I. Bottlenecks in Industrial Park Wastewater Treatment
1.1 Zhuhai Gaolan Port Industrial Park is home to highly polluting industries such as petrochemicals, fine chemicals, and pharmaceuticals. Its wastewater exhibits three highs:
High toxicity: Contains recalcitrant organic matter such as benzene, halogenated hydrocarbons, and polycyclic aromatic hydrocarbons (COD 150–300 mg/L, B/C ratio <0.1);
High salinity: TDS ≥ 15,000 mg/L, inhibiting microbial activity and exacerbating equipment corrosion;
High volatility: Peak-to-valley variations of up to four times (5,000–20,000 m3/d), with instantaneous water quality fluctuations exceeding 30%.
After the 2021 revision of Guangdong Province's "Water Pollutant Discharge Limits" (DB44/26-2001), the effluent COD requirement is now ≤ 50 mg/L (Class IV surface water standard). The traditional "biochemical + ozone" process achieves a removal rate of less than 40%, creating a core bottleneck for the park's sustainable development.
1.2 Urgent Need for Technological Upgrade
Ineffective Single Oxidation Technology: Ozone has low oxidation efficiency for halogenated compounds (<20%), and UV photolysis is ineffective for non-light-absorbing pollutants.
Unmanageable Operating Costs: The addition of ineffective reagents results in treatment costs exceeding ￥15 per ton of water.
Accumulating Ecological Risks: Intermediates with higher toxicity (such as formaldehyde and bromate) pose a threat to offshore ecological safety.
II. ONYX' Three-Stage Advanced Oxidation Technology: Principles and Innovations
ONYX' innovative three-stage process of "pre-oxidation - main reaction - mineralization stabilization" achieves cascaded pollutant degradation.
Technical aspects | Innovative design | Scientific Mechanism |
Pre-oxidation section
| Jet mixer + static mixer to enhance O?/H?O? mass transfer
| H?O? induces O? chain reaction
|
Main reaction section | Vertical flow UV reactor (wavelength 254 nm) nested honeycomb ceramic catalyst
| UV catalyzed O? cracking
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Mineralized section | Medium-pressure UV (MPUV, 200–400 nm) coupled with precise H?O? dosing
| Broad spectrum UV excitation·OH indiscriminate attack
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Efficiency doubling mechanism
·Free radical concentration improvement: The three-stage reaction increases the ·OH yield by 3.8 times compared with the single-stage process;
·Anti-water quality fluctuation: The oxidant addition is regulated by real-time ORP feedback, and the COD removal rate fluctuation is less than 5%;
·Zero secondary pollution: The final products are CO? and H?O, and the bromate generation is less than 10 μg/L (the national standard limit is 50 μg/L).
III. Analysis of the full process implementation of the Zhuhai Gaolan Port project
Project overview and design challenges
·Processing scale: 19,000 m3/d (peak flow rate 2,500 m3/h);
·Influent water quality: COD 150–180 mg/L, benzene series ≥20 mg/L, conductivity 18 mS/cm;
·Emission requirements: COD ≤ 50 mg/L, benzene ≤ 0.1 mg/L, TOC ≤ 15 mg/L.
(1) Key equipment configuration
System
| Device parameters | Technological innovations |
Ozone generator | Output 25 kg/h (reuse and transformation), oxygen source purity ≥ 93%
| Integrated backup module (2 x 2.5 kg/h) to ensure continuous operation
|
UV photocatalytic reactor
| 4 vertical modules, 216 medium pressure lamps (Heraeus light source), single lamp power 2.5 kW | Honeycomb ceramic catalyst (TiO?/activated carbon composite carrier)
|
Hydrogen peroxide dosing system
| Storage tank 8 m3×2, metering pump accuracy ±1% (Saigao brand)
| PID dynamic dosing algorithm based on COD online monitoring |
The team from Tsinghua University completed the reactor flow field-light field collaborative simulation:
·Flow field uniformity: The guide plate angle was optimized to 45°, and the flow rate standard deviation was reduced from 0.41 to 0.15 m/s;
·Light utilization efficiency: The quartz tube is arranged in a ring (radius 200 mm), and the ultraviolet radiation flux is increased to 98 W/cm2.
