UV disinfection

UV disinfection

An environmentally friendly and easy-to-handle method is irradiating water with ultra-violet light (UVC). UV irradiation is permitted according to the German regulation on drinking water TrinkwV (Sec. 11, para. II Disinfection methods) and eliminates bacteria and viruses reliably.

UV light is invisible light with a wavelength of 200 to 400 nm. Light is an electromagnetic wave whose energy is defined by the wavelength. The shorter the wavelength, the higher the energy. UV light is divided by wavelength in UVA, UVB, and UVC irradiation. For UV disinfection, the irradiation with the shortest wavelength and the highest energy, i.e., the UVC light is important. Its wavelength is 200 nm to 280 nm. Maximum efficiency is achieved at a wavelength of 254 nm, since at this point the absorption curve of nucleic acid and the irradiance of the low pressure UV lamps have a common maximum.

The irradiation triggers a photochemical reaction inside the micro-organism's nucleus that destroys the genetic information. Multiplication by cell division is then impossible and the micro-organisms die off. UV disinfection does not contaminate the water with chemical waste products; it is completely harmless and impacts neither odour nor taste of the water. Furthermore, the irradiated micro-organisms cannot develop any resistance.

Herco specialists will gladly consult you and help with the layout of your installation.


Reliable disinfection of the water by ultraviolet light irradiation. Viruses and bacteria are treated in the wavelength range from 200 to 280 nm. UV disinfection by Herco is environmentally friendly and completely harmless to the quality of the water.