4. Establishment The government of Pakistan and United Nations Development Program (UNDP) signed the Kasur Tannery Pollution Control Project document in January 1996. UNDP allocated US$ 2.5 million, whereas the local input was Rs. 199 million.
5. Inflow Wastewater Comes in two drains from the Tanneries. Two drains comes side by side along the road coming from tanneries to the treatment plant
6. Flow measurements Drain 1 : Width = 145 cm = 1.45 m Depth = 54 cm = 0.54 m Velocity of wastewater = 0.13933 m/s Flow = 0.1091 m3/s = 9426.32 m3/d
7. Flow measurements Drain 2 : Width = 90 cm = 0.9 m Depth = 54 cm = 0.54 m Velocity of wastewater = 0.28575 m/s Flow = 0.1388 m3/s = 499.94 m3/hr = 11998.75 m3/d
8. Flow measurements The total discharge coming towards treatment plant is: From Drain 1 ( Q ) = 9426.32 m3/d From Drain 2 ( Q ) = 11998.75 m3/d = 9426.32 + 11998.75 Total Discharge = 21425.07 m3/d
10. Bar screening Manual bar screening: Larger suspended particles are removed Pore size is of 60 mm Removes about 90 % of the suspended particles This is done manually
13. Bar screening Mechanical bar screening After Manual bar screening mechanical bar screening is done The pore size of mechanical bar screening is 6 mm About 95 % of suspended solids are removed
15. Distribution of wastewater to the aeration Tanks A gate valve is installed to control the flow further WW is distributed into two drains which goes to the Aeration tanks
17. Aeration Tanks There are two large aeration tanks Each tank has 8 surface aerators WW is spread in the aeration tanks and aeration is done Detention time is of one day
18. Aeration Tanks Dimensions of each tank: Width = 32.5 m Length = 65.0 m Depth = 4.7 m Volume= 6337.5 m3 Total volume of both tanks = 12675 m3
22. Aeration Tanks Surface Aerators There are 16 aerators in both the tanks Power is 30 KW Oxygen transfer is of 1.6 kg O2 /Wh
23. Pumping system Wastewater is pumped from the aeration tanks to the sedimentation tanks. Three pumps installed for this purpose Two pumps are working and the third one is a stand by pump.
24. Each pump has : Flow = Q= 350 m3 /h Head = 12 m Two pumps has a power of 18 KW One pump has a power of 24 KW
27. Sedimentation tanks There are two sedimentation tanks Each tank has dimensions of : Diameter = 18 m Depth = 3 m Volume = 611 m3 Detention time of 5 – 7 days
28. The equalized effluent is entered to the clarifier for settling under gravity settled sludge is scrapped from the bottom of the tank with the help of the sludge scrapper.
32. Wastewater Lagoons Water from clarifiers goes to the wastewater lagoons There are 32 lagoons, 16 on each side. Totally natural process occur in lagoonsin which the water is placed in the lagoon more than 5 days and during this time period many inorganic and biological reactions take place.
34. The organic layer is laid on the bedding and then water is placed on it the function of this geo layer is that wastewater will not seep into the soil.