What is the primary function of reverse osmosis in water purification?

The primary function of reverse osmosis in water purification is to remove large particles and impurities using a semipermeable membrane. This technology involves forcing water through a membrane that allows only water molecules to pass while blocking larger contaminants such as salts, bacteria, and various other impurities. As a result, the treated water is significantly purer, which is especially important in providing safe drinking water.

The semipermeable membrane is a key component, as it selectively allows water to transfer while excluding unwanted substances, achieving a high level of purification. This makes reverse osmosis particularly effective for removing dissolved solids and contaminants that are not easily filtered out through conventional methods.

In contrast, other options focus on different processes that do not align with the primary role of reverse osmosis. Adding chemicals for taste does not pertain to the purifying function that reverse osmosis serves, nor does aeration or heating serve the same filtration purpose.