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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EDI is a technology that combines ion exchange resins and ion-selective membranes with direct current to remove ionized species from water. For more information, including technical papers, case studies, and product specs, explore the electrodeionization EDI resource page in the Document Library. No ionic breakthrough resulting in a constant high quality of water.
These ions are collected into concentrate streams which can then be put to drain or be recycled. These act as continuous regenerating agents of the ion-exchange resin.
Electrodeionization (EDI) – Lenntech
Some of the advantages of the EDI as opposed to the conventional systems of ionic interchange are: We’re here to help.
EDI is different from ED by using resins in the diluting chambers—the resins allow for more efficient migration of ions in very low conductivity water. The chamber contains a ion exchange resin, packed between a cationic exchange membrane and a anionic exchange membrane.
Argonne National Laboratory estimates that The positively charged ions flow toward the cathode and are rinsed out in the concentrate stream, and the negatively charged electrodeionkzation flow toward electrrodeionization anode and are rinsed out in another concentrate stream.
EDI is used with reverse osmosis to replace ion exchange resin-mixed beds, which require onsite or offsite chemical regeneration. Anion-selective membranes are permeable to anions but not to cations; cation-selective membranes are permeable to eelectrodeionization but not to anions.
electrodeionizatoon Remove residual salts and other aqueous species from your water with up to 18 MOhm-cm resistivity. 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. In this compartment the pH becomes neutral, and H2 gas is generated.
Regenerations of ion exchangers typically takes several hours, require bulk storage and pumping facilities for regenerant chemicals, and usually require a waste neutralization tank.
The ionization reactions occurring in the resin in hydrogen or hydroxide forms for the removal of weakly ionized compounds are listed below:. Please improve this by adding secondary or tertiary sources.
EDI modules can be sized to operate from a fraction of a gpm up to about 50 gpm.
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Case Studies Download Electgodeionization. December Learn how and when to remove this template message. The electrolyte stream flows past the anode and cathode sequentially.
From Wikipedia, the free encyclopedia. Our high-quality modules continually produce ultrapure water up to Enables a simpler system no concentrate recirculation Produces ultrapure water up to 18 megohm. 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.
EDI is a continuous process.
Electrodeionization | Water Solutions
With EDI system membranes and electricity replace the million gallons of acid and caustic chemicals that the old processes required daily. Service Mixed Bed Deionization off-site regenerated rental vessels. Simple and continuous operation Chemicals for regeneration completely eliminated Cost effective operation and maintenance Low power consumption Non pollution, safety and reliablility It requires very few automatic valves or complex control sequences that need supervision by an operator It requires little space It produces high pure water in a constant flow It provides complete removal of dissolved inorganic particles In combination with reverse osmosis pre-treatment, it removes more than Aqueous two-phase system Azeotrope Eutectic.
Ions in the separate chamber are flushed to waste.
High purity water production has traditionally used a combination of membrane separation and ion exchange processes. EDI utilizes chemical-free regeneration.
Ion-selective membranes allow the positive ions to separate from the water toward the negative electrode and the negative ions toward the positive electrode. This technology can be used as an alternative to single-use purification cartridges. Views Read Edit View history. Removal Mechanisms While both ion exchange and EDI use ion exchange resins, the removal mechanisms are quite different.