Sorption processes of UO_2~2+ ions onto zirconium and thorium phosphate surfaces: thermodynamical and structural aspects

摘要

Most of the studies on sorption processes take into account only a thermodynamic approach, and only few studies have paid attention to the structural aspect (i.e. structure of the postulated surface complex). Experiments were conducted to study UO_2~2+ sorption onto zirconium and thorium phosphatc surfaces. Morcover, in order to identify the nature of the sorption sites and the structure of the surface complex, various spectroscopic techniques suchas EXAFS,XPS and laser induced fluorescence have been used. Two different types of sorption sits on the thorium phosphate but only one on the zirconium phosphate have been detected.