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采用水热法获得制备层状硫化物K2xMnxSn3-xS6(KMS-1),用扫描电镜(SEM),X射线衍射仪(XRD),傅里叶红外光谱仪(FTIR)对其形貌及结构进行表征。结果表明制备的KMS-1为层状结构,具有良好的晶体结构。采用静态批式法考察了接触时间、温度、Th(IV)起始浓度,溶液pH、Na+浓度等因素对KMS-1与Th(IV)的离子交换的影响。结果表明,pH值对KMS-1与Th(IV)的离子交换反应有显著影响,吸附容量随着溶液pH的增大而增大,且当pH>4时吸附容量不再随pH的变化而变化,而Na+离子浓度对吸附影响较弱;KMS-1与Th(IV)的离子交换反应在4 h时反应达到平衡,反应过程符合准二级动力学方程,Qe=180.51 mg·g-1,k=2.005×10-4g·mg-1·min-1;R2=0.9987;吸附等温线符合Langmuir等温模型,R2为0.9985;热力学数据分析得出:ΔHo=60.73 kJ·mol-1·K-1,ΔSo=19.02 J·mol-1·K-1和ΔGo<0,说明KMS-1吸附Th(IV)是一个放热且自发的过程,降低温度有利于KMS-1对Th(IV)的吸附。该离子交换反应最大吸附量为180.51 mg·g-1。
The layered sulfide K2xMnxSn3-xS6 (KMS-1) was prepared by hydrothermal method. Its morphology and structure were characterized by SEM, XRD and FTIR . The results show that the prepared KMS-1 has a layered structure with a good crystal structure. The effects of contact time, temperature, initial concentration of Th (IV), solution pH and Na + concentration on the ion exchange of KMS-1 and Th (IV) were investigated by static batch method. The results showed that pH value had a significant effect on the ion exchange reaction between KMS-1 and Th (IV). The adsorption capacity increased with the increase of solution pH. When pH> 4, the adsorption capacity no longer changed with pH Ion exchange reaction of KMS-1 and Th (IV) reached equilibrium at 4 h, and the reaction process was in accordance with quasi-second-order kinetic equation with Qe = 180.51 mg · g-1 , k = 2.005 × 10-4g · mg-1 · min-1, R2 = 0.9987. The adsorption isotherm fitted the Langmuir isothermal model with R2 of 0.9985. The thermodynamic data showed that ΔHo = 60.73 kJ · mol-1 · K- 1, ΔSo = 19.02 J · mol-1 · K-1 and ΔGo <0, indicating that KMS-1 adsorbed Th (IV) is an exothermic and spontaneous process. Adsorption. The maximum adsorption capacity of the ion exchange reaction was 180.51 mg · g-1.