Capture Of Radioactive Iodine Research Articles

Radioactive iodine capture and storage from water using magnetite nanoparticles encapsulated in polypyrrole

The effective capture and storage of radioactive iodine is of importance for nuclear waste storage during nuclear power station accidents. Here we report Fe3O4@PPy powder containing ∼12nm magnetite (Fe3O4) nanoparticles encapsulated in the polypyrrole (PPy) matrix. It shows 1627mg/g uptake of iodine dissolved in water, within 2h at room temperature. Fe3O4@PPy is ferromagnetic in nature and can be separated from water using external magnetic field. The nitrogen gas sweeping test at 30°C shows release of 2% iodine from iodine adsorbed Fe3O4@PPy, revealing stable storage of iodine for a moderate period. The iodine-adsorbed magnetic powder can be regenerated by washing with ethanol. The XPS spectrum of iodine adsorbed Fe3O4@PPy confirmed the presence of polyiodides (I3− and I5−) bound to the PPy surface. This excellent iodine capture and storage from iodine contaminated water is an environment friendly, inexpensive and large scale method.

The high-efficiency and eco-friendly PEGylated ionic liquid systems for radioactive iodine capture through halogen bonding interaction

The kinetics of iodine uptake by eco-friendly PEGylated systems was investigated and the resutls showed that most of the systems could capture iodine from the solution of iodine in cyclohexane efficiently. For example, 86% of iodine could be captured in only 3h by PEG200/NaI system. The efficiency of iodine uptake shows high correlation with the inorganic salts used which might be due to the halogen bonding (XB) interaction between the anion of salt with I2. Besides that, the effect of organic solvents and ionic liquids on the iodine capture were also investigated. The results indicated that PEGylated systems are flexible and reobust for iodine capture, furthermore, they might be applied to other areas as solvents.

X-ray Absorption Spectroscopy Investigation of Iodine Capture by Silver-Exchanged Mordenite

Capture of radioactive iodine is a significant consideration during reprocessing of spent nuclear fuel and disposal of legacy wastes. While silver-exchanged mordenite (AgZ) is widely regarded as a benchmark material for assessing iodine adsorption performance, previous research efforts have largely focused on bulk material properties rather than the underpinning molecular interactions that achieve effective iodine capture. As a result, the fundamental understanding necessary to identify and mitigate deactivation pathways for the recycle of AgZ is not available. We applied X-ray Absorption Fine Structure (XAFS) spectroscopy to investigate AgZ following activation, adsorption of iodine, regeneration, and recycle, observing no appreciable degradation in performance due to the highly controlled conditions under which the AgZ was maintained. Fits of the extended XAFS (EXAFS) data reveal complete formation of Ag0 nanoparticles upon treatment with H2, and confirm the formation of α-AgI within the mordenite chann...

Computational screening of covalent organic frameworks for the capture of radioactive iodine and methyl iodide

Large-scale computational screening results show that COFs are promising materials for the capture of radioactive iodic contaminants from nuclear wastes.

Gold-Nanoparticle-Immobilized Desalting Columns for Highly Efficient and Specific Removal of Radioactive Iodine in Aqueous Media.

There has been worldwide attention on the efficient removal of radioactive iodine, because it is commonly released in nuclear plant accidents. Increasing concerns on environmental problems due to the radioactive iodine are leading us to develop stable and sustainable technology for remediation of radioelement contaminants. In this work, we report a highly efficient chromatographic method for specific and rapid capture of radioactive iodine. The gold nanoparticles immobilized dextran gel columns showed excellent removal capabilities of radioactive iodine in various conditions. These results suggested that our platform technology can be a promising method for the desalination of radioactive iodines in water.

