EPA-600/2-76-264
December 1976 Environmental Protection Technology Series
HANOVER PARK TERTIARY STUDIES
\
Municipal Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to develop and
demonstrate instrumentation, equipment, and methodology to repair or prevent
environmental degradation from point and non-point sources of pollution. This
work provides the new or improved technology required for the control and
treatment of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-76-264
December 1976
HANOVER PARK TERTIARY STUDIES
by
D. R. Zenz
E. Bogusch
C. Lue-Hing
A. W. Obayashi
Metropolitan Sanitary District of Greater Chicago
Chicago, Illinois 60611
EPA Grant No. FWPCA WPRD 92-01-68
Project Officers
Arthur N. Masse
James F. Kreissl
Wastewater Research Division
Municipal Environmental Research Laboratory
Cincinnati, Ohio 45268
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
.:-;.'KO!ECTION
S. tiiVl.vvjm.ii-" • i •-• '
.:••*& ViL 03817.
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DISCLAIMER
This report has been reviewed by the Municipal Environmental
Research Laboratory, U. S. Environmental Protection Agency, and
approved for publication. Approval does not signify that the
contents necessarily reflect the views and policies of the
U. S. Environmental Protection Agency, nor does mention of trade
names or commercial products constitute endorsement or recommen-
dation for use.
-------
FOREWORD
The Environmental Protection Agency was created because of
increasing public and government concern about the dangers of
pollution to the health and welfare of the American people.
Noxious air, foul water, and spoiled land are tragic testimony
to the deterioration of our natural environment. The complexity
of that environment and the interplay between its components
require a concentrated and integrated attack on the problem.
Research and development is that necessary first step in
problem solution and it involves defining the problem, measuring
its impact, and searching for solutions. The Municipal Environ-
mental Research Laboratory develops new and improved technology
and systems for the prevention, treatment, and management of
wastewater and solid and hazardous waste pollutant discharges
from municipal and community sources, for the preservation and
treatment of public drinking water supplies, and to minimize
the adverse economic, social, health, and aesthetic effects of
pollution. This publication is one of the products of that
research; a most vital communications link between the researcher
and the user community.
The development of practical tertiary treatment methods
which allow municipal wastewater treatment facilities to produce
low levels of contaminant concentration compatible with receiving
stream quality maintenance is an integral part of the above
efforts.
Francis T. Mayo
Director
Municipal Environmental
Research Laboratory
111
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ABSTRACT
During a 1-year study, four tertiary treatment units were
tested and evaluated. Three of the units were deep-bed filters
which were used to treat secondary plant effluent. The types
of filters used were: (1) an upflow filter with a sand media,
(2) a downflow gravity filter with mixed-media consisting of
anthracite, sand, and garnet, and (3) a downflow pressure filter
utilizing dual-media of anthracite and sand. The fourth unit
was a continuous flow ion exchanger that employed activated
alumina to remove phosphate from microscreened secondary
effluent.
The filtration studies indicate that comparable effluents
were produced by all three filters with filtration rates from
2 to 6 gpm/ft^. Filter effluents generally contained about
4 to 7 mg/1 suspended solids in the above flow range.
The results of the ion exchange study indicated that
sodium hydroxide successfully regenerated an exhausted activated
alumina bed. In a 9-hour test, the ion exchange column removed
73% of the influent phosphorus, using 0.4N sodium hydroxide as
the regenerant.
This report is submitted in fulfillment of FWPCA Project
Number 11010EZJ under the partial sponsorship of the
Environmental Protection Agency, Office of Research and
Development.
IV
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CONTENTS
Foreword ill
Abstract iv
Figures vi
Tables vii
I Introduction 1
II Conclusions 4
III Recommendations 6
IV Materials and Methods 7
V Results 18
VI Discussion 31
References 34
Appendix 35
v
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FIGURES
Number Paqe
1 Schematic Diagram of the Treatment 2
Processes at the Hanover Water
Reclamation Plant
2 Diagram of the DeLaval Filter g
3 Flow Diagram of the Neptune Microfloc 10
Unit
4 Diagram of the Graver Filter 12
5 Flow Diagram of the Continuous-Flow 13
Ion Exchange Unit
6 Influent Sources of the Hanover 15
Experimental Bay Project
7 Phosphorus Removal by Activated Alumina 29
VI
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TABLES
Number
1 Operation of the DeLaval Filter at Various 19
Hydraulic Loadings: Treatment of Secondary
Effluent
2 Operation of the DeLaval Filter at Various 20
Hydraulic Loadings: Treatment of Alum-Treated
Secondary Effluent
3 Operation of the Neptune Microfloc Unit: 22
Treatment of Secondary Effluent With and With-
out Chemical Addition
4 Operation of the Neptune Microfloc Unit: 24
Treatment of Alum-Treated Secondary Effluent
With and Without Chemical Addition
5 Operation of the Graver Filter at Various 26
Hydraulic Loadings: Treatment of Secondary
Effluent
6 Operation of the Graver Filter at Various 27
Hydraulic Loadings: Treatment of Alum-Treated
Secondary Effluent
7 Operation of the Continuous Flow Ion Exchanger 30
for Phosphorus Removal by Activated Alumina
with Sodium Hydroxide Regeneration
Vll
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SECTION I
INTRODUCTION
The Metropolitan Sanitary District of Greater Chicago
(MSDGC) has long realized that secondary treatment of domestic
sewage, industrial wastewater and storm water was insufficient
to satisfy rising aesthetic values and increasingly stringent
water quality standards. In 1965, work began on the design of
the Hanover Water Reclamation Plant, and by 1969 the 2 mgd *
plant was in operation as the MSDGC's first tertiary treatment
plant.
Originally, the Hanover Plant was a series of oxidation
ponds that are still used during periods of excessive sewage
flow. The sewage to the plant is primarily domestic sewage
from a separate sewer system. However, during storms, the flow
does increase significantly, possibly because of increased
sewer infiltration and rain water connections from sump pumps
and gutters. A schematic diagram of the plant facilities is
shown in Figure 1. The plant has conventional primary
settling and activated sludge facilities. The tertiary portion
of the Hanover Plant consists of two coagulation-sedimentation
tanks, two rapid sand filters, a microstrainer, a chlorination
tank, and a post-aeration tank. These facilities have enabled
the MSDGC to gain experience and knowledge of many tertiary
treatment methods on a plant scale. The Hanover Plant also
provides the capability to study advanced wastewater treatment
on a pilot scale, with a study of ozonation of tertiary effluent
having been completed. The experimental work of this project
was performed entirely at the Hanover Plant.
