Equilibrium and kinetic studies on the removal of Lead from aqueous solutions

The use of activated carbon obtained from walnut shell ash for the removal of lead,which has toxic effect to the health of human being and other living beings,from aqueous solutions at various contact times and initial metal ions concentration was investigated [1].The plant material was chemically modified with H3PO4 in three steps of temperatures and times. The Langmuir,Freundlich,Dubinin-Radushkevich(D-R) and Temkin adsorption models were applied to describe the equilibrium isotherms and the isotherm constants were also determined. The experimental data indicated that the adsorption isotherms are well described by the Langmuir isotherm equation and the calculated adsorption capacity of activated carbon was 14.43(mg/gr) at 25oc.According to these results prepared activated carbon could be used as a low-cost adsorbent for the removal of lead from wastewater processes