Highlights from the Sixth Annual DOE Natural and Accelerated Bioremediation Research (NABIR) Program Grantee/Contractor Meeting
The sixth annual NABIR grantee/contractor meeting was held in Warrenton, VA, on March 17-19, 2003. Over 140 attendees participated including bioremediation researchers from universities and DOE National Laboratories, as well as program managers from the Office of Science and the Office of Environmental Management. The NABIR program supports fundamental research on natural attenuation and immobilization of radionuclides and metals in subsurface environments to decrease risk to humans and the environment. Special sessions were devoted to 1) Numerical modeling in the NABIR program; 2) Research at the Uranium Mill Tailings Remedial Action (UMTRA) sites; 3) Lateral gene transfer in microbial communities, and 4) Functional biodiversity of subsurface microorganisms. One highlight of the meeting was a session devoted to research findings from the NABIR Field Research Center at the Oak Ridge National Laboratory. During this session, a team of investigators from Oregon State University and the University of Oklahoma described how they have performed over 60 push-pull experiments within the contaminated area. These experiments probe the in situ activities of naturally occurring microorganisms and their potential to precipitate uranium and technetium by microbially-mediated reduction. Results revealed that Uranium(VI) could be reduced to the insoluble Uranium(IV) in areas where nitrate (a common co-contaminant) was in low concentration. The reduction of technetium, however, was unaffected by the presence of nitrate. These important findings will lead to the design of more effective remedial strategies for uranium and technetium at contaminated DOE sites.