Comparative Study of Lead (II) Removal from Aqueous Solution Using Different Adsorbents

摘要

Adsorption of lead(II) from wastewater effluents using indigenous cellulose based waste biomass, such as nipa palm nut (NPN), palmyra palm nut (PPN), oil palm empty fruit bunch (EFB), oil palm fibre (OPF), and oil palm shell (OPS), as potential raw materials for the preparation of activated carbons was studied. Chemical activation method was used in preparing the activated carbon. The influence of various factors namely pH, adsorbent dosage, contact time, initial ion concentration and adsorbent particle size was studied to identify the adsorption capacity of the adsorbents. The amount of Pb2+adsorbed increased with increase in adsorbent dosage, and contact time and decreased with increase in particle size and initial ion concentration. The optimum pH was obtained at pH6 for all the adsorbents. The result of adsorption studies showed that activated carbons produced from OPS and NPN are the most efficient adsorbents for the removal of Pb2+from aqueous solutions. Adsorption data were modeled using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich equations. Equilibrium data fitted well to the Freundlich, Langmuir and Tempkin models. The equilibrium data were best described by Freundlich model. It is seen from the study that all the adsorbents can be used as low-cost adsorbents for the removal of Pb2+from aqueous solution