During chlorination, a pump feeds chlorine into the water. Chlorine has a residual effect, which means it works for a while after being added to the water. But if the system is not operated properly, it is expensive and possibly toxic. Also, chlorination byproducts may be harmful. 45N. Ultraviolet radiation removes bacteria and other microbiological contaminants.
Water passes a special light bulb where ultraviolet radiation kills contaminants.
However, this system may not work effectively in cloudy water or when the water flow is too fast. Also, unless the unit is equipped with a special meter, it is hard to know whether the system is doing the job. UV units do not have a residual effect, as chlorination does. It also removes hydrogen sulfide and dissolved iron and manganese when followed by mechanical filtration or an activated carbon filter. With ozonation, water is exposed to ozone gas, which destroys microorganisms.