
June '73
July '73
August '73
*
September '73
October '73
November '73
December '73
Average
Daily
Flow
Gallons
6,928^)
21,503^)
18, 192'1)
16, 331
24, 307
24,615
26,836
27,429
26, 168
25,344
25,917
26,816
24, 324
26,702
26,053
Titles
Issued
During
Month
14
12
21
10
10
11
8
14
13
7
1
3
0
0
2
Cumulative
Titles
Issued
14
26
47
57
67
78
86
100
113
120
121
124
124
124
126
Average
Monthly
Occupancy
7
20
37
52
62
73
82
93
107
117
121
123
124
124
125
Avg. Flow
Per House
Gal. /Dav
990(1>
I.OTSW
492
-------
tn
UD
0
ID
O
I
o
UJ
1972
FIGURE 15
FLOW & OCCUPANCY
DURING THE PLANT START UP
AND BREAK-IN PERIOD
#OF HOJSES OCCUP
FLOW
Of
UJ
li-
UJ
-3
1973
DATE
FREEHOLD TREATMENT PLANT
-------
TABLE 5
RAW SEWAGE CHARACTERISTICS
Month
October '72
November '72
December '72
January '73
February '73
March '73
April '73
May '73
June '73
SS TOC BOD, COD TOD
*j
7.0 266 14 36 93
6.9 119 - -
7.2 185 - - 152 -
7.5 147 - 52 162
7.3 212 46 - 242 272
7.3 165 - 165 356
7.0 280 - 132 345
7.5 208 - 186 333
7.6 191 - 83 403
TKN NH.3iN.
4.3 25.6 28.8
6.4 35.7 28.0
6.5
4.8
6.3
N07
+ ^
Ni3 Acidity Alk.
28 34
4.5
Total
Total Solids
Solids % Ash
12
48
21
504 34
434 52
493 43
NOTE: All units mg/1 except as noted.
FREEHOLD TREATMENT PLANT
-------
TABLE 6
Month
October '72
November '72
December '72
January '73
February '73
March '73
April '73
May '73
June '73
SURGE TANK CHARACTERISTICS
RH
7.3
-
7.2
7.5
7.2
7.1
7.0
7.5
7.5
SS
123
140
120
147
153
181
240
200
230
TOC
17
-
-
40
38
40
39
38
53
BODC
22
-
-
86
98
195
143
154
77
COD TOD
80
-
151
299
216 284
252 185
276 324
332 283
391 354
1
1
4
2
1
3
3
4
7
P
.04
.37
.44
.55
.53
.03
.43
.57
.01
TKN
14.6
17.7
24.2
29.4
38.5
19.0
47.0
50.0
55.0
NH.-N
10.0
14.8
14.8
16.5
16.5
12.4
25.5
22.2
27.2
NO-
+ ^
NO,
0.21
2.1
11 .4
6.3
2.1
0.6
1 .7
2.8
2.6
Acidity Alk.
21.6 93
17.3 106
-
49.7 173
43.2 165
-
175
150
158
Total
Total Solids
Solids % Ash
-
-
-
-
-
-
816 46
442 51
489 41
NOTE: All units mg/1 except as noted.
FREEHOLD TREATMENT PLANT
-------
TABLE 7
ro
Month
Oct. '72 6
Nov. '72 6
Dec. '72 6
Jan. '73 7
Feb. '73 7
Mar. '73 6
Apr. '73 6
May '73 7
June '73 7
.8
.6
.6
.1
.2
.9
.7
.0
PLANT EFFLUENT CHARACTERISTICS
Fe
-
-
-
3.2
0.7
1 .4
1 .4
1.4
0.9
Free
Res.
C12
0.4
0.5
0.9
0.9
1.6
0.9
0.7
2.2
1.5
SS
3.2
1.8
1.3
6.1
2.4
4.1
4.1
4.7
4.0
TOC
4
-
-
11
7
7
6
5
6
BOD
1
3
-
1
5
1
1
4
1
COD
9
1
12
15
44
17
20
26
33
TOD
-
-
-
52
33
22
49
53
49
P
.26
-
.17
.95
.19
.65
.46
.26
.23
TKN
7.9
-
17.0
20.4
20.9
19.0
18.5
40.0
38.0
NH^-
3.
-
12.
11 .
12.
i 10.
15.
16.
21 .
N
9
4
1
2
8
8
5
4
N02
N03
.0:
-
8.1
2.5
1 .0
0.5
0.9
1 .7
1 .6
Total Avg. Daily
Total Solids Flow
Solids %Ash Alk. Col. Gal.
335
381
348
24
43
30
41
42
97
134
91
96
117
0
1
0
0
0
6,928
21,503
18,192
16,331
24,307
24,615
26,836
27,429
26,168
NOTE: All units mg/1 except as noted.
FREEHOLD TREATMENT PLANT
-------
CT>
CO
MONTHLY VARIATION OF BODOF
SEWAGE DURING BREAK-IN PERIOD '
SLRGETANKS:WAGE
R4 ¥ SEWAGE
PLuNTEFFLUEJIT
1972
TIME
1973
FREEHOLD TREATMENT PLANT
-------
FIGURE 17 ;.:
SUSPENDED SOLIDS VARIATION
." DURING BREAK-IN PERIOD
1972
TIME
1973
FREEHOLD TREATMENT PLANT
-------
A schedule of normal sampling and analysis was established in
accordance with Table 8. A schedule of intensive evaluation was
also specified as shown in Table 9. The intensive tests were to
be conducted during eight one-week periods, in addition to the
normal evaluation.
Several changes in these schedules were made during the
course of the test period. Some tests were added or increased
in frequency, while others were dropped, based on evaluation of
the results collected.
a. Normal Evaluation
The analytical schedule for the normal evaluation
included (1) a rather complete set of samples and analyses for
one day each week, (2) somewhat reduced coverage for two addi-
tional days, and (3) minimal analyses on the remaining four days.
A rotating sampling plan was used in order to cover all days of
the week during the 36-week duration of the evaluation. Results
were reported weekly, using the analysis report form typified by
Figure 18. Analytical and operating data were also summarized
and reported on a monthly basis.
(1 ) Raw Sewage Characteri sti cs
(a) Flow
As noted above, the variable and abnor-
mally high average raw sewage flow experienced during the start-
up and break-in period had diminished by June, 1973. This
stabilization in influent flow was due primarily to correction
of the infiltration problems encountered during construction of
the houses in the development. Occupancy and flow data for the
steady-state period are shown in Table 10; the daily flow per
home during this nine-month period averaged 207 gallons, and
ranged from 173 to 226 on a monthly basis. These data are shown
graphically in Figure 19, including the latter six months of the
break-in period from January through June, 1973.
A frequency distribution of the 274 daily
effluent flows occurring during the steady state phase is shown
in Figure 20. These flows are the daily differences read from
the plant effluent totalizing meter at 8:00 a.m. each day.
Approximately 90% of the values fell within the range of 18,000
to 33,000 gallons per day. It should be noted, however, that
these flows are not corrected for changes in surge tank level,
nor do they reflect the effect of the frequent failure and
erratic operation of the lift station. Limited study of these
factors showed that the extremes in effluent flow, both high
and low, were always related either to a lift station failure
or to some other condition causing a substantial change in surge
tank level. These changes in turn required frequent adjustment
65
-------
TABLE 8
ANALYTICAL & SAMPLING SCHEDULE DURING NORMAL EVALUATION
Sample Point
Hydra Sieve Feed
(Raw Sewage)
Analyses & Frequency
pH, Alkalinity, Suspended Solids,
BOD, TOC or COD, Total P, Total
Nitrogen, Ammonia Nitrogen,
Coliform
3 times per week on 24-hour
composi tes
Hydra Sieve Effluent
(Holding Tank)
Same as above + Soluble TOC or
COD + Soluble P
Once per week on 24-hour composite
pH, Suspended Solids, Total P,
Coli form
Once per week on 24-hour composite
Clarifier Effluent
Ferrofilter Effluent
pH, Alkalinity, Suspended Solids,
Total COD or TOC, Soluble TOC or
COD, Total P, Soluble P, Total N,
Ammonia N, Coliform
Once per week on 24-hour composite
Dissolved Q£ once per day (grab
sample)
Carbon Column Effluent
pH, Total & Soluble TOC or COD,
Fe
Once per week on 24-hour composite
D.O. once per day (grab sample)
Plant Effluent
Same as Hydra Sieve Effluent + Fe
+ Cl2 residual
3 times per week on 24-hour
composite
hydra Sieve Solids
Clarifier Sludge
Dewatered Sludge
Total Solids, Volatile Solids
Once per week
GENERAL:
ALL DATA ON
CONSUMPTION
REQUIREMENT
LIQUID AND SLUDGE FLOW, FUEL
, ELECTRICITY USE AND MANPOWER
TO ALLOW FOR ECONOMIC ANALYSIS.
FREEHOLD TREATMENT PLANT
66
-------
TABLE 9
ANALYTICAL & SAMPLING SCHEDULE IN ADDITION TO
NORMAL EVALUATION DURING INTENSIVE EVALUATION
Sample Point
Hydra Sieve Feed
Hydra Sieve Effluent
Frequency
2 days/week
Analyses
pH, Alkalinity, Suspended Solids, BOD, TOG or COD,
Total P, Total N, Ammonia N, Coliform.
Each on 2-6 hour and one 12-hour composite
2 days/week
Same as above + Soluble TOC or COD and Soluble P.
Each on 2-6 hour composites and one 12-hour composite
cr>
Clarifier Effluent
2 days/week
pH, Suspended Solids, Total P, Coliform
Each on 2-6 hour composites, and one 12 hour composite
Ferrofilter Effluent
2 days/week
pH, Alkalinity, Suspended Solids, Total & Soluble COD
or TOC, Total P, Soluble P, Total N, Ammonia N,
Coliform
Each on 2-6 hour composites and one 12-hour composite
Carbon Column Effluent 2 days/week
pH, Total & Soluble TOC or COD, Fe
Each on 2-6 hour composites and one 12-hour composite
Plant Effluent
2 days/week
Same as Hydra Sieve Effluent -*- Fe -t- Cl2 residual
Each on 2-6 hour composites and one 12-hour composite
Solids Handling Loop
Total week
Complete Solids Balance & Sludge Volume Accounting
FREEHOLD TREATMENT PLANT
-------
FIGURE 18
FREEHOLD
WEEKLY ANALYSIS REPORT
12/14/73
Total Solids %
Volatile Solids %
Hydraaieve Clarifier Hold Tank
17.4 4.7
94. 1 48.0
4.4
48. 6
R
SUN. «T
Dec. «
9 MI
CCE
23 386 eal rt
R
MOM. ST
Dec. ct
10 '«
CCE
28. 122 eal. n
R
TUES. ST
Dec. cf
11 FFE
CCE
24. 504 Eal."
R
WED. ST
Dec. «
12 '"
CCE
17. 776 gal. "
R
THURS. ST
Dec. «
13 f«
CCE
23.499 eal. PE
R
FRI. ST
Dec. «
14 '"
CCE
24, S51 eal. "
R
SAT. ST
_Dej:. «
15 "€
CCf
23. 666 Ml. «
•H
7.8
7. 3
8. 7
6.8
8. 2
7. 7
7. 1
7. 1
6.7
6.8
8.2
6.9
6.9
7.0
7. 2
1 7.0
1 6.8
i 7.0
7. 7
7.0
ss
590
0.9
108
10. 0
10. 6
2. 5
328
1.9
8.3
4.0
1.9
622
400
11
17
3
152
4.3
F«
0.2
0. 3
0.5
0.3
1. 5
1. 1
DO
10
8
9
9
10
9
9
9
9
10
9
~R5:
FlM
3.0
0. 8
0.9
1.0
0. 8
3. 0
1.0
='a
TOI«I
7.0
1.9
2.0
2.0
1.2
8. 0
2.5
cou.
