EVOLUTION OF THE ACTIVE SURFACE OF CARBONS PRODUCED FROM VARIOUS RAW-MATERIALS BY STEAM PYROLYSIS ACTIVATION

A one step pyrolysis/steam activation was used to produce activated ca rbons from apricot stones, nuts, coconuts, almond shells and grape see ds, and Bulgarian lignite from Maritza Iztok and Chukurovo deposit. Th e evolution of the active surface of the carbons produced was investig ated. The changes in the structure of activated carbons give evidence for the periodicity of the processes of oxidation and thermal destruct ion. It was established that the adsorption properties of activated ca rbons are dependent on the treatment temperature, soak time and the na ture of the raw materials. The activated carbons produced from various raw materials have a high concentration of surface functional groups, carboxyl and hydroxyl. Activated carbons with predominantly meso- and macropore structures showed high capacity for adsorbing Cu2+ ions fro m solutions.