UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Food and Wood Products Branch
Corvallis Field Station
200 SW 35th Street
Corvallis, OR 97330
January 2, 1976
SUBJECT: Transmission of Waste Treatment Technology for Meat and
Poultry Processing Plants
t As requested, a copy of our most recent publication is being sent
to you. The enclosed paper describes the second phase of a three phase
project. A documentary movie on all three phases will be shown at the
Food Processing Waste Symposium being held April 9-11, 1976 at the
Atlanta American Hotel in Atlanta, Georgia.
The Symposium is held annually at locations in which food processing
is concentrated. The Symposium is co-sponsored this year by the American
Meat Institute, the Southeastern Poultry and Egg Association, and EPA's
Food and Wood Products Branch located here in Corvallis.
Very truly yours,
Jack L. Witherow
Food Wastes Research
Enclosure
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SMALL MEAT-PACKERS WASTES TREATMENT SYSTEMS - II
by
f
Jack L. Witherow
Food and Wood Products Branch
Corvallis, Oregon Field Site
Industrial Environmental Research Laboratory-Cincinnati
INTRODUCTION
The second phase of a research project to demonstrate treatment
technology for meat packing wastewater is reported herein. The first
phase is in the proceedings of this conference in 1973 (1). Since the
project was designed in 1970, National Discharge Guidelines have more
precisely defined the technologies needed by the meat packing industry.
In the second phase the scope of the project was enlarged to meet these
needs.
Because the use of full time waste treatment personnel is not
practical for small meat-packers, minimum operational requirements are
more important than minimum capital cost. To meet this constraint, the
treatment processes were designed to minimize and automate the
mechanical equipment. Full scale processes combined with pilot scale
processes were evaluated in this study (Figure 1). The full scale
processes were a novel extended aeration unit and two aerobic lagoons.
The pilot processes were spray runoff irrigation and intermittent sand
filtration.
The facilities are located at the W. E. Reeves Packinghouse two
miles west of Ada, Oklahoma, on 64 acres of rolling land. The plant
slaughters 500 to 700 cattle per month and 600 to 800 hogs per month, or
about 10 million pounds of live weight annually and produces some 30
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F
U
L
L
EXTENDED
AERA TION
Ist AEROBIC
LAGOON
2nd AEROBIC
LAGOON
Manhole
A
L
E
P
I
L
0
T
S
c
A
L
E
Aerator
Manhole
Automated-
Valves
Manhole
INTERMITTENT
SAND FILTERS
Alum
Addition-^
IRRIGATION PLOT
Man-
hole
Storage Tank
Pump
Figure I. Schematic of Waste Treatment Systems
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items including cut and uncut beef and pork and its own brand of fresh
sausage, bacon, weiners, cold cuts, chili and other meat items.
OBJECTIVES
The objectives were: (1) to demonstrate the technical and economic
feasibility of aerated and aerobic lagoon processes where hydrogen
sulfide odors would be a problem or where ammonia limits are imposed;
(2) to develop the spray runoff irrigation process in conjunction with
the aerated lagoon for 80% removal of nitrogen and phosphorus, and (3)
to demonstrate the capabilities of these processes and sand filtration
to meet National Discharge Guidelines.
EXPERIMENTAL DESIGN
A treatment system, consisting of an extended aeration unit
followed by two aerobic lagoons in series, was evaluated over a 12 month
period. This system was put into operation on July 10, 1973, and
operated 6 months before the evaluation began on January 9, 1974. Since
liquid retention in the three units was four months, this period was
necessary to obtain typical effluents.
The experiments using the pilot scale units were designed after a
year of operation of the full scale treatment system. The first five
months of evaluation of the extended aeration unit alone or in
combination with the first aerobic lagoon indicated that effluents from
both systems would meet National Discharge Limitations if additional
suspended solids could be removed. The needed decrease in oxygen demand
would be accomplished by the suspended solids reduction. No additional
removal of ammonia was needed.
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The spray runoff irrigation process was put into operation in
series with the extended aeration unit on July 2, 1974, and evaluated
for 6 mcnths. Previous studies on this process using anaerobic lagoon
effluent. (1) and raw wastewater (2) indicated that 80% removal of
nitroger would be obtained but that the hydraulic loading would be
severely limited to obtain 80% removal of phosphorus. The experiment
was designed to emphasize suspended solids removal. Phosphate removal
was increased by adding alum to the effluent from the extended aeration
process. The removal of phosphate in the extended aeration process
reduced the needed chemical dosage. With the low organic concentration
in the extended aeration effluent and the chemical addition the decision
was to increase the hydraulic loading using only one of three irrigation
plots ar,d the entire capacity of the delivery system.
The intermittent sand filters were put in operation on September
10, 197E>, and evaluated for three months. The suspended solids from the
extended aeration unit were a biological floe; the suspended solids from
the aerobic pond were mainly algae. The experiment was designed to use
intermittent sand filtration on each of these effluents to determine if
these solids characteristics would affect removal. Intermittent sand
filtration offered a solids removal process requiring simple and infre-
quent maintenance which is critical to small packers. Over a dozen
small meat packing plants in Ohio are using sand filters behind various
primary treatment processes. At two plants visited, the filters appeared
to be operating satisfactorily with minimum maintenance. The Ohio EPA
furnished analytical data on one effluent sample from each of these two
filters, The analyses indicated the suspended solids limits in the
Nationa" Discharge Guidelines could be met. Middlebrooks and Marshall
(3), Reynolds et. al., (4) and Walter and Bugbee (5) have recently
reported on the successful operation of intermittent sand filters to
upgrade municipal lagoon effluent to meet National Discharge Guidelines.
