Study on the Effect of Membrane Flux on Integrated A/O-MBR Process for Municipal Wastewater Treatment

The integrated A/O-MBR process combined the conventional anoxic/oxic process（A/O） with the membrane bioreactor（MBR） to take full advantages of these two processes, and thus has been developed as one of the promising treatments for municipal wastewater. Membrane flux is a key design parameter for the integrated A/O-MBR process. In the present research, effect of membrane flux on integrated A/O-MBR process has been studied.Results indicated that the optimal membrane flux was 20 L/（m2·h）, in this membrane flux,the membrane pressure increased slowly, the frequency of chemical cleaning was lower andthe water yield was high. While the mean removal rate of COD and NH4+-N reached 92.63% and 99.17%. However, the removal efficiency of TN was poor under this condition. After controlling a set of operating parameters, the mean removal rate of TN reached 69.69%. Besides,when the dosage of phosphate removal agent was 50 mg/L, the removal rate of TP could reach 93.61% and the TP content of effluent was under 0.3 mg/L.