Emerging contaminants and antibiotic resistance in the different environmental matrices of Latin America

LED-irradiated photo-Fenton process on pollutant removal: outcomes, trends, and limitations

This manuscript critically reviews the state of the art on the application of photo-Fenton processes irradiated by light-emitting diode arrays (LED) with a focus on the removal of contaminants of emerging concern (CEC) from aqueous matrices. LEDs are clean, low-cost radiation sources with longer lifespan compared to mercury lamps. This study covers the influence of LED sources, wavelengths, and dose upon CEC removal, and the potential for disinfection, abatement of antibiotic-resistant bacteria (ARB), and genes (ARG). The bibliographic search was performed in Scopus database using keyword combinations and resulted in a portfolio containing 52 relevant articles published between 2010-2023. According to reviewed papers, LED photoreactor design has evolved in the past decade aiming to improve CEC degradation in aqueous matrices while reducing construction and operation costs, and energy consumption. Among several reactors (annular, fluidized bed, parallel plate, wireless, pathway systems, and microreactor) surveyed for their performance and scalability, LED chips and strips are particularly suitable for application due to their wide emission angle (≈120°) and small size (mm2), which allow for, respectively, efficient illumination coverage and flexible arrangement and design. LED microreactors are very efficient in the degradation of contaminants and scalable with reduced area requirements. Although most studies were performed in synthetic solutions and at laboratory scale, the externally LED irradiated cylindrical reactor was successful for application in full-scale municipal water treatment plants. Future studies should focus on evaluating CEC removal in wastewater using scalable devices for continuous operation of solar photo-Fenton at night.

Theoretical and experimental studies of cephalexin adsorption on aluminium as a new alternative of removal from wastewater

Cephalexin (CPX) is an antibiotic widely used to treat many infections. CPX has become an emerging pollutant present in wastewater. On the other hand, it is well known that organic compounds can be adsorbed over metal surfaces when the metal is in active state such as when it is rusting. This work proposes an alternative for the elimination of CPX from wastewater, applying electrochemical principles using a conventional and cheap substrate, aluminium. The first part consisted of obtaining the active states of aluminium electrodes carrying out voltametric curves at different pH (4, 7 and 9) to find the particular condition of interaction between CPX and metal surface. The potential was used in the potentiostatic tests to set the activation potential of metal at different times. After the treatment, electrolyte solutions were analysed using UV-vis spectra, and the aluminium surfaces were studied by optical micrographs and X-ray diffraction. In addition, aluminium-CPX interactions were corroborated by quantum-chemical calculations and adsorption isotherms. All results indicate that it was possible for the CPX removal at basic pH conditions, where the molecule adsorption on the aluminium substrate occurs due to a strong electrostatic interaction.

Economic feasibility of complementary treatments for reducing pharmaceuticals in metropolitan drinking water in southern Brazil

This study addresses complementary treatment systems' economic feasibility and environmental benefits to reduce pharmaceutical micropollutants in urban water supplies in Curitiba, Brazil. The research evaluated powdered activated carbon (PAC) dosing systems in drinking water treatment plants (DWTPs), analyzing implementation and operational costs in relation to the environmental benefits represented by the shadow price of removed pharmaceutical micropollutants. The results indicate that while technically viable, the high cost of PAC systems renders the project economically unfeasible, with a removal cost of US$1.3941 per mg/L of micropollutant, far exceeding the estimated environmental benefit of US$0.4134 per mg/L. Over a 30-year horizon, the cost per m3 of treated water with PAC accounts for approximately 78.52% of the cost of a conventional DWTP, emphasizing the need for alternative funding models. The study highlights the critical importance of integrating environmental benefits into economic analyses and proposes an industry-financed fund by pharmaceutical companies to support the modernization of these systems, aligning with principles of social and environmental justice.

