Comprehensive Target, Suspect, and Non-Target Screening Using LC-HRMS of Pharmaceuticals and Their Transformation Products in Biological Treatment Systems

This study employed LC-HRMS-based target, suspect, and non-target screening to investigate the occurrence, behavior, and environmental risk of pharmaceuticals (PCs) and their transformation products (TPs) in a biological treatment system (BTS). A total of 82 compounds (43 confirmed, 39 tentatively identified) were detected. PCA and HCA revealed temporal variations in concentrations and removal efficiencies, with some compounds exhibiting persistent or increasing trends. Fold change analysis enabled classification of TPs as human, microbial, or dual-type metabolites, highlighting active transformation processes in the BTS. PMT/PBT assessments showed that many TPs (e.g., CBZ-EP, CFN-PT, VST-A) exhibited high persistence, mobility, or potential toxicity. Structural modifications, such as ether, ketone, or hydroxylation groups, often contributed to these properties. Compounds like VST-A and PFN-M300 showed increased mobility and resistance to degradation, even after treatment. These findings underscore the importance of including diverse PCs and TPs in environmental assessments. The study demonstrates the applicability of comprehensive screening and statistical methods for identifying substances of environmental relevance and transformation behavior in the BTS. These findings indicate the necessity of comprehensive monitoring and may contribute to future regulatory development.