Sorption of Uranium and other Metal Ions on Amine-Functionalized Silica Materials

Sorption of U(VI) and other metal ions on amine-functionalized silica was studied, including aminopropylsilica (APS), 3-(ethylenediamino)propyl silica (ENPS), and 3-[2-(2-aminoethylamino)ethylamino]propyl silica (DIENPS). DIENPS showed the strongest and fastest sorption for U(VI) that can be described by Langmuir isotherm, suggesting U(VI) was sorbed at well-defined and energetically identical sites independent from each other. The sorption efficiency of DIENPS follows the order: U(VI) > Fe(III) > Cu(II) > Pb(II) > Ni(II) > Mg(II) > Sr(II). Results demonstrate that the amine-functionalized silica materials could be used as efficient sorbents to remove uranium and hazardous metal ions in environmental remediation.