Solid phase extraction coupled to liquid chromatography-tandem mass spectrometry analysis of sulfonamides, tetracyclines, analgesics and hormones in surface water and wastewater in Luxembourg

All-in-one spot test method for tetracycline using molecularly imprinted polymer-coated paper integrated into a portable 3D printed platform with smartphone-based fluorescent detection

A molecularly imprinted polymer (MIP) has been synthetized, characterized, impregnated on paper, and integrated into a 3D printed platform with smartphone-based fluorescent detection for the determination of tetracycline in water samples. The MIP synthesis was performed by precipitation polymerization, which was subsequently deposited onto a glass microfiber paper. The synthesized polymer and the MIP@paper have been characterized by FTIR spectroscopy, scanning electron microscopy, and EDS spectroscopy. Afterward, a 3D printed detection platform that houses monochromatic LED strips as radiation source and a smartphone as detector have been used for determination of tetracycline. Digital image processing was based on the RGB colour model using image J software and the red intensity channel was used as analytical signal due to its higher sensitivity. Several factors that affect the adsorption capacity and fluorescent detection have been optimized. Under optimum conditions, detection limit of 0.04 mg L-1 and good linearity up 5 mg L-1 (r = 0.998), were achieved. The intra- and inter-day precision of 4.9 and 7.2 %, respectively, expressed as relative standard deviation (%RSD) were obtained, showing the good precision of the proposed methodology. Satisfactory recoveries between 87 and 98 % were obtained spiking real water sample matrices at different concentrations (0.1-0.3 mg L-1). The portable 3D platform with smartphone-based fluorescent detection exploiting all-in-one spot test method for tetracycline using MIP@paper was evaluated with AGREE and GAPI metrics, evidencing its environmentally friendly approach. Furthermore, the BAGI tool demonstrated the practicality of the method, in terms of functionality and applicability compared to previous HPLC and spectrofluorometric methods.

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.

Accumulation of antibiotics in the environment: Have appropriate measures been taken to protect Canadian human and ecological health?

In Canada, every day, contaminants of emerging concern (CEC) are discharged from waste treatment facilities into freshwaters. CECs such as pharmaceutical active compounds (PhACs), personal care products (PCPs), per- and polyfluoroalkyl substances (PFAS), and microplastics are legally discharged from sewage treatment plants (STPs), water reclamation plants (WRPs), hospital wastewater treatment plants (HWWTPs), or other forms of wastewater treatment facilities (WWTFs). In 2006, the Government of Canada established the Chemicals Management Plan (CMP) to classify chemicals based on a risk-priority assessment, which ranked many CECs such as PhACs as being of low urgency, therefore permitting these substances to continue being released into the environment at unmonitored rates. The problem with ranking PhACs as a low priority is that CMP's risk management assessment overlooks the long-term environmental and synergistic effects of PhAC accumulation, such as the long-term risk of antibiotic CEC accumulation in the spread of antibiotic resistance genes. The goal of this review is to specifically investigate antibiotic CEC accumulation and associated environmental risks to human and environmental health, as well as to determine whether appropriate legislative strategies are in place within Canada's governance framework. In this research, secondary data on antibiotic CEC levels in Canadian and international wastewaters, their potential to promote antibiotic-resistant residues, associated environmental short- and long-term risks, and synergistic effects were all considered. Unlike similar past reviews, this review employed an interdisciplinary approach to propose new strategies from the perspectives of science, engineering, and law.

Preparation of a Carbon paste electrode with Active materials for the detection of Tetracycline

The Electrochemical sensor based on carbon-clay paste electrode (CCPE) was constructed for sensitive determination of Tetracycline (Tc). The mineralogical composition, morphology, structure and performance of CCPE were characterized using X-ray diffraction powder, Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Cyclic Voltammetry analysis. The CCPE is constituted of two types of clay having the ratio 1/1 and 2/1 characteristic of kaolinite and montmorillonite clay respectively. Its porous structure is ascribed to the presence of graphite. The CCPE exhibited a good electrocatalytic activity towards the oxidation of Tc. The electrochemical kinetics and mechanism of Tc were proposed, showing that Tc electrocatalytic oxidation reaction was controlled by diffusion process and took place in three steps. A low concentration of Tc was detected by amperometry with the linear ranges of 0.5μM-0.8 μM (R2 = 0.98), the sensitivity was 8.01 μA/μM.cm2, the limit of detection and quantification were 5.16x10-3μM(S/N = 3) and 1.72x10-2μM respectively. Thus, the proposed electrode provides a promising and prospective CCPE sensing platform for the detection of Tc in the environment.

Tetracyclines contamination in European aquatic environments: A comprehensive review of occurrence, fate, and removal techniques

Tetracyclines are among the most commonly used antibiotics for the treatment of bacterial infections and the improvement of agricultural growth and feed efficiency. All compounds in the group of tetracyclines (tetracycline, chlorotetracycline, doxycycline, and oxytetracycline) are excreted in an unchanged form in urine at a rate of more than 70%. They enter the aquatic environment in altered and unaltered forms which affect aquatic micro- and macroorganisms. This study reviews the occurrence, fate, and removal techniques of tetracycline contamination in Europe. The average level of tetracycline contamination in water ranged from 0 to 20 ng/L. However, data regarding environmental contamination by tetracyclines are still insufficient. Despite the constant presence and impact of tetracyclines in the environment, there are no legal restrictions regarding the discharge of tetracyclines into the aquatic environment. To address these challenges, various removal techniques, including advanced oxidation, adsorption, and UV treatment, are being critically evaluated and compared. The summarized data contributes to a better understanding of the current state of Europe's waters and provides insight into potential strategies for future environmental management and policy development. Further research on the pollution and effects of tetracyclines in aquatic environments is therefore required.

Estrogen pollution of the European aquatic environment: A critical review

Among the plethora of chemicals released into the environment, much attention is paid to endocrine disrupting compounds (EDCs). Natural estrogens, such as estrone (E1), 17β-estradiol (E2), estriol (E3) are excreted by humans as well as animals, and can enter the environment as a result of discharging domestic sewage and animal waste. These compounds can cause deleterious effects such as feminization, infertility and hermaphroditism in organisms that inhabit water bodies. This study provides an overview of the level of estrogen exposures in surface waters, groundwater and river sediments in European countries. The conducted review shows that estrogen concentrations were within the range of 0.1 ng L - 10 ng /L in the majority of the tested environmental samples. However, the authors of the study point out that there are still many unexplored areas and a limited amount of data that mainly concerns Eastern European countries. The study also analysed the factors that influence the increased emissions of estrogens to the environment, which may be helpful for identifying particularly polluted areas.

A comprehensive review of various approaches for treatment of tertiary wastewater with emerging contaminants: what do we know?

In the last few decades, environmental contaminants (ECs) have been introduced into the environment at an alarming rate. There is a risk to human health and aquatic ecosystems from trace levels of emerging contaminants, including hospital wastewater (HPWW), cosmetics, personal care products, endocrine system disruptors, and their transformation products. Despite the fact that these pollutants have been introduced or detected relatively recently, information about their characteristics, actions, and impacts is limited, as are the technologies to eliminate them efficiently. A wastewater recycling system is capable of providing irrigation water for crops and municipal sewage treatment, so removing ECs before wastewater reuse is essential. Water treatment processes containing advanced ions of biotic origin and ECs of biotic origin are highly recommended for contaminants. This study introduces the fundamentals of the treatment of tertiary wastewater, including membranes, filtration, UV (ultraviolet) irradiation, ozonation, chlorination, advanced oxidation processes, activated carbon (AC), and algae. Next, a detailed description of recent developments and innovations in each component of the emerging contaminant removal process is provided.

