Ozone is one of the most potent oxidants. It is applied in disinfection, deodorization and water treatment, i.e. for initial oxidation or as a sole reagent used in algae removal in the process of ozone flotation. Initial treatment with ozone as means of oxidation of inorganic residues (FE(II), nitrites as well as bromides and bromine) and organic pollution is used in the process of coagulation. Initial ozonation is also utilized before biosorption. Research that concerns wastewater management, water treatment and reduction of odors are carried out in cooperation with Biopasz company (Gdańsk, Poland), a supplier of ozone and oxygen generators.