Response surface methodology (RSM), a facile tool for optimization, was employed to determine the optimum conditions for production of organic acids by using electrodialysis with bipolar membranes (EDBM) In particular, gluconic acid was chosen as the model organic acid, and the Box-Behnken center-united experimental design was used to quantify the effects of current density, electrolyte concentration, and feed concentration on the process cost. According to the ridge and canonical analysis, the optimum conditions were as follows current density. 44.83 mA cm(-2); electrolyte concentration, 0.12 mol dm(-3); feed concentration, 0 15 mol dm(-3) Moreover, the experimental results were in good agreement with the predictions, suggesting that RSM was a good tool for modeling the process of EDBM. (C) 2010 Elsevier B.V All rights reserved