Using diffusive gradients in thin films to probe the kinetics of metal interaction with algal exudates

Levy, Jacqueline; Zhang, Hao; Davison, William; Groben, Rene. 2011 Using diffusive gradients in thin films to probe the kinetics of metal interaction with algal exudates. Environmental Chemistry, 8 (5). 517-524.

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The interaction of metals with organic matter is one of the key processes determining metal speciation and bioavailability in water. Fulvic acid tends to dominate dissolved organic carbon (DOC) in freshwaters, but organic carbon produced in situ, e.g. exudates released by algae and bacteria, is also significant. The technique of diffusive gradients in thin films (DGT) was used to investigate the lability of metal-exudate complexes using a kinetic signature approach. Exudates were harvested from three cultured freshwater alga (Chlorella vulgaris, Cryptomonas pyrenoidifera, Anabaena flos-aquae), and the filtered media supplemented with trace metals. DGT-labile metal concentrations and kinetic signatures were determined (24-h deployment). The relationship between Fe and DOC was a defining feature of the kinetic signatures. Iron was the most kinetically limited metal followed by Al and Cu, while Co, Ni and Pb were effectively completely labile. Exudates from Chlorella vulgaris produced the most DOC and the most marked kinetic limitation.

Item Type: Publication - Article
Digital Object Identifier (DOI):
Programmes: CEH Topics & Objectives 2009 - 2012 > Water > WA Topic 2 - Ecohydrological Processes > WA - 2.1 - Identify and quantify sources, fluxes and pathways of water, chemicals ...
UKCEH and CEH Sections/Science Areas: Parr
ISSN: 1448-2517
Additional Keywords: DGT, dissociation, dissolved organic carbon, phytoplankton, trace metals
NORA Subject Terms: Ecology and Environment
Date made live: 19 Oct 2011 14:32 +0 (UTC)

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