Electrodialysis Reversal Systems treat high TDS waters including brackish water and RO concentrate waste water, blow down water and sequential batch reactor (SBR) effluent and oil and gas field produced water.
How does EDR work?
- A positively charged electrode. This is called an anode
- A negatively charge electrode. This is called a cathode
- A flow path for feed water to be purified and diluted of ions. This is called a D-chamber.
- A flow path for waste water to be concentrated with ions being removed. This is called a C-chamber.
- Cation Exchange membrane to allow positively charged ions to migrate from D to C chambers
- Anion Exchange membrane to allow negatively charged ions to migrate from D to C chambers
The positively charged ions are attracted to the cathode, and negatively charged ions are attracted to the anode. The ions flow through the ion exchange membranes into the concentrate stream. As water flows through D stream, it is desalted and exits as EDR product water. The C stream is concentrated with salts, and are sent to drain. A small percentage of the water is sent across the electrodes and is called electrode flush or electrolyte.
After an adjustable interval of operation, EDR reveres the polarity and flow path to reduce scaling. The cathode becomes the anode and the D-flow becomes C-flow. Likewise, the anode becomes the cathode and the C-flow becomes D-flow. This reversal step allows scale that may started to form on one membrane be electrochemically removed.
Agape Water Electrodialysis Reversal Systems
Agape Water Solutions provides EDR systems around the world. We have significant experience with the Evoqua Nexed technology, as the first OEM to adopt the technology and build the first pilot systems. Agape Water also build the first commercial Nexed system as well as the EDR system used by Evoqua in treating was for building EDI and EDR modules.
Our standard systems include: