The extraction chromatography–electrodeposition(EC–ED) process was proposed for the quantitative recovery of palladium from high-level liquid waste(HLLW) in this study. The process coupled the extraction chromatogra...The extraction chromatography–electrodeposition(EC–ED) process was proposed for the quantitative recovery of palladium from high-level liquid waste(HLLW) in this study. The process coupled the extraction chromatography method to obtain the decontamination of Pd(II) from HLLW with the electrochemical method to recover metallic palladium from the concentrated solution.Separation of Pd(II) from a nitric acid medium by extraction chromatography using iso Bu-BTP/SiO_2-P adsorbent and the electrochemical behavior of Pd(II) in nitric acid solution in the presence of thiourea(TU) were investigated.iso Bu-BTP/SiO_2-P exhibited a high selectivity for Pd(II)over other fission products(FPs), and Pd(II) could be desorbed by TU from loaded BTP/SiO_2-P. The adsorbent performed good stability against HNO_3 because the adsorption performance kept Pd(II) after extended contact with HNO_3 solution. The column experiment achieved the separation of Pd(II) from simulated HLLW successfully.The electrochemical behavior of Pd(II) in palladium desorption solution containing TU and nitric acid was investigated at a platinum electrode by cyclic voltammetry. A weak reduction wave at-0.4 V was due to the reduction in Pd(II) to Pd(0), and the deposition process wasirreversible. In electrowinning experiments, a maximum of92% palladium could be obtained.展开更多
A porous silica-polymer-based adsorbent,isoBuBTP/Si O2-P,was prepared by a vacuum impregnation method and used for the recovery of ruthenium,rhodium,and palladium from nitric acid solution.The experimental results rev...A porous silica-polymer-based adsorbent,isoBuBTP/Si O2-P,was prepared by a vacuum impregnation method and used for the recovery of ruthenium,rhodium,and palladium from nitric acid solution.The experimental results revealed that iso Bu-BTP/SiO2-P exhibited unique adsorption properties such as high saturation adsorption capacity(Ru:0.35 mmol g^-1,Rh:0.32 mmol g^-1,Pd:1.05 mmol g^-1)and excellent selectivity over other metal ions,such as lanthanides(SF(PGM/M)>40)in 1 M HNO3 solution.The adsorption process conformed to the pseudosecond-order model and Langmuir model.From the UV,FTIR,and XPS analyses,it can be concluded that the strong affinity between functional groups(C–N=C)and metal ions as well as NO3-played a role in coordination during the adsorption process.Furthermore,the desorption behavior was studied,and it was found that the adsorbed Pd,Rh,and Ru could be eluted with a 0.01 M nitric acid–0.1M thiocarbamide solution,5M hydrochloric acid,and sodium hypochlorite(CP)solution,respectively.Finally,based on those findings,a simple process for the separation and recovery of Pd,Rh,and Ru from high-level liquid waste using iso Bu-BTP/SiO2-P was designed and proposed.展开更多
Efficient separation of palladium(Pd(Ⅱ))from high-level liquid waste(HLLW)not only helps the safe disposal of nuclear waste,but also is a vital importan supplement to Pd(Ⅱ)resources.Herein,16 kinds of nove Amberlite...Efficient separation of palladium(Pd(Ⅱ))from high-level liquid waste(HLLW)not only helps the safe disposal of nuclear waste,but also is a vital importan supplement to Pd(Ⅱ)resources.Herein,16 kinds of nove Amberlite XAD resins-based adsorbents were prepared by vacuum impregnation method for the separation of Pd(Ⅱ)from simulated HLLW,and the MMBT/XAD7HP prepared using 4-methyl-2-mercaptobenzothiazole(MMBT)as ligand and Amberlite XAD7HP resin(XAD7HP)as the carrier was selected as the optimal research object.Characterization analysis experiments proved the successful preparation of MMBT/XAD7HP,which exhibited ultrahigh adsorption selectivity for Pd(Ⅱ)(distribution coefficient(K_d)≥12584.5 ml·g^(-1),separation factor(SF_(Pd/M))≥2818.4)and superior adsorption capacity(Q≥130.1 mg·g^(-1)).The adsorption kinetics and adsorption isotherms for Pd(Ⅱ)matched with pseudo-secondorder(PSO)kinetics model and Langmuir model,indicating that the adsorption mode for Pd(Ⅱ)by MMBT/XAD7 HP was monolayer chemical adsorption.The dynamic column experiments showed that MMBT/XAD7 HP achieved efficiently separation of Pd(Ⅱ)from simulated HLLW,and the recovery rate was nearly 100% The adsorption mechanism was analyzed by Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and density functional theory(DFT),and the ultrahigh selectivity of MMBT/XAD7 HP is attributed to the preferred affinity of the soft-N,S donor atoms in MMBT for Pd(Ⅱ).MMBT has the shortest frontline molecular orbital energy band gap(HOMO-LUMO)among the four ligands,which makes it easier to become an electron donor to attract Pd^(2+)to participate in coordination.NO_(3)^(-)participates in the adsorption to keep charge balance.In summary,MMBT/XAD7 HP has broad application prospects for the treatment of Pd(Ⅱ)in HLLW.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11305102,91126006,and 21261140335)
文摘The extraction chromatography–electrodeposition(EC–ED) process was proposed for the quantitative recovery of palladium from high-level liquid waste(HLLW) in this study. The process coupled the extraction chromatography method to obtain the decontamination of Pd(II) from HLLW with the electrochemical method to recover metallic palladium from the concentrated solution.Separation of Pd(II) from a nitric acid medium by extraction chromatography using iso Bu-BTP/SiO_2-P adsorbent and the electrochemical behavior of Pd(II) in nitric acid solution in the presence of thiourea(TU) were investigated.iso Bu-BTP/SiO_2-P exhibited a high selectivity for Pd(II)over other fission products(FPs), and Pd(II) could be desorbed by TU from loaded BTP/SiO_2-P. The adsorbent performed good stability against HNO_3 because the adsorption performance kept Pd(II) after extended contact with HNO_3 solution. The column experiment achieved the separation of Pd(II) from simulated HLLW successfully.The electrochemical behavior of Pd(II) in palladium desorption solution containing TU and nitric acid was investigated at a platinum electrode by cyclic voltammetry. A weak reduction wave at-0.4 V was due to the reduction in Pd(II) to Pd(0), and the deposition process wasirreversible. In electrowinning experiments, a maximum of92% palladium could be obtained.
