Matière organique dissoute dans l'estuaire maritime du St-Laurent — comparaison et choix des méthodes

1974 ◽  
Vol 31 (2) ◽  
pp. 133-139 ◽  
Author(s):  
D. Cauchois ◽  
M. Khalil
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Water Column ◽  
Organic Compounds ◽  
Major Part ◽  
Sea Water ◽  
Liquid Extraction ◽  
Total Organic Matter ◽  
Liquid Liquid Extraction

To study quantitatively and qualitatively the dissolved organic matter in the St. Lawrence maritime estuary, a comparison between the different extracting methods has been undertaken. We propose two of them; one based on liquid–liquid extraction, the second by adsorption on a resin (Amberlite XAD-2). The methods used remove different spectrums of organic compounds from sea water. Hydrocarbons were found to constitute the major part of the extracts varying between 3 and 5 mg/liter. None of the methods used extracts more than 20% of the total organic matter present. The concentration of the organic chloro-compounds in the water column is in the order of 80 ppb.

scholarly journals Behaviour of dissolved organic matter and inorganic nutrients during experimental sea-ice formation

2001 ◽  
Vol 33 ◽  
pp. 317-321 ◽  
Author(s):  
Virginia Giannelli ◽  
David N. Thomas ◽  
Christian Haas ◽  
Gerhard Kattner ◽  
Hilary Kennedy ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Sea Ice ◽  
Organic Compounds ◽  
Sea Water ◽  
Ice Cores ◽  
Inorganic Nutrients ◽  
Ice Formation ◽  
Solid Matrix ◽  
Dissolved Organic Compounds

AbstractIt is well established that during sea-ice formation, crystals aggregate into a solid matrix, and dissolved sea-water constituents, including inorganic nutrients, are rejected from the ice matrix. However, the behaviour of dissolved organic matter (DOM) during ice formation and growth has not been studied to date. DOM is the primary energetic substrate for microbial heterotrophic activity in sea water and sea ice, and therefore it is at the base of the trophic fluxes within the microbial food web. The aim of our study was to compare the behaviour of DOM and inorganic nutrients during formation and growth of sea ice. Experiments were conducted in a large indoor ice-tank facility (Hamburg Ship Model Basin, Germany) at −15°C. Three 1 m3 tanks, to which synthetic sea water, nutrients and dissolved organic compounds (diatom-extracted DOM) had been added, were sampled over a period of 5 days during sea-ice formation. Samples were collected throughout the experiment from water underlying the ice, and at the end from the ice as well. Brine was obtained from the ice by centrifuging ice cores. Inorganic nutrients (nitrate and phosphate) were substantially enriched in brine in comparison to water and ice phases, consistent with the processes of ice formation and brine rejection. Dissolved organic carbon (DOC) was also enriched in brine but was more variable and enriched in comparison to a dilution line. No difference in bacteria numbers was observed between water, ice and brine. No bacteria growth was measured, and this therefore had no influence on the measurable DOC levels. We conclude that the incorporation of dissolved organic compounds in newly forming ice is conservative. However, since the proportions of DOC in the brine were partially higher than those of the inorganic nutrients, concentrating effects of DOC in brine might be different compared to salts.

scholarly journals Evidence for significant protein-like dissolved organic matter accumulation in Sea of Okhotsk sea ice

2015 ◽  
Vol 56 (69) ◽  
pp. 1-8 ◽  
Author(s):  
Mats A. Granskog ◽  
Daiki Nomura ◽  
Susann Müller ◽  
Andreas Krell ◽  
Takenobu Toyota ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Sea Ice ◽  
Surface Waters ◽  
Sea Of Okhotsk ◽  
Sea Water ◽  
First Year ◽  
Ice Melt ◽  
Ultraviolet Range ◽  
Considerable Excess

AbstractAbsorption and fluorescence of chromophoric dissolved organic matter (CDOM) in sea ice and surface waters in the southern Sea of Okhotsk was examined. Sea-water CDOM had featureless absorption increasing exponentially with shorter wavelengths. Sea ice showed distinct absorption peaks in the ultraviolet, especially in younger ice. Older first-year sea ice had relatively flat absorption spectra in the ultraviolet range. Parallel factor analysis (PARAFAC) identified five fluorescent CDOM components, two humic-like and three protein-like. Sea water was largely governed by humic-like fluorescence. In sea ice, protein-like fluorescence was found in considerable excess relative to sea water. The accumulation of protein-like CDOM fluorescence in sea ice is likely a result of biological activity within the ice. Nevertheless, sea ice does not contribute excess CDOM during melt, but the material released will be of different composition than that present in the underlying waters. Thus, at least transiently, the CDOM introduced during sea-ice melt might provide a more labile source of fresher protein-like DOM to surface waters in the southern Sea of Okhotsk.

