Fuller, AJ, Shaw, S, Peacock, CL et al. (2 more authors) (2016) EXAFS Study of Sr sorption to Illite, Goethite, Chlorite, and Mixed Sediment under Hyperalkaline Conditions. Langmuir, 32 (12). pp. 2937-2946. ISSN 0743-7463
Abstract
Strontium is an important contaminant radionuclide at many former nuclear sites. This paper investigates the effect of changing pH and ionic strength on the sorption Sr to a range of common soil minerals. Specifically it focuses on the sorption of Sr onto illite, chlorite, goethite and a mixed sediment. The interplay between ionic strength and pH was determined by varying the background ionic strength of the system using both NaCl (for a constant pH) and NaOH (to also vary pH). Under conditions of moderate pH Sr sorption decreased with increasing ionic strength, due to competition between the Na and Sr atoms for the outer-sphere complexes. However, where increasing ionic strength was accompanied by increasing pH Sr sorption remained high. This suggested that Sr was sorbed to the minerals without competition from background Na ions. Extended X-ray Absorption Fine Structure spectra confirmed that at highly alkaline pH (>12.5) Sr was forming inner-sphere complexes on the surfaces of all minerals. This specific adsorption of the Sr (as SrOH) explains why it was still adsorbed to the minerals under very high ionic strength conditions and was not out-competed by Na.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/acs.langmuir.5b04633. Uploaded in accordance with the publihser's self-archiving policy. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Earth Surface Science Institute (ESSI) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 04 Apr 2016 09:27 |
Last Modified: | 14 Apr 2017 04:22 |
Published Version: | http://dx.doi.org/10.1021/acs.langmuir.5b04633 |
Status: | Published |
Publisher: | American Chemical Society |
Identification Number: | 10.1021/acs.langmuir.5b04633 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:96221 |