Highly Effective Large-Area Inactivation of B. subtilis Spore Using a Planar Dielectric Barrier Discharge Jet With CF4/Air Mixture

Abstract

In this paper, we demonstrate that, by adding a small amount of CF4 (2%) into a compressed-air planar dielectric barrier discharge (DBD), one can effectively inactivate a B. subtilis spore up to 50 mm in width in the postdischarge jet region after ten passes of exposure of plasma plume (equivalent plasma exposure time of 1 s) for treatment distance of up to 14 mm for the spore concentration in the range of 10(5)-10(7) CFU/mL. A possible mechanism is proposed, i.e., the chemically active F atoms and CFn (n = 1-3) are generated through the help of abundant excited nitrogen molecules in the postdischarge region.