Consequences of treated water recycling as regards pharmaceuticals and drugs in surface and ground waters of a medium-sized Mediterranean catchment

In Mediterranean regions where the population is rapidly growing, the risk of water resource contamination by wastewater is likely to increase. This is the case of the Hérault watershed (south of France), where the presence of treated wastewater in surface and ground waters has been shown in a previous study. To assess the consequence of these wastewater contaminations as regards pharmaceuticals and other organic compounds, 16 common pharmaceuticals (amitryptilin, acetylsalicylic acid, carbamazepine, clenbuterol, diazepam, diclofenac, doxepin, gemfibrozil, ibuprofen, imipramine, ketoprofen, naproxen, nordiazepam, paracetamol, salbutamol, and terbutalin) as well as wastewater related pollutants (caffeine, gadolinium anomaly, and boron) were analyzed in wells pumped for potable water supply and in two wastewater treatment plant (WWTP) effluents. In addition, a monitoring along the Lergue River (the main tributary of the Hérault River) was achieved to assess pharmaceutical behavior in surface waters. Pharmaceuticals and other wastewater-related contaminants are present in several reservoirs tapped for drinking water, confirming wastewater contamination; paracetamol, caffeine, and diclofenac are the most frequently detected. Paracetamol is present at rather high concentrations (up to 11 microg/L and 211 ng/L, respectively, in a wastewater effluent and in a drinking water sample). Though degradable in WWTP, caffeine is commonly encountered in surface waters and detected in highly polluted groundwater. On the contrary, acetylsalicylic acid concentrations are generally low despite a large consumption in France; this is related to its metabolism in humans and rapid degradation in the aquatic environment. The monitoring of pharmaceuticals along the Lergue River shows that dilution is sufficient to decrease pharmaceutical values.     

Evaluation of pharmaceuticals and personal care products as water-soluble molecular markers of sewage

We examined the utility of 13 pharmaceuticals and personal care products (PPCPs) as molecular markers of sewage contamination in riverine, groundwater, and coastal environments. The PPCPs were crotamiton, ibuprofen, naproxen, ketoprofen, fenoprofen, mefenamic acid, thymol, triclosan, propyphenazone, carbamazepine, diethyltoluamide, ethenzamide, and caffeine. Measurements in 37 Japanese rivers showed positive correlations of riverine flux of crotamiton (r2 = 0.85), carbamazepine (r2 = 0.84), ibuprofen (r2 = 0.73), and mefenamic acid (r2 = 0.67) with the population in the catchments. In three surveys in the Tamagawa estuary, crotamiton, carbamazepine, and mefenamic acid behaved conservatively across seasons within a salinity range of 0.4-29 per thousand, suggesting their utility as molecular markers in coastal environments. Removal of ketoprofen and naproxen in the estuary was ascribed to photodegradation. Ibuprofen and thymol were removed from estuarine waters in summer by microbial degradation. Triclosan was removed by a combination of microbial degradation, photodegradation, and adsorption. These results were consistent with those of river water incubated for 8 d at 25 degrees C in the dark in order to examine the effects of biodegradation and photodegradation. Crotamiton was detected in groundwater from the Tokyo metropolitan area (12 out of 14 samples), suggesting wastewater leakage from decrepit sewers. Carbamazepine, ketoprofen, and ibuprofen (5/14), caffeine (4/14), and diethyltoluamide (3/14) were also detected in the groundwater, whereas the other carboxylic and phenolic PPCPs were not detected and were thought to be removed during their passage through soil. All the data demonstrated the utility of crotamiton and carbamazepine as conservative markers in freshwater and coastal environments. We recommend combining these conservative markers with labile PPCPs to detect inputs of poorly treated sewage.     

