What is the term for the process of removing dissolved ions from water?

The process of removing dissolved ions from water is best described by reverse osmosis. This method utilizes a semi-permeable membrane that allows water molecules to pass through while blocking a significant percentage of dissolved ions and larger molecules. As pressure is applied to the water on one side of the membrane, the water moves towards the area of lower concentration, effectively filtering out impurities, including salts and other ions.

In comparison, flocculation involves the agglomeration of particles into a floc, which is a larger mass that can then be removed from water but does not target dissolved ions specifically. Coagulation is the addition of chemicals to destabilize colloidal particles so they can agglomerate and settle but similarly does not directly remove dissolved ions. Clarification is the process of settling and removing suspended particles from water, which mainly focuses on larger solids, rather than dissolved ions. Thus, the most precise term for the removal of dissolved ions is reverse osmosis.