Occurrence, partition and removal of pharmaceuticals in sewage water and sludge during wastewater treatment

Season and side-chain length affect the occurrences and behaviors of phthalic acid esters in wastewater treatment plants

Emerging pollutants (EPs) are prevalent in aquatic environments globally. Researchers strive to understand their occurrence and behavior prior to their release into the environment. In this study, we examined five wastewater treatment plants (WWTPs), collected 50 wastewater samples and 10 sludge samples. We explored the sources and destinations of phthalic acid esters (PAEs) within these WWTPs using mass balance equations. Wastewater treatment diminished the frequency and concentration of PAEs, and decreased the fraction of short-chain PAEs. We confirmed the increased concentration of PAEs post-primary treatment and modified the mass balance equation. Calculations suggest that weaker "the mix" in winter than in summer and stronger sedimentation in winter than in summer resulted in high efficiency of PAEs removal by winter wastewater treatment. The mass flux of biodegradation was influenced by the combination of biodegradation efficiency and the strength of the particular type of PAEs collected, with no seasonal differences. Mass fluxes for sludge sedimentation were mainly influenced by season and were higher in winter than in summer. This study enhances our understanding of emerging pollutants in manual treatment facilities and offers insights for optimizing wastewater treatment methods for water professionals.

Wastewater reuse and pharmaceutical pollution in agriculture: Uptake, transport, accumulation and metabolism of pharmaceutical pollutants within plants

The presence of pharmaceutical pollutants in water sources has become a growing concern due to its potential impacts on human health and other organisms. The physicochemical properties of pharmaceuticals based on their intended therapeutical application, which include antibiotics, hormones, analgesics, and antidepressants, is quite diverse. Their presence in wastewater, sewerage water, surface water, ground water and even in drinking water is reported by many researchers throughout the world. Human exposure to these pollutants through drinking water or consumption of aquatic and terrestrial organisms has raised concerns about potential adverse effects, such as endocrine disruption, antibiotic resistance, and developmental abnormalities. Once in the environment, they can persist, undergo transformation, or degrade, leading to a complex mixture of contaminants. Application of treated wastewater, compost, manures or biosolids in agricultural fields introduce pharmaceutical pollutants in the environment. As pharmaceuticals are diverse in nature, significant differences are observed during their uptake and accumulation in plants. While there have been extensive studies on aquatic ecosystems, the effect on agricultural land is more disparate. As of now, there are few reports available on the potential of plant uptake and transportation of pharmaceuticals within and between plant organs. This review summarizes the occurrence of pharmaceuticals in aquatic water bodies at a range of concentrations and their uptake, accumulation, and transport within plant tissues. Research gaps on pharmaceutical pollutants' specific effect on plant growth and future research scopes are highlighted. The factors affecting uptake of pharmaceuticals including hydrophobicity, ionization, physicochemical properties (pKa, logKow, pH, Henry's law constant) are discussed. Finally, metabolism of pharmaceuticals within plant cells through metabolism phase enzymes and plant responses to pharmaceuticals are reviewed.

Global performance and trends of research on emerging contaminants in sewage sludge: A Bibliometric Analysis from 1990 to 2023

The pervasive occurrence of emerging contaminants (ECs) in sewage sludge (SWS) poses significant safety challenges concerning the processing, disposal, and secure application, ultimately jeopardizing both human health and the ecological environment. To comprehensively comprehend the evolutionary trajectories, present state, and research advancements in the field of ECs in SWS, a systematic was conducted, scrutinizing the annual publication quantity, disciplinary distribution, core authors, involved nations/regions, pertinent keywords, and citation status of 2082 research publications related to ECs in SWS from 1990 to 2023. The results indicate a substantial upward trajectory in the research literature pertaining to ECs in SWS. The study of ECs in SWS encompasses 78 disciplines, including Environmental Sciences, Environmental Engineering, and Water Resources. China, Spain, and the USA ranked among the top three countries in terms of both total publications and citation frequency. The majority of publications were published in reputable high-impact journals such as Science of the Total Environment, Chemosphere, and Bioresource Technology. Based on high-frequency keywords, co-occurrence networks of keywords, and keywords burst analysis, it is found that the occurrence and environment behavior of ECs in SWS (ARGs, microplastics, PPCPs, and POPs), the detection and analytical methods, the impact on SWS treatment and disposal processes, and the accumulation and ecological risks in plants and soil during SWS land utilization, are the main research directions and hot topics in this field. In the future, the study of the impact of SWS treatment technologies on ECs removal is expected to receive increased research attention.

The Importance of Including Variable Exposure Concentrations When Assessing Toxicity of Sediment-Associated Pharmaceuticals to an Amphipod

Pharmaceuticals have been classified as an environmental concern due to their increasing consumption globally and potential environmental impact. We examined the toxicity of sediment-associated diclofenac and citalopram administered as both single compounds and in a mixture to the sediment-living amphipod Corophium volutator. This laboratory-based study addressed the following research questions: (1) What is the toxicity of sediment-associated diclofenac and citalopram to C. volutator? (2) Can the mixture effect be described with either of the two mixture models: concentration addition (CA) or independent action (IA)? (3) What is the importance of the choice of (i) exposure measure (start concentration, time-weighted average [TWA], full exposure profile) and (ii) effect model (concentration-response vs. the toxicokinetic-toxicodynamic model general unified threshold model for survival in its reduced form [GUTS-RED]) for the derived effect concentration values? Diclofenac was more toxic than citalopram to C. volutator as a single compound (10-day exposure). Diclofenac exposure to C. volutator provided median lethal concentrations (LC50s) within the same range (11 µg g-1 dry wt sediment) using concentration-response based on TWA and both GUTS-RED models. However, concentration-response based on measured start concentrations provided an approximately 90% higher LC50 (21.6 ± 2.0 µg g-1 dry wt sediment). For citalopram, concentration-response parameters were similar regardless of model or concentration used (LC50 85-97 µg g-1 dry wt sediment), however, GUTS-RED with the assumption of individual tolerance resulted in a lower LC50 (64.9 [55.3-74.8] µg g-1 dry wt sediment). The mixture of diclofenac and citalopram followed the CA quite closely, whereas the result was synergistic when using the IA prediction. In summary, concentration-response based on TWA and GUTS-RED provided similar and reasonably good fits compared to the data set. The implications are that GUTS-RED will provide a more flexible model, which, in principle, can extend beyond the experimental period and make predictions based on variable exposure profiles (toxicity at different time frames and at different variable exposure scenarios) compared to concentration-response, which provides contaminant toxicity at one point in time. Environ Toxicol Chem 2024;43:1767-1777. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Occurrence, removal and risk assessment of chemicals of emerging concern in selected rivers and wastewater treatment plants in western Kenya

Water resources play a crucial role in sustaining life on earth yet chemicals of emerging concern (CECs) arising from extensive human applications are an increasing threat towards their existence. In this study, we examined the occurrence, removal and potential risk of CECs found in rivers and wastewater treatment plants (WWTPs) in western Kenya. Samples were prepared by solid-phase extraction and analysed using high performance liquid chromatography-mass spectrometry with a target list of 785 compounds. Out of these, 333 and 352 (influent 322, effluent 265) compounds were quantified in rivers and wastewater respectively, with pharmaceuticals, industrial compounds, and pesticides being frequently detected in both rivers and WWTPs. Compounds with highest concentrations included saccharin (9.9 μg/L), metformin (7.5 μg/L), and oxypurinol (6.5 μg/L) in rivers whereas caffeine (280 μg/L), deoxycholic acid (179 μg/L), 2-oxindole (10.9 μg/L) and ibuprofen (8.1 μg/L) were found at high concentrations in WWTPs. Based on the types of crops grown, samples from maize growing regions recorded the highest number of pesticides (75) which coincided with the spraying season. The WWTP showed the capacity to eliminate some compounds although the removal efficiencies varied greatly with 204 compounds exhibiting an average removal efficiency exceeding 50 %. Based on the risk assessment, crustaceans had the highest potential risk for toxicity with toxic unit (TU) values up to 5.4 driven primarily by diazinon and dichlorvos followed by algae (TU up to 0.07) and fish (TU up to 0.01) in rivers. A similar trend was observed in WWTP with diazinon (TU up to 5.5), diuron (TU up to 0.07) and carbendazim (TU up to 0.006) driving the risk for crustaceans, algae and fish respectively. These findings highlight the significance of surface water and WWTPs as sources and sinks of CECs in the environment translating to potential risks on aquatic organisms and humans.

Radiolysis performance of ibuprofen using ionizing processes: kinetics and energy consumption

ABSTRACTIonizing technologies are used for disinfection and treatment of different industrial wastewaters. For this purpose, the radiolytic degradation of ibuprofen (IBP), selected within the main detected pharmaceuticals in different water locations with different concentrations, was investigated. Irradiation was performed with a gamma irradiator (60Co) and with electron beam accelerator. The degree of ibuprofen degradation was monitored following the evolution of its absorbance, the residual concentration by HPLC, carbon oxygen demand and total organic carbon. The degradation of IBP was higher than the removal of TOC or COD and reached 95% according to residual concentration. This pollutant (at 0.1 mM) was totally degraded when irradiated at 3 kGy and needed higher doses (7-10 kGy) for the highest concentrations (0.8-1 mM). The addition of 1 mM of persulfate ion remarkably enhanced IBP degradation by around 2 and 2.8 times for 5 and 10 kGy, respectively. Pseudo-first-order reaction kinetics could be used to depict the degradation process of IBP in all conditions. Electrical energy per order (EEO) was estimated under various conditions. The smallest EEO was obtained when gamma radiation and persulfate ion were combined. The possible degradation pathways of IBP were proposed. The results achieved in this study can be used to optimize large-scale application of nuclear techniques in water treatment in particular in treating pharmaceutical effluents.

