We supply ion exchange resin equipment for various water treatment processes, such as demineralization, denitrification, decarbonation, or decalcification, among others.
Removal of dissolved ions in water using ion exchange resins is an effective and widely used process in the field of water purification. These resins, which are in the form of small solid particles, have the ability to exchange ions present in the water for other ions of similar charge that are bound to them.
The principle of ion exchange is based on the electrostatic attraction between the dissolved ions in water and the functional groups present in the resins. During the treatment process, undesirable ions, such as heavy metals, hardness ions (calcium, magnesium), and other contaminants, are trapped by the ion exchange resins, while the desired ions remain in the treated water.
As the resins become filled with unwanted ions, their exchange capacity decreases, and it is necessary to regenerate them to restore their adsorption capacity. Regeneration is carried out using regenerants, which are specific chemical substances designed to release the trapped ions in the resins and replace them with ions from the regenerating solution.
Regeneration can be performed using various methods, such as washing with acidic or alkaline solutions, depending on the nature of the ions and resins used. Once regenerated, the resins are ready for a new cycle of treatment and removal of dissolved ions.
Ion exchange resins are synthetic materials, usually spheres of 0.5-1 mm of diameter, designed for industrial wastewater treatment. These are formed by a polymer matrix to which have been attached a large amount of radicals of cation or anion, acid or base. When water passes through, the resin retains the water ions (sodium, chlorine, calcium, magnesium, etc.) and gives back an equal amount of protons or hydroxyls.
Ion exchange resins can be of the following type:
- Strong acid cation resins: they remove cations exchanging sodiums or protons.
- Weak acid cation resins: they remove cations related to bicarbonates.
- Strong base anion resins: they remove all anions. Used to eliminate carbonates and silicates.
- Weak base anion resins: they eliminate strong acid anoins (sulfates, nitrates and chlorides) with high efficiency.
When an ion exchange resin exhausts its ability to exchange ions, it can fully recover its original exchange ability by means of a regenerating solution. The column regeneration is achieved by making a solution of the original ion pass through the resin. The ion bonds with the resin radicals and displaces the captured ions during normal operation. Common salt, hydrochloric or sulfuric acid, or caustic soda are usually used for resin regeneration based on the column type.