Engineering Application of Catalytic Ozone Oxidation Technology in Advanced Treatment of Chemical Wastewater

1.1 Technology Overview and Mechanism

Catalytic ozone oxidation technology offers a highly efficient advanced oxidation process suitable for the advanced treatment of chemical wastewater. It effectively addresses industry pain points—such as the poor performance of traditional biochemical processes in treating recalcitrant organic pollutants and the difficulty of meeting or exceeding discharge standards—by leveraging the activating and synergistic effects of catalysts to decompose ozone into highly oxidizing hydroxyl radicals. These radicals rapidly oxidize and break down recalcitrant pollutants (e.g., halogenated hydrocarbons, aromatic compounds, and dye intermediates).

1.2 Key Applications and Benefits

The technology provides advantages such as high treatment efficiency, no secondary pollution, strong adaptability to operating conditions, and ease of operation and maintenance. It enables the stable, advanced removal of COD, color, and TOC from biochemical effluents and high‑salinity concentrated wastewater, thereby meeting diverse engineering needs such as surface water quality improvement, wastewater reuse, and near‑zero discharge. In practical applications, key parameters influencing treatment performance include catalyst selection, ozone dosage, pH value, and hydraulic retention time; integrating pretreatment coupling processes and intelligent control systems can significantly enhance operational stability while reducing energy and chemical consumption.

1.3 Current Challenges and Future Outlook

Although currently widely applied in sectors such as petrochemicals, coking, pesticides, and fine chemicals, the technology still faces challenges regarding catalyst attrition and limited adaptability to high‑salinity conditions. Further development—through the creation of bimetallic composite catalysts, coupling with micro‑nano bubble technology, and process system optimization—can expand its application scope, making it a core technology of significant value for widespread adoption in the field of advanced chemical wastewater treatment.

Ozone decomposition catalyst

I. Technical Pain Points and Application Requirements in Advanced Chemical Wastewater Treatment

Chemical wastewater exhibits complex pollutant compositions, high organic toxicity, poor biodegradability, high salinity, and intense coloration. Even after conventional anaerobic and aerobic biochemical treatment, the effluent often retains significant concentrations of structurally stable, recalcitrant organic pollutants, rendering it unable to meet current environmental discharge standards or industrial reuse requirements. Traditional advanced treatment processes suffer from significant limitations that hinder efforts to improve the quality and efficiency of chemical wastewater treatment: coagulation‑sedimentation removes only suspended and colloidal pollutants, showing poor efficacy against recalcitrant dissolved organics; activated carbon adsorption faces issues such as rapid saturation, high replacement costs, and the generation of hazardous waste; and conventional ozone oxidation suffers from low radical generation efficiency, poor ozone utilization, and high treatment costs, making it unsuitable for large‑scale industrial applications.

As environmental regulations tighten, the demand for upgrading wastewater treatment standards, water reclamation, and concentrated brine treatment in chemical industrial parks is rising, rendering conventional processes inadequate for meeting high‑standard treatment requirements. Against this backdrop, catalytic ozone oxidation technology has emerged as a preferred mainstream process for advanced treatment and system upgrades. Characterized by high oxidation efficiency, environmental friendliness, and operational flexibility, it overcomes the technical bottlenecks of traditional methods and offers targeted solutions for the advanced treatment of biochemical effluents, RO concentrates, and fine chemical wastewater.

II. Core Principles of Catalytic Ozone Oxidation Technology

Catalytic ozone oxidation is an advanced oxidation process that incorporates a catalyst into traditional ozone oxidation. Its core principle involves the dual action of catalytic activation and adsorption‑enrichment: the catalyst alters the ozone reaction pathway, thereby significantly enhancing oxidation efficiency. The reaction mechanism comprises two synergistic components that work together to achieve the efficient degradation of pollutants.

2.1 Adsorption‑Enrichment Mechanism

On one hand, the catalyst surface features numerous active sites that rapidly adsorb recalcitrant dissolved organic compounds from the wastewater. By concentrating pollutants on the catalyst surface, the process reduces reaction distances and increases local reactant concentrations.

2.2 Hydroxyl Radical Generation and Mineralization

Simultaneously, the catalyst disrupts the stable structure of ozone molecules, accelerating their decomposition and generating hydroxyl radicals—species characterized by higher oxidation potential and non‑selective reactivity. Unlike the selective oxidation typical of ozone molecules, hydroxyl radicals indiscriminately attack various recalcitrant organic pollutants, breaking down their molecular structures. They cleave large organic molecules into smaller fragments, ultimately mineralizing them completely into carbon dioxide and water, thereby effectively eliminating COD, color, and toxic pollutants from the wastewater.

