Sorption of Pb(II) and Cu(II) by low-cost magnetic eggshells-Fe ₃O ₄ powder

This study explored the feasibility of using magnetic eggshell-Fe ₃O ₄ powder as an adsorbent for the removal of Pb(II) and Cu(II) ions from aqueous solution. The metal ions-adsorption media interaction was characterized using XRD and FTIR. The effects of contact time, initial concentrations, temperature, solution pH and reusability of the adsorption media were investigated. The metal ions adsorption was fast and the amount of metal ions adsorbed increased with an increase in temperature, suggesting an endothermic adsorption. The kinetic data showed that the adsorption process followed the pseudo-second order kinetic model. The optimal adsorption pH value was around 5.5 at which condition the equilibrium capacity was 263.2 mg/g for Pb(II) and 250.0 mg/g for Cu(II). The adsorption equilibrium data fitted very well to the Langmuir and Freundlich adsorption isotherm models. The thermodynamics of Pb(II) and Cu(II) adsorption onto the magnetic eggshell-Fe ₃O ₄ powder indicated that the adsorption was spontaneous. The reusability study has proven that magnetic eggshell-Fe ₃O ₄ powder can be employed as a low-cost and easy to separate adsorbent.