Evaluation of polar organic micropollutants as indicators for wastewater-related coastal water quality impairment

Metabolites are overlooked in environmental risk assessments and monitoring of pharmaceuticals: The case study of pantoprazole

The proton-pump inhibitor pantoprazole (PPZ) is one of the most consumed pharmaceuticals worldwide. Despite its high usage, reported PPZ concentrations in environmental water samples are comparatively low, which can be explained by the extensive metabolism of PPZ in the human body. Since most previous studies did not consider human PPZ metabolites it can be assumed that the current environmental exposure associated with the application of PPZ is substantially underestimated. In our study, 4'-O-demethyl-PPZ sulfide (M1) was identified as the predominant PPZ metabolite by analyzing urine of a PPZ consumer as well as the influent and effluent of a wastewater treatment plant (WWTP) using liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS). M1 was found to be ubiquitously present in WWTP effluents (max. concentration: 3 000 ng/L) and surface waters in Germany. On average, the surface water concentrations of M1 were approximately 30 times higher than those of the parent compound PPZ. Laboratory scale experiments demonstrated that activated carbon can considerably adsorb M1 und thus improve its removal during wastewater and drinking water treatment. Laboratory ozonation experiments showed a fast oxidation of M1, accompanied by the formation of several ozonation products. Certain ozonation products (identities confirmed via synthesized reference standards) were also detected in water samples collected after ozonation in a full-scale WWTP. Overall lower signal intensities were observed in the effluents of a sand filter and biologically active granular activated carbon filter, suggesting that the compounds were significantly removed during these post-ozonation treatment stages.

Treatment of real laundry wastewater using vertical flow constructed wetland planted with the ornamental climbing plant Trachelospermum jasminoides: assessing the removal of conventional pollutants and benzotriazoles

This study investigates the effectiveness of vertical flow constructed wetlands (VFCWs) planted with a climbing ornamental plant for on-site treatment of real laundry wastewater. Specifically, the presence or absence of Trachelospermum jasminoides was evaluated for the removal performance of conventional pollutants (turbidity, TSS, COD, TP) and benzotriazoles (BTRs): 1H-benzotriazole (BTR), 5-methyl-1H-benzotriazole (5-TTR), 5-chlorobenzotriazole (CBTR), and xylytriazole (XTR). Results revealed that high removal efficiencies ranging from 92 to 98% were presented in both planted and unplanted systems for turbidity, TSS, and COD. Moreover, high removal rates were observed for CBTR and XTR, which were the only compounds found in real laundry wastewater, in both VFCW systems (planted: 100%; 94%; unplanted: 87%; 92%, respectively). The contribution of plants to the pollutant's removal was not statistically significant for all examined parameters. However, T. jasminoides demonstrated the ability to survive and grow without any visible symptoms under the harsh conditions of laundry wastewater, enabling the development of green facade. According to the findings, the application of VFCWs for on-site laundry wastewater treatment in buildings seems to be a highly promising solution, not only for primarily removing conventional pollutants but also for addressing emerging contaminants, specifically BTRs.

The odd couple: Caffeine and microplastics. Morphological and physiological changes in Mytilus galloprovincialis

In recent years, the presence of pharmaceuticals and microplastics (MPs) in aquatic ecosystems has raised concerns about their environmental impact. This study explores the combined effects of caffeine, a common pharmaceutical pollutant, and MPs on the marine mussel Mytilus galloprovincialis. Caffeine, at concentrations of 20.0 μg L-1, and MPs (1 mg L-1, 35-50 μm size range), was used to mimic real-world exposure scenarios. Two hundred M. galloprovincialis specimens were divided into four groups: caffeine, MPs, Mix (caffeine + MPs), and Control. After a two-week acclimation period, the mollusks were subjected to these pollutants in oxygen-aerated aquariums under controlled conditions for 14 days. Histopathological assessments were performed to evaluate gill morphology. Cellular volume regulation and digestive gland cell viability were also analyzed. Exposure to caffeine and MPs induced significant morphological changes in M. galloprovincialis gills, including cilia loss, ciliary disk damage, and cellular alterations. The chitinous rod supporting filaments also suffered damage, potentially due to MP interactions, leading to hemocyte infiltration and filament integrity compromise. Hemocytic aggregation suggested an inflammatory response to caffeine. In addition, viability assessments of digestive gland cells revealed potential damage to cell membranes and function, with impaired cell volume regulation, particularly in the Mix group, raising concerns about nutrient metabolism disruption and organ function compromise. These findings underscore the vulnerability of M. galloprovincialis to environmental pollutants and emphasize the need for monitoring and mitigation efforts. RESEARCH HIGHLIGHTS: The synergy of caffeine and microplastics (MPs) in aquatic ecosystems warrants investigation. MPs and caffeine could affect gill morphology of Mytilus galloprovincialis. Caffeine-exposed cells had lower viability than the control group in the NR retention test. MPs and mix-exposed cells struggled to recover their volume.

Spatial and temporal variability of micropollutants within a wastewater catchment system

Treated wastewater effluent is a major contributor to concentrations of many anthropogenic chemicals in the environment. Examining patterns of these compounds measured from different catchment areas comprising the influent to a wastewater treatment plant, across many months, may reveal patterns in compound sources and seasonality helpful to management efforts. This study considers a wastewater catchment system that was sampled at six sub-catchment sites plus the treatment plant influent and effluent at seven time points spanning nine months. Wastewater samples were analyzed with LC-QTOF-MS using positive electrospray ionization and GC-QTOF-MS using negative chemical ionization and electron ionization. MS data were screened against spectral libraries to identify micropollutants. As expected, multiple classes of chemicals were represented, including pharmaceuticals, plasticizers, personal care products, and flame retardants. Patterns in the compounds seen at different sampling sites and dates reflect the varying uses and down-the-drain routes that influence micropollutant loading in sewer systems. Patterns in examined compounds revealed little spatial variation, and greater temporal variation. For example, the greatest loads of DEET were found to occur in the summer months. Additionally, groups of compounds exhibited strong correlation with each other, which could be indicative of similar down-the-drain routes (such as a group intercorrelated chemicals that are components of cleaning products) or the influence of similar physicochemical processes within the sewer system. This study contributes to the understanding of dynamics of micropollutants in sewer systems.

The pit latrine paradox in low-income settings: A sanitation technology of choice or a pollution hotspot?

Pit latrines are widely promoted to improve sanitation in low-income settings, but their pollution and health risks receive cursory attention. The present narrative review presents the pit latrine paradox; (1) the pit latrine is considered a sanitation technology of choice to safeguard human health, and (2) conversely, pit latrines are pollution and health risk hotspots. Evidence shows that the pit latrine is a 'catch-all' receptacle for household disposal of hazardous waste, including; (1) medical wastes (COVID-19 PPE, pharmaceuticals, placenta, used condoms), (2) pesticides and pesticide containers, (3) menstrual hygiene wastes (e.g., sanitary pads), and (4) electronic wastes (batteries). Pit latrines serve as hotspot reservoirs that receive, harbour, and then transmit the following into the environment; (1) conventional contaminants (nitrates, phosphates, pesticides), (2) emerging contaminants (pharmaceuticals and personal care products, antibiotic resistance), and (3) indicator organisms, and human bacterial and viral pathogens, and disease vectors (rodents, houseflies, bats). As greenhouse gas emission hotspots, pit latrines contribute 3.3 to 9.4 Tg/year of methane, but this could be an under-estimation. Contaminants in pit latrines may migrate into surface water, and groundwater systems serving as drinking water sources and pose human health risks. In turn, this culminates into the pit latrine-groundwater-human continuum or connectivity, mediated via water and contaminant migration. Human health risks of pit latrines, a critique of current evidence, and current and emerging mitigation measures are presented, including isolation distance, hydraulic liners/ barriers, ecological sanitation, and the concept of a circular bioeconomy. Finally, future research directions on the epidemiology and fate of contaminants in pit latrines are presented. The pit latrine paradox is not meant to downplay pit latrines' role or promote open defaecation. Rather, it seeks to stimulate discussion and research to refine the technology to enhance its functionality while mitigating pollution and health risks.

