The rate at which volatile organic compounds (VOCs) are removed from the vadose zone by forced ventilation may be reduced by slow micro-scale processes such as diffusion through intra-aggregate and pore water and slow reactions at sorption sites located at the soil-water interface. Column experiments using benzene and p-xylene were performed in order to simulate cleanup of VOC's in the vadose zone by forced ventilation. Analytical solutions of the one-dimensional advection-dispersion equation coupled to mass transfer equations were fitted to the data. Parameter estimates were used in order to determine time scales of diffusion through water, desorption from, and sorption to, soil organic matter. Lower limits for the time scales for these processes were calculated to be on the order of minutes. Results indicate that these micro-scale processes reduce the rate of removal on the laboratory scale but may have no effect on the field scale.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/277044 |
| Date | January 1989 |
| Creators | Van de Water, James Gordon, 1963- |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Thesis-Reproduction (electronic) |
| 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. |
Page generated in 0.0021 seconds