Search for dissertations about: "Sediment"

Showing result 6 - 10 of 553 swedish dissertations containing the word Sediment.

2. 6. Lake sediment as environmental archive : natural and anthropogenic influence on the chronology of trace elements

   Author : Evastina Grahn; Stefan Karlsson; Anders Düker; Bo Bergbäck; Örebro universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; lake sediment; environmental pollution; trace elements; chronology; diagenesis; Ag; Be; Ga; In; Pb; Sb; Tl; Environmental chemistry; Miljökemi; Enviromental Science; Miljövetenskap;

   Abstract : The focus of this thesis is the historical pollution of some seldom-monitored trace elements (SMTEs; Ag, Be, Ga, In, Sb and Tl) that have been involuntarily released for several thousands of years but whose usage have increased during the industrial era. Sediment cores from four rural lakes in a south to north transect in central Sweden, and two urban lakes have been used as environmental archives for chronological studies. READ MORE

4. 7. The origin and fate of sediment organic carbon in tropical reservoirs

   Author : Anastasija Isidorova; Sebastian Sobek; Rafael Marcé; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; methane; carbon burial; tropical reservoirs; sediment; carbon cycle; limnology; Biology with specialization in Limnology; Biologi med inriktning mot limnologi;

   Abstract : Recently, the construction of reservoirs has boomed, particularly in the tropics, but the impact of reservoirs on the global carbon cycle is not evident. Reservoirs accumulate sediments that simultaneously bury organic carbon (OC) and thus act as a C sink, and also produce methane (CH4) and thus emit a strong greenhouse gas. READ MORE

5. 8. 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

6. 9. The role of benthic macrofauna in nitrogen cycling in eutrophic lake sediment

   Author : Jonas Martin Svensson; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; nitrogen retention; nitrous oxide; oligochaetes; chironomids; mineralisation; nitrification; denitrification; eutrophic; sediment; lake; Macrofauna; nitrogen cycling; fish reduction.; Ecology; Ekologi;

   Abstract : This thesis concerns the role of sediment-living macrobenthos in the cycling of nitrogen species and nitrogen transformation in eutrophic freshwater sediments. In my thesis I have, employing 15N-isotope techniques in laboratory experiments, shown the importance of infaunal chironomid larvae and oligochaetes on denitrification in eutrophic lake sediments. READ MORE

7. 10. Accumulation and Composition of Gully Pot Sediments under Varying Anthropogenic Activities

   Author : Haoyu Wei; Lian Lundy; Maria Viklander; David Butler; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Catch basin; Stormwater; Sediment; Urban runoff; Xenobiotics; Gully pot maintenance; Emerging pollutant; VA-teknik; Urban Water Engineering;

   Abstract : Gully pots (GPs) are an integral urban drainage component, contributing to conveying runoff from urban surfaces and reducing the load of solids and associated contaminants entering downstream piped systems and receiving waters. Over time, the silting-up of GPs impairs their hydraulic performance, increasing the risk of GP blockage-induced flood events and reducing solids retention performance. READ MORE