The proposed model for the effect of pH on the adsorption of phenol/chlorophenols onto zeolite gives satisfactory fitting of the experimental data. Two types of interaction were quantified by the model. The first is the pH independent interaction of aromatic ring of phenols with the hydrophobic sites of zeolite. The second is the pH-dependent phenolate complexation with metal ions on the hydrophilic sites of zeolite surface. The number of sites of the first type, viz. hydrophobic sites, is greater than those of the second type. The adsorption increases with increasing pH, due to the increase of phenolates complexation with metal ions on zeolite surface. The size of phenol determines their order of adsorption capacity onto the surface of zeolite, where phenol and monochlorophenols revealed higher adsorptivity than dichlorophenols