Temporal Analysis of Pharmaceuticals as Emerging Contaminants in Surface Water and Wastewater Samples: A Case Study

Pharmaceuticals in the environment are a global concern, with studies in all continents highlighting their widespread occurrence and potential ecological impacts, revealing their presence, fate, and associated risks in aquatic ecosystems. Despite typically occurring at low concentrations (ranging from ng/L to µg/L), advancements in analytical methods and more sensitive equipment have enabled the detection of a higher number of pharmaceuticals. In this study, surface and wastewater samples were extracted using solid phase extraction and analyzed using ultra-high-performance liquid chromatography with tandem mass spectrometry. Among the therapeutic classes investigated, nonsteroidal anti-inflammatory drugs/analgesics, antibiotics, and psychiatric drugs showed a higher number of detected pharmaceuticals. Concentrations ranged from below method detection limit ( Collapse

Key Words

• liquid chromatography
• mass spectrometry
• overtime analysis
• pharmaceuticals
• public health
• surface and wastewater samples

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MESH Headings Collapse

Grants

• UIDB/50006/2020 Fundação para a Ciência e Tecnologia
• UIDP/50006/2020 Fundação para a Ciência e Tecnologia
• LA/P/0008/2020 Fundação para a Ciência e Tecnologia
• PTDC/QUI-QAN/3899/2021 Fundação para a Ciência e Tecnologia
• PTDC/EAM-AMB/2023/2021 Fundação para a Ciência e Tecnologia
• MTS/SAS/0077/2020 Fundação para a Ciência e Tecnologia
• P223RT0141/ENOTTA-CA21147 Ibero-American Program on Science and Technology (CYTED) & European Cooperation in Science and Technology (COST)
• 101003777 Fundação para a Ciência e a Tecnologia (FCT) BiodivRestore Joint Call 2020-2021 - European Union's Horizon 2020 research and innovation programme

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Affiliation(s)

Paula Paíga REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4249-015 Porto, Portugal; (L.C.-S.); (M.C.); (S.F.)
Luísa Correia-Sá REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4249-015 Porto, Portugal; (L.C.-S.); (M.C.); (S.F.)
Manuela Correia REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4249-015 Porto, Portugal; (L.C.-S.); (M.C.); (S.F.)
Sónia Figueiredo REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4249-015 Porto, Portugal; (L.C.-S.); (M.C.); (S.F.)
Joana Vieira Águas do Centro Litoral, SA, Grupo Águas de Portugal, ETA da Boavista, Avenida Dr. Luís Albuquerque, 3030-410 Coimbra, Portugal; (J.V.)
Sandra Jorge Águas do Centro Litoral, SA, Grupo Águas de Portugal, ETA da Boavista, Avenida Dr. Luís Albuquerque, 3030-410 Coimbra, Portugal; (J.V.)
Jaime Gabriel Silva Águas do Douro e Paiva, SA, Grupo Águas de Portugal, Rua de Vilar, 235 5°, 4050-626 Porto, Portugal; Departamento de Engenharia Civil, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4249-015 Porto, Portugal
Cristina Delerue-Matos REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4249-015 Porto, Portugal; (L.C.-S.); (M.C.); (S.F.)

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Quantitative Non-targeted Screening to Profile Micropollutants in Sewage Sludge Used for Agricultural Field Amendments

A considerable number of micropollutants from human activities enter the wastewater network for removal. However, at the wastewater treatment plant (WWTP), some proportion of these compounds is retained in the sewage sludge (biosolids), and due to its high content of nutrients, sludge is widely applied as an agricultural fertilizer and becomes a means for the micropollutants to be introduced to the environment. Accordingly, a holistic semiquantitative nontarget screening was performed on sewage sludges from five different WWTPs using nanoflow liquid chromatography coupled to high-resolution Orbitrap mass spectrometry. Sixty-one inorganic elements were measured using inductively coupled plasma mass spectrometry. Across all sludges, the nontarget analysis workflow annotated >21,000 features with chemical structures, and after strict prioritization and filtering, 120 organic micropollutants with diverse chemical structures and applications such as pharmaceuticals, pesticides, flame retardants, and industrial and natural compounds were identified. None of the tested sludges were free from organic micropollutants. Pharmaceuticals contributed the largest share followed by pesticides and natural products. The predicted concentration of identified contaminants ranged between 0.2 and 10,881 ng/g dry matter. Through quantitative nontarget analysis, this study comprehensively demonstrated the occurrence of cocktails of micropollutants in sewage sludges.

Biodegradation behaviour of pharmaceutical compounds and selected metabolites in activated sludge. A forecasting decision system approach

Society's support upon chemicals over the last few decades has led to their increased production, application and discharge into the environment. Wastewater treatment plants (WWTPs) contain a multitude of these chemicals such us; pharmaceutical compounds (PCs). Often, their biodegradability by activated sludge microorganisms is significant for their elimination during wastewater treatment. In this paper the focus is laid on two PCs carbamazepine (CBZ) and diclofenac (DCF) and their main transformation products (TPs). Laboratory degradation tests with these two pharmaceuticals using activated sludge as inoculum under aerobic conditions were performed and microbial metabolites were analyzed by liquid chromatography-mass spectrometry (LC/MS-MS). In two different Mixed liquid Suspended Solids (MLSS) concentrations the biodegradability by activated sludge of CBZ and DCF were evaluated. Also, this article proposes a decision support system to optimize the prediction process of this type of pharmacological compounds. A study and analysis of the techniques of Support Vector Machine, Random Forest, Decision Trees and Multilayer Perceptron Network is carried out to select the most reliable and accurate predictor for the decision system. There are not significant differences in the removal of DCF with 30 mg MLSS/L and 60 mg MLSS/L. DCF was better removed than CBZ in all experiments studied. The TP detected in the samples were mainly 4-OH-DCF for DCF and 10, 11 EPOXICBZ for CBZ. The results show that the best models are obtained with Random Forest and Multilayer Perceptron Network techniques, with a model fit of more than 95% for both carbamazepine and diclofenac metabolites. Obtaining a root means square errors of 0.80 µg/L for the metabolite 4-OH-DCF for DCF with the technique Random Forest and a root means square errors of 1.13 µg/L for the metabolite 10, 11 EPOXICBZ for CBZ with the Multilayer Perceptron Network technique.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40201-023-00890-x.

Occurrence of Pharmaceutical Micropollutants in Lake Nahuel Huapi, Argentine Patagonia

Tourism is one of the most important activities for the economy of Nor Patagonia Argentina. In Bariloche City, located on the shores of Lake Nahuel Huapi, both the permanent and the temporary populations have increased significantly in recent decades, and this has not necessarily been accompanied by an improvement in sewage networks. Emerging micropollutants such as pharmaceutical compounds reach aquatic systems directly, in the absence of a domestic sewage network, or through effluents from wastewater treatment plants (WWTP), which do not efficiently remove these substances and represent a major threat to the environment. Therefore, the objective of our study was to monitor the presence of pharmaceutical compounds discharged both through wastewater effluents and diffusely from housing developments into Lake Nahuel Huapi. The results obtained demonstrate the presence of pharmaceuticals in Lake Nahuel Huapi with concentrations ranging from not detectable (ND) to 110.6 ng L-1 (caffeine). The highest pharmaceutical concentration recorded in WWTP influent corresponded to caffeine (41728 ng L-1), and the lowest concentration was paracetamol (18.8 ng L-1). The removal efficiency of pharmaceuticals in the WWTP was calculated, and ranged from 0% for carbamazepine to 66% for ciprofloxacin. This antibiotic showed the lowest % of attenuation (73%) in Lake Nahuel Huapi. These results on the occurrence of a wide variety of pharmaceuticals are the first generated in Patagonia, representing a regional baseline for this type of micropollutant and valuable information for the subsequent design of removal strategies for emerging pharmaceutical pollutants in surface water. Environ Toxicol Chem 2024;43:1274-1284. © 2024 SETAC.

Fate of contaminants of emerging concern in two wastewater treatment plants after retrofitting tertiary treatment for reduction of nitrogen discharge

More and more previously designed wastewater treatment plants (WWTPs) are upgraded to tertiary treatment to meet the higher effluent discharge standards of conventional pollutants. Contaminants of emerging concern (CECs) can cause adverse effects on organisms and usually flow into WWTPs along with urban sewage. How the retrofitted WWTPs targeting conventional pollutants will influence the treatment efficiency of CECs is seldom discussed. This study investigates the removal of CECs in two full-scale newly retrofitted WWTPs (CD and JM WWTPs), containing high-efficiency sedimentation tank and denitrification deep bed filter for enhancing total nitrogen removal. The overall CEC removal efficiencies in the CD and JM WWTPs were 73.79 % and 93.63 %, respectively. Mass balance results indicated that CD WWTP and JM WWTP release a total of 36.89 and 88.58 g/d of CECs into the environment through effluent and excess sludge, respectively. Analysis of the concentration of CECs along the treatment process revealed most CECs were removed in the biological treatment units. The incorporation of newly constructed tertiary treatment proved beneficial for CEC removal and removed 2.93 % and 2.36 % CECs, corresponding to CEC removal of 2.92 and 27.49 g/d in the CD and JM WWTPs, respectively. The data of this study were further used to evaluate the suitability of the SimpleTreat model for simulating the fate of CECs in WWTPs. The predicted fraction of CECs discharged through the biological treatment effluent were generally within ten-fold difference from the measured results, highlighting its potential for estimating CEC removal in WWTPs.

How to deal with xenobiotic compounds through environment friendly approach?

