WATER POLLUTION CONTROL RESEARCH SERIES
17010FAH07/70
DEVELOPMENT OF PHOSPHATE
REMOVAL PROCESSES
DEVELOPMENT AND DEMONSTRATION OF PHOSPHATE
REMOVAL FACILITIES AT DETROIT USING AN ACTIVATED
SLUDGE PROCESS AND STEEL PICKLING LIQUOR
ENVIRONMENTAL PROTECTION AGENCY • WATER QUALITY OFFICE
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WATER POLLUTION CONTROL RESEARCH SERIES
The Water Pollution Control Research Reports describe the results
and progress in the control and abatement of pollution in our
Nation's waters. They provide a central source of information on
the research, development, and demonstration activities in the
Water Quality Office, in the Environmental Protection Agency,
through inhouse research and grants and contracts with Federal,
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tate information retrieval. Space is provided on the card for the
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Inquiries pertaining to Water Pollution Control Research Reports
should be directed to the Head, Project Reports System, Planning
and Resources Office, Office of Research and Development, Environ-
mental Protection Agency, Water Quality Office, Room 1108,
Washington, D. C. 20242.
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DEVELOPMENT OF PHOSPHATE REMOVAL PROCESSES
Development and Demonstration of Phosphate Removal
Facilities at Detroit Using an Activated Sludge
Process and Steel Pickling Liquor
by
Detroit Metro Water Department
Detroit, Michigan 48226
for the
WATER QUALITY OFFICE
EMflRONMENTAL PROTECTION AGENCY
Program #17010 FAH
Grant #WPRD 51-01-6?
July, 1970
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - Price 65 cents
Stock Number 5601-0114
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WQO Review Notice
This report has been reviewed by the Water
Quality Office and approved for publication.
Approval does not signify that the contents
necessarily reflect the views and policies
of the Water Quality Office, nor does mention
of trade names or commercial products con-
stitute endorsement or recommendation for use.
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ABSTRACT
During approximately twenty months of test operation on a 200 gpm
(max.) facility at the Detroit Regional Wastewater Plant, over 50
experiments on various treatment processes were performed and the
data utilized to develop and confirm design concepts for a full scale
plant.
The major processes tested were chemical pre-treatment, activated
sludge, plastic media trickling filter tower, deep tank aeration and
activated sludge disposal. Results of testing subsequent to June 30,
1969, are not a part of this project report.
As of June 30, 1969:
(l) It was judged that the trickling filter process was not suited to
the present and projected needs of Detroit's regional treatment
plant.
(2) It was concluded, on the basis of testing, that the full scale
plant should be designed for the activated sludge process, with
deep tank aeration, and that the facilities be arranged to accom-
modate both the conventional and step feed process variations.
Further, provisions were to be made for phosphate removal by
injection of steel pickling liquor (ferrous chloride) into the
plant influent.
(3) It appeared that continued research would be required to achieve
a phenol effluent standard requiring about 97$> removal. (Eighty-
five percent removals were achievable with the process tried.)
(k) It was determined that secondary sludge disposal requires con-
tinued research and study for practical and economical solutions.
This report was submitted in fulfillment of Research and Development
Grant No. WPRD 51-01-6? (Program No. 17010 FAH) between the Water
Quality Office and the Detroit Metro Water Department.
Key Words: Phosphate-removal, Activated Sludge, Aeration
111
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CONTENTS
Section Title
ABSTRACT iii
LIST OF FIGURES vi
LIST OF TABLES vii
I SUMMARY, FINDINGS AND CONCLUSIONS
Summary 1
Findings and Conclusions « 1
II INTRODUCTION
Background-History „ 3
Effluent Quality Standards 3
Problems » „ k
Concept Development . „ k
Proposed Study 5
Authorization, Scope and Content of Report 6
III PILOT PLANT FACILITIES
Basic Pilot Plant Layout . 8
Activated Sludge Process . . 8
Trickling Filter Process 12
IV ACTIVATED SLUDGE STUDIES
Introduction 15
Suspended Solids 17
Biochemical Oxygen Demand 1?
Phosphate (Total) 18
Phosphate (Ortho) 19
Oil 20
Phenol 20
Applicability of Process for Detroit 20
V TRICKLING FILTER STUDIES
Introduction 22
Suspended Solids 22
Biochemical Oxygen Demand 22
Phosphate (Total) 22
Phosphate (Ortho) 23
Oil 23
Phenol „ .o 2h
Applicability of Process for Detroit 2k
iv
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CONTENTS (Continued)
Section Title Page
VI SLUDGE DISPOSAL STUDIES
Introduction 26
Vacuum Filter 26
Centrifuge 27
Filter Press 2?
VII DEEP TANK AERATION STUDIES
Introduction 30
Test Tank and Equipment 30
Procedure „ 30
Testing 32
Indicated Power Requirements 37
Test Tank Parameters 37
Conclusions 38
VIII LABORATORY TEST PROCEDURES
Introduction 39
Grease Analys is . „ 39
Sludge Volume Index kd
Suspended Solids and Volatile Suspended Solids ... kO
Dissolved Oxygen UO
Biochemical Oxygen Demand Ul
Iron kl
Chlorine Requirement k2
Inorganic Phosphate Determination U3
Phenol Determination 1*5
IX ACKNOWLEDGMENTS U8
APPENDICES
A Summary - Activated Sludge Testing 50
B Activated Sludge Test Data 51
C Trickling Filter Test Data 5^
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FIGURES
Number Title Page
1 Flow Diagram - Activated Sludge Process ................ 9
2 Test Facility Building ................................. 10
3 Activated Sludge Facilities - Sludge Storage Tank,
Return Sludge Pumps and Two Final Clarif iers ........... 10
k Activated Sludge Facilities - Primary Tank, Aeration
Tank, Final Tank and Mixed Liquor Flocculator .......... 11
5 Activated Sludge Facilities - Sludge Storage Tank, Two
Raw Sewage Flocculators and Primary Tank ............... 11
6 Flow Diagram - Trickling Filter Facilities ............. 13
7 Trickling Filter Facilities - Plastic Media Trickling
Filter ................................................. ih
8 Trickling Filter Facilities - Primary Clarifier and
Two Final Clarif iers ................................... 1^
9 Activated Sludge Testing - Step Feed Modification ...... l6
10 Deep Tank Aeration Studies - Typical Tank Section
Dimensional (One Aeration Unit Shown) .................. 31
11 Deep Tank Aeration Studies - Two Aeration Units - Flow
Pattern - Both On . . . „ .................................. 33
12 Deep Tank Aeration Studies - Two Aeration Units - Flow
Pattern - One On ....................................... 3^
13 Deep Tank Aeration Studies - Flow Pattern - One Aeration
Unit On ................................................ 35
lU Schematic of Modified Laboratory Analysis for Ortho-
phosphate .............................................. kk
15 Schematic of Laboratory Analysis for Phenol ............ U6
VI
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TABLES
Number Title Page
1 Vacuum Filter Test - Primary Sludge 26
2 Filter Press Test 29
3 Summary of Deep Tank Aeration Studies 36
VI1
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SECTION I
SUMMARY. FINDINGS AND CONCLUSIONS
Summary
In May 1966, the City of Detroit signed a Stipulation with the Michigan
Water Resources Commission in which the City agreed to meet certain
effluent quality standards for discharges from its Regional Wastewater
Plant to the Detroit River. The degree of treatment provided by the
primary facilities at Detroit was not adequate to meet the standards.
Conventional secondary processes at other plants had proved effective
in meeting the BOD and suspended solids limitations required. The oil
and coliform limitation could be met by modifying and expanding existing
facilities at the plant. Phosphate and phenol, however, presented a
major problem because conventional processes had not proven to be effec-
tive in their reduction.
In March 196?, the basis of design report for improved treatment and
plant expansion at Detroit proposed the activated sludge process. The
report also offered two alternates:
1. Activated Sludge, step feed modification, with the
addition of iron for the complexing of phosphates.
2. Trickling filter using plastic media filter towers
with the addition of iron.
The effectiveness and applicability of the basic design and the proposed
alternates for Detroit were to be determined through pilot plant opera-
tion. To be included in the pilot study investigation was the Levin and
and BioAbsorption processes.
Also to be included in the test program was the use of polymer and caus-
tic in the treatment processes, deep tank aeration studies and sludge
disposal studies. The basic testing program ran from November 1967 to
June 1969.
Findings and Conclusions
1. Findings and Conclusions of the Activated Sludge Studies. Most of
the activated sludge processes investigated provided reductions of sus-
pended solids and BOD adequate to meet the Michigan Water Resources
Commission's effluent quality standards.
The most effective phosphate reduction was provided in the tests uti-
lizing the conventional process with iron feed to the primary effluent.
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Findings and Conclusions (Continued)
1. Findings and Conclusions of the Activated Sludge Studies (Continued)
The step feed process (with iron) also proved relatively effective.
The addition of polymer and/or caustic to the conventional and step
feed processes did not significantly improve phosphate reduction
across the entire primary-secondary system. The conventional and step
feed process, with the addition of iron, provided reductions of ortho-
phosphate adequate to meet the Michigan Water Resources Commission's
pound limitation but did not meet the percentage removal requirement.
Each of the processes tested indicated reduction of oils adequate to
meet the Stipulation. The coliform effluent requirements are expected
to be met by expanding the chlorination facilities and improving
chlorination techniques. None of the processes tested were able to
reduce the final phenol to 12 ppb as ultimately required by the Stipula-
tion. Additional process study and evaluation of phenol control
measures is required with the ultimate goal of satisfactory phenol
control.
Based on the twenty months of testing, Detroit has selected the conven-
tional activated sludge process. The construction will include
provisions for the step feed modification for versatility and further
plant scale study. A pickle liquor injection system is to be provided
for phosphate reduction. Because it will be some time before the entire
800 mgd secondary system will be in operation, a polymer feed system
will be provided to improve removals in that portion of the flow
receiving only primary treatment.
2. Findings and Conclusions of the Plastic Media Trickling Filter
Tower Studies. This facility did not demonstrate consistent BOD, sus-
pended solids or orthophosphate reduction in the treatment of Detroit's
sewage. For these reasons, and others, the process was determined to
be not suitable for use at Detroit.
3. Findings and Conclusions of the Sludge Disposal Studies. The
testing of a pilot vacuum filter, a centrifuge and a filter press did
not demonstrate that these processes were adequate for the development
of a full-scale sludge dewatering system for Detroit. Further testing
is indicated.
k. Findings and Conclusions of the Deep Tank Aeration Studies. The
deep tank aeration testing demonstrated the applicability of using
aeration tanks with a side water depth of 30 ft and a normal blower
pressure of 7 to 8 psi for Detroit. The testing has provided data for
the design of a full-scale aeration system utilizing the deep tank
aeration concept.
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SECTION II
INTRODUCTION
Background-History
In 19^0 the Detroit Sewage Treatment Plant was completed with a design
capacity (under 19^-0 design criteria and water quality standards) ade-
quate to serve a population of 2,1*00,000 and, with additions, adequate
to serve 14,000,000 people.
The facility currently serves an area of ^76 square miles and a popu-
lation of 3,000,000 persons, 80 per cent of which are served by
combined sewage systems. By 1980 it is estimated that the Detroit
Regional Sewage Disposal System will serve at least U.25 million
persons. "Ultimately" the plant will serve 73000,000 persons and have
an average flow of 1200 MOD.
The plant, as originally designed, provides primary treatment and post
chlorination. Sludge disposal is by vacuum filtration and incineration,
with ash disposal to sanitary land fill. The plant effluent discharges
to the Detroit River, which has an average flow of 180,000 cfs.
Effluent Quality Standards
In May of 1966 the City of Detroit signed a Stipulation with the
Michigan Water Resources Commission in which the City agreed to restrict
the content of sewage and industrial waste discharged to the waters of
the State. The effluent quality standards for the existing and future
service area are as follows:
Existing
Service Area
Future
Service Area
Suspended Solids 32^,000 Ib/day & not
to exceed 50 mg/1
BOD (5-day)
206,000 Ib/day
Phosphate (Ortho) 21,000 Ib/day as P01+ &
not to exceed 20f0 of
influent soluble POi,.
51^,000 Ib/day & not to
exceed 50 mg/1
250,000 Ib/day
26,000 Ib/day as POlj. & not
to exceed 20$ of influent
soluble
Oil
Phenol
Coliforms
Not to exceed 15 mg/1
93 Ib/day
Not to exceed 1000 MPN
monthly mean density
based on daily samples
Not to exceed 15 mg/1
115 Ib/day
Not to exceed 1000 MPN
monthly mean density
based on daily samples
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Problems
To meet the requirements of the Stipulation it was apparent that the
plant would have to be provided with at least secondary treatment
facilities. Conventional secondary processes in other cities had
proved effective in meeting the BOD and suspended solids limitations.
The limitations on oils and coliform could be met by modifying and
expanding existing facilities at the plant. Only the phosphate and
phenol removal requirements presented a major problem.
