Reductive dechlorination of trichloroethene mediated by humic-metal complexes
- Air Force Research Lab., Tyndall AFB, FL (United States)
- Applied Research Associates, Inc., Tyndall AFB, FL (United States)
Experiments were conducted to determine if transition metal-humic acid complexes can act as e{sup {minus}} transfer mediators in the reductive dechlorination of trichloroethene (TCE) using Ti(III) citrate as the bulk reductant. In the presence of Ni-Aldrich humic acid (AHA) complexes, TCE reduction was rapid, with complete removal of TCE in less than 23 h. Cu-AHA complexes were less effective as e{sup {minus}} mediators than Ni-AHA complexes; only 60% of TCE was reduced after 150 h. Partially dechlorinated intermediates were observed during TCE reduction; however, they were transitory, and at no time accounted for more than 2% of the initial TCE mass on a mole C basis. Ethane and ethene were the primary end products of TCE reduction; however, a suite of other non-chlorinated hydrocarbons consisting of methane and C{sub 3} to C{sub 6} alkanes and alkenes were also observed. The results suggest that humic-metal complexes may represent a previously unrecognized class of electron mediators in natural environments.
- OSTI ID:
- 345147
- Journal Information:
- Environmental Science and Technology, Vol. 33, Issue 7; Other Information: PBD: 1 Apr 1999
- Country of Publication:
- United States
- Language:
- English
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