Tratamento de lixiviado e lodo de fossa séptica usando geobag e filtro biológico: estudo em escala laboratorial

Abstract

This work aimed to evaluate the efficiency of a system which was set up with the techniques of geobag and biofilter filter percolator treatment of landfill leachate effluents and septic tank sludge. The study was conducted in laboratory scale and the mixture respected the volumetric relation of 4:1 (tank sludge: leachate). The geobag (that had small dimensions) was installed upstream of the biological filter. The mixture was fed to the geobag and percolated to the biofilter with the assistance of a peristaltic pump. The effluents (leachate and sludge) were collected in the landfill and in a Sewage Treatment Plants. The topics analyzed were: raw leachate, septic tank sludge, mixture of effluents without flocculant (point 1), the output of the geobag (point 2) and the output of the biological filter (point 3). All the samples were submitted to the physicochemical characterization and the acute toxicity experiment. The system operation lasted six months. The outcomes of the physicochemical characterization show a considerable diminution of the ammonium nitrogen parameters (67%) and solids (98%). To the remnant parameters, the reduction was not so significate. The development of the treatment system in relation to the toxicity was analyzed well, and a diminution of the toxicity was verified with the passage of the mixture through the system. Despite the diminution, the mixture remained toxic to the environment. One of the factors that most influenced the system development was the variability of the septic tank sludge characteristics that would change in each new collection throughout the operation. Even with limitations, the system applied can be an alternative to the diminishment of leachate potential polluter in small and average-sized counties, due to low cost and to ease maintenance.