UV disinfection of drinking water - how does it work?


Germs in drinking water can be very dangerous. UV radiation offers a very good and easy way to sterilize drinking water. How this technology can be used in the home and on the go is explained here.

Disinfecting properties of UV radiation

Ultraviolet light is divided into different types of radiation:

  • UV-A radiation (near UV or black light)
  • UV-B radiation (medium UV light) and
  • UV-C radiation
  • EUV radiation (extreme UV)

All types of radiation differ with regard to their wavelength and thus their photon energy.

In particular, UV-A radiation with its wavelength of 380 - 315 nm is very dangerous for living organisms and deadly in intensive action. Inactivation of microbes takes place during water disinfection by UV within fractions of a second.

Advantages of UV disinfection

With sufficient radiation dose, the method is completely reliable. However, existing turbidities or suspended solids in the water should first be filtered out as much as possible, or the radiation dose must be increased accordingly.

Chlorine-resistant pathogens can also be combated by UV disinfection. There are no mutations and no resistance. Many pathogens are now resistant to a variety of chemical disinfectants already in some strains.

In UV disinfection, there are no additions of potentially dangerous chemicals that can accumulate in the water. Odor, taste and pH of the water remain unchanged.

Practical use

Household and business

In the household and for companies there are so-called disinfection systems. They consist of low-pressure mercury vapor lamps which emit an adjustable amount of radiation. The systems are extremely compact and easy to install.

The flow rate for household systems is usually in the range of about 4 m³ per hour, but systems with flow rates up to more than 500 m³ / h are also possible.

On the way and outdoors

With the Steripen water can also be easily sterilized using a handy, pen-shaped device. The devices are intended primarily for the outdoor area. For the purification of the water but additionally a filter for possible chemical substances should be used.

SODIS procedure

The SODIS process was developed for the production of drinking water in the Third World, but is also suitable for outdoor use. Here, the UV radiation of the sun, which acts on a PET bottle used. The process is time consuming but also highly effective and very cost effective.

Tips & Tricks

To inactivate viruses, a frequency of 254 nm is often used in addition. It works primarily on viruses and less on proteins.


Video Board: UV Water Filter & Purification Systems How They Work - FreshWaterSystems.com