Proposta de índice de avaliação de aterros de resíduos desativados a partir do potencial poluidor do lixiviado

Abstract

Upon completion of their activity, landfills and its surroundings should continue to be monitored. The main concern is the pollution of soils, groundwater and surface water from the leachate, posing a risk to public health. Leachate generated in closed landfills may have equal or greater potential for contamination compared to active landfills, but the post-closure monitoring period is summarily ignored in Brazil, and many areas are abandoned at the end of the operation. In this research, the presence of elements with pollution potential in the leachate of deactivated landfill was evaluated through the characterization of the effluent at points in the surroundings and in the landfill during a long period of monitoring. Over the years, concentrations of heavy metals were below the guiding values, BOD and COD decreased, and pH and ammoniacal nitrogen increased. From the study of indicators of closed areas and existing landfills to assess the leachate's polluting potential, it was verified that the weights and importance given to certain parameters are not relevant for application in Brazilian landfills in which the presence of organic matter is high. This research presents a new proposal for the evaluation of enclosed landfill sites. It was concluded that the analysis of only 4 parameters (pH, BOD, COD and ammoniacal nitrogen) would be enough for the decision makers to evaluate the leachate's polluting potential, allowing a better allocation of resources for remediation processes.