title: Reductive transformation of endosulfan in aqueous phase using magnesium-palladium bimetallic systems: a comparative study.
abstract: The efficiencies of reductive transformation of endosulfan by bimetallic systems consisting of zerovalent magnesium (Mg(0)) as the electron donor and three forms of palladium as the catalyst (Pd(0)-alumina, Pd(0)-carbon and Pd-K(2)PdCl(6)) were compared in this investigation. Results revealed that both Pd(0)-alumina and Pd(0)-carbon were able to remove 90 and 93% of 10 mg L(-1) of endosulfan, respectively in 30 min with the concomitant accumulation of trace concentrations of partially chlorinated compounds in the reaction medium. Removal of endosulfan followed first-order kinetics and the rate constant (k(obs)) value was computed to be 0.2 min(-1) for both Pd(0)-alumina and Pd(0)-carbon. Pd(0)-carbon was relatively more stable and reusable in comparison to Pd(0)-alumina. More than 99% of 10 mg L(-1) endosulfan was converted to hydrocarbon end product by Pd-K(2)PdCl(6) system within 6 min of reaction. The formation of hydrocarbon end product suggested desulfurization and complete dechlorination of endosulfan. The efficiencies of removal of α and β endosulfan isomers were nearly the same in reaction media containing acetone or Tween 80 as the pesticide solubilizing agents. Results obtained in this study suggest the possibility of developing a reactor containing immobilized palladium for the treatment of water contaminated with endosulfan.
authors: Centre for Environmental Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, State of Maharashtra, India. prabhuthangadurai@iitb.ac.in
authors: Prabhu
authors: P
authors: Thangadurai
authors: Sumathi
authors: S
authors: Suresh
mesh_terms: D000096:Acetone; D002384:Catalysis; D004726:Endosulfan / Q000737:chemistry*; D007306:Insecticides / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*; D011136:Polysorbates; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D007306:Insecticides; D011136:Polysorbates; D014874:Water Pollutants, Chemical; D000096:Acetone; D010165:Palladium; D008274:Magnesium; D004726:Endosulfan