Thermodynamic description of the plutonium – α-D-isosaccharinic acid system I: Solubility, complexation and redox behavior
| Autor: | Marcus Altmaier, Robert Polly, J. Rothe, A. Tasi, David Fellhauer, Horst Geckeis, Jordi Bruno, K. Källström, M. Böttle, Kathy Dardenne, E. Colàs, Xavier Gaona, Mireia Grivé |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Technology
Hydroquinone Ligand Inorganic chemistry Oxide 010501 environmental sciences 010402 general chemistry 01 natural sciences Pollution Redox 0104 chemical sciences chemistry.chemical_compound chemistry Geochemistry and Petrology Phase (matter) Environmental Chemistry Absorption (chemistry) Solubility ddc:600 0105 earth and related environmental sciences Isosaccharinic acid |
| Zdroj: | Applied geochemistry, 98, 247-264 |
| ISSN: | 0883-2927 1872-9134 |
| Popis: | The impact of α- d -isosaccharinic acid (HISA), a degradation product of cellulose, on the solubility and redox behavior of hydrous Pu(IV) oxide was investigated from undersaturation conditions under Ar atmosphere in 0.1 m NaCl–NaOH–NaISA solutions. Redox conditions were buffered with hydroquinone (HQ) or Sn(II), resulting in (pe + pHm) ≈ 9.0 and 1.5, respectively. The influence of ISA on Pu solubility was investigated as function of pHm (8 ≤ pHm ≤ 13) and ligand concentration (10−6 m ≤ m(ISA)tot ≤ 0.1 m). In-situ X-ray diffraction and X-ray absorption spectroscopic measurements indicate that PuO2(ncr,hyd) controls the solubility of Pu in all investigated systems. Presence of ISA poses an increase in plutonium solubility by up to 2.5 log-units. In HQ systems, slope analysis of solubility data in combination with solid phase characterization and density functional theory calculations resulted in chemical and thermodynamic models including the predominance of Pu(IV)(OH)3ISA–H– and Pu(IV)(OH)3ISA–2H2– complexes below and above pHm ≈ 12, respectively. In Sn(II) systems with pHm |
| Databáze: | OpenAIRE |
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