WATER POLLUTION CONTROL RESEARCH SERIES 12060 EZY 08/71
Complete Mix
Activated Sludge Treatment
of Citrus Process Wastes
U.S. ENVIRONMENTAL PROTECTION AGENCY
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WATER POLLUTION CONTROL RESEARCH SERIES
The Water Pollution Control Research Series describes
the results and progress in the control and abatement
of pollution in our Nation's waters. They provide a
central source of information on the research, develop-
ment, and demonstration activities in the Environmental
Protection Agency, through inhouse research and grants
and contracts with Federal, State, and local agencies,
research institutions, and industrial organizations.
Inquiries pertaining to Water Pollution Control Research
Reports should be directed to the Chief, Publications
Branch, Research Information Division, Research and
Monitoring, Environmental Protection Agency, Washington,
D. C. 20460.
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COMPLETE MIX ACTIVATED SLUDGE TREATMENT
OF CITRUS PROCESS WASTES
by
Winter Garden Citrus Products Cooperative
Winter Garden, Florida
for the
OFFICE OF RESEARCH & MONITORING
Environmental Protection Agency
EPA Grant No. 12060 EZY
August 1971
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - Price $1.25
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EPA Review Notice
This report has been reviewed by the Environmental Protection
Agency and approved for publication. Approval does not
signify that the contents necessarily reflect the views and
policies of the Environmental Protection Agency nor does
mention of trade names or commercial products constitute
endorsement or recommendation for use.
ii
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ABSTRACT
A full-scale, complete mixed activated sludge treatment system effec-
tively treats concentrated wastewater from the Winter Garden Citrus
Products Cooperative. The system was designed for an average daily
flow of 2.0 MGD and a BOD concentration of 2,000 rng/1. This process
has a BOD reduction capability of 99 percent; but it produces 0.5 to
0.6 pounds of waste sludge per pound of influent BOD. Unscheduled
discharge of orange oil and peel press liquor due to citrus processing
plant problems caused periodic reductions in treatment efficiency due
to foaming in the aeration system and solids carryover in the effluent.
Controlling the addition of nitrogen and phosphorus to the influent
of the nutrient deficient wastewater effectively controlled effluent
nitrogen and phosphorus concentrations. Control of pH was unnecessary
with the exception of periods of unscheduled discharge of low pH peel
press liquor.
Waste sludge was mixed with citrus peel and processed as a cattle feed
additive in the existing facilities. The waste activated sludge
represented approximately 1.5 percent of the total cattle feed produc-
tion on a dry weight basis. Treatment plant effluent was reused for
barometric leg and cooling water and was then discharged. Capital and
operating cost of the system averaged 1.5<£ per box of fruit processed
or 3.2<£ per pound BOD removed.
This report was submitted to fulfill EPA Grant No. 12060 EZY under
partial sponsorship of the Water Quality Office, Environmental Protec-
tion Agency.
m
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TABLE OF CONTENTS
Section Page
I CONCLUSIONS 1
II RECOMMENDATIONS 3
III INTRODUCTION 5
IV 1968-69 CITRUS PROCESSING SEASON 15
V 1969-70 CITRUS PROCESSING SEASON 43
VI KINETICS OF SUBSTRATE UTILIZATION 63
VII WASTE TREATMENT SYSTEM CONSTRUCTION COST
AND TREATMENT COST 67
VIII ACKNOWLEDGMENTS 73
IX REFERENCES 75
X PUBLICATIONS 79
XI GLOSSARY 81
XII APPENDICES 85
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FIGURES
NUMBER PAGE
1 PROCESS FLOW DIAGRAM 8
2 WASTEWATER TREATMENT SYSTEM 13
3 INFLUENT AND BIOLOGICALLY TREATED EFFLUENT BOD
(SEMIMONTHLY AVERAGES - 1968-69 SEASON) 25
4 INFLUENT AND BIOLOGICALLY TREATED EFFLUENT COD
(SEMIMONTHLY AVERAGES - 1968-69 SEASON) 26
5 ACTIVATED SLUDGE PROCESS LOADING RATES
(SEMIMONTHLY AVERAGES - 1968-69 SEASON) 27
6 CHEMICALLY TREATED INFLUENT AND EFFLUENT BOD
(SEMIMONTHLY AVERAGES - 1968-69 SEASON) 35
7 CHEMICALLY TREATED INFLUENT AND EFFLUENT COD
(SEMIMONTHLY AVERAGES - 1968-69 SEASON) 36
8 MODIFIED WASTE TREATMENT SYSTEM 44
9 INFLUENT AND EFFLUENT TOTAL NITROGEN AND EFFLUENT AMMONIA
(SEMIMONTHLY AVERAGES - 1969-70 SEASON) 47
10 INFLUENT AND EFFLUENT TOTAL PHOSPHORUS
(SEMIMONTHLY AVERAGES - 1969-70 SEASON) 48
11 INFLUENT AND EFFLUENT ORTHOPHOSPHATE
(SEMIMONTHLY AVERAGES - 1969-70 SEASON) 49
12 FILTERED INFLUENT AND FILTERED EFFLUENT TOTAL PHOSPHORUS
(SEMIMONTHLY AVERAGES - 1969-70 SEASON) 50
13 FILTERED INFLUENT AND FILTERED EFFLUENT ORTHOPHOSPHATE
(SEMIMONTHLY AVERAGES - 1969-70 SEASON) 51
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FIGURES (Continued)
NUMBER PAGE
14 INFLUENT AND EFFLUENT BOD 55
(SEMIMONTHLY AVERAGES - 1969-70 SEASON)
15 INFLUENT AND EFFLUENT COD
(SEMIMONTHLY AVERAGES - 1969-70 SEASON) 56
16 ACTIVATED SLUDGE PROCESS LOADING RATES
(SEMIMONTHLY AVERAGES - 1969-70 SEASON) 58
17 SUBSTRATE REMOVAL VERSUS EFFLUENT BOD 64
18 SUBSTRATE REMOVAL RATE VERSUS TEMPERATURE 65
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TABLES
NUMBER PAGE
1 IMPLANT WASTEWATER STREAMS 11
2 AVERAGE WASTEWATER FLOW AND FRUIT PROCESSED 15
2s STATISTICAL ANALYSIS OF WASTEWATER FLOW AND FRUIT PROCESSED 16
3 AVERAGE AERATION TANK ANALYSES 19
3s STATISTICAL ANALYSIS OF AERATION TANK ANALYSES 20
4 AVERAGE ACTIVATED SLUDGE PROCESS LOADING RATES 23
4s STATISTICAL ANALYSIS OF ACTIVATED SLUDGE MONTHLY AVERAGE
PROCESS LOADING RATES 23
5 WASTE SLUDGE BLOWDOWN 24
6 WASTE ACTIVATED SLUDGE SOLIDS 29
7 SLUDGE PRODUCTION 30
7s STATISTICAL ANALYSIS OF SLUDGE PRODUCTION 30
8 AVERAGE ORGANIC AND SOLIDS ANALYSES OF INFLUENT AND
CHEMICALLY TREATED EFFLUENT 32
8s STATISTICAL ANALYSIS OF INFLUENT AND CHEMICALLY TREATED
EFFLUENT ORGANIC AND SOLIDS CONCENTRATIONS 33
9 LIME TREATMENT REMOVAL OF NUTRIENTS AND ORGANICS 37
9s STATISTICAL ANALYSIS OF LIME TREATMENT REMOVAL OF NUTRIENTS
AND ORGANICS 38
10 AVERAGE WASTEWATER FLOW AND FRUIT PROCESSED 45
10s STATISTICAL ANALYSIS OF WASTEWATER FLOW AND FRUIT PROCESSED 45
11 AVERAGE AERATION TANK ANALYSES 53
11s STATISTICAL ANALYSIS OF AERATION TANK ANALYSES 54
vm
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TABLES (Continued)
NUMBER PAGE
12 AVERAGE ACTIVATED SLUDGE PROCESS LOADING RATES 59
12s STATISTICAL ANALYSIS OF ACTIVATED SLUDGE PROCESS LOADING RATES 59
13 CONSTRUCTION COST BREAKDOWN 68
14 MANUFACTURERS OF MAJOR EQUIPMENT 69
15 OPERATION AND MAINTENANCE COST 71
16 WASTE TREATMENT COST 72
IX
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SECTION I
CONCLUSIONS
1. The complete mixed activated sludge process can effectively re-
move more than 99 percent of the BOD from concentrated citrus
processing wastewater.
2. When treating concentrated citrus wastewater by the complete
mixed activated sludge process, the waste sludge handling facil-
ities should be designed for 0.5 to 0.6 pounds of waste sludge
per pound of BOD in the raw waste. The recommended design
loading rate is 0.3 Ibs BOD/1b MLSS.
3. Effluent nitrogen and phosphorus concentrations can be effectively
regulated by controlling influent nitrogen and phosphorus concen-
trations added to the nutrient deficient wastewater.
4. Waste sludge can be mixed with citrus peel and processed in the
existing rotary kiln dryers as a cattle feed additive. Waste
activated sludge represented approximately 1.5 percent of the
cattle feed production on a dry weight basis.
5. The effluent of the waste treatment plant can be used in the
citrus processing plant for barometric leg and cooling water.
6. The discharge of orange oil and peel press liquor into the treat-
ment plant tends to reduce treatment efficiency by causing foaming
in and solids carryover from the activated sludge system. This is
partially due to the toxicity of D-Limonene and other organic
chemicals in orange oil and peel press liquor.
7. A solid bowl centrifuge proved to be ineffective for thickening
either activated sludge alone or activated sludge mixed with lime
sludge.
8. The capital and operating expense for the treatment system was
1.5<£ per box of fruit processed or 3.2<£ per pound of BOD removed
during the 1969-70 season. These costs are directly affected by
plant production as the plant does not operate at full capacity
on a continuous basis nor does it operate but a few months per
year.
9. The lime treatment unit proved to be unnecessary for nutrient
control but proved to be an effective treatment process for
removal of suspended and colloidal solids.
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SECTION II
RECOMMENDATIONS
The exact causes of foaming in the activated sludge process treating
citrus concentrate processing water need to be determined. If it is
found that foam causing chemicals cannot be eliminated from the waste-
water stream, methods of foam control need to be evaluated.
The factors which influence activated sludge settling rates need to
be evaluated. Methods of increasing settling rates need to be devel-
oped.
The cost of recovering activated sludge as a cattle feed additive
is directly related to the amount of moisture that must be removed
in a rotary kiln dryer. More economical methods of sludge thickening
and dewatering need to be developed.
This program has shown that large quantities of waste activated sludge
can be recovered along with pressed citrus peel as a cattle feed
additive. However, an investigation into the recovery of waste acti-
vated sludge alone as an animal feed is recommended due to its poten-
tial value as a high protein feed.
Further study of inplant processes should be conducted to reduce waste-
water concentration and flow and prevent discharge of orange oil and
peel press liquor into the waste treatment system.
Studies should be conducted to determine the effects of activated
sludge organisms on receiving waters.
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SECTION III
INTRODUCTION
OBJECTIVES
The original objectives of the grant were:
To determine the design and operating parameters for
lime treatment of effluent from an activated sludge
plant treating wastewater from a citrus processing
plant. This included loading rate of lime treatment
unit, lime doses required, and effect of starch on
settling of lime sludge.
To reuse the treated effluent in the citrus processing
plant. To determine in which inplant processes the
treated water was best suited for reuse.
To determine the efficiency of lime treatment for re-
moval of residual organic matter including nutrients.
This included determining-efficiency of removing BOD,
COD, suspended solids, phosphorus and nitrogen.
To determine design and operating parameters for
thickening waste sludge by centrifugation.
To determine suitability of waste sludge as a cattle
feed additive.
To provide an economical evaluation of the system.
The objectives listed above were those used to guide the research
effort during the 1968-69 citrus season. After the 1968-69 season
of operation, major revisions were made in the grant objectives.
During the 1969-70 season, the use of the lime treatment unit was
eliminated and all research associated with this process discontinued.
Major emphasis was placed on demonstrating the complete mixed acti-
vated sludge process for treating concentrated citrus processing water
and controlling effluent nutrient concentrations by controlling the
addition of nutrients to the nutrient deficient wastewater. Research
on the use of the centrifuge for dewatering sludge was de-emphasized
because of its poor performance in thickening a combination of lime
and activated sludge. With the exception of the previously mentioned
changes, the objectives for the 1969-70 citrus processing season were
the same as the 1968-69 season.
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BACKGROUND
Winter Garden Citrus Products Cooperative has been in operation at
its present location in Winter Garden, Florida, for over 25 years.
In early 1967, the Florida Department of Air and Water Pollution
Control cited the Cooperative for discharging essentially untreated
wastewater into Lake Apopka and stated that plans and a construction
schedule for an adequate waste treatment system, including nutrient
control, must be provided within approximately two months or an in-
junction would be sought to prevent the plant from operating during
the 1967-68 season.
Prior to this time, the citrus processing plant had made considerable
modifications inplant to segregate cooling and barometric leg water
from contaminated wastewater. An attempt had been made to treat the
concentrated wastewater during the 1966-67 season by chlorination.
Treatment of citrus waste by chlorination proved ineffective and costly.
Environmental Engineering, Inc., was retained, after the citation was
issued, to develop a waste treatment system and submit preliminary
plans and a construction schedule. A review of existing waste treat-
ment systems and previous research on citrus waste treatment was not
encouraging. The only successful method of citrus waste treatment at
that time was by land irrigation, such as that by Plymouth Citrus
Products, Inc., of Plymouth, Florida, where all of their wastewater
was being effectively disposed of by this method. This method presents
a potential threat to ground water supplies, however, and requires
large land areas which are seldom available. Land irrigation could
not be used for the Winter Garden Citrus Products Cooperative because
of the lack of available land. A waste treatment plant had been con-
structed in Leesburg, Florida, to treat the wastewater from the Minute
Maid citrus processing plant along with the city sewage. This type of
combined treatment could not be attempted at Winter Garden because the
city wanted nothing to do with citrus wastewater.
A waste treatment plant was under construction in Auburndale, Florida,
designed to treat the total flow of 30 MGD from two citrus processing
plants; this included barometric leg and cooling water. This type of
treatment process could not be used at Winter Garden because of the
limitations of available land.
It was decided to test, on a laboratory scale, the complete mixed
activated sludge process for treating the citrus processing waste-
water from Winter Garden Citrus Products Cooperative. A small con-
tinuous feed activated sludge unit was operated for a period of four
weeks in the laboratory. Results from this unit showed that, if the
wastewater pH was controlled and supplemental N and P were added, the
process would provide an effluent BOD less than 20 mg/1. Laboratory
work on lime precipitation was conducted on a batch basis by coagu-
lating effluent from the activated sludge process with a jar test
machine.
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Because of the time limitations set by the Florida Department of Air
and Water Pollution Control, a pilot plant study was not performed.
This meant that a full scale treatment plant had to be designed based
only on laboratory data. The excess sludge handling and centrifuge
dewatering systems were designed without any type of laboratory or
pilot plant data.
DESCRIPTION OF CITRUS PROCESSING PLANT
Fruit is brought into Winter Garden Citrus Products Cooperative pro-
cessing plant by large trailer trucks directly from the fields. The
trailers are unloaded and the fruit graded and placed in storage bins.
From the storage bins, fruit is moved as required by conveyor belt to
the fruit washers where dirt, sand, and other foreign matter is washed
from the fruit surface. This is the first source of wastewater in the
processing plant (see Figure 1). This wash water is passed through a
screen, as is all wastewater, and discharged directly to the waste
treatment plant.
The fruit is again graded, then sized and moved to the extraction
room. Three products, juice, peel, and cold press oil, result from
the extraction process. The extraction process is a major source
of wastewater, as the machines must be cleaned regularly with NaOH
and detergent to prevent a bacterial buildup. This wash water is
screened and discharged to the waste treatment plant.
Cold press oil, a mixture of orange oil and water, comes from the
extractors and is passed through centrifuges for removal of the
orange oil. The water discharged from the centrifuges still con-
tains a quantity of oil and is normally evaporated as it has an ex-
ceedingly high BOD. However, during times of overloading or mechan-
ical failure, it can find its way into the wastewater stream. This
waste is toxic in high concentrations and can cause severe foaming;
therefore, it can cause problems with the operation of an activated
sludge process.
Juice extracted from the fruit is concentrated by vacuum evaporation
then canned or placed in 55 gallon drums for storage and later can-
ning. Condenser water from the evaporators and wash water containing
citrus juice, NaOH, and detergent from the canning operation are the
major sources of wastewater going to the waste treatment plant from
the juice processing operation. After the juice has been put in
either drums or cans, it is cooled, then placed in cold storage for
later shipping. Cooling water for refrigeration equipment is dis-
charged untreated directly to Lake Apopka.
The third product from the extraction process is citrus peel. Peel
from the extraction process is moved by screw conveyor to the peel
bin. Drippings from the peel bin are pumped to the peel press liquor
storage tank. Peel is taken from the peel bin, has lime added to it,
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CENTRIFUGE
COLD
PRESS
OIL
ORANGE OIL
WATER TO EVAPORATOR
00
TO WASTE
TREATMENT
COOLING
WATER
DISCHARGED
UNTREATED
FIGURE 1 PROCESS FLOW DIAGRAM
(Continued on next page)
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PEEL
BIN
LIME
ADDITION
HAMMERMILL
AND/OR
SHREDDER
PUG
MILL
PEEL
SPILLAGE
TO WASTE TREATMENT
SHIPPING
STORAGE BAGGING
STORAGE
EVAPORATOR
BAROMETRIC-^-
LEG WATER
DISCHARGED
UNTREATED
CONDENSATE
TO WASTE
TREATMENT
FIGURE 1 (CONTINUED)
PROCESS FLOW DIAGRAM
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and then is passed through a hammer-mill or shredder. Next the peel
is run through a pug mill for mixing then pressed for the first time.
Peel press liquor is pumped from the press directly to a vacuum
evaporator or to storage for later evaporation. Condensate from the
molasses evaporator is discharged to the waste treatment plant. Baro-
metric water is discharged directly to Lake Apopka untreated as its
BOD is less than 10 mg/1. Molasses from the evaporator is put back
on the peel for recovery as a cattle feed additive or sold directly.
It is cheaper to remove peel press liquor from citrus and evaporate
it to molasses in a vacuum evaporator than to attempt to dry the peel
in the rotary dryers. After the peel is dried, it is bagged and
placed in storage for later shipment. Approximately 350 tons of dried
peel per day are produced for sale as a cattle feed additive at the
Winter Garden plant.
Two potential wastewater sources are from the peel press liquor and
oil mill water. Both of these wastewaters are normally concentrated
by vacuum evaporation and placed on pressed peel for recovery as a
cattle feed additive. These two wastes represent a large volume of
liquid and place a heavy load on the evaporators. In the event that
an evaporator becomes inoperative or cannot handle the volume produced,
these wastes overflow into the waste treatment system. Both the oil
mill water and peel press liquor have BOD's approaching 100,000 mg/1
and contain chemicals toxic to the activated sludge process. Frequently,
large volumes of these wastes were discharged with devastating results
on the waste treatment plant. Every effort should be made to prevent
these wastes from entering the waste treatment system as they can com-
pletely upset the treatment process.
