Inactivation of dinoflagellate Scrippsiella trochoidea in synthetic ballast water by reactive species generated from dielectric barrier discharges

The inactivation of dinoflagellate Scrippsiella trochoidea in synthetic ballast water by a dielectric barrier discharge (DBD) system was investigated. The radical, ozone and hydrogen peroxide generated from the DBD system were measured. Before and after the treatment, the viability of dinoflagellate S. trochoidea was evaluated by analyzing chlorophyll a, protein and saccharide content and morphology of the cells, as well as the pH of the cell culture media. The results show that radical was the major reactive species when humid air was used. The inactivation of S. trochoidea was found to be dependent on the applied voltage and the gas flow rate, and was completed within 4 min at a gas flow rate of 7 L min−1 and an applied voltage of 20 kV. The change of chlorophyll a, protein and saccharide concentrations of S. trochoidea and the morphology of the cells indicates that the reactive species generated from the DBD system can break up the cells via oxidation.