Abstract: In order to inspect the phenomenon of anoxic phosphate uptake with simultaneous denitrification using NO^-₂ as electronic acceptor, a series of batch experiments under sequencing anaerobic/anoxic conditions were carried out. Wide variety concentrations of NO^-₂ were added during the anoxic condition. The results show that under anoxic condition, NO^-₂ had no inhibited behavior to phosphorus uptake bellow the concentration of 3125 mg/L, but at the concentration of 375 mg/L, phosphorus uptake inhibition happened. If the sludge of DPB was domesticated, NO^-₂ can serve as electron acceptor even at very high concentration (75 mg/L). Therefore under anoxic condition, phosphorus and nitrogen can be removed simultaneously via the process of denitrifying dephosphatation with nitrite as electron acceptors. Maximum specific rates of phosphorus uptake is 3.16 mg P/(gMLVSS·h) and denitrification rate is 514 mgNO^-₂-N/(gMLVSS·h).

Key words: denitrifying phosphorus removal bacteria, electron acceptor, ratio of P-uptake, ratio of denitrification