Occurrence and risk assessment of typical PPCPs and biodegradation pathway of ribavirin in wastewater treatment plants

Algae-based biotransformation of COVID-19 antiviral ribavirin: Insight on metabolic effect, wastewater application and biological toxicity

The escalation of the global viral prevalence and the corona virus disease 2019 (COVID-19) pandemic has heightened medicine residues and environmental risks. The pioneering study revealed that freshwater microalgae Chlorella sp. SI-50 tolerated the antiviral ribavirin (RBV) ranging in 1-5 mg/L, notable inhibition was observed at 10 mg/L. The increased oxidative damage, antioxidant enzyme and extracellular polysaccharide levels at 10 mg/L further substantiate this. Remarkably, Chlorella sp. SI-50 achieved RBV removal of 99 %, 61 % and 35 % at 1, 5 and 10 mg/L, respectively. The algae-wastewater group, which inoculated algae, exhibited 87 % of RBV removal, a marked improvement over the 17 % in the blank group devoid of microalgae. Ultimately, the toxicity of byproducts was confirmed to become lower through in vitro of J774A.1 cell and Caenorhabditis elegans, validating the reliability of degradation. This study provided valuable insights and sustainable directions for the biological purification of antiviral or RBV-contaminated wastewater.

Efficient ribavirin removal from medical wastewater by microalgae-centric: Microbial biological action and application of double-layer network hydrogel

Pharmaceutical contaminants (PCs) have emerged as a critical class of emerging pollutants in recent decades. Ribavirin (RBV), a broad-spectrum synthetic nucleoside antiviral targeting both RNA and DNA viruses, served as an important therapeutic option for epidemic viral infection. This study employed two distinct freshwater microalgae strains, Scenedesmus sp. SI-35 and Chlorella sp. SI-55, for RBV remediation, coupled with the development of a sustainable microalgae-immobilized hydrogel system with translational potential. The results demonstrated complete RBV removal within 18 days, with no significant shifts in extracellular polysaccharide subtypes under RBV stress. Mechanistic analysis revealed a unique biodegradation pathway mediated primarily by adenosine kinase, distinguishing this process from conventional enzymatic systems such as like cytochrome P450 or glutathione S-transferase. Notably, both two microalgae achieved complete RBV elimination (100 %) in actual wastewater systems, where parallel factor analysis unveiled detailed dynamic variations in organic components. Ultimately, a novel microalgae/alginate@ agarose-hydrogel (M/A@A-hydrogel) was successfully engineered, integrating rapid RBV adsorption within its dual-network matrix and sustained biodegradation by immobilized microalgae. These findings highlight the potential of microalgae-based biotechnologies for targeted removal of nucleoside antiviral drugs, with promising extrapolation to broader classes of pharmaceutical contaminants in water treatment systems.

The determination of wide-range pharmaceuticals class in Erzurum biological wastewater treatment plant using liquid chromatography coupled to tandem mass spectrometry: occurrence, treatment efficiency, and environmental risk assessment

Pharmaceuticals as an important group of contaminants of emerging concern (CECs) are unintentionally discharged into the aquatic environment due to lack of advanced treatment of classical wastewater treatment plants (WWTPs). Therefore, the detection and monitoring studies of pharmaceuticals and personal care products (PPCPs) in an aquatic environment are getting more important as well as the definition of their ecological risks to the aquatic ecosystem. To conduct these studies successfully, it is necessary to develop sensitive, robust, selective, and reliable methods to be able to analyze PPCPs. This study was carried out in the biological WWTP (BWWTP) of Erzurum City, Türkiye, to investigate the treatment efficiency of pharmaceuticals in the plant and to assess the ecological risks for the Karasu River where treated wastewater is discharged into it. For this purpose, a wide range of pharmaceutical classes in influent wastewater (IWW) and effluent wastewater samples taken from Erzurum BBWWTP, Türkiye was simultaneously identified and quantified with liquid chromatography coupled with tandem mass spectrometry following liquid phase extraction for sample preparation. A total of 55 active pharmaceutical groups in 25 general drug groups (29 subgroups) were detected, with the highest average ratios being 82.459%, 7.306%, 4.949%, and 2.145% for analgesic-anti-inflammatory, antiepileptic, diabetic, and antipyretic pharmaceuticals groups, respectively, in IWW. Although flurbiprofen from the analgesic-anti-inflammatory pharmaceuticals group was treated with the average efficiency of 66.13% during the 12-month treatment period, it had a high risk quotient due to the very high initial concentration in WWT in the range of 809.01-22,901.10 µg/L.

