Kinetic, thermodynamic and mechanism study of the adsorption of phenol on Moroccan clay

Abstract

Phenol is a toxic pollutant commonly found in industrial wastewaters. Thus, the objective of the present study consisted in removing this organic compound from aqueous solution using a clay from Morocco. Adsorbent characterization was performed using XRF, XRD, SEM, BET and FTIR techniques. Phenol adsorption isotherms and kinetics were experimentally quantified and modeling studies were carried out by statistical physics to explain the phenol adsorption on raw and activated clays. Results showed that: i) the activation of the clay by sulfuric acid increased its adsorption capacity, ii) the phenol adsorption was well fitted by the pseudo-second-order kinetic and Langmuir isotherm models, iii) the adsorption mechanism was dominated by electrostatic interactions and was associated to a multi-docking process. To conclude, the present study illustrates the valorization of this Moroccan clay as a low-cost and effective adsorbent for phenol removal from wastewaters.