Contribution of hospital effluents to the load of pharmaceuticals in urban wastewaters: identification of ecologically relevant pharmaceuticals

Selective enrichment, identification, and isolation of diclofenac, ibuprofen, and carbamazepine degrading bacteria from a groundwater biofilm

Diclofenac, ibuprofen, and carbamazepine are three of the most widely detected and most concerning pharmaceutical residues in aquatic ecosystems. The aim of this study was to identify bacteria that may be involved in their degradation from a bacterial biofilm. Selective enrichment cultures in mineral salt solution containing pharmaceutical compounds as sole source of carbon and energy were set up, and population dynamics were monitored using shotgun metagenome sequencing. Bacterial genomes were reconstructed using genome-resolved metagenomics. Thirty bacterial isolates were obtained, identified at species level, and tested regarding pharmaceutical biodegradation at an initial concentration of 1.5 mg l-1. The results indicated that most probably diclofenac biodegrading cultures consisted of members of genera Ferrovibrio, Hydrocarboniphaga, Zavarzinia, and Sphingopyxis, while in ibuprofen biodegradation Nocardioides and Starkeya, and in carbamazepine biodegradation Nocardioides, Pseudonocardia, and Sphingopyxis might be involved. During the enrichments, compared to the initial state the percentage relative abundance of these genera increased up to three orders of magnitude. Except Starkeya, the genomes of these bacteria were reconstructed and annotated. Metabolic analyses of the annotated genomes indicated that these bacteria harbored genes associated with pharmaceutical biodegradation. Stenotrophomonas humi DIC_5 and Rhizobium daejeonense IBU_18 isolates eliminated diclofenac and ibuprofen during the tests in the presence of either glucose (3 g l-1) or in R2A broth. Higher than 90% concentration reduction was observed in the case of both compounds.

Electron beam degradation of the cardiovascular drug salbutamol: Mechanisms and degradation pathways

With the increasing incidence and mortality of cardiovascular diseases, high consumption of the cardiovascular drug salbutamol (SAL) has made this compound an emerging pollutant in natural water and a challenge for traditional wastewater treatment. In this paper, an efficient advanced oxidation process was used to degrade SAL by electron beam (EB) irradiation. The results revealed that 100 mg L^-1 of SAL could be nearly completely removed (95.1%) at 10 kGy and the degradation kinetic well followed pseudo first-order kinetic model. Different factors, including pH, inorganic ions and water matrix, had varying effects on the degradation of SAL owing to their important influence on the formation of reactive species in the aqueous solution. And it was found that e_aq^- played a major role in the degradation of SAL parent. Moreover, the addition of K₂S₂O₈ (20 mM) increased the SAL mineralization rate from 2.9% to 64.2%, suggesting that oxidation free radicals could greatly improve the mineralization rate of SAL. Combining with the theoretical calculations and determined degradation by-products, four possible degradation pathways of SAL by EB irradiation were proposed, including H•, •OH and e_aq^- all participated in the degradation of SAL. Finally, toxicity evaluation suggested that the toxicity of SAL aqueous solution reduced after EB irradiation, indicating that it is an effective method to degrade SAL.

Single adsorption of diclofenac and ronidazole from aqueous solution on commercial activated carbons: effect of chemical and textural properties

The importance of the textural and physicochemical characteristics upon the adsorption capacity of the commercial activated carbons (ACs) Coconut, Wood, Merck, Darco, and Norit towards ronidazole (RNZ) and diclofenac (DCF) from water solution was investigated thoroughly in this work. At pH = 7, Coconut AC and Wood AC presented the highest adsorption capacity towards RNZ (444 mg/g) and DCF (405 mg/g). The maximum mass of RNZ adsorbed onto Coconut AC was higher in this study than those outlined previously in other works. Besides, the maximum capacity of Wood AC for adsorbing DCF was comparable to those found for other ACs. The adsorption capacity of all the ACs was increased by surface area and was favored by incrementing the acidic site concentration. The π-π stacking interactions were the predominant adsorption mechanism for the RNZ and DCF adsorption on ACs, and the acidic sites favored the adsorption capacity by activating the π-π stacking. Electrostatic interactions did not influence the adsorption of RNZ on Coconut AC, but electrostatic repulsion decreased that of DCF on Wood AC. The adsorption of DCF on Wood AC was reversible but not that of RNZ on Coconut AC. Besides, the adsorption of RNZ and DCF on the Coconut and Wood ACs was endothermic in the range of 15-25 °C.

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.

Occurrence and removal of psychiatric pharmaceuticals in the Tehran South Municipal Wastewater Treatment Plant

Psychiatric drugs released by humans in wastewater have received more attention because of their potential risks for aquatic organisms. In this study, the occurrence of the two most common groups of psychiatric drugs (sedatives-hypnotics-anxiolytics and antidepressants) were evaluated in the Tehran South Municipal Wastewater Treatment Plant. All the target sedatives-hypnotics-anxiolytics (alprazolam, phenobarbital, and thioridazine) and antidepressants (fluoxetine, citalopram, sertraline, and venlafaxine) were observed in influent and secondary clarification (SC) effluent. Thioridazine (164.25 ± 218.74 ng/L) and citalopram (672.53 ± 938.56 ng/L) had the highest mean concentrations in the influent, while alprazolam (5.09 ± 2.33 ng/L) and citalopram (776.97 ± 1088.01 ng/L) had the highest concentrations in the SC effluent. The higher concentrations of the psychiatric drugs, except thioridazine, were detected in the SC effluent compared to the concentrations in the influent. The increased drugs concentrations, with negative removal efficiencies, were more distinctive in the cold season samples. Psychiatric drugs processed in the chlorination unit followed a completely different pattern compared to the drugs in the biological treatment unit. All the drugs' concentrations, except thioridazine, decreased in the chlorination unit, ranging between 27 ± 14% for alprazolam and 75 ± 10% for citalopram. However, the mean concentrations of the detected drugs were as follows: sertraline (11.96 ± 11.62 ng/L) and venlafaxine (184.94 ± 219.74 ng/L) which could cause environmental and ecological concerns.

Suspect Screening of Chemicals in Hospital Wastewaters Using Effect-Directed Analysis Approach as Prioritization Strategy

The increasing number of contaminants in the environment has pushed water monitoring programs to find out the most hazardous known and unknown chemicals in the environment. Sample treatment-simplification methods and non-target screening approaches can help researchers to not overlook potential chemicals present in complex aqueous samples. In this work, an effect-directed analysis (EDA) protocol using the sea urchin embryo test (SET) as a toxicological in vivo bioassay was used as simplified strategy to identify potential unknown chemicals present in a very complex aqueous matrix such as hospital effluent. The SET bioassay was used for the first time here to evaluate potential toxic fractions in hospital effluent, which were obtained after a two-step fractionation using C₁₈ and aminopropyl chromatographic semi-preparative columns. The unknown compounds present in the toxic fractions were identified by means of liquid chromatography coupled to a Q Exactive Orbitrap high-resolution mass spectrometer (LC-HRMS) and using a suspect analysis approach. The results were complemented by gas chromatography-mass spectrometry analysis (GC-MS) in order to identify the widest range of chemical compounds present in the sample and the toxic fractions. Using EDA as sample treatment simplification method, the number of unknown chemicals (>446 features) detected in the raw sample was narrowed down to 94 potential toxic candidates identified in the significantly toxic fractions. Among them, the presence of 25 compounds was confirmed with available chemical standards including 14 pharmaceuticals, a personal care product, six pesticides and four industrial products. The observations found in this work emphasize the difficulties in identifying potential toxicity drivers in complex water samples, as in the case of hospital wastewater.