On the other hand, the heterogeneous catalytic systems commonly used in engineering applications effectively circumvent the drawbacks associated with homogeneous catalysis. Heterogeneous catalysts—exemplified by Mn‑Ce bimetallic catalysts supported on alumina—eliminate the need for chemical reagent dosing and avoid secondary pollution. Their long‑term recyclability resolves the issues associated with traditional Fenton and homogeneous catalytic processes, such as high chemical dosage requirements, excessive sludge generation, and complex operation and maintenance. Furthermore, the technology operates under mild conditions (ambient temperature and pressure), requiring no high‑temperature or high‑pressure equipment, making it highly adaptable to the diverse on‑site operating conditions of chemical wastewater treatment projects.

III. Core Engineering Advantages of Catalytic Ozone Oxidation Technology

Compared to traditional advanced treatment processes, catalytic ozone oxidation technology offers outstanding engineering advantages for handling the complex conditions of chemical wastewater—a key factor driving its large‑scale adoption. These advantages are evident in four areas:

1. Comprehensive and highly efficient pollutant removal. The technology excels at removing recalcitrant dissolved organic matter, color, and persistent toxic pollutants from chemical wastewater, effectively degrading stubborn contaminants such as residual aromatic compounds, halogenated organics, and pesticide intermediates. Engineering data indicates that, compared to ozonation alone, catalytic ozone systems increase COD removal rates by over 25% and significantly boost TOC and color removal rates, resulting in much more stable effluent quality.
2. Exceptional process adaptability and compatibility. The technology is highly flexible, suitable for wastewater from various sectors—including petrochemicals, coking, fine chemicals, and pesticide manufacturing—and capable of treating both standard biochemical effluents and concentrated chemical wastewater characterized by high salinity, high COD, and high color. It can also seamlessly integrate with pretreatment processes such as micro‑flocculation, sedimentation, and filtration to form a complete advanced treatment system, making it ideal for both new projects and the upgrading of existing wastewater treatment facilities.
3. Low operation and maintenance costs and no secondary pollution. The heterogeneous catalysts have a long service life and are recyclable, eliminating the need for continuous chemical dosing; sludge production is minimal, drastically reducing hazardous waste disposal costs. Ozone decomposes rapidly into oxygen after the reaction, leaving no residues or secondary pollution, which aligns with green water treatment principles. Additionally, the system features a high degree of automation, including intelligent dosing and monitoring equipment, which reduces the burden of manual operation and maintenance.
4. Flexible adjustment of operating conditions and easy capacity expansion. The technology offers a wide range of adjustable processing loads, allowing for real‑time adjustments to ozone dosage and hydraulic retention time based on fluctuations in influent water quality; this makes it well‑suited for the intermittent discharge and highly variable water quality and quantity characteristic of chemical production. The reactor features a modular design, eliminating the need for extensive civil engineering work during future capacity expansions or upgrades to meet stricter standards, thereby ensuring excellent project implementability.

IV. Typical Application Scenarios and Practical Results in Chemical Wastewater Treatment

Catalytic ozone oxidation technology currently reaches maturity and wide application in advanced treatment projects for various types of chemical wastewater. Process configurations and treatment outcomes vary depending on the specific scenario, demonstrating the technology’s strong adaptability.

In coking wastewater treatment, the biochemical effluent contains high levels of recalcitrant pollutants—such as phenols and pyridines—and exhibits high chroma and toxicity. By employing a split‑type fluidized bed catalytic ozone process under optimal operating conditions, we can achieve COD and TOC removal rates of 83.7% and 72.3% respectively; residual toxic organic compounds degrade thoroughly, and the effluent consistently meets stringent discharge standards.

In petrochemical wastewater treatment, Reverse Osmosis (RO) concentrate poses a challenge for conventional processes due to its high salinity and the stable molecular structure of its organic pollutants. Utilizing a Mn‑Ce/γ‑Al₂O₃ bimetallic catalytic ozone system combined with a micro‑flocculation pretreatment process effectively removes dissolved organic matter from the concentrate, significantly reducing COD and chroma. The treated effluent can be reclaimed for reuse, effectively solving the problem of petrochemical concentrate treatment.

