Effects of estuarine water mixing on the mobility of trace elements in acid mine drainage leachates

This research reports the effects of pH increase on contaminant mobility in acid mine drainage from the Iberian Pyrite Belt by seawater mixing in the laboratory, simulating the processes occurring in the Estuary of Huelva (SW Iberian Peninsula). Concentrations of Al, Fe, As, Cu and REY in mixing sol...

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Detalhes bibliográficos
Autores: Pérez-López, Rafael, Millán-Becerro, Ricardo, Basallote, M. Dolores, Carrero, Sergio, Parviainen, Annika, Freydier, Rémi, Macías, F., Cánovas, Carlos R.
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/289287
Acesso em linha:http://hdl.handle.net/10261/289287
https://api.elsevier.com/content/abstract/scopus_id/85147536577
Access Level:acceso abierto
Palavra-chave:Tinto and Odiel rivers
Contaminants mobility
Estuary of Huelva
Mining pollution
Seawater mixing
Descrição
Resumo:This research reports the effects of pH increase on contaminant mobility in acid mine drainage from the Iberian Pyrite Belt by seawater mixing in the laboratory, simulating the processes occurring in the Estuary of Huelva (SW Iberian Peninsula). Concentrations of Al, Fe, As, Cu and REY in mixing solutions significantly decreased with increasing pH. Schwertmannite precipitation at pH 2.5-4.0 led to the total removal of Fe(III) and As. Subsequently, iron-depleted solutions began to be controlled by precipitation of basaluminite at pH 4.5-6.0, which acted as a sink for Al, Cu and REY. Nevertheless, as the pH rises, schwertmannite becomes unstable and releases back to solution the previously retained As. Moreover, other elements (S, Zn, Cd, Ni and Co) behaved conservatively in mixing solutions with no participation in precipitation processes. Some toxic elements finally end up to the Atlantic Ocean contributing to the total pollutant loads and environmentally threatening the coastal areas.