@article{20b34405a5404c07bc21a7ec3466b25e,
title = "Uranium fate in wetland mesocosms: Effects of plants at two iron loadings with different pH values",
abstract = "Small-scale continuous flow wetland mesocosms (∼0.8 L) were used to evaluate how plant roots under different iron loadings affect uranium (U) mobility. When significant concentrations of ferrous iron (Fe) were present at circumneutral pH values, U concentrations in root exposed sediments were an order of magnitude greater than concentrations in root excluded sediments. Micro X-ray absorption near-edge structure (μ-XANES) spectroscopy indicated that U was associated with the plant roots primarily as U(VI) or U(V), with limited evidence of U(IV). Micro X-ray fluorescence (μ-XRF) of plant roots suggested that for high iron loading at circumneutral pH, U was co-located with Fe, perhaps co-precipitated with root Fe plaques, while for low iron loading at a pH of ∼4 the correlation between U and Fe was not significant, consistent with previous observations of U associated with organic matter. Quantitative PCR analyses indicated that the root exposed sediments also contained elevated numbers of Geobacter spp., which are likely associated with enhanced iron cycling, but may also reduce mobile U(VI) to less mobile U(IV) species.",
keywords = "Iron, Plants, Rhizosphere, Uranium fate, Uranium sequestration, Wetlands",
author = "{Koster van Groos}, {Paul G.} and Kaplan, {Daniel I.} and Chang, {Hyun shik} and Seaman, {John C.} and Dien Li and Peacock, {Aaron D.} and Scheckel, {Kirk G.} and Jaffe, {Peter R.}",
note = "Funding Information: Portions of this work were performed at GeoSoilEnviroCARS (Sector 13), Advanced Photon Source (APS), Argonne National Laboratory. GeoSoilEnviroCARS is supported by the National Science Foundation – Earth Sciences ( EAR-1128799 ) and Department of Energy – GeoSciences ( DE-FG02-94ER14466 ). This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357 . We are grateful for the assistance of Matthew Newville and Antonio Lanzirotti at Argonne National Laboratory's Advanced Photon Source for facilitating the X-ray absorption spectroscopy. We are also grateful for assistance from Matthew Reid and Shan Huang from Princeton University regarding experimental design and sampling. The research described in this paper was funded by the United States Department of Energy's (DOE) Subsurface Biogeochemistry Research program, Contract DE-SC0006847 . Work was conducted at the Savannah River National Laboratory under the DOE contract DE-AC09-96SR18500. Participation of Drs. J. C. Seaman and H. S. Chang were supported by the Savannah River Ecology Laboratory through a Financial Assistance Award DE-FC09-07SR22506 from DOE to the University of Georgia's Research Foundation. Although the U.S. Environmental Protection Agency (EPA) contributed to this article, the research presented was not directly performed by or funded by EPA and was not subject to EPA's quality system requirements. Consequently, the views, interpretations, and conclusions expressed in this article are solely those of the authors and do not necessarily reflect or represent EPA's views or policies. Publisher Copyright: {\textcopyright} 2016 Elsevier Ltd",
year = "2016",
month = nov,
day = "1",
doi = "10.1016/j.chemosphere.2016.08.012",
language = "English (US)",
volume = "163",
pages = "116--124",
journal = "Chemosphere",
issn = "0045-6535",
publisher = "Elsevier Limited",
}