MPN
3x10*
O
). 3x10
0
2.3x10
'.5x10
r.5xio
9xl04
23
TM.
TOC
140
4
96
6
152
144
28
12
10
Sal.
TOC
4
4
20
16
7
8
•OD
384
0
240
0
228
132
12
2
COO
1024
552
55. 1
63
TOO
660
600
126
84
TKN
72. 6
28.0
69.0
20.6
72. 6
54. 4
30. 6
28.0
NOj»
NO,-N
3. 3
1. 5
NHj-N
36.9
24.6
37. 1
14.8
25. 4
31.9
24.6
24.6
Tw.
r
14. 6
.047
9. 25
. 056
18. 0
17.0
. 093
. 074
. 056
lol.
p
.047
. 038
12. 0
. 047
. 047
AlK.
200
128
206
124
158
194
168
130
ChlO'kta
158
180
Toi.
Soluh
880
533
Vol.
Soldi
|
405
42
CO
-------
TABLE 10
OCCUPANCY AND FLOW
Month
1973
July
August
September
October
November
December
Average
Daily Flow
Gal Ions
25,344
25,917
26,816
24,324
26,702
26,053
Cumulative
Titles
Issued
120
121
124
124
124
126
Average
Monthly
Occupancy
117
121
123
124
124
125
Average Flow
Per House
Gallons/Day
217
214
218
196
215
208
1974
January
February
March
28,490
24,134
21 ,737
126
126
126
126
126
126
226
192
173
FREEHOLD TREATMENT PLANT
69
-------
FIGURE 19
400
300
100
AVERAGE MONTHLY FLOW
DURING ORIGINAL OCCUPANCY
200
Jan Feb Mar Apr May Jun July Aug Sept Oct Ncyir Dec Jan Feb Mar Apr May June
1973 FREEHOLD TREATMENT PLANT 1974
-------
FIGURE 20
DAILY EFFLUENT FLOW JULY 1973-MARCH 1974
FREQUENCY DISTRIBUTION
33
32
31
30
29
S27
(X
§26
.3
rt ?c
O
"
CO
J23
H
22
21
20
19
18
17
16
15
0.01
0.05 0.1 0.2
0.5
20 30 40 50 60 70 80 90
PER CENT LESS THAN VALUE
95
98 99 99.8 99.9 99.99
FREEHOLD TREATMENT PLANT
-------
in the process flow to maintain continuous operation without a
surge tank overflow. The most frequent normal operating condi-
tion affecting surge tank level was the weekly transfer of carbon
from the carbon column followed by carbon column backwash and
reloading. This sequence required the internal use of substan-
tial process water with accompanying adjustments in operating
flows to compensate for the abnormal volume of recycle water.
Correction of the recorded effluent
flows for these effects, to obtain daily influent flow, would
undoubtedly have produced a narrower range of values. This
correction was not made for the entire period, but study of
several minimum and maximum values indicated that true influent
flow ranged from approximately 17,000 to 34,000 gallons per day
or roughly plus or minus one third of the mean daily flow of '
25,315 gal Ions .
A 24-hour influent flow profile for the
plant was developed by averaging 10 selected days of surge tank
level and effluent flow data. The smoothed curve is shown in
Fi gure 21.
(b) Raw and Surge Tank Sewage Quality
Raw sewage and surge tank averages for
four major parameters determined during this period are shown
below:
Raw Surge Tank
Suspended Solids 242 182
BOD 207 153
Total Hydrolyzable Phosphorus 10.8 8.3
Total Kjeldahl Nitrogen 44.7 53.1
Raw sewage sampling was subject to the
usual difficulties in obtaining representative composites, and
was discontinued in December, 1973, with a corresponding increase
in the number of Surge Tank samples. The two sets of determina-
tions are, therefore, not strictly suited for direct comparison,
although average values for suspended solids, BOD, and phosphorus
did show similar reductions (25, 21 and 23% respectively) from
the raw to surge tank samples. The suspended solids reduction
is in agreement with calculated removals, based on the weight of
primary screen solids collected during a period of several days.
The same pattern was not evident, however, in other parameters
where comparable reductions might have been expected. The ab-
sence of other correlations is undoubtedly due to a combination
of the limited number of analyses performed, sample variability,
and analytical precision.
72
-------
CO
200
180
FIGURE 21
FREEHOLD TREATMENT PLANT
DIURNAL FLOW PROFILE
12 1
TIME OF DAY
-------
Frequency distributions of raw sewage
and surge tank analyses for suspended solids, BOD, and phosphorus
are shown in Figures 22,23 and 24. As seen from these graphs the
median values and 80% occurence for these properties in the raw
sewage were approximately:
Median 80% Range
Suspended Solids 200 120-400
BOD 190 100-350
Phosphorus 11 4-18
Nitrogen determinations showed low
levels of nitrites plus nitrates in the raw sewage, averaging
less than 2 mg/1 . Ammonia nitrogen averaged somewhat less than
50% of the total Kjeldahl nitrogen. These results are not un-
expected, in view of the close proximity of the treatment plant
to the sewage source. There is some evidence of increased NH-,
nitrogen in the surge tank as would be expected with the 8 to
12 hour detention normally experienced in this vessel.
Other properties of the raw sewage
appeared to be within normal expected ranges for wastewater from
a purely domestic source.
(2) Liquid Treatment Performance
Average values for all analytical determina-
tions made during this period are shown in Table 11. Sampling
points were at the effluent of each vessel or location listed
with the exception of raw sewage, which was taken at the primary
acreen head box. Samples were generally 24 hour composites,
although grab composites were occasionally necessary when samp-
ling pumps or lines became plugged.
As previously indicated, some changes were
made in the sampling schedule during the course of the steady
state period of evaluation. These changes were made to ease the
analytical load in areas where differences between two sampling
points were small or where continued determinations were not
felt to be of sufficient value. For example: nitrite-nitrate
analyses were discontinued because values were always very low;
raw sewage samples were discontinued in December, 1973 because
the surge tank sample was felt to be more representative of the
loading on the treatment processes. Ferrofilter effluent samples
were no longer meaningful when the filter was taken out of ser-
vice in January 1974. Because of these changes certain analyses
have been combined in evaluating plant performance in order to
increase the number of determinations available and thus mini-
mize the effect of sampling and analytical variability. Although
approximately 3,300 major analyses (excluding pH, dissolved
oxygen, iron and residual chlorine) were performed during the
74
-------
FIGURE 22
«9.9 99.8 99 98 95 90 80 70 60 50 40 30 20 10 5 2 1 0.5 0.2 0.1 O.OS 0.01
450
400
350
M
« 300
0
CO
-a
A) -) CA
1
1
200
1 50
100
- SUSPENDED SOLIDS ::;::::::
:-• FREQUENCY DISTRIBUTION
- IN RAW SEWAGE & THE SURGE TANK "::::'""
--• 4-\» -
o.
>fc*^r j_ .
— sty
• • -•• ff t<
- -...) | . . . .
- > |:
! ji ---
- - - g - - -it-"" •••
: : :: : 4 — •
IJJIll || Hill III || Illlllll 1 1 Illlll 1 | 1
•
70 80 90 95 98 99 99.8 99.9 99.99
a Than Value FREEHOLD TREATMENT PLANT
-------
FIGURE 23
99.9 99.8 99 98 95 90 <0 70 60 50 40 30 20 10 5 2 1 O.S 0.2 0.1 0.05 0.01
CT>
400
350
300
-J 250
g
••
a
g 200
150
100
50
0
" IN
BIOCHEMICAL OXYGEr
FREQUENCY DISTRI
RAW SEWAGE & THE
,
r-:::
-91
JDFMAND ~~~'.'- '.''-'.'. '.'.'.
SIIT mw - ....
9U 1 1 UN
SURGE TANK -
•
- __ _.. ,..._. j
_ : " :" ::::::::"::: : p
:::::: . : :.::::: :::.::
— -(--
i
--'----*- -...-..
....... p. __....-.....
— — 11- - -->- ---
-IF ->
»- • >~ .-_.-
fc-
i ::::::::::: ::::::::::::::
. .. L - -
*
H 1 nilillTTinmfrlTniTriTTT
...__3
'"• ' • | r • • - - - — — •
_ . . /&+- - ....
c:::::::V£:: •-:::-::"
---:-W :-:!• : :•::;-::"
--$&>•:--: : ::::::" = -
::^:!:::!::: : ::::::::*-
«* i ,
,*»!_..!. :..:. ....:..,.. rSj
&::i::\ -.:-.-.: : ;:t H-<^
W ----- ' Nr ^4-
T ti 1 M '^G^fr-H-
•--: ----- *UW|1
..is.:::..:.,!, . Wi : . . :
i . _ .
• -•-••---i----- • ------- — —
-(.:.-.-.--__
::::::::::::::! ::::::::__
f-
- - -
- - - -
001 0.08 0.1 0^ OJ 1 2 « 10 20 JO 40 SO 60 70 80 M M MM MJ M4 MJt
Per Cent Equal to or Lett Than Value FREEHOLD TREATMENT
-------
FIGURE 24
99.99 99.9 99.8 99 9» 95 90 10 70 60 50 40 30 20 10 5 2 1 0.5 0.2 0.1 0.05 0.01
il Hydrolyzable Phosphorus, mg/1
>-• *- i— >— »-. t>
O ISJ tfe. O> 00 C
2
0
H
6
4
2 t
_
1
TOTAL HYDROLYZABLE PH
FREQUENCY DISTRIBl
IN RAW SEWAGE & THE SI
" ^i
. . I
-9
OSPHORUS :::::::::::::::
ITION :::::::::::::::
JRGF TANK :::::::::::;:::
, ., ..
-••---•••
-- '
• i j ; • • • • — '
— i .--.
