title: Thallium(I) sorption using Prussian blue immobilized in alginate capsules.
abstract: Prussian blue (PB) was immobilized in alginate capsules. The composite sorbent was used for the recovery of Tl(I) ions from slightly acidic solutions: optimum pH being close to 4. The sorption isotherm can be described by the bi-site Langmuir sorption isotherm. This means that the metal ion can be bound through two different sorption sites: one having a strong affinity for Tl(I) (probably PB), the other having a lower affinity (probably the encapsulating material). The kinetics are described by either the pseudo-second order rate equation or the Crank's equation (resistance to intraparticle diffusion). The ionic strength (increased by addition of NaCl, KCl or CaCl₂) slightly decreased sorption capacity. The SEM-EDX analysis of PB-alginate capsules (before and after Tl(I) sorption) shows that the PB is homogeneously distributed in the capsules and that all reactive groups remain available for metal binding.
authors.affiliation: Ecole des Mines d'Alès, Centre des Matériaux des Mines d'Alès, 6, avenue de Clavières, F-30319 Alès cedex, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Vincent
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Taulemesse
authors.forename: Agnès
authors.initials: A
authors.lastname: Dauvergne
authors.forename: Thomas
authors.initials: T
authors.lastname: Chanut
authors.forename: Flaviano
authors.initials: F
authors.lastname: Testa
authors.forename: Eric
authors.initials: E
authors.lastname: Guibal
mesh_terms: D000327:Adsorption; D000464:Alginates / Q000737:chemistry*; D002214:Capsules; D005295:Ferrocyanides / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D009994:Osmolar Concentration; D013052:Spectrometry, X-Ray Emission; D013793:Thallium / Q000302:isolation & purification*; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D000464:Alginates; D002214:Capsules; D005295:Ferrocyanides; D006603:Hexuronic Acids; D014874:Water Pollutants, Chemical; C027549:thallium chloride; D020723:Glucuronic Acid; D013793:Thallium; C000170:ferric ferrocyanide
keywords: Alginate; SEM-EDX analysis; Sorption isotherms; Thallium; Uptake kinetics