Adsorption/desorption of uranium on iron-bearing soil mineral surface

Abstract

In this study, we evaluated the adsorption/desorption of uranium (U) in pure soil environment using continuous column reactor. We additionally investigated the adsorption/desorption mechanism of U on vivianite surface in molecular scale using quantum calculation. We observed that below 0.1 μM of U was detected after 20 d from U injection (1 μM) in adsorption test. However, all of absorbed U was detached from vivianite surface in 24 h by injection of CARB solution (1.44 × 10 M NaHCO3 and 2.8 × 10 M Na2CO3). Based on exchange energy calculation, we found that UO2 (CO3)2 and UO2 (CO3)3 species have higher repulsive energy than UO2 (OH)2 species. The results obtained from this study could be applied to predict the behavior of uranium in contaminated and remediation sites.