![\"\"](\"https:\/\/banott.com\/wp-content\/uploads\/2026\/07\/EDI1-1.webp\")
\u0427\u0442\u043e \u0442\u0430\u043a\u043e\u0435 EDI-\u043c\u043e\u0434\u0443\u043b\u044c? \u041a\u0430\u043a \u0440\u0430\u0431\u043e\u0442\u0430\u044e\u0442 \u0441\u0438\u0441\u0442\u0435\u043c\u044b \u044d\u043b\u0435\u043a\u0442\u0440\u043e\u0434\u0435\u0438\u043e\u043d\u0438\u0437\u0430\u0446\u0438\u0438 \u0432\u043e\u0434\u044b<\/p><\/div>\n
\u041f\u043b\u0430\u043d \u0441\u0442\u0430\u0442\u044c\u0438<\/h2>\n\n- What is an EDI skid?<\/li>\n
- How does the electrodeionization process work?<\/li>\n
- What components make up an EDI water treatment system?<\/li>\n
- \u041f\u043e\u0447\u0435\u043c\u0443 \u0441\u0438\u0441\u0442\u0435\u043c\u0430 \u043e\u0431\u0440\u0430\u0442\u043d\u043e\u0433\u043e \u043e\u0441\u043c\u043e\u0441\u0430 \u043e\u0431\u044b\u0447\u043d\u043e \u0443\u0441\u0442\u0430\u043d\u0430\u0432\u043b\u0438\u0432\u0430\u0435\u0442\u0441\u044f \u043f\u0435\u0440\u0435\u0434 \u0441\u0438\u0441\u0442\u0435\u043c\u043e\u0439 EDI?<\/li>\n
- How does EDI compare with traditional ion exchange?<\/li>\n
- What water quality can an EDI system produce?<\/li>\n
- What feed-water conditions does an EDI unit need?<\/li>\n
- Where is EDI used in industrial applications?<\/li>\n
- What are the main advantages and limits of EDI?<\/li>\n
- How should an electro-deionized water treatment skid be designed?<\/li>\n
- How is an EDI system operated and maintained?<\/li>\n
- How should EPC contractors select an EDI system supplier?<\/li>\n
- \u0427\u0430\u0441\u0442\u043e \u0437\u0430\u0434\u0430\u0432\u0430\u0435\u043c\u044b\u0435 \u0432\u043e\u043f\u0440\u043e\u0441\u044b<\/li>\n
- \u041e\u0441\u043d\u043e\u0432\u043d\u044b\u0435 \u043c\u043e\u043c\u0435\u043d\u0442\u044b, \u043e \u043a\u043e\u0442\u043e\u0440\u044b\u0445 \u0441\u043b\u0435\u0434\u0443\u0435\u0442 \u043f\u043e\u043c\u043d\u0438\u0442\u044c<\/li>\n<\/ol>\n
What Is an EDI Skid in a Water Treatment System?<\/h2>\n
EDI stands for electrodeionization. An EDI skid is a factory-assembled water purification package that contains one or more EDI<\/a> modules together with the equipment needed to operate, monitor, and control them.<\/p>\nThe skid normally receives highly purified feed water from a reverse osmosis system. It then removes many of the remaining dissolved ionic impurities to make deionized water or high-purity process water.<\/p>\n
A simplified treatment train looks like this:<\/p>\n
Raw Water\r\n \u2193\r\nPretreatment\r\n \u2193\r\nReverse Osmosis\r\n \u2193\r\nRO Permeate\r\n \u2193\r\nEDI Skid\r\n \u2193\r\nHigh-Purity Water\r\n<\/code><\/pre>\nThe word \u201cskid\u201d refers to the physical package. Pumps, valves, EDI modules, instruments, piping, electrical components, and controls are mounted on a structural frame so the system can be manufactured and tested before shipment.<\/p>\n
This is useful for EPC projects because much of the piping and electrical integration takes place in the factory rather than at the project site.<\/p>\n
An EDI module, by contrast, is only the core separation device. An EDI system or skid integrates the module into an operating water treatment package.<\/p>\n
How Does the Electrodeionization Process Work?<\/h2>\n
The EDI process combines three technologies:<\/p>\n
\n- \u0418\u043e\u043d\u043e\u043e\u0431\u043c\u0435\u043d\u043d\u0430\u044f \u0441\u043c\u043e\u043b\u0430<\/li>\n
- Ion exchange membranes<\/li>\n
- Direct electrical current<\/li>\n<\/ul>\n
The resin captures dissolved ions from the water. The applied electric field then causes those ions to migrate through selective membranes and into concentrate channels.<\/p>\n
Positively charged ions, called cations, include substances such as:<\/p>\n
\n- \u041d\u0430\u0442\u0440\u0438\u0439<\/li>\n
- \u041a\u0430\u043b\u044c\u0446\u0438\u0439<\/li>\n
- \u041c\u0430\u0433\u043d\u0438\u0439<\/li>\n
- \u0410\u043c\u043c\u043e\u043d\u0438\u0439<\/li>\n<\/ul>\n
Negatively charged ions, called anions, include:<\/p>\n
\n- \u0425\u043b\u043e\u0440\u0438\u0434<\/li>\n
- \u0421\u0443\u043b\u044c\u0444\u0430\u0442<\/li>\n
- \u041d\u0438\u0442\u0440\u0430\u0442<\/li>\n
- \u0411\u0438\u043a\u0430\u0440\u0431\u043e\u043d\u0430\u0442<\/li>\n
- Silicate species under suitable conditions<\/li>\n<\/ul>\n
The EDI stack contains alternating ion-selective membranes. Cation-exchange membranes favor the movement of positively charged ions, while anion-exchange membranes favor negatively charged ions.<\/p>\n
A simplified view is:<\/p>\n
DC Electric Field\r\n (+) -------------------- (-)\r\n\r\nFeed Water\r\n \u2193\r\n\u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510\r\n\u2502 Resin-Filled Diluting Chamber \u2502\r\n\u2502 \u2502\r\n\u2502 Cations \u2500\u2500\u2500\u2500\u2500\u2500\u25ba Cation Membrane \u2502\r\n\u2502 Anions \u25c4\u2500\u2500\u2500\u2500\u2500\u2500 Anion Membrane \u2502\r\n\u2502 \u2502\r\n\u2502 Purified Water Continues Forward \u2502\r\n\u2514\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2518\r\n \u2193 \u2193\r\n Product Water Concentrate\r\n<\/code><\/pre>\nAs ions migrate away from the product stream, the product water becomes progressively more deionized.<\/p>\n
A key feature is the behavior of the resin. In conventional ion exchange, exhausted resin normally requires acid or caustic regeneration. In EDI, electrical conditions inside the module promote water splitting into hydrogen and hydroxide ions. These help continuously regenerate the resin during operation.<\/p>\n
That is why electrodeionization is often described as a continuous process. Veolia describes continuous EDI as using resin, membranes, and electricity to continuously polish RO permeate without routine chemical regeneration.<\/p>\n
![\"\"](\"https:\/\/banott.com\/wp-content\/uploads\/2026\/07\/EDI3.webp\")
