Isothermal, Kinetic, and Thermodynamic Studies on the Adsorption of Molybdenum by a Nanostructured Magnetic Material

In this study, the magnetic ۳-(trimethoxysilyl) propyl methacrylate (TMSPMA) – poly (۴-vinylpyridine) (P۴VP) was synthesized and characterized. Removal of Molybdenum (Mo) from aqueous solutions using prepared material as nanosorbent was investigated. The magnetic P۴VP was prepared by copolymerization of P۴VP with TMSPMA. The prepared adsorbent was characterized by various techniques including the X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The batch adsorption technique was applied and the effect of several important parameters such as pH of the aqueous solution, adsorbent dose, initial Mo(VI) concentration, contact time, and temperature was evaluated. Desorption behavior of Mo(VI) and the effect of foreign ions (Cd۲+, Ca۲+, Co۲+, Fe۳+, Ba۲+ and Pt۴+) in real samples were also investigated. Co (II) and Pt (IV) had a greater impact on the adsorption process than other foreign ions. The maximum capacity for Mo(VI) adsorption on the prepared adsorbent was ۴.۸۷ mg/g, which was obtained at a temperature of ۴۰°C with an initial concentration of ۱۰ mg/L of Mo(VI). The adsorption isotherms were best fitted with the Weber Van Vliet isotherm model. The kinetic data were fitted well with the pseudo-second-order equation with a high correlation coefficient (R۲ > ۰.۹۹). Based on the negative standard Gibbs free energy change (ΔG° < ۰) and the positive standard enthalpy change (ΔH° > ۰), it was found that the adsorption was an endothermic and a spontaneous process in nature.Keywords: Molybdenum removal, Batch adsorption, ۳-(trimethoxysilyl) propyl methacrylate, Poly (۴-vinylpyridine), Magnetic nanosorbent.

کلیدواژه ها:

Molybdenum removal ، Batch adsorption ، ۳-(trimethoxysilyl) propyl methacrylate ، Poly (۴-vinylpyridine) ، Magnetic nanosorbent