(371q) Demonstration of Iodine Removal Efficiency of MOF-Based Sorbents from Nuclear Waste Solutions in the Presence of Interfering Ions

With rapid development of nuclear industry upon ever-increasing energy demand from growing population, radioactive nuclear wastes have become an important issue. Such wastes need to be remedied urgently in an efficient and timely manner to meet stringent environmental regulations. In that regard, adsorption-based processes for capture of radioactive species from off-gas or solution streams have been demonstrated as an efficient remediation strategy. In our previous investigations^1,2 we evaluated the efficacy of aminosilane-grafted mesoporous alumina and bismuth alumina in iodine immobilization from aqueous solutions by studying the role of amine loading and bismuth content. In our previous investigations^1,2 we evaluated the efficacy of aminosilane-grafted mesoporous alumina and bismuth alumina in iodine immobilization from aqueous solutions by studying the role of amine loading and bismuth content. In this study, we aimed at investigating iodine adsorption performance of MOF-74 and UiO-66 in aqueous solution as a function of capture conditions including, feed concentration and adsorption temperature. Moreover, we aimed at evaluating the effect of interfering ions such as Cl^-, CO₃^-2), that may be present in the aqueous solution along with ^-I₂, on the removal efficiency of the two MOFs. A maximum iodine removal efficiency of 97% was achieved over MOF-74 at 60 ºC. MOF-74 outperformed UiO-66 in immobilizing iodine from aqueous solutions. It was also found that the presence of other interfering ions has different effects on iodine uptake over MOF-74 and UiO-66. The leach test results revealed 12 and 8% iodine leach from UiO-66 and MOF-74, respectively at 25 ºC after 48 h. The kinetics and equilibrium uptake of iodine were represented by Langmuir and pseudo models.

References

(1) M. Alsalbokh, et al., Chem.Eng. J. 2021, 415 (January), 128968.

(2) M. Alsalbokh, et al., Chem.Eng. J. 2021, 409 (November 2020), 128277.