Degradation of tetracycline wastewater by suspended biochar as carriers in moving bed biofilm reactor

To improve the removal efficiency of antibiotics in moving bed biofilm reactor, suspended biochar block was prepared by the one-pot process and was used as carriers to construct a reaction device to study the treatment effect of antibiotic wastewater. The characteristics of the hanging biofilm in wastewater were investigated. And the mechanism of biochar as a biological carrier has been studied. The results showed that in the 45-day experiment, the maximum number of biofilms for suspended biochar carriers was twice 3.4 times that of the high-density polyethylene carriers. When 10 mg/L tetracycline was added to the reactor, the removal efficiency of the tetracycline removal rate was 71.85% and the chemical oxygen demand (COD), total nitrogen (TN), and NH₄⁺-N removal efficiency reached to 89.95, 61.91 and 85.47% respectively. Suspension biochar carriers can reduce fluctuations in redox potentials, thereby improving the cellular efficiency of microorganisms. Meanwhile, it inhibits the production of soluble microbial products and extracellular polymers, reduces toxic effects, and enhances the adhesion between microorganisms and carriers. The microbial communities of the two carriers were investigated by high-throughput sequencing techniques. Suspended biochar significantly increased the relative abundance of Hydrogenophaga and Comamonas, and improved the ability of nitrification and denitrification. Comamonas could be responsible for tetracycline degradation.

Applications of Heterogeneous Photocatalysis to the Degradation of Oxytetracycline in Water: A Review

Photocatalytic processes are being studied extensively as potential advanced wastewater treatments for the removal of pharmaceuticals, pesticides and other recalcitrant micropollutants from the effluents of conventional wastewater treatment plants (WWTPs). Oxytetracycline (OTC) is a widespread antibiotic which is frequently detected in surface water bodies as a recalcitrant and persistent micropollutant. This review provides an update on advances in heterogeneous photocatalysis for the degradation of OTC in water under UV light, sunlight and visible-light irradiation. Photocatalysts based on pure semiconducting oxides are rarely used, due to the problem of rapid recombination of electron–hole pairs. To overcome this issue, a good strategy could be the coupling of two different semiconducting compounds with different conduction and valence bands. Several methods are described to enhance the performances of catalysts, such as doping of the oxide with metal and/or non-metal elements, surface functionalization, composites and nano-heterojunction. Furthermore, a discussion on non-oxidic photocatalysts is briefly provided, focusing on the application of graphene-based nanocomposites for the effective treatment of OTC.

Reduction of multiple antibiotics from the waste water using coated glutathione S-transferase producing biocatalyst

Oxytetracycline is widely used in veterinary and human medicine. It has been detected in wastewater from pharmaceuticals, hospitals and domestic wastewater. In recent years, much more attention has been directed towards glutathione transferases (GSTs) because of their bio-transforming ability of antibiotics. In this study, 19 Lactobacillus strains were initially screened for the production of GSTs and five strains were selected for biotransformation of oxytetracycline. Among the strains, L. fermentum LA6 improved oxytetracyline degradation than other strains. It was subjected to optimize GST production and optimum growth was achieved after 24 h incubation at 32 ± 2 °C and 200 mg/L initial oxytetracycline concentration. The biocatalyst was immobilized and antibiotic degradation efficiency was analyzed. The immobilized culture of L. fermentum LA6 improved biodegradation of oxytetracycline in the wastewater. At 50 mg/L initial antibiotic concentration, 53.2 ± 2.8% oxytetracycline degradation was achieved, however, it improved at 200 mg/L antibiotic concentration in the culture medium (89.1 ± 4.3%) after 24 h. The chemical oxygen demand (COD) of the wastewater decreased significantly after treatment. At 200 mg/L oxytetracycline concentration, COD removal was considerably high (93.6 ± 5.3 mg/L) than 150 mg/L oxytetracycline concentration in the medium. Antibiotic removal efficiency in immobilized form revealed that this method is highly suitable for the removal of antibiotics from the wastewater.

Occurrence, detection and ecotoxicity studies of selected pharmaceuticals in aqueous ecosystems- a systematic appraisal

Pharmaceutical compounds (PCs) have globally emerged as a significant group of environmental contaminants due to the constant detection of their residues in the environment. The main scope of this review is to fill the void of information on the knowledge on the African occurrence of selected PCs in environmental matrices in comparison with those outside Africa and their respective toxic actions on both aquatic and non-aquatic biota through ecotoxicity bioassays. To achieve this objective, the study focused on commonly used and detected pharmaceutical drugs (residues). Based on the conducted literature survey, Africa has the highest levels of ciprofloxacin, sulfamethoxazole, lamivudine, acetaminophen, and diclofenac while Europe has the lowest of all these PC residues in her physical environments. For ecotoxicity bioassays, the few data available are mostly on individual groups of pharmaceuticals whereas there is sparsely available data on their combined forms.

17α-ethynylestradiol and its two main conjugates in seven municipal wastewater treatment plants: Analytical method, their occurrence, removal and risk evaluation

This work shows the existence of both 17-ethinylestradiol-3-sulfate (EE2-3S) and 17-ethinylestradiol-3-glucuronide (EE2-3G) in seven municipal WWTPs with substantial concentrations (n.d-50.10 ng/L). The calculated removal efficiencies of 17-ethinylestradiol (EE2) in the seven municipal WWTPs ranged from 40.8%-100% with an average removal efficiency of 83.3%. However, upon the inclusion of EE2 concentration transformed from EE2-3S and EE2-3G, the corresponding removal efficiencies were increased to 91.4%-100% with an average removal efficiency of 97.3%. This work is the first to clearly illustrate that EE2 conjugates in raw wastewater could greatly underestimate the removal effectiveness of municipal WWTPs on EE2, indicating the importance of the EE2 conjugates in municipal wastewater having been hardly paid with attention. The EE2-derived estrogen equivalence (EEQ) values in the effluents of seven WWTPs ranged from 0 to 0.98 ng E2/L having an average level of 0.45 ng E2/L, which were relatively low. However, upon the inclusion of EE2 transformable from EE2-3S and EE2-3G in effluents, the EE2-derived EEQ values in effluents would be increased to 0.77-4.85 ng E2/L having an average level of 2.71 ng E2/L, which clearly suggested that ignorance of EE2 conjugates in effluent would largely underestimate EE2's environmental risk to receiving water bodies.

Development and Validation of Multi-Residue Method for Drugs Analysis in Human Feces by Liquid Chromatography-Tandem Mass Spectrometry

The use of veterinary drugs in animal production is a common practice to secure animal and human health. However, residues of administrated drugs could be present in animal food products. Levels of drugs in food of animal origin are regulated within the European Union. In recent years, residues have been detected not only in food, but also in the environmental elements such as water or soil, meaning that humans are involuntarily exposed to these substances. This article presents a multiclass method for the analysis of various therapeutic groups of pharmaceuticals in human feces. Pharmaceuticals are extracted from feces with an acid extraction solvent, and after filtration the extract was analyzed by HPLC-MS/MS. A limit of detection of 10 ng/g was achieved for 9 pharmaceuticals, with linearity over 0.99 and repeatability and reproducibility lower than 20%. The method was satisfactorily applied in 25 feces samples of individuals that had declared not to be under medical treatment for the last two months. Results indicate the presence of six different compounds at concentration between 10 and 456 ng/g. This preliminary study showed the involuntary exposure of human gut microbiota to active substances such as pharmaceuticals.

