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 mu M of U was detected after 20 d from U injection (1 mu M) in adsorption test. However, all of absorbed U was detached from vivianite surface in 24 h by injection of CARB solution (1.44 x 10(-2) M NaHCO3 and 2.8 x 10(-3) M Na2CO3). Based on exchange energy calculation, we found that UO2 (CO3)(2)(2-) and UO2 (CO3)(3)(4-) 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.