EPA 43Q/9-78-OG4
MCD-42
I TECHNICAL REPORT
UPGRADING TRICKLING FILTERS
BY
DONALD M. PIERCE
JULY 1978
PREPARED FOR
ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF WATER PROGRAM OPERATIONS
' WASHINGTON, D.C. 20460
-------
DISCLAIMER STATEMENT.
/
This report has been reviewed by the Environmental Protection Agency and
approved for publication. Approval does not signify that the contents
necessarily reflect the views and policies of the Environmental Protection
Agency, nor does mention of trade names or commercial products constitute
endorsement or recommendation for use. In this report there is no
attempt by EPA to evaluate the practices and methods reported.
NOTES
To order this publication, MCD-42, "Upgrading Trickling Filters,"
write to:
General Services Administration (8FFS)
Centralized Mailing Lists Services
Building 41, Denver Federal Center
Denver, Colorado 80225
Please indicate the MCD number and title of publication.
Multiple copies maybe purchased from:
National Technical Information Service
Springfield, Virginia 22151
-------
FOREWORD
In 1972, Congress set into motion a comprehensive program to restore
and maintain the Nation's rivers and lakes by passage of amendments to
the Federal Water Pollution Control Act. The recent Clean Water Act of
1977 reaffirmed this commitment by adopting additional amendments which
strengthened a number of the provisions of the law. -
A major element of the country's clean water strategy is to improve
the^quality of the effluent discharged from municipal wastewater treatment
works. Federal funds for the construction of municipal wastewater
treatment works provide the cornerstone on which the municipal program
is built. With the availability of large amounts of Federal grant
funds,.there may be .a, tendency to .choos.e capital intensive and more
. -,-,-; ,i r_'•-•*-"-(• *? '"- ,-!•». t«u .< s •...»••'! tSIN'lvi Vi • ; -fcr' •« Jt*cir •"• r~;t' /I- r,Y •.<•-«; , •'•-V*'-', ; " • ."* "•'-'• :~
complex newer technology. 'This is not to say that such "technologies •"
will ,npt be needed to cost-effectively achieve many of our objectives.
However, certain "tried and true" systems such as trickling filters can
also pi ay,,an important role in these efforts.
Trickling filters offer advantages of lower energy needs and
relative ease of operation. This report presents operating results from
more than 100 existing trickling filter treatment plants and makes some
general observations concerning the overall successful performance of
these systems. While the report does not pretend to be a complete
analysis of these types of systems, it does indicate that, when properly
designed, constructed and operated, trickling filters are an alternative
which is worthy of further consideration in meeting the discharge
requirements of the law. The basic thrust of the report is that trickling
filters, often in^combination with other treatment techniques, should be
considered for new facilities as well as for continued use in plants
where they presently exist.
It is only by.making full use of all of the .available alternatives
that we will be able to ensure that the best solutions to our pollution
problems are found. We are confident that trickling filters can continue
to provide an important contribution to our Nation's.water pollution
control efforts.
m
-------
CONTENTS
Foreword iii
Figures vi
Tables vii
Findings of Fact and Conclusions 1-3
Background 4-b
Need for Extensive Field Studies 5-6
An Overview of 104 Plants
Selection Criteria 7
Plants Selected 7-9
Study Methods 10
Data Recorded and Analyzed . 10-11
Single-Stage Filters 11-12
Hydraulic Filter Loading Rates 12
Organic Filter Loading Rates 12-23
Relationship of Population to Removal of BOD . . 23-24
Effects of Raw Wastewater Temperature on
Plant Performance 24-25
Effect of Surface Overflow Rates in
Final Settling Tanks 25
Effect of Sludge Handling Practices on
Filter Performance 25-28
Upgrading with A Second-Stage Filter
Hydraulic Filter Loading Rates 29
Organic Filter Loading Rates 29
Comparison: Single-Stage y_s_ Two-Stage 29-36
Observations and Conclusions 36-37
Upgrading with Chemical Treatment
Facilities for Chemical Treatment 38
Chemicals Used 38-39
Phosphorus Removal 39
Removal of BOD5 and Suspended Solids 39-41
Relationship Between Filter.Media and
Performance 41
Relationship Between Recirculation and
Performance ' 41-48
Observations and Conclusions . 48-49
Upgrading with Additional Treatment Works
Mixed Media Gravity Filters 50-51
Gravity Sand Filters - Mechanically
Backwashed 51-52
Intermittent Sand Filters 52
Pressure Mixed Media Filters 52-53
-------
CONTENTS (continued)
Summary of Fine Media Filter Performance .
Stabilization or Oxidation Ponds
Aerated and Short-Term Stabilization Ponds
Long-Verm Stabilization Ponds ......
Activated Sludge ............ .;.
Observations and Conclusions .......
53
54
54
54-58
58
59
Acknowledgements . . ........ . .... . . . 60
Appendix •
.:". Table
of Contents
61
a/i-a/iii
-------
FIGURES
Number
Paqe
Single-Stage Filters
1 Removal of BOD - Relationship to Hydraulic Loading . . 16
2 Effect of Recirculation on Removal of BOD 17
3 Removal of Suspended Solids - Relationship to
Hydraulic Loading . 18
4 Removal of BOD - Relationship to BOD Loading 19
5 Removal of Suspended Solids - Relationship to
Organic Loading 20
6 Relationship of Population to Removal of BOD 22
Two-Stage Filters
7 Removal of BOD - Relationship to Hydraulic Loading . . 31
8 Removal of BOD - Relationship to BOD Loading 31
9 Comparison of Single-Stage vs_ Two-Stage in Removal
of BOD 33
10 Comparison of Single-Stage vs^Two-Stage in Removal
of Suspended Solids 34
Upgrading with Chemical Treatment
11 Probability Plot - Showing Comparison of BOD Removal
with vs_ without Chemical Treatment - Single-Stage
Filters .44
12 Probability Plot - Showing Comparison of Suspended
Solids Removal with vs_ without Chemical Treatment -
Single-Stage Filters 45
13 Probability Plot - Showing Comparison of BOD Removal
with vs_ without Chemical Treatment - Two-Stage
Filters 46
VI
-------
TABLES
Number
1A
IB
1C
Removal of BOD and Suspended Solids by Single-Stage
Filters (69 plants) . . . . .... , . .
Removal of BOD and Suspended Solids by Two-Stage
Filters (20 plants) . . . ... ... . . . . .
Removal of BOD and Suspended Solids with Chemical
Treatment (14 plants) . . ...... . . . . .
Single-Stage Filters
2
3
4
5
6
7
8
9
Effect of Hydraulic Loading on Removal of BOD ; . . .
Effect of Hydraulic Loading on Removal of Suspended
Solids . . .
Effect of Organic Loading on Removal of BOD
Effect of Organic Loading on Removal of Suspended
-Solids ... . . . ... . . . . . . . . . . .... . . .
Removal of BOD and Suspended Solids without Chemical
Treatment .
Relationship of Population to Removal of BOD - Single
and Two-Stage Filters
Relationship "of Raw Wastewater Temperature to Removal
of BOD and Suspended Solids -- Cold Climates . . .
Relationship of Surface Overflow Rates to Removal
of BOD and Suspended Solids . ... . . . . . . . .
Upgrading with a Secondary Filter
10
11
12
13
Effect of Hydraulic Loading on Removal of BOD
Effect of Organic Loading on Removal of BOD. .
Effect of Hydraulic Loading on Removal of Suspended
"Sol/ids . . , .'. ............ . . ••'- • • •
Effect of Organic Loading on Removal of Suspended
Solids . .
13
14
15
17
18
19
20
21
23
26
27
30
30
30
30
-------
TABLES (continued)
Number
Page
14 Distribution of Values - BOD and Suspended Solids -
Single-Stage 32
15 Distribution of Values - BOD and Suspended Solids -
Two-Stage 32
16 Comparison of BOD Removal - Single-Stage vs Two-Stage
at 3 Typical Plants 35
17 Comparison of BOD Removal - Single-Stage vs Two-Stage -
All Plants ~ 35
Upgrading with Chemical Treatment
18 Removal of BOD and Suspended Solids , . . 40
19 Comparison of BOD and Suspended Solids Removal
Before and After Chemical Additions at 6 Plants . . . 42
20 Comparison of Removal of BOD and Suspended Solids by
Primary Sedimentation - with y_s^ without Chemical
Treatment 43
21 Effect of Chemical Treatment on Removal of BOD and ;
Suspended Solids - Single-Stage Filters 47
Upgrading with Additional Treatment Works
22 Improvement in Trickling Filter Effluent by Fine Media
Filters 53
23 Removal of BOD by Trickling Filters and Stabilization
Ponds - 121 North Dakota 56
24 Performance of Trickling Filters and Stabilization
Ponds - 160 Mich 56
25 Removal of BOD and .Suspended Solids by Trickling Filters
and Activated Sludge - 403 Minn 57
26 Removal of BOD and Suspended Solids by Trickling Filters
and Activated Sludge - 402 Minn 57
27 Removal of BOD and Suspended Solids by Trickling Filters
and Activated Sludge (6 Plants in Minnesota) .... 58
28 Upgrading Trickling Filters by Additional Treatment
Processes 59
-------
UPGRADING TRICKLING FILTERS -
- A STUDY OF OVER 100 PLANTS
t>y
. Donald M. Pierce
Findinqs of Fact and Conclusions
The following findings resulted from examination of records of
operation, plant visitations and discussions with operating staffs of
trickling filter plants in Minnesota, Michigan, Pennsylvania, Wisconsin
and North Dakota. A total of 104 plants were selected for study on the
basis of completeness and duration of operational records and the excellent
balance they provided in size of installation, variety of facilities,
and operational modes including sludge treatment and disposal. Plants
providing further treatment of the trickling filter plant effluent were
selected as representative of.the processes employed both in facility
and performance under typical operating conditions.
1. Process Capability
- Trickling filter plants in their simplest combination of unit
processes for grit removal, screening, sedimentation, filters
and sludge treatment and disposal are capable of a high degree
of' treatment when given ordinary and reasonable attention.,
-?Sirigle-stage filter plants are capable of 90% removal of BOD.
and suspended solids from the raw wastewater but may remove as
little as 60%. Statistically, for the 69 plants studied, the
most probable values.of plant effluent are 36 mg/1 BOD. with
83% overall removal and 32 mg/1 suspended solids representing
84% overall removal. There is 90% probability that BOD and
suspended solids removal will not be less than 74%.
- Removal of BOD. at two-stage filter plants is significantly
higher than at single-stage plants. The most probable value
from 20 plants studied was close to 90% removal and 25 mg/1.
:- Removal of suspended solids at two-stage trickling filter
-" plants is at about the same level as at single-stage plants.
^•-Many single-stage and two-stage plants can be loaded much
higher, both hydraulically and organically, without reduction
of effluent quality.
-------
2. Factors Affecting Performance
Loading Rates - Hydraulic and organic loadings at the 76
plants for which adequate information was available indicate
that the degree of removals of BOD,- and suspended solids
appeared to be relatively independent of the magnitude of the
loadings within the ranges studied for both single and two-
stage filter systems. Hydraulic loadings generally ranged
from 100-320 gal/day/ft2 (5-15 MGAD) for single-stage plants.
Slightly higher loadings were typically observed for two-stage
filter systems although some were significantly higher. BOD,,
loadings for both types of systems were usually in the 10-60
lbs/100 ft3 range, although some values were much higher.
Low Temperatures - Relatively low raw wastewater temperatures
during winter generally reduced overall plant removal of BOD
by about 1/3 at 9 plants studied. These adverse effects can
be reduced by providing protection such as housing, windbreaks,
reduction in settling tank detention time and reduced recircu-
lation to reduce heat loss.
Recirculation - No observable relationship was found between
quantity of flow recirculated to the filters and extent of
removal of BOD5 or suspended solids. Plants with no recirculation
or very low rates of recirculation appeared to perform as well
as those with recirculation of up to three times the raw
wastewater flow.
Size - Small plants serving a few hundred people were observed
to operate as effectively, as measured by BODf. and suspended
solids removal, as similar plants serving several thousand.
Type of Trickling Filter Media - Rock media and plastic
media were observed to provide similar levels of treatment for
equal loadings per unit volume of media.
Clarifier Overflow Rates - Detailed information on 23 plants
where reliable data were available indicated similar BOD and
suspended solids removal at plants with final clarifier overflow
rates of 1000 gpd/ft2 and higher compared with plants with
rates of 500 gpd/ft2 or lower. This was observed at both
single-stage and two-stage filters and those where chemical
treatment was provided.
3. Upgrading by Series Operation
- Conversion from a single-stage to a two-stage system without
adding filter media can greatly improve effluent quality, as
measured by BODg -- usually by about 50%.
-------
4. Upgrading with Chemicals
- Chemicals applied prior to primary sedimentation increased
removal of 800. and suspended solids from raw sewage to
clarifier effluent by 34% to 59% and increased suspended
solids removal by 51% to 71%. This greatly reduces loadings
on filters and final settling tanks.
- Chemical treatment with metal salts and polymers (intended
primarily for removal of phosphorus) upgraded single-stage
filter system effluents from an average concentration of 36
mg/1 BODj- to 21 mg/1. Similarly effluent suspended solids
were reduced from 32 mg/1 to 19 mg/1. Similar performance was
. found with lime.
^ ••=.-- The adverse effects of extremely cold sewage and air tempera-
tures on removal of BOD and suspended solids are less at
plants where chemicals are used.
-.Although chemical treatment with metal salts and polymers
greatly increases the solids loadings on sludge digestion and
dewatering facilities, additional or modified solids processing
facilities were not needed at the plants studied. Increased
quantities of digester supernatant and vacuum filter filtrate
are treated with the raw sewage with no particular difficulty
observed.
- Physical alterations for the storage, application and mixing
of chemicals and polymers are quite simple and can be provided
at a reasonable cost.
- The cost of chemicals is not prohibitively expensive.
5... Upgrading with Supplementary Processes
.- Fine media filters: Several typical installations of fine
media filters were studied. The types of filters were mixed
media pressure filters with backwash; fine mixed media gravity
filters with backwash; sand gravity filters with backwash; and
gravity feed intermittent sand filters with underdrains. Each
type of installation markedly upgraded the quality of the
trickling filter effluent. All of the gravity systems produced
effluents less than 10 mg/1 BOD5 and suspended solids.
- Ponds: Hastewater treatment ponds'are quite commonly used for
upgrading trickling filter effluent. Three typical installations
were studied. 'Single-stage filter plant effluents were upgraded
,'-jjc-n to about 95% BOD,- removal. There are strong indications that
ammonia nitrogen was almost completely removed.
-------
- Operational Considerations: Fine media filter systems and
lagoons are relatively easy to control and simple to operate
effectively.
- Activated Sludge: Performance of six plants using activated
. sludge to upgrade trickling filters was studied. Removal of
BOD5 averaged 95% and suspended solids 93%.
6. Selection of Upgrading Techniques
Trickling filters can readily be supplemented by treatment
processes such as fine media filtration, ponds and activated
sludge to produce high quality effluents. These processes,
together with conversion of single-stage to two-stage filters
and/or chemical treatment provide the designer with great
flexibility for upgrading existing trickling filter plants to
the desired performance level or to design new trickling
filter systems for a wide range of specific conditions and
requirements.
BACKGROUND
The purpose of this report is to present information on various
current trickling filter operations which indicates that these systems
are successfully operated, and in many cases, can be economically
upgraded to meet the requirements of the Federal Water Pollution Control
Act Amendments of 1972.
For over 40 years, the trickling filter has been widely recognized
in this country and abroad as a dependable, reliable biological treatment
process, well suited to the needs of small to medium^size communities.
In recent years, the use of this once popular system has diminished in
comparison to other biological and physical processes. The waste
stabilization lagoon proliferated greatly during the fifties and sixties
in small communities and activated sludge in its several modes became
quite generally the process of choice in medium to Targe municipal
installations.
Decreased popularity of the trickling filter has been attributable
principally to the well recognized failure and real inability of some
existing installations to produce the high quality of effluent now
required to meet the national water quality goals. Moreover, there
seems to be a wide diversity of opinion in the field and laboratory as
to parameters for design and operation to produce specified effluent
quality within the entire range of performance of which the process is
capable. Designers, public works officials, and regulatory agency
personnel alike, are often hesitant to seriously consider trickling
filters because of a lack of confidence in precise design criteria.
-------
Several critical evaluations in the available technical literature
on trickling filters confirm this observation. In the comprehensive
Literature Search and Critical Analysis of Biological Trickling Filter
Studies (EPA Project No. 170 50 DDY), summarizing the essence of 5665
references, the authors observe that it is well documented that there
is no well defined theory of design and operation generally accepted by
the principal investigators in the field. Examples,,noted are controversy
over the effects of recirculation rates and points of recirculation,
performance relationships with variations in hydraulic and organic
loadings, types of media, depths of media, single stage vs^ two-stage
operation, with or without intermediate settling, capability to treat
specified industrial wastes and still other considerations. The authors
confirm the finding of others that a great many investigators have
developed mathematical models for predicting performance with signifi-
cant-differences in factors included and in the performance predicted
under similar conditions.. It was observed that in-depth mathematical
'investigations have the'tendency of losing their,usefulness to the non-
mathematicany oriented practioner, and it is very unfortunate that
these valuable studies have not been correlated with the vast operator
experience available. It is further noted that engineers place more
confidence on field or full-scale investigations and relationships
derived therefrom than from laboratory data, with the recognized limi-
tations of uncontrollable environmental conditions, variable waste
sources, and problems in sampling, analyzing and interpreting the data.
On the positive side, the trickling filter is credited with a
degree of reliability in performance, recovery capability from shock
Toads, durability of process elements and relatively low,power require-
ments not characteristic of activated sludge and other competing processes.
And, very importantly, for small and medium size communities, the level
of skill,and technical know-how and size of operating staff required for
continuously effective management and operation of the process .is generally
considerably less for trickling filters than, for, activated sludge and
certain physical/chemical processes.
"Reliable estimates" set the number of municipal trickling filter
installations in this country today at about 4000. The. report indicates
that many of these trickling filter systems are successfully providing
secondary and higher levels of treatment. It must be recognized, however,
that a portion of.these installations do not meet current requirements
for effluent quality based on 30 nig/1 of BODg and suspended solids and
that some discharge to waters to which stringent water quality standards
apply. : ' ' , !' .
."•••• '.!.-. .,.'•.•"? NEED FOR EXTENSIVE FIELD STUDIES : ••/.'.
There is a need to assess the capability of,the trickling .filter
process in all of its customary flow patterns and ranges of loadings by
a'.close and thorough examination of a sufficient number of full scale
field installations to accurately evaluate their performance. It is
particularly important today to identify methods by which existing
-------
installations have been or can be modified in a 'cost-effective manner to
produce higher quality effluents and to determine the extent of predictable
improvement by such methods. Recognition of these needs prompted the
undertaking of this study.
Review of the technical literature and study of the comprehensive
Search and Critical Analysis of Biological Filter Studies, Vols. 1 and
2, reveal a surprising paucity of long period operational data with
pertinent design features. Practically, there is not sufficient information
from these sources to enable the reader to relate loadings and operational
modes and methods with predictable performance. This is not to say that
such information does not exist. Indeed, operators of trickling filter
plants at hundreds of municipal installations have recorded vital data
and valuable observations routinely. Some state regulatory agencies
have required monthly submission of such key information as temperature,
flow, BOD, suspended solids, volatile suspended solids, pH, recirculation
rates, quantity and quality (moisture and volatile content) of sludge
pumped, and pertinent information on digested sludge and supernatant.
In addition, notes on operational and maintenance problems and practices
are also available in many cases. Unfortunately, much of this highly
valuable information is stored without abstracting, analyzing and
keeping key data and other facts for the future use of the municipality,
their designers and others concerned with its practical application
Unusual performance, either on the high or low side, often continues
with little appreciation of the peculiar circumstances responsible for
its departure from what is considered to be normal. Only occasionally
is a case history recorded in the literature which includes in-depth
performance studies. Such articles usually pertain to an installation
where either an unusual or unique problem is identified, a specific
industrial waste is treated or a specific design feature is highlighted.
Seldom are the data reported of sufficient duration or confirmed by
other similar installations and operational procedures to establish its
predictable performance elsewhere. Quite commonly, the data is reported
to confirm or support research studies conducted on laboratory or pilot
plant scale. r
The obvious need, therefore, was to collect performance data produced
and recorded by plant operators at a sufficient number of installations
representative of what exists in municipal installations today, to
establish the performance capability of the process in a wide range of
facility combinations, loadings and operational modes. An equally
important objective was to make in-depth studies at several plants with
special design features or operational methods which illustrate methods
for upgrading the quality of the effluent at existing installations
-------
•:. •'.-- AN OVERVIEW OF 104 PLANTS ,-..,..-
• A broad overall study was made of 104 plants in four northern
states which included in-depth studies at 28 of these.
Selection Criteria . : ^
. For the .broad'overall study, the following criteria were established
and fpllowed: .
"1. Location - a northern state or states having wide seasonal
- variations.in both air and sewage temperatures.,
,' 2. Study ajj_ municipal trickling filter plants in the, selected
_..-..'-", ..0., rltate or states for which •desired data are available - not a
-'•-<••'-•* -• "b lYl'ustra te a ^principle, ar, method.;
,,3v;Study of'typical plants in other states having-more moderate
climate., -..-•-*
For the in-depth studies, plants were to be selected where: , .
:'.'..' K Operational "data,, including laboratory analyses are known to be
' -,, dependable and to be developed and recorded by well-qualified
operators and technicians*
,r 2. / Facilities an
-------
filter without recirculation to installations with several primary
settling tanks, two or more filters with rotary distributors and two or
more final settling tanks. Several methods of recirculation are employed
at various rates. Loadings, hydraulic and organic, range from very low
to very high but mostly they are in the moderate range. Media, usually
rock but also including tile and some other materials, are of varying
shapes, sizes and degrees of uniformity.
Wastewater characteristics are quite representative of the typical
range of municipal wastes applied to trickling filters. In some communities,
the wastes are very dilute as a result of considerable infiltration and
inflow to the sewer system; others are above normal in strength as
measured by BOD,- and suspended solids, reflecting admixtures of wastes
from milk and cneese processing plants, canneries, slaughter houses and
meat packing facilities.
Operating staffs are quite typical with respect to experience,
capability and motivation. A sound practical training program, in
conjunction with an operator certification program, has been conducted
for many years by the Minnesota Pollution Control Agency and its pre-
decessor agencies. This and a close relationship between the Agency
district personnel and the operators has encouraged and fostered good
operational practice. It is to be noted, however, that a large percentage
of the small municipalities contract with commercial laboratories to
perform chemical and bacteriological tests. These data are submitted to
the Agency in addition to other physical and operational data assembled
by the plant operating staff.
The 1973 Annual Summary of Trickling Filter Study Results prepared
by the Minnesota Water Pollution Control Agency lists 163 municipal
plants. Data are provided on year of construction, annual averages for
design and actual flow, and BOD5, total coliform, fecal coliform, total
phosphorus and Kjeldahl NitrogeH for both the plant influent and effluent.
These annual summaries are based on monthly averages abstracted by their
staff personnel from operational reports submitted by the municipalities
and supplemented by Agency field sampling and analyses.
As the study of Minnesota plants progressed, it was found that a
large number of plants did not have sufficient data to permit the depth
of analysis desired. Many plants had incomplete flow data, or none at
all, for the year studied. At others, laboratory data were lacking for
several months. Quite a large number of these trickling filters were
followed by activated sludge, sand filters or stabilization ponds. In
these cases, the data were for the final effluent rather than the trickling
filter effluent. These plants were not used in this study but a11
others with sufficiently complete operating data were included as recorded
in Table 1.
-------
Typical pi ants in Mi chigan and Pennsylvania were selected for
comparison of performance with"the Minnesota plants. A few scattered
.installations in North Dakota and Wisconsin selected for in-depth study
are also included in this tabulation. ,
Plants selected initially for in-depth study were located in Michigan.
Design data and monthly operation reports were made available and personal
contacts with agency personnel and plant operating staffs provided a
depth of knowledge and interpretation.most valuable to an objective and
realistic evaluation of performance in relation to facility and management
techniques; :
». " . . , • . . -. . • " . • - •".'''
All of the Michigan plants were under the control of resident
operators certified as to competency by the State Agency. Operational
programs w§re* Adequate and staffs were observed to be capable and industrious,
Laboratoy analyses were generally performed several times weekly on
composited samples by well-tr.ajned plant technicians. In some plants
these analyses were performed daily. This provided an excellent opportunity
to observe day to day results and trends and to note cause and effect
.relationships of loadings, operational modes, temperature variations and
other variables.
~ Of the 22 Michigan plants studied, 14 have routinely applied chemicals
- and polymers for removal of phosphorus for at least one year .under a
"program requiring removal of at least 80% total phosphorus. Of those
-with chemical "treatment, nine use rock media and five use plastic sheets.
At six of these plants, laboratory data were available for a substantial
period before chemical additions began and for over a year after .chemical
treatment became well established. This provided an excellent opportunity
to evaluate the effect of chemical treatment as here employed on removal
of BOD,- and suspended solids.
0 = .- . . - -. - - - ••-'--•;-..
- • It was also considered desirable to study the extent of ^improvement
in BODC and suspended solids by the Second filter "and its settling tank
"in a two-stage system. Only one installation in Michigan had the necessary
information. -However, one additional'plant in both Wisconsin and Minnesota
was found to have this kind of data. Each of the three were .considered ,
to be representative of the process and generally Similar to 19 other
two-stage plants listed in Table 1, where data on the first stage portion
were lacking. This provided a good opportunity to assess the improvement
to be expected in series compared with parallel operation. r
- Plants were sought which utilize additional treatment processes to
improve the quality of effluent of the trickling filter and its final
settling tank. Although many facilities of this kind were located, only
eight routinely.sample the settling tank effluent following the .trickling
filter when the additional treatment facilities are in operation. Good
reliable data were obtained from each of these eight plants. Four of
the eight Use sand or mixed media filters, two use ponds, one uses an
aerated lagoon followed by ponds and one uses activated sludge. An
opportunity was afforded to compare overall plant removal at these
locations with several others using similar facilities but lacking the
trickling filter effluent data. - .
