Oxidative dissolution of biogenic uraninite in groundwater at Old Rifle, CO
Environmental Science & Technology
Links
- More information: Publisher Index Page (via DOI)
- Open Access Version: External Repository
- Download citation as: RIS | Dublin Core
Abstract
Reductive bioremediation is currently being explored as a possible strategy for uranium-contaminated aquifers such as the Old Rifle site (Colorado). The stability of U(IV) phases under oxidizing conditions is key to the performance of this procedure. An in situ method was developed to study oxidative dissolution of biogenic uraninite (UO2), a desirable U(VI) bioreduction product, in the Old Rifle, CO, aquifer under different variable oxygen conditions. Overall uranium loss rates were 50–100 times slower than laboratory rates. After accounting for molecular diffusion through the sample holders, a reactive transport model using laboratory dissolution rates was able to predict overall uranium loss. The presence of biomass further retarded diffusion and oxidation rates. These results confirm the importance of diffusion in controlling in-aquifer U(IV) oxidation rates. Upon retrieval, uraninite was found to be free of U(VI), indicating dissolution occurred via oxidation and removal of surface atoms. Interaction of groundwater solutes such as Ca2+ or silicate with uraninite surfaces also may retard in-aquifer U loss rates. These results indicate that the prolonged stability of U(IV) species in aquifers is strongly influenced by permeability, the presence of bacterial cells and cell exudates, and groundwater geochemistry.
Suggested Citation
Campbell, K.M., Veeramani, H., Ulrich, K., Blue, L.Y., Giammar, D.E., Bernier-Latmani, R., Stubbs, J.E., Suvorova, E., Yabusaki, S., Lezama-Pacheco, J.S., Mehta, A., Long, P.E., Bargar, J.R., 2011, Oxidative dissolution of biogenic uraninite in groundwater at Old Rifle, CO: Environmental Science & Technology, v. 45, no. 20, p. 8748-8754, https://doi.org/10.1021/es200482f.
ISSN: 1520-5851 (online)
Study Area
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | Oxidative dissolution of biogenic uraninite in groundwater at Old Rifle, CO |
| Series title | Environmental Science & Technology |
| DOI | 10.1021/es200482f |
| Volume | 45 |
| Issue | 20 |
| Publication Date | September 27, 2011 |
| Year Published | 2011 |
| Language | English |
| Publisher | ACS Publications |
| Publisher location | Washington, D.C. |
| Contributing office(s) | Branch of Regional Research-Central Region |
| Description | 7 p. |
| First page | 8748 |
| Last page | 8754 |
| Country | United States |
| State | Colorado |
| Other Geospatial | Old Rifle Site |