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.