Organic Carbon and Nitrogen Removal in a Modified Anoxic/Oxic-Membrane Bioreactor Treating High Strength Wastewater

In this study, the feasibility of simultaneous nitrification and denitrification (SND) in an anoxic/oxic membrane bioreactor (A/O-MBR) without any recirculation was investigated. It was found that SND occurred in the bioreactor. The influent ammonia converted to NO₂ ^--N and NO₃ ^--N via the nitrification process and then further reduced to gaseous nitrogen, directly. It is possible that the aerobic denitrifying bacteria and the partly micro condition play the combination role. Therefore, the high COD_Cr and total nitrogen (TN) removal efficiencies of 96.7% and 94.7% were achieved in the combination system, successfully, regardless of varying influent COD concentration (500-2200 mg L^-1) and NH₄ ⁺-N concentration (50-200 mg L^-1).