Leaching of Heavy Metals in Soils Conditioned with Biosolids from Sewage Sludge

ABSTRACT A promising use of biosolids is as organic fertilizer in agricultural and forestry activities. However, its composition might contain several pollutants, especially heavy metals, which may result in an increase in the concentrations of these elements in the soil and the risk of groundwater contamination. This study aimed to determine the leaching levels of ions in a Ferralsol (clayey texture) and in a Planosol (sandy texture). The experiment was conducted in a greenhouse at Embrapa Agrobiologia, Seropédica, Rio de Janeiro state. Soils were packed in PVC columns and received 2 L/column of biosolids. The concentrations of heavy metals present in the biosolids composition were below the limits established by the legislation (CONAMA 375). In addition, the performed simulations showed the absence of contamination risk of soil or groundwater and surface water, according to the limits allowed by CONAMA 375. However, it should be emphasized the potential of nitrate leaching