Assessment of automated off-line solid-phase extraction LC-MS/MS to monitor EPA priority endocrine disruptors in tap water, surface water, and wastewater

EPA method 539.1 recently introduced an expanded list of priority endocrine-disrupting compounds (EDCs), some of which were also included in the Unregulated Contaminant Monitoring Rule 3 (UCMR3). Though standardized methods are available for drinking water, analysis of steroid hormones and bisphenol A (BPA) at the ultra-trace level remains challenging. This study set out to evaluate the suitability of automated off-line solid-phase extraction (SPE) liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) for the determination of EPA-priority EDCs in environmental water matrixes (tap water, surface water, and wastewater influents and effluents). The target molecules included 14 steroid hormones (altrenogest, androstenedione, equilenin, equilin, α-estradiol, β-estradiol, estriol, estrone, ethinylestradiol, levonorgestrel, medroxyprogesterone, norethindrone, progesterone, testosterone) and BPA. Factors that may influence the analytical performance were assessed. This involved, for instance, testing combinations of SPE materials from different brands and protocol variations. Several materials presented absolute extraction efficiencies in acceptable ranges. Initial sample pH, nature of reconstitution medium, and mobile phase salt concentration were among the potential factors affecting analyte signal. Storage conditions (different preservative agents) possibly exerted the strongest influence, in agreement with the literature. Limits of detection were in the range of 0.03-0.5 ng/L in drinking water, 0.1-0.5 ng/L in surface water, and 0.16-1 ng/L in wastewater. Method validation also involved testing linearity, accuracy, and precision in reagent water and matrix-matched extracted calibrants. The method was applied to field-collected water samples in Eastern Canada. Summed EDC concentrations remained low in tap water (<LOQ-0.92 ng/L), while higher detection frequencies and contamination levels were reported in riverine surface waters (2.6-37 ng/L) and municipal wastewaters (10-424 ng/L).

Biodegradability, environmental risk assessment and ecological footprint in wastewater technologies for pharmaceutically active compounds removal

Several studies have investigated the removal of pharmaceutically active compounds (PhACs) by wastewater treatment technologies due to the risk that these compounds pose to the environment. In this sense, advanced biological processes have been developed for micropollutants removal, such as membrane bioreactors and moving bed biofilm reactors. Thus, this review holistically evaluated the biodegradation of 18 environmentally hazardous PhACs. Biological processes were assessed including removal efficiencies, environmental risk, and ecological footprint (consumption of resources and energy, atmospheric emissions, and waste generation). The maximum concentration of PhACs for a low or negligible risk scenario in treated wastewater and the potential of biological processes to meet this goal were assessed. Among the evaluated PhACs, the most biodegradable was paracetamol, while the most recalcitrant was diclofenac. Combination of conventional processes and advanced biological processes proved to be the most efficient way to remove several PhACs, mainly the osmotic membrane bioreactor.

Occurrence and Distribution of Pharmaceuticals and Their Transformation Products in Luxembourgish Surface Waters

Pharmaceuticals and their transformation products (TPs) are continuously released into the aquatic environment via anthropogenic activity. To expand knowledge on the presence of pharmaceuticals and their known TPs in Luxembourgish rivers, 92 samples collected during routine monitoring events between 2019 and 2020 were investigated using nontarget analysis. Water samples were concentrated using solid-phase extraction and then analyzed using liquid chromatography coupled to a high-resolution mass spectrometer. Suspect screening was performed using several open source computational tools and resources including Shinyscreen (https://git-r3lab.uni.lu/eci/shinyscreen/), MetFrag (https://msbi.ipb-halle.de/MetFrag/), PubChemLite (https://zenodo.org/record/4432124), and MassBank (https://massbank.eu/MassBank/). A total of 94 pharmaceuticals, 88 confirmed at a level 1 confidence (86 of which could be quantified, two compounds too low to be quantified) and six identified at level 2a, were found to be present in Luxembourg rivers. Pharmaceutical TPs (12) were also found at a level 2a confidence. The pharmaceuticals were present at median concentrations up to 214 ng/L, with caffeine having a median concentration of 1424 ng/L. Antihypertensive drugs (15), psychoactive drugs (15), and antimicrobials (eight) were the most detected groups of pharmaceuticals. A spatiotemporal analysis of the data revealed areas with higher concentrations of the pharmaceuticals, as well as differences in pharmaceutical concentrations between 2019 and 2020. The results of this work will help guide activities for improving water management in the country and set baseline data for continuous monitoring and screening efforts, as well as for further open data and software developments.

Oxytetracycline induces anxiety-like behavior in adult zebrafish

Oxytetracycline (OTC) is one of the broad-spectrum antibiotics widely used for the treatment of fish-farm infection. Considering that behavior is directly related to reproduction, individual fitness, and survival, it is important to evaluate the impact of antibiotics on the behavioral repertoire in fish. Zebrafish (Danio rerio) presents a well-described behavioral repertoire to reliably demonstrate complex responses to chemical compound exposure. This work aims to identify the role of OTC in comprehensive behavioral parameters and whole-body cortisol levels in adult zebrafish. Here we report that OTC exposure (10, 20, and 100 mg/L) induces an anxiogenic-like phenotype in the novel tank test. OTC exposure also changes the behavior of social interaction with a shoal of unknown zebrafish - characterized as a stimulus group. Zebrafish exposed to OTC (10 mg/L) remains a longer period in the stimulus zone when compared to the control group. Clonazepam (0.006 mg/L) was able to reverse anxiogenic-like behavior and the changes in social behavior induced by OTC. We also demonstrated that cortisol levels were significantly decreased after exposure to OTC (10, 20, and 100 mg/L), which were not reversed by clonazepam. These findings highlight the growing utility of zebrafish as a model to understand the impact of antibiotics on behavior and their underlying mechanisms.

Development of an Electrochemical Sensor Based on Nanocomposite of Fe3O4@SiO2 and Multiwalled Carbon Nanotubes for Determination of Tetracycline in Real Samples

In this work, an electrochemical sensor (GCE/MWCNT/Fe3O4@SiO2) based on a composite of multiwalled carbon nanotubes (MWCNT) and an Fe3O4@SiO2 (MMN) nanocomposite on a glassy carbon electrode (GCE) was developed for the detection of tetracycline (TC). The composite formed promoted an increased electrochemical signal and the stability of the sensor, combining its individual characteristics such as high electrical conductivity and large surface area. The composite material was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Mössbauer spectroscopy, and scanning electron microscope (SEM). The adsorptive stripping differential pulse voltammetry (AdSDPV) promoted better performance for the electrochemical sensor and greater sensitivity for TC detection. Under optimized conditions, the currents increased linearly with TC concentrations from 4.0 to 36 µmol L−1 (0.997) and from 40 to 64 µmol L−1 (0.994) with detection and quantification limits of 1.67 µmol L−1 and 4.0 µmol L−1, respectively. The sensor was applied in the analysis of milk and river water samples, obtaining recovery values ranging from 91–117%.

