Advanced Oxidation of the Endosulfan and Profenofos in Aqueous Solution Using UV/H2O22 Process

Abstract

Degradation of two pesticides, endosulfan and profenofos, was investigated in aqueous solution using a combination of ultraviolet (UV) light and hydrogen peroxide (H2O2). Photochemical experiments based on the L9 (34) three-level orthogonal array of the Taguchi method with four control factors including initial pesticide concentrations (10, 15 and 20 mg/l), UV irradiation times (30, 60 and 90 min), pH (5, 6.5 and 8) and H2O2 (0.1, 0.01 and 0.05 M) were conducted. The endosulfan and profenofos were analyzed using gas chromatography with electron capture detector (ECD) and gas chromatography with mass spectrometry (GC-MS) respectively. Under the optimum conditions, 96.5% of the endosulfan and 98.5% of the profenofos were removed in about 90 min. The study also showed that the oxidation rate was enhanced more during the UV/H2O2 process in comparison to direct photolysis. The results of our study suggested that the concentration of 0.1 molar H2O2 and 10 ppm of pesticide in the solution at pH 8 with 90 min UV irradiation time were the optimal conditions for the photochemical degradation of two pesticides. The photochemical degradation with UV/H2O2 can be an efficient method to remove the endosulfan and profenofos from aqueous solution.

Keywords

• Endosulfan
• profenofos
• UV irradiation
• UV/H2O2