Three Publications in the April Issue of ES&T Highlight Complex Physical, Chemical and Biological Processes that Influence Contaminant Transport

Summary

To more accurately predict the mobility of contaminants in the environment and to devise new remediation techniques, DOE site managers need to understand the complex physical, chemical and biological processes that influence the mobility of metal and radionuclide contaminants in the subsurface. Three Office of Science, BER research activities, reported in the April 15, 2008, issue of Environmental Science & Technology ( ES&T), highlight the factors affecting the fate of radionuclide contaminants in subsurface environments. The articles highlight results obtained from three different DOE sites and demonstrate the importance of understanding complex biogeochemical processes influencing the mobility of radionuclide contaminants in the subsurface. In one article, researchers from the Lawrence Berkeley National Laboratory used a variety of synchrotron-based techniques to evaluate the potential of persistent iron (III) oxides present under reducing-conditions in sediment columns to reoxidize uranium to a more mobile phase. In a second article, researchers from the University of Massachusetts and the Pacific Northwest National Laboratory examined the sorption of oxidized uranium on cell surfaces in uranium-contaminated sediments during biostimulation as a contributing mechanism to immobilizing uranium in situ. In a third article, researchers from the Idaho National Laboratory examined a biological mechanism for stimulating calcite precipitation in subsurface sediments as means to facilitate precipitation, and therefore immobilization, of Sr-90 in subsurface environments.

References

• Tokunaga, TK; Wan, JM; Kim, YM; et al. , Real-time X-ray absorption spectroscopy of uranium, iron, and manganese in contaminated sediments during bioreduction. ENVIRON. SCI. & TECHNOL., 42 (8): 2839-2844 APR 15 2008
• N’Guessan, AL; Vrionis, HA; Resch, CT; et al., Sustained removal of uranium from contaminated groundwater following stimulation of dissimilatory metal reduction. ENVIRON. SCI. & TECHNOL., 42 (8): 2999-3004 APR 15 2008
• Fujita, Y; Taylor, JL; Gresham, TLT; et al. , Stimulation of microbial urea hydrolysis in groundwater to enhance calcite precipitation. ENVIRON. SCI. & TECHNOL., 42 (8): 3025-3032