At the time this work was performed the water pollution
regulations of Illinois would have required the effluents from
the three major MSDGC treatment plants to contain no more than
5 mg/1 suspended solids and 4 mg/1 five-day biochemical oxygen
demand (BOD) by 1977. In 1974, however, it was determined that
the MSDGC could be classified as an exemption to the 5 mg/1
suspended solids and 4 mg/1 BOD effluent criteria if an in-
stream aeration system were provided to maintain adequate
dissolved oxygen levels in the waterways receiving effluents
from the major MSDGC treatment plants. If this plan were
adopted the effluent criteria for the major MSDGC treatment
plants would be 12 mg/1 suspended solids and 10 mg/1 BOD.
* Metric conversions are given in Appendix
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PRIMARY
40 % Organic Removal
SECONDARY
50 % Organic Removal
TERTIARY
9 % Organic Removal
99 % ORGANIC REMOVAL
99 % BACTERIA KILL
J Coagulation
Settling
EFFLUENT
Figure 1. Schematic diagram of the treatment processes
at the Hanover Water Reclamation Plant.
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Since the MSDGC plants currently treat approximately
1,400 mgd, adequate treatment at these flows is a formidable
undertaking that requires careful design considerations.
Therefore, many forms of advanced waste treatment have been
tested and evaluated in order to determine the most feasible
and economical method.
The Hanover Park Experimental Bay Project was designed to
test three types of deep-bed, high-rate filters and a continu-
ous ion exchange unit. The three filtration units were a
DeLaval upflow filter, a Neptune Microfloc mixed-media filter,
and a Graver dual-media pressure filter. The continuous ion
exchange unit was manufactured by Chemical Separations Corpora-
tion. All four units were placed in operation under direct
supervision of the manufacturers, and no unauthorized modifica-
tions were made during the 1-year testing period.
The objective of this project was to investigate and
optimize the performance of each unit. The filtration devices
treated secondary effluent to remove suspended solids and
associated biochemical oxygen demand. In addition, chemical
coagulation and sedimentation before filtration was investigated
with the Neptune Microfloc unit. The ion exchange unit was
utilized to remove phosphorus from microscreened secondary
effluent.
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SECTION II
CONCLUSIONS
1. All the filtration units tested were able to consistently
reduce the suspended solids and BOD of a secondary effluent
to less than 10 mg/1 at a flow rate of 4 gpm/ft2.
2. At a flow rate of 4 gpm/ft2, the DeLaval filter improved a
secondary effluent of 15 mg/1 suspended solids and 24 mg/1
BOD to 5 mg/1 suspended solids and 6 mg/1 BOD (Test 2).
Removals of suspended solids and BOD were 67% and 73%,
respectively. Filter runs averaged 25.5 hours, and backwash
usage was 1.4% of filter throughput.
3. At a flow rate of 4 gpm/ft2, the Neptune filter improved a
secondary effluent of 16 mg/1 suspended solids and 25 mg/1
BOD to 4 mg/1 suspended solids and 4 mg/1 BOD. Removals of
suspended solids and BOD were 73% and 85%, respectively.
Filter runs averaged 27.2 hours, and backwash usage was
2.5% of filter throughput.
4. At a flow rate of 4 gpm/ft2, the Graver filter improved a
secondary effluent of 15 mg/1 suspended solids and 25 mg/1
BOD to 5 mg/1 suspended solids and 7 mg/1 BOD (Test 2).
Removals of suspended solids and BOD were 69% and 70%,
respectively. Filter runs averaged 51.1 hours and backwash
usage was 0.6% of filter throughput.
5. Based on the above results, which demonstrate representative
filter performance during identical operating periods, the
Neptune filter produced a slightly better effluent than
the Graver and DeLaval filters.
6. Also based on the same results, the Graver filter achieved
the longest filter runs, approximately twice the length of
the filter runs of the DeLaval and Neptune filters.
7. At a flow rate of 10 gpm/ft2, the Graver filter improved a
secondary effluent of 18 mg/1 suspended solids and 11 mg/1
BOD to 8 mg/1 suspended solids and 4 mg/1 BOD. Removals
of suspended solids and BOD were 56% and 64%, respectively.
Filter runs averaged 12 hours and backwash usage was 1.1%
of filter throughput.
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8. Chemical pretreatment in the Neptune unit to increase
suspended solids removal was generally unsuccessful.
9. Activated alumina removed up to 87% of the total phosphorus
from a microscreened secondary effluent in a continuous
flow ion exchanger. Sodium hydroxide concentrations of
0.4N were necessary for effective regeneration of the
alumina.
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SECTION III
RECOMMENDATIONS
This program was limited to filtration of Hanover Park
secondary effluent. Effluent criteria require filtration of
other treatment plant effluents within the jurisdiction of the
Metropolitan Sanitary District of Greater Chicago. This work
should be expanded to include filtration testing at these other
plants in order to design filtration facilities that will meet
effluent criteria.
Filters other than those tested should be tested if it is
possible that they will produce comparable or better quality
effluents. Further investigation of the process of phosphorus
removal by activated alumina should be made to determine if this
process is a practical method of removing phosphorus from a
sewage treatment plant effluent.
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SECTION IV
MATERIALS AND METHODS
Experimental Apparatus
The DeLaval Filter--
The filter used was manufactured by the DeLaval Separator
Company and was an "Upflow Immedium-filter, Model OT-3." The
filter vessel was approximately 3 feet in diameter and 13 feet
deep. The filtering media was silica sand and gravel, with the
filter bed being approximately 7 feet deep. The bed had an
effective surface area of 6.75 square feet and at a maximum
flow rate of approximately 6 gpin/f t^, the unit can filter
about 58,000 gallons daily.
As shown in Figure 2 the flow through the filter was upward,
with the influent entering the unit through a large number of
nozzles located in a distribution plate at the bottom of the
filter vessel. The filter media consisted of four layers, with
the bottom two layers being gravel and top two layers being
sand. The gravel served both to support the sand and to
distribute the flow uniformly. The bottom gravel layer was 4
inches deep, consisting of coarse gravel 1-1/4 to 1-1/2 inches
in diameter. The second layer was 10 inches thick and con-
tained 3/8-to 5/8-inch gravel. On top of the gravel layer was
a 12 inch layer of coarse 2 to 3-millimeter sand and a top
layer consisting of 60 inches of finer 1 to 2 millimeter sand.
The filter bed was held in place by a grid which was buried
near the top of the 60-inch fine sand layer. This filter was
designed to utilize the entire media depth for filtration and
solids storage.
