Acesulfame-K and pharmaceuticals as co-tracers of municipal wastewater in a receiving river

Wastewater treatment plant (WWTP) effluents are important sources of emerging contaminants at environmentally-relevant concentrations. In this study, water samples were collected from a river downstream of two WWTPs to identify practical tracers for tracking wastewater. The results of the study indicate elevated concentrations of Cl-, nutrients (NH3-N and NO2-), the artificial sweetener acesulfame-K (ACE-K), and the pharmaceuticals carbamazepine (CBZ), caffeine (CAF), sulfamethoxazole (SMX), ibuprofen (IBU), gemfibrozil (GEM), and naproxen (NAP) in the river close to the WWTPs that decreased with distance downstream. A correlation analysis using the Spearman Rank method showed that ACE-K, CBZ, GEM, NAP, and Cl- were strongly correlated with each other over a 31 km stretch of the river in the study area. The strong correlations of these target compounds indicate that the artificial sweetener ACE-K and the pharmaceuticals CBZ, GEM, and NAP can potentially be used as co-tracers to track wastewater.