Water Sterilization Using Power UV LEDs

Abstract

This paper presents the process of sterilizing water with help of ultraviolet lights of a certain wavelength. This sterilization of water destroys bacteria and microorganisms in the water because their DNA absorbs UV light, so they can no longer reproduce. Absorption in DNA has a peak at 254nm. For sterilization to be fast and efficient, a power LED is needed, but there are no LEDs available on the market that are accessible at this wavelength. For this reason, this application uses a power LED of 365nm, and one of 420nm, so we can compare their power to clean the water of bacteria. The water samples resulting from the tests performed were analyzed at a specialized laboratory. Thus, the final measurements showed that this type of setup can be used as water sterilizer. The 365nm LED achieved an efficiency of 15.4%, while the 420nm LED achieved an efficiency of 10.5%. This shows that the absorption of UV light is higher at shorter wavelengths. The efficiencies of the LEDs were calculated after exposing the water probes to the UV light for 5 minutes.