• 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

    Coupled Transport, Fractionation and Stabilization of Dissolved Organic Matter and Rare Earth Elements in the Critical Zone

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_etd_12940_sip1_m.pdf
    Size:
    3.084Mb
    Format:
    PDF
    Download
    Author
    Vázquez-Ortega, Angélica
    Issue Date
    2013
    Keywords
    dissolved organic matter
    rare earth elements
    reactive tracers
    reactive transport
    Soil, Water & Environmental Science
    Critical Zone
    Advisor
    Chorover, Jon
    
    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
    It is important to understand the processes that influence the critical zone (CZ) evolution to ensure its sustainability. This thesis reports on laboratory and field experiments designed to measure the behavior of biogenic and lithogenic chemical species and their interaction in the CZ from column to pedon to catchment scales. We postulated that interactions between organic matter and rock-derived metals drive coupled processes of carbon stabilization and chemical weathering and denudation in the Jemez River Basin Critical Zone Observatory (JRB-CZO). First, we observed that secondary mineral coatings (Al and Fe (oxy)hydroxides) on primary silicate surfaces play a major role in sequestering aromatic and "humified" dissolved organic matter (DOM) into sorbate form, significantly retarding their subsurface transport. Further, reinfusion to OM-reacted-porous-media of a different DOM source resulted in exchange reactions consistent with a zonal model of OM adsorption at mineral surfaces. This dissertation also aimed to examine the influence of water and DOM fluxes on the CZ weathering processes. Rare earth elements (REE) were selected because of their coherent trends in reactivity toward organic ligands common to soils. Specifically, trends in REE fractionation were explored for their utility to inform on biogeochemical weathering processes in forested terrain in the JRB-CZO. Mineral weathering mechanisms are expected to differentially influence REE release, fractionation, and transport and the relative importance of such processes should be reflected in REE signatures of bulk soil, pore and surface waters. Our studies showed: (1) REE depletion trends with depth in bulk soils are correlated with topographically-induced variation in water and dissolved organic carbon (DOC) flux (reflected in negative correlations between total water and C fluxes) and solid phase REE concentrations measured at the same depths; (2) REE and DOC concentrations in stream waters were strongly correlated during snowmelt periods of high discharge, consistent with REE complexation and mobilization in association with organic ligands during shallow subsurface flow; (3) preferential sequestration of Eu occurs during formation of secondary Mn(IV)-oxides, explaining patterns of Eu enrichment in bulk soils; and (4) the incremental increase in positive Ce-anomalies with depth in bulk soils are apparently controlled by adsorption/co-precipitation with secondary Fe-(oxy)hydroxide minerals.
    Type
    text
    Electronic Dissertation
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Graduate College
    Soil, Water and Environmental Science
    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.