Removal of benzotriazole micropollutants using Spirodela polyrhiza (L.) Schleid. And Azolla caroliniana Willd

Phytoremediation of benzotriazoles (BTR) from waters by floating macrophytes is not well understood, but it seems to have the potential to be used in conjunction with conventional wastewater treatment plants. The effectiveness of removing four compounds from the benzotriazole group by floating plants Spirodela polyrhiza (L.) Schleid. And Azolla caroliniana Willd. From the model solution, was studied. The observed decrease in the concentration of studied compounds was in the range 70.5%-94.5% using S. polyrhiza, and from 88.3% to 96.2% for A. caroliniana. It was determined using chemometric methods that the effectiveness of the phytoremediation process is mainly influenced by three parameters: exposure time to light, pH of the model solution and the mass of plants. Using the design of experiments (DoE) chemometric approach, the optimal conditions for removing BTR were selected: plant weight 2.5 g and 2 g, light exposure 16 h and 10 h, and pH 9 and pH 5 for S. polyrhiza and A. caroliniana, respectively. Studies on the mechanisms of BTR removal have shown that the reduction in concentration is mainly due to the process of plant uptake. Toxicity studies have proved that the tested BTR affected the growth of S. polyrhiza and A. caroliniana and induced changes in the levels of chlorophyllides, chlorophylls as well as carotenoids. More dramatic loss in plant biomass and photosynthetic pigment contents was observed in A. caroliniana cultures exposed to BTR.

Single and combined effects of caffeine and salicylic acid on mussel Mytilus galloprovincialis: Changes at histomorphological, molecular and biochemical levels

Caffeine (CAF) and salicylic acid (SA) are frequently detected in waterbody, though information on their biological impact is poor. This work assesses the effects of CAF (5ng/L to 10µg/L) and SA (0.05µg/L to 100µg/L) alone and combined as CAF+SA (5ng/L+0.05µg/L to 10µg/L+100µg/L) on mussel Mytilus galloprovincialis under 12-days exposure by histomorphology of digestive gland and oxidative stress defense at molecular and biochemical levels. Besides evaluating tissue accumulation, absence of histomorphological damage and haemocyte infiltration highlighted activation of defensive mechanisms. Up-regulation of Cu/Zn-sod, Mn-sod, cat and gst combined with increased catalase and glutathione S-transferase activity were found in CAF-exposed mussels, while SA reduced ROS production and mitochondrial activity. CAF+SA exposure induced differential responses, and the integrated biomarker response (IBR) revealed more pronounced effects of SA than CAF. These results enlarge knowledge on pharmaceuticals impact on non-target organisms, emphasizing the need for proper environmental risk assessment.

Is adsorption onto activated carbon a feasible drinking water treatment option for persistent and mobile substances?

Persistent and mobile (PM) substances among the organic micropollutants have gained increasing interest since their inherent properties enable them to enrich in water cycles. This study set out to investigate the potential of adsorption onto activated carbon as a drinking water treatment option for 19 PM candidates in batch experiments in a drinking water matrix using a microporous and a mesoporous activated carbon. Overall, adsorption of PM candidates proved to be very variable and the extent of removal could not be directly related to molecular properties. At an activated carbon dose of 10 mg/L and 48 h contact time, five (out of 19) substances were readily removed (≥ 80%), among them N-(3-(dimethylamino)-propyl)methacrylamide, which was investigated for the first time. For five other substances, no or negligible removal (< 20%) was observed, including 2-methyl-2-propene-1-sulfonic acid and 4‑hydroxy-1-(2-hydroxyethyl)-2,2,6,6,-tetramethylpiperidine. For the former, current state of the art adsorption processes may pose a sufficient barrier. Additionally, substance specific surrogate correlations between removals and UVA₂₅₄ abatements were established to provide a cheap and fast estimate for PM candidate elimination. Adsorption onto activated carbon could contribute significantly to PM substance elimination as part of multi barrier approaches, but assessments for individual substances still require clarification, as demonstrated for the investigated PM candidates.

Sartan blood pressure regulators in classical and biofilm wastewater treatment - Concentrations and metabolism

Sartans are a group of pharmaceuticals widely used to regulate blood pressure. Their concentration levels were monitored in 80 wastewater treatment plants (WWTP) in the Baltic Sea Region, reached from limit of detection up to 6 µg/L. The concentrations were significantly different in different countries, but consistent within the respective country. The degradation of sartans (losartan, valsartan, irbesartan) in moving bed biofilm reactors (MBBRs) that utilize biofilms grown on mobile carriers to treat wastewater was investigated for the first time, and compared with the degradation in a conventional activated sludge (CAS) treatment plant. The results showed the formation of six microbial transformation products (TPs) of losartan, four of valsartan, and four of irbesartan in biological wastewater treatment. Four of these metabolites have not been described in the literature before. Chemical structures were suggested and selected TPs were verified and quantified depending on availability of true standards. Valsartan acid was a common TP of losartan, valsartan, and irbesartan. Losartan and irbesartan also shared one TP: losartan/irbesartan TP335. Based on the mass balance analysis, losartan carboxylic acid is the main TP of losartan, and valsartan acid is the main TP of valsartan during the biotransformation process. For irbesartan, TP447 is likely to be the main TP, as its peak areas were two orders of magnitude higher than those of all the other detected TPs of this compound. The effects of adapting biofilms to different biological oxygen demand (BOD) loading on the degradation of sartans as well as the formation of their TPs were investigated. Compared to feeding a poor substrate (pure effluent wastewater from a CAS), feeding with richer substrate (1/3 raw and 2/3 effluent wastewater) promoted the metabolism of most compounds (co-metabolization). However, the addition of raw wastewater inhibited some metabolic pathways of other compounds, such as from losartan/irbesartan to TP335 (competitive inhibition). The formation of irbesartan TP447 did not change with or without raw wastewater. Finally, the sartans and their TPs were investigated in a full-scale CAS wastewater treatment plant (WWTP). The removal of losartan, valsartan, and irbesartan ranged from 3.0 % to 72% and some of the transformation products (TPs) from human metabolism were also removed in the WWTP. However, some of the sartan TPs, i.e., valsartan acid, losartan carboxylic acid, irbesartan TP443 and losartan TP453, were formed in the WWTP. Relative high amounts of especially losartan carboxylic acid, which was detected with concentrations up to 2.27 µg/L were found in the effluent.

