Emerging and legacy per- and polyfluoroalkyl substances in Daling River and its estuary, Northern China.

Strict restriction on legacy per - and polyfluoroalkyl substances (PFASs) has caused a dramatic increase in production and usage of emerging PFASs over the last decades. However, the environmental behaviors of emerging PFASs is largely unknown in Daling River, Northern China. In this study, the potential sources, sediment-water partitioning and substitution trends of PFASs were investigated in overlying water and sediments from Daling River and its estuary. Perfluorooctane sulfonate and 6:2 fluorotelomer sulfonic acid were major compounds, and sodium p -perfluorous nonenoxybenzene sulfonate was first detected. Firefighting foam manufacturing and fluoropolymer production were the main sources of PFASs. Compared to legacy PFASs (C 8), the emerging PFASs (C 6 - C 9) were more incline to distribute into overlying water. Substitution trends indicated 6:2 fluorotelomer sulfonic acid and hexafluoropropylene oxide trimer acid as the important alternatives of perfluorooctane sulfonate and perfluorooctanoic acid, respectively. The results were meaningful for understanding the environmental behaviors of emerging PFASs. • OBS was first detected in water and sediments from Daling River and its estuary. • 6:2 FTSA and PFOS were predominant congeners in both water and sediments. • Emerging PFASs were more inclined to accumulated in water than legacy PFASs. • K ow played the key role in the sediment-water partitioning of PFASs. • 6:2 FTSA and HFPO-DA were the main alternatives of PFOS and PFOA, respectively. [ABSTRACT FROM AUTHOR]