Environmental Engineering Reference
injection of air or oxygen into the waste mass. It is also possible to apply a vacuum to the
waste mass and pull air in through a permeable cap. Liquids are typically added through
leachate recirculation, with the need for additional sources of moisture even more acute than
for anaerobic reactors. The aerobic process does not generate methane.
Figure 2 shows a cut-away view of an aerobic bioreactor. Leachate is removed from the
bottom layer of the landfill and piped to a liquids storage tank. From the tank, the leachate is
piped across the top layer, where it is released to filter down through the landfill to be
collected again. A blower forces air into the waste mass through vertical or horizontal wells
located in the top layer of the landfill. Groundwater monitoring occurs at wells situated
around the perimeter of the landfill (U.S EPA 2004).
Figure 1. Anaerobic Bioreactor Landfill (U.S EPA 2004)
Figure 2. Aerobic Bioreactor Landfill (U.S EPA 2004)