Assessment of 17α-ethinylestradiol effects in Daphnia magna: life-history traits, biochemical and genotoxic parameters

The occurrence of pharmaceuticals in aquatic ecosystems and the need to study them have increased over the years since they enter continuously the environment. Besides, these compounds are not intended for applications with environmental purposes, and therefore, little is known about their ecological effects, particularly in non-target organisms, as invertebrate species. Inside these substances, endocrine disrupting compounds (EDCs) have recently come into the limelight, due to environmental concentrations and consequently their detrimental effects on different organisms. 17α-ethinylestradiol (EE2) has been detected in the aquatic environment in various locations around the globe since it is the main synthetic hormone used as a female oral contraceptive and is also applied in veterinary medicine and animal production. The present study was intended to assess the chronic effects of EE2, in the non-target organism as Daphnia magna. Thus, to analyze the individual and subindividual impact, this aquatic organism was chronically exposed (21 days) to 0.00 (control group), 0.10, 1.00, 10.0, and 100 μg/L of EE2. Results here obtained demonstrated that D. magna exposed to the EE2 concentrations had significant effects in individual (life-history) and sub-individual (biochemical levels) parameters. Alterations as anticipation in the age at first reproduction, a decrease of the growth rate, oxidative stress, and lipid peroxidation were detected, as well as genotoxic damage. Therefore, it was possible to infer that EE2 can disrupt several metabolic pathways and physiological functions of D. magna, since EE2 demonstrated ecotoxicity, at environmentally relevant concentrations. This work reinforces the importance of examining the effects of more relevant exposures (more prolonged and with ecologically pertinent concentrations) of potential endocrine disruptors like EE2, to the freshwater organisms and ecosystem.

Determination of pharmaceuticals in solid samples in municipal wastewater treatment plants by online SPE LC-MS/MS using QuEChERS extraction

In this study, a pretreatment method based on the QuEChERS method has been applied for simultaneously extracting 27 residual pharmaceuticals from wastewater solids. The extracted compounds have been analyzed using online solid-phase extraction (SPE) coupled to liquid chromatography with tandem mass spectrometry (LC-MS/MS). A recovery test was conducted according to the absorbent type, and buffers were added in the sample extraction step. The highest recovery efficiency could be observed when Na₂SO₄ was used as an absorbent and Na₂EDTA was injected during the extraction process; the recovery efficiencies of the proposed method for the target compounds ranged from 61.3 to 137.2%, and the repeatability was 6.8%. These recovery and repeatability data showed that the proposed method could reliably analyze the 27 target residual pharmaceuticals. The concentrations of the target compounds were all below the limits of quantification: 830 ng g^-1 for the target compounds in suspended solids, 2353 ng g^-1 in activated sludge, and 1929 ng g^-1 in waste sludge. The analytical method established in this study can be applied to quantify residual pharmaceuticals in solid samples and to investigate their behaviors in a municipal wastewater treatment plant.

Determination of estrogens and estrogen mimics by solid-phase extraction with liquid chromatography-tandem mass spectrometry

An analytical method has been developed and validated for the determination of six estrogens and estrogen mimics, namely estriol (E3), bisphenol A (BPA), 17β-estradiol (E2), estrone (E1), ethynyl estradiol (EE2) and dienestrol (DIE), with frequent occurrence in the natural environment. Solid phase extraction coupled with liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) using electrospray ionization (ESI) in a negative mode was applied to concentration, identification, and quantification of estrogens and estrogen mimics. The SPE conditions were optimized as the selection of C18 as cartridges and MeOH as an eluent, and the control of solution pH at 9.0. The method was validated by satisfactory recoveries (80-130%) and intra-day and inter-day precision (<18.4%, as relative standard deviation), and excellent linearity for calibration curves (R² > 0.996). The limits of detection (LODs) for six target estrogenic compounds ranged between 2.5 and 19.2 ng/L. The effects of matrix background on the determination were evaluated in terms of LODs, LOQs, analyte recovery, and slopes of calibration curves in five different water matrices. Matrix effects by tap water were negligible. However, both matrix suppression and enhancement (i.e., E3, E1, DIE) were observed in surface water and wastewater. The positive correlation between LODs and TOC in various water matrices indicated the negative effect of organic pollutants on the method sensitivity. The sum of target estrogenic compounds in environmental samples were within 17-9462 ng/L.

Zebrafish and water microbiome recovery after oxytetracycline exposure

Oxytetracycline (OTC) is a broad-spectrum antibiotic widely used in aquaculture, resulting in contamination of aquatic environments. In a previous study, we observed significant effects of OTC sublethal concentrations in zebrafish, its microbiome and the water bacterial community. Here we assessed the extent to which these effects are reversible after a recovery period. Zebrafish adults were exposed to OTC (10,000 μg/L) via water exposure. Effects were analyzed at 5 days (5 dE) and 2 months (2 mE) of exposure and recovery was assessed at 5 days (5dPE) and 1 month (1mPE) after exposure Impacts were observed in fish energetic reserves and in fish and water microbiomes structure, being significant even at 5 dE. At energetic reserves level, the effect in cellular energy allocation (CEA) was dependent on the exposure time: initially CEA increased while after 2 mE CEA decreased. At microbiome level, diversity was not affected but the richness of the water microbiome significantly decreased at 2 mE. Regarding the post-exposure period, at CEA level, organisms seem to recover. In water and gut microbiomes OTC effects were also attenuated after exposure ceases, indicating a recovery. Even so, the structure of water exposed community remained significantly different towards the control, while richness of this community significantly increased at 1mPE. During exposure the relative abundance of 11 and 16 genera was significantly affected in the gut and water microbiomes, respectively, though these numbers decreased to 4 and 8 genera in the post-exposure period. At functional level during exposure 12 and 13 pathways were predicted to be affected in zebrafish gut and water microbiomes respectively, while post-exposure few pathways remained significantly affected. Hence, our results suggest a recovery of the fish fitness as well as of the water and intestine microbiomes after exposure ceases. Even so, some of the effects caused by OTC remain significant after this recovery period.

A novel polyethersulfone/modified activated carbon fiber composite membrane: potential for removal micropollutants from water under the electric field

This study aimed to develop a novel composite membrane based on polyethersulfone (PES) and modified activated carbon fibers (ACFs) to remove of sulfamethoxazole (SMZ) from water. The modification of ACFs was conducted by using acid, Fe, and Mn and was confirmed by Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDS), and water contact angle measurement. Later on, the composite membranes were prepared using PES (9 wt%), N-N-dimethylacetamide (DMAc) (75 wt%), polyethylene pyrrolidone (PVP) (5 wt%), anhydrous lithium chloride (LiCl) (1 wt%), and various types of modified ACFs (0.8 wt%) as additives. It was found that the contact angle of the membrane decreased by more than 20°, and the zeta potential decreased by more than 10 mV. ACF modified by Fe was used as an admixture, membrane obtained the high comprehensive performance. Especially bovine serum albumin (BSA) rejection rate and flux recovery ratio (FRR) reached 98.8% and 98.4%, respectively. And the removal rates of SMZ increased by 24.6% under the electric field. The degradation products were detected by high-performance liquid chromatography/mass spectrometry (HPLC/MS). Based on this result, the possible degradation pathways of SMZ are proposed.

