Equilibrium, kinetic, and thermodynamic studies of lead ion and zinc ion adsorption from aqueous solution onto activated carbon prepared from palm oil mill effluent

An efficient activated carbon was prepared using palm oil mill effluent as a precursor. The adsorption capacity of activated carbon for lead ion and zinc ion from aqueous media was investigated under equilibrium conditions between 303.15 and 353.15 K. The activated carbon Was analyzed using fourier transform infrared spectroscopy, field emission scanning electron microscope, energy dispersive X-Ray, and Nitrogen adsorption-desorption analysis. The adsorption capacity of activated carbon was studied by varying adsorbent dosage, contact time, and temperature. The equilibrium time was attained after 50 min for both ions. The data analysis was performed with different isotherm and kinetic models. Pseudo-second-order kinetic rather than pseudo first-order model is best fitted for both lead ion and zinc ion removal from wastewater. Further, the rate-determining step for both metal ions is chemisorption based on the suitability of the Elovich equation. Langmuir model provides the best fit for both removal of lead ion and zinc ion. The thermodynamic parameters shows the feasibility of adsorption of both ions is endothermic. (C) 2017 Elsevier Ltd. All rights reserved.