Measurements of gas emissions at eight solid waste landfills of the state of São Paulo - Brazil / Medidas da emissão de gases em oito aterros de resíduos sólidos urbanos do Estado de São Paulo - Brasil




Urban solid waste disposal landfills are equipments that must be integrated with the drainage and protection of the public health of municipalities system. Regardless of whether they are well planned, built and operated, they offer environmental impacts to the areas where they are deployed and their surroundings. The present work aimed at measuring, as estimates, in situ, the contribution of the aforementioned equipments in the flux of these gases in nature. The research was developed in 2006 and 2007 in two campaigns in eight municipal solid waste landfills in the state of São Paulo, Brazil. Concentrations of CH IND.4and CO IND.2were measured in the air from landfills; the ground-air emission and the flux from vertical drains, when present. The samples collected of the GAS were analyzed utilizing gas chromatography. The results showed that the concentrations of CH IND.4and CO IND.2in the atmosphere from landfills were 18,000 ppm and 5,500 ppm, respectively. These values correspond to ten thousand and fifteen times greater than those measured on places far away from landfills (background). The results of the ground-air flux indicated a great variability of this emission, not only among the collection sites, but also among the landfills and between the campaigns. The average ground-air emission ranged from 5.66 g/M POT.2.d to 148.20 g/M POT.2.d for CH IND.4and from 17.78 g/M POT.2.d to 223,04 g/M POT.2.d for CO IND.2. The estimated ground-air emission for the landfills ranged from 276.82 to 75,730.20 tons per year of CH IND.4and from 501.02 to 76,312.74 tons per year for CO IND.2. The estimated emission for the landfills from the vertical drains ranged from 73.52 to 307.31 tons per year for CH IND.4and from 165.83 to 692.32 tons per year for CO IND.2. The results also showed that concentration of gases in the environment air of landfills and the emission, especially ground-air, seems to be independent of the operation given: whether it is sanitary landfill, controlled landfill, or dump. They all presented many similarities in the emission process, and major differences among them were not elucidated. Even the presence of the suction system of the GAS to feed the thermoelectric plant (UTEB) at the Bandeirantes landfill, located at the capital of São Paulo, did not differentiate it from the other landfills from the CH IND.4and CO IND.2emission perspective. In a nutshell, it was not possible to correlate variables that pointed to general trends in the emissions of these USW disposal equipments. Based on these results, future prospects for research are suggested.


resíduos sólidos urbanos fugitive emissions aterros de resíduos urban solid waste emissões fugitivas fluxo de metano methane flux solid waste landfills efeito estufa fluxo de dióxido de carbono greenhouse effect carbon dioxide flux

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