Electrodialyzer (ED) is an electrochemical separation device for water desalination based on ion exchange membrane and direct current electric field, belonging to the category of membrane separation technology. The core principle is to selectively pass cations through cation exchange membranes and anions through anion exchange membranes. Under the action of an external electric field, ions in water are directed to migrate, forming freshwater and concentrated water chambers, thus achieving the purpose of desalination.
1、 Main components
Ion exchange membrane: including cation exchange membrane (allowing cations to pass through) and anion exchange membrane (allowing anions to pass through).
Electrodes: typically made of titanium coated ruthenium, graphite, or stainless steel materials.
Partition: used to separate membrane stacks, forming fresh water chambers and concentrated water chambers.
2、 Working principle
Driven by an external DC electric field, ions in water migrate towards the anode and cathode respectively. Cations enter the concentrated water chamber through the cation membrane, anions enter the concentrated water chamber through the anion membrane, and ions in the fresh water chamber are removed, thereby achieving water desalination.
3、 Characteristics
Efficient desalination: capable of processing brackish water with a salt content of up to 60 grams per liter, and producing water with a resistivity of 105 Ω· cm.
Energy saving and environmental protection: Low water production cost, no need for chemical regeneration, reducing acid and alkali consumption.
Widely applicable: Suitable for fields such as seawater desalination, industrial wastewater treatment, food and pharmaceutical pure water preparation, etc.
4、 Application scenarios
Desalination of seawater: solving the problem of drinking water sources in desert areas.
Industrial wastewater treatment: Recycling heavy metals from electroplating and papermaking wastewater.
Pure water preparation: Combined with ion exchange or reverse osmosis technology to produce high-purity water.
Food industry: such as desalination of milk to produce infant formula.