Transport-based source tracking of contaminants in a karst aquifer: Model implementation, proof of concept, and application to event-based field data

Identification and location of contamination sources is crucial for water resource protection - especially in karst aquifers which provide 25% of the world´s population with water but are highly vulnerable to contamination. Transport-based source tracking is proposed and verified here as a complementary approach to microbial and chemical source tracking in karst aquifers for identifying and locating such sources of contamination and for avoiding ambiguities that might arise from using one method alone. The transport distance is inversely modelled from contaminant breakthrough curves (BTC), based on analytical solutions of the 1D two-region non-equilibrium advection dispersion equation using GNU Octave. Besides the BTC, the model requires reliable estimates of transport velocity and input time. The model is shown to be robust, allows scripted based, automated 2D sensitivity analyses (interplay of two parameters), and can be favourable when distributed numerical models are inappropriate due to insufficient data. Sensitivity analyses illustrate that the model is highly sensitive to the input time, the flow velocity, and the fraction of the mobile fluid region. A conclusive verification approach was performed by applying the method to synthetic data, tracer tests, and event-based field data. Transport distances were correctly modelled for a set of artificial tracer tests using a discharge-velocity relationship that could be established for the respective karst catchment. For the first time such an approach was shown to be applicable to estimate the maximum distance to the contamination source for coliform bacteria in karst spring water combined with microbial source tracking. However, prediction intervals for the transport distance can be large even in well-studied karst catchments mainly related to uncertainties in the flow velocity and the input time. Using a maximum transport distance is proposed to account for less permeable, "slower" pathways. In general, transport-based source tracking might be used wherever transport can be described by the 1D two-region non-equilibrium model, e.g. rivers and fractured or porous aquifers.

Sources of microbial contamination in the watershed and coastal zone of Soufriere, St. Lucia

The Sustainable Development Goal 6 calls for global progress by 2030 in treating domestic wastewater and providing access to adequate sanitation facilities. However, meeting these goals will be a challenge for most Small Island Developing States, including Caribbean island nations. In the nearshore zone of the Soufriere region on the Caribbean island of St. Lucia, there is a history of high levels of bacteria of fecal origin. Possible land-based sources of microbial contamination in the Soufriere Bay include discharges from the Soufriere River and transport of wastewater, including fecal material from the town of Soufriere. This area is an important tourist destination and supports a local fishery. To identify the sources of microbial contamination in Soufriere Bay, a range of monitoring methods were employed in this study. In grab samples of surface water collected from the Soufriere River, counts of total coliforms and Escherichia coli were elevated above water quality guidelines. However, the spikes in concentrations of these indicator organisms in the river did not necessarily coincide with the spikes in the levels of total coliforms and E. coli detected in samples collected on the same dates in Soufriere Bay, indicating that there are other sources of pollution in the Bay besides discharges from the river. Monitoring for chemical indicators of wastewater (i.e., caffeine, sucralose, fluconazole) in the Soufriere River indicated that there are inputs of sewage or human fecal material throughout the watershed. However, analysis of Bacteroidales 16S rRNA genetic markers for fecal bacteria originating from humans, bovine ruminants, or other warm-blooded animals indicated that the majority of microbial contamination in the river was not from humans. Monitoring for chemical indicators of wastewater using passive samplers deployed in Soufriere Bay indicated that there are two "hot spots" of contamination located offshore of economically depressed areas of the town of Soufriere. This study indicates that efforts to control contamination of Soufriere Bay by fecal microorganisms must include management of pollution originating from both sewage and domestic animals in the watershed.

Caffeine and Paraxanthine as Tracers of Anthropogenic Wastewater in Coastal Lagoons in Yucatan, Mexico

Due to karstic bedrock geology and poor wastewater management practices, anthropogenic activities are impacting water quality in Yucatan's aquatic systems. Specifically, raw wastewater inputs to the aquifer subsequently flow to coastal lagoons through groundwater fluxes. This study establishes the presence of anthropogenic wastewater by measuring caffeine and its metabolite, paraxanthine, in four of Yucatan's major coastal lagoons: Celestun, Chelem, Dzilam de Bravo, and Ria Lagartos. Concentrations of caffeine ranged from non-detected (ND) to 2390 ng L^-1 and paraxanthine from ND to 212 ng L^-1, which correspond with pollution threats from anthropogenic wastewater inputs. The potential sources are: (1) direct in situ discharges from nearby urban settlements; and (2) contribution from submerged groundwater discharges. Overall, results indicate the potential of caffeine as an environmental tracer of anthropogenic wastewater contamination for the region.

Analysis of micropollutants in a marine outfall using network analysis and decision tree

The presence of micropollutants (MPs), including pharmaceutical, industrial, and pesticidal compounds, threatens both human health and the aquatic ecosystem. The development and extensive use of new chemicals have also inevitably led to the accumulation of MPs in aquatic environments. Recreational beaches are especially vulnerable to contamination, affecting humans and aquatic animals via the absorption of MPs in water during marine activities (e.g., swimming, sailing, and windsurfing). Additionally, marine outfalls in an urbanized coastal city can cause serious chemical and microbial pollution on recreational beaches, leading to an increase in adverse effects on public health and the ecological system. Therefore, the aim of this study was to, with the use of network and decision tree analyses, identify the features and factors that influence the change in MP concentrations in a marine outfall. These analyses were conducted to inspect the relationship between each MP and its hierarchical structure as well as hydrometeorological variables. Additionally, a risk analysis was conducted in this study in which the MPs were prioritized based on their optimized risk quotient values. During our monitoring of MP concentrations over time at the marine outfall, high concentrations of pharmaceutical and industrial compounds were detected when the tide level was low after rainfall. Furthermore, results of the risk analysis and the prioritization revealed that a total of 18 substances identified in our study posed a risk to the ecosystem; these include major ecotoxicologically hazardous substances such as telmisartan, mevinphos, and methiocarb. Results of the network analysis demonstrated distinct trends for pharmaceutical and industrial substances, whilst those for pesticide compounds were irregular. Additionally, the hierarchical structures for most MPs consisted of rainfall, tide level, and antecedent dry hours; this implies that these factors influence MP dynamics. These findings will be helpful for establishing chemical contamination management plans for recreational beaches in the future.

Assessment of a wide array of organic micropollutants of emerging concern in wastewater treatment plants in Greece: Occurrence, removals, mass loading and potential risks

Exploring the contamination profile of multi-class emerging contaminants (ECs) in wastewater is highly desirable. To this end, the occurrence, removal, mass loading and risks associated with a large panel of pharmaceuticals and personal care products, illicit drugs, perfluorinated compounds and organophosphate flame retardants in two wastewater treatment plants (WWTPs) in the region of Thessaloniki (Greece) after a survey is illustrated. Influent and effluent wastewaters were submitted to solid phase extraction on Oasis HLB cartridges, followed by ultra-high-performance liquid chromatography Orbitrap high-resolution mass spectrometry (UHPLC-Orbitrap MS). Influent concentrations in both WWTPs were notably higher than effluent, with caffeine, acetaminophen, irbesartan and valsartan being the most ubiquitous compounds, exhibiting elevated concentrations. Average effluent concentrations ranged from below the method quantification limits (<MQL) to remarkably high values (μg L^-1 scale), such as for caffeine, acetaminophen, diclofenac, irbesartan and valsartan, among others. Removal efficiencies ranged between -273% for lamotrigine and 100%, i.e., for the UV filter BP1. Notably, the polar compounds such as cytarabine, methotrexate and capecitabine were removed at a rate >80% in both WWTPs, allowing the correlation between logK_ow and removals. Interesting trends for the illicit drugs were revealed by means of mass loading estimation, as in the case of benzoylecgonine (71.6 mg/day/1000 inhabitants). Ecotoxicological risk assessment was evaluated for both single components and mixture, using three approaches: risk quotient (RQ), risk quotient considering frequency (RQ_f) and toxic units (TU). Irbesartan and telmisartan posed a high risk in all trophic levels, while fish was the most sensitive taxa for diclofenac. This work aspires to intensify the surveillance programs for the receiving water bodies, as well as to motivate the investigation of toxicity to non-target organisms.

