In a zeolite softening unit, calcium and magnesium ions are replaced with which ions?

In a zeolite softening unit, the primary function is to remove hardness-causing ions, specifically calcium and magnesium, from water. This is achieved through a process known as ion exchange. In this system, the zeolite material contains sodium ions, which are released into the water in exchange for the calcium and magnesium ions present.

When hard water passes through the zeolite, the sodium ions in the zeolite beads swap places with the calcium and magnesium ions in the water. As a result, the water becomes softer—meaning it has less hardness—since the initial hardness-causing minerals have been effectively removed from the water supply. This process helps to prevent scale build-up in plumbing and appliances, improving water quality and extending the life of water-using fixtures. The focus on sodium ions is crucial in this context, as they are the ions that facilitate the ion exchange process leading to softening of the water.