The backwash cycle was accomplished as follows:
The filtration run was terminated when the head loss through
the filter reached a preset level, which was usually 14 psi.
With the filtration run terminated, the backwash cycle was
then initiated by first draining the filter to a point just
above the level of the media. The filter was then fluidized
by forcing air through the filter at a pressure of 5 to 10 psi.
After three minutes of air flow, the filter was flushed with
unfiltered secondary effluent at a rate of 10-13 gpm/ft^.
After approximately ten minutes of flushing, the bed was
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WASTE
SAND RETAINING GRID
SAND (l-2mm)
FLOW
SAND (2-3 mm)
GRAVEL(3/8 - 5/8 )
GRAVEL (I 1/4 -I 1/2")
NOZZLE DISTRIBUTION SYSTEM
INFLUENT »[X}~
WASH *{>
-------
allowed to settle for five minutes.
The Neptune Microfloc Unit--
The unit used was manufactured by Neptune Microfloc Inc. and
was a "Reclamate SWB-27A". The principal tank was 5 feet square
and 6 feet deep and was divided into three compartments: a
flocculation chamber, a settling chamber, and a filter chamber.
The settling chamber contained settling tubes and the filtering
media consisted of anthracite coal, silica sand, and garnet
supported by gravel. The filter bed was 60 inches deep and had
a surface area of 4 square feet, and a maximum flow-through
rate of 10 gpm/ft2 or about 58,000 gpd. The backwash storage
tank was approximately 5 feet in diameter and 7 feet deep.
Flow through the filter was regulated by an effluent pump and
an effluent rate control valve which was operated by a level
transmitter positioned above the bed.
The filter media consisted of from top to bottom: a 30-inch
layer of 1.2-to 1.3-millimeter anthracite coal, a 12-inch
layer of 0. 8-to 0.9-millimeter silica sand, a 6-inch layer of
0.4-to 0.8-millimeter garnet, and a 3-inch layer of 1.5- to 2.0-
millimeter support garnet, with the entire bed resting on a
12-inch layer of 3/16-to 2-inch gravel.
As depicted in Figure 3 the "Reclamate SWB-27A" could be operat-
ed in several different modes. The complete flow pattern in-
cluded chemical addition followed by flocculation, settling
and filtration. This mode of operation could be utilized for
phosphate removal. However, as shown in Figure 3, if chemical
addition was not desired, the flocculation and settling cham-
bers could be bypassed. Therefore, the appropriate mode of
operation can be selected on the basis of the quality of the
influent wastewater, the nature of the suspended solids and
the degree of tertiary treatment desired within the perform-
ance limits of the unit. When the headloss through the unit
increased to the setting on a vacuum switch located between the
filter and the effluent pump, the backwash cycle was initiated.
As shown in Figure 3, both the filter and the settling chamber
were cleaned during the backwash cycle. The backwash flow was
15 gpm/ft and the volume of water required for a backwash was
approximately 650 gallons. Settling after backwash restored
the anthracite coal, silica sand and garnet media to their
proper positions in accordance with their density and size
differences.
-------
CHEMICAL
FEED
MIXED
MEDIA
FILTER
CHAMBER
EFFLUENT
BACKWASH
UJ
(O
Figure 3. Flow Diagram of the Neptune Microfloc Unit.
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The Graver Filter—
The downflow pressure filter manufactured by the Graver Water
Conditioning Company was a "Monoscour Filter. " A diagram of
the Graver filter is shown in Figure 4. The filter vessel was
22 inches in diameter and 7.5 feet in height. The filtering
media consisted of anthracite coal and silica sand, with the
filter bed being approximately 3 feet deep. The bed has an
effective surface area of 2.65 square feet and at a maximum
flow rate of 11.5 gpm/ft2 the unit was capable of filtering
about 43,000 gallons daily. As shown in Figure 4, the back-
wash storage compartment (6 feet in diameter and 5 feet in
height) was positioned directly above the filter vessel.
Two different combinations of anthracite coal and silica sand
were used during the test period. Initially the aggregate size
of the 24-inch layer of anthracite was 1.4 to 1.8 millimeters
and the size of the 12-inch layer of silica sand was 0,8 to
1.0 millimeteis. Later in the study, the filter media was
changed to an anthracite size of 1.0 to 1.4 millimeteis and a
silica sand size of 0.6 to 0.7 millimeters.
As in the case of the other filters, the filtration run was
automatically stopped when the headless through the filter
reached a preset level. The backwash cycle began with the
filter being partially drained to a point above the level of
the media. The filter bed was then air scoured for 5 minutes
at a rate of 15 scfm at 5 psi. Following the air scouring,
the filter bed was allowed to settle for 6 minutes, after which
it was backwashed for 5 minutes at a rate of about 15 gpm/ft2.
The total volume of water used during backwash was about 200
gallons. After backwashing the filter bed, it was allowed to
settle before filtration was begun.
The Continuous-Flow Ion Exchange Unit —
The ion exchange unit used in the study was manufactured by
Chemical Separations Corporation and was a "Downflow Single-
Loop Continuous Countercurrent Ion Exchange Pilot Plant." The
unit was designed for removal of ions which require the regen-
eration of the exhausted exchange material (exchanger) by one
solution. Figure 5 shows a flow diagram of the continuous
flow ion exchange unit (CFIEU). As shown in the figure, the
unit consists basically of the reactor column, where the ion
exchange takes place, and the regeneration loop, where the
11
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t
O ui
V)
i
^
O
<
CD
BACKWASH
STORAGE
FLOW
ANTHRACITE
SANO
DRAIN
EFFLUENT
INFLUENT
BACKWASH
WASTE
AIR
Figure 4. Diagram of the Graver Filter,
12
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INFLUENT
KhH
11
EFFLUENTS
o:
o
Ul
o:
UJ
>
o
WASTE BACKWASH
'AND PULSE WATER
--BACK WASH
10
HI
CO
PULSE WATER
RINSE WATER
UJ
CO
or
o.
or
h-
cn
oc.
UJ
z
UJ
CD
UJ
or
WASTE REGENERANT
AND RINSE WATER
8
REGENERANT
LEGEND
—- Exchanger Flow
Water Flow
Regenerant Flow
Figure 5,
13
Flow Diagram of the
Continuous Flow Ion
Exchange Unit.
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spent exchanger is regenerated.
The CFIEU had overall dimensions of 6.3 feet in width and 21.5
feet in height. The unit was constructed primarily of 4-inch
diameter PVC and pyrex except for the reactor column which was
12-inch diameter 316 stainless steel. The capacity of the
CFIEU was 7 cubic feet of exchanger with a flow of 3 to 18 gpm.
