Mixed Bed Resin is a type of ion exchange resin used primarily in water purification systems to produce high-purity or ultrapure water. Here’s a breakdown of what it is and how it works:

Mixed bed resin is a combination of cation and anion exchange resins in a single vessel or cartridge. These resins are physically mixed together in a specific ratio (typically 1:1 by volume) and work together to remove all ionic contaminants from water.

• Cation Exchange Resin: Removes positively charged ions (e.g., calcium, magnesium, sodium).

• Anion Exchange Resin: Removes negatively charged ions (e.g., chloride, sulfate, nitrate).

Brands: G-ion

Model: GER-8710 & GMB-8415

Origin: USA

CleanTech Engineering Limited

How It Works

When water passes through a mixed bed resin:

1. The cation resin exchanges hydrogen ions (H⁺) for cations in the water.

2. The anion resin exchanges hydroxide ions (OH⁻) for anions in the water.

3. The H⁺ and OH⁻ then combine to form pure water (H₂O).

Applications

• Final polishing in deionization systems (after reverse osmosis or two-bed ion exchange)

• Laboratories needing Type I ultrapure water

• Semiconductor and pharmaceutical manufacturing

• Aquariums (particularly reef tanks) for maintaining water quality

Regeneration

Mixed bed resins can be regenerated, but it’s a complex process:

• Requires separation of the cation and anion resins before regenerating each type with acid (e.g., HCl) or base (e.g., NaOH).

• Most users replace mixed bed cartridges instead of regenerating them due to difficulty and contamination risks.

Advantages

• Produces very high-purity water (resistivity up to 18.2 MΩ·cm)

• Compact and efficient

• Ideal for polishing stages

Disadvantages

• Expensive compared to two-bed systems

• Requires careful handling to avoid fouling

• Difficult to regenerate without specialized equipment