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

    Browse

    All of TUScholarShareCommunitiesDateAuthorsTitlesSubjectsGenresThis CollectionDateAuthorsTitlesSubjectsGenres

    My Account

    LoginRegister

    Help

    AboutPoliciesHelp for DepositorsData DepositFAQs

    Statistics

    Display statistics

    Surface/Geochemistry of Iron and Manganese Oxide Nano-Materials in the Environment

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    Debnath_temple_0225E_10064.pdf
    Size:
    6.034Mb
    Format:
    PDF
    Download
    Genre
    Thesis/Dissertation
    Date
    2009
    Author
    Debnath, Sudeep
    Advisor
    Strongin, Daniel R.
    Committee member
    Spano, Francis C.
    Nicholson, Allen W.
    Kargbo, David M.
    Department
    Chemistry
    Subject
    Chemistry, Physical
    Geochemistry
    Environmental Sciences
    Permanent link to this record
    http://hdl.handle.net/20.500.12613/1064
    
    Metadata
    Show full item record
    DOI
    http://dx.doi.org/10.34944/dspace/1046
    Abstract
    Nanomaterials possess physical and chemical properties that may benefit medicine, catalysis, and environmental remediation. Apart from understanding the structure of nanomaterials, significant amount of research has focused on understanding the structural properties of nanoparticles that lead to their unique reactivity. Ferric hydroxides are important mineral components and the subject of much scientific research in environmental and soil sciences because of their ubiquity in soil, ground water and aquatic sediments Iron oxide nanoparticles found in the environment exhibit size-dependent behavior. Iron oxides also play an important role in environmental chemistry. Ferrihydrite is an important iron oxide mineral as they exist in most of the sediment environment, necessary precursors for more stable iron oxides like hematite. Iron oxides are also important in many living organisms and stored as protein-encapsulated iron(III) oxyhydroxide nanoparticles. Because of the ubiquitous nature of ferrihydrite in soil and sediments, understanding correlation between the surface reactivity and the structure, phase of ferrihydrite ie. homogeneous or heterogeneous phase dependent reaction is important from environmental point of view. Iron oxides also play an important role in atmospheric chemistry and size dependent surface catalytic properties towards atmospheric gases. Green house gases are frequently generated during the burning of fossil fuels in factories and power plants, or derived from natural processes such as volcanic eruptions. Both natural and engineered metal oxides have been utilized as catalysts or sorbents for removal or minimization of green house emissions. In an attempt to understand the structure and reactivity relationship, we have presented ferrihydrite dissolution under reducing conditions and in situ kinetic studies were performed on isolated individual single particles of ferrihydrite using AFM. Bulk batch studies are also presented, where particles exist as agglomerates. Interface dissolution reaction has been characterized with FTIR and results were confirmed with theoretical calculations. Normalized dissolution rate of individual ferrihydrite particle sheds light on the phase behavior of this material. This study indicates that the ferrihydrite is uniform in composition and supports the Michel et al model. The size-dependent reactivity of ferrihydrite toward the environmentally important gas sulfur dioxide SO2 was also studied as atmospheric emission of SO2(g) affects the environment because it promotes the production of acid rain. In this investigation, nano-ferrihydrite particles were synthesized with a narrow size distribution. The surface chemistry and reactivity (SO2(g) sorption) was studied with attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy in combination with molecular orbital/density functional theory (MO/DFT) frequency calculations. Results showed that SO2(g) sorption may be a sensitive function of the structural properties and size of the nanoparticles. Like Iron oxides, Manganese oxides also play a distinctive role in superficial soil or near surface environments. Birnessite is one of the most commonly occurring manganese oxides in the soils and sediments. Birnessite are known to provide a suitable surface for heterogeneous oxidation of As(III) to As(V), and thus contribute to the environmental fate of arsenic species in soil and sediments. In the present study we have made an effort to understand this fundamental geochemistry occurring at birnessite surface at the molecular scale using advanced surface sensitive tools like AFM and spectroscopic techniques like FTIR and XPS. Nano size manganese oxide was also prepared via biological routes. Nano-size manganese oxide was prepared using ferritin protein as the biological precursor. Solution phase arsenic oxidation studies were performed with Ferritin Manganese oxide. Ion chromatography is performed to investigate oxidation of As(III) and reduction of manganese, along with XPS analysis to monitor the oxidation states of arsenic and manganese species. Results were also verified with FTIR spectroscopy for interface speciation.
    ADA compliance
    For Americans with Disabilities Act (ADA) accommodation, including help with reading this content, please contact scholarshare@temple.edu
    Collections
    Theses and Dissertations

    entitlement

     
    DSpace software (copyright © 2002 - 2021)  DuraSpace
    Temple University Libraries | 1900 N. 13th Street | Philadelphia, PA 19122
    (215) 204-8212 | scholarshare@temple.edu
    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.