Japan research team creates radioactive cesium adsorbents from pumice

The Yomiuri Shimbun
Pumice stones collected near Ako fishing port in Miyakejima island are seen.

There are moves to put the gathered pumice stones to use.

A research team from the Kanagawa Institute of Industrial Science and Technology and other institutions announced that they had created from pumice stones zeolites, minerals used as adsorbents. Zeolites are used at the Tokyo Electric Power Company Holdings Inc.’s Fukushima No.1 nuclear power plant to collect radioactive material. Zeolites have numerous holes of around 0.5 nanometers on the surface and adsorbs materials such as radioactive cesium.

The research team aims to put the zeolites into practical use for that and other purposes.

The Okinawa prefectural government has been scooping up pumice stones using heavy machinery and transporting them to a temporary disposal site, but how to finally dispose of them is becoming an issue.

The research team focused on the fact that pumice stones contain aluminum and other materials that are ingredients to creating zeolites. They added pumice stones arriving on the shores of Yoron Island in Kagoshima Prefecture to alkaline aqueous solutions and heated the solutions at around 100 C, forming zeolites on the surface of the stones.