Trace organic compounds and photosensitizing activity in Salvadoran surface and tap water sources: A first look

Despite their potential risks to human health and the environment at ng/L to μg/L concentrations, there has been relatively little effort to measure trace organic compounds (TOrCs) in surface waters of Central America. The concentrations of eighteen TOrCs detected at eleven surface water sites in the Lempa River basin of El Salvador and four sources of drinking water for the cities of San Salvador, Antiguo Cuscatlán, Soyapango, and Santa Tecla are reported here. All samples were analyzed via liquid chromatography with tandem mass spectrometry (LC-MS/MS). Detected TOrCs in surface water included sixteen compounds. Maximum concentrations of 23 μg/L, 6 μg/L, and 2 μg/L were measured for sulfamethoxazole, sucralose, and bisphenol A, respectively. In tap water, a total of fourteen species were found, with peak concentrations of 17 μg/L for sulfamethoxazole, 640 ng/L for bisphenol A, and 224 ng/L for tris(chloropropyl) phosphate (TCPP). To assess potential mechanisms of TOrCs attenuation in surface waters, samples were irradiated with UVA light (315-400 nm) for 12 h in the presence of furfuryl alcohol (FFA) to establish singlet oxygen (1O2) formation. All the samples exhibited photosensitizing activity upon irradiation, resulting in 1O2 concentrations of the order of 10-14 M. To our knowledge, this is the first study that reports the quantification of TOrCs presence and the possible natural attenuation routes in Salvadoran surface and tap water sources.

Development of a new method using dispersive liquid-liquid microextraction with hydrophobic natural deep eutectic solvent for the analysis of multiclass emerging contaminants in surface water by liquid chromatography-mass spectrometry

A new analytical method was developed for the determination of 14 multiclass emerging organic contaminants in surface waters using LC-MS, and Dispersive Liquid-Liquid Microextraction (DLLME) for extraction. Different Natural Deep Eutectic Solvents (NADESs) composed of terpenes and organic acids were tested as extraction solvents and characterized by Fourier Transform Infrared Spectroscopy (FTIR), Hydrogen Nuclear Magnetic Resonance Spectroscopy (1H-NMR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), density, and viscosity, eliminating the need to use traditional chlorinated solvents. NADES produced with butyric acid and thymol showed the best results and was selected for application for the first time in the extraction of emerging organic contaminants of different classes in water samples. Vortex was used as the dispersion mode, eliminating the use of the dispersion solvent. Chromatographic conditions and sample preparation were optimized using multivariate experimental designs. The optimized chromatographic conditions included the column oven temperature, mobile phase modifiers, and stationary phase type. The optimized conditions for sample preparation included the extraction temperature and pH, salting out effect, and extraction solvent volume. The analytical performance was evaluated through repeatability and intermediate precision tests, with RSD values below 20%, and recoveries between 70 and 120%. The coefficient of determination was greater than 0.98 for all analytes. LOQs varied between 1.5 and 35 μg L-1. DLLME is a simple technique, it does not require expensive and specific equipment. Furthermore, replacing traditional chlorinated solvents with NADES makes the procedure more environmentally friendly. The method presented here can be applied to a wide range of analytes for the analysis of fresh, brackish, and salt waters. Up to the present moment, this is the first study using NADES based thymol and butyric acid for the determination of multiclass emerging contaminants in surface waters samples.

Nanoscale water behavior and its impact on adsorption: A case study with CNTs and diclofenac

