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Describing and Predicting Breakthrough Curves for non-Reactive Solute Transport in Statistically Homogeneous Porous Media

dc.contributor.authorWang, Huaguoen
dc.contributor.committeechairPersaud, Naraineen
dc.contributor.committeememberLin, Taoen
dc.contributor.committeememberZelazny, Lucian W.en
dc.contributor.committeememberPachepsky, Yakoven
dc.contributor.committeememberMostaghimi, Saieden
dc.contributor.departmentCrop and Soil Environmental Sciencesen
dc.date.accessioned2014-03-14T20:19:19Zen
dc.date.adate2002-12-06en
dc.date.available2014-03-14T20:19:19Zen
dc.date.issued2002-11-18en
dc.date.rdate2003-12-06en
dc.date.sdate2002-11-29en
dc.description.abstractThe applicability and adequacy of three modeling approaches to describe and predict breakthough curves (BTCs) for non-reactive solutes in statistically homogeneous porous media were numerically and experimentally investigated. Modeling approaches were: the convection-dispersion equation (CDE) with scale-dependent dispersivity, mobile-immobile model (MIM), and the fractional convection-dispersion equation (FCDE). In order to test these modeling approaches, a prototype laboratory column system was designed for conducting miscible displacement experiments with a free-inlet boundary. Its performance and operating conditions were rigorously evaluated. When the CDE with scale-dependent dispersivity is solved numerically for generating a BTC at a given location, the scale-dependent dispersivity can be specified in several ways namely, local time-dependent dispersivity, average time-dependent dispersivity, apparent time-dependent dispersivity, apparent distance-dependent dispersivity, and local distance-dependent dispersivity. Theoretical analysis showed that, when dispersion was assumed to be a diffusion-like process, the scale-dependent dispersivity was locally time-dependent. In this case, definitions of the other dispersivities and relationships between them were directly or indirectly derived from local time-dependent dispersivity. Making choice between these dispersivities and relationships depended on the solute transport problem, solute transport conditions, level of accuracy of the calculated BTC, and computational efficiency The distribution of these scale-dependent dispersivities over scales could be described as either as a power-law function, hyperbolic function, log-power function, or as a new scale-dependent dispersivity function (termed as the LIC). The hyperbolic function and the LIC were two potentially applicable functions to adequately describe the scale dependent dispersivity distribution in statistically homogeneous porous media. All of the three modeling approaches described observed BTCs very well. The MIM was the only model that could explain the tailing phenomenon in the experimental BTCs. However, all of them could not accurately predict BTCs at other scales using parameters determined at one observed scale. For the MIM and the FCDE, the predictions might be acceptable only when the scale for prediction was very close to the observed scale. When the distribution of the dispersivity over a range of scales could be reasonably well-defined by observations, the CDE might be the best choice for predicting non-reactive solute transport in statistically homogeneous porous media.en
dc.description.degreePh. D.en
dc.identifier.otheretd-11292002-234939en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-11292002-234939/en
dc.identifier.urihttp://hdl.handle.net/10919/29777en
dc.publisherVirginia Techen
dc.relation.haspartDissertation.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectScale-dependent Dispersivityen
dc.subjectColumn Experimentsen
dc.subjectSolute Transport Modelingen
dc.subjectStatistically Homogeneous Porous Mediaen
dc.subjectBreakthrough Curvesen
dc.titleDescribing and Predicting Breakthrough Curves for non-Reactive Solute Transport in Statistically Homogeneous Porous Mediaen
dc.typeDissertationen
thesis.degree.disciplineCrop and Soil Environmental Sciencesen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

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