Nitrite Serving as Electronic Acceptor for Simultaneous Denitrification and Phosphorus Removal

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).