Removal of ciprofloxacin antibiotic pollutants from wastewater using nano-composite adsorptive membranes

The emergence of antibiotics in water has been globally recognized as a critical pollution issue. Antibiotics (such as Ciprofloxacin (CPFX) pose a serious threat to humans and to the ecosystem due to its accumulation in water sources which can lead to chronic health problems and endanger aquatic life. It is therefore crucial to properly remove them from water. In this work, a nano-composite adsorptive membrane based on Zirconium Phosphate (ZrP) adsorbent supported on Polyethersulfone (PES) was synthesized and evaluated for the removal of CPFX from synthetic aqueous solutions. The membranes described here showed a very high antibiotic removal rate. The effect of various parameters such as the initial concentration of the antibiotic, the adsorbent dosage, contact time, pH, and temperature was studied. The equilibrium data were found to reasonably best fit with the Temkin isotherm model. The membranes showed a high ciprofloxacin removal (99.7%) as opposed to (68%) when PES membrane alone was used. Moreover, a significant improvement in the membrane's water flux (100.84 L/m².h) and permeability (97.62 L/m².hr.bar) were noticed as opposed to pure PES membrane's flux and permeability. The adsorptive membranes were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET). The results confirmed the successful formation of ZrP nanoparticles adsorbent within the membrane matrix, and with enhanced hydrophilic properties. The membrane was successfully regenerated and reused up to 5 times. The results of this work showed the potential of such membranes for the removal of ciprofloxacin and at a high efficiency.

Occurrence of emerging organic contaminants and endocrine disruptors in different water compartments in Mexico - A review

This review compiles the studies (2007-2021) regarding the occurrence of emerging organic contaminants (EOCs) and endocrine disruptors (EDs) in wastewater, surface water and groundwater in Mexico. A total of 174 compounds were detected, including pharmaceuticals, hormones, plasticizers, personal care products, sweeteners, drugs, and pesticides considered as EDs. The levels of EOCs and EDs varied from ng/L to 140 mg/L, depending on the compound, location, and compartment. Raw wastewater was the most studied matrix, showing a greater abundance and number of detected compounds. Nevertheless, surface waters showed high concentrations of bisphenol-A, butylbenzil-phthalate, triclosan, pentachlorophenol, and the hormones estrone, 17 α-ethinylestradiol, and 17 β-estradiol, which exceeded the thresholds set by international guidelines. Concentrations of 17 α-ethinylestradiol and triclosan exceeding the above-mentioned limits were reported in groundwater. Cropland irrigation with raw wastewater was the principal activity introducing EOCs and EDs into groundwater. The groundwater abundance of EOCs was considerably lesser than that of wastewater, highlighting the attenuation capacity of soils/aquifers during wastewater infiltration. However, carbamazepine and N,N-diethyl-meta-toluamide showed higher concentrations in groundwater than those in wastewater, suggesting their accumulation/concentration in soils/pore-waters. Although the contamination of water resources represents one of the most environmental concerns in Mexico, this review brings to light the lack of studies on the occurrence of EOCs in Mexican waters, which is important for public health policies and for developing legislations that incorporates EOCs as priority contaminants in national water quality guidelines. Consequently, the development of legislations will support regulatory compliance for wastewater and drinking water, reducing the human exposure.

Effect-directed analysis of a hospital effluent sample using A-YES for the identification of endocrine disrupting compounds

An effect-directed analysis (EDA) approach was used to identify the compounds responsible for endocrine disruption in a hospital effluent (Basque Country). In order to facilitate the identification of the potentially toxic substances, a sample was collected using an automated onsite large volume solid phase extraction (LV-SPE) system. Then, it was fractionated with a two-step orthogonal chromatographic separation and tested for estrogenic effects with a recombinant yeast (A-YES) in-vitro bioassay. The fractionation method was optimized and validated for 184 compounds, and its application to the hospital effluent sample allowed reducing the number of unknowns from 292 in the raw sample to 35 after suspect analysis of the bioactive fractions. Among those, 7 of them were confirmed with chemical standards. In addition, target analysis of the raw sample confirmed the presence of mestranol, estrone and dodemorph in the fractions showing estrogenic activity. Predictive estrogenic activity modelling using quantitative structure-activity relationships indicated that the hormones mestranol (5840 ng/L) and estrone (128 ng/L), the plasticiser bisphenol A (9219 ng/L) and the preservative butylparaben (1224 ng/L) were the main contributors of the potential toxicity. Derived bioanalytical equivalents (BEQs) pointed mestranol and estrone as the main contributors (56 % and 43 %, respectively) of the 50 % of the sample's explained total estrogenic activity.

TiO2-immobilized porous geopolymer composite membrane for removal of antibiotics in hospital wastewater

This experimental research proposes an environment-friendly and low-cost porous geopolymer composite membrane (PGCM) to treat antibiotics in hospital wastewater. The proposed PGCM consisted of two layers: a porous support layer and a dense coating layer. The dense coating layer was synthesized by incorporating variable TiO₂ content (0, 2, 6, and 10 wt%) into the geopolymer matrix. The dense coating layer was of hierarchical mesoporous structure with 700 μm in thickness and adhered to the porous support layer. The average pore size, total pore volume, and open porosity of the dense coating layer decreased with an increase in TiO₂, resulting in reduced water permeability. The PGCM was applied to remove six target antibiotics including amoxicillin, ciprofloxacin, norfloxacin, sulfamethoxazole, tetracycline, and trimethoprim in real hospital wastewater. By comparison, the PGCM with 10 wt% TiO₂ achieved the highest antibiotic removal efficiencies, with the adsorption and combined adsorption/photodegradation removal efficiencies for the target antibiotics of 38-75% and 74-86%, respectively. The novelty of this research lies in the use of a tailor-made porous geopolymer composite membrane incorporated with TiO₂ photooxidation as a single-step treatment of recalcitrant antibiotics contained in hospital wastewater.

Critical review of technologies for the on-site treatment of hospital wastewater: From conventional to combined advanced processes

This review aims to assess different technologies for the on-site treatment of hospital wastewater (HWW) to remove pharmaceutical compounds (PhCs) as sustances of emerging concern at a bench, pilot, and full scales from 2014 to 2020. Moreover, a rough characterisation of hospital effluents is presented. The main detected PhCs are antibiotics and psychiatric drugs, with concentrations up to 1.1 mg/L. On the one hand, regarding the presented technologies, membrane bioreactors (MBRs) are a good alternative for treating HWW with PhCs removal values higher than 80% in removing analgesics, anti-inflammatories, cardiovascular drugs, and some antibiotics. Moreover, this system has been scaled up to the pilot plant scale. However, some target compounds are still present in the treated effluent, such as psychiatric and contrast media drugs and recalcitrant antibiotics (erythromycin and sulfamethoxazole). On the other hand, ozonation effectively removes antibiotics found in the HWW (>93%), and some studies are carried out at the pilot plant scale. Even though, some families, such as the X-ray contrast media, are recalcitrant to ozone. Other advanced oxidation processes (AOPs), such as Fenton-like or UV treatments, seem very effective for removing pharmaceuticals, Antibiotic Resistance Bacteria (ARBs) and Antibiotic Resistance Genes (ARGs). However, they are not implanted at pilot plant or full scale as they usually consider extra reactants such as ozone, iron, or UV-light, making the scale-up of the processes a challenging task to treat high-loading wastewater. Thus, several examples of biological wastewater treatment methods combined with AOPs have been proposed as the better strategy to treat HWW with high removal of PhCs (generally over 98%) and ARGs/ARBs (below the detection limit) and lower spending on reactants. However, it still requires further development and optimisation of the integrated processes.

Occurrence and Quantitative Microbial Risk Assessment of Methicillin-Resistant Staphylococcus aureus (MRSA) in a Sub-Catchment of the Yodo River Basin, Japan

The occurrence of Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) in a sub-catchment of the Yodo River Basin, a representative water system of a drinking water source in Japan, was investigated. The chromogenic enzyme-substrate medium method was used for the detection of S. aureus and MRSA by the presence or absence of antimicrobials in the medium for viable bacteria in a culture-based setting. The contributions of S. aureus and MRSA from wastewater to the rivers were estimated based on mass flux-based analysis, and quantitative microbial risk assessment (QMRA) was further conducted for S. aureus and MRSA in river environments. The mean abundance of S. aureus and MRSA was 31 and 29 CFU/mL in hospital effluent, 124 and 117 CFU/mL in sewage treatment plant (STP) influent, 16 and 13 CFU/mL in STP effluent, and 8 and 9 CFU/mL in river water, respectively. Contribution of the pollution load derived from the target STP effluent to river water ranged from 2% to 25%. The QMRA showed that to achieve the established health benchmarks, the drinking water treatment process would need to yield 1.7 log10 and 2.9 log10 inactivation in terms of infection risk and disability-adjusted life year (DALY) indexes, respectively. These findings highlight the link between medical environment and the importance of environmental risk management for antimicrobial-resistant bacteria in aquatic environments.

