Preparation and characterization of activated carbon from Amygdalus Scoparia shell by chemical activation and its application for removal of lead from aqueous solutions

Two series of activated carbon have been prepared by chemical activation of Amygdalus Scoparia shell with phosphoric acid or zinc chloride for the removal of Pb(II) ions from aqueous solutions. Several methods were employed to characterize the active carbon produced. The surface area was calculated using the standard Brunauer-Emmet-Teller method. The microstructures of the resultant activated carbon were observed by scanning electron microscopy. The chemical composition of the surface resultant activated carbon was determined by Fourier transform infrared spectroscopy. In the batch tests, the effect of pH, initial concentration, and contact time on the adsorption were studied. The data were fitted with Langmuir and Freundlich equations to describe the equilibrium isotherms. The maximum adsorption capacity of Pb(II) on the resultant activated carbon was 36.63 mg g⁻¹ with H₃PO₄ and 28.74 mg g⁻¹ with ZnCl₂. To regenerate the spent adsorbents, desorption experiments were performed using 0.25 mol L⁻¹ HCl. Here we propose that the activated carbon produced from Amygdalus Scoparia shell is an alternative low-cost adsorbent for Pb(II) adsorption.