-------
Study Methods
st*tp US6d 1n-,the study was obtained from the responsible
state regulatory agency or plant superintendant or both. Physical data
such as number and capacities of treatment units and their arrangement
FrPn^n^ally o^1"6*?™ the state agency which. approved th7des?gn.
Frequently specify additional information of this kind was also obtained
directly from the plant personnel. Performance data were ?urn shed In
rpnnrtf nanCh%by *he/e9ul^ory agency in the form of month?? opIraJlon
coEpShv aCtS/r-m-them- Many of the Plant superintendents were
contacted by personal visit at the plant, telephone or letter to obtain
useful
o
and a degree of understanding not otherwise obtainable
Data Recorded and Analyzed
All vc PJantS s*1ected for study ^e summarized in Table 1*
All values represent annual means of monthly mean values Terms used in
headings have the following meaning: vo.ues. terms used in
P°P: P0?"13^1? b* I970 ^nsus of the community
heewer system6553" y 1ndlcative of the Population connected to
hofn F1°w-MGD: The average rate of raw sewage flow
before additions of recycled flows within the plant.
nnfi " Kf (B°D5 and Suspended Solids): Wastewater in plant
inflow before anj? in-plant additions.
- PE: Effluent from the primary settling tank. Actual
values unless indicated by an asterisk (*). Asterisk denotes
assumed value of 35% removal compared to raw wastewater.
Eff1uent from the settling tank following trickling
where Q2 is total flow through
filters
- Filter Loading: R =
the filter and Q is raw sewage flow.
- MGAD: Million gallons per acre of media per day.
Plus 6 plants with activated sludge for additional treatment (Table 28)
10
-------
Since data were not readily available at many of the plants on the
quality of effluent from the primary settling tank(s), as measured by
BODf-, these values at such plants were calculated on the basis of 35%
removal of the raw wastes entering the plant. It will be noted from
Table 20 that removal at 16 plants for which extensive data were analyzed
ranged from 18% - 51% with a mean.value of 34%.
For all plants where in-depth studies were made, the monthly mean
values for 12 months or longer were abstracted and calculated from plant
operation reports". Summary data was recorded by month for quantity of
flow (MGD), raw sewage temperature ( F), BOD5 and suspended solids in
plant influent (raw), primary settling tank effluent (PE), final settling
tank effluent following the trickling filters (FE). Where chemicals are
applied for removal of phosphorus,'pertinent information on rates of
chemical feed and the concentration of total phosphorus in plant influent
and plant effluent-is indicated when available. In the appendix, data
sheets have -been prepared to provide information on flow patterns,
loading fates "and"capacTtires^6f various units, including filters, final
settling tanks and sludge digesters. Methods of sludge management of
digested sludge, digester supernatant and vacuum filter filtrate are
also indicated.
Data are inspected to compare hydraulic and organic loadings and
removal of BOD. and suspended solids; effects of recirculation on plant
performance; comparisons of single-stage with two-stage filters in
overall performance throughout the range of loadings experienced;
effects of variations in temperature of the raw sewage; comparison of
performance of filters"'with rock'media vs. plastic media;.effects of
chemical additions (usually iron or aluminum salts and polymers for the
primary purpose of removing phosphorus) on removal of BOD5 and suspended
solids; effects of various methods of sludge treatment and ,disposition
on removal of BODr and suspended solids; and the extent of improvement
provided in plant effluent quality by several additional treatment
processes following trickling filters.
Data are summarized also on facilities used and the dosage rates of
chemicals, with some indications of the pertinent costs.
Patterns in performance are visible'in the summary data derived
from these studies of trickling filter plants. These patterns are
considered categorically as single-stage and two-stage filters, with
some comparison of effects of hydraulic and organic loadings and effects
of chemical treatment. Several methods of upgrading are examined.
These include conversion of single-stage to two-stage alignment, addition
of metal salts and polymers and several processes for further treatment
of trickling filter plant effluents.
Single-stage Filters
The most common design of trickling plants at municipal installations
in operation today throughout this country utilizes single-stage filters.
Usually plant units consist of screening, grit removal, raw sewage
11
-------
pumping, sedimentation, one or two trickling filters operated in parallel
a final settling tank and the plant outfall sewer. The effluent may or '
may not be disinfected. Sludge from the settling tanks is most commonly
pumped to heated sludge digestion tanks, often followed by unheated
sludge digestion or storage tanks. Digester supernatant is most commonly
discharged to the raw sewage before primary sedimentation. Digested
sludge is commonly discharged periodically to open sludge drying beds
but at some locations is discharged to sludge lagoons or hauled to land
application areas, usually for agricultural purposes. In some of the
larger plants, vacuum filters are used for sludge dewatering before
final disposition. A few installations have Imhoff tanks for sedi-
mentation and sludge digestion, obviating the need for cyclinq super-
natant through the plant.
Hydraulic Filter Loading Rates
Hydraulic loadings reported in Table 1 represent average daily
rates of flow in MGAD and in gpd/ft2 (annual average of monthly values)
Recirculated flow is noted under column R. No attempt was made, except
where specifically noted, to determine instantaneous pumping rates or
the capacity of the pumps most commonly in service.
^ t. Iablf.2 shows the ra"9e of Mraulic loading and the relationship
of hydraulic loading to removal of BOD. for the 61 plants studied
These data are plotted in Fig. 1. No Sbservable difference is found
either in the concentration of BOD,- in the plant effluent or percent
removal thereof through these range's of hydraulic loadings. Although
most of these loadings are below 500 gpd/ft2 (13 MGAD of media), three
pf?inpnrRnS1S JaS?e- ,?ne i'o^ h1gh as 163° 9Pd/ft2 <71 MGA°) W1'th an
effluent BODg of 37 mg/1 and 80% removal. Visual examination of the
recirculatioh1 ratios in Table 1 and Fig. 2 in terms of BOD removal does
not reveal any observable differences in performance between systems
with no recirculation, recirculation ratios of 0.1 - 0.3 or those from
I • U "~ o » U •
Table 3 and Fig. 3 are plots of the hydraulic loadings vs. removal
of suspended so ids by the total plant in these same plants.™Effluent
concentrations (mg/1) of suspended solids and average removals thereof
by the entire plant compare quite closely with BOD,- values There is
some indication that removals may be somewhat less^when hydraulic rates
exceed 400_gpd/ft2 although there are not only a relatively small number
ot plants in this loading range on which this observation is based No
observable relationship between recirculation ratios and solids removals
is detectable from these data.
Organic Filter Loading Rates
monthll^val for BOD5 (m9/D again represent the annual average of
*i Ta.bleL4 and Fig\4 show a marked similarity in performance as
!infJ? y ^sJS) a?d Percent rem°val through the plant for all BOD
ih /iSnJJS96!' ;!tnou9h most of these P1a"ts have loadings under 60
lbs/1000ft3 of media, eight of the plants have loadings in the 61-140
Ibs range with no perceptible difference in BOD removal.
12
-------
"Calculated as
65% of raw
sewage strength
NR = No Record
TABLE 1A
REMOVAL OF BOD5 AND SUSPENDED SOLIDS
BY TRICKLING FILTERS
SINGLE STAGE
Mn Minnesota
Mi Michigan
' Pa.... Pennsylvania
' N.D North Dakota
Wi Wisconsin
MUNICIPALITY
State
101. Mn
102. Mn
103. Mn
104. Mn
105. Mn
106. Mn
107. Mi
108. Mn
109. Mn
110. Mi
111. Pa
112. Mi
113. Mn
114. Mn
115. Mn
116. Mn
117. Mn
118. Mn
119, Mn
120. Mn
121. N.D.
122. Mn
123. Pa
124. Mn
125. Mi -
126. Mn
127. Mn
128. Mn
129. Pa
130. Mn
131. Mn
132. Mi
133: Mn
134. Mn
1970
Pop.
711
1823
11,140
11,667
625
2467
391
1974
8244
5913
525
794
.1851
5797
1484
2252
588
1130
NR
939
7728
6439
. 1883
1382
NR
: 567
3142
6314
1162
7467
Sew.
Flow
MGD
0.11
NR.
1.02
0.46
2.10
0.04
1.07
0.53
NR
0.40
2.64
0.77
0.55
NR •
0.51
2.06
0.93
NR
0^25
0.03
5.86
0.14
0.36
0.17
1.28
0.99
0.20
NR
0,73
0.15
0.20
0.94
0.15
1.40
BOD5
Raw
mg/l
208 .
309
285
167
142
148
1 34
392
464
195
432
224
179
225
300
185
259
320
206
162
220
387
215
201
138
159
270
167
.152
258
270
104
431
187
PE
mg/l
*^I35
200
*185
*109
* 92
* 96
99
*255
*302
151
*280
119
*116
*146
*195
*120
*168
*208
*134
*105
*143
*251
*140'
*131
91
*103
*175
*109
* 99
*168
*176
65
*280
*122
FE
mg/l
22
42
59
27
26
38
42
34
31
33
41
63
31
75
40
37
40
25
27
31
56
42
12
31
32
16
52
58
22
29
51
•23
66
19
%
Rem.
PE-
FE
84
79 "
68
75
72
60
58
87
90
78
86
47
73
49
79
69
76
88
80
70
61
83
91
76
65
85
70
47
78
83
71
64
76
84
%
Rem.
Raw-
FE
89
86
79
84
82
74
69
91
93
83
91
72
83
67
87
80
85
92
87
81
75
89
94
85
77
90
81
65
86
89
81
77
85
90
SUSP. SOL.
Raw
mg/l
119
"164
NR'..
185
192
124
139
210
201
183
252
256
111
280
300
193
243
180
300
213
178
229
211
166
178
166
349
160
134
109
174
150
296
217
FE
mg/l
23 .
27
NR
31
40
23
41
21
35
22
45
59
21
61
34
47
37
53
33
31
47
28
10
20
38
17
44
62
21
17
55
21
43
14
%
Rem.
Raw-
FE
81 : ;
84
NR
83
79
81
71
90
83
88
82
77
81
78
89
76 :
85
71.
89
85
74
88
95
88
79
90
87
61
92
84
68
80
85
94
FILTER LOADING
Area
Acres
0.065
0.064
0.180
0.076
0.360
0.009
0.115
0,080
0.016
0.083
0.81 1
0.10
0.360
0.007
0.007
0.029
0.216
0.011
0.009
0.016
1.080
0.036
0.180
0.056
0.36
0.078
0.045
0.029
0.439
0.029
0.016
0.09
0.022
0.101
Vol.
1000
cu.ft,
22.6
17.0
47.1
26.5
125.6
2.5
30.2
23.2
4.2
21.8
185.6
26.5.
9.5
1.9'
2.5
7.5
71.4
9.8
2.3
4.2
422
9.5
51.0
14.7
94.3
20.5
13.7
10.0
114.7
7.5
; ' 5.7
22.8
7.9
26.5
R .
0-2 ,:
0.4
0.3
0
NR
1.0
1.2
2.1
1.0
1.3
NR
0.4
NR
0
0
0
0.5
1.0
0
0.1
1.0
NR
0
0
1.0
0.2
0
NR
0 "
0
0.3
NR'
0
MGAD
2.1
-NR
7.4
6!1
5.8
8.7
21.0
7.0
NR
10.0
3.3
7.6
21.2
. NR
7.3
71.0
4.6
: NR
55.3
1.6
4.6
7-7
2.0
'3.0
3.6
12.6
5.2
NR
1.7
5.2
12.2
13.5
6.8
13.9
Gals.
per
Day
per
sq.ft.
48
NR
170
140
133
200
482
161
NR
230
75
174
487
NR
168
1630
106
NR
127
37
106
177
46
69
83
289
119
NR
38
119
280
310
156
319
Lbs.
BOD
per
1000
cu.ft.
' 6
NR
36
16
13
13
29
49
NR
23
33
29
55
NR
33
275
18
NR
122
5
16
31
8
9
10
41
21
NR
5
28
51
22
45
54
-------
ra oj
Q O.CT
r~CNICMM-COCN«— OCNTUJCMCNr-OJCSJOr-.CMCNCNCN
CNooino.-wijro,--o
CNI CMi-CMCNCjZcMCN
QC
O O T- O O •— O
8*:
? 3
'— CNCN»—
oooocoococoocNf-^Trcocoirio'
to •— coco'3- v-cMt— r-- ^
r- i— iri t»j oi ci CN
n>- o «- o »-
oodooddddodddddddc>dc>dc>dddododddodod
3 LU
ro ^
oo CD oo in r- ^r oo to
*— CMOOIDCOO»—
or
QC
tit ui
Q. "-
CD-—
«— •<3-minininooocNoor-cDa)Ot-~^ocnoCTi<— COTCNOCSIOO
ID
0.
ncococnr—
T
to
CO
CC
COCNCOCMr— C^T-
g 1
w u.
§
'— inoron'S--—
•g
3
C
cp
o
en o
rO'a'incDocor-caomnoonO'— cor-->— •— CCT
ocNor^-CNnoooooroocM'— iTOoooTj-r— -~o
i~-«— oo«— cocDtDtoocooociO'3->— ^3-r^tncocD*:-in
'-•a-'- ^"'"'"cn'^Lo'*" tO'-'-0-«-tnr-n n
CO CM v- v- .
in
CN
oojoc'joo
^
CM
I
CCCC — CCCCCCCCCCCCCCC_C_CC — C.- — CC — CC —
irjtop~ooo50'—
13A
-------
ca
IT"
ui
al
Occ
can
fe>
O ca
• LU
cc
vt -. +5 O
5 ', I |
03 i 2- c
+J CO 4J n
JJ >- «> O
-3 *- QJ <£
o o at u •
— srt 03 "
g
s U!
',« cc
•"to-
1
* §
v= E
*
-9
&*•
84
"
-.- 8
if) o o C3 ra co i^ r~- co o o cc o cc
cMr-cDCDO^-oomcou)t-5'*-^
CMCMCMCM>- .«- CO CO ^ CM ^
ojcri«— T—
CCOO_CCO)_,,O_.O:CO«-DC_OOIO
0
^f od, K r^_«- <>i co oi CNJ. c5.
CM.p^ oincMO'cg-!g
ocM^t-o<-cqpqoc>l5coqco_pt---cq";
d odd odd odd0 dp'dooocM0
•* CM If) 'CM CM 00 CM CM *-'.'*- T- CO CO CM t-- CS O5 tO jf> CD
ooosr-oor^cncocnococir^cocococDi^cooi
^— -v,c35tr)ir>oo)CorotD
O CO O3 CO ID O CD O CM ^ = CO COCDf^T— COCOCDOifl
COCOCOO)C)COO3COO)COI^COCOCOO5O5O3COO3O5
»— ^J-OCMCO^J-OJr^tOCOCOCOO3LOO>C5CnmCM
cococncncocncocoi^-tocnr^r^cococo i^ co o
10 ,i CO CM . .CM • CM CMCMCMT-rCM
r^r^ooi^cocococo'r^cMLOco'inT— cMCDr-coino
in o co co o (D ^ i^ o ^t i^ co o co CD CM ^- CM en T-
Q^ g* r-t— v If) CM «— ^— v- *- -_ T— T- r- CM CM t— CO
CC E CM «-' CM •- •
D pocMpco«-cnmr:rop. ogo-CM^toE.cocM
5 O
co in en g g g CM LO (D to -r rr co if) o s 'in
-° g C^ CM " n 5 - - ^ in E LCT « CM ^ CD -.
T- CO .!-'.._ .
C ro '_C ^,JC ^^^^^^^^JE
-------
-------
ia
ota
idle
ll«l
~ 4= S O .!2
2 S <£ z g
CO
Q
S
2^
QLU
-I
a. <
CO LU
^wfE
5i«|
§<3
"Q|
°T
cog
SI
*tS Q) C
<§ a- C
C
4
c:
a
"5
?
<
6S I
cc
UJ
cc
a>
CC
5?
LU
LL
LU
a.
cc
5 1
u —
CO LL
O
I-.
? <•
1 UJ
£«•
—
t •
0 «J
2 *"•
O D
Tt— O
-s*
1 a sr
i
i
O 3
t- O
(/)
<
5 UJ
« LL
—
E
O>
E
>
S LL
UJ LU
a! u.
t
1
E
a
C3
a.
£
£
(U
a
;3
'c
CD co o CM en «- *-
oo P-* co « — r^- r^* en
o co CM i— LO cnr~-cD
T— ^v-r-i— T—CDCN
CO^COCO^-COLO^-CD
r-^oCMC3LOcO'— coco
T- CO CM CM CO
LOOOOOLOLOLOO
COr^CDCDCOCOCDCDCO
i— CO CM CO CM -—
r~->-cncococMCOCDO
- CO CD LO . 0 LO ,- .
^D C3 • ^3 f^ , • * ^D
CO ^— ^3 ^~
LOCMOOOCDO^fO
^ en CD o *~ en co en LO
CM *—
CM LO
OC3OC3OC3OC3O
B:B8888S8
^^ ^_Oj^_CNJt— CN
coo^oocoocococbcc
CNCO*— «— «— CMCNT— CO
EgSSgSS!S
C^CO T- CM «-«-«- C>
^•COCOOLOCOCOIOCD
CO O5 ^f CO CM LO ^~ CD C'
r^CMCOCDOO'— "d-LO
LOCO«— r^o^'— cncn
'd'CMCO*— CDCnCOOCN
CO
'•5
eu
— LO f- LO
CO LO <- CO »-
O CD CM t CD
CM O O O t—
o o o o o
CD LO >* en co CM
co co en co co en
CM LO CM r- CM LO
CM CM <— T— r- CM
o en CD cj CM CM
r~ CD co en o CM
T— r— T— r— CO
en o en LO co 3
CO CO CO CO CO CO
r~ r~. «— CM CD en
f^. |^ CD LO 1^ LC
< — CO ' — *~ lO C*"
CM «- CM •- T- CM
o en TT co CM T-
cn i^ LO CM CD CD
r^ en o LO r- co
1X3 CO O) r^ i— -3
t~- o ^r to LO
LO co en »— c*
•^ ^ d> <-: o
en cc o co LO
«^- ~y co en CN
<^- <^- en ^f o
en
1 ^5
Q. c~
< 0
1 I > s s s s
Q) °- ^ ci cri T— co
> . .— ^ o *— '—
<; CQ co co co co co
O CO
en co
Is- O
T- CM
£> CM
LO CO
CO CO
LO "d"
co r~
CO O
r- CM
CD CO
LO Is- _
CO LO
CM CD
V)
t/S +-"
*; c
I 1
CQ "CD
trt co
CD O)
CD «3
* ^
15
-------
BODg REMOVAL-PERCENT
g
00
o
O
>
O
CO
TJ
m
3)
o
CO
D
c
>
JO
m
TI
O
O
o
o
g
o
CO
§
o
00
o
o
-•-•-
CO
I 03
O <
o o
mE 30
r~ H m
^ o S
R^i
i5>
1^5-
5 33 °;
Hf2^-
°^g
!-<
S' §
> 22 §
C3
m
16
-------
TABLE 2
EFFECT OF HYDRAULIC LOADING
ON REMOVAL OF 5-DAY BOD
BY TRICKLING FILTER PLANTS - SINGLE STAGE
Filter Loading
Gals, per Day per sq.ft.
Range
0-99
100-199
200-299
300-399
400-499
500-599
, 600-699
700-799
>800 .
Weighted Averages
Mean
62
. 142
242
314
478
- -
620
744
1630
No.
of
Plants
11
21
17
5
4
-
1
1
1
61
BOD;
FE
mg/l
25
37
36
34
36
-
38
37
37
36
Percent Removal
PEto
FE
80
, 76
. 71
' •• 75
,r,64
- •-' -
49
• 81
69
73 .
Raw to
' , FE
87
85
82
84
75
-
65
87
80
83
FIG. 2
EFFECTOR RECIRCULATION
ON REMOVAL OF 5-DAY BOD
100
LLJ
CJ
oc
LLJ
Q.
<
>
o
oc
in
Q
O
CO
60
40
20
0.5
1.0
1.5
2.0
2.5
3.0
RECIRCULATION RATIO(R)
17
-------
TABLE 3
EFFECT OF HYDRAULIC LOADING
ON REMOVAL OF SUSPENDED SOLIDS
BY TRICKLING FILTER PLANTS - SINGLE STAGE
Filter Loading
Gals, per Day per sq.ft.
Range
0-99
100-199
200-299
300-399
400-499
500-599
600-699
700-799
>800
Weighted Averages
Mean
70
140
239
314
478
—
620
744
1630
of
Plants
11
20
16
5
4
-
1
1
1
59
SUSPENDED SOLIDS
RAW
mg/l
171
218
173
261
148
-
93
293
193
195
FE
mg/l
27
32
32
25
38
-
58
45
47
32
Percent Removal
FE
84
85
80
90
75
—
63.
85
76
84
FIG. 3
REMOVAL OF SUSPENDED SOLIDS
BY TRICKLING FILTER PLANTS- SINGLE STAGE
SHOWING RELATIONSHIP TO HYDRAULIC LOADING
60 PLANTS
•z.
HI
o
cc
LU
a.
O
LLI
CC
in
a
o
ca
100
80
60
40
20
* * 11
• •• *•"
V
100 200 300 400 500 600
LOADING - GALS PER DAY PER SQ FT
700
800
-------
TABLE 4
EFFECT OF ORGANIC LOADING
ON REMOVAL OF 5-DAY BOD
BY TRICKLING FILTER PLANTS - SINGLE STAGE
Filter Loading
Lbs. BODS per 1000 cu.ft.
Range
0-20
21-40
41-60
61-80
81-100
101-120
121-140
Weighted Averages
Mean
11
-28
50
69
—
106
124
No.
of
Plants
20
23
10
4
—
2
2
61
BODS
mg/l
FE
27
38
40
38
—
63
32
36
Percent Removal
PE to
FE
73
.74,.,
75
68
~~
76
80
73
Raw to
FE
81
82
.85
78
83
87
83
FIG. 4
REMOVAL OF BODg
BY TRICKLING FILTER PLANTS
SINGLE STAGE
SHOWING RELATIONSHIP TO BOD LOADING
60 PLANTS
100
80
1-
z
01
o
cc
cL 60
•-I
Q
LJU
>
O
S 40
L1J
(E — -•
in
..Q .
O
CO
20
.—i*^^^ v*r
.••
*V
.-..
7s
f *. m
7 * •
:•
* •
a
•
• • • -
.* •
•
•
•
• •
20 40 60 80 100
LBS BOD PER 1,000 CU FT
120
140
-------
TABLE 5
EFFECT OF ORGANIC LOADING
ON REMOVAL OF SUSPENDED SOLIDS
BY TRICKLING FILTER PLANTS - SINGLE STAGE
Filter Loading
Lbs. BODS per 1000 cu.ft.
Range
0-19
20-39
40-59
60-79
80-99
100-119
120-139
>140
Weighted Averages
Mean
11
26
49
69
-
106
124
275
No.
of
Plants
18
24
9
4
—
1
2
1
59
SUSPENDED SOLIDS
FE
mg/l
165
214
177
218
— ;
260
296
193
198
FE
mg/l
29
29
33
48
—
26
39
" 47
32
Percent Removal
Raw to
FE
82
86
81
78
—
90
87
76
84
FIG. 5
REMOVAL OF SUSPENDED SOLIDS
BY TRICKLING FILTER PLANTS-SINGLE STAGE
SHOWING RELATIONSHIP TO ORGANIC LOADING
60 PLANTS
o
-------
8
5 £ z
CO
Q
-j CO
•;* cc
2 ui h-
Sig
IP
LLJ Z in
S3P
to co O -I
3813
Q < I
O I- O
u. ui 3
UJ
DC
CQ
1
3
1
ii.
v>
1
B.
CO
- tn
Q
8
-
dSi
•i « «
c
<
t
c
0
1
I
<1)
CC
UI
u.
UI
a.
1
cc
cc
. &
UI
u.
UI
Q.
1
' s i
CO U.
ill
Uf
*
3
I
e
ll
§
<
| UI
Ju.
m UI
£ u.
E
E
E
g UI
«u.
ii] UI
E
E
O)
Q
O
5
uniAj
en co en o CM in oo •* CD o
CMCMCMr-CMCD'S-CO CO
SI^-COCMOOOOinCDCO
cooocncMT-cncoocn
Td-r-^- COCDCO»-CMCM
CM' - • «- CM •r-. .' r-
•S 2 g 93 o3-S 50
COCMCMCnCMCD-sfincOO
T-coo^cncO'-cncMoo
000°000000
•KSRRSSPESie
5sg,^s8gsfi
en en o op r«» in _ en r~> en
encoeoooocoinT-ooin
co oo in r^* in en co CN in in
«- «- CM «- tr- T- CM »- «-
•S R !J S S "9 S S IE R
CMCococMcooor^r-cnp-
•5fCOCpCOCMCOCOCDCMCM
C^ST— encor~ocDincn
r- o p~ oo f o o to ^ co
X-OOT-O CMr-ocn
iiiililiig
ooooooooo^-
55
00
CO
-
r--
CO
in
CM
CO
o>
CO
*— 03
a.
03
D)
CD" nj
in t!
|
S.
c
o
ll
<*^
-------
BOD5 REMOVAL-PERCENT
o'
IVJ
O
co
O
-o
O
-o
5
I
H
O
I
O
U)
•
•
•
•
•
•
•
•
•
» • V
/•*
ft •• •
• *
* *»
u_ ^00
^J
f
b *.*x
• X
1
•
e
X
X
•*•
x •
X
X
^
o
1
"i
>
m
m
•n
rn
en
33
m
m O
§ S
22
-------
No apparent difference can be observed in plants With fgSir
ios of 1.0 or higher when compared with those with fatiol of
ratios
no recirculation at all.
of 0.2 or
It is indicated in Table 5 and Fig. 5 that suspended solids removal
at all lob loading ranges followed the BOD removal patterns Very closely.
