ELECTRODEIONIZATION SYSTEM PDF
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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The management of CO 2 in water is typically handled in one or two ways: RW-EDI process uses a porous ion exchange resin wafer with cm2 cross-section surface area. Removal Mechanisms While both ion exchange and EDI use ion exchange resins, the removal mechanisms are quite different.
Ion-selective membranes allow the positive ions to separate from the water toward the negative electrode and the negative ions toward the positive electrode. The electrical current is used to continuously regenerate the resin, eliminating the electrpdeionization for periodical regeneration. Only the ions can electroveionization through the membrane, the water is blocked. 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.
You may also be interested in Introduction to EDI gives you the basics. High purity water production has traditionally used a combination of membrane separation and ion exchange processes.
How does it work? This page was last edited on 10 Octoberat Regenerable Mixed Bed Deionization No acid or caustic bulk storage, pumping, waste neutralization or disposal issues.
Each cell consists of an electrode and an electrolyte with ions that undergo either oxidation or reduction. The ionization reactions occurring in the resin in hydrogen or hydroxide forms for the removal of weakly ionized compounds are listed below: The EDI process is a continuous process, utilizes no chemicals for regeneration, does not pollute the environment and requires a fraction of the operator attention necessary for conventional ion exchange systems.
An electrode in an electrochemical cell is referred to as either an anode or a cathodeterms that systen coined by Michael Faraday. 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 electrodeionizationn case with conventional ion exchange processes.
These act as continuous regenerating agents elevtrodeionization the ion-exchange resin. These ions are collected into concentrate streams which can then be put to drain or be recycled. Remove residual salts and other aqueous species from your water with up to 18 MOhm-cm resistivity. No ion exchange process is cost-effective for removal of large amounts of CO 2.
The water produced has met or exceeded customer high-purity water specifications. 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.
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. Argonne National Laboratory estimates that 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 elsctrodeionization 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.
Each electrode may become either the anode or the cathode depending on the voltage applied to ekectrodeionization cell. Some of the advantages of the EDI as opposed to the conventional systems of ionic interchange are:. As the ions go towards the membrane, they can pass through the concentration chamber see figure but eelctrodeionization cannot reach the electrode. The chamber contains a ion exchange resin, packed between systm cationic exchange membrane and a anionic exchange membrane.
The strong, applied electrical potential splits water at the surface of the resin beads, producing hydrogen and hydroxyl ions. 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 based elsctrodeionization their charge.
Electrodeionization | Water Solutions
Through electro dialysis an electrical potential transports and segregates charged aqueous species. From Wikipedia, the free encyclopedia.
Water is fed through the wafer, while an electric current is applied to setup. When fed with low TDS feed e. Service Mixed Bed Deionization off-site regenerated rental vessels. December Learn how and when to remove this template message. Regeneration chemicals are costly, hazardous and, even though they are neutralized prior to releasing to streams and rivers, add a significant amount of dissolved solids to the waterways.
Second pass of RO Eliminates the need for a second bank of RO membranes and associated plumbing, pumping and control equipment. Leaks have been completely eliminated in some modern module designs.
May be registered in one or more countries. Ions in the separate chamber are flushed to waste.
The reject stream electrodeionizayion 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. There are several effective and relatively inexpensive ways to remove CO 2 in the pretreatment system. No acid or caustic bulk storage, pumping, waste neutralization or disposal issues. Electrodeionization EDI is an electrically-driven water treatment technology that uses electricity, ion exchange and resin to remove ionized species from water.