Comparison of three macrophytes to remediate co- contaminated soils with polycyclic aromatic hydrocarbons (PAHs) and trace elements (TEs): implications for green urban infrastructures

M.-C Leroy , Florence Portet-Koltalo (1) , F. Le Derf (1) , Stéphane Marcotte (1) , V Moncond'Huy , M. Legras (2)

1 COBRA - Chimie Organique et Bioorganique : Réactivité et Analyse
2 AGRI'TERR - Unité de recherche en agro-écologie des territoires

Many studies report successful phytoremediation using macrophytes to treat wastewater in wetlands. However, little is known about their capabilities in Low Impact Development (LID) technologies dedicated to road water runoff management where plants are submitted to dry and flood periods. Six representative large-scale outdoor mesocosms planted with Juncus effusus, Iris pseudacorus, Phalaris arundinacea as monospecies were co-contaminated with Polycyclic Aromatic Hydrocarbons (PAHs, i.e. phenanthrene, pyrene and benzo[a]pyrene), and Trace Elements (TEs, i.e. zinc, lead, and cadmium). Mesocosms were studied two years for plant biomass production, PAHs soil dissipation, and metal uptake by plants. PAHs were extracted from soils by microwave assisted extractions and analysed by gas chromatography (GC-MS) while microwave-acid digestion was used to extract metals, which were then analysed by ICP-AES. A special attention was paid to soil microbial community structure through total, fungal and bacterial biomasses using Q-PCR, 16S rDNA and 18S rDNA and total microbial activity using fluorescein diacetate enzymatic activity. A multi-parameter approach was used in order to conclude on the best macrophytes-soil system for TEs and PAHs remediation. I. pseudacorus revealed to be the worst metal accumulator correlated to soil total, bacterial and fungal biomasses. After six months, low molecular weight PAHs concentrations were divided by 10 to 100 and by 2 to 7 for benzo[a]pyrene depending on plant species. Same methods were used to study phytoremediation processes in LID technologies receiving run-off water laterally from the road as the unique source of contamination. Similar conclusions as those obtained with spiked mesocosms were found.Keywords: phytoremediation, polycyclic aromatic hydrocarbons, trace elements, road run-off water, mesocosm, vegetated swales, macrophyte

Mots clés: polycyclic aromatic hydrocarbons; road run-off water; Keywords: phytoremediation; mesocosm; trace elements; vegetated swales; macrophyte

Domaines: Chimie; Chimie analytique; Sciences de l'environnement

M.-C Leroy, Florence Portet-Koltalo, F. Le Derf, Stéphane Marcotte, V Moncond'Huy, et al.. Comparison of three macrophytes to remediate co- contaminated soils with polycyclic aromatic hydrocarbons (PAHs) and trace elements (TEs): implications for green urban infrastructures. International Congress on Phytoremediation of Polluted Soils (PPS 2014), Jul 2014, Vigo, Spain. ⟨hal-02557136⟩