,,. ^ .....
i- i
EEEEE;;;;[ ;EEEEI;E:;;;;;;;
_ = -:::>! ::::::::::::::::
•; : i :;:::::.:::
— ~ — £ ~ -i * p .-.--
L/rnlllllllllll 1 1 1 1 1 1 1 Hill III
_pjL].|.,[l^lliiniii-j l [| 1 1 1 1 llll ill
1 1 1 II i 1 7
_ L
it.
ih^
.: : .. ..i
__. .
i
\^ j _
7wy ^
*3f C C
•f^y . r
, ^7 1
*3f . ' i V^r^
^ j . . . .:: ;. + <>
__. fv- - -
•> -- "XV^L "
. . M5> - - - -
? : v -
••- ...(--
5 —
p1
- :
041 0.05 0.1 0.2 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.8 99.9 99.99
Per Cent Less Than Value FREEHOLD TREATMENT PLANT
-------
TABLE 11
LIQUID TREATMENT PERFORMANCE
AVERAGE VALUES
O>
Analysis, mg/1
Suspended Solids
BOD
TOC
Soluble TOC
TOD
COD
TKN
N0? + NO^-Nitrogen
NH3-N1tr5gen
Phosphorus
Soluble Phosphorus
A 1 k a 1 i n i ty
Chlori de
Total Solids
Volatile Solids
Total Coliform
(MPN per 100 ml )
Iron
pH (units)
Dissolved Oxygen
Free Residual Chlorine
Total Residual Chlorine
Raw
Sewage
242
207
72
_
460
540
44.7
1.8
19.3
10.8
-
202
78
628
324
/»
I.lxl0b
-
7.5
-
-
-
Surge
Tank
182
163
74
27
433
463
53.1
-
28.0
8.3
5.6
205
105
614
314
2.2xl06
-
7.4
-
-
-
C 1 a r i f i e r
12.2
-
_
_
_
_
-
-
-
0.38
-
-
-
_
_
1.4xl05
_
7.1
-
-
_
Ferrof i 1 ter
10.0
35.1
20.1
10.3
143
103
40.2
1.4
24.3
0.31
0.26
151
_
_
_
e.ixio4
_
7.0
8
-
_
Carbon
Column
5.7
4.9
0.9
6.9
8
Plant
Effluent
2.9
1.4
5.6
4.1
72
25
28.8
1.4
17.3
0.16
0.19
110
233
482
111
<3.5
0.7
6.9
9
1.1
3.4
FREEHOLD TREATMENT PLANT
-------
nine month period, an even greater number of determinations would
have added to the confidence level in evaluating overall perform-
ance and unit operation efficiencies.
Average results for the four Tnajor parameters
are summarized in Table 12 where Raw Sewage and Surge Tank values
have been combined for Kjeldahl nitrogen, and Clarifier Effluent
and Ferrofilter Effluent have been combined for BOD and Kjeldahl
nitrogen. These averages were used in calculating the efficien-
cies shown in Table 13. Three sets of efficiency values are
shown :
(a) The individual major process step unit
efficiency, that is: the percentage of pollutant removed in each
step as related to the input to that operation.
(b) The cumulative removal at each process
step as related to the raw sewage (or raw sewage-surge tank
average in the case of Kjeldahl nitrogen). These data are also
shown graphically in Figure 25.
(c) The contribution of each process step in
removing a pollutant, expressed as percent of the raw influent.
Several conclusions are evident from examina-
tion of these results:
(1) Clarification (which includes
chemical treatment) was the most effective step in the removal
of suspended solids, phosphorus, and BOD, accounting for 70, 73
and 62% respectively of these pollutants entering with the raw
sewage. Twelve percent of the Kjeldahl nitrogen was also re-
moved by this step.
(2) Primary screening removed about a
quarter of the suspended solids, phosphorus, and BOD.
(3) Carbon adsorption, although
accounting for removal of only 16% of the original BOD, and 2
and 3% of phosphorus and suspended solids, was quite effective
as a unit operation with efficiencies of 96, 46 and 71% respec-
tively. Twenty-five percent of Kjeldahl nitrogen was also re-
moved by this operation.
(4) Filtration was a relatively in-
effective operation, removing only one percent of the suspended
solids and phosphorus, with unit efficiency of 18%.
(5) Overall removals for the total sys-
tem were 99% for suspended solids, phosphorus, and BOD. Kjeldahl
nitrogen was reduced by 37%.
79
-------
TABLE 12
LIQUID TREATMENT PERFORMANCE
AVERAGE ANALYSES, mg/1
Suspended
Solids Phosphorus BOD
Raw Sewage
Surge Tank
Clarifier Effluent
Ferrofilter Effluent
Plant Effluent
242
182
12.2
10.0
2.9
10.8
8.3
.380
.313
0. 161
207
163
35.1
1.4
Kjeldahl
Nitrogen
\
/
45.9
40.2
28.8
FREEHOLD TREATMENT PLANT
80
-------
TABLE 13
LIQUID TREATMENT PERFORMANCE
EFFICIENCIES, %
Suspended
Solids
1. Unit Efficiency as Per Cent of Unit Input
Primary Screening
Clarification
Filtration
Carbon Adsorption
Cumulative Removal
Primary Screening
Clarification
Filtration
Carbon Adsorption
25
93
18
71
25
95
96
99
3. Unit Efficiency as Per Cent of Raw Influent
Primary Screening
Clarification
Filtration
Carbon Adsorption
Residual
25
70
1
3
1
Phosphorus BOD
23
96
97
99
21
99
Kjeldahl
Nitrogen
23
95
18
46
21
>s
96
_
12
28
12
37
23
73
1
2
1
21
62
16
1
-
12
25
63
FREEHOLD TREATMENT PLANT
81
-------
100
90
80
70
a
-------
Other interesting observations of the average
results show the following:
(6) A threefold increase in chloride
content, as a result of the Fed., addition.
(7) Reduction of alkalinity by 46%.
(8) Reduction of total solids by 23%
despite the increase in chlorides.
(9) Ninety-four percent reduction of
coliform bacteria through the filtration step. Interestingly,
the unit efficiency of the filter for coliform removal was 56%
compared to only 18% for suspended solids and phosphorus.
Figures 26, 27, 28, 29 and 30 show suspended
solids, total phosphorus, BOD, Kjeldahl nitrogen, and NH,-
nitrogen plotted on time scales. Suspended solids is shown on a
weekly basis. For this graph, raw sewage results were averaged
with surge tank data, the latter increased by 25% to correct
for solids removed by the primary screen. Clarifier effluent
and Ferrofilter effluent data were also combined since differ-
ences between these sample points were small. The other para-
meters are plotted from monthly averages, again combining certain
data where appropriate.
Frequency distributions for Clarifier, Ferro-
filter, and plant effluent suspended solids are shown in Figure
31 and 32. The Clarifier-Ferrofi1ter distributions clearly show
the small difference between these sample points as indicated
previously by the average data. A rather sharp change in slope
of the clarifier suspended solids distribution curve is evident
at about the 12 to 15 mg/1 suspended solids level. This break
is indicative of the nature of clarification performance follow-
ing chemical treatment and flocculation. The flat portion of the
curve represents normal operation with a high level of suspended
solids removal efficiency. The steep section shows evidence of
some upset condition with sharply reduced separation efficiency.
The Ferrofilter effluent show substantially lower suspended
solids in this region of the frequency distribution. This
difference is due primarily to the effectiveness of the turbidi-
metric control system following the clarification step which
automatically recycled unacceptable effluent rather than to any
increased Ferrofilter performance at high suspended solids levels
The plant effluent suspended solids distribu-
tion shows a median value of 1.9 mg/1 with 90% of the determina-
tion less than 6 mg/1 and 96% less than 9 mg/1. This reflects
the filtration achieved on the carbon column as the clarifier
effluent median was 9 rag/1.
83
-------
500
FIGURE 26
00
SUSPENDED SOLIDS
WEEKLY AVERAGES
Raw k 1.25 x Surge Tank
Clarifier &
Ferrofliter Effluent
Plant
Effluent
8 10 12
10
Week 246
July 1973
24262830 32 34 35 38 40
FREEHOLD TREATMENT PLANT March 1974
-------
15
FIGURE 27
oo
en
TOTAL HYDROLYZABLE PHOSPHORUS
MONTHLY AVERAGES
10
Mr
FREEHOLD TREATMENT PLANT
-------
300
FIGURE 28
00
BIOCHEMICAL OXYGEN DEMAND
MONTHLY AVERAGES
July
Aug Sept
1973
Oct
Nov
Dec
Jan
Mar
FREEHOLD TREATMENT PLANT
-------
FIGURE 29
| 1 1 1 4 1- 1 1 1 1 1 II
MONTHLY AVERAGES
D
/
00
BO
86
a
V
BO
2
11!
^A
=t
^
2
V
j?
t
$
-
21
t t t
July Aug Sept
1973
Oct
Nov
Dec Jan Feb Mar
FREEHOLD TREATMENT PLANT
-------
FIGURE 30
oo
00
AMMONIA NITROGEN
MONTHLY AVERAGES
Feb Mar
FREEHOLD TREATMENT PLANT
-------
M.M
M.9 99.8
99 M
9S
90
FIGURE 31
SO 70 60 50 40 30
20
10
1 O.S 0.2 0.1 O.OS
0.01
40
30
—i
~&>
a
•s
•A
o
00 W
10 TJ
4)
•§20
&
m
£
10
0
. II
4+
: :
FRE
CLARIF
O
i X.
fflffiM
— H 1 1 1 1 1 Illllll 1 1 1 1 1 1 1 1 II 1 1 1 -
-1 — i iiiiin iiiiiiin i 1 1 1 1 1 1 1 in 1 1 ii -
SUSPENDED SOLIDS
QUENCY DISTRIBUTION \\
[ED & FILTERED EFFLUENT -
Clarifier Effluent : :
Ferrofilter Effluent
EEEEEi I! JIJI! i ! !
= ~: -is!;;:
r •• ~ ~ f~ - "
iiiiiiii
-- — «-•---
-- e
- - i i * • •--
. . . . i. . .
- — i- x
••-
- ;{- --
. _ - _ . . . . _ t ' - '
L
0.01
O.OS 0.1 0.2
10 20 30 40 50 60 70 M 90
Per Cent Equal to or Less than Value
95 «8 M 99J 99.9 99.99
FREEHOLD TREATMENT PLANT
-------
MJ9
FIGURE 32
».« M.8
10
60504030
20
10
0.5 0.2 0.1 0.05
0.01
MIIMIII11 I "
8
SUSPENDED SOLIDS
FREQUENCY DISTRIBUTION
PLANT EFFLUENT
uo
B
CO
1
I*
09
CO
OM 0.1 03
5 10 JO 10 W tO W 70 90 W
Per Cent Equal to or Lets Than Value
M M W MJ 9M MM
FREEHOLD TREATMENT PLANT
-------
Ferrofilter effluent BOD CFigure 33) follows a
normal frequency distribution, with a median of 30 to 35 mg/1
and 95% of the values less than 65 mg/1.
The distribution for plant effluent BOD (Figure
34) is highly skewed, with 62% of the values reported as zero,
90% less than 4, and 99% at 8 mg/1 or less. BOD determination
in this range are subject to substantial error. The zero values
were reported when the seed-corrected oxygen depletion was zero
or a negative number. The minimum detectabi1ity possible with
the method and dilutions used was 0.3 mg/1.
(3) Chemical Consumptions
Chemical consumptions in mg/1 (Table 14) were
calculated on a monthly basis from raw material receipts,
inventory changes, and total effluent flow from the plant.
Consumptions during the period of steady state operation were
substantially higher than anticipated from previous pilot work
and from raw sewage analyses and bench scale tests at the plant.
Several factors contributed to these high values:
(a) The turbidimetric system designed to control
ferric chloride addition was ineffective because of excessive
delay in signal response at the flow rates encountered and also
because of background interferences within the flocculation and
clarification system. This method of control was abandoned early
in the operation and replaced with manual adjustment by the
operator.
(b) As reported previously, the static mixers
in the chemical addition system were removed because of frequent
fouling. Although chemical mixing and flocculation appeared to
be satisfactory without the mixers, it seems highly likely that
their absence contributed to increased requirements of both ferric
chloride (with resulting higher NaOH usage) and polyelectrolyte.
