1. Utilization of electric energy ------ Electrodialysis
2. Utilization of concentration difference ------ Diffusion Dialysis
3. Utilization of electric energy and electrode reaction ------ Electroysis

Selemion: What can it do?

----Electrodialysis Applications----

1. Production of table salt by sea water concentration
   
   
2. Production of drinking (industrial) water by desalination and denitrate of well water, underground water, etc.
   
   
3. Demineralization and purification of enzymes and protein solution
   
   
4. Demineralization and purification of amino acid solutions in the food industry
   a) Demineralization and purification of decomposed or neutralized amino acids solution
   b) Demineralization and purification of waste liquor from seasoning industry,
   to reduce the load of waste water and to recover valuable components
   
   
5. Desalination and purification of sugar solutions
   
   
6. Treatment of dairy products
   
   
7. Production of low salt soy sauce
   
   
8. Desalination and purification of inorganic and organic chemicals
   
   
9. Desalination and purification of electroplating waste liquor or industrial waste water
   a) Denitrification and recycle by electrodialysis to conform to nitrate regulation
   b) Desalination and reuse of waste water and fresh water generating system
   to cope with water shortage or deterioration of water quality
   
   
10. Substitution dialysis
    
    
11. Double decomposition reaction
    
    
12. Recovery of sulfuric acid and production of aluminum sulfate by electrodialysis of the waste acid from the aluminum sulfate system
    
    
13. Desalination recycle and reduction of the volume through concentration of environmental polluted water

--Diffusion Dialysis Applications--

1. Recovery and purification of free acid from acidic waste liquor such as sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, etc.
   a)Recovery of nitric acid from acidic waste liquor containing nitric acid to conform to nitrogen regulations
   
   
2. Deacidification and purification of rare earth, etc. in the above mentioned process
   
   
3. Recovery of free acid from acidic waste liquor containing metallic components
   
   
4. Acid recovery treatment as a first stage in the purification of aluminum sulfate and PAC, etc.
   
   
5. Recovery of waste acid from the alumite/aluminum etching process
   
   
6. Removal of impurities in the acidic waste liquor

Contents

1. Electrolytic oxidation or reduction of organic matter
   
   
2. Recovery of metallic ions by oxidation/reduction
   
   
3. Electrolytic recovery of valuable metals
   
   
4. Production of hydrogen/oxygen through electrolysis of water
   
   
5. Electrolytic regeneration of electroplating waste liquor
   
   
6. Production of acid and alkali through electrolytic decomposition of salt

Electrodialysis: What is its Principle?

Electrodialysis transfers ions as shown in the following figure by using direct current as a driving force. Cation--exchange and anion--exchange membranes are arranged alternately between electrode cells at both ends, and desalination and concentration are carried out utilizing the selectivity that these membranes can provide.

Contents

The principle is to let the raw liquor flow upward from the bottom, and to let water flow downward from the upper portion to the bottom in the adjoining chamber as shown in the following figure. The acid diffuses and moves to the water side through the membrane (anion--exchange) due to the concentration differences of the anion in each cell. At that time, only hydrogen ions among cations (metallic ions) can not permeate due to blocking.

Accordingly, free acids can be separated from metallic ions. Due to the counter current flowing, the concentration of the acid in the feed solution decreases when it goes up, and the concentration in the recovery side increases when it goes down, thus stabilizes the specific gravity and concentration gradient are formed, and consequently high performance can be maintained for a long period of time.