Bioprospecting of plant species in abandoned mines and their phytoremediation potential

Abstract

Like many other economic activities, metal mining changes the geography and physiography of the natural landscape. The waste from this activity is characterised by, among other things, a high content of heavy metals and synthetic chemicals, which represent a serious socio-environmental problem. A closure plan for the mine is expected to include treatment measures involving environmental restoration, which is possible through the application of phytoremediation technologies. To search for new non-exotic phytoremediation species, a bioprospecting and bibliographic evaluation of the remediation potential of aromatic plant species present in two abandoned mining sites in Mendoza, Argentina, was conducted. The physicochemical and textural characteristics of the soil where vegetation grew, as well as the total concentration of heavy metals, were analysed using atomic emission spectrometry with electrothermal atomisation. As a result, 16 different plant species were identified, mainly from the Asteraceae and Poaceae families, all of which had medium to high remedial potential according to the literature consulted. The soil was sandy, with a low organic matter content, and in general the total metal content did not exceed the maximum permissible limits for agricultural soils, except for lead, whose concentration is above 50 mg/kg. In conclusion, the plant species have remediation potential, but this will have to be confirmed experimentally in future laboratory and field tests.