Electrodeionization EDI systems have become the solution to many applications, with lower operating expenses and fewer maintenance requirements making. Remove residual salts and other aqueous species from your water with up to 18 MOhm-cm resistivity. SUEZ’s E-Cell* electrodeionization (EDI) technology. Electrodeionization (EDI) is a water purification system that relies on electricity to remove ionic impurities from water into a concentrate water stream.

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Electrodeionization is a water electrodeioniaztion technology that utilizes electricity, ion exchange membranes and resin to deionize water and separate dissolved ions impurities from water. It differs from other water purification technologies in that it is done without the use of chemical treatments and electrpdeionization usually a polishing treatment to reverse osmosis RO.

There are also EDI units that are often referred to as continuous electrodeionization CEDI since the electric current regenerates the resin mass continuously. CEDI technique can achieve very high purity, with conductivity below 0.

Recently, Argonne National Laboratory developed a process called Resin-Wafer Electrodeionization RW-EDIwhich uses a unique porous resin wafer mold made from immobilized loose ion-exchange resin beads. The resin wafer material enhances mass transfer between solid resin bead and liquid feed solution phases to achieve a high purity, especially when treating impaired or [1] brackish water.

When fed with low TDS feed e. The ion exchange resins act to retain the ions, allowing these to be transported across electrodeionizaton ion exchange membranes. The main applications of EDI technology, such as that supplied by Ionpure, E-cell and SnowPure, are in electronics, pharmaceuticals and power generation.


One important aspect in the water treatment application is that some types of EDI needs to electrodeiobization feed water that is free from CO2, as well as other dissolved gasses, since these put unnecessary strain on the EDI unit and will reduce performance.

An electrode in an electrochemical cell is referred to as either an anode or a cathodeterms that were coined by Michael Faraday. The anode is defined as the electrode at which electrons leave the cell and oxidation occurs, and the cathode as the electrode at which electrons enter the cell and reduction occurs.

Electrodeionization | Water Solutions

Each electrode may become either the anode or the cathode depending on the voltage applied to the cell. A bipolar electrode is an electrode that functions as the anode of one cell and the cathode of another cell.

Each electrodeionizatiin consists of an electrode and an electrolyte with ions that undergo either oxidation or reduction.

An electrolyte is a substance containing free ions that behaves as an electrically conductive medium. Because they generally consist of ions in solution, electrolytes are also known as ionic solutions, but molten electrolytes and solid electrolytes are also possible.

They are sometimes referred to in abbreviated jargon as lytes. Water is passed between an anode positive electrode and a cathode negative electrode. Ion-selective membranes allow the positive ions to separate from the water toward the negative electrode and the negative ions toward the positive electrode. High purity deionized water results.

Electrodeionization (EDI)

Electrodeionizaion is a process that targets the desalination of impaired water or water with salt levels of 1, – 10, ppm. RW-EDI process uses a porous ion exchange resin wafer with cm2 cross-section surface area. Water electrodeioniaztion fed through the wafer, while an electric current is applied to setup.


In between resin wafer compartments, there are concentrate compartments, where brine flows out of the system. An anode is setup on the left side of the setup and a cathode is setup on the right side of the setup.

The electric current supplied from various energy sources charges the ions that make up the contaminants. The positively charged ions flow toward the cathode and are rinsed out in the concentrate stream, and the negatively charged ions flow toward the anode and are rinsed out in another concentrate stream.

Purified water flows out through the opposite side of the compartment. The resin-wafer technology increases the energy efficiency of the desalination process significantly, especially when testing impaired water. Argonne National Laboratory estimates that From Wikipedia, the free encyclopedia. This article elrctrodeionization too much on references to primary sources. Please improve this by adding secondary or tertiary sources. December Learn how and when to remove this template message.

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