Success in Developing Technology for Removing and Recovering Cesium (Stable Isotope)

December 26, 2011

 JNC Corporation (head office: Chiyoda-ku, Tokyo, President: Michio Morita) has succeeded in developing the technology for removing and recovering cesium (stable isotope) in a laboratory scale for cesium-contaminated water including seawater. This technology can also be utilized for removing and recovering radioactive cesium contained in radioactively-contaminated water generated by the Great East Japan Earthquake.

 The technology developed here is provided for removing and recovering cesium from contaminated water by adding water-soluble ferrocyanide to cesium-contaminated water to form a cesium complex, further adding iron chloride to be a magnetic raw material to the cesium complex and allowing them to react, and forming a cesium complex having magnetism using an alkaline aqueous water solution, and then performing magnetic separation of the cesium complex using a magnet.

 According to this technology, as compared with the case of using solid adsorbents such as zeolite, a high rate for removing cesium is achieved in a short treatment time, and furthermore, reduction of waste volume is expected. Moreover, realization of a quick separation operation and treatment in a closed environment or by means of remote control is allowed because the magnetic separation method is applied. Only an industrially easily available and less expensive material is used, and thus reduction of cost for removing cesium is also expected.

 According to the tests using an aqueous solution having a concentration of about 10 ppm of cesium mixed with seawater in the laboratory scale, the treatment operation was completed within ten minutes, combining the reaction time for producing the cesium complex and the magnetic separation time, and 99.5% of cesium was removed in a single operation.

 This technology can be widely applied. For example, this technology is conceivably used for the method for removing cesium from wash water of radioactively-contaminated soil.

 At present, our Company advances technology development in a bench scale by targeting establishment of a process for removing cesium industrially for the purpose of treating a large amount of contaminated water, and intends to bring the technology to early completion.