Ultraviolet water purification lamps produce ultraviolet radiation of much greater intensity than sunlight. Most ultraviolet purification systems are combined with various forms of filtration, as UV light is only capable of killing microorganisms such as bacteria, virus, molds, algae, yeast etc.
UV light provides effective inactivation of microorganisms such as bacteria, viruses, molds and pathogens without the use of chemicals. A fairly dose of ultraviolet can kill 99% of the fecal coli form and fecal streptococcus.
Why ultraviolet (UV) disinfection is use for water treatment?
Bacteria, fungi and algae are found in most surface waters. Bacteria are measured by culturing a sample and counting the colony forming units per milliliter (CFU/ml). Distillation effectively kills microorganisms, reverse osmosis removes them and UV light can control their growth. All ultrapure water systems must have a 0.2 micron or smaller absolute filter on the outlet to prevent bacteria from contaminating the ultrapure product water.