Suspect and Nontarget Screening of Per- and Polyfluoroalkyl Substances in Wastewater from a Fluorochemical Manufacturing Park

Although
per- and polyfluoroalkyl substances (PFASs) have always
been a key issue in the global environmental field, there are still
a lot of undiscovered PFASs in the environment due to new PFAS alternatives
developed by manufacturers. Wastewater treatment plants (WWTPs), as
one of the sources for PFASs, are an important part of the process
of releasing new PFASs into the environment. In this study, suspect
screening and PFAS homologue analysis with quadrupole time-of-flight
tandem mass spectrometry were used to discover PFASs in wastewater
from a WWTP near Yangtze River. Fifteen classes with 90 PFASs were
identified, including 12 legacy PFASs (2 classes), 41 previously reported
PFASs (7 classes), and 37 new PFASs (6 classes), and 18 of these PFASs
were also detected in the nearby Yangtze River. Only 1 PFAS class
was removed through the treatment processes (fold change < 1/6).
Conversely, 4 PFAS classes increased through the treatment processes
(fold change > 6), which could be the transformation products of
PFAS
precursors. These results implied that most discovered PFASs were
not effectively removed in the WWTP. Chlorine-substituted perfluoroalkyl
carboxylates (Cl-PFCAs) as the main component of wastewater were detected
only in downstream, meaning that Cl-PFCAs in downstream possibly originated
from the WWTP.