Adsorption of nitrobenzene and n-pentanol from aqueous solution on hydrophilic and hydrophobic clay minerals

The sorption of nitrobenzene and n-pentanol from dilute aqueous solution on swelling clay minerals and their organophilized derivatives (organo clays) was studied. Adsorption excess isotherms were obtained by the immersion method. The basal spacings of the clay minerals were determined by X-ray diffraction measurements. By combining these two independent methods, composition and structure of the interlamellar space could be calculated. On the hydrophilic surface of montmorillonite negative adsorption of the organic component was observed at low molar fractions of nitrobenzene or pentanol, i.e., water was preferentially adsorbed. On organophilized montmorillonite and vermiculite adsorption of nitrobenzene and pentanol was positive over the whole range of liquid composition. The amount of interlamellar alkyl chains which is determined by the Surface charge of clay mineral inversely affected the adsorption of both solutes.