CAREER: An Adaptive Approach to Oxidize Emerging Organic Contaminants in our Drinking Water

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

1451932 Remucal CAREER: An adaptive approach to oxidize emerging organic contaminants in our drinking water As pressure on our water resources increases in response to population growth and a changing climate, we will be forced to rely on lower quality water sources to meet our needs. In particular, our existing drinking water treatment systems are poorly equipped to deal with contamination from organic pollutants. This project will develop and optimize a chlorine photolysis advanced oxidation process that could be used to upgrade existing chlorine-based disinfection systems in response to decreased source water quality. The photolysis of chlorine, the most commonly used drinking water disinfectant in the United States, produces a series of reactive oxidants, including hydroxyl radical and ozone, which are capable of simultaneously oxidizing numerous organic compounds and inactivating chlorine-resistant pathogens. The hypothesis underlying this research effort is that the irradiation wavelengths and solution conditions (e.g., pH) in a chlorine photolysis-based advanced oxidation process can be optimized to maximize organic contaminant removal while minimizing disinfection by-product production. The research themes will be integrated into formally assessed educational initiatives that will: (1) foster enthusiasm for the field of environmental engineering by engaging K-12 and undergraduate students in a novel interactive learning environment; (2) increase the number of highly qualified students from diverse backgrounds pursuing careers related to environmental engineering and water quality; and (3) raise public awareness of water quality issues. The objectives of the research plan are to: (1) characterize the formation of reactive species during chlorine photolysis using UV light and light in the solar spectrum; (2) assess the formation of conventional disinfection byproducts during chlorine photolysis; and (3) identify changes in dissolved organic matter and the formation of novel disinfection byproducts during chlorine photolysis using two complementary state-of-the-art mass spectrometry techniques. This transformative work will provide the first systematic evaluation of chlorine photolysis for contaminant oxidation and disinfection by-product formation. Unique project outcomes will be: (1) the development of a kinetic model that can be used to predict reactive species production and target contaminant oxidation during chlorine photolysis, and (2) an increased understanding of the formation of disinfection by-products and changes in dissolved organic matter composition on a molecular level during reaction with chlorine in the presence and absence of light.