Emissão de óxido nitroso por lagoas de acúmulo de lixiviado de aterro sanitário

Abstract

Urban solid waste represents a major challenge in the area of management, as its inadequate disposal can generate several harms. The sanitary landfill is one of the ways of disposing of these residues, being also the most used technique in several countries. One of the by-products of landfills is leachate. Its composition is quite complex, with a high concentration of organic compounds and nitrogenous forms. High concentrations of nitrogen can promote the emission of nitrous oxide (N2O), a greenhouse gas with a high warming potential. Thus, this work aimed to evaluate N2O emission in leachate accumulation ponds and compare these emissions with different sources. Leachate samples were collected in lagoons of a landfill located in the State of Rio de Janeiro. In each sample, the following parameters were evaluated: COD, nitrite, nitrate, NTK, ammonia nitrogen and organic nitrogen. For the analysis of the emission of N2O emission, the static chamber technique was used and the emission rate per area of each lake was calculated. These values were extrapolated to landfill leachate ponds located in the State of Rio de Janeiro. An average emission rate of 861 kg N2O ha-1

year-1 was obtained and when,

extrapolated to the other landfills, the emission was 20 t N2O year-1

. Compared to N2O emissions in other sectors, such as agriculture, livestock, energy, industrial processes and land use change and forests, emissions in leachate accumulation ponds were, respectively, 181, 90, 5 and 3 times, minors.