Bacterial inactivation by pulsed corona discharge in water

The decontamination effect of underwater pulsed corona discharge on gram-negative bacteria Escherichia coli and gram-positive bacteria Enterococus faecalis has been investigated. The reactor of needle-plate electrode geometry was used. The concentration of both types of bacteria decreased exponentially with increasing discharge treatment time and supplied energy input. The contribution of UV radiation and hydrogen peroxide in the overall bacterial inactivation efficiency of the discharge has been determined. UV light emitted from the discharge plasma channels was found to have significant effect on the bacterial inactivation and its contribution was estimated to be about 30%. Effect of hydrogen peroxide was small, however, under influence of high electric field its lethal activity was greatly enhanced.