Degradation of carbon tetrachloride by iron metal: complexation effects on the oxide surface

摘要

Dehalogenation of chlorinated aliphatic contaminant at the surface of zero-valent iron metal (Fe~0)is mediated by the thin film of iron(hydro)oxides found on Fe~0 under environmental conditions. To evaluate the role this oxide film plays in the reduction of chlorinated methanes, carbon tetrachloride(CCl_4)degradation by Fe~0 was studied under the influence of various anions, ligands, and initial CCl_4 concentrations([p]_o). Over the range of conditions examined in these batch experiments, the reaction kinetics could be characterized by surface-area-normalized rate constants that were pseudo-first order for CCl_4 disappearance(k_CCl_4), and zero order for the appearance of dissolved Fe~2+(k_Fe~2+).