Water is a fundamental component of life, playing a critical role in regulating metabolic processes and facilitating the dissolution and transport of essential molecules. However, emerging contaminants, such as pharmaceuticals, pose significant challenges to water quality and safety. Nanomaterial-based technologies emerge as a promising solution for removing those contaminants from water. Nevertheless, interfacial water plays a major role in the adsorption of chemical compounds in nanomaterials-as it plays in biological processes such as protein folding, enzyme activity, and drug delivery. To understand this role, in this study, we employ molecular dynamics simulations to explore the adsorption dynamics of potassium diclofenac on single-walled carbon nanotubes (SWCNTs) and double-walled carbon nanotubes (DWCNTs), considering both dry and wet conditions. Our findings reveal that the structuring of water molecules around CNTs creates hydration layers that significantly influence the accessibility of active sites and the interaction strength between contaminants and adsorbents. Our analysis indicates higher energy barriers for adsorption in DWCNTs compared to SWCNTs, which is attributed to stronger water-surface interactions. This research highlights the importance of understanding nanoscale water behavior for optimizing the design and functionality of nanomaterials for water purification. These findings can guide the development of more efficient and selective nanomaterials, enhancing contaminant removal and ensuring safer water resources while contributing to a deeper understanding of fundamental biological interactions.

Synergistic effect of 2D covalent organic frameworks confined 0D carbon quantum dots film: Toward molecularly imprinted cathodic photoelectrochemical platform for detection of tetracycline

The development of high photoactive cathode materials combined with the formation of a stable interface are considered important factors for the selective and sensitive photoelectrochemical (PEC) detection of tetracycline (TC). Along these lines, in this work, a novel type II heterostructure composed of two-dimensional (2D) covalent organic frameworks confined to zero-dimensional (0D) carbon quantum dots (CDs/COFs) film was successfully synthesized using the rapid in-situ polymerization method at room temperature. The PEC signal of CDs/COFs was significantly amplified by improving the light absorption and electron transfer capabilities. Furthermore, a cathodic molecularly imprinted PEC sensor (MIP-PEC) for the detection of TC was constructed through fast in-situ Ultraviolet (UV) photopolymerization on the electrode. Finally, a "turn-off" PEC cathodic signal was achieved based on the selective recognition of the imprinted cavity and the mechanism of steric hindrance increase. Under optimal conditions, the proposed sensor demonstrated a wide linear relationship with TC in the concentration range of 5.00 × 10-12-1.00 × 10-5 M, with a detection limit as low as 6.00 × 10-13 M. Meanwhile, excellent stability, selectivity, reproducibility, and applicability in real river samples was recorded. Our work provides an effective and rapid in situ construction method for fabricating highly photoactive cathode heterojunctions and uniform stable selective MIP-PEC sensing interfaces, yielding accurate antibiotics detection in the environment.

Surface enhanced Raman spectroscopy and machine learning for identification of beta-lactam antibiotics resistance gene fragment in bacterial plasmid

BACKGROUND

Antibiotic resistance stands as a critical medical concern, notably evident in commonly prescribed beta-lactam antibiotics. The imperative need for expeditious and precise early detection methods underscores their role in facilitating timely intervention, curbing the propagation of antibiotic resistance, and enhancing patient outcomes.

RESULTS

This study introduces the utilization of surface-enhanced Raman spectroscopy (SERS) in tandem with machine learning (ML) for the sensitive detection of characteristic gene fragments responsible for antibiotic resistance appearance and spreading. To make the detection procedure close to the real case, we used bacterial plasmids as starting biological objects, containing or not the characteristic gene fragment (up to 1:10 ratio), encoding beta-lactam antibiotics resistance. The plasmids were subjected to enzymatic digestion and without preliminary purification or isolation the created fragments were captured by functional SERS substrates. Based on subsequent SERS measurements, a database was created for the training and validation of ML. Method validation was performed using separately measured spectra, which did not overlap with the database used for ML training. To check the efficiency of recognising the target fragment, control experiments involved bacterial plasmids containing different resistance genes, the use of inappropriate enzymes, or the absence of plasmid.

SIGNIFICANCE

SERS-ML allowed express detection of bacterial plasmids containing a characteristic gene fragment up to the 10-7 concentration of the initial plasmid, despite the complex composition of the biological sample, including the presence of interfering plasmids. Our approach offers a promising alternative to existing methods for monitoring antibiotic-resistant bacteria, characterized by its simplicity, low detection limit, and the potential for rapid and straightforward analysis.

