Activated carbon is a porous organic material characterised by a very large specific surface area. Because of this, it is capable of removing contaminants from water, air and gases. It is produced from various carbon-rich materials such as coal, wood chips, coconut shells, etc.

The activation of carbon-rich materials takes place through a thermochemical process at very high temperatures. This process creates a large internal surface area, making the activated carbon suitable for adsorbing a wide range of compounds. This activation method is the most commonly used technique in the industry.

Activated carbon is produced from various carbon-rich materials such as coal, wood chips, coconut shells, etc. Bio-based variants, such as coconut shells or fruit pits, are becoming increasingly important. Each raw material determines the pore structure of the activated carbon and thus its possible applications.

Adsorption is the process by which contaminants adhere to the surface of activated carbon. This occurs through physical forces or chemical bonds between the activated carbon and the contaminants. In this way, activated carbon effectively removes unwanted substances from water, air, and gases.

Activated carbon is available in various forms, such as powdered carbon, granular carbon, and pelletised (‘extruded’) carbon. Depending on the specific application, a different type of carbon may be selected to achieve optimal purification results.

The quality of activated carbon can be determined using parameters such as internal surface area (BET), iodine number, CTC value, hardness, and ash content. These values indicate the adsorption capacity of the activated carbon and help in selecting the right carbon for a specific application.

PFAS molecules are removed from contaminated water by activated carbon through hydrophobic and electrostatic interactions between the carbon and PFAS. Long-chain PFAS molecules are adsorbed more efficiently and better than short-chain PFAS, but activated carbon still ensures an optimal removal yield for both. A critical parameter in this process is that the activated carbon must have the correct pore structure.

Biogas, produced via anaerobic digestion or from landfill sites, contains H₂S and various volatile organic compounds (VOC). Activated carbon can remove these from the biogas, preventing corrosion in the installation, reducing emissions, and making biogas suitable for energy production. Special impregnated activated carbon types increase the efficiency of this purification process.

The pore size distribution maps the porosity of activated carbon and indicates which types of pores are present and in what proportion. This determines how efficiently activated carbon can capture specific contaminants. Micropores adsorb very small molecules, while mesopores adsorb larger ones and function as transport channels. A proper balance is essential for optimal adsorption.