Abstract:The effects of anaerobic reaction time and COD concentration on denitrifying phosphorus removal efficiency of A2O-BAF process were studied in parallel batch experiments, at the same time the relationship between denitrifying phosphorus uptake amount and nitrate consumption was investigated in anoxic condition. The results found that as anaerobic reaction time from 30min to 120min and COD concentration from 50mg/L to 200mg/L increased, phosphorus release amount, denitrifying phosphorus uptake amount, net phosphorus uptake amount and nitrate removal amount increased, but the ratio of denitrifying phosphorus uptake amount and release amount remained almost unchanged. In the all tests, a good linear relationship between denitrifying phosphorus uptake amount and nitrate consumption was presented in anoxic condition, with the linear coefficient and correlation coefficient ranging from 1.007 to 1.053 and 0.992 to 0.997 respectively, which showed the sludge intrinsic characteristics in the anaerobic/anoxic/aerobic process with biological aerated filter (A2O-BAF) denitrifying phosphorus removal system.