EDI (Continuous Electro-Deionization) is a water treatment technology that organically combines electrodialysis and ion exchange technologies. Its core lies in utilizing the selective permeability of ion exchange membranes and the high migration performance of ion exchange resins to achieve the directional migration of ions in water under the action of a DC electric field. Simultaneously, the H⁺ and OH⁻ ions generated by water ionization under the electric field continuously electro-regenerate the ion exchange resin, thus achieving synchronous deionization and resin regeneration without the need for shutdown and chemical regeneration with acids or alkalis.
1. Water enters the EDI system, with the majority flowing into the resin/membrane interior, while another portion flows along the outer side of the membrane to wash away ions that have permeated through the membrane.
2. The resin retains dissolved ions in the water.
3. Under the action of the electrodes, anions move towards the positive electrode, and cations move towards the negative electrode.
4. Cations permeate through the cation exchange membrane and are discharged outside the resin/membrane.
5. Anions permeate through the anion exchange membrane and are discharged outside the resin/membrane.
6. Concentrated ions are discharged from the wastewater flow path.
7. Deionized water flows out from the resin/membrane.
