The distributions of nicotinic acid (NA) between water and trialkylamine (N235) dissolved in n-octanol was studied. The complexes of N235 and NA were investigated by Fourier transformation infrared spectrometry to ded...The distributions of nicotinic acid (NA) between water and trialkylamine (N235) dissolved in n-octanol was studied. The complexes of N235 and NA were investigated by Fourier transformation infrared spectrometry to deduce the reaction mechanism. It was found that N235/n-octanol was an efficient extractant for extracting nicotinic acid. The favorable operation conditions were equilibrium aqueous pH 4.2 to 5.5 and initial N235 concentration<0.42 mol·L-1 . The reaction processes included the reaction between neutral N235 and neutral NA and the reaction between protonated N235 and anionic NA. Based on the mass action law and some assumptions, an expression for distribution coefficient D was proposed. The apparent extraction equilibrium constants were calculated by fitting the experimental data and the results were satisfactory.展开更多
The extraction of cadmium and zinc with di-(2-ethylhexyl)-dithiophosphoric acid(D2EHDTPA)-toluene and D2EHDTPA-trioctyl amine(TOA)-toluene has been investigated. Infrared spectrum analysis, the nuclear magnetic resona...The extraction of cadmium and zinc with di-(2-ethylhexyl)-dithiophosphoric acid(D2EHDTPA)-toluene and D2EHDTPA-trioctyl amine(TOA)-toluene has been investigated. Infrared spectrum analysis, the nuclear magnetic resonance spectrum(NMR) analysis and conductivity measurements confirm that the probable structures of the extracted complexes are CdA2 and ZnA2. Cadmium can be extracted by D2EHDTPA very easily. Almost all the cadmium can be extracted, but stripping of cadmium from the organic phase is very difficult. When a mixture of D2EHDTPA and TOA is used, selective extraction of cadmium from zinc sulfate solution can be achieved. Cadmium can be easily stripped from the organic phase.展开更多
基金Supported by the Ministry of Education of Henan Province in China (2011A610004)
文摘The distributions of nicotinic acid (NA) between water and trialkylamine (N235) dissolved in n-octanol was studied. The complexes of N235 and NA were investigated by Fourier transformation infrared spectrometry to deduce the reaction mechanism. It was found that N235/n-octanol was an efficient extractant for extracting nicotinic acid. The favorable operation conditions were equilibrium aqueous pH 4.2 to 5.5 and initial N235 concentration<0.42 mol·L-1 . The reaction processes included the reaction between neutral N235 and neutral NA and the reaction between protonated N235 and anionic NA. Based on the mass action law and some assumptions, an expression for distribution coefficient D was proposed. The apparent extraction equilibrium constants were calculated by fitting the experimental data and the results were satisfactory.
基金Supported by the National Natural Science Foundation of China(No.59474009).
文摘The extraction of cadmium and zinc with di-(2-ethylhexyl)-dithiophosphoric acid(D2EHDTPA)-toluene and D2EHDTPA-trioctyl amine(TOA)-toluene has been investigated. Infrared spectrum analysis, the nuclear magnetic resonance spectrum(NMR) analysis and conductivity measurements confirm that the probable structures of the extracted complexes are CdA2 and ZnA2. Cadmium can be extracted by D2EHDTPA very easily. Almost all the cadmium can be extracted, but stripping of cadmium from the organic phase is very difficult. When a mixture of D2EHDTPA and TOA is used, selective extraction of cadmium from zinc sulfate solution can be achieved. Cadmium can be easily stripped from the organic phase.
