Hybrid electrochemical and membrane-based processes for treating water with high silica concentrations

A method of treating feed water having a silica concentration that produces ultra-pure water comprising:

• passing feed water having a silica concentration of 31 to 80 ppm through an electrodialysis reversal unit comprising an inlet stream and a product outlet stream, wherein the inlet stream comprises the feed water;
• routing the product outlet stream of the electrodialysis reversal unit to an ion-exchange unit comprising an inlet stream and a product outlet stream;
• routing the product outlet stream of the ion-exchange unit to an electroacidification unit comprising a product inlet stream, a product outlet stream, a brine inlet stream, and a brine outlet stream;
• routing the product outlet stream of the electroacidification unit to a reverse osmosis unit comprising an inlet stream and a product outlet stream;
• and
• routing the product outlet stream of the reverse osmosis unit to an electrodeionization unit comprising an inlet stream and a product outlet stream, the product outlet stream of the electrodeionization unit producing ultra-pure water.

A method of treating feed water having a silica concentration that produces ultra-pure water comprising:

• passing feed water having a silica concentration of greater than 80 ppm through an electrocoagulation unit comprising an inlet stream and a product outlet stream, wherein the inlet stream comprises the feed water;
• routing the product outlet stream of the solids removal unit to an electrodialysis reversal unit comprising an inlet stream and a product outlet stream;
• routing the product outlet stream of the electrodialysis reversal unit to an ion-exchange unit comprising an inlet stream and a product outlet stream;
• routing the product outlet stream of the ion-exchange unit to an electroacidification unit comprising a product inlet stream, a product outlet stream, a brine inlet stream, and a brine outlet stream;
• routing the product outlet stream of the electroacidification unit to a reverse osmosis unit comprising an inlet stream and a product outlet stream;
• and
• routing the product outlet stream of the reverse osmosis unit to an electrodeionization unit comprising an inlet stream and a product outlet stream, the product outlet stream of the electrodeionization unit producing ultra-pure water.