The contaminant of most concern in groundwater at the Oak Ridge Y-12 Plant's Bear Creek Valley Characterization Area is soluble uranium. The removal mechanism of soluble uranium from groundwater by zero-valent iron (ZVI, Fe0) was investigated. X-ray photoelectron spectroscopy (XPS, ESCA) was used to determine the uranium oxidation state at the Fe0 or iron oxide surface. Product speciation and relative reaction kinetics for the removal of soluble uranium under aerobic and anaerobic conditions with ZVI are presented. Under aerobic conditions, U6+ is rapidly and strongly sorbed to hydrous ferric oxide particulates ('rust'), whereas U6+ is slowly and incompletely reduced to U4+ under anaerobic conditions.
ASJC Scopus subject areas
- Environmental Chemistry