Concentration-dependent Accumulation and Translocation of PFASs by Wetland Plant Alisma orientale

Abstract

This study investigated the concentration-dependent accumulation and translocation of perfluoroalkyl substances (PFASs) by wetland plant Alisma orientale. The concentrations of PFASs in nutrient solution were 0, 5, 10, 50, 100, 200, 500, and 1000 μg·L-1. The electrolytic leakage of roots, Cu concentration in roots and stems, and Ca concentration in stems and leaves decreased with an increase in PFASs concentration in external solution, while the plants were growing well. The removal mass of PFASs by plants increased (0.87-116.50 μg) with an increase in PFASs concentration, while the removal efficiency decreased (20.1%-2.9%). The PFASs concentration in plant roots, stems, and leaves increased linearly with that in nutrient solution, and fitted the Langmuir adsorption isotherm and Michaelis-Menten equation well, which indicated PFASs were uptaken through passive diffusion. The root concentration factor, stem concentration factor, transpiration stream concentration factor, and partition limited quasi-equilibrium factor αpt decreased with that of PFASs in nutrient solution, probably due to the increase in the volume of transpiration water and the longer time to reach equilibrium.