Per- and poly-fluoroalkyl substances in sediments from the water-level-fluctuation zone of the Three Gorges Reservoir, China: Contamination characteristics, source apportionment, and mass inventory and loadings

• Published in: Environmental pollution (1987) 2022-04, Vol.299, p.118895-118895, Article 118895
• Main Authors: Zhang, Siyuan, Li, Xingquan, He, Ding, Zhang, Daijun, Zhao, Zhen, Si, Hongtao, Wang, Fengwen
• Format: Article
• Language: English
• Subjects: Alkanesulfonic Acids - analysis; China; Environmental Monitoring; Fluorocarbons - analysis; Mass inventory and loadings; Per/polyfluoroalkyl substances (PFASs); Rivers - chemistry; Sediments; Source apportionment; Spatiotemporal distribution; Three gorges reservoir; Water; Water Pollutants, Chemical - analysis
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2022.118895

Sixteen paired surface sediment samples (0–5 cm, n = 32) covering upstream to downstream of water-level-fluctuation zone of Three Gorges Reservoir, China were collected in March 2018 (following six months of submergence) and September 2018 (after six months of exposure). Seventeen per- and poly-fluoroalkyl substances (PFASs) were quantified to evaluate contamination characteristics, apportion source categories and estimate mass inventory and loadings. The concentration of ΣPFASs ranged from 0.26 to 0.82 ng·g−1 at high water-level (HWL) and 0.46–1.53 ng·g−1 at low water-level (LWL). Perfluorooctanoic acid (PFOA, mean: 0.32 ng·g−1) and perfluorooctane sulfonate (PFOS, mean: 0.12 ng·g−1) dominated, accounting 44.9% and 16.3% of the total PFASs, respectively. The distribution of PFASs was more influenced by anthropogenic activities than physicochemical parameters of the sediments. Positive matrix factorization (PMF) identified PFOA-based products was the major sources (40.1% and 38.6%, respectively). Besides, the direct sources of PFOA-, PFOS-, PFNA-and PFBA-based products played the predominant role, while the indirect degradation of precursors contributed relatively little. The sediment (0–5 cm) mass inventory of PFASs at LWL (57.5 kg) was higher than HWL (39.3 kg). The annual mass loadings of the total PFASs, PFOA, PFOS, perfluoroundecanoic acid (PFUdA) and perfluorononanoic acid (PFNA) from the upstream to the middle-lower reaches of Yangtze River were 27.4 kg, 11.1 kg, 4.63 kg, 2.89 kg and 2.57 kg, respectively. This study could provide the basic datasets of PFASs in surface sediments of the TGR, and also indicate an important transport of PFASs from upstream to the lower reaches, which should be further studied as well. [Display omitted] •The 17 PFASs averaged 0.58 and 0.84 ng g−1 during HWL and LWL, respectively.•PMF identified PFOA-based products were the major sources.•The annual mass loadings and average inventory of PFASs were 27.4 kg and 48.4 kg, respectively.