LAUSR

Radioactive iodine is one of the nuclear wastes which might be released from nuclear accident. Ionic liquids could uptake iodine by halogen bonding. However, ionic liquids are generally expensive. Therefore, it is desired to enhance the iodine uptake in ionic liquids by cheap materials. In this work, the iodine uptake by mixtures of ionic liquids with various biomass (cellulose, sucrose, glucose, fructose, cyclodextrin, starch, chitosan, chitin, lignin, lysine, serine, glycine, proline, glutamine, alanine, and histidine), solvents (water, DMSO, DMF, CH3OH, and CH3CN), and supported material (montmorillonite, SiO2, coarse activated carbon, and graphene) was investigated. The results showed that iodine uptake could be enhanced by some types of amino acids, biomass polymers, and carbohydrate compounds. The proline dissolved in [BMIM][Ac]/DMSO mixture with a mass ratio of 1:1 can absorbed 92% iodine in 5 h. The glucose and sucrose manifested the highest capacity of 92%, while fructose, chitin, and starch had the lower capacity around 78%. However, the effects of solvents on the iodine uptake depended on the ionic liquids and solvents. Addition of DMSO into I2-phobic ionic liquid [BMIM][BF4] could greatly enhance the iodine uptake, while the addition of solvents into I2-philic ionic liquid [BMIM][Ac] either had no effect or had negative effect on the iodine uptake. Besides that, montmorillonite could enhance iodine uptake for I2-phobic ionic liquid [BMIM][BF4], and water had negative effect on the efficiency of iodine uptake by I2-philic ionic liquid [BMIM][Ac]; thus, the impurities should not be ignored in the iodine uptake.