Abstract: A high mass transfer membrane for use in membrane phase contactors to extract a solute from an aqueous phase to a solvent phase and their method of preparation and use are disclosed. The membrane is formed from polyimide by phase inversion and may optionally be crosslinked to maintain stability even in the solvents from which the membranes were formed by phase phase inversion.

Abstract: There is provided a process for modifying a first organic composition comprising (i) at least one first solvent, (ii) at least one solute, and (iii) optionally, at least one second solvent to produce a modified organic composition in which the concentration of the at least one first solvent is reduced and the concentration of the at least one second solvent is increased, comprising the steps of: (a) providing a selectively permeable membrane having a first surface and a second surface; (b) transferring a portion of the first solvent and optionally a portion of the solute from the first surface to the second surface across the membrane by contacting the first organic composition with the first surface, wherein the pressure at the first surface is greater than the pressure at the second surface, and wherein the membrane is a selectively permeable membrane such that the membrane rejection (R) of the solute is greater than 0%; (c) adding a portion of the second solvent to the organic composition retained at the f

Abstract: 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.

Abstract: There is provided a process for removing and recovering one or more unassociated phenolic compounds dissolved in aqueous fluid, the process comprising the steps of: (a) transferring the one or more unassociated phenolic compounds from the aqueous fluid to an alkaline stripping solution, wherein transfer of the one or more unassociated phenolic compounds from the aqueous fluid to the alkaline stripping solution occurs across a membrane; wherein the membrane is a non porous, selectively permeable membrane; (b) regulating the volume of alkaline stripping solution employed relative to the volume of aqueous fluid treated so that the total phenolic compound concentration in the alkaline stripping solution, comprising the sum of the dissociated and unassociated phenolic compound concentrations, is above the solubility of the phenolic compounds in the acidified stripping solution of step (d); (c) regulating the pH of the alkaline stripping solution in contact with the membrane to a value at least 0.