EDI is a new type of water treatment method that combines electrodialysis (the scene where the charged solute particles in the solution migrate through the membrane under the influence of an electric field) and ion exchange.
EDI is a replacement technology for the traditional ion exchange mixed bed process. The emergence of EDI is an advancement in water treatment technology, marking that the water treatment industry has entered the ranks of the green industry. It organically combines traditional electrodialysis technology and ion exchange technology to continuously produce high-quality pure water, but does not need to use acid or alkali, completely get rid of the problems of acid and alkali consumption, chemical waste liquid pollution, etc., so as to truly achieve Clean Production.
The EDI device fills and sandwiches the ion exchange resin between the anion and cation exchange membranes to form an EDI unit. The working principle of EDI is shown in the figure below. In the EDI module, a certain number of EDI units are separated by a mesh to form a concentrated water chamber. In addition, cathode and anode electrodes are arranged at both ends of the unit group. Driven by the direct current, the anions and cations in the water flow through the fresh water chamber respectively pass through the anion and cation exchange membrane into the concentrated water chamber and are removed in the fresh water chamber. The water passing through the concentrated water chamber takes the ions out of the system and becomes concentrated water. EDI equipment generally uses reverse osmosis (RO) pure water as EDI feed water. The conductivity of RO pure water is generally 2-40μS/cm (@25℃). The resistivity of EDI pure water can be as high as 18 MΩ.cm (25°C), but according to the use of deionized water and system configuration settings, EDI pure water is suitable for the preparation of pure water with a resistivity requirement of 10-15MΩ.cm (25°C)
The process flow of the laboratory ultrapure water machine is generally as follows: Pretreatment---High pressure pump---RO membrane---Ion exchange column (or EDI)---UV lamp---Ultrafiltration (or microfiltration)- --Terminal filter.
Compared with ion exchange technology, EDI as a new technology has the following advantages:
Smart Plus NET Ultrapure Water System
1) 5.0 inch color touch screen
2) 30/60L multifunctional water tank
3) Built-in TOC online detector
4) Ultra-pure column for reducing organic matter
5) Independent research and development of EDI device
6) Mobile water dispenser with parameter display
Smart NE Ultrapure Water System
1) Large-screen LCD multi-parameter display
2) All-plastic mold production, beautiful appearance
3) Independent research and development of EDI device
4) 30/60L multifunctional water tank
5) Standard mobile water dispenser