Anthropogenic Micropollutants Research Articles

Evaluation and comparison of UV/H2O2 and adsorption on active carbon as a tertiary wastewater treatment for pharmaceutical removal within a small WWTP: a pilot study

Pharmaceuticals and their metabolites are ubiquitous in the environment and represent typical anthropogenic micropollutants.

The effect of physicochemical properties on paracetamol photodegradation in cuboid bubble column

Paracetamol is one of the most anthropogenic micropollutants, and their removal from the environment often requires a specialized method of remediation. In this study, a photocatalyst technique aided with air bubbles was used to degrade the pharmaceutical pollutant paracetamol (PCT) from the water via the COD test and HPLC analysis under different operating conditions. The experiments were carried out in a semi-batch rectangular bubble column with dimensions of 1500 mm height, 30 mm depth, and 200 mm width under UV light. Titanium oxide (TiO2) was used as a source of catalyst. The effect of operating conditions of pH (3-10), air flow rate (0-2) L/min, salinity of solution represented by NaCl concentration (0-1000) mg/L, and 240 min irradiation time on the paracetamol removal were studied. The Box–Behnken design was adopted to study the individual effects of pH (A), air flow rate (B), and salinity (C) and their interactive effects. From the experimental and regression data, a second-order polynomial regression model is predicted, and the variance analysis of the regressions shows that the linear terms (A and B), and all quadratic terms (A, B, and C) have significant effects on the removal percentage of COD. According to numerical optimization, the greatest %COD removal is 76.7 in the process conditions of 5.3 pH, 1L/min, and 269 mg/L of NaCl. The experimental results show that the maximum %COD removal was 78% at pH=7, 1L/min, and 0mg/L of NaCl. HPLC analysis shows 91.2% of paracetamol degradation.

Univariate and multivariate kinetic and structural analysis of photoinduced tetracycline degradation

Tetracycline antibiotics found in waters worldwide pose a tremendous ecological and human health hazard due to bacterial resistances. Various processes are currently investigated to eliminate such anthropogenic micropollutants, among them advanced oxidation processes, where hydroxyl radicals cause disintegration of many organic substances. For mechanistic understanding and optimization for potential in-field use, kinetic descriptions and chemical reaction knowledge are important. Structural identification, quantitation and kinetic description of the substances are investigated via a univariate method, i.e. high-performance liquid-chromatography coupled with mass spectrometry and curve-fitting, and a multivariate method, i.e. absorption spectroscopy and curve resolution-alternating least squares fitting. The latter represented a fast, non-laborious analytical method. The univariate approach revealed four known and two new transformation products. First-order kinetics with follow-up reactions were observed. The univariate method yielded rate constants of about 0.33 min−1 for the degradation of both tetracyclines and distinct rate constants for transformation products, while rate constants of about 0.22 and 0.27 min−1 and an overall rate constant for non-identified transformation products were obtained from multivariate analysis due to the insufficient discriminatory power. Structural characterization, fast and easy kinetic parameter determination of photoinduced degradation may contribute to optimize advanced oxidation processes for the removal of antibiotics from waste water.

Determination of anti-SARS-CoV-2 virustatic pharmaceuticals in the aquatic environment using high-performance liquid chromatography high-resolution mass spectrometry.

The Covid-19 pandemic has affected the global population since 2019. The rapid development and approval of vaccines has brought relief. Yet, effective cures are still being researched. Even if the pandemic situation may end, SARS-CoV-2 will remain and, thus, continued application of the drugs will lead to emissions of the active ingredients into the aquatic environment, as with other anthropogenic micropollutants. However, a general method for trace analysis of antiviral drugs is still missing. To this purpose, favipiravir, remdesivir, its active metabolite GS-441524, molnupiravir and its active metabolite EIDD-1931 were selected as representative analytes. A method was developed based on solid phase extraction and high-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight high-resolution mass spectrometry. Optimization comprised the choice of chromatographic columns, elution gradient, mass spectrometry and tandem mass spectrometry parameters. Solid phase extraction proved suitable for increase in limits of detection and quantitation. amelioration of the limits of detection and quantitation. Matrix effects were investigated applying the optimized method to a wastewater sample with added virustatics. All five compounds could be separated with reversed phase chromatography, whereas EIDD-1931 profited from hydrophilic interaction liquid chromatography. The optimized method yielded limits of detection and quantification of 2.1·10-1, 6.9·10-1 µg·L-1 for favipiravir, 1.8·10-3, 5.5·10-3 µg·L-1 for remdesivir, 1.9·10-3, 7.6·10-3 µg·L-1 for GS-441524, 2.9·10-3, 8.7·10-3 µg·L-1 for molnupiravir, and 1.3·10-1, 3.8·10-1 µg·L-1 for EIDD 1931. The method was first applied to compound stability testing at pH2.8 and 9.7. At pH2.8, remdesivir, GS-441524 and molnupiravir proved stable, whereas about 14% of EIDD-1931 and favipiravir were degraded. All five antiviral compounds were almost completely decomposed at pH9.7. The application of the method was further demonstrated for potential transformation product detection on favipiravir ozonation monitoring.

