Which is stronger physically or chemically

Chemical and physical processes for wastewater treatment

Ion exchangers are materials that can be used to replace ions in a solution with other ions. For example, calcium ions are exchanged for sodium ions with a cation exchanger. When this ion exchanger is exhausted, i.e. completely saturated with calcium ions, it must be regenerated.

This method works because ions are bound more strongly to the ion exchanger, the higher their charge and, with the same charge, the larger their ionic radius. The stronger binding ion displaces the weaker binding one.

Ion exchangers are suitable for the targeted removal of heavy metals and anions. They are therefore often used as "police filters" after precipitation / flocculation. They are also used for softening, salinization and desalination of water. This is particularly important in the semiconductor industry, where they are used to produce extremely clean demineralized water, the so-called ultrapure water.

Ion exchangers are also used in the treatment of waste water from galvanic coating systems that contain metal ions, or for the purification of phenol-containing waste water from the chemical industry. Both the metal ions and the phenols can be recovered.