Anion-exchange resin

Anion-exchange resin is a type of ion-exchange resin that is used to exchange negatively charged ions, or anions, in a solution. This process is commonly used in water purification and water softening applications, as well as in the chemical and pharmaceutical industries.

Overview

Anion-exchange resins are made from an organic polymer substrate. The tiny beads of resin are typically made from a substance such as polystyrene, which is then cross-linked with another chemical. The resulting structure has negatively charged sites that attract and hold onto positively charged ions (anions) in the solution that is passed over the resin.

Applications

Anion-exchange resins are used in a variety of applications. In water treatment, they are used to remove negatively charged ions such as chloride, nitrate, and sulfate from water. This can help to soften hard water and to purify drinking water.

In the chemical and pharmaceutical industries, anion-exchange resins are used in processes such as chromatography, where they can help to separate different substances in a mixture. They are also used in the production of some types of drugs, where they can help to remove unwanted substances from the final product.

Types of Anion-Exchange Resins

There are two main types of anion-exchange resins: strong base and weak base.

Strong base resins can exchange all anions, including hydroxide, and are often used in water treatment.

Weak base resins can only exchange certain anions, such as carbonate and bicarbonate, and are often used in the chemical industry.

See Also

• Cation-exchange resin
• Ion-exchange chromatography
• Water treatment