BENCH-SCALE STUDY OF BIOLOGICAL PHOSPHORUS REMOVAL FROM MUNICIPAL WASTEWATER

摘要

A bench-scale study of biological phosphorus removal (BPR) from primary settled wastewater from the Brookings Municipal Wastewater Treatment Facility (BWWTF) was conducted. The study included a mainstream BPR process in two and three stages. The effect of additional soluble BOD on three-stage BPR process performance was also studied. From the influent total phosphorus concentration of 13.0 mg/L at the existing full-scale RBC-activated sludge facility, primary clarification removed 2.8 mg/L and secondary treatment units removed 5.6 mg/L of phosphorous. An overall phosphorus removal of 66% was observed at the BWWTF during this study period. Effluent soluble total phosphorus (STP) concentrations obtained in the two-stage laboratory BPR processes were above 3.7 mg/L as P and were found comparable to the conventional activated sludge process. The University of Cape Town (UCT) type BPR process resulted in effluent phosphorus concentrations as low as 2.3 mg/L as P. The effluent phosphorus concentrations from both the anaerobic-aerobic process and UCT-type process were not significantly affected by influent phosphorus concentrations. The process with enriched soluble BOD resulted in continuously lower effluent STP at increasing concentrations of sodium acetate. The UCT-type process with enriched soluble BOD resulted in effluent STP as low as 0.5 mg/L as P. For successful BPR operation, the amount of soluble BOD in the influent was found more significant than total BOD_5.