Adsorption capability of sawdust of Populus alba for Pb(II), Zn(II) and Cd(II) ions from aqueous solution

Abstract

Sawdust of Populus alba (poplar tree) has been investigated as an adsorbent for the removal of Pb(II), Zn(II) and Cd(II) ions. Since poplar tree is widely grown in almost all parts of Kashmir, it can be a common, most easily available, sustainable and low cost adsorbent for the treatment of wastewaters in this part of the world, where growing industrialization is affecting water quality like elsewhere in the world. Therefore, it is worthwhile to investigate the potential of sawdust of poplar tree as an adsorbent for the removal of Pb(II), Zn(II) and Cd(II) ions from aqueous solution as a first step. Batch experiments were conducted to study the effect of some parameters such as adsorbent dose, contact time, initial concentration of metal ions, solution pH and temperature. Langmuir and Freundlich models were employed for the mechanistic analysis of experimental data obtained. Results reveal that in our system, adsorption follows the Langmuir isotherm. The maximum adsorption capacity of Pb(II), Zn(II) and Cd(II) was found to be 10.1255, 8.477 and 8.877 mg/g, respectively, at optimum conditions. The pseudo-first-order and pseudo-second-order models were employed for kinetic analysis of adsorption process. The adsorption process follows pseudo-second-order kinetics. The efficacy of the adsorbent in the treatment of effluent from cement factory has been investigated, and the results have been found encouraging.