The Analysis of Uranium Binding Form with Mineral Phases by Time- resolved Laser-induced Fluorescence Spectroscopy

Uranium migration is mainly occurred when mobile uranium species from rock piles and old mines are washed by surface water. It is necessary to study the pathway, the species, and the amount of migrating uranium compounds. The objective of this research is to investigate the interactions between solid mineral phases and mobile uranium species such as sorption, precipitation and forming secondary uranium minerals by time-resolved laser-induced fluorescence spectroscopy (TRLFS). This technique has shown to be able to detect a trace amount of uranium (VI) species in both solution and solid phases. TRLFS delivers a fluorescence signal with characteristic features related to the concentration and speciation of fluorescent species in the sample. These features include, the positions of the peak maxima, and characteristic lifetimes of the signals. Results show fluorescent signals of absorbed uranium species on gibbsite and muscovite surfaces. The spectroscopic signatures of these uranium (VI) minerals are useful in identifying uranium (VI) species as colloids, thin coatings on rocks, minor components in soils, or alteration products of nuclear waste.