Every year, a huge amount of lethal compounds, such as synthetic dyes, pesticides, pharmaceuticals, hydrocarbons, etc. are mass produced worldwide, which negatively affect soil, air, and water quality. At present, pesticides are used very frequently to meet the requirements of modernized agriculture. The Food and Agriculture Organization of the United Nations (FAO) estimates that food production will increase by 80% by 2050 to keep up with the growing population, consequently pesticides will continue to play a role in agriculture. However, improper handling of these highly persistent chemicals leads to pollution of the environment and accumulation in food chain. These effects necessitate the development of technologies to eliminate or degrade these pollutants. Degradation of these compounds by physical and chemical processes is expensive and usually results in secondary compounds with higher toxicity. The biological strategies proposed for the degradation of these compounds are both cost-effective and eco-friendly. Microbes play an imperative role in the degradation of xenobiotic compounds that have toxic effects on the environment. This review on the fate of xenobiotic compounds in the environment presents cutting-edge insights and novel contributions in different fields. Microbial community dynamics in water bodies, genetic modification for enhanced pesticide degradation and the use of fungi for pharmaceutical removal, white-rot fungi's versatile ligninolytic enzymes and biodegradation potential are highlighted. Here we emphasize the factors influencing bioremediation, such as microbial interactions and carbon catabolism repression, along with a nuanced view of challenges and limitations. Overall, this review provides a comprehensive perspective on the bioremediation strategies.

Use of micropollutant indicator ratios to characterize wastewater treatment plant efficiency and to identify wastewater impact on groundwater

Contamination by wastewater has been traditionally assessed by measuring faecal coliforms, such as E. coli and entereococci. However, using micropollutants to track wastewater input is gaining interest. In this study, we identified nine micropollutant indicators that could be used to characterize water quality and wastewater treatment efficiency in pond-based wastewater treatment plants (WWTPs) of varying configuration. Of 232 micropollutants tested, nine micropollutants were detected in treated wastewater at concentrations and frequencies suitable to be considered as indicators for treated wastewater. The nine indicators were then classified as stable (carbamazepine, sucralose, benzotriazole, 4+5-methylbenzotriazole), labile (atorvastatin, naproxen, galaxolide) or intermediate/uncertain (gemfibrozil, tris(chloropropyl)phosphate isomers) based on observed removals in the pond-based WWTPs and correlations between micropollutant and dissolved organic carbon removal. The utility of the selected indicators was evaluated by assessing the wastewater quality in different stages of wastewater treatment in three pond-based WWTPs, as well as selected groundwater bores near one WWTP, where treated wastewater was used to irrigate a nearby golf course. Ratios of labile to stable indicators provided insight into the treatment efficiency of different facultative and maturation ponds and highlighted the seasonal variability in treatment efficiency for some pond-based WWTPs. Additionally, indicator ratios of labile to stable indicators identified potential unintended release of untreated wastewater to groundwater, even with the presence of micropollutants in other groundwater bores related to approved reuse of treated wastewater.

Reusable adsorbent of magnetite in mesoporous carbon for antibiotic removal

This study aims to evaluate the feasibility of an innovative reusable adsorbent through adsorption-degradation sequence for antibiotic removal from water. The magnetite/mesoporous carbon adsorbent was prepared using a two-step method of (i) in situ impregnation of magnetite precursor during resorcinol formaldehyde polymerization and (ii) pyrolysis at elevated temperature (800 °C). XRD spectra confirmed that magnetite (Fe3O4) was the only iron oxide species present in the adsorbent, and thermogravimetric analysis revealed that its content was 10 wt%. Nitrogen sorption analysis showed that Fe3O4/carbon features a high fraction of mesopores (> 80 vol.%) and a remarkable specific surface area value (246 m2 g-1), outstanding properties for water treatment. The performance of the adsorbent was examined in the uptake of three relevant antibiotics. The maximum adsorption uptakes were ca. 76 mg g-1, ca. 70 mg g-1, and ca. 44 mg g-1 for metronidazole, sulfamethoxazole, and ciprofloxacin, respectively. All adsorption curves were successfully fitted with Langmuir equilibrium model. The regeneration of adsorbent was carried out using Fenton oxidation under ambient conditions. After three consecutive runs of adsorption-regeneration, Fe3O4/carbon maintained its performance almost unchanged (up to 95% of its adsorption capacity), which highlights the high reusability of the adsorbent.

Comprehensive analysis of a widely pharmaceutical, furosemide, and its degradation products in aquatic systems: Occurrence, fate, and ecotoxicity

Many pharmaceutical compounds end up in the environment due to incomplete removal by wastewater treatment plants (WWTPs). Some compounds are sometimes present in significant concentrations and therefore represent a risk to the aquatic environment. Furosemide is one of the most widely used drugs in the world. Considered as an essential drug by the World Health Organization, this powerful loop diuretic is used extensively to treat hypertension, heart and kidney failure and many other purposes. However, this important consumption also results in a significant release of furosemide in wastewater and in the receiving environment where concentrations of a few hundred ng/L to several thousand have been found in the literature, making furosemide a compound of great concern. Also, during its transport in wastewater systems and WWTPs, furosemide can be degraded by various processes resulting in the production of more than 74 by-products. Furosemide may therefore present a significant risk to ecosystem health due not only to its direct cytotoxic, genotoxic and hepatotoxic effects in animals, but also indirectly through its transformation products, which are poorly characterized. Many articles classify furosemide as a priority pollutant according to its occurrence in the environment, its persistence, its elimination by WWTPs, its toxicity and ecotoxicity. Here, we present a state-of-the-art review of this emerging pollutant of interest, tracking it, from its consumption to its fate in the aquatic environment. Discussion points include the occurrence of furosemide in various matrices, the efficiency of many processes for the degradation of furosemide, the subsequent production of degradation products following these treatments, as well as their toxicity.

Interconnected environmental challenges: heavy metal-drug interactions and their impacts on ecosystems

Industrial expansion and inadequate environmental safety measures are major contributors to environmental contamination, with heavy metals (HMs) and pharmaceutical waste playing crucial roles. Their negative effects are most noticeable in aquatic species and vegetation, where they accumulate in tissues and cause harmful results. Interactions between HMs and pharmaceutical molecules result in the production of metal-drug complexes (MDCs), which have the potential to disturb diverse ecosystems and their interdependence. However, present studies frequently focus on individual pollutants and their effects on specific environmental parameters, leaving out the cumulative effects of pollutants and their processes across several environmental domains. To address this gap, this review emphasizes the environmental sources of HMs, elucidates their emission pathways during anthropogenic activities, investigates the interactions between HMs and pharmaceutical substances, and defines the mechanisms underlying the formation of MDCs across various ecosystems. Furthermore, this review underscores the simultaneous occurrence of HMs and pharmaceutical waste across diverse ecosystems, including the atmosphere, soil, and water resources, and their incorporation into biotic organisms across trophic levels. It is important to note that these complex compounds represent a higher risk than individual contaminants.

Amplification of photocatalytic degradation of antibiotics (amoxicillin, ciprofloxacin) by sodium doping in nano-crystallite hydroxyapatite

In this research, we explain the production of sodium-doped hydroxyapatite (Na_HAp) via wet chemical precipitation, followed by crystal modification. To enhance its photocatalytic activity different % of (0.25, 0.5, 1, and 2) sodium doped into HAp crystal. It has been demonstrated that doping is an effective method for modifying the properties of nanomaterials, such as their optical performance and chemical reactivity. Several instrumental approaches were used to characterize this newly synthesized sodium-doped HAp (Na_HAp), e.g. scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and UV-vis spectrometry were used to analyze the morphology, elemental composition, crystal structure, and optical bandgap, respectively. Under sunlight irradiation, the new Na_HAp photocatalyst was put to use in the process of degrading pharmaceutical pollutants such as antibiotics (amoxicillin and ciprofloxacin). It was found that using a 0.1 g dose of 1% Na_HAp under specified conditions, such as a pH of 7 and 120 minutes of sunlight irradiation, resulted in degradation percentages of 60% and 41.59% for amoxicillin and ciprofloxacin, respectively. Different radical scavengers were utilized to determine the reaction mechanism for the photochemical degradation of antibiotics. Additionally, the ability to be reused and the stability of 1% Na_HAp, a newly developed photocatalyst, were assessed. Therefore, this research adds to our understanding of how to optimize redox capacity for the rapid breakdown of a variety of antibiotics when exposed to sunlight.

Occurrence, removal efficiency, and emission of antibiotics in the sewage treatment plants of a low-urbanized basin in China and their impact on the receiving water

Sewage treatment plants (STPs) are primary sources of antibiotics in aquatic environments. However, limited research has been conducted on antibiotic attenuation in STPs and their downstream waters in low-urbanized areas. This study analyzed 15 antibiotics in the STP sewage and river water in the Zijiang River basin to quantify antibiotic transport and attenuation in the STPs and downstream. The results showed that 14 target antibiotics, except leucomycin, were detected in the STP sewage, dominated by amoxicillin (AMOX), ofloxacin, and roxithromycin. The total antibiotic concentration in the influent and effluent ranged from 158 to 1025 ng/L and 99.9 to 411 ng/L, respectively. The removal efficiency of total antibiotics ranged from 54.7 % to 75.7 % and was significantly correlated with total antibiotic concentration in the influent. The antibiotic emission from STPs into rivers was 78 kg/yr and 4.6 g/km2yr in the Zijiang River basin. The total antibiotic concentration downstream of the STP downstream was 23.6 to 213 ng/L and was significantly negatively correlated with the transport distance away from the STP outlets. Antibiotics may pose a high ecological risk to algae and low ecological risk to fish in the basin. The risk of AMOX and ciprofloxacin resistance for organisms in the basin was estimated to be moderate. This study established antibiotic removal and attenuation models in STPs and their downstream regions in a low-urbanized basin, which is important for simulating antibiotic transport in STPs and rivers worldwide.

