The solvent extinction behavior Of Th(Ⅳ) and Ce(Ⅳ) with Cyanex 925 in nhexane hem nitric acid medium was studied. The extinction mechanisms of Th(Ⅳ)and Ce(Ⅵ) by Cyanex 923 were determined by the method of slope an...The solvent extinction behavior Of Th(Ⅳ) and Ce(Ⅳ) with Cyanex 925 in nhexane hem nitric acid medium was studied. The extinction mechanisms of Th(Ⅳ)and Ce(Ⅵ) by Cyanex 923 were determined by the method of slope analysis, and the extracted species might be Th(NO3)4.S(Cyanex 923)(o) and Ce(NO3)4.2(Cyanex 923)(o). The extraction characteristics with purified Cyanex 925 and commercial Cyanex 925 were compared. Results showed Ce(Ⅳ) and Th(Ⅳ) could be separted with Cyanex 923 hem RE(Ⅲ) in nitric acid solution. The influence of temperature on the Th(Ⅳ) extinction was investigated and the thermodynamic functions were calculated.展开更多
The kinetics of extractive separation of La(Ⅲ) and Ni(Ⅱ) from nitrate medium in the presence of lactic acid (HLac) using di-2-ethylhexyl phosphoric acid (DEHPA) diluted in petrofin was investigated using a cell with...The kinetics of extractive separation of La(Ⅲ) and Ni(Ⅱ) from nitrate medium in the presence of lactic acid (HLac) using di-2-ethylhexyl phosphoric acid (DEHPA) diluted in petrofin was investigated using a cell with constant interfacial area and continuous stirring. The effects of stirring speed, interfacial area, pH, HLac concentration, extractant concentration, concentrations of metal ions and temperature on the extraction rate were examined. Results suggested that the extraction regime is diffusion-controlled. The reaction which occurred at the interface was found to be the rate-determining step. The extraction rates of both metal ions are found to be independent of pH. The extraction rates of La(Ⅲ) and Ni(Ⅱ) are first-order dependent with respect to lactic acid and metal ions (La(Ⅲ) and Ni(Ⅱ)) concentrations. The extraction rate of La(Ⅲ) is first-order dependent on DEHPA concentration and for Ni(Ⅱ), it varies to the power of 1.5. The separation of La(Ⅲ) and Ni(Ⅱ) from nitrate solution is possible at low interfacial area and low stirring speed.展开更多
The sorption study of La(Ⅲ) was carried out on poly[dibenzo-18-crown-6] and L-valine medium. The quantitative adsorption of La(Ⅲ) was found at 1×10-2 to 1×10-5 mol/L L-valine. The various eluting agents we...The sorption study of La(Ⅲ) was carried out on poly[dibenzo-18-crown-6] and L-valine medium. The quantitative adsorption of La(Ⅲ) was found at 1×10-2 to 1×10-5 mol/L L-valine. The various eluting agents were found efficient eluents for La(Ⅲ). The capacity of crown polymer for La(Ⅲ) was found to be 0.43 ±0.01 mmol/g. The tolerance limit of various cations and anions for La(Ⅲ) was determined. La(Ⅲ) was quantitatively separated from other metal ions in binary as well as multicomponent mixtures. The study was extended to sequential separation of La(Ⅲ), U(VI) and Th(IV). The good separation yields were obtained and had good reproducibility (±2%). The method incorporated the determination of La(Ⅲ) in real sample. The method was simple, rapid and selective.展开更多
The transfer behavior of Cr（Ⅲ） through the emulsion liquid membrane system of TBP-Span80-atoleine -kerosene was studied.The effects of membrane phase component, pH value in external phase, concentration of H2SO4 in...The transfer behavior of Cr（Ⅲ） through the emulsion liquid membrane system of TBP-Span80-atoleine -kerosene was studied.The effects of membrane phase component, pH value in external phase, concentration of H2SO4 in internal phase,ratio of emulsion-water （R ew）and coexisting ions on the transport rate of Cr（Ⅲ） were investigated.The results showed that the transport rate of Cr（Ⅲ）could reach 99.5% under the optimun conditions of 7%TBP, 5%Span80, 4% atoleine, 84%kerosene, 1.0 mol·L -1 H2SO 4 in internal phase and pH 3.5 in external phase.This method was applied to the treatment of Cr（Ⅲ） waste-water, and the residual concentration of Cr（Ⅲ） could be reduced to 1.0 mg·L -1 ,which was below the national standard of waste-water discharge.展开更多
