Regeneration of electrolytic ion exchange cells

A method of treating a solution comprising ions in an electrochemical cell comprising a housing comprising first and second electrodes, an ion exchange membrane between the electrodes, and a solution channel, the method comprising:

• (a) in an ion removal step, maintaining the first electrode as the positive electrode and the second electrode as the negative electrode relative to the first electrode, and flowing solution through the solution channel;
• and
• (b) in an ion rejection step, maintaining the first electrode as the negative electrode and the second electrode as the positive electrode relative to the first electrode, and reversing the flow direction of the solution through the solution channel.

A method of treating a solution comprising ions in an electrochemical cell comprising an ion exchange membrane between electrodes, the method comprising:

• (a) in an ion removal step, flowing solution into the cell while applying a voltage to the first and second electrodes to deionize the solution;
• and
• (b) in an ion rejection step, regenerating the ion exchange membrane by flowing solution through the cell while (1) in a first regeneration step, supplying a first voltage to the electrodes for a time period, and (2) in a second regeneration step, supply a second voltage to the electrodes for a time period, the second voltage being a different voltage than the first voltage.