A-670/2-73 103
bruary 1974
Environmental Protection Technology Series
Jaffa
For
oriis
I
55
o
\
LU
CD
Office of Research
U.S. Environmental
Washington, D.C.
-------
HSSI-BSCH F.F.PORTING SERIES
Research reports of the Office of Research and
Monitoring, Environmental Protection Agency, have
been crcuped into five series. These five bread
categories were established to facilitate further
development and application of environmental
technology. Eli.TO.nation of traditional grouping
was consciously planned to foster technology
transfer and a rr.axi::iu;n interface in related
fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
<;. 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.
-------
EPA 670/2-73-103
February 1974
FERRIC CHLORIDE AND ORGANIC
POLYELECTROLYTES FOR THE REMOVAL OF
PHOSPHORUS
Otto Green
Doris VanDam
Bernard LaBeau
Terry L. Campbell
Stacy L. Daniels
Grant No. 11010 ENK
Program Element 1BB043
Project Officer
E. F. Barth
U.S. Environmental Protection Agency
National Environmental Research Center
Cincinnati, Ohio 45268
513/684-82-40
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D. C. 20460
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - Price $1.55
-------
EPA Review Notice
This report has been reviewed by the
Office of Research and Development/ EPA,
and approved for publication. Approval
does not signify that the contents
necessarily reflect the views and
policies of the Environmental Protec-
tion Agency, nor does mention of trade
names or commercial products constitute
endorsement or recommendation for use.
11
-------
ABSTRACT
The primary objective of this project was to demonstrate
the feasibility and economic practicality of chemical removal
of phosphorus from municipal wastewater in the 44 mgd activated
sludge plant at Grand Rapids, Michigan. The full-scale
system for chemical phosphorus removal was implemented to
meet water quality criteria established by the State of
Michigan. The chemical precipitation and flocculation systems
consisted, respectively, of ferric chloride and an organic
polymeric flocculant. Several distinct modes of chemical
treatment were evaluated. Total phosphorus concentrations
below 1 mg/1 in the final effluent were achieved during
the best period of operation, when split addition of chemicals
was practiced.
The performance and economic improvements obtained in other
treatment systems associated with the chemical precipitation
process were demonstrated as secondary objectives of the
study. These improvements during normal flow included:
reduced organic loading to the activated sludge process,
reduced biochemical oxygen demand and suspended solids in
the final effluent, additional removals of some heavy metals,
and improved solids handling and disposal up to the limits
of capacity. The nature of the chemically precipitated
sludge was also evaluated relative to further chemical con-
ditioning, vacuum filtration, and incineration.
This report was submitted in fulfillment of Grant Number 11010 EM, by
the City of Grand Rapids, Michigan under the partial sponsorship of the
Environmental Protection Agency.
111
-------
TABLE OF CONTENTS
Page
ABSTRACT ill
LIST OF TABLES vi
LIST OF FIGURES vii
LIST OF APPENDICES vii
Sections
I CONCLUSIONS 1
II INTRODUCTION 3
III DESCRIPTION OF THE TREATMENT PLANT 6
IV PRELIMINARY STUDIES 10
Phosphorus Removal Feasibility Study 10
Detention Time Study 13
V CHEMICAL STORAGE AND HANDLING 15
Coagulant System 15
Flocculant System 19
Phosphorus Analyzer 21
Points of Chemical Addition 22
VI SAMPLING AND ANALYTICAL PROCEDURES 25
VII PROCESSING OF THE DATA 28
VIII DISCUSSION OF RESULTS BY PERIOD 37
Period 1: No Chemical Treatment 37
Period 2: Metal + Flocculant Addition to Primary . 40
Period 3: Metal Addition Only to Primary 42
Period 4: Split Addition of Metal to Both Primary
and Secondary + Flocculant Only to
Primary 44
Period 5: Metal Addition Only to Secondary 46
IV
-------
Page
Period 6: Metal + Flocculant Addition to Secondary 47
Period 7: Metal + Anionic Flocculant Addition to
Primary + Cationic Flocculant Addition to
Secondary 49
Period 8: Split Addition of Metal to Both Primary
and Secondary + Flocculant Only to
Secondary 49
IX DISCUSSION OF INDIVIDUAL PARAMETERS 53
Phosphorus 53
Biochemical Oxygen Demand and Suspended Solids ... 60
Heavy Metals 62
Iron 62
Chemical Additions and Overflow Rates 64
Recycle Streams 68
Solids Handling 69
Sludge Filtration 74
X ABBREVIATIONS 75
XI ACKNOWLEDGMENTS 76
XII REFERENCES 77
XIII APPENDICES 80
-------
LIST OF TABLES
Page
1. Preliminary Estimates of Chemical Requirements ... 11
2. Detention Times at Headworks of the Grand Rapids
Wastewater Treatment Plant 13
3. Points of Chemical Addition 24
4. Descriptions of Analytical Tests 27
5. Chronology of Operation 29
6. Mean Values for Phosphorus Species and Total
Phosphorus Loadings 31
7. Mean Values for Phosphorus Ratios 32
8. Mean Values for Treatment Chemicals and Compara-
tive Chemical Costs 33
9. Mean Values for Flows, Overflow Rates, and pH .... 34
10. Mean Values for Biochemical Oxygen Demand and
Suspended Solids Concentrations and Loadings ..... 35
11. Mean Values for Heavy Metals 36
12. Summary of Operation in Absence of Chemical
Treatment 39
13. Summary of Operation During Supplemental Period .. 51
14. Comparison of Removal Efficiences for Various
Phosphorus Species 54
15. Comparison of Removal Efficiences for Biochemical
Oxygen Demand and Suspended Solids 61
16. Comparison of Removal Efficiencies for Various
Heavy Metals 63
17. Solids Distribution in Various Process Streams ... 70
18. Comparison of Sludge Compositions 72
19. Filtration Characteristics of Various Sludges .... 74
B-l Periods of Study 97
C-l Listings of Tabulated Data 99
VI
-------
LIST OF FIGURES
Page
1. Schematic of City of Grand Rapids, Michigan,
Wastewater Treatment Plant 7
2. Automatic Control Loop for Phosphorus Removal
from Wastewater 16
3. Coagulant Feed System 17
4. Flocculant Feed System 20
5. Points of Chemical Addition 23
6. Modes of Chemical Addition 38
7. Frequencies of Occurrence of Ortho Phosphorus
During Period 8 56
8. Frequencies of Occurrence of Total Phosphorus
During Period 8 57
9. Frequencies of Occurrences for Final Effluent
Total Phosphorus Concentrations for Selected
Periods 59
10. Suspended Solids Removal as a Function of Influent
Suspended Solids Concentration and Overflow Rate
With and Without Flocculant Addition 66
11. Total Phosphorus Removal as a Function of Ferric
Iron Concentration and Overflow Rate 67
12. Filtration Chemicals Costs and Heat Requirements
as Functions of Sludge Solids Content 73
LIST OF APPENDICES
A. Details of Analytical Tests 81
B. Probability Analysis 93
C. Listings of Tabulated Data 98
vii
-------
SECTION I
CONCLUSIONS
1. Total phosphorus concentrations £1.0 mg/1 were obtained
in the final effluent when split addition of ferric chlor-
ide to both primary and secondary and flocculant addition
only to the secondary system were made.
2. The total phosphorus, organic, and solids loadings to the
activated sludge process were reduced by the addition of
both chemicals to the raw influent wastewater.
3. Removals of heavy metals, particularly chromium and zinc,
were somewhat improved by chemical treatment.
4. There was no net increase in the total iron concentration
in the final effluent under normal hydraulic conditions
when no primary effluent bypassed secondary treatment and
when a polyelectrolyte flocculant was used.
5. The pH of the wastewater was essentially unchanged by the
addition of either ferric chloride or flocculant.
6. Removals of both total phosphorus and suspended solids
are reduced by excessively high primary and secondary overflow
rates, but these reductions can be minimized somewhat by
the addition of more ferric chloride and the addition of
a polyelectrolyte flocculant.
7. Recycle streams such as digester supernate, vacuum fil-
trate, and waste activated sludge, can significantly influence
the phosphorus removal process.
8. Greater quantities of primary sludge were produced during
chemical treatment due to increased capture of solids nor-
mally present in the raw waste and of newly precipitated
iron-phosphate solids.
-------
9. Lesser quantities of waste activated sludge were produced
when both chemicals were added to the raw sewage.
10. The iron and phosphorus contents of both primary and waste
activated sludges increased considerably upon chemical
treatment.
11. The chemically precipitated sludge was more filterable
than sludge collected in the absence of the chemicals.
12. It is advantageous to provide flexibility in locating the
chemical addition points during initial plant design.
13. Total chemical costs for acceptable phosphorus removal
depending upon the degree of treatment ranged from $2.91-
6.60/1000 cu m ($ll-25/MG) of which approximately 90% was
allotted for ferric chloride.
-------
SECTION II
INTRODUCTION
The Grand Rapids City Commission responded affirmatively
in June of 1968 to a request from the Michigan Water Resources
Commission (WRC) to obtain at least 80 percent removal of
total phosphorus by December 1972. The WRC adopted its
standard from the Federal-State Conference on the pollution
of Lake Michigan and its tributary basin held in Chicago
in March 1968. A demonstration grant was awarded to the
City of Grand Rapids in the fall of 1969 by the Environmental
Protection Agency to demonstrate phosphorus removal by chemical
means in an activated sludge plant in the 151,000 to 227,000
cu m/day (40 to 60 mgd) range.
The major objective of this grant was to consistently obtain
a concentration of total phosphorus in the final effluent
of £1.0 mg/1. Secondary objectives were to demonstrate
and evaluate improvements in technical and economical perfor-
mance in other unit processes produced by the chemical pre-
cipitation process. Reduced organic loading to the activated
sludge process, and reduced concentrations of biochemical
oxygen demand (BOD) and suspended solids in the final effluent
were anticipated. It was also expected that the chemically
precipitated sludge would behave differently during chemical
conditioning, vacuum filtration, and incineration.
Chemical removal of phosphorus from wastewater has been
described1'2'3'4'5 and reviewed6'7'8 in the literature.
Contact between phosphate anions and multivalent metal cations
result in formation of finely dispersed precipitates. Inorganic
coagulants are used as precipitants. The suspended phosphorus
which is initially present and that which is newly precipitated
can be removed subsequently by flocculation. Organic polyelec-
trolyte flocculants are used to agglomerate these colloidal
metal-phosphate precipitates into larger, more rapidly settling
-------
particles. This two-step process for phosphorus removal
with variations in points of chemical addition was applied
to the full plant influent flow prior to primary sedimentation
beginning on November 3, 1970. Ferric chloride and PURIFLOC
A23 flocculant, products of The Dow Chemical Company, were
9
the chemicals of choice based on an earlier study (See
section entitled Preliminary Studies).
Full-scale plant operation was planned originally for twelve
consecutive months. The study commenced at a time, however,
when plant expansion was underway and replacement of over-
loaded or unreliable equipment had not been completed. Equip-
ment failures resulted in occasional shutdowns of the primary
and secondary clarifiers, various pumping equipment, vacuum
filters, and the incinerator.
Digester activity ceased completely in August 1970, prior
to the initiation of chemical treatment and continued through-
out the present study. Digestion failure had been occurring
periodically since 1966 at the Grand Rapids Plant and
was not attributable to chemical additions. Exhaustive
studies were made to determine the reason for this digestion
failure before and during the grant without success.
Greater quantities of sludge were produced during chemical
treatment due to the increased capture of solids normally
present and to newly precipitated iron-phosphate solids.
Because of inadequate sludge handling facilities, the phos-
phorus removal study was discontinued on February 25, 1971,
for a period of 2-1/2 months. Emergency measures for sludge
removal were applied to rid the plant of the backlog of
sludge.
-------
Several different modes of chemical treatment were practiced
during the remainder of 1971. Interim activity during early
1972 consisted of installation of chemical feeding equipment
in the secondary portion of the plant. Other modes of chem-
ical treatment were evaluated over a two-month period termin-
ating in June 1972. The most efficient mode of phosphorus
removal was the split addition of ferric chloride to both
primary and secondary portions of the plant and flocculant
addition only to the secondary portion. This was demon-
strated during a two-month extention of the original grant
during January-February 1973. The details of the operation
and demonstration of phosphorus removal by chemical means
are discussed in this report.
-------
SECTION III
DESCRIPTION OF THE TREATMENT PLANT
The City of Grand Rapids, Michigan, encompassing 115 sq
km (44.5 sq miles), is located in the west-central portion
of the lower peninsula 72 km (45 miles) from the entry of
the Grand River into Lake Michigan. The original primary
plant was constructed in 1929 and expanded to include sec-
ondary treatment (activated sludge) between 1953 and 1958.
A schematic of the plant is shown in Figure 1. Current
expansion of facilities during the grant includes a new
grit chamber and scum incinerator, additional primary tanks,
final effluent lift pumps, primary effluent retention basin,
and expanded laboratory facilities.
The present design capacity is 167,000 cu m/day (44 mgd)
average flow, 254,000 cu m/day (67 mgd) maximum dry weather
flow, and 330,000 cu m/day (88 mgd) maximum storm water
flow. The plant currently treats an average flow of 150,000
cu m/day (39.5 mgd) from a connected population of 216,000.
Approximately 70 percent of the flow is pumped through the
Market Avenue Station to the treatment plant. The other
30 percent flows by gravity from the south side of the City
of Grand Rapids and joins the major flow at a point 408
m (1340 ft) upstream from the grit chambers. A signifi-
cant quantity of industrial wastewater is contributed by
the manufacturers of paints, plastics, electronics equipment,
furniture, and metal-working products. There are 35 metal-
plating plants which contribute heavy metals, such as chro-
mium, copper, iron, nickel, and zinc, to the total wastewater
stream. An extensive program of monitoring and pretreatment
regulation was initiated by the City of Grand Rapids to
better define and control these industrial waste sources.
-------
Figure 1 - SCHEMATIC OF CITY OF GRAND RAPIDS, MICHIGAN
WASTEWATER TREATMENT PLANT
I Primary Flocculant Hyi'7\nElevated Water Tank
i i I'M i
I Secondary /-""A ., \ f Chiprin e_Qontact
Machine Shop
Primary Sedimentation! 4 Units )
PRESENT PUNT SITE
DASHED LINES * FUTURE CONSTRUCTION
-------
Plant facilities during the study consisted of mechanical
bar screens and a five-channel grit removal unit with each
channel 18 m (60 ft) long equipped with proportional weirs
to regulate flow. The original primary sedimentation basins
consisted of four 24-m (80-ft) square clarifiers having
3.0-m (10-ft) side water depths. They were arranged with
centrally aerated inlet channels. Effluent channels were
located on the outside. These clarifiers were equipped
with center-supported circular sludge collectors having
corner sweeps. Twelve additional rectangular units were
added in 1953. Each of these units measured 4.9 x 30 x
3.0 m (16 x 100 x 10 ft) (width-length-depth) and was equipped
with a conventional chain-and-flight sludge collection and
skimming mechanisms. The old and new primary tanks theoret-
ically afforded a combined detention time of 1.9 hours at
average flow. The overall surface settling rate was 29J3
cu m/day-sq m (777 gpd/sq ft) at the design flow of 167,000
cu m/day (44 mgd).
The six rectangular Y-wall spiral straight-line aeration
tanks were each 9.8 x 110 x 4.6 m (32 x 360 x 15 ft) having
a total volume of 29,362 cu m (1,036,800 cu ft). Retract-
able headers containing 3,036 saran-wrapped tubes provided
fine-bubble aeration. Air was supplied by three 7.5 rps
positive-displacement blowers. The six final settling tanks
were each 30 m (100 ft) in diameter. They had 3.6-m (12-
ft) side-water depths and were equipped with suction nozzle
mechanisms for continuously removing sludge. These circular
tanks had center feed and peripheral overflow weirs. The
overall surface settling rate was 35.9 cu m/day-sq m (934
gpd/sq ft) at the design flow of 167,000 cu m/day (44 mgd).
Two 1818 Kg (4,000-pound) chlorinators and a 4.0 m x 12
m x 106 m (13 ft x 40 ft x 350 ft) contact chamber provided
disinfection of the final effluent.
-------
During the grant the four flat-bottomed fixed-cover diges-
ters served as gravity thickeners and the two 24-m (80-
ft) diameter fixed-cover digesters served as holding tanks.
Two Eimco vacuum filters, each with 40.9 sq m (440 sq ft)
of surface, and one Nichols seven-hearth incinerator, han-
dled 68,000 kg/day (75 ton/day) of sludge before chemical
addition was begun. Ferric chloride and lime were used
for chemical treatment of the sludge before filtration.
The limited capacity of the incinerator necessitated trucking
some of the sludge cake to landfill during a portion of
the study.
-------
SECTION IV
PRELIMINARY STUDIES
Optimum application of chemical processes for phosphorus
removal requires careful control of chemical feed rates.
The amount of soluble phosphorus present in the raw waste
and the total waste flow is variable. The concentration
of inorganic precipitant must be sufficient to precipitate
the major portion of the soluble phosphorus present in the
raw sewage. Excessive amounts of precipitant, however,
can impair flocculation, waste chemical, and reduce phosphorus
removal. The feed rate of the precipitant should be adjusted
proportional to the product of the concentration of soluble
phosphorus in the raw sewage and the raw sewage flow. The
feed rate for the polyelectrolyte flocculant should be ad-
justed proportional to flow.
PHOSPHORUS REMOVAL FEASIBILITY STUDY
^
The feasibility of phosphorus removal by various chemical
systems was determined by personnel of The Dow Chemical
Company from a series of laboratory and plant studies con-
ducted at the Grand Rapids Wastewater Treatment Plant from
9
March 12 through March 14, 1969 . Laboratory tests were
run using a variable-speed mixing apparatus to simulate
chemical precipitation and flocculation conditions to be
expected in the full-scale plant. The various chemical
systems evaluated were: ferric chloride, ferrous chloride,
aluminum sulfate, and sodium aluminate in conjunction with
PURIFLOC A23 flocculant. Average concentrations of each
inorganic coagulant in conjunction with the organic floccu-
lant are presented in Table 1. Orders of addition, time
of contact, and types of mixing and flocculation were also
studied.
10
-------
TABLE 1
PRELIMINARY ESTIMATES OF CHEMICAL REQUIREMENTS
Chemical
Concentration, mg/1
Concentration/ Ibs/million gal
Ferric chloride
PURIFLOC A23 flocculant
15. as Fe
.3
363. as Fed,
2.5
Ferrous chloride
Lime
PURIFLOC A23 flocculant
15. as Fe
20. as CaO
.3
283. as FeCl,
167. as CaO
2.5
Ferrous chloride
Sodium hydroxide
PURIFLOC A23 flocculant
15. as Fe
24. as NaOH
.5
283. as FeCl,
i
200. as NaOH
4.2
Aluminum sulfate
PURIFLOC A23 flocculant
10. as Al
.4
1029. as A12(S04)3-18
3.4
Sodium aluminate
PURIFLOC A23 flocculant
15. as Al
.4
504. as NaA102-1-1/2
3.3
-------
Any one of the several inorganic coagulants in combination
with the anionic polyelectrolyte flocculant were considered
satisfactory to obtain the desired level of total phosphorus
removal. Ferric chloride was selected over the other inor-
ganic coagulants on the basis of both performance and eco-
nomics. Average concentrations of 15 mg ferric iron/1 and
0.3 mg PURIFLOC A23 flocculant/1 were selected for the study.
These concentrations were chosen to produce a final efflu-
ent containing one mg/1 or less of total phosphorus and
also meet the established WRC criterion of 80 percent removal
of total phosphorus.
For successful plant scale application of the phosphorus
removal process as applied prior to primary treatment, it
appeared necessary to add the inorganic coagulant to the
raw sewage about four minutes upstream from the point of
addition of the polyelectrolyte flocculant. Laboratory
estimations also were made of the flash mix and flocculant
9
requirements of the process after the flocculant was added .
It was found desirable to provide a period of rapid mixing
of 30 to 60 s to thoroughly disperse the flocculant, followed
by a more extended period of gentle mixing to promote floccu-
lation. Based on the detention times measured at the plant
and also on previous raw sewage flocculation experience
at this plant , all mix
the existing facilities.
at this plant , all mixing criteria could be met using
Initially it was decided to add ferric chloride followed
by PURIFLOC A23 flocculant prior to primary sedimentation.
This mode of chemical addition was chosen on the basis of
the laboratory study to provide <1.0 mg total phosphorus/1
in the final effluent. The expected reduction in the bio-
logical load to the secondary portion of the plant was an
additional justification for chosing this mode of chemical
treatment. The split addition of chemicals during both
12
-------
primary and secondary treatment was selected subsequently
as the preferred mode of treatment to obtain <_1.0 mg total
phosphorus/1 in the final effluent.
DETENTION TIME STUDY
Detention times were determined in the headworks of the
plant to better define intervening mixing opportunities
and chemical addition points for the phosphorus removal
process. Small volumes of a concentrated solution of Rhod-
amine B dye were introduced into the wastewater flow at
various points. The times of flow of the first appearance
of dye between selected points then were observed visually.
