Photo-fenton swan neck reactor for air pollutant and microbial removal

Overview

This solution is a modular air-treatment reactor that uses a photo-Fenton reaction — combining ferrous iron, LED-UV light, and hydrogen peroxide — to degrade volatile organic compounds (VOCs) such as benzene, acetone, and toluene while simultaneously inactivating airborne viruses and bacteria. The unit is designed to operate as a standalone module or to be integrated into existing filtration systems, including HEPA-filtered units, without degrading filter performance or producing harmful emissions. Its simple, robust design with no moving parts makes it a low-cost, low-maintenance option for facilities requiring clean, sterile air.

Technical specifications

Core technology:

• Photo-Fenton chemistry generates short-lived hydroxyl radicals that react with VOCs and microbes without leaving residues
• Iron "swan neck" structures serve as both catalyst and reaction surface
• LED-UV light source provides reliable, low-energy activation
• Fine mist of hydrogen peroxide introduced at the reactor inlet
• Open-ended reactor configuration with outer casing to contain UV photons
• No moving parts, minimizing mechanical failure risk

Performance validated in prior studies:

• Achieved 6-log reduction of Geobacillus endospores on masks
• Achieved 5-log reduction of Salmonella on shelled egg surfaces
• Treatment time of approximately 5 seconds
• No detectable hydrogen peroxide emissions at the outlet

Planned validation targets:

• 3-log reduction of resistant microbes including bacteriophages, E. coli, Lactobacillus, Geobacillus endospores, yeast, and moulds
• VOC degradation below 30 ppb detection limit
• Variables under study: reactor configuration, air velocity, hydrogen peroxide concentration, and spray volume

Technology readiness level

The underlying photo-Fenton chemistry has been validated in related applications for water and surface treatment, where hydroxyl-radical generation was confirmed and full degradation of hydrogen peroxide was achieved with no residual emissions. The air-treatment reactor design is currently at an early-to-mid development stage. Prototype construction of the ferric swan-neck UV-LED reactor is planned, with controlled trials against representative VOCs and a panel of viral and microbial targets underway. The technology is positioned for collaborative development with industry partners interested in cleanroom, healthcare, food processing, or indoor air-quality applications.