Instant inactivation of aerosolized SARS-CoV-2 by dielectric filter discharge

This study aimed to evaluate the instant inactivation effect of dielectric filter discharge (DFD) on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) aerosols. The filter consisted of one layer of ZrO2 beads covered by aluminum mesh electrodes; this porous structure of DFD part generates filter-type surface discharge and reactive oxygen species. In a closed cylindrical chamber, DFD treated air flow containing SARS-CoV-2 aerosols, primarily composed of particle diameters of <= 1 mu m. A polypropylene melt-blown filter collected the treated bioaerosols for inactivation analysis. Plaque and polymerase chain reaction assays showed that the aerosolized SARS-CoV-2 that passed through the filter were more than 99.84% inactivated with degradation of SARS-CoV-2 genes (ORF1ab and E). However, ozone exposure without DFD passage was not found to be effective for bioaerosol inactivation in plaque assay.