Preparation and Characterization of Activated Carbon from Palm Tree Leaves Impregnated with Zinc Chloride for the Removal of Lead (II) from Aqueous Solutions

Abstract

Removal of Lead (II) from aqueous solution onto Activated carbon derived from Palm tree leaves (Phoenix dactylifera) as a novel precursor by chemical activation with ZnCl2, at specific condition of carbonization temperature at 500°C and 1 hour as a holding time and detonated as AC(PTL)ZnCl2. The obtained material was submitted to measurements of active surface area, Fourier Transform Infrared Spectroscopy (FTIR) analysis and scanning electron microscope (SEM). Batch- adsorption studied had been carried out to examine the adsorption capacity of the AC(PTL)ZnCl2 for the removal of Lead (II) from aqueous solution. The effect of various process parameters like pH, initial metal concentration, adsorbent dose, contact time, and temperature on the efficiency of Pb (II) removal was investigated. Maximum adsorption of Pb (II) on AC(PTL)ZnCl2(86.4%) was observed at pH 5.81. The optimum conditions for adsorbent dose and temperature were determined as 0.030 g and 25°C, respectively. Initial Pb (II) concentrations has important effect on AC(PTL)ZnCl2 in the studied range (25–125 mg/L) where the removal percentage increases as the metal ion decrease. The highest percentage removal of concentration corresponding to the maximum adsorption was found to be 82.75 ± 3.65. The adsorption equilibrium data was well explained by Langmuir, Freundlich and Dubinin-Radushkevich isotherm. The parameters suggested that the adsorption of Pb (II) on prepared AC(PTL)ZnCl2 is physical adsorption. The Langmuir isotherm which fitted best for the experimental data obtained showed (Correlation Coefficient, R2 = 0.9463) higher than the (Freundlich isotherm, R2 = 0.7554), but more close to (Dubinin-Radushkevich isotherm, R2 = 0.9260). The porous characteristics and adsorption efficiencies of prepared AC(PTL)ZnCl2 were also investigated.