Enhanced biological nitrogen and phosphorus removal using sequencing batch membrane-aerated biofilm reactor

Abstract A sequencing batch membrane-aerated biofilm reactor (SBMABR) combined with intermittent aeration and artificially enhanced biofilm shedding was employed to enhance biological nitrogen and phosphorus removal. A long-term running of 112 days was applied to evaluate the performances of SBMABR. The removal efficiencies of chemical oxygen demand (COD), NH 4 + –N, total nitrogen (TN) and total phosphorus (TP) in SBMABR were maintained above 90%, 96%, 91% and 85% respectively. The periodic backwashing could control the biomass effectively. The stable and abundant amoA and nirS genes were beneficial to maintain the high removal efficiency of SBMABR. Real-time PCR results revealed that SBMABR created the suitable survival environment for ammonia oxidizing bacteria (AOB) and denitrifying bacteria.