It was known that with sufficient dosages of chemicals such as alum,
ferric chloride, ferric sulfate, lime or sodium aluminate, phosphates
could be removed. However, the magnitude and cost of the chemical
handling facilities required is staggering. For example, a lime
dosage of 500 mg/1 (range of 300 to 700 mg/l) at 1200 MGD average flow
would require facilities adequate to handle 2500 tons of lime per day.
It was apparent from the start that some other more economical process
had to be found.
In addition, land in the area is at a premium. The existing plant site
is bounded on the north by residential sites, on the east and south by
industrial complexes and on the west by railroads. Thus, it was impera-
tive that the facilities be constructed in as compact an arrangement as
possible.
Concept Development
Prior to the development of the preliminary design concepts for advanced
treatment, plant data had indicated that ferrous iron may be effective in
a phosphate removal process. Ferrous iron in the form of pickling liquor
(ferrous chloride) is a problem waste for many of the steel manufacturing
plants in the Detroit area. The economic implications for utilizing
pickle liquor in a phosphate removal process are attractive for two basic
reasons:
1. The City will obtain a relatively low cost source of
ferrous iron.
2. The pickling liquor waste disposal problem for the
area's industry will be greatly reduced.
In March 196?, the basis of design for the improved treatment process and
plant expansion was submitted to the Michigan Department of Public Health
and the Michigan Water Resources Commission.
The basic design of the facilities proposed the use of the activated
sludge process.
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Concept Development (Continued)
Two alternate design concepts were also submitted. The first proposed
the use of the activated sludge process with addition of iron at the
primary tanks. Although the suitability of the process had not been
determined, it was believed that the process may offer the following
advantages over the basic design concept.
1. Complexing of the phosphate would be provided in both
the primary and secondary systems.
2. The settleability of mixed liquor suspended solids
would be improved.
3. Permits use of step-feed with consequent adequate
sludge age and low solid load to final clarifiers.
h. The use of an industrial waste product, pickling
liquor, as the iron ion source.
5. More stable operation.
6. Possible savrflg in capital and operating costs.
x
The second alternate proposed the use of plastic media trickling filter
towers with addition of iron at the primary tanks. This process, if
determined to be suitable, may offer the following advantages:
1. Elimination of air blowing other than for channel
aeration.
2. Land area 53$ of aeration tank area.
3. Secondary sludge more amenable to dewatering.
k. The use of an industrial waste product, pickling
liquor, as iron ion source.
5. Simplified operation and control.
6. Possible saving in capital and operating costs.
Proposed Study
The effectiveness of the basic design concept and the proposed alter-
nates had not been determined. Their applicability therefore could
only be determined through a pilot operation. The pilot plant testing
would also provide important data for the development and confirmation
of design parameters.
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Proposed Study (Continued)
The following types of activated sludge processes were to be investi-
gated :
1. Conventional Process
2. Step Feed Process
3. Levin Process
U. Bioabsorption Process
The conventional and step feed processes were to be run using no
chemicals; with pickling liquor; with polymer; with caustic and polymer;
and with pickling liquor, caustic and polymer. The effectiveness of
mixing and flocculation was also to be investigated. No chemical feed
was to be used in the Levin or Bioabsorption processes.
Also to be studied was the applicability of deep (30 ft liquor depth)
aeration tanks for the treatment of Detroit sewage.
Testing of the trickling filter tower was to include the study of chemi-
cal addition.
Various types of sludge dewatering equipment were to be tested to deter-
mine their applicability for the disposal of Detroit's secondary sludge.
Authorization, Scope and Content of the Report
The studies covered in this report were undertaken with the support of
a Demonstration Grant from the Federal Water Quality Administration of
the Department of the Interior. The grant was awarded on December 23,
1966, under the authorization of Section 6 of the Federal Water Pollu-
tion Control Act, as amended. The grant award of $299?800 was made to
the City of Detroit, Department of Water Supply. The total project cost
to June 30, 1969, was $765,579-82.
The ultimate goal of the project was to develop a phosphate removal
process for use at Detroit and establish the necessary design and oper-
ating correlation for this system.
The need for the testing program has been discussed. The basic facili-
ties and equipment for the activated sludge and plastic media trickling
filter test programs are described in Section III.
Descriptions of the activated sludge and trickling filter testing are
included in Sections IV and V respectively. The sections outline the
facilities' effectiveness as they relate to the Stipulation requirements
for reduction of suspended solids, BOD, phosphate, oil and phenol. The
process applicability for treatment of Detroit wastes is included.
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Authorization, Scope and Content of the Report (Continued)
In the development of any wastewater treatment system, sludge disposal
and the costs thereof must be made a major factor to be considered.
Section VI includes a discussion of the testing of a vacuum filter,
centrifuge, and filter press. Although the results obtained are deemed
inconclusive at this time, they will provide guidance for future sludge
disposal testing programs.
To keep land area requirements to a minimum, it was decided to test the
feasibility of utilizing aeration tanks approximately twice the "normal"
depth. Section VII describes the test facilities and outlines the
testing.
Section VIII is a summary of the laboratory test procedures used through-
out the test program. A summary of the mode of operation of the
activated sludge testing is included in Appendix A. Tabulation of the
data for the activated sludge testing and the trickling filter testing
are contained in Appendices B and C respectively.
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SECTION III
PILOT PLANT FACILITIES
Basic Pilot Plant Layout
Raw sewage for each pilot process was taken from the discharge of the
main plant grit chamber utilizing a 200 gpm submersible pumping unit.
The flow passed through a 1/U-inch slot comminuter into a constant head
tank. Feed rate to either process could be varied by V-notch weir
adjustment at the constant head tank outlet. Chemical feed to each pro-
cess was from a 6 ft diameter by 19-5 ft long pickling liquor storage
tank and acid feeders.
Equipment for each process, except for the trickling filter tower, was
housed in a 50 ft wide x 100 ft long x 25 ft high building. A com-
pletely equipped laboratory was included. Space in the building was
also available for sludge dewatering pilot work.
Each process was provided with equipment for flash mixing, floccula-
tion, primary sedimentation and final clarification. Since versatility
of operation and testing were of prime importance, extensive use was
made of by-pass piping, valving, etc.
Activated Sludge Process
The activated sludge pilot facility was designed to operate at a raw
sewage feed rate range of from 50 gpm to 100 gpm. The flow diagram for
the activated sludge process is shown on Figure No- 1. The equipment
provided for this facility included the following:
Raw Sewage Flash Mix - One unit 2^-inch diameter x ^.33 ft
side water depth (swd)
Raw Sewage Flocculators - Two units each 6 ft diameter x 7 ft
side water depth with dual variable
speed mixers
Primary Settling Tanks - One unit 9 ft diameter x 8 ft swd
with mechanical sludge collection
equipment
Aeration Tank - One unit with five compartments, each
3.5 ft x 9 ft x 9 ft swd. Each com-
partment provided with 28 air outlets
each with four 1/U-inch orifices
Mixed Liquor Flash Mixer - One unit 30-inch diameter x 2.67 ft
swd
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SLUDC
PUMP
SLUDGE
HOLDING
TANKS
RETURN
SLUDGE
AERATION
TANK
RETURN SLUDGE
PUMPS
FINAL
EFFLUENT
RAW SEWAGE
GOMMINUTOR
CONSTANT HEAD
TANK WEIR
1
FLASH MIX
(100 GAL.)
L
FLOCCULATOR
(EA leso GAL)
FLOCCULATOR
(EA. 3000 GAL)
FLASH
(98 GAL.)
FLOW METER
(TYPICAL)
MIXED LIQUOR
AERATION TANK
00,600 GAL)
FIGURE 1
FLOW DIAGRAM-ACTIVATED SLUDGE PROCESS
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FIGURE 2 TEST FACILITY BUILDING
FIGURE 3 ACTIVATED SLUDGE FACILITIES
Sludge Storage Tank (right foreground), Return Sludge Pumps
(bottom center) and Two Final Clarifiers (left background)
10
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FIGURE k ACTIVATED SLUDGE FACILITIES
Pri. Tank (left background) , Aeration Tank (right background), Final
Tank (left foreground), and Mixed Liquor Flocculator (right foreground)
FIGURE 5 ACTIVATED SLUDGE FACILITIES
Sludge Storage Tank (foreground), Two Raw Sewage Floccula-
tors (left background) and Primary Tank (right background)
11
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Activated Sludge Process (Continued)
Mixed Liquor Flocculators - Two units each 8 ft diameter x 8 ft
swd with dual variable speed mixers
Final Settling Tanks - Two units each 9 ft diameter x 8 ft
swd with mechanical sludge collection
equipment
Return Sludge Pumps - Two variable speed, metering units
each with capacity of 10 to 60 gpm
Sludge Stabilization Tank - One unit with five compartments, each
6.5 ft x 9 ft x 9 ft swd. Each com-
partment provided with twelve air
outlets each with four 3/l6-inch
orifices. (Return sludge aeration tank)
Air Blowers - Four units at 700 cfm capacity
Sludge Storage Tanks - Two units 8 ft diameter x 9 ft swd
Air Meters - One unit on each compartment of the
aeration tank and sludge stabiliza-
tion tank (10 units total).
Flow Meters - Three units, one each for primary
effluent, return sludge and waste
activated sludge.
Samplers - Six continuous units.
Trickling Filter Process
The trickling filter pilot facility was designed for a flow of from
7 gpm to 28 gpm. The flow diagram for the Trickling Filter Process is
shown on Figure 6. The equipment provided for the facility includes
the following:
Raw sewage flash mix and flocculator - One unit k,5 ft diameter
x 5 ft swd
Primary Settling Tank - One unit 5 ft diameter x 8.25 ft swd
Trickling Filter Tower - One unit area 7 sq ft x 21.6 ft high.
Dow Surfpac plastic media.
Final Settling Tanks - Two units 5 ft diameter x 10.67 ft swd
Samplers - Four continuous units
12
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FINAL EFFLUENT
FINAL
CLARIFIERS
(EA. 9 1010 GAL)
ORIFICE CONTROL
SAMPLER £>
(TYPICAL)
SURGE
TANK
RAW SEWAGE
COMMINUTOR
CONSTANT HEAD
TANK WEIR
FLASH MIX (
FLOCCULATOR
(600 GAL.)
PRIMARY
CLARIFIER
(780 GAL.)
SURGE TANK
PUMP
PLASTIC MEDIA
TRICKLING FILTER
RECIRCULATION PUMP
FIGURE 6
FLOW DIAGRAM-TRICKLING FILTER PROCESS
13
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FIGURE 7 TRICKLING FILTER FACILITIES
Plastic Media Trickling Filter
dtrnrn
fid TT
FIGURE 8 TRICKLING FILTER FACILITIES
Primary Clarifier (right foreground) and
Two Final Clarifiers (left foreground)
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SECTION IV
ACTIVATED SLUDGE STUDIES
Introduction
The activated sludge process testing reported herein covers a period
from November 17, 196?, to June 30, 1969. The testing consisted of a
series of thirty-two (32) experiments conducted at the pilot plant
facility. Test Nos. 17, 19, 20 and 22 were further broken down with
A and B designations to reflect operational modifications and the
effects thereof.
During test periods 1 through l6, 19 and 28, the facility was operated
basically as a conventional activated sludge plant. Tests 17, 18, 21,
22, 2k through 27 and 29 through 32 were run using a step feed modifi-
cation of the activated sludge process. Tests 20 and 23 were run using
the "Levin" process and a bioabsorptlon process, respectively.
Conventional treatment consisted of one to two hours of primary clari-
fication, two to three hours of aeration, and one to four hours of
final clarification. Sludge was wasted, as required, to maintain mixed
liquor solids at predetermined levels. Five aeration chambers were
utilized in each test except in Test No. 28 in which only two chambers
were used. Figure 1 shows the general flow diagram for this process.
The operation of the step feed modification followed the same general
flow pattern as the conventional process. The basic difference in the
processes involved the way in which the primary effluent and return
sludge were fed into the aeration chambers. See Figure 9-
In step feed Test Nos. 17 and 18, the return sludge was fed to, and pro-
vided aeration in, the first chamber. The primary effluent was fed
equally to the next four chambers. In Test Nos. 21, 22, 2h, 25, 26 and
27 the return sludge was aerated in the first chamber and the primary
effluent was fed equally to and aerated in the second, third and fourth
chambers. The mixed liquor was provided aeration in the fifth chamber.
In Test Nos. 29, 30, 31 and 32 the return sludge was fed to the first
chamber and the primary effluent was fed equally to the first four
chambers. The mixed liquor received aeration in the fifth chamber.
Test No. 20 was the Levin process. This process followed the conven-
tional flow pattern but required above normal aeration rates and the
holding of the return sludge under anaerobic conditions to promote the
release of phosphate taken up by the organisms during the aeration
process. During the particular test, the experimental design called
for aeration rates of up to 5-^ cf per gallon of waste, an aeration
time of four hours, an anaerobic detention period of 13 hours, and
mixed liquor solids of 5,000 mg/1 or more.
