Ultraviolet (UV) treatment is the disinfection process of passing water by a light source which produces UV light at a specific wavelength which is known to inactivate harmful micro-organisms. In nature, the Sun provides the critical wavelength as part of its total radiation.
The effective wavelengths for disinfection lie within the UV-C band of the spectrum, with the most effective wavelength being 254nm.
Specialized UV lamps are housed in a protective quartz sleeve, usually within an enclosed vessel and the water being treated flows passed the light source. The UVC is absorbed by the DNA of micro-organisms, interfering with DNA replication and cell reproduction.
This method of water disinfection is rapidly growing in popularity because it does not necessarily require the addition of chemicals. UV treatment does not alter the water chemically, and the inactivated organisms are not removed – they simply cannot reproduce.
In many countries UV is becoming the most common means of disinfection because of concerns about the long term impact of chlorine in chlorinating residual organics in wastewater and in the chlorinating organics in receiving water.
Swimming Pool Applications
The most unpleasant organisms commonly found in swimming pools are humans. The organic compounds which they emit, secrete, or wash off in the pool water react with the chlorine we commonly add for disinfection to produce nasty chloramines which can give a pool that typical "chlorine" smell. These compounds are also responsible for eye, ear and throat irritations that commonly occur in public bathing facilities. UV radiation breaks down these compounds in swimming pools and spas resulting in a more pleasant swim, less irritation and smell, and less damage to pool infrastructure.
