Hara Junko, Ito Hiroyuki, Suto Koichi, Inoue Chihiro, Chida Tadashi
Graduate Schools of Environmental Studies, Tohoku University, 20 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan.
Water Res. 2005 Mar;39(6):1165-73. doi: 10.1016/j.watres.2004.12.011.
The dechlorination of trichloroethene (TCE) with metallic iron is an advantageous method for the remediation of contaminated groundwater and soil. The toxic reaction intermediates such as dichloroethenes (DCEs) and vinyl chloride (VC), however, occasionally accumulate in the pathway of the reaction. We have been trying to suppress these intermediates by using metallic iron powder containing impurities. In order to investigate the reaction pathways, we measured the production rates of the intermediates and the final products of the dechlorination of TCE such as DCEs, VC, ethyne or ethene. Ethyne, ethene, ethane and cis-DCE were observed as the major products, and trans-DCE, 1,1-DCE, VC, C3-hydrocarbons (such as propane, propylene), C4-hydrocarbons (such as n-butane) and methane were observed as the minors. Also the rate constants of TCE to ethyne and ethyne to ethene were larger than any other constants. These fact show the production of ethene/ethane via ethyne is the main pathway of the dechlorination of TCE using the metallic iron powder.
用金属铁对三氯乙烯（TCE）进行脱氯是修复受污染地下水和土壤的一种有效方法。然而，二氯乙烯（DCEs）和氯乙烯（VC）等有毒反应中间体偶尔会在反应过程中积累。我们一直在尝试通过使用含有杂质的金属铁粉来抑制这些中间体。为了研究反应途径，我们测量了TCE脱氯的中间体和最终产物（如DCEs、VC、乙炔或乙烯）的生成速率。观察到乙炔、乙烯、乙烷和顺式DCE是主要产物，反式DCE、1,1-DCE、VC、C3烃（如丙烷、丙烯）、C4烃（如正丁烷）和甲烷是次要产物。此外，TCE生成乙炔和乙炔生成乙烯的速率常数大于其他任何常数。这些事实表明，通过乙炔生成乙烯/乙烷是使用金属铁粉对TCE进行脱氯的主要途径。
