Effect of Nitrite on Biological Phosphorus Removal in Wastewater

Abstract:

Nitrite (NO2-) exists in the biological phosphorus and nitrogen removal system as an intermediate in the biological oxidation of ammonia to nitrate and reduction of nitrate to nitrogen. In enhanced biological phosphorus removal (EBPR) processes, nitrite is an electron acceptor used by denitrifying phosphorous removal bacteria and also an inhibitor to biological phosphorus removal process. This paper reviews metabolic mechanism of phosphorus accumulating organisms (PAOs) under anaerobic, aerobic and anoxic conditions separately. The effect of nitrite on biological phosphorus removal as well as inhibition mechanism of nitrite was introduced. The personal opinions were also suggested.