EU Watch List Research Articles

Field-deployable pencil lead-based electrochemical cell for the determination of the emerging contaminant and antidepressant drug venlafaxine in wastewater

Screening and quantification of emerging contaminants in water is of enormous relevance due to its scarcity and harmful effects on aquatic life and human health. We present a simple and cost-effective electrochemical cell for determination of the antidepressant venlafaxine, an emerging contaminant included in the EU Watch list 2022. The cell consists of pencil leads used as electrodes and a microcentrifuge tube. Modification of the working electrode with carbon nanomaterials improved the signal. Cell-related (e.g., type of pencil leads or electroactive area) as well as experimental (e.g., pH, accumulation potential and time, and scan rate) parameters were thoroughly optimized. The adsorptive nature of venlafaxine process allowed the use of an adsorptive stripping square wave voltammetry methodology to increase the sensitivity. Under optimized variables, a linear range from 0.8 to 10 μmol L−1 with a correlation coefficient of 0.996, a sensitivity of 1.48 μmol L−1, a LOD of 0.4 μmol L−1 and a RSD of 2.4 % were achieved. Selectivity was also studied, especially with respect to the main metabolite, o-desmethylvenlafaxine. The methodology distinguishes its signal from that of the main compound, allowing its determination. A similar linear range was obtained for the metabolite, with a LOD of 0.6 μmol L−1. The platform developed was applied for venlafaxine quantification in spiked wastewaters from the Febros plant in Portugal, obtaining satisfactory recoveries. Furthermore, the versatility of pencil leads made it possible to combine them with modified paper for sampling and buffering in order to decentralize the determination, showing promising results.

Precious metal-based Catalytic Membrane Reactors for continuous flow catalytic hydrodechlorination

This work is focused on the development of Catalytic Membrane Reactors (CMRs) comprising precious metals as active phases for a comparative assessment in continuous-flow catalytic hydrodechlorination (HDC). HDC has proved its remarkable potential for application as polishing step in drinking water treatment plants, but studies operating in continuous mode are scarce. Preliminary experiments were conducted in batch operation using Pd/Al2O3, Rh/Al2O3 and Pt/Al2O3 powder catalysts to evaluate the influence of the active phase on the removal of prochloraz (PCZ) (100 μg L−1), a pesticide listed on the EU Watch List (2022/1307), by HDC. PCZ removal was successfully described by a pseudo-first order kinetic equation and reaction pathways were proposed. Among the catalysts tested, Pt-based suffered a significant deactivation, not warranting the elimination of this micropollutant. Pd/Al2O3 exhibited a faster removal of PCZ than Rh/Al2O3, while this catalyst resulted in further hydrogenation of the non-chlorinated reaction product. Accordingly, different CMRs were developed by decorating cylindrical inert porous alumina membranes with Pd, Rh, and a combination of Pd-Rh as active phases (∼1% wt.). All CMRs showed a remarkable stability along 100 h on stream, being Pd/CMR be the most effective, with a pseudo-first order rate constant value of 0.062 min−1. An assessment of the impact of operating conditions (aqueous flow rate, PCZ initial concentration, temperature and H2 flow rate) was conducted using the Pd/CMR, which notably remained stable for 450 h on stream. The versatility of the system was finally demonstrated in tap water, achieving a steady-state PCZ conversion close to 95 %.

Determination of pollutants, antibiotics, and drugs in surface water in Italy as required by the third EU Water Framework Directive Watch List: method development, validation, and assessment.

In this paper, we report a study concerning the quantification of new emerging pollutants in water as a request from the third European Watch List mechanism. The EU Watch List compound was investigated by an internal method that was validated in terms of detection limits, linearities, accuracy, and precision in accordance with quality assurance criteria, and it was used to monitor several rivers from 11 Italian regions. The methodology developed was satisfactorily validated from 5 to 500 ng L-1 for the emerging pollutants studied, and it was applied to different river waters sampled in Italy, revealing the presence of drugs and antibiotics. Rivers were monitored for 2 years by two different campaigns conducted in 2021 and 2022. A total of 19 emerging pollutants were investigated on 45 samples. The most detected analytes were O-desmethylvenlafaxine and venlafaxine. About azole compounds, sulfamethoxazole, fluconazole, and Miconazole were found. About antibiotics, ciprofloxacin and amoxicillin were found in three and one samples, respectively. Moreover, statistical analyses have found a significant correlation between O-desmethylvenlafaxine with venlafaxine, sulfamethoxazole with venlafaxine, and fluconazole with venlafaxine.

