1. By Fabrice Pellegrin & A.K. Ragen
Chemical treatment of poultry abattoir wastewater
By Fabrice Pellegrin & A.K. Ragen

2. Contents of Presentation
Introduction
Aims & Objectives
Methodology
Results & Discussion
Conclusions & Recommendations

3. Introduction
From the year 2000 to 2006 the poultry production in Mauritius had increased by 40.6 %
Two major slaughterhouses in Mauritius operating on an industrial scale
One of these abattoirs processes about 30,000 birds per day
Poultry slaughterhouses make use of significant quantity of high quality water for their operations

4. About 88 % of the water intake is directly converted into wastewater with a strong organic content
The strong organic wastewater generated contains high levels of oil & grease, total suspended solids (TSS) and nutrients
With the introduction of norms on limiting wastewater discharge, it is now a legal requirement for poultry slaughterhouses in Mauritius to treat their wastewater to such quality to meet discharge norms

5. Parameter Maximum permissible concentration
Discharge parameters to be complied with by poultry abattoirs
Parameter
Maximum permissible
concentration
Chemical Oxygen Demand
1500 mg/l
Chloride (as Cl-) and sulphate
as SO42- combined pH
5 - 9
Total suspended solids
400 mg/l
Oil & grease
150 mg/l
The abattoir under study is equipped with a Dissolved Air Floatation System (DAF) as means of treatment to remove pollution from the wastewater

6. Abattoir Processes
Stunning: process whereby birds are made insensible before slaughtering
Neck severing
Scalding: wetting & partially removing the birds feathers
Plucking
Evisceration: the purpose of evisceration is to remove all the thoracic & abdominal organs and separating the edible viscera from the inedible ones
Spin chilling: to chill & disinfect the carcasses before packaging

7. Aims & Objectives
To determine the specific water intake (SWI) of the abattoir
To characterize the outgoing wastewater streams in terms of COD, pH, chloride, TSS and oil & grease
To carry out standard jar tests to determine the optimum conditions of various chemicals on the wastewater
To find a proper way to dispose of the blood generated by the slaughtering of chicken

8. Methodology 1. Determination of Specific Water Intake (SWI)
The SWI was determined by:
taking the readings of the CWA flowmeter connected on the supply line to the abattoir on each working day for a period of one month
Recording the amount of birds processed on each working day over the same period

9. 2. Characterization of Wastewater Streams
Poultry Abattoir Sewer Map showing sampling locations

10. Sampling of wastewater streams
13 composite samples were taken each day for 5 days (In all 65 samples were taken)
Composite sampling was chosen to eliminate possible errors that might have occurred due to:
An irregular flow of birds on the line shackles
An irregular water flow inside the abattoir

11. Preservation of Samples
Parameter
Container
Preservation
Maximum Holding Time
Chloride
P,G
None required
28 days
Nitrate
Cool, 4oC
48 hours
Oil and grease G
Cool, 4oC H2SO4 to pH < 2
TSS
7 days
BOD
COD
Cool, 4oC H2SO4 to pH < 2
Hydrogen ion (pH)
Analyze immediately
Turbidity

12. Methods of Analysis
Chloride was determined using the Mohr`s method as per the ISO 9297:1989(E) standard
All the other parameters were analyzed by means of the US-EPA approved Hach DR/2000 spectrophotometer.

13. 3. Jar Test Experiments
The wastewater samples for jar tests were taken on 5 days (each day 25 L of grab sample was collected)
Grab sampling was chosen because composite sampling might have obscured some important parameters such as turbidity and pH
The jar tests were carried as per the ASTM D 2035 – 80 (2003) method
Coagulants used were Ferric chloride (FeCl3), Sodium Hexamethaphosphate (HMP), Alum, Primco 730 and Primco 738 and flocculent used was Nalco 9617

14. Collection of wastewater sample at effluent treatment plant
Carrying out of Jar test Experiments
Each time a coagulant was used the optimum dosage was
determined by the turbidity test

15. The tests were repeated by placing the same optimum coagulant dosage in each beaker but that time the pH of the wastewater was varied (different pH in each beaker)
Most of the time, when the optimum coagulant dosage was determined (with or without change in pH), the tests were repeated by placing the same optimum coagulant dosage in each beaker and different doses of Nalco 9617 (flocculent) were added to the beakers

16. Variations in SWI per bird over a period of one month
Results & Discussion
1. SWI results
The SWI varied from 14.3 to 28.4 L/bird
The figure illustrates 4 peaks in the SWI at 28.4, 25.6, 22.3 & 24.8 L/bird
These peaks may be explained by the fact that on those days fewer birds were processed but the same amount of water was used
The average SWI = 17.9 L/bird
Variations in SWI per bird over a period of one month

