[Fabrication of Supported Titanium Xerogel Adsorbent and Performance Evaluation for Arsenite Removal]

Although the adsorption capacity of titanium xerogel(TAX) for arsenite(As(Ⅲ)) is high(254 mg·g^-1), the adsorption rate is slow. Therefore, TAX was loaded onto activated carbon, sponge, and resin to fabricate a supported adsorbent, and the arsenite removal performance was evaluated. Except sponge, activated carbon and resin could successfully load TAX. The results showed that resin and activated carbon loaded TAX improved the As(Ⅲ) removal performance, and more significantly by the resin-based materials. Through wet digestion and adsorption kinetics experiments, the amount of titanium loaded was approximately 1.4% and 5% in the activated carbon-based(TAX@AC) and resin-based(TAX@resin) materials, respectively. For the initial concentration of 1.0 mg·L^-1 As(Ⅲ) solution, the adsorption rate constant of TAX@D201 was 0.85 mg·(g·min) ^-1, which was 21 times higher than that of unloaded TAX[0.04 mg·(g·min) ^-1]. Columns packed with TAX@resin could effectively lower arsenite concentration for up to 560 bed volumes, which is 2.8 times greater than that of the iron-based composites with the same metal mass. Therefore, loading TAX on macroporous resin is an effective strategy and provides an effective approach for the application of TAX in arsenite-containing groundwater.