Urea hydrolysis and long-term storage of source-separated urine for reuse as fertiliser is insufficient for the removal of anthropogenic micropollutants

Human and animal source-separated urine, stored and allowed to naturally hydrolyse (the bio-catalysed transformation of urea to ammonia and bicarbonate), has been used for millennia as a fertiliser in agriculture. In a context of growing water scarcity and climate uncertainty, source-separation of urine is facing a strong revival thanks to the emergence of cost-effective waterless collection systems. Concomitantly, urine source-separation can be used as a method for nutrient recovery and subsequent reuse. In its simplest form, such recovery consists of collection followed by urea hydrolysis and storage as sole treatment. Numerous guidelines, including by the World Health Organisation, consider that this is sufficient to stabilise the nutrients and inactivate any potential pathogens in the urine. However, it is still unclear whether said urine is effectively free from other compounds of concern, such as anthropogenic micropollutants with known toxicological effects. Moreover, it is also currently unknown if the metabolites produced by human consumption of these products behave in similar way during short- and long-term storage i.e. whether any changes in chemical structure mean that these could be sorbed and/or precipitated in a different way, or if they can potentially be degraded by the biomass inherently present in urine collection systems. Finally, there is currently no knowledge of whether the observed concentrations of micropollutants in stored hydrolysed urine could potentially have toxicological effects if/when applied to soils and edible crops. To fill these research gaps, 20 commonly consumed compounds were selected in this study and their concentrations in the liquid and solid phases studied in the short- and long-term (up to ≥ 2 years). During the initial process of urea hydrolysis (≤ 5 days), ethyl-glucuronide was the sole compound effectively removed (by deconjugation), while only two other compounds, erythromycin and its metabolite, saw a reduction in their concentration (likely due to biomass sorption). Subsequently, during early storage (≤ 15 days), only three additional compounds were removed: paracetamol (> 99%), acesulfame (11.5%) and carbamazepine-10,11 epoxide (40.7%). Finally, long-term storage of up to 24 months did not result in any further significant removal for any of the measured compounds, indicating that the procedure of hydrolysis + storage is not effective for the removal of anthropogenic micropollutants. The results of this investigation raise strong concerns about the direct reuse of hydrolysed/stored human source-separated urine, and evidence the need for post-processing before implementation as fertiliser into edible crops due to the inherent toxicological risk, particularly to infants.

In silico ecotoxicity assessment of photoinduced imidacloprid degradation using HPLC–HRMS, QSAR and ecotoxicity equivalents

BackgroundImidacloprid is among the most widely used insecticides and today is found in surface and ground water worldwide. It has been registered in the EU watchlist for monitoring. To prevent imidacloprid from entering water bodies, advanced oxidation processes (AOP) have been intensely researched. Photo-irradiation proved one of the most efficient methods to degrade and eliminate anthropogenic micropollutants from waters. The ecotoxicity assessment of photoinduced degradation and transformation products especially in the absence of reference standards is still heavily explored.ResultsIn this study, UVA and UVC irradiation in combination with titanium dioxide P25 as photocatalyst were investigated for their degrading and eliminating effects and effectiveness on imidacloprid. Humic acid was used as natural organic matter additive. High-performance liquid chromatography coupled with high-resolution mass spectrometry allowed to identify and monitor imidacloprid and its degradation intermediates yielding seven new structures and concentration–time (c–t) profiles. The correlation of structures and the application of radical scavengers and photocatalyst helped distinguish between direct photoinduced and indirect hydroxyl radical-induced degradation mechanisms. The identification of hydroxylated products and intermediates indicated the indirect degradation pathway, which could be suppressed by addition of a radical scavenger. The absence of hydroxylated intermediates and fragments pointed towards the direct absorption-induced degradation. Two degradations products were traced back to the direct mechanism, whereas all other products followed the indirect mechanism. The ecotoxicity of the identified compounds was assessed by quantitative structure–activity relationship (QSAR) analysis. Most products were predicted as less ecotoxic. Ecotoxicity equivalents (ETEs) were introduced allowing a classified ranking of the products and an assessment of the overall hazardous potential of the irradiated solution at a given moment. Generally, the number of hydroxyl substituents was inversely correlated to ecotoxicity. From the c-t curves, time-dependent ETE profiles were established.ConclusionsStructure elucidation and c-t profiles from liquid chromatography–high-resolution mass spectrometry allowed to distinguish between direct and indirect degradation mechanisms. Structure specific ecotoxicity assessment could be achieved through QSAR analysis. Ecotoxicity hazard was ranked based on ETEs. The time-dependent ETE profile proved suitable to reflect the effect of irradiation duration and allow to estimate the irradiation time required to eliminate ecotoxicity, which may be relevant for potential applications in wastewater treatment plants.

