500 Naturwissenschaften und Mathematik
Filtern
Erscheinungsjahr
Dokumenttyp
- Dissertation (29)
- Konferenzveröffentlichung (1)
- Habilitation (1)
Sprache
- Englisch (31) (entfernen)
Schlagworte
- Pflanzenschutzmittel (4)
- Pestizid (3)
- ecotoxicology (3)
- Bodenchemie (2)
- Emissionen (2)
- Landwirtschaft (2)
- agriculture (2)
- pesticide (2)
- pesticides (2)
- risk assessment (2)
- soil organic matter (2)
- sorption (2)
- Ökosystem (2)
- 1H-NMR Relaxometry (1)
- Abwasser (1)
- Abwasserbehandlung (1)
- Agrochemikalien (1)
- Aquatisches Ökosystem (1)
- Arzneistoffe (1)
- Bach (1)
- Belebtschlamm (1)
- Binnengewässer (1)
- Biotransformation (1)
- Biozide (1)
- Boden (1)
- Bodenphysik (1)
- Bodenökologie (1)
- Budongo Forest (1)
- Cations (1)
- Chemische Abwasserreinigung (1)
- Chironomus riparius (1)
- Chromatographie (1)
- Computational Toxicology (1)
- Daphnia (1)
- Differentia Scanning Calorimetry (1)
- Differential scanning calorimetry (1)
- Düngemittel (1)
- East Africa (1)
- Ebullition (1)
- Emission (1)
- Endangerment (1)
- Endokrine Regulation (1)
- Environmental Risk Assessment (1)
- Feldsaum (1)
- Fledermäuse (1)
- Fluss (1)
- Fungicides (1)
- Fungizid (1)
- Galerucinae (1)
- Gammarus fossarum (1)
- Gas storage capacity (1)
- Gasblasen (1)
- Gefrierpunktserniedrigung (1)
- Gefährdung (1)
- Gewässer (1)
- Glasumwandlung (1)
- Glasübergang (1)
- Hyaluronan (1)
- Hyaluronsäure (1)
- Hydratation (1)
- Hydration (1)
- Hydrodynamik (1)
- Hydrogel (1)
- ICM (1)
- ICP-MS (1)
- Integrated Model (1)
- Interparticulate hydrogel swelling (1)
- Kakamega Forest (1)
- Kation-Brücken (1)
- Kationen (1)
- Kohlenstoffkreislauf (1)
- Kolloid (1)
- Lake Kinneret (1)
- Magnetis (1)
- Mass-Spektrometrie (1)
- Methan (1)
- Methane emissions (1)
- Mikroorganismus (1)
- Mikroverunreinigung (1)
- Minderung (1)
- Mixture Toxicity (1)
- Monolepta (1)
- NMR-Spektroskopie (1)
- Nanopartikel (1)
- Natürliches organisches Material (1)
- Nicht-Ziel-Pflanzen (1)
- Non-freezing water (1)
- Nuclear Magnetic R (1)
- Organische Bodensubstanz (1)
- Oriental region (1)
- Ostafrika (1)
- Ozon (1)
- Pesticides (1)
- Pestizide (1)
- Pflanzen (1)
- Plasticization; Glass transition (1)
- Plastifizieren (1)
- Plastifizierung (1)
- Polysaccharide (1)
- Polysaccharides (1)
- Predictive Model (1)
- Regenwald (1)
- Reproduktion (1)
- Revision (1)
- Rheometry (1)
- Risikoabschätzung (1)
- Risikoanalyse (1)
- Risikobewertung (1)
- Risikomanagement (1)
- Schwermetalle (1)
- Soil physics (1)
- Soil structural stability (1)
- Sorption (1)
- Spear (1)
- Staugeregelte Flüsse (1)
- Streams (1)
- Säugetiere (1)
- Süßwasserhaushalt (1)
- Titandioxid-Nanopartikeln (1)
- Torf (1)
- Toxizität (1)
- Transformationsprodukte (1)
- Umwelt (1)
- Umweltchemikalie (1)
- Umwelttoxikologie (1)
- Umweltwissenschaften (1)
- Unterwasserwelt (1)
- Variabilität (1)
- Wachstumsregler (1)
- Wasserverschmutzung (1)
- Wastewater treatment plants (1)
- Wirbellose (1)
- Zooplankton (1)
- Zuckmücken (1)
- activated sludge (1)
- advanced wastewater treatment (1)
- amphibians (1)
- aquatic ecotoxicology (1)
- aquatic environment (1)
- bats (1)
- biocides (1)
- biological degradation (1)
- biologischer Abbau (1)
- biotransformation (1)
- cation bridges (1)
- cation-bridges (CaB) (1)
- chemical force microscopy (1)
- chemical risk assessment (1)
- colloid (1)
- cross-linking (1)
- decomposition (1)
- dry inland waters (1)
- ebullition (1)
- ecological risk management (1)
- ecosystem functioning (1)
- ecosystem functions (1)
- ecotoxicity (1)
