Estudo experimental de wetlands construídos como unidade de polimento no tratamento de lixiviados de aterros sanitários.

Abstract

Large amounts of solid wastes are generated in cities and this is a challenge for environmental sanitation in Brazil. In order to reduce impacts to the environment and to public health, it is necessary to manage these municipal solid wastes appropriately, from their collection to their final disposal. Landfills allow a greater environmental control, provided that they are well designed and operated. Landfill leachate generation results from the decomposition of the organic matter in the wastes, combined with the rainwater that percolates the waste. Landfill leachate has a high pollution potential. Various forms of treatment are proposed in order to attenuate the potential of the leachate to pollute the environment. Constructed wetlands seem to be efficient alternatives in removing leachate pollutants with low operational and implementation costs. The present study investigated the use of subsurface wetlands in pilot scale in a pretreated leachate treatment. The wetlands were monitored in order to obtain results in reducing the concentration and loads of pollutants. The best removal performance of the concentration of ammonia nitrogen, COD and DOC were 91%, 42% and 35%, respectively. The best removal performance of the load of ammonia nitrogen and DOC were 67% and 50%, respectively. The results of the toxicity tests conducted with Vibrio fischeri and Danio rerio revealed that wetlands were effective in reducing the toxicity of the leachate.