Gaseous transport in the vadose zone : computer simulations using the discrete state compartment model

Persistent Link:
http://hdl.handle.net/10150/191978
Title:
Gaseous transport in the vadose zone : computer simulations using the discrete state compartment model
Author:
Seidemann, Rick Hugh,1960-
Issue Date:
1988
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Past disposal practices of TricNoroethylene (ICE) and other halogenated hydrocarbons have resulted in the contamination of groundwater in part of the Tucson Basin, Tucson, Arizona. At the Carranza site, known to overlie a ICE groundwater contamination plume, a nest of gas sampling piezometers was constructed to measure the vertical distribution of TCE vapor in the vadose zone. The distribution of TCE vapor in the vadose zone was found to be nonmonotonically decreasing from the water table to the atmosphere. To investigate this ICE concentration profile, simulation studies were performed using the Discrete State Compartment model to test various hypotheses concerning the transport mechanisms of TCE vapor in the vadose zone. The studies showed that unless a high permeable column by which diffusing gas could by-pass low permeable layers was included in the simulation molecular diffusion alone could not produce the concentrations measured at the Carranza site. The simulation also showed that a nonmonotonic concentration profile similar to the measured concentration profile could be produced if multiple sources are assumed in the vadose zone. Soil gas advection by barometric pressure fluctuations was shown to increase concentrations at all depths in the vadose zone but the effect was minor compared with the effect of the high permeability column bypass for TCE diffusional transport.
Type:
Thesis-Reproduction (electronic); text
LCSH Subjects:
Hydrology.; Zone of aeration -- Arizona -- Tucson Basin.; Trichloroethylene -- Environmental aspects -- Arizona -- Tucson Basin.; Groundwater -- Arizona -- Tucson Basin.
Degree Name:
M.S.
Degree Level:
masters
Degree Program:
Hydrology and Water Resources; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Simpson, Eugene S.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleGaseous transport in the vadose zone : computer simulations using the discrete state compartment modelen_US
dc.creatorSeidemann, Rick Hugh,1960-en_US
dc.contributor.authorSeidemann, Rick Hugh,1960-en_US
dc.date.issued1988en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractPast disposal practices of TricNoroethylene (ICE) and other halogenated hydrocarbons have resulted in the contamination of groundwater in part of the Tucson Basin, Tucson, Arizona. At the Carranza site, known to overlie a ICE groundwater contamination plume, a nest of gas sampling piezometers was constructed to measure the vertical distribution of TCE vapor in the vadose zone. The distribution of TCE vapor in the vadose zone was found to be nonmonotonically decreasing from the water table to the atmosphere. To investigate this ICE concentration profile, simulation studies were performed using the Discrete State Compartment model to test various hypotheses concerning the transport mechanisms of TCE vapor in the vadose zone. The studies showed that unless a high permeable column by which diffusing gas could by-pass low permeable layers was included in the simulation molecular diffusion alone could not produce the concentrations measured at the Carranza site. The simulation also showed that a nonmonotonic concentration profile similar to the measured concentration profile could be produced if multiple sources are assumed in the vadose zone. Soil gas advection by barometric pressure fluctuations was shown to increase concentrations at all depths in the vadose zone but the effect was minor compared with the effect of the high permeability column bypass for TCE diffusional transport.en_US
dc.description.notehydrology collectionen_US
dc.typeThesis-Reproduction (electronic)en_US
dc.typetexten_US
dc.subject.lcshHydrology.en_US
dc.subject.lcshZone of aeration -- Arizona -- Tucson Basin.en_US
dc.subject.lcshTrichloroethylene -- Environmental aspects -- Arizona -- Tucson Basin.en_US
dc.subject.lcshGroundwater -- Arizona -- Tucson Basin.en_US
thesis.degree.nameM.S.en_US
thesis.degree.levelmastersen_US
thesis.degree.disciplineHydrology and Water Resourcesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairSimpson, Eugene S.en_US
dc.contributor.committeememberEvans, Daniel D.en_US
dc.contributor.committeememberBently, Harolden_US
dc.identifier.oclc213298341en_US
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