Preparation of chitosan crosslinked modified silicon material and its adsorption capability for chromium(VI)

Novel chitosan crosslinked modified silicon materials, named ZC and MC, were fabricated successfully, characterized by SEM, XRD, EDS, EA, BET and FT-IR methods and applied for removing Cr(VI) anion from aqueous solutions. All parameters influencing the removal efficiency such as different proportion of silicon material/chitosan, particle size, pH, dosage, time, and competing anions were considered to set up optimal adsorption conditions. The results indicate that the adsorption efficiency of Cr(VI) by ZC and MC could increase 6-fold and 4-fold, respectively, compared with the natural zeolite and montmorillonite. And the experimental data were fitted well to the pseudo-second-order kinetic model and to Freundlich model, indicating the main adsorption mechanism for Cr(VI) of ZC and MC is the chemistry.