Caffeine as a contaminant of concern: A review on concentrations and impacts in marine coastal systems

Caffeine has been identified as emerging contaminant of concern due to its widespread occurrence in the aquatic environment and potential to be biologically active. Recently, these concerns have been translated in an increasing research on its occurrence and effects on biota. However, there is still a limited knowledge on seawater matrices and the implications of caffeine presence in coastal and marine ecosystems are not fully known. The present review aims to fill these knowledge gaps, analysing the existing literature regarding the occurrence, effects and potential risks of caffeine residues to coastal ecosystems, contributing to the risk assessment of this psychoactive drug in the aquatic environment. The analysed literature reported caffeine concentrations in the coastal ecosystems, raising high concerns about the potential adverse impacts on the ecological safety and human health. Caffeine has been found in tissues from coastal and marine biota including microalgae, coral reefs, bivalves and fish due to bioaccumulation after chronic, long-term exposures in a contaminated environment. Additionally, caffeine residues had been demonstrated to have adverse impacts on aquatic organisms, at environmentally realistic concentrations, inducing oxidative stress and lipid peroxidation, neurotoxicity, changing energy reserves and metabolic activity, affecting reproduction and development and, in some cases, causing mortality. Considering the increasing adverse impacts of caffeine pollution in the coastal environment, this review highlights the urgent need to minimize the increasing load of caffeine to the aquatic ecosystems; being imperative the implementation of scientific programs and projects to classify effectively the caffeine as a high-priority environmentally hazardous emerging pollutant.

Seasonal and spatial dynamics of selected pesticides and nutrients in a small lake catchment - Implications for agile monitoring strategies

Intensive anthropogenic pressure such as high inputs of nutrients and pesticides severely threaten most European water bodies. Small catchments ≤10 km² are not monitored under the Water Framework Directive but play an important role in freshwater ecosystems. The high complexity in seasonal and spatial dynamics require more than a one-size-fits-all approach in water quality monitoring. Often located in rural areas with a high agricultural activity, small catchments often carry high amounts of nutrients, pesticides and their transformation products affecting drinking water resources. With a low-cost approach of a monthly sampling campaign over the course of one year combined with meaningful indicators for potential pollution sources within the catchment this study could elucidate catchment dynamics and two hotspots for pesticides and nutrients. Two different groups of pesticides were observed (I) pesticides on long-term use which were applied in high amounts over the last decades (e.g., chloridazon and its transformation products) and (II) pesticides on short-term use, newly introduced into the market. Especially transformation products of pesticides from group (I) together with nitrate showed a steady release from two fields into the receiving water bodies over the year, probably being stored in the soil layers over the years of application slowly leaching out. Pesticides from group (II) showed a strong seasonality, released from another hotspot area probably due to run-off shortly after application. Streamlining this knowledge into targeted measures and an agile monitoring strategy for the respective catchments may allow a sustainable improvement of water quality and a better ecosystem protection.

Occurrence of pharmaceutical residues, personal care products, lifestyle chemicals, illicit drugs and metabolites in wastewater and receiving surface waters of Krakow agglomeration in South Poland

This is the first study of broad range of chemical classes CECs conducted in the upper Wisla river catchment including the biggest WWTPs in this region and surface waters. The list of compounds is extensive and the paper provides, for the first time, better understanding of environmental burden from PCPCs in Poland. Cumulative contribution of hypertension pharmaceuticals, nonsteroidal anti-inflammatory drugs (NSAIDs) and lifestyle chemicals was 89% and 95% in wastewater influent, and 75% in wastewater effluent at both WWTPs. Significant removal efficiencies, exceeding 90%, were found for parabens, UV filters, NSAIDs, steroid estrogens, plasticizers, antibacterials/antibiotics, stimulants and metabolites and lifestyle chemicals. The comparison of the average mass loads of CECs between the influent and effluent, has shown that 27% and 29% of all detected CECs were removed by less than 50%. An increase of concentrations of CECs in the effluent was observed for 18% and 20% of all detected CECs in Kujawy and Plaszow WWTPs, respectively. Negative mass balances of fexofenadine, venlafaxine, o-desmethyltramadol, ketamine and temazepam were noted within WWTPs, which are a result of dissolution of persistent contaminants accumulated in aggregates and/or back-transformation or de-conjugation of metabolites into parent compounds. 44 CECs were detected in surface waters located upstream and downstream of the WWTPs. The concentrations of compounds were largely dependent on the dilution factor of WWTP discharge. The risk quotation (RQ) values for compounds present in surface waters were calculated in relation to their potential for bioaccumulation. Among compounds with high potential for bioaccumulation, with log K_OW ≥ 4.5, diclofenac, atorvastatin and triclosan were found to be of high risk. Many CECs with high, moderate or even low environmental impact have shown high potential for bioaccumulation and should be considered as priority at the same risk level. Moreover, possible synergistic action is still of concern.

Occurrence, sources and fate of pharmaceuticals and personal care products and artificial sweeteners in groundwater

Groundwater is considered as the main source for supplying the public drinking water in many countries and regions; however, pharmaceuticals and personal care products (PPCPs) and artificial sweeteners (ASs) found in groundwater can exert harmful effects on human health and aquatic ecosystems, and therefore, they are of persistent concern. The recent data on the occurrence of a series of PPCPs (including antibiotics, excitants and lipid regulators) and ASs often detected in groundwater are reviewed, in which the PPCPs and ASs occur in groundwater at the concentration from several nanograms to several micrograms per litre. In addition, the spatio-temporal distribution characteristics of PPCPs and ASs are discussed and the main sources and possibly pollution pathways of PPCPs and ASs in groundwater are summarised and analysed. Additionally, the adsorption, migration and degradation of PPCPs and ASs in underground environments are evaluated. Due to the long residence time in groundwater, pollutants are likely to threaten the freshwater body for decades under certain conditions. Therefore, according to the current level of pollution, it is necessary to improve and enhance the supervision on PPCP and AS pollutants and prevent and control groundwater pollution.

Pharmaceuticals in the marine environment: What are the present challenges in their monitoring?

During the last years, there has been a growing interest in the research focused on the pharmaceutical residues in the environment. Those compounds have been recognized as a possible threat to aquatic ecosystems, due to their inherent biological activity and their "pseudo-persistence". Their presence has been relatively few investigated in the marine environment, though it is the last receiver of the continental contamination. Thus, pharmaceuticals monitoring data in marine waters are necessary to assess water quality and to allow enhancing future regulations and management decisions. A review of the current practices and challenges in monitoring strategies of pharmaceuticals in marine matrices (water, sediment and biota) is provided through the analysis of the available recent scientific literature. Key points are highlighted for the different steps of marine waters monitoring as features to consider for the targeted substance selection, the choice of the marine site configuration and sampling strategies to determine spatio-temporal trends of the contamination. Some marine environment specific features, such as the strong dilution occurring, the complex hydrodynamic and local logistical constraints are making this monitoring a very difficult and demanding task. Thus key knowledge gap priorities for future research are identified and discussed. Suitable passive samplers to monitor pharmaceutical seawater levels need further development and harmonization. Non-target analysis approaches would be promising to understand the fate of the targeted molecules and to enhance the list of substances to analyze. The implementation of integrated monitoring through long-term ecotoxicological tests on sensitive marine species at environmental levels would permit to better assess the ecological risk of these compounds for the marine ecosystems.

