Ultraviolet disinfection



UV lamps designed for water disinfection use a gas mixture containing the element mercury (Hg). The Mercury vapour is an advantageous gas for UV disinfection applications because it emits light in the germicidal (‘germs killing’) wavelength range (UVC and UVB).

The light output depends on the concentration of mercury atoms, which is directly related to the mercury vapor pressure. Mercury at low vapour pressure produces essentially monochromatic (single wavelength) UV light at 253,7 nm; this occurs in low-pressure UV lamps. At higher vapour pressures, the frequency of collisions between mercury atoms increases, producing UV light over a broad spectrum, so-called polychromatic (more wavelengths) medium-pressure lamps with an overall higher intensity.

UV light in the UV spectrum between 200 – 400 nm damages the genetic matter (DNA and RNA) and other molecules inside a micro-organism. The damage ‘kills’ the specific micro-organism because it can no longer reproduce.

Bacteria, protozoa, viruses, fungi, algae are all sensitive to exposure to UV light. Because of differences in their shape and structure, their “killing” wavelength varies.

UV light disinfection adds no chemicals and leaves no residuals in the water. This presents a huge advantage over chemical disinfection methods.

Disinfection with UV light is proven to be effective and very friendly to the environment and humans.
