Preparation of magnetic clinoptilolite/CoFe2O4 composites for removal of Sr2+ from aqueous solutions: Kinetic, equilibrium, and thermodynamic studies

In this work, magnetic clinoptilolite/CoFe2O4 composites were prepared, and were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope (TEM), vibrating sample magnetometer (VSM) and Zeta potential. The applicability of the synthesized composites for removal of Sr2+ from aqueous solutions was assessed, and the effective parameters such as initial pH values, adsorbent dosage, contact time, initial concentrations and temperatures on the sorption process were studied and optimized. The results showed that the Langmuir isotherm equation is the best to describe the sorption process. Adsorption kinetics of Sr2+ onto the composites followed the pseudo-second-order kinetic model. The thermodynamic parameters, such as ΔG0, ΔH0 and ΔS0, were also determined and evaluated. Moreover, the saturation magnetization of composites was measured as 11.31 emu g−1, which facilitated magnetic separation of the sample after adsorption process.