title: Biosorbent encapsulation in calcium alginate: Effects of process variables on Cr(VI) removal from solutions.
abstract: Selected biosorbents, brewers draff and grape waste, have been encapsulated in calcium alginate beads and used for the removal of Cr(VI) from aqueous solutions. The effects of encapsulation variables, including the type of waste, the percentage of waste in the beads and the curing time of the beads in CaCl2, on the diameters of the beads and Cr(VI) sorption kinetics have been evaluated. In total, 21 different types of beads were produced. The diameters of the beads increased with increasing amounts of encapsulated biomaterial. Beads that contained grape waste were larger than those containing brewers draff. The most efficient beads for Cr(VI) removal were beads that contained 4% (w/w) of grape waste. No significant differences in the kinetics of Cr(VI) sorption were found with respect to the curing time variable in the case of grape waste calcium alginate beads. Statistical analysis confirmed that the type and percentage of waste are the critical parameters influencing the diameters of the beads and Cr(VI) removal. It was proven that the sorption efficiencies of the beads containing draff and grape waste encapsulated under the optimum conditions were much higher than the efficiencies obtained when using both wastes in their native states.
authors.affiliation: Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6 Suchdol, 165 21, Czech Republic. Electronic address: sillerovah@fzp.czu.cz.
authors.forename: Hana
authors.initials: H
authors.lastname: Šillerová
authors.affiliation: Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6 Suchdol, 165 21, Czech Republic.
authors.forename: Michael
authors.initials: M
authors.lastname: Komárek
authors.affiliation: Chemical Engineering Department, Universitat de Girona, Mª Aurèlia Capmany, 61, 17071 Girona, Spain.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.affiliation: Applied Mathematics Department, Universitat de Girona, Mª Aurèlia Capmany, 61, 17071 Girona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Poch
authors.affiliation: Chemical Engineering Department, Universitat de Girona, Mª Aurèlia Capmany, 61, 17071 Girona, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Villaescusa
mesh_terms: D000327:Adsorption; D000464:Alginates / Q000737:chemistry*; D002214:Capsules; D002857:Chromium / Q000737:chemistry* / Q000302:isolation & purification*; D004785:Environmental Pollutants / Q000737:chemistry* / Q000302:isolation & purification*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D007700:Kinetics; D012996:Solutions; D014866:Waste Products
chemical_list: D000464:Alginates; D002214:Capsules; D004785:Environmental Pollutants; D006603:Hexuronic Acids; D012996:Solutions; D014866:Waste Products; D002857:Chromium; C074702:chromium hexavalent ion; D020723:Glucuronic Acid
keywords: Alginate beads; Chromium sorption; Encapsulation