Ozone is very useful for the purification of industrial effluents from various industries. The use of ozone in the oxidation of these waters increases their biodegradability as well as decreases the concentration of total organic carbon in them. Ozone has many properties: microbicidal, bactericidal, virucidal, fungicidal, sporicidal, deodorant, oxygenating … Like chlorination systems, it is at the end of the purification process.