It is extremely difficult to characterize the chemical composition and
flow rates of each of the waste streams. Plant production depends
upon the availability of fruit and varies widely during the processing
season. The Winter Garden Citrus plant may process from 10,000 to
60,000 boxes of fruit per day. Table 1 shows typical flows and BOD
concentrations during processing at plant capacity.
10
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TABLE 1
INPLANT WASTEWATER STREAMS
Source
Fruit Wash Water
Extraction Room
Juice Condenser
Water
Canning Room
Molasses Condenser
Water
Peel Press Liquor
Centrate Water From
Oil Centrifuge
BOD
(mg/1 )
100 -
600
1000 -
10,000
300 -
600
1000 -
10,000
500 -
1000
100,000
25,000
FLOW
(GPD)
150,000
100,000
450,000
40,000
350,000
--
--
Comments
Contains dirt and grit.
Characteristics depend
upon weather conditions
Intermittent wash water
No suspended solids.
Intermittent wash water
No suspended solids.
Spills
Spills
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DESCRIPTION OF TREATMENT PLANT (1968-69 Season)
Figure 2 shows a schematic of the Winter Garden waste treatment
plant as originally designed and operated during the 1968-69 season.
Plant design was based on a flow of 2 MGD and a BOD of 2000 mg/1.
Design criteria were based on laboratory tests and are shown below:
0.4 Ibs BOD/1b MLSS at 3500 MLSS
Nutrient Addition -- BOD:N:P of 100:20:1
02 Uptake Rate -- 50 mg/1 per hour maximum
Mechanical'Aerator Efficiency -- 2.2 Ibs 02/H.P.Hr. at 20°C
Clarifier Surface Loading Rate -- 700 Gal/ft /day
Lime Feed Rate -- 350 mg/1
Waste Lime Sludge -- 3 tons/day maximum
Waste Activated Sludge -- 0.4 Ibs/lb BOD removed
Nutrients were added in the form of phosphoric acid and anhydrous
ammonia. The pH was controlled with NaOH as required. Pre-screened
wastewater was pumped into two concrete aeration basins 144 feet in
diameter. Side water depth was approximately 12 feet. The original
design called for four 75 H.P. floating mechanical aerators, but
only three were installed due to the flow rate being less than was
originally expected. The aeration basins were designed so they could
be operated in series or parallel.
Effluent from the aeration basins flowed to a clarifier from which
return sludge was pumped back into the influent pipe to the aeration
basins. Effluent from the clarifier flowed to the lime treatment
tank then either back to the citrus plant for reuse or directly to
Lake Apopka. Waste sludge from the clarifier and lime treatment tank
were discharged to a wet well then pumped to a surge tank in the
citrus plant. The surge tank also served as a sludge thickening tank,
although it contained no mechanical thickening equipment. Thickened
sludge from the bottom of the surge tank was pumped to a solid bowl
centrifuge or placed directly on the pressed peel. The supernatant
liquor was returned to the plant influent and the solids cake mixed
with pressed citrus peel for recovery as a cattle feed additive.
The unique features of the waste treatment system design were several.
It was the only treatment plant in Florida treating concentrated
citrus processing plant wastewater alone. The effluent from the acti-
vated sludge plant was further treated for residual organic and nu-
trient removal by lime treatment. All effluent from the treatment
plant could be reused in the citrus plant and all waste sludge was to
be recovered as a cattle feed additive.
12
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pH ADJUSTMENT
NUTRIENTS
NPLANT REUSE
INFLUENTS
SLUDGE TO
DEWATERING
PROCESS
EFFLUENT
OVERFLOW
I. COMPLETE MIXED ACTIVATED SLUDGE TANKS
2. CLARIFIER
3. LIME TREATMENT
4. SLUDGE THICKENING TANK
5. CENTRIFUGE DEWATERING PROCESS
THICKENED
SLUDGE TO
FEED~MILL
FIGURE 2 WASTEWATER TREATMENT SYSTEM
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SECTION IV
1968-69 CITRUS PROCESSING SEASON
WASTEWATER FLOW AND FRUIT PROCESSED
During the 1968-69 citrus processing season, a daily record was kept
on the number of boxes processed and the volume of wastewater treated.
A record was kept also of the type fruit processed, i.e. grapefruit
or oranges. Wastewater flow was measured in a Parshall flume and
recorded on a flow chart as well as a totalizer meter.
Table 2 shows the average number and types of boxes of fruit processed
and the average wastewater flow per day for each month of operation
during the season. These averages include many days in which no fruit
was processed. Depending upon the availability of fruit, a processing
plant may either not operate at all, or operate one, two, or three
shifts per day up to seven days a week. Wastewater flow was not con-
tinuous throughout the season as frequently the plant was not in full
operation during the weekend and only clean-up crews were working. A
complete tabulation of daily wastewater flow and fruit processed may
be found in Table A-l of the Appendix.
TABLE 2
AVERAGE WASTEWATER FLOW AND FRUIT PROCESSED
Month
1969
January
February
March
April
May
June
Average
Daily Flow
MGD
0.98
0.87
0.61
0.87
1.10
1.00
Range
MGD
0.4 - 1.3
0.3 - 1.4
0.1 - 1.2
0.0 - 1.3
0.0 - 1.5
0.0 - 1.5
Average Daily
Fruit Processed
1000 Boxes*
47.2
41.2
16.1
24.9
44.0
36.4
Range
1000 Boxes
0.0
0.0
0.0
0.0
0.0
0.0
- 60.9
- 57.2
- 47.4
- 53.4
- 63.3
-61.5
* one box is 90 pounds of fruit
Data collected shows that for every box of fruit processed (90 pounds
of fruit) approximately 25 gallons of wastewater must be treated.
This wastewater had an average BOD of 1,170 mg/1, therefore, approxi-
mately 0.25 pounds of BOD for each box of fruit processed must be
treated. Data of this type should be used with caution when applying
it to other citrus processing plants as inplant process and water uses
vary widely from plant to plant.
15
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TABLE 2s
STATISTICAL ANALYSIS OF WASTEWATER FLOW AND FRUIT PROCESSED
PARAMETER DATA POINTS MEAN STANDARD DEVIATION
Wastewater Flow
Daily Values 157 0.89 MGD 0.42 M6D
Wastewater Flow
Monthly Averages 6 0.90 MGD 0.15 MGD
01 1000 Boxes of Fruit
Processed
Daily Values 157 33.2 22.9
1000 Boxes of Fruit
Processed
Monthly Averages 6 35.0 11.0
Number of days of zero flow = 6
Number of days of no fruit production = 34
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NUTRIENT ADDITION AND pH CONTROL
The original waste treatment plant design called for nutrient addition
in the form of anhydrous ammonia and phosphoric acid. Control of pH
was to be by addition of NaOH because of the expected low pH of the
wastewater. Ammonia and phosphoric acid were added by variable dis-
charge pumps set manually. Initially, there was no good method avail-
able to control the addition of nutrients to correspond to the wide
fluctuations of wastewater flow and strength because of the lack of a
quick method for determining nutrients in the treatment plant effluent.
Samples were collected and sent to Gainesville for nutrient analysis
in an auto-analyzer. By the time data was available, several days
had passed making this method unacceptable for controlling nutrient
addition. It became apparent that a simple test method would have
to be provided for the operators to run during plant operation. Test
kits were obtained which allowed the operators to run orthophosphate
and ammonia on each shift in a matter of minutes. These tests became
a part of the routine operation and an attempt was made to keep the
ammonia and orthophosphate in the complete mixed activated sludge
aeration tank at approximately 1.0 mg/1 each by increasing or de-
creasing the nutrient addition to the influent. Sampling the effluent
from the sludge clarifier will give erroneous results because the
activated sludge will release excess phosphate if held in the clari-
fier too long. Therefore, nutrient samples must be collected from
the aeration tank.
This method proved successful once the cause of the foaming problem
in the activated sludge process was determined. Table A-2 in the
Appendix gives the average pounds per day of nitrogen and phosphorus
added to the influent for each month. Table A-3 in the Appendix gives
the concentrations in monthly averages of daily nitrogen and phosphorus
in the influent after nutrient addition, and in the biologically treated
effluent. The last few weeks of the citrus season, when the waste treat-
ment plant was working perfectly, the ammonia nitrogen was usually less
than 0.5 mg/1, and the orthophosphate less than 1.0 mg/1. During this
period, the BOD to N ratio was 18 to 1 and the BOD to P ratio was 80
to 1. Therefore, when any nutrient deficient waste is being treated
by the complete mixed activated sludge process, the nutrient addition
and the resulting nutrient concentrations in the effluent can be con-
trolled by frequent nutrient analyses in the aeration tank.
Wastewater pH control was not found to be a problem as the pH was
much higher than expected, ranging from 7.0 to 8.5. This was partly
due to inplant clean-up with NaOH, and also the recycling of lime to
the influent from the sludge thickening tank and centrifuge. The only
time NaOH had to be added to the treatment system was after an unusu-
ally large amount of low pH (3.5 -- 4.5) peel press liquor had been
discharged to the waste treatment plant lowering the pH in the acti-
vated sludge process.
17
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ACTIVATED SLUDGE PROCESS OPERATIONAL PROBLEMS
Operational problems were caused by: (1) discharge of peel press
liquor, (2) discharge of water from the orange oil recovery system,
and (3) inability to waste sludge as desired. The first two prob-
lems were the most serious. It was not unusual to receive 25,000
to 50,000 gallons of press liquor over a short period of time. Peel
press liquor has a BOD of around 100,000 mg/1 and contains orange
oil and d-Limonene which, in high concentrations, are toxic to the
activated sludge process and also cause foaming. In general, when
a slug of peel press liquor was received, the aeration tank D.O. was
lowered drastically, the S.V.I, decreased and foaming occurred. This
resulted in solids overflowing the weirs into the lime treatment tank
significantly reducing the treatment efficiency.
Foaming was perhaps the major problem experienced with the activated
sludge process. Foaming occurred a considerable portion of the
citrus season to varying degrees and caused a reduction in treatment
efficiency for both the activated sludge process and the lime treat-
ment process. It was only during the latter part of the season that
the major cause of foaming was determined to be small quantities of
water from the oil recovery process being discharged into the treat-
ment plant on a continuous basis. As soon as all of this waste stream
was diverted to the evaporators and no excess press liquor was dis-
charged, the activated sludge process performed as designed.
AERATION TANK ANALYSES
Every two hours samples were collected from both aeration tanks to
determine the D.O., pH, MLSS, and SVI. Table 3 contains monthly aver-
ages of these results. Dissolved oxygen concentrations varied widely
during the research period depending upon the load applied to the
treatment plant and concentration of MLSS carried in the aeration
tanks. At times, the D.O. of the aeration tanks would be decreased
below the desirable minimum of 1.0 mg/1. This was due to the combi-
nation of high solids concentration in the tanks and reduced oxygen
transfer efficiency of the mechanical surface aerators as a result
of foam.
The pH of the mixed liquor varied from 7.0 to 8.3. Only when large
volumes of press liquor were discharged did the pH tend to decrease
and require NaOH to be added. The aeration basins were well buffered
and were able to tolerate considerable variation in influent pH with-
out marked influence because of the tremendous dilution capacity of
the complete mixed activated sludge process and its buffering capacity
18
-------
TABLE 3
AVERAGE AERATION TANK ANALYSES
North Aeration Tank
1969
January
February
March
April
May
June
July
MLSS
mg/1
1367
2999
4344
3228
3714
5566
5350
SVI
118
337
296
163
176
D.O.
mg/1
5.0
5.2
3.8
2.2
2.7
4.2
PH
7.3
7.7
7.8
7.6
7.6
7.7
7.8
MLSS
mg/1
1382
2990
3884
3092
3945
5916
5550
South Aeration Tank
SVI
133
334
262
161
171
D.O.
mg/1
5.2
4.5
6.2
3.9
1.7
2.4
3.9
PH
7.8
7.7
7.9
7.8
7.6
7.7
7.9
-------
ro
o
TABLE 3s
STATISTICAL ANALYSIS OF AERATION TANK ANALYSES
North Aeration
MLSS
mg/1
SVI
D.O.
mg/1
pH
Daily Figures
Monthly Averages
Daily Figures
Monthly Averages
Daily Figures
Monthly Averages
Daily Figures
Monthly Averages
Data
Points
142
7
97
5
150
6
154
7
Mean
3987
3795
231
218
3.76
3.85
7.68
7.64
Tank
Standard
Deviation
1592
1348
155
84
2.09
1.10
0.30
0.16
South Aeration Tank
Data
Points
138
7
82
5
151
7
154
7
Mean
3992
3823
229
212
3.72
3.97
7.69
7.77
Standard
Deviation
1596
1443
120
75
2.49
1.43
0.26
0.10
-------
The SVI, which is a measure of the settling rate of the sludge,
varied from 54 to over 800. It is interesting to note that, in
general, lower SVI values were found when the loading rate was in-
creased by the addition of peel press liquor. SVI values increased
to excessive values when water containing emulsified orange oil dis-
charged to the treatment plant and foaming problems resulted. After
the orange oil discharge was stopped, the SVI was consistently less
than 200. This allowed separation of the MLSS from the treated waste
and resulted in a very clear effluent.
MLSS varied considerably during the citrus season. Initially, the
aeration tanks were filled with well water and seeded with activated
sludge from the Leesburg plant. No problem was experienced during
start-up other than a light foam which disappeared as the MLSS con-
centration increased. MLSS concentrations increased to a high of
7,480 mg/1 without adverse effects. The major problem with control-
ling solids concentrations was the inability to waste solids as
desired. As long as orange oil was not discharged to the treatment
process and the SVI remained below 200, MLSS concentrations of 4,000
to 5,000 mg/1 were carried with no difficulty. When solid concen-
trations of this magnitude are carried, it is mandatory that adequate
aeration equipment be provided as well as sufficient clarification
capacity.
ACTIVATED SLUDGE PROCESS TREATMENT EFFICIENCY AND LOADING RATES
As previously mentioned, the activated sludge portion of the waste
treatment plant was designed to treat 2.0 MGD with a BOD of 2,000
mg/1. Aeration was to be provided by four 75 H.P. mechanical surface
aerators in each of the two aerator tanks. Only three 75 H.P. aer-
ators were provided for each tank, however, because the load was ex-
pected to be less than originally anticipated. The maximum and mini-
mum flows occurring in the plant were 1.5 and 0.0 MGD, respectively.
The maximum and minimum BOD concentrations applied were 3,300 and
270 mg/1, respectively.
Activated sludge loading rates varied from 0.014 to 0.378 pounds of
BOD per pound of MLSS. The average loading rate during the citrus
season was 0.143 pounds of BOD per pound of MLSS, which is within
the limits of the loading rates of the extended aeration process.
Maximum and minimum BOD concentrations in the effluent were 129 and
2.0 mg/1, respectively. The 129 mg/1 maximum, however, was due to
solids carryover from the clarifier. Only two 24-hour effluent com-
posites had greater than 100 mg/1 BOD. Figures C3 and C4 in the
Appendix show views of an aeration tank and the clarifier. Table A-4
in the Appendix presents monthly averages of the influent and effluent
BOD, COD, and solids analyses. The monthly averages of the loading
rates are shown in Table 4. The loading rates are presented in more
21
-------
detail in Table A-5 in the Appendix. Figure 3 shows the semimonthly
average influent and effluent BOD concentrations. Figure 4 shows
the semimonthly average influent and effluent COD concentrations.
Figure 5 shows the semimonthly average sludge loading rates.
The influent and effluent BOD concentrations over the entire season
averaged 1170 and 30 mg/1, respectively, for an average efficiency
of 97.5 percent. However, many problems experienced during the
season depressed the efficiency to this figure. A more realistic
picture of what the treatment plant can accomplish occurred in the
latter part of the season, during the period from June 4, to July 2,
1969, when the foaming problem had been solved. BOD values of the
influent and effluent averaged 1000 and 7 mg/1, respectively, during
these four weeks for a treatment efficiency of 99.3 percent.
Table A-4 shows that the suspended solids in the effluent of the bio-
logical treatment process were exceedingly high during a good portion
of the citrus processing season. This was attributed to two factors.
The first was that, in the original design concept, waste activated
sludge was to be wasted over the weirs and recovered with waste lime
sludge. It soon became evident that the lime tank was incapable of
removing large quantities of waste sludge, therefore, activated sludge
was wasted directly to the wet well bypassing the lime tank. The
second major factor was foaming. During a considerable portion of the
citrus season a heavy layer of foam existed on the aeration tanks.
This foam, at times, reached a depth of several feet. It was carried
through the clarifier to the lime treatment tank. The sludge claH-
fier was designed without a surface skimmer which allowed any floating
matter to overlfow the weir. This greatly increased the suspended
solids in the biologically treated effluent as, normally, the foam
would be skimmed and returned to the aeration tanks. The average sus-
pended solids in the clarifier effluent during the period from June 4
through July 2, when the complete plant was operating properly, was
only 12 mg/1.
WASTE ACTIVATED SLUDGE
Table 5 gives the monthly average volume per day of waste activated
sludge which was discharged to control the concentration of the MLSS
in the aeration basins. Waste activated sludge was mixed with waste
lime sludge in a wet well and pumped to a holding tank in the citrus
processing plant. FrequentT-y, a portion of this waste sludge was re-
cycled to the treatment plant because of the inability of the waste
sludge facilities to handle the solids discharged. This recycling
of solids made it almost impossible to determine quantities of waste
sludge produced, as there were no facilities for measuring the volume
and concentration of the recycled solids.
22
-------
TABLE 4
AVERAGE ACTIVATED SLUDGE PROCESS LOADING RATES
MONTH
1969
January
February
March
April
May
June
BOD
mg/1
827
1438
1459
836
1139
1021
Flow Rate
MGD
1.2
1.0
0.9
1.1
1.3
1.3
Average
MLSS (mg/1)
1496
3063
3940
3349
4041
5508
Ibs BOD/
Ibs MLSS
0.234
0.185
0.138
0.118
0.139
0.079
TABLE 4s
STATISTICAL ANALYSIS OF ACTIVATED SLUDGE MONTHLY
AVERAGE PROCESS LOADING RATES
BOD
mg/1
Flow Rate
MGD
Average
MLSS (mg/1)
Ibs BOD/
Ibs MLSS
Data Points
6
6
6
6
Mean
1120
1.1
3566
0.149
Standard Deviation
256
0.1
1206
0.049
23
-------
ro
TABLE 5
WASTE SLUDGE SLOWDOWN
MONTH
1969
January
February
March
April
May
June
ACTIVATED SLUDGE
1000 GPD
10.0
39.9
46.4
53.3
86.5
85.5
LIME SLUDGE
1000 GPD
0.0
14.2
42.4
19.4
13.5
17.9
-------
1800-
cn
01
E
o
o
CQ
Influent
- Effluent
1500-
1200-
900-
600-
- 60
- 50
40
- 30
20
o
o
CQ
300-
- 10
0
JAN
FEE
MAR
APR
MAY
JUN
JUL
FIGURE 3 - INFLUENT AND BIOLOGICALLY TREATED EFFLUENT BOD
(SEMIMONTHLY AVERAGES - 1968-69 SEASON)
-------
4800-
Influent
- - Effluent
-600
rv>
01
CT>
O
O
o
4000-
3200-
2400-
1600-
800-
\
-500
-400
.300
-200
-100
O
O
JAN FEE
MAR APR
MAY JUN JUL
FIGURE 4 - INFLUENT AND BIOLOGICALLY TREATED EFFLUENT COD
(SEMIMONTHLY AVERAGES - 1968-69 SEASON)
-------
.30-
r>o
o
o
CO
oo
.25-
.20-
.15-
.10-
.05-
JAN
FEB
MAR
APR
MAY
JUN
JUL
FIGURE 5 - ACTIVATED SLUDGE PROCESS LOADING RATES
SEMIMONTHLY AVERAGES - 1968-69 SEASON
-------
Table 6 shows the variation in the concentration of the waste activated
sludge solids. Two main factors influence the solids concentration of
the waste sludge. The SVI is a major factor in the concentration of
solids. The lower the SVI, the higher the concentration of solids will
be in the bottom of a clarifier and, of course, the higher the_SVI the
lower the concentration. Sludge concentration is also a function of
the time the solids are allowed to concentrate in the clarifier. Jhe
higher the sludge return rate is, the lower the solids concentration
in the return sludge and waste sludge.
