Mapping of areas suitable for the application of biosolids in the Quadrilátero Ferrífero region, Minas Gerais, Brazil

Abstract

The recovery of degraded areas is imperative for the sustainability of mining ac-tivities. The main action implemented to improve the chemical, physical and biological conditions of soils, tailings and sterile deposits is the incorporation of organic material. Biosolids (hygienized sewage sludge) are among the organic materials that can be ap-plied. However, considering the health risk they represent, not all areas are suitable for receiving this waste. The present research sought to map the environmental suitability of the Quadrilátero Ferrífero (QF) region to assess the applicability of biosolids. For this purpose, maps were elaborated using restrictive criteria established for the safe application of this residue to the soil by means of the Geographic Information System (GIS), using the ArcGIS software, version 10.2. The established criteria were pedology, topography, hydromorphism, presence of protected areas, soil texture, susceptibility to erosion, proximity to urban areas and their overlaps to obtain the final suitability areas. For the exclusion of areas that presented legal restrictions, the criteria of protected area, areas close to water bodies, urban areas, shallow soils and a slope greater than 45% were used, as established in literature, in CONAMA 498/2020 and in the Forest Law-Federal Law 12,652 of 2012. Of the areas analyzed, 58.5% were suitable for biosolid application, equivalent to 10,858.3 ha of the 18,587 ha studied, indicating the feasibility of biosolids application in part of the QF area to be recovered.