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

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.

Sorption of perfluoroalkyl substances (PFASs) to an organic soil horizon - Effect of cation composition and pH.

Accurate prediction of the sorption of perfluoroalkyl substances (PFASs) in soils is essential for environmental risk assessment. We investigated the effect of solution pH and calculated soil organic matter (SOM) net charge on the sorption of 14 PFASs onto an organic soil as a function of pH and added concentrations of Al3+, Ca2+ and Na+. Often, the organic C-normalized partitioning coefficients (KOC) showed a negative relationship to both pH (Δlog KOC/ΔpH = -0.32 ±â€¯0.11 log units) and the SOM bulk net negative charge (Δlog KOC = -1.41 ±â€¯0.40 per log unit molc g-1). Moreover, perfluorosulfonic acids (PFSAs) sorbed more strongly than perfluorocarboxylic acids (PFCAs) and the PFAS sorption increased with increasing perfluorocarbon chain length with 0.60 and 0.83 log KOC units per CF2 moiety for C3-C10 PFCAs and C4, C6, and C8 PFSAs, respectively. The effects of cation treatment and SOM bulk net charge were evident for many PFASs with low to moderate sorption (C5-C8 PFCAs and C6 PFSA). However for the most strongly sorbing and most long-chained PFASs (C9-C11 and C13 PFCAs, C8 PFSA and perfluorooctane sulfonamide (FOSA)), smaller effects of cations were seen, and instead sorption was more strongly related to the pH value. This suggests that the most long-chained PFASs, similar to other hydrophobic organic compounds, are preferentially sorbed to the highly condensed domains of the humin fraction, while shorter-chained PFASs are bound to a larger extent to humic and fulvic acid, where cation effects are significant.