How does activated carbon function in water treatment?

Activated carbon primarily functions in water treatment through a process called adsorption. This is a surface phenomenon where contaminants, such as organic compounds, solvents, and certain heavy metals, adhere to the surface of the activated carbon particles.

Activated carbon has a high surface area and a porous structure, which allows it to trap a significant amount of pollutants effectively. As water passes through a bed of activated carbon, the contaminants in the water are attracted to and held on the surface of the carbon particles, thus removing them from the water. This is particularly effective for removing taste and odor compounds, as well as certain chemicals, making activated carbon an essential component in many water treatment processes.

While the terms absorption and adsorption are sometimes confused, they refer to different processes. Absorption involves a substance being taken up into the bulk of another material, while adsorption refers to a substance adhering to the surface of another. Filtration is a different mechanism that typically involves separating particulates from liquids or gases, while desorption is the process by which a substance is removed from a surface. In the context of water treatment, it is crucial to understand that activated carbon's effectiveness stems from its adsorption properties.