Electrodeionization (EDI)

Daico Electrodeionization (EDI) is the answer in demanding applications that require consistent and economical removal of water impurities without the use of hazardous chemicals.

EDI, in combination with reverse osmosis as pretreatment, strips away more than 99.9% of feedwater ions, significantly outperforming both double-pass RO and straight DI. With lower chemical, energy and labor costs, Daico's state-of-the-art EDI technology is helping meet industry’s ultrapure water needs today and well into the 21st century.

How does EDI work?

The water to be purified flows through ion exchange resins in vertically spiralled cells or chambers.

DC current is applied across the cells, setting up a positive charge (cathode) on one side and a negative charge (anode) on the other.

Contaminant ions, dissolved in the feed water, migrate towards the cathode or anode because of ionic attraction (opposites attract). They are trapped in concentrate chambers by membranes, which selectively allow either cations or anions through. From there they are removed from the system.

The feed water continues to pass through the dilute chamber as impurities are removed. The product - clean water - is collected and leaves the system.