Rapid communication Reduction of concentration polarization in pervaporation using vibrating membrane module

A vibrating membrane module currently marketed for ®ltration applications was evaluated for the separation of volatile organic compounds (VOCs) from aqueous solutions by pervaporation. Preliminary screening experiments with three VOCs, three silicone membranes, and in the presence and absence of a surfactant were performed to determine if further consideration of the vibrating module for a ®eld demonstration project was warranted. The primary process variables studied were vibrational amplitude and liquid ̄ow rate. The vibrations greatly reduced concentration polarization in the system as inferred from an order of magnitude increase in the overall mass transport coef®cient. Mass transfer coef®cients for the vibrating module compared favorably with those for traditional spiral wound modules. # 1999 Elsevier Science B.V. All