The operation of the CFIEU was quite unique in that it was
entirely automated. During the normal run period when the in-
fluent water was processed, only the influent and effluent
valves 1 and 11, as shown in Figure 5, were open. At the start
of the pulse cycle the influent and effluent valves (1 and 11)
were closed, valves 6, 10 and 2 were opened, and valve 4 re-
mained closed. Pulse water then entered the loop through valve
5 and hydraulically pulsed the exchanger around the loop, push-
ing regenerated exchanger into the reactor column and forcing
the exhausted exchanger out of the reactor column and into the
overflow vessel. The pulse period, which usually was set at
10 to 12 seconds, was initiated after the timer controlled
process run was completed. After the pulse period, the ex-
hausted resin was backwashed for a preset time in the over-
flow vessel in order to remove any fines which could have
caused excessive pressure drops. Normal run operation commenced
when the main valves 2, 6 and 10 were closed and valves 1, 11,
8 and 7 were opened. Regeneration was accomplished by pumping
regenerant from valve 8 through valve 7. Regenerant flow was
terminated when the regenerant was sensed by the conductivity
meter (CC-2). The exchanger in the strip rinse section was
rinsed to prevent any regenerant from entering the reactor
column. The rinse water entered through valve 9 and was
eliminated through valve 7. The amount of rinse was controlled
automatically by a conductivity meter (CC-1). The CFIEU was
therefore, not truly a continuous flow system. Since the re-
actor was closed for only a few seconds during pulsing, the
shut down time was insignificant when compared to the process
time between pulses which usually was about 3 to 5 minutes.
Initially, Chemical Separations Corporation delivered Dow X50 AK
resin, which when properly conditioned, the company claimed would
remove both nitrate and phosphates, However, preliminary tests
demonstrated that the resin was neither suitable for phosphate
nor nitrate removal. Thus, the exchanger used in this study
was activated alumina from the Davidson Chemical Company,
Type SMR-9.
14
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Influent Sources
As illustrated in Figure 6, there were two primary sources of
influent to the experimental filters. The first source was
the secondary effluent of the activated sludge process, while
the second was secondary effluent which had undergone coagula-
tion-sedimentation. Normally the influent to the experimental
sand filters was the secondary effluent directly from the final
settling tanks of the activated sludge plant. However, late
in the study, the secondary effluent from the Hanover Plant
deteriorated significantly because plant flow exceeded the
design flow of 2 mgd. In addition, construction of a 4 mgd
plant expansion caused frequent interruptions in normal plant
operations. These conditions resulted in a very poor quality
and highly variable secondary effluent. Rather than terminate
the project, the last filter runs used secondary effluent which
had undergone coagulation-sedimentation. The coagulation
dosage was 15 mg/1 of alum.
As shown in Figure 6, the source of influent to the ion exchange
unit was the tertiary portion of the Hanover plant. In order
to achieve meaningful experimental runs, the suspended solids
coming into the ion exchange unit must be low and therefore,
the source of the influent to the unit was the microscreened
effluent.
Analytical Methods
Chemical Analyses--
All of the analytical work was performed by the Research and
Development Control Laboratory of MSDGC at the North Side
Treatment Works. Biochemical oxygen demand, suspended solids,
volatile suspended solids and pH were analyzed as described
in Standard Methods (1). A Beckman Zeromatic pH meter was
used for pH determinations.
15
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EFFLUENT FROM
ACTIVATED SLUDGE
PROCESS
INITIAL SAND
FILTER INFLUENT
^-
ALUM ADDITION
AT I5mg/l
COAGULATION
SEDIMENTATION
SAND FILTER
INFLUENT
RECEIVING
CHEM. TREATMENT
UIPDnCTBAIRIPB
Mlv/nUol WAlNttx
INFLUENT TO
ION EXCHANGE
UNIT
Figure 6. Influent Sources of the Hanover Experimental Bay Project.
-------
Phosphorus was analyzed by the single reagent method using a
Technicon Auto-analyzer as described by Stanley and Richardson
(2). The single reagent method for total phosphorus included
acid hydrolysis of the condensed phosphates, and persulfate
digestion of organic phosphates to orthophosphate. Ammonium
molybdate and potassium antimony tartrate react with dilute
solutions of orthophosphate in an acid medium to form an
antimony-phosphate-molybdenum complex. The antimony-phospho-
molybdate complex is reduced with ascorbic acid to form an
intensely-blue molybdenum complex. The intensity of the color
was measured by a colorimeter at a wavelength of 650 milli-
microns .
Sampling—
Originally, it was planned to have the samples for the filters
and the ion-exchange unit automatically composited and refrig-
erated. However, due to many problems with the automatic
samplers, they were abandoned. Thus, the influent and effluent
samples were obtained by compositing nine grab samples daily.
17
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SECTION V
RESULTS
Operation of the DeLaval Filter
Table 1 summarizes the operation of the DeLaval filter using
secondary effluent. There were six different test periods with
the hydraulic loadings from 2 to 5 gpm/ft2. As can be seen in
the table, the average effluent suspended solids (SS) were
fairly consistent (5 to 7 mg/1) despite the differences in in-
fluent quality and hydraulic loadings. The influent suspended
solids and BOD varied somewhat, with the result being a fluc-
tuation in the percent removals of suspended solids and BOD.
Although the effluent quality from the DeLaval filter was good
in terms of BOD and suspended solids the length of the filter
runs were drastically reduced as the hydraulic loadings were
increased from 2 to 5 gpm/ft2, with the length of the filter
run falling from 150 hours to 7 hours. A slight increase in
the length of filtration runs and the suspended solids loading
did occur when the hydraulic loading was reduced to 4 gpm/ft2
in test 4. Prior to test 5 the pressure setting which initi-
ates the backwash cycle was changed from 14 to 17 psi. This
change in pressure setting did not significantly lengthen the
average filtration runs.
Before the filtration runs of test 6, a visual inspection was
made of the filter bed and it could be seen that the bed was
not being properly cleaned. In order to improve the backwash
efficiency, the backwash time was increased from 10 to 20
minutes. However, as shown in Table 1, this change had little
effect upon the backwash efficiency, as the average length of
filtration run was only 8.5 hours, even though the influent
suspended solids were only 17 mg/1.
