Assessment of restoration success of former metal mining areas after 30 years in a highly polluted Mediterranean mining area: Cartagena-La Unión

Ecological Potential of Plants for Phytoremediation and Ecorestoration of Fly Ash Deposits and Mine Wastes

“…The values of organic carbon (0.5%, Conesa et al, 2006;0.17-0.48%, Bes et al, 2014;1,55% Randjelović et al, 2016;3.14-6.65%, Parraga-Aguado et al, 2014;15.1-33.3, Santos et al, 2016) and total nitrogen (0.04%, Bes et al, 2014;0.29-0.62%, Parraga-Aguado et al, 2014;0.5-1.2%, Santos et al, 2016) also vary as well as available content of K 2 O (7.67-37.0 mg/100 g, Randjelović et al, 2016;42.3-129.0 g/kg, Santos et al, 2016) and P 2 O 5 (0.05-24.0 mg/100 g, Randjelović et al, 2016;0.9-74.3 mg/kg, Santos et al, 2016) (Table 1). The mine spoils on the tailings showed multielement pollution with high total concentrations of As, Cd, Cu, Fe, Hg, Mn, Ni, Pb, Sb, Zn that exceed local background values and the maximum allowed values proposed by any country legalization as well as agricultural/residential/commercial/industrial use and they largely depend on geochemical partitioning (Gomez-Ros et al, 2013;Parraga-Aguado et al, 2013;Ruiz Olivares et al, 2013;Bes et al, 2014;Randjelović et al, 2016;Santos et al, 2016).…”

“…Mine wastes show great heterogeneity in their texture and physico-chemical properties in metallic mining area. The wide range of mine spoil characteristics is related to differences in mineralogical substrate and composition of mine residue which can come from different ore minerals and veins as well as from the exploitation procedures, plant cover and climatic conditions (Gomez-Ros et al, 2013;Ruiz Olivares et al, 2013). Thus, on the more or less revegetated mining tailings the fractions of sand, silt and clay vary greatly (55-73, 22-33, 5-12% respectively, Conesa et al, 2006;97.8, 0.96, 1.27% respectively, Randjelović et al, 2016) (Table 1).…”

“…Many plant species growing on mine waste rock and tailings showed great potential for phytoremediation (Table 3). Thus, Cistus ladanifer is suitable for phytostabilization of mining areas and can be considered as an excluder plant for Al, Ag, Ba, Bi, Sr, and Sb (Santos et al, 2016); Ricinus communis is an excluder for Cd, Cu, Mn, Pb, and Zn in spite of high concentrations of Mn in shoots (Ruiz Olivares et al, 2013); Coincya monensis is considered as Zn hyperaccumulator whereas, Holcus lanatus, Festuca rubra, Dactylis glomerata present good excluders of Hg and As on the Pb-Zn and Hg-As mining area (Fernandez et al, 2017); Polygonum aviculare grown at slightly acid spoil on mine tailings with Ag, Au, and Zn accumulated Zn is near the criteria for hyperaccumulators (Gonzalez and Gonzalez-Chavez, 2006); Epilobium dodonaei for Cu, Pb, and Zn (Randjelović et al, 2016), Helichrisum decumbens, Zygophylum fabago and Lygeum spartum for Pb, Cu, and Zn (Conesa et al, 2006), Acacia retinoides, Helianthemum syriacum, Pinus halepensis, Teucrium capitatum, and Thymelea hirsuta for As, Cd, Pb, and Zn (Gomez-Ros et al, 2013) and Euphorbia pithysa for Pb, Cu, and Zn (Jimenez et al, 2011) showed low element concentrations in shoots despite highly contaminated mine spoils and they are suitable for phytostabilization; Cynodon dactylon and Sorghum halepense are good for phytostabilization of Pb-Zn mine waste (Madejon et al, 2002); Ditrichia viscosa can be a phytoextractor for As and Zn (Jimenez et al, 2011;Pistelli et al, 2017); Acer pseudoplatanus, Fraxinus excelsior, Robinia pseudoacacia, and Salix sp. are suitable for phytostabilization of mine waste (Mertens et al, 2007).…”

Pedogenesis in mine tails affects macroporosity, hydrological properties, and pollutant flow

“…During these 2500 years, the area suffered important environmental stresses such as the sedimentation of millions of tons of postflotation wastes (sludge) in Portman Bay and Mar Menor coastal lagoon. Metal contamination in this area has been recently confirmed by some authors (Garcia, 2004;García et al, 2008;Gómez Ros et al, 2013;Robles-Arenas et al, 2006).…”

The potential of native species as bioenergy crops on trace-element contaminated Mediterranean lands

“…In addition, biodiesel can be obtained from their oily seeds, with fuel properties comparable to those of mineral diesel, and in agreement with biodiesel standards (Encinar et al, 2002;Ullah et al, 2015). Dittrichia viscosa (L.) Greuter has also been identified as a promising bioenergy crop species for Mediterranean lands (Robledo & Correal, 2013), because of its ability to produce a high biomass in highly degraded soils, including soils contaminated by TE (Martínez-Sánchez et al, 2012;Gómez-Ros et al, 2013).…”