The electrical and physical properties of cation exchange membranes which have been used in the Imam Khomeini Petrochemical Complex for two years have been studied. These membranes are used in the electro-dialysis reversal (EDR) system for purification of wastewater. Ion exchange capacity, water content, membrane potential, selectivity and energy consumption have been the properties, which evaluated in this study. The reduction of membranes performance can be attributed to the absorption of iron ions and polyvalent metal ions on the membrane ion exchange sites.
