Search Results (153)

The article presents a comprehensive comparative performance evaluation and validation of composite adsorbents based on the Se-derivative of 4-amino-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide for U (VI) recovery from complex multicomponent aqueous media. Our results indicate the composite materials to be comparable to, and in some cases to surpass, existing adsorbents in recovery efficiency. Under static sorption conditions for trace U (VI) from real multicomponent solutions (tap, river, and sea water), the sorption efficiency reached 80–98%, while the distribution coefficients ranged from 10⁴ to 10⁶ cm³ g⁻¹. The sorption-selectivity properties of the materials were evaluated in the presence of competing ions (EDTA and oxalate ions), which possess a high chelating capacity and a strong tendency to form complexes with uranium. The dependence of sorption efficiency on the concentration of these ions and the solution pH was investigated. The possibility of reusing the materials over multiple sorption-desorption cycles was assessed. An optimal regenerating eluent agent was identified (NaHCO₃/NH₄NO₃), providing a desorption efficiency of >95% without degrading the material’s sorption properties over repeated cycles. Using a combination of physicochemical methods, including sorption techniques, the mechanism of uranium sorption and its dependence on the material structure were determined. The efficiency of uranium recovery from multicomponent natural waters was also investigated under dynamic conditions over repeated sorption-desorption cycles. The results demonstrate through comparative analysis that the developed composites exhibit a high sorption capacity and possess a high practical potential for the concentration and recovery of uranium from high-salinity solutions with complex composition. Full article

Laser-driven ion acceleration is a rapidly developing branch of plasma physics and laser science whose primary practical goal is to provide a physical and technological basis for the construction and development of new types of ion accelerators. Laser-driven accelerators can be less complex and more compact than currently used RF-driven accelerators, while the intensities, fluences, and powers of laser-accelerated ion beams can potentially exceed those achieved in RF accelerators. This paper focuses on the generation of very intense ion beams driven by a multi-PW femtosecond laser. The acceleration mechanisms enabling the generation of such beams are characterized, and the properties of multi-PW laser-driven uranium ion beams are discussed in detail based on the results of advanced particle-in-cell numerical simulations. The feasibility of generating sub-picosecond, multi-GeV, mono-charge uranium beams with extreme intensities (~>10²⁰ W/cm²) and fluences (~>GJ/cm²) is demonstrated, and methods for controlling the beam parameters are identified. It is shown that using such beams, extreme states of matter with parameters unattainable with ion beams from conventional accelerators can be created. The prospects for applications of ultra-intense laser-driven ion beams in high-energy density physics, inertial confinement nuclear fusion, and in certain areas of nuclear physics are outlined. Full article

Uranium isotopic composition of shallow groundwater in the Jabal Sayid-Mahd Adhab area of western Saudi Arabia was investigated to evaluate geochemical changes resulting from water-rock interactions. The wide range of uranium concentrations (0.75–29.3 ppb) and ²³⁴U/²³⁸U activity ratios (1.11–3.11) reflect variable redox and uranium dissolution conditions across the aquifer. Samples with high uranium concentrations but low activity ratios suggest a recent release of uranium from mineral phases, which is further enhanced by the presence of fluoride ions. Fluoride’s strong reactivity aids in uranium dissolution by forming stable uranyl-fluoride complexes under open-system leaching conditions. Conversely, higher isotopic ratios in low-uranium samples suggest longer water-rock interaction and preferential leaching of ²³⁴U by alpha-recoil processes. The positive correlation between uranium and salinity parameters further indicates that uranium enrichment is linked to increased ionic strength and the abundance of complex ligands. The relationship between activity ratio ²³⁴U/²³⁸U (AR) and 1/U in the studied samples indicates that uranium behavior in the shallow aquifer is dominated by open-system leaching, with local binary mixing superimposed in a few sites. The findings emphasize that uranium isotopic composition is a valuable tool for identifying localized groundwater mixing and assessing the hydrogeochemical impacts of nearby mineralized areas on the aquifer system. These results represent an essential baseline for future environmental monitoring and for evaluating potential temporal changes in uranium behavior. Full article

