UNIFAC Modeling of Cosolvent Phase Partitioning in Nonaqueous Phase Liquid-Water Systems
Publication: Journal of Environmental Engineering
Volume 130, Issue 4
Abstract
In this study, an existing thermodynamic model was used to predict equilibrium phase partitioning behavior of a cosolvent in a two-phase nonaqueous phase liquid (NAPL)–water system. The activity coefficients are calculated using the universal quasichemical functional group activity coefficient (UNIFAC) method. We examined an assortment of cosolvent–NAPL pairs of environmental interest and compared the UNIFAC-predicted ternary phase diagrams against published experimentally derived ternary phase diagrams. Results show that the UNIFAC model is a promising method for predicting equilibrium cosolvent partitioning behavior in NAPL–water systems, and thus can be useful in estimating the potential for NAPL solubilization and mobilization in remediation processes. The cosolvent partitioning behavior is interpreted with regard to changes in the physical properties of the NAPL-water system. Changes in interfacial tension between the two phases were estimated using an existing correlation. A viscosity experiment was conducted for selected mixtures of ethanol, toluene, and water; and the viscosity was found to increase with increasing amounts of the cosolvent.
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Information
Published In
Journal of Environmental Engineering
Volume 130 • Issue 4 • April 2004
Pages: 478 - 483
Copyright
Copyright © 2004 American Society of Civil Engineers.
History
Received: Jun 24, 2002
Accepted: Mar 6, 2003
Published online: Mar 15, 2004
Published in print: Apr 2004
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