METHOD AND APPARATUS FOR THE DEIONIZATION OF ELECTROLYTE SOLUTIONS WHEREIN ALTERNATINGLY ORIENTED ANION-CATION BILAMINATE ION-EXCHANGE MEMBRANES DEFINE THE CHAMBERS OF A MULTICHAMBER ELECTRODIALYSIS CELL AND WHEREIN THE ANION EXCHANGE LAMINAE OF EACH OF SAID MEMBRANES BOUND THE SALT DILUTING CHAMBERS AND THE CATION EXCHANGE LAMINAE BOUND THE SALT CONCENTRATING CHAMBERS. A DIRECT ELECTRIC CURRENT IS PASSED TRANSVERSELY THROUGH ALL OF SAID CHAMBERS AND MEMBRANES WHICH CURRENT IS PERIODICALLY REVERSED.