Phytoremediation potential in soils contaminated with zinc

Abstract

The accumulation of heavy metals in soils and waters represents a risk for both the environmental and human health. In this context, phytoremediation has become an efficient, accessible technological solution to extract or remove inactive metals and metal pollutants from contaminated soils. Our objective is to assess the behavior of different native plants of the Cerrado of Maranhão, ipê roxo (Tabebuia impetiginosa) and aroeira (Myracrodrun urundeuva), in the phytoremediation of soils contaminated with Zinc (Zn) (II) under controlled greenhouse conditions. Between the species investigated, Tabebuia impetiginosa presented a higher biomass production (aerial part/root) than Myracrodrun urundeuva for the period of 25 days. In turn, in the 45-day period, root biomass was higher for Tabebuia impetiginosa in doped soil, while lower biomass production was found in the aroeira control group. The highest Zn concentrations in the root appeared in the period of 25 days for doped soil for both species, with an absorption of 142.10 mg kg-1 for Tabebuia impetiginosa and 150.57 mg kg-1 for Myracrodrun urundeuva. In the aerial part, the aroeira species had higher Zn concentration in doped soil in the 45-day period, 398.97 mg kg-1. Regarding the TF and BF, the species presented higher efficiency in zinc phytoextraction. Both species were able to absorb and tolerate the metals in the soil induced to stress. Finally, we conclude that Tabebuia impetiginosa and Myracrodrun urundeuva can be applied in phytostabilization and phytoextraction processes, with hyperaccumulating potential for the ions of Zn.