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

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

Triclosan inhibits testosterone biosynthesis in adult rats via inducing m6A methylation-mediated autophagy

Triclosan is a potent antibacterial compound widely used in everyday products. Whether triclosan affects Leydig cell function in adult male rats remains unknown. In this study, 0, 50, 100, or 200 mg/kg/day triclosan was gavaged to Sprague-Dawley male rats from 56 to 63 days postpartum. Triclosan significantly reduced serum testosterone levels at ≥ 50 mg/kg/day via downregulating the expression of Leydig cell gene Lhcgr, Scarb1, Star, Cyp11a1, Hsd3b1, Cyp17a1, and Hsd17b3 and regulatory transcription factor Nr3c2 at 100-200 mg/kg. Further analysis showed that triclosan markedly increased autophagy as shown by increasing LC3II and BECN1 and decreasing SQSTM1. The mRNA m6A modification analysis revealed that triclosan significantly downregulated Fto expression at 200 mg/kg while upregulating Ythdf1 expression at 100 and 200 mg/kg, leading to methylation of Becn1 mRNA as shown by MeRIP assay. Triclosan significantly inhibited testosterone output in rat R2C Leydig cells at ≥ 5 μM via downregulating Fto and upregulating Ythdf1. SiRNA Ythdf1 knockdown can reverse triclosan-mediated mitophagy in R2C cells, thereby reversing the reduction of testosterone output. In summary, triclosan caused Becn1 m6A methylation by downregulating Fto and upregulating Ythdf1, which accelerated Becn1 translation, thus leading to the occurrence of autophagy and the decrease of testosterone biosynthesis.

Atrazine degradation through a heterogeneous dual-effect process using Fe-TiO2-allophane catalysts under sunlight

This study investigated the novel application of Fe-TiO2-allophane catalysts with 6.0 % w/w of iron oxide and two TiO2 proportions (10 % and 30 % w/w) for degrading atrazine (ATZ) using the heterogeneous dual-effect (HDE) process under sunlight. Comparative analyses with Fe-allophane and TiO2-allophane catalysts were conducted in both photocatalysis (PC) and HDE processes. FTIR spectra reveal the unique hydrous feldspathoids structure of allophane, showing evidence of new bond formation between Si-O groups of allophane clays and iron hydroxyl species, as well as Si-O-Ti bonds that intensified with higher TiO2 content. The catalysts exhibited an anatase structure. In Fe-TiO2-allophane catalysts, iron oxide was incorporated through the substitution of Ti4+ by Fe3+ in the anatase crystal lattice and precipitation on the surface of allophane clays, forming small iron oxide particles. Allophane clays reduced the agglomeration and particle size of TiO2, resulting in an enhanced specific surface area and pore volume for all catalysts. Iron oxide incorporation decreased the band gap, broadening the photoresponse to visible light. In the PC process, TiO2-allophane achieves 90 % ATZ degradation, attributed to radical species from the UV component of sunlight. In the HDE process, Fe-TiO2-allophane catalysts exhibit synergistic effects, particularly with 30 % w/w TiO2, achieving 100 % ATZ degradation and 85 % COD removal, with shorter reaction time as TiO2 percentage increased. The HDE process was performed under less acidic conditions, achieving complete ATZ degradation after 6 h without iron leaching. Consequently, Fe-TiO2-allophane catalysts are proposed as a promising alternative for degrading emerging pollutants under environmentally friendly conditions.

