硫脲改性壳聚糖微球对Pt^(4+)和Pd^(2+)的吸附特性Ⅰ.吸附平衡和动力学  

Adsorption Performance of Thiourea-Modified Chitosan Microspheres to Pt^(4+) and Pd^(2+) Ⅰ. Adsorption Equilibrium and Kinetics

作　　者：许剑平[1] 周利民[1,2] 黄群武[2] 刘峙嵘[1] 

机构地区：[1]东华理工大学核资源与环境教育部重点实验室,江西抚州344000 [2]天津大学化工学院,天津300072

出　　处：《石油化工》2009年第5期557-562,共6页Petrochemical Technology

基　　金：国防基础科研基金项目(A3420060146);江西省教育厅科技项目(GJJ08302)

摘　　要：利用反相乳液法制备了壳聚糖微球,并经硫脲改性得到硫脲改性壳聚糖微球(TCS),将其用于吸附Pt4+和Pd2+,考察了TCS对Pt4+和Pd2+的吸附特性;利用扫描电子显微镜、傅里叶变换红外光谱和N2吸附-脱附等方法对TCS进行了表征。表征结果显示,TCS的粒径为10～30μm、比表面积为95.6m2/g、平均孔径为12.6nm、孔体积为0.298cm3/g。实验结果表明,在pH=2时,TCS对Pt4+和Pd2+的吸附性能最佳;吸附动力学可用拟二级模型拟合,表明TCS对Pt4+和Pd2+的吸附以化学吸附反应为主;吸附等温线可用Langmuir模型拟合,Pt4+和Pd2+的饱和吸附容量分别为129.87,112.36mg/g。双组分吸附实验结果表明,TCS对Pt4+和Pd2+有良好的吸附选择性,可实现Pt4+(或Pd2+)与Cu2+,Pb2+,Cd2+,Zn2+,Ca2+的选择性分离。Chitosan microspheres were prepared by inverse phase emulsion dispersion method. Adsorption behavior of thiourea-modified chitosan microspheres （TCS） in adsorption of Pt^4＋ or Pd^2＋ especially from binary sail solution mixtures were investigated. TCS was characterized by means of SEM, FTIR and N2 adsorption-desorption. Particle size of TCS was about 10 -30 μm and its specific surface area,average pore diameter and pore volume were 95.6 m^2/g, 12.6 nm, and 0. 298 cm^3/g, respectively. The maximum amount of adsorption occurred at pH about 2 of salt solution. The adsorptive kinetics follows pseudo-second-order kinetic equation, indicating the main adsorption mechanism of chemical adsorption. Adsorption isotherms were well described by Langmuir model and maximum adsorption amounts of Pt^4＋ and Pd^2＋ reach 129.87 mg/g and 112.36 mg/g,respectively. In binary mixture adsorption TCS showed excellent selectivities to Pt^4＋ or Pd^2＋ , thus it is possible for selective separation of either Pt^4＋ or Pd^2＋ from binary mixtures with one of the following CU^2＋ , Pb^2＋ , Cd^2＋, Zn^2＋ and Ca^2＋ salt solution.

关 键 词：壳聚糖微球 硫脲 改性 铂离子 钯离子 吸附平衡 动力学 

分 类 号：TQ425.23[化学工程]