Because of its excellent disinfection and oxidation qualities, ozone is widely used for drinking water treatment. Ozone can be added at several points throughout the treatment system, such as during pre-oxidation, intermediate oxidation or final disinfection. Usually, it is recommended to use ozone for pre-oxidation, before a sand filter or an active carbon filter (GAC). After ozonization these filters can remove the remaining organic matter (important for final disinfection).
Ozone is the triatomic form of oxygen, this is it is composed of three oxygen atoms. Ozone's chemical symbol is O3. Under normal conditions ozone is unstable and quickly decomposed to the more stable gaseous oxygen, O2. Because ozone is unstable and cannot be stored successfully, it must be generated at the point of application.
This combination has several benefits: