Electrodeionization uses an electric field to remove ions and polar species from an aqueous stream. EDI is used with reverse osmosis to replace ion exchange resin-mixed beds, which require onsite or offsite chemical regeneration. By eliminating resin regenerating chemicals, EDI delivers significant economic and environmental benefits. In addition, EDIs continuous process improves water quality by reducing spikes and upsets. The Electropure EDI product line is offered for use in ultrapure water systems for pharmaceutical, electronics, power generation, and laboratory applications.
Enables a simpler system (no concentrate recirculation)
Produces ultrapure water (up to 18 megohm.cm)
Eliminates regeneration chemicals
Single unit capacities from 1/4 gpm to 10 gpm (50 l/hr to 2.3 m3/hr)
Multiple unit arrays up to 1,000 gpm (200 m3/hr)
Compact, lightweight, patented design
EDI process systems replace conventional DI mixed resin beds to produce deionized water. Unlike DI resin, EDI does not require shutdowns for replacing resin beds or for resin regeneration using chemicals. Because of this, EDI: minimizes water quality upsets and minimizes operating costs. EDI removes ions from aqueous streams, typically in conjunction with reverse osmosis (RO) and other purification devices. Our high-quality modules continually produce ultrapure water up to 18.2 M.cm. EDI may be run continuously or intermittently.
Advantages of EDI over Conventional DI EDI is Continuous, does not require shutdowns or changeovers Provides water of consistent quality, EDI does not require chemicals (as does DI resin regeneration) Electropure EDI modules are the smallest and lightest per unit flow on the market; EDI skids are therefore compact Requires little energy Economic use of capital saves operating expense.
Process of Electrodeionization
The Electropure EDI design combines two well-established water purification technologies electrodialysis and ion-exchange resin deionization. Through this revolutionary technique, dissolved salts can be removed with low energy cost and without the need for chemical regeneration; the result is high-quality pure water of multi-M.cm resistivity which can be produced continuously at substantial flow rates.
Electropures EDI removes ions from water by forcing them out of the feed stream into adjacent streams via an electric potential. EDI is different from ED by using resins in the diluting chambers the resins allow for more efficient migration of ions in very low conductivity water. The resins operate in steady state; they act not as an ion reservoir but as an ion conduit.