Sustainable micropollutant bioremediation via stormwater biofiltration system

Waters contaminated with micropollutants are of environmental and public health concern globally. Stormwater is a significant source of anthropogenic micropollutants to receiving waters. Hence, sustainable stormwater remediation is needed to reduce contamination of waterways. Yet designing sustainable bioremediation solutions, including those targeted to remove micropollutants, is a major scientific challenge. This study aimed to adapt the design of stormwater biofiltration systems, to improve the removal of micropollutants and understand the role of the micropollutant-degrading bacteria in this bioremediation process. We investigated the atrazine removal performance of a prototype biofiltration system, in which the filter media was supplemented with Granulated Activated Carbon (GAC). The prototype biofiltration system completely removed atrazine to below detectable limits, significantly exceeding the GAC's adsorption capacity alone, suggesting other biological processes were present. We showed that atrazine degradation capacity, measured by the kinetics of the trzN gene abundance, was accelerated in the prototype system compared to the standard system (which had no added GAC; 0.8 vs. 0.37 week−1, respectively). Notably, this high level of atrazine removal did not come at the expense of the removal performance of other typical stormwater macropollutants (e.g., nutrients, suspended solids). The prototype biofiltration system showed a proof-of-concept of sustaining microbial remediation of a model micropollutant alongside stormwater macropollutants, which could be used to reduce impacts on receiving waterways and protect our ecosystems and human health.

Exposure and Transport of Alkaloids and Phytoestrogens from Soybeans to Agricultural Soils and Streams in the Midwestern United States.

Phytotoxins are naturally produced toxins with potencies similar/higher than many anthropogenic micropollutants. Nevertheless, little is known regarding their environmental fate and off-field transport to streams. To fill this research gap, a network of six basins in the Midwestern United States with substantial soybean production was selected for the study. Stream water (n = 110), soybean plant tissues (n = 8), and soil samples (n = 16) were analyzed for 12 phytotoxins (5 alkaloids and 7 phytoestrogens) and 2 widely used herbicides (atrazine and metolachlor). Overall, at least 1 phytotoxin was detected in 82% of the samples, with as many as 11 phytotoxins detected in a single sample (median = 5), with a concentration range from below detection to 37 and 68 ng/L for alkaloids and phytoestrogens, respectively. In contrast, the herbicides were ubiquitously detected at substantially higher concentrations (atrazine: 99% and metolachlor: 83%; the concentrations range from below detection to 150 and 410 ng/L, respectively). There was an apparent seasonal pattern for phytotoxins, where occurrence prior to and during harvest season (September to November) and during the snow melt season (March) was higher than that in December-January. Runoff events increased phytotoxin and herbicide concentrations compared to those in base-flow conditions. Phytotoxin plant concentrations were orders of magnitude higher compared to those measured in soil and streams. These results demonstrate the potential exposure of aquatic and terrestrial organisms to soybean-derived phytotoxins.

