Dilution versus pollution in watercourses affected by acid mine drainage: a graphic model for the Iberian Pyrite Belt (SW Spain)

The aim of this study was to chemically characterize the water quality impacts of the 88 acid mine drainage (AMD) generating mines in the Spanish sector of the Iberian Pyrite Belt (IPB). This was necessary because the Water Framework Directive of the European Union and the hydrological plans of the Tinto, Odiel, and Piedras river basins require that water quality be improved enough to allow at least some of the rivers in the IPB to sustain healthy fish populations by 2027. The results indicate a clear decrease in metals, arsenic, and sulfate concentrations and increased pH between the AMD-sources and the river channels.info:eu-repo/semantics/publishedVersio

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

Poderosa Mine is an abandoned pyrite mine, located in the Iberian Pyrite Belt which pours its acid mine drainage (AMD) waters into the Odiel river (South-West Spain). This work focuses on establishing possible reasons for interdependence between the potential redox and pH, with the load of metals and sulfates, as well as a set of variables that define the physical chemistry of the water—conductivity, temperature, TDS, and dissolved oxygen—transported by a channel from Poderosa mine affected by acid mine drainage, through the use of techniques of artificial intelligence: fuzzy logic and data mining. The sampling campaign was carried out in May of 2012. There were a total of 16 sites, the first inside the tunnel and the last at the mouth of the river Odiel, with a distance of approximately 10 m between each pair of measuring stations. While the tools of classical statistics, which are widely used in this context, prove useful for defining proximity ratios between variables based on Pearson’s correlations, in addition to making it easier to handle large volumes of data and producing easier-to-understand graphs, the use of fuzzy logic tools and data mining results in better definition of the variations produced by external stimuli on the set of variables. This tool is adaptable and can be extrapolated to any system polluted by acid mine drainage using simple, intuitive reasoning.Comisión Interministerial de Ciencia y Tecnología (CICYT) CGL2010-21268-C02-01Junta de Andalucía P06-RNM-0216

Contributions of the Research Center for Sustainable Mining Engineering to the Tinto and Odiel rivers hydrogeochemical knowledge

El río Tinto nace en Peña del Hierro, recorre 100 km, drenando una cuenca de 720 km2 hasta desembocar en el estuario de la Ría de Huelva, donde confluye con el río Odiel. El río Odiel nace en la Sierra de Aracena y pierde su carácter fluvial 140 km más abajo. La grave contaminación por drenaje ácido de mina que sufren estos ríos es debida a que sus cuencas están atravesadas por la Faja Pirítica Ibérica, que constituye uno de los mayores depósitos mundiales de sulfuros y en la que se encuentran una gran cantidad de explotaciones mineras abandonadas y sin medidas correctoras. Estos ríos han sido estudiados por un gran número de investigadores nacionales e internacionales. En esta comunicación se expone un resumen de las principales aportaciones del Centro de Investigación para la Ingeniería en Minería Sostenible (CIPIMS) al conocimiento hidrogeoquímico de ambos ríos.Tinto river rises in the Peña del Hierro mine (SW Spain) and travels 100 km, draining a basin of 720 km2 before flowing into the estuary of Ria de Huelva, where it joins the River Odiel. The River Odiel rises in Sierra de Aracena and loses its character 140 km river below. Severe pollution by acid mine drainage suffered by these rivers is due to the fact that their basins are crossed by the Iberian Pyrite Belt, which is one of the world's largest deposits of sulphides and where a lot of mines are abandoned without corrective measures. These rivers have been studied by national and international researchers. In this communication a summary of the main contributions of the Research Center for Sustainable Mining Engineering (CIPIMS) to the hydrogeochemical knowledge of both rivers is exposed.Los trabajos incluidos en esta comunicación se han podido desarrollar gracias a la financiación de los siguientes proyectos: de la Comunidad Europea TOROS ENV4-CT96-217 ELOISE EC PROJECT; Proyecto de Excelencia de la Junta de Andalucía P06- RNM-02167;info:eu-repo/semantics/publishedVersio

