Degradation of endosulfan and lindane using Fenton’s reagent

Advanced oxidation of endosulfan and lindane was investigated using Fenton’s reagent (FeSO4/H2O2) in aqueous phase. A pH of 3 was chosen as optimum with the degradation efficiency of 83 % for endosulfan and 92 % for lindane. FeSO4 dose of 50 and 20 mg ml−1 was found to be optimum for endosulfan and lindane, respectively, with the degradation efficiency of ~83 % at pH 3. Further addition of FeSO4 remained unutilized and contributed to the dissolved solid content. FeSO4:H2O2 (w/w) ratio of 1:4.7 and 1:7 was optimized for endosulfan and lindane, respectively. First-order reaction kinetics (5, 7.5 and 10 ppm) were observed for both endosulfan and lindane degradations. Calculated rate constant values (kobs’) for initial endosulfan concentration of 5, 7.5 and 10 ppm were 0.021, 0.133, 0.046 min−1, respectively. While rate constant values (kobs’) of 0.057, 0.035 and 0.034 min−1 were observed for kinetics performed with 5, 7.5 and 10 ppm initial lindane concentrations, respectively. GC–MS analysis revealed that degradation process for endosulfan was sequential with the formation of methyl cyclohexane followed by 1-hexene. While lindane degradation process was spontaneous with the formation of 1-hexene formed by benzene ring fission. © 2014, The Author(s).