Evaluation of the long-term contamination potential of a tailings impoundment in the Apuseni Mountains, Rumania.
Master student Linda Frei (EPF Lausanne) under the supervision of PD. Dr. Bernhard Dold (University of Lausanne) and Prof. Dr. Christof Holliger (EPF Lausanne).

The goal of this study is to investigate the potential long-term risk of metal liberation through sulfide oxidation processes from one selected mine tailings impoundment, which lies in selected river catchments affected by mining activities with different sizes: the upper Crisul Alb, a tributary to the Tisa river and the Certej, a tributary to the Tisa river by/through Mures river, Apuseni Mountains, Rumania. In a field campaign in cooperation with the Rumanian Academy (Prof. Balteanu), solid (depth profiles up to 1.5 m depth) and water samples (existing piezometers and surface waters) from a selected tailings impoundment and surrounding areas will be taken. The risk evaluation will be done by the mineralogical and geochemical characterization (thin sections, X-ray diffraction and X-ray fluorescence analysis at the Centre d’Analyse Minérale CAM, UNIL) of the solid phase from the selected tailings impoundment and by investigation of the current level of ground and surface water contamination. Water analysis (major cations and anions) will be done by ion chromatography at the CAM. Trace metals will be analyzed in the Research Institute for Analytical Instrumentation, Cluj-Napoca, Romania and/or EAWAG, Dübendorf, Switzerland.

The investigation of the solid phases of the tailings impoundment will enable the student to evaluate the acid-base accounting and the potential metal liberation of the waste material in a long-term mean. The water data from the piezometers in the impoundment will gives indication of the current state of evolution of the system, i.e. if metal liberation and mobilization is yet occurring. By geochemical modellisation (e.g. PHREEQC) an evaluation of the metal speciation and mobilization processes of the contaminant can be addresses. The water data from the aquifer in the watershed, will give some indication if this part of the hydrological system is yet affected by the tailings impoundment.

Contacts:
PD. Dr. Bernhard Dold
IMG-Centre d'Analyse Minérale (BFSH 2)
Faculté des Géosciences et de l'Environnement
Université de Lausanne
CH-1015 Lausanne
Switzerland
Tel.:+41-21-6924327
Fax.:+41-21-6924315
Email: Bernhard.Dold@unil.ch
http://www.unil.ch/cam

Prof. Dr. Dan Balteanu
Romanian Academy,
Institute of Geography, IGAR
Dimitrie Racovita, St., 12,
RO- 023993 Bukarest
Romania
Tel.: 004 0213135990
Fax.: 004 021 3111242
Email: geoinst@rnc.ro