Re-extracting environmentally transportable hexavalent uranium from wastew-ater produced by spent fuel reprocessing using the photocatalytic technology is a crucial strategy to avoid uranium pollution and recover nucl...Re-extracting environmentally transportable hexavalent uranium from wastew-ater produced by spent fuel reprocessing using the photocatalytic technology is a crucial strategy to avoid uranium pollution and recover nuclear fuel strategic resources.Here,we have designed S-scheme 2D/0D C_(3)N_(5)/Fe_(2)O_(3)heterojunction photocatalysts based on the built-in electric field and the energy band bend-ing theory,and have further revealed the immobilization process of hexavalent uranium conversion into relatively insoluble tetravalent uranium in terms of thermodynamics and kinetics.According to the results,the hexavalent uranium removal and recovery ratios in wastewater are as high as 93.38%and 83.58%,respectively.Besides,C_(3)N_(5)/Fe_(2)O_(3)heterojunctions also exhibit satisfactory cat-alytic activity and selectivity even in the presence of excessive impurity cations(including Na^(+),K^(+),Ca^(^(2+)),Mg^(2+),Sr^(2+),and Eu^(3+))or various organics(such as xylene,tributylphosphate,pyridine,tannic acid,citric acid,and oxalic acid).It is believed that this work can provide a potential opportunity for S-scheme heterojunction photocatalysts to re-enrich uranium from spent fuel wastewater.展开更多
Graphene oxides(GOs) were synthesized via modified Hummers method, and were applied as adsorbents to remove radionuclides from large volumes of aqueous solutions. The single and competitive sorption of four radionucli...Graphene oxides(GOs) were synthesized via modified Hummers method, and were applied as adsorbents to remove radionuclides from large volumes of aqueous solutions. The single and competitive sorption of four radionuclides(i.e., U(VI), 152+154Eu(III), 85+89Sr(II) and 134Cs(I)) on the GOs from aqueous solutions were investigated as a function of p H, ionic strength and radionuclide initial concentrations using batch technique. The results showed that the GOs had much higher sorption capacity than many other contemporary materials, for the preconcentration of radionuclides from large volumes of aqueous solutions. The sorption of radionuclides on GOs obeyed the Langmuir model, and was mainly attributed to surface complexation via the coordination of radionuclides with the oxygen-containing functional groups on GO surfaces. The competitive sorption results indicated that the selectivity sorption capacities were U(VI)>Eu(III)>Sr(II)>Cs(I). The GOs are suitable materials for the efficient removal and preconcentration of radionuclides from aqueous solutions in nuclear waste management and environmental pollution cleanup.展开更多
基金National Natural Science Foundation of China,Grant/Award Numbers:21976148,11705152National Key Research and Development Project of China,Grant/Award Number:2016YFC1402500+2 种基金Long Shan Talent Project,Grant/Award Numbers:18LZX304,18LZXT04Project of State Key Laboratory of Environment-friendly Energy Materials,Grant/Award Number:18zxhk04Start-up Fund for Introducing Talents of Southwest University of Science and Technology,Grant/Award Number:23zx7171。
文摘Re-extracting environmentally transportable hexavalent uranium from wastew-ater produced by spent fuel reprocessing using the photocatalytic technology is a crucial strategy to avoid uranium pollution and recover nuclear fuel strategic resources.Here,we have designed S-scheme 2D/0D C_(3)N_(5)/Fe_(2)O_(3)heterojunction photocatalysts based on the built-in electric field and the energy band bend-ing theory,and have further revealed the immobilization process of hexavalent uranium conversion into relatively insoluble tetravalent uranium in terms of thermodynamics and kinetics.According to the results,the hexavalent uranium removal and recovery ratios in wastewater are as high as 93.38%and 83.58%,respectively.Besides,C_(3)N_(5)/Fe_(2)O_(3)heterojunctions also exhibit satisfactory cat-alytic activity and selectivity even in the presence of excessive impurity cations(including Na^(+),K^(+),Ca^(^(2+)),Mg^(2+),Sr^(2+),and Eu^(3+))or various organics(such as xylene,tributylphosphate,pyridine,tannic acid,citric acid,and oxalic acid).It is believed that this work can provide a potential opportunity for S-scheme heterojunction photocatalysts to re-enrich uranium from spent fuel wastewater.
基金supported by the National Natural Science Foundation of China(21225730,91326202)the Fundamental Research Funds for the Central Universities+2 种基金the Jiangsu Provincial Key Laboratory of Radiation Medicine,Protectionthe Priority Academic Program Development of Jiangsu Higher Education InstitutionsMCTL Visiting Fellowship Program from Key Laboratory of Marine Chemistry Theory and Technology(Ocean University of China),Ministry of Education
文摘Graphene oxides(GOs) were synthesized via modified Hummers method, and were applied as adsorbents to remove radionuclides from large volumes of aqueous solutions. The single and competitive sorption of four radionuclides(i.e., U(VI), 152+154Eu(III), 85+89Sr(II) and 134Cs(I)) on the GOs from aqueous solutions were investigated as a function of p H, ionic strength and radionuclide initial concentrations using batch technique. The results showed that the GOs had much higher sorption capacity than many other contemporary materials, for the preconcentration of radionuclides from large volumes of aqueous solutions. The sorption of radionuclides on GOs obeyed the Langmuir model, and was mainly attributed to surface complexation via the coordination of radionuclides with the oxygen-containing functional groups on GO surfaces. The competitive sorption results indicated that the selectivity sorption capacities were U(VI)>Eu(III)>Sr(II)>Cs(I). The GOs are suitable materials for the efficient removal and preconcentration of radionuclides from aqueous solutions in nuclear waste management and environmental pollution cleanup.
