Removal of nitrogen and phosphorus in a combined A2/O-BAF system with a short aerobic SRT.

A bench-scale anaerobic/anoxic/aerobic process-biological aerated filter (A2/O-BAF) combined system was carried out to treat wastewater with lower C/N and C/P ratios. The A2/O process was operated in a short aerobic sludge retention time (SRT) for organic pollutants and phosphorus removal, and denitrification. The subsequent BAF process was mainly used for nitrification.