Alginate and Algal-Based Beads for the Sorption of Metal Cations: Cu(II) and Pb(II).
Alginate and algal-biomass (Laminaria digitata) beads were prepared by homogeneous Ca ionotropic gelation. In addition, glutaraldehyde-crosslinked poly (ethyleneimine) (PEI) was incorporated into algal beads. The three sorbents were characterized by scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX): the sorption occurs in the whole mass of the sorbents. Sorption experiments were conducted to evaluate the impact of pH, sorption isotherms, and uptake kinetics. A special attention was paid to the effect of drying (air-drying vs. freeze-drying) on the mass transfer properties. For alginate, freeze drying is required for maintaining the porosity of the hydrogel, while for algal-based sorbents the swelling of the material minimizes the impact of the drying procedure. The maximum sorption capacities observed from experiments were 415, 296 and 218 mg Pb g(-1) and 112, 77 and 67 mg Cu g(-1) for alginate, algal and algal/PEI beads respectively. Though the sorption capacities of algal-beads decreased slightly (compared to alginate beads), the greener and cheaper one-pot synthesis of algal beads makes this sorbent more competitive for environmental applications. PEI in algal beads decreases the sorption properties in the case of the sorption of metal cations under selected experimental conditions.
Ecole des mines d'Alès, Centre des Matériaux des Mines d'Alès (C2MA), Pôle Matériaux Polymères Avancés (MPA) 6, Avenue de Clavières, Alès F-30319 Cedex, France. Shengye.Wang@mines-ales.fr.
Shengye
S
Wang
Ecole des mines d'Alès, Centre des Matériaux des Mines d'Alès (C2MA), Pôle Matériaux Polymères Avancés (MPA) 6, Avenue de Clavières, Alès F-30319 Cedex, France. thierry.vincent@mines-ales.fr.
Thierry
T
Vincent
Institut Européen des Membranes-IEM (UMR 5635 CNRS-ENSCM-UM2)-Equipe Génie des Procédés Membranaires, Université Montpellier cc047, Place Eugene Bataillon, Montpellier 34095 Cedex 5, France. Catherine.Faur@umontpellier.fr.
Catherine
C
Faur
Ecole des mines d'Alès, Centre des Matériaux des Mines d'Alès (C2MA), Pôle Matériaux Polymères Avancés (MPA) 6, Avenue de Clavières, Alès F-30319 Cedex, France. eric.guibal@mines-ales.fr.
Eric
E
Guibal
D065966:Absorption, Physicochemical; D000464:Alginates / Q000737:chemistry*; D002413:Cations, Divalent / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D007795:Laminaria / Q000737:chemistry; D007854:Lead / Q000737:chemistry*; D008863:Microspheres
D000464:Alginates; D002413:Cations, Divalent; D007854:Lead; D003300:Copper
algal beads; heavy metal; sorption