Application of sawdust nanoparticles as a cheap and nontoxic biosorbent for the removal of lead ions from polluted waters

In this study, sawdust nanoparticles are prepared by an innovative vibratory ball mill (Spex). DLS, SEM, and TEM images show that the milled powder includes spherical nanoparticles with 20 nm average diameters. The prepared sawdust nano-biosorbent (SNBS) is used as a new and green nano-biosorbent for the removal of lead ions from polluted waters. Experimental data shows that the sorption of lead ions on SNBS is acceptably fitted to the Langmuir isotherm model. Based on the Langmuir isotherm, a maximum adsorption capacity of 10 mg g(-1) is achieved for adsorption of lead ions on SNBS. FT-IR is used to describe the sorption mechanism of lead ions on SNBS. The experimental optimum conditions for the lead ion removal include pH of 5, 50 ml sample volume, 50 mg SNBS and 20 min contact time in the room temperature. In these conditions, the removal efficiencies of Pb2+, Cu2+, Ag+, Zn2+, Fe2+, Mn2+, and Ni2+ are obtained 97, 64, 55, 44, 37, 36, and 34%, respectively. Desorption studies showed the adsorbed lead ions on sawdust surface can be done by using 1 ml 1.5 M HNO3.