The Temperature Programmed Desorption (TPD) technique with liquid and supercritical water was used to study the heterogeneity of the adsorption of phenol onto different activated carbons. The presence of several desorption peaks in the spectra clearly indicated that phenol was adsorbed onto the activated carbon with different interaction energies. Calculation of the desorption activation energies revealed that most of the phenol was physisorbed, although a small part was always chemisorbed. The study of the textural characteristics of the carbons suggests that the width of the micropores governs the thermal desorption of the physisorbed phenol. (c) 2005 Elsevier B.V. All rights reserved.