Various points annotated along the flow path in the head-
works of the plant prior to primary clarification are shown
in Figure 5 in the next section. The detention times be-
tween these annotated points are summarized in Table 2.
Additional points are described subsequently in Table 3.
TABLE 2
DETENTION TIMES AT HEADWORKS OF
THE GRAND RAPIDS WASTEWATER TREATMENT PLANT
(Average design flow: 167,000 cu in/day (44 mgd)
Detention Times, s
Flow
A to B
B to C
C to D
D to E
Shown on
Figure 5
Differential
188
295
91
239
Cumulative
188
483
574
813
Description of Points:
A - Interceptor junction box
B - Influent sewer manhole
C - Influent grit channels
D - Effluent grit channels
E - Primary tank feeder
13
-------
The following points of chemical addition were proposed
on the basis of the detention time study. Ferric chloride
initially was to be added to the raw sewage in the influent
sewer at the manhole (Point B). PURIFLOC A23 flocculant
was to be added initially in the vicinity of the grit cham-
ber effluent (Point D). In this configuration, the inor-
ganic coagulant would have been in contact with the raw
sewage in excess of the four minutes required prior to the
addition of the polyelectrolyte flocculant. An additional
period of mixing of 240 s was available from the effluent
of the grit chamber to the feeder channel of the primary
tanks.
Permanent facilities for feeding the ferric chloride were
installed near Point A located about 396 m (1300 ft) prior
to the grit chambers at a point immediately downstream from
the confluence of the 1.8 m x 1.8 m (6 x 6 ft) Market Avenue
force main and the 1.5-m (5-ft) diameter southeast gravity-
flow interceptor. Point A was chosen over Point B because
of anticipated interference with ferric chloride deliveries
due to construction activities.
Initially Point C was selected for flocculant addition.
Because of excessive turbulence at Points D and F and pre-
aeration before primary clarification, the addition point
during Period 2 was moved successively from Point C to Points
H, through H0. This latter series of addition points pro-
-L o
vided optimum flocculation but some difficulty was encountered
maintaining uniform flocculant distribution. All points
of chemical addition are described in detail in the section
entitled Chemical Storage and Handling.
14
-------
SECTION V
CHEMICAL STORAGE AND HANDLING
The storage, handling and feeding equipment for both floccu-
lant and coagulant was designed by the Engineering and Con-
struction Services Department of The Dow Chemical Company.
Construction of a steel frame building and installation
of the equipment was completed by local subcontractors in
the fall of 1969. This building was provided with water
and electrical services. It also contained various auto-
matic samplers as well as eye baths and safety showers.
The automatic control loop for phosphorus removal at this
location is shown in Figure 2. The coagulant is added first
on the basis of the product of a flow signal and a phosphorus
concentration signal. The flocculant is added second on
the basis of a flow signal alone. Most of the specialized
instrumentation and control devices were installed by per-
sonnel of The Dow Chemical Company.
Coagulant System
The coagulant feed system is shown in more detail in Figure
3. The coagulant used was flocculation grade ferric chlor-
ide. Solution concentrations were varied seasonally depend-
ing upon anticipated storage temperatures. Deliveries were
made by tank truck and stored outdoors in two 45-cu m (12,000-
gallon) fiberglass-reinforced-plastic (FEP) tanks surrounded
by dikes for safety purposes. Both tanks were provided
with continuous level transmitters and low-level alarms
to facilitate feeding and loading operations. Unloading
and/or transfer pumps, and acid-proof piping and valves
were provided.
15
-------
Figure 2 - AUTOMATIC CONTROL LOOP FOR
PHOSPHORUS REMOVAL FROM
WASTEWATER
TO
SOLIDS
CAPTURE
FLOCCULANT SOLUTION
(PURIFLOC A23 Flocculant)
FLOCCULANT
FEED SYSTEM
GC
D
LU
/
ELECTRONIC
FLOW
METER
I
t
I
FLOW RATE SIGNAL (mgd)
!
,ORTHO P CONCENTRATION
(mg/l) SIGNAL
¥
A
A
UTOMATIC
ORTHO P
NALYZER
\
COAGULANT
FEED SYSTEM
ELECTRONIC
CONVERTER
ORTHO P
I
TOTAL P
TOTAL P LOAD SIGNAL
TOTAL P CON-
CENTRATION
(mg/i) SIGNAL
I
FEED SYSTEM / (Ib/day)
I
4
I
I
N "
I
I
1
1
I
I
RAW
SEWAGE
FLOW
COAGULANT
'SOLUTION
(FERRIC
CHLORIDE)
SIGNAL
MULTIPLIER
16
-------
Figure 3 - COAGULANT FEED SYSTEM
VENTURI
RAW SEWAGE
FLOW
COAGULANT
STORAGE
(FERRIC
CHLORIDE)
FLOW
TRANSMITTER
FLOW (mgd)
ORTHO P (mg/l)
ANALYZER
/•^-ELECTRONIC
\)CONVERTER
7 ORTHO P—* TOTAL P (mg/l)
(X)-
Y SIGNAL
I h
I
MULTIPLIER
TOTAL P LOAD =
I FLOW x TOTAL P
r
eCI3 FLOW x DENSITY .JL
SIGNAL
MULTIPLIER
FLOW RATIO
INDICATING
CONTROLLER
• ELECTRONIC SIGNAL
PNEUMATIC SIGNAL
• SEWAGE FLOW
.COAGULANT FEED
TO COAGULANT
ADDITION POINT
DENSITY
TRANSMITTER
MAGNETIC FLOW
TRANSMITTER OR
FLOW METER
PNEUMATIC
CONTROL VALVE
-------
Concentrated ferric chloride solution was added to the influ-
ent wastewater by gravity flow in proportion to the total
phosphorus load. This load is the product of the total
phosphorus concentration in the influent sewage and the
raw sewage flow rate. An automatic ortho phosphorus analyzer
provided a signal linearly related to the ortho phosphorus
concentration. This signal was multiplied by the ratio
of total phosphorus/ortho phosphorus concentrations. A
multiplying factor of ortho/total phosphorus was obtained
by statistical analysis of the data obtained for the control
Period 1 (See Table 7). This modified signal was further
multiplied by the influent sewage flow rate signal. The
flow sensor was an electronic flow transmitter connected
to an existing 1.83-m (6-ft) Venturi tube. This allowed
addition of the ferric chloride solution proportional to
the total phosphorus load to the plant.
A variable ratio controller was used to proportion the ferric
chloride feed. The flow control devices were pneumatically
operated control valves. A signal proportional to the actual
amount of ferric chloride being fed as determined by a mag-
netic flow transmitter was returned to the flow ratio indi-
cating controller as feedback. Differences between the
required feed rate and the actual feed rate were determined
by the controller which then initiated the appropriate re-
sponse by two pneumatically operated control valves. A
density transmitter consisting of a gamma source and detector
continuously determined the weight concentration of the
ferric iron feed solution. This measurement was multiplied
by the ferric chloride flow rate to provide a signal to
the ratio controller which actually fed ferric iron propor-
tional to total phosphorus.
18
-------
Flexibility in the choice of addition points when designing
a coagulant feed system is a requisite for proper appli-
cation of chemicals throughout the plant. Based upon exper-
iences at Grand Rapids, pneumatically operated control valves
following a head/storage tank probably would not provide
the necessary addition point flexibility particularly in
large plants. Selection of a high-quality positive-displace-
ment metering pump of the proper materials of construction
is recommended. Such a metering system could be controlled
by varying the piston stroke length according to a remote
signal proportional to total phosphorus load.
Flocculant System
A schematic diagram of the flocculant feed system is shown
in more detail in Figure 4. The polyelectrolyte used was
PURIFLOC A23 flocculant. Solutions (0.25% by weight) were
continuously prepared from bags of the dry flocculant using
an automatic disperser. The resulting solution was then
automatically added to the influent sewage by means of a
flow-ratio-indicating controller. The drive of the solution
feed pump was adjusted in proportion to the influent flow
rate utilizing the same type of electronic flow transmitter
previously described for the coagulant feed system. A signal
proportional to the actual amount of flocculant being fed
as determined by a second magnetic flow transmitter was
fed back to the flow-ratio-indicating controller. The con-
troller then determined the difference between the required
feed rate and the actual feed rate and initiated the appro-
priate response by the pump drive. Speed indicators and
low speed alarms were provided on the duplicate variable
speed D.C. drives. Flow totalizers and recorders provided
material balance data on both the coagulant and flocculant
feed systems. It is important when selecting pump drives
19
-------
Figure 4 - FLOCCULANT FEED SYSTEM
to
o
MU IUIVIA Ml, _ . CCUU-LJ-C V
FLOCCULANT RA™ S^GE^
DISPERSER FLOW
" hLUCCULAIMI r-s \
* (PURIFLOC A23 ' i|
FLOCCULANT) /M\
^ CITY WATER 1^
^
' , 1
MOTOR SPEED SETf FLOW (mgd)
CONTROLLER | V y
n- — r
Y S
J FLOW RATIO
< INDICATING
i ' CONTROLLER
1
1
FLOCCULANT
METERING
PUMP
-11-'— 1 VARIABLE
J|___| SPEED MOTOR
^^^ *^"^^ ^^™
.
FLOW TRANSMITTER
- ELECTRONIC SIGNAL
- SEWAGE FLOW
- FLOCCULANT FEED
TO FLOCCULANT
A I~\ I-\ 1 Tl /~\M
MAGNETIC FLOW TRANSMITTER
OR FLOW METER
POINT
-------
for this type of automatic chemical feed system, that they
be properly sized to operate satisfactorily throughout the
anticipated range of hydraulic conditions at the plant.
Very low incoming wastewater flows requiring very low chem-
ical feed rates may cause the variable speed motor drives
to operate at extremely low rates which can result in over-
heating and shutdown of chemical feed. If selection of
the proper variable speed motor is impossible, a metering
pump with automatically controlled stroke length may be
the preferred system.
Phosphorus Analyzer
The addition of an inorganic coagulant in direct proportion
to wastewater flow can lead alternately to excessive or
insufficient concentrations. The phosphorus concentration
itself may not be proportional to flow. This may be partic-
ularly so when significant periodic industrial contributions
are expected. A continuous ortho phosphorus analyzer was
installed at the Grand Rapids plant, therefore, to provide
a permanent record of raw influent ortho phosphorus concen-
tration at ten-minute intervals. An electronic signal was
also generated for adjustment of the ferric chloride addi-
tion rate.
This analyzer was originally developed by The Dow Chemical
12
Company and has been licensed to Ionics, Inc. for com-
mercialization. Ortho phosphorus is determined according
to the standard colorimetric test using aminonaphthol
sulfonic acid as the reductant (SnCl- is also compatible
with the instrument). Each sample is filtered to remove
suspended solids prior to colorimetric analysis as described
in the subsequent section of this report. An acid wash
cycle also is provided to prevent microbial growth on the
internal surfaces of the instrument.
21
-------
Points of Chemical Addition
The points of chemical addition evaluated during the various
periods of study are noted in Figure 5 and summarized in
Table 3. Flexibility in locating the chemical addition
points during initial plant design is considered advanta-
geous .
22
-------
to
CO
\\\ Force Mam (6' x 6'l
POINTS OF CHEMICAL ADDITION
Coagulant
Feed
Svst em
,| rrimary
Sedimentation (4 Units
Return Activated Sludge
2 .M, 4 ,M, 6
_ Storage Activated
Sludge
Machine Shop
\
Primary Sed imentat ion ( 4 Uni ts
5)16
v_X
Digestion
(2 Units)
I—n
k I—. Vacuum
I U Filtration
I | & Incinerat ion
Lb
Gravity Thickening
(4 Units)
PRESENT PLANT SITE
-•— POINTS OF CHEMICAL ADDITION
-------
TABLE 3
POINTS OF CHEMICAL ADDITION
PURIFLOC A23
Period Ferric Chloride Flocculant
1 -
2 A C, D, E, F, G
3 A
4 A, K, I^-Lg Gl"G2
5 L1-L6
6 Ll~L6 M1~M6
7 A Gl-G2
8 A, J^Jg Ll-Lg
Description of Points:
A - Interceptor junction box (1 point)
B - Influent sewer manhole (1 point)
C - Influent grit channels (1 point)
D - Effluent grit channels (1 point)
E - Primary tank feeder (1 point)
F - Venturi discharge (1 point)
G - Primary tank feeder effluent (2 points)
H - Individual primary tank influent (8 points)
I - Activated sludge influent (1 point)
J - Activated sludge individual tanks (6 points)
K - Activated sludge effluent (1 point)
L - Final tank Parshall flume (6 points)
M - Final tank influent center well (6 points)
24
-------
SECTION VI
SAMPLING AND ANALYTICAL PROCEDURES
The raw influent was automatically sampled (Chicago Pump
Automatic Sampler) before screening and grit removal at
a rate of 27.5 ml/1000 cu m (25 ml/240,000 gallons) of waste-
water. After January 1972, hourly grab samples were taken
subsequently after screening and grit removal. This change
was necessitated after heavy earth moving equipment caused
a collapse of the intake line buried under a permanent road-
way. The sample size during this latter period was varied
according to the total influent flow. The nitrogen series
and pH were determined and determinations of the various
phosphorus species were repeated for grab samples of influ-
ent, primary effluent, and final effluent collected each
Wednesday at 8:00 AM. Bacterial analyses of final effluent
were made on daily grab samples collected at 6:00 AM and
at 2:00 PM.
An elaborate sample handling system was important for the
optimum control of chemical addition and the reliable oper-
ation of the ortho phosphorus analyzer. A relatively trouble-
free "trash pump" was installed in a sump near the combined
sewer upstream of all possible chemical addition points.
Approximately 2.5 1/s (40 gpm) was continuously delivered
to the control building and passed through a 0.635 cm (1/4
in) screen for removal of rags and paper, etc. This screen
was installed in a 208-1 (55-gal) drum for ease in routine
cleaning. A second pump then delivered screened raw sewage
from this drum at .63 1/s (10 gpm) to the automatic sampler
described above which operated in proportion to flow. A
portion of the flow from this second pump was also continu-
ously sent to the ortho phosphorus analyzer after first
passing through a motor-driven self-cleaning filter to remove
additional suspended solids. Sample lines to the analyzer
from this filter were washed periodically with a dilute
acid solution to prevent algal growth on glassware.
25
-------
Primary effluent and final effluent were automatically sam-
pled throughout the study. During periods of high flow
some primary effluent bypasses secondary treatment and is
combined with secondary effluent prior to chlorination.
The final effluent sample, therefore, can be a blend of
primary bypass and secondary effluent during high flow.
Final effluent and secondary effluent are synonymous during
normal flow of 167,000 cu m/day (44 mgd). Samples of pri-
mary effluent and final effluent were collected each hour
in proportion to flow. Sample volumes ranged from a minimum
of 25 ml/20 min to a maximum of 25 ml/5 min.
Composite samples of mixed liquor, return sludge, and waste
sludge were automatically collected. A timer was used to
activate the sampling device for 2-1/2 min out of every
10-min period. A daily grab sample of mixed liquor was
also taken at 8:00 AM. Composite grab samples of raw and
digested sludges were collected manually by the operator
at 10-min intervals during sludge pumping. Composite samples
of vacuum filter cake were collected hourly by the operator.
Five separate samples were collected across the belt and
stored in a covered container. A separate composite was
made from each sludge source.
Various analytical tests listed in Table 4 were performed
to evaluate the effects of the chemical precipitation/floccu-
lation process throughout the plant. Most of these tests
were performed on a daily basis prior to and during the
14
study . The analytical procedures were performed in accor-
dance with recognized standard methods unless otherwise
indicated. Details of these analytical tests are provided
in Appendix A.
26
-------
TABLE 4
ANALYTICAL TESTS PERFORMED
1. Ortho Phosphorus
2. Poly Phosphorus
3. Soluble Phosphorus
4. Suspended Phosphorus
5. Total Phosphorus
6. Biochemical Oxygen Demand (BOD^)
7. Chemical Oxygen Demand (COD)
8. Total Suspended Solids (Non-Filterable Residue)
9. Volatile Suspended Solids
10. Total Solids
11. Heavy Metals
12. Metals in Sludge
13. Total Cyanide
14. Ammonia Nitrogen
15. Total Nitrogen
16. Nitrate Nitrogen
17. Nitrite Nitrogen
18. Alkalinity
19. Chloride
20. Chlorine Residual
21. Methylene Blue Active Substances in Sewage (MBAS)
22. Grease and Oil in Sewage
23. Grease Content of Sludges
24. Hydrocarbon and Fatty Matter Content of Grease
25. Volatile Acids
26. Total Coliform Group
27. Fecal Coliform Group
28. Fecal Streptococcal Group
27
-------
SECTION VII
PROCESSING OF THE DATA
The chronology of the present study is presented in detail
in Table 5. It consists of a year-long control period and
ten periods of chemical treatment during which any one of
seven modes of chemical addition was used. Period 2 is
subdivided further into four periods due to intermittent
operations. Period 5 is subdivived into two periods, each
having significantly different ferric iron concentrations.
The beginning and ending days of all periods are denoted
in two ways: the usual month-day-year notation and a sequen-
tial calendar scale. The original contract began on day
182 (July 1, 1969) and ended on Day 1277 (June 30, 1972).
The supplemental Period 8 was conducted on days 1462-1520
inclusive (January 1, 1973-February 28, 1973). All values
for each variable and each location, if applicable, were
subjected initially to probability analysis as described
in Appendix B.
The mean values listed in Tables 6-11 were determined for
groups of selected data. The columns labeled "All" are
listings of mean values calculated from the individual mean
values for the untreated raw influent for four subperiods
in the case of Period 2 or for all of six selected periods
of study (1-6). In this way, any significant differences
existing between the raw influent mean for any given period
and the collective raw influent mean for the six selected
periods can be determined for any parameter. Extreme dif-
ferences which exist are due either to changing waste char-
acteristics due to pretreatment or rainfall, or to opera-
tional changes within the plant such as chemical additions
or units out of service.
28
-------
TABLE 5
CHRONOLOGY OF OPERATION
Date
Days
From To From To
07-01-69 06-30-70 182 - 546
07-01-70 11-02-70 546 - 671
11-03-70 02-25-71 672 - 786
02-26-71 05-09-71 787 - 859
05-10-71 05-25-71 860 - 874
05-26-71 06-06-71 875 - 887
06-07-71 10-20-71 888 - 1023
09-09-71 09-13-71 982 - 986
10-21-71 12-09-71
12-10-71 12-15-71
1024 - 1073
1074 - 1079
12-16-71 12-29-71 1080 - 1093
12-30-71 04-11-72 1094 - 1197
04-12-72 04-17-72
04-18-72 04-30-72
05-01-72 05-09-72
05-10-72 06-03-72
06-04-72 06-30-72
01-01-73 02-28-73
1198 - 1203
1204 - 1216
1217 - 1225
1226 - 1250
1251 - 1277
1462 - 1520
Period 1; No Chemical Treatment
Interim Activity
Period 2A: Metal + Flocculant Addition to Primary
Interim Activity: Removal of sludge backlog; high river
required plant shutdown
Period 2B: Metal + Flocculant Addition to Primary
Interim Activity: Removal of sludge backlog
Period 2C: Metal + Flocculant Addition to Primary
Period 7: Metal + Anionic Flocculant Addition to Primary
+ Cationic Flocculant Addition to Secondary;
Concurrent with Period 2C
Period 3: Metal Addition only to Primary
Period 4: Split Addition of Metal to Both Primary and Secondary
+ Flocculant Addition only to Primary
Period 2D: Metal + Flocculant Addition to Primary
Interim Activity: Construction of new grit chambers
and other new facilities
Period 5A: Metal Addition only to Secondary
Period 5B: Metal Addition only to Secondary
Period 5A: (continued)
Period 6: Metal + Flocculant Addition to Secondary
Interim Activity: End of Contract
Period 8: Split Addition of Metal to Both Primary and Secondary
+ Flocculant Addition only to Secondary
29
-------
The collective means for the 76 parameters listed on Tables
6-11 represent a statistical treatment of over 58,000 indi-
vidual values. Representative listings of tabulated data
are provided in Appendix C. The majority of these daily
values were obtained by various direct chemical analyses.
The average daily flow was determined directly from recorder
charts.
Poly phosphorus and suspended phosphorus values were calcu-
lated as the differences, respectively F between soluble
and ortho phosphorus values, and between total and soluble
phosphorus values. Overflow rates were calculated knowing
flow, clarifier sizes, and number of clarifiers in service
on a given day. Detention times and weir overflow rates
were also calculated but are not tabulated in Appendix C
or these tables of mean values. Percentage removals of
the various phosphorus species, heavy metals, biochemical
oxygen demand, and suspended solids were also calculated
from mean concentrations and are tabulated subsequently
in Tables 14-16.
Total phosphorus loadings (Table 6) were calculated using
mean concentrations (Table 6) and mean flows (Table 9).
Chemical costs (Table 8) were calculated using mean flows
(Table 9) and book prices for ferric chloride ($3.70/cwt
100% FeCl3) and PURIFLOC A23 flocculant ($0.85/lb) plus
freight from Midland to Grand Rapids, Michigan ($0.355/cwt
42% FeCl.,) . Mean total phosphorus loadings (Table 6) and
mean flows (Table 9) were used to calculate costs on other
bases. Organic and solids loadings (Table 10) were calculated
using mean concentrations (Table 6) and mean flows (Table
9). The distributions of the various sludges (Table 17)
were either taken directly from the monthly summary sheets
of plant operation or subsequently calculated.
