United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S2-83-005 Apr. 1983
Project Summary
Multiple Water Reuse in
Poultry Processing:
Case Study in Egypt
Ahmed Hamza, Huda S. Lillard and Jack L Witherow
An industrial-scale multiple water
reuse system was investigated for three
years at a modern poultry processing
plant in Alexandria. Egypt.
The system involved chlorination of
cooling water from compressors and its
successive reuse as feed water for the
chiller, prechiller, washer and finally for
makeup in the scalder. In all four units
poultry carcasses are immersed in
water.
Process waters in the prechiller and
washer were purified alternatively by a
pressure leaf filter.
Response-surface analysis demon-
strated variable interacting effects of
water rate, chlorine dosage and process
time on the chemical and bacterial
qualities of the processed carcasses,
and water used in the immersion pro-
cesses. Models were developed for
prediction of the effect of operating
conditions on poultry quality.
Long-term studies at the plant indi-
cated that successive utilization of pre-
chlorinated water in a multiple system
did not result in significant buildup of
contaminants (total and coliform
counts) and organic pollutants (grease,
nitrogen compounds. BOD and COD)
in the immersion tanks.
The bacterial quality of the carcasses
processed by the multiple reuse water
was superior to the quality of the typical
system which utilizes prodigious quanti-
ties of potable water in a once-through
feed system without filtration and chlo-
rination.
Filtration, when incorporated with the
multiple system, enhanced the water
and carcass quality with progressive
elimination of the organic contaminants
which would interfere with chlorination.
The study demonstrated a potential
for substantial saving in water—an
expensive commodity in arid areas of
Egypt—through application of this mul-
tiple reuse system.
The conclusions and recommenda-
tions of this report are not directly
applicable to poultry processing plants
in the United States, since water use in
those plants is regulated by the U.S.
Department of Agriculture.
This Project Summary was developed
by EPA's Industrial Environmental Re-
search Laboratory, Cincinnati. OH. to
announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
In Egypt water supplies are limited for
new poultry processing plants. The need
for large quantities of processing water
has forced the industry to develop water
reuse systems.
In April 1976, a four-year joint project
between Alexandria University and the
United States Environmental Protection
Agency (EPA) was initiated to develop,
install, and evaluate a multiple reuse
system atthe Alexandria Poultry Process-
ing Plant (APPP).
Conclusions
The following conclusions were drawn
from this field investigation:
1. Multiple water reuse is a practical
and viable option to conserve water
-------
in poultry processing in Alexandria,
Egypt.
2. Chlorination and filtration of the
reused water were effective in re-
ducing accumulation of pollutants
and contaminants of the immersion
water. The total aerobic and coliform
counts of the carcasses were appre-
ciably lower than those counts asso-
ciated with carcasses treated in the
normal once-through system, with-
out Chlorination.
3. In the Alexandria plant, optimum
operation conditions for the multiple
reuse system were achieved by using
a water makeup rate of 20 mVd,
while applying chlorine dosage of 20
mg/l, with filtration of the washer
water in a closed loop.
4. Multiple water reuse reduced use of
immersion water by 54% of the
normal consumption in this plant.
Recommendations
Based on the results of the study, the
following recommendations are pro-
posed.
1. The poultry processing industry in
Egypt should investigate multiple
reuse of the existing once-through
water systems in the carcass-cooling
operation. Water flow to process
units should be monitored.
2. Use of potable water for feather
fluming, flushing of blood tunnels
and cleanup operations should be
replaced by reused water from other
processes.
3. Coordination of activities between
industry, regulatory agencies and
research teams is necessary for
development of efficient water con-
servation schemes.
4. Areas needing further investigation
and evaluation are: long-term evalua-
tion of cost, accumulation of contami-
nants, and operational problems of
the continuous multiple water reuse
system; development of further uses
of byproducts; and use of specific
sensing devices for monitoring of
pollutants in the immersion water.
