STUDY OF THE EMISSIONS GENERATED BY THE PROCESS OF EVAPORATION OF LANDFILL LEACHATE

Abstract

Landfilling is still the most frequently employed alternative in most countries for the treatment and disposal of solid waste. This form of waste treatment is considered safe from the environmental point of view, although it results in the emission of gaseous and liquid pollutants, which, if not properly collected and treated, may become potential sources of environmental pollution. Landfill leachate treatment through evaporation has been investigated by several researchers since the eighties (KONRAD, 1989; BIRCHLER et al., 1994, MARKS et al., 1994; YUE et al., 2007), however, published articles on the subject are still incipient. This work aims to deepen the understanding of leachate evaporation process, in order to identify and measure the pollutant emission resulting from this type of treatment. For the accomplishment of this study, a distillation apparatus has been used, in order to obtain a condensate from the evaporation of the landfill leachate. Physical and chemical analyses of the resulting effluents (condensate and concentrate) have been carried out, in order to quantify the emission of organic and inorganic pollutants generated by leachate evaporation. The tests have been accomplished with leachate from two landfills, two pH conditions being studied in each leachate (with and without adjustment). The results have revealed that ammonia was the pollutant of greatest environmental concern, due to the high concentrations which have been noticed in the condensate obtained from the process without pH adjustment, although it was possible to observe that by adjusting the leachate pH to a slightly acidic condition, it was possible to reduce significantly the ammonia emissions of the condensate effluent.

Key Words: Ammonia, landfill, leachate evaporation