Contaminants of emerging concern: Occurrence, analytical techniques, and removal with electrochemical advanced oxidation processes with special emphasis in Latin America

The occurrence of contaminants of emerging concern (CECs) in environmental systems is gradually more studied worldwide. However, in Latin America, the presence of contaminants of emerging concern, together with their environmental and toxicological impacts, has recently been gaining wide interest in the scientific community. This paper presents a critical review about the source, fate, and occurrence of distinct emerging contaminants reported during the last two decades in various countries of Latin America. In recent years, Brazil, Chile, and Colombia are the main countries that have conducted research on the presence of these pollutants in biological and aquatic compartments. Data gathered indicated that pharmaceuticals, pesticides, and personal care products are the most assessed CECs in Latin America, being the most common compounds the followings: atrazine, acenaphthene, caffeine, carbamazepine, ciprofloxacin, diclofenac, diuron, estrone, losartan, sulfamethoxazole, and trimethoprim. Most common analytical methodologies for identifying these compounds were HPLC and GC coupled with mass spectrometry with the potential to characterize and quantify complex substances in the environment at low concentrations. Most CECs' monitoring and detection were observed near to urban areas which confirm the out-of-date wastewater treatment plants and sanitization infrastructures limiting the removal of these pollutants. Therefore, the implementation of tertiary treatment should be required. In this tenor, this review also summarizes some studies of CECs removal using electrochemical advanced oxidation processes that showed satisfactory performance. Finally, challenges, recommendations, and future perspectives are discussed.

A comprehensive review on the fate and impact of antibiotic residues in the environment and public health: A special focus on the developing countries

The widespread application of antibiotics in human and veterinary medicine has led to the pervasive presence of antibiotic residues in the environment, posing a potential hazard to public health. This comprehensive review aims to scrutinize the fate and impact of antibiotic residues, with a particular focus on the context of developing nations. The investigation delves into the diverse pathways facilitating the entry of antibiotics into the environment and meticulously examines their effects on human health. The review delineates the current state of antibiotic residues, evaluates their exposure in developing nations, and elucidates existing removal methodologies. Additionally, it probes into the factors contributing to the endurance and ecotoxicity of antibiotic residues, correlating these aspects with usage rates and associated mortalities in these nations. The study also investigates removal techniques for antibiotic residues, assessing their efficiency in environmental compartments. The concurrent emergence of antibiotic-resistant bacteria, engendered by antibiotic residues, and their adverse ecological threats underscore the necessity for enhanced regulations, vigilant surveillance programs, and the adoption of sustainable alternatives. The review underlines the pivotal role of public education and awareness campaigns in promoting responsible antibiotic use. The synthesis concludes with strategic recommendations, strengthening the imperative for further research encompassing comprehensive monitoring, ecotoxicological effects, alternative strategies, socio-economic considerations, and international collaborations, all aimed at mitigating the detrimental effects of antibiotic residues on human health and the environment. PRACTITIONER POINTS: Antibiotic residues are widely distributed in different environmental compartments. Developing countries use more antibiotics than developed countries. Human and veterinary wastes are one of the most responsible sources of antibiotic pollution. Antibiotics interact with biological systems and trigger pharmacological reactions at low doses. Antibiotics can be removed using modern biological, chemical, and physical-chemical techniques.

Biochemical Characterization of Laccase from Spirulina CPCC-695 and Their Role in Estrone Degradation

The addition of exogenous endocrine disrupting compounds (EDCs) like estrone, in the food chain through the aquatic system, disrupts steroid biosynthesis and metabolism by altering either the genomic or non-genomic pathway that eventually results in various diseases. Thus, bioremediation of these compounds is urgently required to prevent their addition and persistence in the environment. Enzymatic degradation has proven to be a knight in shining armour as it is safe and generates no toxic products. The multicopper oxidases (E.C. 1.10.3.2 benzenediol: oxygen oxidoreductase), laccase with the potential to degrade both phenolic and non-phenolic substrates has recently gained attention. In this study, the laccase was purified, characterized, and used to study estrone degradation. The culture filtrate (crude laccase) was concentrated and precipitated using cold-acetone and dialyzed against tris buffer (50 mM) giving a four-fold partially purified form, with 45.56% yield and 204.14 U/mg as specific activity and a single peak at 250-300 nm. The partially purified laccase was approximately 80 kDa as estimated by SDS-PAGE preferred ABTS as substrate. Both crude and partially purified laccase showed maximum activity at pH 3.0, 40 °C, and 4 mM ABTS. Kinetic constants (Km, Vmax) of crude and partially purified laccase were found to be 0.83 mM; 494.31 mM/min, and 0.58 mM; 480.54 mM/min respectively. Iron sulphate and sodium azide inhibited laccase maximally. Crude and partially purified laccase degradation efficiency was 87.55 and 91.35% respectively. Spirulina CPCC-695 laccase with efficient estrone degradation ability renders them promising candidates for EDCs bioremediation.

