title: Extraction of uranium from aqueous solutions by using ionic liquid and supercritical carbon dioxide in conjunction.
abstract: Uranyl ions [UO(2)](2+) in aqueous nitric acid can be extracted into supercritical CO(2) (sc-CO(2)) by using an imidazolium-based ionic liquid with tri-n-butyl phosphate (TBP) as a complexing agent. The transfer of uranium from the ionic liquid to the supercritical fluid phase was monitored by UV/Vis spectroscopy using a high-pressure fiber-optic cell. The form of the uranyl complex extracted into the sc-CO(2) phase was identified to be [UO(2)(NO(3))(2)(TBP)(2)]. The extraction results were confirmed by fluorescence spectroscopy and by neutron activation analysis. This technique has potential applications in the field of nuclear waste management for extracting other actinides.
authors.affiliation: Department of Chemistry, University of Idaho, Moscow, Idaho 83844, USA.
authors.forename: Joanna Shaofen
authors.initials: JS
authors.lastname: Wang
authors.forename: Chrystal N
authors.initials: CN
authors.lastname: Sheaff
authors.forename: Byunghoon
authors.initials: B
authors.lastname: Yoon
authors.forename: R Shane
authors.initials: RS
authors.lastname: Addleman
authors.forename: Chien M
authors.initials: CM
authors.lastname: Wai