Powdered activated carbon (PAC) is a carbonaceous material with a high specific surface area and strong adsorption capacity. It is widely used in water treatment, air purification, and industrial pollution control. Its preparation method and performance optimization have a significant impact on its practical application.
The main preparation methods for PAC include physical activation, chemical activation, and a combination of both. Physical activation typically uses water vapor, carbon dioxide, or air as an activator to pyrolyze and activate the carbon precursor at high temperatures (800–1000°C), forming a well-developed porous structure. This method is simple, but the activation time is long and the product's adsorption performance is relatively limited. Chemical activation uses chemical reagents such as phosphoric acid, potassium hydroxide, or zinc chloride to react with the carbon precursor at lower temperatures (400–700°C), etching the carbon precursor to form a rich microporous and mesoporous structure. The activated carbon produced by this method has a high specific surface area and strong adsorption capacity, but chemical residues may affect its safety. In recent years, the combined activation method has combined the advantages of physical and chemical activation, optimizing pore distribution through step-by-step treatment, further enhancing the overall performance of activated carbon.
In terms of application, powdered activated carbon is primarily used to remove organic pollutants, odors, and pigments from water, demonstrating its rapid emergency response capabilities in sudden water pollution incidents. It also plays an important role in waste gas purification, purification of pharmaceutical intermediates, and decolorization in the food industry.
In the future, powdered activated carbon production technology will develop towards greener and more efficient methods. By improving activation processes and developing new precursors, its adsorption performance will be further enhanced and production costs will be reduced to meet increasingly stringent environmental protection requirements.