The Study on the Marine Eco-toxicity and Ecological Risk of Treated Discharge Water from Ballast Water Management System Using Electrolysis

The International Convention for the Control and Management of Ship`s Ballast Water and Sediments was adopted at 2004 and then various BWMS (ballast water management system) have been developed. In this study, WET (whole effluent toxicity) test with algae (diatom) Skeletonema costatum as primary producer, invertebrate (rotifera) Brachionus plicatilis as 1st consumer and fish (olive flounder) Paralichthys olivaceus as predator, chemical analysis and ERA (environmental risk assessment) were conducted to assess the unacceptable effect on marine ecosystem by emitting the discharge water treated with AquaStar BWMS using electrolysis as main treatment equipment for removing the marine organisms in the ship`s ballast water. The most sensitive test organism on discharge water treated with AquaStar BWMS was S. costatum that gave the NOEC value of 25.00%, LOEC value of 50.00% and 72hr- value of 69.97% from WET test result for 20 psu salinity treated discharge water. NOEC and LOEC value of B. plicatilis and P. olivaceus exposed at 20 psu salinity treated discharge water were 50.00% and 100.00%, respectively. In the chemical analysis results, total number of substances produced by AquaStar BWMS was 18 which were bromate, 7 volatile halogenated organic compounds, 7 halogenated acetic acids, 3 halogenated acetonitriles and chloropicrin. Eighteen substances did not consider as persistence and bioaccumulative chemicals. Uncertainty of toxic property of 18 substances was high. PECs of 18 substances calculated by MAMPEC model were ranged from to , PNECs of them were ranged from to . And, the PEC/PNEC ratio of 18 substances did not exceed 1. Therefore, ERA for produced substances indicate that the discharge water treated with AquaStar BWMS does not pose unacceptable effect on marine life. And value of S. costatum on discharge water treated by BWMS using the electrolysis had positive correlation with initial TRO concentration, concentration and kind & level of HAAs.