Dynamics of microbial community composition and function during in-situ bioremediation of a uranium-contaminated aquifer

Journal Article · Sun Aug 15 00:00:00 EDT 2010 · Applied Environmental Microbiology

OSTI ID:1048257

Nostrand, J.D. Van; Wu, L; Wu, W M; Huang, A; Gentry, T J; Deng, Y; Carley, J; Carrol, S; He, Z; Gu, B; Luo, J; Criddle, C S; Watson, D B; Jardine, P M; Marsh, T L; Tiedje, J M; Hazen, T C; Zhou, J

A pilot-scale system was established to examine the feasibility of in situ U(VI) immobilization at a highly contaminated aquifer (U.S. DOE Integrated Field Research Challenge site, Oak Ridge, TN). Ethanol was injected intermittently as an electron donor to stimulate microbial U(VI) reduction, and U(VI) concentrations fell to below the Environmental Protection Agency drinking water standard (0.03 mg liter{sup -1}). Microbial communities from three monitoring wells were examined during active U(VI) reduction and maintenance phases with GeoChip, a high-density, comprehensive functional gene array. The overall microbial community structure exhibited a considerable shift over the remediation phases examined. GeoChip-based analysis revealed that Fe(III)-reducing bacterial (FeRB), nitrate-reducing bacterial (NRB), and sulfate-reducing bacterial (SRB) functional populations reached their highest levels during the active U(VI) reduction phase (days 137 to 370), in which denitrification and Fe(III) and sulfate reduction occurred sequentially. A gradual decrease in these functional populations occurred when reduction reactions stabilized, suggesting that these functional populations could play an important role in both active U(VI) reduction and maintenance of the stability of reduced U(IV). These results suggest that addition of electron donors stimulated the microbial community to create biogeochemical conditions favorable to U(VI) reduction and prevent the reduced U(IV) from reoxidation and that functional FeRB, SRB, and NRB populations within this system played key roles in this process.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: Earth Sciences Division
• DOE Contract Number: DE-AC02-05CH11231
• OSTI ID: 1048257
• Report Number(s): LBNL-4960E; TRN: US201216%%839
• Journal Information: Applied Environmental Microbiology, Vol. 77, Issue 11; Related Information: Journal Publication Date: 2011
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
59 BASIC BIOLOGICAL SCIENCES
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
AQUIFERS
BINDING ENERGY
BIOREMEDIATION
COMMUNITIES
DENITRIFICATION
DRINKING WATER
ELECTRONS
ETHANOL
FUNCTIONALS
GENES
MAINTENANCE
MONITORING
STABILITY
SULFATES
US EPA
VALENCE