Edafología. Volumen 7-3. Septiembre 2000. pág 159-168.
The behaviour of 13 horizons of soils with different properties facing a pollutant solution was analysed. The pollutant solution was obtained by the oxidation of some pyritic tailings from the Aznalcóllar spill. The studied elements were Fe, Cu, Zn, As, Pb, Cd and Tl. The CaCO3 was the parameter which mainly controlled the precipitation of the pollutant elements. In the non-carbonated horizons, the precipitation of Fe, controlled by the cation exchange capacity, regulated the retention of Cu, As and, partially, Tl. The clay content regulated the retention of Zn, Pb, and Tl; in the case of the Pb, together with the pH, and in the case of the Tl, with de Fe.
Keywords: Pyritic tailings, soil pollution, buffering capacity, heavy metals.