I. KampurEDIIntroduction to Membrane Blocks　

　　EDI(ElectrodeionizationAlso known asContinuous electro-deionization technologyIt scientifically integrates electrodialysis technology and ion exchange technology. Through the selective permeation of cations and anions by cation and anion membranes and the exchange of ions in water by ion exchange resins, it realizes the directional migration of ions in water under the action of an electric field, thereby achieving deep purification and desalination of water. And the filled resin is continuously regenerated through the hydrogen ions and hydroxide ions produced by water electrolysis, thusEDIThe water production process can continuously produce high-quality ultrapure water without acid or alkali chemical regeneration. The water quality of the output has excellent stability. It has the advantages of advanced technology, compact structure and simple operation, and can be widely applied in the fields of power, electronics, medicine, chemical engineering and laboratories. It is a green revolution in water treatment technology.

　　Continuous electro-deionizationEDIIt is a method that uses mixed ion exchange resin to adsorb cations and anions in water, and at the same time, These adsorbed ions, under the action of direct current voltage, pass through the anion and cation exchange membranes respectively and enter the concentrated electrode water chamber to be removed. On the other hand, under the action of direct current voltage, water will dissociate to produce sufficientH+ andOH- Regenerate the resin adsorbed with ions to achieve continuous deep desalination. This new technology can replace the traditional ion exchange(DI)It has produced a resistivity as high as18MΩ·cm Ultra-pure water.

　　EDI The advantage of it is that there is no longer a need to regenerate the ion exchange resin with acid and alkali, thus being more environmentally friendly.

　　Electro-deionization water purification technology is a new desalination process that combines electrodialysis and ion exchange. Its English name iselectrodeion ization(EDI).

　　EDIIt can continuously discharge water without the need for chemical agents(Acids, bases, salts)Regeneration,Thus, it will not pollute the environment;It can be fully automatically controlled;Wide adaptability,It can thus be used for water treatment in all walks of life;Low operating cost,It has good economic performance and is easy to popularize and promote. Some foreign arguments and analyses show that,In today's water treatment desalination systems,Adopt reverse osmosis(RO)withEDICombined process,It can ensure the best water treatment process performance,Its economy is also good,For the promotion of this combined process,It offers a promising development prospect.

Ii.Application field

　　CampbellEDIMembrane block

　　1The semiconductor and electronics industries-Ultra-pure water

　　2The biological and pharmaceutical industries-Purified water

　　3Power plant-Deep desalination of boiler feed water

　　4Purified water for petrochemical and chemical industries, surface coating

　　5The consumer goods and cosmetics industry

　　6Replace all kinds of distilled water

　　7Laboratory ultrapure water, pure water for pharmaceutical use

　　8Other industries with high requirements for water purity

　　 EDIPure water can also be used as pharmaceutical distilled water, water for food and beverage production, and other applications of ultrapure water.

　　To meet the diverse needs of different users, Beijing Yuanlai Water Treatment Company can design systems based on the actual situations of users.

Iii.EDIMembrane blockProduct features

　　Due to issues such as membrane surface polarization, when the hardness of the feed water exceeds one part per million, traditional methodsEDIThe components are facing a serious scaling problem. This problem has had a profound impact on the landEDIThe wide application of technology. CampbellS-EDIThe innovation of technology in component structure has enabledEDIThe hardness of the feed water has been increased tenfold, while the power consumption has been reduced75%That's all. One technological advancement isEDIThe wider application of technology provides a technical foundation. It demonstrates advantages in the following multiple aspects.

　　●　Water hardness＜10 ppm

　　●　Low current and voltage

　　●　No need for concentrated water with salt

　　●　Both the initial investment and operating costs are lower

　　●　No need for concentrated water circulation

FourCompared with traditional ion exchangeEDIIn comparison,EDIThe technical advantages it possesses

　　1,EDINo chemical regeneration required,Save acid and alkali

　　2,EDIIt can operate continuously and automatically with high water utilization rate

　　3Provide stable water quality with no sewage discharge

　　4It is convenient to operate and manage, and has low labor intensity

　　5It can be modularly assembled

　　6It occupies less space and reduces the building area

　　7Low operating costs

V."Influence"EDIFactors of system operation

　　(1) EDIThe influence of influent electrical conductivity. Under the same operating current, as the conductivity of the raw water increasesEDIThe removal rate of weak electrolytes decreases, and the conductivity of the effluent also increases. If the conductivity of the raw water is low, the content of ions is also low. The low concentration of ions causes a large electromotive force gradient formed on the surface of the resin and membrane in the dilute chamber, resulting in an increased degree of water dissociation and an increase in the limiting current, which is producedH+andOH-The large quantity enables the regeneration effect of the anion and cation exchange resins filled in the dilute chamber to be good.

　　(2) Working voltage-The influence of electric current. As the working current increases, the quality of the produced water keeps improving. However, if the current is increased after the height increase point, it will be caused by water ionizationH+andOH-Excessive ion content, apart from being used for resin regeneration, a large number of surplus ions act as current-carrying ions to conduct electricity. At the same time, due to the accumulation and blockage of a large number of current-carrying ions during their movement, and even reverse diffusion, the quality of the produced water deteriorates.

　　(3) Turbidity, pollution index(SDI)The influence.EDIThe water production channel of the component is filled with ion exchange resin. Excessively high turbidity and pollution index will cause the channel to be blocked, resulting in an increase in system pressure difference and a decrease in water production.

　　(4) The influence of hardness. IfEDIIf the residual hardness of the feed water is too high, it will cause scaling on the membrane surface of the concentrated water channel, reduce the flow rate of the concentrated water, and decrease the resistivity of the produced water;It affects the quality of the produced water. In severe cases, it may clog the concentrated water and polar water channels of the components, causing the components to be damaged due to internal heating.

　　(5) TOC(Total organic carbon)The influence. If the organic matter content in the influent is too high, it will cause organic contamination of the resin and selective permeable membrane, leading to an increase in the system operating voltage and a decline in the quality of the produced water. It is also prone to form organic colloids in the concentrated water channel, blocking the channel.

　　(6)  In the waterCO2The influence. In the waterCO2GeneratedHCO3-It is a weak electrolyte and is prone to penetrate the ion exchange resin layer, resulting in a decline in the quality of the produced water.

　　(7) Total anion content(TEA)The influence. "Tall"TEAIt will decreaseEDIThe resistivity of the produced water may need to be increasedEDIExcessively high operating current will lead to an increase in the system current and the residual chlorine concentration in the electrode water, which is detrimental to the lifespan of the electrode membrane.

　　In addition, the inlet water temperature,pHValueSiO2And oxides are also correctEDIThe system operation is affected.