Adsorption of radioactive iodine and krypton from off-gas stream using continuous flow adsorption column

Abstract

A novel Engelhard titanosilicate -10 (ETS-10) supported 10 wt% hollow carbon nanopolyhedron (10 wt% C@ETS-10) sorbent developed in our laboratory was investigated for adsorption of the radioactive iodine and krypton from off-gas stream using a continuous flow adsorption column. Adsorption experiments were performed to determine the capacity of 10 wt% C@ETS-10 sorbent for iodine and krypton in multicomponent mixture system by varying operating parameters, such as inlet concentration of iodine (I 2 ) and krypton (Kr), and adsorption column temperature. Pristine and used sorbents were characterized by scanning electron microscopy-energy dispersion spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy to identify the morphology, elemental and vibration analysis of the sorbent before and after the experiments. EDS and XPS spectra of the used samples clearly indicate the presence of iodine on the sorbent. Multicomponent sorption capacities of I 2 and Kr of 10 wt% C@ETS-10 sorbent calculated from the breakthrough curves at 20°C at 25 ppm I 2 and 70 ppm Kr balanced with nitrogen were found to be 41.5 and 0.0323 mg g -1 , respectively.2 Sorption data was found to be best fitted by the Langmuir as well as Freundlich isotherm model. Experimental data were analyzed by Thomas, Yoon-Nelson, and Bohart-Adams sorption kinetics models to predict the breakthrough curves and calculate the characteristic parameters of the column that are useful for process design for the multicomponent system. Results show that 10 wt% C@ETS-10 sorbent has potential sorbent for adsorption of multicomponent (I 2 and Kr) from off-gas stream.

Confinement-Directed Adsorption of Noble Gases (Xe/Kr) in MFM-300(M)-Based Metal–Organic Framework Materials

“…One of the key issues with nuclear energy is handling the spent nuclear fuel which contains a large number of fission and activation products, some of which have exceptionally long radioactive half-lives. 8,9 To minimize the volume of nuclear waste to be stored for long time and to recover the useful elements, the spent nuclear fuel can be reprocessed. Apart from the solid and liquid wastes, reprocessing produces off-gas mixtures such as radioactive noble gases (Xe and Kr), iodine and iodides, carbon dioxide, nitrogen oxides, etc.…”

High‐Silica CHA Zeolite Membrane with Ultra‐High Selectivity and Irradiation Stability for Krypton/Xenon Separation

“…Thes eparation of Kr from Xe is highly challenging but economically attractive due to at en-fold volume reduction for radioactive 85 Kr storage.C ryogenic distillation is technically feasible but energy intensive due to the operation at low temperature and high pressure. [5] Physical adsorption based on activated carbon, [6] zeolites, [6,7] metal-organic frameworks, [8] porous organic frameworks [9] is deemed an energyefficient alternative that can be operated at near-ambient conditions.H owever,t he adsorbents are generally Xe selective over Kr due to the stronger Va nd er Waals interactions (thermodynamic control). [10] Considering the lower abundancyo fK r( Kr/Xe ratio = 9/91), as elective adsorption of Kr over Xe (kinetic control) is preferred to improve the economic feasibility,w hereas this kind of adsorbent is rarely explored.…”

“…Cryogenic distillation is technically feasible but energy intensive due to the operation at low temperature and high pressure [5] . Physical adsorption based on activated carbon, [6] zeolites, [6, 7] metal‐organic frameworks, [8] porous organic frameworks [9] is deemed an energy‐efficient alternative that can be operated at near‐ambient conditions. However, the adsorbents are generally Xe selective over Kr due to the stronger Van der Waals’ interactions (thermodynamic control) [10] .…”

Isothermal Adsorption Behavior of Cesium Ions in a Novel Chitosan‐Prussian Blue‐Based Membrane

“…Adsorption processes for water treatment and purification are in great demand from the viewpoint of various environmental issues including industrial effluents [1,2], synthetic dye pollution [3][4][5], heavy metal contamination [6][7][8], and radioactive substance removal [9][10][11]. An adsorption process is frequently applied in these cases due to its many advantages, such as low operational costs, easy operation, and high efficiency [12].…”