The aim of this research was to reduce the chemical oxygen demand (COD) and sulfide from a spent caustic wastewater using electron-Fenton technique. The experiments were applied to evaluate the effect of several parameters such as pH, reaction time, current density mA/cm2, H2O2/Spent Caustic Wastewater (SCW) (ml/l), H2O2/Fe2+ molar ratio on the performance of the process. The response surface methodology (RSM) was applied to minimize the number of runs and investigate the optimum operating conditions. Five independent variables were carefully considered and optimized in this paper. The optimum conditions were found at pH of 2.96, reaction time of 70.67 min, current density of 58.85 mA/cm2, H2O2/SCW of 1.59 ml/l, H2O2/Fe2+ molar ratio of 3.47 for 81.20 COD removal while the optimum conditions were found at pH of 2.87, reaction time of 65.52 min, current density of 55.47 mA/cm2, H2O2/SCW of 1.38 ml/l, H2O2/ Fe2+ molar ratio of 3.21 for 99.9998 sulfide removal.
