Reductive Dehalogenation of Gas-Phase Chlorinated Solvents Using a Modified Fuel Cell
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- 作者：Zhijie Liu ; Robert G. Arnold ; Eric A. Betterton ; and Eugene Smotkin
- 刊名：Environmental Science & Technology
- 出版年：2001
- 出版时间：November 1, 2001
- 年：2001
- 卷：35
- 期：21
- 页码：4320 - 4326
- 全文大小：115K
- 年卷期：v.35,no.21(November 1, 2001)
- ISSN：1520-5851
文摘
The reductive dehalogenation of gas-phase chlorinatedalkanes (CCl4, CHCl3, and 1,1,1-trichloroethane) and alkenes(perchloroethene (PCE) and trichloroethene (TCE)) wasconducted in a modified fuel cell. The fuel-cell performancewas a function of cathode material, electric potential,temperature, target compound identity and gas-phaseconcentration, partial pressure of O2 in the cathode chamber,and cathode condition (time in service). TCE conversionwas approximately first order in TCE concentration with half-lives of fractions of a second. Under the same reactorconditions, CCl4 transformation was faster than CHCl3, andTCE reduction was faster than PCE. Rates of both CCl4and PCE transformation increased substantially withtemperature in the range of 30-70 
C. At 70 C and apotential (potential of the cathode minus that of the anode)of -0.4 V, single-pass CCl4 conversions were approximately90%. Mean residence time for gases in the porouscathode was much less than 1 s. The presence of even5% O2(g) in the influent to the cathode chamber had adeleterious effect on reactor performance. Performancealso deteriorated with time in service, perhaps due to theaccumulation of HCl on the cathode surface. Conversionefficiency was restored, however, by temporarily eliminatingthe halogenated target(s) from the influent stream or bybriefly reversing fuel-cell polarity.
C. At 70 C and apotential (potential of the cathode minus that of the anode)of -0.4 V, single-pass CCl4 conversions were approximately90%. Mean residence time for gases in the porouscathode was much less than 1 s. The presence of even5% O2(g) in the influent to the cathode chamber had adeleterious effect on reactor performance. Performancealso deteriorated with time in service, perhaps due to theaccumulation of HCl on the cathode surface. Conversionefficiency was restored, however, by temporarily eliminatingthe halogenated target(s) from the influent stream or bybriefly reversing fuel-cell polarity.