title: In situ long-term reductive bioimmobilization of Cr(VI) in groundwater using hydrogen release compound.
abstract: The results of a field experiment designed to test the effectiveness of a novel approach for long-term, in situ bioimmobilization of toxic and soluble Cr(VI) in groundwater using a hydrogen release compound (HRC)--a slow release glycerol polylactate--are described. The field experiment was conducted at the Hanford Site (Washington), a U.S. Department of Energy nuclear production facility, using a combination of hydrogeological, geophysical, geochemical, and microbiological measurements and analyses of water samples and sediments. The results of this experiment show that a single HRC injection into groundwater stimulates an increase in biomass, a depletion of terminal electron acceptors O2, NO3-, and SO4(2-), and an increase in Fe2+, resulting in a significant decrease in soluble Cr(VI). The Cr(VI) concentration has remained below the background concentration in the downgradient pumping/ monitoring well, and below the detection limit in the injection well for more than 3 years after the HRC injection. The degree of sustainability of Cr(VI) reductive bioimmobilization under different redox conditions at this and other contaminated sites is currently under study.
authors.affiliation: Lawrence Berkeley National Laboratory, Berkeley, California, USA.
authors.forename: Boris
authors.initials: B
authors.lastname: Faybishenko
authors.forename: Terry C
authors.initials: TC
authors.lastname: Hazen
authors.forename: Philip E
authors.initials: PE
authors.lastname: Long
authors.forename: Eoin L
authors.initials: EL
authors.lastname: Brodie
authors.forename: Mark E
authors.initials: ME
authors.lastname: Conrad
authors.forename: Susan S
authors.initials: SS
authors.lastname: Hubbard
authors.forename: John N
authors.initials: JN
authors.lastname: Christensen
authors.forename: Dominique
authors.initials: D
authors.lastname: Joyner
authors.forename: Sharon E
authors.initials: SE
authors.lastname: Borglin
authors.forename: Romy
authors.initials: R
authors.lastname: Chakraborty
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Williams
authors.forename: John E
authors.initials: JE
authors.lastname: Peterson
authors.forename: Jinsong
authors.initials: J
authors.lastname: Chen
authors.forename: Shaun T
authors.initials: ST
authors.lastname: Brown
authors.forename: Tetsu K
authors.initials: TK
authors.lastname: Tokunaga
authors.forename: Jiamin
authors.initials: J
authors.lastname: Wan
authors.forename: Mary
authors.initials: M
authors.lastname: Firestone
authors.forename: Darrell R
authors.initials: DR
authors.lastname: Newcomer
authors.forename: Charles T
authors.initials: CT
authors.lastname: Resch
authors.forename: Kirk J
authors.initials: KJ
authors.lastname: Cantrell
authors.forename: Anna
authors.initials: A
authors.lastname: Willett
authors.forename: Stephen
authors.initials: S
authors.lastname: Koenigsberg
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D018533:Biomass; D002857:Chromium / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D009688:Nuclear Reactors; D010084:Oxidation-Reduction; D011108:Polymers / Q000737:chemistry; D014861:Washington; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014881:Water Supply / Q000032:analysis*
chemical_list: D011108:Polymers; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion; D006859:Hydrogen