Phosphorus removal from domestic and industrial wastewater is a key factor in preventing eutrophication of surface waters. Biological phosphorus removal (BPR) in activated sludge systems is one of the most economical and efficient methods for phosphorus removal. The TKN (Total Kjeldahl Nitrogen)/COD ratio indicates the inhibitory effect of nitrate (NO3-) and nitrite (NO2-) in BPR. […]