Chinese Journal of Chemical Engineering, Vol.12, No.1, 137-142, 2004
Extraction behavior and wastewater treatment of amino sulfonic acid with 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, I-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, 1-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.