Advancing decontamination technologies by increasing the efficiency of infected fluid treatment using transparent periodic optical structures penetrated by UV-C radiation.

A new UV-C decontamination device has been tested at laboratory scale for its potential to inactivate microorganisms in commercial baker's yeast solutions used in baking. The device includes a flow chamber in which the liquid follows a helical path generated by a quartz spiral positioned between two concentric quartz tubes, with the space between the spirals filled with periodic optical structures made of quartz periodical optical structures (POS), such as fibers, beads or fragments, and inside this flow system is an 18W UV-C lamp with an irradiance of approximately 18-20 W/m2 at 254 nm. The combined effect of the helical motion of the fluid and the quartz optical structures increases microbial exposure to UV-C radiation, resulting in a significantly increased inactivation rate of pathogens in infected liquids compared to conventional UV systems. Unlike our previous study on the influence of quartz metamaterial packing geometries on UV-C decontamination efficiency, the present work introduces a controlled helical-flow reactor. The key novelty lies in its practical implementation and in demonstrating the physical mechanisms responsible for significantly enhanced microbial inactivation compared to conventional UV-C systems.