Ozone Catalytic Oxidation Technology: An Efficient Degradation Pathway in Wastewater Treatment
In the field of industrial wastewater and domestic sewage treatment, ozone catalytic oxidation technology, with its outstanding organic degradation capability, has become one of the core technologies for solving complex wastewater purification problems, and the ozone catalyst, as the core carrier of this technology, is the key to determining treatment efficiency.
Ozone catalysts are functional catalytic materials specially adapted to wastewater treatment scenarios. Their core role is to significantly improve the utilisation rate and degradation capability of ozone by catalytically activating ozone molecules, rapidly decomposing chemical oxygen demand (COD), refractory organics and other pollutants in wastewater, cutting off pollution transmission paths at the source, ensuring that effluent quality meets standards, and providing an efficient solution for water environment treatment.
According to differences in the form in which the catalyst exists, ozone catalytic oxidation technology can be divided into homogeneous ozone catalytic oxidation technology and heterogeneous ozone catalytic oxidation technology (also known as multiphase ozone catalytic oxidation technology), and the two technical paths each have their own characteristics in reaction mechanism, application scenarios, advantages and disadvantages.
Homogeneous ozone catalytic oxidation technology uses soluble metal ions (such as Fe²⁺, Cu²⁺ and Mn²⁺) as catalysts, and during the reaction the catalyst is uniformly dispersed in the wastewater system, in full contact with ozone and pollutants.
The core advantage of this technology lies in its high catalytic activity: metal ions can react rapidly with ozone, initiating chain reactions that generate large amounts of reactive radicals; the reaction mechanism is clear and well defined, making it easy for researchers to optimise treatment performance by regulating ion concentration, reaction conditions and other parameters, and it is widely used in laboratory research and small treatment units.
However, the limitations of homogeneous technology are also very prominent: the soluble catalyst dissolves completely in water and is difficult to separate effectively from the water body after the reaction, which not only causes substantial catalyst loss and increases operating costs, but also leaves metal ions in the effluent, causing secondary pollution; additional downstream treatment processes are needed to remove residual ions, further increasing the complexity and cost of water treatment and limiting its promotion and application in large-scale wastewater treatment projects.
Heterogeneous ozone catalytic oxidation technology is centred on solid catalysts, with common carriers including activated carbon, alumina, ceramics, metal oxides (such as TiO₂, MnO₂ and CeO₂) and their composite materials. Solid catalysts can accelerate oxidation reactions in the liquid or gas phase under atmospheric pressure.
Its greatest advantage lies in the excellent separability from water: after the reaction, the catalyst can be recovered, regenerated and recycled through simple processes such as filtration and settling, which not only reduces the cost loss caused by catalyst loss but also fundamentally avoids the generation of secondary pollution and significantly simplifies the treatment process. In addition, heterogeneous catalysts can optimise surface structure and active sites by regulating the manufacturing process (such as doping, supporting and compositing), further improving catalytic efficiency and stability and adapting to the wastewater treatment needs of different water qualities.
Therefore, heterogeneous ozone catalytic oxidation technology, with its characteristics of environmental friendliness, high efficiency and easy operation and maintenance, has become a research hotspot and the mainstream application in the field of industrial wastewater treatment.
The series of heterogeneous catalysts developed by SINOKLE
The performance of solid catalysts directly determines the treatment effect of heterogeneous ozone catalytic oxidation technology, and a high-quality catalyst must simultaneously possess good adsorption performance, efficient catalytic activation capability and stable chemical stability.
Studies show that heterogeneous catalysts mainly perform three core functions in the wastewater treatment process:
Adsorption–catalysis synergy: some catalysts (such as activated-carbon-based composites) combine excellent adsorption capacity with catalytic activity. When wastewater comes into contact with the catalyst, the porous structure and active groups on the catalyst surface first rapidly adsorb organic pollutants in the water, forming an affinity surface chelate that enriches the pollutants on the catalyst surface and provides a “locally high-concentration reaction environment” for the ozone oxidation reaction, thereby improving the reaction efficiency between ozone and pollutants and achieving synergistic enhancement of adsorption and catalysis.
Ozone activation: an efficient catalyst can catalytically activate ozone molecules through surface active sites (such as metal ions and oxygen vacancies), breaking the chemical bonds of ozone molecules and promoting their decomposition into strongly oxidising reactive species such as hydroxyl radicals. The oxidation potential of these reactive species is far higher than that of ozone itself, and they have non-selective oxidising capability for various organic pollutants, rapidly degrading pollutants into carbon dioxide, water and other harmless substances, greatly improving the oxidation efficiency of ozone and the degradation depth of pollutants.
Dual adsorption–activation synergy: high-performance heterogeneous catalysts often possess the dual capability of adsorbing organic pollutants and activating ozone molecules at the same time. During the reaction, the catalyst first captures pollutants in the wastewater through adsorption, concentrating them on the catalyst surface, and then catalytically activates ozone molecules to generate reactive radicals, which directly oxidise and decompose the pollutants near the adsorption sites. This continuous “adsorption–activation–degradation” reaction mechanism not only shortens the reaction path and reduces the ineffective loss of reactive species but also significantly improves the overall oxidation effect, making it especially suitable for treating low-concentration, refractory and complex organic wastewater.