(c) Manual control of ferric chloride addition
undoubtedly accounted for a large portion of the excess usage
of both ferric chloride and sodium hydroxide. Operator surveil-
lance was generally limited to normal daylight hours, the period
of maximum ferric chloride demand. A satisfactory rate of ferric
chloride addition during these hours was higher than needed for
the later evening and early morning hours when phosphate and sus-
pended solids levels were at a minimum. The operator's reluctance
to risk an underdose was normal, particularly in view of the
emphasis which was placed on obtaining good operation of the
liquid handling process.
(d) Frequent failure of the lift station caused
excess consumption of all chemicals. This condition resulted in
91
-------
ro
a
4)
nl
u
•<4
e
4)
ji
u
.2
19.99
70
"g
I 60
s
50
40
30
20
10
99.9 99.S
99
90
80
FIGURE 33
70 60 SO 40
30
20
10
0.2 0.1 0.05
0.01
BIOCHEMICAL, OXYGEN DEMAND
FREQUENCY DISTRIBUTION
FERROFILTER EFFLUENT
OM 04 &2 U
t U 20 30 40 SO U 70 tO 99
Per Cent Equal to or Leea than Value
W W W WJ 9M 99.99
FREEHOLD TREATMENT PUNT
-------
00
FIGURE 34
TO W 50 40
0.2 0.1 0.06 OJtt
S 10 20 30 40 SO ef 70 M 90
Per Cent Equal to or Lean Than Value
MM
MJ MJ
MM
FREEHOLD TREATMENT PLANT
-------
TABLE 14
Month
July
Aug.
Sept.
Oct.
Nov.
Dec.
Jan.
Feb.
Mar.
Avg.
325
180
279
269
280
223
252
276
232
267
CHEMICAL CONSUMPTION
NaOH
201
178
102
174
178
168
134
81
166
mg/1
Hercofloc ]
2.6
2.9
3.6
2.9
1. 5
1.9
2.7
2. 0
3. 1
re3o4
4. 5
4. 0
6. 1
3.6
5. 1
8. 3
0.4
-
_
154
2.6
5. 3
(a)
Chlorine
24. 1
28. 4
18.6
22. 3
14. 2
20.6
31.8
34.4
43.4
26.4
(a)
Six Months - July through December
FREEHOLD TREATMENT PLANT
94
-------
a low surge tank level, with automatic recycle of clarifier
effluent to the surge tank in order to maintain an operating
liquid level. Lift station failure during the day could be
corrected by manually operating the lift pumps, but malfunction
at other times caused repeat addition of chemicals to the re-
cycling sewage.
(e) On the average the liquid handling system
produced a high quality effluent with relatively little dif-
ficulty. The need to optimize chemical consumptions, however,
was overshadowed by preoccupation with the solids disposal opera-
tion which posed a number of difficult problems, as will be dis-
cussed 1ater.
(f) High chlorine consumption was due in part
to its use to control blockage in the carbon column. Also, the
degree of chlorination applied to the plant effluent was probably
in excess of that required to meet state standards. As with the
other chemical additions the philosophy was generally "better to
be safe with a bit too much than not enough."
In summary, chemical consumptions could undoubted-
ly have been reduced with more work and greater surveillance. A
detailed analysis would be required to determine the optimum
economic balance among costs of chemicals, plant size, automation
and instrumentation to optimize consumptions, and operating and
maintenance labor.
Activated carbon usage could not be properly
evaluated during this study. Although no thermal carbon regenera-
tion was performed it was necessary, during the course of the
evaluation, to transfer carbon from the column for washing,
followed by column backwash and reloading. Some carbon was lost
physically during these operations (described elsewhere in the
report), and was replaced by virgin carbon. Several samples of
"spent" carbon taken during these transfers were analyzed. None
showed evidence of impending exhaustion. Most exhibited capa-
cities (to adsorb sewage TOC and BOD) of 60 to 80% relative to
virgin carbon.
(4) Operation & Maintenance
During the "steady state" mode, one operator was
normally assigned to the plant for eight hours a day, Monday
through Friday. In addition to making the required operating
adjustments, this operator handled the routine maintenance, con-
ducted the analyses necessary to monitor the performance of the
plant, and did the housekeeping to keep the building and grounds
neat and clean. Weekend coverage was usually limited to the time
required to check the operation, collect samples, and run the
minimum analyses.
95
-------
The vacuum lift station continued to fail at
irregular intervals due to objects hanging in the check valves
and preventing them from closing when the pumps stopped. The
liquid would then drain from the lines and the pump prime would
be lost. This problem was not solved during the report period;
however, at a later date, submersible pumps were installed in
place of the vacuum lift pumps.
Periodically during unattended operation when the
lift station failed or when the sewage flow was appreciably less
than expected, the surge tank would go empty. When this happened
the process sewage flow would drop to zero and ferric chloride
would back up into the steel process line resulting in severe
corrosion. When flow resumed, it was often irregular for a time
and the clarifier operation would be upset. A relay was install-
ed on the surge tank level recorded which, when the level dropped
to 13% would activate the existing automatic valve in the clari-
fier effluent line to recycle the flow to the surge tank, and
when the surge tank level increased to 22% would reset the re-
cycle valve for normal operation. The system then operated
smoothly in the event of lift station failure or low influent
sewage flow, however, chemical consumption was increased.
As explained elsewhere, manual control of ferric
chloride addition accounted for a large portion of the excess
use of chemicals. It was observed that good flocculation was
consistantly obtained when sufficient ferric chloride was added
to depress the pH to about 5.9 to 6.3. A pH detector-controller
was installed and connected so as to regulate ferric chloride
addition to maintain the set pH of about 6.1. Operation was
satisfactory, however, the instrument failed after ten days opera-
tion due to a defective seal. It was returned to the manufac-
turer and not reinstalled during the report period.
The clarifier rake drive bearings failed on July
8, and were replaced on July 10. An inspection revealed that
one of the original bearings supplied in the gear box was defec-
tive. Clarifier effluent turbidity was normal at 3 to 6 JTU
during the two-day period without rake operation, however, the
sludge pumped to the hold tank was very thin, less than 21
total solids.
The Ferrofilter was a major power consumer yet
its efficiency in removing suspended solids was low. In November
the unit was opened and the grids were removed, cleaned, and
replaced. It was estimated that they were 70 to 80% plugged.
There was little improvement so on January 17, use of the unit
was discontinued.
The four woven wire effluent screens at the top
of the adsorber required cleaning every two weeks. During
October, they were replaced with wedge-wire well point screens.
These worked very well. The cleaning frequency was reduced to
96
-------
once per month. Screen boxes were fabricated and installed on
both the adsorber and quench tank drain lines to catch any carbon
that might be lost when backwashing or draining these units.
An occasional problem with poor flocculation in
the clarifier and high Hercofloc consumption was believed to be
caused by non-uniform Hercofloc solutions. The mixing of polymer
and water by the original small agitators was inadequate. Double
bladed agitator shafts driven by 1/4 H.P. motors were provided
in January, 1974. The hercofloc solution and flocculation seemed
to be improved.
Plant operation during the "steady state" period
was generally good and effluent quality was consistantly high.
Only two major deviations from the design concept were made.
First, the Ferrofilter was removed from operation as described
earlier due to poor efficiency and high power consumption.
Second, the carbon was not thermally regenerated because by the
end of the report period, it still had a capacity to adsorb BOD
of at least 60% relative to virgin carbon.
b. Intensive Evaluation I
Sampling for intensive evaluation was conducted under
two different plans. The first, which was shown in Table 9
(Normal Evaluation Section), specified three sets of samples for
each of two days per week for eight weeks. The three samples
consisted of composites taken during the following periods:
Period Hours
1 0800 - 1400
2 1400 - 2000
3 2000 - 0800
The following six locations were selected with the
primary objective of determining parameter variations during
the three sampling periods:
Raw - Lift Station Discharge to Hydrasieve Box
ST - Discharge from Surge Tank
CE - Clarifier Effluent
FFE - FerroFilter Effluent
CCE - Carbon Column Effluent
PE - Plant Effluent
97
-------
uenerally, eleven separate parameters were analyzed
with emphasis stressed primarily on the Raw, Surge Tank, and
Plant Effluent locations.
The above evaluation was terminated at the end of
the fifth week instead of the scheduled eighth week. It was felt
at that point that the trend of the data gathered did not and
would not show the kind of changes which were expected to occur
during the various times of a typical diurnal cycle. Since most
of the other data gathered at this plant showed that there are
indeed variations in the measured parameters during the course
of the day, it can only be postulated that the time periods
chosen were most likely not the best and/or that the number of
periods were too few to show any variation.
At the end of the fifth week, approximately 1400
data points had been determined. The data are summarized in
Table 15. The value given for each time period is an arithmetic
mean of approximately ten determinations. A few values were
missing and several were discarded as being extremely outside the
normal population. The unused and missing numbers comprised
slightly over 1% of the total number of determinations.
Observation
As previously stated, the data accumulated did not
follow the trend expected and must therefore be carefully
scrutinized in order to extract any meaningful conclusions. It
was expected that a significant drop in the absolute values of
the parameters would be observed during the second and third
periods; similar to that displayed by a characteristic diurnal
flow pattern.
Generally, the pollutant parameters measured in the
Raw Sewage and Surge Tank did show a slight drop in the para-
meters for the third period with the exception of alkalinity,
TKN, and NhU-N which were appreciably higher than in the other
two periods. This sequence, however, does not extend to all
the locations sampled. For example, all three periods of the
plant effluent showed a random trend with the exception of the
TOC, Alkalinity, TKN, and NHg-N which displayed a significant
downward trend.
Another observation, for which there is no apparent
explanation, is the large values of total phosphorus in the raw
sewage and surge tank. For the most part, the values are three
times the expected normal and the tendency would be to assume
that the concentrations were expressed as P04 and not P. However,
all laboratory reports indicate that this is not the case. The
soluble phosphorus levels obtained during all three periods do
fall within the expected values.
98
-------
TABLE 15
Total Phosphorus
Peri od
1
2
3
Average
I
Raw
29.1
26.5
26.3
27.3
n tensive Evaluation I
Average Values, mg/1
ST CE
26.4 1.6
23.7 1.6
18.8 1.7
23.1 1.7
Sol uble Phosphorus
1
2
3
Average
A 1 k a 1 i n i ty
1
2
3
Average
Coliform (MPN -
1 7
2 7
3 6
Average 7
218
202
269
230
Geome
.0x10
.7x10
.5x10
.1 xin
8.7
9.6
6.4
8.4
237
225
246
236
trie Mean)
5 5.1xl05 2.7x10
5 1.2xl06 3.1x10
5 7.2xl05 1.6x10'
5 5
7. 7x1(1 ? 4vin
FEE
2.4
3.2
2.1
2.5
0.83
0.92
0.84
0.86
179
168
164
170
2.8x10'
2.5xlo'
1.5x10'
2.0xl(/
PE
0.70
0.74
0.66
0.70
0.43
0.39
0.48
0.43
147
143
130
140
2.4
^1
3.0
2.0
FREEHOLD TREATMENT PLANT
99
-------
TABLE 15 (cont.)
