The Oxidation of Di-(2-Ethylhexyl) Phthalate (DEHP) in Aqueous Solution by UV/H2O2 Photolysis

The oxidation of di-(2-ethylhexyl) phthalate (DEHP) in solution using UV/H2O2 and direct UV photolysis are analyzed in this study. It was found that DEHP was 100% removal in the solution by 180-min UV/H2O2 treatment and 73.5% removal by 180-min direct UV photolysis. The effect of different factors, such as DEHP concentration, H2O2 concentration, and UV light intensity, on photochemical degradation was investigated. The degradation mechanism of DEHP and the acute toxicity of intermediates were also studied. The photochemical degradation process was found to follow pseudo-first-order kinetics. The results of our study suggested that the concentration with 40 mg/L H2O2 and 5 mu g/mL DEHP in the solution at pH 7 with 10.0 x 10(-6) Einstein l(-1) s(-1) UV was the optimal condition for the photochemical degradation of DEHP. The photochemical degradation with UV/H2O2 can be an efficient method to remove DEHP in wastewater.