Accumulation of potentially toxic trace elements (PTEs) by native plant species growing in a typical gold mining area located in the northeast of Qinghai-Tibet Plateau.

Lei Wang,Xiaorong Xie,Qifeng Li,Xixi Wang,Jinrong Liu,Zhifeng Yu,Guangde Hu

doi:10.1007/s11356-021-16076-7

Abstract

Though gold mines provide significant economic benefits to local governments, mining causes soil pollution by potentially toxic trace elements (PTEs) in mining areas, especially in the Qinghai-Tibet Plateau. Screening of native plant species from mining areas is now an effective, inexpensive, and eco-friendly method for the remediation of PTEs in situ. In the present study, we conducted experiments to assess the accumulation of As, Cd, Pb, and Zn in 12 native plant species growing on a typical gold mining area in the Qinghai-Tibet Plateau. Our results showed that rhizosphere soils have high soil organic matter content, high levels of As, and moderate levels of Cd. Geranium pylzowianum accumulated relatively higher As in its shoots and exhibited translocation factor (TF) higher than 1 for As (4.65), Cd (1.87), and Pb (1.36). Potentilla saundersiana had bioconcentration factor of shoot (BCF-S) higher than 1 for Cd (4.52) and Pb (1.70), whereas its TF was higher than 1 for As, Cd, Pb, and Zn. These plant species exhibit strong tolerance to these PTEs. Furthermore, Elymus nutans accumulated low levels of As, Cd, Pb, and Zn in their shoots and exhibited TF values lower than 1 for the four PTEs. Therefore, G. pylzowianum is a promising candidate for the in situ phytoextraction of As, and P. saundersiana can be used as an effective plant for Cd and Pb phytoextraction. E. nutans is better suited for the phytostabilisation of multiple PTEs. This work is of significant importance for screening native plant species that can provide a reference for phytoremediation of PTE-contaminated soils in this area or other place with similar climate, and has a good potential for developing PTE phytoremediation strategies at mining sites.

Highlights

Soils are essential components of terrestrial ecosystems as they play a fundamental role in food safety, ecological stability, and food security (Sun et al, 2019; Keshavarzi and Kumar, 2019)
The Electrical conductivity (EC) varied from 73.43 to 118.07 mS m−1, with the highest value observed at the rhizosphere soil of T. mongolicum
We explored the potentially toxic trace elements (PTEs) concentrations in 12 native plant species and their rhizosphere soils surrounding a typical gold mining area in the northeast of the Qinghai-Tibet Plateau

Summary

Introduction

Soils are essential components of terrestrial ecosystems as they play a fundamental role in food safety, ecological stability, and food security (Sun et al, 2019; Keshavarzi and Kumar, 2019). With the rapid development of the economy, soil contamination by potentially toxic trace elements (PTEs), which is caused by anthropogenic activities, including mining activities, industrial processes, waste disposal, and land use change (Zeng et al, 2020; Gemeda et al, 2021), has become a severe global problem. Among these activities, mining activities are currently the main source of metal contamination in soils (Zhou and Wang, 2019; Chen et al, 2021a). Remediating contaminated soils is of great significance in eliminating PTE contamination and reducing the potential ecological risks in the gold mining areas

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