Aerosol Sterilization by Impulse High Voltage with Different Electrode Structures

Airborne infection is caused by the inhalation of particles floating in a space, while droplet infection is caused by adhesion or inhalation of particles accelerated by coughing or sneezing. The space sterilization and inactivation functions of air purifiers in practical use mainly generate active species (radicals) by discharge plasma and achieve sterilization by their strong oxidizing power. However, because the reaction can only contribute to sterilization for an extremely short period of time, there are no air purifiers that can achieve highly efficient sterilization in real spaces with flow. In addition, those that mechanically collect water particles containing pathogenic bacteria in a space using a filter or fan cause the bacteria to grow inside the device, and the spraying causes the spread of infection. Therefore, in this study, we attempted to inactivate bacteria in aerosols by applying a pulse voltage instead of UV irradiation or ozone disinfection. In addition, while previous attempts have been made to agglutinate and inactivate aerosols in an enclosed space, in this study we attempted to inactivate bacteria in an environment where aerosols are circulating. In addition, since more efficient bacterial inactivation can be expected by changing the distance between electrodes and the electrode structure even at the same applied voltage, experiments were also conducted in this study by changing the electrode spacing and by using wire-mesh electrode and mesh-mesh electrodes. As a result, Gram-negative bacteria and Gram-positive bacteria were sterilized at 10
⁵
CFU/ml or more at the wire-pair mesh electrode.