Mechanisms Involved in Vibratory Destabilization of NAPL Ganglia in Sands
Publication: Journal of Environmental Engineering
Volume 122, Issue 12
Abstract
Immiscible liquids when spilled into the ground or leaked from underground storage tanks tend to remain trapped in the form of discrete ganglia due to strong capillary forces. These ganglia often have low solubility in water and may remain in the subsurface over long periods of time creating a continuous source of pollution. Previous studies, which were exploratory in nature, showed that creation of localized vibrations could recover high percentages of trapped ganglia. In this paper, the mechanisms involved in the vibratory destabilization of ganglia are analyzed using results from two sets of experimental studies. It is postulated that, when vibrations result in compaction of sands, viscous pressures tend to destabilize the ganglia by splitting them whereas buoyancy pressures increase the maximum sustainable lengths. The roles of viscous and buoyancy pressures are reversed when vibrations result in increased porosities due to expansion (dilation) of soil. The volumes of trapped ganglia recovered during the experiments are consistent with these postulates. Experimental results also indicate significant recoveries in the cases where the ganglia are supposed to remain stable. These recoveries are attributed to the transient particle rearrangement during vibrations, which is concluded to be an important mechanism.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Chatzis, I. N., and Dullien, F. A. L.(1983). “Dynamic immiscible displacement mechanisms in pore doublets: theory versus experiment.”J. Colloid and Interface Sci., 91(1), 199–222.
2.
Das, B. M. (1983). Advanced soil mechanics . Hemisphere Publishing Company, Washington, D.C.
3.
Larson, R. G., Davis, H. T., and Scriven, L. E.(1981). “Displacement of residual nonwetting fluid from porous media.”Chemical Engrg. Sci., 36, 75–85.
4.
Mace, R. E., and Wilson, J. L. (1992). “Chapter 17: clay and immiscible organic liquids; greater capillary trapping of the organic phase.”Transport and remediation of subsurface contaminants. D. A. Sabatini and R. C. Knox, eds., American Chemical Society, Washington, D.C.
5.
Melrose, J. C., and Brandner, C. F.(1974). “Role of capillary forces in determining microscopic displacement efficiency for oil recovery by waterflooding.”J. Can. Petr. Technol., 13(42), 54–62.
6.
Mercer, J. W., and Cohen, R. M. (1990). “A review of immiscible fluids in the subsurface: properties, models, characterization and remediation.”J. Contaminant Hydro., 6, 107–6: 163.
7.
Morrow, N. R., and Songkran, B. (1981). “Effect of viscous and buoyancy forces on nonwetting phase trapping in porous media.”Surface phenomena in enhanced oil recovery, D. O. Shah, ed., Plenum Publishing Corp., New York, N.Y., 387–411.
8.
Morrow, N. R., Chatzis, I., and Taber, J. J.(1988). “Entrapment and mobilization of residual oil in bead packs.”SPE Res. Engrg., 3(3), 927–934.
9.
Ojeda, E., Preston, F., and Calhoun, J. C.(1953). “Correlations of oil residuals following surfactant floods.”Producers Monthly, 18(2), 20.
10.
Reddi, L. N., Korfiatis, G. P., and Aguilar, E. (1992). “Integrated vibrorecovery process for remediation of NAPL-contaminated sites.”Proc., Nat. Res. and Devel. Conf. on the Control of Haz. Mat., Hazardous Materials Control Research Institute, San Francisco, Calif., 305–308.
11.
Reddi, L. N.(1994). “Feasibility of in-situ implementation of vibrations to mobilize NAPL ganglia.”J. Soil Contamination, 3(1), 29–46.
12.
Reddi, L. N., and Challa, S.(1994). “Vibratory mobilization of immiscible liquid ganglia in sands.”J. Envir. Engrg., ASCE, 120(5), 1170–1190.
13.
Rowell, D. L. (1994). Soil science: methods and applications . Longman Scientific and Technical, Longman Group UK Limited, Essex, England.
14.
Wilson, J. L., and Conrad, S. H. (1984). “Is physical displacement of residual hydrocarbons a realistic possibility in aquifer restoration?”Proc., NWWA/API Conf. on Petr. Hydrocarbons and Organic Chemicals in Ground Water—Prevention, Detection, and Restoration, National Water Well Association, Worthington, Ohio, 274–298.
15.
Wilson, J. L., Conrad, S. H., Mason, W. R., and Peplinski, W. (1990). “Laboratory investigation of residual liquid organics from spills, leaks, and the disposal of hazardous wastes in groundwater.”EPA/600/6–90/004, U.S. Environmental Protection Agency, Narraganset, R.I.
16.
Wu, H. (1995). “Stability of immiscible liquid ganglia in saturated sands,” MS thesis, Kansas State Univ., Manhattan, Kans.
Information & Authors
Information
Published In
Copyright
Copyright © 1996 American Society of Civil Engineers.
History
Published online: Dec 1, 1996
Published in print: Dec 1996
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.