AWWA WQTC56938

Ultraviolet light (UV) has been receiving increased attention in the drinking water industry for disinfection and oxidation applications. Many water utilities that use Lake Michigan as a source water have experienced taste and odor problems for the past several years. In an effort to control taste and odor, the application of UV treatment was examined. Destruction of geosmin and MIB was not very effective using either low-pressure or medium-pressure UV alone. These results were not unexpected given the fact that neither geosmin nor MIB absorb light significantly in the range where the UV lamps emit most strongly. However, under UV/H2O2 advanced oxidation, MIB and geosmin were reduced from 25 and 10 ng/L respectively, to non-detectable levels at a peroxide dose of 2 mg/L and UV doses of ~1000 and <300 mJ/cm2, respectively. In the presence of peroxide, MP UV was more effective at degrading the taste and odor causing compounds than LP UV. The results from this research show that taste and odor causing compounds can be effectively treated using UV based processes, thus adds to the knowledge base that is required for utilities to make effective treatment process decisions. However, for water utilities to utilize a UV/H2O2 advanced oxidation process for taste and odor removal, several challenges remain including quenching of the initial hydrogen peroxide dose remaining after treatment and the relative costs associated with high UV doses for large-scale treatment of water. Includes 6 references, tables, figures.