15
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FFLUEN-
JLUDGE
r III
1
1
V
*
r
2
s
\
3
V
\f
4
>
1
>
5
— te.
TO FINAL
CLARIFIERS
A) TESTS I7A AND 18
FFLUEN
LUDGE
T III
~\
\
V.
\r
2
>
\
3
V
t
4
J
\
5
— ^
TO FINAL
CLARIFIERS
B) TESTS 21,22 4 24 THRU 27
FFLUEN
LUDGE
Tl 1 1 1
1
1
V
*
r
2
>
1
>
3
V
*
/<
4
>
^
5
^
TO FINAL
CLARIFIERS
C) TESTS 29 THRU 32
FIGURE 9 ACTIVATED SLUDGE TESTING
STEP FEED MODIFICATION
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Introduction (Continued)
Test No. 23 was a form of bioabsorption. The return sludge received
about 6.2 hours of aeration prior to mixing with the primary effluent.
The mixed liquor received 0.6 hours of aeration. Approximately 2.8
hours of final settling was provided.
Suspended Solids
Suspended solids removal under all modes of operation, with and without
chemical addition, were, in general, excellent. The test plant did,
however, receive a wide range in suspended solids in the raw wastewater
with a minimum day at about 130 mg/1 and the maximum day at about
1390 ing/1- Test No. 9 was subjected to the highest average concentra-
tion at 782 mg/1 and Test No« 22A the lowest at 306 mg/1. The average
suspended solids in raw wastewater throughout the twenty-month period
was 420 mg/1.
Except for Test Nos. 1 and 19B, each of the conventional activated
sludge process tests provided suspended solids removals greater than
85$. The majority of the tests provided removals in the 90-95$ range.
When iron or iron and polymer were used, the percentage removals across
the primary portion of the system were generally higher than when no
chemicals were added. However, there is no indication from the testing
at Detroit that the addition of iron and/or polymer significantly
improves suspended solids removal over the entire primary-secondary
system*
Except for Test No. IfB, each of the step feed activated sludge process
tests, with iron, provided suspended solids removals greater than 85$.
Where polymer or polymer and caustic were used, the percentage removals
across the primary portion of the system were generally higher than when
only iron was added. As with the conventional process, no significant
improvement in removals was indicated over the entire primary-secondary
system with the addition of polymers.
The Levin process averaged 92-7$> removal of suspended solids and the
bioabsorption process averaged 86.k%.
Biochemical Oxygen Demand
Biochemical oxygen demand (BOD) reduction under all modes of operation
was, in general, good. The BOD in the raw wastewater ranged from a
minimum day at 60 mg/1 to a maximum day at U25 mg/1. Test No. 11 was
subjected to the highest average at 279 rog/l and Test No. 5 the lowest
at 125 mg/1. The average BOD in the raw wastewater throughout the
twenty-month test period was 185 mg/1.
Except for Test Nos. 1 and 19B, each of the conventional activated sludge
process tests provided BOD reductions greater than 85$. The majority of
the tests provided reductions in the 90-95$ range. The addition' of iron
17
-------
Biochemical Oxygen Demand (Continued)
or iron and polymer did not improve the BOD reduction. Tests 12 and 15
provided reductions of less than 80$. Tests 13, 1^, 16 and 28 provided
reductions between 80$, and 90$. All other testing (Tests 7 through ll)
using iron provided reductions greater than 90$-
Except for Tests 17B and 22B each of the step feed activated sludge pro-
cess tests, with iron, provided BOD reductions greater than 80$. None of
the tests provided reductions greater than 90$- In general, when poly-
mer or polymer and caustic were used, the percentage removals across the
primary portion of the system were generally higher than when only iron
was added. However, no significant improvement in BOD reduction was indi-
cated over the entire primary-secondary system with the addition of polymer.
The Levin process averaged 88.5$ BOD reduction and the bioabsorption
process averaged 8l.2$ reduction.
Phosphate (Total)*
All test facility data for total phosphate is in terms of P. The mini-
mum day total phosphate in the raw wastewater was 1.9 mg/1 and the maxi-
mum day was 26.6 mg/1. Test No. 26 was subjected to the highest average
concentration at 13.0 mg/1 and Test No. 1?A the lowest at h.9 mg/1. The
average total phosphate in the raw wastewater throughout the twenty-
month period was 7-9
None of the conventional activated sludge process tests provided total
phosphate removals greater than 72$. The majority of the tests provided
removals in the 55-70$ range. When iron was used, the majority of the
tests provided removals in the 75-85$ range. Only Test No. 10 provided
a removal greater than 85$. Total phosphate reduction across the pri-
mary system was highest in Test No. 28 where both polymer and iron were
used. However, the total removal across the primary-secondary system
was no better than when just iron was added. In general, the addition
of iron to the conventional activated sludge process provided a rela-
tively consistent total phosphate reduction.
Except for Test Nos. 17 (A & B) and 22B, each of the step feed activated
sludge process tests, with iron, provided total phosphate reductions of
80$ or greater. Only Test No. 2k provided a reduction greater than 85$.
When polymer or polymer and caustic were used, the percentage removals
across the primary portion of the system were generally higher than when
only iron was added. Only one test (No. 29) provided a reduction of
less than 80$. In general, the addition of iron or iron, polymer and
caustic to the step feed activated sludge process provided a relatively
consistent total phosphate reduction.
The Levin process averaged 70.5$ removal of total phosphate and the bio-
absorption process averaged 78-0$ reduction.
*Total phosphate data as reported herein is total inorganic phosphate.
18
-------
Phosphate (Ortho)
All test facility data for soluble ortho phosphate is in terms of P.
The minimum day soluble phosphate in raw wastewater was 0.3 mg/1 and
the maximum day was 5.8 mg/1. Test No. 6 was subjected to the highest
average concentration at 3.3 mg/1 and Test No. 27 the lowest at
0.7 mg/1. The average ortho phosphate concentration throughout the
twenty-month period was 2.0 mg/1.
The conventional activated sludge process tests provided no consistent
ortho phosphate reduction. The maximum removal was provided in Test
No. k at only 53-5%. Test No. 2 actually showed an increase in ortho-
phosphate across the system. The testing indicates that the conven-
tional activated sludge process will not consistently remove soluble
phosphate at Detroit.
Only Test No. 13 provided 80% reduction of soluble phosphate during the
twenty-month testing period. This test along with Test Nos. 10, 11 and
12 provided the most consistent reduction. Each utilized the conven-
tional activated sludge process with the addition of iron to the primary
effluent. In each test, the data indicated an increase in soluble
phosphate across the primary system. The four tests run over a 8^- week
period, averaged 77-5$ reduction. Although iron fed (as Fe) was varied
from 15 mg/1 to 30 mg/1 during this testing, the higher feed did not
exhibit significant improvement in overall ortho phosphate reduction.
The main treatment plant effluent (@ 800 mgd) based on the data from the
four tests, would average 8,950 pounds of PO^ per day. The City's
Stipulation with the Michigan Water Resources Commission limits the
effluent to 21,000 pounds of POi^. per day.
Test Nos. 8, 9 3 1^> 15 and 16 also utilized the conventional activated
sludge process with the addition of iron. In these tests the iron was
fed to the primary influent. Although these tests (average total reduc-
tion at 60$ with k5% across the primary system) were not as effective as
Nos. 10, 11, 12 and 13, the main plant effluent at 800 mgd would average
ll+,300 pounds of POh per day and thus meet the Michigan Water Resources
Commission's daily pound limitations.
Except for Test No. 17B, each of the step feed activated sludge process
tests utilizing iron provided ortho phosphate reductions adequate to meet
the Michigan Water Resources Commission's pound limitation. In this
testing the iron (@ 15 mg/l) was fed to the primary influent. The major
portion of the ortho phosphate reduction was across the primary system.
The average reduction across the entire process for all tests (17A, 17B,
18, 21, 22A, 22B, 2^, 25 and 26) was approximately 60$ and ranged from
33
-------
Phosphate (Ortho) - (Continued)
(27 and 29 through 32) was approximately 70
-------
Applicability of Process for Detroit(Continued)
Based on the twenty months of testing the Detroit Metro Water Department
has selected the conventional activated sludge process for use at
Detroit. For versatility and to allow for continued study on a plant
scale, the step feed modification is to be included in the design of
the facilities.
Facilities are to be provided for the injection of pickling liquor into
the primary influent for phosphate reduction. Also, because it will be
some time before the entire 800 mgd secondary system will be constructed
and in operation, a polymer feed system will be provided, in the interim,
to improve removals in that portion of the flow receiving only primary
treatment.
In the future, when the entire 800 mgd secondary system is in operation,
an alternate pickling liquor feed point to the primary effluent may be
provided.
21
-------
SECTION V
TRICKLING FILTER STUDIES
Introduction
The testing of the plastic media trickling filter tower reported herein
covers a period from June 5> 1968, to April 19 5 1969? an<^- consisted of
a series of sixteen (l6) experiments.
Tests No. 1 through U were run without additive chemicals at application
rates varying from l.lU gallons per minute per square foot of filter
area (gpm/sq ft) to 3.22 gpm/sq ft.
Tests No. 5 through 9 were run with 15 mg/1 of iron added to the raw
sewage at application rates varying from 1 gpm/sq ft to 3.^6 gpm/sq ft.
Tests No. 10 through 1^4 were run with 15 mg/1 of iron plus 0.3 mg/1 of Dow
A 23 polymer added to the raw sewage at application rates varying from
I.lh gpm/sq ft to 3.08 gpm/sq ft.
Tests No. 15 and 16 were run with 15 mg/1 of iron plus 0.3 mg/1 of A 23
polymer plus 30 mg/1 of NaOH added to the raw sewage at application
rates varying from 1.^7 gpm/sq ft to 2.86 gpm/sq ft.
Suspended Solids
Average final suspended solids with the addition of iron was 103 fflg/1
and with the addition of iron, polymer and caustic was 6l mg/1. Best
performance was 37 fflg/1 without chemicals„ Poorest performance was
162 mg/1 with iron. To meet the stipulation the final effluent sus-
pended solids cannot exceed 50 rog/1-
Biochemical Oxygen Demand
Average final effluent BOD with the addition of iron was 58 mg/1 and
with the additions of iron, polymer and caustic was ^9 mg/1- The best
performance was 35 mg/1 with poorest performance 83 mg/l»
The MWRC stipulation limitation for effluent BOD is 31 mg/1 (@ 800 MOD).
Phosphate (Total)*
All test data is in terms of total phosphate as P.
Total phosphate data as reported herein is total inorganic phosphate.
22
-------
Phosphate (Total) - Continued
Without the addition of chemicals, raw phosphate test averages varied
from h.9 to 7.0 mg/1 with final effluent P varying from 3.0 to k.O
mg/1 for removals of from 18$ to 57fo.
With the addition of 15 mg/1 of iron the raw phosphate test averages
varied from 6.9 to 8.6 mg/1 with final effluent P varying from 1.9 to
k.B mg/1 for removals of from 3^% to 77%.
With the addition of 15 mg/1 of iron and 0.3 mg/1 of A 23 polymer raw
phosphate test averages varied from 7-0 to 10.3 mg/1 with final efflu-
ent P varying from 2.0 to h.k mg/1 for removals of from h7% to
With the addition of 15 mg/1 of iron, 003 mg/1 of A 23 polymer and
30 mg/1 of NaOH raw phosphate test averages varied from 8.1 to 10.9
mg/1 with final effluent P varying from 2.1 to 3-6 mg/1 for removals
of from 67% to 78
-------
Oil (Continued)
Stipulation requirements call for not in excess of 15 mg/1 of oil.
Phenol
Raw sewage phenol tests averaged 393 ppb with final effluent averaging
Il6 ppb for removals varying from U6$ to
Stipulation requirements of initial daily limit of 93 pounds, with ulti-
mate of 115 pounds, required an effluent with not over 12 ppb phenol.
Applicability of Process for Detroit
The use of plastic media filters for treating primary effluent at
Detroit was determined to be inappropriate for the following reasons.
1. The process did not consistently result in final effluent
BOD's of 31 mg/1 required to meet the stipulation.
2. The process did not result in final effluent suspended solids
consistently at the 50 mg/1 required to meet the stipulations.
3. Operator control of the plastic media filter process is
limited to changes in the application rate. The tests indi-
cated that for Detroit's sewage, a low uniform application
rate was desirable; so in effect no operator control is
possible to meet the changing treatability of the incoming
sewage.
h. Optimum conditions for maximum removal of phosphate using
plastic media filters requires closely controlled physical
conditions with regard to chemical additions. This involves
specific times for flash mixing flocculation and conduit velo-
city. The existing Detroit primary installation does not
provide the required conditions nor is it practical to add
mixing and flocculation ahead of the existing primary tanks.
In addition, the variation in flow would not allow obtaining
optimum time relationships in the treatment units.
5. No plastic media filter plants of the magnitude of the Detroit
installation are in existence. Problems encountered in
smaller trickling filter installations such as odors, flies
and winter operation could result in major operating diffi-
culties when scaled up to an installation of the size required
at Detroit.
