Removal of Some Heavy Metals from Aqueous Solution by Low-cost Sorbents

This study compares the abilities of different low-cost sorbents ; rock phosphate, sawdust, sugar beet pulp and zeolite, to remove Cd, Ni, Cr, Cu, Zn and Pb from synthetic single ion aqueous solutions. Effect of initial concentration of metal ion was studied. This study was carried out in Alexandria Water Purification Company Lab. It is clear that when the initial concentration of the tested metal ion is increased, the amount of metal sorbed per unit weight of the sorbent (mg/g) is increase, as where the removal percentage is decrease . The experimental data of the sorption equilibrium were correlated by the Langmuir and Freundlich equations.The results proved that Freundlich model gave a better and acceptable fitting to the experimental data of most of the tested metals than Langmuir equation within the used concentrations range of metal ions. However Langmuir equation imposed a better fitting to the experimental data of Cu using rock phosphate, Pb using sawdust, sugar beet pulp, zeolite and rock phosphate sorbents than Freundlich equation. The data also indicated that sugar beet pulp, zeolite and rock phosphate was more effective to remove Cd, Ni, Cr and Pb ions with a highest sorption capacity. The tested sorbents, as low cost materials, were able to reduce the tested ion concentrations in aqueous solutions, suggesting that sugar beet pulp, zeolite and rock phosphate could be used as a low cost- practical option to remediate heavy metals contaminated waters.