Production of Reactive Oxygen Species during Redox Manipulation and Its Potential Impacts on Activated Sludge Wastewater Treatment Processes

Reactive oxygen species (ROS) are ubiquitous in redox-fluctuating environments, exerting profound impacts on biogeochemical cycles. However, whether ROS can be generated during redox manipulation in activated sludge wastewater treatment processes (AS-WTPs) and the underlying impacts remain largely unknown. This study demonstrates that ROS production is ubiquitous in AS-WTPs due to redox manipulation and that the frequency and capacity of ROS production depend on the operating modes. The anaerobic/oxic continuous-flow reactor showed persistent ROS generation (0.8-2.1 μM of instantaneous H2O2), whereas the oxic/anoxic sequencing batch reactor (0.21-0.28 mM of H2O2 per cycle) and the anaerobic/anoxic digestion reactor (0.27-0.29 mM of H2O2 per cycle) exhibited periodic ROS production. Our results illustrated that ROS generated during redox manipulation can contribute to the removal of organic micropollutants. Due to their high activity, ROS can directly accelerate the abiotic oxidation of organic phenolics and Fe(II) minerals in sludges. ROS could also affect biotic nitrification by changing the microbial community composition and regulating the relative expression of functional genes, such as amoA, nrxA, and nrxB. This research demonstrates the ubiquitous production of ROS during redox manipulation in AS-WTPs, which provides new insights into pollutant removal and the abiotic and biotic elemental transformation in AS-WTPs.

Comprehensive eco-geno-toxicity and environmental risk of common antiviral drugs in aquatic environments post-pandemic

The eco-geno-toxicological impacts of the most widely used antiviral drugs against SARS-CoV2 - ribavirin, ritonavir, nirmatrelvir and tenofovir - were investigated in freshwater organisms. Ribavirin and tenofovir exhibited the highest acute toxicity in the rotifer Brachionus calyciflorus at concentrations of a few mg/L while ritonavir and nirmatrelvir showed similar effects at tens of mg/L; acute toxicity of ribavirin was also observed in the crustacean Ceriodaphnia dubia at similar concentrations. In contrast, the crustacean Thamnocephalus platyurus showed the lowest sensitivity to the antiviral drugs tested with no sublethal effects. Chronic toxicity tests revelead that these antivirals induced effects in consumers at concentrations of environmental concern (ng-µg/L). Ribavirin showed the highest toxicity to the alga Raphidocelis subcapitata, while ritonavir showed the highest toxicity to B. calyciflorus and C. dubia. DNA damage and oxidative stress were observed in C. dubia at 0.001 µg/L and 0.1 µg/L when exposed to ritonavir and nirmatrelvir respectively, and at 1 µg/L when exposed to ribavirin and tenofovir. Toxic and genotoxic environmental risks were assessed with risk quotients for ritonavir, tenofovir and ribavirin exceeding the threshold of 1, indicating significant environmental concern.

Occurrence and distribution of emerging contaminants in wastewater treatment plants: A globally review over the past two decades

Emerging contaminants are pervasive in aquatic environments globally, encompassing pharmaceuticals, personal care products, steroid hormones, phenols, biocides, disinfectants and various other compounds. Concentrations of these contaminants are detected ranging from ng/L to μg/L. Even at trace levels, these contaminants can pose significant risks to ecosystems and human health. This article systematically summarises and categorizes data on the concentrations of 54 common emerging contaminants found in the influent and effluent of wastewater treatment plants across various geographical regions: North America, Europe, Oceania, Africa, and Asia. It reviews the occurrence and distribution of these contaminants, providing spatial and causal analyses based on data from these regions. Notably, the maximum concentrations of the pollutants observed vary significantly across different regions. The data from Africa, in particular, show more frequent detection of pharmaceutical maxima in wastewater treatment plants.

Effects of dissolved organic matter from different sources on ritonavir photolysis

With the misuse of antiviral drugs, the residual levels of ritonavir (RTV) in aquatic environments continue to increase, potentially posing threats to ecosystems and human health. However, the current understanding of the photochemical behavior of RTV in water, especially the mechanism by which dissolved organic matter (DOM) from different sources affects the indirect photolysis of RTV, remains limited. This study systematically investigated the effects of DOM from different sources (including sludge, algae, dustfall, and soil, namely SL-DOM, AL-DOM, DF-DOM, and SO-DOM, respectively) on the photodegradation of RTV for the first time. DOM exhibited a dual role in RTV degradation, with SL-DOM and AL-DOM accelerating the degradation process, while DF-DOM and SO-DOM inhibited it. Direct photolysis accounted for 40-53% of the overall photodegradation, underscoring its significant contribution to the degradation process. Quenching and competitive kinetics experiments revealed that 3DOM⁎ is the dominant contributor to the indirect photolysis of RTV. Exogenous DOM (DF-DOM, SO-DOM) exhibited higher generation rate and steady-state concentraiton of 3DOM⁎, while endogenous DOM (SL-DOM, AL-DOM) exhibited higher quantum yields of 3DOM⁎ and reactivity, leading to distinct mechanisms for the indirect photodegradation of RTV. This study explored the effects of DOM from different sources on the photodegradation of RTV, providing important insights into how DOM affects the photochemical behavior and ecological risk of RTV. It also provides a reference for exploring the photochemical behavior of other drugs.