Description of the
Multiple Reuse System
The normal operation of the APPP
involves initial filling of the immersion
tanks (chillers, washer and scalder) and
introducing makeup with once-through
fresh water in all tanks. Details of the
operations, characteristics and flow of
process effluents are described else-
where.1
Figure 1 is a flowsheet of the multiple
reuse system (MRS). The compressor's
cooling water was used for initial filling
and makeup in the immersion tanks.
Makeup water was continuously pumped
at a controlled rate to the chiller, and
repumped at the same rate to the pre-
chiller and washer, in a counter-current
flow arrangement.
The overflow from the washer was
diverted to the scalder as a replacement
for part of the fresh water requirement
during processing. Schematics of the flow
for both normal operation (once-through
makeup) and MRS are shown in Figure 2.
Modes of operation of the MRS system
were as follows:
1. Treatment I. A gas chlorinator (Capi-
tal Control Co., USA) was installed on
the subfeeding line to the immersion
tanks. Metered chlorine dosages
were injected into the line during
initial filling (about one hour prior to
startup). Chlorine dosages were con-
City
Water
Receiving ,
|
0, ,,
T
T
Cleaning
Cleaning
M
Killing f
^*
lleedint
— M
'oil
1,
Pickers'
Evisc.
»— '
^^^
«,.-,.
^^^
Hashing
*
fit ktf
Chiller
/.
Chiller
ii »
0>. |
Mejghir
f *
*
I
Packaging
h >•
^ .^
^ ^
L
r t
Jf ^
r
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'l, *: Steam
' Flume H ^ ^Cooke
i Flume l^J^fFe'ed
' * ** *"
1 ta /r\ k
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» *
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Iff
i- •*-
p—y*.
^ >•
Gizzard
Machine
'
Compressors /^\
vier if
V
trolled during the initial filling, and in
makeup water. Chlorine dosages
used were 10, 20 and 30 mg/l, and
water makeup rates were 10, 20 and
30 mVd.
2. Treatment II. A high-pressure leaf
filter was used for renovation of the
wash water in a closed loop. The
filter (Model 36H-805-4, Amafilter,
Holland) has a net filtering area of 7.5
m2, working pressure 4.5 Atm and an
average capacity of 1000 L/hr fil-
tered water. A local bentonite clay
(equivalent pore size 0.8//) was used
for coating the leaves prior to filtra-
tion.
3. Treatment III. In this mode, the filter
was connected to the prechiller rath-
er than to the washer. Makeup water
rates and chlorine dosages for treat-
ments II and III were the same as
those used in treatment I.
The ratio of makeup water used in the
MRS and the normal nonreuse systems
are given in Table 1.
Wastewater samples
Carcass sampling points
Water meters
Freshwater
Wastewater
Packed Poultry Plant Effluent
Figure 1. Multiple water reuse system at poultry processing plant. Alexandria, Egypt.
-------
Makeup water (7 rrP/d)
Carcass
Line
I14nr>/d> (22.7 m3/d)
i *
Prechiller
5—
Washer
K
t *
Wastewater Wastewater
Scalder
Normal
' Operation
Carcass -^
Line
Chlorination'
Wastewater
Scalder
TRTI
Potable -»( Compressors^
Potable -+\Compressorsj
Carcass
Line
Carcass
Line
TftTIII
Chlorination'—^
Potable *+( Compressors) Filter
Water ^ '
t
Wastewater
Figure 2. Schematics of normal operation and multiple reuse systems.
Table 1. Ratio of Makeup Water in the MRS and Normal Systems
Makeup (MRS)
n?/a
10
20
30
Chiller
(2.5' + 7.0")
1.43
2.86
4.28
Prechiller
(2.5' + 14.0")
0.71
1.43
2.14
Washer
(5.0' + 22. 7")
0.44
0.88
1.32
Z Operations
(10* + 43.7*)
0.23
0.46
0.67
'Initial filling water, m3/d.
^Makeup water in normal system, ma/d.