Aquatic occurrence of phytotoxins in small streams triggered by biogeography, vegetation growth stage, and precipitation

Toxic plant secondary metabolites (PSMs), so-called phytotoxins, occur widely in plant species. Many of these phytotoxins have similar mobility, persistence, and toxicity properties in the environment as anthropogenic micropollutants, which increasingly contaminate surface waters. Although recent case studies have shown the aquatic relevance of phytotoxins, the overall exposure remains unknown. Therefore, we performed a detailed occurrence analysis covering 134 phytotoxins from 27 PSM classes. Water samples from seven small Swiss streams with catchment areas from 1.7 to 23 km2 and varying land uses were gathered over several months to investigate seasonal impacts. They were complemented with samples from different biogeographical regions to cover variations in vegetation. A broad SPE-LC-HRMS/MS method was applied with limits of detection below 5 ng/L for over 80% of the 134 included phytotoxins. In total, we confirmed 39 phytotoxins belonging to 13 PSM classes, which corresponds to almost 30% of all included phytotoxins. Several alkaloids were regularly detected in the low ng/L-range, with average detection frequencies of 21%. This is consistent with the previously estimated persistence and mobility properties that indicated a high contamination potential. Coumarins were previously predicted to be unstable, however, detection frequencies were around 89%, and maximal concentrations up to 90 ng/L were measured for fraxetin produced by various trees. Overall, rainy weather conditions at full vegetation led to the highest total phytotoxin concentrations, which might potentially be most critical for aquatic organisms.

Chemical Pollution Levels in a River Explain Site-Specific Sensitivities to Micropollutants within a Genetically Homogeneous Population of Freshwater Amphipods.

Anthropogenic micropollutants alter chemical and ecological conditions of freshwater ecosystems and impact aquatic species that live along the pollution gradient of a river. Species sensitivity to micropollutants depends on the site-specific exposure; however, it remains unclear to what degree this sensitivity relates to the species' genetic structure. Here, we explored the relationship between the toxic sensitivity and genetic structure of the amphipod species Gammarus pulex (Linnaeus, 1758) along an organic micropollutant gradient in the Holtemme River in central Germany. We determined the river's site-specific micropollutant patterns and analyzed the genetic structure of G. pulex using nuclear and mitochondrial genetic markers. Furthermore, we examined the exposure sensitivities and bioaccumulation of the commonly detected insecticide imidacloprid in G. pulex from different sites. Our results show that throughout the Holtemme River, G. pulex forms a well-connected and homogeneous population with no observable pollution-related differences in the genetic structure. However, G. pulex from polluted sites responded more sensitively to imidacloprid; survival times for half of the amphipods were up to 54% shorter, the percentage of immobile individuals increased up to 65%, and the modeled imidacloprid depuration rate was lower in comparison to amphipods from non-polluted sites. Altogether, these results suggest that the level of sensitivity of G. pulex amphipods to micropollutants in the river depends on the degree of pollution: amphipods may thrive in food-rich but polluted habitats; yet, their sensitivity is increased when chronically exposed to organic micropollutants.

Insights into paracetamol degradation in aqueous solutions by ultrasound-assisted heterogeneous electro-Fenton process: Key operating parameters, mineralization and toxicity assessment

Pharmaceuticals are one of the most reported categories of anthropogenic micropollutants, which often require a specific remediation type to be eliminated from the environment. This study aimed to address the potential of degrading the pharmaceutical pollutant paracetamol (PCT) in the aqueous environment under ultrasound (US) assisted electro-Fenton by Fe2O3 (hematite) nanoparticles (HNPs) as a catalyst. The synthesized sample was characterized by various techniques including XRD, FESEM, EDS, X-ray dot-mapping, and FTIR. The performance of the electro-Fenton (EF) and US processes was evaluated separately and in combination under optimum conditions. The results showed that the sonoelectro-Fenton (SEF) process under optimum conditions, including pH of 5, HNPs dosage 0.15 g/L, applied current 230 mA, initial PCT concentration 20 mg/L, resulted in a PCT degradation of 98.9% within 60 min of electrolysis time. PCT degradation was well-fitted to the pseudo-first-order kinetic model. Meanwhile, scavenging experiments indicated the vital role of OH in the decomposition of PCT compared to the negligible role of O2∙-. The nitrate ions had a strong inhibitory effect, whereas chloride anions affected PCT elimination slightly. The reusability test of HNPs revealed that almost a 14% drop occurred at the end of the fourth cycle. The HNPs showed high catalytic activity for degradation of PCT compared to other conventional homogeneous transition metals. Besides, SEF-HNPs can successfully detoxify the PCT solution based on the bioassay test. The by-products of PCT degradation by SEF-HNPs were determined and degradation pathway was also proposed. Conclusively, the SEF-HNPs process could be an appropriate system for the removal of various contaminants from aqueous solutions.

