Modelling nitrogen removal performance of membrane aerated biofilm reactor by AQUASIM software

Abstract

A biological nitrogen removal model was established by AQUASIM software to model the autotrophic nitrogen removal performance of membrane aerated biofilm (MAB). The effects of biofilm thickness, hydraulic retention time (HRT) and influent ammonia concentration on microbial community and total nitrogen (TN) removal efficiency were investigated. The results show that the large biofilm thickness of counter-diffusion MAB contributed to the small proportion of AOB and low TN removal efficiency. It is worth noting that the TN removal efficiency reached 84% when the membrane thickness was 500 μm. Regarding with the HRT and influent ammonia nitrogen concentration, the low influent ammonia nitrogen concentration and HRT resulted in the high TN removal efficiency. The influent ammonia nitrogen concentration of 450 mg/L and HRT of 5.5 days contributed to the highest TN removal efficiency of 87%.