What is Ultraviolet Disinfection?
Ultraviolet light is radiation that lies between the X-ray region and visible region on the electromagnetic spectrum. UV ranges from 200 nanometers (nm) to 390 nm. Optimally, germicidal action occurs at 260 nm. UV is produced through the conversion of electrical energy in a low-pressure mercury vapor quartz lamp. Electrons flow through the ionized mercury vapor between the electrodes of the lamp, which then create UV light. UV disinfection can kill or render harmless microorganisms such as bacteria, viruses, algae and protozoa. The process consists of the UV light breaking through the cell wall and cytoplasmic membrane, rearranging the DNA and rendering the microorganism harmless. Proper pretreatment must be used to effectively destroy microorganisms to a 99.9 % kill rate. UV does not leave any residuals, so it should be located as close as possible to the final distribution system. Any water treatment device installed downstream of the UV system could recontaminate the water. UV syste
