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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We’re here to help. The ionization reactions occurring in the resin in hydrogen or hydroxide forms for the removal of weakly ionized elctrodeionization are listed below: These ions are collected into concentrate streams which can then be put to drain or be recycled. The strong, applied electrical potential splits water at the surface of the resin beads, producing hydrogen and hydroxyl ions. No ion exchange process is cost-effective for removal of large amounts of CO 2.

One important aspect in the water treatment application is that some types of EDI needs to have 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.

Articles lacking reliable references from December All articles lacking reliable references. This section is dedicated to those who are just learning about Continuous Electrodeionization also known in generic terms as Electrodeionization EDI. By eliminating the periodic regeneration requirement of ion exchange resin, environmental benefits are also realized by avoiding the handling and processing of acid and caustic chemicals brought to the site.

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. CEDI technique can achieve very high purity, with conductivity below 0. Regenerations of ion exchangers typically takes several hours, require bulk storage and pumping facilities for regenerant chemicals, and usually require a waste neutralization tank. High purity water production has traditionally used a combination of membrane separation and ion exchange processes.


No electrldeionization breakthrough resulting in a constant high quality of water. Water Treatment – Old vs. The ion exchange resins act to retain the ions, allowing these to be transported across the ion exchange membranes. For more information, including technical papers, case studies, and product specs, explore the electrodeionization EDI resource page in the Document Library.

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Electrodeionization (EDI) – Lenntech

Each electrode may become either the anode or the cathode depending on the voltage applied to the cell. Remove residual salts and other aqueous electrpdeionization from your water with up to 18 MOhm-cm resistivity. An EDI stack has the basic structure of a deionization chamber. Water is fed through the wafer, while an electric current is applied to setup.

Electrodeionization (EDI)

Conventional water treatment systems rely on chemically-regenerated ion exchange resins to remove dissolved solids. With EDI system membranes and electricity replace the million gallons elecgrodeionization acid and caustic chemicals that the old processes required daily. 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.

Any ionic species formed from the carbon dioxide gas will lower the outlet resistivity of the water produced by EDI. Eliminates the need for a second bank of RO membranes and associated plumbing, pumping and control equipment. They are ideal for multiple applications including: By using this site, you agree to the Terms of Use and Privacy Policy.

Aqueous two-phase system Azeotrope Eutectic. Each cell consists of an electrode electdodeionization an electrolyte with ions that undergo either oxidation or reduction. Water treatment Ions Physical chemistry Separation processes. From Wikipedia, the free encyclopedia. Sensitivity to chlorine EDI is just as sensitive to the chlorine as thin-film reverse osmosis RO processes. Water enters the EDI module, where an applied current forces ions to move through the resins and across the membranes.


An electrode in an electrochemical cell is referred to as either an anode or a cathodeterms that were coined by Michael Faraday. How does it work? The reject stream is usually of electrrodeionization quality than the feed to the RO system, enabling the reject stream to be completely re-used by pumping it back to the pretreatment section of the RO system.


Sensitivity to hardness Most EDI devices have a 1 ppm hardness limit which is easily addressed with proper pretreatment system design. This article relies too much on references to primary sources. In between resin wafer compartments, there are concentrate compartments, where brine flows out of the system.

As a substitute for the more traditional ion-exchange process, EDI brings advances in both energy and operating expenses to the high purity water treatment train. The combination of ion-exchange resins and ion-exchange membranes, which are used to move electrodeionizagion impurities into a waste or concentrate water stream leaving purified product water.

The electrical current is used to continuously regenerate the resin, eliminating the need for periodical regeneration. RW-EDI process uses a porous ion exchange resin wafer with cm2 cross-section surface area. Converting seawater to high purity water at Spain power plant Located in a severely water scarce area in Tarragona, our customer, Gas Natural, needed to convert seawater into ultrapure electrodfionization for sysem production.

This section is broken down into the electrodeipnization topics: An anode is setup on the left side of the setup and a cathode is setup on the right side of the setup.

Electro dialysis systm electrical current and specially-prepared membranes which are semi permeable to ions based on their charge, electrical current, and ability to reduce the ions based to their charge. EDI provides a high quality water, low in particles, partiall due to the fact that there is no resin attrition from backwashing or osmotic shock, as would be the case with conventional ion exchange processes. The chamber contains a ion exchange resin, packed between a cationic exchange membrane and a anionic exchange membrane.

These act as continuous regenerating agents of the ion-exchange resin.