Search for dissertations about: "Sediment biogeochemistry"

Showing result 1 - 5 of 14 swedish dissertations containing the words Sediment biogeochemistry.

  2. 1. Benthic metabolism and sediment nitrogen cycling in Baltic sea coastal areas : the role of eutrophication, hypoxia and bioturbation

    Author : Stefano Bonaglia; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Eutrophication; Sediment; Benthic Flux; Nitrogen Cycle; Denitrification; Baltic Sea; Biogeochemistry; biogeokemi; marin- och brackvattensekologi; Marine and Brackish Water Ecology; Marine Ecology; marin ekologi; geokemi; Geochemistry;

    Abstract : Eutrophication is one of the greatest threats for the Baltic Sea, and one of its more critical consequences is bottom water hypoxia. Nutrient enrichment and oxygen-depletion affect both the deep central basins and a number of coastal areas, even though strategies for nutrient reduction have lately been implemented. READ MORE

  4. 2. Determination of mercury chemical speciation in the presence of low molecular mass thiols and its importance for mercury methylation

    Author : Van Liem-Nguyen; Erik Björn; Ulf Skyllberg; Cynthia Gilmour; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Mercury; methylmercury; LMM thiol; mass spectrometry; biogeochemistry; soil; sediment; ICP; WinSGW; modeling; S XANES; ligand exchange; stability constant; boreal wetlands; analytisk kemi; Analytical Chemistry; Environmental Science; miljövetenskap;

    Abstract : Methylmercury (MeHg) is a neurotoxic compound that threatens the well-being of humans and wildlife. It is formed through the methylation of inorganic mercury (HgII) under suboxic/anoxic conditions in soils, sediment and waters. READ MORE

  5. 3. The Baltic Sea Wave Field : Impacts on the Sediment and Biogeochemistry

    Author : Anette Jönsson; Linköpings universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hydraulic engineering; HYPAS; Wave modelling; Significant wave height; Wave energy; Vattenteknik; Water engineering; Vattenteknik;

    Abstract : The wave field in the Baltic Sea has been modelled for a two-year period with the spectral wave model HYPAS. There is a large seasonal variation in the field and a minor annual one, both reflect the wind variation in the area. Since the Baltic Sea is fetch limited, the dominant wind direction is important for the maximum wave heights. READ MORE

  6. 4. Benthic fluxes of biogenic elements in the Baltic Sea : Influence of oxygen and macrofauna

    Author : Nils Ekeroth; Sven Blomqvist; Per OJ Hall; Bjørn Sundby; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Sediment biogeochemistry; Bioturbation; Benthic nutrient fluxes; Bottom water oxygenation; Box corer; Sediment sampling; Marine Ecology; marin ekologi;

    Abstract : This thesis investigates how benthic fluxes of phosphorus (P), nitrogen (N), and silicon (Si) change upon oxygenation of anoxic soft bottoms in the brackish, eutrophicated Baltic Sea. Direct measurements in situ by benthic landers demonstrated that fluxes of dissolved inorganic P (DIP) from anoxic bottom sediments in the Eastern Gotland Basin are higher than previously thought (Paper I). READ MORE

  7. 5. Drivers of increasing iron concentrations in freshwaters

    Author : Caroline Björnerås; Enhet akvatisk ekologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Järn; Akvatisk ekologi; Biogeokemi; Brunifiering; Iron; Freshwaters; Biogeochemistry; Brownification; Iron biogeochemistry; Browning; Freshwaters;

    Abstract : Iron (Fe) concentrations are increasing in freshwaters (lakes and streams) in Sweden, as well as in other regions in northern Europe. Together with increasing concentrations of organic matter, Fe is contributing to the ongoing browning of freshwaters, which may have serious ecological consequences and implications for ecosystem services. READ MORE