Sorption of toluene and nitrobenzene by dodecyl sulfate intercalated-hydrotalcite was studied as a function of solute concentration. The correlation between the derived partition coefficients and the solubilities of the aromatic solutes in water indicates that the main sorption mechanism is partitioning. The partition behavior of nitrobenzene is Henry ideal, whereas the isotherm for toluene is convex, i.e., type III. These unlike behaviors are accounted for by casting the activity coefficients of the solutes solubilized within the hydrophobic interlamellar space of the hybrid-hydrotalcite in terms of the Flory-Huggins theory, the value of the mixing parameter determining the isotherm shape. (c) 2006 Elsevier B.V. All rights reserved.