No observed relationship to recirculation ratios is apparent.
Table 6 summarizes performance of 10 single-stage installations for
which in-depth studies are included in the Appendix. These facilities
were selected principally on the basi,s of the completeness of the process
information and laboratory analyses and the rather wide range in size,
quantity of flow and strength of wastes. In many respects these plants
are very similar to those reported in Table 1 and are also included with
that listing. On the whole, BOD and suspended solids removals for these
10 plants follow patterns similar to others in Table 1. The BOD of the
effluent from these single-stage plants is quite comparable to the other
plants. However, overall removal on the average is somewhat lower,
influenced mainly by two of the 10 plants with effluents of 63 and 67 mg/1
of BOD (72% and 70% removal respectively, based on raw wastes of 224
mg/1 BOD at both plants). If these plants were excluded, values for the
remaining eight would be 33 mg/1 BOD.in the effluent afid 76% removal.
On the same basis, suspended solids would be 3.5 mg/1 irt the effluent
with 77%' removal .
5000-
lOOdQ
Totals
PERCENT REMOVAL BODg
Relationship of Population to Removal of BOD
Data on BODr removal vs. population are taken fr&fri
in Fig. 6. This information is summarized in table 7.
• ; TABLE 7
Population
of
Municipality
1000
1000-1999
2000-2999,
3000-3999
4000-4999
e 1 and plotted
Single-stage
# Plants .5
11
18
9 •'.' •' ; ;
3 . .
,1 •
11
8
61
Fi 1 ters
'<, Removal
83
85
84' ; •''•.;.
82
87; -
81
78
•'. Tw6-stagi
# Plants
1
"-. 2 : ;'
'•.",3'.'' .'"••:;•
2
1 ... ' . '••
'5 -
4
. 18 ' ''
e Filters
% Removal
95 •
86
91 :
88
•' 95 :'
90
88
23
-------
It is clearly indicated that trickling filter plants in very small
communities are performing as effectively as those in the medium to
large installations. It is noteworthy that this large sampling of
plants, both single and two-stage, includes a great variety of facilities,
ranges of loadings, waste compositions, flow patterns and operational
methods.
Effects of Raw Wastewater Temperature on Plant Performance
Information on raw wastewater temperature and the concentration of
BODr and suspended solids in the plant effluent for the four winter
months (January through April) is compared with corresponding information
for four summer months (June through September) in Table 8.
The monthly averages indicated by these data for 22 plants are
recorded in the Appendix. It is of interest to note that only two of
the filter systems are enclosed in protective housings. Both have two-
stage filters, one with rock media, one with plastic media. At most of
the other installations, special steps are taken to prevent ice formation
on the filter surfaces and to quickly remove ice as it forms in extremely
cold weather. Recirculation rates are reduced in view of the fact that
the sewage temperature drops sharply as the wastes pass through the
filter and settling tanks. At one facility (301) where winter performance
is about the same as summer, one filter and the final settling tank is
taken out of service from mid-November to early April in order to minimize
the temperature drop. Considerably better performance was experienced
when this program was undertaken. An extreme case of temperature drop
and its deleterious effect on plant performance is noted at another
facility (112), where detention in the primary settling tanks averages 4
hours or more and final settling tanks average about 5 hours. With
lower nighttime flows and colder temperatures, these detention times
appear to inhibit biological activity and retard sedimentation in the
final settling tanks.
Some plants have better physical protection from prevailing winds
than others. These include locations with more favorable topography and
natural wind breaks and erection of wind barriers such as baled hay or
straw, snow fences, etc.
A fairly consistent temperature related trend in BOD removal',
generally applicable to the majority of these plants, is found in these
data at plants without chemical treatment. Seven of the nine plants had
lower BOD,- values in summer, with the nine plants averaging 69% of the
winter values. These differences are not as great at plants with chemical
treatments. In general, both groups have a somewhat lower BOD,- in the
effluent during the summer months, averaging about 72% of winter concen-
trations. However, suspended solids concentrations for the 22 plants
remained constant for both groups in summer and winter.
24
-------
Obviously, factors other than the air temperatures and raw wastewater
temperature influence plant performance. The other factors probably
mask to some extent the temperature effects, sometimes aggravating and
sometimes offsetting their influence. A brief inspection of the month-
by-month analytical data for these 22 plants reveals many variations in
effluent quality which cannot.be correlated with temperature variation.
It seems apparent that the trickling filter process is not always
seriously affected by the severe cold weather associated with winter
sewage temperatures. This observation is confirmed by review of the 12-
month records for plants in Minnesota, many in the northern part of the
state, where winter air temperatures are often far below freezing for
very long periods. Because of the severity of winters in most of Minnesota,
it is customary to house the trickling filters to prevent ice formations
on the filter surface, distributors and side walls. Overall performance
in winter compared with rest of the year is generally similar to that
observed at the 22 plants listed in Table 8.
Effect Of Surface Overflow Rates in Final Settling Tanks
Information on sizes of final settling tanks and surface overflow
rates at 23 plants is recorded in the Appendix. Surface overflow rates
at annual average flows for these plants are summarized in Table 9.
Values for BODR and suspended solids of the final settling tank effluent
and overall percent removals are indicated for the various plants (listed
in order of increasing overflow rates). The plants are grouped as
single-stage without chemical treatment, single-stage with chemical
treatment and two-stage of which three have chemical treatment. Data
are reported in the Appendix for three plants for periods both before
and. after chemical treatment was begun (plants 169, 162 and 171). Data
at two of the plants (166 and 1.44), operated in a two-stage mode, are
reported in group C as 219 and 213, respectively.
The range of loadings on the filters and final settling tanks is
sufficiently wide to provide some indication of the effect of surface
overflow rates on effluent quality and overall reduction of BODg and
suspended solids. An examination of the data, however, gives no apparent
indication as to the critical point where performance levels decrease.
In the single-stage group A without chemical treatment, no observable
difference in performance is found in the total range reported (surface
overflow rates from 250 to 1100 gpd/ft2). Similarly, no observable
difference is to be found in Group B, single-stage plants with chemical
treatment where rates range from 290 to 1340 gpd/ft2. Less variation
apparently occurs among these nine plants than those without chemical
treatment, possibly because of the leveling effect of the chemical
treatment. This was also believed to be true of the five two-stage
plants.
Effect of Sludge Handling Practices on Filter Performance
The customary variety of methods of treatment and disposal of
sludge from the primary and final settling tanks are employed in the 25
plants studied. -Eighteen of the plants have anaerobic digesters. All
of the digesters are heated and 15 have two or more digestion tanks,
most commonly operated in series. Supernatant at 17 of these plants is
25
-------
•ii
: |* C
L^S-Q'S
II Ifl
«: s J> ° =
•i
£
Q
23
LU
cc
=)
fc^a
S QCO
LU tup:
Z2
^S5co
< CCH
g CO LU <
coo
O LU
H
LU
CC
gj 1
I6
a
I
E
15
e
g
•
:**
O
m
•
m
Q
O
m
5 **•
«£
8
m
Q
O
CO
s! D-
s g
<3j .a)
'i
.a
c
^
1
i
I
o
i
^
LL
O
gc8S£S|8S8
CMcoint-incMcocoin
*BB.£«E.«
CQOiTt-mCMCOOCOCM
COZCOCOZZI^CD
ococoo*-r»o<33O
OCOO*-CD*-T-COCO
CM O CO *~ O Q O CM in
m2l"inZZI^'inLO
CO
i
s
^
Ch
5
^
^
0
ft c
gSSSSSSSSg
1 ^§Sg»HH>Bi
8 ESSiSSSSSSSSSS
CO CM 00 i~ O3 T*~ ^* ^S* CM O) ^" CO CO CO
in <— moococoLoooooT-oiinoo^i-
CM CMCM »— t— CM CM »— CM »— r- CM
co S 5 § 8 S § S S S § fc %
CO CMr-CM«-CMCM5-«- T-T-CMi-
CO OOOO5COO>r|-CMC35inO>inOCM
CO T— CO<— «— CMCM«— •*»— r-CMCMCM
^ CO O O LO CO CM O> GO O"> O CO Q
mininLnininiom^-'S'in'*^;
CO
-j
'T
il
CTJ Ljj
Q. 3;
< ^
» a: . . . ._ . ._._._._._ ._ ._ ._
s" §
88
§3 S
CM CM
B> r-
r- CM
O P*
CM CM
Q.
i
CM CM -1
Q)
3
w
_
Q-
<
(O
V*
^
43 .E
il s
tO Q. « o
s, a 2
2 2 n
j? .1 Q
< < z
26
-------
TABLES
RELATIONSHIP OF SURFACE OVERFLOW RATES
TO REMOVAL OF BOD5 AND SUSPENDED SOLIDS
WITH AND WITHOUT CHEMICAL TREATMENT
Mn Minnesota
Mi... Michigan
Wi ....Wisconsin
*
Municipality
A. SINGLE-STAG E'W/OUT CHEMICALS
169. Mi
I/O. Ml • — "•• -....,. ,..— ,~ -...--
,117. Mn
112. Mi ' : '
163. Mi ; .
125. Mi ;
162. Mi :
305. Mi •
166. Wi
160. Mi
144. Mn
* Intermediate Settling Tank
B. SINGLE-STAGE WITH CHEMICALS
3Q2. Mi ' ' '•''
301. Mi
310. Mi
313. Mi
308. Mi
314. Mi .. ' - '
307. Mi
305. Mi '• • - •' '- '
309. Mi
C. TWO-STAG EW/OUT CHEMICALS
213. Mn
219. Wi
D. TWO-STAGE WITH CHEMICALS
306. Mi
312. Mi
311. Mi • .. -,..-..•
* "Two-Stages
Overflow
Rate
Gals./Day
per Sq.Ft.
250
QIC
O 1 «J
416
465'
472
522
573
733
880
890,
1100
290
470
503
530
573
630
675
833 ;
1340
900
1028
260
277
560
B(
FE
Mg/l
38 .
... 40
40
63
29
32
67
41
27
17
37
31
21
21
23
34
18
12
14
11
23
14
24 :
21 .
15
3D5
% Rem.
Raw-FE
81
58
88
72
75
77
70
84
• 81
92
78
91
88
89
84
85 ,
. - 80
94
94
85
86
90
88
86
83
Susp.
FE
Mg/l,
39
40
37
59
53
38
43
46
37
47
30
19
26
12
25
21
25
28
29
11
"-30
23
17
24
12
Solids
% Rem.
Raw-FE
83
63
85
77
66
79
81
83
76
75
78
84
86
85
92
90
85
84
88
89
78
85
92
86
88
27
-------
discharged to mix with the raw sewage before it reaches the primary
settling tanks. At one plant, the supernatant is discharged to a sludge
lagoon. Digestion tank capacities range from about 20-80 ft3/lb of
volatile solids added per day. Various methods and equipment are used
for mixing the contents of the primary digesters. The secondary digesters
are usually operated in a quiescent state without mixing. Of the plants
without digesters, two use Imhoff tanks for sludge digestion and primary
sedimentation. One plant uses Imhoff tanks solely for primary digestion
of sludge with a heated digester used as the secondary. No supernatant
or other digested sludge end product from these plants is returned to
the plant flow. Two plants use lime for treatment of raw sludge with no
end product returned to the plant flow. One large plant dewaters raw
sludge after storage by means of vacuum filtration followed by incineration,
The filtrate and the decant from the sludge storage tank are returned to
the raw wastewater flow. One plant uses a wet combustion process
followed by vacuum filtration, with land disposal of the filter cake.
The filtrate and residue from the wet combustion process are returned to
the raw sewage flow. One plant has land disposal. Digested sludges
from digesters and Imhoff tanks are discharged to open drying beds
except where filtered.
Capacities of sludge digestion tanks are shown on the data sheets
in the Appendix under "Capacities and Loadings." Points of discharge of
digested sludge, supernatant or other end products are stated and shown
graphically in the flow pattern diagrams.
Although no observable relationship is apparent from a comparison
of digester loadings and plant performance, operators at all of the
plants are acutely conscious of the deleterious effect of shock loadings
of "strong" supernatant on plant effluent quality. No other single
problem commands as much attention as the continuous maintenance of
effective digestion of sludge in order to produce a supernatant low in
volatile acids, BOD and suspended solids. Customarily, supernantant is
returned to the plant flow at very low rates during period of low diurnal
sewage flow.
28
-------
UPGRADING WITH A SECOND-STAGE FILTER
Studies were made on -20 filter plants where the filters are operated
in series. Each of these plants have an intermediate settling tank or
tanks following the first stage filter. In all other respects, the
plant facilities are similar to those equipped with single-stage filters.
Hydraulic Filter Loading Rates
Data from Table 1, Part B are summarized in Tables 10 and 12 *and
plotted in Fig. 7. No apparent trends in relationships between hydraulic
loading and BOD,- or suspended solids removal are visually detectable.
Loadings are similar in magnitude to those tabulated for the single-
stage filter plants. No observable relationship is apparent between
recirculation ratios and removal of BOD or suspended solids.
Organic Filter Loading Rates
Tables 11 and 13 and Fig. 8 exhibit a high degree of consistency in
removal of BOD and suspended solids throughout the entire range of
organic loadings, which are well distributed up to 40 lbs/1000 ft3.
One plant has a rate'greater than 40 lbs/1000 ft3. Here, as in the
single-stage plants, no observable relationship is apparent between
recirculation ratios and removal of BOD and suspended solids.
Comparison: Single-Stage vs. Two-Stage
Information on the 68 single-stage and 20 two-stage filter plants,
all without chemical treatment, is summarized in the foregoing tables 1-
13. These data provide a good basis for predicting levels of performance
of single (or parallel) filter systems compared with two-stage (series)
operations. Further comparisons are provided in Tables 14 and 15 and in
the statistical probability plots presented in Figs. 9 and 10. These
plots show a normal distribution of BOD values in both single and two-
stage systems with a definite statistically significant difference in
performance of the two systems. The probable value for the single-stage
system is 83% removal compared with 89-90% for two-stage. It may be
further noted that there is 90% probability that BOD removals will be
74% or higher for single-stage systems and 82% or higher for two-stage
systems. The probability curve for removal of suspended solids at
single-stage plants is visually identical with the BOD curve, although
eight of the 54 values plotted fall below the line of best fit. Furthermore,
there is no statistically significant difference in removal of suspended
solids at single-stage and two-stage plants. No signficiant difference
was observed at the 90% probability level with a spread of 85% to 87.5%
removal at the most probable (50%) value.
29
-------
TABLE 10
EFFECT OF HYDRAULIC LOADING
ON REMOVAL OF 5-DAY BOD
BY TRICKLING FILTER PLANTS - TWO STAGE
Filter Loading
Gals, per Day per Sq.Ft.
Range
0-99
100-199
200-299
300-399
Weighted Averages
Mean
70
120
236
326
No.
of
Plants
7
2
6
3
18
BOD5
FE
Mg/l
26
27
23
27
25
Percent Removal
PEto
FE
85
90
83
78
83
Raw to
FE
90
93
89
85
89
TABLE 12
EFFECT OF HYDRAULIC LOADING
ON REMOVAL OF SUSPENDED SOLIDS
BY TRICKLING FILTER PLANTS - TWO STAGE
Filter Loading
Gals, per Day per Sq.Ft.
Range
0-99
100-199
200-299
300-399
400-499 &>
Weighted Averages
Mean
73
120
236
327
No.
of
Plants
7
2
6
3
0
18
Suspended Solids
Raw
Mg/l
232
345
188
234
246
FE
Mg/l
28
28
30
40
31
% Rem.
Raw-FE
87
92
83
80
85
TABLE 11
EFFECT OF ORGANIC LOADING
ON REMOVAL OF 5-DAY BOD
BY TRICKLING FILTER PLANTS - TWO STAGE
Filter Loading
Lbs. BOD per 1000 Cu.Ft.
Range
0-20
21-40
41-60
61-80
Weighted Averages
Mean
9
27
—
74
No.
of
Plants
6
11
0
1
18
BOD5
FE
Mg/l
21
26
_
40
25
Percent Removal
PEto
FE
85
82
_
92
84
FE
90
88
95
89
TABLE 13
EFFECT OF ORGANIC LOADING
ON REMOVAL OF SUSPENDED SOLIDS
BY TRICKLING FILTER PLANTS - TWO STAGE
Filter Loading
Lbs. per 1000 Cu.Ft.
Range
0-19
20-39
40-59
60-79
Weighted Averages
Mean
9
28
74
No.
of
Plants
6
11
0
1
18
Suspended Solids
Raw
Mg/l
165
241
541
232
FE
Mg/l
22
35
42
31
% Rem.
Raw-FE
86
84
92
85
30
-------
FIG. 7
REMOVAL OF BOD5
BY TRICKLING FILTER PLANTS
TWO-STAGE
SHOWING RELATIONSHIP TO HYDRAULIC LOADING
18 PLANTS
100
80
LU
O .
EC '
•J- 60
Q
LU
O
Lu 40
in
Q
s
20
... .6
•'»*
•
••*•*
v
' -
100 200 300 400 500
LOADING -GALLONS PER DAY PER SQ FT
600
FIG.8
REMOVALOFBOD5
BY TRICKLING FILTER PLANTS
TWO-STAGE
SHOWING RELATIONSHIP TO BOD LOADING
.'.-,rr-100
80
LU
O
OC
LU
0_
LU
OC
in
Q
O
60
40
20
40
60
80
100
120
140
160
LBS BOD5 PER 1,000 CU FT
31
-------
TABLE 14
DISTRIBUTION OF VALUES
IN QUALITY OF EFFLUENT & PERCENT REMOVAL
OF 5-DAY BOD & SUSPENDED SOLIDS
SINGLE-STAGE FILTERS
Range
<10
10-19
20-29
30-39
4049
50-59
60-69
70or>
Totals
Quality ~ Mg/l
No. of Plants
BODS
1
6
25
14
9
7
3
3
68
Susp. Sol.
1
11
17
14
13
7
3
66
Percent Removal
Range
<60
60-69
70-79
80-89
90or>
No. of Plants
BODS
0
4
13
35
16
68
Susp. Sol.
2
5
14
33
12
66
TABLE 15
DISTRIBUTION OF VALUES
IN QUALITY OF EFFLUENT & PERCENT REMOVAL
OF 5-DAY BOD & SUSPENDED SOLIDS
TWO-STAGE FILTERS
Range
<10
10-19
20-29
30-39
40-49
50-59
60-79
Totals
Quality ~ Mg/l
' No. of Plants
BODS
4
2
9
2
2
1
0
20
Susp. Sol.
0
6
5
5
1
2
1
20
Percent Removal
Range
<60
60-69
70-79
80-89
90or>
No. of Plants
BOD5
0
0
1
9
10
20
Susp. Sol.
0
1
4
7
8
20
32
-------
(Y) BOD REMOVAL PERCENT
3Z
30 O
•z oi
30 J5;
m '_
O
"Tl
CD
O
O
Ol
-00
°
33
-------
(Y) SUSPENDED SOLIDS REMOVAL PERCENT
3}
m
O
V)
o
m
8
5
i >
>
CO
i!
|!
O
m
O
8;
a
CO
m
?«?
34
-------
TABLE 16
COMPARISON OF BODS REMOVAL
BY SINGLE-STAGE VS TWO-STAGES
AT 3 TYPICAL TWO-STAGE PLANTS
Win Minnesota
Mi Michigan
Pa Pennsylvania
N.D.. North Dakota
Wi Wisconsin
Municipality
211. Mi
213. Mn
219. Wi
Averages
BODS -~ Mg/l
Raw
108
169
144
140
PE
75
105
95
92
IE
38
37
27
34
IE = Intermediate Settling Tank Effluent
FE
24
23
14
20
BOD
PE-
IE
50
64
72
63
Raw-
IE
65
78
81
76
5 Removal
PE-
FE
76
78
85
78
~%
IE-
FE
42
38
48
42
Raw-
FE
78
'86
90
85
TABLE 17
COMPARISON OF BOD5 REMOVAL
BY SINGLE-STAGE VS TWO-STAGES
ALL PLANTS
Stages
All Plants
Single-Stage
Two-Stage
In-Depth Studies
Single-Stage
Two-Stage
No.
of
Plants
68
20
10
3
BOD5 ~ Mg/l
Raw
226
255
1 56
140
Effluent
First
Stage
35
NR
39
34
Two -
Stages
IMA
24
NA
20
% Removal
First
Stage
84
NA
75
76
Two
Stages
NA
90
NA
85
-------
Some additional insight to the comparative level of performance of
single and two-stage systems is provided by the in-depth design and
performance data set forth in the Appendix for ten single-stage and
three two-stage plants. Laboratory analyses for these three plants
include information on the BOD5 of the effluent of the settling tank
following the first stage filter as well as the final settling tank
effluent. This information is shown in Table 16. Data from Table 16
are included in Table 17 showing the numerical distribution of the
effluent BOD by treatment process for single vs. two-stage filter
systems.
Observations and Conclusions
Several observations may now be made from the summarized data and
related discussions:
1. Effluent from final settling tanks following single-stage
filters may be expected to vary considerably. In the plants studied
effluent BODg valus normally range from 10 to 50 mg/1 with removals from
the raw wastewater of 60 to 90% or more. Most probable values of the
plant effluent are 36 mg/1 BOD. and 83% removal. There is a 90% probability
that overall BODg removal will be 74% or higher.
2. Removal of BODg at the 20 two-stage trickling filter plants
studied appears to substantially higher than at single-stage systems.
Removals of 80-90% are commonly experienced, the most probable value
being 89-90% or higher. Thre is a 90% probability that removals will
not be less than 82%.
3. Suspended solids in the effluent from 66 single-stage systems
studied were at approximately the same concentration as the BOD,- and
percent removals followed precisely the same probability, distribution
and magnitude.
4. Removal of suspended solids in the two-stage plants was not
statistically significantly different from that observed in single-stage
systems. The apparent indication is that generally no further removal
of suspended solids can be expected by converting single-stage to two-
stage operation.
5. Removal of BODg and suspended solids at both single-stage and
two-stage filter plants appeared to be relatively independent of the
magnitude of both hydraulic and organic loadings within the loading
limits of 68 single-stage and 20 two-stage systems studied. Hydraulic
loadings varied from 100-320 gpd/ft2 (5-15 MGAD) for single-stage and
slightly higher for two-stage. A few values were considerably higher
Five-day BOD loadings were usually in the 10-60 lbs/1000 ft3 range for
both systems with a few values much higher.
36
-------
6. - No observable relationship was apparent between recirculated
flow ratios and removal of BOD,- or suspended solids. Plants with no or
very low recirculation appeared to perform as well as these with recircu-
lation ratios of 1 to 3 times the raw wastewater flow. This is not to
imply that.recirculation has no value. However, no effect was visually
apparent from these data. * . •
7. Both single-stage and two-stage plants presently operated at
low to moderate hydraulic and organic loadings can be expected to
accomodate much higher loadings without depreciation of effluent quality.
For example: at a single-stage filter loaded at 15 Ibs BOD5/1000 ft3'and
200 gpd/ft2 of media, both hydraulic and organic loadings can be doubled
without lowering the effluent quality.
8. Conversion of a single-stage system to two-stage can be
expected to greatly improve the quality of effluent, with the same
quantity of media. For example, assume two trickling filters operated
in parallel with BOD. loadings at 15 lbs/1000 ft3 and hydraulic loading
of 300 gpd/ft2 are producing-a final settling tank effluent of 35-40
mg/1 BOD,-. If these filters were arranged in series with an intermediate
settling tank and low lift pumps, the plant effluent can be expected to
be in the 25 mg/1 range. ,'...-
,.9., The converted plant in No. 8 above can be expected to reliably
produce an effluent BOD5 of 30 mg/1 or less with about 90% removal
compared to the raw sewage, even if this loading is doubled.
37
-------
UPGRADING WITH CHEMICAL TREATMENT
In-depth studies were made at 14 trickling filter plants in Michigan
where chemicals are added to remove phosphorus pursuant to a regional
requirement for reduction of phosphorus loadings in the Great Lakes. A
minimum of 80% removal is required. Plants selected have been adding
chemicals for this purpose for over two years. All plants have typical
facilities and the operational procedures are representative for the
plant processes involved in this study. Excellent physical and laboratory
data are routinely maintained and were made available .for this study.
Pertinent design information and performance data for'the facilities are
set forth in the Appendix. Flow diagrams are developed for each plant
with points of application of the chemicals. Information includes kinds
of chemicals and feed rates. A year or more of flow and analytical data
for BODg and suspended solids and, where available, total phosphorus,
provide a good indication of performance provided by the primary settling
tanks and filter systems. Summary data are developed from this information
for analysis and discussion in this report.
Facilities for Chemical Treatment
Facilities are representative of those customarily used for removal
of phosphorus by precipitation and removal of a high proportion of
colloids by flocculation or agglomeration. In some of these plants chemical
treatment was undertaken after the plant had been in operation for some
time; in others it commenced when the plant was built.
Generally, facilities are simple and inexpensive with maximum use
of hydraulic properties of the regular facilities to achieve the desired
reactions.
Commonly, facilities consist of the following items for storage and
application of the metal salts: a double-lined storage tank of 5,000-
6,000 gallon capacity, 2 diaphragm pumps paced off the flow meter and a
y to 1" plastic pipe feed line. These facilities are usually located
in the pump room with provision for total containment of spills or
leaks. Points of application are ahead of a comminutor, Parshall flume
introduced
, parshall
flume or aerated grit chamber with 5-10 minutes contact time in the
well-mixed flow before entering the primary settling tank.
Chemicals Used
Of the 14 plants studied, 11 use ferric chloride and an anionic
polymer. Feed rates for most plants range from 25-40 mg/1 as FeCl3.
Polymer dosage is usually from 0.1-0.3 mg/1.
