Magnetic alginate beads for Pb(II) ions removal from wastewater

Abstract

A magnetic adsorbent (called magsorbent) was developed by encapsulation of magnetic functionalized nanoparticles in calcium-alginate beads. The adsorption of Pb(II) ions by these magnetic beads was studied and the effect of different parameters, such as initial concentration, contact time and solution pH value on the adsorption of Pb(II) ions was investigated. Our magsorbent was found to be efficient to adsorb Pb(II) ions and maximal adsorption capacity occurred at pH 2.3–6. The classical Langmuir model used to fit the experimental adsorption data showed a maximum sorption capacity close to 100mgg−1. The experimental kinetic data were well correlated with a pseudo second-order model, 50% of the Pb(II) ions were removed within 20min and the equilibrium was attained around 100min. Moreover our magsorbent was easily collected from aqueous media by using an external magnetic field. These results permitted to conclude that magnetic alginate beads could be efficiently used to remove heavy metals in a water treatment process.