Innovative Ultraviolet Light Source for Disinfection of Drinking Water

New regulations for drinking water treatment are leading to alternatives to chlorine disinfection. As a result, the use of ultraviolet (UV) light for disinfection is growing rapidly. The disinfection capability of commercial UV systems is limited by available mercury lamp technology. Phoenix Science & Technology's innovative Surface Discharge (SD) UV lamp is a promising candidate to both improve the effectiveness and decrease the cost of UV disinfection. Phase I demonstrated the effectiveness of SD lamps at inactivating microorganisms, using three to five times less electricity than the mercury-based UV lamps. Because electricity is the largest operational cost of disinfection, use of the SD lamp can reduce cost. The SD lamp's high intensity and UV spectrum proved more effective at deactivating microorganisms than would be expected based on efficiency alone. The advantages demonstrated in Phase I may be even more important in deactivating viruses that require very high UV doses from mercury lamps. Furthermore, unlike mercury lamps, the SD lamp has no mercury or other toxic materials with environmental disposal issues. The goal of this Phase II program is to conduct research to pursue the advantages of SD lamps for UV disinfection, develop an SD UV reactor, conduct comparative UV disinfection tests with a commercial mercury lamp UV system, and establish the practicality of commercializing SD lamp UV disinfection systems. Disinfection testing will be conducted in collaboration with researchers at Duke University and with a major manufacturer of UV disinfection equipment. This Phase II will incorporate validation testing protocols outlined in the U.S. EPA guidance document on using UV for disinfection, scheduled for release late in 2002. A successful Phase II will lead to commercialization of SD UV disinfection systems.