Elimination of selected acidic pharmaceuticals from municipal wastewater by an activated sludge system and membrane bioreactors

The elimination of six acidic pharmaceuticals (clofibric acid, diclofenac, ibuprofen, ketoprofen, mefenamic acid, and naproxen) in a real wastewater treatment plant (WWTP) using an activated sludge system and membrane bioreactors (MBRs) was investigated by using a gas chromatography/mass spectrometry (GC/MS) system for measurement of the compounds. Limited information is available for some of the tested pharmaceuticals at present. Solid retention times (SRTs) of the WWTP and the two MBRs were 7, 15, and 65 days, respectively. The elimination rates varied from compound to compound. The MBRs exhibited greater elimination rates for the examined pharmaceuticals than did the real plant. Dependency of the elimination rates of the pharmaceuticals on SRTs was obvious; the MBR operated with a longer SRT of 65 days clearly showed better performance than did the MBR with a shorter SRT of 15 days. The difference between the two MBRs was particularly significant in terms of elimination of ketoprofen and diclofenac. Measurements of the amounts of adsorbed pharmaceuticals on the sludge and aerobic batch elimination experiments were carried out to investigate the elimination pathways of the pharmaceuticals. Results of the batch elimination tests revealed that the sludges in the MBRs had large specific sorption capacities mainly due to their large specific surface areas. Despite the sorption capacities of sludges, the main mechanism of elimination of the pharmaceuticals in the investigated processes was found to be biodegradation. Biodegradation of diclofenac, which has been believed to be refractory to biodegradation, seemed to occur very slowly.     

Removal of pharmaceuticals during drinking water treatment

The elimination of selected pharmaceuticals (bezafibrate, clofibric acid, carbamazepine, diclofenac) during drinking water treatment processes was investigated at lab and pilot scale and in real waterworks. No significant removal of pharmaceuticals was observed in batch experiments with sand under natural aerobic and anoxic conditions, thus indicating low sorption properties and high persistence with nonadapted microorganisms. These results were underscored by the presence of carbamazepine in bank-filtrated water with anaerobic conditions in a waterworks area. Flocculation using iron(III) chloride in lab-scale experiments (Jar test) and investigations in waterworks exhibited no significant elimination of the selected target pharmaceuticals. However, ozonation was in some cases very effective in eliminating these polar compounds. In lab-scale experiments, 0.5 mg/L ozone was shown to reduce the concentrations of diclofenac and carbamazepine by more than 90%, while bezafibrate was eliminated by 50% with a 1.5 mg/L ozone dose. Clofibric acid was stable even at 3 mg/L ozone. Under waterworks conditions, similar removal efficiencies were observed. In addition to ozonation, filtration with granular activated carbon (GAC) was very effective in removing pharmaceuticals. Except for clofibric acid, GAC in pilot-scale experiments and waterworks provided a major elimination of the pharmaceuticals under investigation.     

Effects of pharmaceutically active compounds on a mixed microbial community originating from a municipal wastewater treatment plant

The growth and composition of microorganisms found in a municipal wastewater treatment plant were investigated in the presence of four pharmaceutically active compounds (PhACs) [ketoprofen, naproxen, carbamazepine, and clofibric acid] in batch reactors at varying organic loadings. Overall, the data suggest that microbial growth inhibition was correlated to organic loading rather than PhAC concentration. Significant inhibition ranging from 34 to 43% was observed under the lowest organic loading for all PhACs other than clofibric acid. No inhibition was observed at the highest organic loading. Higher microbial inhibition was not observed with increased PhAC concentration for a given organic loading. These results indicatethatthe presence of PhAC may affect microbial growth especially under lower organic loading conditions. Further validation is required with additional PhACs, organic substrates, and a wider loading range. In addition, significant microbial shifts were observed in the presence of ketoprofen and naproxen. These data suggest that, in addition to their effect on overall microbial growth, PhACs may affect the microbial ecology and additional research should be carried out to identify PhACs that have the potential of affecting ecologically important microorganisms in wastewater treatment processes and aquatic environments in general.     

Polar pollutants entry into the water cycle by municipal wastewater: a European perspective

The effluents of eight municipal wastewater treatment plants (WWTP) in Western Europe were analyzed by liquid-chromatography-mass spectrometry for the occurrence of 36 polar pollutants, comprising household and industrial chemicals, pharmaceuticals, and personal care products. In a long-term study of the effluents of three WWTP over 10 months, sulfophenyl carboxylates and ethylene diamino tetraacetate (EDTA) were detected above 10 microg/L on average, while benzotriazoles, benzothiazole-2-sulfonate, diclofenac, and carbamazepine showed mean concentrations of 1-10 microg/L, followed by some flame retardants, naphthalene disulfonates, and personal care products in the range of 0.1-1 microg/L. Half of the determined compounds were not significantly removed in tertiary wastewater treatment. By dividing the effluent concentration of a compound by its relative removal in WWTP a water cycle spreading index (WCSI) was calculated for each compound. We propose that this index provides a measure for the potential of a polar compound to spread along a partially closed water cycle after discharge with municipal wastewater and to occur in raw waters used for drinking water production. Polar pollutants in surface water samples of different catchments showed increasing concentration for compounds with increasing WCSI.     

