RT Journal Article
T1 Rainfall-driven, high-resolution assessment of water acidification in a planned reservoir within an unreclaimed historical mining basin
A1 Romero Matos, Jonatan
A1 Sánchez López, Laura
A1 León, Rafael
A1 Macías Suárez, Francisco
A1 Ruiz Cánovas, Carlos
A1 Olías Álvarez, Manuel
A1 Nieto Liñán, José Miguel
A1 Sánchez López, Laura
K1 High-resolution sampling
K1 Iberian Pyrite Belt (IPB)
K1 Alcolea reservoir
K1 Acid mine drainage (AMD)
K1 Flood events
AB Acid mine drainage (AMD) from historical mining in the Iberian Pyrite Belt severely degrades water quality in southwest Spain. The planned Alcolea Reservoir, intended to supply water from the Odiel River basin in response to growing demands, is widely recognized as being critically constrained by AMD, as existing studies indicate that, without upstream remediation, its impoundment would lead to inevitable deterioration and acidification of water quality. In this sense, a high-resolution sampling campaign was conducted over a hydrological year in the Odiel and Oraque rivers to quantify pollutant fluxes entering the reservoir and to assess the potential risk of water acidification. Despite dilution- and neutralization-driven fluctuations, the inflows showed mostly persistent acidic conditions and high metal concentrations during the monitored year. Floods were the main driver of pollutant transport, with annual net acidity and sulfate loads about 31247 tons eq. CaCO3 and 73598 tons, respectively. During the autumn floods, the highest amounts of acidity and metals were released due to flush-out processes (i.e., redissolution of evaporitic sulfate salts and mobilization of sulfide oxidation products). Estimated reservoir water quality (pH 3.71; 131 mg/L eq. CaCO3 of acidity; and 307 mg/L of sulfate) mostly fails to comply with water guidelines, showing conditions similar to the nearby acidified Sancho Reservoir. In fact, the planned reservoir would receive more (∼24.0%) acidity load than the Sancho Reservoir, proving its potential acidification after construction. Due to the severe pollution by AMD, decision makers should prioritize reclamation of the Odiel River basin before completing the Alcolea Reservoir, ensuring adequate water quality for end users.
PB Elsevier
YR 2026
FD 2026
LK https://hdl.handle.net/10272/28545
UL https://hdl.handle.net/10272/28545
LA eng
NO Romero-Matos, J., Sánchez-López, L., León, R., Macías, F., Cánovas, C. R., Olías, M., & Nieto, J. M. (2026). Rainfall-driven, high-resolution assessment of water acidification in a planned reservoir within an unreclaimed historical mining basin. Environmental Pollution, 405, 128517. https://doi.org/10.1016/j.envpol.2026.128517
NO This research was funded by the the Spanish Ministry of Science, Innovation and Universities under the research project DYNAMICO (PID2023-151504OB-I00) funded by MICIU/AEI/10.13039/ 501100011033; and by the European Council, 2020 Research and Innovation Programme under the I+D+ i ERA-MIN3 SuMRee project (PCI2024-153500) funded by MICIU/AEI/10.13039/501100011033, and the HydroShift project (PCI2025-167130-2). L. S´ anchez-L´ opez acknowledges the “Formaci´ on de Personal Investigador” grant (PRE2021-097651) funded by MCIN/AEI/10.13039/501100011033. J. Romero-Matos is financed by a FPU program of the Spanish Ministry of Education and Vocational Training (FPU20/04441). We are deeply grateful for the assistance provided by the members of the Mineralogy and Environmental Geochemistry research group and other colleagues during the extensive fieldwork. The authors gratefully appreciate the constructive comments and suggestions from the editor Klaus Kümmerer and two anonymous reviewers. Funding for open access charge: Universidad de Huelva/CBUA.
DS Repositorio Institucional de la Universidad de Huelva
RD 13 jul 2026