Spectroscopic and modeling investigation of efficient removal of U(VI) on a novel magnesium silicate/diatomite.

A novel magnesium silicate/diatomite sorbent (MSD) was fabricated using a facile hydrothermal method. The interaction mechanism of U(VI) on MSD was investigated by batch, spectroscopic and modeling techniques. The maximum adsorption capacity of MSD for U(VI) (31.54 mg/g) is significantly higher than that of diatomite (12.74 mg/g). XPS analysis indicated that the oxygen-containing groups (e.g., Si OH) of MSD were responsible for the high efficient removal of U(VI) from aqueous solutions. The fitted results of surface complexation modeling showed that the adsorption of U(VI) on MSD at pH < 4.0 and pH > 4.5 was attributed to cation exchange and inner-sphere surface complexation, respectively. These findings suggested that MSD could be a favorable sorbent for the efficient removal of U(VI) in the environmental cleanup. [ABSTRACT FROM AUTHOR]