Degradation and Mineralization of Simazine in Aqueous Solution by Ozone/Hydrogen Peroxide Advanced Oxidation

摘要

Advanced oxidation of simazine in aqueous solution by the peroxone hydrogen peroxide/ozone treatment was investigated using Box-Behnken statistical experiment design and response surface methodology. Effects of pH, simazine and H2O2 concentrations on percent simazine and total organic carbon TOC removals were investigated. Ozone concentration was kept constant at 45 mg L1. The optimum conditions yielding the highest simazine and TOC removals were also determined. Both simazine and peroxide doses affected simazine removal while pH and pesticide dose had more pronounced effect on mineralization TOC removal of simazine. Nearly 95% removal of simazine was achieved within 5 min for simazine and peroxide concentrations of 2.0 and 75 mg L1, respectively at pH=7. However, mineralization of simazine was not completed even after 60 min at simazine doses above 2 mg L1 indicating formation of some intermediate compounds. The optimum H2O2 /pH/Simazine ratio resulting in maximum pesticide 94% and TOC removal 82% was found to be 75/11/ 0.5mg L1.