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Automatic composite samples were taken of the raw wastewater,
extended aeration effluent, and the effluents from the two aerobic
ponds. Grab samples were taken of the effluents from the two sand
filters and the irrigation plot. Grab samples were considered sufficient
because of the short duration and small volume of discharge from the
sand filters and because of previous experience (6) in sampling the
runoff from the irrigation process. The automatic samplers collected
four samples per hour which were composited in iced containers. Samples
of the raw wastewater were composited on Tuesday over the normal operating
hours at the packinghouse. The three pond effluent samples were composited
between 2 a.m. and 6 a.m., on Wednesday when the effluent was being
discharged. The grab samples were obtained before 11 a.m. on Wednesday
when all samples were taken to the laboratory. Collected samples were
stored at 4°C in the laboratory.
The weekly samples were analyzed for five-day biochemical oxygen
demand (BODg), chemical oxygen demand (COD), pH, total solids (TS),
total volatile solids (TVS), total suspended solids (TSS), ammonia (NH~-
N), nitrate plus nitrite (NCy-NCyN), total Kjeldahl nitrogen (TKN), and
total phosphate (T-P). In situ measurements were made for temperature
and dissolved oxygen (DO) during sample collection. Once a month,
specially collected samples were analyzed for oil and grease (FOG),
settleable solids, and fecal coliforms. Weekly analyses of mixed liquor
suspended solids (MLSS), and mixed liquor volatile suspended solids
(MLVSS), and sludge volume index (SVI) were made on the mixed liquor
from the aerated pond. All analyses were made in accord with EPA Methods
for Chemical Analysisof Water and Wastes, .1971. The chemical analyses
were subjected to standard EPA quality control procedures.
-------
Weekly flow measurements were made of the raw wastewater, the final
discharge and the influent and effluent to the pilot scale units. The
amount of power and chemical used and the live weight killed (LWK) were
recorded, Air temperatures and precipitation measurements were obtained
from tha local weather station.
FACILITIES DESIGN
The design and construction of the three full scale lagoons and the
pilot scale irrigation plots were described in the previous article (1).
In the socond study the first lagoon was changed from an anaerobic
digestion process to an extended aeration process, a storage tank and a
chemical addition unit were added to the flow delivery system for the
irrigation plots, and two intermittent sand filters were constructed and
installed.
Packing plants usually have one operating shift and one cleanup
shift wi ;h little or no flow in the middle of the night. This intermittent
flow is ii disadvantage in most process designs. In this design, the
period of no flow was used advantageously. The anaerobic lagoon was
converted to extended aeration by the addition of a floating aerator and
an automated valve on the outlet. Both the aerator and valve were
controlled by timers. The valve remained closed except from 2 a.m. to 6
a.m. The aerator was operated from 6 a.m. to midnight. This batch
operatici enabled both aeration and settling to occur in one vessel
without ii mechanical sludge collection and handling system.
The extended aeration pond is shaped as an inverted truncated
pyramid, with a volume of 18,500 cu. ft. at 9 ft. water depth. Based on
previous information (1), the average daily flow is 17,800 gallons and
the maximum daily flow is 22,100 gallons. The BOD5 of the raw wastewater
averages 1247 mg/1 and has a standard deviation of 802 mg/1. Using this
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data and a MLSS ranging from 2500 to 4000 mg/1, a series of oxygen
requirements were calculated using alphas of 0.35 and 0.48 and betas of
0.03 and 0.09. With 18 hours of operation per day and 2 Ibs. of oxygen
per Hp-hr., aerator horsepower requirements were calculated. The average
day requirements ranged from 5 to 10 Hp and the maximum day ranged from
7.5 to 11 HP. A 10 Hp Peabody Welles floating aerator with a variable
oxygen transfer valve was selected. This valve when open, reduces power
consumption along with oxygen transfer.
The pond outlet was a submerged 6 inch pipeline. An automated 6
inch valve was placed in the line at a manhole where maintenance could
be performed. An accumulation of one day's flow in the first lagoon
would raise the water level 6 to 9 inches. This small head allowed use
of a rubber stead butterfly valve. An air actuated valve was selected
because of an available air supply and savings in costs over a motor
actuated valve.
The surface areas of the first and second aerobic lagoons were 0.32
and 0.74 acre, respectively. The corresponding volumes were 0.4 and 1.1
million gallons. The minimum and maximum water depths were 3 and 7
feet, respectively.
Since the extended aeration unit discharges only four hours per day
a storage facility was necessary to operate the spray irrigation system
for longer periods. A 3 inch pipeline was connected between the outlet
line of the aerated lagoon and the storage tank. An automated valve was
placed on the 3 inch line near the lagoon and a float switch was located
in the tank. After several minutes of lagoon discharge, the automated
valve was opened by a signal from a timer, and when the tank was full
the float would actuate the valve to close. A small amount of air was
introduced at the bottom of the storage tank to keep the liquid aerobic
and mixed. The 2100 gallon storage facility had sufficient volume to
operate one irrigation plot 8 to 10 hours per day.