Effect of Multiple
Reuse on Chemical
Characteristics of
Process Water
As shown in Table 2, chlorination of
water in the MRS (TRT I) reduced the
Biochemical Oxygen Demand (BOD) and
Chemical Oxygen Demand (COD) of the
washer and chiller waters in comparison
with the normal once-through system.
However, the 600 and COD of the scalder
water were appreciably higher due to the
near absence of residual chlorine and the
significant accumulation of pollutants in
wash water reused as makeup for the
scalder.
Filtration of the chlorinated water in
the MRS (TRTs II and III) further improved
the quality of the washer water and
chiller water as shown in Table 2. As
anticipated, filtration of the washer water
(TRT II) and chiller water (TRT III) produced
noticeable reductions in the suspended
residues (SR).
With minor exceptions, the accumula-
tion of pollutants was decreased by
increasing makeup rate and chlorine
dosages in the MRS. The normal water-
use scheme produced more accumula-
tion of COD, Total Residue (TR), and Oil
and Grease (O&G) in the washer and
chiller. The use of 10 and 20 mVd in the
MRS results in net saving of the immer-
sion water of 77% and 54%, respectively
(Table 1). Despite this appreciable reduc-
tion of water use, the quality of the
washer and prechiller waters was better
in the MRS as compared to the normal
system, due to the influence of filtration
and/or chlorination in reducing the accu-
mulation of pollutants. The ANOVA re-
ported in Table 3 indicates significant
effects of the independent variables (treat-
ments, date, time, and operating condi-
tions [water rate and chlorine dosage]) on
pollutants associated with the process
water in the four immersion tanks. Inter-
actions between the independent varia-
bles were significant in most cases. The
dependent variables are COD, BOD, TR,
volatile residual (VR), dissolved residual
(DR) and O&G.
Effects of Multiple
Reuse on Bacterial
Counts of Water and
Carcasses
Chlorination (TRT I) in conjunction with
filtration (TRTs II and III) produced marked
decreases in total aerobic count and
coliform count of water and carcasses as
compared with the normal system (Table
4). However, minor exceptions were
observed.
Bacterial counts for water in the normal
system were lower than the MRS (TRT I)
when using chlorine dosage of 10 mg/l
and water makeup rate of 10 mVd.
However, increasing the water rate to 20
mVd and chlorine dosages to 20 and 30
mg/l produced marked decrease in bac-
terial counts of process water in the
washer and chillers (Figure 3). On the
other hand, as Figure 4 shows, bacterial
counts on carcasses were consistently
lower in the MRS compared to the normal
system, even at the low water rate of 10
mVd and chlorine dosage of 10 mg/l.
The results reported in Table 4 indicate
that the normal water system was less
effective than MRS in removing bacteria
from both water and carcasses. With
minor exceptions, the MRS modes pro-
duced mean counts lower than the normal
system.
The ANOVA of bacterial counts is
reported in Table 5. In this case, most
independent variables and their interac-
tions produced significant effects on bac-
terial counts. The results generally agree
with ANOVA reported in Table 3.
-------
Table 2. Effect of Treatment on Mean Concentrations of
Table 3.
Pollutants in Process Water, mg/l
Process TRT
Scalder N
COD BOD TR SR
1574 1235 1700
1 2145 1542 2627 1182
II
III
Washer N
1
II
III
Prechiller N
1
II
III
Chiller N
1
II
III
1616 1156 1933 784
1538 1419 2214 762
1434 1220 1744
787 547 1842 523
427 351 830 165
485 396 1137 427
1883 1431 2119
384 226 956 427
402 311 826 386
156 128 500 128
1357 1020 1562
326 218 671 229
325 247 756 295
179 154 505 256
O&G
91
74
93
1OO
242
126
43
99
244
523
102
48
245
75
116
85
N = Normal (once-through) system.
1 = Chlorination of MRS water.
It = Chlorination of MRS and filtration of washing water.
Ill = Chlorination of MRS and filtration of prechiller water.
Data for TRTs 1. II and III are pooled for makeup rates 10-20 m
and chlorine dosage
10-30 mg/l.
3/day
Means of 8 experiments.
