What Is EDT Water Treatment System
The EDI water treatment system is an advanced, continuous deionization technology used to produce high-purity water by removing dissolved ions (salts, minerals, and other charged particles) from water without the need for chemical regeneration (unlike traditional ion exchange systems). It is widely used in industries requiring ultra-pure water, such as electronics manufacturing, pharmaceuticals, power generation, and laboratory applications.
How Does EDI Systems Work
EDI combines ion exchange resin, electrochemical processes, and membrane separation into a single, automated system. Here's a step-by-step breakdown of how it works:
1. Water Feed & Pre-Treatment
* EDI requires pre-treated feedwater (typically reverse osmosis (RO) permeate, with a conductivity of <50 µS/cm). This pre-treatment removes suspended solids, organic matter, and most dissolved ions to protect the EDI modules.
* Feedwater flows into the EDI stack-a modular unit consisting of alternating cation-exchange membranes, anion-exchange membranes, and ion exchange resin-filled compartments.
2. Ion Capture by Resin
* Inside each compartment, mixed cation and anion exchange resins capture dissolved ions (e.g., Ca²⁺, Mg²⁺, Na⁺, Cl⁻, SO₄²⁻) from the water, producing high-purity water in the process.
* Unlike conventional ion exchange systems, EDI does not require periodic chemical flushing (with acids/alkalis) to regenerate the resin.
3. Electrochemical Regeneration
* An electric field is applied across the EDI stack via electrodes at both ends (anode and cathode).
* This electric field splits water molecules into H⁺ (hydrogen ions) and OH⁻ (hydroxide ions). These ions continuously regenerate the resin:
H⁺ replaces captured cationic contaminants (e.g., Na⁺, Ca²⁺) on the cation resin.
OH⁻ replaces captured anionic contaminants (e.g., Cl⁻, SO₄²⁻) on the anion resin.
* The displaced contaminants (ions) are driven by the electric field toward the concentrate compartments (separated by ion-exchange membranes).
4. Water Separation
* The EDI stack produces two streams of water:
Product Water: The deionized, high-purity water (conductivity as low as 0.06 µS/cm, approaching theoretical pure water) that exits the system for use.
Concentrate Water: A small stream (5–15% of feedwater) carrying the removed ions. This stream is either discharged or recycled back to the pre-treatment system (e.g., RO feed).
* A tiny portion of the water is also directed to the electrode chambers to cool the electrodes and carry away any byproducts (e.g., chlorine, oxygen) generated during electrolysis.
Technical Data of EDI Water Treatment System
|
Module Number |
Nominal Flo (m3/h) |
Flow Range (m3/h) |
DC Voltage (V) |
DC Current (A) |
Transport Weight (KG) |
|
CY05 |
0.44 |
0.22-0.67 |
0-55 |
0-5 |
55 |
|
CY10 |
1 |
0.55-1.65 |
0-135 |
0-5 |
71 |
|
CY20 |
2 |
1.0-3.1 |
0-240 |
0-5 |
94 |
|
CY30 |
3.3 |
1.7-5.1 |
0-320 |
0-5 |
124 |
|
CY50 |
5 |
2.55-7.7 |
0-400 |
0-5 |
170 |
Key Components of EDI Water Treatment System
| Component | Function |
| EDI Stack | The core module consists of ion-exchange membranes, resin-filled compartments, and electrodes. |
| Power Supply | Provides a controlled DC voltage to drive the electrochemical regeneration process. |
| Feed Pump | Delivers pre-treated feedwater to the EDI stack at a steady flow rate and pressure. |
| Flow & Conductivity Sensors | Monitor feedwater, product water, and concentrate water quality/flow rates to ensure system stability. |
| Control Panel | Automates system operation, adjusts parameters (e.g., voltage, flow), and alerts for maintenance issues. |
Benefits of EDI Water Treatment System
1. Continuous, Chemical-Free Operation
* No need for acid/alkali regeneration (unlike traditional ion exchange), which eliminates chemical handling costs, safety risks, and wastewater disposal issues.
* Runs 24/7 without downtime for resin regeneration.
2. High Purity & Stable Quality
* Produces ultra-pure water with consistent conductivity (0.06–1 µS/cm) and low total dissolved solids (TDS <0.1 ppm).
* Superior to standalone RO systems for applications requiring the highest water purity.
3. Low Operating Costs
* Minimal chemical and labor costs (no resin replacement or regeneration cycles).
* Low energy consumption compared to distillation systems (another ultra-pure water technology).
4. Compact Footprint
* Modular design takes up less space than traditional ion exchange systems, making it suitable for both industrial and laboratory settings.
Typical Applications
The EDI water treatment system is widely used in industries requiring ultra-pure water, such as electronics manufacturing, pharmaceuticals, power generation, and laboratory applications.
* Electronics Manufacturing: Producing ultra-pure water for semiconductor wafer cleaning, LCD panel production, and battery manufacturing.
* Pharmaceuticals: Purifying water for drug formulation, injection, and cleanroom operations (meets USP, EP, and FDA standards).
* Power Generation: Supplying high-purity water for boiler feedwater (prevents scale buildup and corrosion in turbines).
* Laboratories: Generating reagent-grade water for analytical instruments (e.g., HPLC, mass spectrometry).
* Food & Beverage: Producing pure water for beverage production, bottled water, and food processing.
