NEWater EDI Units

NEWater EDI Units are designed to meet the most stringent water treatment standards. Our high-quality units continuously create ultra-pure water with a purity of 18.2 M/cm, resulting in lower operating costs, energy efficiency, and maintenance requirements, such as fewer facility demands and management oversight, which saves even more labor expenses. NEWater electrodeionization units are adjustable and created with cutting-edge 3D computer technology for precise and tailored results. Boiler feedwater at power stations, process water in the electronics sector, pharmaceutical industry, hospitals, and laboratories are typical EDI applications.

NEWater guarantees that all our products are manufactured of high-quality materials are highly resistant to damage, are built to international standards with great care, and are guaranteed by a one-year warranty and lifetime maintenance. Our expert technicians assure that our equipment suits your needs while remaining functional and cost-effective.

Please contact us at info@newater.com if you require a NEWater EDI Units.

The Ultimate FAQ Guide for Electrodeionization (EDI) Units.

Modern industries such as pharmaceuticals and microelectronics have sophisticated processes which necessitate water with exemplary purity levels. The quality of water used and discharged from these industries is stringently regulated hence necessitating ultra-modern water purification systems.

Efforts to minimize environmental pollution have inspired the development of chemical-free water purifiers consequently shrinking the pollutant load. In the underlying article, we constrict our focus to one of the most advanced water purification technologies; electrodeionization and its respective range of equipment.

➣What is an EDI Unit?

An electrodeionization (EDI) unit is an electrically-driven water deionization machine responsible for eliminating dissolved ions from water using ion exchange resins and membranes. The use of EDI units commenced in 1987 and, in 1998, EDI units were integrated with reverse osmosis. Their deionization capabilities are unrivaled and quite often, EDI units are exploited to generate ultra-pure water for industries like microelectronics, energy manufacturing, and pharmaceutical industries.

Electrodeionization units exploit both ion exchange resins and ion exchange membranes to displace objectionable ions from water. As such, they are more effective compared to traditional water deionizer systems. Presently, EDI water systems are mainly used in tandem with reverse osmosis systems. This lowers the cost of production, elevates the quality of water generated, and protects the EDI system from premature fouling.

Ordinarily, they are used to generate high-purity water for complex industrial applications. The quality of the resulting deionized water is attested to by its high resistivity (18.2MW/cm) and low conductivity. Regeneration in EDI units is electrically driven hence there are no chemicals used. This makes the purification process and equipment environmentally friendly, unlike typical water deionizers. We manufacture state-of-the-art EDI water units designed distinctively to gratify the requirements of different industries.

➣How Do EDI Units Functions?

Water electrodeionization units generate high-purity water by assimilating ion exchange and electrodialysis. Typical electrodeionization modules are made up of chambers holding ion exchange resins, which are alienated by ion-exchange membranes. EDI modules are in effect, the ion exchange bed. The feed water, which has been adequately pretreated to extract suspended solids is driven into the module and directed through the IX resins. Direct current from an external source is simultaneously fed through the anode and cathode electrodes.

The subsequent voltage from the direct current provokes circulation in the ion exchange resins. This pulls the negatively charged ions towards the anode while the positively charged ions are attracted to the cathode. The objectionable ions’ bondage to the media is typically impermanent hence they are harvested as part of the concentrate stream. Subsequently, they are discarded into the drain or recycled.

The pollutant ions in the feed water are ordinarily exchanged for hydrogen (H+) and hydroxide (OH-) ions as they penetrate through the ix resins as well as the ion exchange membranes. The outgoing water, which is essentially deionized water can be used instantaneously or treated further to elevate the purity levels.

Exhausted EDI resins are regenerated electrochemically unlike conventional ion exchange resins, which are regenerated using acidic or basic regenerates. A regenerated EDI unit functions optimally and generates high-purity deionized water. Learn more about water electrodeionization by clicking the following link.

➣What Are the Main Features of Electrodeionization Units?

Electrodeionization water systems are primarily used to generate ultra-pure water for distinct industrial applications. They generate high-purity water by extracting impurity ions using electrodialysis and ion exchange technologies. Underneath, we are going to look at some of the primary features that distinguish EDI units from other water purification systems.

