Browsing by Author "Vines, Melanie"

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    Practical Tools for Disinfection Byproduct Mitigation in Drinking Water Utilities
    (University of Alabama Libraries, 2023) Vines, Melanie; Terry, Leigh G
    Drinking water treatment is crucial to protecting public health. The disinfection of drinking water with chlorine-based disinfectants prevents many waterborne illnesses and is widely considered to be one of the greatest public health advancements of the 20th century. However, these chlorine-based disinfectants react with organic matter and other constituents naturally present in source waters to create disinfection byproducts (DBPs), some of which pose a risk to public health. While over 600 DBPs have been identified, the classes of trihalomethanes (THMs) and haloacetic acids (HAAs) are regulated by the United States Environmental Protection Agency (USEPA) due to their prevalence and suspected carcinogenicity. While the Disinfectants and Disinfection Byproducts Rule has been in its current state since 2006, many utilities still struggle to stay in compliance.This dissertation focuses on three research goals surrounding the prevention and mitigation of DBPs, for which an introduction is given in Chapter 1. The first goal is to use fluorescence spectroscopy to evaluate organic matter removal via biological filtration (biofiltration) for drinking water treatment. Thus, Chapter 2 presents the results of a bench-scale biofiltration study which examined three source waters with varying organic matter character under different biofiltration operating parameters. The second goal is to determine the removal of pre-formed HAAs in a combined granular activated carbon (GAC) adsorbing filter and anthracite-based biological filter. For this purpose, Chapter 3 discusses the removal of HAAs from bromine-spiked tap water by the combined filter system. The third goal is to assess the efficacy of magnetic ion exchange (MIEX) treatment for removing DBP precursors. Chapter 4 presents the results from a comparison study between a pilot-scale conventional treatment train with MIEX pretreatment and a full-scale conventional treatment train without MIEX pretreatment. Finally, Chapter 5 summarizes the main conclusions of the studies conducted for this dissertation and discusses suggestions for future research for utilities to prevent and mitigate DBP formation.
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    Utilizing tree ring chronologies to reconstruct paleo streamflow: a case study at the alabama-florida state border
    (University of Alabama Libraries, 2020-12) Vines, Melanie; Terry, Leigh; University of Alabama Tuscaloosa
    This study examined the results from a statistical screening of tree-ring width records to evaluatethe strength of the hydrological signal in dendrochronological records from the Southeastern region of the United States. We used United States Geological Survey (USGS) streamflow data from five gages near the Alabama-Florida border and 74 regional tree-ring chronologies to create and analyze seasonal flow reconstructions. Prescreening methods included correlation and temporal stability analysis of predictors to ensure practical and reliable reconstructions. Seasonal correlation analysis revealed that several regional tree-ring chronologies were significantly correlated (p≤0.05) with March–October streamflow, and stepwise linear regression was used to create the reconstructions. Reconstructions for all five rivers were considered statistically skillful (R2≥0.50), with lengths ranging from 144 to 782 years. The reconstructions were statistically validated using the following parameters: R2 predicted validation, the sign test, the variance inflation factor (VIF), and the Durbin-Watson (D-W) statistic. The long-term streamflow variability was analyzed for the Choctawhatchee, Conecuh, Escambia, and Perdido Rivers and the recent (2000s) drought was identified as being the most severe in the instrumental record. The 2000s drought was also identified as being one of the most severe droughts when compared to the paleo-records developed for all five rivers.