In tests 7 through 10, the influent to the DeLaval filter was
secondary effluent which had been additionally treated by alum
coagulation-sedimentation. The results of these tests are
summarized in Table 2. As shown in the table, the effluent
quality from the DeLaval filter was similar to that obtained
during tests 1 through 6. As in the case of test 6, the
DeLaval filter during test 7 was backwashed for 20 minutes
instead of 10 minutes. The average length of filtration run
did not improve significantly, as was the case in test 6.
18
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TABLE 1. OPERATION OF THE DELAVAL FILTER AT VARIOUS
HYDRAULIC LOADINGS: TREATMENT OF SECONDARY
EFFLUENT
Test Number
Item
Hydraulic loading,
gpm/ft2
Test period, days
Influent SS , mg/1
Effluent SS, mg/1
SS removal , %
Influent BOD, mg/1
Effluent BOD, mg/1
BOD removal, %
Number of filter runs
Length of filter
runs, hr
SS loading,
Ib/ft2/filter run
SS removal ,
Ib/ft2/filter run
Backwash usage, %
Backwash flow rate
gpm/ft2
Backwash time , min
1
2
21
14.1
7.0
50
17
6
62
4
150.1
2.1
0.96
0.5
9.0
10
2
4
19
14.8
4.9
67
24
6
73
16
25.5
0.77
0.51
1.4
8.7
10
3
5
6
13.0
5.7
56
20
7
65
19
6.9
0.22
0.13
4.4
8.9
10
4
4
19
13.8
6.7
51
9
4
53
29
14.3
0.39
0.20
2.5
8.5
10
5
4
15
25
7
72
29
13
55
23
13
0
0
2
8
10
.5
.9
.3
.3
.74
.52
.5
.5
6
4
7
16
6
74
10
2
80
15
8
0
0
9
9
20
.6
.0
.5
.25
.16
.3
.5
19
-------
TABLE 2. OPERATION OF THE DELAVAL FILTER AT VARIOUS
HYDRAULIC LOADINGS: TREATMENT OF ALUM-TREATED
SECONDARY EFFLUENT
Item
Hydraulic loading, gpm/ft2
Test period, days
Influent SS, mg/1 (alum- treated
secondary effluent)
Effluent SS, mg/1
SS removal , %
Influent BOD, mg/1 (alum-treated
secondary effluent)
Effluent BOD, mg/1
BOD removal , %
Number filter runs
Length of filter runs, hr
SS loading, Ib/ft2/day
SS removal, Ib/ft2/day
Backwash usage, %
Backwash flow rate, gpm/ft2
Backwash time, min
7
4
18
24
7
71
18
6
66
37
10.
0.
0.
8.
10.
20
Test
8
4
19
12
7
44
7
5
26
11
3 43
49 1
35 0
6 2
7 12
20
number
9
4.7
26
14
7
54
17
9
48
16
.0 37.0
.04 1.23
.45 0.67
.5 2.7
.9 14.1
20
10
5
8
14
5
62
18
5
72
5
35
1
0
3
14
20
.4
.24
.70
.7
.0
20
-------
Moreover, because of the longer backwashing period, the back-
wash usage increased to 9.5% for test 6 and 8.6% for test 7.
Finally, it was decided to increase the backwash flow rate from
less than 10 gpm/ft2 to approximately 13 gpm/ft2 in order to
improve the backwashing efficiency. As shown in the table, the
average length of the filtration run did significantly improve
in tests 8, 9 and 10 as a result of the increased backwash flow
rate.
Also, the percent backwash usage was considerably reduced.
Possibly, further reductions of backwash usage could have been
achieved if the backwashing period had been reduced from 20
minutes. No studies were made to determine the necessary
period of backwash at the 13 gpm/ft2 rate, however it was
obvious that the backwash flow rate of 10 gpm/ft was inade-
quate and that a higher backwash flow rate was needed in order
to properly clean the filter.
Since the backwash flow rate was only 10 gpm/ft2 in tests 1
through 7, inclusive, it is difficult to evaluate the DeLaval
filter. However, as adjudged by its performance in tests 8, 9
and 10 the DeLaval filter can adequately handle loadings at
aroung 4-5 gpm/ft , with the effluent suspended solids being
about 5 to 7 mg/1 and the length of the filtration run being
about 40 hours.
Operation of the Neptune Microfloc Unit
Since the Neptune Microfloc unit had the capability for coagu-
lation-sedimentation before filtration, some of the tests
employed chemical addition. Table 3 summarizes the treatment
of secondary effluent using the Neptune Microfloc filter.
Tests 4 and 5 involved the use of ferric chloride, while tests
1, 2 and 3 used no chemicals prior to filtration. In tests 1
and 2 the unit's coagulation-sedimentation tank was bypassed,
while in test 3 the flow passed through the unit's coagulation-
sedimentation tank with no chemical addition.
As shown in the table, the average effluent suspended solids in
tests 1 through 3 were exceptionally low, with the average
being about 4 mg/1. Also, the increase in hydraulic loading
from 2 to 4 gpm/ft2 in these tests did not affect the quality
of the effluent. However, the length of the filter run was
21
-------
TABLE 3. OPERATION OF THE NEPTUNE MICROFLOC UNIT:
TREATMENT OF SECONDARY EFFLUENT WITH AND
WITHOUT CHEMICAL ADDITION
Item
Chemical dosage
Hydraulic loading,
gpm/f t-2
Test period, days
Influent SS , mg/1
Effluent SS, mg/1
SS removal , %
Influent BOD, mg/1
Effluent BOD, mg/1
BOD removal, %
Number of filter runs
Length of filter runs,
hr
SS loading, lb/ft2/
filter run
SS removal, lb/ft2/
filter run
Backwash usage, %
Backwash flow rate,
gpm/f t2
Backwash time , min
1
None
2
9
14.0
3.8
73
22.8
6.0
74
2
106.3
1.53
1.12
1.3
15
10
Test number
2 3
None
4
22
16.1
4.3
73
25.3
3.9
85
19
27.2
0.86
0.64
2.5
15
10
None
4
18
16.6
3.8
N.A. *
15.7
2.6
N.A.
14
26.6
N.A.
N.A.
2.6
15
10
4
Fed o
10mg/l
4
14
11.6
8.6
N.A.
8.5
3.8
N.A.
7
48.0
N.A.
N.A.
1.4
15
10
5
FeCl3
20 mg/1
4
17
16.3
8.4
N.A.
16.5
4.0
N.A.
21
14.8
N.A.
N.A.
4.4
15
10
* Not applicable
22
-------
reduced from 100 hours to 25 hours, with the percent backwash
usage increasing from 1.3% to 2.5%.
