For decades, the preparation of pure water has been at the cost of consuming a large amount of acid and alkali. During the production, transportation, storage and use of acid and alkali, it will inevitably bring environmental pollution, corrosion of equipment, possible injury to human body and high maintenance costs. The application of reverse osmosis technology has greatly reduced the amount of acid and alkali. The widespread use of reverse osmosis and electric desalting (EDI) will bring an industrial revolution to the preparation of pure water.

EDl (Electrodeionization, or ContinuoElectrodeionization) is also known as continuous electric desalting. It is a pure water manufacturing technology that combines ion exchange technology, ion exchange membrane technology and ion electromigration technology. Using EDI to replace the traditional mixed bed to produce ultra-pure water can further promote the development of water treatment towards low-cost, pollution-free, continuous production, high output and easy operation, making the water treatment industry ultimately become a green environmental protection industry. It provides a better choice for industries that need ultra-pure water. Principle

Natural water often contains various dissolved salts. These salts are composed of negative (negative) and positive (positive) ions. Reverse osmosis can remove more than 99% of the ions. Dissolved gases (such as CO2) and other salts must be removed in industrial treatment.

The resistivity of RO outlet water (EDI inlet water) is generally 0.25-0.5mQ * cm. According to different needs, the resistivity of ultra-pure water or deionized water is generally 2-18.2m Ω * cm.

The exchange reaction is carried out in the purification room of the EDI module, where the anion exchange resin uses their hydroxide ion (OH7) to exchange the anions (such as Cl7) in the dissolved salt. Accordingly, cation exchange resins use their hydrogen ions (H+) to exchange cations (such as Na+) in dissolved salts.

Add a DC electric field between the anode (+) and cathode (-) at both ends of the EDI module. The electric potential makes the ions exchanged on the resin migrate along the surface of the resin particles and enter the concentrated water chamber through the membrane

The anode attracts negative ions (such as OH~, Cl), which enter the adjacent concentrated water through the anion membrane, but are blocked by the cation selective membrane, thus remaining in the concentrated water. The cathode attracts cations (such as H *, Na+) in the pure water flow. These ions pass through the cation selective membrane and enter the adjacent concentrated water stream, but are blocked by anions, thus remaining in the concentrated water stream.

When water flows through these two parallel chambers, the ions are removed in the pure water chamber and accumulated in the adjacent concentrated water flow, which then takes them away from the module.