Bismuth-embedded SBA-15 mesoporous silica for radioactive iodine capture and stable storage

Efficient capture and stable storage of the long-lived iodine-129 (129I), released as off-gas from nuclear fuel reprocessing, have been of significant concern in the waste management field. In this study, bismuth-embedded SBA-15 mesoporous silica was firstly applied for iodine capture and storage. SBA-15 was functionalized with thiol (-SH) groups, followed by bismuth adsorption with Bi–S bonding, which was thermally treated to form Bi2S3 within SBA-15. The bismuth-embedded SBA-15s demonstrated high iodine loading capacities (up to 540 mg-I/g-sorbent), which benefitted from high surface area and porosity of SBA-15 as well as the formation of thermodynamically stable BiI3 compound. Iodine physisorption was effectively suppressed due to the large pores present in SBA-15, resulting in chemisorption as a main mechanism for iodine confinement. Furthermore, a chemically durable iodine-bearing material was made with a facile post-sorption process, during which the iodine-incorporated phase was changed from BiI3 to chemically durable Bi5O7I. Thus, our results showed that both efficient capture and stabilization of 129I would be possible with the bismuth-embedded SBA-15, in contrast to other sorbents mainly focused on iodine capture.

Halogen bonds between I2 and ion pairs: Interpreting the ability of ionic liquids in efficient capture of radioactive iodine

To elucidate the efficient removal and reliable storage of radioactive iodine for ionic liquids, halogen bonds in the complexes of I2 with a series of ion pairs were investigated at the M06-2x level of theory in this work. Albeit halogen bonds in these complexes are somewhat weaker than those in the systems of bare anions, these interactions still belong to strong halogen bonds and show some covalent character. The strength of these interactions deceases in the following order: [Cl]−≈[Br]−≈[I]−>[Ac]−≈[NO3]−>[BF4]−, consistent with the experimentally determined trend of the removal efficiency for corresponding ionic liquids. In addition, the electrostatic potential, atoms in molecules, and charge transfer analyses were also undertaken for the complexes under study, to gain a deeper understanding of the nature of these interactions.

Reversible and Irreversible Chemisorption in Nonporous‐Crystalline Hybrids

The tools of synthetic chemistry allow us to fine-tune the reactivity of molecules at a level of precision not yet accessible with inorganic solids. We have investigated hybrids that couple molecules to the superior thermal and mechanical properties of solids. Herein we present, to the best of our knowledge, the first demonstration of reactivity between hybrid perovskites and substrates. Reaction with iodine vapor results in a remarkable expansion of these materials (up to 36 % in volume) where new covalent CI bonds are formed with retention of crystallinity. These hybrids also show unusual examples of reversible chemisorption. Here, solid-state interactions extend the lifetime of molecules that cannot be isolated in solution. We have tuned the half-lives of the iodinated structures from 3 h to 3 days. These nonporous hybrids drive substrate capture and controlled release through chemical reactivity. We illustrate the strengths of the hybrid by considering radioactive iodine capture.

Reversible and Irreversible Chemisorption in Nonporous‐Crystalline Hybrids

AbstractThe tools of synthetic chemistry allow us to fine‐tune the reactivity of molecules at a level of precision not yet accessible with inorganic solids. We have investigated hybrids that couple molecules to the superior thermal and mechanical properties of solids. Herein we present, to the best of our knowledge, the first demonstration of reactivity between hybrid perovskites and substrates. Reaction with iodine vapor results in a remarkable expansion of these materials (up to 36 % in volume) where new covalent CI bonds are formed with retention of crystallinity. These hybrids also show unusual examples of reversible chemisorption. Here, solid‐state interactions extend the lifetime of molecules that cannot be isolated in solution. We have tuned the half‐lives of the iodinated structures from 3 h to 3 days. These nonporous hybrids drive substrate capture and controlled release through chemical reactivity. We illustrate the strengths of the hybrid by considering radioactive iodine capture.

Radioactive Iodine Capture in Silver-Containing Mordenites through Nanoscale Silver Iodide Formation

The effective capture and storage of radiological iodine ((129)I) remains a strong concern for safe nuclear waste storage and safe nuclear energy. Silver-containing mordenite (MOR) is a longstanding benchmark for iodine capture; however, the molecular level understanding of this process needed to develop more effective iodine getters has remained elusive. Here we probe the structure and distribution of iodine sorbed by silver-containing MOR using differential pair distribution function analysis. While iodine is distributed between gamma-AgI nanoparticles on the zeolite surface and subnanometer alpha-AgI clusters within the pores for reduced silver MOR, in the case of unreduced silver-exchanged MOR, iodine is exclusively confined to the pores as subnanometer alpha-AgI. Consequently, unreduced silver-containing zeolites may offer a more secure route for radioactive iodine capture, with the potential to more effectively trap the iodine for long-term storage.