Comparison of the effects of different chemical activation methods on properties of carbonaceous adsorbents obtained from cherry stones

A method for obtaining activated carbons from cherry stones by chemical activation with NaOH is described. Carbonaceous adsorbents were obtained by two methods of activation (physical mixing and impregnation) and two variants of thermal treatment (at a constant or increasing temperature). Cherry stones were proved to be effective cheap precursors of carbon adsorbents, characterised by large pore volume (ranging from 0.22 to 0.47 cm³/g) and good sorption abilities (iodine number from 343 to 996 mg/g). The activated carbons obtained usually have strongly microporous structure and acidic surface character. The best physicochemical properties and adsorption properties towards iodine were found to be shown by the carbon samples obtained by physical mixing of the precursor or char with the activating agent followed by activation at 600 °C.