Removal of simazine from aqueous solution by Fenton's reagent oxidation was investigated. Box-Behnken statistical experiment design and the response surface methods were used to investigate the effects of simazine, H2O2 and Fe (II) concentrations on simazine degradation and mineralization. Total organic carbon (TOC) and simazine removals were investigated at different reagent doses to determine the experimental conditions yielding the highest removal of simazine and TOC. Fe (II) concentration had more profound effect than H2O2 for simazine removal while all parameters affected mineralization (TOC removal). Complete disappearance of simazine was achieved within 6 min reaction period. However, only 32% of simazine was mineralized after 15 min indicating formation of some intermediate products. The optimal H2O2/Fe (II)/simazine ratio resulting in the maximum pesticide (100%) and TOC removal (32%) was found to be 55/15/3 (mg L-1). The initial rate of simazine degradation was found to be first-order with respect to the initial simazine concentration. (c) 2009 Elsevier B.V. All rights reserved.