Phytoremediation Potential of Native Herbaceous Plant Species Growing on a Paradigmatic Brownfield Site

N Matanzas,E Afif,T E Díaz,J R Gallego

doi:10.1007/s11270-021-05234-9

Abstract

Phytomanagement techniques using native species allow the recovery of contaminated soils at low cost and circumvent the ecological risks associated with the use of non-native species. In this context, a paradigmatic brownfield megasite highly contaminated by As and Pb was sampled in order to analyze soil–plant interactions and identify plant species with phytoremediation potential. A survey was first carried out in a 20-ha area to obtain an inventory of species growing spontaneously throughout the site. We then performed another survey in the most polluted sub-area (1 ha) within the site. Pseudototal concentrations of contaminants in the soil, aerial parts of the plants, and roots were measured by ICP-MS. A detailed habitat classification was done, and a specific index of coverage was applied by means of a 1-year quadrat study in various sampling stations. Results converged in the selection of six herbaceous species (Dysphania botrys, Lotus corniculatus, Lotus hispidus, Plantago lanceolata, Trifolium repens, Medicago lupulina). All of these plants are fast-growing, thereby making them suitable for use in phytostabilization strategies. Furthermore, they are all easy to grow and propagate and are generally self-sustaining. All six plants showed accumulation factors below 1, thus revealing them as pseudomethallophytes and excluders. However, L. hispidus and M. lupulina showed translocation capacity and are considered worthy of further study.

Highlights

Recent decades have witnessed the closure of many industrial and mining activities
Phytomanagement approaches emerge as potential alternatives as plants and trees play key roles in the biogeochemical cycling of nutrients and pollutants and can be considered ecosystem engineers (Jones et al, 1994; Robinson et al, 2009)
Phytoremediation is based on the ability of some plants and the associated microorganisms, which can grow in the presence of potentially toxic elements (PTEs) levels that are toxic for non-adapted plants, to degrade, extract, hold, or immobilize PTEs from soils (Khan et al, 2004; Lee, 2013; Leung et al, 2013; Souza et al, 2021; Wei et al, 2021)

Summary

Introduction

Recent decades have witnessed the closure of many industrial and mining activities. These brownfields pollute soil and (ground)water, causing environmental and health threats, as well as economic and social costs (Schädler et al, 2011; Zanchi et al, 2021). Phytomanagement approaches emerge as potential alternatives as plants and trees play key roles in the biogeochemical cycling of nutrients and pollutants and can be considered ecosystem engineers (Jones et al, 1994; Robinson et al, 2009) In this context, phytoremediation is a low-cost alternative to the physico-chemical treatments referred above. PTEs can be removed or immobilized by plants by various processes in function of their metabolic requirements In this context, phytostabilization is used to reduce the mobility of toxic elements from contaminated soil to the environment, whereas phytoextraction uses the plants’ ability to absorb and remove PTEs from the soil and take them up into shoots and leaves (Awa & Hadibarata., 2020; Oyuela et al, 2017)

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