7
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A constant speed positive displacement pump was used to apply and
measure the flow to the irrigation plot. This pump was operated up to
60 hours per week during the regular hours of plant operation. The
application to the plot was determined by measuring the flow per minute
and the length of time the pump was operated. The 0.1 acre plot was 33
ft. by 115 ft. The surface was graded to a 6% slope and planted with
Burmuda grass. A berm was placed on the upper end to divert rainfall
and aluminum stripping was placed along the sides and bottom to direct
the discharge through an outlet structure. The discharge was measured
by a calibrated tipping bucket and counter.
Alum addition was made just prior to the spray pump. The addition
system consisted of a 50 gallon tank and a chemical feed pump. The pump
was started by a timer after the spray pump was operating and stopped
prior to the spray pump to prevent plugging of the pipeline by the
chemical precipitant. The chemical addition system used was one developed
by Thomas, et. al., (7) for this process when treating raw domestic
wastewater.
The two intermittent sand filters were constructed by packinghouse
personnel from 55 gallon metal drums and local gravel and sand. Two
drums were welded together to form a cylinder 5.75 ft. in height with a
surface area of 2.73 sq. ft. A 3 in. drain pipe was welded into the
filter. The filter media consisted of three graded layers of gravel
with a total depth of 14 inches and 28 inches of sand. The bottom
gravel was 8 inches in depth with size ranging from 1/2 to 1-1/2 inches.
Next was a 3 inch layer with size ranging from 1/4 to 1-1/4. The top
layer was 3 inches deep with size ranging from 1/8 to 1/2 inch. Five
local sands were analyzed for particle size. The sand selected had an
effective diameter of 0.2 mm and a uniformity coefficient of 4. Measured
volumes of wastewater were applied manually.
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EVALUATION OF TREATMENT SYSTEM
As shown in the schematic drawing, Figure 1, four different
processes were combined to evaluate six treatment systems. The
evaluation is divided into full scale pond systems, the pilot scale
intermittent sand filter systems, and the pilot scale spray runoff
irrigation system. The discharge from these systems are compared with
the National Discharge Limitations. Systems which meet these
limitations were considered technically feasible and emphasized with
more detailed evaluation.
Full Scale Pond Systems
In Table 1, the discharges from three full scale systems can be
compared with the Best Practicable Technology (BPT) limitations for the
category Low Packinghouse which are to be met by July 1, 1977. The
limitations shown as Means are defined as an average of data collected
during 30 consecutive days. The maximum values (Max) are from a one day
composite sample.
Table 1. Treatment Systems Discharges vs. Effluent Limitations (lb/1000
Ibs LWK)
Items
BOD5 Mean
BOD5 Max.
TSS Mean
TSS Max.
Either extended aeration or extended aeration plus the 1st aerobic
lagoon meets the limits for BODj-. However, only the latter system meets
the limits for TSS. The maximum day TSS discharge for extended aeration
Extended
Aeration
.07
.27
.22
2.46
1st Aerobic
Lagoon
.11
.29
.21
.47
2nd Aerogic
Lagoon
.11
.79
.25
.85
Low Pack.
BPT
.17
.34
.24
.48
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process greatly exceeded that limitation. The addition of the 2nd
aerobic lagoon increased the quantities of BOD5 and TSS discharged.
Other discharge limitations are placed on FOG, fecal coliforms and pH.
Limitations on NH~-N are placed on New Sources of pollutants. The NH,-N
*j 0
and FOG limitations were met by all the systems. The maximum pH limit
of 9.0 was exceeded by both aerobic ponds. The discharge from the 1st
aerobic pond exceeded the pH limitation three out of 45 measurements.
These three samples were all taken in April. The discharge from the 2nd
aerobic pond exceeded the pH limitation 15 out of 46 measurements. All
15 samples were taken during the warm months, July through October.
There were no discharges with a pH of less than 6.0, the lower guideline
limitation. None of the fecal coliform measurements on the discharges
from the tnree ponds met the maximum guideline limitations of 400
mpn/100 ml.
Extended Aeration Unit
The number of analyses (n), mean concentrations of pollutants in
the influent and effluent, and removals in the extended aeration unit
are given In Table 2. The removal efficiencies based on mean
concentrations of BOD5, COD, FOG, NH3-N, and TKN exceeded 90 percent.
Removal of TSS was 96 percent when based on median concentrations.
After the j:irst two months of the study period the TSS in the effluent
dropped from around 200 mg/1 to about the median value of 23 mg/1.
Removal of T-P was lowest at 71 percent; however, no T-P was removed when
this unit v/as operated as an anaerobic lagoon. The maximum discharge of
NH3-N was 7.0 mg/1, except for 4 days when the aerator was off due to
vandalism. Both NHL-N and TKN concentrations decreased in the unit with
only 2% of the decrease accounted for by the increase in N02+N03>
Apparently denitrification occurred during the 6 hours each day when the
aerator was turned off. Within the pH range of 7 to 8 the maximum
ammonia in the form of strippable gas was about 20 percent (8). The
10
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.odors of ammonia or other objectionable compounds i.e., hydrogen sulfide
or mercaptans, were not detected on the banks of the pond.
