Uranium(VI) adsorption from carbonate solutions using cetyltrimethylammonium bromide modified purified-bentonite-MOF composite

Shi, Shilong; Liu, Jun; Shu, Junxiang; Wu, Peng; Zhao, Changsong; Liu, Ning; Lan, Tu

doi:10.1016/j.clay.2023.106986

Cited by 14 publications

(2 citation statements)

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“…Uranium in radioactive wastewater typically exists in the hexavalent oxidation state, U(VI), with the high mobility and radiotoxicity, representing potential environmental hazard in the long term. 1−6 So far, a variety of methods have been developed, such as chemical precipitation, 7 ion exchange, 8,9 solvent extraction, 10,11 membrane separation, 12,13 sorption, 14,15 and photocatalysis, 16−18 to remove it from radioactive wastewater. Among them, photo- selectivity, and the oxidation state transition from soluble hexavalent U(VI) to insoluble tetravalent U(IV).…”

Section: ■ Introductionmentioning

confidence: 99%

“…Uranium is one of the most important raw materials for nuclear power, but radioactive wastewater will be inevitably produced during uranium mining. Uranium in radioactive wastewater typically exists in the hexavalent oxidation state, U(VI), with the high mobility and radiotoxicity, representing potential environmental hazard in the long term. − So far, a variety of methods have been developed, such as chemical precipitation, ion exchange, , solvent extraction, , membrane separation, , sorption, , and photocatalysis, − to remove it from radioactive wastewater. Among them, photocatalytic technology is considered to be one of the most promising options for treating uranium-containing radioactive wastewater, due to the advantages of fast kinetics, high selectivity, and the oxidation state transition from soluble hexavalent U(VI) to insoluble tetravalent U(IV). , …”

Section: Introductionmentioning

confidence: 99%

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Enhanced Photocatalytic Removal of U(VI) from Real Radioactive Wastewater by Modulating the Surface Charge Microenvironment in Porphyrin-Based Hydrogen-Bonded Organic Framework

Wu,

Zhao,

Yin

et al. 2024

ACS Appl. Mater. Interfaces

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Reduction of soluble U(VI) to insoluble U(IV) based on photocatalysts is a simple, environmentally friendly, and efficient method for treating radioactive wastewater. The present study involved the systematic comparison of the photoelectric properties of three metalloporphyrins with different metal centers and the synthesis of a novel porphyrin-based hydrogen-bonded organic framework (Ni-pHOF) photocatalyst by modulating the surface charge microenvironment in porphyrin for enhanced photocatalytic removal of U(VI) from wastewater. Compared to the metal-free HOF, the surface charge microenvironment around the Ni atom in Ni-pHOF accelerated the reduction kinetics of U(VI) under visible light illumination at the initial moment, showing a high removal rate, even in air. The removal rate of U(VI) from aqueous solution by Ni-pHOF can achieve over 98% in the presence of coexisting nonoxidizing cations and only decreased by less than 8% after five cycles, exhibiting high selectivity and good reusability. Furthermore, Ni-pHOF can remove 86.74% of U(VI) from real low-level radioactive wastewater after 120 min of illumination, showcasing practical application potential. Density functional theory (DFT) calculations and electron paramagnetic resonance (EPR) spectra indicated that modulating the surface charge microenvironment in Ni-pHOF through porphyrin metallization is conducive to improving the charge separation efficiency, prompting more e − and • O 2 − to participate in the reduction reaction of U(VI). This work provides new insights into the metallization of porphyrin-based HOFs and paves a new way for the tailoring of porphyrin-based HOFs/COFs by modulating the surface charge microenvironment to achieve efficient recovery of U(VI) from real radioactive wastewater.

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