Direct and indirect electron transfer mechanisms involved in chlorocarbon reduction

Jiankang Wang, James Farrell

Research output: Contribution to journalConference article

Abstract

The electron transfer reactions involved in reductive dechlorination of carbon tetrachloride (CT), trichloroethylene (TCE), and perchloroethylene (PCE) were studied. Increasing CT concentrations were associated with increasing iron corrosion rates, showing that CT was able to directly oxidize the iron wire. However, the current going towards CT reduction was always greater than the measured corrosion current. Since the measured corrosion currents only account for the oxidation of Fe(0) to Fe(II), this indicated that CT reduction also occurred via oxidation of Fe(II) to Fe(III). TCE reduction occurred primarily by reaction with atomic hydrogen produced from reduction of water. At a pH 7 rates of TCE reduction were less than those for PCE. However, at pH 3, the rates for TCE reduction were greater than those for PCE. This difference in relative reaction rates could be attributed to different rates of reaction with atomic hydrogen for TCE and PCE. The fraction of the iron surface covered with atomic hydrogen was much greater at pH value of 3 as compared to pH 7. Thus, the faster rate of TCE reduction at low pH could likely be attributed to its faster rate of reaction with atomic hydrogen. This is an abstract of a paper presented at the 224th ACS National Meeting (Boston, MA 8/18-22/2002).

Original languageEnglish (US)
Pages (from-to)493-495
Number of pages3
JournalACS Division of Environmental Chemistry, Preprints
Volume42
Issue number2
StatePublished - Dec 1 2002
Event224th ACS National Meeting - Boston, MA, United States
Duration: Aug 18 2002Aug 22 2002

    Fingerprint

ASJC Scopus subject areas

  • Chemical Engineering(all)

Cite this