SS
Period Raw
1 261
2 267
3 276
Average 268
TOC
1 132
2 123
3 116
Average 124
SOC
1
2
3
Average
BOD
1 198
2 233
3 200
Average 210
ST CE
304 21.4
298 18.9
207 15.3
272 18.4
117
115
99
114
32.8
31.9
29.4
31 .4
185
172
146
169
FEE CCE
17.4 3.9
18.8 4.1
21.2 4.6
19.2 4.2
26.0 8.5
25.2 8.5
23.7 8.9
25.0 8.6
19.8 6.3
18.4 6.4
18.2 6.0
18.8 6.2
PE
3.5
4.7
3.1
3.7
8.8
8.2
7.6
8.2
7.1
6.8
7.4
7.1
5.7
5.7
5.9
5.8
FREEHOLD TREATMENT PLANT
100
-------
TABLE 15 Ccont.)
TKN
Period
1
2
3
Average
N00+N00-N
L.
-------
Of interest is the significant increase in the amount
of N0? + NO--N in the plant effluent as compared to pre-carbon
column values. These results would indicate a substantial amount
of nitri-nitrafication occuring in the carbon column. Such re-
sults are not totally unexpected considering the significant
amount of bio-activity which is present in the carbon column,
and which is also responsible for extending the observed carbon
life.
c. Intensive Evaluation, II
The second intensive evaluation was performed from
January 17, 1974, to April 7, 1974. In this study, raw sewage
and surge tank samples were taken every two hours (with the ex-
ception of 3 a.m.) for ten separate 24-hour days. The evalua-
tion's main objective was to generate a 24-hour profile of the
raw sewage and surge tank. Each sample taken was analyzed for
eight parameters consisting of BOD, SS, Total P, TOC, TOD, TKN,
pH, and NH3-N.
Approximately 1824 determinations were scheduled
during the evaluation period. Of this number, 140 determinations
(8% of total) were not performed because of missed samples, and
17 (1%) were discarded as being extremely incongruous with the
normal population.
Observations
A summary of the data obtained is presented on Table
16 and graphically represented on Figures 35 thru 42.
In general, the data indicate concentration profiles
similar to the characteristic diurnal flow pattern as shown in
Figure 21 (Normal Evaluation section). The data demonstrate
quite vividly the importance of the surge tank and its function
in accepting the highly variable concentrations in the raw in-
fluent and dampening them into more easily handled fluctuations.
It is also interesting to note that the dampening ability of the
surge tank is much more pronounced during periods of high flow
and high concentration as opposed to lower flow and lower con-
centration of the raw influent. One of the reasons for such a
difference is that lower flows are experienced during the late
evening and early morning hours which are also the hours of
minimum surge tank level and, therefore, minimum dampening
abi1i ty .
In Intensive Evaluation I, it was stated that the
three time periods chosen may not have been the best to produce
the results expected. As an approximate check of this statement,
the data summarized in Table 16 was regrouped as shown in Table
17. The numbers were obtained by averaging the hourly samples
of Table 16 during the following periods:
102
-------
TABLE 16
INTENSIVE
AVERAGE
AM
RAW
S.T
RAW
S.T
RAW
S.T
^ RAW
o S.T
co
RAW
S.T
RAW
S^
.T
RAW
S.T
RAW
S-^
.T
BOD
. BOD
P
. P
SS
. SS
TOC
. TOC
TOD
. TOD
PH
i |
. pH
TKN
. TKN
NH3-N
• NH3-N
1
137
163
5.90
6.98
122
128
47
50
182
211
7.1
6.9
42.8
38.0
25.9
23.5
3 5
79
94
4.60
6.03
107
89
46
36
229
186
7.2
6.8
48.8
43.1
31 .9
21.8
7
139
101
5.87
6.04
256
107
54
40
245
175
7.7
7.1
62.8
47.1
41 .1
25.8
9
169
127
8.40
7.14
177
121
72
47
324
220
7.8
7.3
68.8
56.6
45.1
34.6
EVALUAT
VALUES,
r
11
246
172
10.51
8.20
187
150
117
53
397
248
7.1
7.2
47.8
59.2
33.4
30.0
ION, II
M6/L
1
1
185
181
8.68
8.51
124
189
83
60
319
249
7.0
7.0
38.2
43.4
25.8
29.0
PM
3
146
159
8.26
8.45
183
216
73
62
310
267
7.0
6.9
35.2
35.3
26.5
26.0
5
154
159
7.38
7.37
139
235
65
58
225
235
7.1
6.9
36.2
33.9
22.6
22.1
7
216
158
7
6
173
173
77
56
299
223
6
6
37
35
26
24
9
244
179
.53 6.54
.97 7.38
192
156
65
54
277
221
.9 6.8
.9 6.8
.5 38.1
.4 38.8
.3 22.0
.0 23.0
11
152
190
6.80
7.06
133
179
66
53
251
221
7.0
6.8
35.2
32.9
24.6
20.1
FREEHOLD TREATMENT PLANT
-------
o
-p.
o
Q
UJ
Q
FIGURE 35
INTENSIVE ANALYSIS H
RAW INFLUENT
—o—SURGE TANK
DAILY VARIATION SUSPENDED SOLIDS
10 DAY AVERAGE 2 HOUR FREQUENCY
JANUARY 17.1974-APRIL 7,1974
45678 9 10 II IE
FREEHOLD TREATMENT PLANT
-------
CD
tn
FIGURE 36
INTENSIVE ANALYSIS H
RAW INFLUENT
SURGE TANK
DAILY VARIATION BIOLOGICAL OXYGEN DEMAND
10 DAY AVERAGE,2 HOUR FREQUENCY
JANUARY 17,1974-APRIL 7,1974
5 6 7 8 9 tO II 12
FREEHOLD TREATMENT PLANT
-------
o
en
20
45678 910 II
FREEHOLD TREATMENT PLANT
-------
FIGURE 38
INTENSIVE ANALYSIS E
• RAW INFLUENT
o SURGE TANK
DAILY VARIATION IN TOTAL OXYGEN DEMAND
10 DAY AVERAGE,2 HOUR FREQUENCY
JANUARY 17,1974 -APRIL 7,1974
8 9 10 II 12 I
IZ
4 5 6 7 8 9 10 II 12
FREEHOLD TREATMENT PLAN T
-------
ao
FIGURE 39
INTENSIVE ANALYSIS H
ro
UJ
O
g
90
o
00
UJ 4O
t.
20
K>
RAW INFLUENT
j o SURGE TANK
DAILY VARIATION IN TOTAL KJELDAHL NITROGEN
10 DAY AVERAGE, 2 HOUR FREQUENCY
JANUARY 17,1974-APRIL 7,1974
12 I
K) II 12 I
45678 9 10 II 12
FREEHOLD TREATMENT fLAMT
-------
o
vo
FIGURE 40
INTENSIVE ANALYSIS H
-S-X o
RAW INFLUENT
SURGE TANK
DAILY VARIATION IN PHOSPHORUS
10 DAY AVERAGE, 2 HOUR FREQUENCY
JANUARY I7.I974-APRIL7.I974
12
23458789
FREEHOLD TREATMENT PLANT
-------
FIGURE 41
INTENSIVE ANALYSIS H
RAW INFLUENT
-SURGE TANK
DAILY VARIATION IN AMMONIA-NITROGEN
10 DAY AVERAGE 2 HOUR FREQUENCY
JANUARY 17,1974 - APRIL 7,1974
12
6 7 8 9 10 II 18 I 2
NOON
45678910 II
FREEHOLD TREATMENT PLANT
-------
I o SURGE TANK j ;
DAILY VARIATION IN PH
10 DAY AVER AGE 2 HOUR FREQUENCY
JANUARY 17,1974 -APRIL7.I974
I i i i i !
567 8 9 10 II
FREEHOLD TREATMENT PLANT
-------
TABLE 17
INTENSIVE EVALUATION, II
THREE-PERIOD AVERAGE (MG/L)
Raw Influent
Period
1
2
3
BOD
255
204
108
P
8.18
6.96
5.25
SS
171
166
115
TOC
77.3
69.3
46.5
TOD
304
276
206
TKN
48.2
36.9
45.8
NH3-N
40
24.3
28.9
Surge Tank
1
2
3
150
176
129
7.62
7.14
6.51
170
169
109
53.3
54.4
43.0
232
222
176
46.0
35.7
40.0
27.8
22.4
22.7
FREEHOLD TREATMENT PLANT
112
-------
P eri od Hours
1 6 a.m. - 6 p.m.
2 6 p.m. - 12 midnight
3 12 midnight -6 a.m.
This regrouped data indicates a substantial drop in all the
parameters during the second and third periods of operation with
the exception of TKN and NH3-N. Both of these parameters,
however, did experience a substantial drop during the second
period. Evaluation of concentration changes occuring during
the day is important in evaluating chemical usage, particularly
when chemicals are being added manually. For example, Figure
40 shows significantly less phosphorus in the late evening and
early morning periods than during the 6 a.m. to 6 p.m. period;
however, the rate of FeClo use, which is directly related to
the phosphorus content, is normally controlled at an amount which
corresponds to that required during the late morning-early
afternoon periods. This action, by the operator, of not reset-
ting his chemicals for the late evening-early morning period is
understandable since he does not wish to experience a possible
upset in the early evening when he has left.
Since the treatment plant's sewage collection system
is a relatively tight one, it would be reasonable to propose
the following periods of concentration variations:
Five Peaks
-Early morning shower, breakfast, and grooming
-Middle morning cleaning and cloth washing
-Lunch
-Supper
-Retiring
This, of course, did not occur during the intensive evaluation
period.
Observation of Figures 35 thru 42 do show, however,
that each parameter experiences at least one major peak (with
the exception of BOD in which the raw experiences two major
peaks) and a few minor peaks.
The major peak appears to begin at approximately 5 a.m
and continues until the middle afternoon. The first minor peaks
occur from 5 to 9 p.m., with the last peak beginning at 9 a.m.
and lasting only until 11 p.m. at which time all the parameters
begin their downward plunge. It seems that of the five peaks
proposed, the first three overlap to such an extent that they
appear to be one.
It is interesting to note that all parameters did
113
-------
not experience similar peaks during the day. For example, TOD,
TOC, SS, pH, and BOD experienced more than one significant peak
while TKN, P, and NH3-N did not. The significance of this is
not quite understood at present.
There is also some doubt as to the correctness of the
suspended solids curve (Figure 35). The time interval between
the raw and surge tank peaks seem rather long. The rapid in-
crease and decrease in the raw should have produced a similar
narrow peak in the surge tank curve. The surge tank curve did
not display this peak. It also showed very little dampening
ability.
B. SOLIDS DISPOSAL
1 . Sludge Characteristics
During the first six months of start-up and break-in
operation (October 1972-March 1973) the total solids content of
the clarifier sludge ranged from about two to four percent with
three percent being a typical value. The reason, as described
previously was due to erratic operation of the sludge level
controller which frequently allowed very thin sludge to be pumped
to the Sludge Hold Tank. It was observed that sludge in the hold
tank would settle leaving a relatively clear layer of water on
top. Five nozzles were welded on the hold tank, equally spaced
from the bottom to the top, and drain valves installed so that
the clear water could be decanted. A schedule of regularly de-
canting the tank was established. The solids content of sludge
from the holding tank was increased to about seven percent.
After the problems with the clarifier sludge level con-
troller described in Section VIA1 were corrected the sludge
from the clarifier averaged about seven percent solids. Little
improvement was then obtained by decanting the holding tank.
Considerable difficulty was encountered in reliably pump-
ing the seven percent solids sludge from the hold tank to the
inc nerator. Plugging problem, similar to those described in
Section VIA 1 under Clarifier Sludge Pump, occurred frequently.
