Efficient Removal and Recovery of Uranium by a Layered Organic–Inorganic Hybrid Thiostannate

Abstract

Uranium is important in the nuclear fuel cycle both as an energy source and as radioactive waste. It is of vital importance to recover uranium from nuclear waste solutions for further treatment and disposal. Herein we present the first chalcogenide example, (Me2NH2)1.33(Me3NH)0.67Sn3S7·1.25H2O (FJSM-SnS), in which organic amine cations can be used for selective UO2(2+) ion-exchange. The UO2(2+)-exchange kinetics perfectly conforms to pseudo-second-order reaction, which is observed for the first time in a chalcogenide ion-exchanger. This reveals the chemical adsorption process and its ion-exchange mechanism. FJSM-SnS has excellent pH stability in both strongly acidic and basic environments (pH = 2.1-11), with a maximum uranium-exchange capacity of 338.43 mg/g. It can efficiently capture UO2(2+) ions in the presence of high concentrations of Na(+), Ca(2+), or HCO3(-) (the highest distribution coefficient Kd value reached 4.28 × 10(4) mL/g). The material is also very effective in removing of trace levels of U in the presence of excess Na(+) (the relative amounts of U removed are close to 100%). The UO2(2+)···S(2-) interactions are the basis for the high selectivity. Importantly, the uranyl ion in the exchanged products could be easily eluted with an environmentally friendly method, by treating the UO2(2+)-laden materials with a concentrated KCl solution. These advantages coupled with the very high loading capacity, low cost, environmentally friendly nature, and facile synthesis make FJSM-SnS a new promising remediation material for removal of radioactive U from nuclear waste solutions.

Overcoming the crystallization and designability issues in the ultrastable zirconium phosphonate framework system

“…Inorganic zirconium phosphates and other materials have been intensively investigated as ion-exchange materials for the removal of heavy metal contamination, especially uranium and the fission product caesium, for spent nuclear fuel partitioning and contamination remediation213536373839404142. With their significantly improved porosity and surface area, all these three zirconium phosphonate MOFs could be promising candidates for these applications.…”

Significantly Enhanced Uranium Extraction from Seawater with Mass Produced Fully Amidoximated Nanofiber Adsorbent

“…); C 0 and C t are the initial and final concentrations of uranium (mg L −1 ) at each time point; V is the volume of the solution (L) and m is the mass of the PIDO NFs (g). For the adsorption isotherm study, a series of uranium spiked seawater with different initial concentrations of uranium (1,5,10,20,40,80, and 160 ppm) were contacted with 15 mg of alkaline conditioned PIDO NF mat following a similar procedure as described above. Each set of experiments was conducted three times and the average values were used for calculation.…”

“…The impact of pH on the adsorption performance is investigated with 15 mg of PIDO NF adsorbent in 5 L of uranium aqueous solution (8 ppm) with a pH range of 4.0-9.0. [43] In a highly alkaline environment, uranyl ions form negatively charged complex anions, such as (UO 2 ) 3 (OH) 8 2− , (UO 2 ) 3 (OH) 10 4− and UO 2 (OH) 3− etc., [44] which leads to a decrease of adsorption efficiency. The amount of uranium uptake increase significantly from pH 4.0-7.0 and decreases gradually with further increases in pH.…”

“…[3] The oceans hold ≈4.5 billion tons of uranium, [4] making them a potential huge resource to support nuclear power production for hundreds of years. [10][11][12][13][14][15][16] Among these technologies, the adsorption approach, particularly by using fiber-based adsorbents, is recognized as the most feasible process in terms of practicality, processability, cost, and environmental concerns. In the last decades, researchers worldwide have tried various methods to recover uranium from seawater and aqueous solution, such as coprecipitation, [6] ion-exchange, [7] adsorption via porous organic polymers, [8,9] and organic-inorganic hybrid adsorbents.…”

Cooperative Capture of Uranyl Ions by a Carbonyl‐Bearing Hierarchical‐Porous Cu–Organic Framework

“…Herein, we describe a new hierarchical‐porous MOF material, USC‐CP‐ 1 (USC‐CP stands for University of South China coordination polymer), obtained from the self‐assembly of copper and a semi‐rigid polytopic acid ligand, featuring a copper‐carboxylate framework with carbonyl decorated porosity. USC‐CP‐ 1 exhibits the remarkable uranyl ion sorption capacity of 562 mg g −1 , surpassing Zn‐MOF‐74 (360 mg g −1 ), MIL‐101‐DETA (350 mg g −1 ), and chalcogenide FJSM‐SnS (338 mg g −1 ) …”