• EDI units depend on ion-exchange membranes and resins to extract impurity ions hence they generate high purity water (up to 18 Megaohm-cm).
• They are simply designed and compact, which allows them to efficiently utilize space.
• They are electrically driven and hardly use any chemicals making them environmentally friendly.
• Standard electrodeionization units have a capacity range of 500 to 2000 LPH. This diverse range accommodates the production demands of small, medium, and large-scale applications.
• They are available in power supply options such as 50Hz/60Hz and 220V/380V.
• Typical EDI units have a service flow rate ranging from 0.5 to 50 m3/hr.
• Regeneration is electrically-driven and chemical regenerants are hardly used.
• They have an average recovery rate ranging from 90% to 95%.

➣What Are the Advantages of Integrating Reverse Osmosis with EDI Units?

The assimilation of EDI water treatment systems and reverse osmosis systems as a water purification technique began in 1998. RO-EDI water systems are advanced ultrapure water systems used in complex fields such as pharmaceutical manufacturing and microelectronics. The RO-EDI water purification process commences by forcing water through semi-porous membranes in a process known as reverse osmosis.

Reverse osmosis is a pressure-driven process that eliminates dissolved solids, minerals, organic compounds, bacteria, viruses, and nutrients from the water. The permeate drawn from the reverse osmosis system is subsequently used as the feed water for the EDI water system. Typically, one-pass or two-pass reverse osmosis is employed in the pre-treatment phase.

Presently, you can procure an integrated RO-EDI water system, which is compact, more effective, and has a higher recovery than separate reverse osmosis and EDI water systems. Underneath, we walk through some of the rewards you can expect to reap from your RO-EDI water system.

• Ultra-pure water with a resistivity of 18+ MΩ-cm using one-pass or two-pass reverse osmosis systems.
• Higher flow rates in the EDI unit since there are no suspended solids or dissolved matter in the feed water.
• Improved recovery rates (up to 95%) compared to separate RO and EDI units.
• Lower maintenance costs and production costs.
• Easy installation and lower installation costs.

➣What Quality of Water do EDI Units Generate?

Water electrodeionization systems typically produce first-rate deionized water. They extract practically all impurity ions in the water by swapping them with H+ and OH- ions. The purification grade of the deionized water however differs depending on the quality of feed water and the pretreatment technology deployed. For instance, using RO permeate from a double reverse osmosis system as the feed water for an EDI unit, guarantees ultra-pure water with resistivity levels of 18+ MΩ-cm.

Ultrapure water is ordinarily categorized as Type I water. It is characterized by conductivity scores of <0.056 µS/cm, resistivity levels of 18+ MΩ-cm, TOC levels of <50 ppb, and extremely low TDS levels. This grade of water is mainly utilized in sophisticated processes such as cell culturing, HPLC, tissue culturing, and mass spectrometry. In the absence of an elaborate pretreatment unit, EDI units may generate Type II deionized water. This is purified water characterized by TOC scores of <50ppb, resistivity scores of < 1 MΩ-cm, and conductivity scores of <1 µS/cm.

Type II deionized water suits applications such as media preparation, electrochemistry, and sample dilution. In addition, this grade of water can be used as feed water in a post-treatment system designed to generate ultrapure water. Regular and quality maintenance is mandatory in sustaining the generation of high-quality purified water.

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➣Where Are Electrodeionization Units Mainly Applied?

EDI water purification systems are presently exploited in practically all industries necessitating high-purity water. They are principally employed together with other water treatment systems but their role is mostly constrained to post-treatment. Their application fields cut across the following sectors; biotechnology, veterinary, energy, cosmetics, microelectronics, and pharmaceutical industries. However, we are going to narrow our focus to three principal industries:

● Pharmaceutical manufacturing.

The majority of applications in pharmaceutical industries necessitate water with exceptional purity levels. Parameters such as TOC levels, TSS levels, microbial count, conductivity, and resistivity are strictly regulated by the respective pharmacopeias e.g. the European pharmacopeia (PhEur) and the USP. EDI systems custom-made for pharmaceutical water purification typically assimilate reverse osmosis systems. They are also designed to operate as sanitized hot water systems.