Seasonal variation in the occurrence of pharmaceuticals in effluents from a sewage treatment plant and in the recipient water

The occurrence of five pharmaceuticals (ibuprofen, naproxen, ketoprofen, diclofenac, and bezafibrate) in the influent and effluent water of a sewage treatment plant (STP) in the recipient river water and in a drinking water treatment plant (DWTP) located downstream from the STP was followed during three seasons: winter, spring, and summer. In the STP, the elimination of the pharmaceuticals decreased significantly (an average of 25% compared to spring and summer) in wintertime leading to increased concentrations of pharmaceuticals in the effluent water. The total concentration of all the studied pharmaceuticals in the effluent water was 3-5 times higher in wintertime (about 2500 ng L(-1)) than during the other seasons (about 500-900 ng L(-1)). Accordingly, the highest concentrations (up to 129 ng L(-1)) in the recipient river were measured in the wintertime. Pharmaceuticals were carried longer distances downstream from the STP when the river was covered by ice and snow. During a drastic increase in water flow rate (i.e., during snowmelting), a fast transportation of the pharmaceuticals was observed. The DWTP located downstream from the STP produced water that contained about 8 ng L(-1) of ibuprofen and ketoprofen in the winter sample, whereas in spring and summer the studied pharmaceuticals could not be detected in the drinking water. The results show that cold seasons in boreal areas can severely increase the environmental risk of pharmaceuticals and the risk for contamination of drinking water.     

Reactive tracer test to evaluate the fate of pharmaceuticals in rivers

The fate of pharmaceutically active substances in rivers is still only incompletely understood, especially as the knowledge transfer from laboratory experiments to the real world is complicated by factors like turbidity, hydrodynamics, or heterogeneity. Therefore, we performed a tracer test with pharmaceutically active substances to study their fate and the importance of individual attenuation mechanisms in situ. The experiment was carried out at a small stream in central Sweden. Two dye tracers and six pharmaceuticals were injected as Dirac pulse and water was sampled at five downstream sites along a 16-km-long river reach. Ibuprofen and clofibric acid were the only compounds which were eliminated along the study reach at half-life times of 10 h and 2.5 d, respectively. Based on the shape of the breakthrough curves and the low hydraulic conductivity of the river bed, we can assume that exchange of river water with the hyporheic zone was minor. Thus, the contribution of processes in the hyporheic zone to the attenuation of pharmaceuticals was low. We hypothesize that ibuprofen and clofibric acid were transformed by in-stream biofilms growing on submerged macrophytes and at the water-sediment interface. Phototransformation and sorption were ruled out as major attenuation processes. No attenuation of bezafibrate, diclofenac, metoprolol, and naproxen was observed.     

Behavior of selected pharmaceuticals in subsurface flow constructed wetlands: a pilot-scale study

Subsurface flow constructed wetlands (SSFs) constitute a wastewater treatment alternative to small communities due to the low operational cost, reduced energy consumption, and no sewage sludge production. Although much information is available about conventional water quality parameters in SSF constructed wetlands, few data are available regarding specific contaminants. In this paper, we focus on the behavior of three widely used pharmaceuticals (clofibric acid, ibuprofen, and carbamazepine) in two pilot SSF constructed wetlands planted with Phragmites australis and characterized by different water depths (i.e., 0.3 and 0.5 m). These SSFs partially treat the urban wastewater from a housing development (ca. 200 inhabitants). The three pharmaceuticals and bromide were continuously injected into the two SSFs during a period of 150-200 h, and the effluent concentration was simultaneously measured as 6 h composite samples. Their removal efficiency was calculated from the injected concentration, and the hydraulic parameters were evaluated and compared to bromide as tracer. In this regard, the behavior of clofibric acid was similar to that of bromide, and no sorption into the gravel bed occurred. On the other hand, carbamazepine showed a higher sorption than bromide and clofibric acid, which is attributable to its interaction on the gravel bed. Accordingly, the use of clofibric acid as a hydraulic tracer is proposed, taking into account its low residence time. Ibuprofen removal was 81% in the shallow SSF and 48% in the deep one. Differences in removal efficiency could be explained by the less anaerobic environment of the shallow wetland.     