Structure and QSAR analysis of photoinduced transformation products of neonicotinoids from EU watchlist for ecotoxicological assessment

Current research is increasingly focusing on the ecotoxicity of anthropogenic micro-pollutants and their degradation and transformation products resulting from biological and chemical treatment processes. These products enter the aquatic environment through various routes and may endanger aquatic organisms and plants. In this study, five neonicotinoids from the EU watchlist and their degradation products induced by UVC irradiation were examined. All identified photoinduced degradation or transformation products were subsequently submitted to Quantitative Structure Activity (QSAR) analysis. Among the investigated structures, 15 substances already identified in previous studies and eleven new transformation products were analyzed. By using QSAR analysis, it became possible to predict ecotoxicity of individual substances with mere computational effort. Starting from the chemical structure, lower toxicity against green algae and invertebrates was predicted for the transformation products in general. For other aquatic target organisms, such as branchiopoda, actinopterygii and fathead minnow, the residual hazardous effect as compared to the initial compound depends on the presence of specific structural elements. For the neonicotinoids investigated, the cleavage or elimination of the nitrile or nitro group through the degradation process, was predicted to increase toxicity.

Persistence of native and bio-derived molecules of dissolved organic matters during simultaneous denitrification and methanogenesis for fresh waste leachate

Biological treatment of wastewater always leaves plenty of refractory dissolved organic matters (DOM) in effluents, specifically for fresh waste leachate. Aiming at comprehending the production and removal of these compounds, this study investigated DOM transformation in a simultaneous denitrification and methanogenesis with activated sludge (SDM-AS) system with NO3−/NO2− backflow for raw fresh leachate. Chemical oxygen demand (COD) was reduced to 854 ± 120 mg/L from 63000 ± 470 mg/L, and total nitrogen (TN) decreased from 2500 ± 647 mg/L to 404 ± 75 mg/L, during an operation of 440 days. The SDM reactor was fed at organic loading rate of 6.70 kgCOD/(m3·d) to generate 2.52 L CH4/(L·d). Molecular information of leachate DOM was acquired by using ultra-performance liquid chromatography coupled with Orbitrap mass spectrometry. A DOM classification based on Venn diagram was proposed to divide leachate DOM into seven categories. It revealed that 76–84% of final effluent DOM stemmed from biological derivation. Posteriori non-target screening showed anthropogenic micropollutants, e.g. phosphate flame retardants and industrial agents, probably contributed to the remnant native inert DOM in the effluent at the levels of 5–200 μg/L. DOM Classification also showed a portion of bio-derived DOM can be completely removed by SDM-AS processes, while the rest bio-derived DOM can be partially removed depending on DOM nature and the recirculation ratio. The removal and production rate of a specific bio-derived molecule in respective SDM and AS units theoretically satisfied a hyperbolical and dual relationship in terms of mass balance. The persistence of each DOM category was sorted. These results showed anaerobic degradation could be a promising approach to reduce aerobic bio-derived DOM.

Exclusion of Estrogenic and Androgenic Steroid Hormones from Municipal Membrane Bioreactor Wastewater Using UF/NF/RO Membranes for Water Reuse Application

In the context of water scarcity, domestic secondary effluent reuse may be an option as a reliable source for alleviating acute water shortage. The increasing risks linked with the presence of natural steroid hormones and many emerging anthropogenic micropollutants (MPs) passing through municipal wastewater treatment works (MWWTWs) are of concern for their endocrine-disrupting activities. In this study, domestic wastewater treated by a full-scale membrane bioreactor (MBR) at an MWWTW in the Western Cape Province, South Africa, was used directly as the influent to a reverse osmosis (RO) pilot plant for the removal of selected natural steroid hormones 17β-estradiol (E2) and testosterone (T) as a potential indirect water recycling application. Estrogenicity and androgenicity were assessed using the enzyme-linked immunosorbent assays (ELISA) and the recombinant yeast estrogen receptor binding assays (YES). The influent pH and flux did not influence the rejection of E2 and T, which was most likely due to adsorption, size exclusion, and diffusion simultaneously. RO and nanofiltration (NF) exhibited excellent removal rates (>95%) for E2 and T. All the E2 effluent samples with MBR/ultrafiltration (UF), MBR/NF, and MBR/RO were lower than the US EPA and WHO trigger value of 0.7 ng/L, as well as the predicted no-effect concentration (PNEC) values for fish (1 ng E2/L).