In the treatment of fine chemical and textile dyeing wastewater, a two‑stage heterogeneous catalytic oxidation process targets recalcitrant pollutants such as dye intermediates and auxiliaries. With optimized hydraulic retention time and ozone concentration, COD removal rates exceed 80%, and effluent COD stays stably below 50 mg/L. Chroma almost completely disappears, meeting both industrial reuse requirements and surface water environmental standards.

In the context of treating pesticide and chemical wastewater, a catalytic ozonation system coupled with micro/nano‑bubble gas‑dissolving technology enhances ozone dissolution and utilization rates. This enables efficient treatment at low ozone dosages, keeping operating costs around 1 RMB per ton of water—balancing performance with cost‑effectiveness—and meeting the specific demands of treating highly toxic, recalcitrant pesticide wastewater.

V. Key Control Parameters for Engineering Operations

The treatment performance and operational stability of catalytic ozonation systems rely heavily on the precise control of core process parameters; four key parameters require particular attention during engineering applications.

1. Catalyst selection and dosage parameters. The catalyst is the core functional unit; compared to single‑metal catalysts, bimetallic composite catalysts offer higher activity and stability, making them better suited for complex chemical wastewater. ဦးဇင်း, we must determine catalyst dosage and packing methods based on wastewater characteristics. Fluidized‑bed and fixed‑bed reactors suit different treatment scales and can effectively prevent issues such as catalyst caking or loss.
2. Ozone dosage and gas‑dissolving efficiency. Ozone dosage directly determines oxidation capacity; insufficient dosage leads to incomplete pollutant degradation, while excessive dosage increases energy consumption and operating costs. Integrating high‑efficiency micro/nano‑bubble gas‑dissolving equipment enhances ozone solubility and utilization, reduces ozone off‑gassing, and improves the system’s overall treatment efficiency.
3. Wastewater pH and reaction time. Neutral to weakly alkaline environments favor catalytic ozonation reactions, promoting the generation of hydroxyl radicals, whereas acidic environments inhibit ozone decomposition and reduce treatment effectiveness. Additionally, we must maintain an appropriate hydraulic retention time to ensure sufficient contact and reaction between pollutants, radicals, and the catalyst, preventing effluent quality fluctuations caused by incomplete reactions.
4. Control of pretreatment loads. Excessive suspended impurities and colloidal pollutants in the influent can cover the catalyst’s active sites, leading to catalyst deactivation. Engineering designs must incorporate pretreatment units—such as micro‑flocculation and filtration—to reduce the influent pollution load and ensure the long‑term, stable operation of the catalytic oxidation unit.

VI. Current Technical Limitations and Directions for Engineering Optimization

Extensive engineering practice reveals that catalytic ozonation technology still faces certain limitations: under extreme conditions of high salinity, salt ions slightly inhibit catalyst activity and reduce treatment efficiency; long‑term operation leads to pollutant accumulation on the catalyst surface, resulting in activity decay and caking; and energy consumption for ozone equipment in small‑scale projects is relatively high, leaving room for improvement in operational cost‑effectiveness. Mature optimization strategies have addressed these issues:

• Regarding material optimization, efforts focus on developing highly stable, fouling‑resistant bimetallic composite catalysts and novel support materials to enhance salt and fouling resistance, extend catalyst lifespan, and reduce replacement costs.
• In terms of process coupling, the “micro‑flocculation + catalytic ozonation + effluent recirculation” combined process helps balance influent quality fluctuations, enhances system resilience against shock loads, and further improves pollutant removal rates.
• Regarding intelligent operation and maintenance, the integration of online ORP monitoring and intelligent dosing control systems allows real‑time adjustment of ozone dosage and operating parameters based on influent quality; this enables precise control of the reaction process, reduces energy and chemical consumption, and improves the economic viability of operations.

VII. Conclusion

Amidst industry trends emphasizing quality and efficiency improvements and resource recovery in chemical wastewater treatment, catalytic ozonation technology—leveraging its core advantages of high efficiency, environmental friendliness, and strong adaptability—effectively overcomes the technical bottlenecks associated with treating refractory chemical wastewater. It demonstrates significant value in applications ranging from advanced treatment and discharge standard upgrades to concentrated wastewater management. Through the iterative improvement of catalyst materials, optimization of process system coupling, and upgrades to intelligent operation and maintenance, the technology’s treatment efficiency, operational stability, and cost‑effectiveness will continue to improve. In the future, it is poised to increasingly replace traditional advanced treatment processes, serving as a core supporting technology for high‑standard chemical wastewater treatment and water resource recycling, thereby facilitating the green and low‑carbon development of the chemical industry.

စာရေးသူ: Gloria
ရက်စွဲ:2026/7/10