ioonivahetus

Ioonivahetus, or ion exchange, is a reversible chemical process by which ions are exchanged between a solid and a liquid. This process typically involves the use of ion-exchange resins, which are insoluble solid materials containing charged sites that can attract and bind ions of opposite charge from a surrounding solution. When the solution comes into contact with the resin, ions in the solution can bind to the charged sites on the resin, displacing ions that were previously bound to the resin. This exchange continues until equilibrium is reached or until the resin is saturated with ions from the solution.

The primary applications of ion exchange are in water purification and separation processes. For example, in water softening, calcium and magnesium ions, which cause hardness, are removed from water and replaced by sodium ions. In demineralization, all dissolved salts are removed from water by passing it through cation and anion exchange resins, resulting in highly purified water. Ion exchange is also used in chemical analysis, chromatography, and in the recovery of valuable metals from industrial waste streams. The effectiveness of ion exchange depends on factors such as the concentration of ions in the solution, the type of resin used, and the pH and temperature of the solution. The resin can be regenerated by treating it with a concentrated solution of the original ions, allowing for its reuse.