● Microelectronics.

EDI units are popularly used to purify water for microelectronic industries. For instance, they are commonly exploited to generate high-purity water (at 18 MΩ-cm) for manufacturing semiconductors. They are often integrated with supplemental systems to ensure the desired silica, organic carbon, microbial content, and boron levels are attained.

● Energy production industries.

Energy production industries are quite water-intensive. They necessitate high-grade water to cool high-pressure boilers and generate steam. As such, high-level water purification systems like electrodeionization units are needed. Previously, systems such as two-bed deionizers and mixed-bed deionizers were used but at present, most energy-producing industries prefer EDI units. This is because electrodeionization units can efficiently and economically generate high-purity water characterized by low silica levels and extremely low conductivity scores.

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➣What Quality of Feed Water is Needed by Electrodeionization (EDI) Units?

Although EDI units can sufficiently treat feedwater drawn from varying sources (brackish water, tap water, groundwater, surface water, or seawater), pretreatment is often obligated to condition the feed water. Preconditioning the feed water decreases the likelihood of premature fouling and also elevates the quality of purified water generated. Here are numerous pretreatment systems that can be used to condition electrodeionization feed water.

● Reverse osmosis systems.

Reverse osmosis systems are frequently used to supplement EDI units in varying applications necessitating ultrapure water. As a matter of fact, we manufacture varying RO-EDI water systems for industrial and commercial applications. RO pretreatment systems shrink the TDS levels and extract varying microbial pollutants. In addition to elevating the quality of purified water produced, they shrink the production costs and prolong the electrodeionization unit’s life expectancy.

● Water softeners.

Water softener systems are mainly called upon when purifying moderately or extremely hard water. They expel minerals responsible for water hardness (calcium and magnesium) thereby decreasing the chances of scale accumulation. The most coveted water softeners are ion exchanger water softeners. They utilize the cation exchange filter to expel hardness ions, consequently swapping them with sodium (Na+) or potassium (K+) ions.

● Sediment filters.

The build-up of suspended solids on the ion exchange resins and membranes can lead to clogging, which can consequently lead to deteriorated flow rates and low-quality deionized water. This is often mitigated by employing sediment filters before the electrodeionization process. They seize colloidal particles, dust, microplastics, and virtually all floating solids. They also decrease the feed water’s turbidity.

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➣What is the Difference Between Electrodeionization Units and Water Deionizers?

Water deionizer systems are purification units that expel impurity ions from water using ion-exchange resins. EDI units also expel dissolved ions but they utilize ion exchange resins as well as ion-exchange membranes. Additionally, electrodeionization units are dependent on direct current whereas water deionizers are driven by chemical regenerants. Conventional deionizers are recharged with acidic regenerants (the cationic resins) and basic regenerants (the anionic resins). EDI units regenerate automatically using direct current.

The integration of ion exchange resins and membranes in EDI water systems makes them more effective than traditional deionizers. Water deionizer systems typically produce Type II deionized water while EDI units can generate ultra-pure water (at 18+ MΩ-cm). Electrodeionization water systems have recently been used to post-treat deionized water from dual-bed deionizers. The reliance on chemical regenerants by water deionizers can contribute to environmental pollution. On the contrary, electrodeionization units do not use chemicals and therefore do not discharge toxic waste into the environment.

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➣Do EDI Units Extract Carbon Dioxide (CO2)?

Yes. Ordinarily, carbon dioxide ionizes when it is in water. This makes it difficult to gauge its concentration using conductivity parameters and most water purification systems are incapable of eradicating CO2. This includes reverse osmosis systems. EDI water systems are however capable of extracting CO2 among other objectionable gasses from water.

Carbon dioxide and bicarbonate are eliminated through electrodeionization after easy ions such as sodium and calcium have been eliminated. Other objectionable elements that are considered difficult to eradicate but are removable by electrodeionization systems include boron, silica, and ammonia.

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