Environmentally relevant concentrations of aqueous atorvastatin produce alterations in cholesterol biosynthesis and gene expression patterns in Xenopus laevis

Numerous studies report active pharmaceutical compounds detected in both wastewater effluent and surface waters. Exposure to statin drugs in general, and atorvastatin in particular, is likely to be a concern. We hypothesized that chronic exposure to low concentrations of atorvastatin in water would result in an adverse effect on production of steroids regulating growth and development of the model amphibian Xenopus laevis. The FETAX assay was used to evaluate the effects of a range of doses of atorvastatin on developing embryos. A 60 day metamorphosis assay assessed the effects of aqueous atorvastatin exposure at environmentally concentrations on metamorphosing tadpoles. A 60 day chronic flow-through exposure evaluated the effects of chronic low concentrations of atorvastatin on adults. The purpose of the FETAX assay was to confirm that atorvastatin can reduce circulating cholesterol in X. laevis with a similar manner to that expected in humans. The results of the 60-day flow-through exposure on metamorphosing tadpoles showed significant evidence of altered cholesterol biosynthesis. The dose-dependent increase in cyp19a1 expression also indicated that the steroidogenesis pathway was affected. The RNAseq analysis confirmed that exposure to environmentally relevant concentrations of atorvastatin does cause significant alterations to global transcriptional profiles in a manner consistent with dysregulation of the cholesterol biosynthesis pathway, both through the downregulation of many genes involved in that pathway, but also in the impacts to other, related pathways. The qPCR data for both adult males and adult females indicated only slight changes in expression with the exception that hmgcr was significantly downregulated in males, and cyp3a4 expression was significantly downregulated in females. The data we present here indicated that chronic exposure to environmentally relevant concentrations of atorvastatin does have the potential to impact early life stage frogs, particularly by altering expression of genes involved in critical molecular pathways.

Evaluation of Phenobarbital Adsorption Efficiency on Biosorbents or Activated Carbon Obtained from Adansonia Digitata Shells

The removal of pharmaceutically active compounds present in relatively low concentration in wastewater is critical. This is because they have a severe, negative impact on life and the environment. To address this issue, adsorption was used, which is an effective wastewater treatment method for removing substances found in low concentrations in water. This study compared the adsorption performance of active carbon to three biosorbents derived from Adansonia digitata shells. The adsorbents were prepared and characterized using TGA, SEM, EDX, and FTIR analyses and pHPZC. To better understand the adsorption process, equilibrium and reaction kinetics studies were conducted. The effect of contact time, initial phenobarbital concentration, adsorbent mass, and pH was investigated in static conditions. The adsorption results revealed that the biosorbent B3 has a higher affinity for the eliminated compound, with an equilibrium time of 60 min and an adsorption capacity of 47.08 mg/g at an initial concentration of 50 mg/L. The experimental data are consistent with Langmuir and Sips adsorption isotherm models, and with the pseudo-second order and Elovich models for kinetics description. This indicates strong interactions between the adsorbent materials and the pharmaceutical micropollutant. Based on these findings, it appears that, among the tested materials, B3 biosorbent is the most efficient for removing phenobarbital present in low concentrations in water.

Advanced oxidation and biological integrated processes for pharmaceutical wastewater treatment: A review

The stress of pharmaceutical and personal care products (PPCPs) discharging to water bodies and the environment due to increased industrialization has reduced the availability of clean water. This poses a potential health hazard to animals and human life because water contamination is a great issue to the climate, plants, humans, and aquatic habitats. Pharmaceutical compounds are quantified in concentrations ranging from ng/Lto μg/L in aquatic environments worldwide. According to (Alsubih et al., 2022), the concentrations of carbamazepine, sulfamethoxazole, Lutvastatin, ciprofloxacin, and lorazepam were 616-906 ng/L, 16,532-21635 ng/L, 694-2068 ng/L, 734-1178 ng/L, and 2742-3775 ng/L respectively. Protecting and preserving our environment must be well-driven by all sectors to sustain development. Various methods have been utilized to eliminate the emerging pollutants, such as adsorption and biological and advanced oxidation processes. These methods have their benefits and drawbacks in the removal of pharmaceuticals. Successful wastewater treatment can save the water bodies; integrating green initiatives into the main purposes of actor firms, combined with continually periodic awareness of the current and potential implications of environmental/water pollution, will play a major role in water conservation. This article reviews key publications on the adsorption, biological, and advanced oxidation processes used to remove pharmaceutical products from the aquatic environment. It also sheds light on the pharmaceutical adsorption capability of adsorption, biological and advanced oxidation methods, and their efficacy in pharmaceutical concentration removal. A research gap has been identified for researchers to explore in order to eliminate the problem associated with pharmaceutical wastes. Therefore, future study should focus on combining advanced oxidation and adsorption processes for an excellent way to eliminate pharmaceutical products, even at low concentrations. Biological processes should focus on ideal circumstances and microbial processes that enable the simultaneous removal of pharmaceutical compounds and the effects of diverse environments on removal efficiency.

The occurrence of heavy metals and antimicrobials in sewage sludge and their predicted risk to soil - Is there anything to fear?

The study assessed the occurrence of legally-monitored heavy metals and unmonitored antimicrobials in sludge from small, medium, large and very large municipal wastewater treatment plants (WWTPs), and the predicted environmental risk and risk of resistance selection associated with sludge administration to soil. The temporal variations of the studied compounds in sludge and associated risks to soil were determined by sampling over a year. Although the highest concentrations of heavy metals were noted in sludge from the largest WWTP, i.e. from 1.50 mg/kg (mean 1.61 mg/kg) for Cd to 2188 mg/kg (mean 1332 mg/kg) for Zn, the obtained values only reached a few percent of the legal limits. The same WWTP also demonstrated lower concentrations of antimicrobials compared to the smaller ones. The highest concentrations of antimicrobials, ranging from 24.04 μg/kg for trimethoprim to 900.24 μg/kg for tetracycline, were found in the small and medium WWTPs. However, due to lack of regulations at the national and EU levels, the results cannot be compared with legal limits. Principal Component Analysis (PCA), cluster and heatmap analysis separated samples according to WWTP size. Small WWTP demonstrated correlation with antimicrobials (tetracycline, trimethoprim, clindamycin, ciprofloxacin and ofloxacin), while the large and very large WWTP revealed correlations with heavy metals (Cu and Cr). The obtained environmental risk quotients confirmed that the heavy metals did not present a threat, measured either as individual risk quotients (RQenv), cumulative risk (RQcumulative) or risk of mixture of heavy metals (RQmix-metals). In the case of antimicrobials, only tetracycline demonstrated moderate RQenv, RQcumulative and RQmix-antimicrobials in the small WWTP sludge, with values of 0.1 to 1. Our findings highlight the importance of monitoring sewage sludge before soil application, especially from small WWTPs, to reduce the potential environmental impact of antimicrobials. They also confirm our previous data regarding the environmental risk associated with various toxic compounds, including emerging contaminants, in the sludge from small WWTPs.

Evaluating membrane bioreactor treatment for the elimination of emerging contaminants using different analytical methods

Since wastewater treatment plants (WWTPs) were not originally designed to eliminate contaminants of emerging concern (CECs), alternative strategies like membrane bioreactor (MBR) technology are gaining importance in achieving effective CEC removal and minimising their environmental impact. In this study, composite wastewater samples were collected from the biggest WWTP in the Basque Country (Galindo, Biscay) and the performance of two secondary treatments (i.e. conventional activated sludge treatment, CAS, and MBR) was assessed. The combination of a suspect screening approach using liquid chromatography tandem high-resolution mass spectrometry (LC-HRMS) and multitarget analysis by gas chromatography-mass spectrometry (GC-MS) allowed the detection of approximately 200 compounds in the WWTP effluents. The estimated removal efficiencies (REs) revealed that only 16 micropollutants exhibited enhanced removal by MBR treatment (RE > 70% or 40 - 60%). The environmental risk posed by the non-eliminated compounds after both treatments remained similar, being anthracene, clarithromycin, bis(2-ethylhexyl) phthalate (DEHP) and dilantin the most concerning pollutants (RQ > 1). The Microtox® bioassay confirmed the MBR's efficiency in removing baseline toxicity, while suggesting a similar performance of CAS treatment. These minimal differences between treatments call into question the worthiness of MBR treatment and emphasise the need to seek more efficient alternative treatment methods.

Distribution, fate and removal efficiency of anthelmintic drugs in wastewater treatment plants

The distribution and fate of 19 anthelmintic drugs (ADs) were investigated in two wastewater treatment plants (WWTPs) using different wastewater treatment technologies, including anaerobic-anoxic-aerobic (A2/O) biological process and cyclic activated sludge system (CASS) process. All the 19 ADs were found in the two WWTPs, with concentrations ranging from N.D. to 324.6 ng/L in the influent and from N.D. to 1579.2 ng/L in the effluent. Benzimidazoles were the primary pollutants in the wastewater and suspended particulate matter, accounting for more than half of the total concentration. The concentrations of macrocyclic lactones in the sludge were significantly higher than that of other two media. The ADs removal efficiency of A2/O ranged from -330 % (albendazole sulfoxide) to 100 % (fenbendazole, mebendazole and pyrantel). While the ADs removal efficiency of CASS process ranged from -425 % (albendazole sulfoxide) to 100 % (abamectin, moxidectin and ivermectin). There was no significant difference in the average removal efficiency of the ADs between the two processes (64 % and 63 %, except albendazole sulfoxide). The removal efficiencies of the ADs in the biodegradation stage were better than them in the sedimentation stage. The load per capita of the 19 ADs in two WWTPs ranged from 0 (moxidectin) to 36 μg.d-1.p-1 (albendazole), and the emission in the effluent ranged from 0 (moxidectin) to 163 μg.d-1.p-1 (albendazole sulfoxide). This study provided the first comprehensive data on the occurrence and fate of the 19 ADs and evaluated the removal efficiencies of the 19 ADs in two WWTPs using A2O process and CASS process in the city.

