The terms “activated carbon” and “activated charcoal” often appear interchangeably, leading to confusion about whether they represent distinct materials. Both terms describe a versatile substance with widespread utility across various fields.
Are They the Same Substance?
“Activated carbon” and “activated charcoal” refer to the exact same material. The difference is semantic, often depending on context or industry. “Charcoal” denotes the initial carbon-rich raw material, such as wood or coconut shells, which is then processed to become “activated.” This activation transforms the basic charcoal into a highly effective adsorbent.
Understanding Activated Carbon’s Nature
Activated carbon begins as a carbonaceous source material, like wood or coconut shells, which undergoes carbonization. This involves heating the material in an oxygen-deprived environment (600–900 °C) to remove volatile components and yield a carbon-rich char. The char then undergoes an activation process to develop its unique properties.
Activation increases the material’s internal surface area and creates a network of tiny pores. Two primary methods exist: physical activation and chemical activation. Physical activation heats the char (800-1100 °C) in the presence of gases like steam or carbon dioxide, enlarging existing pores and creating new ones. Chemical activation involves impregnating the char with chemical agents, such as phosphoric acid, followed by heating (250–800 °C), which promotes a porous structure.
This highly porous structure is responsible for activated carbon’s adsorptive capabilities, where substances adhere to its surface. Adsorption occurs through weak intermolecular forces, known as Van der Waals forces, which attract molecules to the carbon’s vast internal surface. A single gram of activated carbon can possess a surface area exceeding 3,000 square meters, offering extensive sites for contaminants to bind. The specific pore sizes and distribution vary depending on the raw material and activation method, influencing which substances it can effectively adsorb.
Diverse Applications of Activated Carbon
Activated carbon’s adsorptive properties make it valuable across numerous applications. In water purification, it effectively removes chlorine, organic compounds, pesticides, and other impurities from drinking water, municipal wastewater, and industrial effluent. It also controls taste and odor in water treatment systems.
For air purification, activated carbon filters trap volatile organic compounds (VOCs), odors, and other gaseous pollutants in industrial and residential air purifiers. Its ability to adsorb airborne contaminants contributes to improved air quality.
In medical contexts, activated charcoal is used to treat oral poisonings and drug overdoses. Its porous structure binds toxins in the gastrointestinal tract, preventing their absorption. It also helps manage gastrointestinal issues like flatulence and diarrhea.
Industrially, activated carbon is used in various processes, including precious metal recovery (e.g., gold), chemical purification, and solvent recovery. It is also employed in the food and beverage industry for decolorization and purification of products such as sugar syrups, fruit juices, and alcoholic beverages.