Crosslinked quaternized chitosan/bentonite composite for the removal of Amino black 10B from aqueous solutions

In this work, the crosslinked quaternized chitosan/bentonite composite was prepared by membrane forming and cross-linking methods, and characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) techniques. Batch mode was adapted for the adsorption studies. The equilibrium data and kinetic data were well described by the Langmuir isotherm and the pseudo-second-order kinetic model, respectively. There was not much drop in adsorption capacity up to 5th regeneration cycle. The maximum monolayer adsorption capacity was obtained at 990.1 mg/g at 298 K and natural pH in terms of the Langmuir model. The high adsorption capacity was attributed to the strong electrostatic interaction as well as the valence forces through the sharing or exchange of electrons between dye molecules and this composite. The thermodynamic parameters indicated the adsorption of Amino black 10B by this composite was a spontaneous and endothermic process. (C) 2016 Elsevier B.V. All rights reserved.