Which process is most commonly associated with demineralization of water?

Reverse osmosis is a membrane filtration process that effectively removes ions, molecules, and larger particles from water by applying pressure to the water on one side of a semipermeable membrane. This process is specifically designed to separate contaminants from water, including dissolved salts and minerals, which are responsible for the hardness of water.

During reverse osmosis, only water molecules can pass through the membrane, while impurities are retained and flushed away. This makes it the preferred method for demineralization, as it can achieve a high level of purity by significantly reducing the concentration of dissolved minerals and other substances in water.

In contrast, chlorination primarily serves the purpose of disinfection, not demineralization. Filtration can remove larger particles but is not effective for dissolved minerals. Coagulation involves the aggregation of particles in water and is used to remove suspended solids rather than to demineralize. Thus, reverse osmosis is the process most commonly associated with demineralization of water.