Environmental fate of pharmaceuticals in water/sediment systems

In recent years there has been growing interest on the occurrence and the fate of pharmaceuticals in the aquatic environment. Nevertheless, few data are available covering the fate of the pharmaceuticals in the water/sediment compartment. In this study, the environmental fate of 10 selected pharmaceuticals and pharmaceutical metabolites was investigated in water/sediment systems including both the analysis of water and sediment. The experiments covered the application of four 14C-labeled pharmaceuticals (diazepam, ibuprofen, iopromide, and paracetamol) for which radio-TLC analysis was used as well as six nonlabeled compounds (carbamazepine, clofibric acid, 10,11-dihydro-10,11-dihydroxycarbamazepine, 2-hydroxyibuprofen, ivermectin, and oxazepam), which were analyzed via LC-tandem MS. Ibuprofen, 2-hydroxyibuprofen, and paracetamol displayed a low persistence with DT50 values in the water/sediment system < or =20 d. The sediment played a key role in the elimination of paracetamol due to the rapid and extensive formation of bound residues. A moderate persistence was found for ivermectin and oxazepam with DT50 values of 15 and 54 d, respectively. Lopromide, for which no corresponding DT50 values could be calculated, also exhibited a moderate persistence and was transformed into at least four transformation products. For diazepam, carbamazepine, 10,11-dihydro-10,11-dihydroxycarbamazepine, and clofibric acid, system DT90 values of >365 d were found, which exhibit their high persistence in the water/sediment system. An elevated level of sorption onto the sediment was observed for ivermectin, diazepam, oxazepam, and carbamazepine. Respective Koc values calculated from the experimental data ranged from 1172 L x kg(-1) for ivermectin down to 83 L x kg(-1) for carbamazepine.     

Oxidation of pharmaceuticals during ozonation of municipal wastewater effluents: a pilot study

To reduce the release of pharmaceuticals and endocrine disruptors into the aquatic environment or to remove them from wastewater intended for direct or indirect reuse, the application of advanced wastewater treatment may be required. In the present study, municipal wastewater effluents were treated with ozone (O3) in a pilot-scale plant consisting of two bubble columns. The investigated effluents, which varied in suspended solids concentrations, comprised an effluent of conventional activated sludge treatment (CAS), the same effluent dosed with 15 mg of TSS L(-1) of activated sludge (CAS + SS), and the effluent of a membrane bioreactor pilot plant (MBR). Selected classes of pharmaceuticals were spiked in the wastewater at realistic levels ranging from 0.5 to 5 microg L(-1). Samples taken at the inlet and the outlet of the pilot plant were analyzed with liquid chromatography (LC)-electrospray tandem mass spectrometry (MS). Macrolide and sulfonamide antibiotics, estrogens, and the acidic pharmaceuticals diclofenac, naproxen, and indomethacin were oxidized by more than 90-99% for O3 doses > or = 2 mg L(-1) in all effluents. X-ray contrast media and a few acidic pharmaceuticals were only partly oxidized, but no significant differences were observed among the three effluents. These results show that many pharmaceuticals present in wastewater can be efficiently oxidized with O3 and that suspended solids have only a minor influence on the oxidation efficiency of nonsorbing micropollutants.     

Fluorescent whitening agents in Tokyo Bay and adjacent rivers: their application as anthropogenic molecular markers in coastal environments

Two kinds of stilbene-type fluorescent whitening agents (i.e., DSBP and DAS1), minor components of laundry detergents, were analyzed in surface waters of Tokyo Bay and adjacent rivers and in sewage effluents to examine their usefulness as molecular markers in the marine environment. Sensitive determination using HPLC (high performance liquid chromatography) with fluorescence detection with postcolumn UV radiator was employed. DSBP and DAS1 were found in Tokyo rivers at concentrations of a few microg/L and approximately 1 microg/L, respectively. DSBP and DAS1 were widely distributed in Tokyo Bay waters at concentrations in the range of 0.019-0.264 microg/L and 0.021-0.127 microg/L, respectively. Comparison of these concentrations with those in sewage effluents (DSBP: 8 microg/L and DAS1: 2.5 microg/L on average) yielded sewage dilutions in Tokyo Bay on the order of 10(2). FWAs-salinity diagram in the Tamagawa Estuary showed fairly conservative behaviors of the FWAs with approximately 20% and approximately 10% removal of DSBP and DAS1, respectively. This is thought to be caused by photodegradation. The persistent nature of FWAs and their widespread distribution in coastal environments demonstrates the utility of FWAs in tracing the behavior of water from rivers and sewage outfalls. The DSBP/DAS1 ratio showed a decreasing trend from sewage effluents, to rivers, to Tokyo Bay, indicating selective photodegradation of DSBP. The DSBP/DAS1 ratio is proposed as an index of the degree of photodegradation and residence time and freshness of water mass in coastal environments.     

