Activated carbon is a generic term for carbon materials such as wood, coal and petroleum coke through pyrolysis and activation processing. It has a developed pore structure, a large specific surface area, rich surface chemical groups, and strong specific adsorption capacity. It is usually powdery or granular porous amorphous carbon with strong adsorption capacity. Solid carbonaceous materials (such as coal, wood, hard shell, fruit core, resin, etc.) are carbonized at 600 to 900 ℃ under isolated air conditions, and then oxidized and activated with air, carbon dioxide, water vapor or a mixture of the three at 400-900 ℃.