RT Journal Article
T1 Wildfire effects on the hydrogeochemistry of a river severely polluted by acid mine drainage
A1 Romero Matos, Jonatan
A1 Ruiz Cánovas, Carlos
A1 Macías Suárez, Francisco
A1 Pérez López, Rafael
A1 León Cortegano, Rafael
A1 Millán Becerro, Ricardo
A1 Nieto Liñán, José Miguel
A1 Romero Matos, Jonatan
AB This study evaluates for the first time the impact of a large wildfire on the hydrogeochemistry of a deeply AMDaffectedriver at the beginning of the wet season. To accomplish this, a high-resolution water monitoringcampaign was performed within the basin coinciding with the first rainfalls after summer. Unlike similar eventsrecorded in AMD-affected areas, where dramatic increases in most dissolved element concentrations, and decreasesin pH values are observed as a result of evaporitic salts flushing and the transport of sulfide oxidationproducts from mine sites, a slight increase in pH values (from 2.32 to 2.88) and decrease in element concentrations(e.g.; Fe: 443 to 205 mg/L; Al: 1805 to 1059 mg/L; sulfate: 22.8 to 13.3 g/L) was observed with the firstrainfalls after the fire. The washout of wildfire-ash deposited in the riverbanks and the drainage area, constitutedby alkaline mineral phases, seems to have counterbalanced the usual behavior and patterns of the riverhydrogeochemistry during autumn. Geochemical results indicate that a preferential dissolution occurs during ashwashout (K > Ca > Na), with a quick release of K followed by an intense dissolution of Ca and Na. On the otherhand, in unburnt zones parameters and concentrations vary to a lesser extent than burnt areas, being the washoutof evaporitic salts the dominant process. With subsequent rainfalls ash plays a minor role on the river hydrochemistry.Elemental ratios (Fe/SO4 and Ca/Mg) and geochemical tracers in both ash (K, Ca and Na) and AMD(S) were used to prove the importance of ash washout as the dominant geochemical process during the studyperiod. Geochemical and mineralogical evidences point to intense schwertmannite precipitation as the maindriver of reduction in metal pollution. The results of this study shed light on the response of AMD-polluted riversto certain climate change effects, since climate models predict an increase in the number and intensity ofwildfires and torrential rain events, especially in Mediterranean climates.
PB Elsevier
SN 0043-1354
YR 2023
FD 2023
LK https://hdl.handle.net/10272/22162
UL https://hdl.handle.net/10272/22162
LA eng
NO Romero-Matos, J., Cánovas, C. R., Macías, F., Pérez-López, R., León, R., Millán-Becerro, R., & Nieto, J. M. (2023). Wildfire effects on the hydrogeochemistry of a river severely polluted by acid mine drainage. In Water Research (Vol. 233, p. 119791). Elsevier BV. https://doi.org/10.1016/j.watres.2023.119791
NO This research was supported by the AIHODIEL project (PYC20 RE 032 UHU) within the 2020 call for grants for the implementation of projects of collaborative interest in the field of innovation ecosystems co-financed by the FEDER program in Andalucía for the period 2014-2020. Jonatan Romero is financed by a FPU program of the Spanish Ministry of Education of Vocational Training (FPU20/04441). C.R Cánovas thanks the Spanish Ministry of Science and Innovation forthe Postdoctoral Fellowship granted under application reference RYC2019–027949-I. Funding for open access charge: Universidad de Huelva / CBUA. The authors gratefully appreciate the constructive comments and suggestions from the editor Mark van Loosdrecht and two anonymous reviewers.
DS Repositorio Institucional de la Universidad de Huelva
RD 30 may 2026