Quality of soil under deposits of dimension stone processing wastes

ABSTRACT

Brazil has a worldwide prominence in the dimension stone Market, where the state of Espírito Santo participates as the main processing pole in the country. Transforming blocks of rocks in polished plates generates a large amount of waste, that has been deposited directly on the ground. The knowledge about the characteristics of soil under the waste disposal sites and in locals certainly not affected by them is requested for adequate waste management. The aim of this work was to analyze the quality of soil and the presence of potentially toxic metals in three landfills of dimension stone waste in Cachoeiro de Itapemirim County (state of Espírito Santo, Southeastern Brazil). The deposits are in different topographic positions (hilltop, slope, and valley) and the vicinity has different types of land usage. In addition to the comparison with control samples, the areas are compared with each other, and some data are compared with thresholds established by CONAMA Resolution 420/2009, as well as with the common variation of soils in the state of Espírito Santo. Interactions between waste and soil were detected by the increased pH-values; K and Na concentrations; in addition to the parameters SB, t, T, and V in sites situated in slope and hilltop. Concerning potentially toxic metals, no clear pattern was observed between their source and the waste; on the contrary, the higher metal levels in the area that receive sewage discharges indicate a possible external source of Cu, Cr, Pb, Zn, and Ni.

Keywords:
abrasive slurry; processing; environmental impacts; soil contamination