CENTRIFUGE OR BELT FILTER PRESS? ODOR CONTROL COULD BE THE PIVOTAL FACTOR

In 1995, Abington Township initiated a review of its biosolids handling practices in response to concerns about aging dewatering equipment, poor performance, operator safety, and wasteful disposal practices. Rather than simply replace the belt press, Abington took the opportunity to evaluate all aspects of the solids handling including stabilization, disinfection, odor control and end use/disposal options. Abington, a suburban township bordering Philadelphia, operates a 3.91 MGD design two stage activated sludge plant which was receiving about 3.3 MGD annual average flow. Solids production is about 80% primary solids, and 20% waste activated sludge. Mixed primary and activated sludges are thickened in a DAF unit to 4.5% solids, followed by anaerobic digestion.