Airborne Virus Capture and Inactivation by an Electrostatic Particle Collector

Abstract

Airborne virus capture and inactivation were studied in an electrostatic precipitator (ESP) at applied voltages from -10 to +10 kV using aerosolized bacteriophages T3 and MS2. For each charging scenario, samples were collected from the effluent air stream and assayed for viable phages using plaque assays and for nucleic acids using quantitative polymerase chain reaction (qPCR) assays. At higher applied voltages, more virus particles were captured from air with maximum log reductions of 6.8 and 6.3 for the plaque assay and 4.2 and 3.5 for the qPCR assay at -10 kV for T3 and MS2, respectively. Beyond corona inception (i.e., at applied voltages of -10, -8, +8, and +10 kV), log reduction values obtained with the plaque assay were much higher compared to those of the qPCR assay because nonviable particles, while present in the effluent were unaccounted for in the plaque assay. Comparisons of these assays showed that in-flight inactivation (i.e., inactivation without capture) was greater for the highest applied voltages with a log inactivation of 2.6 for both phages at -10 kV. We have demonstrated great potential for virus capture and inactivation via continual ion and reactive species bombardment when conditions in the ESP are enforced to generate a corona discharge.

Performance of Conventional and Antimicrobial-Treated Filtering Facepiece Respirators Challenged with Biological Aerosols

“…An LIV > 0 indicates that the penetration of viable particles is lower than would be expected based on a physical filtration mechanism alone, (28) consistent with an AM-FFR that inactivates airborne bioaerosols as they penetrate through it. An advantage of the LIV statistic is that it is a direct comparison of the viable and physical penetrations for a given respirator model.…”

Microwave-irradiation-assisted HVAC Filtration for Inactivation of Viral Aerosols

“…As a direct disinfection technology without filters, an electrostatic precipitator (ESP) at ± 6 kV was reported by Kettleson et al (2009) to exhibit 2-log IE of MS2 and at -10 kV it could reach above 6-log IE. However, using negative corona in ESP disinfection should be cautioned because of the formation of ozone.…”

Soft-X-Ray-Enhanced Electrostatic Precipitation for Protection against Inhalable Allergens, Ultrafine Particles, and Microbial Infections

“…The corona inception voltage is less clear under conditions when the X-ray was turned on (X-ray-on condition). However, based on the magnitude of reduction in applied voltage shown in previous studies incorporating in situ soft X-ray irradiation (19,23,24), a corona inception voltage of approximately Ϫ5.25 kV would be expected in the X-ray-on condition (Fig. 1A).…”

“…Hogan et al (23) demonstrated both enhanced charging and improved collection efficiency of aerosolized bacteriophage MS2. In a follow-up study, molecular microbiological techniques were used to quantify the level of in-flight inactivation of bacteriophages T3 and MS2 passing through a soft-X-ray-enhanced ESP system (24).…”