Adsorption of Quinoline from Aqueous Solutions by Some Clays and Oxides

A. K. Helmy, S. G. de Bussetti and E. A. Ferreiro
Universidad Nacional del Sur, 8000 Bahía Blanca, Repuública Argentina

Abstract: The adsorption isotherms of quinoline from aqueous solutions by some clays and oxides varied from the S type for silica to a form somewhat similar to the Langmuir type for montmorillonite and silicaalumina. The adsorption reaction reached equilibrium in about 2 hr and was irreversible. X-ray powder diffraction studies showed that a single layer of molecules is adsorbed on montmorillonite and that the molecules lie either flat or in an upright position depending on surface coverage. The adsorption showed high sensitivity towards pH, attaining a maximum at pH 6. The decrease below pH 6 was due to competition with protons as well as to problems inherent in surface packing of positively charged quinoline molecules. The decrease above pH 6 is probably due to more exchangeable metallic cations on the surface leading to a favored sorption of water over organic molecules.

Key Words: Adsorption • Montmorillonite • pH • Quinoline • Silica-alumina • X-ray powder diffraction

Clays and Clay Minerals; February 1983 v. 31; no. 1; p. 29-36; DOI: 10.1346/CCMN.1983.0310105
© 1983, The Clay Minerals Society
Clay Minerals Society (www.clays.org)