The extent of the Aznalcóllar pyritic sludge spill and its effects on soils

Habitat quality affects the condition of Luciobarbus sclateri in the Guadiamar River (SW Iberian Peninsula): effects of disturbances by the toxic spill of the Aznalcóllar mine

“…These studies, carried out in the Guadiamar River after the mining accident, have shown an increase in the concentration of Pb and Cd in tissues of P. clarkii and L. sclateri when samples were taken close to the spill point (Moreno-Rojas et al, 2005;Alcorlo et al, 2006). This impact gradient is coincident with other results based on physical indicators such as the depth of the toxic mud layer (Gallart et al, 1999;López-Pamo et al, 1999), or even chemical indicators, since pH increases and heavy metal concentration in water decreases as we move away from the spill point (Olías et al, 2005). In addition, the high correlation and negative relationship between pH and conductivity coincides with results from previous studies (Oliva-Paterna et al, 2003a and2003b).…”

Distribution of As and Zn in Soils Affected by the Spill of a Pyrite Mine and Effectiveness of the Remediation Measures

“…The fine earth, very finely ground (<0.05 mm), was digested in strong acids (HNO 3 + HF + HCl). Since Zn and As were the principal pollutant elements of the soils (Alastuey et al 1999;Cabrera et al 1999;López-Pamo et al 1999;Simón et al 1999), these elements were measured in each digested sample by inductively coupled plasma mass spectrometry (ICP-MS) with a PerkinElmer SCIEX ELAN-5000A spectrometer. The accuracy of the method (Table 1) was corroborated by analyses (six replicates) of Standard Reference Material SRM2711 (Gills and Kane 1993).…”

“…Due to the fact that the penetration of the tailings was highly irregular, varying considerably from one sector to another according to the particle size and structure of each soil (Simón et al 1999), the range of total contamination of the soils was very broad (Cabrera et al 1999;López-Pamo et al 1999), although, only in the sectors where the penetration of the tailings was relatively higher, did As and Zn exceed 50 and 1,000 mg kg −1 , respectively. Nevertheless, as the tailings dried and aerated, complex processes (Stumm and Morgan 1981;Nordstrom 1982;Förstner and Wittmann 1983) oxidised the sulphides to sulphates, lowering the pH and solubilising part of the pollutants that had formerly remained insoluble.…”

Heavy metals and As transport under low and high flows in the River Guadiamar three years after the Aznalcóllar tailings dam failure : implications for river recovery and management

“…Approximately 4600 ha along both sides of the river was flooded, with 2616 ha directly affected by tailings. More than 60% of the solid wastes were deposited in the first 13 km downstream of the breach, reaching depths of 4 m close to the impoundment and a few mm at the spill margins (CMA, 1999;López-Pamo et al, 1999;Eriksson and Adamek, 2000;McDermott and Sibley, 2000). The residues were largely composed of pyrite (>80%) and other sulphide minerals, and contained Pb (0.8 -1.1%); Zn (0.5 -0.8%); As (0.2 -0.5%) and Cu (0.1 -0.2%), with smaller proportions (<0.1%) of Sb, Co, Tl, Cd Ag, Hg and Se (Simón et al, 1999).…”