During the period 6/2/69 through 6/12/69, the activated sludge process
was performing exceptionally well. A close check was made to determine
the amount of excess solids produced during this period. There was no
sludge recycled from the processing plant during this period. Table 7
gives the results of these tests. An average of 1000 gallons per_hour
of 1.34 percent sludge solids was blown down. At an average loading
rate of 0.08 pounds of BOD/1b MLSS, 0.32 pounds of sol ids/1b BOD were
wasted. Perhaps this is the key factor in designing activated sludge
plants for concentrated citrus waste. This is a high solids build-up
rate at such a low loading rate. This, of course, includes non-degrad-
able suspended solids in the influent, solids build-up from BOD removal,
and loss of solids through endogenous respiration. If adequate facil-
ities are not provided to handle the excess sludge, the waste treatment
system cannot function properly.
LIME TREATMENT PROCESS OPERATIONAL PROBLEMS
There were a variety of operational problems associated with the lime
treatment tank. The lime treatment unit was initially designed to
remove all waste activated sludge with the precipitated CaC03 sludge.
However, the lime sludge settled separately from the waste activated
sludge which prevented removal of large quantities of activated sludge.
If the heavier lime sludge was removed fast enough to keep the acti-
vated sludge from going over the weirs, all of the lime sludge was
quickly removed leaving no lime sludge blanket. This problem was
solved by wasting the excess activated sludge directly to the sludge
wet well. The two sludges mixed to some degree in the wet well, and
were then pumped to the citrus processing plant for recovery as a
cattle feed additive.
Although activated sludge was not intentionally discharged to the lime
tank after the first few weeks of operation, unintentional discharge
of solids occurred during most of the citrus season with the exception
of the last few weeks of operation. The main reason for this was the
foam carry-over from the aeration tanks. The inability to produce a
clear effluent was the major result of this solids carry-over. This
significantly affected the treatment efficiency of the lime treatment
process. Only during the last few weeks of operation after the waste-
water containing orange oil was removed from the treatment plant did
the lime tank produce an acceptable and clear effluent. The lime treat-
ment was operated over a wide range of pH values? however, a pH of 10.5
proved most effective.
28
-------
Date
TABLE
WASTE ACTIVATED SLUDGE SOLIDS
Percent Solids
Date
Percent Solids
2/21/69
2/21/69
3/7/69
3/8/69
4/7/69
4/14/69
4/21/69
4/22/69
5/5/69
5/15/69
5/16/69
5/17/69
5/18/69
5/19/69
5/20/69
5/21/69
5/22/69
5/23/69
5/24/69
5/25/69
5/26/69
5/27/69
5/28/69
5/29/69
5/30/69
5/31/69
6/1/69
1.78
0.98
0.86
0.40
1.17
0.86
1.29
1.01
0.81
1.42
1.22
2.32
0.70
2.02
6.06
3.52
1.51
1.74
0.53
4.14
0.91
1.18
0.94
0.85
0.18
0.65
0.85
6/2/69
6/3/69
6/4/69
6/5/69
6/6/69
6/7/69
6/8/69
6/9/69
6/10/69
6/11/69
6/12/69
6/13/69
6/14/69
6/15/59
6/16/69
6/17/69
6/18/69
6/19/69
6/20/69
6/21/69
6/22/69
6/23/69
6/24/69
6/25/69
6/26/69
6/27/69
1.13
1.37
1.04
L.27
1.36
1.38
5.62
1.75
1.35
1.41
1.37
1.48
1.54
0.67
1.39
1.55
1.53
1.41
2.07
1.70
1.01
1.18
4.76
1.17
3.79
1.32
Data Points = 53
Mean = 1.61
Standard Deviation = 1.20
29
-------
TABLE 7
SLUDGE PRODUCTION
Act. Sludge
B.D. Rate
Date GPH %
6/2/69 1100
6/3/69 1100
6/4/69 1100
6/5/69 1100
6/6/69 1100
6/7/69 900
6/9/69 1400
6/10/69 800
6/11/69 800
6/12/69 800
STATISTICAL
Data
Act. Sludge
B.D. Rate, GPH
% Solids
Lbs Solids
Lbs BOD
Lbs Solids
Lbs BOD
Lbs BOD
Lbs MLSS
Lbs Solids Lbs BOD
Solids Lbs Solids Lbs BOD Lbs BOD Lbs MLSS
1.13 2420 4400 .55
1.37 3000 6800 .44
1.04 2280 7500 .30
1.27 2700 10,700 .25
1.36 3000 25,200 .12
1.38 2480 27,400 .09
1.75 4900 9300 .53
1.35 2160 5700 .38
1.41 2240 9700 .22
1.37 2180 8400 .26
TABLE 7s
ANALYSIS OF SLUDGE PRODUCTION
Points Mean Standard Deviation
10 1,020 183
10 1-34 0.18
10 2,736 780
10 H,510 7,622
10 0.31 o.l5
1° 0.086 0.047
.042
.059
.065
.083
.184
.169
.078
.044
.073
.059
30
-------
A series of coagulant aids were tested in dosages recommended by
the manufacturers. Starch, the first aid tested, proved to be use-
less because of the high concentration of activated sludge solids
entering the lime tank. Alum was tried with similar results. Only
after using CaO alone at a high pH was any significant results ob-
tained in settling wastewater containing high concentrations of
activated sludge. This was probably due to the precipitation of
Mg(OH)2 at the higher pH. No problem was experienced with obtaining
a clear effluent as long as the effluent from the sludge clarifier
contained a low solids concentration.
LIME TANK SOLIDS ANALYSES
The normal method used to control a lime treatment unit in a water
softening plant is to determine the concentration of solids in the
upper and lower draft tube, the location of the sludge blanket, and
the pH of the effluent. As long as the sludge blanket is not over-
flowing the weirs, its location is not too meaningful. The concen-
tration of solids in the upper and lower draft tube gives a measure
of the solids contained in the solids contact area.
Throughout most of the citrus processing season activated sludge
entering the lime treatment unit negated any attempt to correlate
solids data with operation. Therefore, the lime unit was operated
almost completely by controlling the pH of the effluent and attempt-
ing to blow down solids fast enough to prevent the blanket from
going over the weirs.
During the last few weeks of operation, when the treatment plant
was working as designed, it was impossible to keep a high solids
concentration in the draft tube. This was because the lime solids
settled rapidly when no activated sludge was present in the influ-
ent. The effluent was sparkling clear and had the appearance of
drinking water.
TREATMENT EFFICIENCY OF THE LIME UNIT FOR BOD, COD AND SOLIDS REMOVAL
The chemical data obtained during the 1968-69 season cannot be used
as a basis for judging the efficiency of lime treatment of an acti-
vated sludge effluent. This is because the waste treatment plant
was not operating properly on a continuous basis until the last few
weeks of the season. After the foaming problem had been solved and
the quantity of solids entering the lime treatment unit had been re-
duced, the data was representative of a properly operating unit.
Table 8 contains monthly average data on the treatment plant influent
and effluent BOD, COD, and solids. Analyses of the influent to the
lime treatment unit are the same as the biologically treated effluent
31
-------
u>
ro
TABLE 8
AVERAGE ORGANIC AND SOLIDS ANALYSES OF INFLUENT AND CHEMICALLY TREATED EFFLUENT
MONTH
1969
January
February
March
April
May
June
BOD*
INF.
827
1438
1458
835
1139
983
EFF.
43
129
55
30
10
COD*
INF.
1960
2375
3551
1545
2571
2132
EFF.
105
382
398
104
74
SS*
INF.
162
338
450
449
197
146
EFF.
171
1141
621
40
27
VSS*
INF.
152
200
333
148
195
76
EFF.
82
452
324
16
13
PH
INF.
10.3
11.2
9.8
9.8
9.8
10.3
EFF.
10.8
10.4
11.0
10.5
11.4
Expressed as mg/1
-------
TABLE 8s
STATISTICAL ANALYSIS OF INFLUENT AND CHEMICALLY TREATED
EFFLUENT
BOD*
Daily Figures
BOD*
Monthly Averages
COD*
Daily Figures
COD*
Monthly Averages
SS*
Daily Figures
SS*
Monthly Averages
VSS*
Daily Figures
VSS*
Monthly Averages
PH
Daily Figures
PH
Monthly Averages
ORGANIC
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF-
EFF.
INF.
EFF.
AND SOLIDS CONCENTRATIONS
Data Points
57
49
6
5
57
49
6
5
57
49
6
5
55
48
6
5
57
49
6
5
Mean
1327
50
1113
53
2419
191
2356
213
302
354
290
400
184
157
184
177
10.1
10.8
10.2
10.8
Standard
Deviation
1261
50
359
41
1409
169
624
145
346
738
128
429
155
289
78
178
1.2
0.9
0.5
0.4
Expressed as mg/1
33
-------
found in Table A-4. Figures 6 and 7 show the chemical treatment
influent and effluent BOD and COD, respectively. The average BOD
in the influent to the lime treatment unit was 30 mg/1 for the
total season while the average BOD of the effluent was 50 mg/1.
There are two reasons for this apparent increase in BOD across the
lime unit. The first is that BOD's were analysed on settled samples
from the activated sludge clarifier, while BOD's were analysed on
the total sample on the effluent of the lime unit. It was necessary
to run BOD's on the settled samples from the activated sludge clari-
fier because solids were purposely wasted to the lime unit for dis-
posal. A more realistic picture of the effectiveness of the lime
treatment unit efficiency can be obtained from data collected from
June 4 to July 2. During this period, average BOD's in the influent
were 7 mg/1 and average BOD's of the effluent were 5 mg/1. Examina-
tion of the data shows that COD and solids removal were in approxi-
mately the same ratio as the BOD removal.
TREATMENT EFFICIENCY OF THE LIME UNIT FOR NUTRIENT REMOVAL
Table A-3 in the Appendix contains monthly averages of the nutrient
analyses performed throughout the plant. Table 9 gives the percent
removal efficiency in monthly averages of the lime treatment unit
for organics and nutrients. Tabulated below are the average influent
and effluent nutrient analyses for the complete citrus season and
for the period June 4 through June 12.
Total Citrus Season June 4 - June 12
Influent Effluent Influent Effluent
mg/1 mg/1 mg/1 mg/1
Total N 3.80 4.95 2.55 1.88
Ammonia N 0.49 0.69 0.84 0.25
Organic N 3.14 4.28 1.78 1.60
N03 + N02-N 0.04 0.49 0.03 0.01
N02 N 0.01 0.01 0.01 0.00
NOs N 0.02 0.03 0.02 0.01
Total P 3.20 2.10 2.33 0.46
Ortho P 1.23 0.67 2.07 0.30
Total P (Filtered) 1.20 0.69 1.26 0.16
Ortho P (Filtered) 0.75 0.25 0.97 0.11
34
-------
180 -
Influent
Effluent
150 -
GO
en
Q
O
CO
120 -
90 -
60 -
30 -
JAN
FEB
MAR
APR
MAY
JUN
JUL
FIGURE 6 - CHEMICALLY TREATED INFLUENT AND EFFLUENT BOD
(SEMIMONTHLY AVERAGES - 1968-69 SEASON)
-------
CO
en
600-
500-
400-
300-
Q
O
O
100.
Influent
effluent
JAN
FEB
MAR
APR
MAY
JUN
JUL
FIGURE 7 - CHEMICALLY TREATED INFLUENT AND EFFLUENT COD
(SEMIMONTHLY AVERAGES - 1968-69 SEASON)
-------
GO
TABLE 9
LIME TREATMENT REMOVAL OF NUTRIENTS AND ORGANICS
Month
1969
February
March
April
May
BOD Total Nitrogen
Effluent Removal Effluent Removal
mg/1 % mg/1 %
43 10 4.21 16
129 0 6.82 8
55 37 6.83 3
30 11 4.30 13
Total Phosphorus
Effluent Removal
mg/1 %
2.51
5.36
1.94
0.62
43
35
22
39
Orthophosphate
Effluent Removal
mg/1 %
1.04 23
1.02 22
0.77 8
0.54 52
pH Coagulant
Type
11.6 CaO
Starch
10.4 CaO
Alum
10.9 CaO
Alone
10.5 CaO
Alone
Lime
Dosage
mg/1
298
314
516
183
June
10
23
2.55
24
0.53 57
0.31
64
11.4
405
-------
TABLE 9s
STATISTICAL ANALYSIS OF LIME TREATMENT REMOVAL
BOD
Daily Figures
BOD
Monthly Averages
Total Nitrogen
Daily Figures
Total Nitrogen
Monthly Averages
Total Phosphorus
Daily Figures
Total Phosphorus
Monthly Averages
Orthophosphate
Daily Figures
Orthophosphate
Monthly Averages
PH
Daily Figures
PH
Monthly Averages
Lime Dosage, mg/1
Daily Figures
Lime Dosage, mg/1
Monthly Averages
OF NUTRIENTS
Effluent,
Removal %
Effluent,
Removal %
Effluent,
Removal %
Effluent,
Removal %
Effluent,
Removal %
Effluent,
Removal %
Effluent,
Removal %
Effluent,
Removal %
AND
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
ORGAN ICS
Data
Points
42
42
5
5
41
41
5
5
44
44
5
5
44
44
5
5
42
5
41
5
Mean
58
12
53
16
4.87
13
4.94
13
2.19
40
2.19
39
0.70
37
0.74
34
10.9
11.0
324
343
Standard
Deviation
58
18
40
13
3.18
19
1.66
7
2.89
28
1.76
11
0.63
31
0.28
21
0.8
0.5
200
112
38
-------
The effect of foaming and carryover of solids is most pronounced
for the nitrogen determinations. The fact that the effluent nitrogen
concentrations are higher than the influent concentrations is attri-
buted to the sampling method. All nutrient analyses on the influent
to the lime treatment tank were conducted on settled samples. This
in effect removed most of the solids associated with foam carryover.
Nutrient analyses on the effluent were made on the complete sample
which included all solids not effectively removed in the lime treat-
ment unit. Due to the quantity of activated solids going into the
lime unit during a considerable portion of the citrus processing
season, it is probable that a portion of these solids were placed
into fine colloidal form or into solution due to the mechanical
interaction of the lime solids.
Over the entire citrus processing season, total phosphorus concentra-
tions in the lime tank influent and effluent averaged 2.98 and 2.19
mg/1, respectively, for a removal efficiency of only 39 percent.
During the period June 4 - June 12, influent and effluent total phos-
phorus concentrations averaged 2.33 and 0.46 mg/1, respectively, for
a treatment efficiency of 80 percent. The use of such a short period
of time to try to indicate the lime treatment unit efficiency, under
optimum conditions, is not desirable. It is questionable whether a
lime unit, with the addition of lime at a cost of $40 to $60 per day,
is justified from an economic standpoint only to remove 1 to 2 mg/1
of phosphorus from a waste treatment plant effluent unless the treated
water is to be reused and requires a high water quality.
The lime unit was taken out of operation the last two weeks of June
and an attempt was made to use this unit as a waste activated sludge
thickener. The lime unit proved too large for continuous sludge
thickening because the long detention time allowed the sludge to be-
come anaerobic.
REUSE OF LIME TANK EFFLUENT INPLANT
Effluent from the treatment plant was successfully reused inplant for
considerable periods of time. Reuse was limited to use as barometric
leg water for two reasons: (1) the high pH from a lime treatment unit
will cause deposition of CaCOs in pipes and on equipment unless the
pH is reduced close to the pHs, (2) extensive piping changes would
have to be made to reuse the water as cooling water in the citrus
processing plant.
Although there was no question that the lime treated effluent could
be reused as barometric leg water and cooling water at Winter Garden
Citrus Products Cooperative by adjusting the pH with CO;? and installing
the required piping, it was cheaper and easier at the time to pump
well water from the abundant groundwater supply.
39
-------
CENTRIFUGE OPERATION
Thickening waste sludge was the most disappointing operation in the
treatment process. Treatment efficiency of any biological waste
treatment system depends largely on the ability to remove excess
sludge from the system, in this case for recovery as a cattle feed
additive. Thickening of the waste sludge was necessary to prevent
overloading of the rotary dryers, and a Bird 24 x 48 inch solid bowl
centrifuge was employed for this purpose.
The centrifuge operated unsatisfactorily during the entire citrus
season. The main problem was the inability to keep the centrifuge
in operation because of shear pin failure. Early in the_season, a
major mechanical failure occurred in the centrifuge and it had to
be rebuilt.
Major factors contributing to the poor performance of the centrifuge
were several: (1) the complete treatment plant design was based on
parameters developed during a six weeks laboratory study; (2) there
were no firm parameters for centrifuge design; and (3) the waste
sludge composition entering the centrifuge was of considerable vari-
ability.
Waste sludge from the treatment plant was pumped to a holding tank
in the citrus processing plant before it was centrifuged. The vari-
ation of the solids from this surge and thickening tank was consider-
able. Lime solids tended to separate from the activated sludge solids
and settle to the bottom. After a long period of time when no solids
had been withdrawn, the solids concentration in the bottom of the
unit increased to as high as 10 to 12 percent (see Table A-6 of the
Appendix). A sudden slug of this material fed into the centrifuge
invariably sheared a pin. Even after a fairly consistent solids con-
centration was fed to the centrifuge, it was difficult to maintain
continuous operation. When the centrifuge was operating, it tended
to classify the solids, removing the heavier lime solids and passing
the activated sludge solids back to the plant.
The manufacturer spent considerable time trying to adjust the machine
in order for it to perform properly. The R.P.M. was reduced toward
the latter part of the season and this seemed to be the answer for
continuous operation.
The inability of the centrifuge to operate properly meant that solids
could not be wasted as desired. When the centrifuge was not operating,
thickened solids from the bottom of the surge tank were placed directly
on the citrus peel for drying. The dryers, however, were already
40
-------
heavily loaded and all of the waste solids could not be recovered
as a cattle feed additive. The resulting solids build up in the
waste treatment plant compounded the foaming problem.
In summary it can be said that a solid bowl centrifuge should not
be considered for sludge dewatering unless extensive pilot plant
testing has proved its efficiency.
