The so-called adsorption method is a process that uses porous solids to treat fluid mixtures so that one or several components are concentrated on the surface of the porous solids and separated from other components. The substance adsorbed to the solid surface is called adsorbate, and the porous solid is called adsorbent. Since the adsorption process can effectively collect pollutants with very low concentrations, the adsorption method is widely used in pollution prevention and control, such as the recovery and purification of organic solvents, deodorization of air conditioners, etc.

According to the nature of the adsorption force that occurs between adsorbents, adsorption can generally be divided into physical adsorption and chemical adsorption.