Sökning: "total organic carbon TOC"

Visar resultat 11 - 15 av 24 avhandlingar innehållade orden total organic carbon TOC.

  1. 11. Infrared spectroscopy as a tool to reconstruct past lake-ecosystem changes : Method development and application in lake-sediment studies

    Författare :Carsten Meyer-Jacob; Richard Bindler; Hendrik Vogel; Jan Karlsson; John F. Boyle; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fourier transform infrared spectroscopy; visible-near infrared spectroscopy; PLS regression; biogenic silica; climate change; carbon cycling; lake-water quality; geochemistry; paleolimnology; Holocene; Lake El’gygytgyn; Torneträsk;

    Sammanfattning : Natural archives such as lake sediments allow us to assess contemporary ecosystem responses to climate and environmental changes in a long-term context beyond the few decades to at most few centuries covered by monitoring or historical data. To achieve a comprehensive view of the changes preserved in sediment records, multi-proxy studies – ideally in high resolution – are necessary. LÄS MER

  3. 12. Regulation of carbon dioxide emission from Swedish boreal lakes and the Gulf of Bothnia

    Författare :Grete Algesten; Mats Jansson; Pirkko Kortelainen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical geography and sedimentology; lakes; boreal; Gulf of bothnia; CO2; NEE; DOC; mineralization; sediment; catchment; net heterotrophy; Naturgeografi och sedimentologi; Physical geography; Naturgeografi; naturgeografi; Physical Geography;

    Sammanfattning : The global carbon cycle is subject to intense research, where sources and sinks for greenhouse gases, carbon dioxide in particular, are estimated for various systems and biomes. Lakes have previously been neglected in carbon balance estimations, but have recently been recognized to be significant net sources of CO2. LÄS MER

  4. 13. Safe drinking water in a changing environment : Membrane filtration in a Swedish context

    Författare :ANGELICA LIDÉN; Avdelningen för Teknisk vattenresurslära; []
    Nyckelord :Boreal lakes; Drinking water; Nanofiltration; Natural organic matter; Ultrafiltration;

    Sammanfattning : Surface water is vital for Swedish drinking water supply. In the past decades, a trend of increased total organic carbon (TOC) concentrations has led to higher consumption of coagulants in drinking water treatment, and has pushed the levels in the outgoing water closer to the allowed levels of TOC. LÄS MER

  5. 14. Subarctic ecosystem responses to climate, catchment and permafrost dynamics in the Holocene

    Författare :Ulla Kokfelt; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; subarctic Sweden; palsa mire development; peat; permafrost history; carbon and nutrient cycling; lake sediments;

    Sammanfattning : This thesis assesses aspects of the wetland development, permafrost dynamics and associated changes in carbon and nutrient cycling of the Stordalen Mire in northern Sweden. Various ecological and biogeochemical analyses of one peat and two lake sediment sequences were conducted, including analyses of organic matter and carbonate content, mosses, diatoms, testate amoebae, pigments, carbon and nitrogen and their stable isotopes, near infrared spectroscopy and biogenic silica. LÄS MER

  7. 15. Macronutrient cycling in surface waters : large-scale patterns and assessment of global change

    Författare :Maria Khalili; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The levels and relative proportions of macronutrients set the conditions for life in surface waters. Man-made disturbances to macronutrient cycling have caused environmental problems such as eutrophication, acidification and global change. LÄS MER