Phytoscreening for Per- and Polyfluoroalkyl Substances at a Contaminated Site in Germany

Abstract

The aim of this study was to perform a phytoscreening of per- and polyfluoroalkyl substances (PFAS) at a contaminated site in Germany, to investigate the applicability of this technique for PFAS contaminations. Foliage of three species, namely, white willow (Salix alba L.), black poplar (Populus nigra L.), and black alder (Alnus glutinosa L.), were sampled to evaluate seasonal and annual variations in PFAS concentrations. The results of the phytoscreening clearly indicated species and specific differences, with the highest PFAS sum concentrations ∑23 observed in October for white willow (0–1800 μg kg–1), followed by black poplar (6.7–32 μg kg–1) and black alder (0–13 μg kg–1). The bulk substances in leaves were highly mobile short-chain perfluoroalkyl carboxylic acids (PFCAs). In contrast, the PFAS composition in soil was dominated by long-chain PFCAs, perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA), as a result of the lower mobility with ∑23PFAS ranging between 0.18 and 26 μg L–1 (eluate) and between 66 and 420 μg kg–1 (solid). However, the PFAS composition in groundwater was comparable to the spectrum observed in leaves. Spatial interpolations of PFAS in groundwater and foliage correspond well and demonstrate the successful application of phytoscreening to detect and delineate the impact of the studied PFAS on groundwater.

Phytoremediation of soil contaminated with per- and polyfluoroalkyl substances (PFAS)

“…When comparing the uptake of PFAS in plant foliage, PFAS concentration was highest in the birch (34-476 ng g -1 dw) > willow (298 ng g -1 dw) > pine (13-179 ng g -1 dw). Previous screening studies in plants at PFAS-contaminated sites have revealed high PFAS concentrations in these species Würth et al 2023). The results demonstrated that plants at contaminated sites are highly capable of accumulating PFAS.…”

“…This can be mainly attributed to the areas' PFAS fingerprints in soil and groundwater (Niarchos et al 2023). Preferential accumulation of short chain PFAS in plant shoots has been observed in various trees and other plant species (Zhou et al 2019;Qian et al 2023;Würth et al 2023). It has been proposed that PFAS root uptake is influenced by the equilibrium between the root sap and the soil solution and the hydrophobicity of longer chain PFAS (Qian et al 2023).…”