Spatial variability of soil gas concentration and methane oxidation capacity in landfill covers

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Autor/in:
Erscheinungsjahr:
2011
Medientyp:
Text
Schlagworte:
  • Landfill
  • Land fill
  • Cover soil
  • Microbial Fuel Cells
  • Anaerobic Digestion
  • Bioreactors
  • Landfill
  • Land fill
  • Cover soil
  • Microbial Fuel Cells
  • Anaerobic Digestion
  • Bioreactors
Beschreibung:
  • In order to devise design criteria for biocovers intended to enhance the microbial oxidation of landfill methane it is critical to understand the factors influencing gas migration and methane oxidation in landfill cover soils. On an old municipal solid waste landfill in north-western Germany soil gas concentrations (10, 40, 90cm depth), topsoil methane oxidation capacity and soil properties were surveyed at 40 locations along a 16m grid. As soil properties determine gas flow patterns it was hypothesized that the variability in soil gas composition and the subsequent methanotrophic activity would correspond to the variability of soil properties. Methanotrophic activity was found to be subject to high spatial variability, with values ranging between 0.17 and 9.80gCH4m-2h-1. Considering the current gas production rate of 0.03gCH4m-2h-1, the oxidation capacity at all sampled locations clearly exceeded the flux to the cover, and can be regarded as an effective instrument for mitigating methane fluxes. The methane concentration in the cover showed a high spatial heterogeneity with values between 0.01 and 0.32vol.% (10cm depth), 22.52vol.% (40cm), and 36.85vol.% (90cm). The exposure to methane raised the oxidation capacity, suggested by a statistical correlation to an increase in methane concentration at 90cm depth. Methane oxidation capacity was further affected by the methanotroph bacteria pH optimum and nutrient availability, and increased with decreasing pH towards neutrality, and increased with soluble ion concentration). Soil methane and carbon dioxide concentration increased with lower flow resistance of the cover, as represented by the soil properties of a reduced bulk density, increase in air capacity and in relative ground level. © 2010 Elsevier Ltd.
Lizenz:
  • info:eu-repo/semantics/closedAccess
Quellsystem:
Forschungsinformationssystem der UHH
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oai:www.edit.fis.uni-hamburg.de:publications/0dbf9158-9df9-48b1-8b8d-3213ed1a2481