Zinc hexacyanoferrate loaded mesoporous MCM-41 as a new adsorbent for cesium: equilibrium, kinetic and thermodynamic studies

Mesoporous MCM-41 has been modified by loading of zinc hexacyanoferrate (ZnHCF) as a new adsorbent for cesium. The ZnHCF-loaded mesoporous MCM-41 (ZnHCF-MCM-41) was characterized using powder X-ray diffraction and nitrogen adsorption–desorption isotherm data, fourier transform infrared spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray. The cesium removal performance of ZnHCF-MCM-41 from aqueous solutions has been studied, and the effect of the various parameters, such as initial pH value of solution, contact time, temperature, and initial concentration of the cesium ion on the adsorption efficiencies of ZnHCF-MCM-41 were investigated systematically by batch experiments. Adsorption kinetics was better described by the pseudo-second-order model and thermodynamic parameters indicated the adsorption process was feasible, endothermic, and spontaneous in nature. Adsorption isotherm of ZnHCF-MCM-41 was studied and the fitted results indicated that Langmuir model could well represent the adsorption process. The maximum adsorption capacity of Cs+ onto ZnHCF-MCM-41 was found to be 103.09 mg g−1.