30
-------
TABLE 6
MEAN VALUES FOR PHOSPHORUS SPECIES AND TOTAL PHOSPHORUS LOADINGS
PERIOD
Ortho Phosphorus, mg/1:
Raw Influent
Primary Effluent
Final Effluent
Poly Phosphorus, mg/1:
Raw Influent
Primary Effluent
Final Effluent
Soluble Phosphorus, mg/1:
Raw Influent
Primary Effluent
Final Effluent
Suspended Phosphorus, mg/1:
Raw Influent
Primary Effluent
Final Effluent
Total Phosphorus, mg/1:
Raw Influent
Primary Effluent
Final Effluent
Total Phosphorus Loadings, Ib/day:
Raw Influent
Primary Effluent
Final Effluent
Final Effluent, % of 1
Overall Removal
1
2.5
2.5
2.4
2.5
2.3
1.6
5.0
4.8
4.0
2.6
2.8
1.3
7.6
7.6
5.3
lay:
!476.
!476.
.727.
100.
749.
2A
2.0
.4
.4
2.7
1.0
.8
4.7
1.4
1.2
2.4
1.6
.8
7.1
3.0
2.0
2556.
1080.
720.
42.
1836.
2B
1.9
.8
.7
4.0
.7
.6
5.9
1.5
1.3
2.3
1.2
1.0
8.2
2.7
2.3
1914.
630.
537.
31.
1377.
2C
2.7
.5
.4
2.3
.6
.4
5.0
1.1
.8
2.3
.9
.8
7.3
2.0
1.6
2287.
627.
501.
29.
1786.
2D
1.9
.8
.4
.9
.7
.6
2.8
1.5
1.0
2.3
1.0
.7
5.1
2.5
1.7
1734.
850.
578.
33.
1156.
ALL
2
2.3
.5
.5
2.4
.7
.6
4.7
1.2
1.0
2.4
1.2
.8
7.2
2.4
1.8
2400.
800.
600.
35.
1800.
3
2.6
.5
.3
1.2
.6
.5
2.8
1.1
.8
2.4
1.4
.9
5.2
2.5
1.7
1530.
735.
500.
29.
1030.
4
1.8
.3
.2
1.6
.7
.5
3.4
1.0
.7
1.0
1.3
1.5
4.4
2.3
2.2
1658.
866.
829.
48.
839.
5A
1.7
1.6
.7
1.8
1.7
1.0
3.4
3.3
1.7
3.0
1.9
1.3
6.4
5.2
3.0
2496.
2028.
1170.
68.
1326.
SB
1.6
1.2
.4
1.8
1.3
.5
3.4
2.5
.9
3.2
1.8
1.2
6.6
4.3
2.1
2524.
1645.
803.
46.
1721.
ALL
6 8 (1-6)
1.6 1.8 2.1
1.4 .6
.8 .2
1.7 - 2.0
1.3
.8 - -
3.3 - 4.1
2.7
1.6
3.0 - 2.4
3.5
.7
6.3 3.8 6.5
6.2 2.0
2.3 .96
2110. 1450. 2225.
2077. 772.
770. 370.
45. 21.
1340. 1080.
-------
TABLE 7
MEAN VALUES FOR PHOSPHORUS RATIOS
OJ
to
Ortho/Total:
Raw Influent
Primary Effluent
Final Effluent
Poly/Total:
Raw Influent
Primary Effluent
Final Effluent
Soluble/Total:
Raw Influent
Primary Effluent
Final Effluent
Suspended/Total:
Raw Influent
Primary Effluent
Final Effluent
PERIOD
1
0.33
.33
.46
.33
.30
.30
.66
.63
.76
.34
.37
.24
2A
0.28
.13
.22
.38
.33
.40
.66
.47
.62
.34
.53
.38
2B
0.23
.28
.30
.49
.26
.25
.72
.54
.55
.28
.46
.45
2£
0.37
.26
.25
.31
.28
.25
.68
.54
.50
.32
.46
.50
21)
0.37
.32
.23
.18
.28
.37
.55
.60
.60
.45
.40
.40
All
0.32
.22
.26
.34
.28
.31
.66
.50
.57
.34
.50
.43
1
0.50
.20
.17
.23
.25
.30
.54
.45
.47
.46
.55
.53
4
0.41
.12
.09
.36
.32
.23
.77
.44
.32
.23
.56
.68
5A
0.26
.31
.23
.28
.32
.33
.54
.63
.56
.47
.37
.44
5B
0.24
.28
.21
.28
.30
.22
.52
.58
.43
.48
.42
.57
6
0.26
.23
.35
.27
.21
.33
.53
.44
.68
.47
.56
.32
All
8^ (1-6)
0.50 0.32
.31
.33
.31
-
_ .
.63
-
_ .
.37
-
-
-------
u>
TABLE 8
MEAN VALUES FOR TREATMENT CHEMICALS AND COMPARATIVE CHEMICAL COSTS
PERIOD
Ferric Iron, mg/1
Ferric/Raw Influent Total P, -
PURIFLOC A23 Flocculant, mg/1
2A
2B
2C
2D
All
2
16.5 20.7
2.5 2.6
.37 .31
20.0 11.1 18.3 19.0
2.9 2.7 2.7 4.6
.32 .32 .32
20.2 10.0
5.2 1.7
.33
5B
20.0
3.3
i i
15.0 18.2
2.6 4.7
.20 .28
Ferric Iron, Ib/day
PURIFLOC A23 Flocculant, Ib/day
5940. 4830. 6267. 3774. 6100. 5589. 7609. 3900. 7650. 5025. 7022.
133. 72. 100. 109. 107. - 124. - - 67. 108.
Ferric Iron, $/MG
PURIFLOC A23 Flocculant, $/MG
Total Chemicals, $/MG
18.15 22.77 22.00 12.21 20.13 20.90 22.22 11.00 22.00 16.50 20.02
2.62 2.20 2.27 2.27 2.27 - 2.34 - - 1.42 1.98
20.77 24.97 24.27 14.48 22.40 20.90 24.56 11.00 22.00 17.92 22.00
Ferric Iron, $/day
PURIFLOC A23 Flocculant, S/day
Total Chemicals, S/day
784.
113.
897.
638.
61.
699.
827.
85.
912.
498.
92.
590.
805.
91.
896.
738.
-
738.
1004.
106.
1110.
515.
-
515.
1010.
-
1010.
663.
57.
720.
927.
92.
1019.
Total Chemicals, S/lb P removed
.49
.50
.51
.51
.50
.72 1.34
.39
.59
.54
.94
-------
u>
Flow, ragd
Primary Overflow Rate, gpd/sq ft
Secondary Overflow Rate, gpd/sq ft
pH, units
Raw Influent
Primary Effluent
Final Effluent
TABLE 9
MEAN VALUES FOR FLOWS, OVERFLOW RATES, AND pH
PERIOD
All
2D 2
All
(1-6)
_ 2A2B2C2D2_ 3 4_ Mill 1
39.1 43.2 28.0 37.6 40.8 40.0 35.3 45.2 46.8 45.9 40.2 46.3 41.1
855 1107 810 840 1123 956 1041 1071 1109 1089 1101 978 1025
847 1067 1084 853 1040 958 899 1151 2981 2927 2203 1180 1518
7.6 7.4 7.4 7.7 7.7 7.5 7.5 7.7 7.8 7.8 7.7 6.9 7.6
7.6 7.4 7.4 7.4 7.5 7.4 7.3 7.5 7.7 7.7 7.8 7.0 7.6
7.6 7.4 7.3 7.3 7.4 7.4 7.3 7.4 7.8 7.8 7.3 7.0 7.5
-------
TABLE 10
MEAN VALUES FOR
BIOCHEMICAL OXYGEN DEMAND AND SUSPENDED SOLIDS CONCENTRATIONS AND LOADINGS
PERIOD
OJ
(Jl
Biochemical Oxygen Demand (5-day), mg/1:
Raw Influent
Primary Effluent
Final Effluent
Suspended Solids, mg/1:
Raw Influent
Primary Effluent
Final Effluent
Organic Loading, 1000 Ib/day:
Raw Influent
Primary Effluent
Final Effluent
Solids Loading, 1000 Ib/day:
Raw Influent
Primary Effluent
Final Effluent
1
111
89
24
139
112
40
36.2
29.0
8.2
45.3
36.5
13.7
2A
101
51
18
112
43
21
36.3
18.4
6.5
40.3
15.5
7.6
2B
111
64
22
124
50
30
25.9
14.9
5.1
28.9
11.7
7.0
2C
110
57
24
130
44
27
34.5
17.9
7.5
40.7
13.8
8.5
2D
104
48
23
113
43
21
35.3
16.3
7.8
38.4
14.6
7.2
All
2
106
55
22
122
44
24
35.3
18.3
7.3
40.7
14.7
8.0
3
105
78
37
139
94
40
30.9
22.9
10.9
40.9
27.6
11.8
4
98
52
53
86
54
80
36.9
19.6
20.0
32.4
20.3
30.1
5A
134
90
24
167
97
37
52.2
35.1
9.4
65.1
37.8
14.4
5B
118
74
25
144
73
30
45.1
28.3
9.6
55.1
27.9
11.5
6
124
106
17
129
120
16
41.5
35.5
5.7
43.2
40.2
5.4
8
100
61
29
126
86
44
38.6
23.5
11.2
48.6
33.2
17.0
All
(1-6)
111
128
38.0
43.8
-------
TABLE 11
MEAN VALUES FOR HEAVY METALS
PERIOD
ON
Chromium, mg/1:
Raw Influent
Primary Effluent
Final Effluent
Copper, mg/1:
Raw Influent
Primary Effluent
Final Effluent
Iron, mg/1:
Raw Influent
Primary Effluent
Final Effluent
Nickel, mg/1:
Raw Influent
Primary Effluent
Final Effluent
Zinc, mg/1:
Raw Influent
Primary Effluent
Final Effluent
1
2.0
1.8
1.0
1.0
.9
.8
2.4
2.1
.9
1.8
1.7
1.6
2.0
2.0
1.1
2A
1.5
.9
.3
.8
.5
.6
1.6
2.1
1.1
1.6
1.3
1.2
1.6
.8
.6
21
1.3
.7
.3
1.0
.6
.6
2.7
2.7
1.1
1.5
1.1
1.0
2.0
1.3
1.0
2C
1.0
.4
.3
.8
.4
.2
2.6
3.2
2.5
1.2
.7
.6
3.9
1.4
1.1
2D
0.8
.5
.3
.6
.3
.2
1.7
4.6
2.0
.8
.6
.3
2.2
1.3
1.0
All
1.2
.6
.3
.8
.4
.4
2.2
2.9
1.9
1.3
1.0
.9
2.8
1.2
.9
1
0.8
.5
.3
.5
.4
.2
1.8
6.3
3.0
.8
.7
.6
4.2
2.2
1.4
£
0.5
.4
.3
.4
.3
.2
1.5
1.8
6.1
.5
.4
.3
1.3
1.2
1.5
5A
0.8
.6
.3
.5
.3
.2
2.7
1.9
1.9
.7
.5
.4
4.0
2.8
2.2
5B
0.8
.5
.3
.4
.3
.2
4.6
2.0
2.4
.5
.4
.3
3.7
2.9
2.1
6
1.2
.8
.2
.4
.4
.2
3.6
3.4
1.1
.8
.7
.4
3.7
3.0
1.3
8
1.2
.8
.4
.4
.5
.3
1.5
4.7
4.3
.6
.7
.6
1.8
2.7
1.9
All
(1-6)
1.1
-
-
.7
-
-
2.5
-
-
1.1
-
-
2.9
-
_
-------
SECTION VIII
DISCUSSION OF RESULTS BY PERIOD
The results obtained during the eight basic periods listed
in Table 5 are discussed in two ways. Features peculiar
to each period, and to each mode of chemical treatment as
depicted in Figure 6, are emphasized in the first discus-
sion in numerical order according to period. Reference
is made to individual mean values previously tabulated.
An occasional comparison is made between a mean influent
value for a selected period and the corresponding collective
mean for Periods 1-6. The significance of each individual
parameter is described in the second discussion appearing
in the subsequent section of this report (See the section
entitled Discussion of Individual Parameters).
Period 1 - No Chemical Treatment (Days 182-546)
The 1969-1970 fiscal year of operation was used as the con-
trol period. This period of one year provides comparative
values for all parameters in the absence of chemical treat-
ment. Daily analyses for one full year were available for
all of the parameters except soluble BOD and COD which are
3-month averages. A summary of values for those parameters
is provided in Table 12. Most values were reported previ-
14
ously . Mean values in parentheses ( ) were determined
by computer techniques for comparison. No data from this
period were discarded for those parameters subjected to
statistical analysis since the total numbers were very large,
The following points are emphasized for Period 1.
a. The mean raw influent analyses were all comparable
to the collective means for six periods (See Tables
6-10) with the exception of a higher chromium con-
centration (2.0 vs 1.1 mg/1) (See Table 11).
37
-------
Figure 6 - MODES OF CHEMICAL ADDITION
PRIMARY
PERIOD CLARIFICATION
No
Chemical
SECONDARY
AERATION CLARIFICATION
CHEMICAL ADDITION:
FeCI3
PURIFLOC A23 Flocculant
1 PURIFLOC C31 Flocculant
38
-------
TABLE 12
SUMMARY OF OPERATION IN ABSENCE OF CHEMICAL TREATMENT
(Period 1: Days 182-546 Inclusive)
Concentration, mg/1 (except as noted)
Raw Primary Final
Parameter Influent Effluent Effluent
Ortho-Phosphorus, as P 2.5 (2.5) 2.5 2.5
Poly Phosphorus, asP 2.5 (2.5) 2.2 1.6
Soluble Phosphorus, asP 4.9 (5.0) 4.7 4.1
Suspended Phosphorus, as P - (2.6)
Total Phosphorus, as P 7.7 (7.6) 7.6 5.4
Biochemical Oxygen Demand (5-day) 111 (111) 89 26
Soluble BOD (5-day) 49 41 16
Chemical Oxygen Demand 308 238 103
Soluble COD 109 107 73
Suspended Solids 139 (139) 112 43
Volatile Suspended Solids 109 85 36
Total Solids 828 812 695
Chromium 2.4 (2.0) 2.5 1.6
Copper 1.3 (1.0) 1.2 1.1
Iron 4.1 (2.4) 4.1 1.4
Nickel 2.0 (1.8) 1.8 1.6
Zinc 3.4 (2.0) 2.9 1.8
Cyanide 1.0 0.9 0.6
Ammonia Nitrogen, as N 9.6 10.1 10.2
Total Nitrogen, as N 10.7 13.0 11.7
Nitrate Nitrogen, as N - - 0.52
Alkalinity, as CaCO3 225 238 223
Chloride 163 176 165
Grease and Oil 110 87 22
PH, Units 7.6 7.6 7.6
Turbidity, JTU - - 90
Total Coliform, no./lOO ml - - 2,218
Fecal Coliform Group, no./lOO ml - 385
Fecal Streptococcal Group,
no./lOO ml - - 1,832
Flow mgd 39.7(39.1)
39
-------
The raw influent and primary effluent each contained
about equal amounts (See Table 6) and equal ratios
(See Table 7) of ortho, poly, and suspended phos-
phorus (each species one-third of total).
The concentrations of the soluble phosphorus species
were relatively unchanged during primary or secondary
treatment (See Table 6).
The overall removal of total phosphorus of about
30 percent (7.6 vs 5.3 mg/1) was due mainly to the
capture of suspended phosphorus since little insolu-
bilization of other species occurred (See Tables
6 and 14).
Primary and overall removals of biochemical oxygen
demand were 20 percent and 78 percent, respectively
(See Tables 10 and 15).
Primary and overall removals of suspended solids
were 20 percent and 71 percent, respectively (See
Tables 10 and 15).
Primary removals of all metals were negligible «20
percent); overall removals of chromium, iron, and
zinc were approximately 50-60 percent; overall re-
movals of copper and nickel were also negligible
«20 percent) (See Tables 11 and 16).
Period 2 - Metal + Flocculant Addition to Primary
(Days 672-786, 860-874, 888-1023, 1080-1093)
Addition points for the two chemicals during this period
had been established during the feasibility study. Ferric
chloride was applied at Point A. The flocculant was applied
most effectively at Point H,-Hg. Other points of addition
listed in Table 2 were less satisfactory.
This large period was subdivided during operation into foior
subperiods of varying lengths spread throughout all seasons.
40
-------
The following points are emphasized for Period 2.
a. Mean raw influent values for all parameters except
chemical additions for the entire period were com-
parable to the collective means for six periods (See
Tables 6-11).
b. Raw influent poly phosphorus concentrations for the
short subperiods 2B and 2D were somewhat atypical
compared to Period 1 (4.0 and 0.9 vs 2.5 mg/1, re-
spectively) (See Table 6).
c. The mean soluble phosphorus concentration in the
final effluent was 1.0 mg/1 after precipitation;
suspended phosphorus was reduced to an average of
0.8 mg/1 (See Table 6).
d. Additional ferric chloride and better liquid-solids
separation is required to reduce the soluble phos-
phorus level and the suspended phosphorus level to
the point where a mean final effluent level of 1.0
mg/1 total phosphorus can be achieved (See Table
6).
e. Primary removal of biochemical oxygen demand was
increased by chemical treatment (48 vs 20 percent);
overall removal remained essentially the same as
that obtained during the control period (79 vs 78
percent) (See Tables 10 and 15).
f. Primary removal of suspended solids was significantly
improved by chemical treatment (64 vs 19 percent);
overall removal was also somewhat improved (80 va
71 percent) (See Tables 10 and 15).
g. Removals of chromium, copper, and zinc were dramat-
ically increased, particularly during primary treat-
ment (>50 vs <10 percent). Removal of nickel was
improved but less dramatically (See Tables 11 and
16) .
41
-------
h. Although the degree of iron removal was reduced,
there was no net increase in iron concentration in
the final effluent as a result of chemical treatment
(1.9 vs 2.2 mg/1) (See Tables 11 and 16).
i. The total phosphorus content of the primary sludge
was increased by about one-third (43 vs 33 mg/g);
the total iron content of this sludge was increased
almost four-fold (8.6% vs 2.2%) (See Table 18).
j. The total phosphorus content of the waste activated
sludge also was increased by about one-third (65
vs 50 mg/g); the total iron content of this sludge
was increased slightly less than three-fold (76 vs
28 mg/g) (See Table 18).
k. The primary sludge during chemical treatment was
higher in solids content than during the period of
no chemical treatment. Its specific resistance to
filtration (7) was reduced a factor of three-fold
(7.9 vs 2.43 m/kg,) (See Table 19).
Period 3 - Metal Addition Only to Primary (Days 1024-1073)
The point of ferric chloride application remained unchanged
at Point A. The reduced effectiveness of ferric chloride
when used in absence of a flocculant was demonstrated during
this period when the iron concentration in the primary efflu-
ent increased. Unfortunately, the raw influent sampler
was inoperative during a major portion of this period and
the apparently high ratio of added iron/raw influent total
phosphorus is based upon data from 20% of the period.
The following points are emphasized for Period 3.
42
-------
a. Raw influent values of ortho phosphorus, flow, bio-
chemical oxygen demand, and suspended solids were
in surprisingly close agreement to those of the con-
trol period considering the lack of a large number
of samples. Raw influent values of all metals except
zinc were similar to the collective means of six
periods (See Tables 6-11).
b. The mean soluble phosphorus concentration in the
final effluent was reduced to less than 1.0 mg/1,
but the raw influent concentration was also the lowest
of all periods studied (2.8 vs 4.1 mg/1) (See Table
6).
c. Overall removal of total phosphorus was somewhat
less than Period 2 on a percentage basis (67 vs 75
percent) but comparable on an absolute concentration
basis (1.7 vs 1.8 mg/1) (See Tables 6 and 14). The
absence of flocculant, however, was inadvertently
compensated in part by an apparently much higher
added iron/raw influent total phosphorus ratio (4.6
vs 3.1) (See Table 8) during this period than for
almost all of the other periods.
d. Removals of biochemical oxygen demand were not im-
proved over those of the control (See Tables 10 and
15).
e. Removals of suspended solids were not improved over
that of the control (See Tables 10 and 15).
f. Removals of all metals except iron were comparable
to Period 2 (See Tables 11 and 16).
g. Substantial net increases in iron concentrations
in both primary (250 percent) and final (167 per-
cent) effluents were observed. These are compared
to overall net decreases during the control Period
1 (62 percent), and also during Period 2 (14 percent)
when a flocculant was added (See Table 16).
43
-------
h. The concentrations of chromium, copper, and nickel
in the raw influent were reduced in Period 3 and
subsequent periods when pretreatment practices were
initiated by local industries.
