UV treatment of water is a common method of combating micro-organisms in water treatment systems. This procedure treats only bacteria that passes the UV bulb and should be regarded as a gatekeeper. This procedure gives no long-term protection.
The infected water is radiated with ultra-violet light with a wave length of 254 nm. The UV rays penetrate the cell wall and damage the genetic information of the bacteria and viruses, disrupting their reproduction systems. UV systems with low or medium pressure lamps are used to treat water. UV devices for building applications are mostly low-pressure systems.
- Effective against free bacteria floating in the water
- Does not affect smell and taste of the water
- Not sensitive to pH value of the water
- No chemicals are used
- There is no long-term effect on bacteria etc.
- Biofilm in hot water tank and pipes are not affected
- The UV bulb is very sensitive to particles and scale in the water Addition of for example acid is necessary to avoid scale precipitation
- The ultraviolet radiation system often includes activated carbon filter to remove metals and particulates
- Medium lifecycle cost