scholarly journals Effects of compositional changes on reactivity continuum and decomposition kinetics of lake dissolved organic matter

2016 ◽  
Vol 121 (7) ◽  
pp. 1733-1746 ◽  
Author(s):  
Alina Mostovaya ◽  
Birgit Koehler ◽  
François Guillemette ◽  
Anna-Kristina Brunberg ◽  
Lars J. Tranvik
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Decomposition Kinetics ◽  
Compositional Changes ◽  
Kinetics Of ◽  
Reactivity Continuum

scholarly journals Assessing the Contribution of Seasonality, Tides, and Microbial Processing to Dissolved Organic Matter Composition Variability in a Southeastern U.S. Estuary

2021 ◽  
Vol 8 ◽  
Author(s):  
Rachel P. Martineac ◽  
Alexey V. Vorobev ◽  
Mary Ann Moran ◽  
Patricia M. Medeiros
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Critical Role ◽  
Bacterial Cells ◽  
Secondary Importance ◽  
Relative Contribution ◽  
Doc Concentration ◽  
Compositional Changes ◽  
Dom Composition

Uncovering which biogeochemical processes have a critical role controlling dissolved organic matter (DOM) compositional changes in complex estuarine environments remains a challenge. In this context, the aim of this study is to characterize the dominant patterns of variability modifying the DOM composition in an estuary off the Southeastern U.S. We collected water samples during three seasons (July and October 2014 and April 2015) at both high and low tides and conducted short- (1 day) and long-term (60 days) dark incubations. Samples were analyzed for bulk DOC concentration, and optical (CDOM) and molecular (FT-ICR MS) compositions and bacterial cells were collected for metatranscriptomics. Results show that the dominant pattern of variability in DOM composition occurs at seasonal scales, likely associated with the seasonality of river discharge. After seasonal variations, long-term biodegradation was found to be comparatively more important in the fall, while tidal variability was the second most important factor correlated to DOM composition in spring, when the freshwater content in the estuary was high. Over shorter time scales, however, the influence of microbial processing was small. Microbial data revealed a similar pattern, with variability in gene expression occurring primarily at the seasonal scale and tidal influence being of secondary importance. Our analyses suggest that future changes in the seasonal delivery of freshwater to this system have the potential to significantly impact DOM composition. Changes in residence time may also be important, helping control the relative contribution of tides and long-term biodegradation to DOM compositional changes in the estuary.

scholarly journals The dissociation kinetics of Cu-dissolved organic matter complexes from soil and soil amendments

2010 ◽  
Vol 670 (1-2) ◽  
pp. 24-32 ◽  
Author(s):  
F. Amery ◽  
F. Degryse ◽  
C. Van Moorleghem ◽  
M. Duyck ◽  
E. Smolders
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Soil Amendments ◽  
Dissociation Kinetics ◽  
Kinetics Of

Influence of dissolved organic matter on the photodegradation and volatilization kinetics of chlorpyrifos in coastal waters

2015 ◽  
Vol 310 ◽  
pp. 189-196 ◽  
Author(s):  
M.I. Pinto ◽  
R. Salgado ◽  
Barbara A. Cottrell ◽  
William J. Cooper ◽  
Hugh D. Burrows ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Coastal Waters ◽  
Kinetics Of

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

2011 ◽  
Vol 8 (5) ◽  
pp. 517 ◽  
Author(s):  
Jacqueline Levy ◽  
Hao Zhang ◽  
William Davison ◽  
Rene Groben
Keyword(s):  
Thin Films ◽  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Matter ◽  
Chlorella Vulgaris ◽  
Metal Speciation ◽  
The Relationship ◽  
Diffusive Gradients ◽  
Kinetics Of

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. AbstractThe 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.

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