Long term study on the fate and environmental risks of favipiravir in wastewater treatment plants and comparison with COVID-19 cases

In recent years especially during COVID-19, the increased usage of antiviral drugs has led to increased interest in monitoring their presence in wastewater worldwide. In this study, it was examined the occurrence, fate and environmental risks of favipiravir which is used for COVID-19 treatment in two wastewater treatment plants (WWTPs) with different treatment processes in Istanbul, Turkey. Favipiravir was measured in WWTPs influent samples, effluent samples and sludge samples with maximum concentrations of 97 μg/L, 64.11 μg/L and 182.47 μg/g, respectively. Favipiravir had removal efficiency below 55 % for both WWTPs. Mass balance analysis showed that favipiravir removal in WWTPs mainly attributed to biodegradation/biotransformation. Statistical analysis revealed a significant correlation between favipiravir concentration and COVID-19 incidence in Istanbul. The microbial distribution analysis indicated that comparison of collected COVID-19 pandemic sludge and post-pandemic period sludge samples, a noteworthy reduction in the Chloroflexi and Actinobacteriota phyla at the phylum level was observed. Environmental risk assessment using risk quotients ranged from 168 to 704, indicating that the presence of this antiviral drug posed significant ecological risks to aquatic organisms. The study concluded that WWTPs were releasing antiviral drugs into the environment, thereby posing risks to both the aquatic ecosystem and public health. The results of this study demonstrate the persistence of favipiravir in WWTPs and offer crucial supporting data for further research into the advancement of wastewater treatment technology. Also, this study shows wastewater based monitoring is supplementary and early warning system for determining the occurrence of antiviral drugs.

Priority list of pharmaceutical active compounds in aquatic environments of Mexico considering their occurrence, environmental and human health risks

Pharmaceutical active compounds (PhACs) are detected pollutants in aquatic environments worldwide at concentrations ranging from ng L-1 to µg L-1. Currently, PhAC monitoring is poorly realized in Mexico. This study proposes a priority list of PhACs in Mexican aquatic environments, considering their occurrence and environmental and human health risks. Ecological risks were assessed as Risk Quotients (RQ) values using the PhAC concentrations detected in surface water, obtaining high risks (RQ > 1) against aquatic organisms, especially of naproxen, ibuprofen, diclofenac, acetaminophen, 17β-estradiol, carbamazepine, ketoprofen, caffeine. In contrast, potential human health risks (RQH) were assessed on the Mexican population using the concentrations quantified in groundwater, demonstrating potential risks (RQH > 0.2) on the population, particularly of DCF and CBZ. Thus, a priority list of PhACs can be used as a reference for environmental monitoring in Mexican water supplies as well as PhACs monitoring in countries of the Caribbean region and Central America.

Prediction of Potential Risk for Flupyradifurone and Its Transformation Products to Hydrobionts

Flupyradifurone (FPF) is considered the latest generation of neonicotinoid insecticides. Here, we investigated the toxicity and ecological risk of FPF and its aerobic transformation products (TPs) to aquatic species using the method of prediction. We found that FPF exhibited moderate or high toxicity to some aquatic species. The 5% hazardous concentration of FPF was 3.84 μg/L for aquatic organisms. We obtained 91 aerobic TPs for FPF, and almost half of FPF TPs exhibited toxicity to fish or Daphnia. Eleven of the TPs of FPF exhibited a high or moderate risk to aquatic ecosystems. All FPF TPs with high and moderate risks contained a 6-chloropyridine ring structure, indicating that the derivant of a pyridine ring exhibits potential risks to aquatic ecosystems. Our results provide insight into the potential risk of FPF to aquatic ecosystems and could be used to help set criteria to control pollution caused by FPF.

Nitrogen-doped mesoporous activated carbon from Lentinus edodes residue: an optimized adsorbent for pharmaceuticals in aqueous solutions

In this study, phosphoric acid activation was employed to synthesize nitrogen-doped mesoporous activated carbon (designated as MR1) from Lentinus edodes (shiitake mushroom) residue, while aiming to efficiently remove acetaminophen (APAP), carbamazepine (CBZ), and metronidazole (MNZ) from aqueous solutions. We characterized the physicochemical properties of the produced adsorbents using scanning electron microscopy (SEM), nitrogen adsorption isotherms, and X-ray photoelectron spectroscopy (XPS). MR1, MR2, and MR3 were prepared using phosphoric acid impregnation ratios of 1, 2, and 3 mL/g, respectively. Notably, MR1 exhibited a significant mesoporous structure with a volume of 0.825 cm3/g and a quaternary nitrogen content of 2.6%. This endowed MR1 with a high adsorption capacity for APAP, CBZ, and MNZ, positioning it as a promising candidate for water purification applications. The adsorption behavior of the contaminants followed the Freundlich isotherm model, suggesting a multilayer adsorption process. Notably, MR1 showed excellent durability and recyclability, maintaining 95% of its initial adsorption efficiency after five regeneration cycles and indicating its potential for sustainable use in water treatment processes.

