CAREER: BrCl and Other Highly Reactive Brominating Agents in Disinfected Waters: Implications for Disinfection By-Product Formation and Control

Towson University, Towson MD

Investigators

Abstract

Title: CAREER: BrCl and Other Highly Reactive Brominating Agents in Disinfected Waters: Implications for Disinfection By-Product Formation and Control PI Name: John D. Sivey Proposal Number: CBET - 1651536 Bromide is present in virtually all natural waters. When these waters are disinfected prior to use as drinking water or in swimming pools, bromide can be converted into several highly reactive brominating agents. The primary objective of this project will be to understand how these brominating agents can react with naturally occurring organic compounds to generate potentially toxic disinfection by-products. In the educational outreach program sixth-grade math students will explore how linear functions are essential to science and engineering. The overarching goal of this program will be to use inquiry-based, hands-on water chemistry activities to help sixth-grade students connect the mathematics they are learning to real-world scientific questions and careers. The reactive bromine species in chlorinated drinking water is typically assumed to be HOBr; nevertheless, several additional bromine species can readily form when bromide-containing waters are disinfected with chlorine, including BrCl, BrOCl, and Br2O (collectively, BrX). Despite being highly reactive toward a range of organic compounds, the influence of BrX on formation of brominated disinfection byproducts (DBPs) has received little attention. This project will quantify the influence of individual BrX species on formation rates, yields, and product distributions of several classes of DBPs, including trihalomethanes, haloacetic acids, halophenols, and halosalicylic acids. Humic acid, natural organic matter surrogates, and natural surface waters will serve as sources of organic DBP precursors. Experimental data will be used to develop models describing the effects of bromine speciation on DBP formation. By evaluating the influence of bromine speciation on DBP formation, the PI will seek to improve our understanding of DBP generation and control measures. As human activities, population growth, and climate change increase halide levels in drinking water (which can, in turn, promote formation of BrX), the importance of understanding bromination processes will be particularly acute. Increased understanding of DBP chemistry will promote societally relevant outcomes, notably the sustainability of drinking water supplies as well as environmental stewardship of other disinfected aqueous systems (e.g., wastewater, ballast water, desalination systems, and swimming pools). The educational component of this project will involve an interdisciplinary K-12 outreach program, entitled "The Mathematics of Color and Light." This program will deliver hands-on, inquiry-based learning activities to sixth-grade math students and will emphasize concepts of light absorption and linear functions. The program will emphasize the role of bleach in water treatment. High school science students, undergraduate researchers, and K-12 teachers will serve as co-facilitators of this program. In total, this project will impact approximately 600 middle school students, 60 high school co-facilitators, several K-12 teachers, and 12 undergraduate students over five years.