Challenges in Detection, Structural Characterization and Determination of Complex Formation Constants of Uranyl-Arsenate Complexes in Aqueous Solutions
Challenges in Detection, Structural Characterization and Determination of Complex Formation Constants of Uranyl-Arsenate Complexes in Aqueous Solutions
Gezahegne, W.; Hennig, C.; Geipel, G.; Planer-Friedrich, B.; Merkel, B. J.
Uranium forms analogous minerals with phosphate and arsenate. In aqueous solutions an analogy is expected to govern the complexes that uranium builds with these ligands. Three uranyl arsenate complexes UO2H2AsO4+, UO2HAsO4 0 and UO2(H2AsO4)2 0 were identified and reported previously with TRLFS in the pH range 1 to 3. Using a similar detection system and elevating the pH range a negatively charged fourth uranyl-arsenate complex, UO2AsO4- was found under circum neutral pH. Determining the complex formation constant for this complex was not possible due to the susceptibility of the fluorescence intensity to external influences and the difficulty of resolving the measured spectra into individual fluorescence contributions. By immediate shock-freezing to 15K we succeeded to measure a reproducible EXAFS spectrum of a uranyl-arsenate species in an aqueous solution at pH 2.
Keywords: Arsenate; Uranyl; aqueous solution; EXAFS; TRLFS
Involved research facilities
- Rossendorf Beamline at ESRF DOI: 10.1107/S1600577520014265
Related publications
- DOI: 10.1107/S1600577520014265 is cited by this (Id 20271) publication
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Book chapter
Merkel, Broder, Schipek, Mandy: The New Uranium Mining Boom, Challenge and lessons learned, Berlin: Springer Geology, 2012, ISBN 978-3-642-22122-4, 607-616
DOI: 10.1007/978-3-642-22122-4_70
Permalink: https://www.hzdr.de/publications/Publ-20271