In this work, the process of starch removal from starchy wastewater using a hydrophilic polyethersulfone membrane was investigated. The pore size of the membrane was 0.65 lm and the pattern of stream in plate and frame handmade membrane module was cross-flow. To design the layout of the experiments, response surface methodology was applied. The performance of the filtration process was evaluated by calculating the (chemical oxygen demand) COD removal percentage (rejection factor) and permeate flux. In this study, five operative parameters were investigated, including trans-membrane pressure, flow rate and temperature of feed, pH, and the COD concentration of starch wastewater. Two models were obtained from experimental data, capable of predicting COD removal percentage and permeate flux in different conditions. To check the precision of the models, analysis of variance combined with F-test was carried out. The predicted values obtained from the regression models were close to the actual ones. According to the models, the optimum condition for achieving a high percentage of COD removal and high value of permeate flux was obtained by using mathematical optimization.

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