Adsorption of U(VI) from sulfate solution using montmorillonite/polyamide and nano-titanium oxide/polyamide nanocomposites

The polyamide-based nanocomposites were formed via inorganic nanosized (montmorillonite clay MMT, or TiO2) particles that incorporated inside a polyamide 6 (PA6) matrix. Moreover, the MMT/PA6 and TiO2/PA6 nanocomposites were prepared by simple dissolution methods. Morphology of the gained nanocomposites was studied by SEM, EDX, TEM, FTIR, and XRD techniques. Batch adsorption was fulfilled to determine the uptake capacities of U(VI) (93.0, 21.0, 134.0, and 125.0 mg/g) on the MMT, PA6, and MMT/PA6 and TiO2/PA6 nanocomposites, respectively from sulfate solution in the pH 4.5, 30 min contact time at room temperature. The adsorption-desorption recycling was indicated that U(VI) adsorption has excellent stability and selectivity after seven cycles by 0.25 M HNO3 eluant. The kinetic data of uranium adsorption on MMT, PA6, and MMT/PA6 and TiO2/PA6 nanocomposites were suited well to a pseudo-second-order mechanism, and the Langmuir isotherm followed the equilibrium adsorption experiments. The tentative mechanism of the adsorption of U(VI) on adsorbents was proposed. Finally, the optimum adsorption conditions for MMT/PA6, and TiO2/PA6 nanocomposites were applied for U(VI) recovery from the El-Sela sulfate leach solution.