Decontamination of Cesium From Contaminated Water Using a Selective Adsorbent and Magnetic Separation

Radioactive cesium was released from nuclear accidents such as Fukushima and Chernobyl's nuclear power plant accident. The released cesium contaminated the water and soil environment around the accident area. Common environmental technologies for water and soil could not be used for the cesium-contaminated environment due to several reasons. The radioactive cesium exists as in a trace amount and with other common cations such as calcium and sodium. The coexisting cations interfere the removal of cesium and increase the final waste. Magnetic separation combined with adsorption technology can be applicable to the removal of radioactive cesium from water environments. In current study, a selective adsorbent for cesium, i.e., silicotitanate, was synthesized and tested for cesium selectivity. The cesium-selective adsorbent was magnetized and separated from water using a superconducting magnet. The decrease of sorption capacity was evaluated after magnetization. The cesium selectivity was sustained after the magnetization. The removal efficiency of magnetized silicotitanate was highly dependent on the magnetic field and magnetizing method. Complete removal of the magnetized adsorbent was achieved by a superconducting magnet, indicating that a superconducting magnet system with magnetized silicotitanate can be an alternative for water treatment from nuclear accident sites.