Identifying Micropollutants in Greywater through Nontarget Screening Using HPLC-QTOF-MS

Abstract

In source-separating wastewater systems, greywater originating from all household activities excluding toilet flushing is a large portion of the wastewater volume and is a promising target for water reuse. However, the presence of various unidentified micropollutants is a problem that requires attention. Using a nontarget analysis and a semiquantitative assessment, the occurrence of micropollutants was assessed in the greywater of a city district (1000 people) and an apartment complex (100 people). The semiquantitative assessment showed that 36% of the detected features were present only at one site. The nontarget screening detected 88 micropollutants that were classified into five groups. Forty-five of these substances originated from personal care products, showing the importance of these products for both greywater treatment and conventional wastewater treatment. Half of the 18 detected pharmaceuticals were administered via routes that lack an obvious pathway to greywater. These pharmaceuticals should not be overlooked in the design of greywater treatment and monitoring strategies. In addition, six pesticides, 13 industrial compounds, and six stimulants were detected. These results emphasize the need for appropriate monitoring and treatment of micropollutants in greywater intended for reuse, as many of the detected compounds pose potential (eco)toxicological concerns.