Denitrifying dephosphatation in enhanced biological phosphorus removal system.

Denitrifying dephosphatation process with nitrate as electron acceptor was studied, adopting sequencing batch reactor (SBR). The results showed that denitrifying phosphate accumulating bacteria existed in the conventional enhanced biological phosphorus removal system. There was a linear relationship between the COD taken up and the phosphate released in the anaerobic. The proportion of denitrifying phosphate accumulating bacteria to phosphorus accumulating organism increased from 13.3% to 69.4% with anaerobic/anoxic strategy. Anaerobic/anoxic SBR operated in steady-statepossessed good properties of enhanced biological phosphorus removal and denitrifying. The concentration of phosphorus in the system at anoxic end was lower than 1mg/L and the efficiency of phosphorus removal was above 89%.