Kinetics and thermodynamics adsorption of phenolic compounds on organic-inorganic hybrid mesoporous material

The objective of this work is thus to study the kinetics, thermodynamics and adsorption isotherms of two phenolic compounds phenol (PhOH) and P-hydroxy benzoic acid (4AHB) on a mesoporous material type MCM- 48 functionalized with an organosilane type trimethylchlorosilane (TMCS) (MCM-48-G). At first, the study of the kinetics, thermodynamics and adsorption isotherms of phenolic compounds in each single solution was performed. In a second step, a similar study was performed on a mixture of these two molecules. Several kinetic models (pseudo-first order, pseudo-second order) were used to determine the kinetic parameters of adsorption. Several adsorption models (Langmuir, Freundlich) were also used to determine the thermodynamic parameters of adsorption isotherms. The effect of three-dimensional pores of MCM-48 and comparison of adsorption of PhOH and 4AHB was examined. It was found that MCM-48-G to a significant adsorption capacity for PhOH and 4AHB, this may be related to the hydrophobicity created by the organic function of TMCS in the MCM-48-G.The results of adsorption and PhOH 4AHB were analyzed using the Freundlich and Langmuir models. It was observed that the adsorption of 4AHB was higher than PhOH. Thermodynamics of adsorption showed that the values obtained for our sample confirm well the interactions with phenol and 4AHB are physical in nature. The adsorption of pollutants on our MCM-48 (G) is a spontaneous and exothermic process.