Appreciatively Efficient Sorption Achievement to U(VI) from the El Sela Area by ZrO2/Chitosan

A Phosphorylated Dendrimer-Supported Biomass-Derived Magnetic Nanoparticle Adsorbent for Efficient Uranium Removal

A novel biomass-based magnetic nanoparticle (Fe3O4-P-CMC/PAMAM) was synthesized by crosslinking carboxymethyl chitosan (CMC) and poly(amidoamine) (PAMAM), followed by phosphorylation with the incorporation of magnetic ferric oxide nanoparticles. The characterization results verified the successful functionalization and structural integrity of the adsorbents with a surface area of ca. 43 m2/g. Batch adsorption experiments revealed that the adsorbent exhibited a maximum adsorption capacity of 1513.47 mg·g-1 for U(VI) at pH 5.5 and 298.15 K, with Fe3O4-P-CMC/G1.5-2 showing the highest affinity among the series. The adsorption kinetics adhered to a pseudo-second-order model (R2 = 0.99, qe,exp = 463.81 mg·g-1, k2 = 2.15×10-2 g·mg-1·min-1), indicating a chemically driven process. Thermodynamic analysis suggested that the adsorption was endothermic and spontaneous (ΔH° = 14.71 kJ·mol-1, ΔG° = -50.63 kJ·mol-1, 298. 15 K), with increasing adsorption capacity at higher temperatures. The adsorbent demonstrated significant selectivity for U(VI) in the presence of competing cations, with Fe3O4-P-CMC/G1.5-2 showing a high selectivity coefficient. The performed desorption and reusability tests indicated that the adsorbent could be effectively regenerated using 1M HCl, maintaining its adsorption capacity after five cycles. XPS analysis highlighted the role of phosphonate and amino groups in the complexation with uranyl ions, and validated the existence of bimodal U4f peaks at 380.1 eV and 390.1 eV belonging to U 4f7/2 and U 4f5/2. The results of this study underscore the promise of the developed adsorbent as an effective and selective material for the treatment of uranium-contaminated wastewater.

Functionalized hydrogen-bonded organic superstructures via molecular self-assembly for enhanced uranium extraction

Effective uranium extraction from water is essential for the development of nuclear power industry and the protection of human health and environment. Nevertheless, it still remains challenging to realize efficient and cost-effective uranium extraction. Herein, a fast and simple method for the direct fabrication of novel functionalized hydrogen-bonded organic superstructures via molecular self-assembly is reported. The as-constructed flower-like superstructures (MCP-5) can allow the exposure of adsorption sites and facilitate the transport of uranyl ions, while synergism between amino and phosphate groups can realize selective uranium extraction. Consequently, MCP-5 possesses excellent uranium adsorption ability with a high saturated adsorption capacity of 950.52 mg g-1, high utilization rate of adsorption sites and adsorption equilibrium time of simply 5 min in uranium-spiked aqueous solution. Furthermore, MCP-5 offers selective uranium adsorption over a broad range of metal ions. The facile synthesis and low-cost raw materials make it have promising potential for uranium capture. Simultaneously, this study opens a design avenue of functionalized hydrogen-bonded organic material for efficient uranium extraction.

Preparation and characterization of nanomuscovite by intercalation method for adsorption of heavy metals from polluted water

In this study, nanomuscovite adsorbents were prepared by intercalation with various organic intercalates (DTAB-TTAB-DTPA-PA-PN) and used to remove Cd2+ and Pb2+ from polluted water. The best nanomuscovite was prepared using DTPA and muscovite (Muc/DTPA) and characterized by XRD, TEM, EDX, FTIR, and BET surface area. The developed nanoadsorbent was used to remove Cd2+ and Pb2+ from polluted water. The effect of various factors, including contact time, adsorbent dosage, solution pH, and temperature, was investigated. The results reveal that the maximum adsorption of Cd2+ and Pb2+ was 91.5% and 97%, respectively, at the initial metal concentration 50 ppm, adsorbent dosage 0.2 g, contact time 60 min, solution temperature 25 °C, and pH 6 for Pb2+ and pH 7 for Cd2+. Adsorption isotherm models (Freundlich, Langmuir, Dubunin-Radushkevich, and Temkin isotherm models) as well as kinetic models (pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion models) were employed to evaluate the experimental results. The adsorption of Cd2+ and Pb2+ on Muc/DTPA fitted well within the Langmuir isotherm model and followed pseudo-second-order kinetics. Thermodynamics parameters of metal adsorption indicated exothermic and spontaneous processes. Results were applied to the real wastewater that showed high Cd2+ and Pb2+ removal.

Characteristic Aspects of Uranium(VI) Adsorption Utilizing Nano-Silica/Chitosan from Wastewater Solution

A new nano-silica/chitosan (SiO₂/CS) sorbent was created using a wet process to eliminate uranium(VI) from its solution. Measurements using BET, XRD, EDX, SEM, and FTIR were utilized to analyze the production of SiO₂/CS. The adsorption progressions were carried out by pH, SiO₂/CS dose, temperature, sorbing time, and U(VI) concentration measurements. The optimal condition for U(VI) sorption (165 mg/g) was found to be pH 3.5, 60 mg SiO₂/CS, for 50 min of sorbing time, and 200 mg/L U(VI). Both the second-order sorption kinetics and Langmuir adsorption model were observed to be obeyed by the ability of SiO₂/CS to eradicate U(VI). Thermodynamically, the sorption strategy was a spontaneous reaction and exothermic. According to the findings, SiO₂/CS had the potential to serve as an effectual sorbent for U(VI) displacement.