Abstract
The adsorption of aqueous organic pollutants, i.e., phenol, monochlorophenols (2-and 4-), and dichlorophenols (2,4-and 3,5-) on natural Jordanian zeolitic tuff was studied. Three simplified kinetic models, viz., pseudo-first order, pseudo-second order, and intraparticle diffusion models were used to fit the kinetics data. The results revealed that at earlier stages of adsorption of phenols onto zeolite, the pseudo-second order and the bulk diffusion rate constants are dependent on the acidity and the hydrophobicity of phenols. Whereas at later stages of adsorption, the adsorption capacity and the intraparticle diffusion rate constants are affected by the molecular size and the extent of dissociation of phenols.