A study of literature reporting on the oxidation of methane in various soil types has shown that the process is successfully removing more carbon emissions than first thought. Microbial oxidation is the process that takes place as a result of microscopic bacteria living in the top soil covering used to cap landfill sites, and helps reduce the amount of methane and other harmful gases being released into the atmosphere.
Current regulations from EPA in the US recommend a 10% oxidation rate, largely due to the difficulty in measuring the rate of oxidation and the lack of a standard methodology for testing and therefore enforcing the rate of oxidation. The Intergovernmental Panel on Climate Change, however, recommends between 0% and 10% oxidation rate. The findings of the results show however that on average, 35% of methane is oxidised by the bacteria.
Findings showed that in clay soil, the amount of methane that was oxidised was on average around 22%, whereas sandier soils proved more efficient with as much as 55% of the methane being oxidised. The literature surveyed covered reports on 42 different determinations of the amount of methane oxidised by the microbes, and out of these 42, only 4 showed figures of less than 10%. The results propose a strong case for higher oxidation rates to be set as standard, and with more research and action, the amount of harmful gases released by landfill sites around the world could be reduced significantly, helping in the fight against global warming.