Analysis of Uranium Sorption in a Laboratory Column Experiment Using a Reactive Transport and Surface Complexation Model

Sorption of uranyl (UO22+(UVI)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathrm{UO}}_{2}^{2+} ({U}_{\mathrm{VI}})$$\end{document}) was found to strongly depend on the surface complexation model, with no significant removal of U_VI by precipitation or ion exchange process.The aluminol surface edges in kaolinite were shown to have a higher affinity for uranyl adsorption, while the hydrous ferric oxide edge on hematite adsorbed most of the uranyl ions.Uranium adsorption on the aluminol edge of kaolinite exceeds adsorption by the C-S-H phase. This result may reflect the lack of surface complexation parameters for C-S-H minerals.