What is Activated Carbon
Activated Carbon is purified, powdered Carbon treated physically or chemically to generate micro-fissures that vastly increase its surface area for adsorption & chemical reactions.
Purified carbon is activated by a carefully controlled oxidation process to develop a porous carbon structure….an imperfect structure that results in a high degree of porosity over a broad range of pore sizes, from visible cracks and crevices to gaps and voids of molecular dimensions. The specified structure of carbon gives it a very large surface area which allows the carbon to adsorb a wide range of compounds.
Produced from carbonaceous source materials – coconuts, nutshells, coal, peat & wood – Activated carbon has the highest volume of adsorbing porosity of any material available to mankind. Activated Carbon has garnered global importance due to its applications infiltration & purification process
Activated carbon is an invaluable tool in environmental sustainability & recovery applications.
Properties of Activated Carbon
The process of activated carbon generation begins with the selection of a raw carbon source. These sources are selected based on design specifications since different raw sources will produce activated carbon with different properties. Some of the more common raw sources include wood, sawdust, lignite, peat, coal, coconut shells, and petroleum residues.
Characteristics of importance in choosing carbon types include pore structure, particle size, total surface area and void space between particles. After selection of a source, preparations for use are made. These preparations most often include dehydration, carbonization, and activation. Dehydration and carbonization involve slow heating of the source in anaerobic conditions.
Chemicals such as zinc chloride or phosphoric acid can be used to enhance these processes. The stage of activation requires exposure to additional chemicals or other oxidizing agents such as a mixture of gases. Depending upon the specifics of the process and the source carbon, the newly activated carbon can be classified according to density, hardness, and other characteristics.
Another important characteristic of activated carbon is the isotherm or breakpoint characteristic for each particular type. This is most often determined by modeling, testing, cost analysis, and pilot studies. The pilot studies ensure that the chosen carbon type effectively removes the desired substances for the particular raw water source and allows the plant to reach desired levels of quality before treatment continues. Once a breakpoint of a particular carbon has been determined the plant operators know approximately how long the carbon will effectively function. As this time approaches the carbon must be changed to ensure adequate removal.
How ADSORPTION works?
Adsorption is the capability of solid substances (called Adsorbents) to attract to their surfaces, molecules of gases or solutions (called Adsorbate) with which they are in contact.
Adsorption can be either physical or chemical in nature.
Physical Adsorption is the process by which activated carbon removes substances.