Mononuclear U(IV) complexes and ningyoite as major uranium species in lake sediments
| Autor: | Jérôme Guillevic, Christelle Courbet, A. Thouvenot, G. Ona-Nguema, Marina Seder-Colomina, Olivier Proux, Sylvain Bassot, John R. Bargar, Jessica Brest, Lucie Stetten, O. Mathon, Guillaume Morin, Arnaud Mangeret, Guillaume Othmane |
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| Přispěvatelé: | Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Université de Clermont-Ferrand, European Synchrotron Radiation Facility (ESRF), Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Stanford Synchrotron Radiation Lightsource (SSRL SLAC), SLAC National Accelerator Laboratory (SLAC), Stanford University-Stanford University |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
inorganic chemicals
media_common.quotation_subject chemistry.chemical_element Mineralogy 010501 environmental sciences 010502 geochemistry & geophysics 01 natural sciences complex mixtures Uranium mine uranium chemistry.chemical_compound Uraninite contamination Geochemistry and Petrology Environmental Chemistry non-uraninite lake 0105 earth and related environmental sciences media_common ningyoite mononuclear U(IV) complexes sediments technology industry and agriculture crystal-chemistry Geology Uranium Phosphate Silicate XANES Diagenesis Speciation EXAFS immobilisation chemistry speciation 13. Climate action [SDU]Sciences of the Universe [physics] Environmental chemistry early diagenesis Alluvial aquifer mineralogy |
| Zdroj: | Geochemical Perspectives Letters Geochemical Perspectives Letters, European Assoication of Geochemistry, 2016, 2 (1), pp.95-105. ⟨10.7185/geochemlet.1610⟩ 'Geochemical Perspectives Letters ', vol: 2, pages: 95-105 (2016) |
| ISSN: | 2410-339X 2410-3403 |
| DOI: | 10.7185/geochemlet.1610⟩ |
| Popis: | International audience; Natural attenuation of uranium in subsurface environments is usually assigned to immobilisation processes due to microbially mediated reduction of U(VI). Recent laboratory studies have established that the end products of such a process include both low solubility biogenic uraninite and more labile non-crystalline U(IV) species. Indeed, biogenic uraninite formation may be inhibited in the presence of organic or inorganic phosphoryl ligands, leading to the formation of non-crystalline U(IV)-phosphate complexes or nanoscale U(IV)-phosphate solids. Such species have been observed in shallow contaminated alluvial aquifers and can thus be suspected to form in other important environments, among which lacustrine sediments have a global environmental significance since they may represent major uranium accumulation reservoirs in riverine watersheds. Here, on the basis of microscopic, spectroscopic and chemical extraction analyses, we report the occurrence of mononuclear U(IV)-phosphate/silicate complexes, accompanied by nano-crystalline ningyoite-like U(IV)-phosphate minerals, as major scavengers for uranium in lacustrine sediments downstream from a former uranium mine in France. This observation reveals that uranium trapping mechanisms during early diagenesis of lacustrine sediments can virtually exclude uraninite formation, which has important implications for better modelling uranium cycling in natural and contaminated freshwaters. Moreover, our results raise issues concerning the long term fate of mononuclear U(IV) complexes and U(IV) phosphate nano-minerals, especially with respect to re-oxidation events. © 2016 European Association of Geochemistry. |
| Databáze: | OpenAIRE |
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