38
-------
At one plant, aluminum chloride (A1C13) is added to the trickling
filter effluent ahead of an aerated mixing chamber with about 10 minutes
detention time at average sewage flow rates. Chemical dosages average
about 38 mg/1 as A1C13. The A1C13 is fed in 25% solution. The polymer
is introduced in the line between the mixing chamber and the final
settling tanks. \
One plant uses, lime, applied at the flocculator - clarifier fpr the
dual purpose, of phosphorus removal and sludge treatment.. Feed rates
average 2,400 Ibs/day as CaO, dry weight, for an average flow of 1.36
MGD (approximately 210 mg/1). Another plant feeds hydrated lime with
1.5 minutes rapid mix followed by 15 minutes aerated flocculation in
primary clarifier.
Phosphorus Removal
Phosphorus in the raw wastes entering the plant is usually in the
6-8 mg/T range. Chemical treatment reduces the phosphorus concentration
to.1-2 mg/1 with some below this range. At the plant feeding lime after
filtration phosphorus averages about 2.6 mg/1.
Removal of BODr and Suspended Solids
. - '.'."• h D . ' ' • .•_••-• i .
Data are summarized in Table 18 from the physical and analytical
information recorded on sheets entitled "Facilities and Loadings" in the
Appendix. ,
Eleven of the plants are operated as single-stage. Two rock media
systems and one plastic media filter system are two-stage. It is noteworthy
that five of the 14 plants have plastic media in 21ft-22ft towers. The
other nine use rock media, eight at customary depths of 6 ft. and one at
8 ft. This provides an excellent opportunity for comparison .of .performance
at various, loadings. Five of the rock media filter plants and one of
the plants with plastic media have reliable data for a significant
period of time: before chemical additions were made. This provides an
excellent basis for comparison of performance with and without chemical
treatment as here;practiced (see Table 19). ;
. It is noted from Table 18 (also Table 1C) that the hydraulic and
organic loadings on all rock media filter systems are typical of those
listed in Table 1 and previously discussed. Hydraulic loadings per unit
area are, of course, higher on the plastic media systems with comparatively
less surface area, but are comparable to the rock filters on a media_
volume basis. Organic loadings are comparable at the rock and plastic
media systems in Table 18 and in the same general range as the 86 plants
listed in Table 1A and IB.
Strength of the raw wastewaters,,as measured by BODg .and suspended
solids, is slightly higher at the rock media plants than the plastic;
media plants but generally comparable to those in Table 1A and IB.
39
-------
i«Mfi
III J i
c,_ j q , J
SSSzS
co
Q
O
CO
Qfe
LU 2
Q LU
2£
Q. <
CO LU
w 5 CC
™ WL_
LU Q I
PS
*- "*z
i
2t
<3
o
LU
OC
! °-
, s
! ^
t
i
O)
_c
! 73
IS
(U
0
<
^ £
S? QJ
cc
LI1
LL
CC
0>
CC
s?
01
LL.
LLJ
Q.
CC
5 %
CO LL
° §
o> o
«
™
I
'(
'i
c
e
-S
cc "-
==:
g1
s s«:
X 0 u
t— o
o -
ui
3
a.
j
•
CD n o CM o i— i—
00 r-- co i— r*^ r^ o
o oo CM t— LO oir--cD
nTrooo^nLnr- CD
r^'ocNOLricot-^coco
<- n ON CNJ co
tnooooLOLOtno
cor--cDtDnrocDCDcD
T— CO CN CO CM •—
l^-t— OOOCOCMCOCDO
oococDLfi^-'c>Lr)'-'r^
°°S°°iS°°
l^CNOOOCOO^-O
•^roicDO'— cncootD
^^r^cNLncorocsji^
CM T—
CN LO
P-.T— o)CQO)n<3-T— o>
r— P^-CNJ^-i— r-i— T— ,—
ooooooooo
«D^CT)OOOOCDCN'^-O
COt— P-OOOOCOOCOO^
cocncncDcncnr^cCt-
CNT-r-r-CNJr-<— CNCM
COOOCNrMCNir-LOLOt—
co«— oin-^ncNr^cNj
*- t- t- CN •— CN .— CN
O<— CO^t-^fCDOO'S-Ln
CO(J)COCOO5COCOO50O
CO^-^^-^^^-Cvj^j
cocor^r--cor-.cor--r*.
f- i— ^rcD^rt-^-cN^
OjpQ^^^-fVjCXj^pr)
r-r-CO^-COOCM^-CO
CQCQ-sTtDCOr--^^^
LOr*-'^cocj)r-Lr)o^r
r-CNOOO^-^COOCN
«— CO i— CNJ T— t— t— CN
' I
ScocooLOcocomcD
oi^rcocsjtDt— coco
OT-or-Or-T-o*-
r^-CMOOCDOO'— TJ- LO
mco»— r^o^T'— O3O)
*a-CNCQ<— CDCT)OOOCM
CNoicNirjCNoo'^rcoa^
CO
re
CJ
^
g sss^^^s^^
T— CNCO^tnCNJCOl^-CO
OOOOOT— ooo
< cocorocococococoro
T
tO O i- O O
CO CC CT) O CO
{ . . . -.. --..
\
\ O CD "0; O> O
•i
' no en o co - o
1 r-" ro c\i Lri cd
i ^r r- *- i- «-
4 -
O ID O O O
10 on to oo CD
CO )~ CD CD CO
; !<• CO O LO O
c<5 r-" cb r*^ o
LO P^ t— CN] CO
CNJ O O O
! o r\i r-^ CN
1 •
i . en co o r- co
^r T— LO r-* LO
CO LO T- CO «-
O CO CN ^T CD
CN O O O T-
o o o' o o"
CO LO -3- Cn CO CN
CO CO CO CO CO CD
. ,
CN LO CN *— CN LO
CN CN <— i— «— CN
j. .
O C7) CO O CN CN
r^- co co c; o CN
<— T- — r- CO
en o en LO rr ^f
CO CO CO CO CC CO
P^. P*» T— CN CO CO
r-- p^- co .in r^ LO
', " '•" '" ' ; '
t— CO r~ r- UO CO
CN t— CN r- i— CN
L ' - - ' . '••' ' J
o en «• I S S i 2
CO —
cu °- -^ o cri >— H
> . <— r- 0 «- >—
< CQ co co n n .co
[
•r ....
!
i
i-
f1
... ...
t '
1
o en
00
r~- o
i- CM
LO CNJ
r- r^
LO CO
OO CO
LO -a-
CD (^
co o
•— ,CN
CD , 00
LO r^
CO LO
CM CD
1 1
CD "5
a s,
CD CO
5 o
> >
< <
40
-------
Removal of BOD in the primary settling "tank of most of these plants,
where chemicals ar«e added to the raw wastewaters, is generally very
high. This is clearly illustrated in Table 19, which summarizes performance
data at the six plants for which information is available before and
after chemical precipitation was commenced. Five-day BOD and suspended
solids removals at the 5.pi ants with chemicals added before primary
sedimentation were 57% and 76% respectively compared with 31% and 55%
for a period of several months before chemical treatment. In other
words, approximately 50% more BOD and suspended solids were removed by
primary sedimentation with chemical treatment in this manner.
A broader base of comparison is provided in Table 20 which summarizes
BOD(- and suspended solids concentrations in the raw wastewater and
primary settling tank effluent at all 23 plants where in-depth studies
were made. Data are summarized from 16 plants without chemical additions
and 13 plants with chemical additions. The six plants in Table 19 are
included here in both categories. The higher percent removal for the 13
plants in Table 20 with chemical treatment is in the same order of
magnitude as for the six plants listed in Table 19.
The marked improvement in effluent quality provided by chemical
treatment at single-stage filter plants is shown in Table 21. Both
effluent BOD,- and suspended solids concentrations were reduced approximately
one-half. It is noteworthy also that effluent quality at the 14 plants
with chemical treatment, as measured by suspended solids, is.substantially
better than observed at the 18 two-stage filter plants without chemicals
summarized in fable 18 although BOD5 values are very similar. These
relationships are portrayed graphically in the probability plots (Figs.
11, 12, and 13).
Relationship Between Filter Media and Performance
As may be noted from Tables 18 and 21, overall performance at the
five plastic media filters is very similar to that experienced at the
nine rock media filters. No apparent difference is found in performance
of the only two-stage plastic media filter compared with the single-
stage filters on the basis of the data gathered for this report.
Relationship Between Recirculation and Performance
Recirculation ratios at rock media filters listed in Table 18 vary
from zero at five plants to 0.8, 1.0 and 3.2 at the other three for
which this information is available. No apparent effect of recirculation
on plant performance, as measured by removal of BOD5 and suspended
solids, were observed in these data.
Recirculation is a common operational practice used for deep plastic
media filters - an inherent characteristic of the process. Very little
recirculation is used, however, at one plant (314) where the raw wastes
are very dilute because of the combined sewer system. On the other
hand, at another plant (309) with a combined sewer system and very
dilute waste, a recirculation ratio of 1.0 is used. Removals at plant
41
-------
= s ™ .=
-Q
• : :
: : :
: :Q
V)
CC
o
a.
w
O
a.
LL
O
III <
CO O
Q g
rf LU
Q "
§CC
LU
t
Q
2
LU
CC
O
LL.
LU
m
Q.
s
|2
Suspended Solids
Q
g
s? £
V
CC
UJ
u.
% Removal
in
u.
UJ
Q_
1
cc
% Removal
UJ
u.
UJ
0.
1
cc
11
§ LL
s ui
1 u.
cc
O)
4 UJ
I U-
CC
. UJ
UJ U.
0.
> UJ
1'
}
01
^.
D)
S uj
cc "•
ss
3UJ
a°-
ro
*C
—
Q
< o ca
Aj!|Bdioiun|/\i
r^o o <* CM co o> T-
m co ro eo T- co CM r^ ra r-. ro
CO CO CD
O r\ ri
o o o
I^-CD CM o T- r-* in ^t co
C0<-^ T-^trit-^OOt-1 CN OJ
STC tMo t-cocooo^a-co T-O
GJ r^r-* oooo coco cooi cocn
r-CQ ITJCO OCM OJ'* COCO COi>-
i>-co r*.oo
CO*- CO CM(O COCO
*
coo «3--<* coco ^ro> com -«t T-CO OO UO^t Olf- CMCM
T-T-,- ^r^CMCMr-T-CMCM
CO O CO CM IO
COCO «3-CMCOCMCMCMCM*t^fr
o*— ocDr-.ooT-T-T-T-
CQ«^ CD^ DQ CO
15 £
V
*2
CO CO fe
to r-. -§
-o
c
r- r-. ra
co in %
+-*
"" M-
Ol
C
tn T- "5
*t CM o
'£
S
in co 15
CM P- -o
"' 1
CO
T— T— 15
co r-. .y
OJ 4_>
' o «> c
nil
1 1 I S 1
g - ^
S S -5
•- £ 'c
co < •g j? g
-00.-=
3 0) °
S £• = fi S
1" 1" s fi 5
g g 2 11 II
< < * CD <
-------
•2«
r- O
fm W
Iffll
S S § O •-
SSo-ZS
CO
Q i-
p! co LU
8^s
u. Q. r-
So
C/) " LU LU
CO ^
O ^
LU
CC
111
111
CO
.0.
'o
'c
O'-O
CDOOOOCDID
'*t* CDCD
OO<£> coi^
cncooo
oooooo
incocnocNQirj
r- CM T- »-
r^cnoo
co
O5 CM CO
r- CM «-
^
O
T— r^ oo o
«— o
T- CM
CO
CO
-J
C
to
•o S- -J
< £7 g
W U3
-------
(Y) BOD REMOVAL PERCENT
G) -^1 CO
-------
(Y) SUSPENDED SOLIDS REMOVAL PERCENT
o
CO
>
CD
•H
-<
m
O
cz
O
O
m
CO
CO
H
CO
30
m
I -t-
FH°
Zj m -n -„
« 30 co rr
O _ <— GJ
i^co •
m
o
TJ
m
D
r-' 3
_j co ri
Si8
^ £75 j—
^S
m
45
-------
(Y) BOD REMOVAL- PERCENT
p
b
o
o
oo
o
3D
o
CD
> 01
CO
H ->
-< o
m
O
O
33
CO
NJ
CO
o
^
O
00
o
s
CO
CO
o
o
o
I
m
I
§
H
O
C
m
S
H
3D
m
|
m
CD
"<
H
30
O
1||
8 = 5
Srg
Im?2i
•o33 o C)
;??°-
H^W
3 z
mr-
> *" ^
Sco S
m = O
m
O
m
46
-------
CO
9n
-J z
Z Q 0.
LU LU Q;
«E Q LU
'HZ 1-
< LU _l
m S; u!
cc 52
1-52
TABLE 21
CHEMICAL
BODS AND i
E TRICKLIIS
u. u. O
o5<
0 ^ <0
LU 5LU
U_ J? -J
LU O O
LU SE Z
£co
O<
-s
i
;
o.
Q
2
£
O? Q)
CC
LU
U.
ro
CC
—
M^
D)
£
o** Q)
CC
LU
LL.
i
"oi
8)
1^1
03
1
w
o r^ *- eg
CO CO O CO ,
[»• CM CO T-
CO CN r- CM
co r» o co
in o> co co
r^ co co co
'«- r- CO O
•<3- CM r- CM
••* CM ID O
CO C55 CM r»
CO O) If) •*
~J5 03
• Crt ^ "~*
g "co ~&
g S 2 "
^ 5> .^ •=
a § 8 ™ =
o j, cc 51 <
i I
47
-------
309 are greater than those at plant 314. This may be attributable to
the periodic high concentration of suspended solids observed in the
primary settling tank effluent of the latter plant during the period of
study.
Observations and Conclusions
The detailed information on chemical treatment and its effects on
overall plant performance at 14 plants studied provided a firm basis for
the following observations and conclusions:
1. Performance at four single-stage and one two-stage trickling
filter plant was greatly enhanced by the addition of metal salts and
polymers to precipitate phosphorus and removal of a high proportion of
colloids by agglomeration and flocculation. Equally effective performance
was experienced at a sixth plant where lime is added following the
trickling filter and its settling tank in a flocculator clarifier.
2. Overall removal of BOD,- at these six plants was increased on
the average from 75 to 87% and suspended solids removal increased from
81 to 89%. This reduces the load in BOD5 and suspended solids on the
waters receiving the plant effluent by approximately 45%. The five-day
BOD and suspended solids in the effluent averaged 21 mg/1 and 19 mg/1,
respectively.
3. Concentrations of BOD5 and suspended solids in the effluent
and overall percent removals at eight other plants studied were at very
similar levels.
4. No apparent difference was observed in performance of plants
with zero or very low recirculation and those with recirculation ratios
as high as 3.0. There is a general belief, however, among most of the
operators of these plants that a certain degree of recirculation is
beneficial to overall performance.
5. No observable relationship between hydraulic or organic loadings
and performance was apparent over the range of rates found in these 14
plants. (See Table 18).
6. No apparent differences were observed in removal- of BOD5 and
suspended solids between filters with rock media and those with plastic
media. Both hydraulic and organic loadings were of similar magnitude in
terms of volume of media and are typical of loadings generally classified
as low to intermediate rates.
7. Physical alterations for the storage, application and mixing
of the chemicals and polymers are quite simple and can be provided for
at low capital cost. Usually, existing plant facilities are adequate
for mixing and contact periods.
48
-------
8. Ferric chloride is most commonly used at these plants by :
reason of its ready availability in Michigan. Dosage to remove 80% of.
total phosphorus usually ranges from 25-45 rng/1 as FeClg. Substantial
improvements in BOD5 and suspended solids removal generally occurred ,.,--;-.'-.
when total phosphorus was reduced to 2.0 mg/1 or less. ;_;«••,:
9. Extremely low wastewater and air temperatures appeared to
reduce removals of BOD,- and suspended solids but to a lesser degree at
plants employing chemical treatment.
10. The effect of increased solids loading on sludge treatment . .
facilities did not necessitate modifications to existing facilities at
the plants studied. Although more supernatant is produced and substantially
increased loadings on primary settling tanks and trickling filters
resulted, plant performance did not deteriorate.
11. In general, chemical treatment by the methods described in
this report is-an extremely effective method of upgrading single-stage
trickling filters, which is easily managed and involves a relatively low
cost.
49
-------
UPGRADING WITH ADDITIONAL TREATMENT WORKS
Several trickling filter plants with facilities
filter plant effluent quality were studied. Each is
common class of facilities.
Mixed Media Gravity Filters
for upgrading
typical of a quite
Mixed media gravity filters were placed in service at plant 304 in
June 1973 to upgrade the quality of effluent from a two-stage trickling
filter system with chemical treatment for removal of phosphorus. The
effluent from the filters had a
mg/1.
BOD5 and suspended solids of about 16
Facilities are shown schematically on the sheet entitled, "Flow
Pattern" in the Appendix. Additions consisted of flocculation tanks
installed between the trickling filters and the final settling tanks and
three 4,500 gpm pumps to feed final settling tank effluent to the four
mixed media filters. Provisions are included for surface washing and
backwashing the filters by either manual or automatic control. Each of
the four filters are divided in two sections, each 10 ft x 10 ft. Media
consists of 9" of gravel, 3" of high density garnet, 4 1/2" of larger
garnet, 9" of silica sand and 16 1/2" of coal for a total depth of 42".
Loading rates average 4,000 gpd/ft2 (2.8 gpm/ft2).
Each section is equipped with two surface wash arms just above the
media, with effluent troughs for the backwash. Surface washing and
backwashing are activated by an alarm when the head loss reaches about
10 ft. This occurs in 18-24 hours. Surface wash rates are about 500
gpm. Backwash pumps operate at a low rate of 1800 gpm and high rate of
3,600 gpm, using stored final effluent from the clear well. The cycle
is completed in about 10 minutes. Backwash water flows by gravity to
the plant inlet.
Rates of flow through the plant are controlled by diverting instanta-
neous flows in excess of about eight MGD to a flow equalization chamber.
Flow to the mixed media filters is held constant at a rate of about 7.2
MGD. This uniformity enhances performance of the filters.
The flocculation tanks can be operated for chemical flocculation,
straight aeration, or short-term activated sludge. Each method has been
tried. The most effective method is to operate as high rate, short-term
activated sludge with about 2,500 mg/1 suspended solids in the mixed
liquor.
Studies were conducted by plant personnel first by applying chlorine
ahead of the mixed media filters to inhibit biological activity for a
period of time. The point of chlorine application was then changed to
the clear well following the filters and resulted in a very low final
50
-------
chlorine residual. The study
portion of the BOD removal is
than simply a straining process
gave convincing proof that a significant
attributable"to biolgical activity"rather
for removal of. solids.
Performance data in the Appendix indicates that in 1973-74 the
mixed media filter system reduced BODr in the trickling filter effluent
from 16 mg/1 to 9 mg/1 and suspended solids from 16 mg/1 to 5 mg/1 at
surface loading rates of 4,050 gpd/ft2 (3.1 gpm/ft2). Expressed in
terms of effluent loadings, 970 Ibs BODr in the final settling tank
effluent was reduced to 545 in the mixea media filter effluent, while
suspended solids dropped from 970 Ibs to 309 Ibs. Discussion with the
plant superintendent revealed that during the summer and fall of 1976,
BOD,- averaged 5 mg/1 and 305 Ibs/day while suspended solids average 2
mg/T and 125 Ibs/day. This represents removal of 95% BODr. and 98%
suspended solids by the total plant on a relatively weak sewage. This
improvement over the 1973-74 period is attributed in large measure to
the beneficial effects of the activated sludge process compared with
straight aeration ahead of the mixed media filters and also the steady
rate of flow.
Gravity Sand Filters - Mechanically Backwashed •'
, *
Facilities at plant 306 consist of two-stage trickling filters
without intermediate sedimentation, followed by gravity sand filters.
Ferric chloride and polymers are added to the raw sewage for removal of
phosphorus. . Sludge from the final settling tanks is brought back to the
raw sewage wet well by gravity at a rate which is paced with the rate of
sewage flow. Pump rates are kept nearly constant at 2.1 MGD by means of
variable speed pumps. The chlorinated final settling tank effluent'is
pumped,to the sand filters at a 3.0 MGD constant rate.
The sand filter system is comprised of a complex of 50 adjoining
chambers which are 12 inches wide by 12.5 feet in length. Filter media
consist of sharp washed sand, ,to a depth of 11 inches, laid on fine- :
slotted ceramic tile at the bottom of each channel. Underdrains convey
the filtered effluent to the outfall sewer with about two-thirds of the
effluent recycled after mixing with the final settling tank effluent:
The sand filters are backwashed with final effluent at a low rate
by means of a traveling pumping system. Controls are set to backwash
twice daily for about 50 minutes at noon and midnight unless head loss
reaches 18 inches in a shorter time. 'Backwash water is returned to the
final settling tanks. Digester supernatant and filtrate from the filter
press are conveyed to the raw sewage wet well.
The sand filter effluent averaged 4 mg/1 BODr and 5 mg/1 suspended
solids during the 12 months, June 1973 - May 1974, with little or no
difference in winter and summer months, as indicated by the data in the
Appendix. With trickling filter effluents containing 24 mg/1 BODr, this
represents a reduction from 236 Tbs to 39 Ibs or 83% removal from the
trickling filter effluent; correspondingly a:reduction from 168 Ibs
suspended solids to 49 Ibs or 71% removal from the trickling filter
effluent.
suspended
Overal1
solids.
plant removals are 99% of the BODK and
of the
51
-------
Chlorine feed rates are vey low because of the relatively low
chlorine demand of the final settling tank effluent.
Intermittent Sand Filters
The open, underdrained, intermittently fed sand filters at plant
169 are typical of this commonly found supplementary treatment process.
The filters are used to upgrade the quality of the trickling filter
effluent during summer months when climatic conditions at this northern
cold climate location are favorable. As noted on the data sheet, which
includes monthly averages from January 1975 - June 1976, the filters
were operated for five months, June through October in 1975. Favorable
temperatures and field conditions in 1976 permitted commencement of
operation on April 1.
The sand filters consist of four beds, each 20 ft x 80 ft, under-
drained to the point of plant discharge. Media is comprised of 24
inches of sharp sand atop 9 inches of graded 1/8-1 inch gravel. The
original sand Had an effective size of 0.6 - 0.9 mm and uniformity
coefficient less than 2.5. Requirements for replacements have been less
rigid.
Plant facilities preceeding the sand filters consist of a grit
chamber, screening, raw sewage pump station, two primary settling tanks,
a trickling filter, a final settling tank, a sludge digestion tank and
open sludge drying beds. Digester supernatant and underdrainage from
the sludge drying beds are discharged to the raw sewage pump station.
Sludge from final settling tanks is returned to the raw sewage pump
station. The final settling tank effluent is disinfected with chlorine.
Trickling filter effluent for the 18 months of study averaged
40 mg/1 for both BODr and suspended solids. Sand filter effluents for
their eight months of operation averaged 8 mg/1 BOD5 and 9 mg/1 suspended
solids. Thus quantities of BOD and suspended solids were reduced from
about 175 Ibs in the trickling filter effluent to about 35 Ibs in the
sand filter effluent. Overall plant removal on a quite weak raw sewage
averaged 91% BOD,- and 92% suspended solids at sand filter loadings of 13
gpd/ft2 or 0.57 MGAD.
Discussions with the plant superintendant reveal that the sand
filters show no sign of operating less effectively at the end of the
five-month summer operation. In his opinion, these filters could be
operated continuously at these loadings with equal effectiveness.
Pressure Mixed Media Filters
At plant 302, four pressure sand filters, each consisting of steel
cylinders, 9ft in diameter and 15 ft long with dished ends, provide
approximately 600 ft2 of filter area. Media consists of layers from top
to bottom of 20 inches of 1.0 mm anthracite, 20 inches of 30-40 mesh
52
-------
garnet and 9 inches of No. 6 mesh
controlled automatically. Normal
3-5 minutes.
garnet. Filtering and backwashing are
backwash rate is 16 gpm/ft for about
Plant facilities preceeding the pressure filters consist of screening,
ferric chloride fed ahead of an aerated grit chamber followed by introduction
of a polymer ahead of primary settling tanks, a pumping station, three
trickling filters and two final settling
settling tanks is pumped to the pressure
tanks. The effluent from the
filters. The filter effluent
before discharge. There are two
tanks. Supernatant is returned to the
is then disinfected with chlorine
heated anaerobic sludge digestion
raw sewage wet we.l 1.
Trickling filter effluent for the 12 month study period averaged 31
mg/1 BODr and 19 mg/1 suspended solids. Pressure filter effluents
averaged 22 mg/1 BODg and 7 mg/1 suspended solids. Overall plant removal
on a quite strong raw waste averaged 93% BODr and 94% suspended solids.
Quantities in the trickling filter effluent were reduced from 500 Ibs
BOD,, to 350 Ibs and from 310 Ibs suspended solids to 115 Ibs.
Summary of Fine Media Filter Performances
The effectiveness of the four filter processes
quality of trickling filter effluents is summarized
in upgrading,the
in Table 22 below.
Type of
Fi1ter
Dosing
Rate ,
gpd/ft"
TABLE 22
'-..'. BODr
• b
FE FME % Removal
mg/1 mg/1 tot.pi ant
SUSP. SOLIDS
FE FME
mg/1 mg/1
% Removal
tot.pi ant
Pressure-mixed , .
media - back-
washed . 3200 31 , 22
Gravity - mixed .
media - back- .
washed " '4050 16
Gravity - sand
backwashed , 2400 24
Intermittent - ;
sand 13 40
FE = Trickling Filter Effluent
FME = Fine Media Effluent
5
4
8
93
95
99
91
19
94
15 2 98
17 5 98
40
92
53
-------
Stabilization or Oxidation Ponds
Several plants were studied where trickling filter effluents are
upgraded by means of supplemental ponds. Three such plants were selected
where facilities are typical of those providing a high quality effluent
and where extensive reliable analyses and flow records are available.