6. At the present time there are only three manufacturers and
suppliers of plastic media for sewage filters compared to the
many suppliers for equipment and facilities for alternate
biological processes.
-------
Applicability of Process for Detroit (Continued)
7- Historically, effluent standards have been gradually
increasing. The practical limit on the treatment efficiency
of trickling filters is somewhat less than that for activated
sludge and this thus constitutes a risk of earlier obsole-
sence. Further it is not as feasible to modify the trickling
filter process and physical plant for greater efficiency and
economy as it is for the activated sludge process.
25
-------
SECTION VI
SLUDGE DISPOSAL STUDIES
Introduction
Vacuum filtration with incineration is currently used for disposal of
Detroit's primary sludge. Tests were run to determine its applicability
to the disposal of waste activated sludges.
Also tested were a centrifuge and a filter press type dewatering device.
Vacuum Filter
Initial testing of vacuum sludge filtering was performed using a ten
square foot test unit. The unit featured a continuously washed belt
as filter media. Belt material was 40 x 40 mesh monofilament nylon.
Although the belt speed could be adjusted, the lowest speed was used in
all testing. A tumbler or cement mixer type flocculator, rotating on a
horizontal axis, was used for flocculation and sludge conditioning.
During the period February 15, 1969) ^o February 25, 1969 5 primary
sludge from the pilot plant (with 6$ to 7$ solids) was filtered in an
attempt to develop a correlation between the test vacuum filter and main
plant vacuum filtration units. Some of the data for the test vacuum fil-
ter for primary sludge dewatering is tabulated in Table 1.
TABLE 1
VACUUM FILTER TEST
PRIMARY SLUDGE
Cake Dry Solids
Test Conditioning Chemicals Solids Filter Yield
Date CaO(jo) FeCl?(f0) Content^) Ib/sq ft/hr
2/15/69 10.0 2.0 29.3
2/17/69 10.0 2.0 25-9
2/17/69 15.0 2.0 26.5
2/19/69 20.0 2.0 30.8
2/24/69 15-0 2.0 1.25
2/24/69 10.0 2.0 0.94
2/25/69 10.0 2.0 27.8 1.44
2/25/69 10.0 2.0 26.4 1.38
Vacuum filtration of sludges averaging 7-2% solids in the main plant for
the month of February 1969 produced cake with a mean solids content of
30.2$. The average doses of lime and ferric chloride were 9-7$ and 2.24$,,
respectively, which produced an average filter yield of 5.4 Ib/sq ft/hr.
Although the solids content of the filter cake was about the same for both
the main plant filters and the test filter, the average yield of the main
plant filters was approximately five times that of the test filter.
26
-------
Vacuum Filter (Continued)
Mixtures of primary and secondary sludges (in a one-to-one ratio) were
conditioned with lime and ferric chloride and with polymer. The sludge
mixture contained 3f0 to 5$ solids. The lime-ferric chloride condi-
tioning (16$ and 2% respectively) produced a cake with 29-9$ solids.
However, the yield was only 0.69 Ib/sq ft/hr. Organic polymers at
rates as high as 60 Ib/ton produced wet thin cakes that would not peel.
The data from the pilot filter testing was only comparative and could
not be scaled up to the plant size filters. Further study on full
scale vacuum filters is required.
Centrifuge
The batch feed centrifuge test unit consisted of a drum or bowl spinning
on a vertical axis. The sludge, after introduction into the center of
the bowl, passed through a series of baffles and was thrown against the
sides by centrifugal force. When the bowl filled to capacity, the
sludge cake was discharged through a withdrawal tube.
Secondary sludges of from 2.1% to 3° 7% were fed to the centrifuge. The
dry solids content of the thickened sludge depended on the rotational
speed of the bowl. The average results are as follows:
1500 rev/min 11.9$ <^Y solids
2000 rev/min lif.Ofo dry solids
2500 rev/min 15.9$ dry solids
The liquid centrate contained between 1000 to 2000 mg/1 of suspended
solids. Feed rates to the centrifuge varied from 2 gpm to if gpm. Fur-
ther testing of this type of equipment, preferably on a larger scale,
would be required before any recommendation could be made for their use
at Detroit.
Filter Press
The test unit consisted of a series of four circular plates held together
by a hydraulic ram. The concave faces of the plate when brought together
formed three ventricular cavities or cells. Covering the surfaces of the
concave faces was a monofilament nylon filter cloth. Backing the cloth
was a large-mesh stainless steel screen support. Openings leading away
from the screen support were provided for filtrate flow. Each plate had
a circular hole in its center for sludge feed. Cake discharge was per-
formed by separating the plates. A sludge filtration pressure of 250 psi
was used.
Primary sludge, mixtures of primary and secondary sludge, and secondary
sludge was tested. Lime, ferric chloride, organic polymers and incinera-
tor ash were used in various tests as filtration aids. Incinerator
ash was also used as a precoat on the filter cloth to improve sludge cake
27
-------
Filter Press (Continued)
separation. Incinerator ash in theory could substitute for chemicals
and under ideal conditions could be the only filter aid required. How-
ever, this did not prove practical at Detroit.
Table 2 is a summary of some of the filter press test data. The tests
have been numbered for identification purposes. The tests are not
necessarily tabulated in the order in which they were run0 The mixture
ratio of the unconditioned sludge is reported on a dry weight basis.
A three-to-one mixture ratio means that primary sludge containing three
pounds of dry solids was mixed with secondary sludge containing one
pound of dry solids. The per cent solids of the unconditioned sludge
is based on the dry weight of solids to the mixture, free of chemicals
and ash. The ash ratio is based on the weight of ash to the weight of
the sludge mixture dry solids. The filter cake is reported in terms of
the weight, in pounds, of one cubic foot of cake and in terms of per
cent dry weight of solids.
Testing using polymers proved unsatisfactory. In general, much longer
filtration times were required. Sludge cake produced was wet and sticky.
Filtration times of four hours with dosages of nearly 50 Ibs of polymer
per ton of dry solids produced wet cakes. It may be noted that the
rather crude test operations may have created a break in the floe. More
sophisticated operation and further testing would be required to prove
feasibility of polymer for use at Detroit.
The basic procedure for the operation was to batch mix the sludges,
determine solids content (and pH), add ash, remix, add conditioning
chemicals, remix again and feed to the filter press. In general it was
found that secondary solids, when fresh, were easier to filter. Secon-
dary solids that had been allowed to become anaerobic for longer than
twenty-four hours were extremely difficult to filter.
Two sizes of filter cells were utilized in the testing. It was found
that ash was required, in addition to ferric chloride and lime, when
filtering secondary sludge with the one and one-half inch cell. Ash
was generally not required when utilizing the one-inch cell. Both lime
and ferric chloride were required ii. all cases when filtering secondary
sludge.
However, ferric chloride was not always required when filtering primary
or primary-secondary sludge mixtures \^ith ash. Lime was required in all
cases. Filtrate samples averaged about; 10 mg/1 suspended solids.
Further study find testing of the filter press would be required to deter-
mine its applicability for v.s<2 at Detroit.
28
-------
TABLE 2
FILTER PRESS TEST
Unconditioned Sludge
Cell Conditioning Filtration
Filter Cake
ro
vo
Test
Run
1
2
3
4
5
6
7
8
9
10
Mixture Ratio Solids
Pri. to Sec.
Secondary
Secondary
Secondary
Secondary
Secondary
3:1
3:1
Primary
Primary *
Primary *
(%}
4.0
4.0
4.0
4.3
4.3
4.7
6.0
3-5
7-4
7.4
PH
6.2
6.5
6.2
6.8
6.8
7.0
7.2
6.9
6.8
6.8
Width
(in)
1.0
1.0
1.0
1.5
1.5
1.5
1.5
1.5
1.5
1.5
Ash
Ratio
0
0
3:2
3:2
3:2
1:1
1:1
1:1
1:1
1:1
Chemicals ($)
CaO FeCl3
12
15
6
12
12
10
10
10
10
10
5.0
7-5
3.0
3.0
6.0
0.0
0.0
0.0
0.0
0.0
Time
(Minutes )
120
120
120
120
150
120
100
120
75
90
Ib/cf
-
72
-
98
96
-
80
91
-
89
Solids
(*)
42. 3
-
37.0
-
58.0
-
59-0
61.2
-
60.0
*Main plant primary sludge
-------
SECTION VII
DEEP TANK AERATION STUDIES
Introduction
Most diffused air aeration tanks in the United States have liquor depths
of about 15 ft requiring blowers operating in the range of 7 psi. Due
to the restricted plant site area available for expansion, it was
decided to develop, if feasible, a coarse bubble aerator system
operating in the range of 7 psi but with tank liquor depth of 30 ft.
This was to be accomplished by the use of individual fixed header air
release units with training walls to act as air lifts for oxygen trans-
fer and circulation of liquor in aeration tanks having a series of
connected bays each 60 ft wide by 132 ft long by 30 ft liquor depth.
Model testing was indicated to determine oxygen transfer efficiency and
circulation adequacy.
Test Tank and Equipment
Available at the existing wastewater treatment plant site was a concrete
tank 70.33 feet long by 18 ft wide by 25 ft liquor depth with a total
volume of 238,000 gallons. The tank was normally used for primary sludge
thickening. This tank was used as the model for the tests. Two air
lifts were provided each consisting of a dual k-inch fixed pipe header
system with centerline 12.5 ft below the surface to which the various air
release devices were attached. Each header system was contained within
baffle walls it.5 ft apart by 16 ft long, 9.0 ft from the surface and
extending down to 20 ft from the surface ending 5 ft above the tank
bottom. A horizontal baffle at the liquid surface directs the flow
laterally.
Each it-inch dual header system was fed at the center by an 8-inch pipe
connected to a constant speed positive displacement blower. A by-pass
air valve provided for air regulation to the air lift devices. Air
measurement was by means of an Ellison Annubar flow meter of the double
probe pitot tube type. Dissolved oxygen uptake was measured at four
(or five) locations in the tank by means of a Bausch and Lomb-VOM-5 con-
tinuous recorder with check calibration by means of a single probe Yellow
Spring dissolved oxygen meter. The test tank and equipment are shown on
Figure 10, as set up for the single air lift tests.
Procedure
All tests were run with City of Detroit tap water. Paper punchings and
rolled oats were used for particle movement observations. Several of the
tests were observed under water by scuba divers.
Before each test, 100 Ibs of sodium sulfite and 1 Ib of cobalt were added
to the tank and mixed to reduce the dissolved oxygen to zero. A steady
30
-------
70'- 4"
HANDRAIL
— 7
8" A,IR SUPPLY
s-*\. 7n
JlMM
NORMAL WATER DEP
.1
f\J
'o\
I
J_
is i
IDES
f\J
HJ
AIR RELEASE DEVICE-
1
to
-TRAINING WALL
DISSOLVED OXYGEN
PROBE (TYPICAL)
FIGURE 10
DEEP TANK AERATION STUDIES
TYPICAL TANK SECTION DIMENSIONED
(ONE AERATOR UNIT SHOWN)
-------
Procedure (Continued)
reading for each probe was recorded each minute of the test. Water
temperature, air temperature, barometric pressure and power require-
ments were recorded. For each test and each probe oxygen deficit in
mg/1 was plotted against time in minutes on semi-log paper and a
straight line fit obtained from which the values of KLa were computed
to obtain the pounds of oxygen supplied per hour at 20 degrees C.
Testing
On September 17, 1968, the tank was operated with two airlift units to
determine the general underwater conditions as to velocity and solid
suspension characteristics. Three scuba divers made visual observations
within the tank during various modes of aeration operation. A compo-
site sketch of their observations is shown on Figure 11. Operation with
two aeration units in service, while giving a high degree of surface
agitation, did result in areas within the tank having little if any
movement. Operation with one unit, as shown in Figure 12, provided a
high degree of surface agitation with surface velocity of 6 fps and
bottom velocity of 2 to h fps with entire tank content in motion. As
a result of these observations it was decided to remove one air lift
unit and move the remaining unit to the center of the tank before pro-
ceeding with the dissolved oxygen uptake tests. On October 2, 1968, the
alteration was completed and scuba diver observations of the operation
were recorded with composite results as shown on Figure 13. Air outlet
was from 56 sparger units set at 6-inch center to center with each unit
providing 8 holes 7/32-inch diameter and two 9/l6-inch blow off pipes
extending 6 inches below the center of the 7/32-inch holes.
On November 15, 1968, Tests 1 and 2 were run for oxygen uptake with
results as shown in Table 3. An indicated oxygen transfer efficiency
of llfo was obtained at an air flow of 2900 scfm and 9.9$ at 700 scfm.
No further testing was done until May 26, 19&9) by which time the air
release devices had been changed to provide 56 units set at 6-inch
center to center with each unit providing 16 holes 3/l6-inch diameter
and four 3/^-inch blow off pipes extending 6 inches below the center of
the 3/l6-inch holes. Tests 3, ^, 5 and 6 were run with these outlets
with results as shown in Table 3. Oxygen transfer efficiency varied
from 8.3f0 to 13.k% with air flow varying from 1200 scfm to 3260 scfm.
