Date of Graduation

Summer 2017

Degree

Master of Science in Chemistry

Department

Chemistry

Committee Chair

Richard Biagioni

Keywords

chlorate, chlorate formation, on-site hypochlorite generation, hypochlorite decomposition, electrochemistry, environmental chemistry

Subject Categories

Chemistry

Abstract

Drinking water is one of the fundamental pillars of modern society, and it is crucial that pathogen-free drinking water be provided to communities. Currently, one third of all drinking water in the U.S. is being disinfected using hypochlorite and the number is rising. However, use of hypochlorite is facing the issue of a hypochlorite byproduct, chlorate ion, which at high concentrations is considered a health risk to humans. During and after its electrolytic generation process, hypochlorite may go through a disproportionation reaction to form chlorate and chloride, a process which is thermodynamically favored. Even though chlorate in drinking water is not regulated yet, the EPA is in the process of regulating chlorate concentrations in the near future. Therefore, it is important to track current concentrations and put mechanisms in place to efficiently reduce chlorate concentrations in generated hypochlorite solutions as well as in drinking water. The purpose of this research was to evaluate the influence of three different parameters in the generation process: pH, temperature and storage time, and also to assess the influence of pH and temperature adjustments during the generation process. Additionally, this research should provide general guidelines on how to reduce chlorate concentrations in on-site generation processes. In all cases, chlorate was observed to increase with time, but increases were less pronounced when storage temperature was decreased and when storage pH was increased. Effects of adjusting pH and temperature during the generation process were not clearly determined in the experimental work.

Copyright

© Lukas Simon Kriem

Open Access

Included in

Chemistry Commons

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