As a special carbonaceous material, activated carbon is widely used in various fields such as environmental protection due to its developed pore structure, large specific surface area, good stability, strong adsorption capacity and excellent regenerative capacity. Emphasis is placed on the application of activated carbon adsorption technology in water treatment.

　　1. Physical and chemical properties of activated carbon

　　1.1 Activated Carbon (AC)

　　Activated carbon is a commonly used non-polar adsorbent with stable performance and corrosion resistance, so it is widely used. It is a general term for a carbon-based substance having adsorption properties. The carbon-containing organic substance is heated and carbonized to remove all volatile matter, and is activated by a medicine (such as ZnCl2 or the like) or water vapor to form a porous carbon structure adsorbent. Activated carbon is available in powdered or granular form, and granular activated carbon is used in industry.

　　Due to the difference of raw materials and preparation methods, the pore size distribution is different, generally divided into: carbon molecular sieve, pore size is below 10×10-10m; active coke, pore diameter is less than 20×10-10; activated carbon, pore diameter is below 50×10-10m .

　　1.2 Activated Carbon Fiber (ACF)

　　Activated carbon fiber is a new type of adsorption functional material. It is made of lignin, cellulose, phenolic fiber, polypropylene fiber, asphalt fiber, etc., and is carbonized and activated. Compared with activated carbon, it has a unique microporous structure, a higher outer surface and specific surface area, and a variety of functional groups. The average pore diameter is also smaller. It is obtained in the fields of wastewater, waste gas treatment and water purification by physical adsorption and physicochemical adsorption. Widely used.

　　The microporous volume of the fibrous activated carbon accounts for about 90% of the total pore volume, and the pore diameter of the pores is mostly about 1 nm, and there are no excessive pores and large pores. The specific surface area is generally from 600 to 1200 m 2 /g, and even up to 3000 m 2 /g. Activated carbon fiber desorption regeneration rate is fast, time is short, and its performance is unchanged, which is better than activated carbon. Like activated carbon, activated carbon fiber has no selectivity when adsorbed, and is mainly used for adsorbing organic pollutants, and is generally used for comprehensive wastewater treatment in refineries.