Highly Effective Large-Area Inactivation of B. subtilis Spore Using a Planar Dielectric Barrier Discharge Jet With $\hbox {CF}_{4}$ /Air Mixture

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 10⁵-10⁷ CFU/mL. A possible mechanism is proposed, i.e., the chemically active F atoms and CF (n = 1 - 3) are generated through the help of abundant excited nitrogen molecules in the postdischarge region.