UV-LED Irradiation Technology for Point-of-Use Water Disinfection

Point-of-use water treatment has been shown to have a greater impact on public health in developing communities than treating water at the source. Ultraviolet (UV) technology is an appropriate option for water disinfection in many developing community households. It requires a low user input and disinfects at a relatively high flow rate. On the downside, current UV lamps use mercury to generate the UV radiation, may only last for 9-12 months, and are packaged in fragile glass and filament tubes. UV light emitting diodes (LEDs) may provide solutions to many of these sustainability issues. They are small and do not contain glass or mercury, aiding their transport and disposal. Warm-up time is not required for LEDs, saving energy and allowing for intermittent use - important characteristics for systems in less-developed areas.Bench-scale testing is being performed to characterize the effectiveness of UV-LEDs for pathogen surrogateE. coli. Log inactivation data appear to be in line with typical low-pressure mercury vapor lamps, if not an improvement. Information from these data will be used with mathematical modeling to determine optimal lamp configuration. A prototype is currently being tested to serve as an example of UV-LED technology for point-of-use water disinfection.