Intensified nitrogen and phosphorus removal by embedding electrolysis in an anaerobic-anoxic-oxic reactor treating low carbon/nitrogen wastewater

A modified anaerobic-anoxic-oxic (AAO) reactor embedding electrolysis was constructed for treatment of low carbon/nitrogen (C/N) wastewater. The effect of different current conditions on the performance of reactor was investigated in this study. When the current ranged from 0 mA to 200 mA, the removal efficiency of total nitrogen (TN) increased from 61.25% (0 mA) to 75.60% (200 mA), and that of total phosphorus (TP) increased from 72.24% (0 mA) to 93.93% (200 mA). In addition, the removal efficiencies of chemical oxygen demand (COD) and NH4+-N were not affected. The results indicated that AAO reactor coupling electrolysis was an effective way to strengthen the removal of nitrogen and phosphorus for treatment of low C/N wastewater.