Ibuprofen and Other Arylpropionics: The Relevance in Immediate Hypersensitivity Drug Reactions

BACKGROUND

Ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), is the most frequent medication to be involved in hypersensitivity drug reactions (HDRs). Other analgesic/anti-inflammatory drugs in the arylpropionic group are also relevant, albeit to a lesser extent. Ibuprofen is widely consumed by people of all ages, both on medical prescription and over the counter; moreover, it is an organic contaminant of surface waters and foods. While numerous drugs cause HDR, ibuprofen's underlying mechanisms are more intricate and involve both specific immunological and non-immunological mediated reactions.

SUMMARY

we concentrate on immediate responses, including urticaria with or without angioedema, anaphylaxis, and angioedema, classifying reactions according to whether they are caused by single or multiple NSAIDs and based on the mechanisms at play. Both groups may experience anaphylaxis, defined as an immediate, severe systemic reaction involving at least two organs, though the frequency and severity can vary. Following this classification, more clinical manifestations can be identified. Diagnosis is partly based on a detailed clinical history, including information about ibuprofen and/or other arylpropionic derivatives involved, the interval between drug intake and symptoms onset, clinical manifestations, number of episodes, and the patient's tolerance or response to other medications - mainly non-chemically related NSAID - both before and after reactions to ibuprofen and/or other arylpropionic drugs. A drug provocation test is frequently necessary to make a diagnosis.

KEY MESSAGE

Because ibuprofen is the most widely prescribed NSAID, it is reasonable to assume its role as the leading cause of HDR will only become more important.

Chlorination of antiviral drug ribavirin: Kinetics, nontargeted identification, and concomitant toxicity evolution

Residual antiviral drugs in wastewater may increase the risk of generating transformation products (TPs) during wastewater treatment. Therefore, chlorination behavior and toxicity evolution are essential to understand the secondary ecological risk associated with their TPs. Herein, chlorination kinetics, transformation pathways, and secondary risks of ribavirin (RBV), one of the most commonly used broad-spectrum antivirals, were investigated. The pH-dependent second-order rate constants k increased from 0.18 M-1·s-1 (pH 5.8) to 1.53 M-1·s-1 (pH 8.0) due to neutral RBV and ClO- as dominant species. 12 TPs were identified using high-resolution mass spectrometry in a nontargeted approach, of which 6 TPs were reported for the first time, and their chlorination pathways were elucidated. The luminescence inhibition rate of Vibrio fischeri exposed to chlorinated RBV solution was positively correlated with initial free active chlorine, probably due to the accumulation of toxic TPs. Quantitative structure-activity relationship prediction identified 7 TPs with elevated toxicity, concentrating on developmental toxicity and bioconcentration factors, which explained the increased toxicity of chlorinated RBV. Overall, this study highlights the urgent need to minimize the discharge of toxic chlorinated TPs into aquatic environments and contributes to environmental risk control in future pandemics and regions with high consumption of antivirals.

Seasonal patterns, fate and ecological risk assessment of pharmaceutical compounds in a wastewater treatment plant with Bacillus bio-reactor treatment

Pharmaceutical compounds (PhCs) pose a growing concern with potential environmental impacts, commonly introduced into the environment via wastewater treatment plants (WWTPs). The occurrence, removal, and season variations of 60 different classes of PhCs were investigated in the baffled bioreactor (BBR) wastewater treatment process during summer and winter. The concentrations of 60 PhCs were 3400 ± 1600 ng/L in the influent, 2700 ± 930 ng/L in the effluent, and 2400 ± 120 ng/g dw in sludge. Valsartan (Val, 1800 ng/L) was the main contaminant found in the influent, declining to 520 ng/L in the effluent. The grit chamber and BBR tank were substantially conducive to the removal of VAL. Nonetheless, the BBR process showcased variable removal efficiencies across different PhC classes. Sulfadimidine had the highest removal efficiency of 87 ± 17% in the final effluent (water plus solid phase). Contrasting seasonal patterns were observed among PhC classes within BBR process units. The concentrations of many PhCs were higher in summer than in winter, while some macrolide antibiotics exhibited opposing seasonal fluctuations. A thorough mass balance analysis revealed quinolone and sulfonamide antibiotics were primarily eliminated through degradation and transformation in the BBR process. Conversely, 40.2 g/d of macrolide antibiotics was released to the natural aquatic environment via effluent discharge. Gastric acid and anticoagulants, as well as cardiovascular PhCs, primarily experienced removal through sludge adsorption. This study provides valuable insights into the intricate dynamics of PhCs in wastewater treatment, emphasizing the need for tailored strategies to effectively mitigate their release and potential environmental risks.

