Application of Prussian blue nanoparticles for the radioactive Cs decontamination in Fukushima region.

Cs decontamination efficiencies of the composites of iron hexacyanoferrate nanoparticles were investigated in comparison with commercial Prussian blue and natural zeolite. In pure water solution, the adsorption rate varied with sizes. In ash extract, where Cs adsorbing ability of zeolite was sharply dropped due to its poor selectivity, the impact of coexisting ions was negligible for FeHCF. FeHCF-n11, having the finest primary and secondary particle size, resulted the highest distribution coefficient, which was comparable to the high efficiency analogues, CoHCF or NiHCF. This observation suggested the possibility of preparing the high performance FeHCF by particle size and composition adjustment. FeHCF nanoparticle in bead form was tested for the removal of radioactive Cs in pilot scale. Due to larger secondary particle size, pronounced effect of solution temperature on the Cs adsorption kinetics on FeHCF bead was observed. Adjusting the mass of the adsorbent for the given solution temperature is recommended for achieving high decontamination rate.