The sorption of uranyl species on a hematite sol

Abstract

The sorption of uranyl species on a hematite sol of narrow size distribution has been studied as a function of uranium concentration and solution pH. The adsorption increases with increasing uranium content in the solution. Raising the pH from 5 to about 6.2 markedly enhances the uptake of uranium. The enhanced uptake coincides with a proportional increase of [Formula: see text]. The sudden increase in adsorption around this pH region does not appear to be due to changes in surface charge of the hematite particles. It may be due to specific interactions between [Formula: see text] and the hematite particles. Results of desorption experiments show that different binding sites may exist on the hematite surface.