Analytical and Numerical Modeling Assessment of Capillary Barrier Performance Degradation due to Contaminant-Induced Surface Tension Reduction
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 133, Issue 2
Abstract
Analytical and numerical models of capillary barrier performance commonly use hydraulic characteristics measured using pure water. However, the potential exists for an infiltrating solution to have a surface tension lower than that of pure water due to the presence of surface-active contaminants (surfactants). A lower surface tension solution may impact capillary barrier performance due to the dependence of capillarity on surface tension. An existing analytical solution for capillary diversion length was modified to include the effect of surface tension reduction on steady-state capillary barrier performance during uniform and constant infiltration. The for a surfactant-contaminated system was found to be less than for a pure water system and equal to for a pure water system multiplied by the relative surface tension. Numerical modeling using HYDRUS-2D also showed that diversion was less in the surfactant-contaminated system and that the difference in the performance of the two systems was due to the fact that the fine layer in the capillary barrier retains less liquid when wetted with surfactant solution.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
Partial funding for this work was provided by a University of North Carolina at Wilmington Summer Research Initiative Grant awarded to the writer.
References
Anderson, M. A., Hung, A. Y. C., Mills, D., and Scott, M. S. (1995). “Factors affecting the surface-tension of soil solutions and solutions of humic acids.” Soil Sci., 160(2), 111–116.
Bear, J. (1972). Dynamics of fluids in porous media, Dover, New York.
Blank, M., and Ottewill, R. H. (1964). “The adsorption of aromatic vapors on water surfaces.” J. Phys. Chem., 68(8), 2207–2211.
Desai, F. N., Demond, A. H., and Hayes, K. F. (1992). “Influence of surfactant sorption on capillary pressure-saturation relationships.” Transport and remediation of subsurface contaminants: Colloidal, interfacial, and surfactant phenomena, D. A. Sabatini and R. C. Knox, eds., American Chemical Society, Washington, D.C., 133–148.
Dury, O., Fischer, U., and Schulin, R. (1998). “Dependence of hydraulic and pneumatic characteristics of soils on a dissolved organic compound.” J. Contam. Hydrol., 33(1), 39–57.
Henry, E. J., and Smith, J. E. (2002). “The effect of surface-active solutes on water flow and contaminant transport in variably saturated porous media with capillary fringe effects.” J. Contam. Hydrol., 56(3–4), 247–270.
Henry, E. J., and Smith, J. E. (2003). “Surfactant-induced flow phenomena in the vadose zone: A review of data and numerical modeling.” Vadose Zone J., 2(2), 154–167.
Henry, E. J., Smith, J. E., and Warrick, A. W. (2002). “Two-dimensional modeling of flow and transport in the vadose zone with surfactant-induced flow.” Water Resour. Res., 38(11), 33-1–33-16.
Kampf, M., Holfelder, T., and Montenegro, H. (2003). “Identification and parameterization of flow processes in artificial capillary barriers.” Water Resour. Res., 39(10), 2-1–2-9.
Kampf, M., and Montenegro, H. (1997). “On the performance of capillary barriers as landfill cover.” Hydrology Earth Syst. Sci., 1(4), 925–929.
Kampf, M., and Von Der Hude, N. (1995). “Transport phenomena in capillary barriers: Influence of temperature on flow processes.” Proc., 5th Int. Landfill Symp., S. Margherita di Pula, ed., Cagliari, Italy, 656–576.
Karagunduz, A., Pennell, K. D., and Young, M. H. (2001). “Influence of a non-ionic surfactant on the water retention properties of unsaturated soils.” Soil Sci. Soc. Am. J., 65(5), 1392–1399.
Karkare, M. V., H. T. La., and Fort, T. (1993). “Criteria for effectiveness of surfactants as water-moving agents in unsaturated wet sand.” Langmuir, 9(7), 1684–1690.
Kim, H., Soh, H-E., Annable, M. D., and Kim, D-J. (2004). “Surfactant-enhanced air sparging in saturated sand.” Environ. Sci. Technol., 38(4), 1170–1175.
Lehman, R. M., Baker, K. E., and Mattson, E. D. (2004). “Distribution of microorganisms and their activities in capillary barriers: Implications for modeling of hydrologic transport through capillary barriers.” Vadose Zone J., 3(1), 134–142.
