Influence of Organic Acid Solution Chemistry on Subsurface Transport Properties. 2. Capillary Pressure-Saturation

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• 作者：David L. Lord ; Avery H. Demond ; Amir Salehzadeh ; and Kim F. Hayes
• 刊名：Environmental Science & Technology
• 出版年：1997
• 出版时间：July 1997
• 年：1997
• 卷：31
• 期：7
• 页码：2052 - 2058
• 全文大小：166K
• 年卷期：v.31,no.7(July 1997)
• ISSN：1520-5851

文摘

Two-phase flow models of subsurface transport oftenrequire the constitutive relationship of capillarypressureas a function of saturation as part of the data input.Thispart of the study correlates the solution chemistryfindingsfrom the previous paper with observed changes in theprimary drainage capillary pressure-saturationrelationshipfor a fine- to medium-grained quartz porous medium.Theresults showed that the solution chemistry was directlyreflected in the capillary pressure-saturationrelationship.The major factor determining the degree of reductionincapillary pressure was the concentration and speciation ofoctanoic acid dissolved in the aqueous phase, the samevariables reported in part 1 as critical in determining thesurfaceand interfacial tension. Because measurements of thecontact angle showed that the system stayed strongly hydrophilic under all conditions, the capillary pressurerelationships could be scaled adequately using theappropriatevalues of surface or interfacial tension only. Sinceorganicacid speciation had opposite effects on capillary pressurein the air-water and o-xylene-water systems, theimpactof pH on the movement of a contaminant front will dependon whether the contamination occurs in the vadose zone(air-aqueous phase system) or saturated zone (organicliquid-aqueous phase system).