This study investigates the interaction of humic acid (HA) with magnetite nanoparticles and its impact on the adsorption behavior of the HA-coated magnetite (Fe₃O₄) nanoparticles towards uranium (U-232) in aqueous solutions. The particle surface modification was performed using HA solutions of varying concentrations (0.01, 0.1, and 1.0 g/L). Zeta potential measurements revealed a significant shift in surface charge—from positive values (+13 mV) for unmodified particles to negative values (down to −30 mV) due to the presence of carboxylic moieties on the particle surface. Batch adsorption experiments at pH 5.6 demonstrated that increasing HA coating markedly improves the U-232 adsorption, with K_d values rising by up to an order of magnitude compared to unmodified Fe₃O₄ nanoparticles. The enhanced performance is linked to both the greater number of surface-active sites and the increased negative surface charge introduced by the HA layer. Despite the HA coating, the hydrodynamic diameter of the particles remains largely unaffected, preserving colloidal stability. The latter is also corroborated by SEM-EDX analysis. Overall, this work highlights the role of HA in the adsorption behavior of magnetite particles towards (radio)toxic metal ions, which is of particular interest regarding their mobility in the geosphere and their removal from contaminated waters. Full article

Thorium occupies a unique position in the global energy agenda, being simultaneously considered a promising nuclear fuel and an ecological risk factor. Its fuel cycle (Th-232 → U-233) offers significant advantages over uranium, including reduced waste, improved resistance to burnup, and lower proliferation risks, while molten salt reactor designs demonstrate potential to reduce electricity costs and consume transuranic elements from spent nuclear fuel. At the same time, the geochemical mobility of Th⁴⁺ ions, prone to forming soluble and colloidal species, increases the likelihood of their migration into soils and waters, with subsequent accumulation in biota and induction of radiotoxic effects. This study applied a comprehensive review of thorium’s energy potential and environmental risks, analyzing advances in reactor technology alongside mitigation methods such as coagulation, membrane separation, ion exchange, and adsorption with natural and modified sorbents. The findings emphasize that thorium’s strategic role in sustainable nuclear power is inseparable from the development of reliable safeguards to protect ecosystems. We conclude that a dual approach—integrating innovative reactor engineering with effective environmental countermeasures—will be essential for safe deployment of thorium technologies, ensuring their contribution to clean energy generation while minimizing ecological impacts. Full article

The concentrations of natural radioactive elements in the groundwater environment are regulated by several factors, including aquifer geology, groundwater hydrochemical properties, and changes in environmental conditions. Many studies have explored these factors, but few have systematically elucidated the mechanisms underlying the dissolution of radioactive elements from their host minerals into groundwater. This study investigated the petrological, mineralogical, and weathering properties of aquifer materials and their effects on the leaching of uranium (U) and thorium (Th) into groundwater. The time required for the U concentration to reach the drinking water standard (30 μg/L) was estimated through artificial weathering experiments performed under diverse environmental conditions. Rock core samples were obtained from three sites differing in their geology and groundwater U concentrations. Mineralogical analyses revealed that thorite, a representative radioactive mineral that contains large amounts of U and Th, was present in samples from all collection sites. Thorite minerals differed in terms of their sizes, shapes, cracks, and chemical compositions between samples from different sites, indicating that geological features, mineral alteration characteristics, and environmental conditions controlled the behavior of U and Th. These factors appear to play crucial roles in regulating the mobility and potential long-term leachability of U and Th. Artificial weathering experiments confirmed that a neutral pH with surplus bicarbonate ions favored U leaching. Under these environmental conditions, aquifer U concentrations were estimated to require 8.7–226 years to reach the drinking water standard, depending on the groundwater dissolved oxygen content. Our results provide scientific evidence that may be used for managing radioactive elements in the groundwater environment, and are likely to inform new environmental policies and regulatory standards. Full article

The exploit of an efficient method for uranium (U) extraction is crucial for the development of nuclear energy. In this study, an aminated lignin-based microsphere (AL-PEI/GMS) was synthesized and used as an adsorbent for the recovery of hexavalent uranium (U(VI)) from salt-lake brine. The effects of adsorbent dosage, initial solution pH value, interfering ions, adsorption time, and temperature on the U(VI) adsorption performance of AL-PEI/GMSs were systematically investigated. The results show that when the adsorbent dosage was 2 g/L, the temperature was 45 °C, and the pH was 8, the adsorption capacity of AL-PEI/GMS for U(VI) could reach 256.4 mg/g. In addition, after five cycles, a high U(VI) adsorption efficiency of over 90% could still be achieved. Furthermore, through a fixed-bed system, AL-PEI/GMS could rapidly adsorb U(VI) from actual salt-lake brine. Therefore, the prepared AL-PEI/GMS is a competitive alternative material compared with other adsorbents in terms of efficiently recovering U(VI) from actual salt-lake brine. Full article

