ELECTRODEIONIZATION PROCESS PDF
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 ion exchange systems are usually supplied in duplicate, to allow one system to provide water while the other one is being regenerated. Applications EDI is useful for any application that requires constant and economic removal of water impurities without using dangerous chemical. Ion-selective membranes operate using the same principle and materials as ionexchange resins, and they are used to transport specific ions away from their counterions. Argonne National Laboratory estimates that The waste regenerants from these systems are usually combined, neutralized and released to the environment.
These regenerated resins allow ionization of neutral or weakly-ionized aqueous species such as carbon dioxide or silica. Through electro dialysis an electrical potential transports and segregates charged aqueous species.
Electrodeionization | Water Solutions
In this way these charged strong-ion species are continuously removed and transferred in to the adiacent concentrating compartments. Articles lacking reliable references from December All articles lacking reliable references. With EDI system membranes and electricity replace the million gallons of acid and caustic chemicals that the old processes required daily.
EDI electrodeionizatipn be run continuously or intermittently.
Eliminates the need for a second bank of RO membranes and associated plumbing, pumping and control equipment. Located in a severely water scarce area in Tarragona, our customer, Gas Natural, needed to convert seawater into ultrapure water for power production.
Removal Mechanisms While both ion exchange and EDI use ion exchange resins, the removal mechanisms are quite different. It will also better prepare you for the content in the Intermediate EDI section. Some of the advantages of the EDI as opposed to the conventional systems of ionic interchange are:.
In this compartment the pH becomes neutral, and H2 gas is generated. This technology can be used as an alternative to single-use purification cartridges. The reject stream is usually of better 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.
December Learn how and when to remove this template message. There are several effective and relatively inexpensive ways to remove CO 2 in the pretreatment system. EDI is a continuous process.
This section is dedicated to those who are just learning about Continuous Electrodeionization also known in generic terms as Electrodeionization EDI. 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 polishing of the RO product water is carried out by continuous electrodeionization EDI which is capable of producing water in excess of 18 megohm resistivity. EDI is just as sensitive to the chlorine as thin-film reverse osmosis RO processes.
In addition, when a diluite stream cleaning was required as result of fouling, product quality was completely recovered. As the ions go towards the membrane, they can pass through the concentration chamber see figure but they cannot reach the electrode. From Wikipedia, the free encyclopedia.
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 Welcome to Introduction to EDI.
An EDI stack has the basic structure of a deionization chamber. Enables a simpler system no concentrate recirculation Produces ultrapure water up to 18 megohm. It differs from other water purification technologies in that it is done without the use of chemical treatments and is usually a polishing treatment to reverse osmosis RO. High purity deionized water results.
Because of this, EDI: Each electrode may become either the anode or the cathode depending on the voltage applied to the cell. The ion-selective membranes are fixed to an inert polymer frame, which is filled with mixed ion-exchange resins to form the purifying chambers.
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. Water is fed through the wafer, while an electric current is applied to setup. Ireland Start search OK.
Under the influence of the applied DC voltage potential, ions are transported across the membranes from the purifying chambers into the concentrating chambers. The ion exchange beds in EDI systems prcess regenerated continuously, so they do not exhaust in the same way as ion exchange beds that are operated in batch mode. This page was last edited on 10 Octoberat 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.
The ionization reactions occurring in the resin in hydrogen or hydroxide forms for the removal of weakly ionized compounds are listed below:. 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 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.