SIDE-BY-SIDE-BY-SIDE PILOT TESTING OF HIGH-SOLIDS DEWATERING EQUIPMENT AT THE DES MOINES WASTEWATER RECLAMATION FACILITY

Black & Veatch assisted the Des Moines Wastewater Reclamation Authority (WRA) with pilot testing of high-solids belt filter presses and centrifuges at the City's regional Wastewater Reclamation Facility (WRF). The primary purpose of the investigation was to determine if modern, high-solids dewatering equipment could reduce the costs of dewatering and biosolids disposal. Over one week of testing in July 2000, two trailermounted, high-solids (14 and 15 roll) belt filter presses (BFP) were tested and compared against the City's belt filter presses. In August 2000, two high-solids centrifuges were simultaneously tested and also compared against the City's presses. Both technologies showed a significant potential for savings in operating cost, as a result of higher dewatered cake solids concentrations, higher throughput, and lower polymer use. Operating cost savings of 22 to 29 percent were projected.