What is the function of an ion exchange unit?

An ion exchange unit serves the critical function of removing unwanted ions from water and replacing them with less harmful ones. This process is essential for water treatment in various applications, particularly in the preparation of feedwater for boilers, where the presence of certain ions can lead to scale formation, corrosion, or other operational issues.

In the ion exchange process, water is passed through a resin that is saturated with specific ions. As the water flows through, undesirable ions, such as calcium and magnesium (which contribute to hardness), are attracted to the resin and exchanged for more benign ions, typically sodium or hydrogen ions. This effectively lessens the water's hardness and improves its quality for subsequent uses. The ability to selectively remove ions makes ion exchange a valuable technique in water treatment.

The other options, while related to water treatment or quality, do not accurately describe the primary function of an ion exchange unit. Adding minerals to water or increasing the boiling point does not pertain to the ion exchange process, and measuring water quality is a different function that involves testing for various parameters rather than altering the chemical composition of the water itself.