Avaliação dos parâmetros de um biodigestor para tratar lixiviados de resíduos sólidos urbanos

Abstract

The costs for the implementation of a landfill and, consequently, a slurry treatment system, are costly for small municipalities. Considering the low maintenance cost and simplicity of operation of biodigesters, when compared to other treatment systems, the objective of this study was to evaluate the pollutant potential of different compositions of urban solid waste and the potential for removal of organic matter and solids total slurry through secondary treatment using biodigesters. For the assembly of the experiment, the residues were weighed and mixed with different percentages of organic matter (0, 30 and 60%), reject and recyclable, following an order for a set of three containers, which were connected to a biodigester for the treatment, denominated Systems 1, 2 and 3. The evaluated parameters were: pH, Chemical Oxygen Demand (COD), Volumetric Organic Load (VOC), alkalinity, total solids. System 3 was the one that presented better performance in relation to the studied parameters, very possibly in relation to the organic matter content, corroborating with the legislation that recommends the grounding of 30% of organic matter for small landfill. The characteristics of the anaerobically digested solid residue leachate indicated that the average organic matter content and solids were still high. The levels of organic matter removal were also not satisfactory, giving a greater efficiency for System 3 of the order of 24%. These results indicate that the effluent has inadequate characteristics at disposal and / or reuse, and the addition of a post-treatment step to adequacy of the effluent is necessary.