THE INFLUENCE OF REDUCTIVE DISSOLUTION OF IRON OXIDES BY S(-II) ON URANIUM MOBILITY

 
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2010 (EN)
THE INFLUENCE OF REDUCTIVE DISSOLUTION OF IRON OXIDES BY S(-II) ON URANIUM MOBILITY (EN)

Alexandratos, V. G.
Van Cappellen, P.
Behrends, T.

This study investigates possible redox transformations of uranium under Ntransient redox conditions. NSpecific focus lies on the fate of U as reductive dissolution of iron oxyhydroxides by S(-II) is initiated. In batch experiments sulfide was incrementally added to a lepidocrocite suspension containing adsorbed U(VI). The partitioning of uranium was monitored during the progressing transformation of lepidocrocite into FeS. Synchrotron-based X-ray absorption spectroscopy was used to resolve the oxidation state of uranium.Upon addition of sulfide intermediate release of U from the solid to the solution was observed. The mobilization of U was followed by immobilization in later stages. XAS reveals that this immobilization coincides with reduction of NU(VI) to U(IV). Consequently, reduction of U(VI) and precipitation of U(IV) solids, due to a shift from oxic to sulfate reducing conditions is possible. NHowever, kinetic effects might lead to an intermediate mobilization of U that should be considered for the risk assessment of nuclear waste repositories and the remediation of sites, contaminated with radionuclides. (EN)

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reductive dissolution (EN)
uranium mobilization (EN)
iron mineral transformation (EN)
iron sulfides (EN)
redox transitions (EN)
X-ray absorption spectroscopy (EN)

Ελληνική Γεωλογική Εταιρεία (EL)
Geological Society of Greece (EN)

Δελτίο της Ελληνικής Γεωλογικής Εταιρίας

2010-01-01


Geological Society of Greece (EN)

0438-9557
2529-1718
Δελτίο της Ελληνικής Γεωλογικής Εταιρείας; Vol 43, No 5 (2010): 12th International Conference of the G.S.G.; 2310-2318 (EL)
Bulletin of the Geological Society of Greece; Vol 43, No 5 (2010): 12th International Conference of the G.S.G.; 2310-2318 (EN)

Copyright (c) 2017 V. G. Alexandratos, T. Behrends, P. Van Cappellen (EN)



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