The removal of heavy metals from aqueous solutions by sawdust adsorption--removal of lead and comparison of its adsorption with copper.

In this work, sorption of lead on sawdust (SD) has been studied by using batch techniques. Similar to the sorption of copper, the equilibrium sorption levels for lead is a function of the solution pH, contact time, sorbent and sorbate concentration. The equilibrium adsorption capacity of sawdust for lead was measured and extrapolated using linear Freundlich and Langmuir isotherms and compared with that for copper. Metal ions which are bounded to the sawdust could be stripped by acidic solution so that the sawdust can be recycled. Non-equilibrium experiments were done by using glass columns. The results indicate the potentially practical value of this method in industries and also provide strong evidence to support the adsorption mechanism proposed. Even though the focus of this work is on lead, some results from previous study for copper have been incorporated here for sake of comparison.