\u0427\u0442\u043e \u0442\u0430\u043a\u043e\u0435 EDI-\u043c\u043e\u0434\u0443\u043b\u044c? \u041a\u0430\u043a \u0440\u0430\u0431\u043e\u0442\u0430\u044e\u0442 \u0441\u0438\u0441\u0442\u0435\u043c\u044b \u044d\u043b\u0435\u043a\u0442\u0440\u043e\u0434\u0435\u0438\u043e\u043d\u0438\u0437\u0430\u0446\u0438\u0438 \u0432\u043e\u0434\u044b<\/p><\/div>\n
What Components Make Up an EDI Water Treatment System?<\/h2>\n
An industrial EDI water treatment system contains much more than the EDI module itself.<\/p>\n
A typical skid can include:<\/p>\n
\n\n\nComponent<\/th>\n Function<\/th>\n<\/tr>\n<\/thead>\n \n\n\u041c\u043e\u0434\u0443\u043b\u044c EDI<\/td>\n Removes remaining ionizable impurities<\/td>\n<\/tr>\n \nFeed isolation valve<\/td>\n Controls incoming RO permeate<\/td>\n<\/tr>\n \nPressure regulator<\/td>\n Maintains suitable operating pressure<\/td>\n<\/tr>\n \nFlow meters<\/td>\n Measure product and concentrate flow<\/td>\n<\/tr>\n \nPressure gauges\/transmitters<\/td>\n Monitor hydraulic conditions<\/td>\n<\/tr>\n \nConductivity\/resistivity meter<\/td>\n Checks product water quality<\/td>\n<\/tr>\n \nDC power supply<\/td>\n Provides the electric field<\/td>\n<\/tr>\n \nControl panel<\/td>\n Operates and protects the system<\/td>\n<\/tr>\n \nPLC\/HMI<\/td>\n Automation and process monitoring<\/td>\n<\/tr>\n \nPiping and valves<\/td>\n Direct feed, product, and concentrate streams<\/td>\n<\/tr>\n \nSample points<\/td>\n Allow water-quality testing<\/td>\n<\/tr>\n \nFrame\/skid<\/td>\n Supports the complete package<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nLarger systems may use several EDI devices in parallel to achieve the required water production capacity.<\/p>\n
The system also needs interlocks. For example, the DC power should not operate without correct water flow. Low flow, excessive pressure, poor inlet quality, or another abnormal condition may trigger an alarm or shutdown.<\/p>\n
For EPC contractors, we usually recommend considering the EDI skid as part of the entire water treatment system, not as a separate box. RO quality, degassing, pumping, storage, recirculation, instrumentation, and downstream hygiene all affect final performance.<\/p>\n
\u041f\u043e\u0447\u0435\u043c\u0443 \u0441\u0438\u0441\u0442\u0435\u043c\u0430 \u043e\u0431\u0440\u0430\u0442\u043d\u043e\u0433\u043e \u043e\u0441\u043c\u043e\u0441\u0430 \u043e\u0431\u044b\u0447\u043d\u043e \u0443\u0441\u0442\u0430\u043d\u0430\u0432\u043b\u0438\u0432\u0430\u0435\u0442\u0441\u044f \u043f\u0435\u0440\u0435\u0434 \u0441\u0438\u0441\u0442\u0435\u043c\u043e\u0439 EDI?<\/h2>\n
EDI is a polishing technology. It is generally not designed to accept untreated raw water.<\/p>\n
Reverse osmosis therefore performs most of the bulk desalination first.<\/p>\n
A common system arrangement is:<\/p>\n
Raw Water\r\n \u2193\r\nPretreatment\r\n \u2193\r\nRO\r\n \u2502\r\n \u251c\u2500\u2500 Removes Most Dissolved Salt\r\n \u2193\r\nEDI\r\n \u2502\r\n \u2514\u2500\u2500 Polishes Remaining Ions\r\n \u2193\r\nHigh Purity Water\r\n<\/code><\/pre>\nVeolia’s commercial RO-CEDI systems combine reverse osmosis and continuous electrodeionization on one skid specifically to produce demineralized, high-grade water.<\/p>\n
This arrangement has an important economic benefit.<\/p>\n
If an EDI unit had to process water with very high ionic loading, it would need to move far more ions through its selective membranes. That creates greater electrical demand, scaling risk, and performance problems.<\/p>\n
RO lowers this burden first.<\/p>\n
The reverse osmosis system also reduces:<\/p>\n
\n- \u0422\u0432\u0451\u0440\u0434\u043e\u0441\u0442\u044c<\/li>\n
- \u041d\u0430\u0442\u0440\u0438\u0439<\/li>\n
- \u0425\u043b\u043e\u0440\u0438\u0434<\/li>\n
- \u0421\u0443\u043b\u044c\u0444\u0430\u0442<\/li>\n
- Many dissolved contaminants<\/li>\n
- Silica to varying degrees<\/li>\n
- Organic contamination to varying degrees<\/li>\n<\/ul>\n
EDI then handles the much smaller ionic load remaining in the RO permeate.<\/p>\n
For high-purity systems, a membrane degasser may also be installed before EDI to control carbon dioxide. CO\u2082 is important because it is not strongly rejected as an ion in its dissolved molecular form and can add to the ionic load after entering the EDI environment.<\/p>\n
DuPont’s EDI technical guidance specifically notes that excessive CO\u2082 and alkalinity can significantly reduce product-water quality.<\/p>\n
How Does EDI Compare With Traditional Ion Exchange?<\/h2>\n
Both EDI and traditional ion exchange can produce demineralized water. The big difference is how the ion exchange resin is regenerated.<\/p>\n
In a conventional mixed-bed or two-bed deionization system, resin eventually becomes exhausted. Operators normally use acids and caustic chemicals to restore its exchange capacity.<\/p>\n
EDI uses electricity to keep the resin active during operation.<\/p>\n
\n\n\n\u0424\u0430\u043a\u0442\u043e\u0440<\/th>\n EDI<\/th>\n Traditional Ion Exchange<\/th>\n<\/tr>\n<\/thead>\n \n\nIon removal<\/td>\n \u041d\u0435\u043f\u0440\u0435\u0440\u044b\u0432\u043d\u044b\u0439<\/td>\n Batch\/cyclic<\/td>\n<\/tr>\n \nResin<\/td>\n Yes<\/td>\n Yes<\/td>\n<\/tr>\n \nSelective membrane<\/td>\n Yes<\/td>\n Usually no<\/td>\n<\/tr>\n \nElectrical field<\/td>\n Yes<\/td>\n No<\/td>\n<\/tr>\n \nRoutine acid\/caustic regeneration<\/td>\n Normally not required<\/td>\n \u041e\u0431\u044f\u0437\u0430\u0442\u0435\u043b\u044c\u043d\u043e<\/td>\n<\/tr>\n \nFeed requirement<\/td>\n High-quality pretreated water<\/td>\n Can accept broader conditions depending on design<\/td>\n<\/tr>\n \nWater quality stability<\/td>\n Continuous when operated correctly<\/td>\n Can change through service\/regeneration cycle<\/td>\n<\/tr>\n \n\u0410\u0432\u0442\u043e\u043c\u0430\u0442\u0438\u0437\u0430\u0446\u0438\u044f<\/td>\n \u0412\u044b\u0441\u043e\u043a\u0438\u0439<\/td>\n Can be automated but regeneration remains necessary<\/td>\n<\/tr>\n \n\u0425\u0440\u0430\u043d\u0435\u043d\u0438\u0435 \u0445\u0438\u043c\u0438\u0447\u0435\u0441\u043a\u0438\u0445 \u0432\u0435\u0449\u0435\u0441\u0442\u0432<\/td>\n Lower for regeneration<\/td>\n Acid\/caustic normally required<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nThis is one reason EDI has become attractive for facilities that want to reduce the routine handling of hazardous chemicals.<\/p>\n