An assessment and characterization of pharmaceuticals and personal care products (PPCPs) within the Great Lakes Basin: Mussel Watch Program (2013-2018)

Defining the environmental occurrence and distribution of chemicals of emerging concern (CECs), including pharmaceuticals and personal care products (PPCPs) in coastal aquatic systems, is often difficult and complex. In this study, 70 compounds representing several classes of pharmaceuticals, including antibiotics, anti-inflammatories, insect repellant, antibacterial, antidepressants, chemotherapy drugs, and X-ray contrast media compounds, were found in dreissenid mussel (zebra/quagga; Dreissena spp.) tissue samples. Overall concentration and detection frequencies varied significantly among sampling locations, site land-use categories, and sites sampled proximate and downstream of point source discharge. Verapamil, triclocarban, etoposide, citalopram, diphenhydramine, sertraline, amitriptyline, and DEET (N,N-diethyl-meta-toluamide) comprised the most ubiquitous PPCPs (> 50%) detected in dreissenid mussels. Among those compounds quantified in mussel tissue, sertraline, metformin, methylprednisolone, hydrocortisone, 1,7-dimethylxanthine, theophylline, zidovudine, prednisone, clonidine, 2-hydroxy-ibuprofen, iopamidol, and melphalan were detected at concentrations up to 475 ng/g (wet weight). Antihypertensives, antibiotics, and antidepressants accounted for the majority of the compounds quantified in mussel tissue. The results showed that PPCPs quantified in dreissenid mussels are occurring as complex mixtures, with 4 to 28 compounds detected at one or more sampling locations. The magnitude and composition of PPCPs detected were highest for sites not influenced by either WWTP or CSO discharge (i.e., non-WWTPs), strongly supporting non-point sources as important drivers and pathways for PPCPs detected in this study. As these compounds are detected at inshore and offshore locations, the findings of this study indicate that their persistence and potential risks are largely unknown, thus warranting further assessment and prioritization of these emerging contaminants in the Great Lakes Basin.

Efficient adsorption of chloroquine phosphate by a novel sodium alginate/tannic acid double-network hydrogel in a wide pH range

In this work, a novel double-network composite hydrogel (SA/TA), composed of sodium alginate (SA) and tannic acid (TA), was designed and fabricated by a successive cross-linking method using Ti(IV) and Ca(II) as crosslinkers. SA/TA exhibited reinforced mechanical strength and anti-swelling properties because of the double-network structure. SA/TA was used as an adsorbent for removal of a popular antiviral drug, chloroquine phosphate (CQ), in water. The adsorption performance of SA/TA was systematically investigated, to study various effects including those of TA mass content, solution pH, adsorption time, and initial CQ concentration. Adsorption was also examined in presence of inorganic and organic coexisting substances commonly found in wastewater, and under different actual water samples. Batch experimental results indicated that SA/TA could maintain higher and more stable CQ uptakes within a wide solution pH range from 3.0 to 10.0, compared to its precursor, SA hydrogel, owing to the addition of TA-Ti(IV) coordination network. The maximum experimental CQ uptake exhibited by the 1:1 (by wt) SA/TA (SA/TA2) was as high as 0.699 mmol/g at the initial pH of 9.0. A high concentration of coexisting NaCl evidently reduced the CQ uptakes of SA/TA2 due to the electrostatic shielding effect, moreover, divalent cations including Ca(II) and Mg(II) also inhibited the adsorption of CQ due to competitive adsorption. However, humic acid had little effect on this adsorption. Considering the apparent adsorption performance, the aforementioned effects of various factors and the spectroscopic characterizations, multi-interactions are suggested for adsorption including chelation, electrostatic interactions, π-π electron donor-acceptor interaction and hydrogen bonding. SA/TA showed a slight loss in adsorption capacity toward CQ and sustained physicochemical structural stability, even after six adsorption-desorption cycles. In addition to CQ, SA/TA could be efficiently used for adsorption of two other antivirus drugs, namely, hydroxychloroquine sulfate and oseltamivir phosphate. This work provides an effective strategy for the design and fabrication of novel adsorbents that can effectively adsorb antiviral drugs over a wide pH range.

