Electrodeionization Edi Water Treatment

electrodeionization edi water treatment industry pure water by cation ion exchange membrane for Pharmaceutical factory high pure fresh water treatment EDI module project for chemical making fresh water. Electrodeionization (EDI) is a process that uses ion exchange resins to absorb ions from a dilute water stream and then transports the absorbed ions through ion-exchange membranes into a concentrate water stream under the influence of an applied electro field. Further more, the ions are removed continually on the direction of water flow. The conductivity value is get lower and lower. H+ and OH- are formed under the direct current to maintain the system current and regenerate the ion-exchange membrane. Thus to realize the continues and deep salt rejection. EDI system water treatment of ultrapure water for electric industrial use.

EDI typically may be used in any applications that require ultra pure water at a resistivity above 1 M9·cm. The typical industries that use ultra pure water include

1. Microelectronic and semiconductor production.
2. Pharmaceutical and biomedical industries.
3. Chemical production.
4. High pressure boiler such as the ones in power plants.

• Feed water hardness can be 10mg/l
• Does not consume salts in operating and need much lower operating expenses.
• Does not need to recycle the concentrate, which makes the system much simpler.
• The EDI systems require a little energy.

4.1 running parameter

The product water quality of EDI is depended on the operation condition.    Which including system designing data, feed water quality, feed water pressure. etc.

• The EDI unit is adopted CP-2000S EDI module, 2 pcs.
• Unit module voltage range: 50-120V
• Unit module current range: 0.5-6A
• System product water flow rate: 2.00-4.00m3/r
• System concentrate flow rate: 0.30-0.60m3/h
• System electrolyte flow rate: 0.12m3/h

4.2 running current and voltage

Warning: the heat produced when current pass through EDI module must be take away by water. Thus, once EDI product and concentrate stream is blocked or stopped, the power should be cut off. Otherwise, EDI module will be burned thoroughly.

4.3 feed water requirement

1. feed water: RO product water
2. TEA< 35ppm.
3. pH : 6.0-9.0
4. Temperature:5-35oC
5. Feed water pressure<0.4Mpa
6. hardness<10.0 ppm.
7. organic glass matter<0.5 ppm.
8. CL2<0.05 ppm , O3<0.02 ppm.
9. conductivity<60US/CM
10. H2S<0.01 ppm.
11. SIO2<0.5 ppm.
12. SDI15<1.0
13. color<5APHA

5.1 Dilute chamber

Dilute chamber is the space for the dilute stream (product water) to pass through. It is formed by a frame, one piece of anionic ion exchange membrane on one side of the frame and a piece of cationic ion exchange membrane on the other side of the frame. Inside the frame there is tightly packed with mixed ion exchange resins.

5.2 Concentrate chamber

Concentrate chamber is the space for the concentrate to pass through. It is created by layers of two dilute chambers. It is also formed by anionic ion exchange membrane, cationic ion exchange membrane and ion exchange resins.

5.3 Electrolyte chamber

Electrolyte chamber is next to an anode and a catholyte chamber next to a cathode. Isolation board and reinforcing plates.