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Efficient removal of uranium from aqueous solution by zero-valent iron nanoparticle and its graphene composite.
- Source :
-
Journal of hazardous materials [J Hazard Mater] 2015 Jun 15; Vol. 290, pp. 26-33. Date of Electronic Publication: 2015 Feb 11. - Publication Year :
- 2015
-
Abstract
- Zero-valent iron nanoparticle (ZVI-np) and its graphene composites were prepared and applied in the removal of uranium under anoxic conditions. It was found that solutions containing 24 ppm U(VI) could be completely cleaned up by ZVI-nps, regardless of the presence of NaHCO3, humic acid, mimic groundwater constituents or the change of solution pH from 5 to 9, manifesting the promising potential of this reactive material in permeable reactive barrier (PRB) to remediate uranium-contaminated groundwater. In the measurement of maximum sorption capacity, removal efficiency of uranium kept at 100% until C0(U) = 643 ppm, and the saturation sorption of 8173 mg U/g ZVI-nps was achieved at C0(U) = 714 ppm. In addition, reaction mechanisms were clarified based on the results of SEM, XRD, XANES, and chemical leaching in (NH4)2CO3 solution. Partially reductive precipitation of U(VI) as U3O7 was prevalent when sufficient iron was available; nevertheless, hydrolysis precipitation of U(VI) on surface would be predominant as iron got insufficient, characterized by releases of Fe(2+) ions. The dissolution of Fe(0) cores was assigned to be the driving force of continuous formation of U(VI) (hydr)oxide. The incorporation of graphene supporting matrix was found to facilitate faster removal rate and higher U(VI) reduction ratio, thus benefitting the long-term immobilization of uranium in geochemical environment.<br /> (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Subjects :
- Humic Substances
Hydrogen-Ion Concentration
Indicators and Reagents
Kinetics
Microscopy, Electron, Scanning
Solutions
Water
Water Purification methods
X-Ray Diffraction
Graphite chemistry
Groundwater chemistry
Iron chemistry
Metal Nanoparticles chemistry
Uranium isolation & purification
Water Pollutants, Radioactive isolation & purification
Subjects
Details
- Language :
- English
- ISSN :
- 1873-3336
- Volume :
- 290
- Database :
- MEDLINE
- Journal :
- Journal of hazardous materials
- Publication Type :
- Academic Journal
- Accession number :
- 25734531
- Full Text :
- https://doi.org/10.1016/j.jhazmat.2015.02.028