Co-transport of colloidal MgAl-LDH and U(VI) in saturated granite particle column: role of colloid concentration, ionic strength, pH and flow rate

Since little is known about the colloidal Layered double hydroxides (LDH) stability and how colloidal LDH influences U(VI) transport, column experiments were performed to study the co-transport of U(VI) and MgAl-LDH colloids in water-saturated granite particle as a function of important environmental factors. It was found that the stability and transport of U(VI)-bearing LDH colloid was affacted by colloid concentration, ionic strength and pH. A two-site kinetic attachment/detachment model was applied to describe the breakthrough curves of U(VI)-bearing LDH colloid. The experimental and modeling results of this study imply that a risk assessment of LDH colloid facilitated transport should be considered.