Quantification of Heavy Metals from A.M.D. Discharged into a Public Water Supply Dam in the Iberian Pyrite Belt (SW Spain) Using Centered Moving Average

Abstract

In this work, the determination of moving averages is proposed as a method for quantifying metal, arsenic, and sulfate discharges into a water course undergoing acid mine drainage processes which flows into a public water supply dam in the Iberian Pyrite Belt. The analysis of the results obtained by applying moving averages shows that the highest metal and sulfate concentrations occur in October, coinciding with the first rainfall and the sponging of mine dumps, with November and December being the months when the highest contributions to the Andevalo Dam take place. The discharge of acid mine waters with its corresponding metal load into the Andevalo Dam means, for a single hydrological year, more than 6,000 t of sulfates, almost 600 t of iron, and 1 t of As, of special relevance for the hydrochemical quality of the stored waters. When they arrive at the dam, these metals precipitate, since the water pH is near 7, and remain latent in the bottom sediment as long as the chemical makeup of the dam water does not change.

Hydrochemical characterization of an acid mine drainage-affected reservoir: the Sancho Reservoir, Huelva, southwest Spain

“…Since As was below the detection limit (<0.001 mg L -1 ) in all samples, the data are not shown. Higher acidity was found in the surface water; therefore, all samples present pH of less than 4, except at depths below 19 m, where it increases, reaching a maximum value of pH 4.67 ( (Grande et al 2005a, 2010d, Valente and Leal Gomes 2009. Arsenic is always below the detection limit, and Ni and Sb are the metals with the lowest concentrations (about 100 times less).…”

“…The IPB is one of the largest metallogenic regions of the world, with numerous giant and supergiant massive sulphide ore deposits (Sáez et al 1999), comprising 1700 Mt of sulphide reserves (Pinedo-Vara 1963). Consequently, the regional drainage network is strongly affected by AMD and acid rock drainage (ARD), as described by several authors: Elbaz-Poulichet et al (1999,2000,2001), Davis et al (2000), Grande et al (2003aGrande et al ( , 2003bGrande et al ( , 2005aGrande et al ( , 2005bGrande et al ( , 2010aGrande et al ( , 2010bGrande et al ( , 2010cGrande et al ( , 2010dGrande et al ( , 2010e, 2011aGrande et al ( , 2011b, Leblanc et al (2000), Borrego et al (2002), Sáinz et al (2002Sáinz et al ( , 2003aSáinz et al ( , 2003bSáinz et al ( , 2004Sáinz et al ( , 2005, Olıás et al (2004Olıás et al ( , 2005aOlıás et al ( , 2005bOlıás et al ( , 2006, Aroba et al (2007), Jiménez et al (2009), de la Torre et al (2009, Carro et al (2011) and Grande (2011).…”

“…However, the vulnerability of the water surfaces to contamination is much greater than that of underground water (Grande et al 2010d).…”

Distribution of heavy metals and pollution pathways in a shallow marine shelf: assessment for a future management

“…As a consequence of the derived acid mine drainage processes (AMD), some tributaries of the Guadiana, Tinto and Odiel rivers have very acid waters, with an extremely high pollution by toxic metals that are discharged into the main channels (Fernández Caliani et al 1997;Grande et al 2010). So, these AMD processes need to be eliminated or diminished, at least, to improve the quality of estuarine and marine waters and sediments.…”

Application of Fuzzy Logic to Qualify the Environmental Impact in Abandoned Mining Sites

“…Generally, these are calculated using an arithmetic weighted index (e.g. Gray 1996Gray , 1998Santos Oliveira et al 2002) and classical statistical approaches (Grande et al 2010a), using physical and chemical parameters.…”