Hybrid grafted ion exchanger for decontamination of radioactive cesium in Fukushima Prefecture and other contaminated areas

Abstract

We have developed a material that can be used to remove cesium (Cs) in Fukushima Prefecture and other contaminated areas. The developed material was prepared by radiation-induced graft polymerization of ammonium 12-molybdophosphate and acrylonitrile onto nonwoven polyethylene fabric. To evaluate the adsorption performance of the developed material, we conducted batch and column experiments by using a Cs solution with a concentration of 1 ppm at pH 7. In the batch study, the adsorbent was able to remove 90, 87 and 64 % of Cs from pure water, acidic water and seawater, respectively. In the column study, adsorbent packed in a column with a diameter of 7 mm and a height of 5 cm was able to remove nearly the entire amount of dissolved Cs. The solution (1 ppm Cs at pH 7) was pumped into the column at a space velocity of 300 h⁻¹, in which the Cs adsorption capacity at the breakthrough point reached 54 g-Cs/kg-adsorbent. Adsorbent grafted into a cartridge with a diameter of 4 cm and a height of 3.8 cm was used in a field test on removing dissolved radioactive Cs in Iitate-mura, and this test was conducted successfully.