Transport of Am(III) was studied through the composite polymer membrane of Cyanex-301 [bis(2,4,4-trimethylpentyl)dithiophosphinic acid] and tri-n-butylphosphate (TBP). Depending on the pH of the strip solution containing alpha-hydroxyisobutyric acid (AHIBA), the transport behaviour of Am(III) was changed significantly. After approximately 70% of the Am(III) transported to the strip side, interestingly, back transport of Am(III) was observed at a pH of 3.5. The back transport phenomenon was not so significant at pH 1 and 5.7. The back transport of Am(III) was attributed to the transport of AHIBA from strip to the feed side due to its interaction with TBP in the membrane and the attainment of Donnan equilibrium because of the presence of Na(+) in the feed as the driving ion. The experimental observations were rationalized using the hydrogen bonding interaction energies obtained through ab initio molecular orbital and DFT calculations.
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http://dx.doi.org/10.1039/b805294h | DOI Listing |
Environ Pollut
June 2024
Key Laboratory of Nuclear Environmental Simulation and Evaluation Technology, China Institute for Radiation Protection, Taiyuan, 030006, China; College of Environmental Science and Engineering, Taiyuan University of Technology, Jinzhong, 030600, China.
Americium (III) (Am(III)) in the natural environment is considered immobile due to its low solubility, strong adsorption, and high affinity to solid surfaces. However, the presence of natural colloids may carry Am(III) transport for long distance. The individual and co-transport behaviors of Am(III) and natural colloids through the unsaturated packed columns were investigated under the influence of pH, electrolyte concentration, velocity, Am(III) concentration and natural colloids concentration.
View Article and Find Full Text PDFEnviron Sci Technol
December 2023
Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, Livermore, California 94550, United States.
Minor actinides are major contributors to the long-term radiotoxicity of nuclear fuels and other radioactive wastes. In this context, understanding their interactions with natural chelators and minerals is key to evaluating their transport behavior in the environment. The lanmodulin family of metalloproteins is produced by ubiquitous bacteria and lanmodulin (LanM) was recently identified as one of nature's most selective chelators for trivalent f-elements.
View Article and Find Full Text PDFDalton Trans
July 2019
Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, Republic of Korea.
Transportation of actinides through the geosphere is facilitated by complexation with organic ligands dissolved in groundwater. Carboxylic groups can interact directly with actinide ions and are found among the most abundant organic ligands in alkaline aquatic systems like underground water. In this study, the complexation of organic carboxylic groups with Am(iii) was investigated by monitoring the interactions of Am(iii) with oxalate (Ox), the simplest dicarboxylate ligand, in solution.
View Article and Find Full Text PDFJ Hazard Mater
March 2016
Fuel Reprocessing Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
Am(III) is one of the most hazardous radionuclide present in nuclear fuel cycle. A new conformationally constrained diamide, (N,N,N',N'-tetra-2-ethylhexyl)7-oxabicyclo[2.2.
View Article and Find Full Text PDFEnviron Sci Process Impacts
November 2015
School for Radiological and Interdisciplinary Sciences, Soochow University, 215123 Suzhou, P. R. China. and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China.
The speciation, migration and transport of radionuclides in the environment are significantly influenced by their interactions with the natural minerals and humic substances therein. In view of this, the effect of temperature and contact order on the sorption behaviors of trivalent Eu(iii) in the γ-Al2O3/Eu(iii) and γ-Al2O3/HA/Eu(iii) systems was studied using batch experiments and the extended X-ray absorption fine structure spectroscopy (EXAFS) technique. The endothermic sorption behavior of Eu(iii) in the γ-Al2O3/Eu(iii) systems was induced by the hydrolysis reaction of Eu(iii) in solution and the complexation of Eu(iii) with the γ-Al2O3 surface sites.
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