Biotic Landfill Cover Treatments for Mitigating Methane Emissions

Landfill methane (CH4) emissions have been cited as one ofthe anthropogenic gas releases that can and should be controlledto reduce global climate change. This article reviews recent research that identifies ways to enhance microbial consumptionof the gas in the aerobic portion of a landfill cover. Use of these methods can augment CH4 emission reductions achievedby gas collection or provide a sole means to consume CH4 atsmall landfills that do not have active gas collection systems.Field studies indicate that high levels of CH4 removal can be achieved by optimizing natural soil microbial processes. Further, during biotic conversion, not all of the CH4 carbonis converted to carbon dioxide (CO2) gas and released to theatmosphere; some of it will be sequestered in microbial biomass.Because biotic covers can employ residuals from other municipalprocesses, financial benefits can also accrue from avoided costsfor residuals disposal.