SOUZA, J. C. M.; CARNEIRO MARTINS DE SOUZA, JORDAN.; http://lattes.cnpq.br/3427392621768495; SOUZA, Jordan Carneiro Martins de.
Resumen:
The performance of final cover layers of landfills can be affected by both geotechnical and
meteorological conditions. In regions with a semi-arid climate, the cover layers, which use soils
with low permeability, may have their performance reduced due to the wetting and drying
cycles, resulting in a loss of efficiency in retaining the flow of liquids and gases and increasing
the emissions of these gases to the atmosphere. One way to improve the performance of cover
layers in terms of fugitive biogas emissions in landfills is to determine factors that influence the
functionality of these layers. Thus, this work has the objective of verifying the influence of the
main intervening factors in the fugitive emissions of biogas in the final cover layer of compacted
soil of sanitary landfill. The experimental field for the development of this research comprises
an area of 40,000 m2 of the cover layer of the Landfill located in Campina Grande-PB. In this
layer, static flux chamber tests were carried out for the mapping of fugitive biogas emissions,
characterization and mapping of the layer's soil and verification of correlations between biogas
emissions and geotechnical and meteorological conditions through statistical analysis. The
results showed CH4 emissions ranging from 0 to 386.7g.m-2.day-1, with an average of 22 gm-
2
.day-1, and CO2 emissions ranging from 0 to 965.90 gm-2.day-1, with an average of 103.73 gm-
2
.day-1. The mapping of biogas emissions indicated a non-homogeneous behavior and with more
accentuated emissions occurring in more peripheral areas of the Cell, with values of more than
17 times the average emissions. In this location, a reduced degree of soil compaction and
thickness below the recommended was observed. With respect to local meteorological
conditions, higher fugitive emissions of biogas were observed occurring with higher
temperatures. As for the geotechnical conditions, although there were low correlations, an
influence of low humidity on higher emission values was observed, which contributed to the
need for studies of soil permeability to air in the unsaturated condition. The analysis of the fit
models indicated that, under the saturation conditions verified in the cover layer of the sanitary
landfill, the permeability of the soil to air approached the maximum, which constitutes a more
favorable condition for the passage of gases.