Activated carbon is a black porous solid carbonaceous material produced from coal by crushing, shaping, or carbonizing and activating uniform coal particles. The main component is carbon, and it contains small amounts of oxygen, hydrogen, sulfur, nitrogen, chlorine and other elements. The specific surface area of ordinary activated carbon is between 500 and 1700 m ²/g. It has strong adsorption performance and is a widely used industrial adsorbent.