Deng, Baolin University of Missouri-Columbia
The principal objectives of this proposal are to systematically identify potential pathways/mechanisms for Cr (III) mobilization via coupled biotic and abiotic processes and to evaluate their relative significance for Cr mobility. Chromium (Cr) is a key contaminant of concern throughout the world because of its carcinogenic and toxic nature combined with common occurrence at numerous hazardous waste sites. Common Cr oxidation states in the aquatic environment are Cr (VI) and Cr (III). Since Cr (VI) species are more water soluble and toxic than Cr (III) species, remediation efforts have focused on the in-situ reduction of Cr (VI) to Cr (III). However, recent studies indicate that certain natural processes may oxidize and mobilize Cr (III), potentially affecting the long-term stability of reductive treatments. This project investigates the mobility of Cr(III) species in the environment in terms of (1) Chromium(III) mobilization through non-oxidative mechanisms; (2) Chromium(III) mobilization through oxidation by Mn oxides; and (3) Impact of coupled biotic/abiotic processes on Cr mobility in complex systems.
Research results will be useful for environmental managers in assessing long-term stability of Cr following reductive treatment and whether Cr (III) oxidation in the subsurface by Mn oxides contributes to the observed Cr (VI) in groundwater. The PI will train undergraduates in the lab and has a recruitment plan for underrepresented minorities at nearby Lincoln University of Missouri, an 1890 land grant HBCU (Historically Black Colleges and Universities) institution.
