EVOLUTION OF METALS IN TWO SOILS CONTAINING SOLID WASTE GENERATED BY THE FOUNDRY INDUSTRY

Abstract

This work evaluates variations in the concentration of metals in the soil in areas where solid waste from the foundry industry is deposited. The study was made at two different sites (A and B) and the metals analyzed were Al, Fe, Mn, Cu, Cd, Zn, Mg, Cr, Ni, Ba and Pb. The two sites chosen were far from each other and had different characteristics; site A with clayey soil and low freatic sheet, and site B with arenous soil and a high freatic sheet. Metal concentrations in the soil were determined by assay of the gross mass of the sample, with the concentration of metals determined by atomic absorption spectrometry. Results show that for all points at site A and site B the metal with the highest concentration is iron, followed by aluminum. The third highest concentrate at site A is manganese and at site B, magnesium is at most, but not all, points. No pattern of behavior was detected in the sequence. There was no detectable level of concentration of cadmium at any point at the two sites. It can be stated that there exists a tendency towards diminution of concentration of metals as a function of depth. Comparing the concentrations, in particular those of iron and aluminum at the two sites with the reference samples, it can be stated that concentrations at site B are much more elevated. However, even when the concentration of some metals was above the concern level or target values they did not exceed CETESB or Dutch legislation intervention values. Key words: Foundry solid waste. Soil. Contamination.