How to improve the oxidizing property of ozone?
Ozone is a clean, efficient and safe strong oxidant, which has broad application prospects in the field of water treatment. However, ozone gas has low solubility and poor stability in aqueous solution, so the utilization efficiency of ozone in the process is generally not high. In addition, ozone has a poor removal effect on refractory organic matter in water, while ▪OH can degrade almost all organic pollutants. Therefore, in order to reduce the treatment cost and improve the efficiency of ozone utilization, researchers adopted a series of strengthening techniques to promote O₃ and convert it into OH. Ozone Sterilizer
OH¯, H₂O₂, Fe²+, Co²+, Mn²+, etc. are the initiators of the ozone chain decomposition reaction. They were first used by researchers as catalysts for the ozone oxidation process and received good strengthening effects. However, these homogeneous catalysts are inconvenient to recycle and reuse, and metal ions cause secondary pollution to the aqueous solution. Subsequently, researchers found that oxides of transition metals such as Fe, Mn, Co, and Cu, and solid-phase materials such as activated carbon also have catalytic ozone oxidation activity. At present, with the continuous improvement of material preparation and characterization technology, the research on catalytic ozone oxidation is also deepening. Emerging carbon materials such as composite and supported metal oxides, graphene, and carbon nanotubes have received extensive attention from researchers, and a large number of research results have been accumulated on the activity, stability and catalytic mechanism of catalysts.
Ozone has ultraviolet absorption activity. Under the irradiation of ultraviolet light, ozone can be decomposed to generate excited oxygen atoms, which undergo a series of reactions in aqueous solution to generate H₂O₂ and OH. Therefore, ozone/UV light is also a potential advanced oxidation technology. The photocatalytic oxidation of TiO2 excited by UV light is the most striking advanced oxidation technology in the 20th century. The researchers found that the introduction of ozone into the photocatalytic oxidation system can synergistically promote the two processes of photocatalytic oxidation and ozone oxidation, resulting in a better treatment effect. Due to the weak penetration of ultraviolet light and high application cost, in recent years, with the development and application of photosensitive catalysts such as C₃N4, WO₃, BiVO4, etc., the photocatalytic ozone oxidation process driven by visible light has been more studied.
Ozone has a strong ability to obtain electrons and has a faster electron transfer rate under the action of an electric field. Therefore, the electrochemical oxidation process and the ozone oxidation process also have a good synergistic effect. In addition, the membrane-catalyzed ozone oxidation process has also received more and more attention. The microporous and nanoporous structures of membrane materials help to improve the mass transfer efficiency and contact reaction efficiency of ozone. The membrane and ozone coupling process integrates catalysis, oxidation and filtration, which can save water treatment costs to a large extent.
The use of catalysis, light excitation, electrical excitation and other strengthening methods can effectively improve the oxidation efficiency of ozone. With the efforts of many scholars at home and abroad, ozone-based advanced oxidation technology is expected to be highly applied in the treatment of industrial wastewater organic pollution. In order to further promote the research and application of this technology, the follow-up will be on heterogeneous catalytic ozone oxidation, photocatalytic enhanced ozone oxidation, electrochemical enhanced ozone oxidation, hydrogen peroxide enhanced ozone oxidation, persulfate enhanced ozone oxidation, membrane catalytic ozone oxidation Summarize and analyze the research status of other technologies.