However, \u201cchemical-free\u201d should not be taken too literally.<\/p>\n
EDI eliminates routine chemical regeneration of the resin during normal production, but an industrial plant may still require chemicals elsewhere for:<\/p>\n
\n- \u041f\u0440\u0435\u0434\u0432\u0430\u0440\u0438\u0442\u0435\u043b\u044c\u043d\u0430\u044f \u043e\u0447\u0438\u0441\u0442\u043a\u0430 \u0441 \u043e\u0431\u0440\u0430\u0442\u043d\u044b\u043c \u043e\u0441\u043c\u043e\u0441\u043e\u043c<\/li>\n
- pH control<\/li>\n
- Membrane cleaning<\/li>\n
- Sanitization<\/li>\n
- CIP operations<\/li>\n
- Scale control<\/li>\n<\/ul>\n
The real advantage is the removal of the recurring acid-and-caustic regeneration cycle that characterizes many traditional ion exchange systems.<\/p>\n
What Water Quality Can an EDI System Produce?<\/h2>\n
\n\n\nWater stage<\/th>\n Typical relative ionic purity<\/th>\n<\/tr>\n<\/thead>\n \n\nRaw water<\/td>\n Low<\/td>\n<\/tr>\n \nSoftened water<\/td>\n Similar total ions, lower hardness<\/td>\n<\/tr>\n \nRO permeate<\/td>\n \u0412\u044b\u0441\u043e\u043a\u0438\u0439<\/td>\n<\/tr>\n \nRO + EDI product<\/td>\n Very high<\/td>\n<\/tr>\n \nRO + EDI + final polishing<\/td>\n Suitable for demanding ultrapure applications when properly engineered<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nActual performance must be defined by the specific project.<\/p>\n
Do not select an EDI system only because a brochure states \u201c18 M\u03a9\u00b7cm.\u201d Product-water quality depends on:<\/p>\n
\n- Feed conductivity<\/li>\n
- CO\u2082<\/li>\n
- \u041a\u0440\u0435\u043c\u043d\u0435\u0437\u0435\u043c<\/li>\n
- \u0422\u0435\u043c\u043f\u0435\u0440\u0430\u0442\u0443\u0440\u0430<\/li>\n
- Feed hardness<\/li>\n
- EDI module loading<\/li>\n
- Recovery<\/li>\n
- \u0420\u0430\u0441\u0445\u043e\u0434<\/li>\n
- Electrical current<\/li>\n
- System condition<\/li>\n<\/ul>\n
In addition, industries often control more than conductivity or resistivity.<\/p>\n
They may also specify:<\/p>\n
\n- \u041a\u0440\u0435\u043c\u043d\u0435\u0437\u0435\u043c<\/li>\n
- \u041d\u0430\u0442\u0440\u0438\u0439<\/li>\n
- \u041e\u0431\u0449\u0435\u0435 \u0441\u043e\u0434\u0435\u0440\u0436\u0430\u043d\u0438\u0435 \u043e\u0440\u0433\u0430\u043d\u0438\u0447\u0435\u0441\u043a\u043e\u0433\u043e \u0443\u0433\u043b\u0435\u0440\u043e\u0434\u0430<\/li>\n
- \u0411\u0430\u043a\u0442\u0435\u0440\u0438\u0438<\/li>\n
- Particles<\/li>\n
- Dissolved oxygen<\/li>\n
- Boron<\/li>\n
- \u0425\u043b\u043e\u0440\u0438\u0434<\/li>\n<\/ul>\n
For semiconductor, pharmaceutical, and other ultrapure water projects, EDI may be one stage in a much larger purification train.<\/p>\n
What Feed-Water Conditions Does an EDI Unit Need?<\/h2>\n
Good EDI performance starts with good pretreated water.<\/p>\n
Hardness is especially important. Calcium and magnesium can form scale inside the EDI concentrate zones because local pH conditions may favor precipitation.<\/p>\n
For example, DuPont’s current EDI-310 technical manual specifies maximum hardness of 0.5 mg\/L as CaCO\u2083 at 90% recovery and 0.1 mg\/L at 95% recovery for that particular module. These figures illustrate how low EDI feed hardness may need to be; the correct limit must always come from the selected module manufacturer.<\/p>\n
Other important feed-water parameters include:<\/p>\n
\n- \u041f\u0440\u043e\u0432\u043e\u0434\u0438\u043c\u043e\u0441\u0442\u044c<\/li>\n
- \u0422\u0432\u0451\u0440\u0434\u043e\u0441\u0442\u044c<\/li>\n
- CO\u2082<\/li>\n
- Alkalinity<\/li>\n
- \u041a\u0440\u0435\u043c\u043d\u0435\u0437\u0435\u043c<\/li>\n
- Iron<\/li>\n
- Manganese<\/li>\n
- Organic contamination<\/li>\n
- Chlorine or other oxidants<\/li>\n
- \u0422\u0435\u043c\u043f\u0435\u0440\u0430\u0442\u0443\u0440\u0430<\/li>\n
- pH<\/li>\n<\/ul>\n
Why does silica matter?<\/h3>\n
Silica can cause difficult deposits under unsuitable water conditions. DuPont warns that excessive influent silica can reduce EDI performance and may contribute to irreversible scaling in concentrate chambers.<\/p>\n
Why does CO\u2082 matter?<\/h3>\n
Carbon dioxide can pass through RO relatively easily compared with ionic salts. Once it enters an EDI unit, reactions involving bicarbonate and carbonate add ionic load.<\/p>\n
For water with significant CO\u2082, engineers may use:<\/p>\n
\n- pH adjustment<\/li>\n
- \u0414\u0435\u0433\u0430\u0437\u0430\u0446\u0438\u044f \u043c\u0435\u043c\u0431\u0440\u0430\u043d\u044b<\/li>\n
- Decarbonation<\/li>\n
- Improved RO configuration<\/li>\n<\/ul>\n
The exact solution depends on the complete feed analysis.<\/p>\n
Where Is EDI Used in Industrial Applications?<\/h2>\n
The industrial applications of EDI are concentrated in processes that need continuous, reliable, low-conductivity water.<\/p>\n
\u041f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0441\u0442\u0432\u043e \u044d\u043b\u0435\u043a\u0442\u0440\u043e\u044d\u043d\u0435\u0440\u0433\u0438\u0438<\/h3>\n
EDI is widely associated with power generation, including production of demineralized water for boiler feed and turbine-related applications.<\/p>\n
Veolia specifically lists boiler feed and turbine injection among the applications for integrated RO-CEDI plants.<\/p>\n
Low ionic contamination helps reduce:<\/p>\n
\n- Boiler deposits<\/li>\n
- Corrosion risk<\/li>\n