Triclosan: occurrence and fate of a widely used biocide in the aquatic environment: field measurements in wastewater treatment plants,surface waters,and lake sediments

Triclosan is used as an antimicrobial agent in a wide range of medical and consumer care products. To investigate the occurrence and fate of triclosan in the aquatic environment, analytical methods for the quantification of triclosan in surface water and wastewater, sludge, and sediment were developed. Furthermore, the fate of triclosan in a wastewater treatment plant (biological degradation, 79%; sorption to sludge, 15%; input into the receiving surface water, 6%) was measured during a field study. Despite the high overall removal rate, the concentration in the wastewater effluents were in the range of 42-213 ng/L leading to concentrations of 11-98 ng/L in the receiving rivers. Moreover, a high removal rate of 0.03 d(-1) for triclosan in the epilimnion of the lake Greifensee was observed. This is due to photochemical degradation. The measured vertical concentration profile of triclosan in a lake sediment core of lake Greifensee reflects its increased use over 30 years. As the measured concentrations in surface waters are in the range of the predicted no effect concentration of 50 ng/L, more measurements and a detailed investigation of the degradation processes are needed.     

Removal of pharmaceuticals and personal care products (PPCPs) from urban wastewater in a pilot vertical flow constructed wetland and a sand filter

Removal efficiencies and elimination kinetics of 13 pharmaceuticals and personal care products (PPCPs) and BOD5, TSS, and ammonium were evaluated in a pilot vertical subsurface-flow constructed wetland (VFCW) and compared with those obtained by a sand filter. On the basis of the observed removals, the PPCPs studied were grouped in relation to their removal efficiency into (i) PPCPs very efficiently removed, that is, >95% removal in one of the systems (caffeine, salicylic acid, methyl dihydrojasmonate, CA-ibuprofen, hydrocinnamic acid, oxybenzone, ibuprofen, OH-ibuprofen); (ii) PPCPs moderately removed, with removals between 70 and 90% in the two systems (naproxen, diclofenac, galaxolide, and tonalide); and finally (iii) PPCPs poorly removed, with elimination rates of <30% (carbamazepine). At design hydraulic loading rate (HLR) the planted VFCW and the nonplanted SF exhibited similar PPCP removal efficiencies, but the VFCWwas less sensitive to removal decline in overloading conditions (up to 2 times the design HLR). Moreover, under a clogging simulation, the HLR and the presence of vegetation were some of the key aspects affecting the PPCPs, BOD5, and ammonium removal from domestic wastewater. The VFCW evaluated was more efficient in terms of removal efficiency and loading rate for most of the PPCPs studied in comparison to constructed wetlands of other configurations (i.e., horizontal subsurface flow) and SF (nonplanted). The shorter hydraulic residence time (a few hours) in VFCW compared to that in other CW configurations ranging from days to weeks makes VFCWs a very appropriate wastewater treatment option in space-limited areas.     

Behavior of the polycyclic musks HHCB and AHTN in lakes, two potential anthropogenic markers for domestic wastewater in surface waters

