ADSORPTION OF LEAD IONS ON NATURAL AND ACID ACTIVATED PRRENJAS MONTMORILLONITE CLAY

The aim of this research work is to study the feasibility of the natural and sulfuric acid activated Prrenjas montmorillonite clay for the removal of Pb2+ from aqueous solutions. In this study montmorillonite clay is used, which is taken from the spring of Prrenjasi. Clay is washed before use and then was activated with sulfuric acid at different concentration (10, 22 and 35%). The optimal conditions on adsorption of Pb2+ on clay were firstly determinate. For this a series of solutions with a certain concentration of Pb2+ ions were prepared. These solutions are put to interact with clay. After the completion of the interaction time the concentration of Pb2+ ions is measured and the amount of Pb2+ ions adsorbed is calculated. Solution concentration measurements are performed with atomic absorber. The adsorption capacity of natural and acid activated montmorillonite clay for Pb2+ ions was also investigated. All specific surface area of natural and acid activated montmorillonite clay was measured by N2 adsorption. The results showed that acid activated clay increased its specific area respectively: natural clay 83.75 m2/g 10 % acid activated 110.4 m2/g, 22 % acid activated 200 m2/g and 35 % acid activated 265 m2/g. The adsorption capacity of natural and acid activated montmorillonite clay were respectively: natural clay 17.9 mg/g, 10 % acid activated 18.79 mg/g, 22 % acid activated 18.91 mg/g, and 35 % acid activated 20.78 mg/g. The experimental results don’t show a significant increase in the adsorption capacity with acid activation. The Langmuir and Freundlich isotherms were applied to explain the adsorption process. The Langmuir model fitted better with the experimental data rather than the Freundulich model. High values of correlation factor R2 (> 0.97) for all clays indicate good agreement between experimental and predicted data using the Langmuir equation. All the RL values for the adsorption of Pb2+ ions onto natural and acid activated montmorillonite clay shows that the adsorption process is favorable. The results of this study showed that the Prrenjas montmorillonite clay powder can be efficiently used as a low-cost adsorbent for the removal of Pb2+, from aqueous solution without nedded to activate with sulphuric acid.