SUMMARY OF 1968-69 CITRUS PROCESSING SEASON
The initial start-up of the activated sludge system proved to, be no
problem as the aeration tanks were initially filled with well water
and a biological floe quickly formed after introduction pf the waste-
water. It was found that seeding would not be necessary. The waste-
water pH proved to be higher than expected; therefore, pH control was
seldom necessary. The control of the addition of nutrients to the
nutrient deficient wastewater was found to be easily controlled by
monitoring the soluble nutrients in the activated sludge system.
This method of nutrient control proved to be highly effective and
resulted in a minimum concentration of nutrients in the effluent of
the activated sludge system.
The two major problems associated with the activated sludge process
were foaming and high MLSS. The high MLSS (3,000 to 7,000 mg/1) was
caused by ,the inability to waste activated sludge as required. Foaming
was caused by slugs of peel press liquor and centrate water from the
orange oil recovery system. Foaming resulted in low D.O. concentra-
tions in the activated sludge process and carry-over of solids into
the lime treatment unit. Foaming was experienced frequently throughout
the season and only came under control when the centrate water from
the orange oil recovery system was diverted to the molasses evaporators
and discharge of peel press liquor was reduced. ,Even with the prob-
lems associated with the activated sludge process, the average treat-
ment efficiency approached 99 percent. ,
The lime treatment proved unable to handle all waste activated sludge
as originally designed. It was found that activated sludge could not
be.wasted over the weirs of the clarifier into the lime unit. It
was found that excess solids carryover caused by foaming in the acti-
vated sludge system would completely disrupt the lime treatment unit.
Only when the effluent from the activated sludge system had very low
suspended solids did the lime unit perform satisfactorily. Because
it was found that the effluent nutrients from the activated sludge
process could be effectively controlled by controlling the influent
nutrient addition, the lime treatment unit proved to be unnecessary.
41
-------
Treatment plant effluent was reused inplant for both cooling water
and barometric leg water. The pH of the lime unit (approx. 10.5)
proved to be too high to be used on a continuous basis because of
deposition of CaCC^. Recarbonation to lower the pH to a more
acceptable level would have allowed continuous use of the effluent
as either cooling or barometric leg water.
Waste activated sludge and lime sludge could not be effectively
thickened or dewatered by the solid bowl centrifuge. Although
numerous attempts were made to obtain satisfactory operation from
the centrifuge, the machine proved to be totally inadequate. This
meant that waste sludge after gravity thickening had to be discharged
directly to the rotary kiln dryers. Because of the limit in the
quantity of water the dryers could evaporate, sludge could not be
wasted as desired. This meant carrying exceedingly high MLSS in the
aeration system.
Waste activated and lime sludge proved to be easily used as a cattle
feed additive with the exception of the high moisture content problem.
Thousands of tons of dried citrus peel containing small quantities
of waste activated and lime sludge were sold and consumed by cattle
with no ill effect.
42
-------
SECTION V
1969-70 CITRUS PROCESSING SEASON
MODIFICATIONS TO WASTE TREATMENT SYSTEM PRIOR TO 1969-70 SEASON
During the 1968-69 processing season, it became obvious that the
lime treatment was not necessary for effluent nutrient control.
Reuse of the treatment plant effluent did not require the low
suspended solids the lime unit was capable of producing. There-
fore, with the approval of the Environmental Protection Agency,
lime treatment was discontinued and the lime unit converted to
a sludge holding tank and aerobic digester. Figure 8 shows a
schematic diagram, and Figures C-l through C-4 in the Appendix
show photographs, of the modified waste treatment system as oper-
ated during the 1969-70 season.
The only modifications to the entire treatment process was conver-
sion of the lime unit to an aerobic digester. This was done quite
inexpensively by installing two 25 h.p. injector aerators which had
been junked at another waste treatment plant. These aerators were
easily installed after removing the outside weir from the lime
treatment unit and installing piping which allowed the discharge of
waste activated sludge into the unit and removal of supernatant
back into the aeration basins. Figure C-2 shows the modified lime
treatment unit.
WASTEWATER FLOW AND FRUIT PROCESSED
A record of the wastewater flow and quantity of fruit processed was
kept each day of the season with the exception of the time from
November 11, 1969, to December 18, 1969. During this period, the
Parshall flume was being bypassed while piping modifications were
being made. Wastewater flow ranged from 0.0 MGD to 1.9 MGD with
an average daily flow of 1.1 MGD.
The number of boxes of fruit processed each day varied widely
during the season. This was due to weather conditions, the avail-
ability of fruit, etc. The number of boxes of fruit processed
varied from 0.0 to 67,800 per day. The average was 34,000 boxes
each day that fruit was processed. Based upon average wastewater
flow and boxes of fruit processed, the average gallons of wastewater
per box of fruit was 31 gallons and the average pounds of BOD per
box of fruit was 0.40. Table 10 is a tabulation of the monthly
average wastewater flow and boxes of fruit processed per day. A
complete tabulation is shown in Table B-l in the Appendix.
43
-------
SODIUM
HYDROXIDE
ANHYDROUS
AMMON I A|
EFFLUENT
OVERFLOW
INFLUENT
PHOSPHORIC
ACID
RETURN
SLUDGE
EXCESS
SLUDGE
-M 3
I. COMPLETE MIXED ACTIVATED SLUDGE
2. CLARIFIER
3. AEROBIC SLUDGE DIGESTOR
4. SLUDGE THICKENER
INPLANT
REUSE
THICKENED
SLUDGE TO
FEED MILL
FIGURE 8 MODIFIED WASTE TREATMENT SYSTEM
-------
TABLE 10
AVERAGE WASTEWATER FLOW AND FRUIT PROCESSED
Month
1969-70
November
December
January
February
March
April
May
June
Flow Rate
MGD
0.8
1.5
1.2
0.7
0.8
1.3
1.3
Oranges
1000 Boxes*
9.1
22.5
47.9
45.6
12.0
27.7
51.7
45.9
Grapefruit
1000 Boxes*
0.0
0.0
0.0
5.5
0.1
0.0
0.0
One box is 90 pounds of fruit.
TABLE 10s
STATISTICAL ANALYSIS OF WASTEWATER FLOW AND FRUIT PROCESSED
Flow Rate, MGD
Fruit
Daily Figures
Monthly Averages
Processed, 1000 Boxes
Daily Figures
Monthly Averages
Data
Points
151
7
228
8
Mean
1.
1.
34.
33.
1
1
5
5
Standard
Deviation
0.
0.
22.
15.
5
3
7
2
Number of days of zero flow = 0
Number of days for which flow data is unavailable
Number of days of no fruit production = 40
= 38
45
-------
NUTRIENT ADDITION AND pH CONTROL
Nutrients were added to the influent wastewater in the form of
ammonia and phosphoric acid as had been done the previous year.
Modifications to the activated sludge system made between the
1968-69 season and the 1969-70 season consisted only of the con-
version of the lime tank to an aerobic digester; therefore the
operation was essentially the same. Test kits were again used to
measure the ammonia nitrogen and orthophosphate in the aeration
tanks in order to control the additions of nutrients to the in-
fluent wastewater. Table B-2 in the Appendix shows the average
pounds per day of anhydrous ammonia as N and average pounds per
day of phosphoric acid as P added to the influent wastewater each
month. Addition of nitrogen and phosphorus varied widely through-
out the citrus season depending upon the loading rate on the acti-
vated sludge process and the ability of the plant operators to
measure the effluent nutrient concentration. Figures 9 through 13
show the influent and effluent nutrient concentrations. The waste-
water required little pH control because of the relatively high pH
of the wastewater. Only when slugs of peel press liquor entered
the system was it necessary to add sodium hydroxide.
ACTIVATED SLUDGE PROCESS OPERATIONAL PROBLEMS
Several operational problems were encountered during the 1969-70
season. Foaming in the aeration tanks was one of the major prob-
lems. Foaming occurred sporadically during most of the season and
usually occurred when quantities of peel press liquor or water
from the centrifuges of the oil recovery system entered the waste
treatment plant. Foaming resulted in a decrease in the aeration
transfer capacity of the surface mechanical aerators. Foaming also
caused suspended solids to be discharged over the weirs of the
clarifier because of the lack of a surface skimmer. These solids
decreased the overall treatment efficiency of the system causing
higher effluent BOD concentrations than were desirable.
Mechanical problems with the surface aerators caused low D,0. con-
centrations for days at a time. The main problem was the failure
of aerator gear boxes which necessitated the aerators being taken
out of service for repair. Aeration capacity was borderline even
with all aerators in service. Therefore, when a mechanical failure
occurred, the D.O. in the aeration tanks decreased to less than
1.0 mg/1. This caused higher effluent BOD's and an overall decrease
in treatment efficiency.
Again, inability to waste sludge as required was a major problem.
The unsatisfactory operation of the centrifuge made it necessary
to discharge waste activated sludge directly to the rotary kiln
dryers without further thickening. Since the rotary dryers could
46
-------
120-
100-
CJ3
O
z.
£
Influent Total N
Effluent Total N
Ammonia Nitrogen
A \ /
UJ
CD
O
cc
NOV ' DEC ' JAN r FEE ' MAR ' APR ' MAY JUN
FIGURE 9 - INFLUENT AND EFFLUENT TOTAL NITROGEN AND EFFLUENT AMMONIA NITROGEN
CSEMIMONTHLY AVERAGES - 1959-70 SEASON)
-------
-Pi
oo
24-
20-
Influent
Effluent
to
16-
12-
4-
NOV ' DEC
JAN r FEE
MAR ' APR
MAY
JUN
FIOJRE 10 - INFLUEOT AND EFFLUENT TOTAL PHOSPHORUS
(SEMIMONTHLY AVERAGES - 1969-70 SEASON)
-------
VO
1/5
OS
P-,
C/D
I
8
24-
20-
16"
12-
4-
Influent
~~~ Effluent
NOV
DEC
JAN
FEE
MAR
APR
MAY
JUN
FIGURE 11 - INFLUENT AND EFFLUENT ORTHQPHOSPH/VTE
(SEMIMONTHLY AVERAGES - 1969-70 SEASON)
-------
12-
Influent
Effluent
10-
cn
O
bfl
CO
4-
2-
NOV ' DEC JAN FEE MAR APR MAY JUN
FIGURE 12 - FILTERED INFLUENT AND FILTERED EFFLUENT TOTAL PHOSPHORUS
(SEMIMONTHLY AVERAGES - 1969-70 SEASON)
-------
12-
Influent
Effluent
10'
8-
oS
o
2-
NOV
DEC
JAN
FEE
MAR
APR
MAY
JUN
FIGURE 13 - FILTERED INFLUENT AND FILTERED EFFLUENT ORTHDPHOSPHATE
CSEMMONTHLY AVERAGES - 1969-70 SEASON)
-------
only handle a limited amount of the waste sludge, sludge disposal
by tank truck to citrus groves was practiced in an attempt to
maintain a desirable MLSS concentration. The MLSS approached
7000 mg/1 which caused increased oxygen uptake rates and low D.O.
concentrations in the aeration basins.
AERATION TANK ANALYSES
Every two hours, samples were collected from both aeration tanks
to determine D.O., pH, MLSS, and SVI. Table 11 contains monthly
averages of these results. Dissolved oxygen concentrations varied
widely during the season. D.O. concentrations below 1.0_mg/l occurred
when foaming and heavy organic loadings of the system existed^or
when an aerator was not in operation because of mechanical failure.
The pH of the mixed liquor varied from 5.7 to 8.1. The pH of 5.7
was measured immediately after a large volume of peel press liquor
was discharged to the treatment system. Although the pH of the in-
fluent waste varied widely, the pH of the aeration basins usually
ranged from 7.1 to 7.8.
The MLSS concentration of the aeration basin was always high. MLSS
values approached 7000 mg/1 on several occasions and normally were
around 4500 mg/1.
The sludge volume index CSVI), which is a measure of the settling
rate of the sludge, varied from 73 to 440. Most SVI values were
between 150 and 250 which meant the sludge settled slowly in the
sludge clarifier.
ACTIVATED SLUDGE PROCESS TREATMENT EFFICIENCY AND LOADING RATES
Table B-3 in the Appendix gives the monthly average influent and
effluent BOD, COD, and solids analyses. Figures 14 and 15 show the
influent and effluent BOD and COD, respectively. Maximum and minimum
BOD concentrations in the influent were 4250 mg/1 and 155 mg/1. Max-
imum and minimum BOD's in the effluent were 90 mg/1 and 1.0 mg/1.
The average influent BOD was 1300 mg/1 and the average effluent BOD
20 mg/1. This is an average BOD reduction of 98.5 percent for the
1969-70 season.
Although this is excellent treatment efficiency, problems with foaming
and excess solids caused lower treatment efficiency than would have
been attainable if closer control could have been maintained on the
discharge of peel press liquor, orange oil, and other high BOD wastes,
and if control of the solids in the aeration basins could have been
maintained. Discharge of peel press liquor and orange oil were caused
by inplant evaporation deficiency or mechanical failure.
52
-------
en
OJ
TABLE 11
AVERAGE AERATION TANK ANALYSES
North Aeration Tank
Month
1969-70
November
December
January
February
March
April
May
June
MLSS
mg/1
3001
4932
5042
4803
3939
3595
4391
4358
SVI
324
199
193
171
240
280
223
- 227
D.O.
mg/1
4.9
4.4
2.0
1.6
4.2
3.1
0.5
1.0
PH
7.5
7.6
7.2
7.8
7.5
7.3
7.4
7.7
MLSS
mg/1
--
3275
4878
4835
3855
3559
4379
4365
South Aeration Tank
SVI
301
195
176
241
285
224
228
D.O.
mg/1
4.4
2.1
2.0
4.6
3.4
0.8
1.4
PH
--
7.3
7.4
7.6
7.7
7.5
7.4
7.7
-------
TABLE 11s
STATISTICS ANALYSIS OF AERATION TANK ANALYSES
MLSS
mg/1
SVI
D.O.
mg/1
pH
Daily Figures
Monthly Averages
Daily Figures
Monthly Averages
Daily Figures
Monthly Averages
Daily Figures
Monthly Averages
North
Data
Points
219
8
219
8
220
8
219
8
Aeration
Mean
4343
4258
226
232
2.7
2.7
7.5
7.5
Tank
Standard
Deviation
924
663
59
46
2.5
1.6
0.4
0.2
South
Data
Points
177
7
177
7
177
7
167
7
Aeration
Mean
4293
4164
226
236
2.7
2.7
7.5
7.5
Tank
Standard
Deviation
863
573
54
42
4.7
1.4
0.3
0.1
-------
240a
Influent
Effluent
en
en
2000-
1600
1200
800
400
.120
-100
80
60
40
20
NOV DEC
JAN FEE MAR APR
FIGURE 14 - INFLUENT AND EFFLUENT BOD
CSEMIMONTHLY AVERAGES - 1969-70 SEASON)
MAY JUN
-------
12,000
Influent
Effluent
-600
10,000-
iOO
8,000-
6,000-
4,000-
2,000.
400
300
200
100
P-. Q
PH O
W O
NOV ' DEC ' JAN ' FEB ' MAR ' APR ' MAY ^ JUN
FIGURE 15 - INFLUENT AND EFFLUENT COD
[SEMIMONTHLY AVERAGES - 1969-70 SEASON)
-------
Figure 16 shows the semimonthly average loading rate in pounds BOD
per pound MLSS. Loading rates varied from a minimum of 0.01 to a
maximum of 0.58 pounds BOD/1b MLSS. Average loading rates during
February 1970 were greater than 0.2 pounds BOD/1b MLSS, which is a
loading comparable to the conventional activated sludge process.
Table 12 shows monthly averages of influent BOD, flow rate, mixed
liquor suspended solids, and loading rate for the complete citrus
season. Daily figures are shown in Table B-4 in the Appendix.
Loading rates varied considerably from day to day depending upon
amount of fruit processed and other inplant operations. It was not
unusual to go several days without any wastewater flow to the treat-
ment system because of the lack of fruit. This had no detrimental
effect on the system as it was able to take wide variations in load-
ing without a decrease in treatment efficiency.
WASTE ACTIVATED SLUDGE
Waste activated sludge was discharged directly to the aerobic di-
gester, which had formerly been the lime treatment unit, where it
was aerated almost continuously. Only while supernatant was being
pumped back to the aeration tanks were the aerators cut off.
Detention time in the digester was approximately 2 days, which was
not enough time to aerobically digest the waste sludge. Digestion
was not necessary, however, since the sludge was to be recovered as
a cattle feed additive. The digester functioned more as a surge and
thickening tank than a digester.
Table B-5 in the Appendix shows the monthly average daily Volume of
sludge wasted from the digester to the citrus plant. This table also
shows the influent and effluent solids. Average influent solids were
0.93 percent and average effluent solids were 2.27 percent. If the
digester was converted to a continuous sludge thickener, a sludge
concentration of approximately 3.5 percent could be realized. When
this was attempted, odor problems resulted because of the long deten-
tion time. Calculations indicate approximately 0.5 to 0.6 pounds of
waste sludge were produced per pound of BOD treated.
CENTRIFUGE OPERATION
The 24" x 48" Bird solid bowl centrifuge was operated intermittently
during the citrus season. Numerous experiments were conducted in an
attempt to obtain the best efficiency from the machine. The influent
feed rate was varied, the pool depth, type of coagulant, dispersion
water, and even the rpm were varied with the centrifuge still giving
unsatisfactory results.
57
-------
en
Co
Q
O
CO
GO
GO
.24-
.20-
.16-
.12-
.08-
.04-
.00
NOV
DEC
JAN
FEB
MAR
APR
MAY ' JUN
FIGURE |6- ACTIVATED SLUDGE PROCESS LOADING RATES
SEMIMONTHLY AVERAGES - 1969-70 SEASON
-------
TABLE 12
AVERAGE ACTIVATED SLUDGE PROCESS LOADING RATES
Month
1969-70
December
January
February
March
April
May
June
BOD
mg/1
668
1715
2409
1334
925
1230
1103
STATISTICAL ANALYSIS
BOD, mg/1
Flow Rate,
MGD
Average MLSS, mg/1
Ibs BOD/1 b
MLSS
Flow Rate
MGD
1.2
1.5
1.2
1.2
1.4
1.4
1.4
TABLE 12s
OF ACTIVATED
Data
Points
7
7
7
7
Average MLSS
mg/1
4237
5319
4824
4119
4073
4346
4344
SLUDGE LOADING
Mean
1341
1.3
4466
0.13
Ibs BOD/
Ib MLSS
.07
.17
.21
.14
.10
.12
.12
RATES
Standard
Deviation
531
0.1
416
0.04
59
-------
Table B-6 in the Appendix shows the average results of analyses run
on samples from the operation of the centrifuge under numerous con-
ditions. A review of this data shows that seldom did the cake from
the centrifuge exceed 7 percent and the recovery was very low. Most
of the time, waste sludge was placed directly on the peel without
thickening for recovery as a cattle feed additive. When the dryers
became overloaded, sludge was hauled by tank truck to citrus groves
for disposal.
WASTEUATER REUSE
Effluent from the treatment plant was used on a continuous basis for
barometric leg water in the molasses evaporators. No problems were_
encountered even during periods of high activated sludge concentrations
in the effluent.
