Mass loads, source apportionment, and risk estimation of organic micropollutants from hospital and municipal wastewater in recipient catchments.

ABSTRACT

Understanding the occurrence and sources of organic micropollutants (OMPs) in aquatic environments is essential for environmental risk assessment and adequate interventions to secure good status of aquatic environments. The occurrence and source apportionment of 77 OMPs in the River Fyris catchment (Uppsala, Sweden) were investigated by comparing hospital wastewater, wastewater treatment plant (WWTP) effluent, and surface water. Hospital wastewater was identified as an important source for some classes of OMPs, e.g., antibiotics (number of OMPs (n) = 6) and antidepressants (n = 4), contributing 38% and 31%, respectively, of the mass loads in total WWTP influent. Painkillers (n = 5) and hormones (n = 3), originating mainly from urban Uppsala, contributed 94% and 95%, respectively. WWTP removal efficiency varied from 100% for acetaminophen to <0% for i.e. clindamycin, lamotrigine, bicalutamide, and sucralose. In the recipient River Fyris, the ΣOMP concentration downstream of the WWTP (738 ng L-1) was more than double that upstream (338 ng L-1), demonstrating the high impact of the WWTP on recipient water quality. Surface water risk quotients (RQs) showed a moderate risk of adverse chronic effects (RQ > 0.1) for trimethoprim, norsertraline, and metoprolol downstream of the WWTP, and for norsertraline in the recipient river upstream and Lake Ekoln downstream of the WWTP. Recipient metoprolol and trimethoprim, compounds poorly removed in the WWTP, mainly (>90%) originated from wastewater from urban Uppsala, whereas recipient norsertraline originated upstream of the city. No risk compound was apparently sourced from hospital wastewater.