Normally, the filter backwash water sludge very tough to remove or separate that one, generally in many plants that will have design the back wash water pipe line laid into main effluent collection tank. But this is not a right method.
Instead of that, try this method, though which has bit of cost investment involve, this is only an perfect method to remove such kind very tiny paste sludge separation with aid of coagulation.
Usually the filter back wash water comes around 2% to 5% of total water processed per Day. The quantity of solids purely depends on the following two factor
- The amount solids applied to the filter
- Suspended solids separates an filter efficiency
But the concentration generally various from 50 to 400 mg/Liter, amount solids applied to the filter depends on the how pretreatment provided. Where sedimentation precedes filtration, typical suspended solids enter into filter range from 5 to 10 mg/l back wash contains solids around 5 to 10 Kg/ML
Attainable sedimentation basin effluent turbidity can be less than 1 nephelometric turbidity unit (ntu); however, typical sedimentation effluent turbidities are 2 to 6 ntu. In the direct filtration process, flocculated water is applied directly to the filter. As a result, solids loading is a function of coagulant dosage and source water turbidity.
Construct a Civil tank Washwater recovery ponds sized to hold backwash water for 24 h or more may recover up to 80% of solids with the use of polymers or other coagulant aids. Reclaimed water is then usually reprocessed through the treatment plant. Flow through washwater clarifiers equipped with V-notch weirs and undercurrent baffle can recover 90% or more of solids.
Parallel plate separator (PPS) is suitable for this purpose, and drain the sediment sludge by the Valve , which has provide that conical bottom .
Use anionic polymer to sediment and separate the sludge normally < 1 ppm is enough. Try jar test and determine dosage level.
How to separate Filter backwash water sludge