Please use this identifier to cite or link to this item:
Author(s): Ingrid M. Dittert
Vítor J. P. Pilar
Eduardo A. B. da Silva
Selene M. A. Guelli U. de Souza
Antônio Augusto U. de Souza
Cidália M. S. Botelho
Rui A. R. Boaventura
Title: Adding value to marine macro-algae Laminaria digitata through its use in the separation and recovery of trivalent chromium ions from aqueous solution
Issue Date: 2012
Abstract: In this study, Laminaria seaweed was used in its protonated form as an effective biosorbent for chromium(III) removal from aqueous solutions. The effect of different operating conditions (pH, initial metal concentration and temperature) on the efficiency of the biosorption process was assessed. Biosorption was strongly dependent on the solution pH and less dependent on the temperature. The Cr(III) adsorption capacity of the seaweed increased with the pH. The maximum uptake capacity for Cr(III) was 42 mg g(-1) at pH 4, considering a maximum initial chromium concentration of 250 mg g(-1), at 25 degrees C. Langmuir and Freundlich models were able to fit well the experimental equilibrium data. The Langmuir equilibrium model parameters at pH = 4 and T = 25 degrees C are q(max) = 41 +/- 1 mg g(-1) and K-L = 0.31 +/- 0.04 L mg(-1). The adsorptive behavior of biosorbent particles was modeled using a batch reactor mass transfer kinetic model, which successfully predicts Cr(III) concentration profiles, with an average homogeneous diffusivity, D-h, of 0.13 x 10(-8) +/- 0.08 cm(2) s(-1). The biosorbent was characterized in terms of apparent density, real density, porosity, particle size and pore size distribution. The chemical characterization of the biosorbent was based on the determination of the main chemical constituents present in the structure of the biomass, and in the identification of active sites on the surface, by the Fourier Transform Infrared Spectroscopy (FTIR) technique. FTIR analysis of Laminaria digitata revealed the complex nature of the biomass, with different binding groups, such as carboxyl and sulfonic, which are responsible for the binding of the metals.
Subject: Engenharia química, Engenharia do ambiente
Chemical engineering, Environmental engineering
Scientific areas: Ciências da engenharia e tecnologias::Engenharia do ambiente
Engineering and technology::Environmental engineering
Related Information: info:eu-repo/grantAgreement/FCT - Fundação para a Ciência e Tecnologia/Programa de Financiamento Plurianual de Unidades de I&D/PEst-C/EQB/LA0020/2011/Projeto Estratégico-LA 20 - 2011-2012/LA 20
Document Type: Artigo em Revista Científica Internacional
Rights: restrictedAccess
Appears in Collections:FEUP - Artigo em Revista Científica Internacional

Files in This Item:
File Description SizeFormat 
  Restricted Access
381.85 kBAdobe PDF    Request a copy from the Author(s)

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.