Date of Award

5-2018

Degree Type

Thesis

Degree Name

Master of Science in Environmental and Ecological Engineering

Department

Civil Engineering

Committee Chair

Ernest R. Blatchley III

Committee Member 1

Amisha Shah

Committee Member 2

Chad Jafvert

Abstract

Disinfection byproducts (DBPs) generated from the chlorination of natural organic matter (NOM) represent a source of concern related to drinking water quality. Vacuum-ultraviolet (VUV <200 >nm), irradiation can be an efficient advanced oxidation process (AOP), has been documented to inactivate pathogens as well as remove micropollutants in drinking water. To compare the effects of VUV and UVC irradiation, four trihalomethanes (THMs) and three chloramines, chloroform (CHCl3), dichlorobromomethane (CHBrCl2), dibromochloromethane (CHBr2Cl), bromoform (CHBr3), monochloramine (NH2Cl), dichloramine (NHCl2) and trichloramine (NCl3), were prepared and analyzed for their degradation reaction rate constant under UVC, VUV/UVC, UVC/Cl2, VUV/UVC/Cl2 processes. A mini-fluidic VUV/UVC photoreaction system (MVPS) was connected directly to a membrane introduction mass spectrometry (MIMS) for many of these experiments to quickly quantify volatile DBPs dynamic behavior. VUV-UVC absorption spectra (180-300 nm) were measured four THMs. THMs and chloramines were found to be degraded faster by VUV irradiation than by UV irradiation. CHBr3 and NCl3 were the fastest degraded compound among THMs and chloramines, respectively. In addition, degradation of total THM as well as trihalomethane formation potential (THMFP) generated from the chlorination of humic acid in the presence of bromide with UVC or VUV irradiation were examined; therefore, specific THM species were also quantified and summarized. Finally, 77% reduction in THMFP was observed in VUV/UVC/Cl2 process and 82% reduction in total THMs was observed in VUV/UVC process.

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