Heavy metal accumulation in waste water could affect aquatic life, human health and overall ecosystem adversely. Therefore, in recent years much emphasis has been given for the use of industrial waste water as low cost adsorbents for the removal of metallic contaminants from waste water. In this paper, the studies on removal of Pb (II) by adsorption on Parthenium stem powder as adsorbent. Batch adsorption experiments were carried out to examine the effect of various parameters such as agitation time, pH of the aqueous solution, initial concentration, adsorbent dosage and temperature on biosorption. The kinetic studies showed that the adsorption process was very fast and equilibrium was reached after about 50 min of contact time. The pseudo-first-order Lagergren equation, pseudo second-order rate equation and second order rate equation were used to describe the kinetic adsorption process. Thermodynamic parameters were determined at different temperatures. The negative values of free energy change indicated the spontaneous nature of adsorption process.
