Chemical and sanitary changes in soils and sterile of mining receiving sewage sludge, organic compost and mineral fertilizer

The objective of this study was to evaluate chemical and sanitary changes in soils and sterile mine in the Quadrilatero Ferrifero region, Minas Gerais, by incorporating the sanitary sewage and commercial organic compost, using a conventional chemical fertilizer as treatment control. The study was carried out in the experimental area of the Mina de Aguas Claras, Minas Gerais, the soils (Latosol and Cambisol) and mine sterile were analyzed for a period of 8 months after fertilization, respectively, 49,9; 59,7 and 54,8 t ha(-1) SS; 117,4; 140,1 and 128,8 t ha(-1) de commercial organic compost; and 150 kg ha(-1) of mineral fertilizer in all materials. Regarding sanitary aspects, the SS and the commercial organic compost were classified as "Class A", according to Conselho Nacional do Meio Ambiente 375/2006. After the application of fertilizers, the contents of organic matter, macro- and micronutrients, cation exchange capacity, base saturation index, aluminum saturation index, Al3+, H+Al, levels of metals were evaluated in the soil and sterile, in addition to quantifying viable helminth eggs. It was observed that the incorporation of sanitary sewage and commercial organic compost was able to increase the levels of organic matter and fertility of materials and, although an application of sanitary sewage also provided an increase in the contents of some heavy metals, it was not enough to lose its environmental quality, according with Conselho Nacional do Meio Ambiente 420/2009 (BRASIL, 2009). There were no sanitary restrictions on the use of sanitary sewage and commercial organic compost in soils and sterile to be recovered in the Quadrilatero Ferrifero mining areas.