• 2025-07-09

Advanced Oxidation Processes (AOPs)

Advanced Oxidation Processes (AOPs)

Advanced Oxidation Processes are chemical oxidation technology systems that achieve deep degradation of pollutants by generating hydroxyl radicals (·OH). Their core mechanism is:

Reaction Mechanism

Radical Generation Path

UV/H₂O₂: H₂O₂ + hν → 2·OH

O₃/UV: O₃ + hν → O₂ + O(¹D) → ·OH

Fenton reaction (Fe²⁺/H₂O₂): Fe²⁺ + H₂O₂ → Fe³⁺ + ·OH + OH⁻

Radical characteristics

Oxidation potential: 2.8V (higher than ozone/chlorine)

Reaction rate constant: 10⁶-10⁹ M⁻¹s⁻¹ (non-selective attack on organic compounds)

Half-life: ≤10⁻⁹ seconds (requires in-situ continuous generation)

Pollutant degradation efficiency

■ Mineralization of organic matter

Objective: To completely oxidize pollutants into CO₂, H₂O, and inorganic ions

Mineralization rate control: Usually set at 70-90% (adjusted according to emission standards)

■ Key removal targets

| Pollutant Type | Removal Rate | Application Case |

|------------------|----------|------------------------|

| Drug Residues | >99% | Hospital Wastewater (Ciprofloxacin) |

| Pesticides | 95-99% | Agricultural Drainage (Atrazine) |

| Dye intermediate | >98% | Textile wastewater (azo dyes) |

Engineering application features

System composition

Oxidant dosing unit (O₃/H₂O₂ generator)

Radiation source (UV lamp 254nm/185nm)

Catalytic reactor (TiO₂ catalyst/iron-carbon micro-electrolysis)

Treating refractory COD (B/C ratio < 0.3)

No secondary pollution (no sludge generation)

Modular design (occupying <30% of conventional process)

Typical design parameters

UV dose: 40-120 mJ/cm² (pathogen inactivation)

Ozone dosage: 3-10 mgO₃/mg pollutant

Reaction time: 15-60 minutes (depending on water quality fluctuations)

Process Advantages