聚丙烯腈-钛硅酸钠球形复合吸附剂对Cs^+的吸附性能研究

Research on Adsorption Property of Cs^+ on PAN-NaTS Spherical Composite Adsorbent

通过静态吸附实验,研究了接触时间、溶液pH值、共存离子、Cs^+初始浓度等对聚丙烯腈-钛硅酸钠(PAN-NaTS)吸附Cs^+性能的影响,从动力学、吸附机理和热力学方面对吸附过程进行了分析,并用扫描电子显微镜(SEM)、傅里叶红外光谱(FT-IR)和X射线衍射(XRD)对吸附剂进行了表征。结果表明:PAN-NaTS对Cs^+的吸附平衡时间约为20h;最佳pH值为3.90~10.87;溶液中含K^+、Na^+、NH^+_4、Ca^(2+)或Mg^(2+)时会抑制PAN-NaTS对Cs^+的吸附。PAN-NaTS对Cs^+的吸附动力学数据符合准一级动力学方程,且颗粒内扩散和膜扩散共同控制吸附速率,颗粒内扩散是决定吸附速率的关键。PAN-NaTS对Cs^+的吸附符合Langmuir等温吸附模型,吸附过程为单分子层吸附;PAN-NaTS对Cs^+的饱和吸附容量可达219.298mg/g。

The effects of contact time,pH,co-existing ions and initial Cs^＋concentration on the adsorption property of Cs^＋on polyacrylonitrile-sodium titanosilicate（PANNaTS）were studied by static experiments.The adsorption process was analyzed by thermodynamics,adsorption mechanism and kinetics,and the PAN-NaTS was characterized and analyzed by SEM,FT-IR and XRD.The results show that the adsorption process of Cs^＋on PAN-NaTS reaches equilibrium after about 20 h,the optimized pH value of solution is in the range of 3.90-10.87,and the existence of K^＋,Na^NH4^＋,Ca2^＋or Mg^2＋has inhibiting effects on the adsorption.The adsorption process of PANNaTS mainly fits the pseudo-first-order equation.In addition,intraparticle diffusion andfilm diffusion control the rate of adsorption simultaneously,and the intraparticle diffusion is the main rate-controlling step.The adsorption of Cs^＋on PAN-NaTS follows Langmuir model and is monolayer adsorption.The saturated adsorption capacity of Cs^＋on PAN-NaTS is up to 219.298mg/g.