scholarly journals Chloroflexi CL500-11 Populations That Predominate Deep-Lake Hypolimnion Bacterioplankton Rely on Nitrogen-Rich Dissolved Organic Matter Metabolism and C1Compound Oxidation

2015 ◽  
Vol 82 (5) ◽  
pp. 1423-1432 ◽  
Author(s):  
Vincent J. Denef ◽  
Ryan S. Mueller ◽  
Edna Chiang ◽  
James R. Liebig ◽  
Henry A. Vanderploeg
Keyword(s):  
Gene Expression ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Water Column ◽  
Lake Michigan ◽  
Expression Patterns ◽  
Metagenomic Data ◽  
Type I ◽  
Deep Lake ◽  
Additional Energy

ABSTRACTTheChloroflexiCL500-11 clade contributes a large proportion of the bacterial biomass in the oxygenated hypolimnia of deep lakes worldwide, including the world's largest freshwater system, the Laurentian Great Lakes. Traits that allow CL500-11 to thrive and its biogeochemical role in these environments are currently unknown. Here, we found that a CL500-11 population was present mostly in offshore waters along a transect in ultraoligotrophic Lake Michigan (a Laurentian Great Lake). It occurred throughout the water column in spring and only in the hypolimnion during summer stratification, contributing up to 18.1% of all cells. Genome reconstruction from metagenomic data suggested an aerobic, motile, heterotrophic lifestyle, with additional energy being gained through carboxidovory and methylovory. Comparisons to other available streamlined freshwater genomes revealed that the CL500-11 genome contained a disproportionate number of cell wall/capsule biosynthesis genes and the most diverse spectrum of genes involved in the uptake of dissolved organic matter (DOM) substrates, particularly peptides.In situexpression patterns indicated the importance of DOM uptake and protein/peptide turnover, as well as type I and type II carbon monoxide dehydrogenase and flagellar motility. Its location in the water column influenced its gene expression patterns the most. We observed increased bacteriorhodopsin gene expression and a response to oxidative stress in surface waters compared to its response in deep waters. While CL500-11 carries multiple adaptations to an oligotrophic lifestyle, its investment in motility, its large cell size, and its distribution in both oligotrophic and mesotrophic lakes indicate its ability to thrive under conditions where resources are more plentiful. Our data indicate that CL500-11 plays an important role in nitrogen-rich DOM mineralization in the extensive deep-lake hypolimnion habitat.

Analytical pyrolysis of suspended particulate organic matter from the Black Sea water column

2006 ◽  
Vol 53 (17-19) ◽  
pp. 1856-1874 ◽  
Author(s):  
Yeşim Çoban-Yıldız ◽  
Daniele Fabbri ◽  
Valentina Baravelli ◽  
Ivano Vassura ◽  
Ayşen Yılmaz ◽  
...  
Keyword(s):  
Organic Matter ◽  
Water Column ◽  
Black Sea ◽  
Particulate Organic Matter ◽  
Sea Water ◽  
The Black Sea ◽  
Analytical Pyrolysis ◽  
Suspended Particulate ◽  
Suspended Particulate Organic Matter

Liquid-liquid extraction of Nd+3 and Eu+3 from aqueous medium using oxytetracycline in dichloromethane

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shabnam Shahida ◽  
Faisal Hayat ◽  
Akbar Ali ◽  
Muhammad Imran Khan ◽  
Shagufta Zafar ◽  
...  
Keyword(s):  
Sea Water ◽  
Liquid Extraction ◽  
Equilibration Time ◽  
Analysis Method ◽  
Acidic Solutions ◽  
Slope Analysis ◽  
Liquid Liquid Extraction ◽  
Extraction Parameters ◽  
Conjugate Base ◽  
Radiometric Technique

Abstract Liquid-liquid extraction system consisting of oxytetracycline (HOTC) in dichloromethane was developed for extraction of Nd+3 and Eu+3 from acidic solutions using radiometric technique. Various extraction parameters such as pH, equilibration time and metals concentration were optimized. Slope analysis method was used to study the composition of product and was found to be M(OTC)3 [here M=Nd+3 or Eu+3 and OTC = conjugate base of HOTC]. Among cations Al+3 and Fe+3 while among anions F− effected the extraction of these metals. Higher separation factor of these metals was found with many others. The method was successfully applied on spiked sea water.

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