During the period June 19 to August 27, 1969, Tests 7, 8, 9, 10 and 11
were run using the air outlets installed for Tests 3 through 6 but with
all 3/l6-inch holes closed forcing all air to outlet from the blow off
pipes with results as shown in Table 3« Test No. 7 with indicated
efficiency of h.h% and Test No. 8 with indicated efficiency of 17.9$ are
to be disregarded due to instrumental difficulties in measuring oxygen up-
take and aor flow. Oxygen transfer in Tests 9, 10 and 11 varied from 5.3fo to
8.1% with air flow varying from 13^ scfm to 1910 scfm.
32
-------
LjTJSiTTl
f ^
^ [E^D
1
1 v _,
L __ -
s.
1
tl
K>
1
J
r\
(
\
f>)
\
(.
VJI'-
•=-;.- y y -,--
\ / '
/ \
, x / DEAD \
AREA
-V \_
t
l^p
1
J
B
i
ft'
1
V
;
—
E
—
~^
.^s
J
FIGURE 11
DEEP TANK AERATION STUDIES
TWO AERATION U NITS T BOTH ON
-------
V**r
I fc"***^
V'
r
\
0,1
It
ti
X
FIGURE 12
DEEP TANK AERATION STUDIES
TWO AERATION UNITS-ONE ON
-------
w
Ul
FIGURE 13
DEEP TANK AERATION STUDIES
ONE AERATION UNIT
-------
TABLE NO. 3
SUMMARY OF DEEP TANK AERATION STUDIES
Test
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Air Release Probe
Device No. 1
Dual Sparjer 5.15
" 1.27
Quad Sparjer 8.77
2.06
3.69
6.31
Blow Off Pipes
Only
9.22
3.65
4.95
1.82
Quad Sparjer 1.60
ii .. 2>7Q
4.21
" 6.19
Discfuser 2.79
8.30
2.04.
4.85
4.43
6.64
1.54
5.62
Probe
No. 2
7.00
1.48
8.72
1.96
3.60
6.23
2.78
8.50
3.42
4.92
1.74
1.63
2.71
4.16
5.78
2.95
7.00
2.08
5.14
3.61
6.18
1.65
6.28
KL(
Probe
No. 3
5.64
1.18
9.08
1.86
3.37
6.36
3.14
9.08
3.79
5.60
1.87
1.63
2.35
4.69
5.66
3.51
8.16
2.04
4.86
5.07
6.20
1.45
7-53
aT
Probe
No. 4
9.60
1.96
7.63
1-91
3.66
6.24
3.23
8.66
3.32
5.20
--
1.51
2.68
3.82
5-71
3.07
9-07
2.10
4.8l
4.74
6.68
1.48
5.75
Probe
No. 5 Avg.
6.83
1.4?
8.55
1.95
3.58
6.28
3.05
8.86
3.54
5.17
1.81
1.59
2.6l
4.22
5.84
3.08
8.13
2.035
4.915
4.46
7.68 6.68
1.64 1.55
6.85 6.4i
(1) & (D
KLa Oxygen Supplied Air
@ Ib/hr Feed
20°C 41.72* x CD SCFM
7.37
1.59
10.05
2.29
4.24
7.38
3-31
9.30
3.35
4.90
1.71
1.57
2.58
4.18
5.77
3.78
9-99
2.56
6.09
5-52
8.27
1.92
7-95
307
66
419
95
177
308
138
388
i4o
205
71
65
108
174
241
157
4i6
106
254
230
345
76
315
.3
-5
.3
.5
.7
.8
.7
.0
.0
2900
700
3260
1200
2133
3100
3269
2384
1990
2636
i4oo
1379
1957
2763
2771
i4io
2820
860
1990
1990
2700
250
2750
©
Oxygen Feed
Ib/hr
0.96x C3)
2780
670
3130
1150
2050
2980
3140
2289
1910
2530
1344
1325
i860
2650
2660
1354
2720
825
1910
1910
2590
240
2640
Efficiency
12) / (4)
11.0
9-9
13.4
8.3
8.6
10.3
4.4
17.0
7.3
8.1
5.3
4.9
5.7
6.6
9.1
11.6
15.3
12.9
13.3
12.0
13.3
31.6
11.9
* 39.6 used for Tests 22 and 23 in which water level was 18 in. below normal.
See Page 38 for sample calculations and equations.
-------
Testing (Continued)
During the period September 8, 1969, to September 19, 1969, Tests 12,
13, 1^ and 15 were run using the air outlets as installed for Tests 35
k, 5 and 6, i.e., air was released from the 3/l6-inch holes as well as
the 3/^-inch blow off pipes, with results as shown on Table 3. Oxygen
transfer efficiency for this series of tests varied from U.9$ to 9«1$
with air flow varying from 1379 scfm to 2771 scfm.
During the period October 31, 19&9} ^o November 6, 1969? Tests 16
through 23 were run using 112 discfuser assemblies for air release.
Each air outlet consisted of a 3/A-inch nipple with a 3-9/l6-inch
diameter polyvinyl chloride floating disc which released air around its
periphery. The air outlets were fed from a central 6-inch pipe with
3/^-inch feed pipes at 3-inch centers. The air outlets were in four
rows with outlets spaced on 6-inch center in each row, all contained
within baffle walls 6'-0" apart. The horizontal area within the baffles
was 96 sq ft. Within the range of air flow from 860 scfm to 2820 scfm
the oxygen transfer efficiency varied from 11.6$ to 15-3$, averaging
12.9$. Test No. 22 at an extremely low air flow of 250. scfm resulted in
an oxygen transfer efficiency of 31.6$; however, under these conditions
circulation velocity and oxygen transfer rate were "impractical for the
proposed aeration system. The uniformly high oxygen transfer efficiency
for this series of tests is attributed to the 33$ increase in the area
contained within the baffles as compared to the results of Tests 1
through 15.
Indicated Power Requirements
Power measurements were significant only when all air from the blower
was being delivered to the air outlets. Tests 3, 6, Ik and 15 averaged
286 pounds of oxygen per hour and required 13^ HP resulting in an average
of 2.1^4 Ibs oxygen/HP-Hr at an average oxygen transfer efficiency of 9-8$.
Test No. 17, 21 and 23 averaged 358 pounds of oxygen per hour equal to
2.67 Ibs of oxygen/HP-Hr at an average oxygen transfer efficiency of
13.5$.
Test Tank Parameters
Air from the 56 sparjers was released at rates varying from 21 to 58
scfm per unit. The 56 sparjers were contained within a baffled 72 sq ft
area. Air release within this area varied from 17 to U5 scfm/sq ft.
The air liquid flow relationship for the 238,000 gal. test tank is as
follows:
37
-------
Test Tank Parameters (Continued)
Total Flow
GPM
1980
1320
Primary Effluent Flow
Return GPM 50$ Return GPM
1530
990
SCFM Air Flow Per Gallon
990
660
Mixed Liquor Detention
Hours
2
3
Primary Effluent Flow
GPM
660
990
1530
The test facility was operated at total air flows ranging from 700 to
3260 scfm. While no actual BOD removalt ests were run the following
BOD relationships have been computed for an average primary effluent
BOD of 130 mg/1 and a tank volume of 31,800 cf.
0.5
330
765
1.0
Total
660
990
1530
1.5
Air Flow
990
1U85
2295
2.0
1320
1980
3060
Primary Effluent Flow
GPM
660
990
1530
Conclusions
BOD per Day
Ibs
1020
1530
2370
Ibs BOD per day
per 1000 cf
Aeration Volume
32.1
148.2
7U.5
Total Air SCFM
to supply
1000 cf/lb BOD
660
1060
1650
The tests have demonstrated the feasibility of using compressed air at
normal blower pressure of 7 to 8 psi using the air lift pumping principal
to provide for oxygen transfer and circulation of contents of deep aera-
tor tanks. The device tested created currents that entrained air
throughout the test tank, provided good mixing and transferred oxygen
within acceptable limits of efficiency and horsepower requirements. The
tests have provided data for the design of a full scale aerator having a
volume of 17,800,000 gallons consisting of 10 bays, each 60 ft wide by
132 ft long by 30 ft swd.
The calculations for the development of Table No. 3 were based on the
following:
4. (t2-tl}
KLa = ^1.72 KLa
02 Supplied @ 200 C Ib/hr = 2.3 '
& 02 Feed Ib/hr = 0.76 x cfm x 60 x 21 -f- 100 = 0.96 x cfm
38
-------
SECTION VIII
LABORATORY TEST PROCEDURES
Introduction
To evaluate the performance of the pilot plant, various analytical
tests, as described in the following pages, were performed. Most of
the analytical tests were performed on a routine daily "basis. Auto-
matic samplers were used to obtain 2U-hour composites of the raw
sewage, primary effluent and final effluent. The mixed liquor and
return sludge samples were grab samples.
The analytical procedures were basically performed in accordance with
methods outlined in the Twelfth Edition of "Standard Methods for the
Examination of Water and Wastewater, 1965", unless otherwise indicated.
Grease Analysis
Reference is made to "Standard Methods," lages 383 through 385.
A one-liter sample of final effluent sewage was collected from the
24-hour composite. The sample was acidified to a pH of about 1.0
with 3 to 5 nils of concentrated HC1.
A Buchner funnel was prepared by taking one gm of Johns-Mansville
celite filter aid and adding it to 100 mis of water to make a slurry.
The slurry was poured into the funnel, which contained a Whatman
No. UO, 12.5 cm filter paper. Vacuum was applied and the slurry fil-
tered. The sample was then filtered until the paper appeared dry.
When completely filtered the paper was removed and put into a Whatman
seamless extraction thimble. Any residue remaining in the funnel was
collected with a piece of cotton soaked in petroleum ether, and the
cotton and residue were added to the extraction thimble. The thimble
was dried for 2 hours at 103°C.
An extraction flask was weighed and recorded. The grease was extracted
for k hours in a Soxhlet apparatus using petroleum ether (boiling point
30°-60°C). Finally the ether was distilled off, and the flask dried
and weighed.
Calculation:
, mg increase in weight of flask x 1000
mg/1 total grease = ml sample used
39
-------
Sludge Volume Index
Reference is made to "Standard Methods," Page 5*H and
The sludge volume index (SVl) of grab samples of mixed liquor and
returned activated sludge were measured daily as the milliliters
occupied by one gram of sludge which settled from one liter of the
sample after 30 minutes of settling in a one-liter graduated cylinder.
Calculation:
ml settled sludge x 1000
mg/1 suspended matter*
Suspended Solids and Volatile Suspended Solids
Reference is made to "Standard Methods," Pages k2k and ^25.
The suspended solids was determined by vacuum filtration in a
Gooch crucible using a Reeves Angel Glass Fiber Filter No. 93^AH,
2.H cm. The vacuum was provided by a Precision Scientific Company
Vacuum Pump, Model 150.
The crucibles were prepared by placing a glass mat in each crucible
and filtering distilled water to remove any loose fibers and to seat
the mat. These crucibles were then fired at 600°C for 20 minutes,
cooled to room temperature, weighed and stored in a dessicator until
used.
At time of use they were placed in a Walters Crucible holder in a
vacuum flask. The sample was added and vacuum applied until all the
liquid had passed through the mat. In most cases, a fifty milliliter
portion of the sample was filtered.
The crucibles were dried at 103°C for at least 30 minutes, cooled and
weighed for suspended solids.
For volatile suspended solids the same crucible was then placed in a
muffle furnace at 600°C for 20 minutes to burn off all volatile solids.
(Note: Any longer time may cause loss in weight of the glass mat).
The crucibles were then cooled and weighed for volatile solids.
Dissolved Oxygen
Reference is made to ''Standard Methods," Pages 1*05 and U06.
The dissolved oxygen (DO) analyses for the pilot plant were run with a
Yellow Springs Instrument Company's Model 50 Oxygen Meter, using #5103
* Suspended matter - obtained from the analysis of suspended solids.
-------
Dissolved Oxygen (Continued)
temperature compensated probe with 0.0005-inch thick teflon membranes.
The probe was completely immersed in the liquid with flow past the
membrane being provided by the motion of the liquid. It was found
that from 1 to 2 minutes was generally required for equilibrium to
be reached. The probe was standardized against water which was stan-
dardized by the Winkler DO method.
Biochemical Oxygen Demand
Reference is made to "Standard Methods," Pages Ul5 to H21.
The Biochemical Oxygen Demand (BOD) was determined for the raw influent,
primary effluent and final effluent samples .
Two BOD determinations were made for each sample. The following con-
centrations were found satisfactory for our samples.