Fate of selected pharmaceuticals in hospital and municipal wastewater effluent: occurrence, removal, and environmental risk assessment

The concentrations and distribution of β-blockers, lipid regulators, and psychiatric and cancer drugs in the influent and effluent of the municipal wastewater treatment plant (WWTP) and the effluent of 16 hospitals that discharge into the wastewater treatment plant mentioned in this study at two sampling dates in summer and winter were examined. The pharmaceutical contribution of hospitals to municipal wastewater was determined. The removal of target pharmaceuticals was evaluated in a WWTP consisting of conventional biological treatment using activated sludge. Additionally, the potential environmental risk for the aquatic receiving environments (salt lake) was assessed. Beta-blockers and psychiatric drugs were detected in high concentrations in the wastewater samples. Atenolol (919 ng/L) from β-blockers and carbamazepine (7008 ng/L) from psychiatric pharmaceuticals were detected at the highest concentrations in hospital wastewater. The total pharmaceutical concentration determined at the WWTP influent and effluent was between 335 and 737 ng/L in summer and between 174 and 226 ng/L in winter. The concentrations detected in hospital effluents are higher than the concentrations detected in WWTP. The total pharmaceutical contributions from hospitals to the WWTP in summer and winter were determined to be 2% and 4%, respectively. Total pharmaceutical removal in the WWTP ranged from 23 to 54%. According to the risk ratios, atenolol could pose a high risk (risk quotient > 10) for fish in summer and winter. There are different reasons for the increase in pharmaceutical consumption in recent years. One of these reasons is the COVID-19 pandemic, which has been going on for 2 years. In particular, hospitals were operated at full capacity during the pandemic, and the occurrence and concentration of pharmaceuticals used for the therapy of COVID-19 patients has increased in hospital effluent. Pandemic conditions have increased the tendency of people to use psychiatric drugs. It is thought that beta-blocker consumption has increased due to cardiovascular diseases caused by COVID-19. Therefore, the environmental risk of pharmaceuticals for aquatic organisms in hospital effluent should be monitored and evaluated.

Metformin-induced alterations in gills of the freshwater fish Astyanax lacustris (Lütken, 1875) detected by histological and scanning electron microscopy

The antidiabetic drug metformin is widely prescribed and found in different concentrations in the environment around the world, raising concern about potential impacts on aquatic life. Analyses of the effects of exposure of biological models to aquatic contaminants are important for assessing pollution effects on fish health. The gills of fishes represent primary targets of disturbance by pollutants, mainly because of the large surface of the respiratory epithelium and the high perfusion rate, which both help the entry of pollutants into this tissue. In this context, the aim of this work was to use gill histological analyses biomarkers to evaluate the toxicity of metformin on aquatic environmental systems, by means of chronic exposure for 90 days of Astyanax lacustris (lambari), an ecologically important neotropical species that can be used as an environmental bioindicator. Histopathological analyses were performed using Light and Scanning Electron Microscopy. The main changes were lamellar fusion, telangiectasia hyperplasia and disappearance of microridges. The morphological changes observed possibly interfere with the gill physiology, indicating an unfavorable situation to the presence of metformin in the water, pointing to a concern that metformin may pose a risk to Astyanax lacustris and likely to other fish species, compromising the dynamics of the aquatic ecosystem as a whole. Graphical abstract.

Recent advances in electrochemical sensor developments for detecting emerging pollutant in water environment

In the latest times, considerable studies have been performed closer to detecting emerging pollutant such as paracetamol in wastewater. Electrochemical sensor developments have recently started to determine in fewer concentrations effectively. The detection of paracetamol using standard protocols corresponding to electroanalytical techniques has a greater impact noticed in directing the detecting process toward biosensors. Non-enzymatic sensors are the peak of all electro analysis approaches. Functionalized materials, such as metal oxide nanoparticles, conducting polymers, and carbon-based materials for electrode surface functionalization have been used to create a fortification for distributing passive enzyme-free biosensors. Synergic effects are possible by enhancing loading capacity and mass transfer of reactants for attaining high analytical sensitivity using a variety of nanomaterials with large surface areas. The main focus of this study is to address the prevailing issues in the identification of paracetamol with the tasks in the non-enzymatic sensors field, followed by the useful methods of electro analysis studies.

Distribution and characteristics of carbapenem-resistant and extended-spectrum β-lactamase (ESBL) producing Escherichia coli in hospital effluents, sewage treatment plants, and river water in an urban area of Japan

Occurrence of profiles of the carbapenem-resistant Escherichia coli (CRE-E) and extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-E) in an urban river in a sub-catchment of the Yodo River Basin, one of the representative water systems of Japan was investigated. We conducted seasonal and year-round surveys for the antimicrobial-resistant bacteria (AMRB) and antimicrobial-resistance genes (AMRGs) in hospital effluents, sewage treatment plant (STP) wastewater, and river water; subsequently, contributions to wastewater discharge into the rivers were estimated by analyses based on the mass flux. Furthermore, the characteristics of AMRB in the water samples were evaluated on the basis of antimicrobial susceptibility tests. CRE-E and ESBL-E were detected in all water samples with mean values 11 and 1900 CFU/mL in the hospital effluent, 58 and 4550 CFU/mL in the STP influent, not detected to 1 CFU/mL in the STP effluent, and 1 and 1 CFU/mL in the STP discharge into the river, respectively. Contributions of the pollution load derived from the STP effluent discharged into the river water were 1 to 21%. The resistome profiles for bla_IMP, bla_TEM, and bla_CTX-M genes in each water sample showed that AMRGs were not completely removed in the wastewater treatment process in the STP, and the relative abundances of bla_IMP, bla_TEM, and bla_CTX-M genes were almost similar (P<0.05). Susceptibility testing of antimicrobial-resistant E. coli isolates showed that CRE-E and ESBL-E detected in wastewaters and river water were linked to the prevalence of AMRB in clinical settings. These results suggest the importance of conducting environmental risk management of AMRB and AMRGs in the river environment. To our knowledge, this is the first detailed study that links the medical environment to CRE-E and ESBL-E for evaluating the AMRB and AMRGs in hospital effluents, STP wastewater, and river water at the basin scale on the basis of mass flux as well as the contributions of CRE-E and ESBL-E to wastewater discharge into the river.

Photochlorination-induced degradation of microplastics and interaction with Cr(VI) and amlodipine

Wastewater treatment plants (WWTPs) are the important source of microplastics (MPs) in the environment, and disinfection processes bear high potential to degrade MPs. This study investigated the physicochemical degradation, dissolved organic products and interaction with co-existed pollutants (heavy metal and pharmaceutical) on polyethylene (PE), polypropylene (PP) and polystyrene (PS) MPs during simulated disinfection processes. Compared to photo or chlorination, photochlorination significantly resulted in the physicochemical degradation, including morphology alteration, fragmentation, and chemical oxidation on PP and PS MPs, but showed relatively low effect on PE, indicating the different resistance among polymers to disinfected treatment. Photochlorination also caused the formation of chain-scission organic compounds and even chlorinated products from MPs (e.g. C₁₁H₁₉O₄Cl for PP and monochlorophenol, dichlorophenol, chloroacetophenone and chlorobenzoic acid for PS), which may form disinfection byproducts to induce healthy risk. The adsorption potentials of MPs for Cr(VI) or amlodipine were enhanced by photochlorination since the cracking and formed oxygen functional groups enhanced the pore filling and surface precipitation of Cr(VI), and the electrostatic attraction and hydrogen bonding with amlodipine. The findings indicated the physicochemical degradation of MPs and the combined pollution with co-existed pollutants, highlighting the health risks of MP-derived organic products during the disinfection treatments (even in normal dosage) in WWTPs.

Detection, characterization, and antimicrobial susceptibility of Yersinia enterocolitica in different types of wastewater in the Czech Republic

AIMS

The purpose of the study was to evaluate the occurrence of Yersinia enterocolitica in different types of wastewater and to characterize the isolates by biotyping, serotyping, and antimicrobial susceptibility testing. In addition, cultivation protocols were evaluated.

