Search for dissertations about: "Natural sediment"

Showing result 1 - 5 of 464 swedish dissertations containing the words Natural sediment.

  2. 1. Sediment resuspension : Impacts and extent of human disturbances

    Author : Ingrid Tjensvoll; Clare Bradshaw; Torgeir Heggelund Bakke; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; marin ekotoxikologi; Marine Ecotoxicology;

    Abstract : Resuspension of sediment by anthropogenic disturbances is a concern due to the impacts it has on organisms and ecosystems. Bottom trawling is one major cause of sediment resuspension. A field study showed that a small trawl created a sediment plume 120 - 150 m wide and 15-18 m high (Paper 1). The sediment in the same study was highly contaminated. READ MORE

  4. 2. 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

  5. 3. Model Studies of Surface Waves and Sediment Resuspension in the Baltic Sea

    Author : Anette Jönsson; Lars Rahm; Åsa Danielsson; Tarmo Soomere; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Surface waves; Wave model; Wave friction velocity; Resuspension; Sediment dynamics; Nitrogen fixation; Baltic Sea; Havsvågor; Östersjön; Oceanografi; Sediment; Oceanography; Oceanografi;

    Abstract : Wave heights and periods of surface waves in the Baltic Sea have been modelled for a two-year period (1999-2000) with the wave model Hypas on an 11x11-km grid scale. There is a clear seasonal variation with higher waves during winter and lower during summer. READ MORE

  6. 4. Diatom-rich sediment formation in lakes

    Author : Petra Zahajská; Kvartärgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Silicon; silica; diatom; biogenic silica; lake; sediment; stable Si isotopes; Ge Si; Yellowstone; Northern Sweden;

    Abstract : Unicellular photosynthetic golden algae called diatoms are one of the most abundant silicifying organisms. Diatoms take up silicon and build their frustules, in the form of biogenic silica (BSi), which have high preservation potential, and thus are found in sediments. READ MORE

  7. 5. Sediment remediation using activated carbon: amending knowledge gaps

    Author : Robert A. Rämö; Jonas S. Gunnarsson; Agnes M. L. Karlson; Francisco J. A. Nascimento; Barbara Beckingham; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; sediment contamination; sediment remediation; sorbent amendment; activated carbon; benthic community; macroinvertebrates; Baltic Sea; Marine Ecotoxicology; marin ekotoxikologi;

    Abstract : Many coastal sediments have accumulated large quantities of contaminants from past anthropogenic activities and now act as a secondary emission source of legacy pollutants to coastal ecosystems. New sediment remediation strategies are needed to address widespread sediment pollution. READ MORE