Extraction of p -aminophenol by D2EHPA, Alamine336 and their mixture were studied under various initial pH ranging 3-10.Both extractants extracted neutral form of p -aminophenol. When the pH value was between p K a1 a...Extraction of p -aminophenol by D2EHPA, Alamine336 and their mixture were studied under various initial pH ranging 3-10.Both extractants extracted neutral form of p -aminophenol. When the pH value was between p K a1 and p K a2 ,a maximum distribution ratio appeared. This pH dependence can be explained by varying the molar fraction of neutral PAP with pH value. The mixed solvent of D2EHPA and Alamine336 had a higher distribution ratio than either Alamine336 or D2EHPA alone, i.e. ,the extraction of p -aminophenol with the mixed solvent showed the synergistic effect,and the molar concentration ratio of D2EHPA to Alamine336 at 1∶1.5 was the synergistic point.展开更多
p-Amino benzene sulfonic acid (PABSA) is selected as the solute with amphoteric functional group, Lewis acid and Lewis base, to be separated from its dilute solutions. An aliphatic, straight chain amine, Alamine 336 ,...p-Amino benzene sulfonic acid (PABSA) is selected as the solute with amphoteric functional group, Lewis acid and Lewis base, to be separated from its dilute solutions. An aliphatic, straight chain amine, Alamine 336 , is used as the extractant, and kerosene, 1-octanol, chloroform, butyl acetate and benzene as the diluent. The effects of pH value of solution, extractant concentration, salt and types of diluent on the distribution coefficient, D, are studied. There is a peak of D value with pH value of solution, the polar diluents are favorable for extracting PABSA, and the salt in aqueous phase reduces values of D apparently. The extraction equilibrium is described using the mass action law, and the calculated data according to the proposed model agree with the experimental data well. Further, the extraction behavior for other amino benzene sulfonic acids, l-amino-8-naphtol-3,6-disulfonic acid (H acid) and 4,4'-diaminostilbene-2,2'-disulfonic acid (DSD acid), is investigated in a wide pH value region. Finally, H acid and DSD acid are successfully removed from wastewater by the extraction with Alamine 336.展开更多
文摘Extraction of p -aminophenol by D2EHPA, Alamine336 and their mixture were studied under various initial pH ranging 3-10.Both extractants extracted neutral form of p -aminophenol. When the pH value was between p K a1 and p K a2 ,a maximum distribution ratio appeared. This pH dependence can be explained by varying the molar fraction of neutral PAP with pH value. The mixed solvent of D2EHPA and Alamine336 had a higher distribution ratio than either Alamine336 or D2EHPA alone, i.e. ,the extraction of p -aminophenol with the mixed solvent showed the synergistic effect,and the molar concentration ratio of D2EHPA to Alamine336 at 1∶1.5 was the synergistic point.
基金Supported by the National Natural Science Foundation of China (No. 29836130).
文摘p-Amino benzene sulfonic acid (PABSA) is selected as the solute with amphoteric functional group, Lewis acid and Lewis base, to be separated from its dilute solutions. An aliphatic, straight chain amine, Alamine 336 , is used as the extractant, and kerosene, 1-octanol, chloroform, butyl acetate and benzene as the diluent. The effects of pH value of solution, extractant concentration, salt and types of diluent on the distribution coefficient, D, are studied. There is a peak of D value with pH value of solution, the polar diluents are favorable for extracting PABSA, and the salt in aqueous phase reduces values of D apparently. The extraction equilibrium is described using the mass action law, and the calculated data according to the proposed model agree with the experimental data well. Further, the extraction behavior for other amino benzene sulfonic acids, l-amino-8-naphtol-3,6-disulfonic acid (H acid) and 4,4'-diaminostilbene-2,2'-disulfonic acid (DSD acid), is investigated in a wide pH value region. Finally, H acid and DSD acid are successfully removed from wastewater by the extraction with Alamine 336.
