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

Citations Over TimeTop 23% of 2011 papers

Abstract

Environmental context Interaction of metals with dissolved organic matter is one of the key processes defining metal bioavailability in water. The technique of diffusive gradients in thin films was used to investigate the kinetics of the interaction between metals and dissolved organic matter released by algae. For most metals the rate at which they were released from the organic matter was fast, but release of iron was kinetically limited. Abstract 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, whereas Co, Ni and Pb were effectively completely labile. Exudates from Chlorella vulgaris produced the most DOC and the most marked kinetic limitation.

Related Papers

• → Effect of Various Natural Dissolved Organic Carbon on Copper Lability and Toxicity to the Tropical Freshwater Microalga Chlorella sp.(2019)45 cited
• → Interpretation of diffusion gradients in thin films (DGT) measurements: a systematic approach(2014)54 cited
• → Assessing effects of dissolved organic carbon and water hardness on metal toxicity to Ceriodaphnia dubia using diffusive gradients in thin films (DGT)(2019)36 cited
• → Lability Criteria in Diffusive Gradients in Thin Films(2012)32 cited
• → Composition and lability of photochemically released dissolved organic matter from resuspended estuarine sediments(2020)22 cited