Adsorption properties of methylene blue on hectorite: kinetic and Thermodynamics studies

Abstract

Hectorite has been designed and synthesized by hydrothermal way, which is used for removal of methylene blue (MB) from aqueous solution. The experiment data was analyzed using pseudo-second-order kinetics, intra-particle diffusion and film diffusion. The characteristic parameters for each model have been determined. Thermodynamic parameters such as activation(E a), standard free energy(ΔG 0), the enthalpy(ΔH 0) and the entropy(ΔS 0) were also evaluated. The negative value of ΔG 0 (kJ/mol) and ΔH 0 (kJ/mol) indicates the spontaneous and exothermic nature of the reactions. The data of E a shows the physisorption process of MB on hectorite.