Degradation of chlorinated aromatic compounds by Mackinawite with transition metals

Mackinawite has effectively transformed chlorinated aliphatic hydrocarbons such as perchloroethylene, trichloroethylene, hexachloroethane, and trichloroethane to less chlorinated compounds. The reductive dechlorination of 1,2-dichlorobenzene (1,2-DCB) and 2,4-dichlorophenol (2,4-DCP) by mackinawite was studied. Because the reaction kinetics by mackinawite was not fast enough to be applied to the treatment of groundwater and soil contaminated with 1,2-DCB and 2,4-DCP, The effect of transition metal addition on the reduction kinetics of 1,2-DCB and 2,4-DCP by mackinawite was evaluated so that an effective method can be developed to enhance the reactivity of mackinawite to treat the contaminated groundwater and soil. Four transition metals (Co(II), Cu(II), Ni(II) and Fe(II)) were selected as potential candidate additives and the effect of transition metal on the reductive dechlorination of chlorinated aromatics were determined by comparing their kinetic rate constants to those obtained from controls. The degradation kinetics followed the pseudo first-order rate law. This is an abstract of a paper presented at the 231st ACS National Meeting (Atlanta, GA 3/26-30/2006).