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Sludge Dewatering

Digested sludge will be dewatered on the Deskins "Quick Dry" Filter Bed Process®.

The Deskins process utilized an inline polymer preparation system that "injects" the polymer into the flocculation device. This technique eliminates the need for batching tanks, mixers and polymer transfer pumps. lnline systems use only the polymer needed and activates the sludge to the maximum performance. The polymer accelerates the particle agglomeration and hence increases the total amount of water that can be drained. Polymer conditioning reduces the amount of water that needs to be evaporated allowing for a greater increase in solids handling.

Inline liquid-solid separation is achieved with a new flocculation system (RapicFloc Mixer) that is mounted on a mobile platform. This new, self-contained technology produces a savings of 40%-60% in polymer usage. The normal sludge production is 10,000 gallons of dewatered sludge per 1 gallon of quality polymer.

The "Quick-Dry" Filter Bed® typically consists of a layer of sand placed over a substratum consisting of differing grades of gravel. Surface and subsurface bed stabilization using the Deskins "Quick-Drying"® Media allows for 100% saturation within 10 minutes from the start of pour. The 'layering' technique utilized here imitates the Earth's natural geological processes of filtering of liquids. Different layers of aggregates including sand and stone are stratified to produce the maximum efficiency of the filtering process. Within this stratification, a stabilization layer consisting of a polyurethane cellular confinement system allows for stabilization of the media as well as the weight distribution needed when sludge retrieval equipment is used. An underdrain system exists beneath the gravel layers. This is a lateral network of perforated pipes that is used to collect the filtrate for recycle to the WWTP. The perimeter of the Filter Bed consists of concrete walls that retain the sludge.