Ultraviolet (UV) disinfection is a non-chemical process whereby a pathogen, contained within a liquid or gaseous medium or present on a surface, is exposed a dosage of ultraviolet radiation near the peak of germicidal effectiveness, being 265 nanometres (nm), resulting in the deactivation of the pathogen's DNA, such that the pathogen is unable to reproduce. Pathogens include bacteria, viruses and fungi.
In simpler terms, exposure of a particular disease causing organism to ultraviolet light having a specific wavelength, intensity, and duration, will prevent the organism from reproducing.
Generation of Germicidal UV Light
Mercury vapour lamps emit an invisible wavelength of ultraviolet light at 253.7nm. This wavelength is very close to 265nm which is the wavelength of peak germicidal effectiveness. Purgo EnviroTech uses low pressure, Amalgam lamps, exclusively in its UV products, as this lamp technology sustains relatively constant lamp output over a 4°C to 40°C temperature range, while maintaining high operating efficiency and extremely long lamp life.
Advantages of UV Disinfection
Unlike most chemical disinfectants, ultraviolet disinfection does not produce any toxic byproducts like those produced when chlorine is used as a disinfectant in drinking water applications. Furthermore, UV does not alter the taste of the water or introduce odor, nor does it remove any beneficial mineral content. UV disinfection is also extremely safe as there are no toxic chemicals to transport or store as in the case of chlorine.
There are also no residuals produced by the UV disinfection process. This lends well to disinfection in the food and beverage industries as well as air disinfection.
In this era of environmental consciousness, Ultraviolet Disinfection is finding its way into more and more applications due to it being a "green" technology that helps to preserve the natural environment.