EDI ultra pure water equipment is a device for producing pure water, using electro deionization technology.
Reverse osmosis (RO) technology can remove 95% -98% of ions from water, greatly reducing the amount of acid and alkali used, but it cannot completely eliminate the use of chemicals. To prepare ultrapure water, reverse osmosis+mixed bed process is usually used. Mixed bed ion exchange technology has always been the standard process for preparing ultrapure water. Due to its periodic regeneration, the use of corresponding chemicals (acid and alkali) during the regeneration process can no longer meet the needs of modern industrial clean production and environmental protection. So the EDI technology formed by the organic combination of electrodialysis technology and ion exchange technology became a revolution in water treatment technology.
Electrodeionization (EDI) is a new technology that combines electrodialysis membrane separation technology with ion exchange technology to prepare ultrapure water (high-purity water). It utilizes the polarization phenomenon during electrodialysis to electrochemically regenerate the ion exchange resin filled in the freshwater chamber.
The EDI membrane stack is mainly composed of alternating cation exchange membranes, concentrated water chambers, anion exchange membranes, fresh water chambers, and positive and negative electrodes. Under the action of a direct current electric field, cations and anions in the ion exchange resin in the freshwater chamber migrate along the channels formed by the resin and membrane towards the negative and positive directions, respectively. Cations pass through the cation exchange membrane, anions pass through the anion exchange membrane, and enter the concentrated water chamber to form concentrated water. At the same time, the cations and anions in the EDI inlet are exchanged with the hydrogen ions and hydroxide ions in the ion exchange resin to form ultrapure water (high-purity water). The excessive current causes a large amount of hydrogen ions and hydroxide ions generated by water electrolysis to continuously regenerate the ion exchange resin. Traditional ion exchange requires chemical intermittent regeneration after the ion exchange resin is saturated. The resin in the EDI membrane stack is continuously regenerated through electrolysis of water, and the operation is continuous without the need for acid-base chemical regeneration.
Application fields:
EDI ultra pure water technology is a clean production technology with advanced technology, easy operation, and no pollution. It is increasingly widely used in fields such as microelectronics, power industry, pharmaceutical industry, chemical industry, and laboratories.