This study aims to inactivate Artemia sp. (Zooplankton) in ballast water through the dielectric barrier discharge (DBD) plasma process. The DBD plasma process has the advantage of enabling direct electric discharge in water and utilizing chemically active species generated by the plasma reaction. The experimental conditions for plasma reaction are as follows; high voltage of 9-22 kV, plasma reaction time of 15-600 s, and air flow rate of 0.5-5.5 L/min. The results showed that the optimal experimental conditions for Artemia sp inactivation were 16 kV, 60 s, 2.5 L/min, respectively. The concentrations of total residual oxidants and ozone generated by plasma reaction increased with an increase of in voltage and reaction time, and the concentration of generated air did not increase above a certain amount.

The International Maritime Organization (IMO) ballast water management agreement (International Convention for the Control and Management of Ship's Ballast Water and Sediments) came into force on September 8, 2017. This study evaluated the disinfection performance of electrolysis, UV treatment, and electrolysis + UV combined, to improve the treatment of zooplankton (size ≥ 50 μm), which is expected to strengthen the standards for biodegradation efficiency. Among the methods used, the disinfection time leading to 100% death was in the order: electrolysis > electrolysis + UV > UV process. For the same level of disinfection performance, the amount of electricity required for the electrolysis, UV, and electrolysis + UV processes were 1,300 W.s, 8,400 W.S, and 4,500 W.s, respectively. The combination of electrolysis + UV process for inactivation of zooplankton in ballast water did not show a synergic effect owing to the slow disinfection time and high power consumption.

Carbon biomass of plankton community, Total Organic Carbon (TOC) and Chlorophyll a (chl.a) concentration were examined in the SeoNakdong river from January to December in 2014, to assess composition of phyto- and zoo-plankton variation, to certify the correlation between chl.a and TOC and to determine the level of contribution of plankton carbon content to TOC in the reservoir-river ecosystem. The correlation level between TOC and chl.a was low in the year 2014 but exceptionally was highly correlated only during the period with cyanobacterial bloom. The high level of contribution of plankton carbon content to TOC was attributed to cyanobacterial carbon biomass from May to November and to Cladocera carbon biomass from March to May, November and December despite of its low abundance. These results suggest that there were inter-relationships between phytoplankton, zooplankton and TOC and also subtle consistency of their properties through the year. These patterns should be discussed in relation to the physiochemical and biological characteristics of the environment, as well as to allochthonous organic matters from non-point pollution sources.

In this study, we discussed about the application of the single physical and chemical treatment processes and the physical-chemical complex treatment processes on the inactivation of Artemia sp. in order to satisfy the USCG Phase Ⅱ (United States Coast Guard). The results showed that initial disinfection rate of ultrasonic process in single batch process is higher than that of electrolysis. However, the inactivation rate showed slower than electrolysis. The inactivation rate of Artemia sp. on the single continuous treatment process ranked in the following order: homogenizer 〉 electrolysis 〉 ultrasonic process. Inactivation rate of Artemia sp. in continuous homogenizer-electrolysis complex process was reached at 100% immediately. A synergistic effect of ultrasonic–electrolytic complex process was found to be a small. The order of processes in a complex process did not affect the disinfection performance.

In order to clarify the seasonal composition and abundance of zooplankton community in Macheon Bay. the study was carried out trimonthly during the period from April 1996 to January 1997. 37 taxa and 7 unconfirmed species of zooplankton was identified. It consisted of 28 species of Protozoa. 1 species of Cnidaria, 1 species of Annelida, 2 larva of Mollusca, 3 species of Rotifera, 4 species and 4 larva of Arthropoda and 1 larva of Echinodermata, respectively. Seasonal succession of the dominant species was Tintinnopsis beroidea in the spring. Copepodite in the summer. Tintinnopsis directa in the autumn and Ceratium fusus in the winter. Abundance of zooplankton ranged from 4.720 to 4 1.215 inds./ . It was high in the summer (4 1.215 inds./ ) and low in the spring (4.720 inds./ 1 ). Dominant index ranged from 0.133 (in the spring) to O. 551 (in the winter). Species diversity index ranged from 1.114 (in the winter) to 1.996 (in the spring).