In-Situ-Aeration of an Old Landfill – a Profound Analysis

This technique is currently used to remediate the old landfill "Heferlbach" close to the Schwechat airport, east of Vienna. Between 1965 and 1973 around 240,000 m 3 of waste have been deposited at this site, mainly made up by MSW (about 62 %) and mineral waste. For the in-situ-aeration, horizontal venting pipes were installed at the site at different depths: the lower pipes are used to inject air into the landfill, whereas the upper venting pipes are used to extract the generated landfill gas. The extracted off-gas is subsequently vented through a compost-filter-system.
The overall goal of the project is to determine technically feasible levels of waste stabilization which can be achieved by in-situ-aeration measures at old landfills. Beside the installation of two monitoring fields on-site, the land-filled waste has been characterized prior to the start of air injection. In addition, lab-scale experiments using so called "landfill simulation reactors" (with an experimental volume of 80 liters) have been set up and are currently in operation. The aims of these experiments are on the one hand to determine the potential gas-production of the land-filled waste and on the other hand to describe the potential performance of the in-situ-aeration.