ABSTRACT
A wide range of pharmaceutical residues is known to occur in the environment. While they are released into surface waters mainly through centralized wastewater treatment plants (WWTPs), their primary emission sources are located upstream in the sewer network. Information on emissions from different types of primary emission sources is scarce. However, such information could help direct emission reduction measures more efficiently. In this study, we analysed the concentrations of selected active pharmaceutical ingredients (APIs) in wastewater samples taken from altogether ten sites, covering primary emission sources (hospitals and households), and conventional WWTPs. The concentrations in WWTP effluents were used to identify APIs causing risk in recipient waterbodies. Furthermore, the API loads from households and hospitals were compared to those reaching the WWTP in mixed influents. Our results confirm previously published observations of several pharmaceuticals exceeding their predicted no-effect concentrations in effluent wastewaters. Moreover, the concentrations of most of the analysed APIs are comparatively high in hospital wastewaters, resulting in elevated risk quotients. While the total API loads are relatively low from primary emission sources, owing to the low wastewater volume generated at those sites, per capita emissions were shown to be several times higher at hospital sites than at household sites for APIs such as metronidazole, trimethoprim, and ofloxacin. These findings indicate, that directing emission reduction measures to hospitals could be an effective way to decrease the loads of several risk-posing APIs into the environment, especially where hospital contribution to overall wastewater flow to WWTPs is high.
ABSTRACT
Anthropogenic chemicals in surface water and groundwater cause concern especially when the water is used in drinking water production. Due to their continuous release or spill-over at waste water treatment plants, active pharmaceutical ingredients (APIs) are constantly present in aquatic environment and despite their low concentrations, APIs can still cause effects on the organisms. In the present study, Chemcatcher passive sampling was applied in surface water, surface water intake site, and groundwater observation wells to estimate whether the selected APIs are able to end up in drinking water supply through an artificial groundwater recharge system. The API concentrations measured in conventional wastewater, surface water, and groundwater grab samples were assessed with the results obtained with passive samplers. Out of the 25 APIs studied with passive sampling, four were observed in groundwater and 21 in surface water. This suggests that many anthropogenic APIs released to waste water proceed downstream and can be detectable in groundwater recharge. Chemcatcher passive samplers have previously been used in monitoring several harmful chemicals in surface and wastewaters, but the path of chemicals to groundwater has not been studied. This study provides novel information on the suitability of the Chemcatcher passive samplers for detecting APIs in groundwater wells.
