Electrodeionization – EDI modules

Cost-effective, reliable, chemical-free high purity water technology with up to 18.2 MΩ∙cm resistivity

Electrodeionization is a highly cost-effective system that requires no chemicals for its operation and produces no hazardous waste. Therefore, EDI is the key technology to replace conventional mixed bed ion exchange, which requires onsite or offsite chemical regeneration.

MEGA is a global supplier of electrodeionization systems for high purity water used in many industries, which need to guarantee the operation time of EDI for many years before their replacement is required.

Advantages of MEGA Electrodeionization (EDI)

• Industrial application EDI modules capable of reaching 18.2 MΩ∙cm product water resistivity.
• Single installed EDI module MPure™ covers flow rates from 0.8 m³/h to 15 m³/h.
• Cost reduction by integrating modules into High Purity Water Systems – RALEX® HPWU with high flow rate up to 135 m³/h (2000 gpm) and beyond.
• Green technology with lower operating costs and high recovery.
• Easy and safe maintenance.
• Small footprint – suitable for operation inside containers.
• Continuous operation with no regeneration needs.
• Modularity and redundancy – cube-shaped modules offer different options of interconnection.
• Option for direct discharge of electrode stream.
• Compact, durable, long-lifetime patented design.

Industrial applications of MEGA continuous electrodeionization

MEGA continuous electrodeionization technology produces high resistivity water with low silica levels, making it attractive for various applications. MEGA EDI modules provide complete high purity production water for a wide range of industries such as:

• energy and heating industry – boiler feed water,
• oil & gas industry,
• petrochemical industry,
• chemical industry,
• microelectronics,
• food & beverage industry,
• pharmaceutical industry.

Electrodeionization process

Electrodeionization (EDI) is a continuous membrane process for water polishing driven by direct current where water passes between positive and negative electrodes. Space in the module is divided by ion exchange membranes and filled with ion exchange resins.

The electric field removes ions, salts, organic acids, and other charged substances from the water, as they pass through ion exchange membranes and resins in EDI modules.

EDI is used to produce high purity water and it is usually operated after pretreatment and reverse osmosis process.

How EDI works

Electrodeionization works under the direct current which removes ions from the water inside the EDI module.

Under the influence of an applied electrical potential, ions in the resin migrate towards their respective electrodes, through IX membranes and into the concentrate loop.

The cations in the diluate chamber move towards the cathode and pass through the cation membrane into a concentrate chamber. These cations are trapped there as they cannot pass the anion membrane. Anions move in the reverse direction towards the anode and are similarly trapped in the concentrate chamber.

Water splitting produces H+ and OH− ions providing continuous regeneration of the resin in the diluate chambers.

Impurity ions trapped in concentrate chambers by membranes, H+ and OH− combine again to produce H₂O.

EDI modules MPure™36, MPure™12, MPure™6

MEGA provides separate EDI modules which vary from different amounts of cell pairs. The MPure™ module produces 16 to 18 MΩ·cm product water quality at very high recovery. These modules are designed to replace mixed bed ion exchange at flow rates from 0.8 to 135 m³/h (3.7 to 2000 gpm) and beyond.

The advanced MPure™ stacks continuously produce high-resistivity water with low silica levels. Stacks can be interconnected to provide high-flow blocks. The robust design prevents both internal and external leaks. Extensive factory testing of each stack guarantees you will receive the stack in optimal condition, ready to plug in.

RALEX® HPWU - High Purity Water Unit by MEGA

MEGA continuous electrodeionization system HPWU is a simple and cost-effective solution based on the range of pre-engineered HPWU systems with MPure™ EDI. Stacks cover flow rates from 5 m³/h to 135 m³/h.

• Dimensions (L×W×H mm): 2 400 × 1 300 × 1 600 (one MPure™36 stack)
• Dimensions (L×W×H mm): 4 100 × 1 300 × 1 600 (three MPure™36 stacks)
• Dimensions (L×W×H mm): 4 800 × 1 500 × 2 600 (nine MPure™36 stacks)

Why choose MEGA high purity water units

• Reduced system manifolds and number of connections.
• Reduced system manufacturing costs.
• The most efficient, trouble-free DC rectifiers.
• Easy assembly and disassembly (victaulic coupling).
• Reliability.