Performance enhancement of electrochemical deionization devices by pre-treatment with cation exchange resins

A method of treating water comprising:

• recirculating a concentrate stream through a first inlet and a first outlet of an electrochemical water treatment device;
• recirculating a dilution stream through a second inlet and a second outlet of the electrochemical water treatment device;
• measuring at least one property of the recirculating dilution stream;
• and
• controlling a first flow path comprising acidic water to the recirculating concentrate stream based at least in part on the at least one measured property of the recirculating dilution stream.

A method for providing treated water comprising:

• passing a recirculating dilution stream through an inlet and an outlet of at least one depleting compartment in an electrochemical water treatment device;
• measuring at least one property of the recirculating dilution stream;
• calculating an LSI of the recirculating dilution stream based on the at least one measured property;
• determining a difference between the calculated LSI to a target LSI;
• and
• controlling a flow path in a flow control device based at least in part on the difference between the calculated LSI to a target LSI.