Delivering Ultrapure Water for a Range of Applications

Customers who need ultrapure water rely on electrodeionization (EDI) from GE Water & Process Technologies. Our EDI system provides key advantages over traditional ion-exchange processes:

	Eliminating expensive and hazardous chemicals used in ion-exchange resin regeneration.
	Reducing energy and operating expenses
	Reducing the facility size requirement
	Helping plants meet ISO 14000 requirements

EDI systems from GE cover many applications including power generation, microelectronics, food and beverage production, and chemical and pharmaceutical manufacturing. Using high-capacity ion exchange membranes, our EDI system removes not only residual salts but also ionizible aqueous species such as carbon dioxide, silica, ammonia and boron.

The heart of the process is a stack of components similar to a plate and frame heat exchanger or filter press. Feedwater flows in a thin sheet between ion exchange membranes through the stack, where a DC electrical field drives salt ions into adjacent concentrating compartments.

The feedwater compartment also contains mixed-bed ion-exchange resin that help ionize such compounds as carbon dioxide and bicarbonate, which are then transferred by the DC field through the membranes. Typical EDI product water contains less than 5 ppb silica and measures 16-18 megohm-cm.