Activated carbons are widely used for the adsorption of many organic compounds from contaminated water and air streams. The adsorption process results from a physical attraction which holds molecules of the absorbate at the surface of a solid by the surface tension of the solid.
Activated carbon is produced from carbonaceous materials such as coal, coconuts, wood and petroleum coke. Granulated activated carbon has an extensive pore structure which provides an enormous amount of surface area for each particle of material.
The ability of activated carbon to adsorb a particular organic chemical compound varies with the compound and also its concentration in the waste stream. In order to evaluate the adsorption rate of carbon for a given compound, isotherms are developed. The isotherm for a specific compound such as benzene, trichlor or PCB, can often be obtained from a carbon manufacturer, EPA literature, or it can be developed using simple laboratory procedures.
Discusses the design of activated carbon systems for removing PCBs.