| abstract |
Cations can be separated from an aqueous salt stream (11) by a process comprising providing an electrolysis cell (10) comprising an anode chamber (1), an electrolysis chamber (2), an intermediate chamber (3) and a cathode chamber (4), an anode (5) being positioned in said anode chamber (1) and a cathode (6) being positioned in said cathode chamber (4), said chambers being separated from each other by membranes (7), (8) and (9), which are selectively permeable for cations, conducting the aqueous stream (11) into the electrolysis chamber (2), applying an electric potential difference between the anode (5) and the cathode (6), carrying off an acidified aqueous stream (15) from the electrolysis chamber (2), carrying off an alkaline aqueous (14) stream from the cathode chamber (4), conducting a stream containing monovalent ions (12) to said intermediate chamber (3), carrying off a stream containing monovalent and multivalent ions (13) from said intermediate chamber (3). |