Photocatalytic oxidation conveyor PCOC system for large scale surface disinfection

In this paper, we present a surface decontamination system that substitutes traditional chemicals and scrubbing agents, which will be useful for the general public during a pandemic. The technique is based on a hybrid process in which UV-C light and its photons interact with metal oxide nano-catalysts to generate hydroxyl radicals, which can enhance the deactivation process, and the system can work even in the shadow regions via a dry process. The optimum number of UV light sources in combination with TiO2 nanoparticles catalysts on aluminum plates have been used synergistically in the system. The UV dose in the disinfection chamber has been optimized, which is between 60 and 500 mJ/cm(2) throughout the disinfection chamber. The concentration of hydroxyl radicals is reported more than 25 000 ions/cm(3) within the disinfection chamber. These ions are circulated throughout the disinfection volume. The disinfection efficiency has been tested on bacteria and spores, and the obtained results are correlated. Around 8 log reductions in the counts of the test bacteria of Escherichia coli and Klebsiella pneumoniae have been achieved in just 2 min of exposure in the continuous operation of the system. Tests have also been performed on Geobacillus stearothermophilus spores, and the method described here is the result of multiple tests, a review of the scientific literature, and the incorporation of current laboratory practice. The deactivation tested in the system is larger than that of known bacteria and viruses in terms of UV-doses, signifying its utility during the pandemic. Published under an exclusive license by AIP Publishing.

Automated summary

This paper presents a surface decontamination system that can replace traditional chemicals and scrubbing agents. The system utilizes UV-C light and metal oxide nano-catalysts to generate hydroxyl radicals, enhancing the deactivation process. It can work in shadow regions and has been optimized for disinfection efficiency. Tests have shown significant reduction in bacterial counts within just 2 minutes of exposure in the continuous operation of the system.