- Steam contamination<\/li>\n
- Turbine deposition<\/li>\n<\/ul>\n
\u0424\u0430\u0440\u043c\u0430\u0446\u0435\u0432\u0442\u0438\u0447\u0435\u0441\u043a\u043e\u0435 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0441\u0442\u0432\u043e<\/h3>\n
Pharmaceutical facilities use purified water systems with tightly controlled microbiological and chemical quality.<\/p>\n
EDI can form part of the purification train after RO, although using an EDI module does not by itself guarantee compliance with a pharmacopeial standard. The entire sanitary design, storage, distribution, monitoring, validation, and operating procedure must meet the applicable requirement.<\/p>\n
\u041f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0441\u0442\u0432\u043e \u043f\u043e\u043b\u0443\u043f\u0440\u043e\u0432\u043e\u0434\u043d\u0438\u043a\u043e\u0432 \u0438 \u044d\u043b\u0435\u043a\u0442\u0440\u043e\u043d\u0438\u043a\u0438<\/h3>\n
Electronics plants need extremely low contamination levels for processes such as:<\/p>\n
\n- Wafer rinsing<\/li>\n
- Component cleaning<\/li>\n
- Surface preparation<\/li>\n
- Chemical blending<\/li>\n<\/ul>\n
RO + EDI is often followed by additional polishing for full ultrapure water production.<\/p>\n
Food and beverage facilities<\/h3>\n
EDI can provide high-quality process water where mineral content must be tightly controlled.<\/p>\n
Laboratories and general manufacturing<\/h3>\n
Labs, coatings, specialty chemical processes, data centers, and many other facilities may use EDI where consistent high purity water is required. Veolia lists power, food and beverage, microelectronics, metals, general manufacturing, and data centers among applications for its RO-CEDI systems.<\/p>\n
![\"\"](\"https:\/\/banott.com\/wp-content\/uploads\/2026\/07\/EDI2.webp\")
\u0427\u0442\u043e \u0442\u0430\u043a\u043e\u0435 EDI-\u043c\u043e\u0434\u0443\u043b\u044c? \u041a\u0430\u043a \u0440\u0430\u0431\u043e\u0442\u0430\u044e\u0442 \u0441\u0438\u0441\u0442\u0435\u043c\u044b \u044d\u043b\u0435\u043a\u0442\u0440\u043e\u0434\u0435\u0438\u043e\u043d\u0438\u0437\u0430\u0446\u0438\u0438 \u0432\u043e\u0434\u044b<\/p><\/div>\n
What Are the Main Advantages and Limitations of EDI?<\/h2>\n
The main attraction of electrodeionization is continuous demineralization without routine acid-and-caustic resin regeneration.<\/p>\n
Main advantages<\/h3>\n\n- Continuous water production<\/li>\n
- Stable product quality<\/li>\n
- No routine resin chemical regeneration<\/li>\n
- Lower chemical storage requirements<\/li>\n
- Compact footprint<\/li>\n
- High automation potential<\/li>\n
- Easy integration after RO<\/li>\n
- Suitable for skid-mounted systems<\/li>\n
- Reduced operator intervention<\/li>\n
- Useful for high-purity industrial water<\/li>\n<\/ul>\n
Continuous operation also removes the service\/regeneration quality cycling found in some conventional deionization systems.<\/p>\n
Important limitations<\/h3>\n
EDI is not suitable for every feed stream.<\/p>\n
Its limits include:<\/p>\n
\n- Need for good pretreatment<\/li>\n
- Sensitivity to hardness<\/li>\n
- Sensitivity to excessive CO\u2082<\/li>\n
- Scaling risk from silica and minerals<\/li>\n
- Electrical power requirement<\/li>\n
- Need for correct hydraulic flow<\/li>\n
- Limited tolerance of major upstream treatment failures<\/li>\n
- Higher engineering demands than a basic cartridge filtration system<\/li>\n<\/ul>\n
In other words:<\/p>\n
EDI is an excellent polishing technology, but a poor substitute for proper pretreatment.<\/p><\/blockquote>\n
An EDI module cannot repair a badly designed RO system.<\/p>\n
How Should Electro-Deionized Water Treatment Skids Be Designed?<\/h2>\n
Good electro-deionized water treatment skids begin with a process specification rather than a module model.<\/p>\n
Before sizing the equipment, engineers need to know:<\/p>\n
\n- RO permeate flow<\/li>\n
- \u041f\u0440\u043e\u0432\u043e\u0434\u0438\u043c\u043e\u0441\u0442\u044c \u043f\u0435\u0440\u043c\u0435\u0430\u0442\u0430 \u043f\u0440\u0438 \u043e\u0431\u0440\u0430\u0442\u043d\u043e\u043e\u0441\u043c\u043e\u0442\u0438\u0447\u0435\u0441\u043a\u043e\u0439 \u043e\u0447\u0438\u0441\u0442\u043a\u0435<\/li>\n
- \u0422\u0432\u0451\u0440\u0434\u043e\u0441\u0442\u044c<\/li>\n
- CO\u2082<\/li>\n
- \u041a\u0440\u0435\u043c\u043d\u0435\u0437\u0435\u043c<\/li>\n
- \u0422\u0435\u043c\u043f\u0435\u0440\u0430\u0442\u0443\u0440\u0430<\/li>\n
- Required product resistivity<\/li>\n
- Product silica requirement<\/li>\n
- Daily operating hours<\/li>\n
- Required redundancy<\/li>\n
- Available footprint<\/li>\n
- \u0418\u0441\u0442\u043e\u0447\u043d\u0438\u043a \u043f\u0438\u0442\u0430\u043d\u0438\u044f<\/li>\n
- Automation requirements<\/li>\n<\/ul>\n
Typical engineering workflow<\/h3>\nFeed Water Analysis\r\n \u2193\r\nRO System Design\r\n \u2193\r\nRO Permeate Analysis \/ Projection\r\n \u2193\r\nEDI Load Calculation\r\n \u2193\r\nEDI Module Selection\r\n \u2193\r\nHydraulic Design\r\n \u2193\r\nPower Supply Selection\r\n \u2193\r\nInstrumentation\r\n \u2193\r\nPLC \/ HMI Programming\r\n \u2193\r\nSkid Fabrication\r\n \u2193\r\nFactory Testing\r\n \u2193\r\nShipping & Commissioning\r\n<\/code><\/pre>\nFor large systems, several modules can operate in parallel.<\/p>\n
For example:<\/p>\n
\u250c\u2500\u2500 EDI Module 1 \u2500\u2500\u2510\r\nRO Permeate \u2500\u2500\u2500\u253c\u2500\u2500 EDI Module 2 \u2500\u2500\u253c\u2500\u2500\u25ba Product Water\r\n \u251c\u2500\u2500 EDI Module 3 \u2500\u2500\u2524\r\n \u2514\u2500\u2500 EDI Module 4 \u2500\u2500\u2518\r\n<\/code><\/pre>\nThis modular structure also allows engineers to provide redundancy. A project may use an N+1 configuration when uptime is critical.<\/p>\n
Skid-based designs are especially useful for containerized plants and EPC projects because the equipment can be assembled, wired, inspected, and partly commissioned before arriving on site.<\/p>\n