METHODS AND RESULTS

The occurrence of Y. enterocolitica was determined in treated and untreated municipal wastewater, as well as in hospital, slaughterhouse, and cowshed wastewater. Y. enterocolitica was detected in 84.1% of the wastewater samples, while the main sources were untreated municipal and slaughterhouse wastewater. In contrast, the lowest incidence was found in hospital wastewater. An exclusive occurrence of biotype 1A (98.3%) was detected. Pathogenic bio-serotypes 4/O:3 and 3/O:3 were isolated only from slaughterhouse wastewater. The highest resistance rates were observed for ampicillin (92.5%) and amoxicillin-clavulanic acid (36.8%).

CONCLUSIONS

Y. enterocolitica was commonly detected in wastewater, although the prevalence varied depending on the origin of the wastewater. No single cultivation protocol was able to recover Y. enterocolitica isolates from such a complex matrix as wastewater.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our study provided data that can contribute to the evaluation of wastewater as a source of Y. enterocolitica and to understanding the threat of wastewater isolates to human health.

QuEChERS-based analysis and ecotoxicological risk of select antibiotics in dumpsite leachates, hospital wastewater and effluent receiving water in Ibadan, Nigeria

There is currently a dearth of information on the determination, occurrence and ecotoxicological risk of antibiotics in dumpsite leachates and hospital wastewater in Africa. A quick, easy, cheap, effective, rugged and safe (QuEChERS) protocol which combines extraction and clean-up in one step was optimized for the determination of antibiotics sulfadoxine, sulfamethazine and trimethoprim in dumpsite leachates and hospital wastewater. The occurrence and ecotoxicological risk of target antibiotics were investigated in wastewater from two hospitals, effluent receiving water and leachates from three dumpsites in Ibadan, Nigeria. Recoveries in hospital wastewater ranged from 53 to 116% while recoveries ranged from 50 to 89% in leachates. Method limits of quantification ranged from 0.7 to 12.1 µg L^-1 in hospital wastewater and from 6.2 to 38.8 µg L^-1 in leachates. Intra-day precisions (% RSD) were ≤ 21%. High concentrations of target antibiotics were measured: up to 475 µg L^-1 for sulfamethazine in leachates, 118 µg L^-1 for trimethoprim in hospital wastewater and 117 µg L^-1 for sulfadoxine in effluent receiving water. Sulfadoxine presented high risk to algae, daphnid and fish in hospital wastewater, effluent receiving water and leachates. This work highlights the need for adequate and sound management of wastes containing pharmaceuticals in Nigeria.

Occurrence of antibiotics and bacterial resistance genes in wastewater: resistance mechanisms and antimicrobial resistance control approaches

Antimicrobial pharmaceuticals are classified as emergent micropollutants of concern, implying that even at low concentrations, long-term exposure to the environment can have significant eco-toxicological effects. There is a lack of a standardized regulatory framework governing the permissible antibiotic content for monitoring environmental water quality standards. Therefore, indiscriminate discharge of antimicrobials at potentially active concentrations into urban wastewater treatment facilities is rampant. Antimicrobials may exert selective pressure on bacteria, leading to resistance development and eventual health consequences. The emergence of clinically important multiple antibiotic-resistant bacteria in untreated hospital effluents and wastewater treatment plants (WWTPs) has been linked to the continuous exposure of bacteria to antimicrobials. The levels of environmental exposure to antibiotics and their correlation to the evolution and spread of resistant bacteria need to be elucidated to help in the formulation of mitigation measures. This review explores frequently detected antimicrobials in wastewater and gives a comprehensive coverage of bacterial resistance mechanisms to different antibiotic classes through the expression of a wide variety of antibiotic resistance genes either inherent and/or exchanged among bacteria or acquired from the reservoir of antibiotic resistance genes (ARGs) in wastewater systems. To complement the removal of antibiotics and ARGs from WWTPs, upscaling the implementation of prospective interventions such as vaccines, phage therapy, and natural compounds as alternatives to widespread antibiotic use provides a multifaceted approach to minimize the spread of antimicrobial resistance.

Recent development on core-shell photo(electro)catalysts for elimination of organic compounds from pharmaceutical wastewater

Pharmaceutical organics are a vital milestone in contemporary human research since they treat various diseases and improve the quality of human life. However, these organic compounds are considered one of the major environmental hazards after the conception, along with the massive rise in antimicrobial resistance (AMR) in an ecosystem. There are various biological and catalytic technologies existed to eliminate these organics in aqueous system with their limitation. Advanced Oxidation processes (AOPs) are used to decompose these pharmaceutical organic compounds in the wastewater by generating reactive species with high oxidation potential. This review focused various photocatalysts, and photocatalytic oxidation processes, especially core-shell materials for photo (electro)catalytic application in pharmaceutical wastewater decomposition. Moreover, we discussed in details about the design and recent developments of core shell catalysts and comparison for photocatalytic, electrocatalytic and photo electrocatalytic applications in pharmaceutical wastewater treatment. In addition, the mixture of inorganic and organic core-shell materials, and metal-organic framework-based core-shell catalysts discussed in detail for antibiotic degradation.

Modeling Risk Dynamics of Contaminants of Emerging Concern in a Temperate-region Wastewater Effluent-dominated Stream

Wastewater effluent-dominated streams are becoming increasingly common worldwide, including in temperate regions, with potential impacts on ecological systems and drinking water sources. We recently quantified the occurrence/ spatiotemporal dynamics of pharmaceutical mixtures in a representative temperate-region wastewater effluent-dominated stream (Muddy Creek, Iowa) under baseflow conditions and characterized relevant fate processes. Herein, we quantified the ecological risk quotients (RQs) of 19 effluent-derived contaminants of emerging concern (CECs; including: 14 pharmaceuticals, 2 industrial chemicals, and 3 neonicotinoid insecticides) and 1 run-off-derived compound (atrazine) in the stream under baseflow conditions, and estimated the probabilistic risks of effluent-derived CECs under all-flow conditions (i.e., including runoff events) using stochastic risk modeling. We determined that 11 out of 20 CECs pose medium-to-high risks to local ecological systems (i.e., algae, invertebrates, fish) based on literature-derived acute effects under measured baseflow conditions. Stochastic risk modeling indicated decreased, but still problematic, risk of effluent-derived CECs (i.e., RQ≥0.1) under all-flow conditions when runoff events were included. Dilution of effluent-derived chemicals from storm flows thus only minimally decreased risk to aquatic biota in the effluent-dominated stream. We also modeled in-stream transport. Thirteen out of 14 pharmaceuticals persisted along the stream reach (median attenuation rate constant k<0.1 h^-1) and entered the Iowa River at elevated concentrations. Predicted and measured concentrations in the drinking water treatment plant were below the human health benchmarks. This study demonstrates the application of probabilistic risk assessments for effluent-derived CECs in a representative effluent-dominated stream under variable flow conditions (when measurements are less practical) and provides an enhanced prediction tool transferable to other effluent-dominated systems.

Efficient Removal of Methylene Blue and Ciprofloxacin from Aqueous Solution Using Flower-like, Nanostructured ZnO Coating under UV Irradiation

Flower-like ZnO architectures assembled with many nanorods were successfully synthesized through Thermionic Vacuum Arc, operated both in direct current (DC-TVA) and a pulsed mode (PTVA), and coupled with annealing in an oxygen atmosphere. The prepared coatings were analysed by scanning-electron microscopy with energy-dispersive X-ray-spectroscopy (SEM-EDX), X-ray-diffraction (XRD), and photoluminescence (PL) measurements. By simply modifying the TVA operation mode, the morphology and uniformity of ZnO nanorods can be tuned. The photocatalytic performance of synthesized nanostructured ZnO coatings was measured by the degradation of methylene-blue (MB) dye and ciprofloxacin (Cipro) antibiotic. The ZnO (PTVA) showed enhancing results regarding the photodegradation of target contaminants. About 96% of MB molecules were removed within 60 min of UV irradiation, with a rate constant of 0.058 min−1, which is almost nine times higher than the value of ZnO (DC-TVA). As well, ZnO (PTVA) presented superior photocatalytic activity towards the decomposition of Cipro, after 240 min of irradiation, yielding 96% degradation efficiency. Moreover, the agar-well diffusion assay performance against both Gram-positive and Gram-negative bacteria confirms the degradation of antibiotic molecules by the UV/ZnO (PTVA) approach, without the formation of secondary hazardous products during the photocatalysis process. Repeated cyclic usage of coatings revealed excellent reusability and operational stability.

