Soil and plant-mediated emissions of methane and nitrous oxide from a municipal solid waste landfill.

摘要

This thesis reports on two separate studies that were designed to gain a better understanding of N₂O and CH₄ emissions from a municipal solid waste (MSW) landfill cover soil, and to determine whether N₂O and CH₄ could be transported from the root zone to the atmosphere internally by Populus deltoides × Populus nigra poplar seedlings. Fluxes of N₂O and CH ₄ from the Park Road landfill were determined in the field using a micrometeorological flux measurement technique. Tree mediated N₂O and CH₄ emissions were monitored in a laboratory-scale experiment.; Nitrous oxide emissions from the MSW landfill were negligible. In contrast, CH₄ emissions were appreciable but varied over time and space. The temporal variability in CH₄ fluxes was explained in part by barometric pressure, wind speed and precipitation.; Nitrous oxide was found to be transported from the roots to the atmosphere via hybrid poplar seedlings. Methane transport/emission was negligible, although physical evidence suggests hybrid poplars growing in a landfill cover soil may be capable of acting as conduits for landfill biogas emissions.