Determination of the equilibrium formation constants of two U(VI)-peroxide complexes at alkaline pH

The formation of uranyl-peroxide complexes was studied at alkaline media by using UV-Visible spectrophotometry and the STAR code. Two different complexes were found at a H2O2/U(VI) ratio lower than 2. A graphical method was used in order to obtain the formation constants of such complexes and the ST...

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Detalles Bibliográficos
Autores: Meca, S., Martínez Torrents, Albert, Martí Gregorio, Vicenç|||0000-0002-1763-0514, Giménez Izquierdo, Francisco Javier|||0000-0003-2094-4458, Casas Pons, Ignasi|||0000-0002-5419-1645, Pablo Ribas, Joan de|||0000-0001-9538-7321
Tipo de recurso: artículo
Fecha de publicación:2011
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/13322
Acceso en línea:https://hdl.handle.net/2117/13322
https://dx.doi.org/10.1039/c0dt01672a
Access Level:acceso abierto
Palabra clave:Radioactive wastes -- Analysis
Uraniun (VI)
Combustibles nuclears gastats
Àrees temàtiques de la UPC::Enginyeria química::Química inorgànica::Equilibris químics
Descripción
Sumario:The formation of uranyl-peroxide complexes was studied at alkaline media by using UV-Visible spectrophotometry and the STAR code. Two different complexes were found at a H2O2/U(VI) ratio lower than 2. A graphical method was used in order to obtain the formation constants of such complexes and the STAR program was used to refine the formation constants values because of its capacity to treat multiwavelength absorbance data and refining equilibrium constants. The values obtained for the two complexes identified [...] At hydrogen peroxide concentrations higher than 10-5 mol dm-3, and in the absence of carbonate, the UO2(O2)2(OH)2 4- complex is predominant in solution, indicating the significant peroxide affinity of peroxide ions for uranium and the strong complexes of uranium(VI) with peroxide.