Assessment of the potential effectiveness of poultry egg shells in the removal of lead ions from contaminated water

Abstract

The influence of pH, initial concentration of Pb²⁺ ions, sorbent (poultry egg shells) dose, and contact time on the adsorption of Pb²⁺ from contaminated water to egg shells was studied. Results indicate that adsorption capacity increases with the increase of Pb²⁺ ion concentration and dose of egg shells, and varied with change of pH. Egg shell was mainly composed of CaCO₃ and other few elements as, S, Al, Mg, Si, Cl, K and Zn. The optimum pH for lead removal was at pH 7 with highest efficiency of 96.65 %, this was also revealed by Freundlich adsorption isotherm that displayed the highest value of K of 3.18419 for wastewater of concentration 0.884 mg/l Pb. The optimum dose of egg shells was 25g with contact time of 90 min and residue lead of 0.027 mg/l which is lower than the Limits for Municipal and Industrial Wastewater discharge (0.1 mg/l). The adsorption isotherms also showed that the lead removal efficiency was descending from pH 7, 12.3 to 3.4. These results suggest that poultry egg shells can be a potential candidate adsorbent material for removal of lead ions from contaminated water.

Keywords: Adsorption, Lead, Egg shells, Sorbent, Poultry, Water