The addition of ferric chloride to the unit's coagulation-
sedimentation tank prior to filtration in tests 4 and 5 did
not improve the quality of the effluent when compared to test
3. In fact, it appears that the effluent was significantly
poorer in quality, since the average suspended solids in the
effluent in tests 4 and 5 were about 8 to 9 mg/1 as compared
to 4 mg/1 in test 3. Note that the influent suspended solids
and BOD concentrations are those of the secondary effluent
and not those introduced directly to the filter for runs 3,
4 and 5. Since the units coagulation and sedimentation com-
partments had been introduced into the flow pattern, the back-
wash usage in test 4 was comparatively low. The backwash
usage in test 5 was high in comparison to test 4 because of
the shorter filtration runs due perhaps to a higher solids
loading to the filter. In general, the addition of ferric
chloride did not improve the quality of the effluent from the
filtration unit, particularly with respect to suspended solids.
In tests 6 through 10, shown in Table 4, the Neptune Microfloc
unit used secondary effluent additionally treated by alum
coagulation-sedimentation. As explained previously this
chemical pretreatment was necessary to maintain overall plant
efficiency during a period of inadequate treatment capacity.
As noted previously, the chemical treatment of the secondary
effluent was 15 mg/1 of alum. In tests 6, 7 and 9, chemicals
were also added to the coagulation-sedimentation tank of the
Neptune Microfloc unit before filtration. Polymers were added
in test 6 and 7, while ferric chloride was added in test 9 to
remove phosphorus.
In test 6, Nalco N17 polymer was used at a dosage of 0.5 mg/1.
The filter effluent averaged 7 mg/1 suspended solids and
9 mg/1 BOD. In test 7, Dow A23 polymer was used at a dosage
of 0.5 mg/1. The filter effluent averaged 8 mg/1 suspended
solids and 9 mg/1 BOD. Thus, both polymers produced effluents
of comparable quality.
In an attempt to remove phosphorus, the Neptune Microfloc unit
was dosed with 70 mg/1 of ferric chloride as FeCl3. An
average of only 55 percent of the incoming 11.6 mg/1 phosphorus
as P was removed, with the average effluent suspended solids
being higher than the influent suspended solids. These results
23
-------
TABLE 4. OPERATION OF THE NEPTUNE MICROFLOC UNIT•
TREATMENT OF ALUM-TREATED SECONDARY EFFLUENT
WITH AND WITHOUT CHEMICAL ADDITION
Item
Chemical dosage
Test period, days
Hydraulic loading,
gpm/ft2
Influent SS , mg/1
(alum treated
secondary effluent)
Effluent SS, mg/1
Influent BOD, mg/1
(alum treated
^secondary effluent)
Effluent BOD, mg/1
Number of filter
runs
Length of filter
runs , hr
Backwash usage, %
Backwash flow,
6
N 17
polymer
0.5 mg/1
14
4
24
7
18
9
25
12.9
5.2
15
Test number
7 8
A 23
polymer
0.5 mg/1
3
4
33
8
18
9
13
6.0
11.3
15
None
10
4
10
6
6
6
9
24.4
2.8
15
9
FeCl3
70 mg/1
26
4
13
24
16
16
41
14.1
4.8
15
10
None
5
6
15
6
18
4
6
21.0
2.2
15
Backwash time, min
10
10
10
10
10
24
-------
indicate that the chemical treatment was improper for phosphorus
removal, and resulted in poor system performance.
In general, the Neptune Microfloc unit operated well at 4
gpm/ft , with the average filtration run being approximately
25 to 30 hours and the effluent suspended solids averaging
about 4 mg/1. Addition of ferric chloride and polymers prior
to filtration produced in most cases an effluent which was
inferior in quality when compared to the tests where no chemi-
cals were added.
Operation of the Graver Filter
Table 5 summarizes the operation of the Graver filter using
secondary effluent from the Hanover Plant as the influent feed.
The hydraulic loadings tested ranged from 2 to 10 gpm/ft . As
shown in the table, the effluents in all of these tests were of
similar quality even though a wide range of hydraulic loadings
were tested. The average effluent suspended solids ranged
from 5 mg/1 to 9 mg/1. The main effect of increasing the
hydraulic loading was a reduction in run lengths with the
average filtration time ranging from 90 hours at 2 gpm/ft
to 21 hours at 10 gpm/ft2.
During tests 8 through 12 the Graver filter processed alum
treated secondary effluent. Table 6 summarizes the results of
these tests. The hydraulic loadings tested ranged from 4 to
6 gpm/ft2 and the quality of the effluent was comparable to
the previous tests 1 through 6. However, there was a notice-
able difference in the length of the filter runs of tests,
8, 9 and 11 when compared to test 2. In all four of these
tests the hydraulic loading was 4 gpm/ft2, however,the length
of the filter runs averaged about 20 hours in tests 8, 9 and
11, while the average filtration run was about 50 hours during
test 2. The difference can be attributed to the difference
between the influent qualities. During tests 8, 9 and 11, the
average during test 2 was 15 mg/1. Therefore, the solids load-
ing was about 30 to 60 percent higher during tests 8, 9 and 11
than in test 2. Another factor which had some effect on fil-
tration is that tests 8, 9 and 11 used secondary effluent
which had undergone alum coagulation-sedimentation. However,
the change in filterability of the suspended solids caused by
this chemical pretreatment was not determined.
25
-------
TABLE 5. OPERATION OF THE GRAVER FILTER AT VARIOUS
HYDRAULIC LOADINGS: TREATMENT OF
SECONDARY EFFLUENT
Item
Hydraulic loading of
gpm/ft2
Number of days
Influent SS, mg/1
Effluent SS, mg/1
SS removal, %
Influent BOD, mg/1
Effluent BOD, mg/1
BOD removal, %
Number of filter runs
1
2
35
16
7
55
20
7
64
10
2
4
26
15
5
69
25
7
70
12
3
8
11
13
6
48
18
7
64
8
Test number
4 5
9
25
14
9
33
10
6
45
17
10
2
18
8
56
11
4
64
3
6
6
19
17
7
61
20
8
60
16
7
6
16
16
6
63
14
3
76
20
Length of filter run,
hr
SS loading, lb/ft2/
filter run
SS removal, lb/ft2/
filter run
Backwash usage %
Backwash flow rate
gpm/ft2
Backwash time, min
90.0 51.1 31.1 32.2 11.8 25.7 18.4
1.45 1.55 1.48 1.92 1.07 1.28 0.89
0.85 1.05 0.71 0.72 0.48 0.78 0.55
0.7 0.6 0.5 0.4 1.1 0.8 1.1
15
5
15
5
15
5
15
5
15
5
15
5
15
5
26
-------
TABLE 6. OPERATION OF THE GRAVER FILTER AT VARIOUS
HYDRAULIC LOADINGS: TREATMENT OF ALUM-
TREATED SECONDARY EFFLUENT
Item
Hydraulic loading,
gpm/ft2
Test period, days
Influent SS, mg/1 (alum
treated secondary effluent)
Effluent SS, mg/1
SS removal , %
Influent BOD, mg/1 (alum
treated secondary effluent)
Effluent BOD, mg/1
BOD removal, %
Number of filter runs
Length of filter run,
hr
SS loading, Ib/ft2/f ilter
run
SS removal, Ib/ft2/f ilter
run
Backwash usage, %
Backwash flow rate
gpm/ft2
Backwash time, min
8
4
13
25
8
69
19
6
66
19
15.2
0.72
0.49
2.1
15
5
Test number
9 10
4
10
24
10
58
13
8
43
10
20.2
0.92
0.54
1.6
15
5
5
24
11
6
41
9
7
22
16
35.5
0.98
0.49
0.7
15
5
11
4
12
20
6
68
20
6
68
13
22.5
0.93
0.64
1.4
15
5
12
6
13
13
5
63
16
5
70
20
14.