Assessment of UV combined with free chlorine for removal of valsartan acid from water samples

Valsartan acid (VALA) is a persistent and mobile pollutant, ubiquitously distributed in the aquatic environment. Herein, we assessed the efficiency of UV/free chlorine for the removal of this pollutant. Degradation experiments were performed using different water samples, considering several pH values and concentrations of inorganic anions. Time-course of VALA was measured by injection of different reaction time aliquots in a liquid chromatography (LC) triple quadrupole (QqQ) mass spectrometry (MS) system, whilst the study of potential transformation products (TPs) was evaluated by LC combined with a hybrid quadrupole time-of-flight (QTOF) MS system. Formation of volatile disinfection by-products (DBPs) was investigated by gas chromatography (GC) with TOF-MS detection. Compared to free chlorine treatment and UV photolysis, the combination of both parameters significantly enhanced the degradability of VALA. At neutral pH, UV/free chlorine was also more effective than UV/H₂O₂ to remove VALA from spiked water solutions. Three TPs of VALA were tentatively identified by LC-QTOF-MS, although only one was stable in the UV/free chlorine media. As regards volatile DBPs, the formation of chloroform, dichloroacetonitrile, di- and trichloroacetic acid was noticed. The mass yield of DBPs formation from VALA varied from 0.3% (dichloroacetonitrile) to 1.1% (chloroform). The efficiency of UV/free chlorine was first investigated in spiked solutions with increasing complexities: ultrapure, river and treated wastewater. Thereafter, the feasibility of reducing VALA levels in polluted river water was demonstrated.

Occurrence of caffeine in the freshwater environment: Implications for ecopharmacovigilance

Owing to the substantial consumption of caffeinated food, beverages, and medicines worldwide, caffeine is considered the most representative pharmaceutically active compound (PhAC) pollutant based on its high abundance in the environment and its suitability as an indicator of the anthropogenic inputs of PhACs in water bodies. This review presents a worldwide analysis of 132 reports of caffeine residues in freshwater environments. The results indicated that more than 70% of the studies reported were from Asia and Europe, which have densely populated and industrially developed areas. However, caffeine pollution was also found to affect areas isolated from human influence, such as Antarctica. In addition, the maximum concentrations of caffeine in raw wastewater, treated wastewater, river, drinking water, groundwater, lake, catchment, reservoir, and rainwater samples were reported to be 3.60 mg/L, 55.5, 19.3, 3.39, 0.683, 174, 44.6, 4.87, and 5.40 μg/L, respectively. The seasonal variation in caffeine residues in the freshwater environment has been demonstrated. In addition, despite the fact that there was a small proportion of wastewater treatment plants in which the elimination rates of caffeine were below 60%, wastewater treatment is generally believed to have a high caffeine removal efficiency. From a pharmacy perspective, we proposed to adopt effective measures to minimize the environmental risks posed by PhACs, represented by caffeine, through a new concept known as ecopharmacovigilance (EPV). Some measures of EPV aimed at caffeine pollution have been advised, as follows: improving knowledge and perceptions about caffeine pollution among the public; listing caffeine as a high-priority PhAC pollutant, which should be targeted in EPV practices; promoting green design and production, rational consumption, and environmentally preferred disposal of caffeinated medicines, foods, and beverages; implementing intensive EPV measures in high-risk areas and during high-risk seasons; and integrating EPV into wastewater treatment programs.

Wide-scope target analysis of emerging contaminants in landfill leachates and risk assessment using Risk Quotient methodology

Raw and treated leachate samples were collected from different landfills in Greece and analyzed for several groups of emerging contaminants using high resolution mass spectrometric workflows to investigate the possible threat from their discharge to the aquatic environment. Fifty-eight compounds were detected; 2-OH-benzothiazole was found at 84 % of the samples and perfluorooctanoic acid at 68 %. Bisphenol A, valsartan and 2-OH-benzothiazole had the highest average concentrations in raw leachates, after biological treatment and after reverse osmosis, respectively. In untreated leachates, Risk Quotients > 1 were calculated for 35 and 18 compounds when maximum and average concentrations were used, indicating an ecological threat for the aquatic environment. Leachates' biological treatment partially removed COD and NH₄⁺-N, as well as 52.3 % of total emerging contaminants. The application of reverse osmosis resulted in a 98 % removal of major pollutants, 99 % removal of total emerging contaminants and a significant decrease of ecotoxicity to Lemna minor. Beside the decrease of the detected micropollutants during treatment, RQs > 1 were still calculated for 13 and 3 compounds after biological treatment and reverse osmosis, respectively. Among these, special attention should be given to 2-OH-benzothiazole and bisphenol A that had RQ values much higher than 1 for all tested organisms.

Non-antimicrobial pharmaceuticals can affect the development of antibiotic resistance in hospital wastewater

Within this study, we were interested in the effects of wastewater on the development of antimicrobial resistance. Microorganisms can relatively promptly adapt to evolutionary pressures of the environment, including antibiotics. Therefore, we tested how the adaptability of the model microorganism Salmonella enterica is affected by wastewater full of pharmaceuticals, illicit drugs, and other micropollutants. Wastewater samples had been taken from effluent of hospitals and from wastewater treatment plant (WWTP) Petržalka influent and effluent. In these samples, presence of 38 substances was monitored. The highest concentration was observed in case of tramadol, citalopram, venlafaxine, cotinine, atenolol, valsartan, carbamazepine, azithromycin, and ciprofloxacin. According to this data, we focused also on individual pharmaceutical compounds presented in wastewater samples in elevated concentrations. Effect on resistance development of two pain relief medications (carbamazepine, tramadol), hypotensive medications (atenolol, valsartan), and the nicotine metabolite (cotinine) was also investigated. For this study, we employed concentrations presented in wastewater as well as in urine of patients and/or users. To determine the frequency of mutations leading to ciprofloxacin resistance, we applied the modified Ames test employing the strain Salmonella Typhimurium. Resistance index increased in the case of all wastewater samples from conventional hospitals where we observed a 1.22-1.69-fold increase of mutations leading to ciprofloxacin resistance. Tested compounds caused rise of resistance index in lower concentrations found in wastewater. The most significant increase of resistance index was detected after carbamazepine treatment.

Risks of caffeine residues in the environment: Necessity for a targeted ecopharmacovigilance program

Due to the huge consumption of caffeinated food, beverages and medicines around the world, caffeine has been considered as a most representative pharmaceutically active compound (PhAC) pollutant based on its high abundance in environment and its indicator property for anthropogenic inputs of PhACs to water bodies. This review analyzed the existing literature about the bioaccumulation and environmental risks of caffeine residues in non-target organisms. There are 6 studies which were published in the last 5 years have reported the distribution of caffeine in tissues of aquatic organisms including fishes, clams, macroalgae and other aquatic plants, suggesting bioaccumulation of caffeine in organisms. The maximum detected levels of caffeine residues in tissues ranged from 1.55 to 344.9 ng/g. Importantly, definitive evidences have been provided that environmentally relevant caffeine concentrations exert adverse impacts on aquatic species and terrestrial insects, which included lethality, decreasing general stress, inducing oxidative stress and lipid peroxidation, affecting energy reserves and metabolic activity, neurotoxic effects, affecting reproduction and development, etc. In view of the severity and potential adverse impacts of caffeine pollution in the environment, we proposed that caffeine should be considered as a high-priority environmentally hazardous PhAC pollutant, and it is necessary to implement an ecopharmacovigilance (EPV) program targeting caffeine to minimize its environmental load from a pharmacy perspective.

