Types and uses of activated carbon

Granulated carbon – activated carbon's granules have irregular shape. These carbons are usually used for fluid purification, though sometimes granulated carbon with bigger grains is also used in purification of air, gases or as a reaction catalyst.

The most popular applications of granulated activated carbon are as follows:

• drinking water treatment in municipal water treatment stations (improvement in colour, flavour and smell, removal of pesticides and humus compounds),
• catalytic removal of chlorine and ozone residue,
• COD and AOX reduction in sewage treatment,
• removal of organic compounds (BTEX) in the process of water and soil remediation
• decolouring of food products (sugar, glucose)
• purification of paraffin and pharmaceutical glycerine

Extruded carbon – this carbon is in the form of rollers with their length a minimum double of their diameter. A filter bed with formed activated carbon provides smaller air resistance than a filler bed of the same height with granulated carbon. For this reason, this type of carbon is mostly used in filtration and ventilation of air and gases.

Its most important applications include:

• reduction of Volatile Organic Compounds (VOC)
• purification of post-process gases of all kinds of pollutants
• protection of the respiratory system
• air deodorization in e.g. waste reloading halls or sewage treatment plant rooms
• recovery of organic solvents
• purification of earth gas and biogas

Impregnated carbon – it is usually extruded carbon, which surface was covered with the appropriate chemical compound (preservative). Selection of the proper activated substance makes it possible to make use of the phenomenon of chemisorption to increase the effectiveness of the reaction. Impregnated carbons are used primarily in the catalytic removal of inorganic compounds from various types of gases. The most popular applications of impregnated carbons include:

• deodorization of air to remove odorants, such as H2S or NH3
• removal of inorganic contaminations from reactivated gases
• purification of biogas to remove hydrogen sulphide
• purification of earth gas to remove mercury

Powdered carbon – this activated carbon's granules have the size of a hundreth fraction of a milimeter after grinding. The use of this type of activated carbon usually requires special dispensing systems. Powdered carbon is used to:

• purify drinking water (surface water in the periods of blooms or the underground reduction of humus compounds)
• removal of organic compounds (such as the type COD or AOX) in sewage treatment
• enrichment of the activated sediment
• decolourisation of chemical and food products
• removal of dioxins, furans and mercury from gases generated during thermal waste treatment

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