الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Dewatering of drinking water treatment sludge aims to reduce the cost of sludge handling and transportation. In Egypt a large quantity of sludge is generated from surface water treatment for potable supplies typically involves coagulation, flocculation, sedimentation, and filtration processes for removing colloidal as well as suspended solids from raw water. A pilot scale filter was tested for dewatering and thickening of alum sludge generated during the production of potable water in a conventional compact water treatment plant (WTP). The alum sludge is produced from coagulation process using aluminum sulfate (Alum) (Al2 (SO4)3. 18H2O). The pilot scale was fabricated from scheduled uPVC pipe. The reactor was filled with floatable media (polystyrene) working as filtration media with counter flow concept. The alum sludge was discharged into the pilot scale setup from the sludge holding tank in the WTP using submersible pump.
The pilot scale filter was tested at different rates of filtration (ROF) ranged from 25 to 400 m3/m2/d. In addition, different media heights (100 – 800 mm) were investigated to study the efficiency of the sludge thickening. The filter rate of washing (ROW) was tested to determine the optimum value that will clean the filter. ROW equal to one to four times the ROF were investigated. The optimum range of ROF was found to be 200 m3/m2/d and the filtration media height 500 mm, at the optimum operating conditions, the floatable media filter had the ability to thicken the alum sludge and, the turbidity of the water produced after thickening were less than 18 NTU.
A comparison between pilot scale filter and the conventional thickener was performed to evaluate the dewaterability for both systems using drying beds as a dewatering method for the thickened sludge produced from pilot scale filter and conventional thickener. The efficiency of the Floatable Media Reactor (FMR) in thickening of the alum sludge is better than the conventional thickener otherwise, the drying bed area shall be decreased to half of required area needed with the conventional thickener.