Phase Stability of Multicomponent NAPLs Containing PAHs

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• 作者：Catherine A. Peters ; Suparna Mukherji ; Christopher D. Knightes ; and Walter J. Weber ; Jr.
• 刊名：Environmental Science & Technology
• 出版年：1997
• 出版时间：September 1997
• 年：1997
• 卷：31
• 期：9
• 页码：2540 - 2546
• 全文大小：177K
• 年卷期：v.31,no.9(September 1997)
• ISSN：1520-5851

文摘

Multicomponent nonaqueous phase liquid (NAPL) contaminants that contain compounds that are solids in theirpure states can undergo phase transformations. Thispaper examines the relationship between NAPL compositionand liquid phase stability for mixtures of polycyclicaromatichydrocarbons (PAHs), most of which are solids in pureform at ambient temperatures. Because any natural orengineered process that acts to selectively extractcompounds will alter NAPL composition, knowledge of phasestability is an important determinant in risk assessment,remediation effectiveness, and research. Ideal solubilitytheorydictates that a NAPL will be a homogeneous liquid if eachconstituent's mole fraction is less than thesolid-liquidreference fugacity ratio at the system temperature.Throughexperimental observation of binary and ternary systems,it is shown that ideal solubility theory is a reliable guideforpredicting PAH-NAPL phase stability. Uncertainty inmelting temperature and entropy of fusion is a significantdeterminant that may limit predictive power. Theprincipleof liquefaction through mixing was exploited to producecomplex synthetic NAPLs which can be used as surrogatematerials to simulate the behavior of contaminants such ascoal tars. NAPL/aqueous phase equilibrium studieswereconducted to demonstrate the utility of these materials inexperimentation.