Benzodiazepine Delorazepam Induces Locomotory Hyperactivity and Alterations in Pedal Mucus Texture in the Freshwater Gastropod Planorbarius corneus

Benzodiazepines, psychotropic drugs, are ubiquitous in the aquatic environment due to over-consumption and inefficient removal by sewage treatment plants. Bioaccumulation with consequent behavioral and physiological effects has been reported in many aquatic species. However, the responses are species-specific and still poorly understood. To improve the knowledge, we exposed the freshwater snail Planorbarius corneus to 1, 5, or 10 µg/L of delorazepam, the most widely consumed benzodiazepine in Italy. Conventional behavioral tests were used to assess the effects on locomotor and feeding behavior. Histological and biochemical analyses were also performed to detect possible changes in the structure and composition of the foot mucus and glands. The results show a paradoxical response with reduced feeding activity and locomotor hyperactivity. Pedal mucus was altered in texture but not in composition, becoming particularly rich in fibrous collagen-like material, and a significant change in the protein composition was highlighted in the foot. In conclusion, exposure to delorazepam induces disinhibited behavior in Planorbarius corneus, potentially increasing the risk of predation, and an increase in mucus protein production, which, together with reduced feeding activity, would severely compromise energy resources.

Further exploration of the collision-induced dissociation of select beta blockers: Acebutolol, atenolol, bisoprolol, carteolol, and labetalol

Beta blockers are a class of drugs commonly used to treat heart-related diseases; they are also regulated under the World Anti-Doping Agency. Tandem mass spectrometry is often used in the pharmaceutical industry, clinical analysis laboratory, and antidoping laboratory for detection and characterization of drugs and their metabolites. A deeper chemical understanding of dissociation pathways may eventually lead to an improved ability to predict tandem mass spectra of compounds based strictly on their chemical structure (or vice versa), which is especially important for characterization of unknowns such as emerging designer drugs or novel metabolites. In addition to providing insights into dissociation pathways, the use of energy-resolved breakdown curves can produce improved selectivity and lend insights into optimal fragmentation conditions for liquid chromatography-tandem mass spectrometry LC-MS/MS workflows. Here, we perform energy-resolved collision cell and multistage ion trap collision-induced dissociation-mass spectrometry (CID-MS) experiments, along with complementary density functional theory calculations, on five beta blockers (acebutolol, atenolol, bisoprolol, carteolol, and labetalol), to better understand the details of the pathways giving rise to the observed MS/MS patterns. Results from this work are contextualized within previously reported literature on these compounds. New insights into the formation of the characteristic product ion m/z 116 and the pathway leading to characteristic loss of 77 u are highlighted. We also present comparisons of breakdown curves obtained via qToF, quadrupole ion trap, and in-source CID, allowing for differences between the data to be noted and providing a step toward allowing for improved selectivity of breakdown curves to be realized on simple instruments such as single quadrupoles or ion traps.

Removal of emerging micropollutants from nanofiltration retentate of municipal wastewater within biological fixed-bed reactors under nitrifying and denitrifying conditions

Municipal water resource recovery facilities are not designed to eliminate micropollutants, leading to many pollutants entering the aquatic environment. Within this study, as part of the project MicroStop, the biological treatment of nanofiltration effluent (retentate) under pure aerobic (without nitrification) as well as nitrifying and denitrifying conditions has been investigated for micropollutant elimination. A potential of further biotransformation under increased hydraulic retention time (HRT) of 14 days was shown. Under both HRT of 7 and 14 days, eliminations below LOQ were achieved in the aerated bioreactor for gabapentin, iomeprol, and metoprolol, reaching > 95%, > 69 to > 92%, and > 72%, respectively. The reduction of diclofenac was positively influenced by longer HRT leading to an elimination of up to 67%. Sulfamethoxazole was reduced under denitrification, but accumulated under aeration, resulting in fluctuating results and an overall elimination of 78% under 14 days HRT. PRACTITIONER POINTS: The micropollutant elimination in fixed-bed bioreactors of highly concentrated nanofiltration retentate was studied. Pure aerobic (without nitrification), nitrifying, and denitrifying conditions were investigated under hydraulic retention times (HRT) of 7 and 14 days. Higher initial pollutant concentrations enhanced the biological degradability in attached growth for substances being moderately degradable in activated sludge systems. 4A potential of further biological micropollutant elimination was shown for gabapentin, iomeprol, metoprolol, and diclofenac.

Pharmaceutically active compounds in aqueous environment: recent developments in their fate, occurrence and elimination for efficient water purification

The existence of pharmaceutically active compounds (PhACs) in the water is a major concern for environmentalists due to their deleterious effects on living organisms even at minuscule concentrations. This review focuses on PhACs such as analgesics and anti-inflammatory compounds, which are massively excreted in urine and account for the majority of pharmaceutical pollution. Furthermore, other PhACs such as anti-epileptics, beta-blockers and antibiotics are discussed because they also contribute significantly to pharmaceutical pollution in the aquatic environment. This review is divided into two parts. In the first part, different classes of PhACs and their fate in the wastewater environment are presented. In the second part, recent advances in the removal of PhACs by conventional wastewater treatment plants, including membrane bioreactors (MBRs), activated carbon adsorption and bench-scale studies concerning a broad range of advanced oxidation processes (AOPs) that render practical and appropriate strategies for the complete mineralization and degradation of pharmaceutical drugs, are reviewed. This review indicates that drugs like diclofenac, naproxen, paracetamol and aspirin are removed efficiently by conventional systems. Activated carbon adsorption is suitable for the removal of diclofenac and carbamazepine, whereas AOPs are leading water treatment strategies for the effective removal of reviewed PhACs.

Review of experimental biodegradation data on pharmaceuticals and comparison with predictive BIOWIN models

In this study the experimental data on the biodegradation of 16 pharmaceuticals in activated sludge were reviewed and also the theoretical biodegradation of these pharmaceuticals was calculated using BIOWIN models. The main aim was to show the similarities or discrepancies between the two. Experimental data were critically reviewed considering biodegradation rates, biodegradation mechanisms and biosorption of pharmaceuticals. For some pharmaceuticals, theoretical BIOWIN estimations and experimental findings deviated from each other. For example, if only BIOWIN estimations are considered, clarithromycin, azithromycin and ofloxacin would be defined as refractory. However, in experimental studies, they appeared to be not completely refractory. One of the reasons is that in most cases pharmaceuticals could be used as secondary substrates in the presence of sufficient bulk organic matter. In addition, all experimental studies indicate that at long Solids Retention Times (SRTs), nitrification activity becomes enhanced and the enzyme AMO leads to the cometabolic elimination of many pharmaceuticals. BIOWIN models prove to be very helpful for having an initial idea about biodegradability of pharmaceuticals. However, in order to estimate the biodegradability under real conditions, the models can be extended to include the different removal mechanisms reported in this study.

Occurrence and removal rate of typical pharmaceuticals and personal care products (PPCPs) in an urban wastewater treatment plant in Beijing, China

The occurrence and removal rate of 52 typical pharmaceuticals and personal care products (PPCPs) were investigated in a wastewater treatment plant in Beijing, China. Thirty-three PPCPs were found in the influent, with caffeine (CF, 11387.0 ng L-1) being the most abundant, followed by N,N-diethyl-meta-toluamide (DEET, 9568.4 ng L-1), metoprolol (MTP, 930.2 ng L-1), and diclofenac (DF, 710.3 ng L-1). After treatment processes, the cumulative concentration of PPCPs decreased from 2.54 × 104 ng L-1 to 1.44 × 103 ng L-1, with the overall removal efficiency (RE) of 94.3%. Different treatment processes showed varying contributions in removing PPCPs. PPCPs were efficiently removed in sedimentation, anoxic, and ultraviolet units. For individual compounds, a great variation in RE (52.1-100%) was observed. Twenty-two PPCPs were removed by more than 90%. The highly detected PPCPs in the influent were almost completely removed. Aerated grit chamber removed nearly 50% of fluoroquinolone (FQs) and more than 60% of sulfonamides. Most PPCPs showed low or negative removals during anaerobic treatment, except for CF which was eliminated by 64.9%. Anoxic treatment demonstrated positive removals for most PPCPs, with the exceptions of DF, MTP, bisoprolol, carbamazepine (CBZ), and sibutramine. DEET and bezafibrate were efficiently removed during the secondary sedimentation. Denitrification biological filter and membrane filtration also showed positive effect on most PPCPs removals. The remaining compounds were oxidized by 16-100% in ozonation. DF, sulpiride, ofloxacin (OFL), trimethoprim, and phenolphthalein were not amenable to ultraviolet. After the treatment, the residue OFL, CBZ, and CF in receiving water were identified to pose high risk to aquatic organisms. Considering the complex mixtures emitted into the environment, therapeutic groups psychotropics, stimulant, and FQs were classified as high risk. These findings provide valuable insights into adopting appropriate measures for more efficient PPCPs removals, and emphasize the importance of continued monitoring specific PPCPs and mixtures thereof to safeguard the ecosystem.

