Carbon isotope fractionation during abiotic reductive dehalogenation of trichloroethene (TCE)

• Published in: Chemosphere (Oxford) 2001-08, Vol.44 (5), p.1281-1286
• Main Authors: Bill, Markus, Schüth, Christoph, Barth, Johannes A.C., Kalin, Robert M.
• Format: Article
• Language: English
• Subjects: Applied sciences; Carbon - chemistry; Carbon isotopes; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; Groundwaters; Halogens - chemistry; Iron - chemistry; Metallic iron; Natural water pollution; Oxidation-Reduction; Palladium; Palladium - chemistry; Pollution; Pollution, environment geology; Reductive dehalogenation; Soil Pollutants - analysis; Solvents - chemistry; TCE; Trichloroethylene - chemistry; Water Pollutants - analysis; Water treatment and pollution
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/S0045-6535(00)00274-5

Dehalogenation of trichloroethene (TCE) in the aqueous phase, either on palladium catalysts with hydrogen as the reductant or on metallic iron, was associated with strong changes in δ 13 C. In general, the δ 13 C of product phases were more negative than those of the parent compound and were enriched with time and fraction of TCE remaining. For dehalogenation with iron, the δ 13 C of TCE and products varied from −42‰ to + 5‰. For the palladium experiments, the final product, ethane, reached the initial δ 13 C of TCE at completion of the dehalogenation reaction. During dehalogenation, the carbon isotope fractionation between TCE and product phases was not constant. The variation in δ 13 C of TCE and products offers a new monitoring tool that operates independently of the initial concentration of pollutants for abiotic degradation processes of TCE in the subsurface, and may be useful for evaluation of remediation efficiency.