Adsorptive potential of cationic Basic Yellow 2 (BY2) dye onto natural untreated clay (NUC) from aqueous phase: Mass transfer analysis, kinetic and equilibrium profile

The thermodynamic parameters such as, Gibbs free energy changes (ΔG°), standard enthalpy change (ΔH°) and standard entropy change (ΔS°) were determined. Adsorption of BY2 on NUC is exothermic and spontaneous in nature. The calculated activation energy of adsorption was found to be 5.24 kJ/mol for BY2. This value indicates that the adsorption process is a physisorption.