Priority and emerging micropollutants distribution from coastal to continental slope sediments: A case study of Capbreton Submarine Canyon (North Atlantic Ocean)

Incising continental margins, submarine canyons are key issue for understanding shelf/deep sea exchange of particulate pollutant, impact on marine ecosystem and global geochemical cycling. The occurrence and distribution of 100 priority and emerging micropollutants were investigated in sediments within the first 25 km of the Capbreton submarine area. The most predominant compounds were polycyclic aromatic hydrocarbons (PAHs), trace metals and metalloid (TMs) (e.g. mercury, lead and arsenic), synthetical musks (e.g. musk ketone, galaxolide), UV filters (e.g. octocrylene and 2-ethylhexyl 4-methoxycinnamate, EHMC) as well as some pharmaceuticals (e.g. azithromycin, acetaminophen). Highest concentrations were measured in submarine canyon sediments, distant from the coast and were correlated with both organic carbon and fine fraction contents, where PAHs, EHMC and musk ketone concentrations up to 7116, 32 and 7 ng g−1 dry weight, respectively. Those results likely demonstrate, that atmospheric inputs of pyrogenic PAHs, and both trapping and transporting of polluted particles along the continuum shore/deep sea by the Capbreton Canyon, might lead to an accumulation of anthropogenic micropollutants. The ecological risk assessment indicates that priority pollutants raise a potentially high risk for benthic organisms (e.g. PAHs, TMs). This might raised a specific concern about how the human can impact this ecosystem.

New relevant pesticide transformation products in groundwater detected using target and suspect screening for agricultural and urban micropollutants with LC-HRMS

Groundwater is a major drinking water resource, but its quality is threatened by a broad variety of anthropogenic micropollutants (MPs), originating from agriculture, industry, or households, and undergoing various transformation processes during subsurface passage. To determine a worst-case impact of pesticide application in agriculture on groundwater quality, a target and suspect screening for more than 300 pesticides and more than 1100 pesticide transformation products (TPs) was performed in 31 Swiss groundwater samples which predominantly originated from areas with intensive agriculture. To assess additional urban contamination sources, more than 250 common urban MPs were quantified. Most of the screened pesticide TPs were experimentally observed by the pesticide producers within the European pesticide registration. To cover very polar pesticide TPs, vacuum-assisted evaporative concentration was used for enrichment, followed by liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS). Based on intensity, isotope pattern, retention time, and in silico fragmentation, the suspect hits were prioritised and verified. We identified 22 suspects unequivocally and five tentatively; 13 TPs are reported here for the first time to be detected in groundwater. In 13 out of 31 groundwater samples, the total concentration of the 20 identified and quantified suspects (1 pesticide and 19 pesticide TPs) exceeded the total concentration of the 519 targets (236 pesticides and TPs; 283 urban MPs) for which we screened. Pesticide TPs had higher concentrations than the parent pesticides, illustrating their importance for groundwater quality. The newly identified very polar chlorothalonil TP R471811 was the only compound detected in all samples with concentrations ranging from 3 to 2700 ng/L. Agricultural MP concentration and detection frequency correlated with agricultural land use in the catchment, except for aquifers, where protective top layers reduced MP transport from the surface. In contrast to agricultural MPs, urban MPs displayed almost no correlation with land use. The dominating entry pathway of urban MPs was river bank filtration.

Optical and impedimetric study of genetically modified cells for diclofenac sensing

Abstract. Whole-cell biosensors, based on genetically modified yeast cells, were employed to detect anthropogenic micropollutants (e.g. drugs). Specific stimuli, e.g. traces of drugs, lead to the induction of fluorescence in the respective cells. Receptors of the cells detect specific signal molecules and induce the formation of fluorescent proteins. In this work, genetically modified cells of the yeast Saccharomyces cerevisiae BY4741 were confined in a four-chamber microfluidic cell, providing an optical monitoring of the cell behaviour and their supply with the nutrients. The measurements of the time-dependent fluorescence intensity were performed with different concentrations of the drug diclofenac, and the sensitivity of yeast cells to diclofenac was demonstrated. Cell viability was monitored by simultaneous impedance recording.

