Breaking the Ozone Oxidation Bottleneck: CDOF Technology Solves the Zero-Liquid-Discharge Challenge for Coal Gasification Wastewater

Driven by the dual imperatives of the 'dual-carbon' goals and the strictest environmental protection law, industrial wastewaterzero-liquid discharge (ZLD)has become a hard requirement for the high-quality development of the coal chemical industry. As a major water consumer and key pollution source, coal chemical wastewater is complex in composition, highly toxic, and difficult to degrade; in particular, the treatment of coal gasification wastewater has long been an industry-recognized 'bottleneck' problem.

Facing stringent environmental standards and water-resource constraints, SINOKLE (Shenzhen), relying on its self-developed core technology, directly addresses the pain points of coal gasification wastewater treatment and provides the industry with an efficient, stable, and implementable zero-liquid-discharge treatment solution.

1. Coal Chemical Industry: High Water Consumption and High Discharge - Environmental Bottlenecks Urgently Need to Be Broken

Coal chemical industry is a core industry that uses coal as raw material and converts it through chemical processing into gaseous, liquid, and solid fuels and chemicals, coveringcoal gasification, coal coking, and coal liquefactionthree mainstream processes that support the production of key products such as synthetic ammonia, methanol, olefins, and oil products.

But behind the rapid development of the industry, water-resource consumption and water-pollution problems are especially prominent:

· coal-to-natural-gas unit water consumption is about10 ton /kNm³, and coal-to-olefins unit water consumption is as high as30 ton per ton of product;

· coal chemical wastewater contains phenol, cyanide, oil, ammonia nitrogen, and large amounts of refractory organics, with strong toxicity and poor biodegradability;

· China's per-capita water resources are less than 25%of the world average, and water-environment pollution has become the core bottleneck constraining the development of new coal chemical industry.

From the national 11th Five-Year Plan, which first promoted industrial wastewater zero-liquid discharge, to the successive introduction of the 'Water Pollution Prevention and Control Action Plan' and the 'Environmental Access Conditions for Modern Coal Chemical Construction Projects,'source separation of clean and polluted water, advanced treatment, quality-based reuse, and zero-liquid dischargehave become an environmental iron law that coal chemical enterprises must obey.

2. Within the Zero-Liquid-Discharge Framework, Where Is Coal Gasification Wastewater Treatment Difficult?

After years of practice, coal chemical wastewater has formeda standard process route of 'pretreatment - biological treatment - advanced treatment - brine treatment - solidification zero-liquid discharge,' but coal gasification wastewater (especially crushed-coal gasification wastewater) still has three major treatment pain points:

1. incomplete pretreatment, and the biological system is prone to “poisoning”after ammonia stripping and phenol removal, the oil content of the wastewater remains as high as100~200mg/L, far exceeding the biological influent limit of <50mg/L , and oils and toxic substances directly inhibit microbial activity, causing a sharp drop in biological treatment efficiency.

2. refractory organics are stubborn, and advanced treatment fails to meet standardsthe biological effluent retains large amounts of macromolecular CODorganics that conventional processes cannot completely decompose, easily leading to effluentCODand ammonia-nitrogen exceeding limits, making it difficult to meet reuse and zero-liquid-discharge requirements.

3. units are prone to fouling and clogging, and the system operation is unstablecolloids, organics, and bacteria easily foul membrane modules and reaction equipment, greatly increasing O&M costs and even causing the entire treatment system to break down.

3. Traditional Processes Have Shortcomings; Advanced Oxidation Is the Key to Breaking the Deadlock

To solve the refractory organics problem, the industry generally adoptsthe 'advanced oxidation + two-stage biological treatment + membrane separation' process, in which advanced oxidation breaks the chains and opens the rings of macromolecular organics to improve biodegradability (B/C), followed by two-stage biological deep degradation.

Comparison of current mainstream advanced oxidation processes:

Among these, ozone oxidation has become a preferred direction because of its clean and efficient nature, butthe traditional ozone process has two fatal defects: low ozone solubility in water and low hydroxyl-radical conversion efficiency, which limit the treatment effect and large-scale application.

4. Technological Breakthrough! SINOKLE's patented technology conquers the industry's difficult problems

To address the technical shortcomings of traditional ozone oxidation, SINOKLE starts frommass-transfer efficiency, catalytic efficiency, and system integrationthree dimensions for comprehensive innovation, creatingcatalytic ozonation- swirl-air-flotation integrated (CDOF) core technology) that thoroughly solves the coal gasification wastewater treatment problem.

1. Dual technical upgrades to break through the ozone application bottleneck

· increase solubility: coupling efficient dissolved-air release and pressurized cooling technology to greatly improve ozone dissolution efficiency in water;

· increase conversion rate: heterogeneous catalyst + and hydraulic cavitation+ and high-gravity swirl technology act synergistically, and the hydroxyl-radical conversion ratecan reach up to 99.98%, with oxidation capacity increasing exponentially.

2. Dedicated catalyst adapted to high-difficulty wastewater

For high-concentration macromolecular organic coal gasification wastewater, SINOKLE developeda new highly loaded ozone catalyst (N-HLC)), using dual-site catalysis, high-porosity micropore forming, and hydrophilic anti-fouling technology, adapted to complex water quality for long-term stable operation.

3. Integrated integration for efficient, stable compliance

CDOFThe technology integratesmultiple catalytic oxidation, hydraulic cavitation, and swirl air flotationinto one unit, with a retention time of <15 minutes and nearly 100% ozone utilization, efficiently degrading COD, removing oil, and detoxifying, safeguarding subsequent biological and membrane treatment.

5. SINOKLE: Guarding Industrial Green Water Through Technological Innovation

As a national high-tech enterprise focused on industrial wastewater treatment, SINOKLE has consistently deepened its work in the field of high-difficulty wastewater treatment, with CDOF,CDFUand other patented technologies at its core, providing the petrochemical, coal chemical, oil and gas, and other industries withcustomized, integrated, zero-liquid-dischargewastewater treatment solutions.

In the future, SINOKLE will continue to deepen water-treatment technology innovation, using hardcore science and technology to solve industrial wastewater treatment problems, helping enterprises achieve green production and compliant development, and contributing technological strength to China's water-resource protection and the realization of the 'dual-carbon' goals!