title: In situ bioremediation of a cis-dichloroethylene-contaminated aquifer utilizing methane-rich groundwater from an uncontaminated aquifer.
abstract: At a trichloroethylene (TCE)-contaminated site in Chikura, Chiba, Japan, TCE had spread over to the first and second aquifers over years. After 8 years of pumping and treatment, finally derivative of TCE, cis-dichloroethylene (c-DCE) remained only in the second aquifer. In this study, feasibility of a low cost in situ bioremediation utilizing groundwater of the third aquifer, which contained natural dissolved methane possibly derived from natural gas field nearby, to stimulate methane-oxidizing bacteria was examined. In vitro experiment showed that a mixture of the groundwater from the second and third aquifers stimulated a growth of methane oxidizing bacteria and enhanced c-DCE degradation. The groundwater of the third aquifer was introduced into the second aquifer in situ. The population of methanotrophs with high V(max) and K(m) for methane uptake increased, resulting in successful degradation of c-DCE at a monitoring well 2m downgradient of the injection well.
authors.affiliation: Department of Aquatic Bioscience, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo 113-8657, Japan. takeuchi-mio@aist.go.jp
authors.forename: Mio
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Kenji
authors.initials: K
authors.lastname: Nanba
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iwamoto
authors.forename: Hisashi
authors.initials: H
authors.lastname: Nirei
authors.forename: Takashi
authors.initials: T
authors.lastname: Kusuda
authors.forename: Osamu
authors.initials: O
authors.lastname: Kazaoka
authors.forename: Masato
authors.initials: M
authors.lastname: Owaki
authors.forename: Ken
authors.initials: K
authors.lastname: Furuya
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D004000:Dichloroethylenes / Q000737:chemistry / Q000378:metabolism*; D008697:Methane / Q000737:chemistry / Q000378:metabolism*; D014867:Water / Q000737:chemistry*; D014877:Water Pollution, Chemical
chemical_list: D004000:Dichloroethylenes; D014867:Water; D008697:Methane