Impacto del drenaje ácido de mina en las características hidrogeoquímicas del estuario de los ríos Tinto y Odiel (SO España)

Abstract

Impacto del drenaje ácido de mina en las características hidrogeoquímicas del estuario de los ríos Tinto y Odiel (SO España) Abstract pH and chlorinity content of estuarine water and behavior in the concentration of some heavy metals characteristics of acid mine drainage in the suspended matter and dissolved phase have allowed the identification of two mixing process in the Odiel-Tinto rivers estuary: a salt-induced mixing typical of marine estuaries and an acid neutralization process as a result of the mixture of acid fluvial water coming from the drainage basins, which are affected by acid mine drainage (AMD). Thus, the estuary is divided into three zones: (1) zone with acid water and with precipitation of sulphate phases during the beginning of the process of neutralization in the absence of salt-induced mixing, (2) zone with pH values between 4.5 and 7 where a removal of heavy metals in their dissolved phase is produced by coexistence of both mixture processes, and (3) zone where water is slightly basic and the salt-induced mixing produces a redissolution of some elements. Spatial location and extent of these zones within the estuarine system have seasonal variations depending on the volume of fluvial discharge.Keywords: Acid mine drainage, Acid and saline mixing, Tinto-Odiel estuary, hydrogeochemistry ResumenEl contenido de pH y clorinidad de las aguas de estuario y el comportamiento en la concentración de algunos metales pesados característicos del drenaje ácido de mina en la materia suspendida y en la fase disuelta ha permitido la identificación de dos procesos de mezcla en el estuario de los ríos Tinto y Odiel: una mezcla sal inducida típica de estuarios marinos y procesos de neutralización ISSN (print): 1698-6180. ISSN (online): 1886-7995

Definition of redox and pH influence in the AMD mine system using a fuzzy qualitative tool (Iberian Pyrite Belt, SW Spain)

“…The AMD processes undergone by the drainage in the environment of the region have been described extensively by various authors: Aroba et al (2007); Borrego (1992); Borrego et al (2002); Borrego et al (2012); Carro et al (2011); Braungardt et al (1998); Davis et al (2000); de la Torre Leblanc et al (2000); Sainz et al (2005).…”

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

“…These acidic and metal(loid)-rich leachates are drained by the Tinto and Odiel Rivers, causing the total pollution of their waters (e.g., Olías et al, 2006;Nieto et al, 2013). The transfer of acidity and potentially toxic elements to the Estuary of Huelva has been the focus of numerous investigations (e.g., Elbaz-Poulichet et al, 2001;Borrego et al, 2002;Braungardt et al, 2003;Carro et al, 2011;Hierro et al, 2014). Pollution levels are so extreme that both rivers and the estuary can be considered one of the most polluted aquatic systems in the world.…”

Control factors on the composition of superficial sediments in estuaries of the coast of Huelva (SW Spain): a statistical approach.

“…However, the combination of acid water from mines, industrial effluents, and fluvial and sea waters plays a determining role in the evolutionary process of the chemical characteristics of the Tinto and Odiel estuary. Consequently, this is a unique and paradigmatic site in the world by the interest that its study raise , Ackerman, 1980Braungardt et al, 2003;Carro et al, 2011;Elbaz-Poulichet et al, 1999Grande et al, 2000Grande et al, -2003aNieto et al, 2007;López-González et al, 2006;Periañez et al, 2012 The fluvial basin of these rivers lies, to a great extent, over Paleozoic materials and, more specifically, on formations of the so-called volcano-sedimentary complex, where there is one of the most important mineralized sulfide areas in the Europe. The ore deposits have been mined since at least 4500 B.P.…”

“…Water acidification results from natural processes known as ARD (Acid Rock Drainage), and from AMD (Acid Mine Drainage), which is related with mining effluents. The AMD and ARD processes that affect the regional drainage network have been broadly described by several authors: Aroba et al, 2007;Carro et al, 2011;Grande et al, 2003a-b. The water acidification results in strong modifications on the biosociology of the media, in such a way that increasing acidity produces reduction in the number of species. Therefore, at pH<4 all the vertebrates and the majority of invertebrates and many species of microorganisms disappear.…”