硫化锡钾的制备及其对Co2 选择性吸附

以碳酸钾、锡粉、硫粉为原料,用水热法合成了硫化锡钾(KSnS),利用SEM、XRD、XPS等对KSn S的形貌和组成进行了表征分析。并通过静态吸附实验分别考察了接触时间、pH、共存离子和Co~(2+)初始浓度对KSnS吸附Co~(2+)效果的影响。结果表明:KSnS对Co~(2+)的吸附平衡时间约为25 min,饱和吸附容量为149 mg/g。当Co~(2+)初始质量浓度为5 mg/L、液固比为2500 mL/g时,KSnS对Co~(2+)的分配系数可达到6.5×10~5 m L/g,去除率为99.84%。当溶液为中性时,KSnS的吸附性能最佳。KSnS对Co~(2+)有较高的选择性,当干扰离子质量浓度是Co~(2+)的100倍时,KSnS对Co~(2+)的去除率仍能达到92%以上。KSnS对Co~(2+)的吸附动力学行为可用准二级动力学方程描述,吸附过程属于化学吸附。通过Weber-Morris模型和Boyd模型分析可知,液膜扩散过程是主导吸附速率的步骤。

Preparation of Potassium Tin Sulfide and Its Selective Adsorption Properties for Co2

The potassium tin sulfied (KSnS) was prepared by hydrothermal method using potassium carbonate, tin powder and sulfur powder as raw materials. The morphology and structure of KSnS were performed by SEM, XPS and XRD. The effects of contact time, pH, coexisting ions, initial cobalt concentration on the adsorption of Co2 by KSnS were investigated via batch experiments. The results show that cobalt sorption of KSnS can reach equilibrium time after about 25 min, and the saturated adsorption capacities is 149 mg/g. When initial concentration of cobalt is 5mg/L and V/m=2500mL/g, the distribution coefficient of KSnS to Co2 can reach 6.3?105mL/g and the removal rate is 99.84%. When the solution is neutral, KSnS has the best adsorption performance. KSnS has high selectivity to Co2 , and high concentration of coexisting ions (K , Na , Ca2 , Mg2 ) has little effect on the removal rate of Co2 . The sorption kinetics of KSnS for Co2 can be described by pseudo-second-order kinetic equations, and the adsorption process is mainly chemical adsorption. According to Weber-Morris model and Boyd model, the liquid film diffusion process dominates the adsorption rate.