Spectroscopic investigation of uranium sorption on soil surface using X-ray photoelectron spectroscopy

A study was carried out to understand the sorption of uranium (U) onto soil surface and identify the species of U on soil surface using X-Ray Photoelectron Spectroscopy (XPS). For the study soil was amended with uranyl nitrate and surface speciation study was carried out by investigating the energy region for U in spectrum. Analysis of spectrum revealed that U is present in U(VI) state. Deconvolution of XPS spectrum of U(VI) sorbed on soil surface revealed that U(VI) species such as, UO2 (2+) and (UO2)(x)(OH) (y) ((2x-y)+) form complex with silanol, aluminol and goethite sites. The possible surface complexation is: Al(OH)(2)UO2 (2+), SiO2UO2, SiO2(UO2)(3)(OH)(5) and Fe(OH)(2)UO2.