A pilot-scale experiment of 20t/h for the treatment of ship＇s ballast water is reported in this paper. When the concentration of the dissolved OH. was 0.68 mg/L during the experiment, 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 rate of photosynthesis pigment was 100%. And the main reason for the cells＇ death was the strong destruction of the monose, amylose, protein, DNA and RNA in the cells. As an advanced oxidation method, the procedure can destroy invasive marine species when a ship is in the process of discharging its ballast water.
Abnormal phenomena that discharge performance declines with the increase in the frequency of power supply have been observed in many DBD devices. DBD systematic resonance formed by transformer leakage induction and equivalent capacitance of the dielectric layer is a key factor causing such abnormal phenomena. Therefore, the parameters of a DBD device should be optimized to avoid resonance damage and improve DBD discharge characteristics.
The performance of dielectric material is a key factor against a long time action in dielectric barrier discharge （DBD） plasma. In this study, the aging of the Al2O3 dielectric material was studied by the Atomic Force Microscope （AFM）, X-ray Photoelectron spectrum （XPS） and Auger electron spectrum （AES） methods. The results showerd that the performance of the dielectric does not descend after an 1000 h aging experiment. Therefore the thin dielectric layers of α-Al2O3 porcelain with a purity above 99% can sustain a long time action of DBD plasma and form gas ionization discharges steadily.
