Membrane contactors, providing a non-dispersive extraction technique, were used for the removal of valeric (n-pentanoic) acid from synthetic aqueous solutions simulating an industrial wastewater from polymer manufacturing. Amberlite LA-2 (secondary amine) in toluene was chosen as the extraction system. Equilibrium conditions were determined and mechanistically modelled for different extractant concentrations allowing the further calculation of mass transfer coefficients. The influence of the hydrodynamics of both the aqueous and organic phases on the overall mass transfer coefficient, calculated through two proposed methods, was studied. The integration of extraction and backextraction was also carried out, allowing a further acid removal with lower extractant concentrations.