What does adsorption refer to in the context of water treatment?

Adsorption in the context of water treatment refers specifically to the process where contaminants adhere to the surface of an adsorbent material. This is a crucial mechanism used to remove various impurities, including organic compounds, metals, and other pollutants, from water.

In this process, the adsorbent typically has a high surface area and is often made from materials like activated carbon, which allows for effective binding and retention of contaminants. As water passes over or through the adsorbent, the molecules of the contaminants are attracted to and held on the surface of the adsorbent. This is different from absorption, where a substance is taken into the volume of another material.

The importance of adsorption lies in its ability to significantly reduce concentrations of undesirable substances in water, thus improving water quality. Effective water treatment systems often incorporate adsorption as part of their overall strategy to ensure safe drinking water and to comply with health regulations.