title: Changes in dissolved organic matter fluorescence and disinfection byproduct formation from UV and subsequent chlorination/chloramination.
abstract: Ultraviolet (UV) irradiation is being increasingly used to help drinking water utilities meet finished water quality regulations, but its influence on disinfection byproduct (DBP) precursors and DBP formation is not completely understood. This study investigated the effect of medium pressure (MP) UV combined with chlorination/chloramination on the fluorescent fraction of dissolved organic matter (DOM) isolated from a United States surface water with median total organic carbon content. Parallel factor analysis was used to understand how UV may alter the capacity of DOM to form DBPs of potential human health concern. The production of chloral hydrate and cyanogen chloride from MP UV followed by chlorine or chloramine, respectively, correlated with a decrease in fluorescence intensity of a protein/tryptophan-like component (R(2)=0.79-0.99) and a humic-like component (R(2)=0.91-1.00). This suggests that the UV-induced precursors to these compounds originated from DOM with similar characteristics to these components. The fluorescent DOM components identified in this study are similar to reoccurring components that have been previously identified in a range of raw and treated waters, and this work demonstrates the value of using fluorescence analysis of DOM to understand the relationships between DOM source and DBP formation under a range of treatment conditions.
authors: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, 146 Rosenau Hall, Chapel Hill, NC 27599, United States.
authors: Bonnie A
authors: BA
authors: Lyon
authors: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, 146 Rosenau Hall, Chapel Hill, NC 27599, United States.
authors: Rose M
authors: RM
authors: Cory
authors: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, 146 Rosenau Hall, Chapel Hill, NC 27599, United States. Electronic address: howard_weinberg@unc.edu.
authors: Howard S
authors: HS
authors: Weinberg
mesh_terms: D002700:Chloramines / Q000737:chemistry*; D002713:Chlorine / Q000737:chemistry*; D004203:Disinfection; D005453:Fluorescence; D015386:Hazardous Substances / Q000032:analysis*; D014466:Ultraviolet Rays; D018508:Water Purification
chemical_list: D002700:Chloramines; D015386:Hazardous Substances; D002713:Chlorine
keywords: Disinfection byproducts; Dissolved organic matter characterization; Fluorescence spectroscopy; Parallel factor analysis; Ultraviolet treatment