Arsenic and metal mobility from Au mine tailings in Rodalquilar (Almería, SE Spain)

• Published in: Environmental earth sciences 2010-03, Vol.60 (1), p.121-138
• Main Authors: Navarro Flores, Andrés, Doménech Rubio, Luis Miguel
• Format: Article
• Language: English
• Subjects: Aigües subterrànies; Alluvial aquifers; Aquifers; Arsenic; Arsènic; Aspectes ambientals; Biogeosciences; Cadmium; Calcite; Contaminació; Contaminants; Deixalles; Drinking water; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Eliminació; Engineering and environment geology. Geothermics; Enginyeria civil; Enginyeria de mines; Environmental aspects; Environmental perception; Environmental Science and Engineering; Exact sciences and technology; Geochemistry; Geologia; Geology; Gold mines & mining; Groundwater; Groundwater pollution; Hidrologia subterrània; Hydrology/Water Resources; Hydroxides; Indústria minera; Kaolinite; Leachates; Lead; Mass transfer; Metal geology; Metallic and non-metallic deposits; Metalls; Metals; Mine tailings; Mine wastes; Mineral industries; Original Article; Pollution, environment geology; Pyrite; Sediments; Terrestrial Pollution; Toxicologia; Water analysis; Water sampling; Zinc; Àrees temàtiques de la UPC
• ISSN: 1866-6280; 1866-6299; 1866-6299
• DOI: 10.1007/s12665-009-0174-6

In the old mining area of Rodalquilar, mine wastes, soil and sediments were characterized and the results revealed high concentration of Au, Ag, As, Bi, Cu, Fe, Mn, Pb, Se, Sb and Zn in tailings and sediments. The contaminant of greatest environmental concern is As. The mean concentration in the tailings was 679.9, and 345 mg/kg in the sediments of Playazo creek. The groundwater samples from the alluvial aquifer showed high concentration of Al, As, Cd, Fe, Hg, Mn, Ni, Pb, Se, Sb and Zn and very high concentration of chloride and sulfate, which were above the concentration defined in the European standards for drinking water. The presence of As in groundwater may be caused by the oxidation of arsenian pyrite, the possible As desorption from goethite and ferrihydrite and the jarosite dissolution. Groundwater concentrations of Cd, Fe, Mn, and possibly Cu, were associated with low values of Eh, indicating the possible dissolution of oxy-hydroxides of Fe and Mn. The mobility of metals in the column experiments show the release of Al, Fe, Mn, Cr, Cu, Ni, V and Zn in significant concentrations but below the detected values in groundwater. However, As, Cd, Sb, Se Pb and Au, are generally mobilized in concentrations above the detected values in groundwater. The possible mass transfer processes that could explain the presence of the contaminants in the aquifer and the leachates was simulated with the PHREEQC numerical code and revealed the possible dissolution of the following mineral phases: jarosite, natrojarosite, arsenian pyrite, alunite, chlorite, kaolinite and calcite.