Surfactant modified clinoptilolite-rich tuff was used for the removal of phenol from aqueous solutions. The zeolitic rock from Oaxaca (Mexico) was treated with sodium chloride and then modified with hexade-cyltrimethylammonium chloride or bencylcetildimethylammonium chloride in different experimental conditions. Phenol sorption isotherms and column experiments were performed; in both cases, phenol was determined in the aqueous solutions by UV-vis spectroscopy. The results showed that the sorption of phenol depends on the quantities of surfactant in the zeolitic rocks, the kind of surfactant, modification conditions and pH of the solutions. When the initial concentration of phenol increased, the adsorption of phenol in the surfactant-modified zeolite increased and the experimental data was best adjusted to the Langmuir model. The saturation of the columns rapidly reached high percentages. (C) 2009 Elsevier B.V. All rights reserved.