Soil pollution by a pyrite mine spill in Spain: evolution in time

J. Aguilar, , C. Dorronsoro, E. Fernández, J. Fernández, I. García, F. Martín and M. Simón

Soil Science Department, Faculty of Sciences, University of Granada, Campus Fuentenueva s/n, 18002 Granada, Spain

Enviromental Pollution 132, 395-401.

Abstract

Soil pollution was studied after the spill of the Aznalcóllar pyrite mine between 1998 and 2001, analyzing As, Zn, Cd, Cu and Pb both in total concentrations as well as in soluble and bioavailable forms. The main remediation measures were: clean-up of the tailings and polluted soils, plus application of amendment materials (liming). The results indicate that, after three years, 50–70% of the acidic soils and 25–30% of the basic soils are still highly polluted in total arsenic. The limit of 0.04 mg kg-1 for water-soluble arsenic is exceeded in 15–20% of all soils. The EDTA-extractable arsenic (bioavailable) exceeds the limit of 2 mg kg-1 only in the acidic sectors. After clean-up, the homogenization of the upper 20–25 cm of the soils appears to be the most recommended measure in the reduction of pollution

Capsule

Remediation measures carried out after the Aznalcóllar pyrite mine spill were effective in the reduction of the pollution, although three years after the accident many areas are still polluted by As.

Keywords: Pyrite; Soil pollution; Heavy metals; Solubility; Bioavailability.