Removal of volatile aromatic contaminants from wastewater by cloud point extraction

Abstract

Abstract Removal of the aromatic contaminants benzene, toluene, and ethylbenzene from wastewater was investigated using cloud point extraction (CPE). A nonionic surfactant, t-octylphenolpolyethoxylate, was utilized as the separating agent. When the nonionic surfactant solution is heated above the cloud point temperature, phase separation is induced. The micellar-rich phase or coacervate phase and the micellar-dilute phase are formed. The aromatic contaminants tend to solubilize into the micelles and concentrate in the coacervate phase. The concentration of the solutes in the coacervate increases as temperature, added electrolyte concentration, and degree of alkylation of the aromatic solutes increase. Acknowledgments Financial support for this work was provided by the The Royal Golden Jubilee Ph.D. Program, The Thailand Research Fund. In addition, support was received from the industrial sponsors of the Institute for Applied Surfactant Research including Akzo Nobel Chemicals Inc., Albemarle Corporation, Amway Corporation, Clorox Company, Colgate-Palmolive, Dial Corporation, Dow Chemical Company, DowElanco, E. I. DuPont de Nemours and Co., Halliburton Services Corp., Henkel Corporation, Huntsman Corporation, ICI Americas Inc., Kerr-McGee Corporation, Lever Brothers, Lubrizol Corporation, Nikko Chemicals, Phillips Petroleum Company, Pilot Chemical Company, Procter and Gamble Company, Reckitt Benckiser North America, Schlumberger Technology Corp., Shell Chemical Company, Sun Chemical Corporation, Unilever Inc., and Witco Corporation. John Scamehorn holds the Asahi Glass Chair in Chemical Engineering at the University of Oklahoma. Surfactant was contributed by Rhodia (USA).