Activated carbon can be derived from many different and cheap sources. The production process consists of carbonization and activation. In carbonization, the process is subjected to high temperatures at predetermined time intervals. The carbonized product is combined with activating agent at specific impregnation ratio and heated to moderate temperature. The resulting activated carbon develop high physical properties and surface characteristics of pore size, pore size distribution, total pore volume, surface area, iodine value and enriched carbon content with high density. These properties of activated carbon depend on factors of activating agent, method of activation, impregnation ratio, temperature of activation and type of starting material. The activated carbon has wide applications in domestic, commercial, industrial and medical settings to the utmost benefit of mankind.
Activated carbon (AC) is one of the most attractive adsorbent which has a wide area of applications. The useful properties of AC have been known since ancient times. In about 1500 B.C, the Egyptians used charcoal as an adsorbent for medical purposes and as a purifying agent, likewise the Hindus societies who purified their water by filtration through charcoal [Echegi, 2013]. In the early 1900s, many plants that use AC as the decolourizing agent emerged in some parts of Europe, and around 20th century, the first plant to produce AC industrially was built for use in sugar refining industry in Germany. During World War I, AC was used in gas masks for the protection against hazardous gases and vapours.
Today, activated carbons are used to remove colour and other impurities from pharmaceutical and food products, as air pollution control devices for industrial and automobiles exhaust, for chemical purification and as electrodes in batteries among others. 500,000 tons per year of AC are produced globally and it is envisaged that the amount will continue to rise due to its ever increasing demands [Echegi, 2013].
Activated carbon is an amorphous form of carbon that has been specially treated so as to improve the adsorptive properties. It is characterized by a vast system of pores of different molecular sizes within the carbon particles. AC consists of non-planar layers of carbon with some linearly or singly bonded atoms. This makes up the entire carbon specimen and explains the existence of porosity and constitution of porosity over the entire surface. The surface area within the pores of the activated carbon is a boundary condition that limits the proximity of the adsorbed atoms or molecules [Amir, 2012]. Limitation of the electron density makes the shape of pores curved. There are some pores which are open to the smaller molecules than the larger ones. It has a large number of very fine pores that give the AC a large inner surface which is the basis of its remarkable adsorption properties.
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