landcare.project@usc.es Program

SOIL AND WATER CONTAMINATION

LandCare for the Future

Short training courses

SOIL AND WATER CONTAMINATION


Landcare

RESTORATION OF THE TOURO MINE

Tutors: Felipe Macías (USC), Grazia Masciandaro (CNR, Italy), Felipe Macías-García (TAN), María L. Fernández Marcos (USC), Xosé L. Otero (USC). Eirini-Koumoutsea (UoA Student Delegate)


The Touro mine is located in a formation of amphibolites mineralized with metal sulphides, mainly pyrite and pyrrhotite. This open cast mine was originally exploited for copper (1974-1988) and more recently for building aggregate. After the mine was closed, the pit faces, spoil dumps, trituration and flotation installations, and the sludge pond were abandoned to the elements for several years. As part of the restoration work, which began in the late 1990s, some of the faces have been partially or totally covered with water and the sludge pond has been partially filled in with soils from the area, and revegetated. The most important environmental problem at the mine is the acidity generated by sulphide oxidation.

The uncontrolled oxidation of sulphides generates hyperacidic (pH 2-3) and hyperoxidizing (> 500 mvol) soils and waters, which leads to high concentrations of sulphates, Fe, Al, Ca and heavy metals. Technosols generated from waste products from urban and industrial processes are used in the recuperation of this area. The application of this subtract is able to reduce the redox potential, increase the pH, reduces the sulphates and heavy metals in solutes and increase the fertility (organic matter and nutrients.