Table 2. Concentrations and Removals - Extended Aeration
Items
BOD5
COD
TSS
FOG
NH3-N
N02+N03-N
TKN
T-P
Influent
Effluent
Removal
42
46
45
10
44
44
46
46
(mg/1)
714.8
1630.2
535.8
138.6
12.5
0.4
7.9.0
11.0
(mg/1)
17.0
121.6
65.4
11.9
1.9
2.6
7.8
3.3
(%)
98
93
88
91
95
—
90
71
The extended aeration unit was organically and hydraulically loaded
lower than usual in this country. The loadings are common for oxidation
ditches used in the Netherlands. The ratio of food to microorganism
(F/M) averaged 0.06 Ib BOD5/lb MLVSS. The mean hydraulic detection was
9.8 days and sludge retention time (SRT) averaged 64 days. Sludge was
wasted five times during the study period. Mixed Liquor Suspended
Solids (MLSS) averaged 3350 mg/1 and the SVI averaged 217.
A previous study (9) evaluated the oxidation ditch (extended
aeration) process at the John Morrell packinghouse in Ottumwa, Iowa. In
that study the F/M averaged 0.26 Ib BOD5/lb MLSS and the detention
averaged 3.6 days. The effluent concentration for BODr, TSS, FOG, and
NH--N averaged 70, 142, 21 and 18 mg/1, respectively. Both the loadings
and the effluent concentrations were several times greater than in this
study. With those higher loadings the extended aeration processes
exceeded the 30 day BPT limitations for BOD,- and TSS five and seven
fold, respectively.
11
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To determine the effects of several operating parameters on effluent
quality, a number of regression analyses were made. The dependent
variables were effluent concentrations of BOD,-, TSS and NH--N. The
independent variables were: hydraulic detention time, organic loading
(Ib BOD/day/1000 ft3), F/M, SRT, SVI, and MLSS. Over the 12 months
study period there were 43 sets of data which included most of these
variables end 35 sets which include all these variables. The statistical
analysis failed to show high enough regression coefficients to predict
effluent ccncentrations from any one operating parameter. Because of
the low effluent concentrations, the measurement techniques account for
a large part of the variation in effluent quality.
Aerobic Pords
The organic loadings on the first and second aerobic ponds were 8
and 5 Ibs EOD5/acre/day, respectively. The detention times based on
influent volume averaged 30 and 84 days, respectively.
Based on average concentrations, the first aerobic pond removed 24%
of the suspended solids and 48% of the oil and grease. The reduction in
suspended solids resulted from a dampening of the high concentrations in
the influert during the first two months. Based on median values, the
suspended solids concentrations almost doubled in the first aerobic
pond.
The combined effects of the first and second aerobic ponds were
most significant in reduction of concentrations of nitrogen. Mean
concentrations of ammonia and total nitrogen in the discharge were 0.4
mg/1 and 4.5 mg/1, respectively. The change in mean concentrations of
BOD, COD, TVS or TSS was not meaningful, but the quantities of these
pollutants were increased in the two ponds, apparently due to algae
production.
12
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The average discharge flow from the second aerobic pond was larger
than the average wastewater flow from the plant. The raw wastewater was
measured 45 times and averaged 18,546 gallons per day. The discharge
was measured on the following day when the flow was released from the
first pond and averaged 26,040 gallons per day over 45 measurements.
The change in flow ranged from a loss of 7000 gallons to an increase of
73,000 gallons. The flow increased when rain occurred and decreased
during periods of high air temperature.
Rainfall data from the local weather station was compared with the
change in flow. The rainfall data was divided into five groups.
Grouping was based on change in flow. Four 10,000 gallon groups were
from -10,000 gallons to +30,000 gallons. The fifth grouping was for
increases in flow over 30,000 gallons. The mean rainfall was found to
increase proportionally with the change in flow. When the increase in
flow exceeded 20,000 gallons, a rainstorm of an inch or more had occurred
either on the day of measurement or during the previous two days. The
surface area of the ponds was slightly larger than one acre and an inch
of rainfall was equivalent to 27,000 gallons.
The increase in flow, due to rainfall, was expected to cause a
short term increase in the quantity of BOD,- and TSS discharged. To test
this, events of rainfalls and flow increases were grouped by mass
discharge values. These events exceeding the maximum day BPT limits
were in one group. Those events less than the maximum day but exceeding
the 30 day average BPT limits were in a second group.
13
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BOD5
2/2
2/2
TSS
7/10
10/10
BOD,
0
4/8
8/8
TSS
6/11
10/11
Table 3. Rainfall and Flow vs Violations of BPT Limits
Number of Events
Events Discharge > Max. Day > Discharge > 30 Day Avg.
Rainfalls/Total
Increased Flow/Total
The data in Table 3 show that both events in which the maximum day
limit for EODr- was exceeded were also rainstorm events. The BPT limits
D
were exceeded when the discharge flow was greater than the wastewater
input in all but one case. In most cases, the BPT limits were exceeded
when a rainstorm occurred on the day of sampling or during the previous
two days. These rainstorms averaged .65 inches and ranged from .13 to
1.5 inches. Rainfall and the resulting increase in flow did cause
increases in mass discharges which resulted in maximum daily limitations
on BODc and TSS being exceeded.
