PERFORMANCE TESTING OF ROTARY PRESS DEWATERING UNIT UNDER VARYING SLUDGE FEED CHARACTERISTICS

Until recently, municipalities had two primary options for dewatering sludge: centrifuges and belt filter presses (BFP's). Among the major issues associated with selecting a sludge dewatering process are dewatering efficiency, ease and cost of operation and maintenance, solids throughput, space limitations, and odor control. Rotary presses, a relatively new sludge dewatering technology from Canada, are now gaining popularity in this country and offer another mechanical dewatering option.An investigation of recent pilot testing and full-scale performance testing results was conducted to evaluate the performance of the rotary press under varying sludge feed characteristics. Field data from the Aberdeen Proving Ground (APG) WWTP will help to confirm the dewaterability of waste activated sludge (WAS) using the rotary press. This information is useful because the majority of previously documented performance data for the rotary press was for facilities dewatering mixed sludge (primary sludge and WAS).Analysis of pilot testing results and full-scale performance data shows the rotary press can obtain similar performance as BFP's and centrifuges for both mixed sludge and WAS facilities and should be considered when evaluating dewatering alternatives.