Pharmaceuticals in the Aquatic Environment: A Review on Eco-Toxicology and the Remediation Potential of Algae

The pollution of the aquatic environment has become a worldwide problem. The widespread use of pesticides, heavy metals and pharmaceuticals through anthropogenic activities has increased the emission of such contaminants into wastewater. Pharmaceuticals constitute a significant class of aquatic contaminants and can seriously threaten the health of non-target organisms. No strict legal regulations on the consumption and release of pharmaceuticals into water bodies have been implemented on a global scale. Different conventional wastewater treatments are not well-designed to remove emerging contaminants from wastewater with high efficiency. Therefore, particular attention has been paid to the phycoremediation technique, which seems to be a promising choice as a low-cost and environment-friendly wastewater treatment. This technique uses macro- or micro-algae for the removal or biotransformation of pollutants and is constantly being developed to cope with the issue of wastewater contamination. The aims of this review are: (i) to examine the occurrence of pharmaceuticals in water, and their toxicity on non-target organisms and to describe the inefficient conventional wastewater treatments; (ii) present cost-efficient algal-based techniques of contamination removal; (iii) to characterize types of algae cultivation systems; and (iv) to describe the challenges and advantages of phycoremediation.

Fingerprinting pharmaceuticals of multiple sources at a provincial watershed scale

Pharmaceutical residues in the aquatic environment have increasingly attracted public concerns but their fingerprint of sources remain unclear at a watershed scale. This study systematically explored pharmaceutical residues in effluent of 8 different type of sources in a provincial watershed in China using a multi-category protocol of pharmaceutical quantification. Seventy-seven out of 94 target compounds from 6 categories were quantified in effluent, up to 71,318 ng L^-1 in total from urban hospital sources with 20 antibiotics and 32 others. The spectrum of the quantified compounds in effluent significantly differentiated the urban (hospitals, domestic sewages, and WWTPs), rural (health centers and domestic sewages), and agricultural production sources (poultry and swine breeding yards, aquaculture ponds, and paddy fields). Compounds of non-steroidal anti-inflammation drugs (NSAIDs), cardiovascular drugs (CVs), and central nervous drugs (CNs) could fingerprint the three groups of sources. However, the three categories contributed 7 out of 10 compounds with high risk (risk quotient >1.0) to the aquatic environment identified by the eco-environmental risk assessment. No high-risk compounds were identified in effluent of urban WWTPs. Findings of this study suggest source identification and compound spectrum fingerprinting are crucial for studies on pharmaceutical residues in the aquatic environment, especially the complexity of pharmaceutical residues in source effluents for exploring source-sink dynamics at a watershed scale.

Antimicrobial Resistance and Implications: Impact on Pregnant Women with Urinary Tract Infections

Urinary Tract Infections (UTI) is one of the most common infections, especially among women. Presently accessible antibiotics are a clinician’s first line of defense to treat infections, but antimicrobial resistance menace to reduce their efficacy. The consequences of multi-drug resistance to antibiotics are enhanced morbidity and mortality rates. The yearly death toll is >700,000 population worldwide, rising to ~10 million by 2050. There is a lack of novel antibiotics for UTIs as the return on its investment is poor compared to medicines for lifestyle diseases. The three organisms of utmost worry are methicillin-resistant Staphylococcus aureus (MRSA), Carbapenems and third-generation Cephalosporins resistant Klebsiella pneumoniae, Fluoroquinolones and third-generation Cephalosporins resistant Escherichia coli (E. coli). Among these, Escherichia coli is the foremost cause of community-acquired UTI infections throughout the globe, mainly due to the absence of alertness and inappropriate wastewater treatment. The purpose of this review article is to explore literature on uropathogens, the pattern of their antimicrobial resistance, and the hospital practices concerning the spread, as inadequate studies have been carried out and published on this topic. Hospital personnel are usually familiar with the management of infections, but most do not understand the conditions in their hospital. Implications of hospital practices play a major role in controlling hospital-acquired UTIs and the burden of its antimicrobial resistance. A complete approach involving financial and human resources will improve the infection control practices in hospitals without a doubt. Strict infection control measures in hospitals can help to reduce the number of hospital-acquired infections in pregnant women.

Histological endpoints and oxidative stress transcriptional responses in the Mediterranean mussel Mytilus galloprovincialis exposed to realistic doses of salicylic acid

Despite the availability of analytic data, little is known about the toxicity of salicylic acid (SA) on aquatic non-target organisms. The present study aimed at evaluating the impact of SA through a short-term exposure of the Mediterranean mussel Mytilus galloprovincialis to five environmentally relevant concentrations of SA. A set of suitable biomarkers was applied at selected time-points on mussel digestive glands, including histological observations and expression of oxidative stress related genes. The obtained results showed a conspicuous hemocytic infiltration among mussel digestive tubules, as confirmed also by a flow cytometric approach that revealed an increase of halinocytes and granulocytes. Interestingly, a significant dose and time dependent decrease in the expression levels of oxidative stress related genes was found in mussels exposed to SA except for the glutathione S-transferase gene that was significantly up-regulated in a time-dependent manner confirming its important role against oxidant species and in the metabolism of pharmaceuticals.

An assessment of hospital wastewater and biomedical waste generation, existing legislations, risk assessment, treatment processes, and scenario during COVID-19

Hospitals release significant quantities of wastewater (HWW) and biomedical waste (BMW), which hosts a wide range of contaminants that can adversely affect the environment if left untreated. The COVID-19 outbreak has further increased hospital waste generation over the past two years. In this context, a thorough literature study was carried out to reveal the negative implications of untreated hospital waste and delineate the proper ways to handle them. Conventional treatment methods can remove only 50%-70% of the emerging contaminants (ECs) present in the HWW. Still, many countries have not implemented suitable treatment methods to treat the HWW in-situ. This review presents an overview of worldwide HWW generation, regulations, and guidelines on HWW management and highlights the various treatment techniques for efficiently removing ECs from HWW. When combined with advanced oxidation processes, biological or physical treatment processes could remove around 90% of ECs. Analgesics were found to be more easily removed than antibiotics, β-blockers, and X-ray contrast media. The different environmental implications of BMW have also been highlighted. Mishandling of BMW can spread infections, deadly diseases, and hazardous waste into the environment. Hence, the different steps associated with collection to final disposal of BMW have been delineated to minimize the associated health risks. The paper circumscribes the multiple aspects of efficient hospital waste management and may be instrumental during the COVID-19 pandemic when the waste generation from all hospitals worldwide has increased significantly.

Are synthetic glucocorticoids in the aquatic environment a risk to fish?

The glucocorticosteroid, or glucocorticoid (GC), system is largely conserved across vertebrates and plays a central role in numerous vital physiological processes including bone development, immunomodulation, and modification of glucose metabolism and the induction of stress-related behaviours. As a result of their wide-ranging actions, synthetic GCs are widely prescribed for numerous human and veterinary therapeutic purposes and consequently have been detected extensively within the aquatic environment. Synthetic GCs designed for humans are pharmacologically active in non-mammalian vertebrates, including fish, however they are generally detected in surface waters at low (ng/L) concentrations. In this review, we assess the potential environmental risk of synthetic GCs to fish by comparing available experimental data and effect levels in fish with those in mammals. We found the majority of compounds were predicted to have insignificant risk to fish, however some compounds were predicted to be of moderate and high risk to fish, although the dataset of compounds used for this analysis was small. Given the common mode of action and high level of inter-species target conservation exhibited amongst the GCs, we also give due consideration to the potential for mixture effects, which may be particularly significant when considering the potential for environmental impact from this class of pharmaceuticals. Finally, we also provide recommendations for further research to more fully understand the potential environmental impact of this relatively understudied group of commonly prescribed human and veterinary drugs.

Migration, Transformation and Removal of Macrolide Antibiotics in The Environment: A Review

Macrolide antibiotics (MAs), as a typical emerging pollutant, are widely detected in environmental media. When entering the environment, MAs can interfere with the growth, development and reproduction of organisms, which has attracted extensive attention. However, there are few reviews on the occurrence characteristics, migration and transformation law, ecotoxicity and related removal technologies of MAs in the environment. In this work, combined with the existing relevant research, the migration and transformation law and ecotoxicity characteristics of MAs in the environment are summarized, and the removal mechanism of MAs is clarified. Currently, most studies on MAs are based on laboratory simulation experiments, and there are few studies on the migration and transformation mechanism between multiphase states. In addition, the cost of MAs removal technology is not satisfactory. Therefore, the following suggestions are put forward for the future research direction. The migration and transformation process of MAs between multiphase states (such as soil-water-sediment) should be focused on. Apart from exploring the new treatment technology of MAs, the upgrading and coupling of existing MAs removal technologies to meet emission standards and reduce costs should also be concerned. This review provides some theoretical basis and data support for understanding the occurrence characteristics, ecotoxicity and removal mechanism of MAs.

