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dc.contributor.authorRey Castro, Carlos
dc.contributor.authorLodeiro, Pablo
dc.contributor.authorHerrero, Roberto
dc.contributor.authorSastre de Vicente, Manuel E.
dc.date.accessioned2016-12-05T10:44:41Z
dc.date.issued2003
dc.identifier.issn0013-936X
dc.identifier.urihttp://hdl.handle.net/10459.1/58775
dc.description.abstractBrown seaweeds are interesting materials to be used as biosorbents for heavy metals due to their high binding ability and low cost. The study of the passive biosorption of protons on this kind of materials and its dependency on pH, ionic strength, and medium composition is essential for the practical application of brown algae in wastewater treatment. This work reports the results of the study of the proton binding equilibria of dead biomass from the seaweeds Sargassum muticum, Cystoseira baccata, and Saccorhiza polyschides by potentiometric titration with a glass electrode in the pH range between 2 and 8. Two different salts, NaCl and KNO3, in concentrations ranging from 0.05 to 2 mol‚L-1 , were used as background electrolytes. The influence of the ionic strength was accounted for by means of the Donnan model in combination with the master curve approach. Different empirical expressions to describe the swelling behavior of the biosorbent were tested. On the basis of the intrinsic affinity distribution analysis a unimodal Langmuir-Freundlich isotherm was selected to describe the proton binding properties. The results show very little influence of the type of salt. The ionic strength dependency of the proton binding is very similar for the three species, and average empirical expressions of the Donnan volume are proposed. The maximum proton binding capacities obtained ranged between 2.4 and 2.9 mol‚kg-1 , with average intrinsic proton affinity constants between 3.1 and 3.3, and heterogeneity parameters of ca. 0.5 for S. muticum and C. baccata, and slightly higher (ca. 0.7) for S. polyschides. The combined Langmuir-Freundlich equation and Donnan model allowed a good description of the experimental charge vs pH curves obtained.ca_ES
dc.description.sponsorshipThis work was funded by the projects BQU2002-02133 (from the Ministerio de Ciencia y Tecnologı´a of Spain) and PGDIT02TAM10302PR (from the Xunta de Galicia). C.R.C. was supported by a FPU fellowship from the Ministerio de Educacio´n, Cultura y Deporte of Spainca_ES
dc.language.isoengca_ES
dc.publisherAmerican Chemical Societyca_ES
dc.relationMICYT/PN2000-2003/BQU2002-02133ca_ES
dc.relation.isformatofReproducció del document publicat a https://doi.org/10.1021/es0343353ca_ES
dc.relation.ispartofEnvironmental Science and Technology, 2003, vol. 37, núm. 22, p. 5159-5167ca_ES
dc.rights(c) American Chemical Society, 2003ca_ES
dc.titleAcid-base properties of brown seaweed biomass considered as a Donnan gel. A model reflecting electrostatic effects and chemical heterogeneityca_ES
dc.typearticleca_ES
dc.identifier.idgrec010580
dc.type.versionpublishedVersionca_ES
dc.rights.accessRightsinfo:eu-repo/semantics/restrictedAccessca_ES
dc.identifier.doihttps://doi.org/10.1021/es0343353
dc.date.embargoEndDate10000-01-01


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