Characterization of poorly crystalline secondary ferrous minerals formed by a subsurface microbial consortium
EMSL Project ID
46192
Abstract
This rapid access proposal is to request 12 hours of instrument time to complete a DOE funded study on microbial transformation of crystalline iron oxides. Recently, we have cultivated of a microbial consortium from Oak Ridge FRC sediments that reduces crystalline goethite (α-FeOOH) and hematite (Fe3O4), and produces amorphous Fe(II)-bearing solids. The reductive dissolution of goethite and hematite by this microbial consortium is concurrent to a striking change in the visual coloration of the iron oxides. We propose to use transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) to characterize these novel amorphous secondary minerals. The objectives of this work are to determine: 1) the size, shape, and elemental composition of the secondary minerals; and 2) the chemical and electronic state of Fe, and the presence and speciation of sulfur. Characterization of these biogenic secondary Fe(II) minerals is an important step to understanding their reactivity towards uranium and other heavy metal contaminants. The results of this research will advance knowledge in microbial interactions with iron oxide minerals and contribute to the EMSL Geochemistry/Biogeochemistry and Subsurface Science theme.
Project Details
Project type
Limited Scope
Start Date
2011-10-20
End Date
2011-12-15
Status
Closed
Released Data Link
Team
Principal Investigator
Related Publications
Shah M, CC Lin, RK Kukkadapu, MH Engelhard, X Zhao, Y Wang, T Barkay, and N Yee. 2013. "Syntrophic Effects in a Subsurface Clostridial Consortium on Fe(III)-(Oxyhydr)oxide Reduction and Secondary Mineralization." Geomicrobiology Journal 31(2):101-115. doi:10.1080/01490451.2013.806610