Pulsed periodic corona discharges for biological decontamination

The present paper explores the possibilities of using impulsive and steady-state corona discharges for biodecontamination operations. A high tension tubular corona electrode was stressed with positive or negative DC voltage with magnitude up to 26 kV, and a grounded mesh was used as an opposite electrode. Different operational regimes of this corona generator were investigated for the production of ozone in air flow and the inactivation of microorganisms. The test microorganism used in this work was E. coli. The results show that corona-generated ozone, and potentially other chemical species, have a strong bactericidal effect, for example positive flashing corona discharges were able to reduce populations of the test microorganism by ~95% within a 30-60 sec time interval. The bactericidal efficiency of different corona discharge modes and its correlation with ozone levels is discussed. The results obtained in this work will help in the design and development of compact plasma systems for environmental applications.