Comprehensive two-dimensional liquid chromatography with high resolution mass spectrometry to investigate the photoelectrochemical degradation of environmentally relevant pharmaceuticals and their degradation products in water

The widespread presence of organic micropollutants in the environment reflects the inability of traditional wastewater treatment plants to remove them. In this context, advanced oxidation processes (AOPs) have emerged as promising quaternary wastewater treatment technologies since they efficiently degrade recalcitrant components by generating highly reactive free radicals. Nonetheless, the chemical characterization of potentially harmful byproducts is essential to avoid the contamination of natural water bodies with hazardous substances. Given the complexity of wastewater matrices, the implementation of comprehensive analytical methodologies is required. In this work, the simultaneous photoelectrochemical degradation of seven environmentally relevant pharmaceuticals and one metabolite from the EU Watch List 2020/1161 was examined in ultrapure water and simulated wastewater, achieving excellent removal efficiencies (overall >95%) after 180 min treatment. The reactor unit was linked to an online LC sample manager, allowing for automated sampling every 15 min and near real-time process monitoring. Online comprehensive two-dimensional liquid chromatography (LC × LC) coupled with high resolution mass spectrometry (HRMS) was subsequently used to tentatively identify degradation products after photoelectrochemical degradation. Two reversed-phase liquid chromatography (RPLC) columns were used: an SB-C18 column operated with 5 mM ammonium formate at pH 5.8 (1A) and methanol (1B) as the mobile phases in the first dimension and an SB-Aq column using acidified water at pH 3.1 (2A) and acetonitrile (2B) as the mobile phases in the second dimension. This resulted in a five-fold increase in peak capacity compared to one-dimensional LC while maintaining the same total analysis time of 50 min. The LC x LC method allowed the tentative identification of 12 venlafaxine, 7 trimethoprim and 10 ciprofloxacin intermediates. Subsequent toxicity predictions suggested that some of these byproducts were potentially harmful.This study presents an effective hybrid technology for the simultaneous removal of pharmaceuticals from contaminated wastewater matrices and demonstrates how multidimensional liquid chromatography techniques can be applied to better understand the degradation mechanisms after the treatment of micropollutants with AOPs.

Occurrence and environmental risk assessment of 4 estrogenic compounds in surface water in Belgiumin the frame of the EU Watch List.

The presence of natural estrogens estrone (E1), 17β-estradiol (E2), estriol (E3) and synthetic estrogen 17α-ethynylestradiol (EE2) in the aquatic environment has raised concerns because of their high potency as endocrine disrupting chemicals. The European Commission (EC) established a Watch List of contaminants of emerging concerns including E1, E2 and EE2. The proposed environmental quality standards (EQSs) are 3.6, 0.4, 0.035ng/L, for E1, E2, EE2, respectively. A thorough evaluation of analytical procedures developed by several studies aiming to perform sampling campaigns in different European countries highlighted that the required limits of quantification in surface water were not reached, especially for EE2 and to a lesser extent for E2. Moreover, data regarding the occurrence of these contaminants in Belgian surface water are very limited. A sampling campaign was therefore performed on a wide range of rivers in Belgium (accounting for a total of 63 samples). The detection frequencies of E1, E2, E3 and EE2 were 100, 98, 86 and 48%, respectively. E1 showed the highest mean concentration (= 4.433ng/L). In contrast, the mean concentration of EE2 was 0.042ng/L. The risk quotients (RQs) were calculated based on the respective EQS of each analyte. The frequency of exceedance of the EQS was 31.7% for E1, EE2, while it increased to 44.4% for E2. The extent of exceedance of the EQS, represented by the 95th percentile of the RQ dataset, was higher than 1 for E1, E2, EE2. The use of a confusion matrix was investigated to try to predict the risk posed by E2, EE2, based on the concentration of E1.

