Investigation of the effects of membrane fouling control strategies with the integrated membrane bioreactor model

The effect of membrane fouling control strategies was investigated with an integrated submerged membrane bioreactor model (SMBR). The model allowed the simultaneous simulation of biological and physical processes in membrane bioreactors (MBRs), which includes the activated sludge model and membrane fouling model. A benchmark simulation model modified for MBRs was applied as a platform to evaluate different membrane fouling control conditions (coarse bubble aeration intensity during membrane filtration time and during idle-cleaning time, and the idle-cleaning time and energy requirements were considered). Simulation results showed the membrane fouling control condition with continuous strong coarse bubble aeration during membrane filtration time could not be a more efficient membrane fouling control for optimizing energy than during idle-cleaning time. Even though the length of idle-cleaning time increased, membrane fouling was not improved continuously but converged because of fouling by the increase of real permeate flux. Therefore, the coarse bubble aeration and idle-cleaning time that contribute operating energy requirement in MBRs must be optimized from the membrane fouling point of view. The proposed modeling approach can be readily applied to other optimization problems of MBRs under various operating conditions.