Examination of Measurement Techniques Used for Current and Emerging UV Treatment Technologies

Abstract

A rapid monitoring technique for UV disinfection and the impact that characterizing UV-LED based collimated beam apparatuses has on computed inactivation rates were studied. A biomass recovery method was developed to monitor UV disinfection efficacy using adenosine triphosphate (ATP). ATP quantification immediately before and after UV treatment, which takes only minutes, shows little reduction in the microbial population. The biomass recovery method incorporates an incubation step to encourage life cycling of microbes and allows for quantification of UV disinfection using an ATP assay in 4 hr. UV-LEDs are inherently different then traditional mercury-based technologies. This study found that inactivation rates of E. coli were underestimated when a radiometer was used to determine average intensities. A protocol which accounts for the inherent differences of UV-LEDs was developed to more accurately determine UV inactivation rates. Overall, two new methods are presented to further the ability to monitor and research UV based technologies.