Subsurface Microbial Community Stimulated to Immobilize Uranium Plume

Summary

The first demonstration of a feasible process for the in situ immobilization of uranium as a bioremediation strategy was conducted by a team of scientists from the University of Massachusetts, the Pacific Northwest National Laboratory, the University of Tennessee, and several other institutions. Under field conditions, the team demonstrated that microorganisms can be stimulated to immobilize uranium in the subsurface. This interdisciplinary research was published in the October issue of Applied and Environmental Microbiology and featured in an on-line Science Update for the international journal Nature on October 13, 2003. The team conducted a two month field study and demonstrated that by adding acetate to the subsurface, they could stimulate the growth and proportion of Geobacter species within the subsurface microbial community. At the same time, the concentration of uranium (U) in the ground water was greatly reduced. During this first field experiment, uranium reduction was not maintained due to the onset of sulfate reduction and a corresponding change in the microbial community. However, a second field experiment has now successfully addressed the sulfate reduction problem by increasing the acetate concentration.