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dc.contributor.authorDiesel, Elizabeth A.en
dc.date.accessioned2014-03-14T21:09:37Zen
dc.date.available2014-03-14T21:09:37Zen
dc.date.issued2011-02-04en
dc.identifier.otheretd-02182011-142724en
dc.identifier.urihttp://hdl.handle.net/10919/37383en
dc.description.abstractDrinking water supplies contaminated with arsenic (As), a toxin and carcinogen, adversely impact the health of millions of people worldwide. Previous work has documented that different inorganic and organic As species vary with respect to their toxicities. It is, however, currently not well understood how As speciation affects bioavailability, defined as the capacity of a contaminant to cross an organismâ s cellular membrane, or how arsenicâ s form (dissolved vs. non-dissolved) can affect bioavailability. This dissertation addresses the effect of speciation and form on As bioavailability through a combination of field and laboratory studies. In the first project, a poultry litter application experiment was conducted to determine if trace elements (As, Cu, and Zn) are released from litter to underlying soil water, and if so, whether the trace elements are present in dissolved form or complexed to nanoparticles, colloids, or particles. Results showed that Cu and Zn released from the litter were dominantly complexed to organic matter or to iron oxides/clay particles, while As was dominantly dissolved or complexed to organic matter. In the second project, a luminescent E. coli bioreporter was created and exposed to different As species, including As(III), As(V), MSMA, and roxarsone. Results showed variable response, with As(III) producing the strongest response, followed by As(V) and MSMA; roxarsone showed no response. The bioreporter was exposed to As solutions with varying cation concentrations to examine the impact of sample geochemistry on performance. Increased monovalent (Na,K) concentrations enhanced luminescent response, while increased divalent (Ca) concentrations inhibited response. These altered responses reflect different As uptake pathways into the cell. The third study addressed bioavailability of As species to Corbicula fluminea, a clam commonly used for biomonitoring. Results demonstrate that As(III) is most bioavailable to Corbicula, followed by As(V), MSMA, and roxarsone. Corbicula also displayed the ability to change As speciation through internal processing and via their shell, demonstrating that Corbicula can affect As speciation in solution. Results of these studies enhance the scientific knowledge of how speciation and form affect As bioavailability, and can also inform regulators who use bioavailability to set remediation goals for As-contaminated systems.en
dc.publisherVirginia Techen
dc.relation.haspartDiesel_EA_D_2011.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectarsenicen
dc.subjectorganoarsenicalen
dc.subjectbioavailabilityen
dc.subjectspeciationen
dc.subjectE. colien
dc.subjectC. flumineaen
dc.subjectcolloiden
dc.subjectnanoparticleen
dc.titleThe Effect of Speciation and Form on the Bioavailability of Arsenic: Insight into the Behavior of Arsenic in Natural Watersen
dc.typeDissertationen
dc.contributor.departmentGeosciencesen
dc.description.degreePh. D.en
thesis.degree.namePh. D.en
thesis.degree.leveldoctoralen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.disciplineGeosciencesen
dc.contributor.committeechairSchreiber, Madeline E.en
dc.contributor.committeememberVikesland, Peter J.en
dc.contributor.committeemembervan der Meer, Janen
dc.contributor.committeememberHochella, Michael F. Jr.en
dc.contributor.committeememberRimstidt, J. Donalden
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-02182011-142724/en
dc.date.sdate2011-02-18en
dc.date.rdate2011-03-15en
dc.date.adate2011-03-15en


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