Effects of aeration parameters on effluent quality and membrane fouling in a submerged membrane bioreactor using Box–Behnken response surface methodology

Membrane bioreactor (MBR), which has been widely used in wastewater treatment, is restricted by membrane fouling and high energy consumption generated by aeration. Research on the effects of aeration on effluent quality and membrane fouling as well as fouled membrane cleaning methods is of great significance.By means of the Box–Behnken response surface methodology experiment, influence significance and interactions of three factors (aeration flow rate, time and position) were studied, and regression models were established. The optimal control parameters of aeration flow rate, time and position were found utilizing the Minitab optimizer. Meanwhile, the comprehensive effluent quality, membrane fouling and aeration energy consumption were considered. The results showed that: compared to aeration position, aeration flow rate and time affected effluent quality more significantly, and the two factors interacted. Effects of the three factors on membrane fouling were sequenced as follows: aeration flow rate>aeration position>aeration time. Besides, aeration flow rate and aeration time also interacted. When aeration flow rate, aeration time and aeration position reached 4.9m3/h, 86.1min and 6cm, respectively, effluent quality could meet the primary A standard of “Cities Sewage Treatment Plant Pollutant Discharge Standard” (GB18918-2002), membrane fouling could be controlled within a smaller range, and energy consumption for unit effluent was minimized.