Comparative study of electro-Fenton and photoelectro-Fenton processes using a novel photocatalytic fuel cell electro-Fenton system with g-C3 N4 @N-TiO2 and Ag/CNT@CF as electrodes

In this study, a novel photocatalytic fuel cell electro-Fenton (PFC-EF) system was constructed using g-C3 N4 @N-TNA and Ag/CNT@CF as electrodes. The composition, structure, and morphology of the electrodes were obtained. The g-C3 N4 @N-TNA, with its 2.37 eV band gap and 100 mV photovoltage, has excellent excitation properties for sunlight. Ag/CNT@CF with abundant pores, CNT 3D nanostructures, and Ag crystals on the surface can improve the electro-Fenton efficiency. A comparative study of rhodamine B (RhB) degradation was performed in this system. It has been shown that electric fields can greatly enhance the oxidation efficiency of both anode photocatalysis and the cathode electro-Fenton process. Under optimal conditions, RhB can be completely removed by the photoelectro-Fenton (PEF) process. The energy consumption of the PEF system was obtained. The electrical energy per order (EE/O) is only 9.2 kWh/m3 ·order, which is only 16.5% of EF and 2.2% of PFC-EF system. The mineralization current efficiency (MCE) of the PEF system reached 93.3% for a 2-h reaction. Therefore, the PEF system has the advantage of saving energy. The kinetic analysis shows that the RhB removal follows a first-order kinetic law, and the reaction rate constant reaches 0.1304 min-1 , which is approximately 5.2 times larger and 4.0 times larger than the electro-Fenton and PFC-EF processes, respectively. RhB removal is a coupling multimechanism in which an electric field enhances photoelectron migration, Ag loading improves H2 O2 generation, UV light coupled with H2 O2 promotes hydroxyl radical (٠OH) generation, and the nanoconfinement effect of CNTs promotes ٠OH accumulation in favor of RhB degradation. PRACTITIONER POINTS: Novel efficiency photocatalytic fuel cell electro-Fenton system was constructed. The electric field greatly enhances the photocatalytic fuel cell electro-Fenton system. Multiple coupling mechanisms of UV/H2O2, UV/Fenton and photo-electro-Fenton have been revealed.

Prevalence of pharmaceuticals and personal care products, microplastics and co-infecting microbes in the post-COVID-19 era and its implications on antimicrobial resistance and potential endocrine disruptive effects

The COVID-19 (coronavirus disease 2019) pandemic's steady condition coupled with predominance of emerging contaminants in the environment and its synergistic implications in recent times has stoked interest in combating medical emergencies in this dynamic environment. In this context, high concentrations of pharmaceutical and personal care products (PPCPs), microplastics (MPs), antimicrobial resistance (AMR), and soaring coinfecting microbes, tied with potential endocrine disruptive (ED) are critical environmental concerns that requires a detailed documentation and analysis. During the pandemic, the identification, enumeration, and assessment of potential hazards of PPCPs and MPs and (used as anti-COVID-19 agents/applications) in aquatic habitats have been attempted globally. Albeit receding threats in the magnitude of COVID-19 infections, both these pollutants have still posed serious consequences to aquatic ecosystems and the very health and hygiene of the population in the vicinity. The surge in the contaminants post-COVID also renders them to be potent vectors to harbor and amplify AMR. Pertinently, the present work attempts to critically review such instances to understand the underlying mechanism, interactions swaying the current health of our environment during this post-COVID-19 era. During this juncture, although prevention of diseases, patient care, and self-hygiene have taken precedence, nevertheless antimicrobial stewardship (AMS) efforts have been overlooked. Unnecessary usage of PPCPs and plastics during the pandemic has resulted in increased emerging contaminants (i.e., active pharmaceutical ingredients and MPs) in various environmental matrices. It was also noticed that among COVID-19 patients, while the bacterial co-infection prevalence was 0.2-51%, the fungi, viral, protozoan and helminth were 0.3-49, 1-22, 2-15, 0.4-15% respectively, rendering them resistant to residual PPCPs. There are inevitable chances of ED effects from PPCPs and MPs applied previously, that could pose far-reaching health concerns. Furthermore, clinical and other experimental evidence for many newer compounds is very scarce and demands further research. Pro-active measures targeting effective waste management, evolved environmental policies aiding strict regulatory measures, and scientific research would be crucial in minimizing the impact and creating better preparedness towards such events among the masses fostering sustainability.

Stability and WBE biomarkers possibility of 17 antiviral drugs in sewage and gravity sewers

