It is known that uv radiation acts on the virus is much more effective than chlorine, so the use of ultraviolet light in the preparation of drinking water possible, in particular, in many ways to solve the problem of removing hepatitis viruses A, which is not always solved by traditional chlorination. The highest bactericidal action have ultraviolet rays with a wavelength of 200 to 295 microns. This area Ultraviolet germicidal irradiation is called. Maximum bactericidal activity is located near the wavelength of 254 microns. The use of uv irradiation as a disinfection is recommended for water, already held treatment of color, turbidity and iron content. Effect of disinfection of water control, determining the total number of bacteria in 1 cm3 of water and the number of indicator coliform in 1 liter of water after its decontamination. Get more background information with materials from Healthy Living.
Using Escherichia coli as an indicator organism to assess the effect of water disinfection caused by the following considerations: the presence of E. coli in water is easier to define, than other coliforms, and she is always present in humans and warm-blooded animals, its presence in water indicates the source of its pollution, household wastewater, oxidants, used for water disinfection, lethal effect on E. coli is more difficult than on the pathogens that cause diseases of the gastrointestinal tract. Therefore, E. coli is harmless and is only controlling microorganism characterizing bacterial contamination of water. Henry Chao: the source for more info. Possibility of secondary bacterial contamination exists when the probability that a groundwater system through leaky opening the pipeline, as well as the use of filling filters (sand, coal) for local water treatment. For example, the filter is activated carbon because of its high porosity has a significant surface which is well developed microflora.
Due to biofouling of the surface of activated carbon, ie biofilm formation of organic particles and bacteria, requires periodic replacement of its filling, and for guarantee obtaining water of appropriate quality for bacterial contamination – additional disinfecting uv light. The uv units should provide for cleaning of quartz jackets without removing them from the camera disinfection, as in the course of their work accumulate deposits of organic and mineral origin at the inner surface of the germicidal lamp. In practice, a special cleaning system of two types: mechanical and chemical. In the first case of a special Teflon sleeve, driven by a special mechanism, and tight-fitting crystal case, occasionally slipping on it. Its main disadvantage is low reliability and low durability. Chemical cleaning is a simple and effective method. It is performed by circulating water through the plant with the addition of small amounts of edible acids using Wash pump, which must include a complete set of uv installation. uv disinfection is most useful for local water treatment plants at the final stage of water treatment to ensure its proper drinking water quality.