[Studies for killing the oceanic harmful organisms in ship's ballast water using hydroxyl radicals]

With a physical method of strong electric-field discharge, O2 in air and H2O at gas state are ionized and dissociated into a number of activated particles such as *OH, O2+, H2O+, etc, which are injected into a part of ballast water to form the dissolved *OH. High concentration of *OH solution was injected into the main pipe of discharge ballast water to effectively and fast kill the oceanic harmful organisms and bacteria in the course of conveying ship's ballast water. In the 10 t x h(-1) experimental system of ship's ballast water, the experiments were carried out for killing the plankton and bacteria using *OH radicals. The *OH concentration is 0.65 mg x L(-1) for 100% killing efficiency. At the same time, cell morphology changes of Chaetoceros muelleri and Nitzschia closterium were observed by a microscope. The cells of algae in their cellular wall, cellular membrane or cell protoplasm were greatly destroyed using *OH radicals.