Efecto del drenaje ácido de minas sobre el agua y el sedimento del estuario de los ríos Tinto y Odiel

Resum

Effect of acid mine drainage in river systems that flow into the estuary of the Tinto and Odiel has been the focus of numerous works (Aroba rivers et at., 2007; Canovas et al, (2008). De la Torre et al (2009, 2010, 2014); Large et al, (2000, 2003, 2005, 2010, 2011, 2013, 2014). Olias et al, (2004);.. Sainz et al, (2000, 2002, 2003 2004, 2005). Sarmiento et al, (2009)), the pollution associated with the mining activity in the area (Nelson and Lamothe, 1993; Van Geen et al., 1997; Ruiz et al., 1998; Elbaz- Poulichet and Dupuy, 1999; Leblanc et al., 2000; Lamb et al., 2002, Achterberg et al., 2003; Braungardt et al., 2003; Large et al., 2003; Sainz et al, 2004), and in reference to the sediment and deposits at the estuary of the Ria de Huelva (Borrego et al, (2004), Lopez - Gonzalez and al, (2006). Lopez - Gonzalez (2009). Sainz et al, (2004 ). However evaluate the process the acid mine drainage effected in the hydrogeochemical and dynamic characteristic of an estuarine system processes and polluting effects on the environment, they have not been accurately assessed. In this line of research, this thesis the study of certain chemical elements and hydrochemistry arises not only from contamination processes, but also of developments in environmental conditions such as exclusive system is the estuary of the rivers Tinto and Odiel . Estuary of the Ria de Huelva is a very peculiar and complex system since in him the mouth of two highly contaminated river systems AMD occurs. It consists of the union of both rivers on one main channel, before emptying into the Atlantic Ocean. Both river systems cross the province of Huelva from North to South the Iberian Pyrite Belt with water with pH below 2.5 average and high dissolved metals content in the past. When the discharge of these waters reaches the limit to the continent in the area of the estuary with tidal influence, the process of mixture of salt water and acidic river water begins to occur. This mixing process involves complex physical and chemical reactions that produce precipitation and / or adsorption of certain metals associated with the dilution of both types of water bodies. The results obtained in the course of the investigation are presented in twelve articles in which the characteristics of sediments, water and estuarine processes in the system are analyzed. The work and results have been grouped into three chapters based on the aspects to be addressed in a study related to the hydrochemistry of the estuary and the impact of acid mine drainage occurs in water and suspended matter is made estuary, analysis of metals and other elements in the sediment, water and suspended matter in order to present an assessment of the quality and bioavailability found in this system and a comprehensive analysis of the land is done rare (REE) in the estuary in terms of the interaction between the processes of salt mixture, which occur in all estuaries, and acid neutralization, arising as a result of pollution by acid mine drainage from the estuary of the rivers Tinto and Odiel . The results of this chapter are presented in five articles in which have been analyzed and established patterns in the division and distribution of these elements in both sediment and dissolved and particulate phase and transfer of these elements. The main objective of this report is to evaluate that produces acid mine drainage in the hydrodynamic and water quality and sediment in the estuary of the Tinto and Odiel rivers, which concludes: The main objective of this report is to evaluate that produces acid mine drainage in the hydrodynamic and water quality and sediment in the estuary of the Tinto and Odiel rivers, which concludes: - The hydrogeochemical characteristics of water in an estuary where the river water and seawater acid mix allow us to define the intervention of two geochemical processes: a typical mixing process salt induced and acid neutralization process water produced by AMD, which It presents a seasonal and longitudinal variability within the estuary. - Heavy metals in the sediment and in the water of the estuary of the Tinto and Odiel rivers have high concentrations of heavy metals associated. Metal contamination affects all sectors of the Ria de Huelva, and not just to sectors with direct influence of river inputs or industrial wastes. - The relationship between pH and the content of REE indicates that pH is the key variable that controls REE geochemistry in estuarine systems affected by acid mine drainage, possibly with fractionation patterns of these elements estuary environmental indicators.