Impacts of Mineralogy and Competing Microbial Respiration Pathways on the Fate of Uranium in Contaminated Groundwater (Zachara, NABIR-U,
PNNL Scope #41648)

Characterize the dominant Fe and S minerals that are likely to limit U speciation in-situ; directly quantify reaction rates and pathways of microbial respiration (terminal electron-accepting) processes which control subsurface sediment chemistry, and identify and enumerate the organisms mediating U geochemistry using molecular biological analysis.