Conductivity of compacted clay soils to water and organic liquids

Anderson, D. C.; Brown, K. W.; Thomas, James C.

doi:10.1016/0734-242x(85)90127-2

Cited by 40 publications

(25 citation statements)

References 7 publications

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“…The latter aspect includes the role of the stress state generated by the flow itself and by the applied experimental procedure (rigid-versus flexible-wall test). The large increase in permeability reported to occur in rigid-wall permemeters has been often ascribed to opening of cracks or macropores in soil (see, e.g., Brown and Anderson 1983;Foreman and Daniel 1986) or to a possible side wall flow (see, e.g., Anderson et al 1985). The reports from other experiments (see, e.g., Fernandez andQuigley 1985, 1988) do not confirm the generation of macrocracks in the studied samples.…”

Section: Modeling Evolution Of Permeability Due To Chemical Dehydrationmentioning

confidence: 69%

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Theoretical assessment of fabric and permeability changes in clays affected by organic contaminants

Hueckel¹,

Kaczmarek²,

Caramuscio³

1997

Can. Geotech. J.

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Permeability of clay is known, from laboratory tests, to increase over four orders of magnitude during low effective stress permeation with some concentrated organic liquids. On an engineering scale, in a one-dimensional purely advective flow through a finite layer, such evolution is shown numerically to cause a substantial acceleration of the progress of the contamination front, compared with a constant permeability case. For a 100-fold increase in intrinsic permeability for a 100% replacement of pore water with an organic, a two times shorter advective transit time is predicted. A series of quantitative fabric models based on interpretations and concepts proposed in the past are reformulated in quantitative terms. These models are associated with adsorbed water withdrawal, particle migration, and deposition leading to pore clogging, changes in connectivity or flocculation. Permeability is derived from the flow through a simplified structure formed by dominant pores in the actual pore size distribution. The formulation is applied to interpret previously published experimental data. It is found that a series connection of the dominant pores must be postulated rather than a parallel one, with the smaller pore acting as a bottle neck. A simple pore enlargement model is found not to be realistic. The numerically most consistent results are obtained for the flocculation model involving a particle rotation generating wedge-shaped channels.Résumé : On sait, sur la base d'essais de laboratoire, que la perméabilité d'une argile peut être augmentée de quatre ordres de grandeur pendant la perméation, de certains liquides organiques concentrés sous contraintes effectives basses. A l'échelle de l'ingénieur, si on considère un écoulement unidimensionnel purement advectif à travers une couche d'épaisseur finie, on peut montrer numériquement qu'une telle évolution cause une accélération substantielle de l'avancée du front de contamination, comparé au cas d'une perméabilité constante. Pour une augmentation de perméabilité intrinsèque de 100 fois avec remplacement complet de l'eau interstitielle par un liquide organique, on prédit un temps de traversée advective deux fois plus court. Une série de modèles micro-structuraux quantitatifs basés sur des interprétations et des concepts proposés dans le passé ont été reformulés en termes quantitatifs. Ces modèles sont associés au retrait de l'eau adsorbée, à la migration et au dépôt de particules conduisant au colmatage des pores, aux changements de connectivité ou à la floculation. On déduit la perméabilité de l'écoulement à travers une structure simplifiée formée des pores dominants dans la distribution granulométrique réelle. On a appliqué cette formulation à l'interprétation de résultats expérimentaux précédemment publiés. On a trouvé qu'un assemblage en série des pores dominants est plus approprié qu'un assemblage en parallèle, le pore le plus petit agissant comme goulet d'étranglement. Un modèle simple d'élargissement des pores n'a pas été trouvé réaliste. D'un point de vue numéri...

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Section: Modeling Evolution Of Permeability Due To Chemical Dehydrationmentioning

confidence: 69%

“…Laboratory experiments show that clays may increase in intrinsic permeability by four orders of magnitude when permeated by concentrated solutions of certain organic or inorganic chemicals under very low effective stress (see, e.g., Fernandez and Quigley 1985, 1988Anderson et al 1985;Bowders and Daniel 1986;Madsen and Mitchell 1989).…”

Section: Introductionmentioning

confidence: 99%

Theoretical assessment of fabric and permeability changes in clays affected by organic contaminants

Hueckel¹,

Kaczmarek²,

Caramuscio³

1997

Can. Geotech. J.

