Electrodeionization (EDI)

Electrodeionization (EDI)
Water Treatment Plants

Electrodeionization (EDI) is used after reverse osmosis for polishing of demineralized water to obtain low levels of conductivity and silica. The EDI uses ion exchange membranes, ion exchange resins and electricity to produce high-quality water with no regeneration downtime. EDI is an alternative to a conventional mixed bed polisher. Electrodeionization System (RO EDI Plant) technique can achiever high purity of Deionized water with conductivity less than 0.1 μS/cm.

EDI advantages


• EDI provides a simple and continuous operation with no downtime due to the electrochemical regeneration.


• EDI utilizes chemical-free regeneration. Therefore, no storage or application of chemicals is required.


• The EDI plants are space-saving due to the very compact design.

Typical applications of EDI

Water for power plant

Instead of using a conventional mixed bed, a membrane degasser in combination with EDI can produce high-quality demineralized water without using any chemicals. This provides corrosion-free boiler feedwater with low conductivity and silica content.

Ultrapure process water

EDI after reverse osmosis supplies ultrapure process water with low conductivity. The photo shows EDI for ultrapure water at a microelectronic company. The EDI is customized with special pharma modules for a hygienic design.

Water for pharma

Purified water production within pharma industries requires a water treatment system in a hygienic design. The EDI is customized to meet the current versions of Standards.