OCEAN DECONTAMINATION: REMOVAL EFFICIEMCY OF RADIOACTIVE CESIUM FROM OCEAN SLUDGE BY USING MICRO BUBBLES AND ACTIVATING MICROORGANISMS

Abstract

The Fukushima nuclear accident of March 11, 2011, soil and water had been contaminated by
radioactive cesium. Moreover, radioactive cesium was found in the sludge in Tokyo Bay by flowing from
rivers. Here, it cannot be easily removed the cesium which is adsorbed to the sludge. On the other hand, one
of the authors had developed the decomposition system for sludge with circulation type by micro-bubbles
and activating microorganisms. Here, based on the hypothesis that radioactive cesium is adsorbed on the
surface of the sludge. It is considered radioactive cesium can be eluted, after decomposing the deposited
sludge by the decomposition system. If the cesium will be eluted to the water, we can fix the cesium by
existing technology such as “Zeolite”. In this study, our objects is to check the removal performance of
cesium after the decomposition and elution from the sludge and then fix of cesium in the decomposition
system. As the results, we obtained the removal efficiency of cesium was 62.7%.