UBC Theses and Dissertations
Evaluation of the removal of disinfection by-products precursors in Seymour water with ozone, UV and the advanced oxidation process ozone-UV Chin, Adeline S.
This research evaluated the treatment potential of ozone (O3), ultraviolet irradiation (UV) and the combined O3-UV advanced oxidation process (AOP) in the removal of two classes of disinfection byproduct (DBP) precursors (quantified as the trihalomethane formation potential (THMFP) and haloacetic acid formation potential( HAAFP)) from water samples obtained from the Seymour Reservoir near Vancouver, Canada. The water from this source, which provides 40% of the drinking water for the Greater Vancouver Regional District, is characterized by low pH (6.4) and low total organic carbon (1.3 — 3.3mg/L) . Laboratory batch scale experiments were carried out at various UV and O3 dosages in order to monitor the reaction kinetics. The combined O3-UV treatment significantly reduced the concentration of both DBP precursors. The reduction is attributed to the mineralization of the total organic carbon (at a rate of 0.044±0.02 minute- 1) and changes in organic constituents (~ 78% decreased in UV254 absorbance). After 30 minutes of O3-UV treatment, THMFP and HAAFP were reduced by approximately 80% and 70%, respectively. Ozone treatment alone provided roughly 50% reduction of both THMFP and HAAFP after 30 minutes of ozonation. Therefore, the O3 treatment proved not to be as effective as the combined O3-UV AOP. Ultraviolet treatment alone proved to be relatively ineffective in reducing the concentrations of the DBP precursors studied. These results indicate that the combined O3-UV AOP is a useful treatment option that could be implemented to reduce the concentration of DBP precursors in Seymour's water.
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