Adsorption of polyfunctional phenols encountered in olive oil mill waste waters was carried Out on an active charcoal at 293 K. The relation between the structure of the phenol and its adsorption capacity was discussed. Different isotherm equations were considered for modelling the experimental data and their parameters and standard deviations were determined. Freundlich equation was found to provide the best fit except for the catechol. (C) 2008 Elsevier B.V. All rights reserved.