The steel pipe and ninety degree elbows were replaced with 2.54
cm. (1 inch) I.D. reinforced synthetic rubber hose, the gear
pump was replaced with a variable speed drive progressing cavity
pump complete with bridge breaker, and a procedure was establish-
ed to flush the lines daily. Plugging was reduced to infrequent
intervals.
Samples of Hydrasieve solids taken over a nine month
period of steady state operation, July 1973 - March 1974, aver-
aged seventeen percent total solids. The solids composition was
about 72% volatile compared to about forty-eight volatile solids
114
-------
in the sludge. The clarifier sludge averaged 6.8% total solids
and the hold tank sludge 6.7%. These data are contained in Table
18. The analyses of intensive evaluation samples performed by
an independent laboratory contained in Table 19 are in agreement.
The wet weight of Hydrasieve solids collected during one
week in April, 1973, averaged 18.2 kilograms (40.2 Ibs). Average
occupancy was eighty-two houses and average sewage flow was
102.66 cu. meters (27,122 gal.) per day. These data are contain-
ed in Table 20.
2. Dewatering
The original concept of solids dewatering and disposal as
described in detail in Section IV-B-1, Continuously Regenerating
Filter, was for the Hydrasieve solids to drop from the screen
through a hopper to a belt conveyer which fed a sand filter de-
veloped and built by the Procedyne Corporation. These solids
together with sludge from the holding tank were to be mixed with
hot recycle sand from the incinerator, dewatered in the filter to
about eighteen percent solids via evaporation, vacuum filtration,
and compression, then fed with a screw conveyor into the fluid
bed of the incinerator.
Several problems developed:
a. The belt conveyor required frequent cleaning. Solids
would accumulate on the drive and guide rolls resulting in poor
tracking. Solids frequently would stick to the belt.
b. The overflow rate of sand from the incinerator to the
filter was erratic, thus the mixing of hot sand, Hydrasieve
solids, and sludge was not uniform. It was necessary to get good
uniform mixing to cool the sand and evaporate part of the water
content of the solids.
c. The filter operation was unsatisfactory. The sand-
sludge mixture did not dewater and move through the filter as
designed. The layer along the wedge wire screen would dewater
and stay in place, blinding the screen, then dewatering would
cease. Sometimes, when the sludge concentration was high, the
sand-sludge mixture would form balls.
d. The feed
being discharged to
frequently carbonized on the screw before
thefluidized bed thus plugging the screw.
It became apparent that further development work was re-
quired. In addition, as the Clarifier operation was improved
and the sludge consistency approached seven percent solids, the
economics of operating the sand filter became marginal due to the
cost of power to run the filter and vacuum pump, and the cost of
oil required to reheat the recycle sand from ambiant to 816°C
(1500 F). The sand filter was removed.
115
-------
TABLE 18
FREEHOLD SLUDGE CHARACTERISTICS
Hydrasieve Solids
Clarifier Sludge
Hold Tank Sludge
DATE
1973-74
July 31
Aug 6
Aug 16
Aug 21
Aug 26
Sept 5
Sept 10
Sept 20
Sept 25
Sept 30
Oct 10
Oct 15
Oct 25
Oct 30
% Total
Solids
14.2
11 .3
12.9
16.7
12.6
16.4
27.7
23.4
16.2
16.1
16.4
13.4
31 .9
23.6
% Volatile
Solids
71 .5
92.6
77.9
68.5
67.7
85.6
40.3
49.4
86.5
71 .0
67.6
81 .6
34.9
59.6
% Total
Sol ids
5.5
5.9
8.3
7.5
10.6
5.8
8.4
9.1
7.0
9.1
9.0
3.6
8.5
2.9
% Volatile
Solids
43.4
48.7
48.6
50.3
73.0
53.6
46.5
49.4
44.1
53.1
40.7
43.1
46.2
50.7
% Total
Solids
6.8
5.5
6.1
9.8
4.0
-
9.8
-
5.2
8.5
6.8
8.6
10.2
3.4
% Volatile
Solids
46.8
41.5
52.6
58.8
52.1
-
46.3
-
53.9
53.0
44.7
41.7
41 .0
47.7
-------
TABLE 18 (Cont'd)
Hydrasieve Solids Clarifier Sludge Hold Tank Sludge
DATE
1973-74
Nov 8
Nov 14
Nov 19
Nov 27
Dec 5
Dec 14
Dec 21
Dec 26
Jan 21
% Total
Solids
13.2
14.3
11 .9
14.0
15.7
17.4
25.2
11 .2
16.2
% Vol
Sol
84
90
70
71
80
94
44
82
86
a tile
ids
.0
.0
.8
.2
.5
.1
.0
.5
.7
% Total
Solids
7
4
6
6
4
9
5
6
.5
.8
-
.3
.3
.7
.5
.5
.2
% Vol
Sol
44
41
-
49
45
48
41
48
56
a t i 1 e
ids
.0
.5
.1
.5
.0
.0
.1
.2
% Total
Sol ids
7
5
5
7
4
8
9
6
.0
.8
-
.6
.8
.4
.3
.4
.1
% Vol
Sol
44
45
-
48
45
48
49
46
56
atile
ids
.7
.0
.5
.4
.6
.6
.9
.2
FREEHOLD TREATMENT PLANT
-------
TABLE 19
INTENSIVE EVALUATION - SLUDGE SAMPLES
CO
AVERAGE
Hydrasieve Solids
Clarifier Sludge
Hold Tank Sludge
DATE
1973
Sept 27
Oct 23
Nov 12
Nov 15
Dec 10
Dec 17
% Total
Solids
14.0
18.2
21 .3
19.0
13.1
26.6
% Volatile
Solids
93.3
84.4
86.4
90.9
87.8
72.4
% Total
Solids
6.6
4.1
6.6
8.9
7.0
7.1
% Volatile
Solids
50.9
55.4
52.0
47.9
52.3
56.5
% Total
Solids
9.0
4.9
7.6
7.0
4.4
6.2
% Volatile
Sol ids
50.1
52.6
53.6
51 .3
64.8
55.6
18.7
85.9
6.7
52.5
6.5
54.7
FREEHOLD TREATMENT PLANT
-------
TABLE 20
HYDRASIEVE SOLIDS COLLECTED
Date
24 Hour Period Ending
Solids Collected
Wet Wt. Ibs.
Sewage Flow
Gal Ions
0830
0830
0900
0800
0830
AVERAGE
4/12/73
4/13/73
4/14/73
4/15/73
4/17/73
45
40
24
46
46
40.2
24,315
29,807
28,611
26,857
26,019
27,122
FREEHOLD TREATMENT PLANT
-------
A vacuum coil filter was installed and tested for sludge
dewatering. This unit was able to produce a filter cake of twelve
to twenty percent solids with a sludge feed of five to ten percent
solids. Suspended solids in the filtrate ranged from 6,000 to
20,000 mg/1. The filter required considerable operator attention
and could not be left operating unattended for long periods of
time. It was removed.
When the sand filter was removed it became necessary to use
a different technique to feed sludge to the incinerator. A spare
nozzle about 30.5 cm (12 inches) above the air distribution plate
was fitted with a plug valve and a packing gland. A sludge feed
gun consisting of a length of 1.25 cm diameter (0.5 inch) type RA
330 stainless steel pipe with a full bore ball valve on the outer
end was inserted through the packing gland, plug valve and nozzle,
extending about 10.16 cm (4 inches) into the sand bed. The sludge
line with an air purge was connected to this gun. The small gun
would plug once or twice a day. This gun was replaced with one
2.54 cm (1 inch) in diameter and an air purge rotometer was in-
stalled so the purge could be regulated at about 0.028 cubic meters
per minute (1 SCFM). Gun plugging was no longer a problem.
3. Incineration
The "Fluidhearth" fluid bed incinerator, instrumentation,
and related auxiliary equipment including that necessary for car-
bon regeneration was designed, fabricated, and installed under the
supervision of the Procedyne Corporation. It is described in
detail in Section IV-B-2.
Installation was completed in November 1972. The refractory
was dried, thirteen hundred pounds of sand was charged to the unit
and it was heated to 816°C (1500°F). The procedure developed to
dry and cure the refractory whenever major alterations or repairs
were made consisted of heating to about 71°C (16QOF) with a propane
torch, inserted through the recycle sand nozzle. After holding at
71°C for eight hours the temperature was increased to 110°C (2300F)
at a rate of about 11°C (2QOF) per hour, and held at 110°F for
eight hours. The temperature was then increased to 316°C (600°F)
at a rate of 28°C (50°F) per hour and held for four hours after
which the regular start-up procedure was followed.
The original start-up procedure consisted of charging the
incinerator with 590 kg (1300 Ibs.) of 20-40 mesh flintshot sand,
igniting the oil fired start-up burner in the plenum and heating
to a bed temperature of 621°C (1150°F). The sand bed at this point
was fluidized and the safety temperature interlocks allowed fuel
oil to be injected directly into the bed via the gun burner. The
bed temperature was increased to 816°C (1500°F), the start-up
burner was shut down, and the controls set for automatic operation.
120
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Shortly after start-up the differential pressure readings
across the fluid bed and the air distribution plate indicated an
absence of sand. The unit was cooled and examined. The ceramic
plate had cracked, several ceramic tuyeres were broken, and the
sand had drained into the plenum. The tuyeres were replaced with
ones made of high temperature alloy (RA330) and a new ceramic
plate was cast on top of the old one. The plate was cured, the
incinerator was loaded with sand, and, following the regular
procedure heated to operating temperature. Again, it was found
that there was considerable leakage of sand to the plenum. In
addition, several hot spots developed on the shell. Upon cool-
ing the unit it was found that the packing around the plate had
blown out. The plate was repaired by packing around the edge
with "Fiberfrax" then building a refractory brick ledge to hold
the packing in place. The hot spots were repaired by removing
the refractory and deteriorated insulating brick in those areas
and replacing with new materials. The unit was reheated and put
on automatic control in late January, 1973.
During the spring and early summer of 1973 the incinera-
tor was operated intermittently burning sludge first from the
sand filter then directly from the sludge holding tank. The
major operating problem was to maintain continuity of operations,
especially during the sand filter operating period. The scrubber
water circulating pump corroded and failed. It was replaced
with a stainless pump. Oil tended to carbonize in the oil feed
gun at low oil flow rates. An air purge similar to that on the
sludge gun was installed. The fluidizing ai> blower failed and
was replaced. The fuel oil pressure regulator failed and was
replaced.
As the sewage flow to the plant and thus the amount of
sludge collected increased, it became desireable for the incinera-
tor to operate burning sludge automatically at night and at other
times when no operator was in attendance. The sludge feed pump
motor circuit was connected via relays to a high-low temperature
controller which allowed the pump to run only when the fluid bed
temperature was in the desired range of about 760° to 843°C
(1400-1550°F). This worked very well.
During this period the carbon regeneration equipment was
tested and made ready for operation. The incinerator carbon
overflow valve was relocated to a better position. The carbon
feed screw was redesigned to provide a new cooling jacket and
stuffing box and a drain line was installed on the feed screw
drain section. The after burner and controls were tested. The
system was then put in stand-by because the carbon was not yet
exausted and did not require regeneration. Later in the year
it became apparent that the life of the carbon was much longer
than originally believed. The incinerator was modified which
precluded carbon regeneration.