Period 4 - Split Addition of Metal to Both Primary and Sec-
ondary + Flocculant Only to Primary (Days 1074-
1079)
During this period, approximately 10 mg/1 of iron were added
at Point A, and an additional 10 mg/1 added at Points L,-
L,.. This was accomplished by setting up a ferric chloride
storage tank, variable speed pump, and proportioning weir
box at the downstream end of the aeration tanks. It was
a logistic problem at that time to add flocculant following
aeration, and it was added only before primary clarification
at Points G -G_.
This period was extremely short and although trends can
be noted, the absolute concentration values are not as sta-
tistically reliable as the other periods of this study.
The split mode of treatment did merit further study as des-
cribed for Period 8. The preferable approach is the addi-
tion of ferric chloride to both primary and secondary. The
flocculant then should be added shortly thereafter near
the sites of both metal additions, or at least after the
second rather than only after the first metal addition.
The following points are emphasized for Period 4.
a. Several of the raw influent values were lower than
those of six other periods. These include: suspended
and total phosphorus, biochemical oxygen demand,
suspended solids, and all of the metals (See Tables
6-11).
44
-------
Soluble phosphorus in the final effluent was reduced
to less than 1.0 mg/1 but suspended phosphorus was
not adequately captured to assure a total phosphorus
concentration of less than 1.0 mg/1 (See Table 6).
The suspended phosphorus ratio remaining in the final
effluent was the largest of all of the periods of
chemical treatment (0.68). This ratio was reduced
when the flocculant was added after the second addi-
tion of ferric chloride prior to secondary clarifi-
cation during Period 8 (See Table 7).
The biochemical oxygen demand in the primary effluent
was comparable to Period 2 (52 vs 55 mg/1); no further
reduction of biochemical oxygen demand occurred during
secondary treatment (53 mg/1) and was probably due
to the relatively high concentration of suspended
solids in the final effluent (See Table 10).
The primary effluent concentrations of suspended
solids was somewhat less than Period 2 (54 vs 44
mg/1); the final effluent concentration was high
(80 mg/1) (See Table 10).
Final effluent concentrations of all metals except
iron and zinc were comparable to Period 2 (See Table
11), even though the percentages of removal were
less because of lower raw influent concentrations
(See Table 16).
The slight increase in the iron concentration of
the primary effluent was comparable to that observed
in Period 2. The large increase in the iron concen-
tration of the final effluent compared to the raw
influent (6.1 vs 1.5 mg/1), however, was exceeded
only by the increase observed in the primary effluent
of Period 3 (6.3 vs 1.8 mg/1) also obtained in the
absence of a flocculant addition after an iron addi-
tion (See Table 11).
45
-------
Period 5 - Metal Addition Only to Secondary (Days 1198-
1225)
Ferric chloride was added at Points L,-L,. Even distri-
J. D
bution of ferric chloride was obtained to all tanks from
one line running from the storage tanks. To add iron at
any other points of aeration, such as midway or one-third
distance, would have required the construction of a tem-
porary header causing a safety and maintenance problem.
This period was subdivided into two subperiods. The effects
of doubling the concentration of iron are illustrated when
comparing Periods 5A and 5B. The removal of certain compo-
nents in the waste were greatly influenced by very high
secondary overflow rates during these periods [1306 cu m/day-
sq m and 1283 cu m/day-sq m (2981 and 2927 gal/day/sq ft)],
respectively for Periods 5A and 5B.
The following points are emphasized for Periods 5A and 5B.
a. Raw influent values for all parameters for both Per-
iods 5A and 5B were comparable to the collective
means of six periods with the exception of a high
mean iron concentration for Period 5B (4.6 vs 2.5
mg/1) (See Tables 6-11).
b. The mean secondary overflow rate for both subper-
iods was approximately three times that of all of
the other periods [1306 cu m/day-sq m and 1283 cu
m/day-sq m vs 385 cu m/day-sq m (2981 and 2927 vs
approx. 1000 gpd/sq ft)] (See Table 9).
c. The soluble phosphorus level in the final effluent
for Period 5A was higher than for Period 5B (1.7
vs 0.9 mg/1) (See Table 6) because of the lower con-
centration of ferric iron added (10 vs 20 mg/1) (See
Table 8).
46
-------
Suspended phosphorus and consequently total phos-
phorus removals suffered somewhat because of the
high secondary overflow rates. The suspended phos-
phorus level in the final effluent of Period 5B after
metal addition, however, was only slightly less than
that of Period 2 (1.2 vs 0.8 mg/1) (See Tables 6
and 14).
Overall removal of biochemical oxygen demand (79
percent, 25 mg/1) was comparable to the control per-
iod (78 percent, 24 mg/1) and to Period 2 (79 per-
cent, 22 mg/1); primary removal (37 percent, 74 mg/1)
was greater than the control (20 percent, 89 mg/1)
but less than Period 2 (48 percent, 55 mg/1) (See
Tables 10 and 15).
Overall removal of suspended solids was comparable
to Period 2 on a percentage basis (79 vs 80 percent)
(See Table 15), but less on an absolute concentration
basis (30 vs 24 mg/1) (See Table 10); primary removal
was somewhat better than the control (73 vs 112 mg/1)
but definitely less than Period 2 (73 vs 44 mg/1)
(See Table 10).
The removals of all metals except zinc were compar-
able to Period 2 (See Tables 11 and 16). The mean
zinc concentration in the final effluent (2.1 mg/1)
was the highest of all periods (See Table 11).
Period 6 - Metal + Flocculant Addition to Secondary (Days
1226-1250)
The ferric chloride feeding system remained unchanged at
Points L,-Lg. The flocculant was added with a pump manu-
ally adjusted proportional to the wastewater flow. The
flocculant was pumped to a constant head splitting box where
it was distributed equally to all entrances to the final
47
-------
sedimentation tanks at Points M,-Mc. This period of chem-
x o
ical treatment was also characterized by very high secon-
dary overflow rates averaging 847 cu m/day-sq m (2203 gal/
day/sq ft).
The following points are emphasized for Period 6.
a. The mean raw influent values for all parameters ex-
cept secondary overflow rate were comparable to the
collective means of six periods (See Tables 6-11).
b. Soluble phosphorus was not insolubilized to the ex-
tent of Period 2 (1.6 vs 1.0 mg/1) (See Table 6),
probably because of a somewhat reduced ferric iron
concentration (15.0 vs 18.3 mg/1) (See Table 8).
c. The suspended phosphorus concentration in the final
effluent (0.7 mg/1) was the lowest of six periods
(See Table 6).
d. Primary removal of biochemical oxygen demand was
comparable to the control period (See Table 15);
the final effluent concentration (17 mg/1) was the
lowest of six periods and slightly better than Period
2 (22 mg/1) (See Table 10).
e. Primary removal of suspended solids was comparable
to the control (See Table 15); the final effluent
concentration of suspended solids (16 mg/1) was the
lowest of all periods (See Table 10).
f. There was a considerable increase in the amount of
waste activated sludge produced compared to Period
1 (See Table 17).
g. The phosphorus and iron concentrations of the waste
activated sludge were both tripled (144 mg P/g and
87 mg Fe/g) over those concentrations obtained in
the absence of chemical treatment (50 mg P/g and
28 mg Fe/g) (See Table 18).
48
-------
Period 7 - Metal & Anionic Flocculant Addition to Primary
+ Cationic Flocculant Addition to Secondary
(Days 982-986)
A cationic polyelectrolyte, PURIFLOC C31 flocculant, was
added at a concentration of 41 mg/1 to the influent to No.
6 secondary clarifier to determine if improved capture of
suspended solids and suspended phosphorus was possible.
This concentration is considered excessive and not econom-
ical. This period was concurrent with Period 2C. Samples
from No. 6 (treated) and No. 5 (untreated) secondary clar-
ifiers were analyzed for suspended solids, volatile sus-
pended solids, biochemical oxygen demand, and total phos-
phorus. Average values were not significantly different
between the treated and untreated clarifiers. The total
phosphorus concentrations averaged about 1 mg/1 for both
samples. A thick scum layer did form on top of the treated
clarifier and collection of representative samples was dif-
ficult. This scum contained 600 mg/1 grease and oil com-
pared to only 39 mg/1 for the underlying clear liquid. An
average of 68 mg/1 grease and oil in the final effluent
was determined for the untreated clarifier during this per-
iod.
Period 8 - Split Addition of Metal to Both Primary and
Secondary + Flocculant Only to Secondary (Days
1462-1520)
The data of this supplemental period are included to demon-
strate the effectiveness of chemical treatment when the
flow was slightly above design, operating conditions were
near normal, all existing units were in service, and there
were no disruptions from construction of new facilities.
One exception was the periodic bypassing of that portion
of the primary effluent ('vlO percent) exceeding the design
49
-------
flow of 167,000 cu m/day (44 mgd) into the final effluent
without benefit of secondary treatment. The overall effect-
iveness of chemical treatment was probably not optimum due
to bypassing. The mean concentrations of ferric iron were
18.2 mg/1 split approximately equally in quantity between
Point A and Points J..-J-. The mean concentration of floc-
l o
culant was 0.28 mg/1 added at Points L,-L,. Results from
Period 8 are summarized in Table 13.
The following points are emphasized for Period 8.
a. The mean raw influent concentration of ortho phos-
phorus was comparable to the collective mean of 6
other periods (1.8 vs 2.1 mg/1) (See Table 6).
b. The mean raw influent concentration of total phos-
phorus was lower than the collective mean of 6 other
periods (3.8 vs 6.5 mg/1) (See Table 6).
c. The mean ortho phosphorus concentration in the final
effluent (0.2 mg/1) was lower than any period except
Period 4 (See Table 6).
d. The mean total phosphorus concentration in the final
effluent (0.96 mg/1) was the lowest of all periods
and met the desired criterion of
-------
TABLE 13
SUMMARY OF OPERATION DURING SUPPLEMENTAL PERIOD
(Period 8: Days 1462-1520 Inclusive)
Concentration, mg/1 (except as noted)
Parameter
Ortho-Phosphorus, as P
Total Phosphorus, as P
Biochemical Oxygen Demand
Suspended Solids
Chromium
Copper
Iron
Nickel
Zinc
pH, units
Flow, mgd
Ferric Iron (to both primary
and secondary)
PURIFLOC A23 flocculant (only to
secondary)
Raw
Influent
1.83
3.85
100.
126.
1.16
0.38
1.54
0.63
1.77
6.9
46.3
Primary
Effluent
0.60
2.01
61.
86.
0.79
0.46
4.66
0.69
2.66
7.0
—
Final
Effluent
0.20
0.96
29.
44.
0.44
0.34
4.29
0.56
1.92
7.0
—
9.1
9.1
0.28
-------
h. Final effluent concentrations of chromium, copper,
nickel, and zinc were comparable to most of the other
periods (See Table 11).
i. The high mean iron concentration in the primary ef-
fluent (4.7 gm/1) was attributed to poor solids cap-
ture in the absense of flocculant. The high mean
concentration of iron in the final effluent (4.3
mg/1) was attributed to periodic bypassing of a portion
of the primary effluent (See Table 11).
52
-------
SECTION IX
DISCUSSION OF INDIVIDUAL PARAMETERS
The independent variables of ferric iron concentration,
polyelectrolyte flocculant concentration, and clarifier
overflow rates have pronounced effects on the various de-
pendent variables indicative of treatment performance. The
responses of these individual dependent variables such as
phosphorus, biochemical oxygen demand, suspended solids,
heavy metals, and other treatment parameters are discussed
in this section.
Phosphorus
The shifting ratios of the three major phosphorus species,
ortho, poly, and suspended, expressed as fractions of the
total phosphorus, were summarized previously in Table 7.
The three fractions, ortho/total, poly/total, and suspended/
total, at any given plant location all add up to a value
of unity or 100 percent of the total. Initially in the
raw influent the three fractions are about equal. Upon
addition of the ferric chloride, both ortho and poly phos-
phorus fractions decrease due to insolubilization and the
suspended fraction increases. Upon addition of PURIFLOC
A23 flocculant, the suspended fraction is decreased by floc-
culation and sedimentation and the ortho and poly fractions
are increased. The concentration of total phosphorus in
the wastewater decreases progressively through primary and
secondary treatment as solids settle and are removed from
the system.
A comparison of phosphorus removal efficiencies for the
major periods is provided in Table 14. Conversion of ortho
phosphorus to an insoluble form was 75-90 percent complete
except for Period 6. The mean concentration of ferric iron
53
-------
TABLE 14
COMPARISON OF REMOVAL EFFICIENCIES FOR VARIOUS PHOSPHORUS SPECIES
(Locations: PE = Primary Effluent, FE = Final Effluent)
Period
In
JS
Chemicals
Ferric Iron
PURIFLOC A23
Flocculant
Phosphorus Species
Ortho
Poly
Soluble
Suspended
Total
Location
Primary
Secondary
Primary
Secondary
1
0
0
0
0
2
18
0
0
0
3_
£
Concentrations ,
.3 19.0 10.0
0
.32 0
0
10.0
0.33
0
Removal Efficiencies, %
PE
FE
PE
FE
PE
FE
PE
FE
PE
FE
0
4.
8.
36.
4.
20.
0
50.
0
30.
78
78
71
75
74
79
50
67
67
75
81.
88.
50.
58.
61.
71.
42.
62.
52.
67.
83.
89.
56.
69.
71.
79.
0
0
48.
50.
5B
mg/1
0
20.0
0
0
(cumulative)
25.
75.
28.
72.
26.
74.
44.
62.
35.
68.
6_
0
15.0
0
0.20
12.
50.
24.
53.
18.
52.
0
77.
2.
63.
8
9.1
9.1
0
0.28
67.
89.
-
-
-
-
-
-
49.
75.
-------
added during Period 6, however, was about 25 percent less
than those of the other periods. Conversion of poly phos-
phorus to an insoluble form was somewhat less efficient
than the conversion of ortho phosphorus. With the excep-
tion of Period 6, the conversion of soluble phosphorus (ortho
and poly phosphorus) was 70-80 percent complete.
The major limitation to removal of total phosphorus was
not the conversion of soluble phosphorus to an insoluble
form but rather the capture of the suspended phosphorus.
This latter species consists of two fractions. One frac-
tion is comprised of suspended phosphorus originally pre-
sent in the raw influent, probably as inorganic solids or
insoluble organic phosphorus. The second fraction of sus-
pended phosphorus is comprised of newly precipitated iron
phosphates. At the Grand Rapids plant it was necessary
to add an anionic flocculant to flocculate the suspended
phosphorus from either source and thereby enhance sedimentation.
The frequencies of occurrence of ortho phosphorus in the
raw influent, primary effluent and final effluent during
Period 8 are shown in Figure 7. The mean ortho phosphorus
concentration in the final effluent was the lowest of all
other periods except Period 4 for which the same mean con-
centration was observed. Split additions of comparable
amounts of ferric iron were made in both Period 4 and Per-
iod 8. Insolubilizations of ortho and poly phosphorus,
therefore, were expected to be comparable.
The frequencies of occurrence of total phosphorus during
Period 8 in various plant locations are shown in Figure
8. The mean total phosphorus concentration in the final
effluent during Period 8 was 0.96 mg/1. This concentration
met the desired goal of this study of 1 mg/1. Period 8
was the only period of study in which ferric chloride was
55
-------
iao
Figure 7 - FREQUENCIES OF OCCURRENCE OF
ORTHO PHOSPHORUS DURING PERIOD 8
Standard Deviation
3.O -2.5 -2.O -1.5 -1.0 -0.5 0.0 0.5 l.O 1.5 2.O 2.5 3.0
ao
6.0
4.0
EC
o
2.0
Mam Deviation
• Rawlnflumt
A Pnirary Efflumt
• Fiml EffkMit
1.83
.60
.67
.39
.11
0.1 1. 2. 5. 1O 2O 3040506070 80 9O 95 98.99 99.9
Cumulative Percent of Occurrence
-------
Figure 8 - FREQUENCIES OF OCCURRENCE OF
TOTAL PHOSPHORUS DURING PERIOD 8
10.0
-3.0 -2.5 -2.0 -1.5
Standard Deviation
i.o -0.5 o.o 0.5 i.o
1.5 2.0 2.5
3.0
8.0
fg 6.0
tr
O
I
O
o.
-> 4.0
2.0
0
0.1
• Raw Influent
A Primary Effluent
• Final Effluent
Mean Deviation
3.85
2.01
.96
1.06
.82
.61
5. 10 20 3040506070 80 90 95 98 99
Cumulative Percent of Occurrence
99.9
-------
added during both primary and secondary treatment and PURI-
FLOC A23 flocculant was added only to secondary. The reduced
efficiency of removal of total phosphorus during primary
treatment during Period 8 is attributed directly to inade-
quate flocculation (no flocculant). The overall removal
of total phosphorus during Period 8 is somewhat less than
optimum due to some primary effluent bypassing secondary
treatment. Split addition of both chemicals is recommended
for optimum phosphorus removal at the Grand Rapids plant.
The frequencies of occurrence of the total phosphorus con-
centrations in the final effluent for several selected Per-
iods 1, 2, 3, 6, and 8 are shown in Figure 9. Similar data
collected for Periods 4, 5, and 7 were limited in number
and were not included. The relative efficiencies of overall
removals of total phosphorus can be compared for the various
periods when operating under different modes of chemical
treatment. The mean values previously included in Table
6 were represented as 50 percent occurrences, i.e., a given
concentration is expected to be equal to or greater than
the mean value 50 percent of all occurrences and equal to
or less than the mean value 50 percent of all occurrences.
A concentration of <_1 mg/1 total phosphorus is expected
to occur £0.35 percent for the control Period 1 but >5Q
percent for Period 8.
The mean loadings of total phosphorus (Table 6) entering
the secondary treatment stage and/or the receiving stream
(Grand River) are significantly reduced by chemical treat-
ment prior to primary and/or secondary treatment. The total
phosphorus load to the Grand River during the control Per-
iod 1 was 782 kg/day (1727 Ib/day). This agrees well with
the value of 739 kg/day (1632 Ib/day) calculated on the
basis of an average river flow of 85.8 cu m/sec (3032 cu
ft/sec) and average total phosphorus concentrations in the
58
-------
Figure 9 - FREQUENCIES OF OCCURRENCES FOR FINAL EFFLUENT
TOTAL PHOSPHORUS CONCENTRATIONS FOR SELECTED
PERIODS
l/i
vo
Standard Deviation
-3.O -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0
1.5 2.0 2.5 3.0
10.0
8.0
6.0
a 4.0
1
2.0
Period
1
6
2
3
8
0.0
0.1
Mean
5.3
2.3
1.8
1.7
.96
Deviation
1.6
.8
.9
1.0
.61
/Objective Of
g /_ Thjs Gram _
1. 2. 5. 10 20 3040506070 80 90 95 98 99
Cumulative Percent of Occurrence
99.9
-------
river of 0.16 and 0.26 mg/1, respectively, above and below
the plant outfall. During chemical treatment the load of
total phosphorus to the river decreased four-fold to as
low as 168 kg/day (370 Ib/day) (Period 8).
Biochemical Oxygen Demand and Suspended Solids
The removal efficiences of BOD (5-day) and suspended solids
for several major periods are provided in Table 15. Removal
of BOD during primary treatment was improved if both ferric
chloride and the anionic flocculant were added prior to
primary sedimentation. This was illustrated by the results
for Periods 2 and 4. The removals of BOD during primary
treatment for Periods 3 and 6 were not appreciably different
from those obtained during the control Period 1 since no
flocculant was added in primary treatment during either
period. Overall removals of BOD were not improved by chem-
ical treatment except in Period 6, which was the only per-
iod in which all of the required iron and the flocculant
were added during secondary treatment.
Removals of suspended solids were improved if at least 15
mg/1 of ferric iron were added and followed by PURIFLOC
A23 flocculant. This was evident during primary treatment
during Period 2 compared to Period 3, and during secondary
treatment during Period 6 compared to Period 5B. The re-
movals of suspended solids and suspended phosphorus can
be equated to a first approximation. Any reduced effici-
ency of removal of suspended solids also resulted in reduced
removal of suspended phosphorus.
The organic and solids loadings (Table 10) at various loca-
tions in the plant can be significantly influenced by chem-
ical treatment. The effects of recycled suspended solids
60
-------
TABLE 15
COMPARISON OF REMOVAL EFFICIENCIES FOR
BIOCHEMICAL OXYGEN DEMAND AND SUSPENDED SOLIDS
(Locations: PE = Primary Effluent, FE = Final Effluent)
Chemicals
Ferric Iron
PURIFLOC A23
Flocculant
Component Removed
BOD (5 -day)
Suspended Solids
Location
Primary
Secondary
Primary
Secondary
PE
FE
PE
FE
1
0
0
0
0
20.
78.
19.
71.
2
18.
0
0.
0
48.
79.
64.
80.
3
Period
4
Concentrations ,
3 19.0 10.0
0
32 0
0
10.0
0.33
0
Removal Efficiencies, %
26. 47.
65.
32.
71.
46.
37.
7.
5B
mg/1
0
20.0
0
0
(cumulative)
37.
79.
49.
79.
6_
0
15.0
0
0.20
15.
86.
7.
88.
£
9.1
9.1
0
0.28
39.
71.
32.
65.
-------
and biochemical oxygen demand and the formation of chemically
precipitated solids ahead of primary treatment are not in-
cluded in the raw influent loadings but are by necessity
included in the primary effluent loading to secondary treat-
ment and the final effluent loading to the receiving stream.