Effluent was also used for cooling of refrigeration equipment on a
trial basis. No problems were encountered; however, effluent was not
used for this purpose on a continuous basis because the total flow
could more easily be used for barometric leg water. Wastewater reuse
was considered in several other processes; however, it was rejected
due to potential contamination of the food product.
The reuse of the treatment plant effluent decreased the pumping of
well water by an amount approximately equal to the plant's discharge,
1.0 to 1.5 MGD. This represents a reduction in the fresh water usage
of approximately 20 percent and is a significant step toward total
water recycling.
SUMMARY OF 1969-70 CITRUS PROCESSING SEASON
The 1969-70 season was not greatly different from the previous season
with the exception that the lime treatment unit had been converted to
an aerobic digester and sludge thickener. The construction of the
aeration tanks did not allow them to be dewatered; therefore, they
contained activated sludge which was aerated throughout the off-season.
The system was placed into operation by discharging wastewater into
the system and excellent treatment was immediately realized.
The soluble nutrient concentrations in the aeration basins were con-
trolled as they had been the previous year by manually adjusting the
addition of phosphoric acid and anhydrous ammonia to the influent.
The pH had to be controlled only when a slug of peel press liquor
lowered the pH of the aeration basins. Control was accomplished by
the addition of sodium hydroxide.
Although foaming was still a major problem throughout the 1969-70
season, it was not as severe as it had been during the previous season.
Inplant modifications had reduced the discharges of peel press liquor
and water from the orange oil recovery system.
60
-------
Inability to waste solids as desired caused high MLSS concentrations
in the aeration tanks. These high concentrations combined with
mechanical problems with the surface aerators to lower D.O. concen-
trations below the minimum desired.
In spite of all the problems causing reductions in efficiency of
the activated sludge system, the system averaged a 98.5 percent BOD
removal during the season.
Waste activated sludge was discharged to the aerobic digester where
it was aerated and thickened before being discharged to a holding
tank. Sludge was pumped from the holding tank either through the
centrifuge to the rotary kiln dryers or directly to the dryers.
Since the centrifuge proved itself to be unsatisfactory for dewatering
waste activated sludge alone, most of the time the sludge was pumped
directly to the dryers. When the dryers became overloaded, excess
sludge was hauled away by tank truck for land disposal on citrus groves.
Treatment plant effluent was reused on a continuous basis as barometric
leg water. Tests showed that it could also be used as cooling water.
Reuse of the effluent as barometric leg water was not a closed system
as the barometric waste was discharged to Lake Apopka; however, reuse
of the effluent did reduce plant water usage and total wastewater
disposal by some 1.5 MGD.
61
-------
SECTION VI
KINETICS OF SUBSTRATE UTILIZATION
Eckenfelder^ ' has used the Michaelis-Menton relationship to define
microbial growth rate and substrate removal in a completely mixed
activated sludge system and has developed a simplified equation
describing substrate removal:
where
Ka = BOD rate constant
S = effluent BOD
Sr = BOD removed
Xv = average mixed liquor suspended solids
t = detention time
Figure 17 shows plots of BOD removal versus effluent BOD. The slopes
of the first order curves passing through (0,0) are equal to the BOD
rate constant for the given temperatures.
Figure 18 is a semi-logarithmic plot of the BOD rate constant, Ka,
versus temperature. The equation of the straight line is the BOD
rate constant temperature correction.
Kt = 0.0072 x 1.278(t"20)
where
Kt = BOD rate constant at temperature t (°C)
t = temperature (°C)
It must be noted that the narrow range of aeration basin temperatures
did not allow verification of the temperature correction equation over
a wide range of temperatures. It must also be noted that soluble
effluent BOD and volatile MLSS would have given a more accurate repre-
sentation of substrate utilization, but these data were unavailable.
63
-------
0.20
CTv
-P.
I
15
I
20
5 10 15 20 25
BOD mg/1
FIGURE 17 - SUBSTRATE REMOVAL VERSUS EFFLUENT BOD
30
-------
CTi
cn
0.03 -I
0.02 -I
« 0.01
* 0.009
- 0.008
| 0.007
g 0.006
o
o
O
CQ
0.005-
0.004-
0.003-
0.002H
0.001
!
12
i
16
t
20
t
24
i
30
Temperature °C
FIGURE 18 - SUBSTRATE REMOVAL RATE VERSUS TEMPERATURE
-------
SECTION VII
WASTE TREATMENT SYSTEM CONSTRUCTION COST AND TREATMENT COST
Haste Treatment System Construction Cost
Winter Garden Citrus Products Cooperative served as their own general
contractor with major portions of the construction subcontracted to
a private contractor. Since the grant only covered partial funding
of the construction of the lime treatment, water re-use, and centri-
fuge systems a detailed cost breakdown of the total plant is not
available. However a general cost breakdown for the treatment plant
is shown in Table 13. A list of manufacturers of the major equipment
is shown in Table 14.
Several items should be noted in the cost breakdown of the treatment
process. The system was designed to handle approximately 33,000 Ibs
of BOD per day at a cost of only $550,000, and this included approxi-
mately $100,000 for tertiary treatment by lime and $30,000 for water
reuse facilities. Subtracting the cost of lime treatment and water
reuse and adding the cost of two aerators which would be required to
handle the design load, the cost for BOD removal alone would have been
approximately $450,000.
There are two major reasons for the low cost of the activated sludge
system: (1) low cost of aeration tanks, and (2) use of existing equip-
ment for sludge handling. Every conceivable type of construction was
considered to provide the volume required for the aeration tanks. Cost
estimations showed that simple circular concrete 144-foot diameter tanks
would provide the required aeration volume. The specially designed
concrete tanks were actually cheaper than steel, prestressed concrete,
or lined earthen lagoons.
The walls of the concrete tanks are 1.0 ft thick and 15.67 ft high.
The wall sits on a 1.0 ft thick by 3.17 ft slab. The walls did not
require circular forms as standard 4 ft X 8 ft plywood was used. This
saved considerable money when compared to circular forms. The tank
bottom was not a structural bottom but simply a 4.0 inch thick concrete
slab. The only disadvantage is that the tanks cannot be completely
dewatered when the water table is high.
In domestic waste treatment plants the cost of proper sludge handling
facilities may cost as much as 50 percent of the total construction
cost. Winter Garden Citrus was in an unusual position in that the
waste sludge from the treatment plant could be recovered as a cattle
feed additive. This eliminated the need for sludge digestion and
disposal facilities which would have added greatly to the capital cost.
67
-------
TABLE 13
CONSTRUCTION COST BREAKDOWN
Raw Waste Pumping Structure $ 15,000
Raw Waste Pumps (3) 5>000
Aeration Tank Structures 90,000
Mechanical Surface Aerators (6) 80,000
Activated Sludge Clarifier Structure 35,000
Activated Sludge Clarifier - Mechanical 10,000
Activated Sludge Return Pumps (3) 5,000
Lime Treatment Structure 45,000
Lime Treatment - Mechanical 35,000
Lime Storage Silo 6,000
Lime and Waste Activated Sludge Transfer Pumps (2) 7,000
Laboratory and Control Building 10,000
Reuse Water Pumping Structure 15,000
Reuse Water Pumps (3) 5,000
Centrifuge 30,000
Chemical Tanks 6,000
Piping 75,000
Electrical 15,000
Controls and Miscellaneous 10,000
Land 21,000
Engineering Services 30,000
TOTAL $ 550,000
68
-------
TABLE 14
MANUFACTURERS OF MAJOR EQUIPMENT
Original Construction For 1968-69 Season
Raw Waste Pumps - 3
Motor Drives - 3
Pump Controls - 1
Ammonia Feeder - 1
Phosphoric Acid Feed Pump - 1
Surface Aerators - 6
Sludge Collector - 1
Sludge Return Pumps - 3
Lime Reactor
Lime Silo - 1
Lime Slurry Equipment - 1
Lime Feed Pumps - 2
Lime & Activated Sludge Pumps - 2
Effluent Meter and Recorder
Water Reuse Pumps - 3
Pump Controls - 1
Centrifuge, 24" x 48" Solid Bowl
Gorman Rupp
U.S. Electric Motors
Healy Ruff
Wallace & Tiernan
Wallace & Tiernan
Permutit
Link Belt
Cornell Pumps
Grave Water Conditioning Co.
Florida Metal craft
Wallace & Tiernan
Moyno
Moyno
Chronoflo
Worthington
Healy Ruff
Bird Centrifuge
69
-------
The use of the complete mixed activated sludge process, simple con-
struction techniques, floating surface mechanical aerators, and
recovery of waste activated sludge as a cattle feed additive can
substantially reduce capital construction cost when compared with
cost of other treatment processes.
Treatment Cost
A comparison of the cost of BOD removal for the Winter Garden Citrus
treatment plant with other treatment plants is difficult to make
because the plant is only operated a few months each year. To
correctly compare treatment costs, systems should be operated on a
full load basis 365 days a year. It is not possible to compare a
plant which operates 150 days a year with a plant which operates
365 days a year. Winter Garden Citrus is a good example of an
industrial waste treatment plant which operates only a few months
each year and only a few weeks at full capacity. Yet, the waste
treatment plant must be designed to handle the peak load.
The capabilities of the waste treatment plant as designed were:
Hydraulic loading - 2.0 MGD
BOD - 2,000 mg/1
BOD - 33,300 Ibs/Day
Table 15 shows the operation and maintenance cost for the 1968-69
season and the 1969-70 season. Assuming the $550,000 capital cost
is amortized at 8 percent over 20 years, the annual investment re-
tirement cost would be $56,000. Table 16 shows waste treatment cost
for both processing seasons for both actual operating conditions and
assuming 365 days per year operation at full capacity.
It should be noted that the reused water has a value which has not
been credited to the capital or operating cost of the treatment
plant. Assuming that the operating cost of the reuse pumps and the
operating cost of well pumps capable of delivering the same quantity
of water would be the same, then a capital credit of $15,000 should
be applied to the reuse system as the cost to replace the reuse
system with an equivalent water well.
70
-------
TABLE 15
OPERATION AND MAINTENANCE COST
1968-69 Citrus Processing Season
Three Operators @ $8,000/year $ 24,000
Maintenance for season 6,000
Ammonia 58,000 Ibs @ 9<£/lb 5,200
Phosphoric Acid 40,000 Ibs @ 5.85<£/lb 2,340
Lime 240 tons @ $22/ton 5,300
Electricity (1.7 x 106 Kwh @ l<£/Kwh) 17,000
TOTAL $ 59,840
1969-70 Citrus Processing Season
Three Operators @ $8,000/year $ 24,000
Maintenance for season 6,000
Ammonia 128,000 Ibs @ 9
-------
TABLE 16
WASTE TREATMENT COST
1968-69 Citrus Processing Season
Total Cost $ per box
-------
SECTION VIII
ACKNOWLEDGEMENT
Numerous persons contributed time and effort to make this project
successful. First of all Mr. James H. Bock, General Manager, and
Mr. James W. Hayes, Plant Manager, of Winter Garden Citrus Products
Cooperative should be acknowledged for their close cooperation
throughout the project. Mr. Hayes was also project director and
directly involved in guiding the project from start to finish.
Mf; Less Barr, Chief Plant Operator, deserves special recognition
for the numerous hours he spent insuring that the treatment plant
operated properly. Mr. Al Garner of Winter Garden Citrus also
deserves special recognition for his assistance throughout the
project.
Special recognition also goes to Dr. Richard H. Jones of Environ-
mental Engineering, Inc., technical director of the grant, who
designed the treatment system and directed the research program.
During the first season of operation, Mr. Victor W. Randecker was
engineer in charge of plant operation and personally conducted all
chemical analyses on site. Mr. Marvin Hamlin performed the same
task during the second season of operation. Without them the pro-
ject would not have been successful.
The support of the project by the Office of Research, Industrial
Pollution Control Program under the direction of Mr. William J.
Lacy and Mr. H. G. Keeler, program manager, Environmental Protection
Agency, and Dr. David Hill, the grant project officer, is acknowl-
edged with sincere thanks.
- 73 -
-------
SECTION IX
REFERENCES
1. Bamford, R.A., "Centrifugal Dewatering of Paper Mill Effluents."
TAPPI, 47, 1, 187A (January 1964).
2. Conway, R.A., "Cationic Organic Coagulants in Wastewater Treat-
ment." Water and Sewage Works, 109. 9, 342 (September 1962).
3. Curry, J.J. and Wilson, S.L., "Effects of Sewage-borne Phos-
phorus on Algae." Sewage and Industrial Wastes, Vol. 27, No. 11,
pp 1262-1266 (1955).
4. Danatos, S., "Progress in Centrifugal Separations." Chemical
Engineering, 7J_, 21, 205 (October 12, 1964).
5. Eckenfelder, W.W., "Comparitive Biological Waste Treatment
Design," Journal of the Sanitary Engineering Division, ASCE.
13_, SA6, 157, (December, 1967).
6. Feng, T.H., "Phosphorus and the Activated Sludge Process." Water
and Sewage Works. 109, 431 (November 1962).
7. Frampton, G.A., "Evaluating the Performance of Industrial Centri-
fuges." Chemical and Process Engineering. 44, 8, 402, (August
1963).
8. Hart, R.R., "General Considerations to Aid in Centrifuge Selec-
tion." Indust. Chemist. 38, 448, 270 (June 1962).
9. Johnson, W.K., "Nutrient Removals by Conventional Treatment
Processes." Proc. 13th Ind. Waste Conf., Purdue University,
Ext. Ser., 96, 151 (1958).
10. Johnson, W.K., and Schroepfer, G.J., "Nitrogen and Phosphorus
Removals by Conventional Treatment Processes." Sanitary Eng.
Progress Report 104S, University of Minnesota, Minneapolis,
(September 1956).
11. Landis, D.M., "Centrifugal Coalescers." Chemical Engineering
Progress, 61_, 10, 58 (October 1965).
12. Lea, W.L., Rohlich, G.A., and Katz, W.J., "Removal of Phosphates
from Treated Sewage", Sewage and Industrial Wastes. Vol. 26, No. 3,
pp 261-275, 1954.
75
-------
13. Malhotra, S.,., Lee, G.F., and Rohlich, G.A., "Nutrient Removal
from Secondary Effluent by Alum Flocculation and Lime Precipi-
tation." International Journal of Air and Hater Pollution,
Vol. 8, Nos. 8 and 9, pp 487-500, (1964).
14. McGauhey, P.M., Eliassen, R., Rochlich, G., Ludwig, H.F., and
Pearson, E.A., "Comprehensive Study on Protection of Water Re-^
sources of Lake Tahoe Basin Through Controlled Waste Disposal,"
Prepared for the Board of Directors, Lake Tahoe Area Council,
Al Tahoe, California, 157 pages, (1963).
15. Montanaro, W.J., "Sludge Dewatering by CentrifugesRecent
Operating Experiences." Presented at the 37th Annual Conference
Water Pollution Control Association of Pennsylvania, Penn State
University (August 1965).
16. Neil, J.H., "Problems and Control of Unnatural Fertilization of
Lake Waters." Engineering Bulletin, Proceedings of the Twelfth
Industrial Waste Conference, Purdue University, pp. 301-316
(1957).
17. Ohle, W., "Phosphorus as the Initial Factor in the Development
of Eutrophic Waters." Vom Wasses, Vol. 20, pp. 11-23; Water
Pollution Abstracts, Vol. 28, No. 4, Abs. No. 893 (1953).
18. Owen, R., "Removal of Phosphorus from Sewage Plant Effluent with
Lime." Sewage and Industrial Wastes. 25_, 548 (1953).
19. Owen, R., Sewage and Industrial Wastes, 25_, 5, 548 (1953).
20. Parkhurst, J.D. and Sanders, S.R., "Centrifuging and Screening
of Sludge." Water and Waste Treatment, 9., 12, 596 (Mar.-Apr.,
1964).
21. Rippert, I., Possibilities of Elimination of Phosphate from
Sewage by Chemical Methods, Gesundheitsing, 79, 333-337, 1957-
WPS 128, 33, 22, Jan. 1960.
22. Rohlich, G. A., "Chemical Methods for the Removal of Nitrogen
and Phosphorus from Sewage Plant Effluents." Algae and Metro-
politan Wastes, U.S. Public Health Service, SEC TR W61-3, pp.
130-135 (1961).
23. Sawyer, C.N., "Some New Aspects of Phosphates in Relation to
Lake Fertilization," Sewage and Industrial Wastes. 24, 6, 768
76
-------
24. Sawyer, C.N., Sewage and Industrial Wastes. 26_, 3, 317 (1954).
25. Schaffer, R.B., "Polyelectrolytes in Industrial Waste Treat-
ment." Industrial Water & Wastes, 8, 34 (Nov.-Dec., 1963).
26. Tenny, M.W., and Stumm, W., "Chemical Flocculation of Micro-
organisms in Biological Waste Treatment." Purdue University
Extension Service Publication. 117, Part 2, 518 (1965).
27. "The Use of Activated Sludge as an Adjuvant to Animal Feeds,"
Proc. 12th Ind. Waste Conf., Purdue University, 1957, p. 395.
28. VanVuran, J.P.J., "Soil Fertility and Sewage." Dover Publica-
tions, Inc., New York, 236 pp. (1948).
29. White, W.F., "Centrifugal Treatment of Industrial Waste Waters."
Industrial Water & Wastes. 8, 40 (Nov.-Dec., 1963).
77
-------
SECTION X
PUBLICATIONS
Jones, R. H., "Lime Treatment and In-Plant Reuse of An Activated
Sludge Plant Effluent in the Citrus Processing Industry," Pro-
ceedings First National Symposium on Food Processing Wastes 1970,
Portland, Oregon.
Jones, R.H., "Treatment of Citrus Processing Wastewater Including
Effluent Nutrient Control," Hater, 107, 67, 1971.
79
-------
SECTION XI
GLOSSARY OF TERMS AND ABBREVIATIONS
ACTIVATED SLUDGE - Sludge floe produced in raw or settled wastewater
by the growth of zoogleal bacteria and other organisms in the
presence of dissolved oxygen and accumulated in sufficient con-
centration by returning floe previously formed.
ACTIVATED SLUDGE PROCESS - A biological wastewater treatment process
in which a mixture of wastewater and activated sludge is agitated
and aerated. The activated sludge is subsequently separated from
the treated wastewater (mixed liquor) by sedimentation and wasted
or returned to the process as needed.
AERATION - The bringing about of intimate contact between air and a
liquid by one or more of the following methods: (a) spraying the
liquid in the air, (b) bubbling air through the liquid, (c) agi-
tating the liquid to promote surface absorption of air.
AERATOR - A device that promotes aeration.
AEROBIC DIGESTION - Digestion of suspended organic matter by means
of aeration.
AEROBIC TREATMENT - A biological treatment process conducted in the
presence of oxygen.
ALUM - Aluminum sulfate; a coagulant.
AMMONIA NITROGEN (AN) - All nitrogen existing as ammonium ion.
BAROMETRIC LEG WATER - That water used in the formation of a vacuum.
BIOCHEMICAL OXYGEN DEMAND (BOD) - The quantity of oxygen used in the
biochemical oxidation of organic matter in a specified time, at a
specified temperature, and under specified conditions.
