Although a powdered form of hydroxyapatite (p-HdA) has been studied for the adsorption of heavy metals that contaminate the restoration sites of decommissioned nuclear power plants, most of the studies are limited in the laboratory due to the head loss and post-separation in practical applications. Herein, we fabricated a porous bead form of HdA (b-HdA) as a novel adsorbent for removing radionuclides from aqueous environments via a facile synthesis by mixing the p-HdA precursor and polyvinyl butyral (PVB) as a binder and added a sintering process for the final production of a porous structure. The spherical b-HdA with an approximate diameter of 2.0 mm was successfully fabricated. The effectiveness of the b-HdA at removing Co(II) was investigated via the adsorption equilibrium at various experimental temperatures. The b-HdA exhibited the adsorption capacity for Co(II) ions with a maximum of 7.73 and 11.35 mg/g at 293 K and 313 K, respectively. The experimental kinetic data were well described using a pseudo-second-order kinetic model, and the adsorption mechanisms of Co(II) onto the b-HdA were revealed to be a chemisorption process with intraparticle diffusion being the rate-limiting step. In addition, the competitive adsorption onto the b-HdA with the order of U(VI) > Co(II) > Ni(II) > Sr(II) > Cs(I) was also observed in the multi-radionuclides system. Considering the advantages of the size, applicability to the continuous-flow column, and the easy separation from treated water, the b-HdA can be an excellent absorbent with high potential for practical applications for removing radionuclides.

Volatile, flammable carbonate-based liquid electrolytes, although they show good electrochemical performance suitable for practical use, have posed a critical threat to safeties of lithium-ion batteries. This safety concern becomes more serious in newly-emerging application fields such as (hybrid) electric vehicles and grid scale energy storage systems, which employ large-sized, high-capacity lithium-ion batteries. One promising solution to address the liquid electrolyte-induced safety issues is to replace with nonflammable, thermally-stable electrolytes. Here, we demonstrate a new electrolyte system composed of 1M LiTFSI (lithium bis-trifluoromethanesulphonimide) in sebaconitrile (SBN). The SBN is featured with high boiling temperature (~ 375 oC) and nonflammability, which are expected to enable significant improvements in high-temperature performance of SBN-based electrolytes. Based on the characterization of thermal/electrochemical properties of SBN-based electrolytes, their application to lithium-ion batteries is explored as a function of operating temperature. Notably, the cell incorporating SBN-based electrolytes show stable cycling performance at 80 oC. This advantageous effect of SBN-based electrolytes on thermal stability of cell, in comparison to conventional carbonate-based liquid electrolytes, is discussed by scrutinizing the variation in AC impedance of cells and ionic conductivity of the electrolytes as a function of temperature.