Elaborating PFAS characteristics for Chinese electroplating industry by target and nontarget analysis.

Per- and polyfluoroalkyl substances (PFAS) have been extensively used in the electroplating globally, yet the source characterization remains inadequately quantified. This study provides a high-resolution characterization of PFAS for the Chinese electroplating industry by combining target and nontarget analysis of samples, including chrome mist suppressants, plating bath solutions, wastewater, and sludge. A total of 91 PFAS homologues, spanning 14 classes, were identified by nontarget analysis. Predominant congeners include perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), 6:2 fluorotelomer sulfonic acid (6:2 FTSA), 6:2 chlorinated polyfluorinated ether sulfonic acid (6:2 Cl-PFESA), perfluorooctanoic acid (PFOA), monohydro-substituted perfluorobutanoic acid (H-PFBA), and sodium p-perfluorous nonenoxybenzenesulfonate (OBS). These originate from the diverse applications of mist suppressants, wetting and cleaning agents. Chromium plating wastewater exhibits distinct differences in both PFAS concentration and characteristics compared to other electroplating wastewaters. Notably, H-PFBA and OBS, two major PFAS identified through nontarget analysis, are reported for the first time in electroplating samples, warranting further investigation into their sources. With the ongoing implementation of the Stockholm Convention and stricter Chinese regulations on PFOS and PFHxS, an increased detection frequency and concentration of 6:2 FTSA as an alternative are anticipated. This is the first comprehensive study on PFAS characteristics for Chinese electroplating industry, providing critical insights for the source allocation of PFAS in the environment.