Adsorption of Acid Red G dye on octadecyl trimethylammonium montmorillonite

The adsorption of Acid Red G(ARG, C18H13N3Na2O8S2) onto octadecyl trimethylammonium montmorillonite was investigated in aqueous solution. The amount of adsorption of ARG onto octadecyl trimethylammonium montmorillonite decreased with increasing pH. The isotherms were fitted by the Langmuir model. The pseudo-second-order kinetics model represented the experimental data better than the pseudo-first-order model. The activation energy, Gibbs free energy, enthalpy and entropy of adsorption were also evaluated.