Commercial plug-and-play RO-CEDI systems are also offered for container transport and fast installation, demonstrating the practicality of this approach.<\/p>\n
How Is an EDI System Operated and Maintained?<\/h2>\n
EDI requires less routine regeneration work than conventional deionizers, but it is not maintenance-free.<\/p>\n
Operators should monitor:<\/p>\n
\n- Feed conductivity<\/li>\n
- \u041f\u0440\u043e\u0432\u043e\u0434\u0438\u043c\u043e\u0441\u0442\u044c \u043f\u0440\u043e\u0434\u0443\u043a\u0442\u0430<\/li>\n
- Product resistivity<\/li>\n
- Feed pressure<\/li>\n
- Product pressure<\/li>\n
- Concentrate pressure<\/li>\n
- Feed flow<\/li>\n
- \u041f\u043e\u0442\u043e\u043a \u043f\u0440\u043e\u0434\u0443\u043a\u0446\u0438\u0438<\/li>\n
- \u0420\u0430\u0441\u0445\u043e\u0434 \u043a\u043e\u043d\u0446\u0435\u043d\u0442\u0440\u0430\u0442\u0430<\/li>\n
- Module voltage<\/li>\n
- Module current<\/li>\n
- \u0422\u0435\u043c\u043f\u0435\u0440\u0430\u0442\u0443\u0440\u0430<\/li>\n<\/ul>\n
Stable trending is often more useful than one isolated measurement.<\/p>\n
Typical warning signs<\/h3>\n
\n\n\n\u041d\u0430\u0431\u043b\u044e\u0434\u0435\u043d\u0438\u0435<\/th>\n Possible cause<\/th>\n<\/tr>\n<\/thead>\n \n\nProduct resistivity falls<\/td>\n Feed quality change, CO\u2082, module loading<\/td>\n<\/tr>\n \nPressure drop increases<\/td>\n Fouling or obstruction<\/td>\n<\/tr>\n \nElectrical current changes sharply<\/td>\n Feed ionic load or operating problem<\/td>\n<\/tr>\n \nProduct flow drops<\/td>\n Hydraulic restriction<\/td>\n<\/tr>\n \nSilica rises<\/td>\n Upstream or EDI performance issue<\/td>\n<\/tr>\n \nHardness appears in feed<\/td>\n RO or pretreatment upset<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nThe upstream RO system should also be monitored closely.<\/p>\n
If RO rejection suddenly deteriorates, the ionic load entering the EDI system can rise sharply. Continuing to run the EDI skid without correction may lead to scaling or poor product water quality.<\/p>\n
Good PLC programming can therefore include alarms for:<\/p>\n
\n- High feed conductivity<\/li>\n
- Low flow<\/li>\n
- High pressure<\/li>\n
- Poor product resistivity<\/li>\n
- Power-supply fault<\/li>\n
- Tank level<\/li>\n
- Pump fault<\/li>\n<\/ul>\n
This is one reason automation matters in an integrated water treatment plant.<\/p>\n
How Does an EDI Skid Fit Into a Complete Pure Water Treatment Plant?<\/h2>\n
For most industrial projects, EDI is not a stand-alone treatment technology.<\/p>\n
A complete system might look like this:<\/p>\n
Raw Water\r\n \u2193\r\nMultimedia \/ UF Pretreatment<\/a>\r\n \u2193\r\nActivated Carbon or Dechlorination\r\n \u2193\r\nCartridge Filter\r\n \u2193\r\nReverse Osmosis\r\n \u2193\r\nCO\u2082 Control if Required\r\n \u2193\r\nEDI\r\n \u2193\r\nUV \/ Final Polishing if Required\r\n \u2193\r\nPure Water Tank\r\n \u2193\r\nDistribution Loop\r\n<\/code><\/pre>\nA more demanding electronics system might use:<\/p>\n
Pretreatment\r\n \u2193\r\nRO\r\n \u2193\r\nSecond-Pass RO\r\n \u2193\r\nEDI\r\n \u2193\r\nUV\r\n \u2193\r\nTOC Polishing\r\n \u2193\r\nFinal UF\r\n \u2193\r\nUltrapure Water\r\n<\/code><\/pre>\nWastewater-reuse projects may begin much earlier:<\/p>\n
Industrial Wastewater\r\n \u2193\r\nBiological Treatment\r\n \u2193\r\nMBR\r\n \u2193\r\nRO\r\n \u2193\r\nEDI\r\n \u2193\r\nHigh-Quality Reuse Water\r\n<\/code><\/pre>\nThis integrated approach is central to our work as a manufacturer and engineering-oriented provider of water and wastewater treatment systems in China.<\/p>\n
We manufacture and integrate:<\/p>\n
What Is an EDI Skid in a Water Treatment System?<\/h2>\n
EDI stands for electrodeionization. An EDI skid is a factory-assembled water purification package that contains one or more EDI<\/a> modules together with the equipment needed to operate, monitor, and control them.<\/p>\n The skid normally receives highly purified feed water from a reverse osmosis system. It then removes many of the remaining dissolved ionic impurities to make deionized water or high-purity process water.<\/p>\n A simplified treatment train looks like this:<\/p>\n The word \u201cskid\u201d refers to the physical package. Pumps, valves, EDI modules, instruments, piping, electrical components, and controls are mounted on a structural frame so the system can be manufactured and tested before shipment.<\/p>\n This is useful for EPC projects because much of the piping and electrical integration takes place in the factory rather than at the project site.<\/p>\n An EDI module, by contrast, is only the core separation device. An EDI system or skid integrates the module into an operating water treatment package.<\/p>\n The EDI process combines three technologies:<\/p>\n The resin captures dissolved ions from the water. The applied electric field then causes those ions to migrate through selective membranes and into concentrate channels.<\/p>\n Positively charged ions, called cations, include substances such as:<\/p>\n Negatively charged ions, called anions, include:<\/p>\n The EDI stack contains alternating ion-selective membranes. Cation-exchange membranes favor the movement of positively charged ions, while anion-exchange membranes favor negatively charged ions.<\/p>\n A simplified view is:<\/p>\n As ions migrate away from the product stream, the product water becomes progressively more deionized.<\/p>\n A key feature is the behavior of the resin. In conventional ion exchange, exhausted resin normally requires acid or caustic regeneration. In EDI, electrical conditions inside the module promote water splitting into hydrogen and hydroxide ions. These help continuously regenerate the resin during operation.