摘要：The effect of factors affecting the Fenton process including H2O2/Fe2+ ratio, pH and reaction time on the removal of BOD5, COD, color and total phenolic compounds from olive mill wastewater as well as variations of the BOD5/COD ratio was investigated using central composite design and response surface methodology. The ranges of H2O2/Fe2+ ratio, pH and reaction time were considered as 4.64-11.36, 2.32-5.68 and 9.6-110.4 min, respectively.Based on ANOVA and regression results, the high values of the obtained R2 (0.86-0.99) indicated that removal of the contaminants could be defined by the polynomial quadratic model and there was a good agreement between the model prediction and experimental data. The removal efficiencies of BOD5, COD, color and total phenolic compounds were 87%, 93.8%, 42.85% and 70.4%, respectively. Also, measuring the BOD5/COD ratio showed that this value increased from 0.16 to 0.44 after the process. Therefore, response surface methodology is a powerful tool for optimizing the Fenton process during olive mill wastewater treatment. Increased BOD5/COD ratio indicated that the Fenton process, as a pre-treatment, could prepare the wastewater for complementary biological treatment by reducing the level of toxic and recalcitrant contaminants.
