Comparison of disinfection performance of UVC-LED and conventional upper-room UVGI systems

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Detail(s)

Original languageEnglish
Pages (from-to)180-191
Journal / PublicationIndoor Air
Volume30
Issue number1
Online published5 Nov 2019
Publication statusPublished - Jan 2020

Abstract

We developed a novel, compact upper-room ultraviolet germicidal irradiation system with light-emitting diode sources (UR-UVGI-LED) to enhance the disinfection of bioaerosols in an enclosed room space. Its effectiveness was evaluated and compared with the conventional upper-room ultraviolet germicidal irradiation system with mercury vapor sources (UR-UVGI-MV). Escherichia coli, Serratia marcescens, and Staphylococcus epidermidis were atomized under the well-mixed condition and exposed to UR-UVGI-LED (or UR-UVGI-MV) device. The intensity output of the UR-UVGI-LED was also varied from 0% (no LED), 25%, 50% to 100% to further evaluate the UR-UVGI-LED disinfection effectiveness under different power levels. The decay rates for UR-UVGI-LED ranged from -0.1420 ± 0.04 min-1 to -0.3331 ± 0.07 min-1 for Escherichia coli, -0.1288 ± 0.01 min-1 to -0.3583 ± 0.02 min-1 for Serratia marcescens, and -0.0330 ÷ 0.01 min-1 to -0.0487 ± 0.01 min-1 for Staphylococcus epidermidis. It was noticed that the intensity level had a non-linear influence on the UR-UVGI-LED's performance. The decay rates achieved by the UR-UVGI-MV system were -0.3867 ± 0.08 min-1, -0.4745 ± 0.002 min-1, and -0.1624 ± 0.02 min-1 for Escherichia coli, Serratia marcescens, and Staphylococcus epidermidis, respectively. Hence, the disinfection performance of both UR-UVGI-LED and UR-UVGI-MV systems was comparable for Escherichia coli and Serratia marcescens. These results demonstrate that the UR-UVGI-LED system has a high potential to be used as a safe and effective irradiated light source to disinfect indoor airborne pathogens.

Research Area(s)

  • airborne pathogens, disinfection bioaerosols, IAQ, light-emitting diode, ultraviolet C, upper-room UVGI, ULTRAVIOLET GERMICIDAL IRRADIATION, HVAC SYSTEMS, AIR, TRANSMISSION, BACTERIA, SUSCEPTIBILITY, INACTIVATION, TUBERCULOSIS, FILTRATION, EFFICIENCY