Long-Term Study of Antibiotic Presence in Ebro River Basin (Spain): Identification of the Emission Sources

Water monitoring is key to determining the presence of potentially hazardous substances related to urban activities and intensive farming. This research aimed to perform a long-term (four years) quantitative monitoring of selected antibiotics (azithromycin, enrofloxacin, trimethoprim and sulfadiazine) both in rivers and wastewaters belonging to the Ebro River basin (North of Spain). The target antibiotics were chosen on the basis of a preliminary multispecies screening. The analysis of the antibiotics was carried out by LC-MS/MS on wastewater-treatment plant (WWTP) effluent, effluents of a slaughterhouse and hospital, rivers downstream and upstream of these WWTPs, and rivers close to extensive farming areas. The ANOVA test was performed to study the significant differences between the points exposed to concrete emission sources and antibiotic concentration. The monitoring, carried out from 2018 to 2020, has been essential to illustrating the presence of the most abundant antibiotics that were detected in the Ebro River basin. Enrofloxacin has appeared in river waters in significant concentrations, especially near intensive farming, meanwhile azithromycin has been frequently detected in wastewaters.

An Initial Approach to the Presence of Pharmaceuticals in Wastewater from Hospitals in Colombia and Their Environmental Risk

Hospital wastewater (HWW) from three different cities in Colombia was characterized. Wastewater quality indicators and 38 relevant pharmaceuticals were examined. The HWW had pH from 6.82 to 8.06, chemical oxygen demand was between 235.5 and 1203 mg L−1, and conductivity ranged from 276.5 to 717.5 µS cm−1. Additionally, most of the target pharmaceuticals (20 of 38) had 100% occurrence frequency in the samples due to their high and continuous consumption in the hospitals. Indeed, acetaminophen, diclofenac, azithromycin, ciprofloxacin, sulfamethoxazole, losartan, metoprolol, and omeprazole were present in all samples at concentrations from one up to some hundreds of μg L−1. Once pharmaceuticals are discharged into local sewage systems or rivers, because of the high dilution of HWW, the individual environmental hazards are low (i.e., risk quotients, RQ < 0.1 were determined). The action of conventional treatments on HWW also decreased the individual environmental risks of pharmaceuticals (RQ values < 0.1). However, the mixture of pharmaceuticals in the HWW had potential environmental risks (as RQ > 0.1 were found), remarking the need for efficient processes to eliminate pharmaceuticals from HWW. This work provides an initial view on the characterization of diverse Colombian HWW, which could be useful for the understanding of the current situation of pollution by pharmaceuticals in Latin America.

A multi-biomarker approach for the early assessment of the toxicity of hospital wastewater using the freshwater organism Daphnia magna

Hospital wastewater (HWW) contains different hazardous substances resulting from a combination of medical and non-medical activities of hospitals, including pharmaceutical residues. These substances may represent a threat to the aquatic environment if they do not follow specific treatment processes. Therefore, we aimed to investigate the effects of the untreated effluent collected from a general hospital in Mahdia City (Tunisia) on neonatal stages of the freshwater crustacean Daphnia magna. Test organisms were exposed to three proportions (3.12%, 6.25%, and 12.5% v/v) of HWW. After 48 h of exposure, a battery of biomarkers was measured, including the quantification of antioxidant enzymes [catalase (CAT) and total and selenium-dependent glutathione peroxidase (total GPx; Se-GPx)], phase II biotransformation isoenzymes glutathione-S-transferases (GSTs), cyclooxygenases (COX) involved in the regulation of the inflammatory process, and total cholinesterases (ChEs) activities. Lipid peroxidation (LPO) was measured to estimate oxidative damage. The here-obtained results showed significant decreases of CAT and GSTs activities and also on LPO content in daphnids, whereas Se-GPx activity was significantly increased in a dose-dependent manner. Impairment of cholinesterasic and COX activities were also observed, with a significant decrease of ChEs and an increase of COX enzymatic activities. Considering these findings, HWW was capable of inducing an imbalance of the antioxidant defense system, but without resulting in oxidative damage in test organisms, suggesting that peroxidases and alternative detoxifying pathways were able to prevent the oxidant potential of several drugs, which were found in the tested effluents. In general, this study demonstrated the toxicity of hospital effluents, measured in terms of the potential impairment of key pathways, namely neurotransmission, antioxidant defense, and inflammatory homeostasis of crustaceans.

Photoaged polystyrene microplastics serve as photosensitizers that enhance cimetidine photolysis in an aqueous environment

Microplastics (MPs) have received much attention in recent years because of their continuous photoaging process in aquatic environments. However, little research has been conducted on the photochemistry of aged microplastics and the associated effects on coexisting pharmaceuticals. This study investigated the photodegradation of cimetidine via aged polystyrene microplastics (PS-MPs) with different aging times (0-7 d) under simulated sunlight irradiation (700 W/m²). PS-MPs with 5 d of aging time resulted in much faster cimetidine degradation (>99%) after 2 h of irradiation than pristine PS-MPs (<8%). The enhanced photodegradation of cimetidine by aged PS-MPs was related to the increase in chromophoric oxygenated groups (CO, C-O) followed by redshifted absorbance through the photoaging process, which induced the formation of the environmentally persistent free radicals (EPFRs) OH, ¹O₂ and ³PS*. However, only ¹O₂ and ³PS* contributed to enhanced cimetidine photodegradation, with ¹O₂ playing a more important role in our case. This work also demonstrated that other compounds that are susceptible to indirect photolysis, such as codeine and morphine, are likewise significantly degraded under irradiation in the presence of aged PS-MPs. Although previous studies have reported how MPs can increase the persistence of contaminants, this study demonstrates that MPs can serve as photosensitizers and alter the fate of coexisting pharmaceuticals in aquatic environments.

Abundance, fate, and effects of pharmaceuticals and personal care products in aquatic environments

Pharmaceuticals and personal care products (PPCPs) are found in wastewater, and thus, the environment. In this study, current knowledge about the occurrence and fate of PPCPs in aquatic systems-including wastewater treatment plants (WWTPs) and natural waters around the world-is critically reviewed to inform the state of the science and highlight existing knowledge gaps. Excretion by humans is the primary route of PPCPs entry into municipal wastewater systems, but significant contributions also occur through emissions from hospitals, PPCPs manufacturers, and agriculture. Abundance of PPCPs in raw wastewater is influenced by several factors, including the population density and demography served by WWTPs, presence of hospitals and drugs manufacturers in the sewershed, disease burden of the population served, local regulations, and climatic conditions. Based on the data obtained from WWTPs, analgesics, antibiotics, and stimulants (e.g., caffeine) are the most abundant PPCPs in raw wastewater. In conventional WWTPs, most removal of PPCPs occurs during secondary treatment, and overall removal exceeds 90% for treatable PPCPs. Regardless, the total PPCP mass discharged with effluent by an average WWTP into receiving waters (7.35-20,160 g/day) is still considerable, because potential adverse effects of some PPCPs (such as ibuprofen) on aquatic organisms occur within measured concentrations found in surface waters.

Mechanisms underlying the effect of chlorination and UV disinfection on VBNC state Escherichia coli isolated from hospital wastewater

The occurrence of viable but non-culturable (VBNC) bacteria in the wastewater system poses a huge threat to environmental and public health, in particular in hospital wastewater treatment system (HWTS). HWTS-oriented studies have been conducted to assess the effectiveness of chlorination and UV disinfection using indigenous bacteria. Results revealed that the VBNC Escherichia coli and ARGs remained persistent even at high chlorination (12 mg/L for 2.5 h) and UV doses (1000 mJ/cm²). The molecular mechanisms underlying chlorination-/UV-induced VBNC state in E. coli were explored through the transcriptomics and results suggested that most energy-dependent physiological activities (e.g., metabolism) have been suppressed in VBNC E. coli, while the pathogenicity-related genes varied insignificantly compared to the culturable cells, indicating that the VBNC E. coli could potentially display pathogenicity. Further Galleria mellonella model experiment has confirmed that although the disinfection-induced VBNC state made cells less infectious, these cells could regain their pathogenicity after resuscitation. This in vitro study can be used as a reference for studies on infections from VBNC bacteria and highlights the health risk due to VBNC pathogens in hospital effluents. There is a need to develop effluent standards specifically for healthcare facilities, and a stricter downstream disinfection strategy should be considered for the removal of VBNC cells and ARGs in the effluent.

