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Monitoring of radionuclide concentration in natural samples is important for assessing environmental safety. The low concentration of long-lived radionuclides require concentration from large volumes of natural water samples. This paper presents a method for sequential separation and simultaneous determination of radioisotopes of U, Pu, Am and Tc in water samples. Actinides and technetium were pre-concentrated by coprecipitation with iron hydroxides from the aqueous sample. Separation of actinides and Tc was achieved by extraction chromatography. The developed method allows separation of actinide and technetium from 100 L water with chemical yields between 40 and 70%. [ABSTRACT FROM AUTHOR]

As a strategic resource, the safe management and recovery of uranium (U(Ⅵ)) is of great significance for environmental protection and resource recycling. To address it, the effective capture of U(Ⅵ) from wastewater is necessary but still challenging. In this work, an environmental-friendly adsorbent amidoxime and carboxyl functionalized microspheres (ACBs) were successfully prepared, characterized and evaluated for U(Ⅵ) adsorption. The ACBs exhibited outstanding adsorption abilities for U(Ⅵ) with high adsorption capacity, fast kinetics, good selectivity and excellent reusability. The U(Ⅵ) adsorption mechanism onto ACBs was synthetically investigated by various characterizations and DFT calculations, suggesting that the amidoxime and carboxyl groups coordinated with U(Ⅵ) by π and σ bonds. Further investigation in actual water samples and degradation experiments suggested that the ACBs can not only effectively remove U(Ⅵ) from wastewater, but also it can be completely degraded to achieve waste-free goals after the adsorption-desorption process. This work provides new insight into the significance of designing efficient and environmental-friendly adsorbent material for U(Ⅵ) removal from wastewater. [Display omitted] • An environmentally friendly adsorbent was prepared and used for U(VI) removal. • ACB shows powerful adsorption abilities for U(VI) under different conditions. • Adsorption mechanism was revealed as mixed coordination structures. • ACB can be degraded completely by bacteria to achieve no waste discharge. [ABSTRACT FROM AUTHOR]

[Display omitted] • U-PSresin was synthesized to use for separation and detection of U(VI). • U-PSresin shows good irradiation and thermal stability. • U-PSresin is demonstrated a highly sensitive detection efficiency of U(VI). • U-PSresin is proved to be used for continuous measurement of U(VI). It is extremely significant to monitor the radioactive uranium during the process of nuclear energy mining and disposal because of its high levels of chemical and radiological toxicity. In this work, a novel uranium plastic scintillator resin (U-PSresin) was successfully synthesized by suspension polymerization and used to rapidly enrich and determine uranium by Liquid Scintillation Counting (LSC). The U-PSresin shows excellent irradiation stability, extremely appropriate adsorption capacity of U(VI) (9.35 mg/g), which is convenient for the accurate measurement of LSC. Meanwhile, U-PSresin has a deviation of less than 5 % in adsorption and measurement repeatability and can be utilized to accurately measure more than 1 mg of natural uranium after enrichment. For different types of spiked water samples, the measurement deviation of U-PSresin is less than 15 %. This work demonstrates that U-PSresin can selectively enrich and quantitatively measure uranium in an aqueous environment, showcasing its significant potential in nuclear emergency scenarios and environmental monitoring. [ABSTRACT FROM AUTHOR]

Removal of uranium from radioactive wastewater with TPEAC. [Display omitted] • A phosphine-oxime modified adsorbent (TPEAC) was successfully prepared. • TPEAC exhibited exceptional selectivity and efficiency for adsorption of uranium. • TPEAC displayed a high recovery of 99.6% using real uranium mining wastewater. • Adsorption mechanism was elucidated through experiments and characterization. Efficient removal of uranium from radioactive wastewater is paramount for the sustainable development of nuclear energy. However, the exploitation of superior adsorbents with practical applications remains a challenge. In this work, we engineered and synthesized an adsorbent (TPEAC) enriched with phosphine-oxime, featuring a matrix composed of hydrophilic modified amidoxime functional groups. TPEAC exhibited exceptional selectivity (Multiple ion coexistence R% > 99 %) and efficiency in uranium adsorption, with a higher adsorption rate (reach equilibrium around 400 mins) and capacity (243.9 mg/g) than raw-amidoxime (133.3 mg/g) and modified-amidoxime (175.4 mg/g) materials. Moreover, it maintained robust stability and reusability even after six adsorption–desorption cycles, with removal ratio still above 95 %. In-depth mechanistic investigations through DFT and XPS elucidated that P-O (P=O) groups exhibited a stronger affinity for U(VI) compared to other functional groups, and the adsorption of TPEAC towards U(VI) primarily due to the synergistic interaction among P-O (P=O) groups, C(NH 2) = N-OH, and carboxyl groups, which significantly facilitated the effective removal of U(VI). Most prominently, TPEAC performed considerable potential in processing actual uranium mine wastewater, with its dynamic column device achieving a U(VI) recovery up to 99.6 %. This work not only furnishes an efficacious and economical solution for uranium wastewater treatment but also provides new approaches for scalable application uranium materials. [ABSTRACT FROM AUTHOR]

• A highly efficient adsorbent was prepared and used for the treatment of uranium wastewater. • MXene/PAO hydrogel beads exhibit outstanding adsorption capacity under different conditions. • MXene/PAO hydrogel beads have excellent practicality coupling through columns. • Adsorption mechanism under F− conditions is the coordination of MXene and amidoxime to uranium complexes. The treatment of radioactive wastewater is crucial to ensure the safe and rapid development of nuclear energy. However, efficient disposal of uranium wastewater containing high concentrations of fluoride ions (F−) generated during uranium enrichment and conversion poses a formidable and pressing challenge. In this study, we successfully synthesized MXene/PAO hydrogel beads (MPH beads) by self-assembling two-dimensional Ti 3 C 2 T x MXene nanosheets with amidoxime through ionic cross-linking. MPH beads exhibited exceptional uranium adsorption capacity (625 mg/g), remarkable adsorption selectivity, and good reusability. Notably, MPH beads demonstrated a maximum uranium adsorption capacity of 400 mg/g in an aqueous solution containing 8000 ppm F−. Furthermore, MPH beads showed favorable F− resistance and were able to remove>95% of U(Ⅵ) even after being immersed in an extreme environment for 15 days. Additionally, MPH beads achieved a high U(Ⅵ) recovery of 98.2% from real environment water samples using dynamic column experiments, showcasing their excellent application performance. The efficient U(Ⅵ) adsorption and anti-fluoride effect were mainly attributed to the combined complexation between the C(NH 2) = N-OH, C-Ti-OH groups and U(Ⅵ), as demonstrated by experiments, characterization, and DFT calculations. Our study highlights the significant potential of MPH beads in the treatment of uranium from radioactive wastewater, especially wastewater with high concentrations of F−. [ABSTRACT FROM AUTHOR]