Aerated and Short-Term Stabilization Ponds
The trickling filter at plant 117 is followed by an aerated pond
and a stabilization pond. The effluent is then distributed evenly over
a 20 acre peat absorption bed. The plant consists of the usual components:
screening, pumping, grit removal, primary sedimentation, single-stage
trickling filters and final settling tanks. Effluent is pumped to the
aerated lagoon. Sludge is digested in a heated anaerobic digester /
followed by an unheated sludge storage tank. Storage sludge is withdrawn
periodically to a sludge lagoon. Supernatant is also discharged to the
lagoon.
The aerated pond is three acres in area and six feet deep. The
pond provides a detention time of about six days for average flows of
0.93 MGD treated during the 12 months study period. Aeration is provided
by a floating surface type aerator with a 15 hp motor which theoretically
supplied oxygen at a rate of 1,350 Ibs/day. Loading on this pond averaged
310 Ibs BOD,- and 285 Ibs suspended solids per day, as noted in the
monthly averages summarized with other information in the Appendix for
this plant. Removal of both BOD5 and suspended solids is quite consistent
during the year, averaging 55% and 8%, respectively.
The overflow from the aerated pond passes to a stabilization pond
with a surface area of 25 acres and a water depth of three feet. Detention
time at the observed average flow rate of 0.93 MGD is about 25 days.
Effluent quality is seven mg/1 for both BOD5 and suspended solids. The
poorest performance occurred in April, undoubtedly associated with
accelerated anaerobic biological activity as the ice cover melted and
temperature rose in the lagoon.
Performance on a total treatment facility basis is as follows:
2,000 Ibs of BODr in the raw sewage was reduced to 55 Ibs for over 97%
removal; and 1,980 Ibs of suspended solids reduced to 55 Ibs for 97%
removal.
Long-Term Stabilization Pond
At plant 121, six'waste stabilization ponds totalling 540 acres are
used to upgrade the quality of the effluent of an ordinary trickling
filter plant which consists of screening, pumping, grit removal, primary
sedimentation, single-stage filters and final sedimentation. Sludge
from final settling tanks is returned to the raw sewage pumping station.
Sludge treatment is accomplished by two heated digesters followed by two
secondary digesters. Digested sludge is discharged to open drying beds
and supernatant is piped to the primary sedimentation tanks. Under-
drainage of sludge drying beds is discharged to the raw sewage pumping
station.
54
-------
The plant effluent is pumped to the waste stabilization ponds which
occupy one square mile. There are six ponds, each with a surface area
of 90 acres. Five are operated in parallel, the sixth serving as a
secondary pond. Each of the five primary ponds are operated in turn,
filling for a period of 20-30 days depending on rainfall and evaporation
rates. The pond is then discharged to the secondary pond where it is
held for about 20-30 days before discharge. Late in the fall the contents
of all primary ponds are lowered for winter storage during ice coyer and
discharged quite rapidly in the spring after which the regular fill,
hold and discharge cycle is followed. Time of discharge is governed to
some extent by river flow conditions.
Operational data for both the plant and the ponds are summarized in
Table 23 and in the Appendix. The trickling filter plant effluent is
quite typical of single-stage filters in the northern climate averaging
about §5 fiig/1 BODr and 45 mg/1 suspended solids. The effluent is
upgraded to values of 6-15 mg/1 BODg and 10-15 mg/1 suspended solids on
an annual basis. Thus the loading on the receiving stream is"reduced
from about 2,800 Ibs BOD,- per day in the trickling filter effluent to
about 875 Ibs and the loading from the plant is completely eliminatpd in
the ponds by storage during three winter months. Overall removals by
plant and pond are in the order of 95% of the BODg and 93%'of the
suspended solids.
Although analyses are not made on nitrogen, it is reasonable to
expect that considerable nitrification takes place in the ponds with
ammonia dropping to very low levels. This.was the experience at plant
160. The" effluent from this Imhoff tank and trickling filter plant
required a g"reat deal of upgrading to meet a rigid effluent requirement
including a very low ultimate BOD. ' . -
Ponds Were constructed on State owned property, consisting of three
cells with piping for either parallel or series operation's. Maximum
water depth was 10 feet, providing a theoretical detention time of about
100. days at the average 1.1 MGD flow. Table 24 summarizes performance
during calendar year-1971. During the previous November, the lagoons
were drawn down moderately when stream flows were relatively high.
Storage during December brought all of the ponds to the 10 ft stage,
ready for series flow-through operation, for the winter months as
indicated in the schematic flow diagram in the Appendix.
The values for percent removal in Table 24 represent overall performance
for the to'tal facility, which includes the filter plant and ponds. It
is interesting to note that the filters substantially reduced ammonia
values ea'ch month of the year by more than 50%, increasing to about 60%
during the summer. The residual ammonia was lowered to less than 0.5
rng/l during warm summer months. Annual averages were 13.6 mg/1 NhL-N
in the raw Sewage, 5.8 mg/1 in the filter plant effluent and 0.81 fng/1
in the pfind effluent. Correspondingly, total phosphorus was 6.1 mg/1 in
the raw wastewater, 4.8 mg/1 in the filter effluent and J.I mg/1 in the
ponds effluent.
55
-------
TABLE 23
REMOVAL OF BODS
BY TRICKLING FILTERS AND STABILIZATION PONDS
121 N.D.
Month
1975-76
November
December
January
February
March
April
May
June
July
August
September
October
Averages
Sew.
Flow
MGD
5.41
4.91
5.10
5.45
6.66
6.53
6.09
6.38
6.25
5.93
5.78
5.77
5.86
PONDS
Discharge
MGD
18.55
8.24
0
0
0
8.08
8.28
0
8.49
0
9.17
14.35
6.29
BOD5 - Lbs/Day x 1000
Raw
10.53
8.53
10.14
10.51
13.24
13.20
10.42
10.76
10.33
11.24
9.94
10.31
10.76
Filter
Eff.
2.39
2.54
2.81
2.59
3.00
3.27
3.00
2.66
2.24
2.38
3.09
2.84
2.73
Lagoon
Eff.
0.93
0.62
0
0
0
1.01
0.83
0
0.78
0
0.77
1.08
0.05
TABLE 24
PERFORMANCE OF
TRICKLING FILTER PLANT & STABILIZATION PONDS
160 Mich.
1971
Month
January
February
March
April
May
June
July
August
September
October
November
December
Average
Low
High
Inf.
Flow
MGD
35.78
33.99
36.18
34.02
38.47
34.96
34.36
33.30
31.12
32.16
31.86
32.99
33.62
(403.68)
PH
.-
8.2
7.9
8.2
8.4
8.8
9.0
9.5
9.8
9.6
9.4
8.8
8.4
8.8
7.9
9.8
D.O.
mg/l
9.3
9.2
8.5
8.2
7.7
8.7
10.1
9.9
10.1
9.7
10.6
12.0
9.6
7.7
12.0
S.S.
mg/l
18
23
27
50
93
82
66
44
33
25
29
29
43
18
93
%
Rem.
90
88
85
70
45
53
63
73
82
86
82
84
75
45
90
BOD5
mg/l
4.6
8.9
7.2
10.7
19.5
22.0
15.0
10.0
7.0
7.0
6.0
8.0
11.0
4.6
22.0
%
Rem.
98
95
95
93
87
87
90
95
97
97
97
97
94
87
98
Ammonia
mg/l
1.40
1.67
0.95
0.87
0.77
0.52
0.46
0.21
0.21
0.17
0.70
1.78
0.81
0.17
1.78
%
Rem.
80
80
89
91
94
98
96
98
98
99
84
92
92
80
99
Phosphorus
mg/l
2.01
2.37
2.52
2.20
1.04
0.57
0.35
0.16
0.15
0.14
0.85
1.13
1.12
0.14
2.52
%
Rem.
58
55
52
61
80
85
92
97
98
98
88
73
78
52
98
BOD20
mg/l
14.1
13.6
33.0
33.0
37.0
34.0
27.5
13.6
37.0
BOD20
filterd
mg/l
23.0
19.0
21.0
Composited samples
Flow Pattern: January 1 through May 16th -flow through to river at 10,0 ft. stage.
May 17 through November 8th - storing In series.
November 8 - 23rd. - discharging to river
November 24th to December 31st. - Storing In series.
-------
TABLE 25
REMOVAL OF BOD AND SUSPENDED SOLIDS
BY TRICKLING FILTERS & ACTIVATED SLUDGE
403, Minn.
Month
1973
. January
February
March
April
May
June
July
August
September
October
November
December
Average
Sew.
Flow
MGD
2.8
2.8
3.4
3.2
3.1
2.9 ^
2.8
2.8
3.9
3.5
3.1
3.1
3.1
5-Day BOD
Raw
mg/l
334
276
281
323
302,
297
262
303
280
324
345
406
311
FE
mg/l
19
17
14
8
14
10
4
6
5
15
11
14
11
Rem
Raw-FE j
94
94
95
98
95
97
98
98
98
95
97
97
96
Susp. Solids
Raw
mg/l
162
162
203
190
188
199
202
182
144
190
173
205
183
FE
mg/l
7
6
7
4
5
12
8
7
5
9
6
7
7
Rem
Raw-FE
96
96
97
98
97
94
96
96
97
95
97
97
96
TABLE 26
REMOVAL OF BODS AND SUSPENDED SOLIDS
BY TRICKLING FILTERS AND ACTIVATED SLUDGE
" " . 402, Minn.
Month
1975-76
August
September
October
November
December
January
February
March
April
May
June
July
Averages
Sew.
Flow
MGD
1.04
1.11
1.07
0.98
'0.95
0.47
0.46
0.48
0.48
0.79
0.96
0.92
BODS
Raw
mg/l
657
552
553
592
602
771
. 646
620
495
425
426
428
564
FE
mg/l
27
26
22
26
29
32
28
17
17
22
28
16
24
%
Rem
96
95
96
96
95
96
96
97
97
95
93
96
96
Susp. Solids
Raw
mg/l
336
406
377
411
430
577
661
623
599
474
319
298
459
FE
mg/l
20
26
13
19
27
37
59
25
42
24
19
20
28
%
Rem
94
94
97
95
94
94
91
96
93
95
94
93
94
-------
The stabilization ponds reduced BOD,- levels from about 17 mg/1 in
the filter influent to 11 mg/1 in the pond effluent, removing about 35%
from an excellent filter plant effluent for overall removal of 94%.
Suspended solids in the pond effluent remained at about the same level
as the trickling filter effluent on an annual basis. Unquestionably,
algae cells accounted for a high proportion of the final solid concentrations.
Activated Sludge
Several plants were studied where activated sludge follows trickling
filters. A variety of flow patterns and loadings are used. At plant
403, for example, flow from the primary sedimentation tanks is divided
in two equal parts. One-half is pumped to a trickling filter, the other
half to the activated sludge reactors. The effluent from the settling
tank following the trickling filter mixes with the primary effluent
going to the aeration tanks. Filter effluent and activated sludge mixed
liquor are returned to the raw sewage wet well and recycled to the
primary sedimentation tanks with the raw wastes. Loading on the activated
sludge system is about 75 Ibs of BOD5/1,000 ft3. Average detention time
is four hours including return activated sludge. Raw BODr is reduced
from 311 mg/1 to 11 mg/1 and suspended solids from 183 mg/1 to 7 mg/1
representing 96% removal of both as shown in Table 25.
At plant 402 the trickling filter effluent is discharged directly
to the activated sludge process without intermediate settling. A strong
waste averaging 564 mg/1 BOD,- for the 12 months studied is reduced to 24
mg/1 in the plant effluent for 96% reduction. Correspondingly, 94% of
the suspended solids in the 459 mg/1 raw waste is removed leaving 28
mg/1 in the plant effluent. Equally good performance is accomplished
throughout the year as may be noted from Table 26.
Data were reviewed at four other plants in Minnesota where trickling
filters are followed by activated sludge. Overall performance of the
six plants is summarized in Table 27 below.
TABLE 27
REMOVAL OF BOD,- AND SUSPENDED SOLIDS
BY TRICKLING FILTERS FOLLOWED BY ACTIVATED SLUDGE
ANNUAL MEAN OF MONTHLY MEANS
Municipality
401 MN
402 MN
403 MN
404 MN
405 MN
406 MN
Averages
Flow
MGD
Raw
BOD
Rem
SUSP. SOLIDS
Raw EFF
Rem
4.69
0.82
3.13
0.28
2.22
0.65
191
564
311
248
222
153
281
9
24
11
9
12
11
13
95
96
96
96
95
93
95
170
459
184
344
293
162
269
22
28
7
26
17
15
19
' 94
••• 94
96
92
94
91
93
58
-------
Observations and Conclusions
A rather wide variety of supplementary treatment processes..for
upgrading trickling filter effluents were examined. Extensive data from
"' full-scale field installations were studied and summarized
Selection of the method to be used is dependent on many
considerations and circumstances related to the individual installation.
Performance capability of the several processes for improvement of
trickling filter effluent quality is reflected in the following summary
(Table 28). ' • ' ,
. — •-f
several typical
in this report.
TABLE 28
UPGRADING TRICKLING FILTER EFFLUENTS
BY ADDITIONAL TREATMENT PROCESSES
- • *
Tertiary Process
A.
B.
C.
D.
Fine Media Filters
with Backwashing
1 . Mixed Media-Gravity
2. Mixed Media-Pressure
3. Sand-Gravity
Sand Filters-Intermittent
Waste Stabilization Lagoons
1 . Short Term Following
Aerated Lagoons
2. Long Term - 1 Plant
Long Term — 1 Plant
Activated Sluge - 6 Plants
BOD5
Filter
Eff.
mg/l
16
31
24
40
18
56
17
IMD
Tert.
Eff.
mg/l
5
22
4
8
. 7
10
11
13
% .
Rem.
Raw-
Final
.':
95 "
93
99
91
97
95
94
95
Susp. Solids
Filter
Eff.
mg/l
15
19
17
40
18
47
47
ND
Tert.
Eff.
mg/l
2
7
5
9
7
13
43
19
%
Rem.
Raw-
Final
98
-• 94
98
92
97
93
75
93
59
-------
ACKNOWLEDGEMENTS
The information set forth in this report is, in large measure, the
product of the combined efforts, cooperation and interest of staff
engineers and technicians in the water pollution control agencies of
Michigan, Minnesota, North Dakota, Pennsylvania, and Wisconsin, and the
plant superintendants and operators of all of the plants for which data
were provided for the in-depth field performance studies. A great many
of these people not only furnished facts and figures but, very importantly,
provided valuable insight and understanding of day to day operations,
problems and solutions and shared in many of the value judgements
expressed herein. Their participation, assistance and counsel are
gratefully acknowledged.
60
-------
APPENDIX
The Appendix contains key information on facilities, loadings and
performance ;of 26 trickling filter plants discussed in this report. Raw
data for each plant on physical.features, daily records^of sewage flow
and temperatures and 1 aboratory analyses were furnished by, the responsible
state regulatory .agencies and plant superintendants.;,
These plants were selected from a large number of municipal facilities
of similar designs, modes of operation, loadings and overall performance.
Daily records for each plant, usually for two or more years;, were examined
in order to establish normal loadings and performance of the plant.
Flow patterns are shown for each plant. Routing of wastewater
through the unit processes, points of recirculation and points of discharge
of digester supernatant and other sludge fractions are indicated. These
flow diagrams are not drawn to scale nor do they necessarily portray the
shape or number of units such as pumping stations, settling tanks, etc.
Plants are grouped alphabetically by classification as single-
stage, two-stage, those with chemical treatment and those followed by
additional facilities.
61
-------
-------
TABLE OF CONTENTS - APPENDIX
PLANT NO.
Single-Stage Filters
107 Mi
110 Mi
112 Mi
SUBJECT
125 Mi
132 Mi
160 Mi
163 Mi
Two-Stage Filters
213 Mn
219 Wi
Facilities and Loadings
Table A-l: Removal of BOD and SS
Facilities and Loadings
Table A-2: Removal of BOD and SS
Facilities and Loadings
Table A-3: Removal of BOD and SS
Fig. A-l: Curves - Effect of Sewage Temp.
on Removal of 'BOD
Facilities and Loadings
Table A-4: Removal of BOD and SS
Facilities and Loadings
Table A-5: Removal of BOD and SS
Fig. A-2: Curves - Removal of BOD
Facilities and Loadings
Table A-6: Removal of BOD and SS
Facilities and Loadings
Table A-7: Removal of BOD and SS
Facilities and Loadings
Table A-8: BOD Loadings and Removals -
8 years
Table A-9: Removal of BOD and SS
Table A-10: Removal of BOD - 8 years
Facilities and Loadings
Table A-ll: Comparison of BOD Removals by
First and Second Stage Filters
Filters with Chemical Precipitation
301 Mi
302 Mi
Facilities and Loadings
•Table A-12: Removal of BOD and SS
Facilities and Loadings
Table A-13: Removal of BOD, SS and P
Fig. A-3: Curves - Removal of BOD by
Trickling Filters and Pressure Filters
PAGE
A-l
A-2
A-3
A-4
A-5
A-6
A-7
A-8
A-9
A-10
A-ll
A-12
A-13
A-14
A-15
A-16
A-17
A-18
A-18
A-19
A-20
A-21
A-22
A-23
A-24
A-25
A-26
a/i
-------
TABLE OF CONTENTS - APPENDIX
PLANT NO.
303 Mi
211 Mi
304 Mi
305 Mi
312 Mi
306 Mi
307 Mi
308 Mi
314 Mi
310 Mi
309 Mi
Continued
SUBJECT PAGE
Facilities and Loadings A-27
Table A-14: Removal of BOD, SS and P A-28
Fig. A-4: Curves - BOD Removal A-29
Facilities and Loadings before Tertiary
Treatment A-30
Table A-15: Comparison of BOD and SS
Removals by First and Second Stage Filters A-31
Facilities and Loadings - Trickling Filters
and Gravity Sand Filters A-32
Fig. A-5: Flow Pattern - Trickling Filters
and Gravity Sand Filters A-33
Table A-16: Removal of BOD, SS and P A-34
Fig. A-6: Curves - Removal of BOD before
and after chemical precipitation A-35
Facilities and Loadings A-36
Table A-17: Removal of BOD, SS and P A-37
Fig. A-7: Curves - Removal of BOD before
and after chemical precipitation A-38
Facilities and Loadings A-39
Table A-18: Removal of BOD and SS A-40
Facilities and Loadings A-41
Table A-19: Removal of BOD, SS and P A-42
Fig. A-8: Curves - Removal of BOD A-43
Facilities and Loadings A-44
Table A-20: Removal of BOD, SS and P A-45
Fig. A-9: Curves - Removal of BOD A-46
Facilities and Loadings A-47
Table A-21: Removal of BOD, SS and P A-48
Facilities and Loadings A-49
Table A-22: Removal of BOD and SS A-50
Facilities and Loadings A-51
Table A-23: Removal of BOD, SS and P A-52
Fig. A-10: Curves - Removal of BOD before
and after chemical precipitation A-53
Facilities and Loadings A-54
Table A-24: Removal of BOD, SS and P A-55
a/ii
-------
PLANT NO.
311 Mi
313 Mi
TABLE OF CONTENTS - APPENDIX
Continued
SUBJECT
Facilities and Loadings
Table A-25: Removal of BOD, SS and P
Facilities and Loadings
Table A-26: Removal of BOD and SS
Filters Followed by Additional Treatment Works
169 Mi
117 Mn
121 ND
Facilities and Loadings
Table A-27: Removal of BOD and SS by
Trickling Filters and Sand Filters
Facilities and Loadings
Table A-28: Removal of BOD and SS
Table A-29: Removal of BOD and SS —
Trickling Filters and Ponds
Facilities and Loadings
Table A-30: Removal of BOD and SS by
Trickling Filters and Lagoons
PAGE
A-56
A-57
A-58
A-59
A-60
A-61
A-62
A-63
A-63
A-64
A-65
a/iii
-------
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
107, MICH
FLOW PATTERN
Final tank sludge
I
I
FS
FE
CAPACITIES AND LOADINGS
FILTER
1-80 ft. Diam. -6 ft. deep
Area = 0.115 Acres
Volume = 30,160 cuft.
Loading
Hydraulic @ Average Flow = 1.07 MGD and R = 1.3 MGD = 2.37 MGD
= 20.6 MGAD - 475 gd/sqft
u. 1 1 b
Organic @ 99 mg/l in PE
= 1.07 x 8.35 x 99 =
30.16
cuft
FINAL SETTLING TANK
1-45' Diam. Area = 1,590 sqft.
Surface Overflow rate @ 900 GPM Pump rate
- = 800 gals/day/sqft
SLUDGE TREATMENT AND DISPOSAL
1 -Digester 30' Diam. 20 ft. deep
vol. = 14,150 cuft.
Digested sludge to open drying beds
Supernatant to raw sewage wet well
a/1
-------
o
CO
o
Ul
O
z
Ul
a.
O
CD
UL
O
O
UJ
CC
T3
1
1
Q
2
ID
O
IT)
JO
CO
g
ro
cc c
E
0)
CC
«#
111
UL
Ul
Q.
5
E
0)
CC
*4
Ul
U.
Ul
Q.
1
O
U.
i!
+*
c
o
s
Ul
LL
0
CC
c
—
c
—
s
Ul
II.
ro
CC
f
^
s
Q
(3
"*
j.
CO
^x
O
SSSSSSco^corSi^S
CMOT-OOOCMCNOOCN^-CO'*
cscnooooror^orooocMooco
'-cor- ooojincor-oco
CN«— ^— oo^— omoor— ooo«—
^Sr:[S8§5^gSc3^
^^co«§^§^$5^f5
eMOCDOOmCMOOCMCNCNOCM
cnoooocDooocNCMocococo
M'3-COOT'-CMOLOOOOCMCO
»-ocDO)»— T— coi^oomcoco
»»....,...
— . •- 0? -». 4-*
CZT ^^ m f"» m" C ulT" 'P^ Q ^^ ^ ti
..<.020
•^
-
5
05
co
CO
CM
0)
o>
s
D
1
O)
<
&/'<
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
110, MICH
FLOW PATTERN
R
PC
• o
r
t"
, X~
ik f
V r
CAPACITIES AND LOADINGS
FILTER
1-68 ft. Diam.
Area = 3,630 sqft. '= 0.083 Acres
Volume = 21, 800 cuft.
Loading
Hydraulic @ Average Flow"= 0.4 MGD and R - 1 .25
gpd/sqft
Organic
- 23lbS/1000cuft
• oonn
21 ,800
Primary settling tank is IMHOFF Tank
SLUDGE TREATMENT AND DISPOSAL
1-Digester-15,500 cuft.
Supernatant to. Imhoff tank
Digested sludge to open drying beds
CHEMICAL TREATMENT-None
FS
C
FE
a/3
-------
CD
CQ
CD
O
p»-
o
co
CO
2
CO
CO
23
00
CO
c,
NJ
ro
oo
00
r> < 5? "S cQ*<^-<~t-tcr^
CDcDO(j)C — • O ""* C
cr 1- ™ 1- rt " •<
£? S? S^ •<
oooooooooooo
K5 ro ro co to r*- fs. ^, ^ji pw ^j js.
cn-vicoNJOoroco'^ioococDco
ODN3-»— 'CD-vlOl-vIOlOOOOCD
NJ oo^o^i^iiococnio
8a2^S^!^^S2S3^
coi^iococoro^cococococo
OOOOOOOOOOCOvJOOOOOO'vlOO
oo^^oo^coooco^o,-^
| ± g o co co o g g co g 03
^S^^^g^olK^ol^
COCOCOCOCOOO^vlOOOOOOOOOO
3
CO
ID
^
(Q
€
T3
m
TO
m
ss
30
CD
3
Tl
O
€
01
O
D)
CO
O
D
(V)
V)
•o
CD
i.
8
V)
o
a.
m
^
O
CD
O
oo >
C tSJ
en
TJ
m
co
O
a/4
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
112, MICH
FLOW PATTERN
R+S
G
X,
t
P
PS
PE /
"^Sludge (S)
CAPACITIES AND LOADING
FILTER
1-75 ft. Diam. 6ft. deep
Area = 4,420 sqft = 0.101 Acres
Volume = 30,000 cuft.
Loading
Hydraulic @ Average Flow (0.77 MGD) plus R =0.5-1.0
9als/day/SC
-------
CO
g
_J
o
CO
Q
LLI
Q
ss
o
CO
111
DC
-a
1
V)
Q
O
CO
(0
in
L
re
'CC
1
CC
LU
LL.
LU
Q.
CO
CC
§
CC
5?
LU
LU
Q.
S?
(0
CC
? C
3 C
L e
1 1
w ^
.£
+•
c
SLU
CB n
CC
c
1
1
rr "
— -
O)
S
s
_
en
3
3
»
i
: u.
5 o
t
i
i
______
SSKS^S^^gSEg S5£S££S
>.oO>eM '*OCDOLOTt-C5
»- i-CMCM«-OOOOOOiCNO)O O O> O «- «— 051s*
COCOIOO5OCMCMOOOOCMCM '*o)oo«a-CDT-c«;
CNCMCNCMCMCMCMCMCMCMCMCM CMCNCOCMCMCMCN
ogsSrSLocMS55Sco co^coocoLog
mcoooor^-ocococooooo '3-Lor-T-cococo
cQcooor*i^LO'«toO'OC)C5
CO ^* T~" ^* ^^ LO CD *""* O5 CO 00 1^ ^N ^^ C^ ^^ f^ JQ c^
LO LO LO LO CO CD P^ f^ CD C^5 CO ^5 LO LO LO LO CO fO 1*^
1^1 i 111 Ills II lilllIlS
g
§
S3
CM
CM
CO
CO
O)
N
(^
o
en
•^
a/6
-------
tsj *»
o o
8 S
BOD5~Mg/e
o to *;
o o o
TEMP-°F
T 1 1"T
o
en
_>
CO
O
| S
V)
^ >
tO
05 _,
L
a/7
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
125, MICH
FLOW PATTERN
G
X
p
PS
PS
PS
CAPACITIES AND LOADINGS
FILTERS
2-100 ft. Diam.-6 ft. deep
Total Area = 15,700 sqft.-0.360 Acres
Total Volume-94,250 cuft.
