Please use this identifier to cite or link to this item: https://hdl.handle.net/10216/107491
Author(s): Mazur, LP
Pozdniakova, TA
Mayer, DA
de Souza, SMAGU
Rui Boaventura
Vitor Vilar
Title: Cation exchange prediction model for copper binding onto raw brown marine macro-algae Ascophyllum nodosum: Batch and fixed-bed studies
Issue Date: 2017
Abstract: The cation exchanger properties of brown marine macro-algae Ascophyllum nodosum for copper separation from aqueous solutions were studied in batch and continuous mode. The total amount of light metals present on the surface of raw biomass was 2.4 mEq/g. The raw macro-algae were converted in different ionic forms achieving a similar binding capacity, indicating that the conversion of seaweeds to different ionic forms consists in an ion exchange process. Carboxylic (approximate to 1.3 mEq/g) and sulphonic (approximate to 1.1 mEq/g) groups were identified as the main functional groups responsible for cations binding. Equilibrium and kinetic experiments were conducted at different pH values using different algae forms. Cation exchange equilibrium model was formulated using a mass action law being able to determine the selectivity coefficients between all ionic species for carboxylic and sulphonic groups. In the fixed-bed column, for four cycles of saturation/elution/regeneration, the operating capacity varied between 0.6 and 0.8 mEq Cu2+/g, treating 27-33 L of influent until the breakthrough point of 0.02 mEq Cu2+/L, corresponding to a service capacity of 301-367 BV. Higher elution efficiency was observed for 3.0% HCl in counter-flow mode and no biomass damage was observed after four elution cycles. A mass transfer model, considering equilibrium given by the mass action law, and a linear driving force model for intraparticle diffusion, was able to predict well the ion exchange process during the saturation and elution steps for all chemical species in the liquid and solid phase. The regeneration step was successfully performed with CaCl2 0.1 M at pH = 8.0 making possible the reuse of the biomass in multiple cycles.
Subject: Tecnologia ambiental, Engenharia do ambiente
Environmental technology, Environmental engineering
Scientific areas: Ciências da engenharia e tecnologias::Engenharia do ambiente
Engineering and technology::Environmental engineering
URI: https://repositorio-aberto.up.pt/handle/10216/107491
Related Information: info:eu-repo/grantAgreement/FCT - Fundação para a Ciência e Tecnologia/Projectos de I&DT em Todos os Domínios Científicos/PTDC/AAG-TEC/2685/2012|FCOMP-01-0124-FEDER-027877/Valorização de macroalgas marinhas na separação e recuperação de iões metálicos tóxicos presentes em água/ALGAEVALUE
info:eu-repo/grantAgreement/FCT - Fundação para a Ciência e Tecnologia/Projetos Estratégicos/UID/EQU/50020/2013- POCI-01-0145-FEDER-006984/Laboratório de Processos de Separação e Reação - Laboratório de Catálise e Materiais/LSRE-LCM
Document Type: Artigo em Revista Científica Internacional
Rights: restrictedAccess
Appears in Collections:FEUP - Artigo em Revista Científica Internacional

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