RT journal article
T1 Seasonal variability of extremely metal rich acid mine drainages from the Tharsis mines (SW Spain)
A1 Moreno González, Raúl
A1 Ruiz Cánovas, Carlos
A1 Olías, Manuel
A1 Macías, Francisco
A2 Ciencias de la Tierra
K1 Acid mine drainage
K1 Elemental ratios
K1 Metal pollution
K1 Mine wastes
K1 Sulphides
AB The Tharsis mine is presently abandoned, but the past intense exploitation has left large dumps and other sulphide-rich mining wastes in the area generating acid mine drainages (AMD). The main goal of this work is to study the effect of hydrogeochemical processes, hydrological regime and the waste typology on the physicochemical parameters and dissolved concentrations of pollutants in a deeply AMD-affected zone. Extreme leachates are produced in the area, reaching even negative pH and concentrations of up to 2.2 g/L of As and 194 g/L of Fe. The results of the comparison of ore grades of sulphide deposits with dissolved concentrations in waters shows that Pb is the least mobile element in dissolution probably due to the precipitation of Pb secondary minerals and/or its coprecipitation on Fe oxyhydroxysulphates. Arsenic, Cr, and V are also coprecipitated with Fe minerals. Seasonal patterns in metal contents were identified: elements coming from the host rocks, such as Al, Mn and Ni, show their maximum values in the dry period, when dilution with freshwater is lower and the interaction of water-rock processes and evaporation is higher. On the other hand, As, Cr, Fe, Pb and V show minimum concentrations in the dry period due to intense Fe oxyhydroxysulphate precipitation. In this sense, large sulphide rich waste heaps would be a temporal sink of these elements (i.e. Pb, As, Cr and V) in the dry period, and a significant source upon intense rainfalls.
PB Elsevier Ltd
SN 1873-6424
YR 2020
FD 2020-04
LK http://hdl.handle.net/10498/38621
UL http://hdl.handle.net/10498/38621
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 08-nov-2026