Distribución de los contenidos de Fe y Pb en escombreras, suelos y sedimentos del distrito minero de Linares (Jaén)

Abstract

Soils and sediments from historical metallic sulphides mining and smelting areas in Linares (jaén) have been sampled for both the determination of the total amount of heavy metals and the analysis by a 5-step sequential extraction procedure. Fe and Pb have been determined on each extraction solution, defined as: exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and sulphides, and residual. High concentrations of the total metals were found in all the 12 studied samples. The maximum contents for total Fe (80.000 to 200.000 mg/kg) are related to smelting tailings. This is not the case for total Pb, with maximum levels (20.000 mg/kg) located in soils and sediments near the mining tailings. The most marked difference found between Fe and Pb distribution is the much higher proportions and concentrations of Pb in the exchangeable fraction, indicating greater mobility and bioavailability of this toxic metal which is a feature of important environmental concern