Activated carbon is a special treatment of carbon, with numerous small pores, a large surface area, the surface area per gram of activated carbon 500-1500m2. Activated carbon has a strong physical adsorption and chemical adsorption function, but also has the role of detoxification. Detoxification is the use of its huge area, the poison adsorbed on the activated carbon in the micro pores, so as to prevent the absorption of poison. At the same time, activated carbon can be combined with a variety of chemical substances, thereby preventing the absorption of these substances. Activated carbon adsorption is the adsorption of one or more substances on the surface of the activated carbon to achieve the purpose of purifying water quality.

 Factors affecting the adsorption of activated carbon: adsorption capacity and adsorption rate is a measure of the main indicators of the adsorption process. The size of the adsorption capacity is measured by the adsorption capacity, and the adsorption rate is the mass of the adsorbent in the unit time. In the process of water treatment, the adsorption rate determines the need of sewage and the contact time of the adsorbent. The adsorption capacity of activated carbon is related to the pore size and structure of activated carbon. Generally speaking, the smaller the particle, the faster the pore diffusion rate is, the stronger the adsorption ability of activated carbon is. The pH value and the temperature of wastewater have an effect on the adsorption of activated carbon. Activated carbon generally has a higher adsorption capacity than under alkaline conditions. The adsorption reaction is usually exothermic reaction, so the temperature is low and the adsorption reaction is favorable. Of course, the adsorption capacity of activated carbon is related to the concentration of sewage. At a certain temperature, the adsorption capacity of activated carbon increases with the increase of the concentration of adsorbed species.
Activated carbon filter material is the most important, the most used of the adsorption material (other adsorption materials as well as: neutral macroporous resin, macroporous anion resin, molecular sieve, diatomite, etc.). Activated carbon is made of coconut shell, shell as raw material, through carbonization of braised furnace), activation in the processes of SERP furnace of 800 DEG C high temperature water vapor activation), crushing, screening, winnowing, washing, drying, and so on to. As early as 1930s, people used activated carbon adsorption of phenol from coking plant wastewater, therefore, the application of activated carbon in water treatment has been nearly eighty years of history. Recorded in the United Kingdom in 1862 using activated carbon to purify drinking water. In our country, the earliest net water is also a kind of water purification material with activated carbon. It can be said that since the birth of the water purifier, water purification and activated carbon have been inseparable, inextricably involved. Activated carbon filter can remove the water smell and taste, color, chlorine, colloid, organic matter (synthetic detergents, pesticides, herbicides, pesticides, synthetic dyes, three halogen methane, haloacetic acids, endocrine disrupting chemicals (EDCs) such as o phthalic acid esters PAEs, etc.), heavy metal, such as mercury, silver, cadmium, chromium, lead, nickel, etc., radioactive material is net water use the earliest and most extensive practical water purification materials.