The influence of activation procedure on the physicochemical and sorption properties of activated carbons prepared from pistachio nutshells for removal of NO2/H2S gases and dyes

Pistachio nutshells were chosen as activated carbons precursor because current method of their disposal - combustion - is not profitable due to the low calorific value. Carbonaceous adsorbents were prepared by means of chemical, physical and direct activation of starting material. The influence of different parameters of activation procedure on the porous structure development, acidic and basic surface functional groups formation was determined. The sorption properties of the materials prepared toward gas and liquid pollutants were tested. Depending on the variant of thermochemical treatment of pistachio nutshells, the final products were microporous adsorbents, characterized by quite well developed surface area ranging from 277 to 1204 m(2)/g, showing much diverse acid-base character of the surface. It is proved that through physical activation of pistachio nutshells it is possible to obtain universal adsorbents with very high sorption capacity toward gases of acidic character (nitrogen dioxide and hydrogen sulfide) as well as liquid inorganic and organic pollutants of molecular size similar to that of iodine and methyl red sodium salt molecules. (C) 2017 Elsevier Ltd. All rights reserved.