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Non-enzymatic interactions between U(VI) and biogenic mackinawite

EMSL Project ID


Reduction of subsurface contaminant uranium to a sparingly soluble mineral; uraninite (UO2) is being extensively researched as a remediation strategy for mitigating uranium contamination in-situ. The present study addresses the potential for abiotic/non-enzymatic reduction of uranium by a biogenic Fe(II)-sulfide mineral; mackinawite (FeS). Recent batch studies in our laboratory have demonstrated adsorption and reduction of hexavalent uranium [U(VI)] to UO2 on the surface of biogenic mackinawite. We hypothesize that uranium reductions occurs due to the structural Fe(II) within the biogenic mackinawite via a direct electron transfer process. If this hypothesis is true, it is reasonable to assume phase transformations within the biogenic mackinawite sample due to the formation of ferric ions. The propensity of various biogenic Fe(II)-bearing minerals to reduce U(VI) is consistent with prior DOE-supported studies

Project Details

Project type
Limited Scope
Start Date
End Date


Principal Investigator

Harish Veeramani
Virginia Polytechnic Institute

Team Members

Nikolla Qafoku
Pacific Northwest National Laboratory

Michael Hochella
Pacific Northwest National Laboratory

Related Publications

Veeramani H, A Scheinost, N Monsegue, N Qafoku, RK Kukkadapu, M Newville, A Lanzirotti, A Pruden, M Murayama, and MF Hochella. 2013. "Abiotic Reductive Immobilization of U(VI) by Biogenic Mackinawite." Energy & Environmental Science 47(5):2361-2369. doi:10.1021/es304025x
Xu J, H Veeramani, N Qafoku, G Singh, MV Riquelme Breazeal, A Pruden, RK Kukkadapu, BN Gartman, and MF Hochella, Jr. 2017. "Efficacy of Acetate-Amended Biostimulation for Uranium Sequestration: Combined Analysis of Sediment/Groundwater Geochemistry and Bacterial Community Structure." Applied Geochemistry 78:172-185. doi:10.1016/j.apgeochem.2016.12.024