Simultaneous nitrogen and phosphorus removal under low dissolved oxygen conditions

摘要

A full scale test was operated by using low dissolved oxygen activated sludge process to enhance biological nitrogen and phosphorus removal. When the influent concentrations of COD Cr , TN and TP varied in a range of 352.9 mg/L—1338.2 mg/L, 34 4 mg/L —96.3 mg/L, and 2.21 mg/L—24.0 mg/L, the average removal efficiencies were 94.9%, 86.7% and 93.0%, respectively. During the test period of two months, effluent meas of COD Cr , BOD 5, NH 3 N, TN and TP were below 50 mg/L, 25 mg/L, 10 mg/L and 1.0 mg/L, respectively. The low dissolved oxygen activated sludge process has a simple flow sheet, fewer facilities and high N and P removal efficiency. It is very convenient to retrofit the conventional activated sludge process with the above process.