Pervaporation: importance of concentration polarization in the extraction of trace organics from water

• Published in: Journal of membrane science 1988, Vol.36, p.373-384
• Main Authors: Psaume, R., Aptel, Ph, Aurelle, Y., Mora, J.C., Bersillon, J.L.
• Format: Article
• Language: English
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/0376-7388(88)80030-9

The extraction of trichloroethylene in dilute aqueous solutions by pervaporation was studied using silicone tubing as a membrane. In this process, the feed water solution flows over the surface of the membrane while a portion of the solution, enriched in contaminant, is transported through the membrane and emerges as vapor. The vapor is then condensed in a cold trap. The aqueous feed solution was fed through the fiber bores of a hollow fiber membrane module. Analysis at the inlet and the outlet of the bundle was performed with a gas chromatograph using an electron capture detector. The reduction in contaminant level at outlet of the module was evaluated as a function of different inlet feed concentrations and axial Reynolds numbers. It appears that the solute concentration does not affect the permeation flux of the water while the flux of the organic compound increases with the feed concentration and the Reynolds number. The experimental data fit very well with a model of concentration polarization based on the film theory.