Proposal for priority emerging pollutants in the Nakdong river, Korea: Application of EU watch list mechanisms

The Nakdong River, the longest in Korea, has received numerous pollutants from heavily industrialized and densely populated areas while being used as a drinking water source. A number of research have reported occurrences of emerging pollutants (EPs) in the river. The results requested efficient monitoring and systematic management strategies such as EU watch list under Water Framework Directive. The aim of this study is to propose a watch list through preliminary monitoring of the river and risk-based prioritization approach. As candidates for monitoring target, 632 substances were selected based on literature and database searches. Among them, 175 substances were subjected to target screening method whereas 457 were evaluated via suspect screening. A risk-based prioritization was applied to substances quantified through target screening based on concentrations, and a scoring-based prioritization was applied to substances tentatively identified through suspect screening. Sampling campaigns (n = 12) were conducted from October 2020 to September 2021, at 8 sampling sites along the river. As a result, 130 target substances were quantified above the LOQ. Among the 21 substances whose priority score was assigned through risk-based prioritization, telmisartan and iprobenfos were identified with very high environmental risk while candesartan, TBEP, imidacloprid, azithromycin and clotrimazole were classified with high or intermediate risk. As result of the scoring system for 39 tentatively identified substances, 6 substances (benzophenone, caprolactam, metolachlor oxanilic acid, heptaethylene glycol, octaethylene glycol and pentaethylene glycol), which were then confirmed with reference standards, showed a potential environmental risk. Those substances prioritized through target and suspect screening followed by scoring systems can be a subset for the watch list and potential targets for nationwide water quality monitoring program in the future.

A One-Health environmental risk assessment of contaminants of emerging concern in London’s waterways throughout the SARS-CoV-2 pandemic

The SARS-CoV-2 pandemic had huge impacts on global urban populations, activity and health, yet little is known about attendant consequences for urban river ecosystems. We detected significant changes in occurrence and risks from contaminants of emerging concern (CECs) in waterways across Greater London (UK) during the pandemic. We were able to rapidly identify and monitor large numbers of CECs in n = 390 samples across 2019–2021 using novel direct-injection liquid chromatography-mass spectrometry methods for scalable targeted analysis, suspect screening and prioritisation of CEC risks. A total of 10,029 measured environmental concentrations (MECs) were obtained for 66 unique CECs. Pharmaceutical MECs decreased during lockdown in 2020 in the R. Thames (p ≤ 0.001), but then increased significantly in 2021 (p ≤ 0.01). For the tributary rivers, the R. Lee, Beverley Brook, R. Wandle and R. Hogsmill were the most impacted, primarily via wastewater treatment plant effluent and combined sewer overflows. In the R. Hogsmill in particular, pharmaceutical MEC trends were generally correlated with NHS prescription statistics, likely reflecting limited wastewater dilution. Suspect screening of ∼ 1,200 compounds tentatively identified 25 additional CECs at the five most impacted sites, including metabolites such as O-desmethylvenlafaxine, an EU Watch List compound. Lastly, risk quotients (RQs) ≥ 0.1 were calculated for 21 compounds across the whole Greater London freshwater catchment, of which seven were of medium risk (RQ ≥ 1.0) and three were in the high-risk category (RQ ≥ 10), including imidacloprid (RQ = 19.6), azithromycin (15.7) and diclofenac (10.5). This is the largest spatiotemporal dataset of its kind for any major capital city globally and the first for Greater London, representing ∼ 16 % of the population of England, and delivering a foundational One-Health case study in the third largest city in Europe across a global pandemic.

Transformation products of contaminants of emerging concern in water by UV-based processes

Abstract Contaminants of emerging concern (CECs) and their respective transformation products (TPs) formed following photodegradation pose considerable threats to the environment and our health. The formation of TPs during UV-LED-based degradation of three target pollutants in the EU Watch List of CECs was accessed by LC-MS-Orbitrap, and their reaction pathways were elucidated. The influence of different matrices and treatments of choice on TP formation was investigated. Results showed that matrix changes did not produce different reaction pathways during UV-A photocatalysis, although plots of TP peak areas vs. time were different for each case. A new TP was found for the antidepressant venlafaxine, (1-[2-(dimethylnitroryl)-1-(4-methoxyphenyl)ethyl]cyclohexanol. When comparing UV-A photocatalysis with UV-C photolysis, dissimilar pathways were observed due to the distinct reaction mechanisms of each process, since photocatalysis, unlike photolysis, relies on radical-based reaction routes. Different levels of confidence were obtained for each TP depending on the availability of MS2 data in the literature and of standards for comparison. All the found TPs had similar molecular masses in comparison to their respective parent compounds. Most of the TPs remained in the effluent after 6 hours of photodegradation, which highlights the importance of their control, close-monitoring, and further toxicity assessments.

