Doehlert experimental design as a tool to study liquid-liquid systems for the recovery of Uranium (VI) traces
Candela, Angélica María (Universitat Autònoma de Barcelona. Departament de Química)
Coello Bonilla, Jordi (Universitat Autònoma de Barcelona. Departament de Química)
Palet i Ballús, Cristina (Universitat Autònoma de Barcelona. Departament de Química)

Date:	2013
Abstract:	The objective of this study was the development and optimization of a method for the liquid-liquid extraction and recovery of Uranium (VI) traces (0. 10 mg/L). A comparison was made of three different extracting agents at 0. 10 mol/L: tri-n-butyl phosphate, methyltrioctylammonium chloride, and bis(2-ethylhexyl) phosphoric acid. As the optimized chemical conditions of the liquid-liquid systems are very important for the future applications for the extraction, recovery and pre-concentration of Uranium (VI) traces, whether in bulk liquid membranes or in supported liquid membranes systems, a response surface methodology was adopted. A Doehlert design is used to obtain a quadratic function relationship between the percentage of recovery of uranyl ion and the amount of bis(2-ethylhexyl) phosphoric acid in kerosene, as extracting agent (0. 001-0. 050 mol/L) and that of phosphoric (0. 192-0. 718 mol/L) and citric (0. 206-0. 698 mol/L) acids, mixed as recovery agents. From the results, the most important effects on the recovery are the concentration of bis(2-ethylhexyl) phosphoric acid in the organic phase and the concentration of phosphoric acid in the stripping solution, while the concentration of citric acid only favors the extraction of Uranium (VI) when the other compounds are at opposite levels of concentration. From the mathematical model, optimal conditions for the back-extraction of Uranium (VI) were found with predicted recoveries of 99%, which were later corroborated experimentally.
Note:	Altres ajuts: the authors acknowledge financial support from the Universitat Autònoma de Barcelona for the scholarship granted (B-I3INT2006) that made this work possible.
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Doehlert experimental design ; Liquid-liquid systems ; Response surface methodology ; Uranium (VI)
Published in:	Separation and Purification Technology, Vol. 118 (October 2013) , p. 399-405, ISSN 1873-3794

DOI: 10.1016/j.seppur.2013.07.017

Postprint 26 p, 793.0 KB

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