CHEMICAL OXYGEN DEMAND (COD) - A measure of the oxygen-consuming
capacity of inorganic and organic matter present in water or waste-
water. It is expressed as the amount of oxygen consumed from a
chemical oxidant in a specific test. It does not differentiate
between stable and unstable organic matter and thus does not neces-
sarily correlate with biochemical oxygen demand. Also known as OC
and DOC, oxygen consumed and dichromate oxygen consumed, respectively.
81
-------
CLARIFIER - A tank or basin in which quiescent conditions are
approached sufficiently for a portion of the suspended solids
to be removed by gravity settling.
COAGULANT - A compound responsible for coagulation; a floe-forming
agent.
COAGULANT AID - Any chemical or substance used to assist or modify
coagulation.
COAGULATION - In water and wastewater treatment, the destabilization
and initial aggregation of colloidal and fined divided suspended
matter by the addition of a floe-forming chemical or by biological
processes.
COLLOIDAL PARTICLES - Finely divided solids which will not settle
but may be removed by coagulation or biochemical action or mem-
brane filtration.
COMPLETE MIXED ACTIVATED SLUDGE - An activated sludge process in
which the influent is applied throughout the aeration basin.
CONCENTRATED WASTEWATER - Wastewater containing BOD concentrations
greater than 1000 mg/1.
DETENTION TIME - The theoretical time required to displace the con-
tents of a tank or unit at a given rate of discharge (volume
divided by rate of discharge).
DIGESTION - The biological decomposition of organic matter in sludge,
resulting in partial gasification, liquefaction, and mineralization,
DISSOLVED OXYGEN (D.O.) - Uncombined oxygen in solution in a liquid.
EFFLUENT (EFF.) - Liquid flowing out of a containing space.
EXCESS ACTIVATED SLUDGE - The sludge produced in an activated sludge
treatment plant that is not needed to maintain the process and is
withdrawn from circulation.
GALLONS PER DAY (GPD) - A common volume per unit time expression
of liquid flowrate.
INFLUENT (INF.) - Liquid flowing into a containing space.
82
-------
MILLIGRAMS PER LITER (mg/1) - The mass of a substance in milligrams
contained in one liter of liquid.
MILLION GALLONS PER DAY (MGD) - A common volume per unit time
expression of liquid flowrate.
MIXED LIQUOR SUSPENDED SOLIDS (MLSS) - The concentration in milli-
grams per liter by dry weight of solids in the activated sludge
unit.
NUTRIENT - A substance which promotes cellular growth in organisms.
ORGANIC NITROGEN (ON) - All nitrogen existing in organic compounds.
pH - The negative logarithm of the hydrogen ion concentration of
a solution; a measure of the acidity of alkalinity of a solution.
RETURN SLUDGE - Sludge which has settled in the final clarifier and
is returned to the activated sludge unit.
SLUDGE - Accumulated solids which have been separated from wastewater
and which contain a high enough moisture content to have a semi-
liquid form.
SLUDGE BLANKET - The interface formed in a clarifier between the
region of clarified fluid and the region of uniform suspension.
SLUDGE THICKENING - Reduction of the moisture content of a sludge
resulting in a reduced volume.
SLUDGE VOLUME INDEX (SVI) - The ratio of the volume in milliliters
of sludge settled from a 1 ,000-ml sample in 30 min to the con-
centration of mixed liquor in milligrams per liter multiplied by
1,000.
SLUG - A high concentration of a substance in a flowing liquid;
generally beginning and ending abruptly and lasting for a rela-
tively short period of time.
SUPERNATANT LIQUOR - The liquid overlying deposited solids.
SURGE TANK - A basin or chamber which provides either positive or
negative pressure relief to a pumping system.
83
-------
SUSPENDED SOLIDS (SS) - Those particles in a liquid which are not in
solution and can be removed by filtration.
TOTAL NITROGEN (TN) - The sum of nitrogen existing in the forms of
ammonia nitrogen and organic nitrogen.
VOLATILE SUSPENDED SOLIDS (VSS) - The quantity of suspended solids in
wastewater lost on ignition at 600°C.
WASTE SLUDGE - See excess activated sludge.
84
-------
SECTION XII
APPENDICES
COLLECTED AND AVERAGED DATA, 1968-69 SEASON
Table A-l Wastewater Flow and Fruit Processed
Table A-2 Average Addition of Nutrients to the Influent
Table A-2s Statistical Analysis of Nutrient Addition to
Influent
Table A-3 Average Nutrient Analyses of Influent and
Effluents
Table A-3s Statistical Analysis of Nutrients in Influent
and Effluents
Table A-4 Average Organic and Solids Analyses of Influent
and Biologically Treated Effluent
Table.A-4s Statistical Analysis of Influent and Biologi-
cally Treated Effluent Organic and Solids
Concentrations
Table A-5 Activated Sludge Process Loading Rates
Table A-5s Statistical Analysis of Activated Sludge Process
Table A-6
Loading Rates, Daily Figures
Centrifuge Solids
COLLECTED AND AVERAGED DATA, 1969-70 SEASON
Table B-l Wastewater Flow and Fruit Processed
Table B-2 Average Addition of Nutrients to the Influent
Table B-2s Statistical Analysis of Nutrient Addition to
Influent
Table B-3 Average Organic and Solids Analyses of Influent
and Effluent
Table B-3s Statistical Analysis of Influent and Effluent
Organic and Solids Concentrations
85
-------
c.
Table B-4
Table B-4s
Table B-5
Table B-5s
Table B-6
PHOTOGRAPHS
Figure C-l
Figure C-2
Figure C-3
Figure C-4
Activated Sludge Process Loading Rates
Statistical Analysis of Activated Sludge
Process Loading Rates
Aerobic Sludge Digester
Statistical Analysis of Aerobic Sludge Digester
Centrifuge Solids
Aerial View of Waste Treatment Plant
Aerobic Digester (Modified Lime Treatment Plant)
Complete Mix Activated Sludge Unit
Clarifier
86
-------
APPENDIX A
COLLECTED AND AVERAGED DATA, 1968 - 69 SEASON
TABLE A-l
WASTEWATER FLOW AND FRUIT PROCESSED
Date
1/19/69
1/20/69
1/21/69
1/22/69
1/23/69
1/24/69
1/25/69
1/26/69
1/27/69
1/28/69
1/29/69
1/30/69
1/31/69
2/1/69
2/2/69
2/3/69
2/4/69
2/5/69
2/6/69
2/7/69
2/8/69
2/9/69
2/10/69
2/11/69
2/12/69
2/13/69
2/14/69
2/15/69
2/16/69
2/17/69
2/18/69
2/19/69
2/20/69
2/21/69
2/22/69
2/23/69
2/24/69
2/25/69
Flow
Rate
MGD
0.8
0.4
1.0
1.2
1.0
1.0
1.0
0.4
1.3
1.2
1.2
1.2
1.1
1.1
0.5
1.0
1.0
1.1
1.0
1.0
1.0
0.3
1.2
0.9
0.9
0.9
0.9
0.4
0.1
0.5
1.1
0.9
1.0
1.0
1.4
0.3
0.9
0.9
Oranges
1000
Boxes*
41.2
0.0
60.9
59.6
61.0
59.1
58.0
0.0
56.2
57.6
54.2
54.0
52.3
57.3
0.0
55.0
45.5
56.5
54.6
55.8
52.5
0.0
57.2
55.1
54.8
45.2
46.9
47.8
0.0
35.7
48.3
43.1
48.0
47.5
50.6
0.0
46.0
36.1
Grape -
Fruit
1000
Boxes
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.5
0.0
0.0
0.0
0.0
8.8
4.4
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Date
2/26/69
2/27/69
2/28/69
3/1/69
3/2/69
3/3/69
3/4/69
3/5/69
3/6/69
3/7/69
3/8/69
3/9/69
3/10/69
3/11/69
3/12/69
3/13/69
3/14/69
3/15/69
3/16/69
3/17/69
3/18/69
3/19/69
3/20/69
3/21/69
3/22/69
3/23/69
3/24/69
3/25/69
3/26/69
3/27/69
3/28/69
3/29/69
3/30/69
3/31/69
4/1/69
4/2/69
4/3/69
4/4/69
Flow
Rate
MGD
1.1
1.1
0.9
0.3
0.1
0.1
1.0
1.2
1.0
0.8
0.7
0.4
0.6
0.6
0.7
0.9
1.1
0.7
0.4
0.2
0.6
0.1
1.0
0.8
0.5
0.1
0.1
0.8
0.8
0.8
0.9
0.7
0.5
0.3
0.9
0.9
1.1
1.2
Oranges
1000
Boxes*
36.0
29.7
47.5
5.9
0.0
0.0
38.7
30.9
47.2
47.4
10.6
0.0
28.7
30.6
30.5
29.3
37.8
3.7
0.0
0.0
12.4
0.0
16.4
30.2
14.4
0.0
0.0
15.5
19.0
17.0
16.9
7.6
0.0
9.8
15.7
18.0
15.8
16.4
Gr ape-
Fruit
1000
Boxes
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
21.1
6.2
0.0
0.0
0.0
21.9
8.7
13.5
22.4
6.5
0.0
13.2
22.0
21.3
23.1
19.9
One Box is 90 pounds of fruit.
87
-------
TABLE A-l
(Continued)
WASTEWATER FLOW AND FRUIT
Date
4/5/69
4/6/69
4/7/69
4/8/69
4/9/69
4/10/69
4/11/69
4/12/69
4/13/69
4/14/69
4/15/69
4/16/69
4/17/69
4/18/69
4/19/69
4/20/69
4/21/69
4/22/69
4/23/69
4/24/69
4/25/69
4/26/69
4/27/69
4/28/69
4/29/69
4/30/69
5/1/69
5/2/69
5/3/69
5/4/69
5/5/69
5/6/69
5/7/69
5/8/69
5/9/69
5/10/69
5/11/69
5/12/69
Flow
Rate
MGD
0.7
0.3
0.2
1.1
0.7
1.5
1.0
1.1
0.0
1.2
1.0
1.0
1.2
0.8
0.1
0.0
1.2
1.2
1.0
1.0
1.0
0.9
0.1
1.3
1.3
1.0
1.1
1.0
1.2
0.0
1.3
1.3
1.2
1.2
1.4
1.0
0.2
1.3
Oranges
1000
Boxes*
0.0
0.0
0.0
17.6
18.7
17.3
14.2
0.0
0.0
0.0
18.6
19.4
15.1
10.7
0.0
0.0
0.0
21.3
0.0
13.1
14.5
0.0
0.0
34.4
38.9
53.4
60.6
56.8
24.6
0.0
61.8
62.9
55.0
58.4
59.4
31.1
0.0
56.5
Grape-
Fruit
1000
Boxes
0.0
0.0
0.0
21.7
24.9
24.5
20.0
0.0
0.0
0.0
25.3
21.4
19.0
9.1
0.0
0.0
0.0
24.2
29.8
25.1
28.6
6.0
0.0
15.4
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Date
5/13/69
5/14/69
5/15/69
5/16/69
5/17/69
5/18/69
5/19/69
5/20/69
5/21/69
5/22/69
5/23/69
5/24/69
5/25/69
5/26/69
5/27/69
5/28/69
5/29/69
5/30/69
5/31/69
6/1/69
6/2/69
6/3/69
6/4/69
6/5/69
6/6/69
6/7/69
6/8/69
6/9/69
6/10/69
6/11/69
6/12/69
6/13/69
6/14/69
6/15/69
6/16/69
6/17/69
6/18/69
6/19/69
PROCESSED
Flow
Rate
MGD
1.4
1.5
1.4
1.4
1.2
0.2
1.5
1.3
1.3
1.3
1.3
0.2
0.0
1.3
1.3
1.2
1.3
1.3
1.4
0.0
1.2
1.4
1.4
1.4
1.3
1.0
0.6
1.3
1.3
1.5
1.4
1.5
0.6
0.0
1.5
0.8
1.3
0.1
Oranges
1000
Boxes*
61.9
59.7
45.8
54.0
30.3
0.0
59.1
7.0
59.8
42.7
46.6
30.4
0.0
63.3
62.1
61.5
61.5
61.9
30.4
0.0
61.3
48.1
46.0
50.4
54.4
7.9
0.0
54.4
58.0
54.5
45.7
54.4
15.8
0.0
61.5
59.4
57.8
0.0
Grape-
Fruit
1000
Boxes
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
One box is 90 pounds of fruit
88
-------
TABLE A-l
(Continued)
WASTEWATER FLOW AND FRUIT PROCESSED
Date
6/20/69
6/21/69
6/22/69
Flow
Rate
MGD
1.2
1.0
0.1
Oranges
1000
Boxes *
44.0
28.1
0.0
Grape-
Fruit
1000
Boxes
0.0
0.0
0.0
Date
6/23/69
6/24/69
Flow
Rate
MGD
1.2
1.3
Oranges
1000
Boxes*
57.2
52.1
Grape-
Fruit
1000
Boxes
0.0
0.0
89
-------
TABLE A-2
AVERAGE ADDITION OF NUTRIENTS TO THE INFLUENT
Month, 1969
January
February
March
April
May
June
Pounds/Day
N
282
218
68
116
614
455
Pounds/Day
P
90
97
36
42
123
91
TABLE A-2s
STATISTICAL ANALYSIS OF NUTRIENT ADDITION TO INFLUENT
Data Points Mean Standard Deviation
Pounds of Nitrogen,
daily figures 162 296 290
Pounds of Nitrogen,
monthly averages 6 292 190
Pounds of Phosphorus,
daily figures 161 79 88
Pounds of Phosphorus,
monthly averages 6 80 31
90
-------
TABLE A-3
AVERAGE NUTRIENT ANALYSIS OF INFLUENT AND EFFLUENT
MONTH
1969
TN
AN
ON
NO +NO
-N
2 NO -N
2
NO--N
3
Total
P
Ortho
P
Total P
Filtered
Ortho P
Filtered
INFLUENT*
February
March
April
May
June
July
35.9
24.5
23.2
60.8
50.32
32.5
15.7
8.6
11.7
32.58
22.13
16.9
19.8
15.9
12.6
30.58
29.01
15.40
0.20
0.23
0.34
0.25
0.21
0.25
BIOLOGICALLY
February
March
April
May
June
July
February
March
April
May
June
4.33
4.05
3.80
4.46
2.77
1.69
4.21
7.93
6.21
4.13
2.25
0.39
0.40
0.35
1.32
0.76
0.23
0.53
0.72
0.61
1.22
0.23
*All results expressed as
3.94
3.35
3.45
3.15
2.27
1.46
3.69
7.21
5.60
2.97
2.32
mg/1
0.02
0.04
0.09
0.03
0.02
0.00
CHEMICALLY
0.03
0.09
0.10
0.02
0.02
0.02
0.08
0.07
0.07
0.07
0.05
0.18
0.14
0.26
0.17
0.14
0.19
10.95
7.49
5.60
8.29
9.20
19.60
2.97
2.28
2.96
6.97
7.63
8.34
3.
1.
3.
5.
5.
8.
50
62
26
09
47
16
1.92
0.82
1.28
3.46
4.71
2.29
TREATED EFFLUENT*
0.01
0.02
0.02
0.01
0.01
0.00
0.01
0.02
0.07
0.02
0.02
0.00
4.54
7.69
1.95
1.45
1.90
0.33
1.80
1.16
0.47
1.18
1.60
0.31
3.
0.
0.
0.
0.
0.
11
86
55
98
99
26
1.86
0.38
0.13
0.83
0.75
0.23
TREATED EFFLUENT*
0.01
0.03
0.02
0.01
0.00
0.02
0.05
0.08
0.02
0.02
2.15
5.35
1.72
0.75
0.54
1.03
1.03
0.69
0.50
0.30
0.
1.
0.
0.
0.
81
48
73
43
18
0.13
0.51
0.23
0.25
0.12
TN = Total Nitrogen
AN = Ammonia Nitrogen
ON = Organic Nitrogen
-------
TABLE A-3s
STATISTICAL ANALYSIS OF NUTRIENTS IN INFLUENT AND EFFLUENTS
10
TN
Daily Figures
TN
Monthly Averages
AN
Daily Figures
AN
Monthly Averages
ON
Daily Figures
ON
Monthly Averages
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Data Points
50
51
46
6
6
5
50
51
46
6
6
5
50
51
46
6
6
5
Standard Deviation
mg/1
39.82 23.11
3.80 2.15
4.95 3.41
37.87 14.86
3.52 1.05
4.95 2.18
18.13 11.54
0.67 1.38
0.69 1.45
17.94 8.53
0.58 0.44
0.66 0.36
22.05 14.73
3.09 1.76
4.29 3.12
20.55 7.54
2.94 0.92
4.36 2.01
-------
TABLE A-3s
(Continued)
STATISTICAL ANALYSIS OF NUTRIENTS IN INFLUENT AND EFFLUENT
10
CO
NO +NO -N
Daily Figures
Monthly Averages
NO -N
Daily Figures
Monthly Averages
Daily Figures
NO -N
Monthly Averages
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Data Points Mean Standard Deviation
50
51
46
6
6
5
50
51
46
6
6
5
50
51
46
6
6
5
mg/1
0.24
0.04
0.04
0.25
0.33
0.05
0.06
0.01
0.01
0.06
0.01
0.01
0.18
0.03
0.03
0.18
0.02
0.04
mg/1
0.09
0.04
0.06
0.05
0.33
0.52
0.03
0.08
0.02
0.02
0.01
0.04
0.08
0.03
0.05
0.04
0.02
0.08
-------
10
-Pi
Total P
Daily Figures
Total P
Monthly Averages
Ortho P
Daily Figures
Ortho P
Monthly Averages
Total P Filtered
Daily Figures
Total P Filtered
Monthly Averages
TABLE A-3s
(Continued)
STATISTICAL ANALYSIS OF NUTRIENTS IN INFLUENT AND EFFLUENT
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Data Points
50
51
46
6
6
5
50
51
46
6
6
5
50
51
46
6
6
5
10.19
2.98
2.10
4.97
1.23
0.70
19
09
0.71
4.05
1.26
0.70
4.52
1.12
0.73
Standard Deviation
5.52
4.12
2.39
4.94
2.69
1.93
4.23
1.38
0.64
2.74
0.58
0.32
3.86
1.26
0.67
2.26
1.02
0.49
-------
Ortho P Filtered
Daily Figures
Ortho P Filtered
Monthly Averages
TABLE A-3s
(Continued)
STATISTICAL ANALYSIS OF NUTRIENTS IN INFLUENT AND EFFLUENT
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Influent
Biologically Treated Effluent
Chemically Treated Effluent
Data Points
Mean
mg/1
50
51
46
6
6
5
2.59
0.75
0.24
2.41
0.70
0.25
Standard Deviation
mg/1
3.00
1.10
0.22
1.45
0.63
0.16
10
en
TN = Total Nitrogen
AN = Ammonia Nitrogen
ON = Organic Nitrogen
-------
TABLE A-4
AVERAGE ORGANIC AND SOLIDS ANALYSES OF INFLUENT AND BIOLOGICALLY TREATED EFFLUENT
MONTH
1969
January
February
March
April
10 ^
en
May
June
July
BOD*
INF.
827
1438
1458
835
1139
983
630
EFF.
54
23
63
44
30
12
5
COD*
INF.
1960
2375
3551
1545
2571
2132
3895
EFF.
