Development of a pilot 1000LPH(1m3 per hour/24TPD) system and installation at an NTPC Station for study of system efficiency in terms of water recovery and ion removal capacity
Technology:
Electro-Dialysis Reversal (EDR) is an advanced water treatment process based on electrically charged membranes. In EDR, ion exchange membranes are used to separate ionic impurities from water under the influence of DC electric field through flowing water.
Recent developments in membrane technology (leading to cost reduction) and tightening of environmental norms for water disposal and wastewater treatment has renewed interest in EDR technology as an alternative to RO based technologies
Comparison with RO:
EDR Systems have many inherent advantages over RO Systems which are tabulated as below-
| S.No. | Feature | Reverse Osmosis | Electrodialysis |
|---|---|---|---|
| 1 | Power Consumption | ~5.0kwh/m3 | ~2.0kwh/m3 |
| 2 | Water Recovery | <50% for Single Stage Systems | >70% for Single Stage Systems |
| 3 | Membrane Life | Around 3 years | More than 10 years due to polarity reversal and absence of high pressure. |
| 4 | Operating Conditions | Low Operating Temperature Range and Chemical Withstand | High Temperature and Chemical Withstand (upto 50 °C and 1–2 ppm chlorine) |