Iodine capture by ionic liquids and recovery by compressed CO2

Ionic liquids are tunable and environmental-friendly solvents, which have been widely applied in many fields. Radioactive iodine is one of the detrimental nuclear wastes released from the nuclear weapon manufacture, nuclear energy production, and particularly nuclear accident (e.g., Chernobyl disaster in 1986 and Fukushima Daiichi nuclear accident in 2011). Here, we screen ca. 90 ionic liquids for iodine entrapment. Specifically, these ionic liquids include conventional ionic liquids, protic ionic liquids and poly-ionic liquids. Also, the effects of structural (e.g., alkyl chain, anion, cation, C2 methylation, functionalization) and external (e.g., concentration, mass) factors of ionic liquids for uptaking iodine are investigated. It is also interestingly found that recovery of iodine from iodine/ionic liquids mixture could be achieved by compressed CO2. This work could provide a guide for engineers, chemists, environmentalists or policymakers for utilization of ionic liquids for storing and recovery iodine in nuclear industry.