Ozone was initially used in the treatment of drinking water, subsequently as a strong oxidizing agent for industrial production and, since the 1970s, also for water purification. Today there are dozens of different industrial applications, united by the peculiarity of ozone of being one of the strongest oxidants available. Occurring in nature by the action of ultraviolet rays on the upper layers of the atmosphere, ozone (O3) is an allotropic form of oxygen and due to its characteristics of instability and reactivity it must be produced in the field immediately before its use. The progress of technology allows you to choose ozone generators that produce from a few g / h up to over 200 kgO3 / h with specific electricity consumption from 6.5 to 13 kWh depending on the temperature of the cooling water and the production concentration. . Ozone can be applied individually or in combination with ultraviolet rays (UV), hydrogen peroxide (H2O2) and dedicated catalysts to create more performing AOP (Advanced Oxidation Process) processes for oxidation and consequent destruction of substances. harmful and many pollutants present in drinking water, waste water and gaseous effluents.