The synthetic polycyclic musks HHCB and AHTN are potential chemical markers for domestic wastewater contamination of surface waters. Understanding their environmental behavior is important to evaluate their suitability as markers. This study focuses on the quantification of the processes that lead to an elimination in lakes. Rate constants for all relevant processes were estimated based on laboratory studies and models previously described. In lake Zurich, during winter time, both compounds are eliminated primarily by outflowing water and due to losses to the atmosphere. In summer, direct photolysis represents the predominant elimination process for AHTN in the epilimnion of lake Zurich (quantum yield, 0.12), whereas for HHCB, photochemical degradation is still negligible. HHCB and AHTN were then measured in effluents of Swiss wastewater treatment plants (WWTPs), in remote and anthropogenically influenced Swiss surface waters, and in Mediterranean seawater using an analytical procedure based on SPE and GC-MS-SIM with D6-HHCB as internal standard (LODs for natural waters, 2 and 1 ng/L, respectively). In winter, concentrations of HHCB and AHTN in lakes (<2-47 and <1-18 ng/L, respectively) correlated with the anthropogenic burden by domestic wastewater (ratio population per water throughflow), demonstrating the suitability of these compounds as quantitative, source-specific markers. In summer, however, no such correlations were observed. Vertical concentration profiles in lake Zurich indicated significant losses in the epilimnion during summer, mainly for AHTN, and could be rationalized with a lake modeling program (MASASlight), considering measured, average loads from WWTP effluents (0.80 +/- 0.22 and 0.32 +/- 0.11 mg person(-1) d(-1) for HHCB and AHTN, respectively) and the estimated rate constants for elimination processes.     

Biodegradation of acidic pharmaceuticals in bed sediments: insight from a laboratory experiment

Pharmaceutical residues are commonly detected micropollutants in the aquatic environment. Biodegradation in sediments is a potentially significant removal process for these compounds in rivers which is constrained by the transfer of water and solutes into the sediment. The aim of this study was to determine the combined effect of flow velocity and sediment dynamics and thus of water-sediment interactions on the attenuation of 6 acidic pharmaceuticals. We carried out experiments with river water and sediment in a bench-scale annular flume at two different hydraulic boundary conditions (flat sediment surface vs moving sediment). The effective biodegradation half-lives of 4 compounds (diclofenac, bezafibrate, ibuprofen, naproxen) were in the range of 2.5 to 18.6 days and were much shorter when the exchange of surface and pore water was fast. For gemfibrozil, a half-life of 10.5 d was determined in the experiment with moving sediment, whereas no degradation was observed with flat sediment bed. These findings can be attributed to the limited transfer of water and solutes into the sediment at low flow velocity and flat sediment bed which rapidly induced anaerobic conditions in the sediment. The only compound that was efficiently removed in deeper, anoxic sediment layers was naproxen. The calculated half-life distances in rivers ranged from 53 to 278 km. Our results indicate that it could be favorable to increase the rate of exchange between surface and pore water during river restoration to enhance the attenuation of organic micropollutants like acidic pharmaceuticals.     

Elimination of pharmaceuticals and personal care products in subsurface flow constructed wetlands

Removal efficiency and elimination rates of 11 pharmaceuticals and personal care products (PPCPs)were measured in two subsurface horizontal flow constructed wetlands (SSFs) characterized by different water depths (i.e. 0.3 and 0.5 m) in a 2-year study. Dissolved and particulate phases of wastewater and gravel samples were collected and analyzed. The PPCP influent concentration ranged from 1 to 25 microg L(-1). The best removal efficiency was found in the shallower bed SSF due to its less negative redox potential. PPCPs were classified in four groups according to their removal behavior: (i) the efficiently removed (>80%) namely caffeine, salicylic acid, methyl dihydrojasmonate, and carboxy-ibuprofen, (ii) the moderately removed (50-80%) namely ibuprofren, hydroxy-ibuprofen, and naproxen, (iii) the recalcitrant to the elimination namely ketoprofen and diclofenac, and,finally, (iv) compounds that were eliminated by hydrophobic interactions namely polycyclic musks (i.e. galaxolide and tonalide). These compounds were removed more than 80% from the effluent but occurred at high concentrations (up to 824 microg kg(-1)) in the gravel bed. Accordingly, their elimination by sorption onto the organic matter retained is the predominant removal mechanism. Furthermore, the constructed wetland clogging appears to induce a negative effect in the PPCP degradation in the SSF evaluated. The PPCP elimination classified as efficiently and moderately removed through the shallow bed fitted to either zero- or a first-order areal kinetics. Finally, the apparent distribution coefficients between suspended solids (Kd'ss) or gravel bed (Kd'gb) and water were determined in the different sampling points of the wetland obtaining values comparable to the described previously for sewage sludge.     