Biodegradability assessment of food additives using OECD 301F respirometric test

The ready biodegradability of twenty food additives, belonging to the classes of artificial sweeteners, natural sweeteners, preservatives and colorings, was investigated using activated sludge as inoculum and OECD 301F respirometric test. According to the results, saccharin, aspartame, sodium cyclamate, xylitol, erythritol, maltitol, potassium sorbate, benzoic acid and sodium ascorbate are characterized as readily biodegradable compounds, partial biodegradation (<60% during the test) was noticed for steviol, inulin, alitame, curcumin, ponceau 4R and tartrazine, while no biodegradation was observed for the other five compounds. The duration of lag phase before the start of biodegradation varied between the target compounds, while their ultimate biodegradation half-life values ranged between 0.7 ± 0.1 days (benzoic acid) and 24.6 ± 1.0 days (curcumin). The expected removal of target compounds due to ultimate biodegradation mechanism was estimated for a biological wastewater treatment system operated at a retention time of one day and percentages higher than 40% were calculated for sodium cyclamate, potassium sorbate and benzoic acid. Higher removal percentages are expected in full-scale Sewage Treatment Plants (STPs) due to the contribution of other mechanisms such as sorption to suspended solids, (bio)transformation and co-metabolic phenomena. Further biodegradation experiments should be conducted under different experimental conditions for the food additives that did not fulfill the requirements of the applied protocol. Future studies should also focus on the occurrence and fate of food colorants and natural sweeteners in full-scale STPs.

Occurrence, interactive effects and ecological risk of diclofenac in environmental compartments and biota - a review

Diclofenac, a nonsteroidal anti-inflammatory drug has turned into a contaminant of emerging concern; hence, it was included in the previous Watch List of the EU Water Framework Directive. This review paper aims to highlight the metabolism of diclofenac at different trophic levels, its occurrence, ecological risks, and interactive effects in the water cycle and biota over the past two decades. Increased exposure to diclofenac not only raises health concerns for vultures, aquatic organisms, and higher plants but also causes serious threats to mammals. The ubiquitous nature of diclofenac in surface water (river, lake canal, estuary, and sea) is compared with drinking water, groundwater, and wastewater effluent in the environment. This comprehensive survey from previous studies suggests the fate of diclofenac in wastewater treatment plants (WWTPs) and may predict its persistence in the environment. This review offers evidence of fragmentary available data for the water environment, soil, sediment, and biota worldwide and supports the need for further data to address the risks associated with the presence of diclofenac in the environment. Finally, we suggest that the presence of diclofenac and its metabolites in the environment may represent a high risk because of their synergistic interactions with existing contaminants, leading to the development of drug-resistant strains and the formation of newly emerging pollutants.

Biological transformation of fexofenadine and sitagliptin by carrier-attached biomass and suspended sludge from a hybrid moving bed biofilm reactor

Laboratory-scale experiments were conducted to investigate the (bio)transformation of the antidiabetic sitagliptin (STG) and the antihistamine fexofenadine (FXF) during wastewater treatment. As inoculum either attached-growth on carriers or suspended sludge from a hybrid moving bed biofilm reactor (HMBBR) was used. Both target compounds were incubated in degradation experiments and quantified via LC-MS/MS for degradation kinetics. Furthermore transformation products (TPs) were analyzed via high resolution mass spectrometry (HRMS). Structural elucidation of the TPs was based on the high resolution molecular ion mass to propose a molecular formula and on MS² fragmentation to elucidate the chemical structure of the TPs. In total, 22 TPs (9 TPs for STG and 13 TPs for FXF) were detected in the experiments with STG and FXF. For all TPs, chemical structures could be proposed. STG was mainly transformed via amide hydrolysis and conjugation of the primary amine moiety. In contrast, FXF was predominantly transformed by oxidative reactions such as oxidation (dehydrogenation) and hydroxylation. Furthermore, FXF was removed significantly faster in contact with carriers compared to suspended sludge, whereas STG was degraded slightly faster in contact with suspended sludge. Moreover, the primary TP of FXF was also degraded faster in contact with carriers leading to higher proportions of secondary TPs. Thus, the microbial community of both carriers and suspended sludge catalyzed the same primary transformation reactions but the transformation kinetics of FXF and the formation/degradation of FXF TPs were considerably higher in contact with carrier-attached biomass. The primary degradation of both target compounds in pilot- and full-scale conventional activated sludge (CAS) and MBBR reactors reached 42 and 61% for FXF and STG, respectively. Up to three of the identified TPs of FXF and 8 TPs of STG were detected in the effluents of pilot- and full-scale CAS and MBBR.

Sated by a Zero-Calorie Sweetener: Wastewater Bacteria Can Feed on Acesulfame

The widely used artificial sweetener acesulfame K has long been considered recalcitrant in biological wastewater treatment. Due to its persistence and mobility in the aquatic environment, acesulfame has been used as marker substance for wastewater input in surface water and groundwater. However, recent studies indicated that the potential to remove this xenobiotic compound is emerging in wastewater treatment plants worldwide, leading to decreasing mass loads in receiving waters despite unchanged human consumption patterns. Here we show evidence that acesulfame can be mineralized in a catabolic process and used as sole carbon source by bacterial pure strains isolated from activated sludge and identified as Bosea sp. and Chelatococcus sp. The strains mineralize 1 g/L acesulfame K within 8-9 days. We discuss the potential degradation pathway and how this novel catabolic trait confirms the "principle of microbial infallibility." Once the enzymes involved in acesulfame degradation and their genes are identified, it will be possible to survey diverse environments and trace back the evolutionary origin as well as the mechanisms of global distribution and establishment of such a new catabolic trait.

Qualitative and quantitative use of micropollutants as source and process indicators. A review

Nowadays, micropollutants such as pharmaceuticals, pesticides and personal care products can be found ubiquitously in the anthropogenically influenced water cycle. As micropollutants have virtually no natural background concentrations they are significantly more sensitive in detecting processes and flow paths than classic inorganic tracers and indicators and at the same time they are often highly source specific. Therefore, using micropollutants as environmental indicators for anthropogenic activities is a common and frequently applied method today. As they interact in many ways with environmental matrices they can be used for source apportionment as well as to estimate flow paths and residence times in waterbodies. This review gives a systematic overview over the large variety of micropollutants used as indicators in the aquatic environment over the last decades together with the prerequisites on their use. Their application is subdivided into their qualitative (compound presence or absence) and quantitative (volume flows) use and shows the numerous possibilities from gaining basic information on the water regime up to advanced applications such as wastewater-based epidemiology.

Tracing the potential pollution sources of the coastal water in Hong Kong with statistical models combining APCS-MLR

In this study, variety of statistical methods were performed to reveal the spatiotemporal distribution characteristics of pollutants and parsing pollution sources of the coastal water in Hong Kong. The temporal-spatial distribution characteristics of the water pollution were various among the three distinct areas, which might be ascribed to the different dominant pollution sources. Cluster and network analysis showed preliminary pollution sources in these areas, and also indicated the temporal characteristics of Deep Bay water pollution, which could divided into two parts before and after 2010. According to the principal component analysis/factor analysis results, three factors in Deep Bay, Tolo Harbour and Victoria Harbour could explained 68.72%, 54.87% and 72.28% of the total variances, respectively. The contribution rate of different pollution source on water quality variables in each area had calculated by absolute principal component score-multiple linear regression model. The contribution rate was roughly ranked as: point source pollution > non-point source pollution > overland runoff > river input. It is the first time to combine multivariate statistical methods, network analysis and regression model to profoundly analyze spatiotemporal variation of seawater quality and parsing the pollution sources. This novel analysis method can provide reference for the water quality evaluation and management of other water bodies.

