Formation and Stability of Ozonation By-Products in Drinking Water

EPA Grant Number: R826833
Title: Formation and Stability of Ozonation By-Products in Drinking Water
Investigators: Weinberg, Howard S.
Institution: University of North Carolina at Chapel Hill
EPA Project Officer: Nolt-Helms, Cynthia
Project Period: November 1, 1998 through October 31, 2001
Project Amount: $441,261
RFA: Drinking Water (1998) RFA Text |  Recipients Lists
Research Category: Drinking Water , Water


A project is proposed that will study a wide-range of by-products resulting from the combined use of ozone (as a pre-oxidation treatment) with terminal disinfectants chlorine and chloramine. This study will first investigate new methodologies for targeting as yet unidentified by-products and then apply these as well as refined existing techniques for studying the impact of water quality parameters on the formation and stability of these compounds in distributed drinking waters. The objectives are, therefore, to investigate the relative occurrence of these by-products in treated drinking waters, and to determine water quality, treatment, and distribution system conditions which influence their relative concentrations. Their kinetics of formation and stability need to be characterized and in order to understand the underlying causes of the relative differences in by-product formation in different waters, a controlled study needs to be conducted in which the various contributory factors are investigated.


The pool of identifiable by-products resulting from the combined use of ozone and post-disinfectant will be expanded by targeting compounds observed in the literature from laboratory studies on synthetic solutions containing natural organic matter (NOM) in a variety of treatment scenarios. This research will utilize a combination of in-situ derivatization techniques in combination with solid phase extraction (particularly micro-extraction) to target a broad range of polar by-products produced by ozonation that might be subsequently chlorinated by post- disinfectant. Positive identification will be achieved by a combination of complimentary spectroscopic tools. Once the target by-products are established, studies of their formation and stability will be conducted both on a bench-scale and in the field, at actual full-scale treatment plants and their respective distribution systems. The study will have three components: (1) development of analytical methods for new ozonation by-products; (2) bench-scale, controlled, laboratory ozone/chlorination and ozone/ chloramination study using waters with differing NOM characteristics from different regions of the U.S. and ozonated/disinfected under a variety of solution conditions: (3) a full-scale plant study to assess the distribution and speciation of by- products in a variety of different waters from geographically diverse regions, with differing water quality, treatment, and distribution system characteristics.

Expected Results:

This study will rigorously evaluate new procedures for the identification of polar by-products and brominated by-products of ozonation and their subsequent products resulting from post-disinfection with either chlorine or chloramine. Using quality assured procedures, the results generated by the bench-scale studies will assess the impact of various water quality and treatment characteristics on by-product formation and stability under controlled conditions in different types of waters. These results will aid in the interpretation of the findings in the full-scale plant studies and provide a thorough understanding of the factors affecting by-product formation and distribution in drinking water.

Publications and Presentations:

Publications have been submitted on this project: View all 18 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 1 journal articles for this project

Supplemental Keywords:

disinfection, exposure, organics, analytical methods, ozonation., RFA, Scientific Discipline, Water, Environmental Chemistry, Chemistry, Analytical Chemistry, Drinking Water, alternative disinfection methods, public water systems, water quality parameters, exposure and effects, disinfection byproducts (DPBs), exposure, stability, community water system, chlorine-based disinfection, treatment, chloramines, water quality, DBP risk management, drinking water contaminants, water treatment, formation, drinking water system

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Progress and Final Reports:

  • 1999 Progress Report
  • 2000 Progress Report
  • Final Report