Raw sewage: 1.% and 2%
Primary effleunt: 2% and 3%
Final effluent: 10f0 and 15
-------
Iron (Continued)
The reagents were:
a) Buffered ortho-phenanthroline solution containing 50 grams
sodium acetate, 25 grams sodium hydroxide, and 0.35 grams
1,10-phenanthroline monohydrate per liter of distilled water.
b) Hydroxylamine solution containing 100 gm hydroxylamine hydro-
chloride per liter of distilled water.
c) Concentrated hydrochloric acid.
A Bausch & Lomb "Spectronic - 20" Spectrophotometer was used for iron
analysis of the raw influent, primary effluent and final effluent
samples.
A 50 ml sample was measured into a 150 ml graduated beaker. To the
sample was added 2 ml concentrated hydrochloric acid and 2 ml of
hydroxylamine solution. The sample was mixed and heated in an auto-
clave at 230°F for 15 minutes. After cooling, 30 mis of phenanthroline
solution was added. The sample was diluted to 100 mis with distilled
water, mixed and allowed to set at least 10 minutes for color develop-
ment.
After the "Spectronic - 20" was allowed to warm up for at least 15
minutes, the absorbence of the sample was measured, using distilled
water as the blank. The wave length was set at 510 millimicrons.
The absorbence reading was compared to those of standard iron solutions
previously analyzed.
Chlorine Requirement
Reference is made to "Standard Methods," Pages 112 to 11^ and Pages 38!
to 383.
The chlorine requirement of the final effluent after a 15 minute contact
period was determined to measure the minimum amount of chlorine neces-
sary to provide a free chlorine residual.
Chlorine water was prepared by bubbling chlorine gas through tap water
until a medium yellow color developed, and then by diluting a part of
the solution to 2 parts of tap water. The weaker solution was analyzed
daily for its chlorine content.
Approximately 0.2 gm of reagent grade potassium iodide crystals and six
drops of 50$ glacial acetic acid (sufficient to drop the pH to ^.0) were
added to 100 mis of distilled water in a 300 ml Erlenmeyer flask. After
adding 10.0 mis of chlorine water the solution was immediately filtrated
with 0.025 normal sodium thiosulfate solution to a faint yellow color.
-------
Chlorine Requirement (Continued)
Starch indicator solution was added, and the titration continued until
the blue color disappeared. The starch indicator contained 5 gm starch
and 17 gm potassium iodide per liter. The following formula was used
to determine the chlorine content.
ml Na2S20o x Normality Wa^S^O-i x 35-^6 rag/ml
mg/ml Cl = —— : 7
to/ ml chlorine water
The chlorine requirement was determined from a grab sample of the final
effluent. After determining the temperature of the sample, it was mixed
and poured into each of five graduated 300 ml Erlenmeyer flasks (200 ml
of sample into each). Chlorine water was added to the samples
increasing the amount by 0.^ ml in each successive flask, so that the
third flask contained approximately that amount necessary to satisfy the
chlorine demand previously estimated by an analysis or spot plate test.
Fifteen minutes after the last chlorine water addition (a timer was set),
approximately 5 ml of starch indicator solution was added to each
flask. The amount of chlorine water that produced the faintest blue
color was noted. Usually that amount had to be estimated between the
successive dosages. The following formula was used to calculate the
chlorine requirement.
, ml Clo water x me Cl per ml Clo water x 1000
mg/1 Cl = ± ?
200 ml of sample
Inorganic Phosphate Determination
Reference is made to Technicon Corporation's "Operating Instruction
Manual" for the Technicon Auto Analyzer.
Each sample was set up to determine the inorganic phosphate concentra-
tion to three levels, (l) The total inorganic phosphate concentration
was determined from a portion of the sample which had been hydrolyzed
for the conversion of inorganic phosphate to ortho phosphate. Hydroly-
sis was accomplished by autoclaving 25 ml of sample with 0.5 ml of
strong acid solution for 15 minutes at 230°F and 15 psi. The sample
was cooled and filtered through S & S fluted filter paper (#588, 18 cm)
to remove turbidity. (2) The total dissolved inorganic phosphate con-
centration was run on the filtrate of the suspended solids test after
undergoing hydrolysis. (3) The dissolved inorganic phosphate concen-
tration was determined from the filtrate of the suspended solids test
but was not subjected to hydrolysis.
These samples were then run on a Technicon Auto Analyzer using a
modified version of Technicon's Inorganic Phosphate Method (N-Vb).
The modified version is illustrated in Figure 1^. The samples were
treated with acidified ammonium molybdate reagent, producing phospho-
molybdic acid, and immediately reduced with l-amino-2-naphthol-!4-sulfonic
-------
RESOLUTION WATER-O.I 10
WATER
SAMPLER E
(TECHNICON)
RATE: 50/HR.
(2'')
C
WATER - 0.065
AMINO-NAPHTHOL 0.073
IL
v — j —
AIR-
SAM
0.090
PI F- n ov^
, WASTE
SULFURIC MOLYBDATE 0.081
NOTE' TUBE SIZES,INCHES
HEATING BATH 95* C
0.073
PROPORTIONING
PUMP
COLORIMETER
50mm TUBULAR
FLOWCELLS
660mu FILTERS
RECORDER
RANGE EXPANDER
FIXED EXPANSION,
SETTING = I
FIGURE 14
MODIFIED ANALYSIS ORTHO
PHOSPHATE
44
-------
Inorganic Phosphate Determination (Continued)
acid reagent. The reaction mixture passed through a 95°C heating bath
to develop the blue color resulting from the formation of molybdenum
blue. The optical density of the resultant solution was proportional
to the amount of phosphate present. It was measured at 660 millimicrons
in a tubular flow cell having a 50 mm light path and graphed on a strip
chart. The peaks were compared to those of standard phosphate solu-
tions previously analyzed.
The strong acid solution was prepared by adding 300 ml of concentrated
sulfuric acid to 600 ml of water. After cooling, k.O ml of concen-
trated nitric acid was added to the solution. The solution was then
diluted to one liter.
The stock solution of sulfuric molybdate (See Figure 1^) was prepared by
dissolving 75 gm of ammonium molybdate in approximately 1 liter of water.
Concentrated sulfuric acid (530 ml) was added and the solution was
mixed, cooled and diluted to 2 liters. The working solution was pre-
pared by mixing one part of the stock solution with four parts water.
The amino napthol stock solution (See Figure 1^) was prepared by
dissolving 2^0 gm of sodium bisulfite and 8.0 gm of sodium sulfite in
800 ml of water. After heating the solution to 50°C, ^.0 gm of 1-amino-
2-napthol-U-sulfonic acid was added. The solution was diluted to two
liters. The working solution was prepared by mixing one part stock
solution with four parts water.
The phosphate standard solution of 1 mg P/ml was prepared by mixing
^•3937 gm of potassium dihydrophosphate with one liter of water.
Phenol
Reference is made to "Standard Methods," Page 51^ and to the Technicon
Corporation's "Operating Instruction Manual for the Technicon Auto
Analyzer . "
Phenol determinations were run on the raw influent, primary effluent and
final effluent. One ml of 10$ phosphoric acid was added to a 50 ml
sample in a 300 ml boiling flask with boiling chips. The mixture was
distilled until ^0 ml of distillate was collected. After the flasks
cooled, 10 ml of distilled water was added. The distillation was con-
tinued until a total of 50 ml of distillate was obtained.
Portions of the distillate were processed through the Technicon Auto-
Analyzer as illustrated in Figure 15- The reading was compared to
those of standard phenol solutions previously analyzed.
-------
TO WASTE
0.01 IP-RESOLUTION H20
- 0.030-4%FERRICYANIDE
SOLUTION
SAMPLER II
(TECHNICON)
RATE: 30 / HR
NOTE: TUBE SIZES, INCHES
0.073-AIR
O.I 10-SAMPLE
0.030- 1.5% AMINOANTIPYRENE
COLORIMETER
50™»r> TUBULAR
FLOWCELLS
526^u FILTERS
RECORDER
RANGE EXPANDER
FIXED EXPANSION,
SETTINGS
FIGURE 15
PHENOL ANALYSIS
46
-------
Phenol (Continued)
The 1.5$ buffered aminoantipyrene solution (See Figure 15) was prepared
by dissolving 15 gm ^-aminoantipyrene, 30 gm of sodium carbonate and
30 gm sodium bicarbonate and diluting to one liter. The solution was
filtered after mixing.
The 4.0$ buffered ferricyanide solution (See Figure 15) was prepared
by dissolving kO gm potassium ferricyanide, 30 gm sodium carbonate and
30 gm sodium bicarbonate and diluting to one liter. The solution was
filtered after mixing.
-------
SECTION IX
ACKNOWLEDGMENTS
Board of Water Commissioners
John H. McCarthy Henry R. Kozak
Charles H. Beaubien William Haxton
Oscar A. Wagner George J. Fulkerson
John D. McEwen David Boston, Secretary to the Board
Gerald J. Remus, General Manager and Chief Engineer
Engineering Division
Harvey E. Werner - Assistant Chief Engineer
E. Cedroni - Head Engineer, Engineering Services
C. Schultz - Head Engineer, Field
D. Suhre - Head Engineer, Wastewater Systems
F. Daskus - Electrical Engineer
I. Schuraytz - Mechanical Engineer
R. Hagen - Sr. Associate Civil Engineer
J. Kegler - Sr. Associate Civil Engineer
C. Barksdale - Associate Civil Engineer
Operations Division
George Dehem - Superintendent of Operations
A. Shannon - Chief of Water and Sewage Treatment
J. Urban - Chief Engineer, Wastewater Plant
P. Skupeko - Supervisor of Filtration
Consultants
George E. Hubbell - President, Hubbell, Roth & Clark, Incorporated
Dr. Gilbert V. Levin - President, Biospherics Incorporated
Federal Water Quality Administration
Dr. Robert L. Bunch - Chief, Biological Research Activities
-------
ACKNOWLEDGMENTS
(Continued)
Project Steering Committee
R. Bunch - Federal Water Quality Administration
G. Hubbell - Hubbell, Roth & Clark, Incorporated
J. Kegler - Detroit Metro Water Department
G. Levin - Biospherics Incorporated
A. Shannon - Detroit Metro Water Department
P. Skupeko - Detroit Metro Water Department
D. Suhre - Detroit Metro Water Department
J. Urban - Detroit Metro Water Department
Pilot Plant Operations
P. Skupeko
J. Grasel
S. Finkelstein
W. Cebalt
R. Encelewski
J. VanHavermaat
W. Nagi
J. Troiano
J. Grogenski
C. Leen
Report Delineation and Production
S. Beer
C. Porter
E. Tulecki
B. Walker
Q. Washington
-------
APPENDIX A
SUMMARY ACTIVATED SLUDGE TESTING
TBT NUMBER PROCESS
TREATMERT U1CITS*
REMARKS
01
o
1
2
3
k
5
6
7
8
9
10
11
12
13
it
15
16
17A
17B
18
19A
19*
2QA
SOB
21
22A
22B
23
2U
25
26
27
28
29
30
31
32
Conventional
Conventional
Conventional
Conventional
Conventional
Conventional
Conventional
Conventional
Conventional
Conventional
Conventional
Conventional
Conventional
Conventional
Conventional
Conventional
Step Feed
Step Feed
Step Feed
Conventional
Conventional
Levin
L«vin
Step Feed
Step Feed
Step Feed
Bioataorption
Step Feed
Step Feed
Step Feed
Step Feed
Conventional
Step Feed
Step Feed
Step Feed
Step Feed
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP*
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
IP,
5ML,
9ML,
5ML,
5ML,
5ML,
5ML,
5ML,
5ML,
5ML,
5ML,
5ML,
5ML,
5ML,
5ML,
5ML,
5ML,
IBS,
IBS,
IRS,
5ML,
5ML,
5ML,
UML,
IRS,
IBS,
IRS,
URS,
IRS,
IBS,
IRS,
IBS,
2ML,
USF,
USF,
USF,
USF,
2F
2F
2F
2F
2F<
2F
2F
2F
2F
2F
2F
2F
2F
2F
2F
2F
USF,
3SF,
USF,
2F
2F
2F
2F
3SF,
3SF,
3SF,
1ML,
3SF,
3SF,
3SF,
3SF,
2F
1ML,
1ML,
1ML,
1ML,
2F
2F
2F
1ML, 2F
1ML, 2F
1ML, 2F
2F
1ML, 2F
1ML, 2F
1ML, 2F
1ML, 2F
IF
2F
2F
2F
No chemical feed
No chemical feed
No chemical feed
No chemical feed
No chemical feed
No chemical feed
No chemical feed
Iron feed to raw sewage
Iron feed to mixer and flocculate ahead of primary
Iron feed direct to aeration tank
Iron feed direct to aeration tank
Iron feed direot to aeration tank
Iron (7 x dilution) feed direct to aeration tank
Iron (7 x dilution) feed direct to raw sevage
Iron feed direct to raw sewage
Iron feed direct to raw sevage
Iron feed direct to raw sewage
Iron feed direct to raw sewage
Iron feed direct to raw sewage, raw sewage flow varied in proportion to main plant flow
No chemical feed
No chemical feed
Return sludge under zero DO for 12.5 hours
Return sludge under zero DO for 13-0 hours
Iron feed to raw sewage
Iron feed to raw sewage
Iron feed to raw sewage
Iron and waste sludge feed to raw sewage, mixed and flocculated
Iron feed to raw sewage, mixed and flocculated
Iron feed to raw sewage, mixed
Iron and waste sludge feed to raw sewage, mixed and flocculated, polymer to a«r»t«*
Iron feed to raw sewage, polymer into flocculator
Iron feed to raw sewage, caustic and polymer into mixer, mixed and flocculated
Iron feed to raw sevage, caustic to mix, flocculate, polymer to aeration tank
Iron feed to raw sewage, flocculate, polymer to aeration tank
Iron feed to raw sewage, caustic to mixer, flocculate, polyatr to aerator
•Treatment Units: P
and F = final tank.
primary tank, ML = mixed liquor compartment, RS = return sludge compartment, SF = step feed c
The prefix nunber Indicates the number of units utilized.
ent
-------
APPENDIX B
ACTIVATED SLUDGE TEST DATA
U1
Te*t No.
