交联壳聚糖-亚铁氰化镍钾球形复合吸附剂制备及其对Cs^+吸附性能研究

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

通过反相悬浮-溶胶凝胶法制备了壳聚糖-亚铁氰化镍钾(CTS-KNiFC)球形复合吸附剂,分析测试了其对铯离子的选择性吸附性能,并利用傅里叶红外光谱和扫描电镜进行了样品表征。吸附动力学模型分析结果表明,CTS-KNiFC对Cs^+的吸附过程以化学吸附为主。静态吸附实验结果表明,吸附过程在5h左右能达到平衡。当溶液Cs^+初始浓度大于100mg/L时,CTS-KNiFC对铯离子的饱和吸附容量约为70mg/g。溶液的pH值以及溶液中Na^+和Mg^(2+)的共存对吸附效果影响不大,NH_4^+及K^+的存在则会对吸附过程有明显的抑制作用。利用Boyd液膜扩散模型和Weber-Morris颗粒内扩散模型对实验数据进行拟合,结果表明,颗粒内扩散和液膜扩散对吸附速率均有影响。CTS-KNiFC对Cs^+的吸附更符合Langmuir模型,表明吸附过程为单分子层吸附。

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 Mg^2＋ have a iittie influence on the performance of adsorption, while the existence of NH^＋ and 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.