Simultaneous nitrification and denitrification coupled with phosphorus removal in an modified anoxic/oxic-membrane bioreactor (A/O-MBR)

In this study, simultaneous carbon, nitrogen and phosphorus (PO43−-P) removals using an anoxic/oxic-membrane bioreactor (A/O-MBR) system without any circulation was investigated. The total nitrogen (TN) removal efficiency was above 84.6%, and the average removal efficiencies of COD and PO43−-P were 94.6 and 90.0%, respectively. Ammonium (NH4+-N) removal without nitrite (NO2−-N) and nitrate (NO3−-N) accumulation in the reactor suggested that simultaneous nitrification and denitrification (SND) occurred. The phosphorus-accumulating organisms (PAOs) accumulated in the reactor. AnOx/Oxic test indicated that intracellular organic carbon might be utilized as denitrification electron donor in nitrogen removal process.