RECOVERY OF TARTARIC AND MALIC-ACIDS FROM DILUTE AQUEOUS EFFLUENTS BYSOLVENT-EXTRACTION TECHNIQUE

Solvent extraction deserves consideration for the recovery of carboxyl ic acids from wastewater in order to clean up industrial effluents. Ta rtaric and malic acids are present in low concentration in the effluen ts of distilleries producing grape sugar. The separation of these acid s from dilute aqueous solutions by the technique of dissociation extra ction employing respectively tributylphosphate dissolved in dodecane a nd triisooctylamine (tris-(6-methylheptyl)-amine) dissolved in 1-octan ol as solvents was explored in this study. With a solvent ratio of 0.5 and a solvent containing 0-6 mole of triisooctylamine per dm3 of the triisooctylamine + 1-octanol mixture, the best percentages of malic an d tartaric acids recovered were respectively 92 mass% and 99 mass% rel ative to the quantities of these acids present in the initial aqueous solutions.