Pharmaceutical residues are ubiquitous in rivers, lakes, and at coastal waters affected by discharges from municipal wastewater treatment plants. In this study, the presence of 17 different pharmaceuticals and six different phase I metabolites was determined in the bile of two wild fish species, bream (Abramis brama) and roach (Rutilus rutilus). The fish were caught from a lake that receives treated municipal wastewater via a small river. Prior to analyses, the bile content was enzymatically hydrolyzed to convert the glucuronide metabolites into the original pharmaceuticals or phase I metabolites. The solid phase extracts of hydrolyzates were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the multiple reaction monitoring mode. The anti-inflammatory drug naproxen could be detected in all the six bream and roach bile samples. Diclofenac was found in five of the bream and roach samples, while ibuprofen was detected in three bream and two roach samples. The observed bile concentrations of diclofenac, naproxen, and ibuprofen in bream ranged from 6 to 95 ng mL(-1), 6 to 32 ng mL(-1), and 16 to 34 ng mL(-1), respectively. The corresponding values in roach samples ranged from 44 to 148 ng mL(-1), 11 to 103 ng mL(-1) and 15 to 26 ng mL(-1), respectively. None of the other studied compounds could be detected. The study shows that pharmaceuticals originating from wastewater treatment plant effluents can be traced to the bile of wild bream and roach living in a lake where diclofenac, naproxen, and ibuprofen are present as pollutants.

An urgent need exists to assess the exposure of fish to pharmaceuticals. The aim of the present study was to assess the uptake and metabolism of waterborne pharmaceuticals in rainbow trout (Oncorhynchus mykiss). A further objective was to determine the possibility of monitoring exposure to low levels of pharmaceuticals by bile assays. Rainbow trout were exposed for 10 d under flow-through conditions to mixtures of five pharmaceuticals (diclofenac, naproxen, ibuprofen, bisoprolol, and carbamazepine) at high and low concentrations. The low concentration was used to mimic the conditions prevailing in the vicinity of the discharge points of wastewater treatment plants. The uptake and the bioconcentration were determined by blood plasma and bile analyses. The average bioconcentration factor in plasma ranged from below 0.1 for bisoprolol to 4.9 for diclofenac, the values being approximately similar at low and high ambient concentrations. The biotransformation of diclofenac, naproxen, and ibuprofen was considered efficient, because several metabolites could be detected in concentrations clearly exceeding those of the unmetabolized compounds. The glucuronides were the dominant metabolites for all three pharmaceuticals. The total bioconcentration in the bile was two to four orders of magnitude higher than in the plasma. The results of this work show that the exposure of fish to pharmaceuticals in environmentally relevant concentrations may be monitored by blood plasma and bile analyses, the latter allowing detection at markedly lower ambient concentration.

The findings suggest that fish living downstream WWTPs may take up NPX and metabolize the compound. Consequently, NPX and its metabolites in bile can be used to monitor the exposure of fish to NPX.

Pharmaceuticals are ubiquitous in surface waters as a consequence of discharges from municipal wastewater treatment plants. However, few studies have assessed the bioavailability of pharmaceuticals to fish in natural waters. In the present study, passive samplers and rainbow trout were experimentally deployed next to three municipal wastewater treatment plants in Finland to evaluate the degree of animal exposure. Pharmaceuticals from several therapeutic classes (in total 15) were analyzed by liquid chromatography-tandem mass spectrometry in extracts of passive samplers and in bile and blood plasma of rainbow trout held at polluted sites for 10 d. Each approach indicated the highest exposure near wastewater treatment plant A and the lowest near that of plant C. Diclofenac, naproxen, and ibuprofen were found in rainbow trout, and their concentrations in bile were 10 to 400 times higher than in plasma. The phase I metabolite hydroxydiclofenac was also detected in bile. Hence, bile proved to be an excellent sample matrix for the exposure assessment of fish. Most of the monitored pharmaceuticals were found in passive samplers, implying that they may overestimate the actual exposure of fish in receiving waters. Two biomarkers, hepatic vitellogenin and cytochrome P4501A, did not reveal clear effects on fish, although a small induction of vitellogenin mRNA was observed in trout caged near wastewater treatment plants B and C.

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In this study, the concentrations of 15 pharmaceuticals were monitored during four seasons (February, May, July, and November 2010) along a 32 km stretch of a highly wastewater polluted watercourse (River Rakkolanjoki, Lake Haapajärvi) in Eastern Finland. The aim was to study the seasonal variation in the elimination of the pharmaceuticals and the stability of the compounds along the watercourse. The analysis was carried out using a liquid chromatography tandem mass spectrometry (LC-MS/MS) method combined with extraction and preconcentration on HLB solid phase extraction (SPE) cartridges. Pharmaceutical concentrations were determined at 9 points along the watercourse, and loads and removal of parent compounds were calculated using flow data from the discharge point and the last sampling point. The pharmaceuticals were found in concentrations ranging from low ng l(-1) to low μg l(-1) values at the discharge point and at concentrations of 0-556 ng l(-1) at the last sampling point. The rate of elimination of the pharmaceutical load was significantly higher in May and July than in February and November. There were clear differences in the stability of the individual compounds along the watercourse. Carbamazepine was not eliminated during any season, while ibuprofen, ketoprofen and sertraline were fully eliminated over the studied stretch of river during the summer months. Other compounds showed continuous elimination independent of the season, indicating different elimination paths, such as sorption, biodegradation and phototransformation, for the studied compounds.

Several mono- and bimetallic Pd, Pt, Rh and Ru supported on alumina and active carbon catalysts were characterized by CO chemisorption, nitrogen adsorption, XPS and XRD and acidity titrations were performed for active carbon supported catalysts. These catalysts were tested in oxidation of two sugars, namely lactose and rhamnose, at 60 °C and at 70 °C under slightly alkaline conditions (pH 8) with molecular oxygen. The results revealed that there is an optimum metal particle size in a range of 3-10 nm giving the highest initial TOFs for both oxidations. Furthermore, the catalytic activities and conversions were related to other catalyst properties, such as the type and amount of promoters and the presence of different phases. In situ catalyst potential measurements revealed that there is an inverse correlation between the increase of catalyst potential as a function of sugar conversion and the catalyst activity after prolonged reaction times. This method is a valuable tool for in situ characterization of catalysts correlating well with their activities.