Systematic study of the synergistic and kinetics effects on the removal of contaminants of emerging concern from water by ultrasound in the presence of diverse oxidants

The enhancement of the ultrasound system by adding diverse oxidants to remove a model contaminant (acetaminophen, ACE) in water was investigated. Different parameters were evaluated to study their effect on both the degradation kinetics and the synergy of the combination. The variables studied were the ultrasonic frequency (575, 858, and 1135 kHz), type of oxidant (hydrogen peroxide, sodium peroxydisulfate (or persulfate, PDS), and potassium peroxymonosulfate (PMS)), ACE concentration (4, 8, and 40 µM), and oxidant concentration (0.01, 0.1, 1, and 5 mM). Particular interest was placed on synergistic effects, implying that one process (or both) is activated by the other to lead to greater efficiency. Interestingly, the parameters that led to the higher synergistic effects did not always lead to the most favorable degradation kinetics. An increase in ACE removal of 20% was obtained using the highest frequency studied (1135 kHz), PMS 0.1 mM, and the highest concentration of ACE (40 µM). The intensification of degradation was mainly due to the ability of ultrasound to activate oxidants and produce extra hydroxyl radicals (HO•) or sulfate radicals (SO4•-). Under these conditions, treatment of ACE spiked into seawater, hospital wastewater, and urine was performed. The hospital wastewater matrix inhibited ACE degradation slightly, while the urine components inhibited the pollutant degradation completely. The inhibition was mainly attributed to the competing organic matter in the effluents for the sono-generated radical species. On the contrary, the removal of ACE in seawater was significantly intensified due to "salting out" effects and the production of the strong oxidant HOCl from the reaction of chloride ions with PMS.

Wastewater-Based Surveillance Does Not Belong in a Regulatory Framework Designed to Protect Waters That Receive Treated Wastewater. Comment on Wright, T.; Adhikari, A. Utilizing a National Wastewater Monitoring Program to Address the U.S. Opioid Epidemic: A Focus on Metro Atlanta, Georgia. Int. J. Environ. Res. Public Health 2023, 20, 5282

We read with great interest the work by Wright and Adhikari on "Utilizing a National Wastewater Monitoring Program to Address the U.S. Opioid Epidemic: A Focus on Metro Atlanta, Georgia" [...].

Complete Biodegradation of Diclofenac by New Bacterial Strains: Postulated Pathways and Degrading Enzymes

The accumulation of xenobiotic compounds in different environments interrupts the natural ecosystem and induces high toxicity in non-target organisms. Diclofenac is one of the commonly used pharmaceutical drugs that persist in the environment due to its low natural degradation rate and high toxicity. Therefore, this study aimed to isolate potential diclofenac-degrading bacteria, detect the intermediate metabolites formed, and determine the enzyme involved in the degradation process. Four bacterial isolates were selected based on their ability to utilize a high concentration of diclofenac (40 mg/L) as the sole carbon source. The growth conditions for diclofenac degradation were optimized, and bacteria were identified as Pseudomonas aeruginosa (S1), Alcaligenes aquatilis (S2), Achromobacter spanius (S11), and Achromobacter piechaudii (S18). The highest percentage of degradation was recorded (97.79 ± 0.84) after six days of incubation for A. spanius S11, as analyzed by HPLC. To detect and identify biodegradation metabolites, the GC-MS technique was conducted for the most efficient bacterial strains. In all tested isolates, the initial hydroxylation of diclofenac was detected. The cleavage step of the NH bridge between the aromatic rings and the subsequent cleavage of the ring adjacent to or in between the two hydroxyl groups of polyhydroxylated derivatives might be a key step that enables the complete biodegradation of diclofenac by A. piechaudii S18, as well as P. aeruginosa S1. Additionally, the laccase, peroxidase, and dioxygenase enzyme activities of the two Achromobacter strains, as well as P. aeruginosa S1, were tested in the presence and absence of diclofenac. The obtained results from this work are expected to be a useful reference for the development of effective detoxification bioprocesses utilizing bacterial cells as biocatalysts. The complete removal of pharmaceuticals from polluted water will stimulate water reuse, meeting the growing worldwide demand for clean and safe freshwater.

Comprehensive micropollutant characterization of wastewater during Covid-19 crisis in 2020: Suspect screening and environmental risk prioritization strategy

Micropollutants monitoring in wastewater can serve as a picture of what is consuming society and how it can impact the aquatic environment. In this work, a suspect screening approach was used to detect the known and unknown contaminants in wastewater samples collected from two wastewater treatment plants (WWTPs) located in the Basque Country (Crispijana in Alava, and Galindo in Vizcaya) during two weekly sampling campaigns, which included the months from April to July 2020, part of the confinement period caused by COVID-19. To that aim, high-resolution mass spectrometry was used to collect full-scan data-dependent tandem mass spectra from the water samples using a suspect database containing >40,000 chemical substances. The presence of > 80 contaminants was confirmed (level 1) and quantified in both WWTP samples, while at least 47 compounds were tentatively identified (2a). Among the contaminants of concern, an increase in the occurrence of some compounds used for COVID-19 disease treatment, such as lopinavir and hydroxychloroquine, was observed during the lockdown. A prioritization strategy for environmental risk assessment was carried out considering only the compounds quantified in the effluents of Crispijana and Galindo WWTPs. The compounds were scored based on the removal efficiency, estimated persistency, bioconcentration factor, mobility, toxicity potential and frequency of detection in the samples. With this approach, 33 compounds (e.g. amantadine, clozapine or lopinavir) were found to be considered key contaminants in the analyzed samples based on their concentration, occurrence and potential toxicity. Additionally, antimicrobial (RQ-AR) and antiviral (EDRP) risk of certain compounds was evaluated, where ciprofloxacin and fluconazole represented medium risk for antibiotic resistance (1 > RQ-AR > 0.1) in the aquatic ecosystems. Regarding mixture toxicity, the computed sum of toxic unit values of the different effluents (> 1) suggest that interactions between the compounds need to be considered for future environmental risk assessments.

Occurrence and fate of an emerging drug pollutant and its by-products during conventional and advanced wastewater treatment: Case study of furosemide

Conventional wastewater treatment systems are not designed to remove pharmaceutical compounds from wastewater. These compounds can be degraded into many other transformation products which are hardly, if at all, studied. In this context, we studied the occurrence and degradation of furosemide, a very frequently detected diuretic, along with its known degradation products in several types of wastewater. Influent and effluent from the Seine-Centre Wastewater Treatment Plant (WWTP) (Paris, France) as well as outlet of residential care homes (Dordogne, France) were analyzed by Ultra-Performance Liquid Chromatography-tandem Mass Spectrometry (UPLC-MS/MS) to quantify furosemide and its known degradation products, saluamine and pyridinium of furosemide. Oxidation experiments (chlorination, ozonation and UV photolysis with hydrogen peroxide) were then performed on furosemide solutions and on water from residential care facilities to study the degradation of furosemide by potential advanced processes, and also to identify unknown oxidation products by high-resolution mass spectrometry. Furosemide was well degraded in Seine-Centre WWTP (>75%) but did not increase the concentrations of its main degradation products. Saluamine and pyridinium of furosemide were already present at similar concentrations to furosemide in the raw wastewater (∼2.5-3.5 μg.L^-1), and their removal in the WWTPs were very high (>80%). Despite their removal, the three compounds remained present in treated wastewater effluents at concentrations of hundreds of nanograms per liter. Chlorination degraded furosemide without pyridinium production unlike the other two processes. Chlorination and ozonation were also effective for the removal of furosemide and pyridinium in residential care home water, but they resulted in the production of saluamine. To our knowledge this is the first evidence of saluamine and pyridinium of furosemide in real water samples in either the particulate or dissolved phase.

Global trends in the research and development of medical/pharmaceutical wastewater treatment over the half-century

The COVID-19 pandemic has severely impacted public health and the worldwide economy. The overstretched operation of health systems around the world is accompanied by potential and ongoing environmental threats. At present, comprehensive scientific assessments of research on temporal changes in medical/pharmaceutical wastewater (MPWW), as well as estimations of researcher networks and scientific productivity are lacking. Therefore, we conducted a thorough literature study, using bibliometrics to reproduce research on medical wastewater over nearly half a century. Our primary goal is systematically to map the evolution of keyword clusters over time, and to obtain the structure and credibility of clusters. Our secondary objective was to measure research network performance (country, institution, and author) using CiteSpace and VOSviewer. We extracted 2306 papers published between 1981 and 2022. The co-cited reference network identified 16 clusters with well-structured networks (Q = 0.7716, S = 0.896). The main trends were as follows: 1) Early MPWW research prioritized sources of wastewater, and this cluster was considered to be the mainstream research frontier and direction, representing an important source and priority research area. 2) Mid-term research focused on characteristic contaminants and detection technologies. Particularly during 2000-2010, a period of rapid developments in global medical systems, pharmaceutical compounds (PhCs) in MPWW were recognized as a major threat to human health and the environment. 3) Recent research has focused on novel degradation technologies for PhC-containing MPWW, with high scores for research on biological methods. Wastewater-based epidemiology has emerged as being consistent with or predictive of the number of confirmed COVID-19 cases. Therefore, the application of MPWW in COVID-19 tracing will be of great interest to environmentalists. These results could guide the future direction of funding agencies and research groups.

