Comparative Inactivation of Bacillus subtilis Spores Using a DBD-Driven Xenon Iodide Excilamp and a Conventional Mercury Lamp

In this paper, we compared the inactivation of
Bacillus subtilis
spores in water by means of a dielectric-barrier-discharge (DBD)-driven XeI* excilamp and a low-pressure mercury lamp. The main part ( ~ 76%) of the excilamp output was due to the
B
→
X
transition of XeI* exciplex at 253 nm. It is shown for the first time that a better sterilization action is achieved with the DBD-driven XeI* excilamp compared with the monochromatic mercury lamp at the same UV dose. The contribution of an atomic iodine emission in the range of 178-207 nm has been confirmed. Germ-reduction experiments with the XeI* excilamp have been carried out in a steady-state mode and in a water-flow reactor.