Short-chain PFAS predominate in large-scale lithium battery industrial parks, Eastern China: Source apportionment and...

The rapid growth of the lithium-ion battery (LIB) industry has attracted great attention to the release of related emerging contaminants, especially per- and polyfluoroalkyl substances (PFAS). Yichun, known as the "Lithium Capital of Asia", is one of the largest lithium battery industry clusters in China, but our understanding of PFAS occurrence in LIB industry parks is limited. This study, combining self-organizing maps (SOM), positive matrix factorization (PMF), redundancy analysis (RDA), and risk quotient (RQ), aims to elucidate the distribution characteristics, sources, and ecological risks of 23 PFAS from wastewater treatment plants (WWTPs) and their receiving rivers (Jinjiang and Yuanhe) in the Yangtze River Basin. Our findings revealed that total concentrations ranged from 2.25 to 164.49 ng/L (mean: 29.05 ng/L in rivers, 44.54 ng/L in WWTPs), with short-chain PFAS (perfluorobutanoic acid and perfluorobutane sulfonic acid) accounting for 57.2 % of total PFAS. Source apportionment revealed three primary contributors: urban domestic wastewater (37.3 %), traditional industry (31.4 %), and LIB industry (31.3 %). The flux of total PFAS to Poyang Lake was 416.93 kg/year. Risk quotient (RQ) assessment results indicated that the risk level of perfluorooctane sulfonate (PFOS) was higher than that of other PFASs, indicating potential ecological risks downstream. The prevalence of short-chain PFAS correlates with the LIB industry's adoption of alternatives, underscoring the need for fluorine-free electrolytes and WWTP upgrades. While LIB production increases short-chain PFAS in aquatic environments, traditional industries remain non-negligible sources due to inadequate management, highlighting the urgency of integrated regulation addressing both emerging and legacy risks to safeguard long-term aquatic ecosystem health.