Co-degradation of coexisting pollutants methylparaben (mediators) and amlodipine in enzyme-mediator systems: Insight into the mediating mechanism

Catalyzed oxidative reactions mediated by enzymes have been proposed as an effective remediation strategy to remove micropollutants. However, enzyme-catalyzed oxidation processes are usually limited to the substrates of phenols and amine compounds. The addition of synthetic redox mediators could extend the types of enzyme-catalyzed substrates. However, the actual applications were hindered by the high cost and potential toxicity of mediators. Here, we discovered a potential HRP-mediator system by exploring the removal of co-existing pollutants amlodipine (AML) and methylparaben (MeP). It was found that MeP served as a redox mediator could efficiently mediate the removal of AML by HRP/H₂O₂ system. Surface electrostatic potential analysis of AML molecule suggested that MeP radicals (MeP_OX) could abstract hydrogen from the N-H site on dihydropyridine moiety of AML and then be reduced to MeP. By exploring the mediating effects of substances with MeP-like structure, Hirshfeld charge was used to evaluate the mediating efficiency of mediators. For mediating the degradation of AML, when the Hirshfeld charge of mediator radical was around - 0.3000, the mediating efficiency was the highest. This study improved the HRP-mediated system and provided an efficient and green method for the degradation of co-existing pollutants AML and MeP.

Amlodipine removal via peroxymonosulfate activated by carbon nanotubes/cobalt oxide (CNTs/Co3O4) in water

Amlodipine (AML) is an effective drug that has been widely used for hypertension and angina. However, AML is frequently detected in aqueous environments, posing potential risks to human and ecological health. In this study, the degradation of AML via peroxymonosulfate (PMS) activated by CNTs/Co₃O₄ was investigated. CNTs/Co₃O₄ was prepared via a facile method, and multiple characterizations suggested that Co₃O₄ were uniformly dispersed on the surface of MWCNTs-COOH. Experimental results indicated that complete removal of 10 μM AML was achieved within 30 min by using 2 mg/L CNTs/Co₃O₄ and 4 μM PMS at 25 °C in PBS buffered solution (pH 7.0). The observed pseudo-first-order rate constant was calculated to be 0.1369 min^-1. Interestingly, the presence of 100 mM Cl^- resulted in a slight enhancement of AML removal rate from 0.0528 to 0.0642 min^-1. The addition of 100 mM HCO₃^-, 5 mg/L Pony Lake fulvic acid (PLFA), or Suwannee River humic acid (SRHA) retarded AML degradation by 15.5, 0.7, and 1.6 times, respectively. As per the quenching experiments, SO₄^⦁- rather than ⦁OH were verified to be the dominant reactive oxygen species (ROS). Additionally, ten major intermediates were identified using TOF-LC-MS and three associated reaction pathways including ether bond broken, H-abstraction, and hydroxylation were proposed. We outlook these findings to advance the feasibility of organic contaminants removal via CNTs/Co₃O₄ + PMS systems that have extremely low-level PMS.

Teratogenic effects induced by paracetamol, ciprofloxacin, and their mixture on Danio rerio embryos: Oxidative stress implications

Even though the toxic effects of paracetamol (PCM) and ciprofloxacin (CPX) have been deeply studied in the last decades, the impact of the PCM-CPX mixture may induce in aquatic organisms is poorly known. Thus, the objective of this work was to investigate the teratogenic effects and oxidative stress that PCM, CPX, and their mixture induce in Danio rerio embryos. Moreover, we aimed to determine whether the PCM-CPX mixture induces more severe effects on the embryos than the individual drugs. For this purpose, zebrafish embryos (4 hpf) were exposed to environmentally relevant concentrations of PCM, CPX, and their mixture until 96 hpf. In addition, at 72 hpf and 96 hpf, we also evaluated the oxidative stress biomarkers (superoxide dismutase, catalase, glutathione peroxidase, lipid peroxidation, and hydroperoxides and carbonyl content) in the embryos. Our results demonstrated that PCM, CPX, and their mixture reduced the survival rate of embryos by up to 75%. In addition, both drugs, induced morphological alterations in the embryos, causing their death. The most observed malformations were: scoliosis, craniofacial malformations, hypopigmentation, growth retardation, pericardial edema. Concerning oxidative stress, our integrated biomarkers response (IBR) analysis demonstrated that PCM, CPX, and their mixture induce oxidative damage on the embryos. In conclusion, PCM, CPX, and their mixture can alter zebrafish embryonic development via an oxidative stress response.

Instrumental and bioanalytical assessment of pharmaceuticals and hormone-like compounds in a major drinking water source-wastewater receiving Zayandeh Rood river, Iran

Zayandeh Rood river is the most important river in central Iran supplying water for a variety of uses including drinking water for approximately three million inhabitants. The study aimed to investigate the quality of water concerning the presence of pharmaceutical active compounds (PhACs) and hormonelike compounds, which have been only poorly studied in this region. Sampling was performed at seven sites along the river (from headwater sites to downstream drinking water source, corresponding drinking water, and treated wastewater) affected by wastewater effluents, specific drought conditions, and high river-water demand. The targeted and nontargeted chemical analyses and in vitro bioassays were used to evaluate the presence of PhACs and hormonelike compounds in river water. In the samples, 57 PhACs and estrogens were detected with LC-MS/MS with the most common and abundant compounds valsartan, carbamazepine, and caffeine present in the highest concentrations in the treated wastewater in the concentrations of 8.4, 19, and 140 μg/L, respectively. A battery of in vitro bioassays detected high estrogenicity, androgenicity, and AhR-mediated activity (viz., in treated wastewater) in the concentrations 24.2 ng/L, 62.2 ng/L, and 0.98 ng/L of 17β-estradiol, dihydrotestosterone and 2,3,7,8-TCDD equivalents, respectively. In surface water samples, estrogenicity was detected in the range of <0.42 (LOD) to 1.92 ng/L of 17β-estradiol equivalents, and the drinking water source contained 0.74 ng/L of 17β-estradiol equivalents. About 19% of the estrogenicity could be explained by target chemical analyses, and the remaining estrogenicity can be at least partially attributed to the potentiation effect of detected surfactant residues. Drinking water contained several PhACs and estrogens, but the overall assessment suggested minor human health risk according to the relevant effect-based trigger values. To our knowledge, this study provides some of the first comprehensive information on the levels of PhACs and hormones in Iranian waters.

Occurrence of Pharmaceutically Active Compounds and Potential Ecological Risks in Wastewater from Hospitals and Receiving Waters in Sri Lanka

The presence of pharmaceutically active compounds (PACs) in the environment and their associated hazards is a major global health concern; however, data on these compounds are scarce in developing nations. In the present study, the existence of 39 non-antimicrobial PACs and six of their metabolites in wastewater from hospitals and adjacent surface waters in Sri Lanka was investigated from 2016 to 2018. The highest amounts of the measured chemicals, including the highest concentrations of atorvastatin (14,620 ng/L) and two metabolites, mefenamic acid (12,120 ng/L) and o-desmethyl tramadol (8700 ng/L), were detected in wastewater from the largest facility. Mefenamic acid, gemfibrozil, losartan, cetirizine, carbamazepine, and phenytoin were detected in all the samples. The removal rates in wastewater treatment were 100% for zolpidem, norsertaline, quetiapine, chlorpromazine, and alprazolam. There was substantial variation in removal rates of PACs among facilities, and the overall data suggest that treatment processes in facilities were ineffective and that some PAC concentrations in the effluents were increased. The estimated risk quotients revealed that 14 PACs detected in water samples could pose low to high ecological risk to various aquatic organisms. Compounds such as ibuprofen, tramadol, and chlorpromazine detected in untreated and treated wastewater at these facilities pose a high risk to several aquatic organisms. Our study provides novel monitoring data for non-antimicrobial PAC abundance and the associated potential ecological risk related to hospitals and urban surface waters in Sri Lanka and further offers valuable information on pre-COVID-19 era PAC distribution in the country. Environ Toxicol Chem 2022;41:298-311. © 2021 SETAC.