Scalder
COD
BOD
TR
VR
OR
O&G
Washer
COD
BOD
TR
VR
OR
O&G
Prechiller
COD
BOD
TR
VR
OR
O&G
Chiller
COD
BOD
TR
VR
OR
O&G
Effect of Treatment and Operating Conditions on Chemical
Characteristics of Process Water
TRT
m
s
S
S
S
s
s
N
s
s
s
N
S
S
S
S
S
S
N
S
S
S
S
S
S
OPCON
(0)
s
s
s
s
s
s
s
N
S
S
s
N
S
S
S
S
S
s
s
s
s
s
s
s
T.O.
s
s
s
s
s
s
N
N
N
N
N
S
N
S
N
N
N
S
N
S
S
S
S
S
Date
s
S
S
S
S
N
S
S
S
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
Hours
W
s
s
s
s
s
s
s
s
s
s
s
s
s
s
5
s
s
s
s
s
s
s
s
s
H.T.
s
S
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
H.O.
s
s
s
s
s
N
s
s
N
N
S
s
N
S
s
s
s
s
s
s
N
N
N
N
H.T.O.
N
N
S
S
S
S
S
S
S
S
S
S
N
N
N
S
S
S
S
S
S
S
S
s
OPCON (O) - 1 water makeup 10 m3/d and C/z dose = 10 mg/l
= 2 water makeup 20 m3/d and C/z dose = 20 mg/l
= 3 water makeup 20 m3/d and C/z dose = 30 mg/l
TRTsfT) I, II and III
Hours (H) 1. 2. 3. 4. 5 and 6
S Significant difference at the 5% level
N Not significant difference at the 5% level
-------
TUT
III
§>
-j
0.5 7.5 3.0
6.0
5.2
4.4
3.6
2.8 -^.f^'-r r
5.0 6.0 0.5 /.5 3.0
3.2T
0.5 1.5 3.0 5.0 6.0
5.0 6.0 0.5 1.5
4.00
3. SO
3.00
2.50
2.00
3.O 5.0 6.0
0.5 1.5 3.0 5.0 6.0
0.5 1.5 3.0 5.0 6.0
0.5 1.5 3.0 5.0 6.0
O.5 1.5 3.O S.O 6.O
Processing time, hours
O.S 1.5 3.0 S.O 6.O
Water
mVd
10
20
20
Normal
C/2
mg/l
10
20
30
Comparing the effects of TRT tt and TRT
\\\ on the bacterial counts of the chilled
carcasses shown in Table 4 and Figure 4
indicates that TRT II (filtering the washer
water) produced a better quality of chilled
carcasses. Since shelf-life is dependent
on the bacterial quality of the carcasses in
the last immersion process (chilling), it is
recommended that the filter be used in
conjunction with the washer in plants
that use immersion washers so as to
reduce bacterial levels most effectively.
Effect of Chlorination,
Water Makeup Rate and
Processing Time on
Bacterial Counts of the
Chiller
Contour plots available in the full report
clearly demonstrate the favorable effect
of Chlorination on the bacterial quality of
water and carcasses. Contours of rela-
tively low bacterial counts were dominant
when using chlorinated water, whereas
the use of nonchlorinated water in the
MRS was associated with higher total
aerobic and coliform counts.
As processing time increased, bacterial
counts also increased. However, toward
the end of the operation, the Chlorination
controlled counts at lower levels than
nonchlorinated water. The use of non-
chlorinated water resulted in rapid in-
crease in bacterial counts in the last
stages of the operation period.
Although the effect of water makeup
rate did not follow a uniform pattern, the
contours for chlorinated water indicate
an optimum water makeup rate of 20
mVd. The use of this water makeup rate
in the MRS resulted-in a net water saving
of 54% compared to normal usage (Table
1).
Reference
1. Hamza, A., Saad, S. and Witherow,
J., "Potential for Water Reuse in an
Egyptian Poultry Processing Plant,"
Journal of Food Sci. 43, (1978).
Figure 3. Effect of treatment on bacterial counts of process water.
