Factors affecting diffusion of atmospheric fluorocarbons into unsaturated porous materials

Persistent Link:
http://hdl.handle.net/10150/191744
Title:
Factors affecting diffusion of atmospheric fluorocarbons into unsaturated porous materials
Author:
Earp, Douglas E.(Douglas Eugene)
Issue Date:
1981
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:
Atmospheric buildup of two fluorocarbon gases, CC1₃F (F-11) and CC1₂F₂ (F-12), during the past forty years has been documented by previous workers. The present study involved measurements of F-11 and F-12 concentrations in soil air within unconsolidated porous materials. Measurable concentrations of both gases were found at depths as great as forty-four meters at field sites near Lubbock, Texas. Agreement between measured concentrations and concentrations predicted using mathematical models based on molecular diffusion theory suggests that gaseous diffusion was the primary mechanism by which atmospheric fluorocarbons were transported within the subsurface. Analytical models were employed to derive effective diffusion coefficients of F-11 and F-12 under field conditions (0.005 cm²/sec. and 0.012 cm²/sec., respectively) and under controlled laboratory conditions (0.017 cm²/sec. for F-11 and 0.021 cm²/sec. for F-12). A finite difference model was used to estimate in situ tortuosity values (mean = 0.10) for unsaturated porous materials at one field site.
Type:
Thesis-Reproduction (electronic); text
LCSH Subjects:
Hydrology.; Chlorofluorocarbons -- Environmental aspects.; Soil absorption and adsorption.
Degree Name:
M.S.
Degree Level:
masters
Degree Program:
Hydrology and Water Resources; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Thompson, Glenn M.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleFactors affecting diffusion of atmospheric fluorocarbons into unsaturated porous materialsen_US
dc.creatorEarp, Douglas E.(Douglas Eugene)en_US
dc.contributor.authorEarp, Douglas E.(Douglas Eugene)en_US
dc.date.issued1981en_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.abstractAtmospheric buildup of two fluorocarbon gases, CC1₃F (F-11) and CC1₂F₂ (F-12), during the past forty years has been documented by previous workers. The present study involved measurements of F-11 and F-12 concentrations in soil air within unconsolidated porous materials. Measurable concentrations of both gases were found at depths as great as forty-four meters at field sites near Lubbock, Texas. Agreement between measured concentrations and concentrations predicted using mathematical models based on molecular diffusion theory suggests that gaseous diffusion was the primary mechanism by which atmospheric fluorocarbons were transported within the subsurface. Analytical models were employed to derive effective diffusion coefficients of F-11 and F-12 under field conditions (0.005 cm²/sec. and 0.012 cm²/sec., respectively) and under controlled laboratory conditions (0.017 cm²/sec. for F-11 and 0.021 cm²/sec. for F-12). A finite difference model was used to estimate in situ tortuosity values (mean = 0.10) for unsaturated porous materials at one field site.en_US
dc.description.notehydrology collectionen_US
dc.typeThesis-Reproduction (electronic)en_US
dc.typetexten_US
dc.subject.lcshHydrology.en_US
dc.subject.lcshChlorofluorocarbons -- Environmental aspects.en_US
dc.subject.lcshSoil absorption and adsorption.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.chairThompson, Glenn M.en_US
dc.identifier.oclc212844767en_US
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