Removal of Pb, Cr, Cu, and Zn Ions through adsorption using libyan sand

Heavy metal pollution is an environmental problem of worldwide concern. Several industrial waste water streams may contain heavy metals such as, Pb, Cr, Cd, Ni, as well as Zn, As, Hg, Cu, and Ag. A wide range of low-cost adsorbents have been studied by many researchers for heavy metal removal. It is evident from our literature survey that inexpensive and locally available materials could be used instead of conventional expensive adsorbents. The sand is one of the effective and environmentally suitable, low cost materials for treatment of polluted water. The removal of four heavy metals, i. e. Pb. Cr. Cu. and Zn from aqueous solutions, using ordinary sand as an adsorbent, was studied at 20o C. The amount of metal adsorbed to form monolayer on sand, obtained from Freundlich isotherm, exhibited the preference of metals for sand in the order Pb > Cr > Cu > Zn. The heavy metal-sand adsorption phenomena can be illustrated on the basis of the interaction between surface functional group of silicates (sand) and the metal ions. It is deduced that sand can be used as a low cost adsorbent for the removal of heavy metal from waste water (containing low concentration of metals) especially in the developing countries.