Net decreases in both organic and solids loadings are evident
after primary treatment (Periods 2, 3 and 4) and secondary
treatment (Periods 2 and 6).
Heavy Metals
A comparison of the percentages of removal of iron and four
other metallic species is provided in Table 16. Increased
removals of chromium and zinc paralleled the increased re-
movals of suspended solids when both ferric chloride and
the polyelectrolyte flocculant were added. The removals
of copper and nickel were not as dramatically affected by
chemical treatment. Gradually decreasing concentrations
of the various metals in the raw influent were measured
as the study progressed. These decreases were probably
the result of operation of new pretreatment facilities by
all of the larger metal-plating plants in the Grand Rapids
area. The removals of chromium, copper, nickel, and zinc
during the control Period 1 were comparable to those re-
ported in the absence of chemical treatment.
Iron
Addition of soluble iron salts to wastewater usually does
not result in increased iron concentrations in the final
effluent if an aerobic process is utilized. The addition
of an anionic flocculant after iron addition and reaction
was found to be necessary at the Grand Rapids plant to ag-
glomerate any fine iron-phosphate floes that did not settle
readily in the hydraulically overloaded secondary clarifiers,
62
-------
TABLE 16
COMPARISON OF REMOVAL EFFICIENCIES OF VARIOUS HEAVY METALS
(Locations: PE = Primary Effluent, FE = Final Effluent)
Chemicals
Ferric Iron
PURIFLOC A23
Flocculant
Metal Species
Chromium
Copper
Iron
Nickel
Zinc
Location
Primary
Secondary
Primary
Secondary
PE
FE
PE
FE
PE
FE
PE
FE
PE
FE
Period
1
2
1
4
Concentrations ,
0
0
0
0
18.
0
0.
0
3 19.0
0
32 0
0
10.0
10.0
0.33
0
Removal Efficiencies, %
10.
50.
10.
20.
12.
62.
6.
11.
0
55.
50.
75.
50.
50.
-32.
14.
23.
31.
57.
68.
38.
62.
20.
60.
-250.
-167.
12.
25.
48.
67.
20.
40.
25.
50.
-120.
-407.
29.
43.
30.
45.
5B
mg/1
0
20.0
0
0
(cumulative)
38.
62.
25.
50.
57.
48.
20.
40.
22.
43.
6_
0
15.0
0
0.20
33.
83.
0
50.
6.
69.
12.
50.
19.
65.
i
9.1
9.1
0
0.28
32.
62.
-21.
11.
-203.
-179.
-10.
11.
-50.
-8.
-------
No net increases in iron concentration were observed in
the present study except in those cases where no flocciilant
was added after an iron addition; e.g. Periods 3 and 8 in
primary treatment, and Period 4 in secondary treatment.
Some reduced efficiency in the removals of biochemical oxy-
gen demand, suspended solids, and iron during primary treat-
ment occurred during Period 8 compared to Period 6. This
is attributed to periodic bypassing of approximately 10
percent of the primary effluent into the final effluent
and a high primary overflow rate. Final effluent concen-
trations of iron, therefore, were higher than optimum during
Period 8.
The pH of the chemically treated wastewater (Table 9) did
not change significantly upon the addition of the relatively
small amounts of the acidic solution of ferric chloride.
Very slight decreases «.2 pH unit) were observed in labor-
atory studies and when ferric chloride was added before
primary treatment (Periods 2 and 3). The natural alkalinity
of the Grand Rapids wastewater (225 mg CaCO.,/1, Table 12)
is sufficient to buffer at least 20 mg ferric iron/1 (58.1
mg FeCl3/l).
Chemical Additions and Overflow Rates
The concentrations of both ferric iron and the polyelectro-
lyte flocculant are two important parameters of the chemical
removal process. The equal importance of designing and
maintaining low hydraulic overflow rates during both primary
and secondary clarification is emphasized. The hydraulic
overflow rates existing during primary and secondary clari-
fication have significant effects upon the removals of sus-
pended solids and total phosphorus. The effects of exces-
sively high overflow rates in hydraulically overloaded plants
can be compensated in part by the addition of more ferric
chloride and/or flocculant.
64
-------
The increased removal of suspended solids in the Grand Rapids
plant upon addition of another anionic polyelectrolyte (PURI-
FLOC A21 flocculant) has been reported previously . Removals
of suspended solids decreased with increased concentrations
of suspended solids in the raw influent and with increased
overflow rates as shown in Figure 10. The two families
of curves were obtained with and without the addition of
flocculant. An inorganic coagulant such as ferric chloride
was not added in either case. For any selected combination
of raw influent suspended solids concentration and primary
overflow rate, the primary removal of suspended solids is
increased by the addition of a flocculant. At an overflow
rate of 3^5 cu m/day-sq m (1000 gpd/sq ft) and a raw influ-
ent suspended solids concentration of 128 mg/1, for example,
the primary removal of suspended solids is increased from
47 to 70 percent upon the addition of the flocculant.
Decreased removals of total phosphorus can be expected when
overflow rates are increased even though flocculation is
acceptable. This influence also is illustrated for the
various overflow rates shown in Figure 11. The individual
curves are based on computer-generated contours [not shown)
fitted through several hundred data (also not shown) col-
lected during Period 2. The curves were essentially iden-
tical for both primary and secondary clarification. These
curves are for illustrative purposes only and should not
be construed for design purposes to represent conditions
existing in all plants.
The removal of phosphorus from solution by ferric iron is
not stoichiometric and increasing amounts of iron are re-
quired per unit of phosphorus removed as the phosphorus
concentration decreases ' . This effect is illustrated
for any selected overflow rate in Figure 11. The decrease
in removal of total phosphorus as overflow rate is increased
65
-------
Figure 10 - SUSPENDED SOLIDS REMOVAL AS A FUNCTION OF INFLUENT
SUSPENDED SOLIDS CONCENTRATION AND OVERFLOW RATE
WITH AND WITHOUT FLOCCULANT ADDITION
Ill
oc
2
g
o
oc
in
Q
O
C/3
Q
LU
a.
in
Without
Flocculant
PRIMARY
OVERFLOW
RATE
gpd/sq ft
(Data from ref. 11)
With
Flocculant
Example
Flocculant Removal, %
No 47
Yes 70
(Overflow rate
1000 gpd/sq ft)
MEAN
CONCENTRATION
(This Study)
O
10
Q
_l
O
to
Q
I
in
80
128 160 240 320 400
SUSPENDED SOLIDS IN RAW INFLUENT, mg/l
480
66
-------
Figure 11 - TOTAL PHOSPHORUS REMOVAL AS A FUNCTION OF
FERRIC IRON CONCENTRATION AND OVERFLOW RATE
Example
Overflow Rate
gpd/sqft
PERIOD 2
OVERFLOW RATE
gpd/sq ft
I
FERRIC IRON/INFLUENT TOTAL PHOSPHORUS (WEIGHT RATIO)
-------
can be compensated in part by the addition of more iron.
Removal of 80% of the total phosphorus can be achieved,
for example, at overflow rates of 30.8, 34j5 and 38,5 cu m/day-
sq m (800, 900 and l,000gpd/sq ft), upon addition of 8.5,
13.4 and 22.1 mg Fe/1, respectively. These estimates assume
a constant concentration of total phosphorus in the raw
influent and the use of a constant amount of flocculant.
The comparative costs of chemical treatment are dependent
upon the degree of phosphorus removal desired (Table 8).
Total chemical costs for the Grand Rapids plant ranged from
$.18-.61/kg ($.39-1.34/lb) total phosphorus removed. This
corresponded to about $2.51-6.60/1000 cu m ($ll-25/MG).
About 90% of the total chemical cost was for ferric chloride
and the remainder for the anionic flocculant.
Recycle Streams
There are three recycle streams entering the raw influent
as shown in the detailed portion of Figure 5. The digester
supernatant, the waste activated sludge, and the filtrate
from vacuum filtration all contribute to the primary loadings
of suspended solids, biochemical oxygen demand, the various
phosphorus species, and heavy metals.
The effects of those recycle streams upon the overall chem-
ical precipitation process should not be overlooked. Con-
tributions of both soluble and total phosphorus, and sus-
pended solids not receiving adequate chemical treatment
can be significant. This is particularly true when the
recycle stream addition points follow chemical addition
points in the treatment flow sequence. It is reasonable
to expect that any soluble phosphorus entering the waste-
stream after coagulant addition will not be insolubilized
68
-------
with additional biological treatment. The sources of recycle
include vacuum filtrate, waste activated sludge returned
to primary, and digester supernate. An example of the con-
tribution of one of these waste streams occurred in January,
1971. Average soluble phosphorus in the supernatant based
on 9 samples was 439 mg/1. The total volume of supernatant
returned to the raw sewage following coagulant addition
was 2,289,000 gallons. This loading distributed equally
for the average daily flow for the month is 0.80 mg/1 or
12.8% of raw influent phosphorus.
Solids Handling
The relative distribution of solids in the various main
and recycle process streams is altered by chemical treat-
ment. The average values reported in Table 17 were taken
directly from the monthly summary sheets of plant operation
or subsequently calculated. Greater quantities of primary
sludge solids generally were produced when phosphorus re-
moval by chemical means was practiced. This usually was
due to increased capture during primary treatment of solids
normally present in the raw influent and to precipitated
and flocculated iron-phosphate compounds. This increase
is noted during periods of chemical treatment by the greater
differences occurring between the dry weights of primary
sludge weight actually measured and those calculated as
the quantity: raw influent + waste activated + digester
supernatant - primary effluent. The net increases in pri-
mary sludge production, particularly during Period 2 of
about 30 percent, caused an overloading of the existing
sludge handling facilities. Overloading also occurred after
Period 8. The sludge produced during chemical treatment
was generally easier to handle but additional capacity cur-
rently under construction is needed to handle the larger
quantities.
69
-------
TABLE 17
SOLIDS DISTRIBUTION IN VARIOUS PROCESS STREAMS
Suspended solids, 10s Ib/mo
Raw
Date Influent
1
1969-10 1.387
7-70 1.576
B 1.264
9 1.480
10 1.696
11 1.230
12 1.640
1-71 1.367
2 1.230
3 1.026
4 1.306
5 1.256
6 1.319
7 1.030
8 1.345
9 1.282
10 1.352
11
12 1.172
1-72 1.210
2 1.254
3 1.366
4 1.633
5 1.738
6 1.549
7 1.448
8 1.851
9 1.377
10 1.686
11 1.391
12 1.410
1-73 1.768
2 1.245
3 1.424
4 1.486
5 1.433
6 1.291
•Calculated from
••FePO,. and Fe(OH)
Kaste
Activated
Sludge
2
1.002
1.838
1.411
1.097
1.292
.229
.402
.768
.818
.352
1.142
.802
.452
.332
.433
.254
.373
.802
.423
.379
.700
.463
.863
1.401
1.522
.725
.775
1.020
1.061
1.121
.982
1.411
.804
1.038
1.414
1.133
.841
total phosphorus
4 calculated froi
Digester
Supernate
3
0.683
.973
.540
.705
.798
.346
.642
.712
.045
.435
.489
.299
.532
1.149
1.042
.960
1.156
.109
.174
.067
.075
.112
.102
.552
2.207
1.960
1.282
1.161
1.311
1.775
1.164
.383
.439
.481
1.068
.460
.269
analyses
Q total ph
Primary
Loading
4-1+2+3
3. OBI
4.387
3.245
3.282
3.786
1.805
2.684
2.847
2.083
1.813
2.937
2.357
2.303
2.511
2.820
2.496
2.881
-
1.769
1.655
2.030
1.941
2.598
3.691
5.278
4.133
3.907
3.559
4.058
4.286
3.556
3.562
2.488
2.943
3.968
3.025
2.401
Primary
Effluent
5
1.119
1.252
1.159
1.492
1.535
.362
.502
.613
.984
.858
1.205
.890
.640
.436
.504
.397
.610
.855
.688
.922
.955
.976
.982
1.214
1.435
1.081
1.020
.939
1.050
.822
1.019
1.183
.914
1.222
.962
.778
.634
only, not corrected for
Calculated
Primary
Sludge
6>4-5
1.962
3.136
2.086
1.790
2.251
1.443
2.183
2.234
1.099
.955
1.732
1.467
2.110***
2.075
2.316
2.099
2.271
-
1.081
.733
1.074
.965
1.616
2.477
3.843
3.052
2.888
2.620
3.008
3.465
2.537
2.379
1.574
1.721
3.006
2.247
1.767
baseline.
Actual
Primary
Sludge
7
1.797
2.135
2.229
2.370
1.998
2.179
3.459
2.439
2.051
1.158
1.640
2.472
2.497
3.873
3.481
2.785
3.456
1.708
1.612.
1.406
1.637
1.508
1.999
2.659
4.204
3.651
3.048
2.630
2.639
3.476
2.686
1.766
1.656
1.624
3.001
2.391
2.210
Difference
(Actual-
Calculated)
8-7-6
-0.165
-1.001
.143
.579
-.253
.736
1.276
.205
.952
.160
-.092
1.005
.387
1.798
1.165
.686
1.185
-
.531
.673
.563
.542
.383
.182
.362
.599
.160
.010
-.369
.012
.149
-.413
.082
-.097
-.005
.143
.444
Final
Effluent
9
0.426
.464
.242
.432
.371
.220
.245
.248
.323
.172
.382
.334
.266
.263
.187
.323
.338
.394
.419
.564
.309
.413
.423
.229
.320
.449
.365
.470
.469
.416
.522
.520
.582
1.046
.646
.259
.306
Ferric
Phosphate*
10
0.110
.085
.112
.126
.171
.282
.261
.251
.192
_
.130
.204
.254
.148
.267
.231
.201
_
.183
.075
.115
.061
.250
.228
.156
.075
.149
.066
.035
.057
.098
.177
.147
.143
.113
.057
.043
Chemically
Precipitated
Sludqe"
11
O.UO
.085
.112
.126
.171
.276
.472
.419
.467
-
.130
.308
.447
.506
.502
.481
.486
-
.403
.075
.115
.153
.396
.228
.156
.075
.149
.066
.035
.057
.098
.172
.190
.205
.154
.071
.043
Added
10' lb/»o Period**'
12
1
_
_
-
•
0.192 2A
.495 2A
.526 2A
.520 2A
_
-
' .278 2B
.468 2C
.562 2C
.551 2C
.535 2C t 7
.559 2C, 3
.471 3
.444 3, 4, 2D
_
.
.122 5
.409 5, 6
-
.
-
_
_
_
_
-
.166 a
.226 8
.2(2
.174
.031
-
•"Include* .447 x 10* lb/rao lime sludge from water plant.
i***For detailed chronology of operation see Table 5.
-------
There were lesser quantities of waste activated sludge pro-
duced when chemicals were added to the raw influent. The
quantities of chemically precipitated sludge can be esti-
mated by assuming that all of the total phosphorus removed
is precipitated as ferric phosphate [FePO.] and that the
added iron in excess of stoichiometric quantities for phos-
phorus precipitation is precipitated as ferric hydroxide
[Fe(OH)_]. The chemically precipitated sludge accounts
for about half of the total primary sludge increase.
The iron and phosphorus contents of both sludges increase
as a result of chemical treatment. Comparisons of phos-
phorus and iron concentrations in both primary and secon-
dary (activated) sludges for selected periods are shown
in Table 18. When chemical additions were made prior to
primary clarification during Period 2, the phosphorus con-
tent of both sludges increased about one-third and the iron
content increased about three-fold. When chemical additions
were made just prior to secondary clarification during Per-
iod 6, the phosphorus content and the iron content of the
secondary sludge increased about three-fold. The primary
sludge solids were increased from an average of about 5-
7 percent dry weight without chemical addition to 8 percent
dry weight with chemical addition during primary treatment.
This increase resulted in decreased chemical requirements
for vacuum filtration and decreased heat requirements for
incineration with attendant savings. Chemical costs for
filtration and heat requirements for incineration as func-
tions of solids content at the Grand Rapids plant are shown
in Figure 12.
71
-------
TABLE 18
COMPARISON OF SLUDGE COMPOSITIONS
Period
to
Chemicals
Ferric Iron
PURIFLOC A23
Flocculant
Location
Concentrations, mg/1
Primary
Secondary
Primary
Secondary
0
0
0
0
8.3
0
0.32
0
0
15.0
0
0.20
Component
Phosphorus
Iron
Phosphorus
Iron
Primary
Primary
Secondary
Secondary
33.
22.
50.
28.
Composition, mg/g
43.
86.
65.
76.
33. (est)
22. (est)
144.
87.
-------
Figure 12 - FILTRATION CHEMICALS COSTS AND
HEAT REQUIREMENTS AS FUNCTIONS
OF SLUDGE SOLIDS CONTENT
10
o
I 8
.§
I
u
I
u.
Heating
Requirement
00
£
I
Filtration
Chemicals
Cost
678
Primary Sludge, % Dry Solids
10
73
-------
Sludge Filtration
One index for sludge dewatering improvement is the specific
resistance to filtration. The specific resistance test
is an extension of the Buchner funnel test . It is a method
of quantitatively comparing the filterability of sewage
sludges. The calculated specific resistance to filtration
is independent of most variables. Various sludges can be
compared in an unbiased manner. A low specific resistance
indicates a sludge with rapid filtration characteristics;
a high specific resistance indicates poor filtration char-
acteristics. A limited number of comparative data for two
sludges and three different operating conditions at Grand
Rapids are provided in Table 19.
TABLE 19
FILTRATION CHARACTERISTICS OF VARIOUS SLUDGES
Specific Resistance
SJLudge Chemical (m/kg x 1013)
Primary None 7.9
Flocculant only 4.95
Ferric chloride + flocculant 2.43 (this study)
Digested None 13.6
Flocculant only 6.6611
Filtration of mixed primary and secondary sludge collected
using an anionic flocculant during primary treatment was
conducted as part of a previous study . Filtration of
sludge collected using both ferric chloride and flocculant
for phosphorus removal was conducted as part of the current
grant.
74
-------
SECTION X
ABBREVIATIONS
BOD = biochemical oxygen demand (five-day unless otherwise denoted)
Btu = British thermal unit
cm = centimeter
COD = chemical oxygen demand
cu = cubic
DO = dissolved oxygen
F.E. = final effluent
FRP = fiberglass-reinforced-plastic
ft = ft
gal = gallon
gpd = gallons/day
gpm = gallons/min
hp = horsepower
JTU = Jackson Turbidity Unit
kg = kilogram
km = kilometer
Ib = pound
m = meter
MG = million gallons
mgd = million gallons/day
»»
mg/g = milligrams/gram
mg/1 = milligrams/liter
min = minute
ml = milliliter
N = nitrogen (atomic weight 14.01)
nm = nanometer
P = phosphorus (atomic weight 30.97)
P.E. = primary effluent
rem. = removal
rps = revolutions/second
s = second
sq = square
WRC = Water Resources Commission (State of Michigan)
cwt = hundred (pound) weight
75
-------
SECTION il
ACKNOWLEDGMENTS
This report was prepared by Otto Green, Superintendent;
Doris Van Dam, Assistant Superintendent; Bernard La Beau,
Laboratory Director; and Carl Nowak, Chief Chemist, all
of the Wastewater Treatment Plant of the City of Grand Rapids,
with the assistance of Dr. Stacy L. Daniels, Senior Research
Engineer, Mr. Terrance Campbell, Research Engineer, Mr.
Gavin Frantz, Ms. Mary Jo Hunt, Secretary, Ms. Loretta Demers,
Science-Engineering Secretary, and Ms. Lauri Kline, Secretary,
of the The Dow Chemical Company. The guidance given by
the project officer, Mr. Edwin Barth, of the Office of Research
and Development, U.S. Environmental Protection Agency, was
greatly appreciated. The inspiration and consul of Mr.
Huntley DeLano, former Superintendent, and the assistance
of Laboratory Technicians, Richard Draper, Louis Weiner,
John DeLiefde, Dan Wolz, and Richard Griffin, and Ms. Evelyn
Vanden Boogart, Secretary, all of the City of Grand Rapids,
are also gratefully acknowledged.
76
-------
SECTION XII
REFERENCES
1. Earth, E. F., and M. B. Ettinger. Mineral Controlled
Phosphorus Removal in the Activated Sludge Process.
J. Water Pollution Control Federation 39; 1362-8, 1967.
2. Campbell, T. L., and S. L. Daniels. Phosphorus Removal
by Chemical Precipitation and Flocculation During Primary
Treatment. In: Process Manual for Phosphorus Removal,
Black and Veatch, Consulting Engineers. U.S. Environ-
mental Protection Agency Technology Transfer, Program
No. 17010 GNP. October 1971.
3. Daniels, S. L. Phosphorus Removal from Wastewater by
Chemical Precipitation and Flocculation, presented at
the American Oil Chemists Society 1971 Short Course,
"Update on Detergents and Raw Materials," Lake Placid,
New York, June 16, 1971.
4. Schuessler, R. G. Phosphorus Removal - A Controllable
Process. Chem. Eng. Prog. Sym. Series ^7_(107) : 536,40,
1970.
5. Wukasch, R. F. New Phosphate Removal Process. Water
and Wastes Engineering 5_(9) : 58,60, 1968.
