BRIEF PROCESS DESCRIPTION OF EFFLUENT TREATMENT PLANT
EFFLUENT TREATMENT PLANT Capacity: 16 KLD
Parameter for design considered:
INLET PARAMETER TREATED PARAMETER
1. pH: 7 to 8 6-8
2. Oil & Grease: 400 mg/lit 10 ppm
3. COD 3000 mg/lit 250 mg/lit
4. BOD 800 mg/lit 30 ppm
5. TSS 1000 mg/lit . 100 ppm
BRIEF PROCESS:
The effluent water coming from plant would first come Oil & Grease Separation chambers, fitted with Siphon pipes and ultimately to the Equalization basin. Compressed air from an Air blower would be purged through Air bubble Diffusers, inside the Equalisation/ Collection chamber for proper mixing as well as to cool down the temperature of the effluent. (If any)
Water from Equalisaton basin would overflow to the neutralisation pit, a part of the same chamber, where the effluent would be neutralized by addition of requisite neutralizing chemicals, like lime solution along with other coagulant, like Poly Aluminum Chloride (PAC) Solution and Polyelectrolyte Solution for effective sedimentation of the sludge in the next unit operation, in the Primary Clarifier. These mentioned Chemicals can be added by On-Line Dosing to the Lifting Pump Suction.
The Chemical Sludge, formed out of the Process of Neutralisation, would be sedimented with in the Primary Clarifier conical end. As the Primary Clarifier would be placed on the Sludge Drying Beds, opening the bottom Valves at the conical end, the sedimented sludge would be drained off, directly to Sludge Drying Beds. The leachate coming out from the Sludge Drying Beds would be returned to Collection Chamber for further treatment.
Due to this chemical treatment maximum of the COD load and partly the BOD load would be decreased. Clear water after Primary Clarifier would overflow to Aeration Chamber for Microbial Treatment in the Activated Sludge Process.
Sludge free & oil free, neutralized, comparatively cold water, would be then allowed for an effective microbial treatment in Activated Sludge Process and MLSS concentration in the Aeration chamber would be maintained at the level of 2000 to 2500 ppm. The aeration would be done by a Twin-Lobe Blower and would be distributed through bubble diffusers, which will purge air at the bottom of the chamber.
Aerated water along with the microbial mass would overflow to Secondary Clarifier; The microbial mass would be sedimented at the conical bottom of the Secondary Clarifier and the sediment bacterial mass can be easily recycled to the Aeration chamber by a Re-Cycling Pump to maintain the desired MLSS concentration within the Aeration Chamber.
Finally the water would overflow the secondary Clarifier and allowed to be discharged to intermediate sump, where from it would be pumped through a multi-grade sand grabbles and Activated Carbon filtration unit, as a final Polishing of the treated water, to reduce the TSS level, if any.
The excess part of the deposited Bacterial sludge at the Clarifier bottom would be discharged to the Sludge Drying Beds where it would become dry sludge after de-watering. The dry sludge is highly enriched with the microbial residue, which can easily be used as good manure in the field of agriculture/gardening.
The final polished treated water after the Multi-Grade Sand-grabbles unit can be either discharged to any water body, which will comply the every norms as per Pollution Control Board.
PROCESS BLOCK DIAGRAM OF PROPOSED EFFLUENT TREATMENT PLANT