Method for removing and recovering aromatic amines by using a non-porous membrane

摘要

A process for removing and recovering undissociated aromatic amines dissolved in aqueous fluid comprises the steps of (a) transferring undissociated aromatic amines from the aqueous fluid to an acidic stripping solution across a membrane wherein the membrane is a non-porous, selectively permeable membrane; (b) regulating the volume of acidic stripping solution employed relative to the volume of aqueous fluid treated so that the total aromatic amine concentration in the acidic stripping solutions, comprising the sum of the dissociated and undissociated aromatic amine concentrations, is above the solubility of the aromatic amine in water; (c) regulating the pH of the acidic stripping solution in contact with the membrane so that the membrane remains selectively permeable; (d) adjusting the pH of the aromatic amine containing acidic stripping solution to a value above the acidic dissociation constant of the aromatic amine and (e) separating the resulting aromatic amine and the acidic stripping solution.