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Electrodeionisation · Post-RO Polishing

Electro De-Ionisation System

Final polish after RO Pharma PW / WFI Semiconductor UPW Chemical-free · continuous

Ahura Aqua integrates electro de-ionisation (EDI) as the final polishing stage downstream of reverse osmosis — for the continuous, chemical-free production of high-purity and ultra-pure water.

We specialise in EDI for pharmaceutical Purified Water & WFI pre-treatment and semiconductor & electronics ultra-pure water (UPW) — delivering consistent low-conductivity water without the chemical handling of a conventional mixed-bed DI.

Where We Apply It
Built for Pharma PW / WFI & Semiconductor UPW
In validated pharmaceutical and semiconductor facilities, the chemical storage, neutralisation and regeneration downtime of a conventional mixed-bed DI are liabilities. EDI polishes RO permeate to high-resistivity water continuously, with no acid or caustic — the natural fit ahead of a PW / WFI loop or UPW distribution.
Where EDI Fits RO Permeate → Ultra-Pure Water
Polishes RO permeate continuously · regeneration-free →
Working Principle Resin + ion-selective membranes + DC field
01 Dilute Compartments
RO permeate flows through mixed-bed resin packed between a cation-selective and an anion-selective membrane.
02 DC-Field Migration
An applied DC field drives cations toward the cathode and anions toward the anode into adjacent concentrate streams, flushed to drain.
03 In-Situ Regeneration
The same field splits a fraction of water into H⁺ & OH⁻ that continuously regenerate the resin — no chemicals, no downtime.
2H₂O → H⁺ + OH⁻ The DC field splits water in-situ — resin stays permanently regenerated, no acid or caustic
Configuration Options
Higher hardness · silica · boron
Two-Stage (Fractional) EDI
Stage one removes strongly-ionised impurities such as hardness, lowering scaling potential; stage two runs at higher voltage & current to polish out silica & boron — raising product quality, hardness tolerance and reliability.
Pharma / biomedical
Hot-Water Sanitisable Modules
Hot-water sanitisable EDI modules are available for pharmaceutical & biomedical duties with stringent sanitisation requirements ahead of a PW / WFI loop.
Why EDI Over Mixed-Bed DI
No Hazardous Chemicals
Eliminates the acid / caustic storage, handling & neutralisation of a conventional DI.
Continuous Output
High-purity water with no interruption for resin regeneration.
Energy-Efficient
Electrical current is applied only where required across the stack.
Smaller Footprint
Lower lifecycle cost than an equivalent mixed-bed DI train.
Standard Features
✓ No chemical regeneration — no acid or caustic handling
✓ Compact, skid-mounted modules
✓ Produces up to < 1 µS/cm conductivity (high-resistivity ultra-pure water)
✓ Continuous operation with no regeneration downtime
✓ High silica & boron rejection with two-stage / fractional configuration
✓ Hot-water sanitisable variant for pharma / biomedical (optional)
✓ PLC / HMI automation
Flow Rate Range
2 – 50 M³/hr
Per integrated train, scalable in parallel
Product Conductivity
< 1 µS/cm
High-resistivity ultra-pure water
Chemical Regeneration
None
Continuous, regeneration-free operation
Typical Applications
Pharmaceutical
Purified Water & WFI generation (post-RO polishing)
Semiconductor
OSAT, electronics & solar wafer cleaning / rinsing (UPW)
Power
High-pressure boiler feed water
Green Hydrogen
Electrolyser feed water
Food & Beverage
F&B and laboratory ultra-pure water
Looking to replace a chemically-regenerated DI train with continuous EDI?
We'll specify the right EDI stage for your pharma PW / WFI or UPW system.
Call us →