In situ long-term reductive bioimmobilization of Cr(VI) in groundwater using hydrogen release compound.
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.
Faybishenko
Boris
B
Lawrence Berkeley National Laboratory, Berkeley, California, USA.
Hazen
Terry C
TC
Long
Philip E
PE
Brodie
Eoin L
EL
Conrad
Mark E
ME
Hubbard
Susan S
SS
Christensen
John N
JN
Joyner
Dominique
D
Borglin
Sharon E
SE
Chakraborty
Romy
R
Williams
Kenneth H
KH
Peterson
John E
JE
Chen
Jinsong
J
Brown
Shaun T
ST
Tokunaga
Tetsu K
TK
Wan
Jiamin
J
Firestone
Mary
M
Newcomer
Darrell R
DR
Resch
Charles T
CT
Cantrell
Kirk J
KJ
Willett
Anna
A
Koenigsberg
Stephen
S
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*
D011108:Polymers; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion; D006859:Hydrogen