Soil column test to study the influence of dimension stone fine wastes on water quality

ABSTRACT

The generation of fine wastes from cutting of ornamental stones grows at the same rate of plate production for civil construction. The adoption of safe, remediating and punitive measures are linked to the knowledge of the actual potentiality that these materials have for causing negative impacts to the environment. The aim of this work was to simulate, in laboratory, possible alterations in the recharging groundwater quality provoked by the improper disposal of these wastes. We conducted tests of percolating water through soil columns covered by wastes with different humidity rates: wastes without treatment, outgoing directly from the looms (TE); wastes that passed by filter press for humidity reducing (FP) and wastes dried in a drying pond (LS). Percolated water was analyzed to evaluate alterations of its quality in relation to a blank (B) or control. Significant changes did not occur in pH-values of percolated water in any of the cases studied. However, many water quality parameters were changed during TE treatment. The water percolated through FP residues was similar to that of the looms in relation to some parameters and with the LS wastes, in others. We concluded that the wastes that just left the loom have high potential for changing water quality, but the reduction of waste´s humidity is efficient for minimizing environmental risks. The use of drying bed could be as efficient as the filter press, if conducted in a proper form and according to legal regulations.

Keywords:
abrasive slurry; water pollution; drying ponds; filter press