Multicompartment occurrence and partitioning of alternative and legacy per- and polyfluoroalkyl substances in an impacted river in China

Lijuan Gao; Jingling Liu; Kun Bao; Nannan Chen; Bo Meng

doi:10.1016/j.scitotenv.2020.138753

Multicompartment occurrence and partitioning of alternative and legacy per- and polyfluoroalkyl substances in an impacted river in China

Sci Total Environ. 2020 Aug 10:729:138753. doi: 10.1016/j.scitotenv.2020.138753. Epub 2020 Apr 18.

Authors

Lijuan Gao¹, Jingling Liu², Kun Bao¹, Nannan Chen¹, Bo Meng¹

Affiliations

¹ School of Environment, Beijing Normal University, State Key Laboratory of Water Environment Simulation, Beijing 100875, China.
² School of Environment, Beijing Normal University, State Key Laboratory of Water Environment Simulation, Beijing 100875, China. Electronic address: jingling@bnu.edu.cn.

PMID: 32375068
DOI: 10.1016/j.scitotenv.2020.138753

Abstract

Per- and polyfluoroalkyl substances (PFASs) are emerging global environmental contaminants. Exploring the occurrence and environmental behavior of PFASs in the aquatic environment is a key step in solving global fluorine chemical pollution problems. In this study, surface water, pore water, and sediment were collected from the main tributary and the middle and lower reaches of the Daling River, adjacent to the Fuxin fluorochemical manufacturing facilities in Liaoning Province in China, to elucidate the occurrence and partition behavior of PFASs. The total concentrations of PFASs ranged from 48.4 to 4578 ng/L in the overlying water, from 173 to 9952 ng/L in the pore water, and from 2.16 to 40.3 ng/g dw in the sediment fraction. Generally, perfluorobutanoic acid (PFBA) and perfluorobutane sulfonate (PFBS) were the predominant congeners in the samples, with the mean relative content fractions being almost consistently >40% in the dissolved phase and >25% in the sediment. Hexafluoropropylene oxide dimer acid (HFPO-DA) and chlorinated polyfluorinated ether sulfonic acid (6:2 Cl-PFESA) were detected, albeit at low levels. In addition, the detection frequency and the contribution of legacy long-chain PFASs in sediment were higher than those in the overlying water and pore water. Except for perfluorohexane sulfonate (PFHxS), the concentrations of the alternative PFASs in the pore water were higher than in the overlying water. The organic carbon fraction was a more important controlling factor for PFAS sediment levels than cations content. As with legacy long-chain PFASs, HFPO-DA and 6:2 Cl-PFESA tended to partition into the solid phase, whereas short-chain PFASs were readily distributed in the aqueous phase. Such research results will be helpful in modeling the transport and fate of PFASs released by point sources into coastal waters through rivers and in developing effective risk assessment and management strategies for the control of PFAS pollution.

Keywords: Alternatives; Occurrence; Partitioning; Perfluoroalkyl substances (PFASs); Pore water.