Thorium has emerged as a promising alternative to uranium in nuclear energy systems due to its higher natural abundance, favorable conversion to fissile ²³³U, and reduced generation of long-lived transuranic waste. This review provides a comprehensive overview of advanced techniques for thorium recovery from primary ores and secondary resources. The main mineralogical carriers—including monazite, thorianite, thorite, and cheralite as well as industrial by-products such as rare-earth processing tailings—are critically examined with respect to their occurrence and processing potential. Physical enrichment methods (gravity, magnetic, and electrostatic separation) and hydrometallurgical approaches (acidic and alkaline leaching) are analyzed in detail, highlighting their efficiencies, limitations, and environmental implications. Particular emphasis is placed on modern separation strategies such as solvent extraction with organophosphorus reagents, diglycolamides, and ionic liquids, as well as extraction chromatography, nanocomposite sorbents, ion-imprinted polymers, and electrosorption on carbon-based electrodes. These techniques demonstrate significant progress in enhancing selectivity, reducing reagent consumption, and enabling recovery from low-grade and secondary feedstocks. Environmental and radiological aspects, including waste minimization, immobilization, and regulatory frameworks, are discussed as integral components of sustainable thorium management. Finally, perspectives on hybrid technologies, digital process optimization, and economic feasibility are outlined, underscoring the need for interdisciplinary approaches that combine chemistry, materials science, and environmental engineering. Collectively, the analysis highlights the transition from conventional practices to integrated, scalable, and environmentally responsible technologies for thorium recovery. Full article

Organophosphonates have manifold applications in the chemical industry, of which one of the most commonly used is 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC). It is widely used as a cement additive and may pose a potential risk of complexing radionuclides such as uranium in nuclear waste repositories. PBTC, in its fully deprotonated form, has four negatively charged groups, one phosphonate and three carboxylate groups, which makes it a superior ligand for metal ion complexation. In this study, for the first time, its complexation behavior towards hexavalent uranium, U(VI), in the pH range from 2 to 11, has been investigated using various spectroscopic methods. The structure-sensitive methods NMR, IR, and Raman spectroscopy were used to characterize the complex structure. The interpretation of the results was supported by density functional calculations. Over almost the entire pH range studied, U(VI) and PBTC form a chelate complex via the phosphonate and the geminal carboxylate group, highlighting the strong chelating ability of the ligand. UV-Vis spectroscopy combined with factor analysis was applied to determine the distribution of differently protonated chelate species and their stability constants. Time-resolved laser-induced luminescence spectroscopy (TRLFS) was additionally used as a complementary method. Full article

The development of effective materials for uranium extraction from seawater is vital for advancing sustainable energy solutions. However, the efficient recovery of uranium from seawater presents significant challenges due to its extremely low concentration, the presence of competing ions, and the complex marine environment. To address these issues, various materials such as inorganic and organic sorbents, chelating resins, nanostructured sorbents, and composite materials have been explored. More recently, the functionalization of carbon-based materials for enhanced adsorption properties has attracted much interest because of their high specific surface area, excellent chemical and thermal stability, and tunable porosity. These materials include activated carbon, graphene oxide, biochar, carbon cloths, carbon nanotubes, and carbon aerogels. The enhancement of carbonaceous materials is typically achieved through surface functionalization with chelating groups and the synthesis of composite materials that integrate other high-performance sorbents. This review aims to summarize the work of these functionalized carbon materials, focusing on their adsorption capacity, selectivity, and durability for uranium adsorption. This is followed by a discussion on the binding mechanisms of uranium with major chelating functional groups grafted on carbonaceous sorbents. Finally, an outlook for future research is suggested. We hope that this review will be helpful to researchers engaged in related studies. Full article

Exploring materials for the uranium extraction from seawater holds great significance for the sustainable development of the nuclear industry. Though many adsorbents have been investigated to extract uranium, they still suffer from the issues of low adsorption performance and high production cost. In this work, biomass nanofiber adsorbents (PA-CS NFs) were prepared by the electrospinning of chitosan followed by functionalization with phytic acid. Based on the cost analysis, the preparation expense of PA-CS NFs was $16.4 kg⁻¹, lower than those of common synthetic polymer adsorbents. In addition, PA-CS NFs showed fast removal kinetics (equilibrium time = 60 min), high uptake capacity (457.8 mg g⁻¹), and good selectivity (the ratio of uranium/competing ion capacities > 3.8) from uranium spiked solution. PA-CS NFs also exhibited the ability to remove trace uranyl ions (distribution coefficient = 4.7 × 10⁵ mL g⁻¹) and satisfy recycling capacity. The experimental tests and theoretical calculations confirmed that the phosphate groups in the functionalized phytic acid displayed the main contribution to the uranyl ion adsorption, which had higher binding energy than the functional groups in chitosan. Benefiting from the good adsorption ability, low cost, and macroscopical membrane form, PA-CS NFs were applied to natural seawater for uranium extraction, and an extraction capacity of 4.52 mg g⁻¹ could be achieved after 35 days’ testing. On account of the obtained results, this study offers an efficient and low-cost nanofiber adsorbent for uranium extraction. Full article

