Produção de resíduos sólidos e lixiviados em aterros sanitários na Amazônia

Abstract

The production and disposal of solid waste is still a complex issue and mostly unresolved in developing countries, especially in countries that are part of the Amazon, as the per capita generation of solid waste increases with population growth. As there is usually no selective collection system, the solid waste goes to final disposal and its decomposition generates leachate with a high polluting degree. Associated with these problems is the presence of extreme rainfall due to the El Niño and La Niña phenomenon, which can increase the degree of impact of leachate on the surroundings. Thus, the objective of this research was to estimate the spatial variation of the per capita generation related to demographic, socioeconomic, sanitary, and ecological factors, to predict impacts associated with leachate (modeling) and its parameters for the elaboration of hydrological scenarios (flow generation) in a landfill in the Amazonia international and a case study was carried out for the landfill in the municipality of Macapá-AP. In the relationship of per capita generation with the factors, represented by 18 independent variables, the variables country, Gini index were found to be significant (RCountry 2= 60,09%, RGINI2=30.83%) regardless of being in Amazon (RBioma2=5.34%). The multivariate models showed a variation in explainability, depending on the number and type of variable chosen [54.47%≤Raj2≤70.83%]. On the other hand, average (0.45 m3 s -1 ), minimum (0.07 m3 s - 1 ) and maximum (0.72 m3 s -1 ) flow were estimated. In the hydrological models, a maximum correlation coefficient R=99% was obtained, without significance. The results of the flow estimates can predict different concentrations of physicochemical compounds (BOD, COD, NH3, etc) concerning landfill operations, where there is a lack of information. Rainfall estimates at different return periods allowed us to assume the possible impact that affects the water and leachate flow in extreme events. Furthermore, in the modeling performed for three variations of Macapá controlled landfill drainage systems, in relation to hydrology and leachate volume, leachate did not present significant differences between the different geometric arrangements of the pipes, as well as in the physicochemical compounds, during the year of closing of the controlled landfill, where it was possible to find compatible atypical values expected in similar situations. It was concluded that RPC forecasts reflect the reality regarding solid waste management and public policies in these countries. In addition, there is the possibility of an increase in leachate in extreme events at a time of high rainfall, because of the lack of water control in the landfill’s operational management, threatening a leachate overflow, impacting the physicochemical composition of the ecosystem and the population. The modeling performed can be useful to optimize the closure of controlled landfills and implementation of landfills through simulations. On the other hand, the methodologies used were relevant and aligned with multiple scenarios and factors or variables that can facilitate decision-making to improve current and future projects, with an emphasis on places with a deficit of technical information, such as in the Amazon and in countries in development that present great inequalities.