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.
High purity water production has traditionally used a combination of membrane separation and ion exchange processes.
EDI modules can be sized to operate from a fraction of a gpm up to about 50 gpm. As impurities leave via the concentrate water system, their build-up does not exhaust the resin and therefore prolongs resin lifespan. These systems typically use cation exchange vessels followed by anion exchange to handle the bulk of the demineralization.
There electrodeionizaiton also EDI units that are often referred to as continuous electrodeionization CEDI since the electric current regenerates the resin mass continuously.
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. It will also better prepare you for the content in the Intermediate EDI section.
If you’d like to talk with a sales representative about purchasing SUEZ’s products and services, you can reach us here. The ionization electrodeiionization occurring in the resin in hydrogen or hydroxide forms for the removal of weakly ionized compounds are listed below: State-of-the-art water treatment systems utilize reverse osmosis RO membranes to do the bulk of the demineralization.
EDI utilizes chemical-free regeneration. Each electrode may become either the anode or the cathode depending on the voltage applied to the cell. EDI is a process which combines semi-impermeable membrane technology with ion-exchange media to provide a high efficiency demineralization process.
Introduction to Electrodeionization
High purity deionized water results. Argonne National Laboratory estimates that Simple and continuous operation Electrodeionizzation 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 Eectrodeionization 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 The resins operate in steady state; they act not as an ion reservoir but as an ion conduit.
In some cases, the eoectrodeionization exchange resins actually contribute to the TOC content in the water. Purified water flows out through the opposite side of the compartment. This section is broken electrodfionization into electrodeionozation following topics: Most EDI devices have a 1 ppm hardness limit which is easily addressed with proper pretreatment system design.
As the ions go towards the membrane, they can pass through the concentration chamber see figure but they cannot reach the electrode. Electrofeionization of large EDI systems is not required, because a single EDI module may be taken off line for maintenance or repair while the remaining modules operate at a slight increase in flow rate to maintain the required flow through the system. Aqueous two-phase system Azeotrope Eutectic.
The ion exchange resins act to retain the ions, allowing these to be transported across the ion exchange membranes. Electrodeionization EDI is an electrically-driven water treatment technology that uses electricity, ion exchange and resin to remove ionized species from water.
Unlike DI resin, EDI does not require shutdowns for replacing resin beds or for resin regeneration using chemicals. When flow enters the resin filled diluiting compartment, several processes are set in motion.
Electrodeionization (EDI) Systems | E-Cell | SUEZ
We’re here to help. The ion exchange beds in our EDI systems are regenerated continuously so that they do not exhaust in the same way as ion exchange beds that are operated in batch mode.
This section is broken down into the following topics:. Service Mixed Bed Deionization off-site regenerated rental vessels. 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.
This page was last edited on 10 Octoberat Water enters the EDI module, where an applied current forces ions to move through the resins and across the membranes. 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.
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.
They are blocked by the contiguous membrane, that contains a resin with the same charge. They are ideal for multiple applications including: Each cell consists of an electrode and an electrolyte with ions that undergo either oxidation or reduction.
With EDI system membranes and electricity replace the million gallons of acid and caustic chemicals that the old processes required daily. 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 chamber contains a ion exchange resin, packed between a cationic exchange membrane and a anionic exchange membrane. EDI is a technology that combines ion exchange resins and ion-selective membranes with direct current to remove ionized species from water. A single EDI unit may operate for many eelctrodeionization before a replacement is required.
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. Home page Technical Electrodeionization.