Complete Dechlorination of Endosulfan and Lindane Using Mg0/Pd+4Bimetallic System

A Mg0/Pd+4 bimetallic system was evaluated to dechlorinate endosulfan and lindane in the aqueous phase. Studies were conducted with endosulfan and lindane separately, with or without acid in a 1:1 (v/v) water:acetone phase. In the absence of any acid, higher degradation of endosulfan and lindane was observed using Mg0/Pd+4 doses of 10/0.5 and 4/0.1 mg/mL, respectively. Acetone plays an important role in facilitating the dechlorination reaction by increasing the solubilities of pesticides. Dechlorination kinetics for endosulfan and lindane (30 and 50 mg/L [30 and 50 ppm] concentration of each pesticide) were conducted with varying Mg0/Pd+4 doses, and the time-course profiles were well-fitted into exponential curves. The optimum observed rate constants (kobs') for endosulfan and lindane were obtained with Mg0/Pd+4 doses of 5/0.5 and 4/0.1 mg/mL, respectively. Gas chromatography-mass spectrometry analyses revealed that endosulfan and lindane were dechlorinated completely into their hydrocarbon skeletons—Bicyclo [2,2,1] hepta 2–5 diene and benzene, respectively.