Loading
Hydraulic @ Average Flow = 1.28 No recirculation
= oJf- = 3'56 MGAD = 1f?S700°° = 81 gals/day/sqft
Organic®91 mg/l in PE
_ 1.28 x 8.35 x 91
94.25
= 10.3 #/1000 cuft
SLUDGE TREATMENT AND DISPOSAL
2-Digesters @ 25,000 cuft. each
Total Volume = 50,000 cuft.
Digested sludge to drying beds
Supernatant (see Flow Pattern)
FINAL SETTLING TANKS
3-18'x 45'
Total Area - 2,450 sqft.
Surface overflow rate @ 1.28 MGD
_ 1,280,000 _00 . / . , .
- ' 245Q— = 522 gals/day/sqft
a/8
-------
LU
LL
i
CC
O)
£
s-
8
Q
LU
O
2
LU
8>
III
LU
Q.
m
CC
S8S3.533858E58.
00
CO
§8
00
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
132, MICH
FLOW PATTERN
j//
RAW
^
r> 1
J
-------
CO
Q
8
Q
UJ
Q
UJ
a.
o
CO
o
LU
CC
en
^3
"o
CO
a.
Q
O
CO
s
LO
0)
CC
*
LU
LL
LU
Q.
I
CC
O)
CC
ss
LU
LL
-
LU
a.
re
CC
1
LL
JC
0
LU
LL
g
CO
CC
*S*
?
57
D>
S
—
s
LU
LL
5
CC
'S
^
_
^33
S
^
'£
O
CD
r~.coLocO'«-oo'*oooLOLoa) ^-toooooLootocj
oooor-ooOTOomoomoor^co oooor^r^oooooooo
CD CN C? 00 n O^ CO Oi F~^ rt 00 f"^ CO * — Oi C>j CO O3 ^ *T
l-CMCO-'-CMT-r-T-T-CMCO'- T-CMr-CNr-
- .- . " • , ; - •• • ":
^^ ^* y? ff* « ~& P^ p? £^J 5x QQ ^ to f>^, «-*• LO LO r** r^* oo
r\i oo *— CO 00 O CO COCDOLOO5 CO'd't^-CMOOCOOO^t
CMLOCMCOLOCOOinCOLOLOLO «- LOOOO'-'*'*O)
• : •<:•;.
....'-. '• _-'....
LO oo LO co r> s?*'- o c» en ro oo ^'^'"ScolSSro
'.'-.. • --."'..'.--•,
CMCOCMCMCMCMCMCMCMCMCMCM CMCM'— CN*-CNCSCM
i i^ 10 to oo cn r^ LO
f**« *d" CM. r^ CO *~" *Nt" CO CO CO C3 *f ^^ J^ . |^r ^^ ^Q j^^ ^Q
SSS8SS2i=i8??SS 88SSS££g
O) CM CO COOOCOCMLOCOCOaiCM S^^^SSSiom
oor^.'-oooooocococococnoo cnenr-^enpr^Lqcq
QOf-ooooo-dooo oo»-o»-opo
llillilllllllliiliil*!
§
CM
o
1^.
o
LO
£
.LO
CO
CM
LO
CO
0
en
o
1
1
a/11
-------
BOD5~Mg/£
CO
-j
CO
CD
CO
O
I
330
Or->
•n H is>
m rn
01
CO
O
a/12
-------
• cr
CO
73
CO
tu
CO 2 «D
UJ Z «-
II
cc.
LU
5
o.
O
LU
ca
CD
cl
o
85
Q
63
H
AND LOADINGS
CO
LU
1-
^
^5
St
CJ
2
UJ
.UDGE TREATM
CO
•o
.I"
>•
45
c
CD
Q.
O
o
« &
c 8.
a •B
«t ^
° T3
"c B
C CO
CQ Q
I I
CM CD
CO
z
H
INAL SETTLING
LU
11
03
"£
1
1
< S
5 «=
^ 1
' 1
§ 0
x g
fe ^e
CN CO
Q
O
r^.
^
cr
«*^
CO
^2
8
CO
111
_l
N
N
O
D
LU
X
CO
Q. O-
f-5 ^
CN ™ 4S "g :*"
LO
CO
II
00
X
CO o O
CM I— I—
a/13
-------
o
CO
O
UJ
O
HI
a.
co
"9 3 i
^oc^co cocv.^r.o
oi-r— oor-co aicocooo
SSSSS5 SS5S2
3D O5 (J) Ol O) Ol OJOiCOOJCT
sssss" '»-gj«a
cDinco^fcMco co T— o co in
incocDCDinif) co^rMcoco
RfllMEIigME
SSSSSSfSSSSZ
cnoo-incDCCoi^cocMO
llf'c^g^lslll
CO
5
CO
to
CO
CO
to
^
8-
£
CM
CD
-
S
1
\J
^
?
a/14
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
163, MICH
FLOW PATTERN
R+S
RAW
: >•
"x
r~ ~
|
p
— -*
PS
PS
-- — Tr
DC /*Z""N 1
* C) ^
/^—
-------
CO
00
HI
CO
LU
CC
LU
oc
UJ
OQ
LO
LU
cc
§ Q
O CJ
CO LL.
£ t LL
Q) O
CO r- t- |>. CO
in LO o if)
LOcoLOf~(~.cop*-r--Lr
r:£2S£2H?S:ci!{5l»M'-oo
00 LO ^f
oo ^ co
CM t— co r- o T- o
*- «- «- r- CN CM T-
5P£?£?POOLni^|^o°ooo
C55 Ifl CO LO O OT C5
o »— to
CNCMCMOMOOCMCMCMCNCO 00 OO
JOOOOr— CMOCMI^I^OOCDO
oocoLOt^.'^'^oqoooocNioMLq
OOOOC3C)OC3C3C)COC3
n in LO S LO co
c £} i- i- >•
QJ ro o_ co
LL S < S
LO l>~ LO •* CN 1^
CD CO CD CO CO LO
<8o£ &
CD
CD
CO
in
LO
a/16
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
213, MINN
FLOW PATTERN
-»• s
G
P
CAPACITIES AND LOADINGS
FILTERS
Primary Filters:
1-58' Diam: Area =2642 sqf t = 0.0606 Ac.; Vol = 15850 cuft
1-77' Diam: Area = 4657 sqft = 0.1069 Ac.; Vol = 27940 cuft
Total Area = 7300 sqft =0.168 Ac.; Total Vol = 43,800 cuft
Loading
Hydraulic @ 2.4 MGD + R( 1.1 MG) = 3.5 MGD
= 21 MGAD
= 480 gals/day/sqft; ;
Organic @ 2085* BOD5 in PE
= fff = 47-6*/1000cuft
Secondary Filters:
2 filters same sizes as Primaries
Loading
Hydraulic @ 3.5 MGD = 480 gals/day/sqft '
Organic @ 739ff BODS in IE
= 16.9#/1000 cuft
Total System
Organic,© 2085* BOD5 in PE
= ^rf =:23.8*/1000 cuft
INTERMEDIATE SETTLING TANKS (IS)
2-54' x 20' x 12.5' = 2160 sqft
1-67' x 15' x 9.5' = 1005 sqft
Total Area = 3165 sqft
Surface Overflow Rate @ 3.5 MGD
= 11 00 gals/day/sqft
FINAL SETTLINGTTANKS (FS)
2-67' x 20' x 9'
Area = 2680 sqft
Volume = 24000 cuft
Surface Overflow Rate @ 2.4 MGD
2,400,000
2680
= 900 gals/day/sqft
SLUDGE TREATMENT AND DISPOSAL
1-Primary Digester —Volume = 100,000 cuft
1-Secondary Digester —Volume = 27,600 cuft
Digested Sludge partly to open drying beds,
partly hauled wet to fields
a/17
-------
TABLE A-8
REMOVAL OF BOD5
213 MINN.
TWO STAGE TRICKLING FILTER PLANT
Year
1963
1964
1965
1966
1967
1968
1969
1970
Avg
Raw
Flow
MGD
1.48
1.69
2.10
2.19
2.77
3.24
3.17
2.59
2.40
MGAD
8.8
10.0
12.5
13.1
16.5
19.3
18.9
15.5
14.4
Loading on
Primary Filter
BOD in PE
(Lbs.)
1347
1552
1613
2085
2267
2787
2673
2357
2085
Lbs. per
1000 cu.ft.
30.76
35.44
36.83
47.61
51.76
63.63
61 .94
53.82
47.61
Ths. cu.ft.
per MGD
29.6
27.6
20.9
20.0
15.8
13.5
13.8
16.9
19.8
% Removal
PEto
IE
64
65
61
54
65
69
67
70
64
PEto
FE
75
79
77
71
82
83
81
75
78
Legend:
PE = Primary settling tank effluent
IE = Intermediate settling tank effluent
FE = Final settling tank effluent
TABLE A-9
REMOVAL OF BOD AND SUSPENDED SOLIDS
213 MINN.
Month
(1973)
January
February
March
April
May
June
July
August
September
October
November
December
Averages
Sew.
Flow
MGD
2.3
2.2
3.5
3.4
3.7
2.6
2.5
2.8
2.5
2.7
NR
2.4
2.8
5-Day BOD
Raw
Mg/l
184
166
109
138
122
178
184
171
176
142
NR
NR
157
FE
Mg/l
22
27
29
23
27
23
29
40
33
33
NR
NR
29
%
Rem.
88
84
73
83
78
87
84
77
81
77
82
Susp. Solids
Raw
Mg/l
150
157
130
109
97
119
157
138
145
153
NR
NR
136
FE
Mg/l
28
36
30
39
24
31
30
28
28
31
NR
NR
31
%
Rem.
81
77
77
64
75
74
81
80
81
80
77
a/18
-------
CL
OC
UJ
slli
.
II
^cl
i £
1
•s
1
Q
§
I
£'
• 3
CD
CC
1
*•
UJ
u.
a.
g
oc
o
i.
s
»- a.
o E
S
*
UJ
U.,
Ul
U_
UJ
a.
UJ
u.
uV
LU
*
a
LU
LU
Q.
Raw-PE
1
I
£
1
1
i
1
f^
o"
o
S
r-.'cococ-. |
^- in T- ^- m as r*"o i
cococomtocDCor^ *
r-wr*-cDT-co^-CMLO
^•^3-^cocococococo
^-tooococDr-co^-»—
cocMtooT-ooocgco
COCOCOlD^-^-mLOCD
CNCNMCOr-T-T-CNCM
CMO«-O3COCOCO^r
ootnco as "to co 5t- eg n co .
co co co in. co co co co '
r^CMcom'r^Scor-o
-«r m •.— co to. co r- ITS r-
COm
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
219 WISC
FLOW PATTERN
p
-J
1
r
r
._*^
PS
PS
CAPACITIES AND LOADINGS
FILTERS
1-Primary 120' Diam. Area = 11,304 sqft
1- Primary 170' Diam. Area = 22,686 sqft
1-Secondary (fixed nozzles) = 59,840 sqft.
1-Secondary 200' Diam. Area = 31,400 sqft.
LOADINGS
Hydraulic© 10 MGD
inn
294
Secondary =
Organic
91240
= 110 gals/day/sqft
Primary© 95 mg/l BOD s =
10 x
x 95
INTERMEDIATE SETTLING TANKS
2-85' Diam. Area = 11,350 sqft.
Surface overfow rate = —
= 880 gals/day/sqft
FINAL SETTLING TANKS
1-40' x 40'; 1-50' x 50'; 1-75' x 75'
Total Area = 9,725 i
Surface overflow rate = 1°'°°^.000 = 1028 gals/day/s
SLUDGE TREATMENT AND DISPOSAL
2-Primary Digesters Total Volume = 130,475 cuft.
2 Secondary Digesters Total Volume = 85,000 cuft.
Supernatant to raw sewage pumping station
Secondary @ 27 mg/l BOD5 =
10 x 8.35 x 27
550
39 #/1000 cuft
= 4#/1000cuft
Note: Data on first stage facilities through IS (intermediate settling) reported in Table 1 arid A-11 under plant 166 wi.
a/20
-------
CO
DC
LU
CO
uico
<2
COQ
Oui
Z a.
QW
^ ai co .
<"9w
"68"
SEu.
u-o
it -1
-I
oQ
O
O
£
Ul
I
I
u
ui
Suspended Solids , ]
§
oa
d
in
0)
CC
S9
Ul
UL
LLI
LLI
Q.
1
CC
0)
CC
5S
lil
LL
LU
LU
Q.
ra
CC
|i
CO U.
Q.
1
1
Ul
U.
m
CC
111
U.
-to
CC
Ul
i
^
=;
O)
<=i
»
Ul
U.
i
Ul
CC
i
i
1
}
Q
(D
u.
o
LL
0
€ «
i ?
cooc-r-'.cocNComLocMcna)
OOCnCOCOCOCOCOCOOOCOOOOO
^(•r--tQr— cocooof-oomcMco
r^i-.cocc>r».r-»p-r-.r-r-ooco
tDoiLoocotocMiOT-r-eoo
CNT-^CMCMCMCOCMCNCMr-CM
o>noocoLOO'*«-co oo r-
co^-^j-inwn^rnrococNco
CM o oo P- in~o co ro r- w r~ CM
CMCooooorocno5t»-r^oor>-o>
T--*oooor-CDtfla>CMOOir>
inco»-ijoin>*eO'*nLoraoo
OO GOOOO^G)C3)OG)G)G>O>C2
COCOinCMCO'*T-r-«— <*«*LO
r~.r-.r»ooopoococooocooooo
OOJCOCMCMCMCMCNCMCO^in
«— oo mcMr— ^-cocor-comoo
•3-COCMCNCNCMCMCMCNCMCNCM
^-cotDoor-cooocncDOjin
i-«-rs-r--ooc350oooo>O5O'-
oor~»ocococMO3r»T— **r-p-
coiaooicNiamm^r^fioco
coocooo*-oiai0'^t-T-oooo
roo«-'-'-ocncncno5Coco
i>«i^O)coooeo'oso>io«-i^cN
'fr'sf'Sj'tOLOCOCQCQCDCDIOm
cDLOcoinrocMcocooocO'S-T-
u>mir>mmcooco(oco(oco
c-gfe^^|-|§>&6§g
-^i£s
in
in
o
CD
CO
•*
r»-
'CM
LD
C5
|
°2
en
1
1
O>
^
a/ 21
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
301, MICH
Digester
Supernatant
FeCI3 Polymer
Note: G is aerated
CAPACITIES AND LOADINGS
FILTERS
1-68 ft. Diam.-6 ft. deep
1-70 ft. Diam.-6 ft. deep
Total Area = 7,480 sqft. = 0.1717 Acres
Total Volume = 44,500 cuft.
Loading:
Hydraulic @ Average flow = 0.64 MGD
3'73 MGAD ~
85
Organic @ 61 mq/l. in primary effluent
_ 0.64 x 61 x 8.35
44.5
= 7.3 Lbs BODS per 1000 cuft
Note: Nov. to Apr. trickling filter T,& FV1S, not operated
SLUDGE TREATMENT AND DISPOSAL
DIGESTERS:
1-30 ft. Diam., Vol = 10,900 cuft
1-45 ft. Diam., Voi = 23,950 cuft
Total Volume = 34,850 cuft.
Loading @ 975 #solids/day = 34950 = °-028 #/cuft
Sludge disposal—sludge drying beds
Digester supernatant & sludge bed waterdrains (see above)
CHEMICAL TREATMENT FOR PHOSPORUS REMOVAL
See Flow Diagram above
Dosage: FeCI., 25-40 mg/l; Polymer 0.1-0.3 mg/l
FINAL SETTLING TANKS
1-12 ft. by 35 ft; 1-35 ft. Diam.-Total Area = 1,358 sqft.
Surface overflow rate = = 470 gals/day/sqft
a/22
-------
TABLE A-12
REMOVAL OF BOD AND SUSPENDED SOLIDS
301 MICH.
Month
1974
May
June
July
Aug
Sept
Oct
Nov
Dec
1975
Jan
Feb
Mar
Apr
May
June
July
Aug
Sept
Oct
Nov
Dec
1976
Jan
Feb
Mar
Apr
• May
June
July
Avg
Raw
Sew.
Temp.
°F
—
59
60
64
63
57
53
51
49
50
50
51
52
53
—
—
66
66
64
60
56
61
61
60
60
65
65
Flow
MGD
0.63
0.62
0.62
0.51
0.54
0.73
OI70
0.65
0.70
0.65
0.75
0.80
0.66
0.75
0.75
0.41
0.55
0.60
0.51
0.50
0.53
0.61
0.80
. 0.74
0.72
0.70
0.71 '
0.64
5-Day BOD
Raw
Mg/l
240
172
151
147
110
170
169
174
180
180
150
154
166
194
169
168
179
255
210
177
137
171
185
150
189
209
176
175
PE
Mg/l
65
55
48
68
49
50
47
57
57
61
49
52
52
60
67
48
70
92
105
66
52
63
67
50
62
65
57
61
FE
Mg/l
13
22
19
17
15
18
18
23
21
23
22
24
21
21
15
15
33
42
25
26
23
21
16
19
23
22
15
21
% Rem.
Raw-
FE
95
87
87
88
83
89
89
87
88
87
86
84
87
89
91
91
82
84
88
85
83
88
91
84
88
89
91
88
Susp. Solids
Raw
Mg/l
169
209
183
171
177
182
192
173
232
140
187
173
183
189
178
180
156
250
252
178
191
163
223
202
186
145
199
188
PE
Mg/l
110
50
41
56
59
48
54
61
75
73
74
55
50
63
57
59
80
— •
95
79
72
7.8.
54
56
38
66
65
65
FE
Mg/l
28
29
22
20
21
23
24
30
36
26
26
19
18
19
18
26
23
—
80
31
41
37
25
24
21
30
25
26
% Rem.
Raw-
FE
83
86
89
88
88
87
88
83
84
81
86
89
90
90
90
86
85
—
88
83
79
77
89
88
89
79
87
86
a/23
-------
AG-Aerated «£ ^
Grit Chamber \ %.
\^> *•
\\
RAVV
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
302, MICH
F LOW PATTERN
4
3 1
A
G
*
\
it
PS
PS
PS
-
1 F
CAPACITIES AND LOADINGS
FILTERS
3-II5 ft Diam-8 ft. Deep
Total Area = 31,160 sqft ~ 0.72 Acres
Total Volume = 250,000 cuft.
Loading
Hydraulic @ Average Flow = 1. 93 MGD No R
1 Q9
= 072 = 2-70MGAD
Organic© 161 mg/l in PE
= 1.93 x 8.35 x 161
250
FINAL SETTLING TANKS
= 62 gals/day/sqft
= 10.4 #/1000 cuft
2-65' Diam 10'swd
Total Area = 6636 sqft
Surface Overflow Rate@ 1.93 MGD
=290 gals/day/sqft
TERTIARY TREATMENT
4-Pressure Sand Filters @ 9 ft. Diam
Total Area = 600 sqft. Loading = 1'9^°-)'°00 =3200 gals/day/sqft
Media - 20" - 1mm anthracite; 20" 30-40 Mesh Garnet; 9" No 6 Garnet
Backwash to raw sewage flow
DISINFECTION—2,000 #/day capacity-Chlorine Contact Chamber
CHEMICALS FOR PHOSPHORUS REMOVAL
Points of Application (see Flow Pattern)
FeCI3—Ahead of Aerated Grit Chamber
Polymer—Quick mix then to pipe following aerated grit Chamber
Dosage Rates
FeCI3-25-40 mg/l
Polymer-0.1 - 0.2 mg/l a/24
SLUDGE TREATMENT AND DISPOSAL
Digesters
1-primary-33,780 cuft.
1-secondary-33,780 cuft.
1-storage-50,000cuft
Supernatant returned to primary settling tankl
-------
CO
a:
a.
CO
O
a.
Q
<
CO
o
J CO
Q
g
O
UJ
CC
CL
5
•s
&
1
•o
£
§
i
UJ
u.
UJ
u.
E
1
1
UJ
u.
a.
UJ
u.
ILI
Q.
I
CC
55
UJ
u.
a.
ut
u.
Ul
a.
. CC
ii
w u_
3 O-
1
—
^
s
I
»
i UJ
S u.
cc a.
1 m
i
i
I
s
is
CC 0-
i m
cc "•
—
i
i
1
Q
fe
U.
o^o^co^tnto^oococo
OCM cMr--r-.coi-iocM
3-5333333SS33
ir)f^COCD«— O)COt-;OCDOJl£>
.>«»«.••«»
r*cooooocococococop^coco
..**»-.--s«g
CM^-t-^i-T-^-T-CM^CMCM
*~ CM T—
8SSS8SRBS9.2B
.8s8V58^Ms
85858*S88*8S
8a?5oS8!s4S,aa
ssasssaasissa
,_ T_ ^ ^ T-r-CMCMCMT-
T- CO COCMtOtOOJCDP^OOC
S S S $ fi 5 8 S 5 S S S
EM8888R8I.88
4.2 1, It it US'! a
^
CO
c?
3
»
cS
r-
0)
0
CO
CO
en
ro
CM
CM
CO
5
r*.
CM
CO
g
"
I
a/25
-------
FIG A-3
REMOVAL OF BOD5
TRICKLING FILTERS AND PRESSURE FILTERS
WITH CHEMICAL TREATMENT FOR PHOSPHORUS REMOVAL
302, MICH
TRICKLING FILTER
EFFLUENT
PRESSURE FILTER EFFLUENT
I I I I
a/26
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
303, MICH
FLOW PATTERN
CAPACITIES AND LOADINGS
FILTERS
2-90 ft Diam 6ft Deep
total Area = 0.292 Acres ~ 12725 sqft
Total Volume = 76,300 cuft;
Loading
•. Hydraulic @ 0.43 MGD plus R = 1.53 MGD = 2.0 MGD
DIGESTERS-Sludge Treatment and Disposal
I Primary @ 12,700 cuft.; l-Secondary-same
Total Volume = 25,400 cuft.
Digested Sludge to open drying beds
Supernatant to Grit Chamber
= -0292 = 6.8MGAD--
Organic @ 48 mg/l in PE
= 0.43 x a35 x 48 = 2 26 #/1000cuft
7b.o
PHOSPHORUS REMOVAL
= 157 gals/day/sqft FeCI3 & Polymer Feed—See Flow Pattern
Feed Rates: FeCI3 @ 40± mg/l;
Polymer @ 0.3 mg/l
a/27
-------
TABLE A-14
REMOVAL OF BOD, SUSPENDED SOLIDS AND PHOSPHORUS
303 MICH.
Month
1972
May
June
July
August
September
October
November
December
1973
January
February
March
April
May
June
July
August
September
October
November
December
1974
January
February
March
April
May
June
Averages
Sew.
Temp.
°F
58
63
66
67
68
64
58
52
48
46
53
53
58
64
67
68
69
67
61
55
47
47
48
51
56
61
Flow
MGD
0.44
0.29
0.27
0.26
0.27
0.24
0.39
0.39
0.47
0.43
0.52
0.52
0.57
0.52
0.46
0.41
0.35
0.31
0.33
0.42
0.66
0.52
0.57
0.53
0.51
0.43
0.43
5-Day, BOD
Raw
Mg/l
59
93
92
97
106
133
58
85
68
93
84
84
84
63
66
68
119
126
130
91
67
66
52
64
62
76
84
PE
Mg/l
41
53
52
62
57
73
36
44
47
60
53
53
44 -
34
32
32
46
58
67
57
45
50
36
37
31
38
48
FE
Mg/l
8
8
8
13
12
13
10
12
15
18
21
21
19
9
7
5
11
12
11
16
19
21
17
19
17
17
14
% Rem.
Raw-FE
86
91
91
87
92
90
83
86
78
81
75
75
77
86
89
93
91
90
92
82
72
68
67
70
73
78
83
Susp. Solids
Raw
Mg/l
85
107
130
111
113
117
89
118
80
98
89
89
115
72
80
113
142
127
117
79
72
79
59
68
67
80
92
PE
Mg/l
53
58
58
59
44
45
50
50
61
61
62
62
58
45
41
41
41
47
55
54
61
61
40
40
40
43
51
FE
Mg/l
5
5
9
18
14
17
24
14
17
12
28
28
34
31
22
19
14
10
10
13
,17
20
19
25
33
33
19
% Rem.
Raw-FE
94
95
93
84
88
85
73
88
79
88
69
69
70
57
73
83
90
92
91
84
76
75
68
63
51
59
79
Total P I
Raw
Mg/l
5.1
7.7
7.7
8.0
6.9
7.8
5.7
6.2
5.0
5.5
3.8
3.8
4.7
4.8
5.3
6.4
7.9
8.9
8.8
5.9
4.5
4.7
3.5
4.6
4.1
5.2
5.9
PE
Mg/l
2.4
3.3
3.2
4.6
2.2
2.7
2.4
2.2
2.7
2.8
2.2
2.2
2.6
2.3
2.4
2.7
3.3
3.6
4.3
3.6
2.8
3.5
2.1
2.3
1.9
2.1
2.8
FE|
Mg/
-7S
1 2
1 4
2 7
1 3
1.3
1.2
0.6
^Lj
0.6
0.7
0.9
0.9
1.3
1.3
0.8
0.7
0.7
0.8
1.0
1.6
1.1
1.8
1.2
1:5
1.7
1.7
1.2
a/28
-------
BOD5~Mg/£
CD
O
WCJ1
a/29
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
211 MICH
/
FLOW PATTERN
BEFORE
TERTIARY TREATMENT AND HEAT TREATMENT
1972
CAPACITIES AND LOADINGS
FILTERS-PRIMARY-First Stage (SECONDARY
2-80 ft. Diam.-6 ft. deep
Total Area = 0.23 Acres ~ 10,050 sqft.
