Removal of ⁹⁰Sr from highly Na⁺-rich liquid nuclear waste with a layered vanadosilicate

Abstract

Capture of trace amounts (parts per trillion or ppt level) of 90Sr from highly Na+-rich (5 M or 115 000 parts per million) liquid wastes produced from reprocessing of spent nuclear fuel rods is crucial for continuous operation of nuclear power plants.

Ten Years of Aberration Corrected Electron Microscopy for Ordered Nanoporous Materials

“…However, electron microscopy (if images are of high quality) can provide direct visualization of the framework that in combination with electron diffraction allow a precise determination of many structural features. In this sense, transition metal silicates as vanadium silicates and titanosilicates exhibit unique and improved properties as for example nuclear waste treatment where the SGU‐7, which structure was resolved based on advances electron microscopy methods, presented the best performance in order to capture radioactive 90 Sr not only in terms of activity but also towards selective in the presence of Na + . Within the titanosilicate family, ETS‐10 is amongst the most important ones due to its high ion exchange capabilities; to be used in catalysis, photochemistry or gas adsorption .…”

Fe–Mn Oxides Based Multifunctional Adsorptive/Electrosensing Nanoplatforms: Dynamic Site Rearrangement for Metal Ion Selectivity

“…All the obtained current signals were background-corrected by the subtraction of the baselines from the experimental voltammograms. Electrochemical impedance spectroscopy (EIS) was performed at an oscillation amplitude of 10 mV and a sweeping frequency from 100 mHz to 1 MHz in an electrolyte containing 5 mM K 3 Fe(CN) 6 performed at different scan rates (5−200 mV s −1 ), and the electrochemical surface area (ECSA) was estimated based on the linear model of the peak current versus the square root of the scan rate.…”

“…Managing these risks requires the construction of multifunctional adsorptive/sensing platforms for the simultaneous assessment of the exposure to and remediation of heavy metals . Various adsorbents have been reported for the efficient removal of heavy metals from water, , and their affinities further benefit the sensitive electroanalysis of heavy metals. , However, the adsorptive selectivity of these adsorbents for contaminant removal − and quantified analysis , is yet to be realized. Layered materials have great potential to capture metal ions and show much structural superiority over their bulk counterparts, owing to their open accessible sites. − The unique cation exchange capacities, based on the soft Lewis acid–base interactions, , offer an efficient way to separate heavy metals from the coexisting hard ions (such as H­(I), Na­(I), and Ca­(II)).…”

Synthesis of Glue-Free NaA Zeolite Granules from Natural Kaolin for the Adsorption of Pb(II) Ions in Aqueous Solution Using a Fixed-Bed Column Study

“…The negative charge centers are often neutralized by cations such as Na + , K + , and Ca 2+ , which would be eventually exchangeable with certain heavy metal ions in solutions . Depending on the framework type and composition of zeolites, their microstructure property could vary from hydrophilic to highly hydrophobic and show outstanding behaviors in adsorption application such as high selectivity to radioactive Cs and Sr metal ions or radioactive iodine and methyliodide molecules. − Of a large number of synthetic zeolites, Linda Type A (LTA) zeolite has the lowest silicon/aluminum (Si/Al) ratio of 1:2, leading to the highest cation exchange capacity. , LTA zeolite is one of the most common zeolites used to remove heavy metal and radioactive metal ions from aqueous solution. − Several approaches have been applied to synthesize LTA zeolite such as using pure chemicals, fly ash, silicate minerals, and kaolin minerals. ,,, Among the natural material sources for LTA zeolite synthesis, kaolinite is the most popular precursor due to its low cost, abundance, and similar Si/Al ratio to LTA zeolite. , However, to be used for LTA zeolite preparation, kaolin has to be calcined to turn to amorphous metakaolin form. Depending on the original source, kaolin materials may contain impurities that affect the quality and property of zeolite products such as iron oxide, manganese oxide, or titanium oxide. , There was another route to utilize natural kaolin for zeolite synthesis without activation by calcination.…”