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dc.contributor.advisorBurbey, Thomas J.en_US
dc.contributor.advisorRimstidt, J. Donalden_US
dc.contributor.advisorSchreiber, Madelineen_US
dc.contributor.authorWalker, Forest P.en_US
dc.date.accessioned2011-08-06T16:01:24Z
dc.date.available2011-08-06T16:01:24Z
dc.date.issued2004-04-20en_US
dc.identifier.otheretd-04212004-201854en_US
dc.identifier.urihttp://hdl.handle.net/10919/9881
dc.description.abstractThe objective of this study is to use a mixed flow reactor system to determine the dissolution rate and infer potential mechanisms of arsenopyrite (FeAsS) oxidation by dissolved oxygen at 25°C and circumneutral pH. Release rates for iron, arsenic and sulfur are calculated for a variety of initial dissolved oxygen (DO) concentrations. Results indicate that the rate of arsenopyrite oxidation, represented by the rate law r = A(6.76 x 10-11) where the rate, r, is in mol/s and surface area, A, is in m2, is not significantly dependent on DO concentration. Arsenic and sulfur are released in a 1:1 molar ratio while iron is released more slowly due to precipitation of iron oxyhydroxides. Our results suggest that the rate determining step in arsenopyrite oxidation is determined by the attachment of oxygen at the anodic site in the mineral, and not the transfer of electrons from the cathodic site to oxygen, as is suggested for other sulfide minerals such as pyrite. Previous work on FeAsS oxidation has been limited to low pH conditions with ferric iron as the oxidant. However, not all arsenopyrite weathering occurs exclusively in acidic environments. For example, at an abandoned arsenopyrite mine in Virginia, the pH of ground and surface waters is consistently between 4 and 7. Results of this study provide important insight to arsenic mobilization processes and rates, at field-relevant conditions, consequently aiding in the effort to understand arsenic release and retention in the environment.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.relation.haspartThesis_front.pdfen_US
dc.relation.haspartTitle_page_abstract.pdfen_US
dc.relation.haspartThesis_body_back.pdfen_US
dc.rightsThe authors of the theses and dissertations are the copyright owners. Virginia Tech's Digital Library and Archives has their permission to store and provide access to these works.en_US
dc.source.urihttp://scholar.lib.vt.edu/theses/available/etd-04212004-201854en_US
dc.subjectarsenopyriteen_US
dc.subjectarsenicen_US
dc.subjectoxidationen_US
dc.titleKinetics of Arsenopyrite Oxidative Dissolution by Oxygenen_US
dc.typeThesisen_US
dc.contributor.departmentGeosciencesen_US
dc.description.degreeMSen_US


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