Views: 0 Author: Site Editor Publish Time: 2024-04-09 Origin: Site
Activated carbon filters are porous materials, typically made from carbon-rich sources like coconut shells, wood, or specific grades of high-quality coal. What sets them apart is their activation process, which creates a vast network of pores and increases their surface area, enabling them to adsorb a wide range of contaminants effectively. This activation process involves subjecting the carbon to high temperatures and steam, in an oxygen-free environment, resulting in a structure with millions of microscopic pores.
The effectiveness of activated carbon filters stems from their porous structure and adsorption capabilities. The porous nature provides a large surface area for contaminants to adhere to, essentially trapping them within the carbon matrix. Activated carbon exhibits a particularly high affinity towards organic molecules, thanks to its chemical composition, further enhancing its adsorption capacity.
The primary mechanism by which activated carbon filters work is adsorption. Adsorption is the adhesion of molecules from a gas, liquid, or dissolved solid to a surface, in this case, the surface of the activated carbon. The activated carbon’s high surface area and porous structure allow it to trap and hold impurities within its pores as water, air or certain gases pass through.
In addition to adsorption, activated carbon filters can also facilitate chemical reactions, using carbons that have been impregnated with carefully selected functional chemicals. Certain contaminants, particularly inorganic species such as hydrogen sulfide (H2S) and ammonia (NH3), may undergo chemical reactions with the modified carbon surface, leading to their removal or transformation into less harmful substances.
Activated carbon filters may also physically trap larger particles suspended in water or air, although this is not their primary function. Activated carbon is generally used as a ‘polishing’ step to remove chemical impurities at a molecular level, once larger particles have been removed by other physical filtration technologies.