Chelating resin and adsorption Resin: Principles, Applications and Differences

Resin adsorption technology plays a significant role in fields such as environmental protection water treatment, organic waste gas (VOCs) control, and hydrometallurgy. Among them, chelating resin and adsorption resin are two common types of polymer functional materials, but there are significant differences in their structures, mechanisms of action and application scenarios.

Chelating resin

Chelating resin is a functionalized polymer material, whose surface or interior contains coordination groups (such as amino groups, carboxyl groups, thiol groups, etc.) that can form stable chelates with specific metal ions. It selectively adsorbs target ions through chemical bond bonding and is suitable for highly selective metal separation and recovery.

Typical functional groups:

Iminodiacetic acid (IDA)

Ethylenediaminetetraacetic acid (EDTA)

· thiourea group

· 8-hydroxyquinoline group

· meglumine

· Amoxime

Adsorption resin

Adsorption resin is a kind of physical adsorption material, featuring a high specific surface area and well-developed pore structure. It adsorbs organic substances (such as pigments, antibiotics, natural products, etc.) by means of van der Waals forces, hydrogen bonds or π-π interactions. Its adsorption process is mainly based on physical action and usually does not involve chemical reactions.

Typical classification

·Non-polar resins (such as styrene-divinylbenzene copolymer)

· Weakly polar resin

·Polar resins (containing hydroxyl groups, amide groups, etc.)

The application of chelating resin

Heavy metal wastewater treatment: Selective adsorption of Cu²⁺, Pb²⁺, Ni²⁺, etc. in electroplating wastewater.

Precious metal recycling: Enrichment of gold, platinum, palladium, etc. from electronic waste and mining.

Nuclear industry: Separation of radioactive elements such as uranium and thorium.

The application of adsorption resin

Pharmaceutical industry: Extraction of effective components of traditional Chinese medicine (such as ginkgo biloba flavonoids, ginsenosides).

In the field of environmental protection: It is mainly applied to wastewater treatment in industries such as petrochemicals, coal chemicals, fine chemicals (dyes, pesticides, pharmaceuticals), electroplating, and electronics.

Summary

Although chelating resins and adsorption resins both belong to functional resins, their principles and applications are quite different. Understanding their differences is helpful for optimizing processes and improving efficiency in fields such as wastewater treatment, resource recovery, and pharmaceuticals. In the future, with the advancement of materials science, the performance of these two types of resins will be further expanded, providing more possibilities for industrial separation.