Selective determination of sartan drugs in environmental water samples by mixed-mode solid-phase extraction and liquid chromatography tandem mass spectrometry

Herein, a method for the simultaneous determination of the currently prescribed sartan drugs (eprosartan, EPR; olmesartan, OLM; losartan, LOS; candesartan, CAN; telmisartan, TEL; irbesartan, IRB; and valsartan, VAL), and the biodegradation product valsartan acid (VALA), in water samples (raw and treated wastewater, river and tap water) was developed. Solid-phase extraction (SPE) and ultra-performance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS) were employed as concentration and determination techniques, respectively. Different sorbents and elution solvents were tested for sample preparation. Under optimized conditions, samples at neutral pH (6-8 units) were concentrated using mixed-mode (reversed-phase and anionic exchange) cartridges. Thereafter, the sorbent was washed with 5 mL of a methanol: water (1:1) solution, dried under a nitrogen stream and compounds were eluted with 2 mL of methanol: NH₃ (98:2). The accuracy of the method (accounting for SPE efficiency and matrix effects during electrospray ionization) was investigated using solvent-based calibration standards. Global recoveries, obtained for different water matrices (tap, river, treated and raw wastewater), ranged from 82% to 134%, with standard deviations between 2 and 18%. LOQs varied from 2 to 50 ng L^-1. Analysis of un-spiked samples confirmed: (1) the incomplete removal of sartans at sewage treatment plants (STPs), (2) the formation of VALA during municipal water treatment, and (3) the presence of VALA in the processed tap water samples. Additional findings of the current study are the detection of hydroxylated derivatives of the sartan drugs IRB and LOS in wastewater, and the E-Z isomerization of EPR in environmental water samples.

Psychoactive pharmaceuticals and illicit drugs in coastal waters of North-Western Spain: Environmental exposure and risk assessment

The knowledge on the presence of pharmaceutical compounds, and possible risks, in coastal and marine systems is still limited. This study represents the first attempt at monitoring psychoactive pharmaceuticals (PaPs) (benzodiazepines and anxiolytics) and illicit drugs (IDs) in the Rías Baixas coastal area of Northwestern Spain, an area of economic and ecological relevance, leader in shellfish production. Fourteen PaPs and 9 IDs were detected in the water samples with venlafaxine (59%), benzoylecgonine (40%), EDDP (40%), and citalopram (36%) showing the highest detection frequencies. The highest concentrations were measured for venlafaxine (291 ng L^-1), benzoylecgonine (142 ng L^-1), lorazepam (95.9 ng L^-1), and citalopram (92.5 ng L^-1). Risk assessment, based on hazard quotients suggested that venlafaxine, citalopram, sertraline, and EDDP were present in concentrations potentially able to cause chronic effects in exposed organisms. Based on the results obtained further monitoring of venlafaxine, citalopram, and EDDP in coastal waters is recommended.

Growth inhibition and fate of benzotriazoles in Chlorella sorokiniana cultures

Benzotriazoles are among the most commonly found organic micropollutants in the aquatic environment. In this study, toxicity experiments were conducted in order to investigate the effects of different benzotriazoles on Chlorella sorokiniana growth. Four compounds were tested; 1H-benzotriazole (BTR), xylytriazole (XTR), 5-methyl-1H-benzotriazole (5TTR) and 5-chlorobenzotriazole (CBTR). The fate of these micropollutants was also studied under batch conditions and the effect of different mechanisms on their elimination was investigated. According to the results, the EC₅₀ values in single-substance toxicity experiments were calculated to 8.3 mg L^-1 for BTR, 22 mg L^-1 for 5TTR and 38.7 mg L^-1 for CBTR. A slight inhibition on microalgae growth was noted at the maximum tested concentration of XTR (77 mg L^-1), while no inhibition was observed when a mixture of target BTRs was tested at 200 μg L^-1. Calculation of the Risk Quotient (RQ) showed no possible ecological threat in the presence of 5TTR, XTR and CBTR, while RQ values close or higher than 1 were estimated for BTR. All target contaminants were significantly eliminated in microalgae experiments that lasted 16 days. Their removal efficiency ranged between 42.2 ± 3.1% (XTR) to 97.2 ± 0.9% (XTR), while their half-life values were estimated to 2.4 ± 0.5 days for 5TTR, 6.5 ± 0.6 days for BTR, 15.2 ± 1.4 days for CBTR and 20.7 ± 2.0 days for XTR. Photodegradation was the main mechanism affecting BTR, XTR and CBTR removal, while bioremoval processes enhanced 5TTR elimination. The addition of sodium acetate decreased the removal efficiency of BTRs possibly due to catabolite repression. This is the first study investigating the toxicity and fate of BTRs in microalgae cultures.

Ozonation of valsartan: Structural elucidation and environmental properties of transformation products

The pharmaceutical valsartan is classified as a trace organic compound and is released into wastewater from human consumption. Trace organic compounds are not completely removed during conventional wastewater treatment. In order to prevent their release into the aquatic environment, advanced wastewater treatment technologies such as ozonation are currently implemented. Ozonation leads to the formation of transformation products (TPs), which then enter the receiving waters. In the present work, laboratory-scale ozonation experiments of valsartan solutions were performed. The resulting TPs were analyzed by HPLC-MS and searched for using a non-targeted approach. Of the 51 compounds detected, 27 have tentative structural suggestions based on MS/MS experiments. Ozonation of valsartan does not lead to the formation of TPs with higher toxicity towards A. fischeri than the parent compound. According to QSAR-based environmental behavior estimations, most TPs reveal lower lipophilicity, increased biodegradability as well as decreased acute and chronic toxicities concerning fish, daphnia and algae compared to their parent compound valsartan.

Occurrence of emerging pollutants in estuaries of the Basque Country: Analysis of sources and distribution, and assessment of the environmental risk

In this study, the spatial and temporal-distribution of 41-multiclass organic compounds were assessed in three estuaries of the Basque Country, from winter 2016 to winter 2017 by grab (active) sampling methods and an extra campaign combining both, grab and passive sampling methods. Wastewater treatment plant (WWTP) effluents were also evaluated to assess their impact on the estuaries. Moreover, the physicochemical features (phosphate and nitrate concentrations, pH, etc.) of each site were measured and included in the statistical analysis. Anti-inflammatory drugs (diclofenac and acetaminophen), hypertensive drugs (irbesartan and valsartan), a stimulant (caffeine), an artificial sweetener (acesulfame) and a corrosion inhibitor (2-hydroxybenzothiazole) were the most ubiquitous compounds. Due to the stratification of the waters in the estuary of Bilbao two independent sources were identified: WWTP and harbour activities. In the case of Gernika and Plentzia, both are estuaries with a high tidal dilution, and the main sources were localized in the effluents of the WWTPs. In addition to this, the use of POCIS provides an efficient way to monitor emerging pollutants over a relatively long sampling period. Finally, risk quotient (RQ) values of each contaminant were estimated from the maximum values determined at each estuary and WWTP effluent for acute and chronic effects. In the case of acute toxicity the highest RQ values (»1) were obtained for the angiotensin II receptor blockers (telmisartan, eprosartan, etc.), diuron and diclofenac. In the case of the chronic toxicity the highest RQ values (»1) were estimated for caffeine, diclofenac, bezafibrate and sulfadiazine.