Caffeine,an anthropogenic marker for wastewater comtamination of surface waters

The suitability of caffeine as a chemical marker for surface water pollution by domestic wastewaters was assessed in this study. Caffeine concentrations in influents and effluents of Swiss wastewater treatment plants (WWTPs, 7-73 and 0.03-9.5 microg/L, respectively) indicated an efficient elimination of 81-99.9%. Corresponding loads in untreated wastewater showed small variations when normalized forthe population discharging to the WWTPs (15.8 +/- 3.8 mg person(-1) d(-1)), reflecting a rather constant consumption. WWTP effluent loads were considerably lower (0.06 +/- 0.03 mg person(-1) d(-1)), apart from installations with low sludge age (< or = 5 d, loads up to 4.4 mg person(-1) d(-1)). Despite the efficient removal in most WWTPs, caffeine was ubiquitously found in Swiss lakes and rivers (6-250 ng/ L), except for remote mountain lakes (<2 ng/L; analytical procedure for wastewater and natural waters: SPE, GC-MS-SIM or GC-MS-MS-MRM, internal standard 13C3-labeled caffeine). Caffeine concentrations in lakes correlated with the anthropogenic burden by domestic wastewaters, demonstrating the suitability of caffeine as a marker. A mass balance for Greifensee revealed that approximately 1-4% of the wastewaters had been discharged without treatment, presumably on rainy days when the capacity of WWTPs had been exceeded. For Zürichsee, it could be shown that the monthly inputs of caffeine correlated with precipitation data. The depth- and seasonal-dependent concentrations in this lake were adequately rationalized by a numerical model considering flushing, biodegradation, and indirect photodegradation via HO. radicals as elimination processes and caffeine inputs as fitting variables.     

Simultaneous determination of psychoactive drugs and their metabolites in aqueous matrices by liquid chromatography mass Spectrometry

A multi-residue method was developed that allows for the simultaneous determination of psychoactive compounds such as opioids, tranquilizers, antiepileptics (primidone, carbamazepine plus two metabolites),the cocaine metabolite benzoylecgonine, the antidepressant doxepin, as well as the calcium channel blocker verapamil in raw and treated wastewater, surface water, groundwater, and drinking water. After solid-phase extraction with Oasis HLB at neutral pH, the analytes were detected by LC electrospray tandem MS in the positive ion mode. With a few exceptions relative recoveries of the analytes exceeded 70%. The limits of quantification were in the low ng/L range. Matrix effects were compensated by using appropriate deuterated or 13C-15N-labeled surrogate standards. For raw and treated wastewater, concentration factors were lowered to reduce matrix effects. Most analytes (15 of 20) were found in raw and treated wastewater as well as in surface water, and hence, are presumably ubiquitously present in the environment. Antiepileptics, the opium alkaloids morphine and codeine, dihydrocodeine, the two tranquilizers oxazepam and temazepam, the opioid tramadol, doxepin, and verapamil were detected in STP discharges and German rivers at concentrations up to the microg/L range. In drinking water, only carbamazepine, its metabolite 10,11-dihydroxy-10,11-dihydrocarbamazepine, and primidone were present at concentrations up to 0.020 microg/L.     

Benzotriazole and tolyltriazole as aquatic contaminants. 1. Input and occurrence in rivers and lakes

The complexing agents benzotriazole (BT) and tolyltriazole (TT) are not only widely applied as anticorrosives, e.g., in aircraft deicer and anti-icer fluid (ADAF), but they are also used for so-called silver protection in dishwasher detergents. Due to their low biodegradability and limited sorption tendency, BT and TT are only partly removed in wastewater treatment. Residual concentrations of BT and TT were determined in ambient surface waters in Switzerland including 7 rivers which have distinct water flows and receive treated wastewater effluents at various dilution ratios. A maximum BT concentration of 6.3 microg/L was found in the Glatt River, and a maximum mass flow of 277 kg BT per week was observed in the Rhine River. In most cases, TT was about a factor 5-10 less abundant. During winter 2003/4, BT mass flows at 2 locations in the lower stretch of the Glatt River clearly indicated the input from nearby Zurich airport, where BT was applied as an anticorrosive ADAF component. BT concentrations measured in the three lakes Greifensee, Lake Zurich, and Lake Geneva were approximately 1.2, 0.1-0.4, and 0.2 microg/L, respectively. The observed environmental occurrences indicate that BT and TT are ubiquitous contaminants in the aquatic environment and that they belong to the most abundant individual water pollutants.