Abiotic reductive dechlorination of cis-DCE by ferrous monosulfide mackinawite.
Cis-1,2,-dichloroethylene (cis-DCE) is a toxic, persistent contaminant occurring mainly as a daughter product of incomplete degradation of perchloroethylene (PCE) and trichloroethylene (TCE). This paper reports on abiotic reductive dechlorination of cis-DCE by mackinawite (FeS1-x), a ferrous monosulfide, under variable geochemical conditions. To assess in situ abiotic cis-DCE dechlorination by mackinawite in the field, mackinawite suspensions prepared in a field groundwater sample collected from a cis-DCE contaminated field site were used for dechlorination experiments. The effects of geochemical variables on the dechlorination rates were monitored. A set of dechlorination experiments were also carried out in the presence of aquifer sediment from the site over a range of pH conditions to better simulate the actual field situations. The results showed that the suspensions of freshly prepared mackinawite reductively transformed cis-DCE to acetylene, whereas the conventionally prepared powder form of mackinawite had practically no reactivity with cis-DCE under the same experimental conditions. Significant cis-DCE degradation by mackinawite has not been reported prior to this study, although mackinawite has been shown to reductively transform PCE and TCE. This study suggests feasibility of using mackinawite for in situ remediation of cis-DCE-contaminated sites with high S levels such as estuaries under naturally achieved or stimulated sulfate-reducing conditions.
Groundwater Department, Korea Institute of Geoscience and Mineral Resources (KIGAM), 124 Gwahang-no, Yuseong-gu, Daejeon, 305-350, South Korea. sphyun@kigam.re.kr.|Department of Civil and Environmental Engineering, The University of Michigan, Ann Arbor, MI, 48109, USA. sphyun@kigam.re.kr.
Sung Pil
SP
Hyun
Department of Civil and Environmental Engineering, The University of Michigan, Ann Arbor, MI, 48109, USA.
Kim F
KF
Hayes
D004785:Environmental Pollutants / Q000737:chemistry*; D005025:Ethylene Dichlorides / Q000737:chemistry*; D005296:Ferrous Compounds / Q000737:chemistry*; D054879:Halogenation; D010084:Oxidation-Reduction; D013750:Tetrachloroethylene / Q000737:chemistry; D014241:Trichloroethylene / Q000737:chemistry
D004785:Environmental Pollutants; D005025:Ethylene Dichlorides; D005296:Ferrous Compounds; D014241:Trichloroethylene; C024565:ethylene dichloride; C022597:ferrous sulfide; D013750:Tetrachloroethylene
Abiotic reductive dechlorination; Mackinawite; cis-DCE