Production of activated carbon from eucalyptus bark (camaldulensis dehn) by physical activation for removal of lead

Abstract

This research investigated the production of activated carbon from Eucalyptus camaldulensis Dehn bark by physical activation. The experiment was composed of two steps: the first step was the carbonization and the second was the activation. For the carbonization, the optimal condition was found to be 500℃ and 45 minutes. The optimal activation condition with steam as activating agent was at 900℃ for 120 minutes using N[subscript 2] gas as a carrier at the flow rate of 200 cubic cm min[superscript -1] where the properties of the prepared activated carbon were: bulk density 0.37 g cm[superscript -3], ash content 37.3%, yield 52.5%, iodine number 694 mg g[superscript -1] and BET surface area 794 sq.m. g-[superscript -1]. At the same activation condition, change activating agent to carbon dioxide instead, the properties of the prepared activated carbon were: bulk density 0.39 g cm[superscript -3], ash content 30.9%, yield 58.5%, iodine number 352 mg g[superscript -1] and BET surface area 274 m[superscript 2] g[superscript -1 ]. The activated carbon product from steam activation process was tested for its adsorption capacities for Pb(II). Experiments demonstrated that Pb(II) was best adsorbed at pH 4 where the adsorption reached equilibrium within 30 minutes for the whole range of initial heavy metal concentrations investigated here (10-50 mg L[superscript -1]). The adsorption isotherm followed Langmuir better than Freundlich models where the maximum sorption capacity was 54.6 mg g[superscript -1].