Removal of Toxic Metals from Aqueous Solution by Saw Dust

Abstract

In this work, feasibility studies of using a natural and low cost adsorbent; saw dust for the removal of Cr(VI), Ni(II), Fe(II) and Cd(II) from aqueous solution was carried out. The efficiency of the adsorbent was judged from the variation of the % adsorption with (i) contact time, (ii) adsorbent dose, (iii) initial metal ion concentration, (iv) effect of pH variation of the adsorbate solution, (v) activation of the adsorbents and (vi) particle size. Changes in the concentrations of the metallic ions after the adsorption process were monitored using Shimadzu AA650 Double-Beam Digital Atomic Absorption/Flame Spectrophotometer. Results suggest that the adsorbent employed in this work have the ability to remove the tested ions from their aqueous solutions with adsorption order onto the adsorbent varying according to Cr > Fe > Ni > Cd. Also for each ion there is an optimum pH for maximum adsorption beyond which the efficiency declined.

Keywords: Saw dust, adsorption, adsorbent, metal ion, % removal