The owner of the facilities, W. E. Reeves, placed several hundred
fish, mainly black bass, catfish and carp in the aerobic ponds. The
fish survivad and grew. Black bass fingerlings grew from 3 to 8 inches
in one warm season. The fish also acted as an effluent monitor. During
a weekend ii October vandals cut the mooring ropes to the floating
aerator and it moved to the bank and shut off. The aerator was returned
to service on Tuesday. On Monday, about a hundred dead fish were
floating on the surface of the aerobic ponds. Measurement on Wednesday
showed NHo-N concentrations had significantly increased in the first
aerobic and remained above 6.5 mg/1 for two weeks. The second aerobic
pond with v:s large volume discharged a maximum NHL-N of 1.5 mg/1 three
weeks after the occurrence. Dissolved oxygen in the two aerobic ponds
remained near saturation. The detention and dilution in the aerobic
ponds reduced the ammonia concentration and prevented a fish kill in the
14
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receiving stream. However, overall the disadvantages of the aerobic
ponds outnumbered their advantages in meeting National Discharge Limi-
tations for the meat industry.
The importance in including in the design more than one aerator,
steel cable morrings, an alarm system or a means of temporary storage
was dramatically demonstrated by the rapid increase of ammonia concen-
tration and the resulting fish kill when the aerator was shutdown. The
use of captive fish population in the aerobic ponds or in the discharge
has obvious merit as a monitoring tool.
Pilot Scale Intermittent Sand Filter Systems
The utilization of intermittent sand filters was to upgrade the
effluents from both the extended aeration pond and the first aerobic
pond to meet the BPT limitations and the Best Available Technology (BAT)
limitations which will be required by July 1, 1983. A comparison of the
discharges from these two systems with BPT and BAT limits is shown in
Table 4 for BODr and TSS. Both systems meet these limitations for BPT
but neither meet the BAT limits. The amount the discharge of BOD5
exceeded the BAT limits was within the accuracy of measurements. An
additional 50% reduction of TSS was needed to meet those BAT limits.
The BAT limits for NHj-N, FOG, and pH were met. All fecal coliform
measurements exceeded the limit.
15
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Extended
Aeration
Effluent
.05
.11
.11
.22
Aerobic
Lagoon
Effluent
.05
.09
.11
.22
Low Packinghouse
BPT BAT
.17
.34
.24
.48
.04
.08
.06
.12
Table 4. Sand Filters Discharges Vs. Effluent Limitations
(lb/1000 Ibs LWK)
Items
BOD5 Mean
BOD5 Max.
TSS Mean
TSS Max.
Each filter was dosed around 10 a.m. with 30 gallons (0.5 mgad)
five days per week. Cleaning of the filters was not required during
three months of operation. An additional analysis, total volatile
suspended solids (TVSS) was determined on the influents and effluents.
An initial washout of fines in the filter media was expected to increase
the suspended solids but not the volatile suspended solids in the effluent.
The rrean concentrations and resulting removal efficiencies for the
two sand filters are given in Table 5. Both filters had significant
removals of BODgS COD, NH3-NS T-N, and T-P. The extended aeration
effluent and the first aerobic lagoon effluent were applied to sand
filters No. 1 and sand filter No. 29 respectively. Filter No. 2,
usually had higher removal efficiencies, especially in regard to the
critical parameter, TSS. However, this was caused by the higher TSS
concentrations in the influent. The difference in effluent concentrations
was not significant. Because of the wash out of filter media, the 44 to
66% removal of TVSS is considered more representative of filter performance
than the values shown for TSS. Oil and grease measurements on the
effluents from each filter give concentrations less than 5 mg/1, the
accuracy o" the analysis. Influent concenterations varied from less
than 5 mg/1 to 26 mg/1. During the study period the pH of the influent
16
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and effluent of both filters ranged between 7 and 9. At pH 9, the
maximum NH3-N in the form of strippable gas was about 50 percent. The
NOp+NOo-N was usually increased about 1 mg/1 in both filters. Removals
were mainly due to solid-liquid separation, but oxidation, air stripping
and perhaps denitrification also played a part.
Table 5. Intermittent Sand Filters (Mean values)
Items
BOD5
COD
TSS
TVSS
NH3-N
T-N
T-P
Influents (mg/1) Effluents (mg/1) Removals (%)
No. 1
26.0
71.2
35.5
25.4
4.3
10.3
2.9
No. 2
28.7
99.7
46.8
32.3
2.7
6.5
4.3
No. 1
10.4
40.4
23.8
14.4
0.3
3.3
0.8
No. 2
8.1
48.1
22.2
11.1
0.1
3.3
2.1
No. 1
60
44
33
44
93
68
73
No. 2
72
52
53
66
96
50
52
The water temperature dropped from a high of 25°C in September to a
low of 5°C in December. The change between influent and effluent
temperatures was small. Temperature and dissolved oxygen (DO) concen-
tration were not inversely related. The DO consistently increased in
Filter No. 1. In Filter No. 2, DO concentrations increased half of the
time. Effluent concentrations of DO ranged from 5 mg/1 to 9.8 mg/1.
Three measurements for fecal coliforms were made on the influent
and on the effluent of both filters. A reduction in number of fecal
coliforms occurred in 5 of 6 sets of measurements. Maximum and minimum
counts in the effluent were 14,000 mpn/100 ml and 1000 mpn/100 ml,
respectively.
17
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Pilot Scale Spray Runoff Irrigation System
A con pan'son of the quantity of BODr and TSS in the raw wastewater,
extended aeration effluent, and spray irrigation discharge are compared
with the BAT limitations for the category Low Packinghouse in Table 6.
