In this study, polyacrylonitrile (PAN) flat-sheet membranes were prepared using phase inversion method for the wastewater treatment by membrane bioreactor (MBR). Twelve processing factors in the membrane preparation were investigated by Plackett-Burman design (PBD) in order to prepare high-performance membranes. Test results showed that none of the twelve processing factors had a significant effect on membrane pore size. The casting thickness, non-woven fabric type and casting speed were found to have substantial negative effects on the pure water flux values, and were identified as the significant factors determining the membrane pure water flux. It was also found that the non-woven fabric type, casting speed and casting thickness had significant positive effects on the fouling rate. Moreover, the model using membrane fouling rate as a response value was more credible and in good linear correlation within the tested range. (C) 2012 Elsevier B.V. All rights reserved.