No abstract

A B S T R AC TRemovals of perfl uorooctanoic acid (PFOA) and perfl uorooctane sulfonate (PFOS) in pilot-scale constructed wetland were investigated in this study. Phytoextraction by four aquatic plants (Hygrophila pogonocalyx Hayata, Ipomoea aquatic Forssk, Ludwigia (x) taiwanensis and Eleocharis dulcis) and sorption onto soil were determined. Both PFOA and PFOS were fairly phytoextracted by four aquatic plants; the uptake capacity was found in the following order: Hygrophila pogonocalyx Hayata > Ipomoea aquatic Forssk ≈ Ludwigia (x) taiwanensis > Eleocharis dulcis. In the soil sorption experiment, equilibria for PFOA and PFOS were achieved within 6 d; sorption capacity of 2-3 μg/g was observed at the end of the 15 d experiment. Experimental results and literature review suggest that phytoextraction and soil sorption were the most signifi cant mechanisms for PFOA and PFOS disappearance in the pilot-scale constructed wetland, while contributions of biodegradation, photolysis, volatilization and hydrolysis were negligible.