文摘The solvent extinction behavior Of Th(Ⅳ) and Ce(Ⅳ) with Cyanex 925 in nhexane hem nitric acid medium was studied. The extinction mechanisms of Th(Ⅳ)and Ce(Ⅵ) by Cyanex 923 were determined by the method of slope analysis, and the extracted species might be Th(NO3)4.S(Cyanex 923)(o) and Ce(NO3)4.2(Cyanex 923)(o). The extraction characteristics with purified Cyanex 925 and commercial Cyanex 925 were compared. Results showed Ce(Ⅳ) and Th(Ⅳ) could be separted with Cyanex 923 hem RE(Ⅲ) in nitric acid solution. The influence of temperature on the Th(Ⅳ) extinction was investigated and the thermodynamic functions were calculated.
基金DST, Govt. of India for the award of INSPIRE fellowship
文摘The kinetics of extractive separation of La(Ⅲ) and Ni(Ⅱ) from nitrate medium in the presence of lactic acid (HLac) using di-2-ethylhexyl phosphoric acid (DEHPA) diluted in petrofin was investigated using a cell with constant interfacial area and continuous stirring. The effects of stirring speed, interfacial area, pH, HLac concentration, extractant concentration, concentrations of metal ions and temperature on the extraction rate were examined. Results suggested that the extraction regime is diffusion-controlled. The reaction which occurred at the interface was found to be the rate-determining step. The extraction rates of both metal ions are found to be independent of pH. The extraction rates of La(Ⅲ) and Ni(Ⅱ) are first-order dependent with respect to lactic acid and metal ions (La(Ⅲ) and Ni(Ⅱ)) concentrations. The extraction rate of La(Ⅲ) is first-order dependent on DEHPA concentration and for Ni(Ⅱ), it varies to the power of 1.5. The separation of La(Ⅲ) and Ni(Ⅱ) from nitrate solution is possible at low interfacial area and low stirring speed.
基金Project supported by the University Grants Commission,New Delhi
文摘The sorption study of La(Ⅲ) was carried out on poly[dibenzo-18-crown-6] and L-valine medium. The quantitative adsorption of La(Ⅲ) was found at 1×10-2 to 1×10-5 mol/L L-valine. The various eluting agents were found efficient eluents for La(Ⅲ). The capacity of crown polymer for La(Ⅲ) was found to be 0.43 ±0.01 mmol/g. The tolerance limit of various cations and anions for La(Ⅲ) was determined. La(Ⅲ) was quantitatively separated from other metal ions in binary as well as multicomponent mixtures. The study was extended to sequential separation of La(Ⅲ), U(VI) and Th(IV). The good separation yields were obtained and had good reproducibility (±2%). The method incorporated the determination of La(Ⅲ) in real sample. The method was simple, rapid and selective.
文摘The transfer behavior of Cr（Ⅲ） through the emulsion liquid membrane system of TBP-Span80-atoleine -kerosene was studied.The effects of membrane phase component, pH value in external phase, concentration of H2SO4 in internal phase,ratio of emulsion-water （R ew）and coexisting ions on the transport rate of Cr（Ⅲ） were investigated.The results showed that the transport rate of Cr（Ⅲ）could reach 99.5% under the optimun conditions of 7%TBP, 5%Span80, 4% atoleine, 84%kerosene, 1.0 mol·L -1 H2SO 4 in internal phase and pH 3.5 in external phase.This method was applied to the treatment of Cr（Ⅲ） waste-water, and the residual concentration of Cr（Ⅲ） could be reduced to 1.0 mg·L -1 ,which was below the national standard of waste-water discharge.