Occurrence and fate of antibiotics, antibiotic resistant genes (ARGs) and antibiotic resistant bacteria (ARB) in municipal wastewater treatment plant: An overview

The occurrence and fate of antibiotics and antibiotic resistant genes (ARGs) and antibiotic resistant bacteria (ARB) in Municipal Wastewater Treatment Plants (WWTPs) worldwide were reviewed. The prevalence of antibiotics in WWTPs among different periods (1999-2009 and 2010-2019) and geographical areas (Europe, America, Asia and Africa) was summarized, analyzed and evaluated. The classes of macrolides (clarithromycin, erythromycin/erythromycin-H₂O, azithromycin, roxithromycin), sulfonamides (sulfamethoxazole), trimethoprim, quinolones (ofloxacin, ciprofloxacin, norfloxacin) and tetracyclines (tetracycline) were the antibiotics most frequently detected, while bla (bla_CTXM, bla_TEM), sul (sul1, sul2), tet (tetO, tetQ, tetW) and ermB genes were the ARGs commonly reported in WWTPs. There was a positive correlation between antibiotics and ARGs commonly detected in WWTPs, except for β-lactam antibiotics and bla genes. The genes bla were found frequently, despite β-lactam antibiotics were seldom detected owing to the hydrolysis. Most of antibiotics had lower levels in the period 2010-2019 in Asian countries than that in period 1999-2009 in North American and European countries. In the effluent of secondary treatment, the concentration of trimethoprim was the highest (138 ng/L in median) and the concentration of other antibiotics remained at lower than 80 ng/L, while the relative abundance of ARGs ranged 2.9-4.6 logs (copies/mL, in median). Future researches on the development of effective antibiotic removal technologies, such as advanced oxidation processes, are suggested to focus on antibiotics frequently detected and their corresponding ARGs in WWTPs.

Tetracycline and Sulfonamide Antibiotics in Soils: Presence, Fate and Environmental Risks

Veterinary antibiotics are widely used worldwide to treat and prevent infectious diseases, as well as (in countries where allowed) to promote growth and improve feeding efficiency of food-producing animals in livestock activities. Among the different antibiotic classes, tetracyclines and sulfonamides are two of the most used for veterinary proposals. Due to the fact that these compounds are poorly absorbed in the gut of animals, a significant proportion (up to ~90%) of them are excreted unchanged, thus reaching the environment mainly through the application of manures and slurries as fertilizers in agricultural fields. Once in the soil, antibiotics are subjected to a series of physicochemical and biological processes, which depend both on the antibiotic nature and soil characteristics. Adsorption/desorption to soil particles and degradation are the main processes that will affect the persistence, bioavailability, and environmental fate of these pollutants, thus determining their potential impacts and risks on human and ecological health. Taking all this into account, a literature review was conducted in order to shed light on the current knowledge about the occurrence of tetracycline and sulfonamide antibiotics in manures/slurries and agricultural soils, as well as on their fate in the environment. For that, the adsorption/desorption and the degradation (both abiotic and biotic) processes of these pollutants in soils were deeply discussed. Finally, the potential risks of deleterious effects on human and ecological health associated with the presence of these antibiotic residues were assessed. This review contributes to a deeper understanding of the lifecycle of tetracycline and sulfonamide antibiotics in the environment, thus facilitating decision-making for the application of preventive and mitigation measures to reduce its negative impacts and risks to public health.

Effect of the tetracycline antibiotics on performance and microbial community of microbial fuel cell

The adverse effect of tetracycline antibiotics on microbial activity is one of the serious risks for the biologic wastewater treatment process. The microbial fuel cells (MFCs) are a promising technology for wastewater treatment and renewable power generation process. For this reason, the investigation of the inhibition effect of the tetracyclines on the MFCs is essential for reducing damage on the environment. This paper focused on the performance of MFCs under different antibiotic concentrations at the range of 0.25-50 mg/L. The power generation performance, microbial community and biofilm characteristics (morphology, resistance and viability) of MFCs were investigated in detail. The results indicated that the increase in the antibiotic concentration significantly affected the MFC performance and microbial community. A modified non-competitive inhibition model was used to predict the inhibition effect of tetracycline antibiotics on the MFCs.

Development and Validation of a LC-MS/MS Method for Determination of Multi-Class Antibiotic Residues in Aquaculture and River Waters, and Photocatalytic Degradation of Antibiotics by TiO2 Nanomaterials

This study presents a multi-residue method for simultaneous qualitative and quantitative analysis of eight antibiotics from some common classes, including beta-lactam, tetracyclines, lincosamides, glycopeptides, and sulfonamides in 39 aquaculture and river water samples from the Mekong Delta (Vietnam) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). As a result, doxycycline (DXC), oxytetracycline (OTC), lincomycin (LCM), sulfamethoxazole (SMX), and sulfamethazine (SMZ) were detected with high frequency over 65% and an average concentration of 22.6–76.8 ng·mL−1. The result suggests that antibiotic residues in the aquaculture and river waters are considered as an emerging environmental problem of the region. To address this issue, we fabricated the well-defined TiO2 nanotube arrays (TNAs) and nanowires on nanotube arrays (TNWs/TNAs) using the anodization method. The TNAs had an inner tube diameter of ~95 nm and a wall thickness of ~25 nm. Meanwhile, the TNWs/TNAs had a layer of TiO2 nanowires with a length of ~6 µm partially covering the TNAs. In addition, both TNAs and TNWs/TNAs had pure anatase phase TiO2 with (101) and (112) dominant preferred orientations. Moreover, the TNAs and TNWs/TNAs effectively and rapidly degraded the antibiotic residues under UV-VIS irradiation at 120 mW/cm2 and obtained over 95% removal at 20 min. Indeed, the photocatalytic reaction rate constants (k) were in the range of 0.14–0.36 min−1 for TNAs, and 0.15–0.38 min−1 for TNWs/TNAs. Noticeably, the k values of TNWs/TNAs were slightly higher than those of TNAs for LCM, DXC, OTC, SMZ, and SMX that could be attributed to the larger surface area of TNWs/TNAs than TNAs when TNWs/TNAs had an additional ~6μm TNWs top layer.

Selected Pharmaceuticals in Different Aquatic Compartments: Part I-Source, Fate and Occurrence

Potential risks associated with releases of human pharmaceuticals into the environment have become an increasingly important issue in environmental health. This concern has been driven by the widespread detection of pharmaceuticals in all aquatic compartments. Therefore, 22 pharmaceuticals, 6 metabolites and transformation products, belonging to 7 therapeutic groups, were selected to perform a systematic review on their source, fate and occurrence in different aquatic compartments, important issues to tackle the Water Framework Directive (WFD). The results obtained evidence that concentrations of pharmaceuticals are present, in decreasing order, in wastewater influents (WWIs), wastewater effluents (WWEs) and surface waters, with values up to 14 mg L⁻¹ for ibuprofen in WWIs. The therapeutic groups which presented higher detection frequencies and concentrations were anti-inflammatories, antiepileptics, antibiotics and lipid regulators. These results present a broad and specialized background, enabling a complete overview on the occurrence of pharmaceuticals in the aquatic compartments.

