A new UVC-LED system for disinfection of pathogens generated by toilet flushing

摘要

A new disinfection system utilizing UVC-LED irradiation was developed. The systemwas affixed to the toilet seat, and it was challenged by three bacteria strains.Different configurations were tested: 3-LEDs, 5-LEDs (two variants), and 8-LEDs. Todetermine the arrangement designs of LEDs with the optimum efficacy, two variantsof 5-LEDs configurations were additionally considered-uniform and concentrated(2-sided) distributions. It was noticed that disinfection efficacy initially increasedwith the number of LEDs, but with 8-LEDs, the trend became almost non-obviousfor surface disinfection and just marginally increased for airborne disinfection.The mean efficiencies for the surface disinfection ranged from 55.17 ± 23.89% to72.80 ± 4.13% for E. coli; 36.65 ± 2.99% to 50.05 ± 13.38% for S. typhimurium; and8.81 ± 3.23% to 39.43 ± 9.33% for S. epidermidis. Likewise, the mean efficiencies forairborne disinfection ranged from 42.17 ± 8.18% to 70.70 ± 4.80%; 40.40 ± 17.90%to 58.31 ± 13.87%; and 24.16 ± 3.81% to 42.79 ± 10.20% for E. coli; S. typhimurium;and S. epidermidis, respectively. Furthermore, the efficacy of the uniform irradiationwas nearly twice that of the concentrated irradiation for surface disinfection and17.70% higher for airborne disinfection, when tested against E coli. Collectively, thesevery promising results showcased that this compact, sustainable, and localized disinfectionsystem has a high potential for the next generation of disinfection devices.