Preparation of Polyacrylonitrile-potassium Titanate Spherical Composite Adsorbents and Their Adsorption Properties for Sr2+

Polyacrylonitrile-potassium titanate spherical composite adsorbents (PAN-KTiO) were prepared by supporting KTiO powder on PAN to remove Sr²⁺ from aqueous solution. PAN-KTiO was characterized by SEM, XRD, etc. Sr²⁺ adsorption on PAN-KTiO as a function of contact time, pH, competition ions and initial Sr²⁺ concentration was studied via batch experiments. Furthermore, the adsorptive kinetics and isotherms were analyzed. The results show that the Sr²⁺ adsorption on PAN-KTiO can reach equilibrium after about 24 h. The optimized pH value of solution for Sr²⁺ adsorption on PAN-KTiO is about 6.55. Among the competitive ions, Ca²⁺ and Mg²⁺ significantly hinder Sr²⁺ adsorption on PAN-KTiO. Sr²⁺ adsorption on PAN-KTiO follows a pseudo-second-order kinetic model and is in best agreement with the Langmuir isotherm model, indicating a saturated adsorption capacity of 53.850 mg/g, which also indicates that the Sr²⁺ adsorption on PAN-KTiO is monolayer adsorption and a chemical adsorption process.