Wastewater-based epidemiology (WBE) is a promising technique for monitoring the rapidly increasing use of antiviral drugs during the COVID-19 pandemic. It is essential to evaluate the in-sewer stability of antiviral drugs in order to determine appropriate biomarkers. This study developed an analytical method for quantification of 17 typical antiviral drugs, and investigated the stability of target compounds in sewer through 4 laboratory-scale gravity sewer reactors. Nine antiviral drugs (lamivudine, acyclovir, amantadine, favipiravir, nevirapine, oseltamivir, ganciclovir, emtricitabine and telbivudine) were observed to be stable and recommended as appropriate biomarkers for WBE. As for the other 8 unstable drugs (abacavir, arbidol, ribavirin, zidovudine, ritonavir, lopinavir, remdesivir and efavirenz), their attenuation was driven by adsorption, biodegradation and diffusion. Moreover, reaction kinetics revealed that the effects of sediments and biofilms were regarded to be independent in gravity sewers, and the rate constants of removal by biofilms was directly proportional to the ratio of surface area against wastewater volume. The study highlighted the potential importance of flow velocity for compound stability, since an increased flow velocity significantly accelerated the removal of unstable biomarkers. In addition, a framework for graded evaluation of biomarker stability was proposed to provide reference for researchers to select suitable WBE biomarkers. Compared with current classification method, this framework considered the influences of residence time and different removal mechanisms, which additionally screened four antiviral drugs as viable WBE biomarkers. This is the first study to report the stability of antiviral drugs in gravity sewers.

The photolytic behavior of COVID-19 antivirals ribavirin in natural waters and the increased environmental risk

Increasing drug residues in aquatic environments have been caused by the abuse of antivirals since the global spread of the COVID-19 epidemic, whereas research on the photolytic mechanism, pathways and toxicity of these drugs is limited. The concentration of COVID-19 antivirals ribavirin in rivers has been reported to increase after the epidemic. Its photolytic behavior and environmental risk in actual waters such as wastewater treatment plant (WWTP) effluent, river water and lake water were first investigated in this study. Direct photolysis of ribavirin in these media was limited, but indirect photolysis was promoted in WWTP effluent and lake water by dissolved organic matter and NO3-. Identification of photolytic intermediates suggested that ribavirin was photolyzed mainly via C-N bond cleavage, splitting of the furan ring and oxidation of the hydroxyl group. Notably, the acute toxicity was increased after ribavirin photolysis owing to the higher toxicity of most of the products. Additionally, the overall toxicity was greater when ARB photolysis in WWTP effluent and lake water. These findings emphasize the necessity to concern about the toxicity of ribavirin transformation in natural waters, as well as to limit its usage and discharge.

Study on the removal characteristics and degradation pathways of highly toxic and refractory organic pollutants in real pharmaceutical factory wastewater treated by a pilot-scale integrated process

Introduction

Pharmaceutical wastewater frequently contains high levels of toxic pollutants. If they are discharged untreated, they pose a threat to the environment. The traditional activated sludge process and the advanced oxidation process do not sufficiently remove toxic and conventional pollutants from pharmaceutical wastewater treatment plants (PWWTPs).

Methods

We designed a pilot-scale reaction system to reduce toxic organic pollutants and conventional pollutants from pharmaceutical wastewater during the biochemical reaction stage. This system included a continuous stirred tank reactor (CSTR), microbial electrolysis cells (MECs), an expanded sludge bed reactor (EGSB), and a moving bed biofilm reactor (MBBR). We used this system to further investigate the benzothiazole degradation pathway.

Results and discussion

The system effectively degraded the toxic pollutants (benzothiazole, pyridine, indole, and quinoline) and the conventional chemicals (COD, NH4+-N, TN). During the stable operation of the pilot-scale plant, the total removal rates of benzothiazole, indole, pyridine, and quinoline were 97.66, 94.13, 79.69, and 81.34%, respectively. The CSTR and MECs contributed the most to the removal of toxic pollutants, while the EGSB and MBBR contributed less to the removal of the four toxic pollutants. Benzothiazoles can be degraded via two pathways: the benzene ring-opening reaction and the heterocyclic ring-opening reaction. The heterocyclic ring-opening reaction was more important in degrading the benzothiazoles in this study.

Conclusion

This study provides feasible design alternatives for PWWTPs to remove both toxic and conventional pollutants at the same time.

Photodegradation of ibuprofen laden-wastewater using sea-mud catalyst/H2O2 system: evaluation of sonication modes and energy consumption

The main goal of the current investigation was to decontaminate ibuprofen (IBP) from hospital wastewater using sea mud as an H2O2 activator. Sea sludge was converted into catalysts at different temperatures and residence times in furnaces, and then tested in the removal of IBP, and the most efficient ones were reported for the production of catalysts. The catalyst was optimized at 400 °C and 3 h. SEM-mapping, FTIR, EDX, BET, and BJH experiments were used to characterize the catalyst. Experiments were done at two pulsed and continuous ultrasonication modes in a photoreactor, and their efficiencies were statistically compared. The designed variables included IBP concentration (10-100 mg/L), the catalyst concentration (0-3 g/L), pH (4-9), and time (10-90 min). The oxidation process had the maximum efficiency at pH 4, treatment time of 60 min, catalyst quantity of 5 g/L, and IBP content of 50 mg/L. The catalyst was recycled, and in the fifth stage, the removal efficiency of IBP was reduced to 50%. The amount of energy consumed for treating IBP laden-wastewater using the evaluated catalyst in two modes of continuous and pulsed ultrasonic was calculated as 102 kW h/m3 and 10 kW h/m3, respectively. IBP oxidation process was fitted with the first-order kinetic model. The system can be proposed for purifying hospital and pharmaceutical wastewaters.