Determination of 17α-ethinylestradiol and toxic metals in surface waters, and estimation of daily intake

The presence of substances such as hormones and toxic metal in aquatic ecosystem is interesting to the scientific community due to their adverse effects. We quantified 17α-ethynylestradiol (EE2) and toxic metals in the surface waters from Sorocaba and Pirajibu Rivers, in São Paulo State, and we estimated the daily intake for hormone, based on the amount of water consumed. EE2, Cd, Hg, As, Pb, and Mn were seasonally quantified in six different locations along the rivers. EE2 was evaluated by high-performance liquid chromatography. Toxic metals were determined by inductively coupled plasma mass spectrometer. Considering the entire sample year, EE2 concentrations ranged from 4.5 to 48.2 μg L^-1. Comparing Sorocaba and Pirajibu rivers, the sample point in the entrance of the Pirajibu River through the city of Itu, São Paulo State, had higher amounts of EE2. Regarding metals, all results are according to the Brazilian and World Health Organization guidelines for drinking-water quality, except for Mn levels, which were higher than the limits in Autumn season in two locations. The estimated daily intake ranged from 13.45 to 40.9 μg/day/person. In conclusion, concentrations of EE2 in the Sorocaba and Pirajibu Rivers were higher than in other countries. The levels were as high as an intake of one pill for each person every day (considering an oral contraceptive has 0.03 mg of ethinylestradiol). Even though concentrations of toxic elements are in accordance with the Brazilian Regulation and World Health Organization, legislation for hormones and drugs needs to advance.

Occurrence and risk assessment of multiple classes of antibiotics in urban canals and lakes in Hanoi, Vietnam

Very little information on the occurrence and risk assessment of antibiotics in the aquatic environment is reported for Vietnam, where antibiotics are assumed to be omnipresent in urban canals and lakes at high concentrations due to the easy accessibility of antibiotics without doctor prescription. This study provides comprehensive analysis of the occurrence of 23 antibiotics in urban canals (To Lich and Kim Nguu) and lakes (West Lake, Hoan Kiem, and Yen So) in Hanoi, Vietnam. Of these 23 antibiotics, 18 were detected in urban canals at above 67.9% detection frequency (DF). The concentrations of detected antibiotics were in the range from below quantification limit (MQL) to almost 50,000 ng/L, depending on the compound and sampling site. In urban canals, median concentration of amoxicillin, erythromycin, and sulfamethoxazole was >1000 ng/L while other antibiotics such as ampicillin, chloramphenicol, clindamycin, sulfamethazine, tetracycline, tylosin and vancomycin were detected at median concentrations of <100 ng/L. Similarly, 16 target antibiotics were also detected in urban lakes. Macrolides (azithromycin, clarithromycin, and erythromycin-H₂O), fluoroquinolones (enrofloxacin and ofloxacin), lincosamides (clindamycin and lincomycin), and trimethoprim were ubiquitously detected in urban lakes (DF = 100%). In this study, potential risks of antibiotics in the investigated urban canals and lakes were assessed based on the predicted no-effect concentration (PNEC) from the existing literature for antibiotic resistance selection (PNEC_ARM) and ecological toxicity to aquatic organisms (PNEC_Ecotox). Ampicillin, amoxicillin, azithromycin, ciprofloxacin, clarithromycin, enrofloxacin, erythromycin, ofloxacin, tetracycline, and trimethoprim were found in the investigated urban canals at concentrations exceeding their PNEC_ARM and PNEC_Ecotox. Similarly, most of the target antibiotics (i.e. amoxicillin, ciprofloxacin, clarithromycin, clindamycin, enrofloxacin, erythromycin, lincomycin, ofloxacin, sulfamethoxazole, tetracycline, trimethoprim and tylosin) were detected in the investigated urban lakes at concentrations close to or exceeding PNEC_Ecotox for aquatic organisms. Further investigations on the occurrence and fate of antibiotic residues and antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in surface waters are recommended.

Fate of antibiotics and antibiotic resistance genes in a full-scale restaurant food waste treatment plant: Implications of the roles beyond heavy metals and mobile genetic elements

Is our food safe and free of the crisis of antibiotics and antibiotic resistance (AR)? And will the derived food waste (FW) impose AR risk to the environment after biological treatment? This study used restaurant FW leachates flowing through a 200 tons-waste/day biological treatment plant as a window to investigate the fate of antibiotics and antibiotic-resistance genes (ARGs) during the acceptance and treatment of FW. Sulfonamides (sulfamethazine, sulfamethoxazole) and quinolones (ciprofloxacin, enrofloxacin, ofloxacin) were detected during FW treatment, while tetracyclines, macrolides and chloramphenicols were not observable. ARGs encoding resistance to sulfonamides, tetracyclines and macrolides emerged in FW leachates. Material flow analysis illustrated that the total amount of antibiotics (except sulfamethazine) and ARGs were constant during FW treatment processes. Both the concentration and total amount of most antibiotics and ARGs fluctuated during treatment, physical processes (screening, centrifugation, solid-liquid and oil-water separation) did not decrease antibiotic or ARGs concentrations or total levels permanently; the affiliated wastewater treatment plant appeared to remove sulfonamides and most ARGs concentrations and total amount. Heavy metals Ni, Co and Cu were important for disseminating antibiotics concentrations and MGEs for distributing ARGs concentrations. Humic substances (fulvic acids, hydrophilic fractions), C-associated and N-associated contents were essential for the distribution of the total amounts of antibiotics and ARGs. Overall, this study implied that human food might not be free of antibiotics and ARGs, and FW was an underestimated AR pool with various determinants. Nonetheless, derived hazards of FW could be mitigated through biological treatment with well-planned daily operations.

Degradation of sulfadimethoxine by permanganate in aquatic environment: Influence factors, intermediate products and theoretical study

The excess sulfadimethoxine (SDM) in the environment could lead to antibiotic resistance by microorganisms and may do harm to many aquatic organisms. In this work, the removal of SDM by potassium permanganate (KMnO₄) was comprehensively studied. The influence of various factors, including the pH, oxidant doses, and temperature, on SDM removal were investigated. The optimal reaction conditions were determined to be pH 5.0, T = 25 °C and [KMnO₄]₀ = 200 μmol L^-1. Anions (Cl^-, SO₄^2-, HCO₃^2-, and NO₃^-) and cations (K⁺, Ca²⁺, Mg²⁺, and NH₄⁺) had no significant influence on the removal of SDM. However, H₂PO₄^- improved the efficiency of SDM removal by KMnO₄. Humic acid (0-10 mg L^-1) promoted the removal of SDM, which was attributed to the generation of in situ MnO₂. Meanwhile, the degradation of SDM in various water matrices was studied, and the removal order was ultrapure water > Jiuxiang river water ≈ synthetic water > secondary clarifier effluent. According to ten intermediate products identified and a frontier electron densities (FED) calculation, several pathways were proposed that involve the oxidation of amidogen, the cleavage of CS and SN bonds, and an oligomerization reaction. The predicted toxicity assessment indicated that most of the degradation products were not harmful to aquatic organisms except SDM dimers (connection by HNNH), suggesting that byproducts, such as dimers, formed during the oxidation of SDM and other sulfonamides should be taken into consideration. In sum, KMnO₄ has the potential to remove SDM from the aquatic environment.

