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Title:
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Interactions of Cadmium(II) and protons with dead biomass of marine algae Fucus sp.
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Author:
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Herrero, Roberto; Cordero Pérez, Bruno; Lodeiro, Pablo; Rey Castro, Carlos; Sastre de Vicente, Manuel E.
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Notes:
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Samples of dead biomass from the marine brown algae Fucus ceranoides, F.
vesiculosus and F.serratus were studied for their ability to remove cadmium from
aqueous solutions. The metal sorption process is rapid, with 90% of the metal uptake
completed within the first 25 min. of contact. The kinetic data was described
successfully by a pseudo second order chemical sorption process with rate constants of
ca. 0.6 g·mmol-1
·min-1. At pH 4.5, the raw biomass of the three species exhibited
equilibrium uptake capacities for Cd as high as 0.8 mmol·g-1 (90 mg·g
-1), on a dry
weight basis, without chemical pretreatment. These sorption capacities are much higher
than those reported for activated carbon and chitin. The sorption of Cd was found to
increase as pH increases, reaching a plateau at pH 5.
Batch sorption experiments and continuous potentiometric titrations of acidtreated
biomass samples in 0.05M NaNO3 were used to derive thermodynamic binding
parameters according to the NICCA model. The total amount of acid sites was 2.4-2.9
mmol·g
-1, with median values of the affinity distribution for protons and cadmium ions,
log KH
~ and log KCd
~ , of 3.7 and 2.69 respectively (conditional values). The apparent
heterogeneity of the sorbent was successfully taken into account by the empirical
1
NICCA isotherm, which described very well the competition between protons and metal
ions, in contrast with a simpler discrete competitive Langmuir model.
The experimental results demonstrate that these seaweeds constitute a
promising, efficient, cheap and biodegradable sorbent biomaterial for cadmium removal
from wastewaters. This use would represent an example of exploitation of a renewable
marine resource in water treatment technologies for the prevention of heavy metal
pollution in the environment.
This work was funded by the projects BQU2002-02133 (from the Ministerio de Ciencia y Tecnología of Spain) and PGDIT02TAM10302PR (from the Xunta de Galicia). |
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Subject(s):
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-Biosorption
-Wastewater treatment
-Heavy metals
-Marine algae |
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Rights:
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cc-by-nc-nd, (c) Elsevier, 2006
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
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Document type:
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article
acceptedVersion |
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Published by:
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Elsevier
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Share:
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