If you’re like most people, you’re probably wondering what activated carbon is, and its application. Simply put, it is a processed form of carbon, which makes it extremely porous thereby increasing its surface area used for adsorbent or chemical reactions. This substance is commonly used to adsorb pollution and other contaminants. After reading this, you should have a better idea of what activated carbon is and how it works.

There are a couple of ways that activated carbon can be produced from substances such as wood, nutshells, or coal. One method involves a process called carbonization. In this process, carbon content is heated up to 600-900 °C, in an atmosphere of inert gases such as argon or nitrogen. Another method, called Oxidation, exposes the carbonized materials to oxidizing atmospheres such as oxygen, carbon dioxide, or steam, at temperatures between 600-1200 °C. Both techniques physically alter the structure of the molecules, which increase the surface area available for chemical reactions or adsorption.

Activated carbon can be created in a variety of different physical forms. Powdered activated carbon has a large surface area to volume ratio and is generally used in raw water intakes, rapid mix basins, clarifiers, and gravity filters. Granular activated carbon is larger than the powdered version and, consequently, has a smaller surface area to volume ratio. This substance is preferred in the adsorption of gases and vapors. Impregnated activated carbon products, which name stems from being “impregnated” by several types of inorganic substances (Al, Mn, Zn, Fe, Li, Ca), has been used in air pollution control in museums and galleries. While activated carbon may take many different physical forms, its application is still the same – to remove pollutants and other contaminates.

How does activated carbon work in purification? Let’s take the case of a Britta water filter that’s used to clean tap water in homes. When tap water passes through the filter, organic compounds are attracted to the activated carbon and the two substances chemically bond to one another. The pollutants never make it into your glass or sink because the molecules are too larges to pass through the pores in the filter.

Now, you should have a better idea of how activated carbon is produced, the physical forms it can take, its purpose, and how it works.  Look into activated charcoal as well.  For more information see this blog on activated carbon and  activated charcoal.