Total Volume = 60,000 cuft.
same capacity)
Loading on Primary
Hydraulic @ 6.20 MGD— No recirculation
= 615gals/day/sqft
Organic @ 75 mg/l in PE
= 6.2 x 8^35 x 75 = 65#/1000cuft
Loading on Secondary
Hydraulic same as primary
Organic @ 38 mg/l in IE
_ 6.2 x 8.35 x 38
60
= 33 #71000 cuft
Loading on Total Filters
Hydraulic = ^~ - 13.5 MGAD
Organic = 32.5 #/1,000 cuft.
Note: Data on first stage filter plant through IS (intermediate settling) reported in Table 1 under plant 139 Mich.
a/30
-------
TABLE A-15
COMPARISON OF FIRST AND SECOND STAGE FILTERS
FOR REMOVAL OF BODS AND SUSPENDED SOLIDS
211 MICH.
TWO STAGE
Month
1972
January
February
March
April
May
June
July
August
September
October
November
December
Averages
Raw.
Sew.
Temp.
°F
55
51
49
49
54
60
64
66
67
64
59
55
Flow
MGD
5.31
4.60
6.41
9.04
7.49
6.08
6.08
7.72 .
4.35
5.50
6.38
5.53
6.20
5-Day BOD
Raw
Mg/l
155
131
100
84
80
104
104
76
112
125
109
118
108
PE
Mg/l
71
92
73
50
60
80
76
58
'76
96
75
89
75
Filters
PRIM*
Mg/l
38
49
41
30
36
38
34
26 •
' '39
45
38
46
38
" SEC
Mg/l
25
25
29
22
25
26
20
20
23
26
24
27
24
% Rem.
Pri.
Fill.
63
62
59
58
55
63
67
66
65
64
65
61
62
Sec.
Filt.
77
78
71
70
.'. 70
75
81
74
80
79
78
77
76
Susp. Solids
RAW ,
Mg/l
99
' 104
98
74
88
107
84
81
85
104
88
99
93
PE
Mg/l
53
66
68
47
• 61
67
56
48
56
58
56
64
58
Filters
PRIM*
Mg/l
' 31
38
41
32
38
34
28
25
33
32
33
38
34
SEC
Mg/l
19
21
23
18
21
20
14
15
14
17
17
20
18
% Rem.
Pri.
Filt.
69
63
58
57
57
68
67
69
61
69
63
62
63
Sec.
Filt.
81
80
77
76
76
81
83
69
84
84
81
80
81
'Intermediate Settling tank (IS) effluent (designated plant 139 mi
in Table 1). . . ..:..:". .. .
a/31
-------
304, MICH*
FACILITIES AND LOADINGS
TRICKLING FILTERS, GRAVITY SAND FILTERS AND
WITH CHEMICAL TREATMENT
1973-74
TRICKLING FILTERS.
TWO-STAGE
Total Area = 0.46 Acres
Total Volume = 120,000 cuft.
Loading on Total Filters
Hydraulic @ 7.26 MGD No Recirculation
120,000
7.26
SAND FILTERS (MIXED MEDIA)
4 @ 400 sqft. = 1,600 sqft.-42" Deep
Loading
Hydraulic 3-4,500 GPM Pumps
@ 6.5 MGD =
= 4050 gals/day/sqft
= 15.8 MGAD;
Organic @ 61 mg/1 in PE
= 16,500 cuft/MGD
@ 13.0 MGD = 8,100 gals/day/sqft.
Organic @ 16 mg/l in Filter Effluent
_ 6.50 x 8.35 x 16 _
= 7.26 x 8.35 x 61 = 30.8#/ 1000 cuft
1600
= 0.543 #/day/sqft
= 540#/day/1,000 sqft.
* Plant 211 Mich with addition of advanced treatment.
(See Fig. 5A)
a/32
-------
cc
UJ
(£ '
cc
111
a/33
-------
CC CO
QQ
zw
4
in
\
V
Ij
01
s
5
cc
E.
5S
UJ
UJ
UJ
Q.
1
Q)
CC
s?
UJ
5
LU
LLJ
Q_
1
11
3 U-
II
J
Ul
.s
^
1
cc
<
cc
^
s
—
01
•a
i
cc
i
cc
1
^
—
—
Q
o
S
U.
o
S
Ci
^
O)
£
LU
5
LU
Q.
JLJ
5
LU
LL.
T- CO T- CM CO CM ^t
O lO O O CO CD O
in to r- Is* P- P- to
co co co eg r- co co
C31 CJ) Ol CD O) O) O5
OJ r- t- CM CM T- gj
CO Ol G) O) CD Ol CO
"* CD 10 co r- CN co
in co CN co in p^ CM
«* CO •* ^- CO CO CD
CD CO in O CO CM OJ
co «3- co ^ ^r •* ^~
O) CM CO O) ^- T- CM
CM in in to o> co us
r^ o ** co co o t-
CO OJ CR O) Ol Ol O>
SLO CD CO CO (O CD
CO CO CO CO CO CO
in
v- T- r-. o> oi CM o
•^ r~. CD in r- P- in
CO ^ O 'd- O T- T-
^- to CD r- 01 co r-
CO r- CO CO CO CM O
CO T- T- CM CO CM t-
in in ^ T- r- r^ in
co en r^- co o r- en
r- in in in in in co
o co co o> CD T- r-
CD CD CO CO CO CD in
o <» W
f f « C •?
« >I* o 1 i
§ •= 3 §• tJ 0 «
-^ ^ < w O Z Q
cnr^comcor^oco
oooooo^-o
OCMCOCntOOCMO
coiocococo^frinr-
r*-rvCMincomcoco
O)O5OlO5OlO>OiC31
oir-^T— in LD CD T- T—
cocococococoocn
r-r-O)T-LOCDlOCM
^•uir^cocococMco
r*.cno>ocoincocD
r^.cocM'srcMcocO'-
^t-^^t^j-^-coco^
SCO O> r- r- ^ O ^J-
'y Ol CO CM CO ^t" CO
ST— CO O) O T- *t **
O) CO CO O3 CJ) Cn Ol
coeNr-.oco<*3-in
COCOP'-COCOCOCOCO
CO
r- co r-^ co en P- CD co
cor-.^^j-incop-oi
inr^cocMp-coin^t
comco^rT*<<3-r*-r*.
P^CMCMi-COOCOO
OO1CDP-COCOOCO
cocOT-inr^ocoo
P-^P^CO^CMCNCD
r-cooicnoioicoin
CMOCDO-^-T-P-O
inin^-inincocDr^
, si- §
a !•§!&! It?
^-3U_S
-------
BOD5~Mg/£
ro
CO
O
CO
mx
^E
mS33
O o m
O H O
cn
30X
m m
"
§2
m
<°. , -
a/35
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
305, MICH
FLOW PATTERN
RAW
;
CO
O
£
G ' '
>
£
— *•
N^
f
s.
DC
PS
PE
p
>l ) •— *
^ x/
FS
FS
— ^>
Cl
FE
CAPACITIES AND LOADINGS
FILTER
1 — 104 ft Diam — 6ft Deep
Area = 0.195 Acres ~ 8495 sqft
Volume = 51,000 cuft
Loading
Hydraulic @ 0.25 MGD (175 GPM Pump) - No R.
= 0195= 1-28 MGAD-
Organic© 133 mg/l in PE
0.25x8.35x133
8495
= 30 gals/sqft/day
SLUDGE TREATMENT AND DISPOSAL
2 - 25 ft Diam Digesters
Volume = 20,000 cuft
Digested Sludge to open drying beds
Supernatant to raw sewage inlet
FINAL SETTLING TANK
1 - 10 ft x 30 ft x 10 ft Area = 300 sqft
Surface Overflow Rate = 25° = 833 gals/day/sql
51
= 5.4 No./1000 cuft
a/36
-------
TABLE A-17
REMOVAL OF BOD, SUSPENDED SOLIDS AND PHOSPHORUS
SHOWING EFFECT OF CHEMICAL TREATMENT
305 MICH.
Month
1972
January
February
March
April
May
June
July
August
September
October
November
December
Average
1973
January
February
March
April
May
June
July
August
September
October
November
December
1974
January
February
March
April
May
June
July
August
Air
Range
°F
-20-30
-7-31
7-38
16-52
41-57
40-68
50-73
45-68
40-63
20-58
17-47
2-38
0-33
-6-34
20-46
22-60
29-58
54-70
60-70
50-74
39-70
32-60
23-42
0-42
-5-34
-10-32
5-43
20-6Q
32-59
45-65
Raw
Sew.
Temp.
°F
57
56
55
58
58
61
65
66
68
65
62
58
56
55
54
55
58
63
64
67
69
67
64
6,1
6§
56
55
§.6
5B,
61
6,3
67
Average 1973-Aug. 1974
Flow
MGD
0.21
0.21
0.22
0.23
0.23
0.21
0.21
0.21
0.20
0.20
0.24
0.24
0.22
1.25
0.23
0.29
0.27
0.26
0.25
0.24
0.22
0.22
0.21
0.22
0.23
0.26
0.26
0.34
0.32
0.28
0.24
0.24
0.22
0.25
5-Day BOD
Raw
Mg/1
258
335
327
243
261
201
210
216
224
268
240
265
254
238
229
214
216
236
• 244
222
228
254
270
286
327
298
280
210
213
219
248
273
270
249
PE
Mg/l
189
256
234
202
198
163
141
187
184
172
166
206
191
156
142
112
121
121
140
123
117
119
140
141
170
141
136
111
115
123
134
148
141
133
FE
Mg/l
53
66
76
49
42
21
16
36
27
27
37
42
41
36
35
.. 24
20
21
21
11
10
11
17
17
19
29
22
18
16
14
15
15
18
14
% Rem.
Raw-FE
79
80
77
80
84
90
92
83
88
90
85
84
84
85
85
89
•91
91
91
95
92
96
94
94
94
90
92
91
92
94
95
95
93
94
Susp. Solids
Raw
Mg/l
272
276
305
260
260
262
232
240
280
267
262
239
263
286
268
244
228
244 '
222
242
263
288
170
' 294
272
256
255
181
189
200
248
248
243
242
PE
Mg/l
112
125
142
130
116
132
128
122
115
106
108
123
122
82
54
51
62
56
55 ,
51
- 50
54
62
55
49
40
45
38
40
49
46
49
52
52
FE
Mg/l
33
38
46
44
48
63
44
44
41
43
49
42
46
33
22
25
28
32
:3Q
32
30
34
36
27
23
24 .
22
19
20
31
34
40
38
29
% Rem.
Raw-FE
88
86
85
83
82
76
81
80
85
84
81
83
83
88
92
90
- 88
87
86
87
89
88
87
91
9,2
91
91
90
85
85
86
84
84
88
Total P
Raw
Mg/l
8
8
7
9
9
10
9
9
9
9
8
10
8.7
7.7
9.0
7.9
7.9
7.3
7.7
8.0
7.8
9.1
7.8
7.7
7.9
6,3
6.1
5.6
5.2
6.7
6.6
7.8
6.7
7.3
PE
Mg/l
6
6
6
8
7
9
8
7
8
8
8
8
7.4
2.6
2.1
2.4
2.9
2.6
2.4
2.4
• 2.0
2.3
1.2
1.8
3.0
1.4
1.5
0.9
,1.1
1.6
1.9
1.9
1.5
1.5
FE
Mg/l
5
5
5
7
6
7
7
7
7
7
7
7
6.4
-1.4
1.7
1.9
2.3
2.1
2.0
1.8
1.5
1.7
1.6
1.7
1.8
1.3
1.4
0.6
0.8
1.4
1.3
1.2
1.3
1.5
Note: Began chemical treatment Jap. 1973.
Dosage: 90#FeCI3 and 1# polymer/day.
a/37
-------
FIG A-7
REMOVAL OF BOD5
TRICKLING FILTER PLANT
BEFORE AND AFTER CHEMICAL TREATMENT FOR PHOSPHORUS REMOVAL
305, MICH
RAW WASTEWATER
PRIMARY EFFLUENT
TRICKLING FILTER EFFLUENT
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
PAW PAW LAKE, MICH
312
FLOW PATTERN
RAW
P-
G
•a
I.
11
i"
R
t
I
]
4
PS
PS
> (
\T
PE V T
FILTERS
CAPACITIES AND LOADINGS
Primary 2-60 ft diam 7 ft deep
Area = 0.130 Acres — 5655 sqft
Volume = 39,600 cuft
Loading on primary
Hydraulic© 1.33 MGD
1 oo 1 -ion
' = 013 = 10'2 MGAD ~ 5655
Organic @ 70 mg/l in PE
, 1.33'x 8.35 x 70
39.6
= 19.6
= 235 9als/day/sqft
cuft
Loading on all filters (secondary same size as primary)
Hydraulic @ 1.33 MGD = 5.1 MGAD
Organic @ 70 mg/l in PE .
= 1.33x^35x70 = 9.8#/1000cuft
FINAL SETTLING TANKS . .
2 - 25810 cuft Each; Total Surface Area = 4800 sqft
Surface Overflow Rate =
4300
nnn
= 277 9als/day/sqft
CHEMICAL TREATMENT
Lime fed to rapid mix 1.5 minutes followed by 15 min aerated flocculation in primary clarifier
SLUDGE TREATMENT AND DISPOSAL
Lime treatment of raw sludge in thickening tanks
Filter Press '
Filter cake hauled to orchards
a/3.9"
-------
O
UJ
UJ
oo
O
I- Q CO
O
CQ
LL
O
O
s
UJ
CC
I
tn
CQ
I
LO
HI
CC
UJ
IF
Q
C3
O
CM CM CM CM T- CM
co
00
C53
CM
CO
CO
S3
S
CM •<- «tf'CO T- CM
CM
S
co
CO
1
a/40
-------
FACILITIES AND LOADINGS
TRICKLING FILTER-SAND FILTER PLANT
306, MICH
FLOW PATTERN
4x
Final tank sludge
RAW
i
CO
o
/ ' ' Filters
i
£
CAPACITIES AND LOADINGS
FILTERS
2 in Series 62 ft Diam 5'-6" Deep
Total Area = 0.138 Acres ~ 6038 sqft
Total Volume = 33,000 cuft •
Loading
Hydraulic @ 2.19 MGD (R = 1.0 MGD Avg-FS Sludge)
SAND FILTERS
2 Beds, each .12.5 ft by 50 ft = 1250 sqft
Loading
Hydraulic @ 3.0 MGD (MAX)
= 363 gals/day/sqft
Organic @ Av. Flow = 1.2 MGD; BOD in PE =67 mg/l
^ 1.2 x 8.35 x67
33
= 20.3 #BOD5/1000 cuft
= 2400 gals/day/sqft = 1.67 gals/min/sqft
Organic @ 24 mg/l in Filter Effluent
= 1.2x835x24 = Q 2Q #BODs/sqft/day
IzoU
SLUDGE TREATMENT AND DISPOSAL
1 - Primary -,12500 cuft; 1 - Secondary - 12,400 cuft
Digested Sludge to filter press & open drying beds
PHOSPHORUS REMOVAL
Feed points (see flow pattern)
FeCI., @ 30-35 mg/l
Polymer @ 0.5-0.75 mg/l
a/41
-------
TABLE A-19
REMOVAL OF BOD, SUSPENDED SOLIDS AND PHOSPHORUS
BY TRICKLING FILTERS AND SAND FILTERS
WITH CHEMICAL TREATMENT
306 MICH.
Month
(1972)
Jan
Feb
Mar
Apr
May
June
Avg.
Raw
Temp.
°F
54
53
53
54
57
59
Flow
MGD
1.2
1.1
1.2
1.2
1.2
1.2
1.2
5-Day BOD
Raw
Mg/l
229
208
213
179
140
192
193
PE
Mg/l
145
157
128
111
84
97
121
FE
Mg/l
77
72
64
53
30
40
56
% Rem.
Raw-FE
66
65
70
70
79
79
71
Susp. Solids
Raw
Mg/l
386
219
251
137
211
140
224
PE
Mg/l
137
84
109
52
56
69
85
FE
Mg/l
51
47
37
27
25
29
36
% Rem.
Raw-FE
87
79
85
80
88
79
84
Month
(1973-4)
June
July
Aug
Sept
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Avg
Raw
Sew.
Temp.
°F
62
65
66
67
64
61
57
54
52
52
54
57
£«
Sew.
Flow
MGD
1.2
1.2
1.1
1.0
1.0
1.0
1.0
1.3
1.2
1.4
1.4
1.3
1.2
5-Day BOD
Raw
Mg/l
230
176
193
190
187
208
176
158
155
164
163
158
180
PE
Mg/l
85
54
50
56
65
62
61
60
65
57
63
64
62
FE
Mg/l
37
27
22
22
21
20
22
20
24
25
28
23
24
SFE
Mg/l
6
2
3
3
4
3
2
3
4
3
6
9
4
% Rem.
Raw-FE
81
85
89
88
89
90
88
87
85
85
83
85
87
Susp. Solids
Raw
Mg/l
279
294
160
271
339
281
204
169
204
145
219
199
247
PE
Mg/l
47
45
37
40
58
50
48
60
56
65
47
44
50
FE
Mg/l
16
12
14
14
16
13
19
15
37
17
16
20
17
SFE
Mg/l
5
4
4
2
4
3
4
4
6
5
4
5
5
% Rem.
Raw-FE
94
96
94
95
95
95
91
91
82
93
93
90
93
Total P
Raw
Mg/l
NR
NR
7.1
8.8
NR
16.4
8.8
6.4
6.1
7.1
9.9
9.1
8.9
FE
Mg/l
NR
NR
1.9
1.4
NR
3.2
2.6
1.9
2.2
3.0
2.6
3.6
2.5
Overall plant removal: BODS = 98+% ; Susp. Sol. = 98%
Note: Chemical treatment began 1973.
a/42
-------
FIG A-8
REMOVAL OF BOD5
TRICKLING FILTER-SAND FILTER PLANT
306, MICH
RAW WASTEWATER
PRIMARY EFFLUENT
TRICKLING FILTER EFFLUENT
SAND FILTER EFFLUENT
N J
I
M
M J
1973
a/43
N
M M J
1974 I
-------
-
qcc_
ell
"oi fo
r" W
E -a
"5- +1 -S CD ^
4-> ro O : —
*^" "O T— 4t
d OT
O" *^C. f"^ -i t,
<0 CO ^ J* ^.0)
§ a s 7
r>. 10 ja "
CD - i 1
€. £ II 6 '•§ -
« < B, -2
CO
C3
O
3
Q
<
CO
UJ
p
u
Q.
U
INAL SETTLING TANKS
LL.
CO
DC
HI
_l
0 TJ S
ro oj *-v
LO C O
*~ J3 +-• S
ii c **— CD
II E cr •
co C [ « '-
CO 0 oo
*|8 '
E ro ii "
.1 TO CO C
5 ™ P
0 J?
+J Cl)
Q
*:
CO
1
,
E
.2 +j
^^ *^"
CT
4«i tn
"*" 00
LO O
CD 05
'-'*+-
•- II tz
& » 3
03 £ o
£"*"*..
CD »— CM
O
E u 1
.2 CD 3
Q|o t
uveriiow naLe 2358
HOSPHORUS REMOVAL
Q.
*=• w
.= C/3
1 g
•o 01
S >
CD CO
cB ^
CA
0>
l_ -M
OS ** CO
CD ^3 | • (™ >
Ilil!
ro <-• lO D5 5
— ~- ._ jj
«4_» vP .. — ' f^
*o b o <" 43
Q-
s
LO
Q
<
U o
o> co 4: o s
S || O f"-
3 C
j= C
o. ^
•— - c
Q C£
O t-
> £
' oop 5±
to --
DC r
to <"
3 »
• «n
> en » ffi co
> •* C
or po co
'. o ~ "^ °. rr
-1 CQ i- O O "-
JB m
i § a ? 1 1
O C3 UJ
""""** ^ CXr "
| CN .E 5
*""* O3 "
> „ E LO
< » _,. co
@ <3- 00
o
= C£
— CO *"
f2 @ x
?r: o -
I T3 II £L 1
H~ •— ^^ u v' i
"""" *^~ T^ ^" •"•
S— C
LO =5 "
> _j E
"c= .0)
§ ." H
.. "5 CD
"^ IS £ «
^ CO >. §
§• z: co
_ u.
i_ C — '
^ O O C
A H H -
D
J
a/44
-------
TABLE A-20
REMOVAL OF BOD, SUSPENDED SOLIDS AND PHOSPHORUS
307 MICH.
Month " •
1973
January
February
March
April
, May
'June
July
August
September .
October
November
December
1974
January
February '
March
April
May
June
July
August
Averages
Sew.
Temp.
°F
52
52
51
'54 "
.56
63
66
68
68
67
62
56
51
49
50
51
55
60
."
67
Raw
Sew..
Flow
MGD
0.72
0.58
0.85
0.76
0.74
0.64
0.50
0.46
0.45
0,45
0.53
0.61
0.77
0.72
0.91
0.90
o:69
0.51
6.46
0.65
5-Day BOD
RAW
Mg/l
137
198
165
141
184
187
177
.217
262
275'
261
203
97
151
165
141
158
., 193
210
190
PE
Mg/l
49
•67
54
46
50
79
43
40
31
42
47
47
46
33
38
34
29
35
28
44
FE
Mg/l
. 14
12
12
12
11
9
8
6
7
7
9
11
21
24
24
18
12
12
7
12
% Rem.
Raw-FE
90
94
93
91
94
95
95
97
97
97
97
95
58
84
79
87
92
94
97
94
Susp. Solids
RAW
Mg/l
t
144
200
183
— - '"
148
173
183
—
224
251
— •
175
170
148
138
132
150
169
220
175
PE
Mg/l
69
107
98 .
— '"
106
—
142
—
51
' 57
—
79
49
35
38
33
35
36
47.
65
FE
Mg/l
34
41
39
— •
32
29
25
—
29
27
—
32
30
25
25
21
17
19
20
28
% Rem.
Raw-FE
76
80
79
78
83
86
87
89
82
82
83
82
84
89
89
91
84
Total P.
RAW
Mg/l
5.8
7.2
7.1
7.3
6.9
—
9.0
10.2
11.6
12.0
9.7
8.4
8.0
6.7
5.6
5.5
7.0
8.7
10.1
8.2
PE
Mg/l
2.6
3.1
3.7
3.8
4.2
—
5.9
4.1
1.2
2.0
2.2
3.0
1.7
1.1
1.3
1.2
1.4
1.4
1.5
2.5
FE
Mg/l
1.0
0.7
0.8
0.8
0.6
0.7
0.7
0.5
0.8
0.7
0.7
0.6
0.7
0.7
0.7
0.6
0.7
0.7
0.8
0.7
a/45
-------
FIG A-9
REMOVAL OF BOD5 THROUGH PLANT
TRICKLING FILTER PLANT
WITH CHEMICAL TREATMENT FOR PHOSPHORUS REMOVAL
307, MICH
280
PRIMARY EFFLUENT
a/46
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
308, MICH
FLOW PATTERN
FC - Flocculater-Clarifier (Upflow)
PE
RAW
S
G
PS
PS
A
-
p
J
v F
CAPACITIES AND LOADINGS
FILTER
1-104 ft Diam 6.5 ft Deep
Area = 8495 sqft = 0.195 Acres
Volume = 55000 cuft
Loading @ Avg Flow = 1.36 MGD & 163 Mg/l in PE
Hydraulic @ 1.36 MGD ~ No recirculation
Organic @ 163 Mg/l in PE
= 1.36 x 8.35 x 163 = 337#/1000 cuft
55
SLUDGE TREATMENT & DISPOSAL ,
Lime treated sludge pumped to Lime Sludge Lagoons.
Lagoon Area = 321,600 sqft - Depth 2.5 ft.
CHEMICAL TREATMENT FOR PHOSPHORUS REMOVAL
Lime fed to Flocculator-clarifier for sludge treatment
and phosphorus removal
Feed rate = 2400*/day as CaO dry weight
FINAL SETTUNG JANK_
1-55 ft DiarnT Area''=-'2375 sqft; Volume =191,000 gals
Surface Overflow Rate = ^^y"00 = 573 gals/day/sqft
a/47
-------
TABLE A-21
REMOVAL OF BOD, SUSPENDED SOLIDS AND PHOSPHORUS
308 MICH.
Month
(1975)
~Jan
Fob
Mar
Apr
May
June
July
Aug
Sept
Oct
Nov
Doc
Awg
Raw
Sow.
Tamp.
°F
61
57
56
60
66
72
75
77
74
73
69
60
-
Sew.
Flow
MGO
1.38
1.37
1.34
1.41
1.34
1.28
1.32
1.44
1.35
1.39
1.34
1.34
1.36
Raw
Mg/l
241
234
218
228
218
202
222
199
232
231
216
242
224
PE
Mg/l
207
204
178
173
161
136
155
144
158
158
146
136
163
5-Day BOD
FE,
Mg/l
107
112
106
107
88
59
58
40
30
34
26
33
67
FE2
Mg/l
50
43
55
46
38
31
37
29
16
25
20
23
34
% Removal
Raw-
FE,
56
52
51
53
60
71
74
80
87
85
88
86
70
Raw-
FE2
79
82
75
80
83
85
83
85
93
89
91
90
85
Susp. Solids
Raw
Mg/l
200
178
202
216
188
221
223
194
231
224
263
316
221
PE
Mg/l
107
106
136
108
82
74
73
79
77
97
93
73
92
FE,
Mg/l
53
52
58
76
41
32
30
31
27
42
39
32
43
FE2
Mg/l
15
18
16
21
22
22
19
19
28
31
21
19
21
% Removal
Raw-
FE,
74
71
71
65
78
86
87
84
88
81
85
90
81
Raw-
FE2
93
90
92
90
88
90
91
90
88
86
92
94
90
Total P
FE2
Mg/l
1.6
2.3
1.1
1.6
2.3
2.6
2.4
2.8
2.6
2.6
4.8
4.6
2.6
Note;
FE| » Final settling tank effluent before addition of lime
FE2 * Effluent from flocculator-clarifier after lime addition
a/48
-------
OtC
eoO
UJ Z CO
H J
II
cc
Ul
s
u.