<\/p>\n That is why electrodeionization is often described as a continuous process. Veolia describes continuous EDI as using resin, membranes, and electricity to continuously polish RO permeate without routine chemical regeneration.<\/p>\n \u0427\u0442\u043e \u0442\u0430\u043a\u043e\u0435 EDI-\u043c\u043e\u0434\u0443\u043b\u044c? \u041a\u0430\u043a \u0440\u0430\u0431\u043e\u0442\u0430\u044e\u0442 \u0441\u0438\u0441\u0442\u0435\u043c\u044b \u044d\u043b\u0435\u043a\u0442\u0440\u043e\u0434\u0435\u0438\u043e\u043d\u0438\u0437\u0430\u0446\u0438\u0438 \u0432\u043e\u0434\u044b<\/p><\/div>\n An industrial EDI water treatment system contains much more than the EDI module itself.<\/p>\n A typical skid can include:<\/p>\n Larger systems may use several EDI devices in parallel to achieve the required water production capacity.<\/p>\n The system also needs interlocks. For example, the DC power should not operate without correct water flow. Low flow, excessive pressure, poor inlet quality, or another abnormal condition may trigger an alarm or shutdown.<\/p>\n For EPC contractors, we usually recommend considering the EDI skid as part of the entire water treatment system, not as a separate box. RO quality, degassing, pumping, storage, recirculation, instrumentation, and downstream hygiene all affect final performance.<\/p>\n EDI is a polishing technology. It is generally not designed to accept untreated raw water.<\/p>\n Reverse osmosis therefore performs most of the bulk desalination first.<\/p>\n A common system arrangement is:<\/p>\n Veolia’s commercial RO-CEDI systems combine reverse osmosis and continuous electrodeionization on one skid specifically to produce demineralized, high-grade water.<\/p>\n This arrangement has an important economic benefit.<\/p>\n If an EDI unit had to process water with very high ionic loading, it would need to move far more ions through its selective membranes. That creates greater electrical demand, scaling risk, and performance problems.<\/p>\n RO lowers this burden first.<\/p>\n The reverse osmosis system also reduces:<\/p>\n EDI then handles the much smaller ionic load remaining in the RO permeate.<\/p>\n For high-purity systems, a membrane degasser may also be installed before EDI to control carbon dioxide. CO\u2082 is important because it is not strongly rejected as an ion in its dissolved molecular form and can add to the ionic load after entering the EDI environment.<\/p>\n DuPont’s EDI technical guidance specifically notes that excessive CO\u2082 and alkalinity can significantly reduce product-water quality.<\/p>\n Both EDI and traditional ion exchange can produce demineralized water. The big difference is how the ion exchange resin is regenerated.<\/p>\n In a conventional mixed-bed or two-bed deionization system, resin eventually becomes exhausted. Operators normally use acids and caustic chemicals to restore its exchange capacity.<\/p>\n EDI uses electricity to keep the resin active during operation.<\/p>\n This is one reason EDI has become attractive for facilities that want to reduce the routine handling of hazardous chemicals.<\/p>\n However, \u201cchemical-free\u201d should not be taken too literally.<\/p>\n EDI eliminates routine chemical regeneration of the resin during normal production, but an industrial plant may still require chemicals elsewhere for:<\/p>\n The real advantage is the removal of the recurring acid-and-caustic regeneration cycle that characterizes many traditional ion exchange systems.<\/p>\n Actual performance must be defined by the specific project.<\/p>\n Do not select an EDI system only because a brochure states \u201c18 M\u03a9\u00b7cm.\u201d Product-water quality depends on:<\/p>\n In addition, industries often control more than conductivity or resistivity.<\/p>\n They may also specify:<\/p>\n For semiconductor, pharmaceutical, and other ultrapure water projects, EDI may be one stage in a much larger purification train.<\/p>\n Good EDI performance starts with good pretreated water.<\/p>\n Hardness is especially important. Calcium and magnesium can form scale inside the EDI concentrate zones because local pH conditions may favor precipitation.<\/p>\n For example, DuPont’s current EDI-310 technical manual specifies maximum hardness of 0.5 mg\/L as CaCO\u2083 at 90% recovery and 0.1 mg\/L at 95% recovery for that particular module. These figures illustrate how low EDI feed hardness may need to be; the correct limit must always come from the selected module manufacturer.<\/p>\n Other important feed-water parameters include:<\/p>\n Silica can cause difficult deposits under unsuitable water conditions. DuPont warns that excessive influent silica can reduce EDI performance and may contribute to irreversible scaling in concentrate chambers.<\/p>\n Carbon dioxide can pass through RO relatively easily compared with ionic salts. Once it enters an EDI unit, reactions involving bicarbonate and carbonate add ionic load.<\/p>\n For water with significant CO\u2082, engineers may use:<\/p>\n The exact solution depends on the complete feed analysis.<\/p>\n The industrial applications of EDI are concentrated in processes that need continuous, reliable, low-conductivity water.<\/p>\n EDI is widely associated with power generation, including production of demineralized water for boiler feed and turbine-related applications.<\/p>\n Veolia specifically lists boiler feed and turbine injection among the applications for integrated RO-CEDI plants.<\/p>\n Low ionic contamination helps reduce:<\/p>\n Pharmaceutical facilities use purified water systems with tightly controlled microbiological and chemical quality.<\/p>\n EDI can form part of the purification train after RO, although using an EDI module does not by itself guarantee compliance with a pharmacopeial standard. The entire sanitary design, storage, distribution, monitoring, validation, and operating procedure must meet the applicable requirement.