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Olías M, Cánovas CR, Basallote MD, Macías F, Pérez-López R, González RM, Millán-Becerro R, Nieto JM. Causes and impacts of a mine water spill from an acidic pit lake (Iberian Pyrite Belt). Environ Pollut 2019; 250:127-136. [PMID: 30991281 DOI: 10.1016/j.envpol.2019.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 02/27/2019] [Accepted: 04/03/2019] [Indexed: 06/09/2023]
Abstract
In May 2017, a spill from La Zarza pit lake (SW Spain) resulted in the release of approximately 270,000 m3 of extremely acidic waters to the Odiel River. Around 780 × 103 kg of Fe, 170 × 103 kg of Al, 2.15 × 103 kg of As and high amounts of other trace metals and metalloids were spilled. The purpose of this study is to explain the causes, consequences and impacts of the mine spill on the receiving water bodies. To this end, an extensive sampling along the mine site, river and estuary as well as a hydrological model of the pit lake was performed. Around 53 km of the Odiel River's main course, which was already contaminated by acid mine drainage (AMD), were affected. The mine spill resulted in an incremental impact on the Odiel River water quality. Thus, dissolved concentrations of some elements increased in the river up to 450 times; e.g. 435 mg/L of Fe and 0.41 mg/L of As. Due to low pH values (around 2.5), most metals (e.g., Cu, Zn, Mn, Cd) were transported in the dissolved phase to the estuary, exhibiting a conservative behavior and decreasing their concentration only due to dilution. However, dissolved concentrations of Fe, Cr, Pb, Se, Sb, Ti, V and especially As decreased significantly along the river due to Fe precipitation and sorption/coprecipitation processes. At the upper zone of the estuary, a noticeable increment of metal concentrations (up to 77 times) was also recorded. The water balance illustrates the existence of groundwater inputs (at least 16% of total) to the pit lake, due probably to local infiltration of rainwater at the mining zone. The probable existence of an ancient adit connected to the pit lake indicates that potential releases could occur again if adequate prevention measures are not adopted.
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Affiliation(s)
- M Olías
- Department of Earth Sciences & Research Centre on Natural Resources, Health and the Environment (RENSMA), Faculty of Experimental Sciences, University of Huelva, Campus "El Carmen", E-21071, Huelva, Spain
| | - C R Cánovas
- Department of Earth Sciences & Research Centre on Natural Resources, Health and the Environment (RENSMA), Faculty of Experimental Sciences, University of Huelva, Campus "El Carmen", E-21071, Huelva, Spain.
| | - M D Basallote
- Department of Earth Sciences & Research Centre on Natural Resources, Health and the Environment (RENSMA), Faculty of Experimental Sciences, University of Huelva, Campus "El Carmen", E-21071, Huelva, Spain
| | - F Macías
- Department of Earth Sciences & Research Centre on Natural Resources, Health and the Environment (RENSMA), Faculty of Experimental Sciences, University of Huelva, Campus "El Carmen", E-21071, Huelva, Spain
| | - R Pérez-López
- Department of Earth Sciences & Research Centre on Natural Resources, Health and the Environment (RENSMA), Faculty of Experimental Sciences, University of Huelva, Campus "El Carmen", E-21071, Huelva, Spain
| | - R Moreno González
- Department of Earth Sciences & Research Centre on Natural Resources, Health and the Environment (RENSMA), Faculty of Experimental Sciences, University of Huelva, Campus "El Carmen", E-21071, Huelva, Spain
| | - R Millán-Becerro
- Department of Earth Sciences & Research Centre on Natural Resources, Health and the Environment (RENSMA), Faculty of Experimental Sciences, University of Huelva, Campus "El Carmen", E-21071, Huelva, Spain
| | - J M Nieto
- Department of Earth Sciences & Research Centre on Natural Resources, Health and the Environment (RENSMA), Faculty of Experimental Sciences, University of Huelva, Campus "El Carmen", E-21071, Huelva, Spain
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