基金This work was supported by the National Natural Science Foundation of China(Nos.11705032,11675102,and 11975082)the Natural Science Foundation of Guangxi Province(No.2017GXNSFBA198175)the Science and Technology Major Project of Guangxi Province(No.AA17204100).
文摘A porous silica-polymer-based adsorbent,isoBuBTP/Si O2-P,was prepared by a vacuum impregnation method and used for the recovery of ruthenium,rhodium,and palladium from nitric acid solution.The experimental results revealed that iso Bu-BTP/SiO2-P exhibited unique adsorption properties such as high saturation adsorption capacity(Ru:0.35 mmol g^-1,Rh:0.32 mmol g^-1,Pd:1.05 mmol g^-1)and excellent selectivity over other metal ions,such as lanthanides(SF(PGM/M)>40)in 1 M HNO3 solution.The adsorption process conformed to the pseudosecond-order model and Langmuir model.From the UV,FTIR,and XPS analyses,it can be concluded that the strong affinity between functional groups(C–N=C)and metal ions as well as NO3-played a role in coordination during the adsorption process.Furthermore,the desorption behavior was studied,and it was found that the adsorbed Pd,Rh,and Ru could be eluted with a 0.01 M nitric acid–0.1M thiocarbamide solution,5M hydrochloric acid,and sodium hypochlorite(CP)solution,respectively.Finally,based on those findings,a simple process for the separation and recovery of Pd,Rh,and Ru from high-level liquid waste using iso Bu-BTP/SiO2-P was designed and proposed.
基金financially supported by the National Natural Science Foundation of China(Nos.22066005,U1967218 and 11975082)the Science and Technology Innovation Program of Hunan Province(No.2023RC1067)the Natural Science Foundation of Guangxi Province(No.2021GXNAFAA220096)。
文摘Efficient separation of palladium(Pd(Ⅱ))from high-level liquid waste(HLLW)not only helps the safe disposal of nuclear waste,but also is a vital importan supplement to Pd(Ⅱ)resources.Herein,16 kinds of nove Amberlite XAD resins-based adsorbents were prepared by vacuum impregnation method for the separation of Pd(Ⅱ)from simulated HLLW,and the MMBT/XAD7HP prepared using 4-methyl-2-mercaptobenzothiazole(MMBT)as ligand and Amberlite XAD7HP resin(XAD7HP)as the carrier was selected as the optimal research object.Characterization analysis experiments proved the successful preparation of MMBT/XAD7HP,which exhibited ultrahigh adsorption selectivity for Pd(Ⅱ)(distribution coefficient(K_d)≥12584.5 ml·g^(-1),separation factor(SF_(Pd/M))≥2818.4)and superior adsorption capacity(Q≥130.1 mg·g^(-1)).The adsorption kinetics and adsorption isotherms for Pd(Ⅱ)matched with pseudo-secondorder(PSO)kinetics model and Langmuir model,indicating that the adsorption mode for Pd(Ⅱ)by MMBT/XAD7 HP was monolayer chemical adsorption.The dynamic column experiments showed that MMBT/XAD7 HP achieved efficiently separation of Pd(Ⅱ)from simulated HLLW,and the recovery rate was nearly 100% The adsorption mechanism was analyzed by Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and density functional theory(DFT),and the ultrahigh selectivity of MMBT/XAD7 HP is attributed to the preferred affinity of the soft-N,S donor atoms in MMBT for Pd(Ⅱ).MMBT has the shortest frontline molecular orbital energy band gap(HOMO-LUMO)among the four ligands,which makes it easier to become an electron donor to attract Pd^(2+)to participate in coordination.NO_(3)^(-)participates in the adsorption to keep charge balance.In summary,MMBT/XAD7 HP has broad application prospects for the treatment of Pd(Ⅱ)in HLLW.
