SUEZ Water - Water Technologies & Water

Electrodialysis Reversal (EDR)

A robust high-recovery brackish water desalination technology that can treat a variety of challenging waters

EDR meets the growing for higher recoveries of desalinated brackish water.  EDR, with idemandts continuous self-cleaning operation, allows for higher recoveries than RO in desalination applications.

Benefits

EDR Benefits

Higher turbidity allowance

Water flows through channels along the surface of ion exchange membranes while electricity moves ionized salts through the membrane, so it can handle higher levels of turbidity in feedwater.

Silica tolerance

Silica is an uncharged molecule, so it simply flows through the stack with no impact to the membranes.

Variability of feeds

The flexibility of EDR allows for wide variations of TDS and temperature without significant upset to process or performance. Voltage adjustments are all that is needed to meet changing needs.

Economics of high recovery

Savings from reduced brine disposal cost and associated replenishment of supply can lead to operating costs for EDR that are lower in more than 80% of cities around the world.

Reduced Pre-treatment requirements

EDR is an alternative desalination technology that requires less pretreatment than reverse osmosis, while often providing a more robust and reliable operation.

EDR Applications

EDR Applications

Ionics EDR is used on a range of water types for the removal of charged contaminants such as nitrate, arsenic, radionuclides, fluoride, sulfate, and chloride. The most typical applications are:

  • Desalination of ground and surface brackish water for potable use
  • TDS removal from tertiary-treated wastewater for irrigation or to meet discharge requirements
  • Recovery of industrial wastewater in O&G extraction, semiconductor facilities, and more.

New V Series EDR

Our new V Series EDR has improved every aspect of our EDR offering, leading to lower costs without sacrificing performance. Savings from reduced brine waste can lead to operating costs for EDR that are lower in more than 80% of cities around the world.

For drinking water, EDR has lower operating costs than traditional RO when water and wastewater charges exceed $0.20/m3. In drinking water, V Series systems can have up to 40% lower capital cost than previous generations of Ionics EDR systems, leading to up to 40% lower capital cost than an MMF-RO solution. 

Also, in wastewater desalination or reuse for irrigation applications, the V Series offers lower lifetime cost than MF/UF-RO with up to 50% lower capital cost and 20% lower operating cost, even before water savings associated with higher recovery.

How It Works

Electrodialysis is an advanced membrane technology that utilizes this ion movement to desalinate water.Video scene

In Electrodialysis, the ions move through selective ion exchange  membranes which only allow either cations or anions to pass through them. By alternating these membranes with spacers between them, it creates two separate streams: a desalinated stream and a concentrated salt stream

Electrodialysis Reversal, or EDR also uses electricity to clean the electrodialysis cell. In normal use, hardness scaling and fine organic material can accumulate on the membrane surface. But by reversing the flow of the applied direct current, salts and organics are driven back into solution and cleaned off the membrane surface. This self-cleaning procedure helps provide consistent, high recovery of desalinated water from brackish water feeds.