Sulfonamides represent a versatile class of biologically active compounds, best known for their antibacterial activity, but increasingly investigated for their potential in oncology. Free sulfonamides themselves display cytotoxic properties; however, coordination with metal ions often enhances both selectivity and potency, while also introducing new mechanisms of action. Although numerous studies have reported sulfonamide–metal complexes with anticancer activity, a systematic overview linking biological properties to the central metal atom has been lacking. This review summarizes current research on sulfonamide complexes with transition metals and selected main-group elements, focusing on their pharmacological potential as anticancer agents. The compounds discussed include complexes of titanium, chromium, manganese, rhenium, ruthenium, osmium, iridium, palladium, platinum, copper, silver, gold, iron, cobalt, nickel, uranium, calcium, magnesium and bismuth. For each group, representative structures are presented along with cytotoxicity data against cancer cell lines, comparisons with reference drugs such as for example cisplatin, and where relevant, studies on carbonic anhydrase inhibition. The survey of available data demonstrates that many sulfonamide–metal complexes show cytotoxic activity comparable to or greater than existing chemotherapeutic agents, while in some cases exhibiting reduced toxicity toward non-cancerous cells. These findings highlight the promise of sulfonamide–metal complexes as a fertile area for anticancer drug development and provide a framework for future design strategies. This review covers the research on anti-cancer activity of sulfonamide complexes during the years 2007–2025. Full article

3,4-dihydroxybenzenesulfonyl-functionalized polyethyleneimine (PS), a novel polymeric chelator, was synthesized by conjugating 3,4-dihydroxybenzenesulfonyl (CAM) groups with branched polyethyleneimine (BPEI, MW = 600 Da) via N-acylation. PS demonstrated a high uranium adsorption capacity of 78.08% at a concentration of 4 mg/mL, accompanied by significant selectivity over competing ions such as Ca²⁺, Zn²⁺, and Cu²⁺. Notably, in competitive adsorption experiments, PS exhibited a uranium adsorption rate of 59.49%, which was 3.95 times higher than that of calcium (15.06%) in the Ca²⁺ system. Cytotoxicity assays revealed enhanced biocompatibility (IC₅₀ = 86.98 μg/mL), surpassing CaNa₃-DTPA 3.7-fold. In a uranium exposure model (200 μg/mL), PS significantly improved cell survival rates and reduced intracellular uranium levels by 77.37% (immediate administration) and 64.18% (delayed administration). These findings establish PS as a potent and safe polymeric chelator for uranium decorporation, offering a promising strategy for mitigating the hazards of radioactive materials. Full article

In this study, a novel adsorbent, UiO-66-H₃IMDC, was successfully prepared by functionalizing UiO-66 with imidazole-4,5-dicarboxylic acid (H3IMDC). The effective functionalization of H₃IMDC on UiO-66 was confirmed by powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FT-IR). The relationships between the adsorption of U(VI) on UiO-66-H₃IMDC and the contact time, the pH of the solution, as well as the initial concentration of U(VI) were investigated. Additionally, the selective adsorption of U(VI) by UiO-66-H₃IMDC and its cyclic regeneration performance were also studied. The results demonstrate that the UiO-66-H₃IMDC adsorbent exhibits excellent adsorption performance for uranium in aqueous solutions. Full article

The sustainable treatment of uranium-containing wastewater is of significant importance for environmental protection. This study reports a novel Polyethyleneimine-4-cyanobenzaldehyde/p-Phthalaldehyde-Amidoxime (PEI-PAC-AO) adsorbent for the effective extraction of uranium from aqueous solutions. The structural and performance characteristics of the adsorbents were analyzed through FT-IR, TGA, SEM, CA, and ICP-MS. Adsorption mechanisms were investigated using X-ray photoelectron spectroscopy (XPS), revealing that uranium adsorption is due to coordination with N and O atoms in the amidoxime groups. Batch adsorption experiments showed that PEI-PAC-AO exhibited excellent removal efficiency at pH 6. The static adsorption performance better fits the Langmuir model and pseudo-second-order kinetics. Adsorption results indicated that the removal extent of uranium ions remained at 80% after nine consecutive adsorption cycles using 0.5 M nitric acid as the eluent. These findings suggest that PEI-PAC-AO is a sustainable and promising material for the efficient removal of uranium from wastewater, offering a sustainable and environmentally friendly approach that contributes to environmentally responsible wastewater treatment strategies. Full article