Use of a Micellar-Rich Coacervate Phase to Extract Trichloroethylene from Water

Abstract

At temperatures above the “cloud point,” aqueous nonionic surfactant micellar solutions can separate into two phases: a micellar-rich coacervate phase and a dilute phase. Because the coacervate phase is a concentrated micellar solution, organic solute tends to concentrate in the coacervate as a result of solubilization. In this study up to 91% of trichloroethylene (TCE) was extracted into the coacervate phase in one stage. The TCE concentration in the coacervate can be over two orders of magnitude greater than that in the dilute phase. Increasing temperature, surfactant concentration, and added NaCl concentration all improve the fraction of TCE extracted.

ACKNOWLEDGMENTS

Financial support was provided by National Science Foundation Grant CBT 8814147, an Applied Research Grant from the Oklahoma Center for the Advancement of Science and Technology, the Center for Waste Reduction Technologies of the American Institute of Chemical Engineers, Agreement No. N12-N10, the TAPPI Foundation, the National Research Council of Thailand, TunTeX Petrochemical Co. Ltd. (Thailand), and U.S. Agency for International Development (University Development Linkages Project). In addition, support was received from the industrial sponsors of the Institute for Applied Surfactant Research including Akzo Nobel, Albemarle, Clorox, Colgate-Palmolive, Dial, Dow, DuPont, Halliburton, Huntsman, ICI, Kerr-McGee, Lubrizol, Nikko Chemical, Phillips Petroleum, Pilot Chemical, Procter and Gamble, Reckitt and Coleman, S. C. Johnson Wax, Schlumberger, Shell, and Unilever. Surfactant was provided by Rhodia Co. Ltd. (Thailand). Dr. Scamehorn holds the Asahi Glass Chair and Dr. Harwell holds the Conoco/DuPont Professorship in chemical engineering at the University of Oklahoma.