Search for dissertations about: "nitrous"

Showing result 1 - 5 of 78 swedish dissertations containing the word nitrous.

  2. 1. Nitrous oxide emission from soil : On extrapolation from soil environmental factors

    Author : Kerstin Robertson; Linköpings universitet; []
    Keywords : SOCIAL SCIENCES; SAMHÄLLSVETENSKAP; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; N20 emission; denitrification; soil factors; soil moisture; N03-; NH4 ; regression analysis; PLS analysis; IR remote sensing; INTERDISCIPLINARY RESEARCH AREAS; TVÄRVETENSKAPLIGA FORSKNINGSOMRÅDEN;

    Abstract : Nitrous oxide(N20) is a natural component of the atmosphere which contributes both to the greenhouse effect and to the destruction of stratospheric ozone. National as well as global inventories indicate thatboth natural and anthropogenic emissions from terrestrial ecosystems constitute a large fraction of the annual loading of N20 on the atmosphere. READ MORE

  4. 2. Risk of nitrous oxide emissions and potential of bioaugmentation when treating digester supernatant via nitrification-denitrification

    Author : Fredrik Stenström; Institutionen för kemiteknik; []
    Keywords : Bioaugmentation; Digester supernatant; Inoculation; Nitrification-denitrification; Nitrifiers; Nitrous oxide emissions; Reject water; Bioaugmentation; Digester supernatant; Inoculation; Nitrification-denitrification; Nitrifiers; Nitrous oxide emissions; Reject water;

    Abstract : This thesis examines two different impacts of sidestream treatment of digester supernatant via nitrification-denitrification in a sequenced batch reactor (SBR). One of the impacts is the detrimental formation of nitrous oxide, and the other is the positive boosting of nitrifiers to the mainstream process through bioaugmentation. READ MORE

  5. 3. Nitrous Oxide Emission from Circulating Fluidized Bed Combustion

    Author : Lars-Erik Åmand; Chalmers University of Technology; []
    Keywords : air supply dependence; fluidized beds; homogeneous heterogeneous reactions; fluidized-bed boilers; bed temperature dependence; N2O emissions; circulating fluidized-bed boilers; gas-concentration profiles;

    Abstract : In the present thesis N2O results are presented from several measurement projects on two commercial circulating fluidized bed (CFB) boilers. Traditional parameter studies have been carried out, as well as test programs where various nitrogen-containing species were injected into the furnace or gas-concentration profiles in the combustion chamber were measured. READ MORE

  6. 4. Denitrifying and nitrous oxide reducing genotypes : ecophysiology and niche differentiation

    Author : Lea Wittorf; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Keywords : NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES;

    Abstract : Denitrification is a biogeochemical process of major importance for nitrogen loss from ecosystems. This four-step pathway is modular, as organisms can have different subsets and variants of the genes involved in each step. The last step is the only known biological sink of nitrous oxide, a potent greenhouse gas and ozone depleting substance. READ MORE

  7. 5. Nitrogen Losses from a Clay-rich Soil used for Cereal Production in south-western Sweden

    Author : Magdalena Wallmann; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; nitrogen; fertilisers; soil; nitrous oxide; nitrogen leaching; 15N; nitrogen use efficiency; nitrogen budget; agriculture; Sweden;

    Abstract : Addition of fertiliser nitrogen (N) in crop production increases yields and protein contents, but all is not taken up by the crop. Instead, some of the N is lost to air and waters, contributing e.g. to climate change, stratospheric ozone depletion, eutrophication and acidification. READ MORE