0.
0.
1.
15
5
4
58
37
5
27
-------
Before test 11, the filter medium was changed to a slightly
smaller size. The anthracite layer size range was reduced
from 1.4 to 1.8 millimeters, to 1.0 to 1.4 millimeters while
the sand layer size range was reduced from 0.8 to 1.0 milli-
meter to 0.6 to 0.7 millimeter. As shown in Table 6, the
changes in the filter media sizes did not significantly change
performance characteristics of the unit, although effluent
suspended solids concentrations were somewhat lower.
Operation of the Continuous Flow Ion Exchange Unit
To demonstrate that the activated alumina could successfully
remove phosphorus, and experimental run was made using the
ion exchange column in which there was no regeneration of the
activated alumina. The results of the test are shown in
Figure 7. The linear reduction of phosphorus removal efficien-
cy rather than a typical breakthrough curve is due to the fact
that the alumina was intermittently pulsed through the loop.
Thus the phosphate was exchanged uniformly with all the alumina
instead of the progressive complete exhaustion of an exchanger
that normally occurs in a fixed bed. The primary reason the
ratio of the effluent concentration of phosphorus to the in-
fluent concentration of phosphorus was 0.15 and not zero
initially was because the activated alumina only removes the
soluble phosphates and therefore, the remaining 15% consisted
of insoluble phosphorus forms.
Table 7 shows the results of using sodium hydroxide in re-
generating the activated alumina. As shown in the table, the
use of sodium hydroxide as a regenerant was fairly successful
at normalities of 0.4 to 0.5. At these concentrations about
70% of the total phosphorus was removed and effluent phos-
phorus averaged less than 1.5 mg/1 as total phosphorus. Re-
generant use was less than 4% of process flow.
28
-------
NJ
o
3E
UJ
a:
cr.
o
x
a.
o
x
a.
o
100
90
80
70
60
50
40
30
20
10
Type of Alumina - SMR-9 (Davidson
Chem. Co.) Volume of Alumina -
7 cubic feet
Flow Rate - 15 gpm
Regeneration - None
10
20
30
40
50
60
70
80
90
100
THOUSANDS OF GALLONS PROCESSED
Figure 7. Phosphorus Removal By Activated Alumina
-------
TABLE 7. OPERATION OF THE CONTINUOUS FLOW ION EXCHANGER
FOR PHOSPHORUS REMOVAL BY ACTIVATED ALUMINA
WITH SODIUM HYDROXIDE REGENERATION
Item
Normality NaOH
Length of test, hr
Process flow, gpm
Process time, min
Regenerant flow, gph
Regeneration time, min
Regenerant usage, %
Number of samples
Influent total P, ppm
Effluent total P, ppm
Total P reduction, %
1
0.1
7
8.5
4
14
3.5
2.45
5
9.9
8.1
18
Test number
234
0.2
8
8.5
4
15
3.5
2.57
3
6.3
5.3
16
0.3
10
8.5
4
15
3.5
2.57
4
8.6
4.0
54
0.4
9
8.5
4
16.5
3.5
2.83
5
5.2
1.4
73
5
0.
4
8.
4
13.
3.
3.
2
2.
0.
68
5
5
5
5
58
8
9
30
-------
SECTION VI
DISCUSSION
During the first part of the study, the influent to the sand
filters was secondary effluent from the Hanover Plant. During
the later part of the study, the influent to the filters was
coagulated and settled secondary effluent. Since the Hanover
Park secondary effluent was of poor quality at that time, it
was decided to add alum and utilize the available coagulation-
sedimentation basin in order to enhance suspended solids
removal. Also, during both periods additional chemical studies
were run using the Neptune Microfloc unit since it also had a
coagulation-sedimentation basin, as well as the mixed media
filtration system. These studies were run to determine phos-
phorus removal as well as filtrability.
Filtration of Secondary Effluent
In terms of effluent quality, all three units, the DeLaval up-
flow filter, the Neptune Microfloc mixed media filter, and the
Graver dual media pressure filter, consistently produced an
effluent of less than 10 mg/1 suspended solids when filtering
a secondary effluent with influent suspended solids of about
13 to 18 mg/1. Since the Neptune Microfloc filter contained
the smallest particle size (0.4 to 0.8 millimeter garnet) of
the three filters tested, it was not particularly surprising to
observe that the average effluent suspended solids was the
lowest (3 to 4 mg/1) at hydraulic loadings of 2 to 4 gpm/ft .
Even with the backwashing difficulties encountered with the
DeLaval filter during the first part of the study, the effluent
quality was good in terms of suspended solids and averaged
5 to 7 mg/1 in the hydraulic loading range of 2 to 5 gpm/ft2.
The Graver filter also produced an effluent similar to the
DeLaval filter, with the effluent suspended solids of 5 to
7 mg/1 in hydraulic loading range of 2 to 4 gpm/ft2. Further-
more, at higher hydraulic loadings of 8 to 10 gpm/ft2 to the
Graver filter the effluent suspended solids concentrations were
still fairly low, averaging 6 to 9 mg/1.