Mixtures of sediment chemical contaminants at freshwater sampling sites across Europe with different contaminant burdens

Extended chemical analyses of fluvial sediments were undertaken to establish the key pollutant pressures and mixtures present across nine European Union inland waterways. A wide range of chemical components and physical parameters were investigated including substances from the EU Priority List and Watch List. The data set was examined for key indicator compounds, however it was found that a wide range of pollution pressures were present in the different sediments including organic hydrocarbons, metal(loid)s, nutrients, polycyclic aromatic hydrocarbon (PAH), polychlorinated biphenyl (PCB) compounds, perfluoroalkyl and polyfluoroalkyl substances and pesticides, some of which exceeded regulatory guidance at different sampling points. The presence of such a wide range of compounds underpins the complex chemical composition of sediments that have acted as sinks for many decades absorbing contaminants from urban, industrial and agricultural sources. This dataset has been used to describe average overall toxicity of the sediments sampled, a calculation which was based on key components identified by Principal Component Analysis (PCA) and for those that had existing freshwater sediment regulatory values. A total of 33 components were used including PCBs, PAHs, metal(iod)s and pesticides. This analysis reflected the contamination of each site, with most indicating some level of toxicity during the sampling period. Watch List chemicals triclosan (TCS) and diclofenac (DIC) were also investigated; levels were relatively low, typically 10–100's ng L−1, however they were present at all sampling sites. The dataset is available as a resource for future chemical, and toxicological, sediment analysis comparisons.

Photoinduced degradation of three azole compounds from 3rd EU watchlist monitored by high-resolution higher-order mass spectrometry – part II A critical in silico ecotoxicity assessment and application of ecotoxicity equivalents

Photoinduced degradation of three azole compounds from 3rd EU watchlist monitored by high-resolution higher-order mass spectrometry – part II A critical in silico ecotoxicity assessment and application of ecotoxicity equivalents

Insights on the removal of the azole pesticides included in the EU Watch List by Catalytic Wet Peroxide Oxidation

Insights on the removal of the azole pesticides included in the EU Watch List by Catalytic Wet Peroxide Oxidation

Photoinduced degradation of three azole compounds from 3rd EU watchlist monitored by high-resolution higher-order mass spectrometry – Part I: A mechanistic study

• Nine new degradation and transformation products of azoles were identified. • HR-MS and HR-MS/MS revealed structures from hydroxyl radical and photo-absorption induced reactions. • Direct and indirect mechanism of degradation could be discerned. Pesticides are found in water bodies worldwide. Among them, there are azoles which are used as fungizides. Hence, tebuconazole, imazalil and penconazole have been included into the 3 rd EU watchlist to survey their presence in water bodies. Pesticides mostly enter the aquatic environment through leaching from agriculture, fruit washing or via conventional sewage water treatment plants, which are often not able to completely eliminate these pesticides. Advanced purification processes have become intensely researched. The advanced oxidation process, UVC and UVA irradiation and addition of the radical scavenger tert -butanol, was investigated using high-resolution higher-order mass spectrometry to gain kinetic and mechanistic insight. Structure elucidation of degradation and transformation products revealed fragments and also multiple hydroxylated intermediates depending on the UV source and the presence of radical scavenger. Hydroxyl radical-induced indirect degradation was found to dominate a direct photoreaction pathway induced by photo-absorption by the initial substance. The indirect mechanism did not occur during UVA irradiation due to the lack of hydroxyl radicals. The radical scavenger decelerated or prevented degradation. In total, nine new degradation and transformation products were identified. Mass spectrometry revealed product structures of the pesticides substituted with one or more hydroxyl radical groups, cyclization and substitution of chlorine by a hydroxyl radical.

Nanostructured Metal Oxide Sensors for Antibiotic Monitoring in Mineral and River Water.

