Practical Tools for Disinfection Byproduct Mitigation in Drinking Water Utilities

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.