Since the Graver filter was a pressure filter (backwashed at a
headloss of 13 ft of water) and contained a relatively coarse
31
-------
media, the time between backwashes was generally the longest
among the filters tested at a given hydraulic loading. The
time between backwashes ranged from 90 hours at 2 gpm/ft2 to
11.8 hours at 10 gpm/ft2. The Neptune filter, with a finer
media, a deeper bed, and a terminal headless (backwashed at
7 ft of water) less than the Graver filter, averaged 27 hours
between backwashes at 4 gpm/ft2. In comparison, at the same
hydraulic loading and influent suspended solids of 13 to
16 mg/1, the time between backwashes for the Graver filter
averaged 51 hours. As described earlier, there were problems
in backwashing the DeLaval filter, therefore the time between
backwashes as well as the percentage of effluent water used for
backwashing cannot be evaluated.
Because of the relatively long filter runs of the Graver filter,
the backwash requirements ranged from 0.4 to 1.1% at hydraulic
loadings of 2 to 10 gpm/ft2. The backwash percentage for the
Neptune Microfloc filter varied from 1.3% at 2 gpm/ft2 to 2.5%
at 4 gpm/ft2.
Filtration of Secondary Effluent Treated with 15 mg/1 of Alum
To reiterate, the chemical treatment was undertaken to preserve
effluent quality during a period of poor operation caused by
construction activities during a 4 mgd plant expansion. The
secondary effluent which had undergone this chemical treatment
did not show any discernable change in appearance in comparison
with the secondary effluent used previously in the study. A
comparison of influent suspended solids and BOD for both in-
fluent sources shows that they were very similar. However,
since it is likely that the chemical treatment caused some
changes in particle size and composition, the data for each
influent source have been treated separately.
The importance of proper backwashing to the efficient operation
of the DeLaval filter was demonstrated. Test 7 of the DeLaval
filter shows similar performance for the treatment of alum
treated secondary effluent and the normal secondary effluent
used in tests 4 and 6 (all at 4 gpm/ft2). However, when the
backwash flow was increased from 10 gpm/ft2 to 13 gpm/ft2 in
test 8 the length of filter runs increased approximately three-
fold, abruptly stopping the trend progressively shorter runs at
a given hydraulic loading. It is logical to conclude that if
the backwash flow had been 13 gpm/ft^ in tests 1 through 6,
32
-------
increased filter run times would have resulted.
Tests 6 through 10 of the Neptune Microfloc unit were made
using alum treated secondary effluent as the influent source
to the filter. These tests were performed to determine the
effectiveness of chemical treatment utilizing the unit's own
coagulation and settling chambers. Since the filter influent
was treated twice with chemicals before filtration, these re-
sults may not reflect the best performance obtainable with
this unit.
Polymer addition in tests 6 and 7 showed no improvement in
effluent quality and resulted in shorter filter runs. Ferric
chloride addition in test 9 did not effectively remove phos-
phorus as anticipated.
The performance of the Graver filter in treating alum dosed
secondary effluent was very similar to that achieved with normal
secondary effluent. The significant difference was a 50% de-
crease in solids loadings and removals (both expressed as
Ibs/ft2/filter run). It is likely that this difference was
caused by a change in particle characteristics because of the
treatment with alum.
Phosphorus Removal by the Continuous Ion Exchange Unit
Activated alumina is capable of removing phosphorus from a
treatment plant effluent as shown in the results presented in
Section V. Unfortunately the data obtained are insufficient
to make any judgements regarding the applicability of the
process on a plant scale. Some unresolved issues are:
1) Can this process achieve the desired effluent quality
of 1 mg/1 total phosphorus?
2) What are the optimum operating parameters? Parameters
such as regenerant strength, flow rates and run times
would require much more testing to find the optimum
mode of operation of the continuous ion exchange unit.
3) Disposal of waste regenerant may be a problem since
the large amounts of waste sodium hydroxide cannot be
recycled through the plant without pH adjustment and
phosphorus removal.
It is apparant that further investigation of this process is
necessary.
33
-------
REFERENCES
1. Anon., "Standard Methods for the Examination of Water and
Wastewater." 12th Ed., Araer. Pub. Health Assn., N.Y. (1968)
2, Stanley, G. H., and Richardson, G. R., "The Automation of
the Single Reagent Method for Total Phosphorus." Presented
at the Technicon International Contress (1970).
34
-------
APPENDIX
Metric Conversions
Length
mm
m
Area
Volume
Mass
Flow
Kg
0.03937 in
3.28 ft
10.76 ft'
0.264 gal
2.205 Ib
rnVday = 2.64X104 mgd
2.64X102 gpd
1/min = 0.264 gpm
Hydraulic Loading
m3/m2 - 24.51 gal/ft2
Mass Loading
kg/m2 = 0.205 lb/ft2
Pressure
N/m2
0.000145 lb/in2
35
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-76-264
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
5. REPORT DATE
December 1976 (Issuing Date)
HANOVER PARK TERTIARY STUDIES
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
D. R. Zenz, E. Bogusch, C. Lue-Hing
and A. W. Obayashi
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Metropolitan Sanitary District of Greater
Chicago
100 E. Erie Street
Chicago, Illinois 60611
10. PROGRAM ELEMENT NO.
1BC611
11. CONTRACT/GRANT NO.
EPA FWPCA
WPRD 92-01-68
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final 1-71 to 1-72
14. SPONSORING AGENCY CODE
EPA-ORD
15. SUPPLEMENTARY NOTES
16. ABSTRACT
a Qne year 3 tudy , four tertiary treatment units were test
ed and evaluated. Three of the units were deep-bed filters which were
used to treat secondary plant effluent. The types of filters used were:
(l)an upflow filter with a sand media, (2)a downflow gravity filter with
mixed-media consisting of anthracite, sand, and garnet, and (3) a downflow
pressure filter utilizing dual-media of anthracite and sand. The fourth
unit was a continuous flow ion exchanger that employed activated alumina
to remove phosphate from microscreened secondary effluent. The filtra-
tion studies indicate that comparable effluents were produced by all
three filters with filtration rates from 2-6 gpm/ft2. Filter effluents
generally contained about 4-7 mg/1 suspended solids in the above flow
range. The results of the ion exchange study indicated that sodium
hydroxide successfully regenerated an exhausted activated alumina bed.
In a 9-hour test, the ion exchange column removed 73% of the influent
phosphorus, using 0 . 4N sodium hydroxide as the regenerant.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
COSATI Field/Group
Sewage Treatment
Filtration
Phosphorus
Tertiary Treatment
BOD Removal
SS Removal
13B
13. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report)
UNCLASSIFIED
21. NO. OF PAGES
44
20. SECURITY CLASS (This page)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
36
^ U.S. GOVERNMENT PRINTING OFFICE: 1977-757-056/5't'i8 Region No. 5-11
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