267
159
276
410
122
90
92
SS*
INF.
162
338
450
449
197
146
609
EFF.
107
269
969
397
45
18
13
vss
INF.
152
200
333
148
195
76
373
EFF.
96
230
753
227
35
14
9
PH
INF.
10.3
11.2
9.8
9.8
9.8
10.3
9.4
EFF.
7.7
7.8
7.7
7.9
7.8
8.0
7.9
*Expressed as mg/1
-------
TABLE A-4s
STATISTICAL ANALYSIS OF INFLUENT AND BIOLOGICALLY TREATED
EFFLUENT ORGANIC AND SOLIDS CONCENTRATIONS
Data Points Mean Standard Deviation
BOD*
Daily Figures
BOD*
Monthly Averages
COD*
Daily Figures
COD*
Monthly Averages
SS*
Daily Figures
SS*
Monthly Averages
VSS*
Daily Figures
VSS*
Monthly Averages
pH
Daily Figures
PH
Monthly Averages
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
59
58
7
7
59
59
7
7
59
58
7
7
57
56
7
7
59
58
7
7
1167
29
1044
33
2469
189
2576
202
312
285
336
260
190
220
211
195
10.1
7.8
10.1
7.8
775
28
293
20
1459
174
790
111
344
419
163
319
158
331
98
244
1.2
0.2
0.5
0.1
*EXpressed as mg/1
97
-------
TABLE A-5
ACTIVATED SLUDGE PROCESS LOADING RATES
Date
1/28/69
1/29/69
1/30/69
2/2/69
2/4/69
2/5/69
2/6/69
2/10/69
2/11/69
2/12/69
2/13/69
2/18/69
2/19/69
2/20/69
2/21/69
2/25/69
2/26/69
2/27/69
2/28/69
3/4/69
3/5/69
3/6/69
3/7/69
3/12/69
3/13/69
3/14/69
3/25/69
3/26/69
4/1/69
4/2/69
4/10/69
4/17/69
4/22/69
4/23/69
4/30/69
BOD
750
930
800
1170
930
2160
3180
390
675
900
2340
480
1350
2685
1455
400
625
2050
2220
1000
435
1170
3250
1725
2250
1200
1200
900
400
650
1200
1275
600
600
1125
Flow Rate
MGD
1.2
1.2
1.2
0.5
1.0
1.1
1.0
1.2
0.9
0.9
0.9
1.1
0.9
1.0
1.1
1.0
1.1
1.0
0.9
1.0
1.2
1.0
0.8
0.7
0.9
1.1
0.8
0.8
0.9
0.9
1.5
1.2
1.2
1.0
1.0
Avg.MLSS
mg/1.
1378
1505
1605
1750
2385
2815
3030
3040
3260
3396
4268
2720
2285
3045
3050
3420
3140
3225
4177
2970
3815
4165
3445
3785
2987
3040
5000*
6250*
5545
4580
3865
3200
2397
1850
2003
Ibs .BOD/
Ibs .MLSS
0.220
0.267
0.215
0.120
0.140
0.304
0.378
0.055
0.067
0.086
0.178
0.070
0.191
0.318
0.189
0.378
0.079
0.229
0.172
0.091
0.049
0.101
0.272
0.115
0.242
0.156
0.139
0.083
0.023
0.046
0.166
0.170
0.107
0.117
0.200
Only one aeration tank in use.
98
-------
TABLE A-5
(Continued)
ACTIVATED SLUDGE PROCESS LOADING RATES
Date
5/5/69
5/6/69
5/7/69
5/13/69
5/14/69
5/15/69
5/20/69
5/21/69
5/22/69
5/23/69
6/2/69
6/3/69
6/4/69
6/5/69
6/6/69
6/7/69
6/8/69
6/9/69
6/10/69
6/11/69
6/12/69
BOD
rag/i
750
600
750
780
1650
780
2200
305
2075
1500
480
580
640
920
2160
3300
270
855
525
780
720
Flow Rate
MGD
1.3
1.3
1.2
1.4
1.5
1.4
1.3
1.3
1.3
1.3
1.2
1.4
1.4
1.4
1.4
1.0
0.6
1.3
1.3
1.5
1.4
Avg.MLSS
mg/1
2079
2265
2160
3140
3485
4580
6374
4950
5086
6290
4939
4770
4930
5542
5865
6985
5080
5110
5510
5705
6150
Ibs .BOD/
Ibs.MLSS
0.168
0.123
0-149
0.124
0.254
0.085
0.160
0.029
0.189
0.111
0.042
0.059
0.065
0.083
0.184
0.169
0.014
0.078
0.044
0.073
0.059
TABLE A-5s
STATISTICAL ANALYSIS OF ACTIVATED SLUDGE PROCESS LOADING RATES
DAILY FIGURES
BOD,mg/1
Flow Rate, MGD
Ave. MLSS, mg/1
Ibs BOD/lbs MLSS
Data Points
56
56
56
56
Mean Standard Deviation
1198 775
1.1 0.2
3810 1430
0.143 0.086
99
-------
TABLE A-6
CENTRIFUGE PERCENT SOLIDS
Date
2/18/69
2/21/69
2/21/69
2/24/69
2/24/69
2/25/69
2/25/69
3/4/69
3/11/69
3/13/69
3/13/69
3/13/69
3/13/69
3/14/69
3/29/69
4/11/69
4/12/69
4/12/69
4/12/69
4/16/69
4/16/69
4/16/69
4/17/69
4/17/69
4/18/69
4/18/69
4/18/69
4/22/69
4/22/69
4/23/69
4/23/69
4/23/69
4/23/69
4/23/69
4/25/69
4/25/69
Influent
%
Solids
3.12
12.90
3.52
10.40
5.03
8.76
2.32
3.81
3.81
3.37
3.54
4.24
3.44
2.71
8.16
5.39
2.42
3.49
2.95
5.40
4.26
4.10
7.00
7.59
5.60
6.53
7.16
5.64
5.25
6.00
7.86
8.37
3.54
5.84
7.05
3.36
Effluent
%
Solids
0.28
3.45
0.48
4.27
2.35
1.48
1.23
1.18
1.18
1.24
1.58
2.07
1.72
1.58
2.76
4.10
1.79
2.82
2.18
4.10
0.82
1.03
1.87
2.63
2.12
2.58
2.82
3.26
1.45
0.30
0.83
4. .06
1.12
1.18
3.83
1.09
Cake Influent Coagulant Dispersion
% Feed Rate Coagulant Feed Rate Water Feed
.qoi-i^c. GPM Tvpe GPM Rate, GPM
20.6
50.6
25.2
45.0
50.9
40.4
22.5
36.4
36.4
30.0
27.3
29.0
47.5
28.4
31.6
51.8
49.4
55.6
57.8
51.8
48.0
6.3
10.8
18.8
13.1
12.1
9.9
9.2
8.6
4.3
16.7
18.1
8.6
7.0
31.2
12.5
- - -
_
- - -
- -
- - -
- -
- -
- - -
25
32
38
25
_
_
_
_
_
- -
- - -
_ _
_
_
_
- -
_ _ _
-
25
25 Nalco 672 1.0
25 Nalco 672 1.0
25 - 0.0
40 - 0.0
40 Nalco 672 1.0
40 Nalco 672 0.5
40 - 0.0
40 Nalco 672 0.5
-
~
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
4
6
0
0
5
5
0
5
100
-------
TABLE A- 6
(Continued)
CENTRIFUGE PERCENT SOLIDS
Influent
Effluent
Cake Influent
Coagulant Dispersion
% % % Feed Rate Coagulant Feed Rate Water Feed
Date
5/19/69
5/21/69
5/21/69
5/23/69
5/23/69
5/23/69
5/28/69
5/28/69
5/28/69
6/11/69
6/13/69
6/17/69
6/17/69
6/24/69
6/25/69
6/25/69
6/27/69
6/27/69
6/27/69
6/28/69
7/2/69
7/2/69
7/3/69
Solids
0.87
1.47
1.45
2.49
2.46
2.78
2.99
2.74
2.51
3.71
2.40
4.44
2.64
5.24
4.35
1.86
1.77
1.48
1.40
2.74
1.81
2.00
1.76
Solids
0.40
0.65
0.78
0.72
0.88
0.74
0.65
0.66
0.60
0.84
0.21
0.71
0.36
0.66
2.34
1.06
0.35
0.06
0.05
0.87
0.72
0.65
0.44
Solids
13.1
4.6
4.0
13.4
15.7
13.9
6.5
6.4
6.5
17.6
15.0
25.2
16.4
31.4
17.0
5.2
8.3
7.1
6.8
9.0
9.9
5.4
7.4
GPM
40
40
40
40
50
40
40
40
40
-
-
40
40
40
40
40
20
20
20
20
20
20
20
Type
Nalco 672
Nalco 672
Nalco 672
Nalco 672
Nalco 672
Nalco 672
Nalco 672
Nalco 672
Nalco 672
-
-
Cat. Floe
Cat. Floe
Nalco 607
Nalco 607
-
-
Nalco 607
Nalco 607
Nalco 607
Nalco 607
Nalco 607
-
GPM
0.5
0.5
0.9
0.9
0.9
0.5
0.5
0.25
0.25
-
-
0.25
0.25
0.25
0.25
0.0
0.0
0.5
0.25
0.25
0.25
1.25
-
Rate, GPM
10
10
10
10
10
10
10
10
5
-
-
5
5
5
5
0
0
5
5
5
5
5
5
101
-------
APPENDIX B COLLECTED AND AVERAGED DATA 1969-70
SEASON
TABLE B-l
WASTEWATER FLOW AND FRUIT PROCESSED
Flow
Date Rate
MGD
11/11/69
11/12/69
11/13/69
11/14/69
11/15/69
11/16/69
11/17/69
11/18/69
11/19/69
11/20/69
11/21/69
11/22/69
11/23/69
11/24/69
11/25/69
11/26/69
11/27/69
11/28/69
11/29/69
11/30/69
12/1/69
12/2/69
12/3/69
12/4/69
12/5/69
12/6/69
12/7/69
12/8/69
12/9/69
12/10/69
12/11/69
12/12/69
12/13/69
12/14/69
12/15/69
12/16/69
12/17/69
12/18/69
Oranges
1000
Boxes*
6.3
7.3
6.7
7.7
0.0
o.o
8.7
9.4
9.7
11.6
12.1
6.4
0.0
16.9
21.3
19.4
0.0
20.2
17.6
0.0
19.6
22.4
20.7
22.1
18.5
14.8
0.0
26.0
19.6
7.3
20.5
33.7
8.3
0.0
33.6
32.6
32.8
33.1
Grape-
Fruit
1000
Boxes
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Date
12/19/69
12/20/69
12/21/69
12/22/69
12/23/69
12/24/69
12/25/69
12/26/69
12/27/69
12/28/69
12/29/69
12/30/69
12/31/69
1/1/70
1/2/70
1/3/70
1/4/70
1/5/70
1/6/70
1/7/70
1/8/70
1/9/70
1/10/70
1/11/70
1/12/70
1/13/70
1/14/70
1/15/70
1/16/70
1/17/70
1/18/70
1/19/70
1/20/70
1/21/70
1/22/70
1/23/70
1/24/70
1/25/70
Flow
Rate
MGD
0-9
0.8
o.i
1.1
0.9
0-1
0.1
o.i
0-9
1.0
1.3
1.3
1.3
1.6
1.5
0-5
o.i
1.3
1.2
0.4
1.4
1.6
1.7
1.9
1.9
1.7
1.7
1.6
1.4
0.9
1.7
1.5
1.6
1.6
1.7
1.6
1.6
1.6
Oranges
1000
Boxes*
32.6
17.2
0.0
39.4
22.4
0.0
0.0
0.0
30.3
34.0
48.7
52.1
56.3
55.6
45.2
6.7
0.0
48.1
31.0
0.0
49.6
46.8
48.8
49.5
53.5
54.7
54.6
60.3
39.8
22.0
60.0
62.3
60.8
62.0
67.8
64.9
61.4
65.7
Grape-
Fruit
1000
Boxes
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
*One box is 90 pounds of fruit
102
-------
TABLE B-l
( Continued)
WASTEWATER FLOW AND FRUIT
Date
1/26/70
1/27/70
1/28/70
1/29/70
1/30/70
1/31/70
2/1/70
2/2/70
2/3/70
2/4/70
2/5/70
2/6/70
2/7/70
2/8/70
2/9/70
2/10/70
2/11/70
2/12/70
2/13/70
2/14/70
2/15/70
2/16/70
2/17/70
2/18/70
2/19/70
2/20/70
2/21/70
2/22/70
2/23/70
2/24/70
2/25/70
2/26/70
2/27/70
2/28/70
3/1/70
3/2/70
3/3/70
Flow
Rate
MGD
1.6
1.8
1.7
1.6
1.6
1.2
1.7
1.3
0.8
1.5
1.7
1.2
0.9
0.9
1.1
1.0
0.9
1.3
1.0
1.1
1.3
1.6
1.0
1.0
1.5
1.4
1.4
0.4
1.2
1.3
1.3
1.2
1.4
0.8
0.1
0.7
1.4
Oranges
1000
Boxes*
65.1
61.3
67.4
62.7
58.0
50.6
56.4
24.4
0.0
35.0
57.6
60.5
61.1
60.7
56.4
60.7
59.7
63.8
59.2
55.0
53.3
28.6
10.6
36.8
59.8
59.2
57.8
0.0
49.0
50.8
47.4
33.7
32.1
47,3
0.0
24.8
45.9
Grape-
Fruit
1000
Boxes
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
o.o
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
o.Q
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Date
3/4/70
3/5/70
3/6/70
3/7/70
3/8/70
3/9/70
3/10/70
3/11/70
3/12/70
3/13/70
3/14/70
3/15/70
3/16/70
3/17/70
3/18/70
3/19/70
3/20/70
3/21/70
3/22/70
3/23/70
3/24/70
3/25/70
3/26/70
3/27/70
3/28/70
3/29/70
3/30/70
3/31/70
4/1/70
4/2/70
4/3/70
4/4/70
4/5/70
4/6/70
4/7/70
4/8/70
4/9/70
PROCESSED
Flow
Rate
MGD
1.3
1,5
1.4
0.2
0.1
1.2
1.4
1.4
1.5
1.3
1.4
0.3
0.4
1.1
1.2
0.9
1.0
0.1
0.1
0.1
0.1
0.9
0.1
0.1
0.1
0.1
0.1
0.4
0.4
0.4
0 .4
0 .1
0 .1
0 .1
0 .1
1.0
1.0
Oranges
1000
Boxes*
38.1
30.8
37.3
0.0
0.0
16.1
36.2
17.0
34.3
36.2
6.0
0.0
10.3
11.7
10.5
9.0
6.1
0.0
0.0
0.0
0.0
2.9
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
28.1
33.2
Gr ape-
Fruit
1000
Boxes
8.6
18.5
0.0
0.0
0.0
20.1
0.0
23.9
19.1
13.8
1.4
0.0
0.0
18.0
20.5
1.7
11.2
0.0
0.0
0.0
0.0
9.7
4.1
0.0
0.0
0.0
0.0
0.0
0.0
3.8
0.0
0.0
0.0
0.0
0.0
0.0
0.0
*0ne box is 90 pounds of fruit
103
-------
TABLE B-l
(Continued)
WASTEWATER FLOW AND FRUIT
Date
4/10/70
4/11/70
4/12/70
4/13/70
4/14/70
4/15/70
4/16/70
4/17/70
4/18/70
4/19/70
4/20/70
4/21/70
4/22/70
4/23/70
4/24/70
4/25/70
4/26/70
4/27/70
4/28/70
4/29/70
4/30/70
5/1/70
5/2/70
5/3/70
5/4/70
5/5/70
5/6/70
5/7/70
5/8/70
5/9/70
5/10/70
5/11/70
5/12/70
5/13/70
5/14/70
5/15/70
5/16/70
5/17/70
5/18/70
Flow
Rate
MGD
0-4
0.4
0.1
0.7
1.4
1.3
1.2
1.2
0.4
0.1
1.3
1.5
1.4
1.4
1.5
1.4
0.4
1.3
1.4
1.5
1.3
1.4
1.7
1.4
1.5
1.1
1.2
1.2
1.2
1.3
1.2
1.0
1.5
1.3
1.4
1.3
1.5
1.7
1.6
Oranges
1000
Boxes*
11.5
0.0
0.0
24.9
38.5
43.1
41.4
46.0
2.3
0.0
54.0
55.8
52.5
53.9
56.3
49.1
0.0
59.4
56.1
59.5
55.5
59.6
57.3
55.5
54.8
55.2
57.9
56.6
55.8
54.8
53.6
53.8
54.2
57.1
52.9
57.6
54.7
53.9
53.8
Grape-
Fruit
1000
Boxes
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
3.5
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Date
5/19/70
5/20/70
5/21/70
5/22/70
5/23/70
5/24/70
5/25/70
5/26/70
5/27/70
5/28/70
5/29/70
5/30/70
5/31/70
6/1/70
6/2/70
6/3/70
6/4/70
6/5/70
6/6/70
6/7/70
6/8/70
6/9/70
6/10/70
6/11/70
6/12/70
6/13/70
6/14/70
6/15/70
6/16/70
6/17/70
6/18/70
6/19/70
6/20/70
6/21/70
6/22/70
6/23/70
6/24/70
6/25/70
PROCESSED
Flow
Rate
MGD
1.5
1.4
1.4
1.5
1.4
1.6
1.6
1.2
1.4
1,5
1.5
0.7
0.1
1.0
1.4
1.4
1.5
1.2
1.4
1.5
1.7
1.6
1.6
1.6
1.6
1.7
1.5
1.5
1.6
1.6
1.3
1.1
1.0
1.0
1.3
1.0
1.0
1.3
Oranges
1000
Boxes *
55.2
53.8
54.4
52.8
51.8
55.1
53.7
49.7
51.4
56.1
52.3
18.7
0.0
36.3
59.1
51.6
54.3
57.3
54.5
56.8
53.0
52.7
50.8
52.9
58.2
58.9
57.0
50.2
49.0
50.5
48.1
46.5
43.9
28.9
28.1
22.7
26.8
0.0
Gr ape-
Fruit
1000
Boxes
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
*One box is 90 pounds of fruit
104
-------
TABLE B-2
AVERAGE ADDITION OF NUTRIENTS TO THE INFLUENT
Month
1969-70
November
December
January
February
March
April
May
June
Pounds
Nitrogen
151
230
821
571
328
381
629
592
Pounds
Phosphorus
101
184
99
64
21
22
28
26
TABLE B-2s
STATISTICAL ANALYSIS OF NUTRIENT ADDITION TO INFLUENT
Data Points Mean Standard Deviation
Pounds Nitrogen Added,
daily figures 217 488 301
Pounds Nitrpgen Added,
monthly figures 8 463 212
Pounds Phosphorus Added,
daily figures 219 69 133
Pounds Phosphorus Added,
monthly figures 8 68 54
105
-------
TABLE B-3
AVERAGE ORGANIC AND SOLIDS ANALYSES OF INFLUENT AND EFFLUENT
o
CT)
Month
1969-70
November
December
January
February
March
April
May
June
BOD*
INF.
452
704
1715
2408
1323
926
1230
1104
EFF.
