Swimmers introduce organic and mineral compounds into the water which react with the chlorine to give unwanted by-products: among them are the chloramines. A part of these chloramines are volatile, especially the nitrogen trichloride (NCl3). This molecule is responsible for numerous problems of health (irritations, respiratory ailments, eyes, skin and mucous membranes get irritated) among the various users (competitive swimmers, swimming babies, lifeguards, etc.).
Some countries have limitated to limit NCl3 to some limit in the air (i.e. 0.3 – 0.5 mg/m3). To maintain quality of water and optimal air conditions below regulatory limit values, pool managers have different ways to decrease the chloramines such as adding fresh water, hyper chlorinating, mono per sulfate treatment, and expensive ozonation. To eliminate these by-products of disinfection the treatment through UV is widely used today. Devices equipped with medium pressure lamps are the most effective to reduce all the chloramines, in parlticular the NCl3.
Chloramines in water are to values lower than 0.2mg/liter and NCl3 can be decreased up to 30%. THe quality of the water and the air is improved. The water consumption of swimming pools is optimized while maintaining quality of water and air.