Abstract
The gas fluxes from two pieces of gas ventilation equipment and a monitoring well in a controlled landfill site for industrial waste with about 45 meter depth were investigated using hot-wire anemometers for 18 years.
In the composition of the landfill gas, the methane to carbon dioxide ratio was high. The maximum concentrations of methane and carbon dioxide were 81.6% and 12.3%, respectively. The concentration of landfill gas decreased year by year.
The average gas flux on measurement days was 203 L/min at maximum and tended to decrease year by year. From factor analysis using 10-minute intervals, the gas flux decreased when atmospheric pressure rose for the most recent interval. In contrast, the gas flux tended to increase during decreases in atmospheric pressure. The rate of increase of the gas flux decreased after much gas emission.
From factor analysis at 1-minute intervals, it was inferred that atmospheric pressure changes in several tens of minutes influenced the gas flux of the whole landfill site, and the atmospheric pressure change in several minutes influenced the fluctuation of the gas flow near the gas ventilation equipment.