6. Jenkins, D., J. F. Ferguson and A. B. Menar. Chemical
Processes for Phosphate Removal. Water Research 5_: 369-
89, 1971.
7. Marson, H. The Removal of Phosphate from Sewage, Part I.,
Removal During Normal Sewage Treatment. Effluent Water
Treatment Journal 11: 390-11, 313, 315, 1971.
8. Phosphorus in Fresh Water and the Marine Environment,
Proceedings of an International Conference held at
University College, London, April 11-13, 1972, Water
Research 7_: 1-342, 1973.
9. The Dow Chemical Company. Phosphorus Removal Feasibility
Study. Grand Rapids, Michigan. March 1969. Unpublished.
10, Voshel, D. Gas Recirculation and CRP Operation. Wastes
Engineering 3£(9) : 452-55, 476, 1963.
11. Voshel, D., and J. G. Sak. Effect of Primary Effluent
Suspended Solids and BOD on Activated Sludge Production.
J. Water Pollution Control Federation 40: R203-R212,
1968.
77
-------
12. Ionics, Inc. Automatic Phosphate Analyzer Model 1836,
Specifications. 65 Grove St., Watertown, Mass. 02172,
1972.
13. American Public Health Association. Standard Methods
for the Examination of Water, Sewage, and Industrial
Wastes. 13th Edition. New York, 1971. p. 530.
14. City of Grand Rapids, Michigan. Annual Report on Opera-
tion of the Wastewater Treatment Plant for the Year
1969-1970, Sept. 3, 1970.
15. Earth, E. F., J. N. English, B. V. Salotto, B. N. Jackson,
and M. B. Ettinger. Field Survey of Four Municipal
Wastewater Treatment Plants Receiving Metallic Wastes.
J. Water Pollution Control Federation 37: 1101-17, 1965.
16. U.S. Environmental Protection Agency, Water Quality
Office. Process Design Manual for Phosphorus Removal.
Prepared by Black and Veatch, Consulting Engineers,
St. Louis, Mo. Program No. 17010 GNP. October 1971.
17. Gale, R. S. Research in Filtration of Sewage Sludges.
Filtration and Separation 9_: 431-8, July/August 1972.
18. U.S. Department of Health, Education, and Welfare,
Division of Water Supply and Pollution Control, Cincin-
nati, Ohio, Interaction of Heavy Metals and Biological
Sewage Treatment Processes, Public Health Service Publi-
cation No. 999-WP-22, May 1965.
19. American Public Health Association. Standard Methods
for the Examination of Water, Sewage, and Industrial
Wastes. 13th Edition. New York, 1971. p. 527.
20.
21.
22.
23.
24.
25.
26.
27.
28.
Ibid.
Ibid.
Ibid.
Ibid.
Ibid.
Ibid.
Ibid.
Ibid.
Ibid.
P-
P-
P.
P-
P-
P.
P-
P.
P-
523.
526-7.
479.
477.
537.
538.
539.
399, 402.
453.
78
-------
29.
30.
31.
32.
33.
34.
35.
Ibid.
Ibid.
Ibid.
Ibid.
Ibid.
Ibid.
Taras,
P-
P-
P-
P-
P-
P-
M.
461.
240.
52.
99.
112.
339.
J-,
Taras, M. J., and K. A. Blum. Determination of Water
Emulsifying Oil in Industrial Wastewater. J. Water
Pollution Control Federation 40: R404-11, 1968.
36. American Public Health Association. Standard Methods
for the Examination of Water, Sewage, and Industrial
Wastes. 13th Edition. New York, 1971. p. 412.
37. Ibid. p. 413.
38. Ibid. p. 679.
39. Ibid. p. 684.
40. Ibid. p. 690.
79
-------
SECTION XIII
APPENDICES
80
-------
APPENDIX A
DETAILS OF ANALYTICAL TESTS
18
1. Ortho Phosphorus *
Samples were initially filtered through 0.45 micron membrane
filters. Ortho phosphorus was determined for each filtrate
using the colorimetric method based on ortho phosphorus
complexation with vanado-molybdophosphoric acid. A similar
colorimetric method was used in the automatic ortho phosphorus
analyzer described previously.
The filtrate was mixed with 10 ml of vanadate molybdate
reagent in a volumetric flask until a final volume of 50
ml was reached. The absorbance was measured after 10 minutes
of color development at a wavelength of 420 nm against a
reagent blank. Ortho phosphorus concentration (mg P/l,
P = elemental phosphorus, atomic weight 30.97) was calculated
from a calibration curve previously prepared from standards
and multiplied by the dilution factor of 1.25 (40 ml of
sample brought to 50 ml) .
2. Poly Phosphorus
The concentration of poly phosphorus (non-ortho soluble
phosphorus)(mg P/l) was the calculated difference between
soluble and ortho phosphorus analyses.
19
3. Soluble Phosphorus
Soluble phosphorus (total filterable phosphorus)(mg P/l)
consists of ortho phosphorus and various forms of poly phos-
phorus. Samples were filtered through a 0.45 micron membrane
filter, and then acid digested according to the procedure
for total phosphorus. The soluble phosphorus thus hydrolyzed
to the ortho form was then determined colorimetrically as
described above.
*See References
81
-------
4. Suspended Phosphorus
The concentration of suspended phosphorus (particulate acid-
hydrolyzable phosphorus)(mg P/l) was the calculated difference
between total and soluble phosphorus analyses.
5. Total Phosphorus
The stannous chloride method was used until January 1972.
Thereafter the vanadate method with preliminary digestion
was used. Equivalent results were obtained using each method
on common samples. One ml of strong acid and 0.8 g potassium
persulfate were added to 100 ml of sample in an Erlenmeyer
flask. The sample was boiled to less than 75 ml (30 minutes
or more), cooled, and brought back to a 100 ml volume with
distilled water.
Acid-digested sewage was mixed with 10 ml of vanadate reagent
in a volumetric flask to a final volume of 50 ml. After
10 minutes the absorbance was measured against a reagent
blank at a wavelength of 420 nm. Total phosphorus (mg P/l)
calculated from a calibration curve previously prepared
from standards was multiplied by the dilution factor of
1.25 (40 ml of sewage diluted with reagent to 50 ml). For
sludge samples, one ml volumes were diluted to 100 ml and
then analyzed according to the above procedure. The result
obtained was multiplied by a dilution factor of 125.
21
6. Total Biochemical Oxygen Demand (BOD,-)
One BOD test was run on each sample using the following
dilutions:
Raw sewage 4%
Primary effluent 4%
Final effluent 10%
Filtered raw influent 10%
Filtered primary effluent 10%
Filtered final effluent 20%
82
-------
A portion of sample was pipetted into a 300 ml BOD bottle
and diluted with dilution water of known dissolved oxygen
(DO) concentration. The dilution water was prepared by
adding sodium bicarbonate to distilled water and then aerating
the solution. The BOD bottles and a blank were incubated
for 4, 5, or 6 days at 20°C. After incubation, the samples
and blank were removed and the DO concentrations determined
with an oxygen meter (Yellow Springs Instrument Company
Model 54 fitted with a No. 5420 oxygen probe and agitator).
The DO meter was calibrated using water of known DO concen-
tration determined by the azide modification of the iodo-
22
metric method
The following formula was used to determine the BOD of samples
of 4 percent dilution.
BOD (rag/1) = a ~ b
On BOD dilutions greater than 4 percent, the initial DO
was calculated. The following formula was used to determine
the BOD.
BOD (mg/1) = ^ X e) - ^c X s) - b
For BOD dilutions greater than 4 percent which required
seeding (with 1 percent primary effluent), the following
formula was used to determine the BOD.
BOD (mg/1) = (a X e) + (c X s) - (g + B)
where a = DO of dilution water blank after incubator
b = sample DO after incubation
c = decimal fraction of sample
e = decimal fraction of dilution water
s = DO of original undiluted sample
g = 1 percent of the BOD of the primary effluent
used for seed
83
-------
Friday, Saturday, and Sunday samples were stored under refrig-
eration until Monday when they were set up for a 4-day BOD.
Monday samples were set up for a 6-day BOD.
All 4-day BOD results were multiplied by 1.16 and all 6-
day BOD results were multiplied by 0.91 to correct them
to 5-day BOD values.
7. Soluble Biochemical Oxygen Demand
Each sample was homogenized in a high-speed blender and
filtered through a 0.45 micron membrane filter prior to
dilution, reseeding, and incubation. All other procedures
were identical to those followed in determining the total
biochemical oxygen demand.
8. Total Chemical Oxygen Demand (COD)
Values of COD were determined instrumentally (Precision
AquaRator®). This involved injection of the samples into
a combustion chamber, oxidation in a stream of carbon dioxide,
and detection of the amount of carbon monoxide produced.
Samples were homogenized in a high-speed blender. A 20
ml sample was then injected into the instrument. The maximum
meter reading was recorded and the COD (mg/1) was then cal-
culated from a standard curve.
9. Soluble Chemical Oxygen Demand
Each sample was homogenized in a high-speed blender and
filtered through a 0.45 micron membrane filter prior to
analysis which was then identical to that performed for
total chemical oxygen demand.
10. Total Suspended Solids (Non-Filterable Residue)23
Suspended solids were determined by vacuum filtration of
the sample through a Buchner funnel containing a glass fiber
filter (9 cm, Reeve Angel No. 934 AH). The filters were
84
-------
stored in a desiccator until used at which time they were
weighed, placed in Buchner funnels and seated with distilled
water. Samples were added and vacuum applied until all
the liquid had passed through the filter. Sample volumes
were 200 ml for influent and primary effluent, and 250 ml
for final effluent. The filters were then placed in a 103°C
drying oven for 45 minutes, cooled and weighed.
, , n . , ,-,/-, v AX 1000
Suspended solids (ml/1) = ^
where A = mg suspended solids
B = ml sample
24
11. Volatile Suspended Solids
The filter disc used for suspended solids was ignited in
a muffle furnace at 550°C for 15 minutes, cooled, and weighed.
Weight loss upon ignition, divided by the liters of sample,
was reported as volatile suspended solids (mg/1).
12. Total Solids25
An evaporating dish was dried in an oven, stored in a desic-
cator and weighed. One hundred ml of sewage was added to
the dish. The moisture was driven off on a steam bath.
The dish was then cooled, placed in a desiccator and weighed.
The weight of dry solids in milligrams multiplied by 10
equaled total solids (mg/1).
13. Heavy Metals
Chromium, copper, iron, nickel, and zinc (mg/1) were deter-
mined by atomic absorption spectroscopy (Model 2SOB Perkin-
Elmer atomic absorption spectrophotometer). Samples were
usually run on daily composited sewage. Occasionally, a
composite sample (proportional to flow) was made of Monday
through Friday samples and another composite was made of
Saturday and Sunday samples. These composites were made
85
-------
from the daily 24-hour composite samples which were homo-
genized in a high speed blender. Samples were added to
a volume of 70 percent nitric acid calculated to be approx-
imately 2.5 percent of the final volume. These samples
were then analyzed using the atomic absorption spectrometer
for concentrations from 0 to 10 mg/1 of each metal. More
concentrated samples were diluted 1:10 prior to analysis
and the meter reading multiplied by a factor of 10.
14. Metals in Sludge
One ml samples of raw sludge, digested sludge, or mixed
liquor were combined with 0.5 ml of concentrated HNO_ and
5 ml of HC1 in an Erlenmeyer flask. The samples were heated
for 5 minutes on a hot plate. Samples were then diluted
(to 200 ml for raw and digested sludge or to 25 ml for mixed
liquor) and run on the atomic adsorption spectrophotometer
described above using 2 mg/1 standards. The meter reading
(mg/1) was multiplied by the proper dilution factor (200
or 25).
15. Total Cyanide26
A sample volume of 250 ml was added to a modified Claisson
flask. Then 20 ml of mercuric chloride reagent, 10 ml mag-
nesium chloride reagent, and 12.5 ml of concentrated sul-
furic acid were added to the flask. Hydrogen cyanide was
distilled for 40 minutes into an evacuated gas washer con-
taining 50 ml of 1 N sodium hydroxide. The contents of
the gas washer were emptied into a 300 ml flask along with
two water rinses of the gas washer. One-half ml of indicator
solution was added to the sample which was then titrated
with 0.0048 N silver nitrate. The milliliters of silver
nitrate used then equalled cyanide (mg/1).
86
-------
27
16 . Ammonia Nitrogen
One ml of zinc sulfate solution was added to 100 ml sample
and mixed; 0.5 ml of NaOH solution was added and mixed.
The sample was then filtered. Five ml of the treated sample
were placed in a Nessler tube and the volume increased to
50 ml with distilled water. One ml of Nessler reagent was
added. After 10 minutes of color development, the absorbance
was measured at a wavelength of 425 nm using a spectropho-
tometer (Bausch and Lomb Spectronic 20) . The ammonia nitrogen
concentration (mg N/l) was calculated from a calibration
curve previously prepared from standards and multiplied
by a dilution factor of 10.
17. Total Nitrogen
A 20 ml sample was added to a micro Kjeldahl flask along
with 30 ml of acid sulfate reagent and boiled slowly for
2 hours. The sample was transferred to an 800 ml Kjeldahl
flask. Three hundred ml of ammonia- free water and 50 ml
of sodium hydroxide-thiosulf ate reagent were added. The
sample was distilled into a 300 ml Erlenmeyer flask. The
distillate was collected below the surface of a 50 ml boric
acid indicating solution. Distillation continued until
the 250 ml mark was reached. The distillate was collected
below the surface of a 50 ml boric acid indicating solution.
Distillation continued until the 250 ml mark was reached.
The distillate was titrated with 0.02 N sulfuric acid. A
blank was carried through all the steps and a correction
applied to the results. The results were added to the ammonia
concentration (mg/1) and the sum was recorded as total nitrogen.
Kjeldahl nitrogen (mg/1) - (D
Total nitrogen (mg/1) = Kjeldahl + Ammonia nitrogen
where D = titrant used on sample (ml)
E = titrant used on blank (ml)
87
-------
9 o
18. Nitrate Nitrogen
To each of two 50 ml beakers a 2 ml sample was added. Ten
ml of sulfuric acid was added to two additional 50 ml beakers,
One ml of distilled water was added to one sample for a
blank. One ml of brucine sulfanilic acid reagent was added
to the other sample. The blank was poured into one of the
acid beakers and poured back and forth five or six times.
The same procedure was followed with the remaining sample
and acid beakers. After 3, but less than 10 minutes of
color development, the absorbance was read at a wavelength
of 410 nm using a spectrophotometer (Bausch and Lomb Spec-
tronic 20). The nitrate nitrogen concentration (rag N/l)
was calculated from a calibration curve previously prepared
from standards. Chlorinated samples required one drop of
sodium arsenite in 50 ml for every 0.1 mg/1 of chlorine
residual plus one drop in excess.
19. Nitrite Nitrogen
Five ml of sewage (coagulated and filtered from the ammonia
test) was added to a 50 ml volumetric flask containing 20
ml of nitrite-free distilled water. One ml of sulfanilic
acid was added. After 3, but less than 10 minutes, 1 ml
of sodium acetate and 1 ml of naphthylamine hydrochloride
reagent was added. The sample was brought to 50 ml with
nitrite-free distilled water. After 10 to 30 minutes the
absorbance was measured at a wavelength of 520 nm against
a reagent blank. The nitrite nitrogen concentration (mg
N/l) was calculated from a calibration curve previously
prepared from standards.
_T.. .. , >,/n x yg nitrite N
Nitrite (mg N/l) = ^ sample
88
-------
20. Alkalinity30
Bromcresol green-methyl red indicator was added to a 100
ml sample in a 250 ml Erlenmeyer flask. The sample was
titrated with 0.02 N sulfuric acid until all blue color
had disappeared.
Total alkalinity (mg Caccyi) = B
where B = titrant to endpoint (ml)
N = normality of acid
21. Chloride31
To a 50 ml sample in an Erlenmeyer flask 1 ml of potassium
chromate indicator was added. The sample was titrated with
0.0282 N silver nitrate to the red endpoint.
m lm~n\ _ A X N X 35,450
Cl (mg/1) mi sample
where A = titration for sample (ml)
N = normality of silver nitrate
32
22. Chlorine Residual
A 200 ml sample was added to a sample jar and placed on
the titrator. The agitator was started and 5 ml of phenyl-
arsene oxide solution was added to the sample and mixed.
Then 4 ml of buffer solution (pH 4) was added and mixed,
followed by the addition of 1 ml of potassium iodide solution
and again mixed. The adjusting knob on the amperometric
titrator (Wallace and Tiernan) was rotated so that the pointer
read approximately 20 on scale. Iodine solution (0.0282
N) was added in small increments from a 1 ml pipette until
the endpoint was reached (when a small addition of iodine
gave a permanent pointer deflection to the right).
Chlorine (mg/1) = phenylarsene oxide (ml) - 5 X iodine (ml)
89
-------
23. Methylene Blue Active Substances in Sewage (MBAS)
A 20 ml sample was added to a separatory funnel. The sample
was made alkaline with 1 N NaOH using phenolphthalein as
the indicator. The pink color was then discharged with
1 N sulfuric acid. Then 10 ml of chloroform and 25 ml of
methylene blue reagent were added. The separatory funnel
was rocked for 30 seconds and the bottom chloroform layer
was drawn off into a second separatory funnel. This proce-
dure was repeated three times adding 10 ml of chloroform
each time, rocking and drawing off the chloroform layer
each time .
Fifty ml of wash solution were added to the second separa-
tory funnel and shaken vigorously for 30 seconds. The chloro-
form layer was drawn off through glass wool into a 100 ml
volumetric flask. The washing was repeated two more times
each with 10 ml of chloroform, drawing off the chloroform
into the volumetric flask each time. The sample was diluted
to the mark with chloroform and the absorbance of the extracted
sample solution was measured spectrophotometrically at a
wavelength of 652 run (Bausch and Lomb Spectronic 20) . The
MBAS, expressed as total apparent LAS (linear alkylsulfonate) ,
were calculated from a calibration curve previously prepared
from standards.
Total apparent LAS (mg/1) =
34
24 . Grease and Oil in Sewage
To 500 ml of sewage in a 1000 ml beaker, 125 g of sodixim
chloride and 5 ml of concentrated HCl were added. The solu
tion was allowed to stand for 24 hours. To the sample,
10 g of asbestos were added and stirred. The sample was
then poured through an ashless filter paper {11 cm, Whatman
No. 40) in a Buchner funnel. The filter and sample was
placed in a Soxhlet extraction thimble. The Buchner funnel
90
-------
and beaker were wiped out with a cotton ball soaked with
hexane which was added to the thimble. The thimble was
placed in a Soxhlet extraction tube and placed over a 300
ml flat bottomed flask (previously dried and weighed) con-
taining 200 ml of hexane. The top of the extraction tube
was connected to the bottom of a reflux condenser. The
sample was refluxed for 4 hours. The tube was removed and
hexane distilled off. The flask and remaining residue was
again weighed. The second weighing was subtracted from
the first.
_ j • -I / /-i \ rag increase in weight of flask X 1000
Grease and oil (mg/1) = -2 - ml sample used -
25. Grease Content of Sludges
A 20 g sample of sludge was weighed in a beaker and one
ml of HC1 was added. Previously dried magnesium sulfate
monohydrate was added and mixed. The sample was transferred
to a Soxhlet extraction thimble and extracted with hexane
into a previously dried and weighed 300 ml flat -bottomed
flask. After 4 hours of extraction the hexane was distilled
from the flask which was dried in a desiccator and weighed.
Grease (% drv solids) - gain in weight of flask (g) x 100
Grease (% dry solids) - weight of wet solids (g) X dry solids (%)
26 . Hydrocarbon and Fatty Matter Content of Grease
Into the flask used for the grease analysis 70 ml of hexane
was poured, 10 ml at a time. Each 10 ml portion of hexane
was passed through an adsorption column of activated alumina
and collected in a tared flask. The hexane was distilled
from the flask which was then cooled in a desiccator and
weighed.
Hydrocarbon (%) = A XTa100
where A = increase in weight of flask (mg)
B = total grease (mg)
91
-------
27. Total Coliform Group37
One ml of final effluent was filtered through a sterile
47 iron diameter 0.45 micron filter. This filter was then
plated on previously prepared M-Endo broth and incubated
in air for 24 hours at 35.5°C. Round colonies with a green
sheen were counted and reported as colonies per 100 ml of
sample.
n~i ~- o t*n /inn ™i ^ colonies counted X 100
Colonies (no./lOO ml) = filtered sample (ml)
38
28. Fecal Coliform Group
A ten ml sample was filtered through a sterile 47 mm diameter
0.45 micron filter. This filter was plated on previously
prepared MFC broth and incubated at 44.5°C for 24 hours
in a water bath. The blue colonies were counted and reported
as colonies per 100 ml of sample.
n^ r,-; o r«« /inn ™i ^ colonies counted x 100
Colonies (no./lOO ml; = ,.. -, . 3 * -,—s-r—
/ filtered sample (ml)
39
29. Fecal Streptococcal Group
A 20 ml sample was filtered through a sterile 47 mm 0.45
micron filter. The filter was plated on previously prepared
KF Streptococcus agar and incubated for 48 hours at 35.5°C
in air. The red colonies were counted and reported as colonies
per 100 ml of sample.
