A REVIEW ON ORGANISM REGROWTH IN UV-BASED BALLAST WATER TREATMENT SYSTEMS FOR THE APPROVAL OF NEW G8 GUIDELINES

Abstract

In light of urgent need of approval of ballast water management system against the new G8 guidelines, organism regrowth within treated ballast water should be assessed. However, it’s the first time for mandatory demands on the evaluation of organism regrowth in ballast water. For the existances of DNA repair enzymes, UV-based systems have the risks of organisms regrowth after treatment. So far a range of algae and bacteria have been observed the recovery after UV irridation in the simulated ballast water or real ballast water during 1-day to 9-day culture. The target organisms, UV doses, recovery date and regrowth enviroment will be compared in such regrowth experiments. Also, the possible pathways of the regrowth will be discussed in the paper, with the consideration of both light repair and dark repair. Based on the reviews of current researches, the available methods will be explored to inhibit the organism regrowth in the UV-based ballast water treatment systems. For the compliance of the new G8 guidelines, UV-based systems are supposed to be assessed on organism regrowth, and the modificaiton methodologies were suggested for the currently approved UV-based systems to minimize the regrowth risks.