Theses and Dissertations from UMD

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New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM

More information is available at Theses and Dissertations at University of Maryland Libraries.

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Author: search.filters.author.Geis Asteggiante, Lucia GiorginaSubject: search.filters.subject.Chesapeake Bay

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    Utilizing herbicide degradation products and artificial sweeteners as stable tracers to examine agricultural and urban nutrient sources within two tributaries of the Chesapeake Bay
    (2013) Geis Asteggiante, Lucia Giorgina; Torrents, Alba; McConnell, Laura; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Eutrophication of the Chesapeake Bay has contributed to a decline in ecosystem health within the watershed. In this study, MESA (a metabolite of metolachlor) and sucralose were proposed as stable tracers that could be used to discriminate nutrient contributions from agricultural versus urban sources. Two estuaries of the Chesapeake Bay were chosen as model systems: the Choptank River (agricultural) and the Anacostia River (urban). Surface water samples were collected and analyzed for herbicides, metabolites, artificial sweeteners and nutrients. Results supported the hypothesis that sucralose is present in waterways influenced by wastewater plants, and MESA was correlated with changes in nitrate concentration in the Choptank indicating agricultural sources. This work provides proof of concept that tracers can be used in the Chesapeake Bay region to distinguish the influence of urban and agricultural nutrient loads and provides a path to better assess restoration efforts and improved allocation of total maximum daily loads.