Diurnal variations in sulfur transformations at the chemocline of a stratified freshwater lake
| Autor: | Alexey Kamyshny, Khoren Avetisyan, Alyssa Findlay, Werner Eckert |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Biogeochemical cycle
010504 meteorology & atmospheric sciences Sulfide Hydrogen sulfide chemistry.chemical_element Chemocline 01 natural sciences Sulfur cycle chemistry.chemical_compound Stratified lake Triple sulfur isotopes Phototrophic sulfide oxidation Environmental Chemistry Photic zone Sulfate 0105 earth and related environmental sciences Earth-Surface Processes Water Science and Technology Thiosulfate chemistry.chemical_classification Seiche 04 agricultural and veterinary sciences Sulfur chemistry Environmental chemistry 040103 agronomy & agriculture 0401 agriculture forestry and fisheries |
| Zdroj: | Avetisyan, K, Eckert, W, Findlay, A J & Kamyshny, A 2019, ' Diurnal variations in sulfur transformations at the chemocline of a stratified freshwater lake ', Biogeochemistry, vol. 146, no. 1, pp. 83-100 . https://doi.org/10.1007/s10533-019-00601-5 |
| Popis: | In order to characterize biogeochemical sulfur cycling in the metalimnion of a thermally stratified freshwater lake, we followed changes in the concentrations and isotopic composition of sulfur species during a 24-h period, during which the chemocline oscillated at an amplitude of 5.3 m due to internal wave activity. Hourly sampling at a fixed depth (17.1 m) enabled study of redox changes during the transition from oxic to sulfidic conditions and vice versa. The oxidation–reduction potential, pH, conductivity and turbidity correlated linearly with the water temperature (a proxy for depth relative to the chemocline). The highest concentrations of thiosulfate and sulfite were detected approximately 2.5 m below the chemocline. Concentrations of zero-valent sulfur increased ~ 10 fold when the chemocline rose into the photic zone due to phototrophic sulfide oxidation. Triple isotopic composition of sulfur species indicates a shift with depth from values typical for sulfate reduction right below the chemocline to values which may be explained by either sulfate reduction alone or by a combination of microbial sulfate reduction and microbial sulfate disproportionation. We conclude that consumption of hydrogen sulfide at the chemocline of Lake Kinneret is controlled by the combination of its chemical and/or chemotrophic oxidation to sulfur oxoanions and predominantly phototrophic oxidation to zero-valent sulfur. |
| Databáze: | OpenAIRE |
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