Phytoextraction of metals by native plants from mining wastes in Zacatecas, Mexico
Noria de Angeles, a small town in Mexico, is surrounded by mining wastes; it is an arid landscape with its atmosphere, groundwater and soil polluted by toxic metals, which represent an environmental and health problem for the nearby population. Metal content and physicochemical properties were determined in tailing heaps and soils in 18 sites. Concentrations of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) in soils were 1-4, 30-95, 50-420, and 60-250 g kg-1, respectively, while metal content was up to 6 times greater in the heaps than in soils. Vegetal species were dried and milled to quantify metal concentrations, which showed that phytotoxic limits of Cu, Pb and Zn were exceeded in almost all sites. Samples of Acacia farnesiana contained up to 78, 113 and 383 g kg-1 of dry matter of Cu, Pb and Zn, respectively; for Prosopis laevigata, the figures were 58, 107 and 291 g kg-1; for Schinus molle, 65, 116 and 415 g kg-1; and for Larrea tridentata, 30, 30 and 163 g kg-1. The four plant species studied can be used for phytoremediation, since they are tolerant to extreme temperatures, water scarcity and saline soils polluted with toxic metals.
Ibarra-García, A.R., Barceló-Quintal, I.D., García-Albortante, J., López-Lafuente, A.L., González-Huecas, C., Quintana-Nieto, J.R. and Mugica-Alvarez, V. (2018). Phytoextraction of metals by native plants from mining wastes in Zacatecas, Mexico. Acta Hortic. 1227, 409-416
toxic metals, mining wastes, phytoremediation, Mexico