Measurement of biogas emissions from air-soil interface in the MSW landfill of Legoli (Pisa, Italy)

In 2001, a survey of biogas flux from soil to estimate the amount of biogas lost in the atmosphere was carried out in the landfill of Legoli (Pisa).A total of 252 measurement sites were distributed over an area of 66,500 m2. The accumulation chamber method to measure CO2 flux from soil has been utilized. Many anomalous degassing zones have been identified. The estimation of total diffuse biogas flux was 286 Nm3/h with a specific flux of 5.8 Nl/m2day. This value corresponds to the difference between the theoretical amount of biogas yielded by the landfill, obtained by mathematical models, and the actual total biogas burnt in the plant to produce electric power. This result strongly supports the idea that this kind of biogas flux survey allows us to obtain optimum management conditions for the exploitation of landfills to produce electric power and minimize the amount of biogas lost in the atmosphere.