Combining resin and selective membranes with an electric field for continuous high-purity water without chemical regeneration.
EDI uses ion exchange resins together with selectively permeable membranes under an electric field. As water passes through resin-filled compartments, cations move towards the cathode and anions towards the anode; the membranes admit only certain ions and collect them in a separate reject stream.
Its most decisive characteristic is continuity: because the resin is continuously regenerated by the electric current, there is no need for the acid–caustic regeneration of conventional demineralization, nor for the shutdown that regeneration brings.
EDI is fed with water from a reverse osmosis outlet; it does not work without that stage.
Water passes through resin-filled compartments separated by membranes.
Ions are carried towards the electrodes; the resin stays continuously regenerated.
High-purity water goes to the process, the concentrate to the reject line.
Feedwater that must stay at low conductivity continuously.
Process lines that need uninterrupted high purity.
Avoiding chemical storage and regeneration waste.
Bringing the reverse osmosis outlet to its final quality.
An EDI module is not a treatment system in itself; it is designed to be fed with water from a reverse osmosis outlet. If the feedwater carries hardness, chlorine or a high organic load, the module loses performance quickly.
That is why we always engineer EDI as a whole together with the RO ahead of it and the pretreatment ahead of that. A decision made by looking at a single stage puts the next stage at a loss.
With suitable feedwater, yes — and it requires no chemical regeneration. If the feed quality does not hold, a mixed bed may be the safer choice.
The main item is electricity; the cost of acid, caustic and regeneration waste disappears. We make that comparison in our efficiency calculations.
If the outlet quality and flow rate of the existing RO are suitable, it can; we carry out a system analysis first.
High-recovery industrial reverse osmosis units for process and boiler feedwater.
View →Resin softeners for hardness removal; resin replacement and regeneration tuning.
View →Complete system delivery with filter face piping, control panel and field installation.
View →Let us size the system together; we will survey the site in person if needed.
