Synthesis of modified nanocomposite material and its use on removal of cesium from aqueous media

A nanocomposite containing Fe₃O₄, chitosan (Ch), and hexacyanoferrate (HCF) was synthesized in the form of powder. The physicochemical properties of this nanocomposite are determined using different techniques including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM). The existence of Cs (Cs) ions onto the surface of the nanocomposite was verified by dispersive X-ray spectroscopy (EDX). FTIR spectra confirmed that the nanocomposite was well coordinated. The batch technique was applied to evaluate the influences of initial pH value, temperature, contact time, shaking rate, initial Cs concentration, and competing cations on the efficiency of Cs removal. The maximum adsorption capacity for Cs ions of nanocomposite was determined as 34.36 mg/g at the initial pH = 5 of the aqueous solution. The equilibrium data fitted well the linearized Langmuir isotherm equation, which has the higher correlation coefficient (0.999). Thermodynamic parameters such as free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) indicated that the adsorption was exothermic and not spontaneous.