Development of a tool to routinely monitor wastewater systems via non-target screening utilizing spatial fingerprinting and temporal trend analysis as prioritization techniques

Non-Target Screening (NTS) is a valuable technique for exploring the chemical composition of aquatic systems. Although target screening has already been established in the quality control of water samples, adopting NTS, especially in data processing, requires further refinements. Herein, we introduce an approach to bring NTS closer to a practical application in routine wastewater monitoring. An in-house tool was developed, specifically designed for quick and efficient NTS data processing based on temporal analysis and spatial fingerprinting as prioritization techniques. This tool enables the creation of a fingerprint database for each emission source. It then uses this database to track the origin of each compound in downstream samples and conducts trend analysis if data from more downstream samples are available. As proof of concept, we successfully applied NTS and this tool to monitor a wastewater system in a chemical industrial park, aiming to routinely safeguard the wastewater treatment plant against potential threats. Specifically, compounds in the influent originating from particular plants were prioritized and their intensity profiles were monitored. Further substances with signal intensities increasing over time were also investigated, and possible transformation products were linked to their respective emission source. For these applications, a tedious structural elucidation of the individual compounds was not required since pattern and trend analyses were based on features. All in all, our NTS-based tool expanded the monitoring scope and demonstrated effectiveness and efficiency in routine wastewater management within the industrial park.