Effect of COD/TP ratio on biological nutrient removal in A2O and SBR processes coupled with microfiltration and effluent reuse potential

Abstract

ABSTRACTTwo bench-scale hybrid processes, anaerobic/anoxic/oxic (A2O) reactor and sequencing batch reactor (SBR), each followed by the microfiltration (MF) system, were simultaneously operated to compare their performances on the removal of organics and phosphorus from both synthetic and real wastewater to further explore the potential for effluent reuse. The effects of different influent chemical oxygen demand (COD) to total phosphorus (TP) ratios (27, 50, 80, and 200) were investigated. For both processes, when the influent COD/TP ratio was 200, the effluent quality was satisfactory for some reuse potential. The MF membrane system showed an evident further removal of COD (20–89%) and color (18–60%), especially the removal of suspended solids (SS) and turbidity with the final effluent SS <1 mg/L and turbidity <0.1 NTU. When real wastewater was tested, the effluent quality was adequate and met the standard goals for regional reuse purposes.