Céline Guéguen
Canada Research Chair in Aquatic Sciences and Biogeochemistry
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Assistant professor |
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Isolation and Characterization
of Dissolved Organic Matter from Algal Cultures The composition and transport of DOM depend primarily on whether the origin is from soil and plant material or from in situ production. Pedogenic organic matter results from leaching of decomposition byproducts of micro organisms and higher plants. It is largely composed of refractory and aromatic humic substances. The in situ production of DOM is often small compared to the soil-derived DOM in major rivers. Nevertheless, the variation in chemical composition of DOM derived from algal activities remains poorly understood. In this work we are examining the nature and composition of DOM released from two monoalgal cultures, green algae and diatoms. |
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Tracing Terrestrially-Derived
Dissolved Organic Matter in the With about 10% of the global river discharge into only 1% of the global
ocean volume, the |
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Impacts of climate change on
proton and metal cation binding by dissolved organic matter Dissolved organic matter acid-base properties are part of the essential factors which influences its complexing ability towards contaminants such as trace metals. We are investigating the proton binding of DOM in three boreal watersheds affected by acid rains in the 70s and 80s. |
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Monitoring aquatic environmental
nanoparticles Aquatic inorganic and organic nanoparticles (1-1000nm) exist in all aquatic
systems including lakes, rivers and oceans. They strongly interact with
contaminants and thus amplify or attenuate their toxicity. Little is know of
their reactivity in the aquatic ecosystems. In this project we are interested
in the behaviour and fate of nanomaterials formed by natural biogeochemical
processes as well as those produced by human activities in rivers and streams.
Field-flow fractionation is developed to separate nanoparticles according to
their particle size. The detection techniques used here are fluorescence,
Q-TOF and ICPMS. |
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Influence of mining activities on metal speciation Trace metals in the environment may provide benefits or risks to aquatic life and humans. They can arise naturally, or result partly or wholly from man-made pollution. In this study, we are investigating how the human activity may change physical-chemical forms of heavy metals. Our approach consists of a combination of field and laboratory measurements, and geochemical modeling. |