<\/p>\n Electronics plants need extremely low contamination levels for processes such as:<\/p>\n RO + EDI is often followed by additional polishing for full ultrapure water production.<\/p>\n EDI can provide high-quality process water where mineral content must be tightly controlled.<\/p>\n Labs, coatings, specialty chemical processes, data centers, and many other facilities may use EDI where consistent high purity water is required. Veolia lists power, food and beverage, microelectronics, metals, general manufacturing, and data centers among applications for its RO-CEDI systems.<\/p>\n \u0427\u0442\u043e \u0442\u0430\u043a\u043e\u0435 EDI-\u043c\u043e\u0434\u0443\u043b\u044c? \u041a\u0430\u043a \u0440\u0430\u0431\u043e\u0442\u0430\u044e\u0442 \u0441\u0438\u0441\u0442\u0435\u043c\u044b \u044d\u043b\u0435\u043a\u0442\u0440\u043e\u0434\u0435\u0438\u043e\u043d\u0438\u0437\u0430\u0446\u0438\u0438 \u0432\u043e\u0434\u044b<\/p><\/div>\n The main attraction of electrodeionization is continuous demineralization without routine acid-and-caustic resin regeneration.<\/p>\n Continuous operation also removes the service\/regeneration quality cycling found in some conventional deionization systems.<\/p>\n EDI is not suitable for every feed stream.<\/p>\n Its limits include:<\/p>\n In other words:<\/p>\n EDI is an excellent polishing technology, but a poor substitute for proper pretreatment.<\/p><\/blockquote>\n An EDI module cannot repair a badly designed RO system.<\/p>\n Good electro-deionized water treatment skids begin with a process specification rather than a module model.<\/p>\n Before sizing the equipment, engineers need to know:<\/p>\n For large systems, several modules can operate in parallel.<\/p>\n For example:<\/p>\n This modular structure also allows engineers to provide redundancy. A project may use an N+1 configuration when uptime is critical.<\/p>\n Skid-based designs are especially useful for containerized plants and EPC projects because the equipment can be assembled, wired, inspected, and partly commissioned before arriving on site.<\/p>\n Commercial plug-and-play RO-CEDI systems are also offered for container transport and fast installation, demonstrating the practicality of this approach.<\/p>\n EDI requires less routine regeneration work than conventional deionizers, but it is not maintenance-free.<\/p>\n Operators should monitor:<\/p>\n Stable trending is often more useful than one isolated measurement.<\/p>\n The upstream RO system should also be monitored closely.<\/p>\n If RO rejection suddenly deteriorates, the ionic load entering the EDI system can rise sharply. Continuing to run the EDI skid without correction may lead to scaling or poor product water quality.<\/p>\n Good PLC programming can therefore include alarms for:<\/p>\n This is one reason automation matters in an integrated water treatment plant.<\/p>\n For most industrial projects, EDI is not a stand-alone treatment technology.<\/p>\n A complete system might look like this:<\/p>\n A more demanding electronics system might use:<\/p>\n Wastewater-reuse projects may begin much earlier:<\/p>\n This integrated approach is central to our work as a manufacturer and engineering-oriented provider of water and wastewater treatment systems in China.<\/p>\n We manufacture and integrate:<\/p>\nRaw Water\r\n \u2193\r\nPretreatment\r\n \u2193\r\nReverse Osmosis\r\n \u2193\r\nRO Permeate\r\n \u2193\r\nEDI Skid\r\n \u2193\r\nHigh-Purity Water\r\n<\/code><\/pre>\nHow Does the Electrodeionization Process Work?<\/h2>\n
\n
\n
\n
DC Electric Field\r\n (+) -------------------- (-)\r\n\r\nFeed Water\r\n \u2193\r\n\u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510\r\n\u2502 Resin-Filled Diluting Chamber \u2502\r\n\u2502 \u2502\r\n\u2502 Cations \u2500\u2500\u2500\u2500\u2500\u2500\u25ba Cation Membrane \u2502\r\n\u2502 Anions \u25c4\u2500\u2500\u2500\u2500\u2500\u2500 Anion Membrane \u2502\r\n\u2502 \u2502\r\n\u2502 Purified Water Continues Forward \u2502\r\n\u2514\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2518\r\n \u2193 \u2193\r\n Product Water Concentrate\r\n<\/code><\/pre>\nWhat Components Make Up an EDI Water Treatment System?<\/h2>\n
\n\n
\n \nComponent<\/th>\n Function<\/th>\n<\/tr>\n<\/thead>\n \n \u041c\u043e\u0434\u0443\u043b\u044c EDI<\/td>\n Removes remaining ionizable impurities<\/td>\n<\/tr>\n \n Feed isolation valve<\/td>\n Controls incoming RO permeate<\/td>\n<\/tr>\n \n Pressure regulator<\/td>\n Maintains suitable operating pressure<\/td>\n<\/tr>\n \n Flow meters<\/td>\n Measure product and concentrate flow<\/td>\n<\/tr>\n \n Pressure gauges\/transmitters<\/td>\n Monitor hydraulic conditions<\/td>\n<\/tr>\n \n Conductivity\/resistivity meter<\/td>\n Checks product water quality<\/td>\n<\/tr>\n \n DC power supply<\/td>\n Provides the electric field<\/td>\n<\/tr>\n \n Control panel<\/td>\n Operates and protects the system<\/td>\n<\/tr>\n \n PLC\/HMI<\/td>\n Automation and process monitoring<\/td>\n<\/tr>\n \n Piping and valves<\/td>\n Direct feed, product, and concentrate streams<\/td>\n<\/tr>\n \n Sample points<\/td>\n Allow water-quality testing<\/td>\n<\/tr>\n \n Frame\/skid<\/td>\n Supports the complete package<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \u041f\u043e\u0447\u0435\u043c\u0443 \u0441\u0438\u0441\u0442\u0435\u043c\u0430 \u043e\u0431\u0440\u0430\u0442\u043d\u043e\u0433\u043e \u043e\u0441\u043c\u043e\u0441\u0430 \u043e\u0431\u044b\u0447\u043d\u043e \u0443\u0441\u0442\u0430\u043d\u0430\u0432\u043b\u0438\u0432\u0430\u0435\u0442\u0441\u044f \u043f\u0435\u0440\u0435\u0434 \u0441\u0438\u0441\u0442\u0435\u043c\u043e\u0439 EDI?<\/h2>\n
Raw Water\r\n \u2193\r\nPretreatment\r\n \u2193\r\nRO\r\n \u2502\r\n \u251c\u2500\u2500 Removes Most Dissolved Salt\r\n \u2193\r\nEDI\r\n \u2502\r\n \u2514\u2500\u2500 Polishes Remaining Ions\r\n \u2193\r\nHigh Purity Water\r\n<\/code><\/pre>\n\n