CO
o
D
g
o
CO
Ul
CAPACI
UL
a/49
-------
CO
O
O
CO
Q
UJ
Q
Z
UJ
Q CO
S
u_
O
O
LU
CC
%
"8
!
U)
o
8
I
in
cc
59
Ill
LL
i s t
oc (g ,2
LO T—
CM O O «—
T- r- CM n »-
CM CM
CM
CM CM
§
in
00
U)
CM
00
OJ
G)
CO
s
.
I E
8 '-o
TO C
O OT
51
^ I
o
00
00
II
"ll +-•
5- &
.E y
•8 S
OS
-a
w
a>
00
c o>
2
§ £•
8 I
ft
tl <«
O o
C ">
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
310, MICH
FLOW PATTERN
p
r
G
V.F. = Vacuum Filter •„
CAPACITIES AND LOADINGS
FILTER (Plastic Media) ^ r_ t. , / _
2 - 38'-8" Diam.:~;21.5' Deep
Total Area = 2348 sqft = 0.054 Acres
Total Volume = 50,500 cuft
Loading ; " ...
Hydraulic @ 1.6 MGD +-R =(2.75 MGD)= 4.35 MGD
= 432348° - ' 185° gals/sqft/day •= ^pr = 80 MGAD
Organic @ 54 hng/l BOD5
1 6 x 54 x 8
FINAL SETTLING TANKS
2-45 ft Diam -Surface Area = 3180 sqft
Surface Overflow R'ate = 1.6 MGD
50.5
='14.3 BOD, 71000 cuft
SLUDGE TREATMENT AND DISPOSAL
T— Primary Digester ~ 21,200 cuft
1 - Secondary Digester ~ 21,200 cuft
1 - Vacuum Filter '& open Sludge Drying Beds
Sludge to Sanitary Landfill
• Supernatant & Filtrate to Raw Sewage Pump Station
PHOSPHORUS REMOVAL
Chemical feed (sef flow pattern)
FeCI3 - 40 mg/j; Polymer -.0.5 - 1.6 mg/l
a/51
-------
TABLE A-23
REMOVAL OF BOD, SUSPENDED SOLIDS AND PHOSPHORUS
310 MICH.
Month
1972
January
February
March
April
May
June
July
August
September
October
November
December
1973
January
February
March
April
May
June
July
August
September
October
November
December
1974
January
February
March
April
May
June
July
August
Raw
Sew.
Temp
°F
52
52
50
47
53
52
60
61
62
61
59
54
49
50
47
49
52
56
59
62
63
63
61
54
50
48
46
50
54
Average 1973-1974
Averages Jan-June
Sew.
Flow
MGD
1.4
1.0
2.1
1.0
0.5
0.5
0.4
0.4
0.7
0.9
1.2
1.6
2.3
1.1
4.1
2.1
1.4
1.5
1.0
0.8
1.0
0.9
1.1
1.8
2.1
1.9
3.0
2.9
1.7
1.1
1.1
0.9
1.6
1.1
RAW
Mg/l
166
188
141
145
294
243
234
245
289
251
186
158
158
232
154
152
181
201
213
193
189
195
153
223
170
152
102
229
212
195
235
259
190
196
1972-before chemical
treatment
Averages Jan-June
2.0
177
1 947-af ter chemical
precipitation well established
5-Day BOD
PE
Mg/l
86
123
84
81
135
112
93
56
69
72
54
44
38
57
25
37
53
59
44
53
67
85
62
53
53
54 •
36
32
41
70
78
77
54
104
49
FE
Mg/l
31
37
37
45
42
33
30
24
25
26
28
30
24
21
8
17
21
28
28
32
29
19
16
24
15
25
17
18
22
21
20
18
21
38
% Rem.
Raw-FE
81
80
74
69
86
86
87
90
91
90
85
81
85
91
95
89
88
86
87
83
85
90
90
89
91
84
83
92
90
89
91
93
89
81
RAW
Mg/l
210
266
264
149
261
237
217
234
266
175
169
146
154
253
246
181
123
214
245
163
127
149
154
148
100
133
97
329
272
198
227
210
186
231
20
89
188
Susp. Solids
PE
^Mg/l
86
111
120
71
124
94
64
42
43
38
33
32
30
33
24
35
38
41
40
51
41
33
29
24
21
40
23
30
26
41
62
44
35
101
30
FE
Mg/l
36
41
53
35
37
33
17
20
17
11
13
11
11
11
11
10
17
19
15
13
10
12
11
13
9
12
11
7
8
8
12
15
12
39
% Rem.
Raw-FE
83
85
80
77
86
86
92
91
94
94
92
92
96
96
94
86
91
94
92
92
92
93
91
91
91
89
98
97
96
95
93
94
83
Total P
RAW
Mg/l
7.8
8.0
7.8
7.8
11.5
12.0
12.7
10.4
7 9
69
6.7
5.2
8.7
5.0
5.3
6.4
8.6
11.8
10.0
11.9
9.0
11.7
9.0
5.5
5.5
3.4
6.2
7.8
8.8
10.4
10.0
8.0
8.6
9
95
6.2
PE
Mg/l
3.9
5.6
3.9
4.9
9.3
2.4
1.7
3.4
2 1
1 4
1.2
1 2
1.4
0.9
1.3
1.9
3.8
1.9
5.0
3.9
2 1
2.3
1.8
1.0
2.7
1.9
1.1
1.5
2.7
3.4
1.5
2.2
5.5
1.8
FE
Mg/l
2.8
3.2
2.4
2.9
7 0
1 2
0.9
2.5
1 R
1 "3
1.4
1 0
1 0
0.8
0.8
1.4
2.1
2.0
4.0
3 7
1 6
2.0
1.0
1.0
1.0
0.6
1.2
1.2
1.6
2.0
1.5
1.6
3.6
1.1
a/52
-------
FIG A-23
REMOVAL OF BOD5
310, MICH. TRICKLING FILTER PLANT
SHOWING IMPROVEMENT
WITH CHEMICAL TREATMENT
BEGAN CHEM. DOSAGE
FOR PHOSPHORUS REMOVAL
PRIMARY EFFLUENT
a/53
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
309, MICH
FLOW PATTERN
&
s
V^
P
STORM
WATER
j
CO
o
0)
u.
G
1
1
H PS t
^H PS \
CAPACITIES AND LOADINGS
FILTER (Plastic Media)
1 -30' Diam;Area = 700 sqft;Volume = 15000 cuft
Loading
Hydraulic @ 1300 GPM (Constant Rate); R @ Avg Flow = 1.0
= 0.94 x 8.35 x 23 = 12
= 117 MGAD
Organic @ 23 mg/l BODS in PE and Avg Flow = 0.94 MGD
cuft
CHEMICALS FOR PHOSPHORUS REMOVAL
Points of Application ~ See Flow Pattern
FeCI3 -40-50 mg/l ; Polymer 0.25-0.35 mg/l
Note: Dosage reduced to 20-25 mg/l in 1975-76 with similar removal of total phosphorus
FINAL SETTLING TANK
1 - 14' x 50' x 11' - 6" Area = 700 sqft
Surface Overflow Rate = 94°ff° = 1340 gals/day/sqft
SLUDGE TREATMENT AND DISPOSAL
1 — Primary Digester 34' Diam by 20' Volume = 18000 cuft
1 - Storage Digester 20' Diam by 14' Volume - 4400 cuft
Note: Primary Settling Tanks are Clariflocculators
a/54
-------
TABLE A-24
REMOVAL OF BOD, SUSPENDED SOLIDS AND PHOSPHORUS
309 MICH.
Month
1972
September
October
November
December
1973
January
February
March
April
May
June
July
August
September
October
November
December
1974
January
February
March
April
May
June
July
August
Average
Raw
Sew.
Temp.
°F
71
65
55
49,
46
46
45
49
58
70
73
76
75
66
58
52
51
46
46
49
54
60
70
71
Sew.
Flow
MGD
0.94
0.95
1.03
1.10
0.98
0.81
0.85
0.80
1.36
1.23
1.30
0.97
0.94
0.63
0.82
0.85
0.89
0.94
1.19
Flow
Mete
Out
0.67
0.59
0.94
5-Day BOD
RAW
Mg/l
81
58
52
62
x
64
70
35
30
46
47
58
56
62
109
102
95
92
91
62
69
115
113
108
121
75
PE
Mg/l
13
16
15
17
16
27
12
13
15
13
16
13
19
45
42
27
29
35
21
16
30
32
32
44
23
FE
Mg/l
6
7
9
8
11
14
9
6
8
9
10
13
12
14
12
13
18
13
15
10
16
13
-13
14
11
% Rem.
Raw-FE
91
88
83
87
83
80
74
80
83
81
83
77
81
87
88
86
80
86
76
86
86
88
88'
88
85
Susp. Solids
RAW
Mg/l
139
89
92
209
110
107
82
55
61
97
96
90
152
82
77
86
44
70
44
65
136
183
89
121
99
PE
Mg/l
14
14
20
20
27
22
19
10
10
13
13
10
13
25
28
15
12
18
12
12
19
32
20'
28
18
FE
Mg/l
11
12
14
12
18
11
15
12 -
9
10
8
8
8
13
8
9
9
10
9
8.
9
11
9
16
1-1
% Rem.
Raw-FE
92
87
85
94
84
90
82
78
85
90
92
90
95
84
90
90
80
86
80
88
93
94
90
95
89
Total P
RAW
Mg/l
5.4
5.5
4.2
4.8
3.9
5.4
2.8
2.7
3.3
2.8
4.1
3.5
4.6
9.0
8.5
5.7
3.3
4.9
3.3
4.1
5.9
7.0
6.8
7.8
5.0
PE
Mg/l
0.26
0.62
0.54
0.79
0.97
0.92
0.52
0.24
0.30
0.19
0.21
0.23
0.33
0.89
0.69
0.43
0.44
0.40
0.44
0.28
0.35
0.46
0.39
0.56
0.48
FE
Mg/l
0.3
0.6
0.6
0.6
0.89
0.71
0.50
0.37
0.26
0.21
0.19
0.26
0.31
0.46
062
0 43
0.36
0.41
0.41
0.29
0.29
0.26
0.35
0.70
0.43
Chemical Dosage:
FeCI3-Avg.44 mg/l
Polymer—Avg. 0.3 mg/l
a/55
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
311, MICH
F LOW PATTERN
CAPACITIES AND LOADINGS
FILTERS (Plastic Media)
2 - 32.33' x 27'
Total Area = 1745 sqft = 0.040 Acres
Total Volume = 1475 x 21.6' = 37,690 cuft
Loading
Hydraulic @ 1.1 MGD (variable speed pump); No R.
= 630 gals/sqft
= 27.5 MGAD
Organic @ 56 mg/l in PE
1.1 x 8.35x56 = 13_6 |bs BQD Q cuft
oy -j — i»J.\j iua a\^U5
CHEMICALS FOR PHOSPHORUS REMOVAL
Points of Application ~ See Flow Pattern
FeCI3 — 55 mg/l Dosage ; Polymer 0.35 mg/l
FINAL SETTLING TANK
1 - 50' Diam. Area = 1960 sqft
Surface Overflow Rate
= 560 ga.s/day/sqft
SLUDGE TREATMENT AND DISPOSAL
2 - Primary Digesters - Total Volume = 25,200 cuft
1 - Final Digester ~ Volume = 12,600 cuft
Vacuum Filter
Supernatant & Filtrate returned to primary settling tank]
Note: Intermediate Settling Tank Same Size as
Final Settling Tank
Abbrev: AG = Aerated grit chamber
a/56
-------
TABLE A-25
REMOVAL OF BOD, SUSPENDED SOLIDS AND PHOSPHORUS
311 MICH,
Month
1975
February
April
May
July
August
September
October
.November
December
Averages
Flow
MGD
0.97
0.93
1.03
1.10
0.97
0.99
1.00
1.18
1.30
1.00
1.03
1.09
1.05
Sew.
Temp.
°F
50
50
49
52
59
64
68
,68
65
64
59
53
-
5-Day BOD
Raw
Mg/i
116
113
127
123
129
130
145
117
;102
128
113
141
121
PE
Mg/l
67
68
70
56
53
53
45
49
42
57
50
58
56
FE
Mg/l
26
25
26
24
19
18
13
16
14
19
18
, 22
20
% Rem.
Raw-FE
• 78
78
80
80
85
86
91
86
85 ' " '
85
81
84
83
Susp. Solids
Raw
Mg/l
102
95
131
• 108
111
110
123
98
87
96
114
109
107
PE
Mg/l
38
42
44
41 "
39
39
43
'30 "
37
39
34
30
39
FE
Mg/l
16
19
18
15
13
11
12
8
8
11
8
11
12
% Rem.
Paw-FE
84
80
86
86
88
90
' 90
92
91
86
93'
90
89
Total P
Raw
Mg/l
6.6
6.8
6:e
7.4
8.3
8.1
8.3
7.0
6.2
8.1
7.5
6.4
7.3
FE
Mg/l
0.7 .
0.5
0.6
0.6
0.8
1.0
0.9
0.5
. 0.8
. 0.9.'
0.6
0.7
0.7
a/57
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
313, MICH
FLOW PATTERN
RAW
PE
P
FE
CAPACITIES AND LOADINGS
FILTER (Plastic Media)
2 -21.5' x 21 .5' deep
Total Area = 725 sqft = 0.01 7 Acres
Total Volume = 15610 cuft
Loading _ '
Hydraulic @ 700 GPM (constant rate) R = 1'°~ °'35 = 1.8
u.ob
= 10°°20°° = 1380gals/day/sqft = 59 MGAD
Organic @ Avg Flow = 0.35 MGD and 60 mg/l BOD5 in PE
= 0.35
x 60 = 11#BODs/1000cuft
CHEMICALS FOR PHOSPHORUS REMOVAL
Points of Application — See Flow Pattern
Dosage
FeCI3 - 30-40 mg/l
Polymer - 0.1 - 0.3 mg/l
FINAL SETTLING TANKS
2 -~34 -8" Diam 9' SWD
Total Surface Area = 1890 sqft
Surface Overflow Rate
_ 1.000.000
- =
, , , ,,
gals/sqft/day
SLUDGE TREATMENT AND DISPOSAL
.Raw sludge stored in storage tank and
transferred to regional plant. Decant to
pump station.
a/50
-------
CO
Q
3
u_o
oE
O
S
UJ
CC
vt
TO
i
Q.
3
tn
Q
2
|
u.
gs
ua
u.
1
CC
5?
LU
LL
s
<
CC
Q
O
. SE
£
c
05
DC
_
^
Ol
^
f
V
CC
en
f
_ ^
^>
's
co
in
05
-en8c3)acooocoooooo)oo.o>oajoi-o>ooo>c>.o>-o>o>-o>o>
CMI^OOCDCOOOt-r^CM'a-OOCOCOLnOOCMOTCOCMCOCOCOO
CY5 CD r>«r r— LO CO CM CO *— ^ O O5CMCDI^-^"I^C33O CO CD *3" O ,*^"
S^Kr^cnScDr--inRcor«.cocMCMr-coo>cD.U50'*inoo
Om<*COr-^CD'*«roCOCMTOCM'*COCMt-CM,S,pOI^.O'=f
''•'•'" ; "" ' • •.'•"'.: •.''• '"•; ._,
8- ' ' - • • ' ' • • '....-•
^, ^, r- r- *, X- - ....... ^ ^ ,.._.,-.-.- — --
- - :. ""-'•- •• • '••• .-
,"--•.!•
o in CM coLn^oor^inr^-tD^t mo co co in O.CM r^ o CM co P--
CD CD CD CD CD CD CD O O O CD CD CD CD CD CD O ^3 c^ C3 tj *tj. \—j tj
-!*!!*£ ••'• Jill>^
S«^ll5E-S= a, 3 I -i s 1 § E •§.-. .».«.».
^ cIS i S 1 £ i Si ^ 1 < c^ o i a ^ ,£ i ^i ^ 1
CM
O)
in
CM
CM
CO
"33
s i
Q3
o
in
X
o
J3 Q-
^Sl **\
V>J Q.
O3
s
_
13
oo 'Z
•* c
*™ • o
; ^
^_
CO
c
in .E
2 *
"• c
, 0
S
. TS
Q)
~
£
w — ;
a> —1
0)
CO
l_ CU
CU 4-J
2 0
< z.
a/59
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
169, MICH
FLOW PATTERN
Final tank Sludge
RAW
G
—\*
"*,
p
SAND
SFE|
—*•
FILTERS
CAPACITIES AND LOADINGS
FILTER
1 — 50' Diam
Area = 1960 sqft = 0.045 Acres
Volume = 12000 cuft
Loading
Hydraulic @ 0.5 MGD Pump Rate
_ 500,000 _ ,,,-f-
1960 ZM
0.5
MGAD
@ 0.78 MGD Pump Rate = 400 gals/day/sqft
Organic @ Avg Flow = 0.5 MGD and 64 mg/l BOD5 in PE
0.5 x 8.35 x 64 _ „„
J2 ""
FINAL SETTLING TANK
l 1000 cuft
1 - 45' Diam. 8'-0" SWD
Surface Area = 1590 sqft
Surface Overflow Rate @ 0.5 MGD
_ 500.000
1590
= 315 gals/day/sqft
SLUDGE TREATMENT AND DISPOSAL
1 - Digester 35' Diam 30' SWD
Volume = 29000 cuft
Digested sludge to open drying beds
Supernatant to pump station
INTERMITTENT SAND FILTERS (open)
4 beds 120' x 80' each; 9" Graded gravel 1/8" - 1"; 24" sand eff. size 0.6-0.9 mm: U.C. < 2.5
Operate only in Summer — about May-Oct.
Dose Intermittently —fill & draw — dry out — cultivate
Loading @ 0.5 MGD
a/60
-------
ww
o
-J it
< 0
p
ui>
CC ™
en
T3
1
cl
Q1
0
m
•
;
(
C/
s?
UJ
u_
re
CC
S5
Ul
u.
UJ
o.
re'
CC
i °
} U-
1
o
.
5
CC
o>
O)
o
CC
o>
^£
ER
Q
S
(O
in
*O ^>r J^? H? ~jj ]£? f2 S^ Q* Q! : rr) to CD CO CO CD 00 O)
„
fT ^r ^T CO C^ # # •
88S88BR8.88KSRSB888-
5=5SS5SSsS8SSSSSS8S
st- ^ ^- co oo * * * * • * <*>>r^r
-------
FACILITIES AND LOADINGS
TRICKLING FILTERS & PONDS
117, MINN
FLOW PATTERN
RAW
FS
FS
P
FE
>• To Aerated
Pond and
Stabilization
Pond.
LOADINGS AND CAPACITIES
FILTERS (2)
1-97' Diam (ROCK) Area = 7390 sqft = 0.17 Ac; Vol = 59120 cuft
1-51' Diam (TILE) Area = 2040 sqft = 0.047 Ac; Vol = 12240 cuft
Total Area = 9430 sqft = 0.216 Ac; Vol = 71360 cuft
Loading
Hydraulic @ 1MGD
= 106 gals/day/sqft = 4.6 MGAD
Organic @ 0.93 MGD and 168 mg/l in PE
= 0-93x^68x8.35 = ^
FINAL SETTLING TANK
2-20 x 60 = 2400 sqft
Surface Overflow Rate @ I MGD
= 416 Sals/day/sqft
SLUDGE TREATMENT AND DISPOSAL
1-Digester Vol = 25,288 cuft
Digested sludge to sludge storage tank to lagoons
AERATED POND
Area = 3 Acres ~ 6' Deep floating aerator 15 HP
Detention @ 1.0 MGD = Approx 25 days
STABILIZATION POND
Area = 25 Acres ~ 3' Deep
Detention @ I MGD = Approx 25 days
Effluent distributed by piping to 20 acre peat
absorption bed
a/62
-------
TABLE A-28
REMOVAL OF BOD AND SUSPENDED SOLIDS
117 MINN.
Month
Jan
Feb
Mar
Apr
May
June
July
Aug
Sept *
- Oct •-.-•'
• Nov- •"•
Dec '' "
Avg
Sew.
Flow
MGD
0.90
0.86
1.10
0.82
0.88
0.94
1.06
... 0.96
0.93 ..-:
1.00
0.95
0.83
0.93
. 5-Day BOD .-.'_, v
Raw
Mg/l
270
224
240
229
280
250
260
270
, 271
302
288
242
259
FE
Mg/l
38
42
39
44 '
35
46
48
36
36
39 '
40
37
40
% Rem.
Raw-FE
86
81
-•• 84 '
81
88
' 82
82
87 -,•
87
87
86
85
85
Susp. Solids
Raw
Mg/l
251
239
239
238
242
280
272
212
262 .
• 230
225
233
243
FE
Mg/l
38
42
33
33
29
44
33
42 *
31
34 _
30
49
37
% Rem.
Raw-FE
85
82
86
86
88
84
88
80
88
85
87
79
85
Note:
For Tertiary Treatment results, see Table A-29
Assuming 35% removal in primary settling tanks,
PE = 0.65 x 259 = 168 mg/l 5-day BOD
TABLE A-29
REMOVAL OF BODS & SUSP. SOLIDS
TRICKLING FILTERS & PONDS
117 MINN.
Month
Jan
Feb
Mar
Apr
May
June
July
Aug
Sept
Oct
Nov
Dec
Avg
Flow
MGD
0.90
0.86
1.10
0.82
0.88
0.94,
1.06
0.96
0.93
1.00
0.95
0.83
0.93
BOD5 ~ Mg/l
Raw
270
224
240
229
280
250
260
270
271
302
268
242
• 259
FE
38
42
39
44
35
46
48
36
36
39
40
37
40
AP
27
20
18
24
15
19 "
11
,10
12
21
19
15
18
SP
10
7 -', •
8
15
4
3
7
11
4
4
5
2
7 -
Susp. Solids ~; Mg/l;;
Raw
251
239
239
1 238
. . -242
280 .
272
. 212
262 ;
230
225 ,
233 ;
243
FE
. 38
42
33
33
.29 .
44
33
42
.. 31
34
• • 30-
"". 49
37
AP
19
14
14
M7,, ,
31
• 31
,16
H'5.';
24
15. ,
to. ;
19 .
. -18
SP
7
9
6
20
5
4
6
11 ,
6
4
5
1
7
Abbreviations:
AP - Aerated Pond Effluent
SP - Stabilization Pond Effluent
FE - Trickling Filter Effluent
a/63
-------
FACILITIES AND LOADINGS
TRICKLING FILTER PLANT
121, N. DAKOTA
FLOW PATTERN
RAW
Dosing
tank
s
p
I
1
1
G
PS
PS
PS
PS
Final tank Sludge
CAPACITIES AND LOADINGS
FILTERS
1 - 220' x 135' (Fixed Nozzles) 9' deep
1 — 148' Diam. (Rotary) 9 deep
Total Area = 46,900 sqft = 1 .08 Acres
Total Volume = 422,000 cuft
Loading (2-5 MGD Pumps & 1 Variable Speed)
Hydraulic @ 5 MGD Pumping Rate
= 106 gals/day/sqft; 4.63 MGAD
@ 10 MGD Pumping Rate
_ 10,000.000 _ „,„ ., f
-- 46,900 ~ 213 9Pd/S£lft
Organic @ Avg Flow = 5.85 MGD and 140 mg/l in
|bs/1000 cuft
= 5.85 x 8.35 x 140 =
SLUDGE TREATMENT AND DISPOSAL
2 — Primary Digesters 75' Diam — Volume = 176,000 cuft
2 — Secondary Digesters 55' Diam — Volume = 46,000 cuft
Supernatant returned directly to primary settling tank
Digested sludge to open drying beds — underdrains to
pumping station.
OXIDATION PONDS
6 Lagoons Each 90 Acres
Total Area 540 Acres
Operate 5 in parallel, discharge each in turn to No. 6, hold
and discharge to river
Time required to fill @ 6 MGD & 4' depth
= 90 x 43560 x 4 x 7.5 „
PE 6,000,000 ^
Hold another 10-20 days before discharge
No discharge during winter months
FINAL SETTLING TANK
1 — 110' Diam Area - 9500 sqft
Surface Overflow Rate @ Avg Flow = MGD
= 630 gals/day/sqft
a/64
-------
09
Q
LLI
01
CC
at
•a
1
a.
en
3
CO
tn
a
O
CD
C
53)
Ji
c
HI
111
LL
3
CC
LU
LU
LU
...
co
cc
. k.
" Q)
3* SL
" h?
5 5
a>
*8
|u.
1
2
o>
O)
£>
i
•a
o
S
0
S
Q
C7
LO
cn
tO CO | | | LO T- | O | r- CO
3955SB338E555
O5 ^^ 00 O5 O5 00 CO •" ^^ CO CD ^^ ^^
COO>| | I LO CM | »— | O O)
SSSBSSSSSSSS
CO C3 CO CO CO ^" CD C* C^ ^M ^3 ^~
CMCMCMCMCMCMCMCM»-CMCMCM
CO •<* CO CO CO CM O
CO LO ^2 ^^ {^ ^^ CO i CO {^ LO LO
LO I.O ^if LC? CD 1^ ^3*
LO CM CM CM CM CM «*
T— «— oLococoroooiocooor^
^f Ijyi ^~ ^f" CO LO ^^ Cty C^ O ^^ F^
LO ^J* LO LO CD CD CD CO CD LO LO LO
"^^ QJ ^^ +J
CO
1-^
CO
r*.
o
CO
LO
o
CM
CM
CM
O)
§
LO
o
*
CO
01
O
. E
<"»
- OJ*-
™CM
17
§ I
CM-1
11 £
§-S
_o '»-
u. §,
™ "S cS
wQ £
O3 CO Jj£
'cS
C/l
•Q
•8 I
II
Q
CD
•i-*
51
o>
CO «
.> Q
Jg O
CM CO
CO
Q §
o g>
Q.
jS oc
op
a/65
.S. GOVERNMENT PRINTING OFFICEi 1980-31 t- 132/1
-------
------- |