Trace Organic Removal during River Bank Filtration for Two Types of Sediment

The process of bank filtration acts as a barrier against many anthropogenic micropollutants, such as pharmaceuticals and industrial products, leading to a substantial improvement of groundwater quality. The performance of this barrier is, however, affected by seasonal influences and subject to significant temporal changes, which have already been described in the literature. Much less is known about spatial differences when considering one field site. In order to investigate this issue, two undisturbed cores from a well-investigated bank filtration field site were sampled and operated in the course of a column study. The ultimate aim was the identification and quantification of heterogeneities with regard to the biodegradation of 14 wastewater derived micropollutants, amongst others acesulfame, gabapentin, metoprolol, oxypurinol, candesartan, and olmesartan. While six of the compounds entirely persisted, eight compounds were prone to degradation. For those compounds that were subject to degradation, degradation rate constants ranged between 0.2 day−1 (gabapentin) and 31 day−1 (valsartan acid). Further, the rate constants consistently diverged between the distinct cores. In case of the gabapentin metabolite gabapentin-lactam, observed removal rate constants differed by a factor of six between the cores. Experimental data were compared to values calculated according to two structure based prediction models.

Detection of artificial sweeteners and iodinated X-ray contrast media in wastewater via LC-MS/MS and their potential use as anthropogenic tracers in flowing waters

The detection of wastewater impact on stream chemistry is often hindered by high background concentrations of ubiquitous solutes. In the present study we tested the applicability of artificial sweeteners (AS) and iodinated X-ray contrast media (ICM) as tracers to detect this impact by examining wastewater treatment plant (WWTP) effluents and surface water samples. The developed direct injection LC-MS/MS method enabled the detection of these anthropogenic micropollutants in aqueous samples down to trace level concentrations. The 2-h-composite sampling of WWTP effluent revealed fluctuating ICM concentrations between and within days with highest concentrations at the end of the week. Diatrizoic acid (DTZ) and iopromide (IOP) were the predominant ICM with concentrations up to 7 μg/L. Concentrations of the AS acesulfame (ACE) fluctuated between 0.5 μg/L and 1 μg/L. Concentrations of AS and ICM in surface water were both associated with wastewater impact. DTZ contamination was more widespread whereas some sampling points exhibited a more pronounced contamination with non-ionic ICM. Surface water was frequently contaminated with AS. Particularly ACE was detected in every surface water sample indicating that it is chemically stable and that inputs to the aquatic environment via WWTP effluents are widespread. The broad application of ACE as food additive enables its application as a tracer throughout Germany. Furthermore, the developed LC-MS/MS method enables rapid detection of ACE down to the low ng/L-range. Nonetheless, DTZ or IOP could be used in addition to ACE to verify anthropogenic influences on natural waters.

Environmental exposure of anthropogenic micropollutants in the Prut River at the Romanian-Moldavian border: a snapshot in the lower Danube river basin.

The Prut River, the second longest tributary of the Danube river, was investigated for a wide range of anthropogenic organic pollutants to fill the data gap on environmental contamination in eastern European surface waters. In this study, the occurrence of a wide range of organic pollutants was measured along the transboundary Prut River, between Sculeni and Branza in 2010-2012. Using two different analytical methods, gas chromatography coupled to mass spectrometry and liquid chromatography coupled to high-resolution mass spectrometry, over 300 compounds were screened for and 88 compounds were determined in the Prut River. In general, the chemicals occurred at low levels. At the last sampling site upstream of the confluence with the Danube river at Branza, the highest average concentrations (≥ 100ngL-1) were determined for the artificial sweetener acesulfame, the pharmaceuticals metformin, 4-acetamidoantipyrene, and 4,4,5,8-tetramethylchroman-2-ol, the antioxidants 2,4-di-tert-butylphenol, 3-tert-butyl-4-hydroxyanisol, and 3,5-di-tert-butyl-4-hydroxy-toluene, the personal care products HHCB (galaxolide), 4-phenyl-benzophenone, and octyl dimethyl-p-aminobenzoic acid, the industrial chemical diphenylsulfone, and the sterol cholesterol. Low concentrations of agricultural pesticides occurred in the catchment. At Branza, the total accumulated load of all measured compounds was calculated to be almost 19kgday-1. In comparison to the Rhine River, the loads in the Prut, determined with same LC-HRMS method for the same set of analytes, were two orders of magnitude lower. Discharge of wastewater without proper treatment from the city of Iasi in the Jijia catchment (Romania) as well as from the city of Cahul (Moldova) revealed a distinct increase in concentrations and loads in the Prut at Frasinesti and Branza. Thus, an implementation of wastewater treatment capacities in the Prut River basin would considerably reduce the loads of micropollutants from urban point sources.