Which Micropollutants in Water Environments Deserve More Attention Globally?

Increasing chemical pollution of aquatic environments is a growing concern with global relevance. A large number of organic chemicals are termed as "micropollutants" due to their low concentrations, and long-term exposure to micropollutants may pose considerable risks to aquatic organisms and human health. In recent decades, numerous treatment methods and technologies have been proposed to remove micropollutants in water, and typically several micropollutants were chosen as target pollutants to evaluate removal efficiencies. However, it is often unclear whether their toxicity and occurrence levels and frequencies enable them to contribute significantly to the overall chemical pollution in global aquatic environments. This review intends to answer an important lingering question: Which micropollutants or class of micropollutants deserve more attention globally and should be removed with higher priority? Different risk-based prioritization approaches were used to address this question. The risk quotient (RQ) method was found to be a feasible approach to prioritize micropollutants in a large scale due to its relatively simple assessment procedure and extensive use. A total of 83 prioritization case studies using the RQ method in the past decade were compiled, and 473 compounds that were selected by screening 3466 compounds of three broad classes (pharmaceuticals and personal care products (PPCPs), pesticides, and industrial chemicals) were found to have risks (RQ > 0.01). To determine the micropollutants of global importance, we propose an overall risk surrogate, that is, the weighted average risk quotient (WARQ). The WARQ integrates the risk intensity and frequency of micropollutants in global aquatic environments to achieve a more comprehensive priority determination. Through metadata analysis, we recommend a ranked list of 53 micropollutants, including 36 PPCPs (e.g., sulfamethoxazole and ibuprofen), seven pesticides (e.g., heptachlor and diazinon), and 10 industrial chemicals (e.g., perfluorooctanesulfonic acid and 4-nonylphenol) for risk management and remediation efforts. One caveat is that the ranked list of global importance does not consider transformation products of micropollutants (including disinfection byproducts) and new forms of pollutants (including antibiotic resistance genes and microplastics), and this list of global importance may not be directly applicable to a specific region or country. Also, it needs mentioning that there might be no best answer toward this question, and hopefully this review can act as a small step toward a better answer.

Montmorillonite promoted photodegradation of amlodipine in natural water via formation of surface complexes

The photolysis of amlodipine (AML) as a ubiquitous pollutant in natural water has been extensively studied. Montmorillonite (MMT), a major component of suspended particles in surface aquifers, plays key roles in the natural transportation and transformation of organic contaminants in the environment. However, literature has scarcely focused on whether and how suspended particles affect the phototransformation of AML. This study systematically investigated the phototransformation behavior of AML in MMT suspensions under simulated sunlight. The results obtained showed that MMT significantly enhanced the photolysis of AML. The photodegradation of AML in 0.05 g/L MMT suspension reached 92.2 % after 3 h irradiation under the simulated sunlight. The photodecomposition followed the pseudo-first-order kinetic with a rate constant of 0.803 h^-1 in the presence of 0.05 g/L MMT, which is about 19 times larger than that in the absence of MMT (0.0421 h^-1). Further mechanistic investigation suggested that MMT accelerated the photolysis of AML by the formation of surface complexes between cationic amino groups of AML and the negatively charged sites on MMT surface, which greatly facilitated light absorption and electron transfer for the production of cationic radical AML^+·. Meanwhile, the hydroxyl radicals generated by irradiated MMT also played an important role in the photocatalytic degradation of AML. The probable photodegradation pathways of AML in MMT suspension further supported the proposed mechanisms. The toxicity evaluation of phototransformation products of AML with ECOSAR program indicated that photolysis could reduce its potential threats. These findings reveal an important and previously overlooked phototransformation mechanisms of AML in the presence of MMT clays, which is of importance in assessing the environmental fate of other similar organic contaminants.

Adsorption and detoxification of pharmaceutical compounds from wastewater using nanomaterials: A review on mechanism, kinetics, valorization and circular economy

Antibiotics overuse, inappropriate conduct, and discharge have led to adverse effects on various ecosystems. The occurrence of antibiotics in surface and drinking water is a matter of global concern. It is responsible for multiple disorders, including disruption of endocrine hormones and high chronic toxicity. The hospitals, pharmaceutical industries, households, cattle farms, and aquaculture are the primary discharging sources of antibiotics into the environment. This review provides complete detail on applying different nanomaterials or nanoparticles for the efficient removal of antibiotics from the diverse ecosystem with a broader perspective. Efforts have been made to focus on the degradation pathways and mechanism of antibiotic degradation using nanomaterials. More light has been shed on applying nanostructures in photocatalysis, which would be an economical and efficient solution. The nanoscale material or nanoparticles have incredible potential for mineralizing pharmaceutical compounds in aqueous solutions at low cost, easy handling characteristics, and high efficacy. Furthermore, nanoparticles can absorb the pharmaceutical by-products and wastes at a minimum cost as they can be easily recycled. With the increasing number of research in this direction, the valorization of pharmaceutical wastes and by-products will continue to expand as we progress from old conventional approaches towards nanotechnology. The utilization of nanomaterials in pharmaceutical wastewater remediation is discussed with a major focus on valorization, energy generation, and minimization and its role in the circular economy creating sustainable development.

Recent Progress and Prospects in Catalytic Water Treatment

Presently, conventional technologies in water treatment are not efficient enough to completely mineralize refractory water contaminants. In this context, the implementation of catalytic processes could be an alternative. Despite the advantages provided in terms of kinetics of transformation, selectivity, and energy saving, numerous attempts have not yet led to implementation at an industrial scale. This review examines investigations at different scales for which controversies and limitations must be solved to bridge the gap between fundamentals and practical developments. Particular attention has been paid to the development of solar-driven catalytic technologies and some other emerging processes, such as microwave assisted catalysis, plasma-catalytic processes, or biocatalytic remediation, taking into account their specific advantages and the drawbacks. Challenges for which a better understanding related to the complexity of the systems and the coexistence of various solid-liquid-gas interfaces have been identified.

Microalgal Systems for Wastewater Treatment: Technological Trends and Challenges towards Waste Recovery

Wastewater (WW) treatment using microalgae has become a growing trend due the economic and environmental benefits of the process. As microalgae need CO2, nitrogen, and phosphorus to grow, they remove these potential pollutants from wastewaters, making them able to replace energetically expensive treatment steps in conventional WW treatment. Unlike traditional sludge, biomass can be used to produce biofuels, biofertilizers, high value chemicals, and even next-generation growth media for “organically” grown microalgal biomass targeting zero-waste policies and contributing to a more sustainable circular bioeconomy. The main challenge in this technology is the techno-economic feasibility of the system. Alternatives such as the isolation of novel strains, the use of native consortia, and the design of new bioreactors have been studied to overcome this and aid the scale-up of microalgal systems. This review focuses on the treatment of urban, industrial, and agricultural wastewaters by microalgae and their ability to not only remove, but also promote the reuse, of those pollutants. Opportunities and future prospects are discussed, including the upgrading of the produced biomass into valuable compounds, mainly biofuels.

A review on disinfection technologies for controlling the antibiotic resistance spread

The occurrence of antibiotic-resistant bacteria (ARB) in water bodies poses a sanitary and environmental risk. These ARB and other mobile genetic elements can be easily spread from hospital facilities, the point in which, for sure, they are more concentrated. For this reason, novel clean and efficient technologies are being developed for allowing to remove these ARB and other mobile genetic elements before their uncontrolled spread. In this paper, a review on the recent knowledge about the state of the art of the main disinfection technologies to control the antibiotic resistance spread from natural water, wastewater, and hospital wastewater (including urine matrices) is reported. These technologies involve not only conventional processes, but also the recent advances on advanced oxidation processes (AOPs), including electrochemical advanced oxidation processes (EAOPs). This review summarizes the state of the art on the applicability of these technologies and also focuses on the description of the disinfection mechanisms by each technology, highlighting the promising impact of EAOPs on the remediation of this important environmental and health problem.