Fluorescence Detection of Trace Disinfection Byproducts by Ag Nanoprism-Modulated Lanthanide MOFs

Disinfection byproducts (DBPs), as an emerging water pollutant, present increasing concern and risk in public health and water safety. Due to their low concentration levels and inherent similarity in molecular structures, sensitive and accurate determination of DBPs is still a challenge especially for onsite or online detection. Herein, a self-regulated fluorescent probe based on the Ag nanoprism-modified lanthanide metal-organic framework (AgNPR@EuMOF) is designed for trichloroacetic acid (TCAA) detection. The EuMOF is constructed with Eu as the metal node and 5-boronoisophthalic acid as the ligand. By introducing sulfhydryl groups into EuMOF, AgNPR can be anchored on the EuMOF surface through Ag-S bonds, enabling the synthesis of stable AgNPR@EuMOF composites. During the sensing process, the triangle AgNPR will react with the organic halogen molecule, accomplished with the blue shift of surface plasmon resonance absorption peak and the significant change in the fluorescence of EuMOF. This probe can detect TCAA in a wide concentration range (0.1-40 μM) with high sensitivity and specificity. The density functional theory calculation on binding energies between DBPs and AgNPR suggests that TCAA has the largest interaction ability with AgNPR than other DBPs. Moreover, the detection of TCAA in real tap water and swimming pool water is also demonstrated with high accuracy. The reported AgNPR@EuMOF represents one of the pioneer fluorescence probes in DBP detection, which holds great promise for onsite or online analysis of trace DBPs in water.

Biocatalyst developed with recovered iron-rich minerals enhances the biotransformation of SARS-CoV-2 antiviral drugs in anaerobic bioreactors

The biotransformation of the SARS-CoV-2 antiviral drugs, ribavirin and tenofovir, was studied in methanogenic bioreactors. The role of iron-rich minerals, recovered from a metallurgic effluent, on the biotransformation process was also assessed. Enrichment of anaerobic sludge with recovered minerals promoted superior removal efficiency for both antivirals (97.4 % and 94.7 % for ribavirin and tenofovir, respectively) as compared to the control bioreactor lacking minerals, which achieved 58.5 % and 37.9 % removal for the same drugs, respectively. Further analysis conducted by liquid chromatography coupled to mass spectroscopy revealed several metabolites derived from the biotransformation of both antivirals. Interestingly, tracer analysis with ¹³CH₄ revealed that anaerobic methane oxidation coupled to Fe(III) reduction occurred in the enriched bioreactor, which was reflected in a lower content of methane in the biogas produced from this system, as compared to the control bioreactor. This treatment proposal is suitable within the circular economy concept, in which recovered metals from an industrial wastewater are applied in bioreactors to create a biocatalyst for promoting the biotransformation of emerging pollutants. This strategy may be appropriate for the anaerobic treatment of wastewaters originated from hospitals, as well as from the pharmaceutical and chemical sectors.

Nanocomposites of Titanium Dioxide and Peripherally Substituted Phthalocyanines for the Photocatalytic Degradation of Sulfamethoxazole

Phthalocyanines (Pcs) are often used in photosensitization of titanium(IV) oxide, a commonly employed photocatalyst, as such an approach holds the promise of obtaining highly stable and efficient visible light-harvesting materials. Herein, we report on the preparation, characterization and photoactivity of a series of composites based on TiO₂ and peripherally modified metallophthalocyanines: either tetrasulfonated or 4,4',4'',4'''-tetraazaphthalocyanines, with either copper(II), nickel(II) or zinc(II) as the central metal ion. Physicochemical characterization was performed using UV-Vis diffuse reflectance spectroscopy, hydrodynamic particle-size analysis, surface-area analysis using N₂ adsorption-desorption measurements and thermogravimetry combined with differential scanning calorimetry. The band-gap energy values were lower for the composites with peripherally modified phthalocyanines than for the commercial TiO₂ P25 or the unsubstituted zinc(II) phthalocyanine-grafted TiO₂. TG-DSC results confirmed that the chemical deposition, used for the preparation of Pc/TiO₂ composites, is a simple and efficient method for TiO₂ surface modification, as all the Pc load was successfully grafted on TiO₂. The photocatalytic potential of the Pc/TiO₂ materials was assessed in the photocatalytic removal of sulfamethoxazole-a commonly used antibacterial drug of emerging ecological concern. To compare the activity of the materials in different conditions, photodegradation tests were conducted both in water and in an organic medium.