Performance and Analysis of Tracer Studies to Determine Compliance with the Disinfection Requirements of the Surface Water Treatment Rule
Public Deposited- Last Modified
- February 28, 2019
- Creator
-
Teefy, Susan M.
- Affiliation: Gillings School of Global Public Health, Department of Environmental Sciences and Engineering
- Abstract
- The Surface Water Treatment Rule includes disinfection requirement which will apply to all water systems using surface water sources. One objective of this project was to conduct tracer studies at selected water treatment plants in order to determine the residence time distributions of various process units. The plants were evaluated to determine whether they will be able to comply with the disinfection requirements of the Surface Water Treatment Rule. CT's, the Concentration of disinfectant multiplied by the Time it is in contact with the water, were determined for each plant under different conditions. These were compared to CT values supplied by the Environmental Protection Agency for specific degrees of pathogen inactivation. A second objective was to develop a more precise method for estimating the CT. This theoretical construct, the "effective CT", made use of the residence time distributions and the kinetics of chlorine decay to more accurately predict the degree of pathogen inactivation as expressed by the chlorine concentration multiplied by the contact time. All three of plants studied will be able to meet the disinfection requirements of the Rule. As demonstrated by comparing the "effective CT's" to the CT's allowed by the Surface Water Treatment Rule, a substantial margin of safety is implied in the degree of inactivation allowed by the Rule. Problems were discovered with using fluoride as a tracer in the presence of aluminum hydroxide; sodium was demonstrated to be a more effective tracer.
- Date of publication
- December 1989
- DOI
- Resource type
- Rights statement
- In Copyright
- Advisor
- Singer, Philip
- DiGiano, Francis A.
- Sobsey, Mark
- Degree
- Master of Science in Environmental Engineering
- Academic concentration
- Water Resources Engineering
- Degree granting institution
- University of North Carolina at Chapel Hill
- Graduation year
- 1989
- Language
- Deposit record
- ad7e9272-7c4f-43e0-afeb-7a5f2526ad76
Relations
- Parents:
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