Electrodeionization (EDI)
Electrodeionization (EDI)
Electrodeionization (EDI) is an advanced water purification technology that combines ion-exchange membranes, resins, and electric current to remove dissolved ions and produce ultra-pure water. EDI is widely used in industries where continuous, chemical-free, and high-purity water is required—such as pharmaceuticals, power plants, electronics, and laboratories.
Unlike traditional mixed-bed deionizers, EDI does not use chemical regeneration, making it an eco-friendly and low-maintenance water treatment solution.
Why EDI Technology Is Important
EDI provides a permanent solution for industries that demand extremely low conductivity and low total dissolved solids (TDS). It ensures:
Consistent high-purity water
Chemical-free operation
Lower operational cost
Reduced downtime
Sustainable purification process
How Electrodeionization (EDI) Works
EDI uses electrical current to continuously regenerate the ion-exchange resin. It performs:
Cation removal
Anion removal
Silica, Sodium, and Carbon Dioxide reduction
Process Flow:
Pre-treated water enters the EDI module
Ion-exchange resins trap dissolved salts
Electric current pulls ions through selective membranes
Purified water flows out as ultra-pure water
Concentrated waste ions are removed as reject stream
This continuous process ensures stable output without using acids or caustic chemicals.
Frequently Asked Questions
Electrodeionization (EDI) is an advanced water purification technology that uses ion-exchange membranes, electricity, and resin to remove dissolved ions from water. It is commonly used to produce high-purity or ultrapure water for industries like pharmaceuticals, electronics, power plants, and laboratories.
EDI works by combining ion exchange and electrical regeneration.
As water passes through the resin and membranes, ions are continuously removed and driven towards the electrode chamber, eliminating the need for chemical regeneration. This makes EDI a continuous, eco-friendly, and low-maintenance purification method.
EDI offers several advantages:
No chemical regeneration required
Continuous and automatic operation
Lower operating and maintenance costs
Higher and more consistent water purity
Environment-friendly process
Long-lasting resin life
This makes it a superior choice for industries requiring consistent purity.
EDI is used in industries that need high-purity or ultrapure water, including:
Pharmaceutical & biotech manufacturing
Semiconductor and electronics production
Power plants (boiler feed water)
Laboratories and R&D centers
Food & beverage processing
RO + EDI packaged drinking water plants
EDI is usually paired with Reverse Osmosis (RO).
RO removes most dissolved impurities, while EDI acts as a polishing unit to achieve ultrapure water levels. The RO + EDI combination produces water with very low conductivity, making it ideal for demanding industrial applications.