Optimizing Cr(VI) and Tc(VII) Remediation through Nanoscale Biomineral Engineering

Cutting, Richard S.; Coker, Victoria S.; Telling, Neil D.; Kimber, Richard L.; Pearce, Carolyn I.; Ellis, Beverly L.; Lawson, Richard S.; van der Laan, Gerrit; Pattrick, Richard A. D.; Vaughan, David J.; Arenholz, Elke; Lloyd, Jonathan R.

Abstract

The influence of Fe(III) starting material on the ability of magnetically recoverable biogenic magnetites produced by Geobacter sulfurreducens to retain metal oxyanion contaminants has been investigated. The reduction/removal of aqueous Cr(VI) was used to probe the reactivity of the biomagnetites. Nanomagnetites produced by the bacterial reduction of schwertmannite powder were more efficient at reducing Cr(VI) than either ferrihydrite “gel”-derived biomagnetite or commercial nanoscale Fe3O4. Examination of post-exposure magnetite surfaces indicated both Cr(III) and Cr(VI) were present. X-ray magnetic circular dichroism (XMCD) studies at the Fe L2,3-edge showed that the amount of Fe(III) “gained” by Cr(VI) reduction could not be entirely accounted for by “lost” Fe(II). Cr L2,3-edge XMCD spectra found Cr(III) replaced ∼14%−20% of octahedral Fe in both biogenic magnetites, producing a layer resembling CrFe2O4. However, schwertmannite-derived biomagnetite was associated with approximately twice as much Cr as ferrihydrite-derived magnetite. Column studies using a γ-camera to image a 99mTc(VII) radiotracer were performed to visualize the relative performances of biogenic magnetites at removing aqueous metal oxyanion contaminants. Again, schwertmannite-derived biomagnetite proved capable of retaining more (∼20%) 99mTc(VII) than ferrihydrite-derived biomagnetite, confirming that the production of biomagnetite can be fine-tuned for efficient environmental remediation through careful selection of the Fe(III) mineral substrate supplied to Fe(III)-reducing bacteria.

Citation

Cutting, R. S., Coker, V. S., Telling, N. D., Kimber, R. L., Pearce, C. I., Ellis, B. L., Lawson, R. S., van der Laan, G., Pattrick, R. A. D., Vaughan, D. J., Arenholz, E., & Lloyd, J. R. (2010). Optimizing Cr(VI) and Tc(VII) Remediation through Nanoscale Biomineral Engineering. Environmental Science and Technology, 44(7), 2577-2584. https://doi.org/10.1021/es902119u

• Journal Article Type: Article
• Acceptance Date: Feb 15, 2010
• Online Publication Date: Mar 2, 2010
• Publication Date: Apr 1, 2010
• Deposit Date: May 22, 2024
• Journal: Environmental Science & Technology
• Print ISSN: 0013-936X
• Electronic ISSN: 1520-5851
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 44
• Issue: 7
• Pages: 2577-2584
• DOI: https://doi.org/10.1021/es902119u
• Public URL: https://keele-repository.worktribe.com/output/831150
• Publisher URL: https://pubs.acs.org/doi/10.1021/es902119u