The effect of restriction membranes on mass transfer in an electrodialysis with filtration membrane process

Abstract

In an electrodialysis with filtration membrane (EDFM) separation process, a pair of restriction membranes is used to prevent leakage of molecules into the electrode solution. Driven by the electrical potential gradient, ions transport across these membranes in different directions, resulting in concentration changes in the feed and permeate compartments respectively. However, the effects of these restriction membranes have not been systemically studied to date. In the present work, the performance of a non-charged polyacrylamide (PAm) membrane and two ion-exchange membranes were compared. PAm restriction membranes were found to give the most stable operation, with only slight concentration a..