The effluent from the extended aeration unit was sprayed on the irrigation
plot. The discharge from the spray irrigation process met the BODr and
TSS limitations for BPT and except for maximum day TSS met these limita-
tions for BAT. The BAT limits for FOG, NH3-N, and pH were met, but the
fecal coliform limitation was exceeded by an order of magnitude.
Table 6. Spray Irrigation Discharge Vs. Effluent Limitations
[lb/1000 Ibs LWK)
Raw Extended Runoff Low Pack.
Items Wastewater + Aeration + Irrigation BAT
BOD5 Mean 3.03 .07 .01 .04
BOD,- Max. 7.25 .27 .03 .08
b
TSS Mean 2.24 .22 .01 .06
TSS Max. 5.55 2.46 .21 .12
The raw wastewater values in Table 6 are less than normal for
packinghouses because of in-plant control. The lower wastes loads aid
in obtaining the low quantities of pollutants in the discharge from the
two processes. The extended aeration values are repeated here to compare
the two treatment processes. Both processes have high removal efficiencies
and both have a maximum day discharge of TSS an order of magnitude
greater than average conditions. These high maximum day discharges
prevented the extended aeration unit and that unit plus the spray runoff
irrigation from meeting the limitations for BPT and BAT, respectively.
However, thtire was a difference in frequency and cause of these violations.
18
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The extended aeration unit due to high concentrations of TSS exceeding
the maximum day limit in four of the first five weekly measurements.
The spray irrigation discharge exceeded the maximum day limit once when
it discharged both its highest flow and highest concentration of TSS due
to 5.6 inches of rainfall during the seven days prior to sampling. On
this occasion, the concentrations of COD, TVS, TSS, TVSS were greater in
the effluent than in the influent.
A study (2) in which the raw packinghouse wastewater was applied to
these same irrigation plots also demonstrated the importance of rainfalls.
A conclusion from that study was, "During periods when wastewaters are
applied, rainfalls of greater than 0.7 inch/day can increase the quantity
of BODf- and TSS discharged to as much as ten times average conditions,
exceeding the maximum daily BAT limitations." Control of the discharge
in respect to volume and/or suspended solids concentration is necessary
during intense rainfall to meet BAT limitations. Temporary storage with
a controlled discharge and facilties for partial recycle to the irrigation
area could offer this control at minimum cost.
Evaluation of the spray irrigation dicharge data indicated two
modes of operation. The difference was most noticeable in terms of TSS.
The effluent concentrations were 10 mg/1 or less from July through
September; however, in October concentration in the effluent significantly
increased. The data collected was grouped by these two time periods and
the means (x) and differences are shown in Table 7. A statistical test
was made and the levels of probability at which the means are different
are given in Table 7.
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Table 7. Spray Irrigation Effluent
Items July thru Sept. Oct. thru Dec. Difference Probability
(x-|) (x2) (x-r*2^ p(x-|^x2)
Flow on (gpd) 1887 1826 61 0.900
Flow off (gpd) 207 452 245 0.995
Temp. (°C) 25.3 15.2 10 0.995
BOD5 (mg/1) 3.5 10.2 6.7 0.975
COD (mg/1) 78.1 63.5 14.6 0.950
TSS (mg/1) 8.1 59.3 51.2 0.975
The difference in Flow off (the discharge), BOD,- and TSS and the
decrease in temperature in the fall were most meaningful. To retain the
low discharge volume and concentrations obtained in the summer, a lower
rate of application would be needed in the fall. The similar study (2)
utilizing raw packinghouse wastewater supports this observation, that
the waste load discharge can be controlled by matching hydraulic loading
with seasonal conditions. In that study, loadings of 16,600 gallons per
acre per clay (gpad) in the summer and 6500 gpad in the winter resulted
in identical waste load discharges which met the BAT limits for BOD,- and
TSS.
The loadings on the irrigation plot in terms of flow and nutrients
are given in Table 8. The hydraulic loading is equivalent to 20,500
gpad. All loading values are based on means established during the six
months of operation. The nitrogen loading is important because a few
states put limitations on this nutrient to protect ground water supplies.
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Table 8. Spray Runoff Irrigation Loadings
Parameter Units Daily Annual
Flow
BOD5
TSS
NH3-N
T-N
T-P
inches
Ibs/acre
Ibs/acre
Ibs/acre
Ibs/acre
Ibs/acre
.75
3.6
4.6
0.8
2.2
0.5
195
936
1196
200
572
130
The total phosphate concentration averaged 11.1 mg/1 in the raw
wastewater, which is the same as the 11.4 mg/1 average obtained in the
first study (1). The extended aeration unit reduced this concentration
by 71% to 3.3 mg/1. Alum was added to the spray irrigation influent to
reduce T-P below 1.0 mg/1.
A series of jar tests were run in which the alum dosage was varied
and the residual of T-P in the supernatant determined. The residuals
ranged from 1.9 to < 0.01 mg/1. The minimum dosage of alum which
reduced the residual below 1.0 mg/1 was selected. This dosage of 120
mg/1 gave an A1:P ratio of 3:1 and required 1.7 Ibs of alum per day.
Alum was applied during the study period except for a three weeks
which the chemical feed system was being repaired. During the study
period, the influent, sampled prior to the point of alum addition, had
a mean concentration of 3.76 mg/1. The effluent from the plot sampled
when alum was added had a mean concentration of 2.85 mg/1. The decrease
in T-P concentration was only 25%. A statistical test showed no signi-
ficant difference in mean concentrations of T-P in the effluent with or
without alum addition to the influent. Alum addition was of little
benefit in reduction of the T-P concentration of the effluent. However,
greater than 80% of the water applied to the plots was lost to evaporation
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and seepage, and 88% of the quantity of phosphorus applied to the plots
was removed from the effluent. The water seeping below ground, the
plant and tie soil were all vehicles for T-P removal from the effluent.
