TiO2 microsphere impregnated alginate: a novel hybrid sorbent for uranium removal from aquatic bodies

This study presents a simple method of synthesizing TiO2 microspheres and their impregnation into an alginate matrix. TiO2 microspheres were prepared through emulsion polymerization of styrene using PVP as a surfactant followed by a sol-gel process. The microspheres were impregnated into an alginate matrix using a displacement reaction to form beads. The product was characterized by FTIR, XRD, zeta sizer, BET and SEM. The TiO2 microsphere impregnated alginate beads were used to efficiently remove uranium (70-97%) from groundwater in the 0.1 mu g mL(-1) to 100 mu g mL(-1) concentration range. Batch experiments were carried out for uptake studies. The developed beads showed maximum uptake at pH 4-6. Sorption isotherms were tested and the uptake process followed the Langmuir model. The sorption capacity evaluated from the Langmuir model was 31.4 mg g(-1). The reaction kinetics was explained by the pseudo first order law. The mechanism of sorption was proposed based on the zeta potential of the TiO2 microspheres along with the species of uranium present at various pH values.