Problems in ozone catalytic oxidation technology for sewage treatment

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At present, the feasible technology of advanced sewage treatment process engineering is relatively limited, such as activated carbon adsorption, chemical adsorbents, Fenton method advanced oxidation, membrane method and aeration biological filter, etc. Despite their advantages, they all have certain application limitations.In contrast, catalytic ozone oxidation stands out with its unique green process characteristics.Catalytic ozone oxidation is regarded as a green process mainly because its oxidation process is efficient and environmentally friendly.Compared with the traditional Fenton process, catalytic ozone oxidation also relies on the strong oxidant?OH, but the production path is quite different.The Fenton process requires the use of Fe2+ to catalyze H2O2 under acidic conditions, which not only involves the addition of chemicals, but also produces a large number of iron mud and sulfate.Catalytic ozone oxidation uses "transition metal compounds" as catalysts and is carried out under neutral pH conditions, which not only avoids the production of iron mud and sulfate, but also truly realizes the recycling of catalysts.

In advanced treatment, the reason why ozone needs to be catalyzed is that although simple ozone can oxidize a variety of organic compounds, it can not completely remove them.Ozone oxidizes macromolecular organic compounds into small molecular alcohols, aldehydes, organic acids, etc., which does not mean that organic compounds are completely removed.And the catalytic ozone can be decomposed to produce a stronger oxidant? OH, not only can more thoroughly oxidize organic matter, but also oxidize more kinds of organic matter.
The application of catalytic ozone in depth treatment is regarded as a new process, mainly because its application in water treatment is completely different from the traditional disinfection and decolorization.Deep treatment requires thorough oxidation of organic matter, which requires higher ozone dosage and the use of catalysts.
As one of the ozone catalysts, iron-based catalysts have a variety of forms and crystal types.They are characterized by high catalytic efficiency and lasting stability.There are differences in the preparation methods and catalytic capacity of different types of iron-based catalysts, but in general, they can effectively catalyze the ozone oxidation process.
In the process of ozone depth treatment, the difficulty mainly lies in how to efficiently and stably produce and use?OH.Catalytic ozone process by using solid-phase catalysts, catalyzed under pH neutral conditions, not only avoids some problems in the traditional process, but also improves the oxidation efficiency.
As another effective ozone catalyst, iron-based catalyst has unique advantages.The FeOOH formed on the surface after modification not only has catalytic effect, but also protects the zero-valent iron in the iron scrap, thus improving the stability and catalytic effect of the catalyst. In addition, the use of regularized packing further improves the catalytic effect on the project, avoids the wear during transportation and use, and optimizes the microscopic mass transfer conditions, so that the?OH can oxidize organic compounds in the liquid more effectively.