Since a material balance on T-P was not attempted, the total effect of
the alum addition is unknown.
Costs
Costs have been determined for four treatment systems. Costs on
the full scc.le systems were based on actual expenditures. Costs for the
pilot seals processes were estimated from design and operational infor-
mation obtained in these studies.
The cost of the full scale treatment system is given in Table 9.
The capital cost for the three lagoons and appurtenances was obtained by
competitive bidding in 1971. The equipment cost was the sum of prices
for the floating aerator, control panel, automated valve, air compressor,
pneumatic and electrical supplies, and for their installation. To
obtain the annual capital cost, the lagoon and structures were amortized
at 7% over 23 years and the equipment was amortized at 7% over 10 years.
Annual equipment repair was estimated at 3% of capital cost. Annual
operating and maintenance were based on 8 to 10 man hours per week
needed durinij a year when the evaluation was inactive. This manpower
covered mowings, daily inspection, and occasional repairs. Electrical
power costs v/ere determined from separate billings for the waste treatment
system. Power usage was 4600 KWH per month. Monitoring costs were
based on the NPDES permit requirements, sampling by plant personnel and
analyses by a commercial laboratory.
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Table 9. Treatment Costs for Full Scale System
CAPITAL COSTS
Three Lagoons and Appurtenances $20,000
Installed Equipment 6,000
Capital Cost $26,000
ANNUAL COSTS
Amortized Structure (7% - 20 years) 1,890
Amortized Equipment (7% - 10 years) 850
Equipment Repair (3%) 180
Operating and Maintenance 1,200
Electrical Power 1,100
Monitoring and Reporting 980
Total Annual Costs $6,200
Installation Cost: $1.40/gpd Capacity
Treatment Cost: $0.21/lb BOD5 Applied
The capital costs of the extended aeration unit and the first
aerobic pond was determined at $16,000. The cost of the two lagoons and
appurtenances was $10,000. This reduction in captial cost would reduce
the total annual cost to $5,250.
A full scale intermittent sand filter is to be constructed at the
plant this summer. A design was prepared for a 0.5 mgad sand filter.
After determining cost of local materials and services, cost of construc-
tion was estimated at $13,300. The cost of the first deep pond and
appurtenance was 1/3 of the total pond system or $6,700. Capital cost
of the extended aeration unit and intermittent sand filter would be
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$26,000. Annual costs would be identical to those in Table 9 with a
total of $6,200.
Cost of a spray irrigation system was estimated from a layout
sketch made to match conditions at the packing plant. The system
included an 18,000 gallon wet well, two - 2 Hp pumps, automated valves,
timers, 900 ft. of pressure pipe, 100 ft. of gravity pipeline, sprinkler
nozzles and risers, a diversion dike, a collection and storage dike, and
2.5 acre;, of land. Prices were based on those developed in a previous
study (2]. Total capital cost for the irrigation system was $9,300.
The land, structure, and pipelines were $7500 and the installed equipment
was $1800. Capital costs for the extended aeration unit were $6,700 for
structures and $6000 for equipment. Total capital cost of the extended
aeratin unit and the spray irrigation system was estimated at $22,000.
Annual costs were computed the same as in Table 9. Equipment repair and
electric power costs were increased. Annual costs for both treatment
processes were estimated at $6100.
In sjmmary, capital and annual costs would be nearly the same for
the extended aeration unit followed by (1) the two aerobic lagoons,
(2) the iitermittent sand filter or (3) a spray runoff irrigation system.
Annual co:;ts for the extended aeration unit and one aerobic lagoon were
about 15% less than the above. To all of these systems an additional
$200 per year will be needed to cover chlorine and amortization of the
chlorinat'on equipment. Additional cost for maintaining the pH below
9.0 would be incurred in a treatment system utilizing aerobic lagoons.
CONCLUSIONS
Four processes (extended aeration, aerobic lagoons, spray-runoff
irrigation and intermittent sand filtration) were combined into six
treatment systems and evaluated at a small meatpacking plant.
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The extended aeration process in conjunction with (1) an intermittent
sand filter, (2) spray runoff irrigation, or (3) one aerobic lagoon and
an intermittent sand filter meet the BPT limitations, except for fecal
coliforms. None of the six treatment systems meet the limitation for
fecal coliforms of 400 mpn/100 ml. Disinfection will be a necessary
addition to these systems.
Treatment of meatpacking wastewater by extended aeration was
demonstrated as an advantageous substitute when anaerobic treatment
causes a problem due to hydrogen sulfide or ammonia production.
The extended aeration unit, except for maximum day limits on
suspended solids and fecal coliforms, meet the BPT limitations. Removal
of BOD5, COD, TSS, FOG, NH3~N and TKN ranged from 88 to 98 percent at a
F/M of 0.06.
The batch operation used in the extended aeration unit was apparently
able to nitrify and denitrify the wastewater reducing the mean concen-
trations of total nitrogen from 92 to 12 mg/1. Due to the batch operation,
both aeration and solid-liquid separation were accomplished in the same
basin without sludge return equipment.
