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

• Published in: Journal of colloid and interface science 2011-10, Vol.362 (2), p.486-492
• Main Authors: Bée, Agnès, Talbot, Delphine, Abramson, Sébastien, Dupuis, Vincent
• Format: Article
• Language: English
• Subjects: Adsorbents; Adsorption; Alginate; Alginates; Beads; Chemical Sciences; Chemistry; Colloidal state and disperse state; Encapsulation; Exact sciences and technology; Ferrofluid; General and physical chemistry; heavy metals; Hydrogen-Ion Concentration; ions; Kinetics; lead; Lead - isolation & purification; Magnetic alginate beads; magnetic fields; Magnets; Magsorbent; Mathematical models; Microspheres; nanoparticles; Pb(II); Physical and chemical studies. Granulometry. Electrokinetic phenomena; sorption isotherms; Surface physical chemistry; Waste water; wastewater; Water Pollutants, Chemical - isolation & purification; Water Purification - methods; water treatment
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2011.06.036

Magnetic beads (magsorbent) of chitosan containing citrate-coated maghemite nanoparticles are efficiently used to remove Pb(II) ions from aqueous solution. [Display omitted] ► Green synthesis of a magsorbent based on alginate. ► Encapsulation of nanoparticles in alginate does not alter their magnetic properties. ► Magnetic alginate beads are efficient for the removal of Pb(II) ions (100mg/g). ► Adsorption of Pb(II) ions by the magsorbent is pH-dependent. ► The magsorbent could be reused after regeneration with HNO3 2mol/L. 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.