MX-80 bentonite was detected using acid-based titration, XRD and FTIR in detail. The sorption behavior of 63Ni(II) from aqueous solution to MX-80 bentonite was investigated as a function of solid content, ionic streng...MX-80 bentonite was detected using acid-based titration, XRD and FTIR in detail. The sorption behavior of 63Ni(II) from aqueous solution to MX-80 bentonite was investigated as a function of solid content, ionic strength and pH by using batch technique. The experimental data of 63Ni(II) sorption on MX-80 bentonite was obtained using the diffuse layer model (DLM) with the aid of FITEQL 3.1 program. The results indicated that the sorption of 63Ni(II) on MX-80 bentonite was mainly dominated by surface complexation, and cation exchange also contributed partly to 63Ni(II) sorption at low pH values. The sorption isotherms were simulated by Langmuir and Freundlich models, and the results indicated that Freundlich isotherm model fitted the sorption data better than the Langmuir isotherm model. The results are crucial to evaluate the sorption and migration of radionickel in MX-80 bentonite.展开更多
Cyclodextrin-modified graphene oxide nanosheets(denoted as CD/GO) were synthesized by an in-situ polymerization method and characterized by as well as Fourier transform-infrared spectroscopy, X-ray photoelectron spect...Cyclodextrin-modified graphene oxide nanosheets(denoted as CD/GO) were synthesized by an in-situ polymerization method and characterized by as well as Fourier transform-infrared spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and potentiometric acid-base titration. The characterization results indicated that CD was successfully grafted onto GO surfaces by forming a chemical bond. Mutual effects on the simultaneous removal of hexavalent uranium and humic acid by CD/GO from aqueous solution were investigated. The results indicated that U(VI) and humic acid(HA) sorption on CD/GO were greatly affected by pH and ionic strength. The presence of HA enhanced U(VI) sorption at low pH and reduced U(VI) sorption at high pH, whereas the presence of U(VI) enhanced HA sorption. The surface adsorbed HA acted as a "bridge" between U(VI) and CD/GO, and formed strong inner-sphere surface complexes with U(VI). Sorption isotherms of U(VI) or HA on CD/GO could be well fitted by the Langmuir model. This work highlights that CD/GO can be used as a promising material in the enrichment of U(VI) and HA from wastewater in U(VI) and humic substances obtained by environmental pollution cleanup.展开更多
The development of efficient materials for high extraction of uranium(UO22+) from seawater is critical for nuclear energy. Poly(amidoxime)-reduced graphene oxide(PAO/rGO) composites with excellent adsorption capabilit...The development of efficient materials for high extraction of uranium(UO22+) from seawater is critical for nuclear energy. Poly(amidoxime)-reduced graphene oxide(PAO/rGO) composites with excellent adsorption capability for UO22+ were synthesized by in situ polymerization of acrylonitrile monomers on GO surfaces, followed by amidoximation treatment with hydroxylamine. The adsorption capacities of PAO/rGO composites for UO22+ reached as high as 872 mg/g at pH 4.0. The excellent tolerance of these composites for high salinity and their regeneration-reuse properties can be applied in the nuclear-fuel industry by high extraction of trace UO22+ ions from seawater.展开更多
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20501019 and J0630962)973 Projects (Grant No. 2007CB936602)
文摘MX-80 bentonite was detected using acid-based titration, XRD and FTIR in detail. The sorption behavior of 63Ni(II) from aqueous solution to MX-80 bentonite was investigated as a function of solid content, ionic strength and pH by using batch technique. The experimental data of 63Ni(II) sorption on MX-80 bentonite was obtained using the diffuse layer model (DLM) with the aid of FITEQL 3.1 program. The results indicated that the sorption of 63Ni(II) on MX-80 bentonite was mainly dominated by surface complexation, and cation exchange also contributed partly to 63Ni(II) sorption at low pH values. The sorption isotherms were simulated by Langmuir and Freundlich models, and the results indicated that Freundlich isotherm model fitted the sorption data better than the Langmuir isotherm model. The results are crucial to evaluate the sorption and migration of radionickel in MX-80 bentonite.
基金supported by the National Natural Science Foundation of China(91326202,21375148,21207136,21225730)the Hefei Center for Physical Science and Technology(2012FXZY005)
文摘Cyclodextrin-modified graphene oxide nanosheets(denoted as CD/GO) were synthesized by an in-situ polymerization method and characterized by as well as Fourier transform-infrared spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and potentiometric acid-base titration. The characterization results indicated that CD was successfully grafted onto GO surfaces by forming a chemical bond. Mutual effects on the simultaneous removal of hexavalent uranium and humic acid by CD/GO from aqueous solution were investigated. The results indicated that U(VI) and humic acid(HA) sorption on CD/GO were greatly affected by pH and ionic strength. The presence of HA enhanced U(VI) sorption at low pH and reduced U(VI) sorption at high pH, whereas the presence of U(VI) enhanced HA sorption. The surface adsorbed HA acted as a "bridge" between U(VI) and CD/GO, and formed strong inner-sphere surface complexes with U(VI). Sorption isotherms of U(VI) or HA on CD/GO could be well fitted by the Langmuir model. This work highlights that CD/GO can be used as a promising material in the enrichment of U(VI) and HA from wastewater in U(VI) and humic substances obtained by environmental pollution cleanup.
基金supported by the Chinese National Fusion Project for ITER(2013GB110005)the National Natural Science Foundation of China(91326202,21207136,21272236,21225730)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions,the Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions,Hefei Center for Physical Science and Technology(2012FXZY005)the Science Foundation of Institute of Plasma Physics(DSJJ-13-YY01)
文摘The development of efficient materials for high extraction of uranium(UO22+) from seawater is critical for nuclear energy. Poly(amidoxime)-reduced graphene oxide(PAO/rGO) composites with excellent adsorption capability for UO22+ were synthesized by in situ polymerization of acrylonitrile monomers on GO surfaces, followed by amidoximation treatment with hydroxylamine. The adsorption capacities of PAO/rGO composites for UO22+ reached as high as 872 mg/g at pH 4.0. The excellent tolerance of these composites for high salinity and their regeneration-reuse properties can be applied in the nuclear-fuel industry by high extraction of trace UO22+ ions from seawater.