Study on the photocatalytic degradation of metronidazole antibiotic in aqueous media with TiO2 under lab and pilot scale

Nowadays, the increased consumption of antibiotics, such as metronidazole (MTZ), leads to their introduction in wastewater as well as in the receiving surface waters due to their incomplete removal by conventional wastewater treatment plants. Heterogeneous photocatalysis is a versatile technology that can efficiently degrade such organic contaminants. In the present research, the photocatalytic degradation of MTZ with TiO₂ P25 was studied under lab and pilot (CPC reactor) conditions. The antibiotic was efficiently removed at high rates in both cases (100 % and 91 %) following pseudo-first order kinetics with rate constants equal to 0.0452 min^-1 (±RSD% = 0.68 % - 2.57 %) and 0.0462 L KJ^-1 (±RSD% = 8.94 % - 21.64 %) respectively. Also, by scavenging lab scale experiments, the contribution of the generated reactive species was investigated and hydroxy radicals (HO^•) were proposed as the predominant species. By applying high resolution mass spectrometry techniques, the transformation products (TPs) were identified and possible transformation pathways were proposed. The ecotoxicity of the TPs was assessed in silico using the ECOSAR software with the results revealing that most of them were less toxic than the parent compound. Similarly, the mutagenicity, developmental toxicity and bioconcentration factors of the TPs were predicted by utilizing the T.E.S.T. software and in their majority, were found to be less mutagenic and developmentally toxic than MTZ. The ecotoxicity monitoring with the Vibrio fischeri bioassay in both laboratory and pilot scale experiments indicated that through heterogeneous photocatalysis it is possible to reduce the toxicity of wastewater containing MTZ. Finally, the stability and reusability of the photocatalyst was investigated through three consecutive catalytic cycles with the results showing that the performance of TiO₂ decreased after each use. For the heterogeneous photocatalysis with TiO₂ to be a "real life" applicable technique, further studies focusing on catalyst regeneration and optimization of the catalytic conditions must be conducted.

Environmental concerns and bioaccumulation of psychiatric drugs in water bodies - Conventional versus biocatalytic systems of mitigation

The COVID-19 pandemic has brought increments in market sales and prescription of medicines commonly used to treat mental health disorders, such as depression, anxiety, stress, and related problems. The increasing use of these drugs, named psychiatric drugs, has led to their persistence in aquatic systems (bioaccumulation), since they are recalcitrant to conventional physical and chemical treatments typically used in wastewater treatment plants. An emerging environmental concern caused by the bioaccumulation of psychiatric drugs has been attributed to the potential ecological and toxicological risk that these medicines might have over human health, animals, and plants. Thus, by the application of biocatalysis-assisted techniques, it is possible to efficiently remove psychiatric drugs from water. Biocatalysis, is a widely employed and highly efficient process implemented in the biotransformation of a wide range of contaminants, since it has important differences in terms of catalytic behavior, compared to common treatment techniques, including photodegradation, Fenton, and thermal treatments, among others. Moreover, it is noticed the importance to monitor transformation products of degradation and biodegradation, since according to the applied removal technique, different toxic transformation products have been reported to appear after the application of physical and chemical procedures. In addition, this work deals with the discussion of differences existing between high- and low-income countries, according to their environmental regulations regarding waste management policies, especially waste of the drug industry.

Spatial Distribution and Risk Assessment of Antibiotics in 15 Pharmaceutical Plants in the Pearl River Delta

Pharmaceutical plants are an essential source of antibiotics emitted into the aqueous environment. The monitoring of target antibiotics in pharmaceutical plants through various regions is vital to optimize contaminant release. The occurrence, distribution, removal, and ecological risk of 30 kinds of selected antibiotics in 15 pharmaceutical plants in the Pearl River Delta (PRD) were investigated in this study. Lincomycin (LIN) showed the highest concentration (up to 56,258.3 ng/L) in the pharmaceutical plant influents from Zhongshan city. Norfloxacin (NFX) showed a higher detection frequency than other antibiotics. In addition, the spatial distribution of antibiotics in pharmaceutical plants showed significant differences, with higher concentrations of total antibiotics found in pharmaceutical plant influents in Shenzhen City than those of different regions in PRD. The treatment processes adopted by pharmaceutical plants were commonly ineffective in removing antibiotics, with only 26.7% of antibiotics being effectively removed (average removal greater than 70%), while 55.6% of antibiotics had removal rates of below 60%. The anaerobic/anoxic/oxic (AAO)-membrane bioreactor (MBR) combined process exhibited better treatment performance than the single treatment process. Sulfamethoxazole (SMX), ofloxacin (OFL), erythromycin-H₂O (ETM-H₂O), sulfadiazine (SDZ), sulfamethazine (SMZ), norfloxacin (NFX), and ciprofloxacin (CIP) in pharmaceutical plant effluents posed high or moderate ecological risk and deserve particular attention.

Seasonal analysis of commonly prescribed antibiotics in Istanbul city

Antibiotics are among the most common medicine groups since they are used to treat infectious diseases, as nutritional supplements in livestock breeding, and for preservation in the food industry. Turkey is among the highest antibiotic consumers in the world. In the present study, the most popular 14 antibiotics available in Turkey were monitored in one hospital sewage and two urban wastewater treatment plant influents and effluents seasonally in Istanbul province, the largest metropolitan center in Turkey. The present research aimed to develop a robust analytical method to determine 14 antibiotics, including six chemical groups, in environmental matrices which are considered significant antibiotic pollution sources, namely hospital sewage and urban wastewater. Solid-phase extraction (SPE) and UPLC-MS/MS analysis parameters included optimized column temperature, eluent, mobile phase, and flow rate. Three SPE cartridges were employed in recovery studies. The antibiotic recovery rates varied between 40 and 100%, and all analytes were identified within 3 min with UPLC-MS/MS under optimal conditions. It was determined that method detection limits (MDLs) varied between 0.07 and 2.72 µg/L for the antibiotics. In all seasons, the highest beta-lactam group antibiotic concentrations were identified in hospital sewage. The season with the greatest variety of antibiotics in urban wastewater was spring. Clarithromycin and ciprofloxacin were the antibiotics determined at the highest concentration in the influent and effluent of the wastewater treatment plant in all seasons. This study showed that the most widely used beta-lactam group antibiotics were found in high amounts in hospital sewage wastewater but in low concentrations in the treatment plants, and hence, it is seen that the degradability of beta-lactam group antibiotics was high. The presence of clarithromycin, ciprofloxacin, lincomycin, levofloxacin, and trimethoprim antibiotics in hospital sewage in higher amounts and also in inlet and outlet of wastewater treatment plants proves that those are resistant antibiotics.

MCDA-DEA approach to construct a composite indicator for effluents from WWTPs considering the influence of PPCPs

Considering current water situation, reuse is an effective solution to meet water demand and reduce pressure on conventional water sources. However, pharmaceutical and personal care products (PPCPs) in effluents from wastewater treatment plants (WWTPs) decrease their quality and suitability. With the aim of identifying and monitoring both the influence of PPCPs and the suitability of effluents to be reused, this study proposes the development of a composite indicator (CI) related to PPCP presence in WWTPs, through the common weight multi-criteria decision analysis (MCDA)-data envelopment analysis (DEA) model. Obtaining a CI for PPCPs is a novel approach in the published literature, showing a new perspective in PPCP management and their influence in wastewater treatment. Furthermore, this study proposes an improvement on MCDA-DEA model which maintains the initial hierarchy obtained for the units analyzed. The development of CI is based on information about the technological, environmental, social, and biological issues of WWTPs. Results show that 4 of the 33 WWTPs analysed had the best CI values, meaning that their effluents have lower environmental impact. The development of a CI related to PPCPs in WWTPs suggests that further steps are needed to manage the WWTP effluents. Hence, the need to implement preventive measures in WWTPs has been shown, even though the removal of PPCPs is not yet part of European law. This work highlights the importance of considering PPCPs as priority pollutants in wastewater management and reuse frameworks, to guarantee low environmental impact and adapt wastewater reuse based on a circular economy approach. HIGHLIGHTS: Emerging contaminants (PPCPs) are used as effluent quality indicators. A composite indicator for PPCPs performance has been developed through MCDA-DEA model. Indicator obtained allow decision makers implementing concrete actions to assess effluent quality. Results show the improvement capacity of the effluents quality through PPCPs removing.

Assessing the impact of antineoplastic drugs in the aquatic environment: State of the art and future perspective for freshwater organisms

Since the late 70s, the continuous pharmaceuticals` input into the environment has raised concerns regarding the eventual risk posed by such compounds to human and environmental health. A major group of pharmaceuticals in terms of environmental impact are the antineoplastic agents (AAs). Herein, we followed a systematic review method to retrieve antineoplastic agents (AAs') ecotoxicological information regarding freshwater species. In this analysis, data from diverse taxonomic groups, from microorganisms to vertebrate species, looked at different levels of biological organization, including cell lines. Furthermore, this review gathers ecotoxicological parameters (EC₅₀ and LC₅₀) for imatinib (IM), cisplatin (CisPt), and 5-fluorouracil (5-FU) in species sensitivity distribution (SSD) curves and estimates the hazard concentration (HC₅) considering the protection of 95% of the ecological community. Lastly, we suggest how we can improve AAs' Environmental Risk Assessment (ERA), considering potential adoptable toxicity endpoints, test duration, AAs metabolites testing, and AAs mixture exposure.

Occurrence, consumption level, fate and ecotoxicology risk of beta-agonist pharmaceuticals in a wastewater treatment plant in Eastern China

Beta-agonist pharmaceuticals are widely used in humans and livestock for disease treatment, legal or illegal growth promotion in food animals, bodybuilding, weight loss, and sports doping. The occurrence of beta-agonists in wastewater treatment plants and their subsequent environmental impacts require greater attention. This study determined the levels of 12 beta-agonists in a wastewater treatment plant and evaluated their ecotoxicological risks as well as consumption levels and risks to human health. Among the 12 selected beta-agonists, all were detected in wastewater and 11 in sludge. In most cases, the concentrations of beta-agonists were higher in spring than in summer. Their total average daily mass loads per capita in the influent and effluent were 1.35 μg/d/p and 2.11 μg/d/p, respectively. The overall removal efficiencies of individual beta-agonists ranged from -295.3 to 71.2%. Ecotoxicological risk assessment revealed a low risk to daphnid and green algae from the levels of fenoterol and the mixture of 12 selected beta-agonists in the effluent. The daily consumption levels of individual beta-agonists per capita were 0.028-1.200 μg/d/p. Regular monitoring of beta-agonists in municipal sewage systems and their risk assessment based on toxicological data are urgently required in the future.

