(Electrodeionization) is a revolutionary high-tech water treatment technology, which neatly combines electrodialysis, ion exchange, and membrane separation. can be used for continuous water purification. It doesn’t require chemical regeneration, like ion-exchange units and can be fully automated. This is an easy-to-use environmentally friendly technology. It has been mainly used in pharmaceutical, electrical, power generation, chemical, and several other industries where high-resistive water (as low as18 MΩ*cm) is required, but becomes more and more popular for conventional water treatment aiming for up-to-date green technologies with lowest environmental impact.
Advantages of EDI technology
Highly purified water (resistance up to 10-18 mΩ-cm);
Simultaneous production and regeneration;
Modular approach and ease of PLC automatic control;
No chemicals required for regeneration, no acid sewage discharge;
Doesn’t stop for regeneration, minimal downtime;
Low maintenance cost;
Low energy consumption.
Feed water is divided into two streams, where main flow goes into the membrane/resin compartment, while the other part (rinse stream) washes the electrodes and gets saturated with ions;
Main flow goes through a combination of membranes and resin, which retains ions;
Negatively charges ions (anions) go to the anode (+) and positively charged ions (cations) go to the catode (-);
Using cation and anion membranes allows separating the ions. Cation membrane allows only cations to go through and stops anions. Anion membrane stops the cations while anions can pass;
Ions are concentrated and carried away by a rinse stream;
Purified water exits the system leaving most of the ions behind;