Antibiotic pollution in surface fresh waters: Occurrence and effects

Worldwide, antibiotic usage exceeds 100,000 tons per year and there is increasing concern over the fate of these substances. Antibiotics are ubiquitous in the environment and significant concentrations have been detected in fresh waters. In this review, we highlight important aspects of antibiotic pollution in fresh waters: that concentrations of antibiotics in the environment are substantial, that micro-organisms are susceptible to this, that bacteria can evolve resistance in the environment, and that antibiotic pollution affects natural food webs while interacting with other stressors; which taken together poses a number of challenges for environmental scientists. In the literature, we found examples of considerable antibiotic pollution in fresh waters. In the Americas, antibiotic concentrations of up to 15 μg/L have been measured; with higher concentrations reported from European and African studies (over 10 μg/L and 50 μg/L respectively), and in Asian-pacific countries concentrations over 450 μg/L have been detected. While these concentrations might not be deemed harmful to humans, non-target freshwater organisms could be affected by them. Bioassays show that some of the antibiotics found in surface waters affect microbes at concentrations below 10 μg/L. Among the most potent antibiotics are those that prevail in streams and rivers in these concentrations, such as ciprofloxacin. Sub-lethal concentrations might not kill prokaryotes but contribute to increased bacterial resistance and change the composition of single-celled communities, as demonstrated in laboratory experiments. This has implications for the microbial food web (e.g. interactions among and between bacteria and their protozoan consumers) and by extension, larger organisms and ecosystem health. The fact that the effects of antibiotics are extremely context-dependent represents a challenge, particularly for in vitro research. We suggest future research avenues, taking into account food web experiments, antibiotics interacting with one another (and other stressors) and discuss how these can help to answer multi-layered research questions.

Long-term effects of oxytetracycline exposure in zebrafish: A multi-level perspective

Oxytetracycline (OTC) is a broad-spectrum antibiotic widely used in livestock production. Like many other pharmaceuticals, OTC is not completely metabolized by the organism and thus, increasing amounts of the compound are being detected in the aquatic environment. The assessment of the environmental risk of pharmaceuticals is hindered by their very low concentrations and specific modes of action and thus relevant exposure scenarios and sensitive endpoints are needed. Thus, this work aimed to study the long-term effect of OTC exposure in zebrafish (at behavior and biochemical levels) and associated bacterial communities (fish gut and water bacterial communities). Results revealed that at behavioral level, boldness increase (manifested by increased exploratory behavior of a new environment) was observed in fish exposed to low OTC concentrations. Moreover, changes in fish swimming pattern were observed in light periods (increased stress response: hyperactivity and freezing) probably due to photo-sensibility conferred by OTC exposure. Effects at biochemical level suggest that long-term exposure to OTC interfere with cellular energy allocation mainly by reducing lipids levels and increasing energy consumption. Moreover, evidences of oxidative damage were also observed (reduced levels of TG, GST and CAT). The analysis of water and gut microbiome revealed changes in the structure and diversity of bacterial communities potentially leading to changes in communities' biological function. Some of the effects were observed at the lowest concentration tested, 0.1 μg/L which is a concentration already detected in the environment and thus clearly demonstrating the need of a serious ecotoxicological assessment of OTC effects on non-target organisms.

Ultra-high-performance liquid chromatography coupled to quadrupole orbitrap high-resolution mass spectrometry for multi-residue screening of pesticides, (veterinary) drugs and mycotoxins in edible insects

A generic extraction and UHPLC-Q-Orbitrap™-HRMS method was developed for four insect species (mealworm, grasshopper, house cricket and black soldier fly) analyzing a large spectrum of organic chemical contaminants, including pesticides (n = 25), (veterinary) drugs (n = 29), and mycotoxins (n = 23). To prove the method as 'fit-for-purpose', a successful validation was performed, both qualitatively, by determining the screening detection limit (SDL), selectivity and specificity, as well as semi-quantitatively, by assessing the within-day precision (relative standard deviation (RSD)) and recovery. For both the mealworm, grasshopper, house cricket and black soldier fly, 64, 61, 59 and 62 compounds were detected at the respective SDL levels (1-100 μg kg^-1), predominantly below existing maximum residue limits for other edible matrices. Mean recoveries ranged between 70% and 120% and RSD-values were in line with European regulations (CD 2002/657/EC; SANCO). Finally, the potential of the screening methodology was demonstrated on real insect samples, revealing minor to no contamination.

Theoretical environmental risk assessment of ten used pharmaceuticals in Belo Horizonte, Brazil

An evaluation of the environmental risk assessment (ERA) proposed by European Medicines Agency (EMA) and its applicability in Brazil was performed on ten of Belo Horizonte's most pharmaceuticals by the Brazilian National Health Service (SUS). The predicted environmental concentrations (PECs) was proposed, with some refinements to a better representation of the city of study. All PECs obtained were compared only to measured environmental concentrations around the world, due to the lack available data in the city of study and in Brazil. During the performance of EMA's guideline, the risk quotient (RQ) of impact was established through the ratio of PECs and predicted no-effect concentrations (PNECs). The PECs obtained in more refined phases show the initial evaluation of EMA's guideline, possible subdimensions, and the potential risks. The RQ for all studied pharmaceuticals ranges from clonazepam (1.26) to losartan (5457.45). These results indicate potential risks to the aquatic life present in the streams that receive the wastewater treatment plant's effluent. This risk can be spread since the streams carry these contaminants to other water bodies that undergo to multiple cities of Brazil, and even after dilutions, it can still be potentially toxic to the biotic life. ERA shows that it can be a useful tool for a better understanding and modeling of pharmaceuticals fate in the environment, specifically in water bodies. In addition, the usage of this model shows to be a useful tool that determines which contaminant should follow a more thorough study since the detection and analysis of pharmaceuticals in environmental samples are costly and technically challenging.

Evaluation of hydrochar efficiency for simultaneous removal of diclofenac and ibuprofen from aqueous system using surface response methodology

Pharmaceutically active compounds like diclofenac (DFS), ibuprofen (IBP), and other drugs that persist in the environment are listed as emerging contaminants. These escape from normal wastewater treatment plants and find their way to water streams; therefore, alternate treatment processes are needed. Herein, a sorbent material is reported that is prepared through hydrotermal carbonization from dried fruit powder of Zizipus mauritiana L. (HTC-ZM) and applied for simultaneous removal of DFS and IBP. Carbonized material (HTC-ZM) was found as agglomerates of approximately 1 μm particle size with surface area of 1160 m²/g having oxygen functional groups (e.g., COO, O, C=O) on surface. Simultaneous removal of IBP and DFS onto HTC-ZM was studied using response surface methodology with a set of 18 experiments using factors such as pH, amount of sorbent, contact time, and sorbate concentration. Maximum removal efficiency was obtained 88% and 97% for DFS and for IBP, respectively, with adsorption capacity of 2.03 mmol g^-1 for DFS and 2.54 mmol g^-1 for IBP. Kinetics modeling and "mean free energy" values predicted that sorption is mainly governed by physical interactions followed by "pore filling" mechanism for uptake of DFS and IBP.

Chlortetracycline and melanin biopolymer - The risk of accumulation and implications for phototoxicity: An in vitro study on normal human melanocytes

Tetracyclines belong to antimicrobial classes with the highest consumption in veterinary medicine and agriculture, which leads to the contamination of the environment and food products, as well as to antibiotic resistance and adverse drug reactions. Chloro-derivatives of tetracyclines are thought to be relatively more phototoxic than others and belong to the most frequently cited drugs as photosensitizers. Melanins are heterogenous biopolymers determining skin, hair and eye colour. They are biosynthesized in a multistep process in melanocytes. Melanins, besides photoprotective and antioxidant properties, may also contribute to adverse skin drug reactions, which involve e.g. hyperpigmentation disorders and phototoxic reactions. Furthermore, they have the ability to form a drug-melanin complex, which leads to deposition of the drug or its metabolites in pigmented tissues. The aim of the study was to examine the ability of chlortetracycline to form a complex with melanin, as well as the effect of the drug on viability, antioxidant defence system and melanogenesis in normal human epidermal melanocytes exposed to the UVA radiation. The obtained results show for the first time that chlortetracycline forms a complex with melanin polymers, which creates a possibility of the drug accumulation in pigmented tissues. A simultaneous exposition of normal melanocytes to chlortetracycline and to the UVA radiation decreases cell viability, proportionally to the drug concentration and the irradiation time. The phototoxic effect appears to be related to the induction of oxidative stress in melanocytes, mainly through an increase of SOD and a decrease of the CAT activity. Chlortetracycline itself does not influence the melanin content or the activity of tyrosinase. The UVA radiation appeared to be a conditioning factor stimulating melanogenesis, whereas the presence of the drug augmented this effect.

