Diagnóstico ambiental: análise física e química do solo e da água de um aterro inativado no município de Caçapava do Sul

Abstract

The large population growth, coupled with industrial development, provides increasing waste generation. Their destination, however, does not always happen properly, causing contamination to both water resources and the soil. In Caçapava do Sul, from 1997 to 2005, one of the inadequate forms of disposal of solid urban waste, called “dump”, worked. After its closure, the garbage dump was licensed by FEPAM to undergo recovery of degraded areas, having as some of the measures taken the grounding of cells with soil and grass. Considering the problem of the constant generation of leachate in the site, the present work aimed to evaluate the water quality that is under the influence of the controlled landfill through the Water Quality Index and the comparison of its physical, chemical and biological parameters with National Environmental Council Resolution 357/2005, and geochemical characterization of the landfill soil through particle size analysis, X-ray fluorescence analysis and pH. Water was collected at two points: one upstream and one downstream. The water classification, according to the Water Quality Index, was good for both points analyzed. According to CONAMA Resolution 357/2005, the two points obtained most of their parameters classified as Class 1 freshwater, except BOD (5,20), which was classified as Class 2. Regarding the fluorescence analysis of X-ray of the water, only the point that is after the discharge of the lagoons presented elements such as Al and Cd, which may originate from this source of contamination. A soil analysis collection was performed in eight points respecting three depths (one of them being the point for control). The soil showed a high incidence of coarse gravel (gravel and sand), favoring leachate percolation. The pH values found showed an acid soil. Regarding soil element analysis, only Ca and Zn did not present higher than expected concentrations for granitic soils. However, it is recommended that further studies be conducted to identify the degree of hydraulic conductivity of the area and whether the origin of the elements above the expected natural concentrations is anthropogenic.