Seasonal distribution and dynamic evolution of antibiotics and evaluation of their resistance selection potential and ecotoxicological risk at a wastewater treatment plant in Jinan, China

The seasonal distribution and dynamic evolution of antibiotics in wastewater from main treatment areas and in sludge and their resistance selection potential and ecotoxicological risk were studied at a municipal wastewater treatment plant in Jinan, East China. Ten antibiotics were selected, and all were detected in wastewater and sludge samples, with fluoroquinolones showing the highest detection concentrations and frequencies. Seasonal fluctuations in the antibiotic concentrations in the influent, effluent, and sludge were observed, with the highest values in winter in most cases. The dynamic evolution of antibiotics during the treatment process differed among the seasons. The antibiotic removal efficiencies were incomplete, ranging from - 40.47 to 100%. Mass balance analysis showed that sulfonamides, roxithromycin, and metronidazole were mainly removed through biological processing, whereas fluoroquinolones, doxycycline, and chloramphenicol were removed through sludge adsorption. Levofloxacin, as well as a mixture of the 10 antibiotics from the effluent, could pose a low ecotoxicological risk to Daphnia in the receiving waters. Additionally, levofloxacin and ciprofloxacin in the effluent and ciprofloxacin and metronidazole in the sludge may facilitate the selection of antibiotic-resistant bacteria in the environment.

Profiling of intracellular and extracellular antibiotic resistance genes in municipal wastewater treatment plant and their effluent-receiving river

The presence of antibiotic resistance genes (ARGs) and heavy metal resistance genes (MRGs) in extracellular and intracellular DNA (eDNA and iDNA) has received considerable attention in recent years owing to the potential threat to human health and the ecosystem. As a result, we investigated six ARGs, three MRGs, and two mobile genetic elements (MGEs) in the municipal wastewater treatment plant (MWWTP) and its adjacent environments. Results revealed that the absolute abundances of eARGs and eMRGs were lower than iARGs and iMRGs in MWWTP. By contrast, eARGs and eMRGs were higher in river sediments. Among ARGs, aminoglycoside resistance genes (aadA) was the most abundant gene (3.13 × 10² to 2.31 × 10⁶ copies/mL in iDNA; 1.27 × 10³ to 7.23 × 10⁵ copies/mL in eDNA) in MWWTP, while zntA gene (9.4 × 10² to 3.97 × 10⁶ copies/mL in iDNA; 3.2 × 10³ to 6 × 10⁵ copies/mL in eDNA) was amongst the MRGs. Notably, intI1 was enriched and positively correlated with iDNA (tetA, sul1, blaCTX-M, ermB, and merA) and eDNA (blaCTX-M, ermB, and merA), demonstrating its function in the proliferation of resistance genes. This widespread distribution of ARGs, MRGs, and MGEs in MWWTP and its adjacent river sediments will help clarify the transmission routes within these environments and provide a theoretical basis for better monitoring and mitigation of such dissemination.

Elucidating the Effects of the Lipids Regulators Fibrates and Statins on the Health Status of Finfish Species: A Review

The most documented fibrates are gemfibrozil, clofibrate and bezafibrate, while for statins, the majority of the published literature focuses on atorvastatin and simvastatin. The present work reviews previously published research concerning the effects of these hypocholesterolaemic pharmaceuticals on fish, with a particular focus on commercially important species, commonly produced by the European aquaculture industry, specifically in recirculated aquaculture systems (RAS). Overall, results suggest that both acute and chronic exposures to lipid-lowering compounds may have adverse effects on fish, disrupting their capacity to excrete exogenous substances, as well as both lipid metabolism and homeostasis, causing severe ontogenetic and endocrinological abnormalities, leading to hampered reproductive success (e.g., gametogenesis, fecundity), and skeletal or muscular malformations, having serious repercussions on fish health and welfare. Nonetheless, the available literature focusing on the effects of statins or fibrates on commonly farmed fish is still limited, and further research is required to understand the implications of this matter on aquaculture production, global food security and, ultimately, human health.

Mechanism of β-blocker biodegradation by wastewater microorganisms

The recalcitrant β-blockers have been widely detected in aquatic environments up to several hundred μg/L, which are major contributors to β1 antagonistic activities in wastewater. Their biodegradation mechanisms remain obscure, hindering the development of efficient removal techniques. This study constructed the biodegradation pathways for three typical β-blockers, namely atenolol, metoprolol, and propranolol, assessed the toxicity of their major biotransformation products, and identified the key enzyme catalyzing the O-dealkylation reaction leading to pollutant mineralization. Atenolol and metoprolol degradation was more efficient than that of propranolol by activated sludge, producing metoprolol acid (MTPA) as a major intermediate. Hydrogenophaga sp. YM1 isolated from activated sludge possess the α-ketoglutarate dependent dioxygenase (TfdA) responsible for O-dealkylation of MTPA and propranolol, producing 4-hydroxyphenylacetic acid (4-HPA) that can be further degraded and ultimately enters the TCA cycle. The role of TfdA was verified by proteomics, enzyme stimulation/inhibition tests, and gene knockout experiments. Molecular docking suggests its different interactions with MTPA and propranolol. Acetate facilitated the degradation of β-blockers efficiently. The results may shed light on enhanced biological removals of broader β-blockers and their transformation products in the environment.

A charged nanocomposite membrane via co-deposition of gallic acid and polyethyleneimine-silver for improving separation and antibacterial properties

Pharmaceuticals have been continuously detected from surface water and groundwater. In order to improve the rejection performance of pharmaceuticals by a nanofiltration membrane (NF), a positively charged membrane was prepared by co-deposition of natural gallic acid and polyethyleneimine on the polyacrylonitrile hydrolysis membrane. Effects of gallic acid concentration, polyethylene imine concentration, reaction time, and the molecular weight of polyethylene imine were documented. The physical and chemical properties of the membrane were also investigated by surface morphology, hydrophilicity, surface charge, and molecular weight cut-off. The optimized membrane had a molecular weight cut-off of about 958 Da and possessed a pure water permeability of 74.21 L·m^-2·h^-1·MPa^-1. The results exhibited salt rejection in the following order: MgCl₂ > CaCl₂ > MgSO₄ > Na₂CO₃ > NaCl > Na₂SO₄, while the rejection ability of pharmaceuticals is as follows: amlodipine > atenolol > carbamazepine > ibuprofen, suggesting that the positively charged membrane has enhanced retention to both divalent cations and charged pharmaceuticals. In addition, the antibacterial membrane was obtained by loading silver nanoparticles onto the positively charged membrane, which greatly improved the antibacterial ability of the membrane.

Evaluating chemicals of emerging concern in the Ganga River at the two major cities Prayagraj and Varanasi through validated analytical approaches

Evaluating environmental water quality means to assess and protect the environment against unfriendly impacts from various organic impurities emerging from industrial emissions and those released during harvesting. Potential risks related with release of polycyclic aromatic hydrocarbons (PAHs), pesticides and pharmaceuticals (PhAcs), and personal care products (PCPs) into the environment have turned into an increasingly serious issue in ecological safety. Monitoring helps in control of chemicals and ecological status compliance to safeguard specific water uses, for example, drinking water abstraction. A longitudinal review was carried out for 55 different persistent organic pollutants (POPs) for the Ganga River which passes through the urban areas of Prayagraj and Varanasi, India, through validated analytical approaches and measurement uncertainty (MU) estimation to assess their potential use for routine analysis. Furthermore, environmental risk assessment (ERA) carried out in the present study has revealed risk quotient (RQ) higher than 1 in a portion of the aquatic bodies. Using a conservative RQ strategy, POPs were assessed for having extensive risks under acute and chronic exposure, proposing that there is currently critical ecological risk identified with these compounds present in the Ganga River. In general, these outcomes demonstrate a significant contribution for focusing on measures and feasible techniques to minimize the unfavorable effects of contaminants on the aquatic environment.

Further transformation of the primary ozonation products of tramadol- and venlafaxine N-oxide: Mechanistic and structural considerations

Ozonation has been used to effectively remove micropollutants from the secondary effluent in several wastewater treatment plants. It is known that ozonation transforms tertiary amine compounds into their respective N-oxides, however in an earlier study a mass balance could not be closed at elevated ozone concentrations, leading to the assumption that more ozonation products are possible. This study was conducted to elucidate which (hitherto unknown) ozonation products can be formed from venlafaxine and tramadol when ozonating wastewater. Ozonation experiments were performed with tramadol and venlafaxine N-oxide in two different set-ups. Both tramadol- and venlafaxine N-oxide degraded during ozonation in pure (deionized) water in both semi-continuous and batch mode ozonation set-ups. 13 and 17 new transformation products were detected from tramadol- and venlafaxine N-oxide respectively, using high resolution mass spectrometry with ESI(+) ionization. Empirical chemical formulas were proposed based on the determination of the exact masses and interpretation of the product ion spectra. These transformation products result from the addition of one to three oxygen atoms and removal of C, -CH₂, C₂H₂, C₃H₆, etc., from the parent molecule, respectively. Quenching experiments suggested that most of the transformation products originated from the direct reaction with ozone (eight for tramadol N-oxide and ten for venlafaxine N-oxide), whereas fewer products originated from the reaction with OH radicals (three for tramadol N-oxide and three for venlafaxine N-oxide). Reaction mechanisms and chemical structures of products are proposed, based on the available active sites and past literature on ozone reaction mechanisms. The experimental results are compared to theory and literature on ozone reactive sites and ozone reaction mechanisms. All in all this shows that there can be multiple ozonation products, and ozonation pathways can be complex, even if initially only one ozonation product is formed.