层状金属硫化物硫化锡钾的制备及其对Sr2+的吸附性能研究

本文用水热法合成了硫化锡钾（KSnS），利用扫描电镜（SEM）、X射线衍射（XRD）仪等对KSnS的形貌和组成进行了表征分析，并通过静态吸附实验分别研究了pH值、接触时间、共存离子和Sr²⁺初始浓度对KSnS吸附Sr²⁺的影响。结果表明，在40 ℃、pH=7.25、Sr²⁺初始浓度为5.5 mg/L的条件下，KSnS对Sr²⁺的吸附平衡时间约为35 min，Sr²⁺去除率为99.62%。吸附反应可操作pH值范围较宽，52+去除率保持在80%以上。溶液中含有K⁺、Na⁺、Ca²⁺和Mg²⁺等共存离子时，二价离子的干扰大于一价离子。KSnS对Sr²⁺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，液膜扩散是主导吸附速率的步骤。

Preparation of Layered Metal Sulfide Potassium Tin Sulfide and Its Adsorption Property for Sr2+

Potassium tin sulfide (KSnS) was prepared by hydrothermal method. The morphology and structure of KSnS were performed by SEM and XRD. The effects of pH, contact time, coexisting ions, initial Sr²⁺ concentration on the adsorption of Sr²⁺ by KSnS were investigated via batch experiments. The results show that under the condition of 40 ℃, pH=7.25, and initial Sr²⁺ concentration of 5.5 mg/L, the adsorption equilibrium time of KSnS for Sr²⁺ is about 35 min, and the Sr²⁺ removal rate is 99.62%. The adsorption reaction can be operated in a wide pH range, and when 52+ removal rate is maintained above 80%. The interference of divalent ions is greater than that of monovalent ions when K⁺, Na⁺, Ca²⁺ and Mg²⁺ were added to solution separately. The sorption kinetics of KSnS for Sr²⁺ can be described by pseudo-second-order kinetic model, 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.