Metals as Catalysts for Ozonation

Ozonation is an efficient process for water and wastewater treatment, widely used for the disinfection and oxidation of organic pollutants. This process is effective, however, some pollutants are ozone-resistant. For better oxidation, enhanced production of hydroxyl radicals (HO•) can be obtained through the transition metals insertion in solution, known as homogeneous catalytic ozonation. These metals may react directly with O3 to produce HO• or interact with organics such as humic substances in the water matrix to promote O3 transformation to HO•. In this chapter, a short review of the homogeneous catalytic ozonation, including key aspects, such as pH effect, metals concentration, catalytic mechanisms, drawbacks of the homogeneous catalytic ozonation application, and the possible solution for it was provided.