2
16
34
23
32
9
22
5
COD*
INF.
975
2156
3817
7322
3775
2625
3579
4481
EFF.
41
81
479
396
386
83
154
119
SS*
INF.
104
486
828
2585
485
250
329
462
EFF.
15
87
537
618
626
181
225
122
vss*
INF.
93
366
675
1977
425
204
281
435
EFF.
15
77
504
453
558
152
210
116
PH
INF.
9.3
8.6
10.2
9.6
7.7
8.2
8.6
8.1
EFF.
7.6
7.5
7.5
7.7
7.5
7.4
7.3
7.7
*mg/l
-------
TABLE B-3s
STATISTICAL ANALYSIS OF INFLUENT AND EFFLUENT
ORGANIC AND SOLIDS CONCENTRATIONS
Data Points Mean Standard Deviation
BOD*
Daily Figures
BOD*
Monthly Averages
COD*
Daily Figures
COD*
Monthly Averages
SS*
Daily Figures
SS*
Monthly Averages
VSS*
Daily Figures
VSS*
Monthly Averages
PH
Daily Figures
PH
Monthly Averages
INF.
EFF.
INF.
EFF
INF.
EFF
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
INF.
EFF.
67
56
8
8
67
67
8
8
62
63
8
8
62
63
8
8
67
67
8
8
1290
19
1245
18
3685
234
3591
217
705
324
691
301
568
282
557
261
8.9
7.5
8.8
7.5
869
20
598
11
2312
275
1755
162
830
409
743
235
649
376
561
198
1.8
0.3
0.8
0.1
*mg/l
107
-------
TABLE B-4
ACTIVATED SLUDGE PROCESS LOADING RATES
Date
12/22/69
12/28/69
12/29/69
12/30/69
1/6/70
1/8/70
1/14/70
1/15/70
1/16/70
1/19/70
1/20/70
1/21/70
1/26/70
1/27/70
2/2/70
2/5/70
2/9/70
2/10/70
2/11/70
2/16/70
2/17/70
2/23/70
2/24/70
3/3/70
3/4/70
3/5/70
3/9/70
3/10/70
3/11/70
3/16/70
3/17/70
3/18/70
4/14/70
4/15/70
4/16/70
4/20/70
BOD
mg/1
502
400
590
1175
770
540
1200
1620
3840
1250
1740
975
2460
2760
4250
600
2460
2850
1935
2070
1710
3300
2510
1100
2100
2135
540
2500
2165
155
505
810
720
650
1500
850
Flow Rate
MGD
1.1
1.0
1.3
1.3
1.2
1.4
1.7
1.6
1.4
1.5
1.6
1.5
1.6
1.8
1.3
1.7
1.1
1.0
0.9
1.6
1.0
1.2
1.3
1.4
1.3
1.5
1.2
1.4
1.4
0.4
1.1
1.2
1.4
1.3
1.2
1.3
Avg.MLSS
mg/1
4946
3750
3850
4400
4325
4180
5925
5700
6600
5850
5460
5180
5600
4370
3200
3925
5000
5500
5925
4600
5400
4870
5000
4120
4310
4170
4210
4175
4280
3800
3990
4020
2980
3565
3900
4020
Ibs .BOD/
Ibs .MLSS
0.07
0.04
0.07
0.12
0.07
0.06
0.11
0.15
0.27
0.11
0.17
0.10
0.23
0.38
0.58
0.09
0.18
0.17
0.10
0.24
0.11
0.27
0.22
0.12
0.21
0.26
0.05
0.28
0.24
0.01
0.05
0.08
0.11
0.08
0.15
0.09
108
-------
TABLE B-4
(Continued)
ACTIVATED SLUDGE PROCESS LOADING RATES
Date
4/21/70
4/22/70
4/27/70
4/28/70
4/29/70
5/4/70
5/5/70
5/11/70
5/12/70
5/13/70
5/18/70
5/19/70
6/2/70
6/3/70
6/9/70
6/10/70
6/16/70
6/17/70
6/23/70
6/24/70
BOD
mg/1
1050
1300
600
760
900
770
2110
1300
900
960
1320
1250
1500
840
1300
1690
950
750
900
900
Flow Rate
MGD
1.5
1.4
1.3
1.4
1.5
1.5
1.1
1.0
1.5
1.3
1.6
1.5
1.4
1.4
1.6
1.6
1.6
1.6
1.0
1.3
Avg.MLSS
mg/1
4150
4235
4620
4550
4640
4335
4470
4635
4560
4575
3960
3890
3955
3895
4495
4500
4420
4550
4635
4300
Ibs .BOD/
Ibs.MLSS
0.13
0.14
0.06
0.08
0.10
0.09
0.17
0.09
0.12
0.08
0.18
0.16
0.18
0.10
0.15
0.20
0.11
0.09
0.06
0.09
109
-------
TABLE B-4s
STATISTICAL ANALYSIS OF ACTIVATED SLUDGE
PROCESS LOADING RATES
Data Points Mean Standard Deviation
BOD, mg/1
Flow Rate, mg/1
Avg. MLSS, mg/1
Ibs BOD/lbs MLSS
56
56
56
56
1416
1.3
4526
0.14
873
0.2
705
0.09
no
-------
TABLE B-5
AEROBIC SLUDGE DIGESTER
Month
1969-70
December
January
February
March
April
May
June
Influent
(%
-
1.
0.
0.
1.
0.
0.
Solids
)
-
23
7
6
0
8
7
Effluent Solids
(*)
1.
2.
2.
1.
1.
3.
3.
7
1
2
5
9
7
1
Effluent
(1000 gal
47
56
81
41
24
51
53
Sludge
/day)
TABLE B-5s
STATISTICAL ANALYSIS OF AEROBIC SLUDGE DIGESTER
Data Points Mean Standard Deviation
Solids \
Daily Figures
Solids %
Monthly Figures
Effluent Sludge
Daily Figures
Effluent Sludge
Monthly Figures
INF.
EFF.
INF.
EFF.
52
64
6
7
184
0.93
2.27
0.84
2.31
51
50
0.32
0.81
0.21
0.74
35
16
111
-------
IV)
TABLE B-6
CENTRIFUGE PERCENT SOLIDS
Actual Influent
Date (%)
12/8/69
12/9/69
12/11/69
12/12/69
12/29/69
1/5/70
1/8/70
1/9/70
1/14/70
1/14/70
1/14/70
1/15/70
1/18/70
1/19/70
1/20/70
1/21/70
1/22/70
1/22/70
1/23/70
1/25/70
1/26/70
1/27/70
1/28/70
1.4
1.0
1.1
1.3
1.4
2.0
1.6
1.7
1.6
1.6
1.8
1.7
1.9
1.5
3.0
1.6
1.4
1.4
1.6
1.5
1.6
1.8
0.0
Centrate Cake
(%) (%)
0 .65
0.05
0.07
0 .02
0.64
1.1
0.81
0 .89
0.72
0 .67
0 .89
1.1
1.1
1.3
1.9
1.1
0 .68
0 .20
0 .73
0 .86
1.0
1.3
1.2
2.26
1.84
4.7
6.5
4.6
4.7
4.6
4.9
3.7
4.8
4.2
4.1
6.6
6.4
5.8
4.8
2.5
3.7
2.7
6.1
7.1
8.4
7.4
Influent
Feed
" Rate
(gpm)
10-15
10-15
20-25
20-25
20-25
20-25
20-25
20-25
20-25
20-25
20-25
20-25
40
40
40
40
40
35
35
35
35
20-25
20-25
R Pool
P Depth
M Inches
1600
1600
2100
2100
1750
1750
1750
1750
1750
1750
1750
1750
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2.6
2.6
2.6
2.6
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.6
2.6
2.6
2.8
Coagulant
Type
None
None
None
None
None
None
None
None
None
None
None
None
None
None
Nalco 607
Nalco 607
Nalco 607
Nalco 607
Nalco 607
None
None
None
None
Coagulant
Feed
Cone.
(%)
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.5
0.5
0.5
0.25
0.25
0.0
0.0
0.0
0.0
Coagulant
Feed
Rate
(gpm)
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.5
0.5
0.5
0.25
0.25
0.0
0.0
0.0
0.0
Disp.
HO Recovery
(gpm) (%)
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
75
97
95
98
63
58
60
58
68
67
64
48
50
16
54
40
70
90
74
49
43
33
35
-------
TABLE B-6
(Continued)
CENTRIFUGE PERCENT SOLIDS
Actual
Date
1/28/70
1/29/70
1/30/70
1/30/70
1/30/70
1/31/70
2/2/ 70
2/2/70
2/2/70
2/2/70
2/5/70
2/6/70
2/7/70
2/8/70
2/10/70
2/11/70
2/12/70
3/4/70
3/4/70
3/4/70
3/4/70
Influent Centrate Cake
(%) (%) (%)
2.1
2.1
1.8
1.9
1.9
1.7
2.2
2.1
2.1
2.1
1.6
1.6
1.9
1.1
1.5
1.4
1.4
1.2
2.0
1.3
1.4
1.4
0.82
0.97
0.28
0.58
0.71
0.97
0.78
1.0
1.2
0.86
0.99
1.3
0.88
0.87
0.62
0.65
0.52
0.82
0.10
0.13
7.2
7.6
6.9
6.2
5.7
6.6
6.7
6.6
6.4
6.3
6.3
7.9
6.8
6.3
6.3
6.0
5.7
2.3
2.9
2.5
2.4
Influent
Feed
Rate
(gpm)
20-25
20-25
20-25
20
20
20
20
20
20
20
20-25
20-25
20-25
20-25
20-25
20-25
20-25
20-25
20-25
20-25
20-25
R Pool
P Depth
M Inches
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2.8
2.8
2.8
2.8
2.8
2.8
2.8
2.8
2.8
2.8
2.8
2.6
2.6
2.6
2.6
2.6
2.6
2.6
2.6
2.6
2.6
Coagulant
Type
Nalco 607
Nalco 672
None
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
None
None
None
None
None
None
None
Cat Floe
Cat Floe
Cat Floe
Coagulant
Feed
Cone.
(%)
0.5
0.5
0.0
5.0
5.0
5.0
1.0
1.0
0.38
0.38
0.50
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.76
0.76
0.76
Coagulant
Feed Disp.
Rate HO
(gpm) (gpm)
0.8
0.25
0.0
0.9
0.25
0.25
0.57
0.57
0.73
0.57
0.80
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.75
0.86
0.63
0.0
0.5
0.0
5.0
5.0
5.0
0.8
2.0
2.2
2.2
5.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
5.2
5.2
5.2
Recovery
(%)
41
68
53
89
77
65
65
71
60
52
53
43
39
23
48
62
60
73
82
96
95
-------
TABLE B-6
(Continued)
CENTRIFUGE PERCENT SOLIDS
Actual
Date
3/4/70
3/4/70
3/5/70
3/5/70
3/5/70
3/5/70
3/5/70
3/6/70
3/6/70
3/6/70
3/6/70
3/10/70
3/10/70
3/10/70
3/12/70
3/12/70
3/13/70
3/13/70
3/13/70
3/13/70
3/13/70
Influent
(%)
1.4
1.3
1.1
1.6
1.4
1.5
1.2
1.1
0.82
1.2
1.2
1.6
1.8
1.9
1.6
1.6
2.0
1.5
1.5
1.7
1.6
Influent
Feed
Centrate Cake Rate
(%) (%) (gpm)
0.15
0.26
0.18
1.1
0.67
0.30
0.35
0.37
0.45
0.50
0.34
1.2
0.96
1.2
0.54
1.1
1.9
1.0
0.89
1.0
1.0
2.7
2.6
2.3
2.9
3.0
3.4
2.6
2.3
2.2
2.1
2.3
3.4
2.8
2.8
2.7
2.7
3.6
5.2
2.2
2.2
2.2
20-25
20-25
20-25
20-25
20-25
20-25
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
R
P
M
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
Pool
Depth
Inches
2.6
2.6
2.6
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
Coagulant
Type
Cat Floe
Cat Floe
Cat Floe
None
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
None
Hercules
Hercules
Hercules
Hercules
None
None
Betz 1150
Betz 1150
Betz 1150
Coagulant
Feed
Cone.
(%)
0.76
0.90
0.50
0.0
0.70
0.70
0.70
0.50
0.50
0.50
0.50
0.0
0.50
0.50
0.50
0.50
0.0
0.0
0.25
0.25
0.25
Coagulant
Feed
Rate
(gpm)
0.47
0.80
0.63
0.0
0.60
0.86
0.86
0.63
0.60
0.27
0.73
0.0
0.86
0.50
0.70
0.37
0.0
0.0
0.73
0.37
0.18
Disp.
H2°
(gpm)
2.5
5.0
5.0
0.0
4.1
4.0
7.8
8.1
8.1
7.7
8.6
0.0
7.0
7.0
7.0
7.0
0.0
0.0
8.0
8.0
8.0
Recovery
(%)
94
88
90
50
67
87
81
79
56
76
84
38
71
64
82
52
10
41
68
75
68
-------
TABLE B-6
(Continued)
CENTRIFUGE PERCENT SOLIDS
en
Actual
Date
3/17/70
3/17/70
3/18/70
3/18/70
3/18/70
3/18/70
3/18/70
3/18/70
3/19/70
3/19/70
3/19/70
3/19/70
3/19/70
3/19/70
3/19/70
3/19/70
3/19/70
3/19/70
3/19/70
Influent
(%)
1.7
1.7
1.5
1.5
1.6
1.5
1.8
1.7
1.7
1.7
1.8
1.5
1.4
1.5
1.6
1.6
1.7
1.7
1.8
Centrate
(%)
1.3
1.3
1.2
0.8
0.9
0.9
1.0
1.1
1.1
1.2
1.2
0.9
0.8
0.9
1.0
1.0
1.5
1.1
1.2
Influent
Feed R Pool
Cake Rate P Depth
(%) (gpm) M Inches
4.4
2.7
2.2
2.3
2.3
2.3
2.3
2.2
2.1
2.2
2.2
2.4
2.7
2.8
2.6
2.6
2.0
2.4
2.4
30
30
40
40
40
40
40
40
40
40
40
30
30
30
30
30
40
40
40
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2100
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
Coagulant
Type
None
Betz 1150
None
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
None
Hercofloc
834.1
Hercofloc
834.1
Hercofloc
Hercofloc
Hercofloc
Hercofloc
Hercofloc
Coagulant
Feed
Cone.
(%)
0.0
0.50
0.0
1.4
1.4
1.4
1.4
1.4
1.4
0.90
0.90
0.0
0.66
0.66
0.66
0.66
0.66
0.66
Coagulant
Feed
Rate
(gpm)
0.0
0.73
0.0
0.96
0.96
0.92
0.92
0.75
0.60
0.81
0.90
0.0
0.95
0.93
0.40
0.35
0.82
0.67
Disp.
H2°
(gpm)
0.0
7.5
0.0
8.7
8.0
8.0
8.0
9.0
9.0
7.3
6.0
0.0
4.9
4.9
6.1
5.1
7.7
7.7
Recovery
(%)
33
45
43
65
58
50
73
55
56
53
60
60
60
47
43
50
57
62
54
-------
TABLE B-6
- (Continued)
CENTRIFUGE PERCENT SOLIDS
01
Actual
Date
4/14/70
4/15/70
4/16/70
4/17/70
4/21/70
5/5/70
5/5/70
5/6/70
5/8/70
5/8/70
5/8/70
5/8/70
5/12/70
5/13/70
Influent
(%)
1.8
1.5
2.3
1.5
1.5
1.4
1.4
0-5
1.2
1.3
1.4
1.5
1.0
0.8
Influent
Feed
Centrate Cake Rate
(%) (%) (gpm)
1.2
1.5
1.1
1.0
1.1
1.3
1.9
0-2
0.6
0.9
0.7
0.9
0.5
0.4
13.8
7.0
14.0
10.5
12.9
5.8
5.8
5.0
4.9
4.7
5.8
5.1
4.7
4.3
20
30
35-40
20
20
20
20
20
29
38
9
22
20
20
R Pool
P Depth
M Inches
2100
2100
2100
2100
2100
2450
2450
2450
2450
2450
2450
2450
2450
2450
2.4
2.4
2.4
2.4
2.4
2.45
2.45
2.45
2.45
2.45
2.45
2.45
2.45
2.45
Coagulant
Type
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
None
None
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Cat Floe
Coagulant
Feed
Cone.
(%)
0.50
0.50
0.50
0.50
0.50
0.0
0.0
0.5
0.5
0.5
0.6
0.5
0.5
0.5
Coagulant
Feed Disp.
Rate HO
(gpm) (gpm)
0.75
0-75
0.75
0.75
0-75
0.0
0.0
0.5
0.5
0.68
0.20
0.36
0.5
0.5
6.0
9.0
9.0
9.0
9.0
0.0
0.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
Recovery
(%)
50
35
56
36
29
9
5
62
32
25
32
29
55
55
-------
APPENDIX C-PHOTOGRAPHS
FIGURE C-l - AERIAL VIEW OF WASTE TREATMENT PLANT
-------
00
FIGURE C-2 - AEROBIC DIGESTER
(Modified Lime Treatment Unit)
-------
FIGURE C-3 - COMPLETE MIX ACTIVATED SLUDGE UNIT
-------
ro
FIGURE C-4 - CLARIFIER
-------
1
Accession Number
w
5
Organization
2
Subject Field &. Group
05D
Winter Garden Citrus
SELECTED WATER RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
Products Cooperative
Winter Garden, Florida
Title
COMPLETE MIX ACTIVATED SLUDGE TREATMENT OF CITRUS PROCESSING WASTES
I Q Author(s)
Jones, Richard H.
16
21
Project Designation
EPA, WQO Grant No.
12060 EZY
Note
22
Citation
23
Descriptors (Starred First)
*Citrus fruits, *Wastewater treatment, *Activated sludge,
Estimated costs, Kinetics, Nutrient requirements, organic
loading, seasonal
25
Identifiers (Starred First)
*Complete mix, *Lime Treatment, *Aerobic digestion
27
Abstract
A full-scale, complete mixed activated sludge treatment system
effectively treats concentrated wastewater from the Winter Garden Citrus
Products Cooperative. This process has a BOD reduction capability of
99 percent; but it produces 0.5 to 0.6 pounds of waste sludge per pound
of influent BOD. The efficiency was reduced by periodic foaming and
solids carryover in the effluent caused by the unscheduled discharge of
orange oil and peel press liquor to the treatment plant.
Controlling the addition of nitrogen and phosphorus to the influent
of the nutrient deficient wastewater effectively controlled effluent
nitrogen and phosphorus concentrations.
Waste sludge was mixed with citrus peel and processed as a cattle
feed additive in the existing facilities. The waste activated sludge
represented approximately 1.5 percent of the total cattle feed produc-
tion on a dry weight basis. Treatment plant effluent was reused for
barometric leg and cooling water and was then discharged.
Abstractor
RirharH H. Jone;
Institution
Fnvironmental Engineering, Inc.
WR:102 (REV. JULY 1969)
WRSIC
SEND WITH COPY OF DOCUMENT. TO: WATER RESOURCES SCIENTIFIC INFORMATION CENTER
SEND. Wl U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. D. C. 20240
U.S. GOVERNMENT PRINTING OFFICE: 1972-484-483/91 1-J
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