Lead (II) Adsorption Onto Activated Carbon Prepared From Date Stems By Zinc Chloride Activation—Isotherm, Kinetic And Thermodynamic Studies

H. Hadoun*¹, A. Belgacem², I. Ouldbrahim², I. Toumert¹

¹Nuclear Research Center of Algiers, 02, Bd Frantz Fanon, B.P. 399, Algiers, (ALGERIA)
²University of Science and Technology Houari Boumediene, FGMGP, B.P. 32 EL-Alia Bab-Ezzouar, Algiers, (ALGERIA)

PAGE NO: 92-109

ABSTRACT – DOI: https://dx.doi.org/10.47204/EMSR.3.2.2022.92-109

The present study reported the adsorption of lead ions from aqueous solutions on activated carbon synthesized from date stems an agricultural waste locally available in huge amount. Chemical activation with ZnCl₂ was performed to convert date stems to activated carbons at temperature of 450, 500 and 550°C for 1 hour in an inert atmosphere. Physico-chemical characteristics of the obtained carbons were analyzed using BET surface area analyzer, Fourier Transform Infrared Spectroscopy, X-Ray Diffraction and Scanning Electron Microscopy analysis. It showed that carbon with large surface area (1426.43m²g^-1), high pore volume (0.69cm³g^-1) and rich in functional groups was obtained at temperature of 500°C. Batch adsorption experiments were performed to investigate the ability of this activated carbon to remove lead ions from aqueous solutions under various operating parameters such as initial pH, initial lead ions concentration, contact time, temperature and adsorbent dose. Results showed that the adsorption is strongly dependent on pH value and maximum removal was found to be 98% at pH 6 using only 2.5gL^-1 of carbon dose for 180 min. Equilibrium data best fitted to Langmuir model with maximum adsorption capacity of 71.43mgg^-1. According to the kinetic study pseudo-second-order model best represented the kinetic data and finally, thermodynamic study revealed the feasibility, the spontaneity and exothermic nature of the adsorption process.