Leverett, M. C. (1941). “Capillary behavior in porous solids.” Trans. AIME, 142, 152–169.
Lord, D. L., Demond, A. H., and Hayes, K. F. (2000). “Effects of organic base chemistry on interfacial tension, wettability, and capillary pressure in multiphase subsurface waste systems.” Transp. Porous Media, 38(1–2), 79–92.
Lord, D. L., Demond, A. H., Salehzadeh, A., and Hayes, K. F. (1997). “Influence of organic acid solution chemistry on subsurface transport properties. 2: Capillary pressure-saturation.” Environ. Sci. Technol., 31(7), 2052–2058.
Mallants, D., Volckaert, G., and Marivoet, J. (1999). “Sensitivity of protective barrier performance to changes in rainfall rate.” Waste Manage., 19(7), 467–475.
Morris, C. E., and Stormont, J. C. (1997). “Capillary barriers and subtitle D covers: Estimating equivalency.” J. Environ. Eng., 123(1), 3–10.
Mualem, Y. (1976). “A new model for predicting the hydraulic conductivity of unsaturated porous media.” Water Resour. Res., 12(3), 513–522.
Oldenburg, C. M., and Pruess, K. (1993). “On numerical modeling of capillary barriers.” Water Resour. Res., 29(4), 1045–1056.
Piet, S. J., Jacobson, J. J., Martian, P., Martineau, R., and Soto, R. (2003). “Modeling and simulation of long-term performance of near-surface barriers.” Proc., Waste Management Symp. 2003, WM Symposia, Tucson, Ariz., 1–17.
Ross, B. (1990). “The diversion capacity of capillary barriers.” Water Resour. Res., 26(10), 2625–2629.
Salehzadeh, A., and Demond, A. H. (1994). “Apparatus for the rapid automated measurement of unsaturated soil transport properties.” Water Resour. Res., 30(10), 2679–2690.
Simunek, J., Sejna, M., and van Genuchten, M. Th. (1999). The HYDRUS-2D software package for simulating the two-dimensional movement of water, heat, and multiple solutes in variably-saturated media, Version 2.0. IGWMC-TPS-53C, International Ground Water Modeling Center, Colorado School of Mines, Golden, Colo.
Smith, J. E., and Gillham, R. W. (1994). “The effect of concentration-dependent surface tension on the flow of water and transport of dissolved organic compounds: A pressure head-based formulation and numerical model.” Water Resour. Res., 30(2), 343–354.
Smith, J. E. and Gillham, R. W. (1999). “Effects of solute concentration-dependent surface tension on unsaturated flow: Laboratory sand column experiments.” Water Resour. Res., 35(4), 973–982.
Steenhuis, T. S., Parlange, J.-Y., and Kung, K.-J. S. (1991). “Comment on ‘The diversion capacity of capillary barriers’ by Benjamin Ross.” Water Resour. Res., 27(8), 2155–2156.
Tumeo, M. A. (1997). “A survey of the causes of surfactant-induced changes in hydraulic conductivity.” Ground Water Monit. Rem., 17, 138–144.
van Genuchten, M. Th. (1980). “A closed-form equation for predicting the hydraulic conductivity of unsaturated soils.” Soil Sci. Soc. Am. J., 44(5), 892–898.
Warrick, A. W., Wierenga, P. J., and Pan, L. (1997). “Downward water flow through sloping layers in the vadose zone: Analytical solutions for diversions.” J. Hydrol., 192(1–4), 321–337.
Webb, S. W. (1997a). “Generalization of Ross tilted capillary barrier diversion formula for different two-phase characteristic curves.” Water Resour. Res., 33(8), 1855–1859.
Webb, S. W. (1997b). “Comparison of Ross’ capillary barrier diversion formula with detailed numerical simulations.” Proc., 1997 Int. Containment Technology Conf. and Exhibition, U.S. Department of Energy, St. Petersburg, Fla., 289–295.
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 133 • Issue 2 • February 2007
Pages: 231 - 236
Copyright
© 2007 ASCE.
History
Received: Dec 22, 2005
Accepted: Jul 14, 2006
Published online: Feb 1, 2007
Published in print: Feb 2007
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.