• Login
    View Item 
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Microbial and peat effects on the oxidation of alpha-(4-pyridyl-1-oxide)-N-tert-butyl-nitrone by hydroxyl radicals in soil

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_td_9720580_sip1_c.pdf
    Size:
    19.73Mb
    Format:
    PDF
    Download
    Author
    Huling, Scott Gage, 1957-
    Issue Date
    1996
    Keywords
    Engineering, Chemical.
    Environmental Sciences.
    Advisor
    Arnold, Robert G.
    
    Metadata
    Show full item record
    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
    The Fenton reaction involves the reaction between H₂O₂ and ferrous iron that yields a hydroxyl radical (·OH). H₂O₂ has been used to generate ·OH in soil and aquifer material to oxidize undesirable contaminants. However, non-target chemical species, both natural and anthropogenic also react with ·OH. That is, non-target chemical species can "scavenge" ·OH and limit the "oxidation capacity" of the treatment system. A laboratory study was conducted to determine whether soil microbiota or soil organic matter in the form of peat would scavenge ·OH and compete with a probe compound (alpha-(4-pyridyl-1-oxide)-N-tert-butyl-nitrone (4-POBN)) for ·OH. 4-POBN was used because of the numerous advantages regarding its fate in soil and ease of analysis, however, it would be rare to find this probe as a contaminant in ground water or soil. A soil slurry composed of silica sand (SiO₂), goethite (FeOOH), 4-POBN and either a suspension of catalase-positive bacterium (Shewanella putrefaciens) or Pahokee peat was amended with H₂O₂. An analytical technique was used to estimate the steady-state ·OH concentration, the rate of ·OH production, the natural scavenging conditional rate constant, and the rate of ·OH scavenging. The oxidation efficiency was calculated which provided an empirical measure of treatment. Parameter values were compared to evaluate the roles of microbes and peat as determinants of ·OH availability under the conditions of the experiment. Microbes did not significantly effect the rate of ·OH production. The steady-state ·OH concentration was estimated to be approximately the same in the microbial-amended and unamended reactors, and the treatment efficiency was slightly greater in microbial-amended reactors. These results indicate that microbes had a minimal scavenging role. Pahokee peat increased the rate of ·OH production which was partially attributed to the iron contained in the peat. The conditional natural scavenging reaction rate constant was lower in the peat-amended reactors, and the steady-state ·OH concentration was greater in the peat-amended reactors. The rate of ·OH scavenging and the total ·OH scavenged were greater in the peat-amended reactors. Although the conditional natural scavenging rate constant was lower in peat-amended reactors, the rate of scavenging increased. This was attributed to the increased concentration of ·OH. The degradation rate of 2-chlorophenol, a common ground water contaminant, was successfully predicted using 4-POBN transformation data obtained under similar experimental conditions.
    Type
    text
    Dissertation-Reproduction (electronic)
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Graduate College
    Chemical and Environmental Engineering
    Degree Grantor
    University of Arizona
    Collections
    Dissertations

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.