Innovative CDOF Integrated System for Efficient Treatment of Refractory Industrial Wastewater
In the context of high-quality industrial environmental development, the treatment of refractory wastewater has become a critical challenge in petrochemicals, pharmaceuticals, metallurgy, landfill leachate management, and oilfield environmental protection. As wastewater discharge standards become increasingly stringent, traditional processes are inefficient at removing high-molecular polymers, dissolved oil, and refractory organics, making it difficult to balance treatment effectiveness, operational costs, and regulatory compliance. The demand for high-efficiency, intensive, and green water treatment technologies is therefore becoming more urgent.
Shenzhen Clear Science & Technology Co., Ltd (SINOKLE) has focused on industrial water treatment R&D for many years. It independently developed the CDOF Integrated Ozone Advanced Catalytic Oxidation–Hydrocyclone–Dissolved Air Flotation (DAF) system, deeply integrating three core technologies: multiple catalytic oxidation, hydrocyclone separation, and dissolved air flotation. Leveraging internationally leading patented technology, it provides a comprehensive solution to refractory wastewater treatment challenges, offering one-stop solutions for various high-difficulty industrial wastewater treatment and upgrade projects with broad market potential.
I. Industry Urgency: Refractory Wastewater Treatment is Imperative
Industrial wastewater treatment has shifted from removing conventional pollutants to advanced treatment of refractory, highly toxic, and high-concentration organic wastewater. Waste streams such as oilfield fracturing flowback, pharmaceutical and chemical wastewater, refinery effluent, and landfill leachate face high treatment difficulty and stringent discharge requirements. These wastewaters commonly contain refractory organics, dissolved oil, and high-molecular polymers, which conventional biochemical, settling, and filtration processes cannot effectively remove, causing pollution and impacting downstream units, thereby constraining production and regulatory compliance.
Meanwhile, industrial wastewater treatment is transitioning toward integration, high efficiency, low carbon footprint, and zero secondary pollution. Companies urgently need solutions with small footprints, stable operation, thorough treatment, and easy maintenance that meet strict environmental standards while controlling long-term operational costs. SINOKLE’s CDOF integrated system, a Chinese innovation and internationally advanced water treatment technology, precisely addresses these core industry needs. It is suitable for oilfield wastewater, chemical wastewater, black-and-odorous water remediation, and upgrade projects, offering strong market promotion value and industry demonstration significance.
II. Existing Challenges in Refractory Wastewater Treatment and Limitations of Traditional Processes
Refractory industrial wastewater is complex and extremely difficult to treat. The industry faces three core challenges, highlighting the limitations of traditional processes that cannot meet modern treatment requirements:
1. Recalcitrant pollutants: Conventional processes are inefficient. Dissolved oil, high-molecular polymers, and stubborn organics are chemically stable. Ordinary flotation and biochemical methods cannot effectively degrade them, resulting in poor COD and color removal and unstable compliance.
2. Low ozone utilization and high cost: Traditional ozone oxidation suffers from poor mass transfer efficiency and low utilization, requiring excessive ozone input. Energy and material costs are high, making it unaffordable for enterprises.
3. Dispersed processes with large footprint and complex operation: Traditional treatment requires multiple connected units, resulting in long process flows, large footprint, high sludge production, and potential secondary pollution, failing green and environmental requirements.
III. Detailed Introduction to SINOKLE’s CDOF Core Process
The CDOF system (Ozone Advanced Oxidation–Hydrocyclone–DAF Integrated System) is SINOKLE’s independently developed, internationally patented technology. It breaks the single-process limitations of conventional treatment, innovatively integrating multiple catalytic ozone oxidation, hydrocyclone, and DAF technologies to achieve efficient catalytic oxidation and comprehensive removal of refractory pollutants. The entire process is highly integrated and fully enclosed.
The process relies on the synergy of three core modules: wastewater is first pressurized and sent to the hydrocyclone-DAF unit for preliminary removal of floating oil, suspended solids, and large particles, reducing the downstream oxidation load. Next, wastewater enters the ozone microbubble reaction zone, combined with proprietary catalysts and a supercritical catalytic device to trigger multiple catalytic oxidation reactions. Ozone decomposes into highly reactive hydroxyl radicals, rapidly degrading refractory organics, dissolved oil, and odorous compounds. Finally, deep DAF separation removes residual pollutants and reaction residues, discharging compliant clean water, while floating oil and sludge are collected for centralized disposal. The process is short, fast, and eliminates treatment blind spots.
The equipment is highly adaptable, with stable core parameters: maximum capacity 200 m³/h, medium temperature ≤50°C, operating pressure ≤0.1 MPa, ozone dosing 10–200 mg/L, adjustable for different wastewaters. The COD-to-ozone dosing ratio is ≥2, achieving treatment efficiency far beyond conventional processes, suitable for pre-treatment and advanced treatment of various high-difficulty industrial wastewaters.
IV. Core Advantages of SINOKLE’s CDOF Process
Compared to traditional water treatment, the CDOF integrated system offers five irreplaceable advantages, with industry-leading performance:
1. Patented, internationally advanced technology: Multiple proprietary technologies integrated; domestic innovation with international advancement. Multi-catalytic oxidation increases ozone oxidation efficiency over six times, overcoming traditional bottlenecks.
2. High ozone utilization, low-carbon and energy-saving: Proprietary ozone microbubble technology greatly enhances mass transfer, increasing ozone utilization, reducing dosage, energy consumption, and operating costs.
3. Efficient and thorough treatment, stable compliance: Rapid removal of high-molecular polymers, dissolved oil, and refractory organics; color reduction >90%; efficient deodorization; COD, color, and oil content stably compliant.
4. Green and environmentally friendly, no secondary pollution: Oxidation produces no harmful by-products, sludge generation reduced by >90%, minimizing secondary pollution risks.
5. Highly integrated, compact footprint, simple operation: Skid-mounted, fully enclosed, automated operation; short process, small footprint, safe and stable, minimal supervision required, reducing maintenance and labor costs.
V. Engineering Applications and Promotion Value
SINOKLE’s CDOF system has been successfully applied in multiple benchmark projects, including landfill leachate treatment in Hubei, China, oilfield fracturing flowback treatment, and chemical wastewater upgrading, achieving excellent results, long-term stable operation, and treatment performance exceeding client expectations, earning high industry recognition.
The technology now covers oilfield wastewater, pharmaceutical and metallurgical wastewater, refinery and chemical wastewater, black-and-odorous river remediation, wastewater upgrading, and EOR wastewater treatment. With its mature technical system and extensive engineering experience, it has become a benchmark technology for refractory wastewater treatment.