- emerging micropollutants (1)
- endocrine disrupting chemicals (1)
- endokrine Regulation (1)
- energetics (1)
- engineered nanoparticles (1)
- environmental fate (1)
- environmental surfaces (1)
- erweiterte Abwasserbehandlung (1)
- field margin (1)
- fluid disturbances (1)
- freshwater ecosystem (1)
- freshwater organisms (1)
- fungicide (1)
- glass transition (1)
- global carbon cycle (1)
- humic acid (1)
- hydrodynamic chromatography (1)
- hydrodynamische Chromatographie (1)
- impounded rivers (1)
- in situ (1)
- invertebrates (1)
- kinematics (1)
- landscape (1)
- lead desorption (1)
- leaf beetles (1)
- life cycle test (1)
- macroinvertebrates (1)
- mammals (1)
- microorganisms (1)
- micropollutants (1)
- mitigation (1)
- mitigation measures (1)
- modelling (1)
- monitoring (1)
- nanoparticle (1)
- natural organic matter (1)
- neuartige Spurenstoffe (1)
- nicht gefrierbares Wasser (1)
- non-target plants (1)
- off-field habitats (1)
- organic pollution (1)
- ozone (1)
- peat (1)
- pharmaceuticals (1)
- plant protection products (1)
- point source (1)
- pollution (1)
- probabilistic (1)
- rainforest (1)
- reproduction (1)
- runoff (1)
- silver nanoparticles (1)
- soil (1)
- spatial and temporal varibility (1)
- stream (1)
- swarming (1)
- swimming behaviour (1)
- transformation (1)
- transport (1)
- vascular plants (1)
- vaskuläre Planzen (1)
- vegetated treatment systems (1)
- wastewater treatment (1)
- water-molecule-bridges (WaMB) (1)
- zooplankton (1)
- Ökosystemdienstleistung (1)
- Ökotoxikologie (1)
- Ökotoxologie (1)
- Überwachung (1)
By the work presented in this thesis, the CH4 emissions of the River Saar were quantified in space and time continuously and all relevant processes leading to the observed pattern were identified. The direct comparison between reservoir zones and free-flowing intermediate reaches revealed, that the reservoir zones are CH4 emission hot spots and emitted over 90% of the total CH4. On average, the reservoir zones emitted over 80 times more CH4 per square meter than the intermediate reaches between dams (0.23 vs. 19.7 mol CH4 m-2 d-1). The high emission rates measured in the reservoir zones fall into the range of emissions observed in tropical reservoirs. The main reason for this is the accumulation of thick organic rich sediments and we showed that the net sedimentation rate is an excellent proxy for estimating ebullitive emissions. Within the hot spot zones, the ebullitive flux enhanced also the diffusive surface emissions as well as the degassing emissions at dams.
To resolve the high temporal variability, we developed an autonomous instrument for continuous measurements of the ebullition rate over long periods (> 4 weeks). With this instrument we could quantify the variability and identify the relevant trigger mechanisms. At the Saar, ship-lock induces surges and ship waves were responsible for over 85% of all large ebullition events. This dataset was also used to determine the error associated with short sampling periods and we found that with sampling periods of 24 hours as used in other studies, the ebullition rates were systematically underestimated by ~50%. Measuring the temporal variability enabled us to build up a conceptual framework for estimating the temporal pattern of ebullition in other aquatic systems. With respect to the contribution of freshwater systems to the global CH4 emissions, hot spot emission sites in impounded rivers have the potential to increase the current global estimate by up to 7%.