_, n . , /inn -11 colonies counted X 100
Colonies (no./lOO ml) = filtered sample (ml)
92
-------
APPENDIX B
PROBABILITY ANALYSIS
A series of observations collected for a given system under
various conditions or at various times can be arranged in
increasing order of magnitude to form an array of values
that can be analyzed using conventional statistical methods.
The cumulative occurrence of any one observation can be
expressed as a percentage less than or equal to the numerical
value of that observation. The cumulative frequency for
a normal population of values then can be plotted as a sym-
metrical S-shaped curve. By the use of a special probability
scale this curve can be transformed into a straight line.
This linear form is particularly convenient for the determination
of certain statistical parameters such as the mean and standard
deviation.
The statistical mean of a given set of data is the intercept
of the linearized cumulative probability plot at the 50
percent occurrence level. The statistical mean will approach
the arithmetical mean as the data become more normal. The
standard deviation of the data is the slope of this line.
Departure from a straight line on the normal probability
plot is a sign of skewness of another type of statistical
distribution. It should be emphasized that the standard
deviation of such data is usually meant as a deviation from
the mean occurrence and not a deviation from a mean analysis.
For example, total phosphorus might occur 5.6 + 2.3 mg P/l
within averaged analyses for a population of 30 samples
but range 3.3 + 0.2 mg P/l within a series of replicate
analyses on a single sample of this population. The deviation
of occurrence is usually much larger than the deviation
of analysis. A population of a dozen or more values is
usually required for the statistical analysis to be significant.
For very large populations the data can be grouped within
consecutive ranges of values.
93
-------
The following procedure was followed in developing a statis-
tical analysis of data assumed to follow a normal form.
1. Arrange the n-values of data (sample number = i = 1,2,..
....,n) in a table by increasing numerical order.
2. Determine the cumulative percentages of occurrence as
the quotient 100i/(n+l).
3. Plot the data at the appropriate cumulative percentages
of occurrence on probability paper.
4. Establish the line of best fit using a least-squares
procedure.
5. Determine the statistical mean as the intercept at the
50 percent occurrence level.
6. Determine the standard deviation as the difference be-
tween the mean (50 percent occurrence level) and either
the 84.13 percent or the 15.87 percent occurrence level.
The mean and standard deviation of parameters such as sus-
pended solids, biochemical oxygen demand, total phosphorus,
etc., can be determined quite easily using graphical techni-
ques. Differences between influent and effluent values
of a given parameter for two distinct populations, such
as two influents or two effluents, can be distinguished
readily by overlaying the appropriate probability plots
if consistent scales are used. Most populations of data
of the various parameters of waste treatment expressed in
absolute units are normally distributed and lead to well-
behaved linear correlations.
94
-------
Although corresponding separate populations of influent
and effluent values may lead to linear plots, the differ-
ence between them, expressed as a dimensionless ratio or
percent removal, may be skewed. This condition is most
prevalent as the removals asymptotically approach 100 per-
cent. Removals less than 0 percent or greater than 100
percent usually are indicative of analytical or sampling
errors, or of unusual occurrences within the treatment plant
such as operational upsets or intermittent internal flows.
For certain parameters the data alternatively may be as-
sumed to follow a logarithmic normal probability distribu-
tion or some other skewed distribution.
Probability plots of normal data were created by a customized
computer program using the IBM 1130 Computing System and
an IBM 1627 plotter. The means and standard deviations
were determined by fitting the data using a least squares
procedure. The program provided fast, accurate, and con-
venient statistical analyses and simultaneous graphical
presentations.
The data for each period for each variable at each location
were plotted using normal probability coordinates resulting
in a maximum of 14 graphs for each period. Those days for
which the concentrations of either treatment chemical, ferric
iron or PURIFLOC A23 flocculant, were greater than one standard
deviation from the fitted least squares line were discarded.
Those days for which two or more combined analyses of biochem-
ical oxygen demand, suspended solids, any of the five phos-
phorus species, or any five metals for a given day exceeded
this deviation were also discarded. These deviant data
usually occurred when chemical feed pumps were started up
or shut down, or when severe disruptions in plant operation
occurred. Chemical/physical equilibrium could not always
be assured during the first and last days of a given period
of study.
95
-------
The total days listed in Table B-l, therefore/ were reduced
by this selection process. The number of good and bad days
represent the maximum possible in each category. Occasional
missing data reduce these numbers further for individual
variables. Greater than 80 percent of the available data
in almost all periods was considered to be statistically
representative of those values expected during normal plant
operation.
96
-------
TABLE B-l
PERIODS OF STUDY
PERIOD
Beginning
Ending
Total Days
Good Days
Bad Days
% Good
1
07-01-69
182
06-30-70
546
365
-
-
-
2A
11-03-70
672
02-25-71
786
115
84
31
73
2B
05-10-71
860
05-25-71
874
15
12
3
80
2C
06-07-71
888
10-20-71
1023
136
112
24
82
2D
12-16-71
1080
12-29-71
1093
14
10
4
71
2
11-03-70
672
12-29-71
1093
280
218
62
78
3
10-21-71
1024
12-09-71
1073
50
46
4
92
4
12-10-71
1074
12-15-71
1079
6
5
1
83
5A
04-12-72
1198
05-09-72
1225
15
12
3
80
5B
04-18-72
1204
04-30-72
1216
13
12
1
92
6
05-10-72
1226
06-03-72
1250
25
22
3
88
7
09-09-71
982
09-13-71
986
5
5
-
-
8
01-01-73
1462
02-28-73
1520
59
45
14
76
Period 1 No Chemical Treatment
Period 2 Metal + Flocculant Addition to Primary
Period 3 Metal Addition Only to Primary
Period 4 Split Addition of Metal to Both Primary and Secondary + Flocculant Only to Primary
Period 5 Metal Addition Only to Secondary
Period 6 Metal + Flocculant Addition to Secondary
Period 7 Metal + Anionic Flocculant Addition to Primary + Cationic Flocculant Addition to Secondary
Period 8 Split Addition of Metal to Both Primary and Secondary + Flocculant Addition Only to Secondary
-------
APPENDIX C
LISTINGS OF TABULATED DATA
Listings of tabulated data are included in Table C-l. The
complete tabulations of over 58,000 individual values are
too detailed for this report.
Representative listings of all available forms for December
1970 are included for illustration. Missing or incalculable
data are designated by asterisks (*).
98
-------
TABLE C-l
LISTINGS OF TABULATED DATA
Definition
Months
inclusive Days
vo
Phosphorus Species, Raw Influent
Phosphorus Species, Primary Effluent
Phosphorus Species, Final Effluent
Iron, BOD, and Suspended Solids
Metal Removals
Weir Overflow Rates and Total Phosphorus Levels
38 182-1277, 1462-1520
38 182-1277, 1462-1520
38 182-1277, 1462-1520
38 182-1277, 1462-1520
38 182-1277, 1462-1520
20 672-1277
-------
o
o
FERRIC CHLORIDE AND ORGANIC POLYELECTROLYT6S FOR THE REMOVAL HF PHOSPHORUS
GRAMT NO. 11010 6NK, GRAND RAPIDS, MICHIGAN.
PHOSPHORUS SPECIES FOR DECEMBER, 1970, PERIOD 2, RAW INFLUENT
OAYPMOY FLOW FE + 3 FLOC OP PP SP XP TP DP/IP PP/TP SP/TP XP/TP
7002120
7012120
7022120
7032120
7042120
7052120
7062120
7072120
7082120
7092120
7102120
7112120
7122120
7132120
7142120
7152120
7162120
7172120
7182120
7192120
7202120
7212120
7222120
7232120
7242120
7252120
7262120
7272120
72B2120
7292120
7302120
50.2
43.9
42.9
47.0
40.7
39.1
45.2
45.0
45.9
45.2
44.6
46.8
41.0
47.0
46.7
46.1
49.1
49.2
53.2
44.9
48.2
50.8
49.2
43.4
38.0
38.7
38.2
4^.7
46.0
44.8
41.3
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
0.18
0.33
0.42
0.31
0.25
0.15
0.40
0.32
0.32
0.32
0.30
0.38
0.31
0.43
0.20
0.31
0.31
0.33
0.33
0.33
0.32
0.33
0.31
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.31
1.00
1.80
1.90
1.60
2.00
1.65
1.30
1.90
1.60
1.30
1.50
2.40
2.30
1.80
1.50
1.40
1.40
1.20
1.50
1.75
1.45
1.30
1.30
1.20
1.30
0.95
1.45
0.20
1.40
0.70
1.45
3.00
1.60
1.30
2.60
4.60
3.35
2.90
2.10
0.0
2.30
4.60
3.20
4.10
2.20
1.90
1.50
1.80
4.00
2.50
2.25
3.35
2.10
2.10
4.10
2.10
3.55
2.75
0.80
2.60
1.70
3.85
4.00
3.40
3.20
4.20
6.60
5.00
4.20
4.00
1.60
3.60
6.10
5.60
6.40
4.00
3.40
2.90
3.20
5.20
4.00
4.00
4.80
3.40
3.40
5.30
3.40
4.50
4.20
1.00
4.00
2.40
5.30
0.80
4.00
3.40
1.10
2 .60
2.80
3.00
1.60
5.60
3.30
0.0
1.30
1.60
2.40
2.40
2.90
2.90
0.40
2.10
7.20
0.0
3.00
3.00
1.60
1.10
2.10
1.60
7.00
2.40
4.60
0.80
4.80
7.40
6.60
5.30
9.20
7.80
7.20
5.60
7.20
6.90
6.10
6.90
8.00
6.40
5.80
5.80
6.10
5.60
6.10
11.20
4.80
6.40
6.40
6.90
4.50
6.60
5.80
8.00
6.40
7.00
6.10
0.208
0.243
0.288
0.302
0.217
0.212
0.181
0.339
0.222
0.188
0.246
0.348
0.288
0.281
0.259
0.241
0.230
0.214
0.246
0.156
0.302
0.2Q3
0.203
0.174
0.289
0.144
0.250
0.025
0.219
0.100
0.238
0.625
0.216
0.197
0.491
0.500
0.429
0.403
0.375
0.0
0.333
0.754
0.464
0.512
0.344
0.328
0.259
0.295
0.714
0.410
0.201
0.698
0.328
0.328
0.594
0.467
0.538
0.474
0.100
0.406
0.243
0.631
0.833
0.459
0.485
0.792
0.717
0.641
0.583
0.714
0.222
0.522
1.000
0.812
0.800
0.625
0.586
0.500
0.525
0.929
0.656
0.357
1.000
0.531
0.531
0.768
0.756
0.682
0.724
0.125
0.625
0.343
0.869
0.167
0.541
0.515
0.208
0.283
0.359
0.417
0.286
0.778
0.47«
0.0
0.188
0.200
0.375
0.414
0.500
0.475
0.071
0.344
0.643
0.0
0.469
0.469
0.232
0.244
0.318
0.276
0.875
0.375
0.657
0.131
HF OFf.FKRFR . 1970
-------
FFRRTC CHLORTOF. AM) ORGANIC POL YEL ECTROL YTES FOR THE REMOVAL OF PHOSPHORUS
NO. noin F.NK, GRAMD RAPIOS, MICHIGAN
?, PKl EFFLUENT
OAYPtfOY
7002120
7012120
7022120
7032120
7042120
7052120
7062120
7072120
7082120
7092120
7102120
7112120
7122120
7132120
7142120
7152120
7162120
7172120
7182120
7192120
7202120
7212120
7222120
7232120
7242120
7252120
7262120
7272120
7282120
7292120
7302120
F|_0 1*
50.2
43.9
42.9
47.0
40.7
39.1
4 5. -2
45.0
45.9
'45.2
44.6
46. «
41.0
47.0
46.7
46.1
49.1
49.?
53.?
44.9
4«.7
50. «
49.2
43.4
3«.0
38.7
38.?
44.7
46.0
44.8
41.3
FE+3
17.19
I7.io
17.19
1 7 . 1. 9
17.19
17.19
17.19
17.10
17.19
17.19
17. IP
17.19
17.19
17.19
17.19
17.19
17.19
1 7 . 1 o
17.1^
17.19
17.19
17.10
17.19
17.19
17.19
17.19
17.19
17.19
17.].o
17.19
17.19
• FI.OC
0.18
0 . 3 3
0.42
0.31
0.25
0.15
0.40
0.32
0.32
0.32
0.30
0.3R
0.31
0 .43
0.20
0.31
0.31
0.33
0.33
0.33
0.32
0.33
n.31
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.31
OP
0.01
0.20
0.70
0.01
0.40
0.30
0.01
0.15
0.30
0.15
0.01
0.01
0.40
0.55
0 . n 0
O.RO
0.9S
0.20
0.30
0 .20
0.70
"0.20
0. 20
n . 40
0.15
0.20
0.15
0. 55
0.45
1.45
0.15
PP
1.59
0.0
0.60
0.49
0.40
0.70
0.79
O.H5
0.50
1.4S
2.39
0.09
1.70
0.7S
1.80
1 . 60
1.45
\.un
0.70
0.30
2.20
0.60
0.60
0.40
0.05
0.30
0.05
0.45
1.35
1.95
0.35
SP
1 .60
0.20
1.30
0.50
0. 80
1 .no
0. 80
1.00
0.80
1.60
2.^0
l.on
'.10
O.HO
2.60
2.40
? .40
1 .60
1 .00
0 . 50
2.90
0. RO
0.80
0.80
0.20
o.so
0.20
1.00
1.80
3 .40
0.50
XP
1.60
2 .70
0.80
1 .30
1.30
O.RO
1 . 60
0.0
1.30
1 .00
0.0
2.20
1.10
1 .00
0.80
1. .30
O.RO
0.0
0.80
I .30
o.o
7 .60
2.60
n . HO
0.80
0.50
1 .90
1.10
1 . 60
1. . 1 0
1 .30
TP
3.20
2.90
2.10
1 .80
2. 10
1.80
2.40
1.00
? . 1 r<
? .60
2.40
3.20
3.20
1 .RO)
3.40
3.70
3.20
1 .60
1 .80
1.80
? .90
3.40
3.40
1 .60
1 .00
1 .00
2.10
2.10
3.40
4.50
1 .80
OP/TP
0.003
0 .069
0.333
0.006
0. 190
0.167
0.004
0.150
0.]>3
0 .OSS
0.004
0.003
0.125
0 .306
0. ?35
0.21.6
0.297
0.125
0.167
0.111
0.241
0 .059
0.059
0 .250
0. 150
0 .700
0.071
0.262
0.132
0 .322
0 . 0 4 3
PP/TP
0.497
0.0
0.286
0.272
0.190
0.389
0.329
0.850
0.23H
0.558
0.996
0.309
0.531
0.139
0.5? 9
0.43?
0.453'
O.R75
0.389
0.167
0.759
0 . 1 7 ft
0 .176
0..750
0.050
0.300
0.024
0 . 2 1 4
0.397
0.433
O . 1 9 A
S P / T P
0.500
0.069
0.619
0.278
0.381
0.556
0.333
1 .000
0.3P1
0.615
1 .000
0.31 3
0.656
O.4V+
0.765
0.
-------
o
Kl
CHLORIDE AND ORGANIC POLYELECTROLYTES FOR THF REMOVAL OF PHOSPHORUS
NO. 11010 ENK, GRAND RAPIDS, MICHIGAN
SPECIES FUR DECEMBER, 1970, PERIOD ?, FIN EFFLUENT
OAYPMDY FLO*' FE + 3 FU)C HP PP SP XP TP OP/TP PP/TP SP/TP XP/TP
7002120
7012120
7022120
7032120
7042120
7052120
7062120
7072120
7082120
7092120
7102120
7112120
7122120
7132120
7142120
7152120
7162120
7172120
7182120
7192120
7202120
7212120
7222120
7232120
7242120
7252120
72*2120
7272120
7282120
7292120
7302120
50.2
43.9
42.9
47.0
40.7
39.1
45.2
45.0
45.9
45.2
44.6
46. R
41.0
47.0
46.7
46.1
49.1
49.2
53.2
44.9
48.2
50.8
49.2
43.^
38.0
38.7
3«.2
44.7
4fr.O
44.8
41.3
17.19
17.19-
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
0.18
0.33
0.42
0.31
0.25
0.30
0.70
0.45
0.15
0.15
2.30
0.10
0.85
0.65
0.65
0.15************
0.40
0.32
0.32
0.32
0.30
0.38
0.31
0.43
0.20
0.31
0.31
0.33
0.33
0.33
0.32
0.33
0.31
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.31
0.45
0.70
0.15
0.15
0.01
0.01
0.45
1.00
0.70
1.40
1.20
0.30
0.40
0.15
0.30
0.45
0.45
0.45
0.15
0.20
0.30
0.40
1.10
0.70
0.30
2.75
0.10
2.25
1.45
0.79
0.19
0.35
1.10
0.60
1.00
1.20
0.70
0.90
0.35
I. 00
0.75
0.75
0.35
0.05
0.0
O.?0
0.40
1.00
1.10
0.50
2.60
0.80
1.30
0.80
0.80
0.20 '
3.20
0.80
?.40
1.60
0.80
0.20
0.80
2.10
1.30
2.40
2.40
1.00
1.30
0.50
1.30
1.20
1.20
0.80
0.20
0.20
0.50
0.80
2.10
1.80
0.80
0.30
2.60
0.50
1.30
2.10
3.00
1.30
0.0
0.20
0.20
0.80
0.30
0.80
0.50
0.80
0.50
0.20
0.0
0.30
0.80
0.70
0.40
0.40
0.20
0.60
0.60
0.0
0.50
0.50
0.80
0.50
2.90
3.40
1.80
2.10
2.90
0.103
0.20.6
0.250
f ' . 0 7 1
0.052
0.793
0.029
0.472
0.310
0.224
3.20************
4.50
0.80
2.60
1.80
1.60
O.SO
1.60
2.60
2.10
2.90
?.60
1.00
1.60
1.30
2.00
1.60
1.60
1.00
0.80
0.80
0.50
1.30
2.60
2.60
1.30
0.100
0.875
0.058
0.083
0.006
0.020
0.281
0.385
0.333
0.483
0.462
0.300
0.250
0.115
0.150
0.281
0.281
0.450
0.187
0.250
0.600
0.308
0.423
0.269
0.231
0.611
0.125
0.865
0.806
0.494
0.380
0.219
0.4?3
O.P86
0.345
0.462
0.700
0.563
0.269
0.500
0.469
0.469
0.350
0.063
0.0
0.400
0.308
0.385
0.423
0.385
0.897
0.?35
0.722
0.381
0.276
0.063
0.711
1.000
0.923
0.889
0.500
0.400
0.500
0.808
0.619
0.828
0.923
1.000
0.812
0.385
0.650
0.750
0.750
0.800
0.250
0.250
1.000
0.615
0.808
0.692
0.615
0.103
0.765
0.278
0.619
0.724
0.937
0.289
0.0
0.077
0.111
'0.500
0.600
0.500
0.192
0.381
0.172
0.077
0.0
0.188
0.615
0.350
0.250
0.250
0.200
0.750
Q.750
0.0
0.385
0.192
0.308
0.385
OF DECEMBER, 1970
-------
OAY = OAY OF MONTH
P = PERIOD OF STUDY
I = PERIOD OF NO CHEMICAL TRFATMFNT
? = PERIOD OF METAL + Fi.OCCIM.ANT 4ODITIOM
3 = PERIOD OF METAL ADDITION ONLY TO PRI-IA
4 = PERIOD OF SPLIT ADDITION OF MFTAi. TO H
5 = PERIOD OF METAL ADDITION ONLY in SFOIM
6 = PERIOD OF METAL + FI.OCCULANT MKIITIOM
7 = PERIOD OF METAL + ANIONJC FLnr.oii'. A«IT A
8 = PERIOD OF "SPLIT ADDITION OF MFTAL T'l a
MO = MONTH
Y = YEAR
FLOW = DAILY AVERAGE FLOW, «GD
FE-t-3 = FERRIC IRON, MG/L
FLOC = PURIFLOC A?3 FLOCCIJL ANT, MG/L
OP = ORTHO PHOSPHORUS, MC,/t_
PP = POLY Pi MG/L (Pp = SP - (1P)
SP = SOLOR'.E P, MG/L
XP = SUSPENDED P, MG/L (XP = TP - SP)
TP = TOTAL P, MG/L
TO PHI'-'A-tY
RY
UTH QUINARY +
IMHY
in SFCO^DARY
-,lli\ll)/V
-------
FERRIC CHLORIDE AND ORGANIC POLYELECTROLYTES FOR.-JHE REMOVAL DF PHOSPHORUS
GRANT NO. 11010 ENK, GRAND RAPIDS, MICHIGAN
IRON, BOD, AND SUSPENDED SOLIDS FOR DECEMBER, 1970 , PERIOD 2
DAYPNOY FLOW FE+3 FLOC FEO FE1 FE2 PRFE ORFE 80DO ROD1 BOD2 PRBO ORBD SUSO SUS1 SUS2 PRSS ORSS
7002120
7012120
7022120
7032120
7042120
7052120
7062120
7072120
7082120
7092120
7102120
7112120
7122120
7132120
7142120
7152120
7162120
7172120
7182120
7192120
7202120
7212120
7222120
7232120
7242120
7252120
7262120
7272120
7282120
7292120
7302120
50.2
43.9
42.9
47.0
40.7
39.1
45.2
45.0
45.9
45.2
44.6
46.6
41.0
47.0
46.7
46.1
49.1
49.2
53.2
44.9
48.2
50.8
49.2
43.4
38.0
38.7
38.2
44.7
46.0
44.8
41.3
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
0.18 0.08 1.10 0.70*****-775. 103. 43.