Date Start
Dace Bod
Iron Feed rag/1 Pc++
Cauctic Peed mg/1 NaOH
Polymer Feed mg/l Dow A 23
CPM Raw'Sewage
GPM Return (Act. Sludge
CPM Waste K'.A.S.
S.V.l.R.A.S.
S.V.I. Mixed Liquor
Mixed Liquor Solid* mg/l
Return Act.Sludge Solid* mg/l
Pound* of Aerator Solid*
Pound* of BOO per d*y
BOD Sludge Age Day*
BOD Raw Sewage mg/l
BOD Primary Eff. mg/l
BOD Final Eff. mg/l
Air C.F. per Gallon
Air C.F. per Pound of App. BOD
Suspended Solid* Raw Sewage mg/l
Suspended Solid* Pri. Eff. mg/l
Suspended Solid* Final Eff. mg/l
Primary Sealing Rat* gal/af/dty
Primary Sealing Time Hr*.
Mixed Liq. Aeration Time Hr*.
Final Settling Rate gal/if/day
Final Settling Time Hn.
Total Fhocphate a* P Raw mg/l
Total PhMphate a* P Pri. Eff. mg/l
Total Phoaphatc a* P Final mg/l
Total Phoaphate a* P M.L. mg/l
Total Pbo*phate a* P RAS mg/l
Soluble Phoaphate a* P Raw mg/l
Soluble Pho*phate a* P Pri. Eff. mg/l
Soluble Phoaphate a* P Final mg/l
Oil Final mg/l
Phenol Raw ppb
Phenol Final ppt>
I 23 4 56 7 8 9 10 II 12
1/17/67 12/5/67 12/18/67 1/12/68 1/24/68 1/14/68 3/1/68 3/28/68 4/8/68 4/23/68 5/4/68 5/17/68
12/4/68 12/17/67 1/9/6* 1/22/68 2/13/68 2/29/68 3/27/68 4/7/68 4/22/68 5/3/68 5/16/68 6/6/68
15 15 15 30 15
60
20
0.44
65
o9
23SO
6480
210
84
2.5
148
117
26
0.94
968
308
191
59
1350
1.05
2.2
675-1350
2. 1-1. OS
6.7
5.8
3.0
57
134
2.1
2.3
1.8
283
12
45
15
0.75
46
34
2120
8200
190
63
3.0
187
114
10
0.98
1000
393
170
21
1050
1.4
3.0
525
2.8
6.9
5.6
2.4
48
170
1.3
1.6
1.4
11.4
248
58
45
IS
0.26
92
68
2720
7450
240
6J
3.5
223
125
16
0.83
790
500
193
M
10SO
1.4
3.0
S2S
2.8
6.8
6.1
3.0
59
146
1.9
1.9
1.9
13.5
318
88
54
26
0,58
11
67
3330
10500
295
%
3.1
254
149
14
1.22
990
SIS
247
31
1240
1.16
2.2
620
2.32
8.6
7.7
2.4
85
228
2.8
1.6
1.3
18.4
365
50
55
26
0.73
64
40
4180
12200
367
65
5.6
125
98
17
0.94
1150
346
177
19
1260
1.14
2.2
630
2.28
6.0
5.1
2.2
80
200
2.3
1.2
1.1
13.0
227
39
30
30
0.55
85
55
4606
8930
405
52
7.8
180
144
18
1.97
1625
383
181
27
700
2.1
3.0
350
4.2
8.2
7.2
2.8
125
230
3.3
2.0
1.6
8.4
404
39
44. 5
22.2
1.30
71
55
3140
8850
275
66
4.2
208
124
16
1.31
1275
457
233
23
1040
1.38
2.6
520
2.76
7.8
6.6
2.6
70
172
1.7
1.7
1.3
5.9
415
S3
40
20
0.76
SO
37
2554
6729
225
60
3.75
207
125
19
0.98
935
445
202
40
900
1. 51
3.0
460
3.06
6.4
4.5
1.2
52
127
1.1
.5
O.S
6.0
309
49
35
20
0.99
72
55
2520
7000
220
57
3.86
272
136
21
1.12
1000
782
206
32
800
1.80
3.2
400
3.60
8.7
6.0
1.5
60
1S6
1.6
1.0
0.7
11.0
335
48
40
20
1.23
104
71
2928
7900
260
79
3.30
231
166
21
1.31
960
630
211
25
900
1.58
3.0
460
3.16
7.7
7.1
1.2
86
187
2.0
2.3
0.6
16.0
344
44
42
18
1.70
86
58
2410
7050
212
80
2.66
279
159
25
1.30
980
582
245
31
950
1.53
3.0
480
3.06
7.5
5.9
0.9
60
144
2.0
2.2
0.4
9.0
397
85
63
14
1.56
54
34
2265
8951
200
88
2.27
153
117
39
0.83
855
320
181
46
1430
1.0
2.3
715
2.0
6.2
5.6
1.5
54
195
1.8
2.0
0.4
9.0
256
75
-------
APPENDIX B
ACTIVATED SLUDGE TEST DATA
01
10
Teat No.
Due Start
Date tod
lion Peed mg/1 Fe-H-
Guattc Peed mg/1 NkOH
Polymer Feed mg/1 Dow A 23
CPM lav Sewage
GPM Return Acl. Sludge
GPMWaateR.A.S.
S.V.l.R.A.S.
S.V.I. MUvd Liquor
Mixed UajMor Solid* mg/1
Retain Act. Sludge Solid* mg/l
Pound* af Aerator Solids
Pound* of BOO per diy
BOD STadga Age Daya
BOD Raw Sewage rof/l
BOD Primary Ell. rag/1
BODFkml V. mg/l
Air C.F. Per Gallon
Air C.P. per Pound of App. BOD
SMpeoded Solid* Raw Sewage mg/1
Suspended Solid* Prl. EH. mg/l
Suapeooxd loildi Final EH. mg/l
Primary Settling Rate gal/a.f./day
Primary Settling Time Hr*.
Mind Liq. Aeration Time Hr*.
Pinal Settling Rate gal/*, f./day
Final Sealing Time Hr*.
Total Phoaphate aa P Raw ng/l
Total Phoaphate aa P Prl Bff. mg/l
Total Pboaphate a* P Final mg/l
Total Pboaphate aa P M.L. mg/l
Total Phoaphate aa P RAS mg/l
Soluble Phoaphate aa P Raw mg/l
Soluble Phoaphate a* P Prl. Bff. mg.l
Soluble Pnoaphate a* P Piaal mg/l
Oil Flail mg/l
Phenol Raw ppb.
Phenol Piaal ppb.
13
/7/68
30/68
19
52
14
1.74
5*
37
2730
12500
240
76
3.16
189
122
38
1.16
1140
482
195
34
1200
1.2
2.66
600
2.4
7.4
6.0
1.1
77
287
2.1
2.3
0.4
7.4
4SS
67
14
6/21/68
7/11/68
.18
S5
13
1.65
56
41
2540
10900
226
62
3.64
160
94
26
C.%
1210
438
179
35
1240
1.1
2.60
620
2.2
5.5
3.7
1.3
54
199
1.6
.7
0.6
6.5
338
S3
15
7/12/68
7/25/68
16
60
13
1.97
82
56
2440
9950
215
78
2.76
166
108
33
0.8*8
977
322
179
21
1360
l.OS
2.43
680
2.10
5.9
S.I
1.5
67
239
2.5
1.6
0.9
5.0
530
67
16
7/26/68
8/8/68
15
46
16
1.6
106
72
2400
0160
210
54
3.89
149
97
21
1.25
1120
333
184
30
1010
1.40
2.83
505
2.80
5.2
4.1
1.3
57
172
1.8
0.9
0.8
6.4
410
45
I7A
8/9/68
8/22/68
15
58
19
1.9
82
75
2905
11550
452
88
5.14
173
127
25
1.79
1700
33H
226
25
1330
1.08
2.30
660
2.16
4.9
4.8
1.5
61
229
1.6
1.0
0.7
9.1
231
44
17B
8/23/68
9/5/68
IS
65
23
1.7
80
62
2690
10940
395
112
3.53
209
143
45
1.15
960
364
221
64
1500
0.97
2.0
750
1.94
7.0
6.3
3.1
78
278
2.7
1.6
1.3
20.6
353
93
!••
9/6/68
10/3/68
17
45
22
2.1
105
76
2580
7590
387
73
5.3
196
136
25
1.67
1480
405
18*
IS
1000
1.40
2.63
500
2. BO
7.5
6.2
1.3
76
1*1
2.7
0.9
0.9
7.0
369
25
19A
10/4/68
10/17/6*
45
23
2.6
82
65
2452
6745
227
6*
3.6
169
117
25
1.39
1430
4*1
235
31
1000
1.4
2.60
500
2. BO
6.9
6.8
3.0
52
120
2.3
1.7
2.4
9.4
331
47
I9B
10/18/68
11/7/68
54
25
2.2
90
70
2884
9731
252
98
2.6
196
151
61
1.25
990
503
261
159
1230
1.08
2.23
615
2.25
• .6
7.6
5.8
60
159
2.9
3.0
2.9
36.5
460
172
20A
11/7/68
11/25/68
36.1
43
38
4802
23959
420
69
4.1
198
160
28
5.44
4100
592
221
47
1200
1.2
3.9
680
2.10
9.7
7.8
3.0
105
597
2.8
2.4
1.8
14.2
390
77
208
11/26/68
12/9/68
35.2
36
39
5502
28378
483
69
7.0
214
163
22
2.44
1790
462
240
27
1200
1.2
4.17
695
2.16
9.8
8.0
2.7
166
827
2.3
2.4
1.6
14.2
427
40
21
12/10/68
12/31/68
15
40
20
1.77
83
68
3255
12395
552
84
6.6
198
174
28
1.98
1360
439
253
IS
900
1.60
2.96
450
3.2
8.2
8.3
1.3
90
306
2.1
1.3
0.8
7.7
363
43
-------
APPENDIX B
ACTIVATED SLUDGE TEST DATA
01
U
Test No.
Due Sun
Date aid
Iron Peed mg/l Pe++
Cauattc Peed mg/1 NaOH
Polymer Peed mg/1. Dow A 23
CPM Ka* Sewage
CPM Return Act. Sludge
CPM Wa*te R.A.S.
S.V.I.R.A.S.
S.V.I. Mixed Liquor
Mixed Liquor Solids mg/l
Return Act. Sludge Solid* mg/l
Pounds ft Aerator Solid*
Pound* of BOD per day
BOD Sludge. Age Day*
BOD R*w> Sewage mg/1
BOD Primary Eff. mg/1
BOD Fl**l Mr. mg/1
Air C.F. Per Gallon
Air C.P. per Pound of App. BOD
Suspended Solid* Raw Sewage mg/l
Suspended Solid* Pit. Eff. mg/l
Suspended Solid* Fin*I Eff. mg/l
Primary Settling Rate gal/*.f./day
Primary Settling Time Hr*.
Mixed Liq. Aeration Time Hr*.
Final Settling Rate gal/*.f./day
Final Settling Time Hr*.
Total Phosphate •• P Raw mg/l
Total Phoapfaate a* P Prl Eff. mg/l
Total Pho*phate a* P Final mg/l
Total Phosphate a* P M.L. mg/l
Total Phosphate a* P HAS mg/l
Soluble Pbocphate a* P Raw mg/l
Soluble Phoaphate a* P Prl. BO. mg.l
Soluble Phoaphate a* P Final mg/l
Oil Final mg/l
Phenol Raw ppb.
Phenol Flaal ppb.
22A
1/3/69
1/20/69
IS
52.4
12.0
0.50
81
68
2500
13686
490
90
5.5
163
144
20
1.32
995
306
220
29
1180
1.2
2.73
590
2.47
8.5
7.6
1.7
73
353
2.1
1.0
0.7
9.6
454
43
22B
1/21/69
1/31/69
15
48
10
0.05
39
36
2135
21730
660
58
11.4
126
100
36
0.76
910
311
290
38
1080
1.3
3.0?
