ACTIVATED CARBON

Among the commonly used industrial adsorbents, the most important of the currently used adsorbents for environmental pollution control is activated carbons with high porosity. Commercially activated carbons are obtained by activating carbons obtained from wood, peat, lignite, coal, charcoal, bone, coconut shell, rice husk, nut shell and oil products through various processes.

In the early 1900s, patents were issued that formed the basis of current activated carbon production. These patents explain two basic principles of activated carbon production that are still valid today. These are chemical activation and gas activation. After 1920, activated charcoal was first used for water purification, but it was not widely used. However, in Germany in 1927, the use of activated carbon during the preparation of city water has gained great importance, since the smell of chlorophenol in drinking water created a great problem. Activated carbon was used in granular form at Hamm Water Works in 1929, independently by Harrison in 1930 in Bay City, Michigan, and again in 1929 by Spalding in powder form to remove odors from drinking water. By 1932, 400 factories in the USA and approximately 1200 factories in 1943 used activated carbon to control unwanted odors.

Types of Activated Carbon

The best activated carbons used today for wastewater treatment are obtained from various coals and natural materials. These are: coal, charcoal, peat, lignite, wood, bone; Coconut, hazelnut and rice husks; fruit seeds and oil products. Activated carbons obtained from these materials are generally hard and dense. They can be used for a long time without decomposing in water. Activated carbons can be produced in forms with different properties. These;

1. Powdered activated carbons,      
2. Granulated activated carbons,
3. Activated carbons in pellet form.,

 

As a result of chemical activation of carbon, powdered activated carbons are obtained. These carbons are the most used activated carbons in wastewater cleaning processes today. Granulated products and pellets made by gas activation are mostly used in the purification of gases. However, it is stated that granulated activated carbons also give very good results in wastewater treatment systems. Granulated and powdered activated carbons give excellent results in the removal of organic and inorganic substances. These activated carbons have also been used for years to clean biologically treated wastewater and wastewater containing industrial wastes of organic origin.

 

The most widely used raw materials for the production of activated carbon

Coconut shells are scraps of coal, wood and oil. Most of the raw materials used in activation normally have an inner surface area of ​​10 – 20 m2 / gram in their untreated state. The activation process is to subject the carbon to a controlled oxidation using steam so that the inner surface area is highly enhanced. The increase in the inner surface area between 700-1500 m2/gram depends on the process conditions and the type of raw material used. The inner surface area is formed by a highly developed network of holes of different diameters. All activated carbons in their structure; contain a mixture of micro and macro holes.

 

Usage areas

Currently, many city water treatment plants in the world use activated carbon to purify taste, odor, color and toxins. It can be used to remove volatile organic substances that cause air pollution, as well as for inorganic pollutants. Activated carbon is used safely in home use, to get rid of unwanted odors, and in the industrial field, for the treatment of solvents that need to be recovered from many production processes.

In addition, it can be used safely in the filtration of drinking and utility water of wide-ranging entertainment complexes, hotels and holiday villages, in the cleaning of spring and well water of bottling and filling facilities, in the supply of good quality process water needed by industry and industrial facilities of all sizes.