121
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On July 13, 1973 when restarting the unit after a power
failure, a hot spot developed. An inspection revealed that the
plate had cracked again. A 2.54 cm (1 inch) high temperature
alloy type RA330 plate and tuyeres were installed. To insure
fluidization in case of seal leakage a 3.18 cm diameter
(1-1/4 inches) type RA330 air sparge pipe was inserted into the
center of the bed from the top of the unit and valved to the
fluidizing air blower. This system operated satisfactorily.
On August 31 the unit was examined by a licensed pro-
fessional engineer from an independent laboratory while it was
burning sludge at about design rate. Stack gas samples were
taken as described in the New Jersey and Federal air pollution
regulations. The results certified to the state show a particu-
late content of 0.011 grains/ftj and an opacity reading of zero.
During September the unit operated continuously and auto-
matically to burn sludge, unattended at nights and checked only
briefly on weekends. It shut down automatically on September 29,
reason unknown, and was restarted September 30. The unit burned
sludge faster than it was produced, thus when the holding tank
level was low the sludge feed pump was stopped and the incinera-
tor idled until the sludge inventory increased. During the month
approximately 16,805 liters (4,440 gals.) of sludge at an average
7.8% solids was burned in 415 hours, a rate of 40.5 1/hr (10.7
gal/hr). Fuel oil consumption was 10.2 1/hr (2.7 gals/hr). Total
ash removed from the dry cyclone was 360.6 Kg (795 Ibs.) Fuel
consumption averaged 730 gallons per ton of dry solids. At a
fuel price of 18.4 c/gal the fuel cost per ton of dry solids was
$130. These data are contained in Table 21.
The incinerator operated continuously until October 15
burning sludge as required. Air leakage around the plate seal
became excessive and the unit was shut down. It was decided to
relocate the start-up burner from the plenum to the top of the
incinerator, remove the plate and in its place install an in-
verted concical shaped stainless distribution plate can. The
tuyeres were on the top of the can and fluidizing air was piped
from the blower through the plenum wall to the low point of the
can. Sand was then added to the incinerator. The diameter of
the distributor plate can was about 12.7 cm (5 in.) less than
the inside diameter of the refractory thus the can was surrounded
on all sides by sand and was free to expand and contract as the
temperature increased and decreased. In addition there were no
plate seals to erode. The unit was heated by down firing using
the start-up burner on the top of the incinerator. The gun
burner interlocks were changed so that the bed oil gun could be
started when the temperature reached 566°C (1,050°F).
122
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TABLE 21
INCINERATOR OPERATING DATA
SEPTEMBER 1975
Hours of sludge burning = 415
Volume of sludge burned gals. = 4,440
Weight of sludge burned Ibs. = 37,740
Sludge analyses % Solids = 7.8
Weight of dry solids burned Ibs. = 2,944
Fuel oil used gals. =1 ,120
Gallons fuel per dry ton solids = 761
Cost of fuel
-------
The Incinerator was restarted in February 1974. The new
air distributor plate can concept worked well. Bed fluidization
appeared good, however hot spots developed at points on the shell
above the oil and sludge feed gun nozzle. The cast refractory at
these nozzles was found to be cracked and the insulation eroded.
This was repaired by drilling holes and pumping in castable
insulation which sealed the cracks and filled the eroded voids.
however upon subsequent operation, hot spots developed at other
places on the shell. It was concluded that to make the unit
operable the original brick-type insulation should be removed
and the area between the refractory brick and the shell be filled
by pouring castable insulation.
By the spring of 1974 the price of fuel oil and power
were twice that in September 1973 and economics of operating such
small units dictated hauling the sludge to landfill as long as
sites were available and regulations permitted. It was finally
decided to remove the incinerator and use the space for other
purposes.
c• PLANT MODIFICATION^
During the 2 year period since the spring of 1974 an
attempt has been made to achieve reduced operating costs, lower
attendant requirements, achieve greater consistency of results
and measure the local community acceptance and reaction to the
facility. Listed plant modifications are as follows:
1. Installed automatic hot water spray system for the
Bauer Screen with timing devices controlling frequency and
duration of flushing to eliminate grease and solid buildup on
screens.
2. Installed a retention loop consisting of water storage
tanks in series after the surge tank and prior to the clarifier
for chemical mixing.
3. Added positive displacement pumps to the pump station
eliminating the problems of the prior type which required fre-
quent operator attention and caused recycling in the plant during
periods of ailure.
4. Eliminated the magnetic filter with its head loss and
power needs. '
5. Removed the incinerator.
6. Installed a water pump to permit more efficient back-
wash with effluent rather than fresh water.
124
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7. Replaced the carbon column supports with stainless
steel and modified piping to simplify maintenance.
8. Added 2" decanting line from Bauer screen hopper.
9. Installed a 4,860-gallon ferric chloride storage
tank to permit bulk delivery and allow automated feed and
mi xi ng.
10. Installed pH meter.
The above modification program has significantly reduced
operating costs identified in the financial section.
125
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SECTION VII
FINANCIAL CONSIDERATIONS
INTRODUCTION
Treatment plants have two major elements of cost (capital
and operating costs) which are of concern to both the initial
and ultimate owner. Funding, initially, is often the burden of
a developer, but ultimately, all costs must be borne by the
homeowner. The major problem is to balance the capital and
operating expenses to achieve the best economic solution for the
project. In today's society with changing criteria and more
stringent qual i ty requirements for effluent discharge, together
with frequent moratoriums on new connections to the sewage
system, a simple low labor intensive treatment plant producing
a high quality effluent is very desirable. By low labor cost
we are reflecting the desire to utilize part-time operators for
four hours or less per day on a six-day basis with alarm systems
and dualization of key elements to avoid breakdown problems.
Such a plant can be justified to permit residential growth if
the capital cost per dwelling unit and subsequent operating
costs fall within the following ranges:
1. capital cost: $500-1,900 per dwelling unit
2. operating cost: $100-200 per dwelling unit per year
The above costs must be weighed against all alternates in
the following situations:
1. Cost of pump station and force main to a trunk sewer.
2. Will interim facilities meet all quality needs and
if so can the effluent meet stream discharge permitting require-
ments or will ground water recharge have a more desirable environ-
mental impact.
3. Will the facility permit use of land that is currently
unusable and is the enhanced land value greater than the total
plant cost.
The system being constructed may be for an interim
facility which will be ultimately abandoned, or it may be one
which will have an extended life, requiring modifications to
provide for future growth and for changing criteria. Such a
plant may initiaially be owned and operated by a developer and
126
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may ultimately be deeded to or purchased by a government agency.
These factors should be considered in the design of the proposed
plant as its future fate will effect choice of process and
equipment and lead to design considerations which will be directly
related to the ultimate costs to the customer.
n this project of extremely limited size a major attempt
was made to arrive at lowest potential operating costs while at
time recognizing that capital costs, although important,
the major variable consideration.
In
t
the same time recognizing that capital cos
were not the major variable consideration.
SIGNIFICANT COST DATA
During the research phase of this project extensive cost
records were maintained which are not significant in the long-
range operational mode because of the high cost of sampling.
most of which would not be required for routine operation, and
because the continuous modification occurred in this experimental
plant.
Subsequently, the second series of costs were developed
which indicated serious underestimating of operating cost in the
original designs due to the following:
1. Plant design produced excessive chemical need
requirements;
2. Major increase in utilities cost because of fuel
adjustment and rate increases to the power company;
3 Increased cost of chemicals.
4. Significantly increased labor costs.
The estimated costs of Table 22 (top set of numbers)
were prior to construction and the actual costs in Table 22
(middle set of numbers) were during the evaluation phase. Sub-
sequently, the following major modifications were made in the
plant to improve operations, reduce labor, and permit lower
purchase prices for the necessary chemicals:
1. Positive head pumps were installed at the lift
station to reduce recycling and thus eliminate a major main-
tenance problem.
2. Underground bulk storage of ferric chloride was
provided reducing its purchase price and handling costs to
less than half of those previously incurred.
127
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TABLE 22
OPERATING COSTS
FREEHOLD TREATMENT PLANT
ESTIMATED COST^1 )
EPA GRANT APPLICATION 1970
ITEM COST $/1.000 GAL
Direct Labor (8 hrs./week) $ .092
Materials (includes chemicals) .134
Electric .208
Gas .038
Maintenance .046
$0.518
ACTUAL COST(2)
STEADY STATE OPERATING PERIOD
JULY 1973-MARCH 1974
ITEM COST $/1,000 GAL
Labor (6 hrs./day, 7 days/week) $ .793
Chemicals .400
Electric .266
Fuel Oil .150
Maintenance .066
Sludge Hauling .350
Telephone .050
$2.075
PRESENT COST(2)
1976 OPERATION
HE! COST $/1 .000 GAL
Labor (4 hrs./day, 7 days/week) $ .57
Chemicals .27
Electric .32
Fuel Oil .08
Maintenance & Supplies .20
SludgeHauling .39
Telephone (Ans. Service) .02
$1 .85
^ ^Cost based on 50,000 GPD
based on 28,000 GPD
128
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3. Major modifications were made in the flow pattern
permitting increased mixing and detention time prior to the
clarification thus reducing the quantity of chemicals required
per 1,000 gallons of flow treated.
4. pH control of the process permitted reduced (required)
dosage of ferric chloride.
5. The magnetic filter was eliminated.
6. Adjustments were made to improve the backwash
capability in the carbon column.
The modifications cited above resulted in reducing the
operating costs to the levels recorded in Table 22 for 1976
operations (lowest set of numbers).
IDEAS ON FURTHER COST REDUCTION
Based on the experience with this plant, further cost
reductions are possible if initial designs incorporate the
following concepts:
1. A new configuration of the plant can reduce labor
needs and energy costs.
2. Proper design with equipment selected for long life
and minimum maintenance will reduce the operating cost.
3. Increased sludge tank holding capacity will decrease
the frequency of trucking sludge and also reduce costs.
4. Using ferric chloride to achieve phosphate removal
in high quality effluent may not be the most economic selection
of coagulant. At other locations, other chemicals might be used
such as primary polymer or alum and polymer and thus simultan-
eously reduce the need for caustic soda which we have had to
use to correct pH. (Ferric chloride as used in this plant
reduced the pH to a point where it was necessary to raise it
with sodium hydroxide in order to provide the optimum pH for
coagulation).
5. The substitution of alternate coagulants for the
ferric chloride would eliminate the need for PVC piping and
epoxy coated tank linings and thus reduce total equipment and
mixing requirements and costs.
Based on the above considerations a projection of
operating costs independent of capital costs and independent
of inflation costs has been made for different size plants as
shown on Figure 43 and Table 23.
129
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FIGURE 43
ESTIMATED
OPERATING COST vs. PLANT SIZE
150 200 250
500
PLANT SIZE GPD x I03
FREEHOLD TREATMENT PLANT
130
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TABLE 23
PROJECTED OPERATING COSTS
$/l,000 GALLONS
PLANT SIZE
ITEM
LABOR
ELECTRIC
FUEL OIL
REPAIR AND
MAINTENANCE
CHEMICALS
FERRIC CHLORIDE
SODIUM HYDROXIDE
CHLORINE
POLYMER
TOTAL OPERATING
COST/1,000 GALLONS
55,000 GPD
$ .28
.18
.04
.16
.10
.13
.02
.02
$ 0.93
100,000 GPD
$ .18
.14
.03
.12
.08
.12
.02
.02
$ 0.71
250,000 GPD
$ .16
.14
.03
.12
.08
.10
.02
.02
$ 0.67
500,000 GPD
$ .14
.12
.02
.10
.07
.10
.02
.02
$ 0.59
LO
FREEHOLD TREATMENT PLANT
-------
APPENDIX A
PROCEDURES FOR ANALYZING FREEHOLD SAMPLES
Freehold samples which were analyzed at the Marshallton lab
were performed in accordance with the references and procedures
listed below. Where a test is referenced to Standard Methods or
EPA, it was done as directed in the reference. Any modifications
of a standard are listed. Those tests which are performed by
some technique other than Standard are listed with backgrounds
and explanations for their use.