Assessment of the origin and transport of four selected emerging micropollutants sucralose, Acesulfame-K, gemfibrozil, and iohexol in a karst spring during a multi-event spring response

The assessment of vulnerability in karst systems reveals to be extremely challenging since it varies significantly with time and highly depends on the identification of diffuse and concentrated infiltration from surface karst features. The origin, consumed loads, and transport mode of selected micropollutants (MPs) including two artificial sweeteners (ASWs) Sucralose (SUC) and Acesulfame-K (ACE-K), in addition to other less investigated pharmaceuticals such as the lipid regulator Gemfibrozil (GEM), and the contrast media Iohexol (IOX) were investigated in a karst system under dynamic conditions. A detailed analysis of selected spring responses' chemograph and hydrograph following a multi precipitation event shows that three of the tracked MPs, especially ACE-K, and to the exception of IOX, can be used as specific indicators for point source domestic wastewater in karst systems. They have revealed to be persistent, source specific, conservative, and highly correlated with in-situ parameters easily measurable at the spring (chloride and turbidity). Even if the selected MPs are found in the system during low flow periods, they are mostly transported to the spring through fast flow pathways from flushed wastewater with surface water or flood rainwater. The highest mass inflow of ACE-K, IOX and GEM originated from a sinking stream, while SUC infiltrated exclusively through fast infiltration points (dolines). Their breakthrough curves coincide with the arrival of new waters and turbidity peaks. Unlike IOX, the mass fluxes of ASWs, and GEM to a lesser extent, can be linearly correlated with chloride mass fluxes and turbidity flux. Moreover, the variance of the normalized breakthrough curves of the MPs with respect to a mean transit time, increases in that order IOX<GEM<Turbidity<SUC<ACE-K indicating a higher restitution time for ACE-K with respect to other spring signals.

Does the presence of caffeine in the marine environment represent an environmental risk? A regional and global study

Caffeine is an emerging contaminant considered to be an indicator of human contamination that has been widely detected in various aquatic systems, especially in continental waters. Nevertheless, the extent of its possible environmental impact is yet to be determined. This study determined the presence of caffeine, and evaluated the environmental hazard posed by this substance, in the "Rías Gallegas", a series of costal inlets in north-west Spain which are of great ecological value and in which fishing and bivalve farming, are a significant source of income. Caffeine was found to be present at concentrations higher than the limit of quantification (LOQ=3.07ngL^-1) in 15 of the 23 samples analysed, with the highest seawater concentration being 857ngL^-1 (the highest measured in seawater in Spain). Six out of 22 seawater samples resulted in a hazard quotient (HQ) from chronic exposure higher than 1 with the highest being 17.14, indicating a high probability of adverse effects in the aquatic environment. Environmental Exposure Distributions (EEDs) generated from a literature review of caffeine levels reported previously in four out of the five continents, showed that 28% of all seawater samples, and 69% of all estuary water samples where caffeine has ever been measured resulted in HQ>1 for chronic exposure. Further studies into the potential adverse effects that may arise from exposure to caffeine in aquatic systems are still required. Indeed, the need to gain a more in-depth understanding of the long-term ecotoxicological effects of caffeine is essential to ensure the quality of our health and environment.

Removal mechanisms of benzotriazoles in duckweed Lemna minor wastewater treatment systems

The fate of five benzotriazoles (1H-benzotriazole, BTR; 4-methyl-1H-benzotriazole, 4TTR; 5-methyl-1H-benzotriazole, 5TTR; xylytriazole, XTR and 5-chlorobenzotriazole, CBTR) was studied in batch and continuous-flow Lemna minor systems and the role of different mechanisms on their removal was evaluated. Single and joint toxicity experiments were initially conducted using the Organization for Economic Co-operation and Development (OECD) protocol 221 and no inhibition on specific growth rate of Lemna minor was observed for concentrations up to 200μgL^-1. All tested substances were significantly removed in batch experiments with Lemna minor. Excepting 4TTR, full elimination of CBTR, XTR, 5TTR and BTR was observed up to the end of these experiments (36d), while the half-life values ranged between 1.6±0.3d (CBTR) and 25±3.6d (4-TTR). Calculation of kinetic constants for hydrolysis, photodegradation, and plant uptake revealed that for all BTRs the kinetic constants of plant uptake were by far higher comparing to those of the other mechanisms, reaching 0.394±0.161d^-1 for CBTR. The operation of a continuous-flow Lemna minor system consisted of three mini ponds and a total hydraulic residence time of 8.3d showed sufficient removal for most target substances, ranging between 26% (4TTR) and 72% (CBTR). Application of a model for describing micropollutants removal in the examined system showed that plant uptake was the major mechanism governing BTRs removal in Lemna minor systems.

Anthropogenic contamination of Portuguese coastal waters during the bathing season: Assessment using caffeine as a chemical marker

Bathing water quality standards are based on international standards and legislations. However, in Europe, only the microbiological parameters are to be accomplished. Recent research has focused on chemical indicators that can determine human fecal contaminants in water. Therefore, the suitability of caffeine as a chemical marker of seawater pollution in the north Portuguese coastal area in the Atlantic Ocean during the bathing season was assessed in this study. The quality of water from the coasts of five cities was monitored. 101 seawater samples were collected from 14 beaches, and their water quality was classified as sufficient, good, and excellent. Caffeine was detected in all samples in concentration range of 18 to 525ng/L. The highest average concentration of caffeine was found in seawater samples collected in July from beaches classified as having sufficient water quality, which were located in cities with high population density and high tourist affluence.

Advancing Sequential Managed Aquifer Recharge Technology (SMART) Using Different Intermediate Oxidation Processes

Managed aquifer recharge (MAR) systems are an efficient barrier for many contaminants. The biotransformation of trace organic chemicals (TOrCs) strongly depends on the redox conditions as well as on the dissolved organic carbon availability. Oxic and oligotrophic conditions are favored for enhanced TOrCs removal which is obtained by combining two filtration systems with an intermediate aeration step. In this study, four parallel laboratory-scale soil column experiments using different intermittent aeration techniques were selected to further optimize TOrCs transformation during MAR: no aeration, aeration with air, pure oxygen and ozone. Rapid oxygen consumption, nitrate reduction and dissolution of manganese confirmed anoxic conditions within the first filtration step, mimicking traditional bank filtration. Aeration with air led to suboxic conditions, whereas oxidation by pure oxygen and ozone led to fully oxic conditions throughout the second system. The sequential system resulted in an equal or better transformation of most TOrCs compared to the single step bank filtration system. Despite the fast oxygen consumption, acesulfame, iopromide, iomeprol and valsartan were degraded within the first infiltration step. The compounds benzotriazole, diclofenac, 4-Formylaminoantipyrine, gabapentin, metoprolol, valsartan acid and venlafaxine revealed a significantly enhanced removal in the systems with intermittent oxidation compared to the conventional treatment without aeration. Further improvement of benzotriazole and gabapentin removal by using pure oxygen confirmed potential oxygen limitation in the second column after aeration with air. Ozonation resulted in an enhanced removal of persistent compounds (i.e., carbamazepine, candesartan, olmesartan) and further increased the attenuation of gabapentin, methylbenzotriazole, benzotriazole, and venlafaxine. Diatrizoic acid revealed little degradation in an ozone–MAR hybrid system.

Efficient electrochemical remediation of microcystin-LR in tap water using designer TiO2@carbon electrodes

Microcystin-leucine arginine (MC-LR) is the most abundant and toxic secondary metabolite produced by freshwater cyanobacteria. This toxin has a high potential hazard health due to potential interactions with liver, kidney and the nervous system. The aim of this work was the design of a simple and environmentally friendly electrochemical system based on highly efficient nanostructured electrodes for the removal of MC-LR in tap water. Titania nanoparticles were deposited on carbon (graphite) under a simple and efficient microwave assisted approach for the design of the electrode, further utilized in the electrochemical remediation assays. Parameters including the applied voltage, time of removal and pH (natural tap water or alkaline condition) were investigated in the process, with results pointing to a high removal efficiency for MC-LR (60% in tap water and 90% in alkaline media experiments, under optimized conditions).