Selenite Sorption on Hydrated CEM-V/A Cement in the Presence of Steel Corrosion Products: Redox vs Non-redox Sorption
| Autor: | Delphine Tisserand, Pierre Henocq, Laurent Charlet, Alejandro Fernandez-Martinez, Kaifeng Wang, Sarah Bureau, Bin Ma, Benoît Madé |
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| Přispěvatelé: | Institut des Sciences de la Terre (ISTerre), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA) |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Cement
Construction Materials Radioactive waste chemistry.chemical_element Sorption General Chemistry [CHIM.MATE]Chemical Sciences/Material chemistry 010501 environmental sciences [CHIM.INOR]Chemical Sciences/Inorganic chemistry Selenious Acid 01 natural sciences Redox Corrosion chemistry Chemical engineering Steel [CHIM.CRIS]Chemical Sciences/Cristallography Environmental Chemistry Cementitious Ternary operation Oxidation-Reduction Selenium 0105 earth and related environmental sciences [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy |
| Zdroj: | Environmental Science and Technology Environmental Science and Technology, American Chemical Society, 2020, 54 (4), pp.2344-2352. ⟨10.1021/acs.est.9b06876⟩ Environmental Science and Technology, 2020, 54 (4), pp.2344-2352. ⟨10.1021/acs.est.9b06876⟩ |
| ISSN: | 0013-936X 1520-5851 |
| Popis: | International audience; Reinforced cementitious structures in nuclear waste repositories will act as barriers that limit the mobility of radionuclides (RNs) in case of eventual leakage. CEM-V/A cement, a ternary blended cement with blast furnace slag (BFS) and fly ash (FA), could be qualified and used in nuclear waste disposal. Chemical interactions between the cement and RNs are critical but not completely understood. Here, we combined wet chemistry methods, synchrotron-based X-ray techniques, and thermodynamic modeling to explore redox interactions and nonredox sorption processes in simulated steel-reinforced CEM-V/A hydration systems using selenite as a molecular probe. Among all of the steel corrosion products analyzed, only the addition of Fe0 can obviously enhance the reducing ability of cement toward selenite. In comparison, steel corrosion products showed stronger reducing power in the absence of cement hydrates. Selenium K-edge X-ray absorption spectroscopy (XAS) revealed that selenite immobilization mechanisms included nonredox inner-/outer-sphere complexations and reductive precipitations of FeSe and/or Se(0). Importantly, the hydrated pristine cement showed a good reducing ability, driven by ferrous phases and (bi)sulfides (as shown by sulfur K-edge XAS) originated from BFS and FA. The overall redox potential imposed by hydrated CEM-V/A was determined, hinting to a redox shift in underground cementitious structures. |
| Databáze: | OpenAIRE |
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