Suspended Sol ids:
Coliform:
Chemical Oxygen DemandL
Total Solids:
Volatile Solids
A1 k a 1 i n i ty:
Chloride:
Biochemical Oxygen Demand
Phosphorus:
Standard Methods for the Examina^
tion of Water and Wastewater, 13th
Edition
p. 537.
(1971) Method 224 C
Standard Methods. Method 407 A & D
p. 664.
Standard Methods, Method 220,
p. 495.
Standard Methods. Method 224 A,
p. 535.
Standard Methods. Method 224 B,
p. 536.
Standard Methods. Method 102,
p~! 52, modified on 1 y by using
methyl purple instead of methyl
orange as indicator.
Standard Methods. Method 112 A,
p. 96.
Standard Methods. Method 219,
p. 489, modified for Weston and
Stack Dissolved Oxygen Probe as
approved by Methods for Chemical
Analysis of Water and Wastes, EPA
(1971), p. 60.
Methods for Chemical Analysis of
Water and Wastes. EPA(1971) pp.
235-245.
132
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Nitrate and Nitrite: Water Analysis Handbook. Hach
Chemical Co. (1973), modified
from Standard Methods, Method
213 B, p. 458.
The Hach procedure is like Standard Methods in that it is
a photometric color adsorbtion of a sample in which the nitrate
has been reduced by calmium. However, the Hach test is much
faster and more convenient because it employs reagent powder
pillows instead of a reduction column.
A Nitra Ver IV Powder Pillow is added to 25 ml of sample
and shaken for one minute. If nitrate or nitrite are present,
a pink color will develop which is measured against a blank in
a Fisher Electrophotometer II using a greem filter with a wave-
length of 525 m/1. The number from the Photometer scale is
then applied to a calibration curve from which the Photometer
scale is then applied to a calibration curve from which Nitrate/
Nitrite - Nitrogen is read in mg/1.
Total Oxygen Demand: Instruction Manual Model 225,
Total Oxygen Demand Analyzer,
Ionics, Inc. (1970).
The Ionics Model 225 TOD Analyzer is an automatic accurate
instrument capable of graphically recording the oxygen demand of
dissolved and suspended oxidizable constituents in an aqueous
sample. Its advantages over other common methods are that it is
rapid, automatic, more precise, and has a chemical reaction
efficiency at or approaching theoretical. The instrument can be
set to perform within oxygen demand limits of 0-50 ppm for the
low range, extending to 1000 ppm for high range applications.
A 20 microliter sample drop is automatically injected into
a furnace tube containing platinum catalyst at 900°C. A nitrogen
stream containing a fixed, known amount of oxygen continuously
flows through the furnace tube and supplies the oxygen necessary
for combustion. The vaporized, oxidized sample along with the
oxygen depleted nitrogen stream, then passes through a fuel
cell containing platinum and lead electrodes in a medium of 20%
KOH solution. The fuel cell reacts to the loss of oxygen in the
nitrogen stream and converts this imbalance to electrical impulses
which are translated to a chart read-out from which oxygen demand
is read in mg/1 TOD.
Total Organic Carbon: Analytical Chemistry, Vol. 37,
No. 6, May 1965, p. 769; Vol. 39,
No. 4, April 1967, p. 503.
The same sample which is oxidized in the TOD analyzer
passes through a MSA Lira Infrared Analyzer Model 300 wherein
the TOC of the sample is measured and recorded. Prior to sampling
133
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by the TOD analyzer, the sample is adjusted to pH<3 and then
sparged with nitrogen to remove inorganic carbon compounds, thus
leaving only the organic carbon compounds to be oxidized to C02
and measured by the infrared optical bench and graphed as mg/1
TOC.
Ammonia: Refer to letter to J. D. Beach
from R. A. Conte, dated November
19, 1974, RE: Analysis for Ammonia
Ni trogen.
Add about 50-80 ml of sample into a 100 ml beaker containing
a stirring bar. To this, add 1 ml of 10 M NaOH for each 100 ml
of sample. This addition raises the pH of the sample above 11
so that all of the ammonium ion is converted to ammonia which
can be detected by the probe. The probe is then inserted into
the sample solution which is agitated by a magnetic stirring bar.
The digital millivolt read-out is then applied to a calibration
curve which yields mg/1 ammonia. Multiply mg/1 ammonia by 0.82
to get mg/1 ammonia nitrogen. Rinse probe well between samples.
To prepare a calibration curve, use serial dilutions of
ammonia chloride for samples containing 100, 10, 1, and 0.1 mg/1
ammonia. Using the 100 ppm ammonia sample and above procedure,
set the meter at -75 mv. Then run the remaining standards and
record the mv for each. Plotting these data points on 4 cycle,
semi-log paper should give a straight line.
Total Kjeldahl Nitrogen:
Refer to letter to J. D. Beach
from R. A. Conte, dated November
19, 1974, RE: Analysis for Ammonia
Ni trogen.
This Kjeldahl test converts organic nitrogen to an ammonium
ion state which can then be readily converted to ammonia and read
by the Orion Ammonia Probe.
Using a micro Kjeldahl apparatus, a 50 ml sample is digested
in the presence of a digestion reagent (see Standard Methods,
13th Edition, p. 245, 3.a.). The digestion is carried out until
$03 fumes appear and then subside. After cooling, the digestion
flask is rinsed with distilled water into a 100 ml volumetric
flask. After several rinsings, the volume is made up to 100 ml.
From this, a 20 ml aliquot is put into a 150 ml beaker to which
is added 0.5 ml of a Saturated KI solution and 78 ml distilled
water. The beaker with a stirring bar is then placed on a
magnetic stirring motor and the ammonia probe is inserted into
the solution. Add 1.5 ml of the 10 M NaOH and read the milli-
voltage; then add 10 ml of a 76.4 mg/1. NH4C1 solution and again
read the millivoltage on the meter.
134
-------
This potential difference is applied to a known addition
chart supplied with the ammonia probe. The chart reading is
then multiplied by 200 and this is reported as mg/1 Total
Kjeldahl Nitrogen.
135
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APPENDIX B
PHOTOGRAPHS
FREEHOLD TREATMENT PLANT
DECEMBER 1975
VIEW OF PLANT AND MANASAQUAN RIVER TREE LINE
*>
•
VIEW OF PLANT EFFLUENT LINE INTO MANASAQUAN RIVER
136
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View of main floor from
carbon column to clarifier
to chemical mixing loop
against wall on the far
end of building. Entrance
door is to the left at the
far end of bui1di ng .
[-View of chemical mixing
loop with ferric chloride
caustic soda and polymer
tanks .
FREEHOLD TREATMENT PLANT
137
-------
U)
00
View of main floor instrument panel;
carbon column and door leading to
office and laboratory
View of basement floor carbon column
and carbon column instrument panel
FREEHOLD TREATMENT PLANT
-------
View of basement floor with retention loop for
chemical mixing to immediate left, sludge holding
tank far left and carbon column feed tank far right
View of basement floor
loop for chemical mixing
primary feed pumps to
with retention
to the right and
the far left
FREEHOLD TREATMENT PLANT
139
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APPENDIX C
CONVERSION TABLE
(1)
TO CONVERT FROM
foot
ft2
gal lon(U.S. 1 iquid)
ga1(U.S. 11qu1d)/m1n.
grain(l/7000 Ib avoirdupois)
horsepower (electric)
inch
in2
in3
pound(lb avoirdupois)
ton(short,2000 Ib)
yard
yd2
y«3
degree Fahrenheit
TO
metre(m)
2 2)
metre (m'
3 3
metre (m)
metre (m3)
3 3
metre /sec(m /s)
kilogram (Kg)
watt (W)
metre(m)
2 2
metre (m )
metre (m )
kilogram(Kg)
kilogram(kg)
metre(m)
2 2
metre (m )
metre (m )
degree Celsius
MULTIPLY BY
3.048000 E-01
9.290304 E-02
2.831685 E-02
3.785412 E-03
6.309020 E-05
6.479891 E-05
7.460000 E+02
2.540000 E-02
6.451600 E-04
1.638706 E-05
4.535924 E-01
9.071847 E+02
9.144000 E-01
8.361274 E-01
7.645549 E-01
t°c=(t°f-32)/1.8
As per Standard for Metric Practice E380-76
American Society for Testing and Materials
140
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-78-168
2.
RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Advanced Waste Treatment for Housing and
Community Developments
PORT DATE
eptember 1978(Issuing Date)
PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Russell Bodwell
. PERFORMING ORGANIZATION REPORT NO.
,
. PERFORMING ORGANIZATION NAME AND ADDRESS
Levitt and Sons, Incorporated
51 Weaver Street, Office Park 5
Greenwich, Connecticut 06830
10. PROGRAM ELEMENT NO.
1BC611
11. CONTRACT/fcKXMX NO.
68-01-0077
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory--Cinn., OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final Report 4/71 - 6/75
14. SPONSORING AGENCY CODE
EPA/600/14
15. SUPPLEMENTARY NOTES
Project Officer: Irwin J. Kugelman
513-684-7633
16. ABSTRACT
Treatment of wastewater from a subdivision in a physical-chemical treatment
plant (screening, chemical coagulation,-sedimentation, filtration, carbon adsorption,
chlorination) was evaluated. The 190 nr/day (50,000 gal/day) plant was housed in the
shell of a standard house on a standard lot in a 127 home subdivision. During the
18 month evaluation period excellent treatment was achieved (99% removal of BOD5>
Suspended Solids, and Total Phosphorus). Shock loadings had almost no effect on
plant performance because an equilization tank leveled out peaks and because of the
ability of the physical-chemical processes to absorb excess loading. Extensive data
on temporal characteristics of wastewater from a subdivision were collected during
the evaluation. An experimental sludge filter and fluidized bed incinerator were in-
stalled to process the sludge but were not extensively used. The former did not
function, the latter suffered from repeated mechanical breakdowns. Sludge was perio-
dically hauled to a landfill by a septic-tank-hauler. Acceptance of the presence of
a sewage treatment plant in the midst of the subdivision was excellent. No complaints
of any type were registered by the homeowners. The system cost was higher than for a
conventional plant. The actual construction cost exceeded $300,000 and operational
expenses were greater than $0.53 per cubic meter ($2.00 per 1000 gallons). At the
measured flow of 206 gal per home per day this represents a cost of $0.40 per home per
day. It is anticipated that significant reductions in these costs would result from
a redesign based on the experiences gained during the demonstration
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
COSATI Field/Group
Sewage Treatment
Sewers
Sludge Disposal
Subdivision Wastewater
Small Flow Treatment
13 B
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
153
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220.1 (R.v. 4-77)
141
U.S. GOVERNMENT PRINTING i
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