INDEX TO EVALUATE CLOSED LANDFILLS BASED ON LEACHATE PARAMETERS

Abstract

After the end of their useful life, waste landfills and their surroundings should continue to be monitored constantly. The main concern is pollution of groundwater and surface water from leachate, posing a risk to public health. The effluent generated by closed landfills may have equal or greater potential for contamination compared to active landfills. The proposal of an index to evaluate the landfill conditions after closure was the main motivation for this work. The insufficiency of data on the waste entering these areas causes uncertainty as to how long the material will continue to degrade. In this article, the presence of polluting elements in the leachate of a deactivated landfill was evaluated through the characterization of the effluent during a ten-year monitoring period. From the study of existing indexes to evaluate the leachate of closed waste disposal areas, we verified the importance given to certain parameters that are not relevant for Brazilian landfills, in which the presence of organic matter is high. The present work contributes by generating information for a better understanding of the impacts caused by landfills in Brazil and in most countries of the Third Word, in which organic waste represents at least 50% of the waste discarded in landfills. With the application of the proposed Deactivated Landfill Assessment Index (DLAI), involving four-parameter analysis (pH, BOD, COD and ammoniacal nitrogen), possible threats of pollution can be detected, allowing prioritizing areas for remediation and better allocation of resources.