Phytoextraction of Cu, Cd, Zn and As in four shrubs and trees growing on soil contaminated with mining waste

HEREDIA, BELÉN; TAPIA, RAUL; YOUNG, BRIAN JONATHAN; HASUOKA, PAUL; PACHECO, PABLO; ROQUEIRO, GONZALO

CHEMOSPHERE

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2022

0045-6535

Abstract2 Mining activity has degraded large extensions of soil and its waste is composed of metals, anthropogenic3 chemicals, and sterile rocks. The use of native species in the recovery of polluted soils improves the4 conditions for the emergence of other species, tending to a process of ecosystem restoration. The objective5 of this study was to evaluate the bioaccumulation of metal(loid)s in four species of native plants and the6 effect of their distribution and bioavailability in soil with waste from an abandoned gold mine. Soil samples7 were taken from two sites in La Planta, San Juan, Argentina: Site 1 and Site 2 (mining waste and reference8 soil, respectively). In Site 1, vegetative organ samples were taken from Larrea cuneifolia, Bulnesia retama,9 Plectrocarpa tetracantha, and Prosopis flexuosa. The concentration of metal(loid)s in soil from Site 1 wereZn>As>Cu>Cd, reaching values of 7123, 6516, 240 and 76 mg kg-110 , respectively. The contamination11 indices were among the highest categories of contamination for all four metal(loid)s. The spatial12 interpolation analysis showed the effect of the vegetation as the lowest concentration of metal(loid)s were13 found in rhizospheric soil. The maximum concentrations of As, Cu, Cd and Zn found in vegetative organswere 371, 461, 28, and 1331 mg kg-114 , respectively. L. cuneifolia and B. retama presented high15 concentrations of Cu and Zn. The most concentrated metal(loid)s in P. tetracantha and P. flexuosa were16 Zn, As and Cu. Cd was the least concentrated metal in all four species. The values of BAF and TF were17 greater than one for all four species. In conclusion, the different phytoextraction capacities and the18 adaptations to arid environments of these four species are an advantage for future phytoremediation19 strategies. Their application contributes to the ecological restoration and risk reduction, allowing the20 recovery of ecosystem services.