Crosslinked Chitosan-potassium Nickel Hexacyanaferrate（Ⅱ） Spherical Composite Adsorbent and Its Adsorption Property for Cs⁺

Chitosan-potassium nickel hexacyanaferrate (CTS-KNiFC) spherical composite adsorbent was synthesized by combining sol-gel method with reverse phase suspension method, and its property of selective adsorption was tested. Its structures were analyzed by utilizing the techniques of FT-IR and SEM. The kinetic model analysis shows that the adsorption process of Cs⁺ is mainly chemical adsorption. Static adsorption experiments indicate that the equilibrium is achieved after about 5 h. When Cs⁺ initial concentration is more than 100 mg/L, CTS-KNiFC can reach its saturated adsorption capacity of about 70 mg/g. pH of solution and the existence of Na⁺ and Mg²⁺ have a little influence on the performance of adsorption, while the existence of NH⁺ 4and K⁺ obviously inhibits the process of adsorption. In addition, intraparticle diffusion and liquid film diffusion control the rates of adsorption simultaneously, which is proved by Boyd model and Weber-Morris model analysis. The adsorption data are successfully fitted with Langmuir model which shows that adsorption of Cs⁺ on CTS-KNiFC is monolayer.