统计方法计算受Iberian黄铁矿带酸性废水影响的水库污染物运移速度

The El Sancho reservoir is located in the Odiel River basin, which crosses the Iberian Pyrite Belt. The reservoir receives acid mine drainage (AMD) from the Meca River, a tributary of the Odiel River. Two multi-parameter probes, one placed at the tail (up-gradient) end of the reservoir, where the contaminants enter, and another close to the reservoir dam were used to characterize acidity migration through the Sancho reservoir. The probes both measured pH and conductivity every 30 min. Two different levels of contamination were found, due to dilution that takes place within the reservoir and changes in the AMD composition. The cross-correlation function allowed quantification of the migration process from tail to dam. For both pH and conductivity, the maximum correlation occurred 17 days after sampling, indicating a mean transit time of 17 days. Since the distance between the two sampling points was 14,500 m, the contaminant transit speed was 0.0098 m/s.Das El Sancho Reservoir ist im Odiel Flussbecken, welches den Iberischen Pyritgürtel durchquert. Das Reservoir erhält die sauren Wässer (AMD) über den Meca River, einem Nebenfluss des Odiel Fluss. Zwei Multiparameter-Sonden wrden verwendet. Eine wurde am Auslauf des Reservoirs, in welches die Schadstoffe eingeleitet werden und eine andere in der Nähe der Staumauer platziert. Die Säure Migration durch die Sancho Reservoir soll damit charakterisiert werden. Die Sonden messen pH und Leitfähigkeit alle 30 Minuten. Zwei verschiedene Kontaminationslevel aufgrund der Verdünnung im Reservoir und damit den Veränderungen in der Zusammensetzung des AMD wurden gefunden. Die Kreuzkorrelationsfunktion erlaubt die Quantifizierung des Migrationsprozesses vom Ablauf zum Damm. Sowohl für pH und Leitfähigkeit trat die maximale Korrelation 17 Tage nach der Messung auf. Dies weist auf eine mittlere Durchgangszeit von 17 Tagen hin. Da der Abstand zwischen den zwei Abtastpunkten war 14.500 m. Die Durchlaufgeschwindigkeit der Schadstoffe betrug im Mittel 0,0098 m/s.El reservorio El Sancho está localizado en la cuenca del río Odiel que atraviesa el cinturón ibérico de pirita. El reservorio recibe drenaje ácido de mina (AMD) del río River, que es un tributario del río Odiel. Se utilizaron dos sondas multiparamétricas, una ubicada a la altura de las colas (gradiente arriba) donde los contaminantes entran y la otra ubicada cerca del dique del reservorio, para caracterizar la migración de la acidez a través del reservorio El Sancho. Las sondas midieron pH y conductividad cada 30 minutos. Se encontraron dos diferentes niveles de contaminación debido a la dilución que tiene lugar dentro del reservorio y a los cambios en la composición del AMD. La función de correlación cruzada permitió la cuantificación del proceso de migración desde la cola hasta el dique. La máxima correlación entre pH y conductividad en ambos puntos ocurrió 17 días después del muestreo, indicando un tiempo de tránsito medio de 17 días. Como la distancia entre los dos puntos de muestreo fue 14.500 m, la velocidad de tránsito de contaminantes fue 0,0098 m/s.El Sancho水库位于Odiel流域,Odiel河穿过Iberian黄铁矿带。来自Iberian的酸性废水(AMD)从Odiel河的支流Meca河汇入El Sancho水库。利用两个多参数探头监测库内酸度的迁移,一个探头位于污染物汇入侧的水库边缘,另一个探头位于库内大坝附近。两个探头每30分钟记录一次pH值和电导率。由于水库稀释和AMD成分变化,库内水污染表现为两个污染水平。交叉相关分析能够用以定量推算污染物自水库边至库中大坝的运移过程。pH值与电导率滞后取样17天达到最大相关,表明污染物的平均运移时间为17天。两个取样点间距为14500 m,因此污染物运移速度为0.0098 m/s.The authors acknowledge financial support provided by the DGCICYT National Plan, Project CGL2010-21268-C02-01 and the Andalusian Autonomous Government Excellence Projects, Project P10-RNM-6570.info:eu-repo/semantics/publishedVersio

Characterization of acid mine drainage sources in the Iberian Pyrite Belt : base methodology for quantifying affected areas and for environmental management

The present work aims to propose a method- ology for quantifying the sources of acid mine drainage (AMD) and to characterize the magnitude of the affected areas in the Iberian Pyrite Belt (SW Spain). Such an approach allows the creation of a support tool for managing land and natural resources valorization, which may be easily applied in similar mining regions. The motivation and usefulness of this work can be realized by focusing on two main emerging strategic issues: (1) water resources management, with the example of Alcolea dam that will receive water from affected areas in the Iberian Pyrite Belt; and (2) mineral resources valorization, especially, regarding copper exploration due to increasing market prices. The used methodology included the following general steps: it started with an inventory of the mines in the Iberian Pyrite Belt, followed by field cartography campaigns and finally the quantification of affected areas and contaminant discharges. The results of the present work serve to confirm and quantify the magnitude of the AMD pollution in the Pyrite Belt. A total affected area of about 4,847 ha was estimated. Taking into account this figure and combining it with the annual average precipitation (650 L/m2) results in an estimation of 31,503,680 m3/year of discharging water affected by the presence of sulphides. In this scenario, a total annual contribution of 260,056 tonnes/year was obtained for sulphates, which means more than 712 tonnes a day. In the case of arsenic, a toxic element, the total annual contribution is more than 20 tonnes, or close to 55 kg/day. Regarding copper, this economically interesting metal translates into total contributions of 10,364 tonnes/ year in the generating medium. This gave more than 28 tonnes/day, which today sits at 8,200 dollars/tonne. This result suggests that solutions aimed at recovering this resource should be searched. It may represent a financial return at the same time that it would mean overcome environmental liabilities.DGCICYT National Plan - Project CGL2010-21268-C02-0

Characterisation of AMD pollution in the reservoirs of the Iberian Pyrite Belt

A number of water-supply dams have been built in the semi-arid Iberian Pyrite Belt (SW Spain) in a fluvial network affected by acid mine drainage (AMD). There are almost a hundred mines, most of which are closed, which emit low pH leachates with high metal and sulphate loads to reservoirs intended for urban supply. The Iberian Pyrite Belt contains 23 of these reservoirs spread along the Tinto and Odiel river basins, which are the main water courses affected by AMD, and the Chanza and the Guadiamar river basins, which are affected to a lesser extent. We characterised the degree of pollution in the various reservoirs that receive AMD-affected waters; this will eventually allow the development of a risk map of the overall extent of the problem in reservoirs in the Iberian Pyrite Belt.DGCICYT National Plan, Project CGL2010-21268-C02-0