-------
Washer
Prechiller
Chiller
TRTI
0.5 1.5 3.0 4.5 6.0 0.5 1.5 3.0 4.5 6.0 0.5 1.5 3.0 4.5 6.0
0.5 1.5 3.0 4.5 6.O 0.5 1.5 3.0 4.5)6.0 0.5 1.5 3.0 4.5 6.0
4.5 6.0
TRTII
§>
0.5 1.5
4.5 6.0 0.5 1.5 3.0 4.5 6.0 0.5 1.5 3.0 4.5 6.0
TRT III
0.5 1.5 3.C 4.5 6.0 0.5 1.5 3.0 4.5 6.0 0.5 1.5 3.0 4.5 6.0
4.96
0.5 1.5 3.0 4.5 6.0 0.5 1.5 3.0 4.5 6.0 0.5 1.5 3.O 4.5 6.0
Processing time, hours
Log TC = Log 10 total aerobic count/Ca
Log CC = Logw coliform count/Ca
Figure 4. Effect of treatments on bacterial counts of carcasses.
6
Water
m3/d
10
20
20
Normal
CI-,
mg/l
10
20
30
-------
Table 4.
Process
Washer
Prechiller
Chiller
LogTW a
LogCW a
Log TW a
LogCC a
Effect of Treatments on Mean Logarithmic Counts of
Carcasses and Water
TRT Log TW Log TC Log CW Log,0CC
N 5.00 8.30 3.30 6.90
I 4.04 4.45 3.67 3.71
II 3.40 3.73 3.01 328
III 3.99 4.68 3.74 4.17
N 4.69 6.20 3.32 4.99
1 3.59 4.08 3.25 3.61
II 3.15 3.07 3.88 2.68
III 3.65 3.78 3.29 2.37
N 4.83 6.27 3.11 4.75
1 3.17 3.29 2.76 277
II 2.59 2.71 2.32 2.30
III 2.93 3.21 2.57 2.88
Logto total aerobic count in water/ml.
Logio coliform count in water/ml.
Log-io total aerobic count of carcasses.
Log-to coliform count of carcasses.
Other conditions are similar to those of Table 2.
Table S.
Scalder
LogTW
LogCW
LogTC
LogCC
Washer
LogTW
LogCW
LogTC
LogCC
Prechiller
LogTW
LogCW
LogTC
Log CC
Chiller
LogTW
LogCW
LogTC
LogCC
Effect of Treatments and Operating Conditions on
Bacterial-Counts of Carcasses and Process Water
TRT OPCON T.O Date Hours T.H H.O
m
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
10)
s
s
s
s
s
s
s
s
s
s
s
N
s
s
N
s
N
s
s
s
s
N
S
S
s
s
s
s
s
s
N
S
S
s
s
s
N
S
N
S
N
S
S
N
N
N
S
S
tut
S
S
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
N
s
s
s
N
s
s
s
N
s
s
s
N
S
N
S
H.T.O
N
S
S
S
S
S
N
S
S
S
s
s
s
s
N
S
Log TW - Log 10 total aerobic count in water/ml.
LogCW = Login coliform count in water/ml.
LogTC - Log 10 total aerobic count of carcasses.
Log CC - Logto coliform count of carcasses.
Other conditions are those of Table 3.
Ahmed Hamza is with the High Institute of Public Health, 165 EI-Horria Avenue,
Alexandria. Egypt; Huda S. Lillard is with the USDA, ARS, Richard B. Russell
Agricultural Research Center, Athens, GA; and the EPA author Jack I.
Witherow (also the EPA Project Officer, see below for contact) is with the Robert
S. Kerr Environmental Research Laboratory, Ada, OK 74820.
The complete report, entitled "Multiple Water Reuse in Poultry Processing: Case
Study in Egypt," (Order No. PB 83- 756 76O; Cost: $13.OO, subject to change)
will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
For information contact Kenneth Dostal at:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
. S. GOVERNMENT PRINTING OFFICE: 1985/659-095/1919
-------
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