(3) Intelligent control system
·Multi-parameter linkage: ORP/pH/COD online instrument (Hash brand) real-time control of O?, H?O?, and UV output;
·Zero leakage of tail gas: Catalytic destructor (filled with MnO?/CuO) ensures that tail gas O? is less than 0.1 ppm;
·Cloud platform management: Data is connected to the "Anlis Smart Water Brain" to achieve remote start and stop and fault diagnosis via mobile phone APP.
IV. Operation efficiency and economic analysis
4.1 Pollutant removal efficiency
Index | Influent mean
| Average water output | Removal rate
| National standard limit |
COD (mg/L) | 168 | 38 | 77.4% | ≤50 |
Benzene series (mg/L) | 22.5 | 0.08 | 99.6% | ≤0.1 |
TOC (mg/L) | 51.3 | 9.2 | 82.1% | ≤15 |
Acute toxicity (TU) | 8.7 | 0.9 | 89.7% | ≤1 |
4.2 Cost-effectiveness comparison
Cost Items
| Traditional O? process
| Three-stage AOP | Savings
|
Cost of water per ton (￥) | 6.8 | 3.6 | 47% |
Power consumption per ton of water (kWh) | 4.2 | 2.1 | 50% |
Equipment maintenance fees (10,000 yuan/year) | 320 | 180 | 44% |
Annual comprehensive benefits: Save ￥12.6 million in operating costs and reduce hazardous waste disposal fees by ￥3.5 million. |
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4.3 Environmental and Social Value
·Ecological Restoration: Annual COD reduction of 1,850 tons, equivalent to eliminating 52,000 tons of domestic sewage pollution;
·Water Reuse: Recycled water is used in the industrial park's cooling system, saving 7 million cubic meters of water annually;
·Technical Benchmark: Providing a "near-zero emission" model for 47 industrial parks in the Guangdong-Hong Kong-Macao Greater Bay Area.
V. Industry Promotion and Future Evolution
5.1 Verification of Technology Applicability
Project | Water quality characteristics | COD removal rate | Cost per ton of water
|
Shandong Huangshuihe Wastewater Treatment Plant
| Printing and dyeing wastewater (containing azo dyes) | 81.2% | ￥3.8/m3 |
Longkou Second Sewage Treatment Plant | Petrochemical wastewater (containing phenol)
| 79.5% | ￥4.1/m3 |
Wenshang Chemical Park | Pesticide wastewater (containing organochlorine) | 76.8% | ￥4.3/m3 |
5.2 Future Technology Directions
·Low-carbon Operation: Photovoltaic-driven UV System (energy consumption reduced by another 30% during the pilot phase);
·AI Optimizer: Neural networks predict free radical yields and precisely match pollutant degradation pathways;
·Modular Equipment: Containerized AOP units, suitable for distributed wastewater treatment scenarios.
VI. Conclusion: Defining New Standards for Advanced Industrial Wastewater Treatment
The success of the Zhuhai Gaolan Port project demonstrates the triple value of the three-stage advanced oxidation technology:
·Technical Value: Solve the challenge of deep removal of recalcitrant organic matter, achieving a stable COD ≤ 50 mg/L;
·Economic Value: Reduce lifecycle costs by 40% compared to traditional processes, with an ROI of less than 3 years;
·Ecological Value: Transform emissions from "compliant" to "eco-friendly," facilitating the transition to green manufacturing.
ONYX's core technology system, encompassing "free radical targeted regulation, precise energy efficiency management, and intelligent collaborative control," is driving industrial wastewater treatment from "passive compliance" to a new era of "active ecological value creation."
Municipal Wastewater
Municipal water supply
Recycled Water Reuse
Township water supply and drainage
Industrial Park
New pollutant control
Water ecological restoration project
