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DOI: 10.5445/IR/230102172

U redox state and speciation of U in contact with magnetite nanoparticles : High resolution XANES, EXAFS, XPS and TEM study

Pidchenko, I.; Schild, D.; Yokosawa, T.; Kvashnina, K.; Bohnert, E.; Heberling, F.; Finck, N.; Schäfer, T.; Rothe, J.; Geckeis, H.; Vitova, T.

In this work, redox states and speciation of U in U coprecipitated with and sorbed on magnetite nanoparticles are investigated by U M₄ HR-XANES, L₃ EXAFS, XPS and TEM techniques. Coexistence of U(V), U(IV) and U(VI) in varying ratios is clearly detect by the U M₄ HR-XANES technique. Mainly U(V) stable for more than 240 days of contact time is found In a coprecipitated sample with lowest U loading (1000 ppm U). Coprecipitated sample with highest U loading (10000 ppm) undergoes reduction to U(IV) within less than 7 days. Reduction kinetics of U and long term stability of U(V) is discussed for both batch sorption and coprecipitation systems.

Zugehörige Institution(en) am KIT Institut für Nukleare Entsorgung (INE)
Publikationstyp Vortrag
Jahr 2015
Sprache Englisch
Identifikator URN: urn:nbn:de:swb:90-AAA2301021721
KITopen-ID: 230102172
HGF-Programm 32.27.01 (POF III, LK 01)
Veranstaltung 16th International Conference on X-Ray Absorption Fine Structure (XAFS16), Karlsruhe, Germany, 23rd - 28th August 2015
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