The main adsorption principle of activated carbon (working principle):
The surface of activated carbon has adsorption effect. Adsorption can be regarded as a surface phenomenon, so adsorption is closely related to the surface properties of activated carbon. Activated carbon has a huge internal surface and pore distribution. The role of its external surface area and surface oxidation state is small, and the external surface is to provide many channels that communicate with the internal cavities. The main role of surface oxides is to make the hydrophobic carbon framework hydrophilic, giving activated carbon an affinity for many polar and non-polar compounds. Activated carbon has surface energy, and its adsorption is caused by the unbalanced force on the carbon atoms constituting the surface of the pore wall, resulting in surface adsorption.
Activated carbon is an ideal adsorbent for water and wastewater treatment. Because the regeneration problem of activated carbon has been satisfactorily solved, and the manufacturing cost of activated carbon has also been reduced, activated carbon adsorption technology is gradually popularized and used at home and abroad. The most used ones are tertiary wastewater treatment and water supply deodorization. Internationally, activated carbon adsorption is an effective means of water purification. The use of activated carbon for carbon disulfide wastewater treatment and granular activated carbon for industrial wastewater treatment has developed rapidly in terms of technology, application scope and treatment scale. In the treatment of oil refining wastewater, explosives wastewater, printing and dyeing wastewater, chemical wastewater, electroplating wastewater, etc., it has formed a large-scale application in production, and achieved satisfactory results.
Activated carbon is used in wastewater treatment:
Activated carbon has different forms, and currently it is still mainly granular and powdery in water treatment. Powdered activated carbon is used for intermittent adsorption, that is, according to a certain proportion, powdered carbon is added to the water to be treated, mixed evenly, and the carbon and water are separated by precipitation or filtration. This method is also called static adsorption; granular activated carbon is used for For continuous adsorption, the treated water passes through the carbon adsorption bed to purify the water. This method is exactly the same as the fixed bed in form, and is also called dynamic adsorption. There are many substances that can be adsorbed by activated carbon, including organic or inorganic, ionic or non-ionic. In addition, the surface of activated carbon can also play a catalytic role, so it can be used in many different occasions.