A solid-phase extraction resin SIRs-P227/XAD-7 HP was prepared by impregnating extractant P227 onto macroporous resin XAD-7 HP beads. SIRs-P227/XAD-7 HP beads were characterized by Fourier transform infrared spectrosc...A solid-phase extraction resin SIRs-P227/XAD-7 HP was prepared by impregnating extractant P227 onto macroporous resin XAD-7 HP beads. SIRs-P227/XAD-7 HP beads were characterized by Fourier transform infrared spectroscopy(FTIR) and scanning electron microscopy(SEM) equipped with energy-dispersive spectroscopy(EDS). The adsorption kinetics, particle size effect,adsorption isotherm, pH_(equilibrium)–lg D relationship(where D is distribution coefficient), desorption, adsorption selectivity for heavy rare earths, and impurity ions were studied. The results showed that the adsorption kinetics of Lu(III) on the SIRs-P227/XAD-7 HP beads fitted the Morris–Weber model best. The adsorbance decreased as the particle size increased. The pH_(equilibrium)–lg D relationship fitted well with a straight line, and the slope was 1.56. The experimental data fitted well with Langmuir adsorption.The calculated maximum adsorption capacity was23.8 mg·g^(-1), while the experimental datum was22.7 mg·g^(-1) at the given conditions. The adsorbed Lu(III)can be easily stripped by 0.1 mol·L^(-1) HCl. The adsorption selectivity of SIRs-P227/XAD-7 HP for heavy REs exhibited the following order: Lu>Yb>Tm>Er>Ho. The adjacent heavy rare earth(RE) separation factors β_(Lu/Yb),β_(Yb/Tm), β_(Tm/Er), and β_(Er/Ho)were 1.57, 3.00, 3.03, and 2.23,respectively, at liquid/solid ratio(L/S) equal to 3:20. The adsorption selectivity for impurity ions exhibited the followingorder:Fe >Lu>Tm>Zn>Mg>Ca>Ho>Co>Ni>Cu>Al.展开更多
This paper reports on the selective transport of Lu(Ⅲ)from La(III)and Sm(III)through a polymer inclusion membrane(PIM)composed of 40 wt%di(2-ethylhexyl)phosphinic acid(P227)and 60 wt%poly(vinylidene fluoride)(PVDF).B...This paper reports on the selective transport of Lu(Ⅲ)from La(III)and Sm(III)through a polymer inclusion membrane(PIM)composed of 40 wt%di(2-ethylhexyl)phosphinic acid(P227)and 60 wt%poly(vinylidene fluoride)(PVDF).Basically,the changes in surface morphology,thickness and water contact angle of this PVDF-based PIM containing P227(P227@PVDF PIM)with different polymer concentrations were investigated.By solvent extraction experiments,it is found that Lu(Ⅲ)can be selectively extracted from La(Ⅲ)and Sm(Ⅲ)at pH 1.5 in hydrochloric acid solution.According to this result,P227@PVDF PIM was used to selectively transport Lu(Ⅲ)from hydrochloric acid feed solution containing similar concentration of La(Ⅲ)and Sm(Ⅲ).The recovery factor of Lu(III)is 91% after 36 h,and about 5%of Sm(Ⅲ)was also transported through the PIM.The concentration of La(III)in the feed solution and the stripping solution does not change.Furthermore,to overcome the ubiquitous decline of transport efficiency caused by the loss of carrier or the damage of membrane structure after long-term use of PIMs,a process for regenerating PIMs was first proposed and implemented.By comparison of the regenerated PIM with the normal PIM,there is almost no difference in the SEM image,ATR-FTIR spectrum and Lu(III)transport efficiency.It is expected that P227@PVDF PIMs have the potential to be applied to the grouped separation of rare earth elements(REEs),and this study also can be as an inspiration for the further study on the PIMs regeneration process.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51974026 and 21301104)the National Key R&D Program of China(No.2018YFC1900604)the Fundamental Research Funds for the Central Universities(No.FRF-TP-16019A3)。
文摘A solid-phase extraction resin SIRs-P227/XAD-7 HP was prepared by impregnating extractant P227 onto macroporous resin XAD-7 HP beads. SIRs-P227/XAD-7 HP beads were characterized by Fourier transform infrared spectroscopy(FTIR) and scanning electron microscopy(SEM) equipped with energy-dispersive spectroscopy(EDS). The adsorption kinetics, particle size effect,adsorption isotherm, pH_(equilibrium)–lg D relationship(where D is distribution coefficient), desorption, adsorption selectivity for heavy rare earths, and impurity ions were studied. The results showed that the adsorption kinetics of Lu(III) on the SIRs-P227/XAD-7 HP beads fitted the Morris–Weber model best. The adsorbance decreased as the particle size increased. The pH_(equilibrium)–lg D relationship fitted well with a straight line, and the slope was 1.56. The experimental data fitted well with Langmuir adsorption.The calculated maximum adsorption capacity was23.8 mg·g^(-1), while the experimental datum was22.7 mg·g^(-1) at the given conditions. The adsorbed Lu(III)can be easily stripped by 0.1 mol·L^(-1) HCl. The adsorption selectivity of SIRs-P227/XAD-7 HP for heavy REs exhibited the following order: Lu>Yb>Tm>Er>Ho. The adjacent heavy rare earth(RE) separation factors β_(Lu/Yb),β_(Yb/Tm), β_(Tm/Er), and β_(Er/Ho)were 1.57, 3.00, 3.03, and 2.23,respectively, at liquid/solid ratio(L/S) equal to 3:20. The adsorption selectivity for impurity ions exhibited the followingorder:Fe >Lu>Tm>Zn>Mg>Ca>Ho>Co>Ni>Cu>Al.
基金supported by the National Basic Research Program of China(2012CBA01202)the National Natural Science Foundation of China(51174184)the Key Research Program of the Chinese Academy of Sciences(KGZD-EW-201-1)。
文摘This paper reports on the selective transport of Lu(Ⅲ)from La(III)and Sm(III)through a polymer inclusion membrane(PIM)composed of 40 wt%di(2-ethylhexyl)phosphinic acid(P227)and 60 wt%poly(vinylidene fluoride)(PVDF).Basically,the changes in surface morphology,thickness and water contact angle of this PVDF-based PIM containing P227(P227@PVDF PIM)with different polymer concentrations were investigated.By solvent extraction experiments,it is found that Lu(Ⅲ)can be selectively extracted from La(Ⅲ)and Sm(Ⅲ)at pH 1.5 in hydrochloric acid solution.According to this result,P227@PVDF PIM was used to selectively transport Lu(Ⅲ)from hydrochloric acid feed solution containing similar concentration of La(Ⅲ)and Sm(Ⅲ).The recovery factor of Lu(III)is 91% after 36 h,and about 5%of Sm(Ⅲ)was also transported through the PIM.The concentration of La(III)in the feed solution and the stripping solution does not change.Furthermore,to overcome the ubiquitous decline of transport efficiency caused by the loss of carrier or the damage of membrane structure after long-term use of PIMs,a process for regenerating PIMs was first proposed and implemented.By comparison of the regenerated PIM with the normal PIM,there is almost no difference in the SEM image,ATR-FTIR spectrum and Lu(III)transport efficiency.It is expected that P227@PVDF PIMs have the potential to be applied to the grouped separation of rare earth elements(REEs),and this study also can be as an inspiration for the further study on the PIMs regeneration process.
