Heavy Metals Concentration in Plants and Soils of Pan de Azúcar Mine (Jujuy-Argentina).

PLAZA CAZÓN JOSEFINA, ,, ; BENÍTEZ LEONARDO; DONATI EDGARDO; KIRSCHBAUM PABLO

Conferencia; International Conference on Mining and the Environment; 2013

Abstract Pan de Azúcar Mine is located in Jujuy Province, Northwest of Argentina, at an altitude of 3700 m.s.n.m. The site is vetiforme type, with primary Pb, Zn, Ag, and Sb sulfides. The activities at the mine ceased in 1990, since then the site was abandoned without adequate mine closure. The passive mine is located at 25 Km south of Laguna Pozuelos, National Natural Monument, Biosphere Reserve (UNESCO 1990) and Ramsar site (1982). The Cincel River, the mainly tributary of the lake receives direct input from acid mine drainage that drained during the summer season. The aim of this work was characterized and detected the effect of heavy metal contamination on the surrounding areas. Eight sampling sites were selected based on the distance from mine, topography, vegetation and slope. In order to determine the abundance of each species of plants in soils, eight 25 m2 plots were analyzed. Plants samples (leaves and roots,) were collected from every plot. Soils samples were also collected at the same time and the same place where the plants were sampled. Plants and soils samples were treated with a mixture of acids. The acid solutions were filtered with membrane 0.45 µm before were analyzed with atomic absorption spectrophotometer. Different plant species were identified, Parastrephia lepidophylla, Parastrephia lucida, Festuca argentinensis, Adesmia horrida, being Deyeuxia breviaristata the species disseminated in all the sites even covering 100% of soil in some of the plots. In addition, its biomass accumulated great amounts of metals. In the sample where the contents in soil were 670 mg Kg-1 Zn and 126 mg Kg-1 Pb, 136 mg Kg-1 and 204 mg Kg-1of Zn and Pb, respectively, were detected in the biomass. This plant would be considered for reclamation metal contaminated sites, stabilise the soils, immobilize trace elements in the rhizosphere and reducing the risk of the dissemination of metalliferous dust by water erosion or by downward water percolation from the root zone.