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“…For matrix flow, however, they asserted that conductivity increased as E increased, although this is not supported by the data (Fig. On a different set 64 E. R. Graber and U. Mingelgrin Brown and Thomas 1984) of soils Anderson et al (1985) also showed that compacted clays were more conductive to organic solvents than to water by two to four orders of magnitude. Brown and Thomas (1984) measured Ks for three compacted clays to solvents including water, acetone, xylene, gasoline, kerosene, diesel fuel, and motor oil in fixed wall laboratory permeameters.…”

Section: Permeability and Conductivity Changes In Porous Mediamentioning

confidence: 88%

Soil and Aquifer Pollution

Rubin¹,

Narkis²,

Carberry³

1998

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“…The soil physical parameter of importance in soil-contaminant interaction is the soil hydraulic conductivity (for soils with k > l o p 8 m/s), as it controls the fluid movement through the soil. There have been a number of studies of the effects of nonpolar alkanes (heptane, cyclohexane) and aromatic hydrocarbons (benzene, xylene) on the hydraulic conductivity of clays (Green et al 1983;Acar et al 1985;Anderson et al 1985aAnderson et al , 1985bBowders 1985;Fernandez and Quigley 1985;Uppal and Stephenson 1989). Mitchell and Madsen (1987) have reviewed the various investigations and arrived at the following conclusions about the effect of hydrocarbons on the hydraulic conductivity of clay soils.…”

Section: Bonding Mechanisms Possible Between Soil Functional Groups Amentioning

confidence: 99%

Mechanistic evaluation of mitigation of petroleum hydrocarbon contamination by soil medium

Yong¹,

Rao²

1991

Can. Geotech. J.

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Present in situ chemical treatment technologies for mitigation of petroleum hydrocarbon contamination are in the developmental stage or being tested. To devise efficient strategies for restricting the movement of petroleum hydrocarbon (PHC) molecules in the contaminated soil, it is proposed to utilize the sorption-interaction relationships between the petroleum contaminants and the soil substrate. The basic questions addressed in this paper are as follows (i) What are the prominent chemical constituents of the various petroleum fractions that interact with the soil substrate? (ii) What are the functional groups of a soil that interact with the contaminants? (iii) What are the bonding mechanisms possible between the soil functional groups and the PHC contaminants? (iv) What are the consequent changes brought about the soil physical properties on interaction with PHC's? (v) What are the factors influencing the interactions between PHC molecules and clay particles of the soil substrate? (vi) What is the possibility of improving the soil's attenuation ability for PHC's? The development of answers to the basic questions reveal that petrol$um hydrocarbons comprise a mixture of nonpolar alkanes and aromatic and polycyclic hydrocarbons, that have limited solubility in water. The bonding mechanism between the nonpolar PHC's and the clay surface is by way of van $er Waals attraction. The adsorption of the nonpolar hydrocarbons by the clay surface occurs only when their (i.e., the hydrocarbon molecules) solubility in water is exceeded and the hydrocarbons exist in the micellar form. Dilute solutions of hydrocarbons in water, i.e., concentrations of hydrocarbons at or below the solubility limit, have no effect on the hydraulic conductivity of clay soils. Permeation with pure hydrocarbons invariably influences the clay hydraulic conductivity. To improve the attenuation ability of soils towards PHC's, it is proposed to coat the soil surface with "ultra" heavy organic polymers. Adsorption of organic polymers by the clay surface may change the surface properties of the soil from highly hydrophilic (having affinity for water molecules) to organophilic (having affinity for organic molecules). The organic polymers attached to the clay surface are expected to attenuate the PHC molecules by van der Waals attraction, by hydrogen bonding, and also by adsorption into interlayer space in the case of soils containing swelling clays.Les technologies actuelles de traitement chimique pour diminuer la contamination aux hydrocarbures du pitrole sont au state du developpement ou presentement testees. Afin de concevoir des strategies efficaces pour restreindre le mouvement des molecules des hydrocarbures de petrole (HCP) dans le sol contarnine, l'on propose l'utilisation des relations sorption-interaction entre les contaminants de petrole et le sous-sol. Les questions fondamentales qui sont traities dans le present article sont (i) Quels sont les principaux constituants chimiques des diverses fractions du petrole qui reagissent avec le sous-sol?...

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Conductivity of compacted clay soils to water and organic liquids

Cited by 40 publications

References 7 publications

Theoretical assessment of fabric and permeability changes in clays affected by organic contaminants

Theoretical assessment of fabric and permeability changes in clays affected by organic contaminants

Soil and Aquifer Pollution

Mechanistic evaluation of mitigation of petroleum hydrocarbon contamination by soil medium

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