Efficacy of acetate-amended biostimulation for uranium sequestration: combined analysis of sediment/groundwater geochemistry and bacterial community structure

Xu, J., Veeramani, H., Qafoku, N. P., Singh, G., Riquelme, M. V., Pruden, A., Kukkadapu, R. K., Gartman, B. N. and Hochella, M. F. (2017) Efficacy of acetate-amended biostimulation for uranium sequestration: combined analysis of sediment/groundwater geochemistry and bacterial community structure. Applied Geochemistry, 78, pp. 172-185. (doi: 10.1016/j.apgeochem.2016.12.024)

Abstract

Systematic flow-through column experiments were conducted using sediments and ground water collected from different subsurface localities at the U.S. Department of Energy's Integrated Field Research Challenge site in Rifle, Colorado. The principal purpose of this study is to gain a better understanding of the interactive effects of groundwater geochemistry, sediment mineralogy, and indigenous bacterial community structures on the efficacy of uranium removal from the groundwater with/without acetate amendment. Overall, we find that the subtle variations in the sediments' mineralogy, redox conditions, as well as contents of metal(loid) co-contaminants showed a pronounced effect on the associated bacterial population and composition, which mainly determines the system's performance with respect to uranium removal. Positive relationship was identified between the abundance of dissimilatory sulfate-reduction genes (i.e., drsA), markers of sulfate-reducing bacteria, and the sediments' propensity to sequester aqueous uranium. In contrast, no obvious connections were observed between the abundance of common iron-reducing bacteria, e.g., Geobacter spp., and the sediments' ability to sequester uranium. In the sediments with low bacterial biomass and the absence of sulfate-reducing conditions, abiotic adsorption onto mineral surfaces such as phyllosilicates likely played a relatively major role in the attenuation of aqueous uranium; however, in these scenarios, acetate amendment induced detectable rebounds in the effluent uranium concentrations. The results of this study suggest that immobilization of uranium can be achieved under predominantly sulfate-reducing conditions, and provide insight into the integrated roles of various biogeochemical components in long-term uranium sequestration.

• Item Type: Articles
• Additional Information: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research under Award Number DE-SC0006825.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Veeramani, Dr Harish
• Authors: Xu, J., Veeramani, H., Qafoku, N. P., Singh, G., Riquelme, M. V., Pruden, A., Kukkadapu, R. K., Gartman, B. N., and Hochella, M. F.
• College/School: College of Science and Engineering > School of Engineering > Infrastructure and Environment
• Journal Name: Applied Geochemistry
• Publisher: Elsevier
• ISSN: 0883-2927
• ISSN (Online): 1872-9134
• Published Online: 29 December 2016