Antibiotics represent a class of pharmaceuticals used to treat bacterial infections. However, the ever-growing use of antibiotics in agriculture and human and veterinary medicine has led to great concern regarding the outbreak of microbe strains resistant to antimicrobial drugs. Azithromycin, clarithromycin, and erythromycin are macrolides, a group of molecules with a broad spectrum of antibiotic properties, included in the second EU watchlist of emerging pollutants which emphasizes the importance of understanding their occurrence, fate, and monitoring in aquatic environments. Thus, the aim of this study was to develop sensors based on nanostructured thin films deposited on ceramic substrates with gold interdigitated electrodes, to detect azithromycin, clarithromycin, and erythromycin in water matrices (mineral and river water). Impedance spectroscopy was employed as the transducing method for the devices’ electrical signal, producing multivariate datasets which were subsequently analyzed by principal component analysis (PCA). The PCA plots for mineral water demonstrated that ZnO- and TiO2-based sensors produced by DC magnetron sputtering either with 50% or 100% O2 in the sputtering chamber, were able to detect the three macrolides in concentrations between 10−15 M and 10−5 M. In river water, the PCA discrimination presented patterns and trends, between non-doped and doped, and sorting the different concentrations of azithromycin, clarithromycin, and erythromycin. Considering both matrices, by applying the e-tongue concept, sensitivity values of 4.8 ± 0.3, 4.6 ± 0.3, and 4.5 ± 0.3 per decade to azithromycin, clarithromycin, and erythromycin concentration, respectively, were achieved. In all cases, a resolution of 1 × 10−16 M was found near the 10−15 M concentration, the lowest antibiotic concentration measured.

A miniaturized passive sampling-based workflow for monitoring chemicals of emerging concern in water

The miniaturization of a full workflow for identification and monitoring of contaminants of emerging concern (CECs) is presented. Firstly, successful development of a low-cost small 3D-printed passive sampler device (3D-PSD), based on a two-piece methacrylate housing that held up to five separate 9 mm disk sorbents, is discussed. Secondly, a highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method reduced the need for large scale in-laboratory apparatus, solvent, reagents and reference material quantities for in-laboratory passive sampler device (PSD) calibration and extraction. Using hydrophilic-lipophilic balanced sorbents, sampling rates (Rs) were determined after a low 50 ng L−1 exposure over seven days for 39 pesticides, pharmaceuticals, drug metabolites and illicit drugs over the range 0.3 to 12.3 mL day−1. The high sensitivity LC-MS/MS method enabled rapid analysis of river water using only 10 μL of directly injected sample filtrate to measure occurrence of 164 CECs and sources along 19 sites on the River Wandle, (London, UK). The new 3D-PSD was then field-tested over seven days at the site with the highest number and concentration of CECs, which was down-river from a wastewater treatment plant. Almost double the number of CECs were identified in 3D-PSD extracts across sites in comparison to water samples (80 versus 42 CECs, respectively). Time-weighted average CEC concentrations ranged from 8.2 to 845 ng L−1, which were generally comparable to measured concentrations in grab samples. Lastly, high resolution mass spectrometry-based suspect screening of 3D-PSD extracts enabled 113 additional compounds to be tentatively identified via library matching, many of which are currently or are under consideration for the EU Watch List. This miniaturized workflow represents a new, cost-effective, and more practically efficient means to perform passive sampling chemical monitoring at a large scale. SynopsisMiniaturized, low cost, multi-disk passive samplers enabled more efficient multi-residue chemical contaminant characterization, potentially for large-scale monitoring programs.

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.

Enhanced removal of neonicotinoid pesticides present in the Decision 2018/840/EU by new sewage sludge-based carbon materials

Due to the increasingly strict legislation about the disposal of sewage sludge, it is necessary to find sustainable solutions to manage this waste at low-cost conditions. In addition, priority contaminants are now attracting much attention since they are usually detected in WWTP effluents. In this work, five sludge have been used as precursors for the synthesis of activated carbons subsequently tested in the removal by adsorption of three neonicotinoid pesticides listed in the EU Watch List: acetamiprid (ACT), thiamethoxam (THM), and imidacloprid (IMD). Generally, the activated carbons were prepared by chemical activation using ZnCl2 as an activating agent and then the resulting materials were pyrolyzed at 800 °C for 2 h. The synthesized activated carbons showed different textural properties; thus, the best adsorption results were found for AC-Industrial activated carbon, obtained from an industrial origin sewage sludge, with high equilibrium adsorption capacities (qe = 104.2, 137.0, and 119.9 mg g−1), for ACT, THM, and IMD, respectively. Furthermore, it was elucidated that the use of CO2 in the synthesis generated an opening, followed by widening, of the narrowest microporosity, increasing the specific surface area of the carbon materials. The kinetic and isotherm adsorption experimental data were obtained for each of the pesticide-activated carbon systems; thus, the kinetic curves were well-fitted to the pseudo-second-order kinetic model, as well as, Freundlich and Guggenheim-Anderson-de Boer (GAB) empirical models were used for the fitting of the equilibrium adsorption isotherms, finding that GAB model best fitted the experimental data. Additionally, the regeneration of the activated carbons using methanol as a regenerating agent and the single and simultaneous adsorption of a hospital wastewater effluent, fortified with the three studied pesticides have been explored.

