Insertion of Filtration Membranes into Electrodialysis Stack and Its Impact on Process Performance

Abstract

The goal of this paper is to investigate the impact of the insertion of different filtration membranes into electrodialysis stack on the process performance and therefore, to gain a tool for choosing membranes suitable for certain applications. Six filtration membranes with different MWCO (molecular weight cut-off), matrix type and specific electric resistance were inserted into diluate chambers of laboratory electrodialysis stack and desalination of sodium chloride solution was conducted at three voltages (1, 2 and 3 V/cell). When determined the electrodialysis characteristics, it was found that the best results (expressed by mass fluxes) was obtained with filtration membranes with PES (polyethersulfone) matrix, whose specific resistance was the most similar to the one of ion exchange membranes. The pore size of filtration membranes did not affect the mass flux significantly except of the stack with nanofiltration membranes.