Suspect screening analysis of the occurrence and removal of micropollutants by GC-QTOF MS during wastewater treatment processes

Highlights: • An approach for the identification of noticeable compounds was presented. • A total of 117 micropollutants were identified in the whole treatment process. • The fate of identified micropollutants was described. • Wastewater treatment can efficiently remove semi-volatile micropollutant. -- Abstract: The presence of micropollutants in wastewater treatment plant (WWTP) poses potential risks to the aquatic system and human health. This study comprehensively characterized the presence, elimination, and transformation of micropollutants in the WWTP using the suspect screening approaches by employing the gas chromatography coupled with quadrupole time-of-flight mass spectrometry. Overall, 5724 features were identified in influent, while only 3418 features existed in effluents. Hierarchical cluster analysis (HCA) was used to group features based on intensity profiles to investigate the behavior and fate of detected features. Four representative trends were defined with the corresponding features. Among 117 compounds identified during the treatment process, there were 99 compounds in influent, 10 biological transformation products (TPs), 3 ozone TPs, and 5 ultraviolet TPs. Furthermore, the removal efficiencies for the detected compounds were determined. The study findings highlight the importance of the removal of emerging pollutants and TPs such as fipronil, fipronil sulfide, and fipronil sulfone.