Removal of nitrogen and phosphorus using a new biofilm process-INRS (Innovative Nutrient Removal System)

Abstract

Adopting various process configurations may perform biological nutrient removal (BNR) from sewage. To get a compact BNR process, biofilm reactors were chosen for nitrification and denitrification. Enhanced biological nitrogen and phosphorus removal in a new fixed biofilm reactor was investigated in operation strategies with two reaction phases: anaerobic/anoxic/aerobic process with post-anoxic/aerobic biofilm process (Run 2A) and Run 2A with exogenous carbon sources for denitrifying and removing phosphorus (Run 2B). The influent used was “J” WWTP influent that consisted of wastewater from nearby a factory district area, leachate, and sewage. Therefore, the influent contained a great deal of refractory organic compound. The mean concentrations of COD, NH 4 + -N and T-P in the influent were about 297.0 mg/L, 64.92 mg/L and 2.63 mg/L, respectively. The C: N: P ratio of influent was 113: 25: 1 and it was not suitable for growth of microorganism compared with 100: 5: 1 of proper growth C:N:P ratio. But, at a total HRT of the system of 16 hours in Run 2, the system worked successfully obtaining removal of COD, T-N and T-P of the case of Run 2A, 80.1 %, 74.9 %, and 50.8 %, respectively, and Run 2B(c) with exogenous carbon source (Na-acetate) obtained 86.2 % T-N removal efficiency. The results of this research showed that an innovative nutrient removal system (INRS) process packed with SAC media could be applicable for treatment of nutrients from municipal wastewater.