Comportamento de um aterro sanitário experimental: avaliação da influência do projeto, construção e operação

Abstract

The accomplishment of research concerning the urban solid waste characterization and sanitary landfills behavior is of great relevance, considering the importance and safety requirements of these structures. In this context, the present work aimed to investigate the influence of operational issues, mainly those concerning waste compaction, in the behavior of sanitary landfills. The study was carried out with the construction and monitoring of an Experimental Sanitary Landfill for urban solid wastes disposal, operating in real scale. The study also aimed at evaluating the mechanical behavior of the Experimental Sanitary Landfilland the evolution of the physical and chemical parameters of the leachate and gases generated, as well as evaluating the water balance and the performance of the landfill final cover. In general, the study demonstrated that the operational procedures influenced the behavior of Experimental Sanitary Landfill. The compaction study indicated that the compacted waste density is influenced directly by the inclination of the compaction slope and the number of passes of the compactor equipment. The lower densities were obtained with the small inclinations and numbers of the passes. In the same way larger densities were obtained with higher number of passes. It was also verified that the increase in waste densities were not significant when more passes of the equipments were used. The compressibility study evidenced the influence of the initial densities in the waste settlements. The observed difference between the results of the long term settlement models suggests that the modelsmust be used together, for the definition of settlement ranges. The evapotranspirative and capillary barriers final covers presented good performances, indicating the possibility of using alternative materials with lower costs. Concerning the water balance, the field data indicatedthe limitations of the conceptual model used and had confirmed a relationship between the precipitation and the level and content of leachate inside the landfill, as well as the discharges. The study of the leachate evolution, associated wiht the results of the gases monitoring,indicated that the landfill entered the methanogenic phase one hundred days after the end of the waste disposal. The study indicated the influence of the precipitation in the evolution of the physical and chemical leachate parameters, suggesting the importance of the accomplishment of the analysis of the behavior of these parameters in terms of bothconcentration and effluent load.