ABSTRACT
Laboratory experiments and modelling studies were carried out to characterise the oxidation of pyrite and other sulphides that are present at the soil after the accident at the mine tailing impoundment from Aznalcóllar (SE Spain). Results show that, in the absence of calcite, pH drops enhancing the dissolution of silicate. Moreover, high metal and sulphate concentrations causes the formation of an iron sulphate hydroxide and, temporally, Al(OH)3(am) and Fe(OH)3(am). A sequence of dry and wet periods causes the mobilisation of sulphate, iron and heavy metals.
