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dc.contributor.authorQuesada, Ginna
dc.date.accessioned2021-12-01T20:10:02Z
dc.date.available2021-12-01T20:10:02Z
dc.date.issued2021-05
dc.identifier.urihttp://hdl.handle.net/11122/12564
dc.descriptionThesis (M.S.) University of Alaska Fairbanks, 2021en_US
dc.description.abstractPesticides used at mid latitudes can accumulate in Arctic environments. Two commonly detected pesticides in Arctic lakes are chlorothalonil and chlorpyrifos. In surface waters, photolysis can play an important role in the attenuation of contaminants. The chemical characteristics of dissolved organic matter (DOM) can further alter the extent of photolytic degradation of pollutants. To determine the relative effect of natural Arctic lake water and its DOM on the photolysis of chlorpyrifos, experiments were conducted under natural Arctic irradiation and under artificial irradiation. Similarly, the effect of Arctic DOM was investigated for chlorothalonil under artificial irradiation. The fulvic acid (FA) fraction of DOM was isolated from Fog 1 and from Toolik Lake in May and July. Lake waters significantly enhanced the photodegradation of chlorpyrifos under natural light by up to an order of magnitude. FA's significantly increased the degradation of chlorpyrifos (>2x) and chlorothalonil (>100x) under artificial irradiation relative to 18 MΩ-cm Water. Toolik Lake FA isolated in May, significantly enhanced the photolysis of both contaminants relative to the isolate collected in July. In the presence of iron, a lower ratio of carbohydrates and peptides to aromatics in the FA's was associated with faster degradation for chlorothalonil.en_US
dc.description.sponsorshipNational Science Foundationen_US
dc.language.isoen_USen_US
dc.subjectPesticidesen_US
dc.subjectBiodegradationen_US
dc.subjectChlorpyrifosen_US
dc.subjectToolik Lakeen_US
dc.subjectFungicidesen_US
dc.subjectArctic regionsen_US
dc.subjectWateren_US
dc.subjectOrganic compoundsen_US
dc.subjectFulvic acidsen_US
dc.subjectOrganochlorine compoundsen_US
dc.subject.otherMaster of Science in Chemistryen_US
dc.titlePhotosensitized degradation of chlorothalonil and chlorpyrifos in the presence of Arctic derived dissolved organic matteren_US
dc.typeThesisen_US
dc.type.degreemsen_US
dc.identifier.departmentDepartment of Chemistry and Biochemistryen_US
dc.contributor.chairGuerard, Jennifer
dc.contributor.chairRasley, Brian
dc.contributor.committeeGreen, Thomas
refterms.dateFOA2021-12-01T20:10:03Z


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