EDI (Electro-de-ionization) is a pure water manufacturing technology combining ion exchange technology, ion exchange membrane technology and ion electro-migration Technology (electrodialysis). The technology utilizes ion exchange energy deep desalination to overcome electrodialysis polarization and desalination, and the use of electrodialysis polarization and the occurrence of hydro-electric and oh ion to achieve resin regeneration of h and the defects after the resin failure to overcome the chemical regeneration through the new technology since in the 1980 of the 20th century. After a teenager's development, EDI technology has been in North America and Europe to occupy a considerable part of the ultra-pure water market.
EDI devices include yin/cation exchange membrane, ion exchange resins, DC power supply and other equipment. The anion exchange membrane allows only anions to pass through, and does not allow cation, while cationic exchange membranes only allow cation through, not allowing anions to pass. Ion-exchange resin is sandwiched between yin and yang ion exchange membrane forming a single processing unit, and constitutes a freshwater chamber. The unit is separated from the cell with a mesh, forming a dense water chamber. The electric field is formed by the cathode electrode of the DC power supply at both ends of the unit. Water flow through the freshwater chamber, the water in the anion in the electric field, through the anion exchange membrane is cleared, into the dense water chamber. The ion exchange resin filled between the ion-exchanger membranes greatly improves the speed of the ions being cleared. At the same time, the water molecules produced hydrogen ions and hydrogen-oxygen roots ions in the electric field, which continuously regenerated ion exchange resins to keep the ion exchange resins optimally. The EDI device divides the water supply into three separate streams: pure water, dense, and extremely water. Pure water (90%-95%) for the eventual gain of water, concentrated aqueous (5%-10%) can be recycled, polar water (1%) discharged. Figure 2 shows the basic process of EDI.