Electrodeionization (EDI) process removes ionizable species from liquids using electrically active media and using an electrical potential to influence ion transport.
Continuous water purification without regeneration chemicals, Reverse Osmosis replaces primary cation/anion exchange, and Electrodeionization replaces mixed bed ion exchange
Proven in a wide range of demanding applications:
- Power, Utilities, and boiler feed water
- Biotechnology and Pharmaceuticals
- Semiconductors and electronics
- Surface finishing, especially for automotives
- Consumer goods and Cosmetics
- General Industry
How EDI Works
All EDI Devices have the following:
- Cation exchange membranes
- Anion exchange membranes
- Cation/anion exchange resin
Benefits of EDI
- No bulk storage of regeneration chemicals.
- No waste neutralization required
- Facility footprint/overhead can be significantly reduced.
- Affords complete control over water system in house – nothing leaves or comes into plant.
- No risk of cross contamination with other customer resins.
- Reduction of EHS risks
- Continuous, not batch operation
- Stable water quality over time.
Limitations of EDI
High hardness leads to scaling which can lead to thermal damage. To counter this, E-Cell has developed a trending spreadsheet to help protect your system. System needs to be cleaned in a timely manner.
Number 1 reason EDI systems produce poor product quality in the field is CO2 in the feed water. The resin within the stack can be overwhelmed Most people only look at conductivity into the EDI system, but fail to look at CO2 because it is not readily checked. To counter this, ensure that a proper projection is completed on the feed water. CO2 should be checked at regular intervals. Hach has a very easy test kit that can be used.
Physical, biological and chemical contamination must be prevented Physical: PVC shavings; metal shavings; dirt; dust; pollen; welding debris; resin beads/fines Chemical: oxidizers such as chlorine; polyvalent cations, such as iron, manganese Sources of contamination: open storage tank, degasifier, or softener without filtration before E-Cell