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Investigation of consolidation-induced solute transport. I: effect of consolidation on transport parameters / Jangguen Lee in Journal of geotechnical and geoenvironmental engineering, Vol. 135 N° 9 (Septembre 2009) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 9 (Septembre 2009) . - pp. 1228–1238 Titre : Investigation of consolidation-induced solute transport. I: effect of consolidation on transport parameters Type de document : texte imprimé Auteurs : Jangguen Lee, Auteur ; Fox, Patrick J., Auteur ; John J. Lenhart, Auteur Année de publication : 2009 Article en page(s) : pp. 1228–1238 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Soil  consolidationParametersSolutesSorptionInorganic  chemicals Résumé : This paper presents an experimental investigation of the effect of clay consolidation on parameters that govern the advective-dispersive transport of an inorganic solute. Batch, diffusion, dispersion, and solute transport tests were conducted using kaolinite clay and dilute solutions of potassium bromide (KBr). Batch tests produced the highest levels of K+ sorption and indicated that equilibrium sorption was achieved in approximately 10–30 min. The increase in sorption observed in the batch tests, as compared to the dispersion or solute transport tests, reflects the significantly lower solids-to-solution ratio and more efficient mixing process. By comparison, kaolinite consolidation had little effect on sorption due to the relatively small change in porosity. Values of hydrodynamic dispersion coefficient (Dh) , effective diffusion coefficient (D∗) , and apparent tortuosity factor decreased with decreasing porosity. Values of D∗ obtained for Br− were generally larger than for K+ , whereas Dh values for Br− were significantly smaller than for K+ . Values of longitudinal dispersivity (α) were larger for K+ than Br− and showed no clear trend with decreasing void ratio. In general, the experimental results suggest that changes in D∗ and Dh should be taken into account during clay consolidation whereas the sorption isotherm and α may be considered as unchanged during the consolidation process. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000047 [article] Investigation of consolidation-induced solute transport. I: effect of consolidation on transport parameters [texte imprimé] / Jangguen Lee, Auteur ; Fox, Patrick J., Auteur ; John J. Lenhart, Auteur . - 2009 . - pp. 1228–1238. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 9 (Septembre 2009) . - pp. 1228–1238 Mots-clés : Soil  consolidationParametersSolutesSorptionInorganic  chemicals Résumé : This paper presents an experimental investigation of the effect of clay consolidation on parameters that govern the advective-dispersive transport of an inorganic solute. Batch, diffusion, dispersion, and solute transport tests were conducted using kaolinite clay and dilute solutions of potassium bromide (KBr). Batch tests produced the highest levels of K+ sorption and indicated that equilibrium sorption was achieved in approximately 10–30 min. The increase in sorption observed in the batch tests, as compared to the dispersion or solute transport tests, reflects the significantly lower solids-to-solution ratio and more efficient mixing process. By comparison, kaolinite consolidation had little effect on sorption due to the relatively small change in porosity. Values of hydrodynamic dispersion coefficient (Dh) , effective diffusion coefficient (D∗) , and apparent tortuosity factor decreased with decreasing porosity. Values of D∗ obtained for Br− were generally larger than for K+ , whereas Dh values for Br− were significantly smaller than for K+ . Values of longitudinal dispersivity (α) were larger for K+ than Br− and showed no clear trend with decreasing void ratio. In general, the experimental results suggest that changes in D∗ and Dh should be taken into account during clay consolidation whereas the sorption isotherm and α may be considered as unchanged during the consolidation process. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000047

Investigation of Consolidation-Induced Solute Transport. II: Experimental and Numerical Results / Jangguen Lee in Journal of geotechnical and geoenvironmental engineering, Vol. 135 N° 9 (Septembre 2009) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 9 (Septembre 2009) . - pp. 1239–1253 Titre : Investigation of Consolidation-Induced Solute Transport. II: Experimental and Numerical Results Type de document : texte imprimé Auteurs : Jangguen Lee, Auteur ; Fox, Patrick J., Auteur Année de publication : 2009 Article en page(s) : pp. 1239–1253 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Soil  consolidationSolutesDispersionSorptionNumerical  modelsClays Résumé : This paper presents an experimental and numerical investigation of consolidation-induced solute transport. Diffusion and large strain consolidation tests were performed on composite specimens of kaolinite clay consisting of an upper uncontaminated layer and a lower layer contaminated with potassium bromide. Experimental measurements of effluent concentration, solute mass outflow, and final concentration profiles were obtained for a variety of initial, boundary, and loading conditions, including unload/reload. Numerical simulations were conducted using a computational model in which solute transport occurs by advection, dispersion, and sorption and is consistent with temporal and spatial variations of porosity and seepage velocity in the consolidating layer. Large strains were taken into account as well as variation of effective diffusion coefficient with porosity and nonlinear nonequilibrium sorption effects. The numerical simulations are in good to excellent agreement with the experimental measurements. Results indicate that, depending on conditions, diffusion and consolidation-induced advection can make important contributions to solute transport and mass outflow. Thus, both mechanisms should be considered for transport analyses involving soft contaminated clays undergoing large volume change. Results also indicate that nonequilibrium sorption effects were not significant for the materials and test conditions used in this study. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000048 [article] Investigation of Consolidation-Induced Solute Transport. II: Experimental and Numerical Results [texte imprimé] / Jangguen Lee, Auteur ; Fox, Patrick J., Auteur . - 2009 . - pp. 1239–1253. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 9 (Septembre 2009) . - pp. 1239–1253 Mots-clés : Soil  consolidationSolutesDispersionSorptionNumerical  modelsClays Résumé : This paper presents an experimental and numerical investigation of consolidation-induced solute transport. Diffusion and large strain consolidation tests were performed on composite specimens of kaolinite clay consisting of an upper uncontaminated layer and a lower layer contaminated with potassium bromide. Experimental measurements of effluent concentration, solute mass outflow, and final concentration profiles were obtained for a variety of initial, boundary, and loading conditions, including unload/reload. Numerical simulations were conducted using a computational model in which solute transport occurs by advection, dispersion, and sorption and is consistent with temporal and spatial variations of porosity and seepage velocity in the consolidating layer. Large strains were taken into account as well as variation of effective diffusion coefficient with porosity and nonlinear nonequilibrium sorption effects. The numerical simulations are in good to excellent agreement with the experimental measurements. Results indicate that, depending on conditions, diffusion and consolidation-induced advection can make important contributions to solute transport and mass outflow. Thus, both mechanisms should be considered for transport analyses involving soft contaminated clays undergoing large volume change. Results also indicate that nonequilibrium sorption effects were not significant for the materials and test conditions used in this study. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000048