Abstract

In this work the electrochemical degradation of polychlorinated compounds using Co(dmgH)(2)Cl(py), Co(dpgH)(2)Cl(py), Co(chgH)(2)Cl(py) and Co(dbegH)(2)Cl(py) (where dmgH is dimethylglyoximato, dpgH is diphenylglyoximato, chgH is 1,2-cyclohexanedionedioximato and dbegH is 4,4'-((1E,2E)-1,2-bis(hydroxyimino)ethane-1,2-diyl)dibenzoate) is described. The degradation was studied using cyclic voltammetry by monitoring current changes in the zone near to the Co(II/I) half wave potential as the concentration of the organochloride in the electrochemical cell is increased. Hexachloroethane (HCA) was used as organohalide substrate, while gamma-hexachlorocyclohexane (lindane), 1,2-dichloroethane, and 1,1,1-trichloroethane were used for comparative studies. The major dechlorination product of HCA, detected through head space GC-MS experiments after bulk electrolysis, was tetrachlorethylene. The rate constants of the dechlorination processes were estimated using the foot-of-the-wave analysis (FOWA), the values obtained were 1.10x10(5), 2.59x10(4), 4.91x10(4) and 1.83x10(4) for Co(dmgH)(2)Cl(py), Co(dpgH)(2)Cl(py), Co(chgH)(2)Cl(py) and Co(dpegH)(2)Cl(py) respectively.