Download scientific diagram | Electrodeionization process diagram from publication: Study on the influence of applied voltage and feed concentration on the. Introduction to continuous electrodeionization concepts. EDI may be considered to be a competitive alternate process to: Regenerable Mixed Bed. Discover electrodeionization (EDI) solutions from SUEZ which offer superior provide key advantages compared to traditional ion-exchange processes.
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The membranes are not water-permeable. You may also be interested in These ions are collected into concentrate streams which can then be put to drain or be recycled.
As the ions go towards the membrane, they can pass through the concentration chamber see figure but they cannot reach the electrode. Sensitivity to hardness Most EDI devices have a 1 ppm hardness limit which is easily addressed with proper pretreatment system design. This section is broken down into the following topics: Conventional water treatment systems rely on chemically-regenerated ion exchange resins to remove dissolved solids.
In addition, when a diluite stream cleaning was required as result of fouling, product quality was completely recovered. Because of this, EDI: Water treatment Ions Physical chemistry Separation processes. EDI utilizes chemical-free regeneration. 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  brackish water. RW-EDI is a process that targets the desalination of impaired water or water with salt levels of 1, – 10, ppm.
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. Since installation EDI units perform quite reliably, providing the customers with high purity production water for either power plant boiler feed or microchip rinse water.
The resin-wafer technology increases the energy efficiency of the desalination process significantly, especially when testing impaired water. Each cell consists of an electrode and an electrolyte with ions that undergo either oxidation or reduction. The ion exchange systems are usually supplied in duplicate, to allow one system to provide water while the other one is being regenerated. Go to the document library.
With EDI system membranes and electricity replace the million gallons of acid and caustic chemicals that the old processes required daily. December Learn how and when to remove this template message. The combination of ion-exchange resins and ion-exchange membranes, which are used to move ionic impurities into a waste or concentrate water stream leaving purified product water. The ion-selective membranes are fixed to an inert polymer frame, which is filled with mixed ion-exchange resins to form the purifying chambers.
It also enables you to see elecgrodeionization benefits of EDI, understand how to design an EDI system and watchouts during design and operation to maintain your system.
Unlike DI resin, EDI does not require shutdowns for replacing resin beds or for resin regeneration using chemicals. A single EDI unit may operate for many years before a replacement is required. They are blocked by the contiguous membrane, that contains a resin with the same electrodeionnization.
Water is fed through the wafer, while an electric current is applied to setup. These regenerated resins allow ionization of neutral or weakly-ionized aqueous species such as carbon dioxide or silica.
Each electrode may become either the anode or the cathode depending on the voltage applied to the cell. An EDI stack has the basic structure of a deionization chamber. 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.
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. Ions in the separate chamber are flushed to waste.
Electro dialysis employ electrical current and specially-prepared membranes which are semi permeable to ions based on their charge, electrical current, and ability to reduce the ions electrodeionizayion to their charge. This page was last edited on 10 Octoberat If you’d like to talk with a sales representative about purchasing SUEZ’s products and services, you can reach us here.
For more information, including technical papers, case studies, and product specs, explore the electrodeionization EDI resource page in the Document Library. In this way these charged strong-ion species are continuously removed and transferred in to the adiacent concentrating compartments.
ELGA Process Water │Electrodeionization (EDI)
Welcome to Introduction to EDI. How EDI removes ionized species from water. Advantages 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.
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 water for power production.
Electrodeionization EDI is an electrically-driven water treatment profess that uses electricity, ion exchange and resin to remove ionized species from water. May be registered in one or more countries.
The ion exchange resins act to retain the ions, allowing these to be transported across the ion exchange membranes. As impurities leave via the concentrate water system, their build-up does not exhaust the resin and therefore prolongs resin lifespan. Water passes through one or more chambers filled with ion exchange resins held between cation or anion selective membranes.
A bipolar electrode is an electrode that functions as the anode of one cell and the cathode of another cell.
Remove residual salts and other aqueous species from your water with up to 18 MOhm-cm resistivity. Through electro dialysis an electrical potential transports and segregates charged aqueous species. Purified water flows out through the opposite side of the compartment. Most EDI devices have a 1 ppm hardness limit which is easily addressed with proper pretreatment system design. Sensitivity to chlorine EDI is just as sensitive to the chlorine as thin-film reverse osmosis RO processes.
Under the influence of the strong direct current field applied across the stack of components, charged ions are pulled off the resin and drawn towards the respective, oppositely-charged electrodes.
Argonne National Laboratory estimates that