17. Evisceration section (S8) Spin chilling section (S11)
2. Effluent streams characterization results pH
COD
(mg/l)
Oil & grease
TSS
Chloride
Sampling
location
Range
mean
Killing section (S2)
6.45 -
6.65
6.47
5230 -
6260
5840
536 -
604
575
1745 -
2325
2099
165.1-
195.3
179.5
Evisceration section (S8)
6.70 -
6.85
6.77
3870-
4425
4205
302-
474
414
664-
745
705
72.7-
104.9
86.4
Spin chilling section (S11)
7.74-
7.87
7.79
3425-
4330
3905
28.3-
43.0
36.8
515-
685
593
137.2-
156
148
Live dock section (S12)
9.30-
9.47
9.38
2420-
3440
3075
12.3- 21
16.8
196-
237
220
72.8-
99.5
87.2
The pollution load in some streams varied quite widely
The cause of such variations was probably due to an irregular flow of birds on the line shackles at some time when the wastewater samples were taken

18. Summary of characterization results from the different sections
The COD load from 4 streams in the evisceration section complied with the discharge norms
1 Stream from the killing section and 2 streams from the evisceration section did not comply with the discharge norms in terms of oil and grease
The TSS load from 4 streams in the evisceration section complied with the discharge regulations
4 Streams were not polluted these were the outlet from the vent opener (S3), neck cracker (S5), inside outside washer (S7) & spin washer 2 (S10)

19. Result of the characterization of the final effluent
Parameter
Pollution range
Mean pollution load
Discharge limit pH
6.51 – 6.72
6.63
5 – 9
COD (mg/l)
3885 – 4685
4230
1500
Oil & grease (mg/l)
44.3 – 163.2
57.2
150
TSS (mg/l)
605 – 930
789
400
Chloride
67.5 – 92.3
76.8
The highest value for oil & grease occurred because on one sampling day the rotary screen at the treatment station was not working
The TSS and the COD loads did not comply with the discharge norms

20. Combinations of Coagulants and Nalco 9617
3. Jar Tests Results
Combinations of coagulants and Nalco 9617 dosages giving lowest turbidity
Combinations of Coagulants and Nalco 9617
Turbidity (FTU)
225 ppm FeCl ppm Nalco 9617 29
175 ppm HMP + FeCl3 (1:1) mixture ppm Nalco 9617 23
175 ppm HMP + 15 ppm Nalco 9617 40
325 ppm Alum + 10 ppm Nalco 9617 62
Lowest turbidity with combination of 225 ppm FeCl3 & 10
ppm Nalco 9617
The combination of 325 ppm of alum + 10 ppm Nalco 9617
gave the highest turbidity

21. Resulting turbidity range
Comparison of the efficiency of chemicals on the effluent in terms of pH
Coagulants
Best working
pH range
Resulting turbidity range
(FTU)
FeCl3
5.3 – 6.0
38 – 79
HMP + FeCl3 (1:1)
3.3 – 4.3
21 – 28
HMP
3.5 – 4.5
18 – 65
Alum
6.0 – 8.0
40 – 82
Alum gave better results at a higher pH range than the other coagulants and the mixture of FeCl3 + HMP gave appreciable turbidity results at a low pH range

22. Comparison of Efficiency of combinations coagulants & Nalco 9617
The combination of HMP & Nalco 9617 removed the highest percentage of COD from the wastewater
The combination of FeCl3 & Nalco 9617 removed the highest percentage of turbidity and TSS

23. Cost of effluent treatment per m3
Combinations of chemicals
Cost of treatment
(Rs/m3)
FeCl3 + Nalco HCl
14.48
50 % FeCl % HMP + Nalco HCl
26.43
HMP + Nalco HCl
27.30
Alum + Nalco HCl
16.55
Least cost is obtained by treating the effluent with a combination of FeCl3 + Nalco 9617
Highest cost is obtained by treating the effluent with chemical combinations containing HMP

24. Raw effluent
Effluent treated with HMP
Effluent treated with FeCl3
Effluent when treated with alum

25. Conclusion & Recommendations
Conclusions:
The SWI was found to be 17.9 L/bird
Wastewater streams S3, S5, S7 & S10 completely complied with the discharge regulations
The combination of HMP + Nalco 9617 removed the highest percentage of COD whereas the combination of FeCl3 + Nalco 9617 removed the highest percentage of turbidity & TSS
Treating the effluent with combinations containing HMP would be more expensive

26. Recommendations: Further research:
All hoses should be fitted with self-closing nozzles to eliminate wastage when not in use
The effluents from streams which completely conforms with the discharge regulations amounts to 96 m3/day. This 96 m3 of effluent can be directly sent to the sewer network or use to rinse the blood in the blood trough during the neck severing process
Further research:
Determining the best disposal option for the 96 m3 of effluent which completely conforms with the discharge regulations

27. Thank you for your kind attention
QUESTIONS???