p-Aminobenzenesulfonic acid was selected as a typical solute with amphoteric functional groups to be separated from dilute solution.A quaternary ammonium chloride,Aliquat 336, was used as the extractant. The effects o...p-Aminobenzenesulfonic acid was selected as a typical solute with amphoteric functional groups to be separated from dilute solution.A quaternary ammonium chloride,Aliquat 336, was used as the extractant. The effects of pH, extractant concentration and diluent types on distribution coefficient,D,were investigated. Meanwhile,the ion exchange reaction for Aliquat 336 with p-aminobenzenesulfonic acid in the extraction process was discussed.The description of D was proposed according to the mass action law.The results show that the D in non-polar diluents,kerosene and CCl4,is larger than that in polar diluent,1-octanol and chloroform.The sodium sulfate in aqueous phase affects D strongly due to exchange of sulfate ions with Aliquat 336. Finally,the removal of 4,4′-diaminostibene-2,2′-disulfonic acid (DSD) acid), an amino sulfonic acid,was successfully achieved from wastewater by the extraction with Aliquat 336.展开更多
The solvent extraction of cadmium(II) from nitrate medium was studied. The using extractants were quaternary ammonium-based room temperature ionic liquid Aliquat 336 in either the chloride [(C8H17)3 CH3N+·Cl-], t...The solvent extraction of cadmium(II) from nitrate medium was studied. The using extractants were quaternary ammonium-based room temperature ionic liquid Aliquat 336 in either the chloride [(C8H17)3 CH3N+·Cl-], thiocyanate [(C8H17)3CH3N+·SCN-] and hydrogenophosphate forms, diluted in the kerosene. The effects of different parameters such as equilibration time, initial pH, O/A molar ratio (nextractant/nCd), initial extractant concentration and ionic strong on extraction of cadmium(II) were investigated. The extraction yields of cadmium(II) increase with increasing initial pH and initial extractant concentration. The stoichiometry of the extracted species was determined on the basis of slope analysis. The effect of various salts such as KSCN and NaNO3 in the feed solution within the concentrations of 10 to 100 mM on extraction of cadmium(II) was studied at optimal initial pH = 6.2. The relation between the percentages of the extracted species () and the extraction yields were investigated by a calculation program using CHEAQS V. L20.1. The results showed that the decrease of the extraction yield of Cd(II) was related with the decrease gradually of percentage of cadmium(II) free and the increase of percentage of and species with the addition of KSCN. More the hydrophobic character of the extractant is high, more the extraction is better. The metal ion was stripped out satisfactorily using nitric acid as stripping agent, in one step.展开更多
The recovery of caproic acid from the aqueous stream is of practical relevance due to its market value and the stringent environmental standards. The profound success of reactive extraction has been noted in the recov...The recovery of caproic acid from the aqueous stream is of practical relevance due to its market value and the stringent environmental standards. The profound success of reactive extraction has been noted in the recovery of carboxylic acids from dilute solutions. In present paper, equilibrium of caproic acid with aliquat-336, a quaternary amine compound, in xylene and Methyl Isobutyl Ketone (MIBK) has been studied. Equilibrium parameters such as distribution coefficients, loading ratio, degree of extraction and equilibrium complexation constants have been presented. The data obtained is useful in understanding the equilibrium characteristics and efficient design of the recovery process of caproic acid by reactive extraction.展开更多
基金Supported by the National Natural Science Foundation of China (No. 29836130).
文摘p-Aminobenzenesulfonic acid was selected as a typical solute with amphoteric functional groups to be separated from dilute solution.A quaternary ammonium chloride,Aliquat 336, was used as the extractant. The effects of pH, extractant concentration and diluent types on distribution coefficient,D,were investigated. Meanwhile,the ion exchange reaction for Aliquat 336 with p-aminobenzenesulfonic acid in the extraction process was discussed.The description of D was proposed according to the mass action law.The results show that the D in non-polar diluents,kerosene and CCl4,is larger than that in polar diluent,1-octanol and chloroform.The sodium sulfate in aqueous phase affects D strongly due to exchange of sulfate ions with Aliquat 336. Finally,the removal of 4,4′-diaminostibene-2,2′-disulfonic acid (DSD) acid), an amino sulfonic acid,was successfully achieved from wastewater by the extraction with Aliquat 336.
文摘The solvent extraction of cadmium(II) from nitrate medium was studied. The using extractants were quaternary ammonium-based room temperature ionic liquid Aliquat 336 in either the chloride [(C8H17)3 CH3N+·Cl-], thiocyanate [(C8H17)3CH3N+·SCN-] and hydrogenophosphate forms, diluted in the kerosene. The effects of different parameters such as equilibration time, initial pH, O/A molar ratio (nextractant/nCd), initial extractant concentration and ionic strong on extraction of cadmium(II) were investigated. The extraction yields of cadmium(II) increase with increasing initial pH and initial extractant concentration. The stoichiometry of the extracted species was determined on the basis of slope analysis. The effect of various salts such as KSCN and NaNO3 in the feed solution within the concentrations of 10 to 100 mM on extraction of cadmium(II) was studied at optimal initial pH = 6.2. The relation between the percentages of the extracted species () and the extraction yields were investigated by a calculation program using CHEAQS V. L20.1. The results showed that the decrease of the extraction yield of Cd(II) was related with the decrease gradually of percentage of cadmium(II) free and the increase of percentage of and species with the addition of KSCN. More the hydrophobic character of the extractant is high, more the extraction is better. The metal ion was stripped out satisfactorily using nitric acid as stripping agent, in one step.
文摘The recovery of caproic acid from the aqueous stream is of practical relevance due to its market value and the stringent environmental standards. The profound success of reactive extraction has been noted in the recovery of carboxylic acids from dilute solutions. In present paper, equilibrium of caproic acid with aliquat-336, a quaternary amine compound, in xylene and Methyl Isobutyl Ketone (MIBK) has been studied. Equilibrium parameters such as distribution coefficients, loading ratio, degree of extraction and equilibrium complexation constants have been presented. The data obtained is useful in understanding the equilibrium characteristics and efficient design of the recovery process of caproic acid by reactive extraction.
