A pilot-scale experiment of 20 t/h for the treatment of ship’s ballast water is re-ported in this paper. When the concentration of the dissolved OH· was 0.68 mg/L during theexperiment, the rate of destroying bacteria, mono-algae, protozoan reached 100% within 2.67 s.The effect of hydroxyl radicals on biochemical processes was also studied. The attenuation rateof photosynthesis pigment was 100%. And the main reason for the cells’ death was the strongdestruction of the monose, amylose, protein, DNA and RNA in the cells. As an advanced oxida-tion method, the procedure can destroy invasive marine species when a ship is in the process ofdischarging its ballast water.
Abnormal phenomena that discharge performance declines with the increase in thefrequency of power supply have been observed in many DBD devices. DBD systematic resonanceformed by transformer leakage induction and equivalent capacitance of the dielectric layer is a keyfactor causing such abnormal phenomena. Therefore, the parameters of a DBD device should beoptimized to avoid resonance damage and improve DBD discharge characteristics.
The performance of dielectric material is a key factor against a long time actionin dielectric barrier discharge (DBD) plasma.In this study,the aging of the Al_2O_3 dielectricmaterial was studied by the Atomic Force Microscope (AFM),X-ray Photoelectron spectrum(XPS) and Auger electron spectrum (AES) methods.The results showerd that the performanceof the dielectric does not descend after an 1000 h aging experiment.Therefore the thin dielectriclayers of α-AL_2O_3 porcelain with a purity above 99% can sustain a long time action of DBDplasma and form gas ionization discharges steadily.
