The role of colloidal matter in transfer of chemical elements in the boreal zone (European Russia)

• Main Author: Ilina, Svetlana
• Other Authors: Géosciences Environnement Toulouse (GET), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier - Toulouse III, Jérôme Viers
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: HAL CCSD 2012
• Subjects: boreal zone; trace elements; organic matter; colloids; natural waters; zone boréale; éléments traces; matière organique; colloïdes; spéciation; eaux naturelles; filtration; isotopes; [SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology; [SDE.MCG]Environmental Sciences/Global Changes; karelia*; Subarctic
• Online Access: https://theses.hal.science/tel-00709183; https://theses.hal.science/tel-00709183/document; https://theses.hal.science/tel-00709183/file/THESE_Ilina_Svetlana.pdf

The objective of this thesis was to study element speciation and migration in the boreal environments (Karelia and Central Russia). Specific goals were to i) characterize the molecular weight distribution of trace elements and organic matter (OM) in various types of natural waters, ii) reveal the TE colloidal forms dependence in the continuum soil solution - bog - stream - feeding and terminal lakes in the surface waters of boreal watersheds, and iii) quantify the dependence of stable and radiogenic element isotopic composition on the size fraction, element speciation and physico-chemical conditions of surface waters. The main originality of the work is to apply the method of cascade filtration to study the molecular weight distribution of trace elements in surface waters and to combine the geochemical and isotope techniques, for the first time on the same natural objects, and particularly within the watershed continuum soil solution - bog - stream - feeding and terminal lakes, in order to better understand the factors that control biogeochemical cycling of elements in the subarctic region. The first part is devoted to general introduction and the insight into the problems. The second chapter is aimed at studying natural organic matter size distribution in the natural waters with different redox and hydrodynamic conditions in the continuum soil solution - bog - stream - feeding and terminal lakes for a small watershed with homogeneous bedrock composition. In particular, we investigate organic matter concentrations, weight-average molecular weights, optical properties and carbon/nitrogen ratios to get the information about the origin of DOM (autochthonous / allochthonous), its aromaticity, and its hydrophility / hydrophobicity. The third chapter describes the study the molecular weight distribution of trace elements and it provides quantitative characterization of TE colloidal speciation in pristine, organic-rich rivers and surface waters. We demonstrate that, using TE correlations with iron and OM in the ...