Immobilization of heavy metals from contaminated environments is an emerging field of interest from both resource conservation and environmental remediation points of view. This paper describes the adsorption of lead ions from aqueous solutions by modified sawdust. Sawdust was chemically modified by a two-step procedure consisting of acidification with HCl and subsequent modification with diethylenetriamine (DETA). This chemical modification procedure was studied to compare the fourier transform of infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) before and after the modification. The optimum initial pH of solution, adsorbent dose, contact time, and agitation speed were determined. The modified sawdust had a high uptake capacity in room temperature and removed Pb(II) (100 mg L-1) of about 94% with 1.0 g/L of adsorbent, in only 2 min. Langmuir and Freundlich isotherms were employed for the study of the adsorption of Pb(II) onto DETA-sawdust. Adsorption kinetics of Pb(II) onto the adsorbent followed the pseudo-second-order kinetic model. The method was applied to the removal of lead in wastewater, tap water and river water samples from different parts of Khouzestan, Iran.
Modified sawdust; Removal; lead; adsorption;