The two aerobic lagoons reduced the concentrations of ammonia and
total nitrogen and dampened high incoming concentrations of suspended
solids and ammonia during periods of upset in extended aeration unit.
The aerobic lagoons increased the quantities of BODj- and suspended
solids, apparently because of algae production. Both aerobic lagoons
had pH values greater than 9.0, the National Effluent Limitation.
Rainfall increased the discharge volume and was the usual cause for the
quantities of BODg and suspended solids discharged exceeding the maximum
daily value in the BPT limitations. The disadvantages of the aerobic
lagoons outnumbered their advantages in meeting National Discharge
Limitations for the meat industry.
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For small packers aerated systems should include alarms and dual
i
pieces of equipment or alternate schemes of operation in case of equipment
failure to prevent fish kills due to ammonia. The use of captive fish
populations in the discharge has merits as a monitoring tool.
Intermittent sand filtration following extended aeration offers
potential for meeting the 1983 National Discharge Limitations but a 50
percent increase in removal of suspended solids will be necessary.
Spray runoff irrigation following extended aeration will meet the
1983 National Discharge Limitations if provisions are made for control
of the discharge volume with partial recycle to the irrigation area
during intense rainfalls. The quantity of pollutants discharged from a
spray irrigation system is also controlled by matching hydraulic loading
with seasonal conditions.
Spray runoff irrigation in conjunction with extended aeration
removed in excess of 80% of the nitrogen and phosphorus in the packing-
house wastewater. Alum addition to the influent of the irrigation
system was of little benefit in reducing the total phosphate concentration
in the effluent.
Capitil and annual costs would be nearly the same for the extended
aeration unit followed by either two aerobic lagoons, intermittent sand
filters, or spray runoff irrigation. For small packers installation
cost for these three systems would be $1.40/gpd capacity and treatment
cost would be $0.21/lb BOD5 applied. Additional costs would be incurred
for disinfection on all systems and for pH control where aerobic lagoons
are used.
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ACKNOWLEDGEMENTS
This research project was a cooperative study by W. E. Reeves
Packinghouse, East Central Oklahoma State University, Robert S. Kerr
Environmental Research Laboratory, and the Industrial Environmental
Research Laboratory. The project was supported in part by the U. S.
Environmental Protection Agency under Grant No. 120560 GPP and Contract
No. 68-03-0361.
0
Special recognition is given to Dr. Mickey L. Rowe, Director,
School of Environmental Science, East Central Oklahoma State University;
to Jimmie L. Kingery, Mathematical Statistician, Robert S. Kerr Environ-
mental Research Laboratory; and to W. E. Reeves, President, W. E.
Reeves Packinghouse; without these individuals, the project could not
have succeeded. Messers, Michael Cook and Kenneth Jackson, chemistry
technicians at the Kerr Laboratory, gave outstanding performance in
aiding packinghouse and university personnel in operating, sampling and
analytical quality control procedures. Dr. Ralph Ramsey and Mr. James
Arnold, University pesonnel, most satisfactorily managed plant operation,
sample collection and weekly report preparation.
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REFERENCES
1. Withei-ow, Jack L. Small Meat-Packers Waste Treatment Systems.
Proceedings of the 28th Industrial Waste Conference, Purdue University,
Lafayotte, IN. May 1973.
2. Witherow, Jack L., Mickey L. Rowe and Jimmie L. Kingery, Meat
Packing Wastewater Treatment by Spray Runoff Irrigation. Proceedings
Sixth National Symposium on Food Processing Wastes. EPA-660/2-75-
045, L.S. Government Printing Office. April 1975.
3. Middlebrooks, E. J., and G. R. Marshall. Stabilization Pond
Upgracing with Intermittent Sand Filters. Upgrading Wastewater
Stabilization Ponds to Meet New Discharge Standards. Utah State
University, Logan, Utah, November, 1974.
4. Reynolds, J. H., S. E. Harris, D. Hill, D. S. Filip and E. J.
Middlebrooks. Intermittent Sand Filtration to Upgrade Lagoon
Effluents - Preliminary Report. Upgrading Wastewater Stabilization
Ponds to meet New Discharge Standards. Utah State University,
Logan, Utah. November 1974.
5. Walter, C. M., and S. L. Bugbee. Progress Report. Blue Springs
Lagoon Study, Blue Springs, Missouri. Upgrading Wastewater Stabili-
zation Ponds to Meet New Discharge Standards. Utah State University,
Logan, Utah, November 1974.
6. Law, Je.mes R., R. E. Thomas and Leon H. Myers. Nutrient Removal
from Cc.nnery Wastes by Spray Irrigation of Grassland. Robert S.
Kerr Weter Research Center, Ada, OK. November 1969.
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7. Thomas, P. E., K. Jackson and L. Penrod. Feasibility of Overland
Flow for Treatment of Raw Domestic Wastewater. EPA-660/2-74-087,
U.S. Government Printing Office. December 1974.
8. Adams, Carl E. and W. W. Eckenfelder. Process Design Techniques
for Industrial Waste Treatment. Enviro. Press. Austin, Texas.
1974.
9. Paulson, W. L., L. D. Lively and J. L. Witherow. Analysis of
Wastewater Treatment Systems for a Meat Processing Plant. Proceedings
of the 27th Industrial Waste Conference. Purdue University, Lafayette.,
Indiana. May, 1972.
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