The equilibrium experiments were carried at 30, 40 and 50 C in order to see the performance of bentazon adsorption by SFHAC. The results showed that adsorption capacity increases with increasing the temperature indicating the endothermic nature of the adsorption (Fig. 10). Generally, at high temperature pore size becomes swollen upon heating that makes more room for the bentazon molecules on the surface of the SFHAC. The thermodynamic parameters associated with the adsorption process such as standard free energy change (DG), enthalpy change (DH) and entropy change (DS) are measured to check the thermodynamic feasibility and the spontaneity of the adsorption process. The thermodynamic parameters can be calculated by the following van’t Hoff equation: