Adsorption performance of low-cost gelatin–montmorillonite nanocomposite for Cr(iii) ions

Abstract

A gelatin–montmorillonite (G–MMT) nanocomposite was prepared by Na–montmorillonite (Na–MMT) and a biomaterial gelatin through an intercalation method. Samples were studied by XRD and FTIR and the results indicated that gelatin has been successfully intercalated into the interlayers of MMT. The effect of G–MMT nanocomposite adsorbed Cr(III) from aqueous solution was investigated in terms of the initial concentration of Cr(III), adsorption temperature and solution pH. The maximum adsorption capacity was 52.91 mg g⁻¹ for an initial Cr(III) concentration of 300 mg L⁻¹, temperature of 343 K and pH value of 5.5. Furthermore, kinetic and isotherm models were used for the description of the adsorption process. The results demonstrated that the adsorption process was fitted to a pseudo-second-order kinetic model and the equilibrium data gave good fits with both Freundlich and Langmuir equations. The thermodynamic study revealed the endothermic and non-spontaneous nature of the adsorption process, and the increased randomness at the solid–solution interface.