Veterinary pharmaceutical residues from natural water to tap water: Sales, occurrence and fate

Veterinary pharmaceuticals (VPs) increasingly used in animal husbandry have led to their presence in aquatic environments -surface water (SW) or groundwater (GW) - and even in tap water. This review focuses on studies from 2007 to 2017. Sixty-eight different veterinary pharmaceutical residues (VPRs) have been quantified worldwide in natural waters at concentrations ranging from nanograms per liter (ng L^-1) to several micrograms per liter (μg L^-1). An extensive up-to-date on sales and tonnages of VPs worldwide has been performed. Tetracyclines (TCs) antibiotics are the most sold veterinary pharmaceuticals worldwide. An overview of VPRs degradation pathways in natural waters is provided. VPRs can be degraded or transformed by biodegradation, hydrolysis or photolysis. Photo-degradation appears to be the major degradation pathway in SW. This review then reports occurrences of VPRs found in tap water, and presents data on VPRs removal in drinking water treatment plants (DWTPs) at each step of the process. VPRs have been quantified in tap water at ng L^-1 concentration levels in four studies of the eleven studies dealing with VPRs occurrence in tap water. Overall removals of VPRs in DWTPs generally exceed 90% and advanced treatment processes (oxidation processes, adsorption on activated carbon, membrane filtration) greatly contribute to these removals. However, studies performed on full-scale DWTPs are scarce. A large majority of fate studies in DWTPs have been conducted under laboratory at environmentally irrelevant conditions (high concentration of VPRs (mg L^-1), use of deionized water instead of natural water, high concentration of oxidant, high contact time etc.). Also, studies on VPRs occurrence and fate in tap water focus on antibiotics. There is a scientific gap on the occurrence and fate of antiparatic drugs in tap waters.

Oxytetracycline effects in specific biochemical pathways of detoxification, neurotransmission and energy production in Oncorhynchus mykiss

Oxytetracycline (OTC) is a tetracycline antibiotic, widely used in human and veterinary medicines, including in aquaculture. Given this use, OTC has been detected in different aquatic environments. Some recent works have demonstrated unintentional biological activity of OTC in non-target aquatic organisms. This study investigated the acute and chronic effects of OTC on the physiology of the fish species Oncorhynchus mykiss (rainbow trout), namely through the quantification of the activity of enzymes involved in different biochemical pathways, such as detoxification (phase II - glutathione S-transferases - GSTs, uridine-diphosphate-glucuronosyltransferases - UGTs), neurotransmission (acetylcholinesterase - AChE) and energy production (lactate dehydrogenase - LDH). The here-obtained data demonstrated the induction of GSTs activity in gills, and inhibition of AChE activity in eyes tissue, in chronically exposed organisms, as well as alterations in LDH activity following both exposures. Considering this set of results, we can infer that OTC exposure may have induced the glutathione pathway of detoxification in gills with the involvement of GSTs, or indirectly due to the metabolites that may have been produced. In turn, these metabolites may have interfered with the mechanism of neurotransmission, also causing physiological and biochemical disturbances in rainbow trout after OTC exposure, namely disturbances in energetic metabolism. In addition, it is important to stress that such occurrences took place at low, environmentally realistic levels of OTC, suggesting that organisms exposed in the wild may be putative targets of toxic effects by commonly used drugs such as antibiotics.

Seasonal and spatial variations in the occurrence, mass loadings and removal of compounds of emerging concern in the Slovene aqueous environment and environmental risk assessment

This study reports the development of a multi-residue method for determining 48 compounds of emerging concern (CEC) including three diclofenac transformation products (TP) in Slovenian wastewater (WW) and surface water (SW). For solid-phase extraction (SPE), Oasis™ Prime cartridges were favoured over Oasis HLB™. The validated method was then applied to 43 SW and 52 WW samples collected at nine locations. Ten bisphenols in WW and 14 bisphenols in SW were traced in Europe for the first time. Among all of the 48 targeted CEC, 21 were >LOQ in the influents and 20 in the effluents. One diclofenac TP was also quantified in WWs (3.04-78.1 ng L^-1) for the first time. As expected, based on mass loads in the wastewater treatment plant influents, caffeine is consumed in high amounts (105,000 mg day^-1 1000 inhab.^-1) in Slovenia, while active pharmaceutical ingredients (APIs) are consumed in lower amounts compared to other European countries. Removal was lower in winter in the case of four bisphenols (17-78%), one preservative (36%) and four APIs (-14-91%), but remained constant for caffeine, one API, two UV-filters and three preservatives (all >85.5%). Overall, a constructed wetland showed the lowest (0-80%) and most inconsistent removal efficiencies (SD > 40% for some CECs) of CECs including caffeine, two UV-filters, two preservatives and two APIs compared to other treatment technologies. The method was also able to quantify Bisphenol S in SW (<36.2 ng L^-1). Environmental risk was assessed via risk quotients (RQs) based on WW and SW data. Two UV-filters (oxybenzone and dioxybenzone), estrone and triclosan, despite their low abundance posed a medium to high environmental risk with RQs between 0.282 (for HM-BP) and 15.5 (for E1).

Effects of florfenicol and oxytetracycline on the tropical cladoceran Ceriodaphnia silvestrii: A mixture toxicity approach to predict the potential risks of antimicrobials for zooplankton

Antimicrobials are commonly used in aquaculture to treat infectious diseases in fish. The overuse of these chemicals, however, has made them a contamination source for the aquatic environments. In this study, single and combined effects of florfenicol (FLO) and oxytetracycline (OTC), two antimicrobials widely used in the fish farming, were evaluated in acute and chronic toxicity tests using the tropical cladoceran Ceriodaphnia silvestrii as a model species. Also, a preliminary risk characterization of FLO and OTC for zooplankton was carried out, taking into account different exposure scenarios. The results obtained revealed that FLO and OTC have adverse effects on the mobility, reproduction and population growth rate of C. silvestrii in single exposures. In addition, mixture effects on the C. silvestrii were more severe than predicted effects based on the Concentration Addition model, showing a synergistic deviation for the mobility and a dose-level dependent deviation for the reproduction (synergism at higher levels than EC₆₀). In relation to the risk characterization, risk quotients (RQs) exceeded 1 for chronic toxicity data obtained in both OTC and mixture exposures, indicating that the concentrations of these chemicals in Brazilian freshwater bodies could potentially present risks for the reproduction of zooplankton species in tropical regions. The RQs obtained for the mixtures were higher than those obtained for each chemical separately. Therefore, it is highly recommended that RQs are derived from single and mixture exposure data in order to obtain a more accurate risk characterization.