Activated carbon is a great surface area, porous carbon structure. Classification of raw materials can be divided according to their coal activated carbon, wood charcoal, husk charcoal and bone charcoal; charcoal column can be divided according to their shape, crushed charcoal, activated carbon fibers and carbon powder. The main raw material of activated carbon coal, wood, shell and other carbon-rich organic material, formed by the activation of complex pore structure adsorption capacity. 20000nm pore radius greater than the large hole in the hole between 150-20000nm is less than 150nm of micropores. Activated carbon adsorption occurs mainly in these voids and surface, activated carbon pore walls of a large number of molecules can produce strong gravitational water and impurities in the air to attract the pores.
Activated carbon adsorption can be divided into physical adsorption and chemisorption. Physical adsorption occurs mainly in the pores of the activated carbon-rich, for the removal of water and impurities in the air, the molecules of these impurities must be less than the diameter of the activated carbon pore size. Different raw materials and processing technology resulting in a different activated carbon pore structure, specific surface area and pore size, suitable for different needs. Activated carbon not only contain carbon, and containing functional groups on its surface with adsorbed substances react chemically with the adsorbed species so often it occurs in the activated carbon surface. The medium of impurities by physical adsorption and chemisorption continuously into the porous structure of activated carbon, the activated carbon adsorption saturation adsorption effect is reduced. Activated carbon adsorption saturation needs to be activated after regeneration to restore its adsorption capacity reused. Activated carbon adsorption performance evaluation of the main values of methylene blue, iodine and caramel adsorption, etc., the greater the adsorption capacity, adsorption better.
Activated carbon can be used in air and water purification, wastewater treatment, used to separate air and water or collect impurities in the medium. Granular activated carbon and carbon powder same effect, it can be used for water treatment. Granular activated carbon loss is not easy, repeated use of renewable, for less pollution, water treatment process should run continuously. Powdered Activated Carbon difficult recovery, usually for a single use, for more serious contamination intermittent water treatment process. Granule activated carbon for water treatment in general and micro hole developed, should meet the three requirements: a large adsorption capacity, absorption speed, good mechanical strength. In addition to the requirements of powdered activated carbon with the above features, the smaller the particle size the better the adsorption.
Activated carbon filter for the water treatment in the advanced treatment process, can effectively remove the water color, odor odors and dissolved organic pollutants, improve water quality. Granular activated carbon in the course of regular backwashing according to raw water quality conditions. Water will generally take the form of six days backwash once the recoil strength required to achieve more than 30% of filter expansion. Mainly in the new carbon-based physical and chemical adsorption, after a certain time the carbon surface biofilm formation, places biodegradation based. When the index evaluation activated carbon adsorption effect is reduced to the following standards or some pollutant index penetrate the carbon bed when it must be replaced or regenerated. Need to soak 24 to 48 hours when using a new carbon, should be carried out after backwashing to remove the residual tar and carbon powder activated carbon and other impurities. Backwash frequency and drainage turbidity can be determined based on the use of treated water, water treatment activated carbon backwash effluent turbidity can generally be controlled at 2-5NTU.
Powdered activated carbon treatment water burst smell, aspect of industrial pollutants have good application in the use of powdered charcoal, adsorption tests must be carried out according to the type and concentration of contaminants to be removed in order to determine the type of activated carbon and the required amount of carbon powder . Before adding powdered charcoal, attention should first be made uniform toner CIP quantitative added water, the longer the contact time, the better the decontamination effect. In the process of using carbon powders should be aware of the following safety issues; in case of fire when dust concentration reaches a certain proportion of explosive occurs, it operated from smoking, sparks and open flames; mix with oxidants should be avoided; small particles of the powder carbon, light, shall be noted in dust pollution, the operator shall be equipped with a dust mask to avoid inhalation of the lungs.