Extraction of antibiotics identified in the EU Watch List 2020 from hospital wastewater using hydrophobic eutectic solvents and terpenoids

The increasing consumption of pharmaceuticals, along with the ineffectiveness of conventional wastewater treatment, has resulted in an increased presence of these pollutants in both drinking water supplies and aquatic environments. The potential adverse health effects and environmental impact of these chemicals are drawing the attention of several bodies around the world. For instance, some antibiotics such as ciprofloxacin, trimethoprim, and sulfamethoxazole have been included in the most recent European Surface Water Watch List under the EU Water Framework Directive (Decision 2020/1161). The present work proposes the use of terpenoids and eutectic solvents, as effective and green solvents with low toxicity, for multicomponent liquid–liquid extraction of ciprofloxacin, trimethoprim, and sulfamethoxazole from ultrapure water and hospital wastewater. The COSMO-RS method was used for a predictive initial solvent screening. Thymol, carvacrol, eutectic solvents (thymol + fatty acids), and conventional solvents (methyl isobutyl ketone and ethyl acetate) were selected to be used in the experiments. The influence of the volumetric S/F ratio, aqueous matrix, and pH was analysed. Conventional solvents show significantly lower overall extraction yields than those observed for eutectic solvents and terpenoids at any pH and matrix. Carvacrol presented the most favourable conditions, reaching overall extraction yields above 98.0% (98.9% for trimethoprim, 99.5% for ciprofloxacin, and 97.0% for sulfamethoxazole) with hospital wastewater at pH 5.0 and S/F ratio of 1.00. Carvacrol showed a feasible operation in a continuous extraction column at room temperature, providing effective reuse and regeneration processes in this study.

Performance of TiO2/UV-LED-Based Processes for Degradation of Pharmaceuticals: Effect of Matrix Composition and Process Variables.

Ultra-violet light-emitting diode (UV-LED)-based processes for water treatment have shown the potential to surpass the hurdles that prevent the adoption of photocatalysis at a large scale due to UV-LEDs’ unique features and design flexibility. In this work, the degradation of five EU Watch List 2020/1161 pharmaceutical compounds was comprehensively investigated. Initially, the UV-A and UV-C photolytic and photocatalytic degradation of individual compounds and their mixtures were explored. A design of experiments (DoE) approach was used to quantify the effects of numerous variables on the compounds’ degradation rate constant, total organic carbon abatement, and toxicity. The reaction mechanisms of UV-A photocatalysis were investigated by adding different radical scavengers to the mix. The influence of the initial pH was tested and a second DoE helped evaluate the impact of matrix constituents on degradation rates during UV-A photocatalysis. The results showed that each compound had widely different responses to each treatment/scenario, meaning that the optimized design will depend on matrix composition, target pollutant reactivity, and required effluent standards. Each situation should be analyzed individually with care. The levels of the electrical energy per order are still unfeasible for practical applications, but LEDs of lower wavelengths (UV-C) are now approaching UV-A performance levels.

Photoinduced Degradation Of Three Azole Compounds from 3rd Eu Watchlist Monitored by High-Resolution Higher-Order Mass Spectrometry – Part I: A Mechanistic Study

Photoinduced Degradation Of Three Azole Compounds from 3rd Eu Watchlist Monitored by High-Resolution Higher-Order Mass Spectrometry – Part I: A Mechanistic Study

Photoinduced Degradation of Three Azole Compounds from 3rd EU Watchlist Monitored by High-Resolution Higher-Order Mass Spectrometry – Part I: A Mechanistic Study

Photoinduced Degradation of Three Azole Compounds from 3rd EU Watchlist Monitored by High-Resolution Higher-Order Mass Spectrometry – Part I: A Mechanistic Study