Different roles of pedogenic fulvic acids and aquagenic biopolymers on colloid aggregation and stability in freshwaters

Article Article scientifique Article Different roles of pedogenic fulvic acids and aquagenic biopolymers on colloid aggregation and stability in freshwaters eng 2003-12-22 1997-12-22 author Wilkinson Kevin 29725 author Joz-Roland Anthony Jean-Marc 45659 author Buffle Jacques 24673 1714-1724 10.4319/lo.1997.42.8.1714 0024-3590 http://doi.wiley.com/10.4319/lo.1997.42.8.1714 Carbohydrates have been shown to attain 25% of the organic matter pool during periods of high productivity in a small eutrophic lake. The chemical nature of the organic matter in the water column, as determined by its source, had an important influence on its role in the coagulation and aggregation of inorganic colloids. During periods of high productivity, inorganic colloids were observed to be depleted at depths of maximum polysaccharide concentrations. Furthermore, in field experiments, depletion rates of colloidal particles were correlated to the presence of aquagenic biopolymers. In controlled laboratory experiments, the coagulation rate of colloidal montmorillonite was increased in the presence of 2.0 or 4.0 mg C liter−1 of aquagenic biopolymers. Sedimentation also increased with increasing biopolymer concentrations (0–2.3 mg C liter−1). On the other hand, 0.1–6.3 mg C liter−1 of pedogenically derived fulvic acids were shown to stabilize colloidal solutions, in agreement with previous studies. Dewey 540 40 Département de chimie minérale, analytique et appliquée 145 false Limnology and oceanography 42 8 76f3f4b2-1d4f-4afe-9d62-743e66e07d00 Article (Published version) Restricted Wilkinson_LO_1997421714.pdf 2826769 application/pdf restrictedAccess Faculté des sciences / Section de chimie et biochimie / Département de chimie minérale, analytique et appliquée

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Different roles of pedogenic fulvic acids and aquagenic biopolymers on colloid aggregation and stability in freshwaters	Limnology and oceanography			1997	102	0

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Joz-Roland, Anthony Jean-Marc