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The effect of Tf2N−, as a common anion in aqueous and ionic liquid (IL) phases, on Cs extraction in the IL system was investigated using C2mimTf2N as an IL and DCH18C6 as an extractant. The "common anion (Tf2N−) effect" operated via the movement of Cs+·Tf2N− from the aqueous phase into the IL phase by extraction in the form of Cs+·extractant·Tf2N−, without any traditional cation exchange. The extraction product was recovered as a precipitate using a small amount of IL, which facilitated precipitation via supersaturation. [ABSTRACT FROM AUTHOR]

The spontaneous reductive decomposition behavior of HMnO4 in water as a function of the initial HMnO4 concentration and reaction temperature was investigated. The decomposition of HMnO4 was fast in the early stage of the reaction and thereafter slowed down significantly, regardless of the initial HMnO4 concentration. The loss of HMnO4 by spontaneous reductive decomposition increased with increasing reaction temperature. Based on the experimental results and the classical nucleation theory, a mathematical model was developed using a combination of two first-order reactions representing the nucleation and crystal growth of MnO2 to predict the spontaneous reductive decomposition behavior of HMnO4. [ABSTRACT FROM AUTHOR]

In this study, copper ferrocyanide-functionalized, multi-walled carbon nanotubes (MWCNT-CuFCs) were synthesized. The MWCNT-CuFCs exhibited a high capacity for sorbing Cs from aqueous solutions because of their strong affinity for Cs and high specific surface area. The sorption capacity of the MWCNT-CuFCs for Cs was dependent upon the initial pH of the solution. The sorption ability of the MWCNT-CuFCs for Cs was maintained even in the presence of co-existing ions (K and Na). To determine the degree of Cs desorption from the MWCNT-CuFCs, a column-based desorption experiment was performed. [ABSTRACT FROM AUTHOR]

The process characteristics of a new solid-liquid Cs+ separation from the radioactive liquid waste using a crown ether dicyclohexano-18-crown-6 as an extractant and an ionic liquid of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide were studied. The physicochemical properties of the precipitate containing Cs+ which is an solid-liquid extraction product were investigated to identify the solid-liquid phase separability and Cs+ loading. The Cs+ separation process performances were compared experimentally with those of the conventional adsorption system for pretreatment requirement and the amount of Cs+ waste. It was observed that the solid-liquid separation method using ILs has high Cs+ separation performance especially in the low Cs+ concentration. [ABSTRACT FROM AUTHOR]

Zinc hexacyanoferrate functionalized magnetic carbon nanotube composites were synthesized to be used as adsorbents for the selective removal of Cs. The synthesized adsorbents exhibited a high adsorption capacity that could be successfully improved by increasing the loading of zinc hexacyanoferrate, which plays a major role in selectively adsorbing and removing Cs from the adsorbent surface. Although the saturation magnetization value for the synthesized adsorbents decreased with increasing zinc hexacyanoferrate loading, the adsorbents could be sufficiently separated by using a permanent magnet. [ABSTRACT FROM AUTHOR]

Selective separation of Cs from liquid radioactive waste by 'precipitation' was observed in a hydrophobic ionic liquid containing the Cs-selective extractant dicyclohexano-18-crown-6. The precipitate was formed by the cation exchange mechanism, which simplified the treatment of Cs after extraction. Solid-liquid extraction is a more economical extraction system than liquid-liquid extraction because it uses smaller quantities of ionic liquids. This work showed the possibility of developing a new method for removing Cs from liquid radioactive waste using solid-liquid phase separation instead of the conventional liquid-liquid separation in an ionic liquid extraction system. [ABSTRACT FROM AUTHOR]