540
2.60
6.6
7.2
1.9
63
423
1.1
0.6
•.S
14.2
385
105
23
2/1/69
2/9/69
15
44.9
11.4
0.4
57
35
4139
16800
910
73
17.9
159
138
30
1.97
1730
316
293
46
1050
1.4
0.62
520
2.80
8.2
8.2
1.8
103
411
1.2
0.6
0.6
12.4
490
43
24
2/10/69
2/25/69
15
53.3
12.6
1.8
84
58
1966
10729
375
89
4.2
213
139
26
1.23
1065
470
193
28
1230
1.09
2.7
500
2.80
9.8
6.0
1.2
57
305
1.4
0.7
0.5
8.3
643
35
25
2/26/69
3/10/69
15
51.2
18.9
1.0
100
80
2SS5
13489
530
93
5.7
212
152
32
1.02
810
438
27j
43
1180
1.13
2.5
480
2.92
9.4
9.4
1.7
69
307
0.9
0.7
0.6
14.8
520
87
26
3/11/69
3/20/69
15
48.5
16.8
0.90
88
105
3122
11567
468
92
5.1
197
157
37
0.98
747
430
252
40
1090
1.29
2.7
507
3.04
13.0
9.6
2.4
115
347
1.4
0.7
0.7
11.2
634
62
27
3/2l'/69
3/31/69
15
0.3
41.9
19.2
0.5
74
56
2714
7781
368
40
9.2
163
80
31
1.10
1650
358
114
51
940
1.43
2.9
438
3.50
9.3
3.8
1.9
68
183
0.7
0.5
0.4
13.6
355
85
28
4/2/69
4/27/69
IS
0.3
48.5
17.9
0.9
52
36
2980
11867
100
48
2.08
151
83
26
0.44
775
351
135
39
1090
1.29
1.05
507
3.04
8.0
5.4
2.0
92
332
1.2
0.8
0.6
14.1
373
51
29
4/28/69
5/7/69
15
30
0.3
59.6
27.7
1.6
74
48
2946
12275
428
76
5.6S
.213
106
50
0.72
•20
536
203
127
1340
1.05
2.0
1250
1.24
12.8
6.0
3.3
104
361
2.5
1.0
0.7
22.4
601
79
30
5/8/69
5/15/69
15
30
0.3
67.5
24.2
1.3
64
43
2157
9154
288
63
4.56
127
78
18
0.74
1140
389
84
24
1520
0.93
1.9
705
2.2
7.4
2.9
1.4
67
264
1.3
0.7
0.5
13.4
2*6
43
31
5/16/69
6/4/69
15
0.3
68.1
24.0
0.6
66
45
25$ I
14530
425
60
6.25
164
83
23
0.69
990
355
124
35
1530
0.92
1.9
765
2.16
9.0
5.4
1.8
134
467
2.4
1.2
0.6
8.0
458
32
32
6/5/69
6/30/69
IS
30
0.3
72.3
25.0
1.0
77
50
2213
10882
330
78
4.25
169
89
31
0.64
•SO
459
106
38
1620
0.87
1.8
810
1.74
10.6
4.3
2.1
78
341
2.6
1.2
o.»
12.0
465
43
-------
APPENDIX C
TRICKING FILTER TEST DATA
Teat No.
Date Start
Date End
Iron Peed mg/1 FC-+-+
Polymer Feed mg/1 Dow A23
Caustic Feed mg/1 NaOH
Filter Feed gpm
Filter Feed gjm/aq ft
Filter Recycle gpm
Raw BOD mg/1
Filter Feed BOD mg/1
Final Bff. BOD mg/1
BOD Load/1000 cf/day
Filter Feed Ratio SS/BOD
Primary Tank Feed gpm
Primary Overflow Rate
gal/.f/day
Primary Hre Detention
Raw Suip. Solids mg/1
Prl. Eff. SS mg/1
Final Tank Feed gpm
Final Overflow Rate
gal/«q ft/day
Final Hr» Detention
Final Eff. SS mg/1
Total Raw P mg/1
Total Filter Feed P mg/1
Total Final P mg/1
Raw Ortho P mg/1
Filter Feed Ortho P mg/1
Final Ortho P mg/1
Final Oil mg/1
Raw Phenol ppb
Final Phenol ppb
10
11
12
13
1U
15A
15B
16
6/5
6/25
8
1.1U
0
187
108
39
68.5
1.53
16.0
1170
1.50
511
165
7.0
51k
U.32
37
7.0
5P
•c
3-0
2.6
2.U
2.2
U32
86
7/1
7/31
12
1.72
0
161
109
37
103-5
1.79
16.0
1170
1.50
3^3
195
7.0
51U
U.32
Ult
5.8
U.9
3~2
2.2
2.0
1-9
7.7
U75
68
7/26
8/8
1U
2.00
0
lUg
126
U2
lUO.O
1.58
31.0
2300
0.80
388
199
12.8
900
2.36
77
5.2
L f.
t . o
3.1
2.2
2.1
2.0
8.6
uio
10U
8/9
8/22
22.6
3.22
0
181
159
57
28U.O
1.60
37.6
2700
0.67
338
25U
13-9
1060
2.18
101
U.9
U.O
2.0
2.1
2.0
23.3
231
102
8/23
9/12
15
2U.2
3.U6
0
213
159
80
3OU.O
2.U3
37.0
2700
0.67
U03
386
13-5
1000
2.2U
151
7.3
U.8
3-1
1-5
1.7
UU.5
353
155
9/13
10/3
15
1U
2.00
0
183
_ 175
83
19U.O
2.05
32.0
2UOO
0.75
380
359
13.0
950
2.32
162
7.3
It. 6
2.7
1.0
1.0
3U.2
369
130
10/U
10/17
15
7
1.00
0
169
136
U2
75.3
2.8U
29.0
2020
0.85
U91
385
7.0
51U
U.32
8U
6.9
1.9
2.3
0.9
0.5
17.2
365
98
10/18
10/31
15
7
1.00
0
205
1U7
Ul
81.5
2.37
30.2
226O
0.79
505
3Ug
5.0
368
6.05
59
8.6
2.1
2.9
0.6
0.5
15.6
362
13U
11/2
11/11
15
8
1.1U
0
206
1U2
U2
90.2
1.38
31.7
2350
0.78
629
295
7.0
51U
U.32
61
8.2
7 f,
f • O
1-9
2.8
0.5
O.U
8.U
U52
102
11/12
11/26
15
0.3
8
1.1U
0
195
105
35
65.8
1.58
31.7
2350
0.78
57U
166
7.0
51U
U.32
52
10.3
• C' C
?• J
2.2
2.8
0.7
O.U
1U.8
U5U
79
11/27
12/16
15
0.3
1U
2.00
0
22U
120
5U
133.0
1.37
31.7
2350
0.78
Uio
165
7.0
51U
U.32
8U
9.5
5 «7
• f
3-1
2.U
0.8
0-9
21.6
U06
95
12/17
12/31
15
0.3
21.6
3.08
0
209
135
69
231.0
1.U5
31-7
2350
0.78
5U5
196
11.2
790
2.70
100
7.0
e O
P .O
3-0
1-9
0.7
O.U
19.0
U66
136
1/2
1/13
15
0.3
20.5
2.gu
0
15U
120
65
195-0
1.30
33-2
2U60
0.75
301
1U7
9-0
635
3-36
83
8.3
f. Q
O . O
u.u
2.5
1.6
1.2
21. U
U92
267
1/lU
2/3
15
0^3
10.2
1.U6
0
1U7
103
Ug
83.0
1.52
21.1
1560
1.18
298
156
7.9
557
3.8U
U5
7-3
51
. J-
2.0
1-3
0.5
0.5
9-9
286
93
2/3
2/28
15
0.3
30
10.3
l.U?
0
196
95
55
79-0
1.15
22.7
1580
1.08
U35
110
8.8
650
3-30
62
9-3
3Q
. y
2.1
1.3
0.7
0.5
10.6
Ull
99
3/1
3/26
15
0.3
30
11.3
1.62
0
19U
121
55
108.0
1.16
27.3
1900
0.90
U37
8.3
610
3-50
70
10.9
5-7
• (
3.6
1.1
1.2
0.9
18. U
U55
135
3/27
U/19
15
0.3
30
20
2.86
0
155
70
37
111.0
1.U5
29.3
20UO
0.8U
3UU
101
8.U
620
3.U6
52
8.1
3>7
- 1
2.7
0.9
0.9
0.8
16.3
252
7U
-------
BIBLIOGRAPHIC: Detroit Metro Water Department. Development
of Phosphate Removal Processes. FWQA Publication No. ORD-
17010FAH07/70, July 1970
ABSTRACT: The development and demonstration of phosphate re-
moval facilities at Detroit using an activated sludge process and
steel pickling liquor are reported. The report is based on the
data from over 50 experiments performed over a period of a-
bout twenty months on a 200 gpm (max.) test facility at the
Detroit Regional Wastewater Plant. The major processes tested
included chemical pre-treatment, activated sludge, pisstic-media
trickling filter tower and deep tank aeration. It was concluded
that the full scale plant at Detroit should be designed for the
activated sludge process, with deep tank aeration, and that the
processes be arranged to accommodate both the conventional
and step feed process variations. Further provisions were to be
made for phosphate removal by injection of steel pickling liq-
uor into the plant influent.
ACCESSION NO:
KEY WORDS:
Phosphate-removal
Aeration
Activated Sludge I
I
BIBLIOGRAPHIC: Detroit Metro Water Department. Development
of Phosphate Removal Processes. FWQA Publication No. ORD-
17010FAH07/70, July 1970.
ABSTRACT: The development and demonstration of phosphate re-
moval facilities at Detroit using an activated sludge process and
steel pickling liquor are reported. The report is based on the
data from over 50 experiments performed over a period of a-
bout twenty months on a 200 gpm (max.) test facility at the
Detroit Regional Wastewater Plant. The major processes tested
included chemical pre-treatment, activated sludge, plastic-media
trickling filter tower and deep tank aeration. It was concluded
that the full scale plant at Detroit should be designed for the
activated sludge process, with deep tank aeration, and that the
processes be arranged to accommodate both the conventional
and step feed process variations. Further provisions were to be
made for phosphate removal by injection of steel pickling liq-
uor into the plant influent.
ACCESSION NO:
KEY WORDS:
Phosphate-removal
Activated Sludge
Aeration
BIBLIOGRAPHIC: Detroit Metro Water Department. Development
of Phosphate Removal Processes. FWQA Publication No. ORD-
17010FAH07/70, July 1970.
ABSTRACT: The development and demonstration of phosphate re-
moval facilities at Detroit using an activated sludge process and
steel pickling liquor are reported. The report is based on the
data from over 50 experiments performed over a period of a-
bout twenty months on a 200 gpm (max.) test facility at the
Detroit Regional Wastewater Plant. The major processes tested
included chemical pre-treatment, activated sludge, plastic-media
trickling filter tower and deep tank aeration. It was concluded
that the full scale plant at Detroit should be designed for the
activated sludge process, with deep tank aeration, and that the
processes be arranged to accommodate both the conventional
and step feed process variations. Further provisions were to be
made for phosphate removal by injection of steel pickling liq-
uor into the plant influent.
ACCESSION NO:
KEY WORDS:
Phosphate-removal
Activated Sludge
Aeration
-------
1
5
Accession Numbrr
~ Subjei-t Fn-M & G'oup
05D
SELECTED WATER RffiOURCES ABSTRACTS
INPUT TRANSACTION FORM
Organization
Detroit Metro Water Apartment, Detroit, Michigan
Title
prrpT*-. of Phosphate Removal Processes
10
22
^i I'ryject Designation
Program No. 17010FAH
J!1J
/Vore
FV/QA Grant No. WPRD 51-01-6?
23
Descriptors (Staffed First)
^r.iosphate-removal, ^Activated Sludge, *Aeration, Nutrient Water Quality,
Tertiary treatment, Activated sludge
25
Identifiers (Starred First)
Detroit
27
Abstract
The development and demonstration of phosphate removal facilities at Detroit
using an activated sludge process and steel pickling liquor are reported. The
report is based on the data from over 50 experiments performed over a period
of about twenty months on a 200 gpm (max.) test facility at the Detroit
Regional Wastewater Plant. The major processes tested included chemical pre-
treatment, activated sludge, plastic-media trickling filter tower and deep
tank aeration. It was concluded that the full scale plant at Detroit should
be designed for the activated sludge process, with deep tank aeration, and that
the processes be arranged to accommodate both the conventional and step feed
process variations. Further provisions were to be made for phosphate removal
by injection of steel pickling liquor into the plant influent.
Abstractor
D. Suhre
Institution
Detroit Metro Water Department
WR;I02 (REV. JULY 1909)
WRSIC
SEND TO: WATER RESOURCES SCIENTIFIC INFORMATION CE1>
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. D. C 20240
• CPO: 1B8B-359-339
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