What Is a UV-C LED-Driven Advanced Oxidation Process?
Ultraviolet Advanced Oxidation Process (UV-AOP) is a water and wastewater treatment technology that combines ultraviolet (UV) light with an oxidant — most commonly hydrogen peroxide, but also chlorine, ozone, persulfate, or others — to generate highly reactive free radicals, primarily hydroxyl radicals (•OH), that destroy organic contaminants. UV-AOP is widely used for micropollutants and contaminants of emerging concern that conventional treatments struggle to remove.
How UV-C LED AOP Works
An oxidant (e.g., H₂O₂) is added to the water upstream of a UV reactor.
In the UV chamber, the oxidant absorbs UV light (UV-C LED typically around 275 nm).
Photolysis splits the oxidant into reactive radicals:
These radicals — especially •OH, one of the strongest oxidants — attack contaminant molecules non-selectively, breaking chemical bonds and degrading them into smaller, less harmful compounds (ideally CO₂, water, and mineral acids).
Direct UV photolysis can break down some contaminants that absorb UV light themselves, and the UV also provides disinfection by inactivating microorganisms.
Pharmaceutical and laboratory effluents contain antibiotic residues, EDCs, and toxic aromatic intermediates. These induce antimicrobial resistance (AMR) and threaten drinking water safety. Conventional processes remove less than 50% of these trace contaminants.
Low photon utilization, needs quenching of residual oxidant, high O&M costs.
Generates multiple radicals in situ, residual chlorine disinfects, no quenching step, better economics.
UV-C LEDs (270–280 nm) enable tunable wavelength, instant on/off, mercury-free operation, and >20,000-hour lifespan.
UV-C LED arrays replace mercury lamps in modern UV-AOP reactors.
Customizable 265–310 nm emission matches target contaminants, maximizing photon efficiency.
No preheating; instant on/off with precise electronic intensity control.
No mercury pollution risk and no ozone generation during operation.
>15,000 hours vs. 8,000–10,000 hours for low-pressure mercury lamps.
- Direct photolysis: UV (255–295 nm) breaks contaminant bonds.
- Indirect oxidation: •OH, •Cl, •ClO, •Cl₂⁻ attack via hydrogen abstraction, addition, hydroxylation, deamination, and C–N cleavage.
Dominant radicals depend on contaminant and pH (e.g., •SO₄⁻ for antibiotics, •OH/•Cl under acidic conditions, •OH/•ClO under alkaline conditions).
The UV-C LED-coupled chlorine process overcomes the efficiency and adaptability limits of traditional UV/chlorine. It offers a green, cost-effective route for treating toxic trace contaminants in pharmaceutical and laboratory effluents.
It simplifies workflows, cuts O&M costs, achieves degradation and disinfection simultaneously, and reduces disinfection by-products—ideal for SMEs and aligned with “Dual Carbon” goals.
