Enhanced denitrifying phosphorous removal in a novel anaerobic/aerobic/anoxic (AOA) process with the diversion of internal carbon source

► A novel anaerobic/aerobic/anoxic (AOA) process is proposed to realize denitrifying phosphorous removal in municipal wastewater treatment. ► Part of the anaerobic mixed liquid is transferred to the post-anoxic zone. ► NO3--N and PO43--P are removed simultaneously in the anoxic zone, and part of TN is removed in the aerobic zone via simultaneous nitrification and denitrification (SND). ► The AOA process is suitable to treat wastewater with low C/P or C/N ratios and its process configuration is simple.