0.33 1.10 0.35 0.30 68. 73. 98. 35.
0.42 2.65 0.32 0.68 88. 74. 100. 35.
13.
17.
14.
58.
64.
65.
87.
83.
86.
0.31 1.12 1.45 1.25 -29. -12 .*************************
0.25 0.69 1.68 0.92-143. -33. *************************
0.15 0.35 1.15 0.79-229. -126. *************************
0.40 1.08 1.18 1.35 -9. -25. 98. 39.
0.32 1.52 0.45 0.82 70. 46. 96. 35.
0.32 1.45 1.32 1.00 9. 31. 110. 45.
0.32 0.55 0.43 0.35 22. 36. 113. 58.
0.30 2.36 ?.00 0.81 15. 66. 116. 34.
0.38 0.55 3.71 1 . 15-575. -1 09. 79. 20.
0.31 1.77 1.97 1.05 -11. 41. 76. 40.
0.43 1.05 1.45 1.08 -38. -3. 91. 36.
0.20 1.78 0.31 0.35 83. 80. 105. 4fl.
0.31 3.33 1.92 0.75 42. 77. 93. 4S.
0.31 3.32 2.11 0.70 36. 7V. 85. SO.
0.33 0.85 0.64 0.27 25. 74. 94. 34.
0.33 0.35 0.40 0.32 -14. 9. 91. 40.
0.33 0.10 0.24 0.58-140. -480. 66. 33.
0.32 0.82 2.12 0.58-159. 29. 82. 46.
0.33 1.38 1.95 0.57 -41. 59. 108. 70.
0.31 2.61 3.60 0.88 -38. 66. 105. 70.
0.33 0.88 2.02 1.15-130. -31. 82. 44.
0.33 0.25 1.15 0.60-360. -140. 62. 26.
0.33 0.34 1.40 0.70-312. -106. 60. 21.
0.33 0.35 1.91 0.78-446. -123. 68. 34.
15.
17.
20.
14.
17.
22.
14.
21.
20.
27.
17.
21.
19.
10.
12.
11.
14.
20.
23.
12.
in.
60.
64.
59.
49.
71.
75.
47.
60.
S4.
52.
41.
64.
56.
50.
44.
35.
33.
46.
5fl.
6S.
50.
85.
82.
82.
88.
85.
72.
82.
77.
81.
71.
HO.
78.
79.
85.
85.
90.
R7.
76.
63.
80.
85.
0.33 1.20 1.25 0.90 -4. 25 .*********>!***************
0.33 3.40 2.33 1.21 31. 64. *************************
0.33 0.38 0.35 0.18 8. 53. 115. 58.
0.31 1.81 2.75 1.58 -52. 13. 95. 34.
28.
13.
50.
64.
76.
H6.
136.
116.
221.
102.
92.
72.
116.
111.
116.
113.
119.
131.
112.
113.
116.
108.
130.
104.
94.
64.
102.
121.
157.
72.
52.
95.
89.
129.
114.
112.
124.
40.
24.
38.
38.
43.
25.
30.
28.
45.
24.
49.
71.
61.
40.
48.
58.
52.
32.
30.
22.
55.
49.
67.
56.
31.
52.
52.
28.
50.
35.
55.
44.
37.
37.
31.
19.
17.
45.
33.
20.
15.
14.
20.
19.
28.
23.
24.
16.
19.
12.
11.
14.
15.
19.
8.
21.
9.
7.
27.
19.
19.
20.
71.
79.
83.
63.
53.
65.
74.
75.
61.
79.
59.
46.
46.
65.
59.
46.
60.
69.
68.
66.
46.
60.
57.
22.
40.
45.
42.
78.
56.
69.
56.
68.
68.
83.
70.
79.
76.
61.
70.
83.
87.
88.
85.
83.
75.
80.
78.
88.
82.
87.
83.
86.
88.
88.
89.
60.
91.
92.
79.
83.
83.
84.
END OF RECORD FOR DECEMBER, 1970
-------
o
en
DAY = OAV OF MONTH
P = PERIOD OF STUDY
1 = PERIOD OF
2 = PERIOD OF
3 = PERIOD OF
* = PERIOD OF
5 = PERIOD OF
6 = PERIOD OF
7 = PERIOD OF
8 = PERIOD OF
MO = MONTH
Y = YEAR
FLOW = DAILY AVERAGE FLOW,
FE+3 =i FERRIC IRON, MG/L
FLOC = PURIFLOC FLOCCULANT, MG/L
FE = IRON, MG/L
BOO * BIOCHEMICAL OXYGEN DEMAND,
SUS = SUSPENDED SOLIDS, MG/L
0 = RAW INFLUENT
1 = PRIMARY EFFLUENT
2 = FINAL EFFLUENT
PR ~ PRIMARY REMOVAL,
OR = OVERALL REMOVAL,
NO CHEMICAL TREATMtNT
METAL + FLOCCULANT ADDITION TO PRIMARY
METAL ADDITION ONLY TO PRIMARY
SPLIT ADDITION OF METAL TO BOTH PRIMARY + SECONDARY + FLOCCULANT ADDITION ONLY TO PRIMARY
METAL ADDITION ONLY TO SECONDARY
METAL + FLOCCULANT ADDITION TO SECONDARY
METAL * ANIONIC FLOCCULANT ADDITION TO PRIMARY + CATIONIC FLOCCDLANT ADDITION TO SECONDARY
SPLIT ADDITION OF METAL TO BOTH PRIMARY + SECONDARY * FLOCCULANT ADDITION ONLY TO SECONDARY
MGO
MG/L
PER
PER
CENT
CENT
-------
FERRIC CHLORIDE AND ORGANIC POLYELECTROLYTFS FOR THE REMOVAL OF PHOSPHORUS
GRANT NO. 11010 ENK, GRAND RAPIDS, MICHIGAN
METAL REMOVALS FOR DECEMBER, 1970, PERIOD 7.
OAYPMOY CRO CR1 CR2 PRCR ORCR N10 Nil MI2 PRN1 ORNI CUO CU1 CU2 PRCU ORCU ZNO ZN1 ZN2 PRZN ORZN
7002120 0.70 0.60 0.25
7012120 1.82 0.80 0.10
7O22120 0.45 0.35 0.15
7032120 1.45 0.92 0.30
7042120 1.70 1.55 0.62
7052120 0.11 0.10 0.19
7062120 1.12 0.56 0.20
7072120 1.20 0.50 0.30
7082120 1.73 0.82 0.23
7092120 1.35 0.46 0.10
7102120 2.35 0.82 0.15
14.
56.
22.
37.
9.
9,
50.
58.
53.
66.
65.
7112120 0.20 0.50 0.20-150.
7122120 1.14 0.25 0.20
7132120 1.48 0.57 0.22
7142120 1.37 0.34 0.08
7152120 2.39 1.00 0.19
7162120 2.05 0.89 0.17
7172120 3.12 1.49 0.09
7182120 0.85 0.41 0.15
7192120 0.10 0.08 0.10
7202120 1.44 1.59 0.45
7212120 2.20 1.40 0.20
7222120 1.48 0.79 0.28
7232120 0.81 0.30 0.19
7242120 0.06 0.09 0.09
7252120 0.22 0.12 0.09
7262120 0.29 0.20 0.09
7272120 1.84 0.62 0.16
7282120 2.60 1.08 0.34
7292120 1.65 1.2B 0.05
7302120 1.45 0.45 0.18
78.
61.
75.
58.
57.
52.
52.
20.
-10.
36.
47.
63.
-50.
45.
31.
66.
58.
22.
69.
64.
95.
67.
79.
64.
-73.
82.
75.
87.
93.
94.
0.
82.
85.
94.
92.
92.
97.
82.
0.
69.
91.
81.
77.
-50.
59.
69.
91.
87.
97.
88.
0.90
1.42
0.98
1.25
0.97
0.59
1.40
1.45
1.42
0.99
5.26
0.74
3.36
.67
.59
.66
.52
.75
.08
0.35
0.88
1.90
1.56
1.10
0.18
0.60
0.69
2.37
2.31
7.10
1.40
0.92
0.98
0.74
1.05
0.85
0.56
1.20
1.16
1.21
0.96
3.03
3.35
1.27
1.16
1.31
1.51
1.19
1.43
1.30
0.58
1.45
1.41
1.35
1.05
0.92
0.93
1.04
1.00
0.91
0.65
1.05
1.09
1.21
1.17
1.67
-2
31
24
16
1?
5
14
20
15
3
4?
5.18-353
1.38
1.20
1.29
1.39
1.21
1.70
1.37
0.55
1.06
1.3H
1.80
1.18
6?
31
18
9
22
1H
-70
-66
-65
76
13
5
0.^7 0.78-131
0.60
0.65
1.48
1.96
1.86
1.60
0.47
0.75
1.25
2.09
1.40
1.95
0
6
38
15
11
-14
. -7.
. 35.
. -6.
. 20.
6.
. -10.
. 25.
. 25.
. 15.
. -IB.
68.
i-600.
. 59.
78.
. 19.
. 16.
. 70.
. 31.
. -77.
. -57.
. -20.
. 27.
. -15.
. -7.
.-333.
. 22.
. -9.
. 47.
. 10.
. 33.
. -39.
0.25
0.31
0.38
1.45
0.50
0.10
0.90
0.55
0.66
o.so
0.70
0.70
0.84
0.98
0.65
0.90
1.00
0.65
n.i?
0.0?
0.45
1. 10
1.70
0.71
0.12
0.21
0.18
0.95
2.00
0.35
0.70
0.25
0.14
0.18
0.80
0.40
0.22
0.50
0.22
0.36
0.19
0.32
0.44
0. ?O
0.56
0.3S
0.65
0.6O
0.35
0.15
0.02
0.55
0.50
1 . ?0
0.30
0.15
0.19
0.20
0.4H
1.35
0.73
0.55
0.17
0.24
0.26
0.95
0.57
0.
55.
53.
45.
20.
0.17-120.
0.50
0.47
0.58
0.32
0.50
0.39-
0.70
0.59
0.50
0.66
0.70
0.45
0.18
0.04
0.37
0.78
1.20
0.68
0.10
0.10
0.10
0.40
1.81
0.56
0.84
44.
60.
45.
62.
54.
120.
64.
43.
46.
28.
40.
46.
-25.
0.
-22.
55.
0.
-43.
-25.
10.
-11.
49.
32.
34.
21.
32.
23.
32.
34.
-14.
-70.
44.
15.
12.
36.
29.
-95.
76.
40.
23.
27.
30.
31.
-50.
-100.
18.
79.
0.
-274.
17.
52.
44.
58.
9.
-60.
-20.
1.20
1.20
1.30
1.51
0.90
0.45
0.85
0.85
0.90
0.50
1.00
2.70
0.87
3.80
2.00
3.00
4.10
1.05
0.50
O.44
0.76
2.77
2.10
0.56
0.35
0.45
0.25
0.87
1.15
0.43
0.85
0.69
0.50
0.52
0.86
0.75
0.55
0.50
0.35
0.45
0.20
0.58
0.80
0.60
0.75
0.65
1.45
0.75
0.80
0.66
0.45
0.75
1.10
1.05
0.85
0.60
0.50
0.55
0.35
0.65
0.30
0.78
0.45
0.39
0.65
0.86
0.71
0.51
0.50
0.33
0.44
0.25
0.38
0.71
0.35
0.45
0.44
0.74
0.55
0.75
0.52
0.50
0.54
0.55
0.90
1.02
0.55
0.50
0.45-
0.37
0.46
0.15
0.55
42.
58.
60.
43.
17.
-22.
41.
59.
50.
60.
42.
70.
31.
80.
67.
52.
87.
24.
-32.
-2.
1.
60.
50.
-52.
-71.
-IV.
120.
60.
43.
30.
8.
67.
67.
50.
43.
21.
-13.
41.
61.
51.
50.
67.
74.
60.
8P.
78.
75.
«7.
79.
-4.
-14.
29.
80.
57.
-87.
-S7.
-11.
-80.
57.
61).
65.
35.
END Of RECORD FOR DECEMBER, 1970
-------
DAY = DAY OF MONTH
P = PERIOD OF STUDY
1 = PERIOD OF NO CHEMICAL TREATMENT
2 = PERIOD OF METAL + FLOCCULANT ADDITION TO PRIMARY
3 = PERIOD OF METAL ADDITION ONLY TO PRIMARY
4 = PERIOD OF SPLIT ADDITION OF METAL TO BOTH PRIMARY + SECONDARY + FLOCCULANT ADDITION ONLY TO PRIMARY
5 = PERIOD OF METAL ADDITION ONLY TO SECONDARY
6 = PERIOD OF METAL + FLOCCULANT ADDITION TO SECONDARY
7 = PERIOD OF METAL + ANIONIC FLOCCULANT ADDITION TO PRIMARY + CATIONIC FLOCCULANT ADDITION TO SECONDARY
8 = PERIOD OF SPLIT ADDITION OF METAL TO BOTH PRIMARY + SECONDARY + FLOCCULANT ADDITION ONLY TO SECONDARY
MO = MONTH
Y = YEAR
CR = CHROMIUMt MG/L
NI = NICKEL, MG/L
CU = COPPER., MG/L
ZN = ZINC, MG/L
0 = RAM INFLUENT
1 = PRIMARY EFFLUENT
2 = FINAL EFFLUENT
PR = PRIMARY REMOVAL, PER CENT
OR = OVERALL REMOVAL, PER CENT
-------
hFRRIC CHLORIDE AND ORGANIC POLYELECTROLYTFS FOR THE REMOVAL OF PHOSPHORUS
O
oo
GRAMT NO. H010 ENK, GRAND RAPIDS, MICHIGAN
WEIR LOADING RATES AND TOTAL PHOSPHORUS LEVELS'FOR
DAYPMOY FLOW FE + 3 FLOC POVER SOVER RMTP
TPO
DECEMBER, 1970 , PERIOD 2
TP1 TP2 PRTP ORTP RATPL
7002120
7012120
7022120
7032120
7042120
7052120
T062120
7072120
7082120
7092120
7102120
7112120
7122120
7132120
7142120
7152120
7162120
7172120
7182120
7192120
7202120
7212120
7222120
7232120
7242120
7252120
7262120
7272120
7282120
7292120
7302120
50.2
43.9
42.9
47.0
40.7
39.1
45.2
45.0
45.9
45.2
44.6
46.8
41.0
47.0
46.7
46.1
49.1
49.2
53.2
44.9
48.2
50.8
49,2
43.4
38.0
38.7
38.2
44.7
46.0
44.8
41,3
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
17.19
0.18
0.33
0.42
0.31
0.25
0.15
0.40
0.32
0.32
0.32
0.30
0.38
0.31
0.43
0.20
0.31
0.31
0.33
0.33
0.33
0.32
0.33
0.31
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.31
1516.
1326.
1296.
1420.
1229.
1181.
1365.
1359.
1386.
1365.
1347.
1413.
1238.
1420.
1410.
1392.
1483.
1486.
1607.
1356.
1456.
1534.
1486.
1311.
1148.
1169.
1154.
1350.
1389.
1353.
1247.
1278.
1118.
1092.
1197.
1036.
996.
1151.
1146.
1169.
1151.
1285.
1490.
1305.
1496.
1487.
1328.
1250.
1253.
1355.
1143.
1227.
1294.
1253.
1105.
968.
985.
973.
1138.
1171.
1141.
1052.
3.58
2.32
2.60
3.24
1.87
2.20
2.39
3.07
2.39
2.49
2.82
2.49
2.15
2.69
2.96
2.96
2.82
3.07
2.82
1.53
3.58
2.69
2.69
2.49
3.82
2.60
2.96
2.15
2.69
2.46
2.82
4.80
7.40
6.60
5.30
9.20
7.80
7.20
5.60
7.20
6.90
6.10
6.90
8.00
6.40
5.80
5.80
6.10
5.60
6.10
11.20
4.80
6.40
6.40
6.90
4.50
6.60
5.80
8.00
6.40
7.00
6.10
3.20
2.90
2.10
1.80
2.10
1.80
2.40
1.00
2.10
2.60
2.40
3.20
3.20
1.80
3.40
3.70
3.20
1.60
1.80
1.80
2.90
3.40
3.40
1.60
1.00
1.00
2.10
2.10
3.40
4.50
1.80
2.90
3.40
1.80
2.10
2.90
3.20
4.50
0.80
2.60
1.80
1.60
0.50
1.60
2.60
2.10
2.90
2.60'
1.00
1.60
1.30
2.00
1.60
1.60
1.00
0.80
0.80
0.50
1.30
2.60
2.60
1.30
33.
61.
68.
66.
77.
77.
67.
82.
71.
62.
61.
54.
60.
72.
41.
36.
48.
71.
70.
84.
40.
47.
47.
77.
78.
85.
64.
74.
47.
36.
70.
40. -0.219
54. -0.338
73. -0.564
60. -0.402
68. -0.501
59. -0.387
37. -0.204
86. -0.845
64. -0.442
74. -0.584
74. -0.581
93. -1.140
80. -0.699
59. -0.391
64. -0.441
50. -0.301
57. -0.370
82. -0.748
74. -0.581
88. -0.935
58. -0.380
75. -0.602
75. -0.602
86. -0.839
82. -0.750
88. -0.916
91. -1.064
84. -0.789
59. -0.391
63. -0.430
79. -0.671
EWD OF RECORD FOR DECEMBER, 1970
-------
o
VD
DAY
P
1
2
3
7
R
MO
V
FLOW
FE + 3
FLOC
POVER
RMTP
TP
0
1
?
PR
OR
R4TPI
Til
PERIOD OF METAL
PERIOD OF METAL
DAY OF MONTH
PERIOD OF STOOY
PERIOD OF NO CHEMICAL TREATMENT
PERIOD OF METAL + FLOCCULANT ADDITION
PERIOD OF METAL ADDITION ONLY TO PRIMARY
PERIOD OF SPLIT ADDITION OF METAL TO RflTH PKIMARY
PERIOD OF METAL ADDITION ONLY TO
FLOCCULANT ADDITION TO
+ ANIOMC FLOCCULANT ADDITION TO
PERIOD OF SPLIT ADDITION OF METAL TO BOTH PRIMARY
MONTH
YEAR
DAILY AVERAGE FLOW, MGD
FERRIC IRON, W,/L
PORIFLOC A23 FLOCCULANT, MR/I.
PRIMARY OVERFLOW RATE, GAL/DAY/FT?
SECONDARY OVERFLOW RATE, RAL/i'AY/FT?
RATIO OF FERRIC IRON/HAW TOTAL P
TOTAL PHOSPHORUS, MG/L
RAW INFLUENT
PRIMARY EFFLUENT
FINAL EFFLUENT
PRIMARY RFMOVAL, PER CENT
OVERALL REMOVAL, PER CENT
LOG FRACTION TP RFMAINING IN F 1 '-'
+ SECONDARY + FLOCCIILANT ADDITION ONLY TO PRIMARY
• CAT IONIC FLOCCULANT ADDITION TO SECONDARY
• ^SECONDARY + FLOC.CULANT ADDITION ONLY TO SECONDARY
-------
SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
1. Report No.
w
FERRIC CHLORIDE AND ORGANIC POLYELECTROLYTES FOR THE
REMOVAL OF PHOSPHORUS
5. Kcpcn Date NOV. 1973
6,
8. V » ' • oat . •
Otto Green, et al.
Wastewater Treatment Plant
City of Grand Rapids
Grand Rapids, Michigan 49502
1BB043 21-ASO 07
11010 ENK
i;. s<-
Environmental Protection Agency
Environmental Protection Agency report
number EPA-670/2-73-103, February 1974.
The primary objective of this project was to demonstrate the feasibility and
economic practicability of chemical removal of phosphorus from municipal wastewater
in the 44 mgd (166,500 m3) activated sludge plant at Grand Rapids, Michigan. The
full-scale system for chemical phosphorus removal was implemented to meet water
quality criteria established by the gtate of Michigan. Ferric chlorine and polymer
flocculant were introduced into the raw wastewater flow by automated systems. During
the period of best performance when split dosage of chemicals was employed, residual
phosphorus concentrations of less than 1 mg/1 could be obtained. Total phosphorus
concentrations in the final effluent were related to final clarifier overflow rates.
The nature of the chemically precipitated sludge evolved by the process was also
evaluated relative to further chemical conditioning, vacuum filtration and
incineration.
^Municipal wastewater, ^Phosphorus removal, Biological treatment, Sludge disposal
^Chemical precipitation, ^Automatic control systems, Process efficiency
05D
19. Secustly CUss.
(Rertorti
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. O.C. 20240
E. F. Earth
NERC-Cincinnati
------- |