How Does EDI Compare With Traditional Ion Exchange?<\/h2>\n
\n\n
\n \n\u0424\u0430\u043a\u0442\u043e\u0440<\/th>\n EDI<\/th>\n Traditional Ion Exchange<\/th>\n<\/tr>\n<\/thead>\n \n Ion removal<\/td>\n \u041d\u0435\u043f\u0440\u0435\u0440\u044b\u0432\u043d\u044b\u0439<\/td>\n Batch\/cyclic<\/td>\n<\/tr>\n \n Resin<\/td>\n Yes<\/td>\n Yes<\/td>\n<\/tr>\n \n Selective membrane<\/td>\n Yes<\/td>\n Usually no<\/td>\n<\/tr>\n \n Electrical field<\/td>\n Yes<\/td>\n No<\/td>\n<\/tr>\n \n Routine acid\/caustic regeneration<\/td>\n Normally not required<\/td>\n \u041e\u0431\u044f\u0437\u0430\u0442\u0435\u043b\u044c\u043d\u043e<\/td>\n<\/tr>\n \n Feed requirement<\/td>\n High-quality pretreated water<\/td>\n Can accept broader conditions depending on design<\/td>\n<\/tr>\n \n Water quality stability<\/td>\n Continuous when operated correctly<\/td>\n Can change through service\/regeneration cycle<\/td>\n<\/tr>\n \n \u0410\u0432\u0442\u043e\u043c\u0430\u0442\u0438\u0437\u0430\u0446\u0438\u044f<\/td>\n \u0412\u044b\u0441\u043e\u043a\u0438\u0439<\/td>\n Can be automated but regeneration remains necessary<\/td>\n<\/tr>\n \n \u0425\u0440\u0430\u043d\u0435\u043d\u0438\u0435 \u0445\u0438\u043c\u0438\u0447\u0435\u0441\u043a\u0438\u0445 \u0432\u0435\u0449\u0435\u0441\u0442\u0432<\/td>\n Lower for regeneration<\/td>\n Acid\/caustic normally required<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n
What Water Quality Can an EDI System Produce?<\/h2>\n
\n\n
\n \nWater stage<\/th>\n Typical relative ionic purity<\/th>\n<\/tr>\n<\/thead>\n \n Raw water<\/td>\n Low<\/td>\n<\/tr>\n \n Softened water<\/td>\n Similar total ions, lower hardness<\/td>\n<\/tr>\n \n RO permeate<\/td>\n \u0412\u044b\u0441\u043e\u043a\u0438\u0439<\/td>\n<\/tr>\n \n RO + EDI product<\/td>\n Very high<\/td>\n<\/tr>\n \n RO + EDI + final polishing<\/td>\n Suitable for demanding ultrapure applications when properly engineered<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n
\n
What Feed-Water Conditions Does an EDI Unit Need?<\/h2>\n
\n
Why does silica matter?<\/h3>\n
Why does CO\u2082 matter?<\/h3>\n
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Where Is EDI Used in Industrial Applications?<\/h2>\n
\u041f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0441\u0442\u0432\u043e \u044d\u043b\u0435\u043a\u0442\u0440\u043e\u044d\u043d\u0435\u0440\u0433\u0438\u0438<\/h3>\n
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\u0424\u0430\u0440\u043c\u0430\u0446\u0435\u0432\u0442\u0438\u0447\u0435\u0441\u043a\u043e\u0435 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0441\u0442\u0432\u043e<\/h3>\n
\u041f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0441\u0442\u0432\u043e \u043f\u043e\u043b\u0443\u043f\u0440\u043e\u0432\u043e\u0434\u043d\u0438\u043a\u043e\u0432 \u0438 \u044d\u043b\u0435\u043a\u0442\u0440\u043e\u043d\u0438\u043a\u0438<\/h3>\n
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Food and beverage facilities<\/h3>\n
Laboratories and general manufacturing<\/h3>\n
What Are the Main Advantages and Limitations of EDI?<\/h2>\n
Main advantages<\/h3>\n
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Important limitations<\/h3>\n
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How Should Electro-Deionized Water Treatment Skids Be Designed?<\/h2>\n
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Typical engineering workflow<\/h3>\n
Feed Water Analysis\r\n \u2193\r\nRO System Design\r\n \u2193\r\nRO Permeate Analysis \/ Projection\r\n \u2193\r\nEDI Load Calculation\r\n \u2193\r\nEDI Module Selection\r\n \u2193\r\nHydraulic Design\r\n \u2193\r\nPower Supply Selection\r\n \u2193\r\nInstrumentation\r\n \u2193\r\nPLC \/ HMI Programming\r\n \u2193\r\nSkid Fabrication\r\n \u2193\r\nFactory Testing\r\n \u2193\r\nShipping & Commissioning\r\n<\/code><\/pre>\n \u250c\u2500\u2500 EDI Module 1 \u2500\u2500\u2510\r\nRO Permeate \u2500\u2500\u2500\u253c\u2500\u2500 EDI Module 2 \u2500\u2500\u253c\u2500\u2500\u25ba Product Water\r\n \u251c\u2500\u2500 EDI Module 3 \u2500\u2500\u2524\r\n \u2514\u2500\u2500 EDI Module 4 \u2500\u2500\u2518\r\n<\/code><\/pre>\nHow Is an EDI System Operated and Maintained?<\/h2>\n
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Typical warning signs<\/h3>\n
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\n \n\u041d\u0430\u0431\u043b\u044e\u0434\u0435\u043d\u0438\u0435<\/th>\n Possible cause<\/th>\n<\/tr>\n<\/thead>\n \n Product resistivity falls<\/td>\n Feed quality change, CO\u2082, module loading<\/td>\n<\/tr>\n \n Pressure drop increases<\/td>\n Fouling or obstruction<\/td>\n<\/tr>\n \n Electrical current changes sharply<\/td>\n Feed ionic load or operating problem<\/td>\n<\/tr>\n \n Product flow drops<\/td>\n Hydraulic restriction<\/td>\n<\/tr>\n \n Silica rises<\/td>\n Upstream or EDI performance issue<\/td>\n<\/tr>\n \n Hardness appears in feed<\/td>\n RO or pretreatment upset<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n
How Does an EDI Skid Fit Into a Complete Pure Water Treatment Plant?<\/h2>\n
Raw Water\r\n \u2193\r\nMultimedia \/ UF Pretreatment<\/a>\r\n \u2193\r\nActivated Carbon or Dechlorination\r\n \u2193\r\nCartridge Filter\r\n \u2193\r\nReverse Osmosis\r\n \u2193\r\nCO\u2082 Control if Required\r\n \u2193\r\nEDI\r\n \u2193\r\nUV \/ Final Polishing if Required\r\n \u2193\r\nPure Water Tank\r\n \u2193\r\nDistribution Loop\r\n<\/code><\/pre>\nPretreatment\r\n \u2193\r\nRO\r\n \u2193\r\nSecond-Pass RO\r\n \u2193\r\nEDI\r\n \u2193\r\nUV\r\n \u2193\r\nTOC Polishing\r\n \u2193\r\nFinal UF\r\n \u2193\r\nUltrapure Water\r\n<\/code><\/pre>\nIndustrial Wastewater\r\n \u2193\r\nBiological Treatment\r\n \u2193\r\nMBR\r\n \u2193\r\nRO\r\n \u2193\r\nEDI\r\n \u2193\r\nHigh-Quality Reuse Water\r\n<\/code><\/pre>\n