A systematic review on the current situation of emerging pollutants in Mexico: A perspective on policies, regulation, detection, and elimination in water and wastewater

Emerging pollutants (EPs) emerged as a group of new compounds whose presence in the environment has been widely detected in Mexico. In this country, different concentrations of pharmaceutical compounds, pesticides, dyes, and microplastics have been reported, which vary depending on the region and the analyzed matrix (i.e., wastewater, surface water, groundwater). The evidence of the EPs' presence focuses on the detection of them, but there is a gap in information regarding is biomonitoring and their effects in health in Mexico. The presence of these pollutants in the country associated with lack of proper regulations in the discharge and disposal of EPs. Therefore, this review aims to provide a comprehensive view of the current environmental status, policies, and frameworks regarding Mexico's situation. The review also highlights the lack of information about biomonitoring since EPs are present in water even after their treatment, leading to a critical situation, which is high exposure to humans and animals. Although, technologies to efficiently eliminate EPs are available, their application has been reported only at a laboratory scale thus far. Here, an overview of health and environmental impacts and a summary of the research works reported in Mexico from 2014 to 2023 were presented. This review concludes with a concrete point of view and perspective on the status of the EPs' research in Mexico as an alert for government entities about the necessity of measures to control the EPs disposal and treatment.

Unveiling antimicrobial resistance in Chilean fertilized soils: a One Health perspective on environmental AMR surveillance

Antimicrobial resistance (AMR) poses a significant threat to humans and animals as well as the environment. Within agricultural settings, the utilization of antimicrobial agents in animal husbandry can lead to the emergence of antimicrobial resistance. In Chile, the widespread use of animal-derived organic amendments, including manure and compost, requires an examination of the potential emergence of AMR resulting from their application. The aim of this research was to identify and compare AMR genes found in fertilized soils and manure in Los Andes city, Chile. Soil samples were collected from an agricultural field, comprising unamended soils, amended soils, and manure used for crop fertilization. The selected genes (n = 28) included genes associated with resistance to beta-lactams, tetracyclines, sulfonamides, polymyxins, macrolides, quinolones, aminoglycosides, as well as mobile genetic elements and multidrug resistance genes. Twenty genes were successfully identified in the samples. Tetracycline resistance genes displayed the highest prevalence, followed by MGE and sulfonamides, while quinolone resistance genes were comparatively less abundant. Notably, blaOXA, sulA, tetO, tetW, tetM, aac (6) ib., and intI1, exhibited higher frequencies in unamended soils, indicating their potential persistence within the soil microbiome and contribution to the perpetuation of AMR over time. Given the complex nature of AMR, it is crucial to adopt an integrated surveillance framework that embraces the One Health approach, involving multiple sectors, to effectively address this challenge. This study represents the first investigation of antimicrobial resistance genes in agricultural soils in Chile, shedding light on the presence and dynamics of AMR in this context.

Degradation of ciprofloxacin by persulfate activated by Fe(III)-doped BiOCl composite photocatalyst

Fe-BOC-X photocatalyst was successfully prepared by solvothermal method. The photocatalytic activity of Fe-BOC-X was determined by ciprofloxacin (CIP), a typical fluoroquinolone antibiotic. Under sunlight irradiation, all Fe-BOC-X showed better CIP removal performance than original BiOCl. In comparison, the photocatalyst with iron content of 50 wt% (Fe-BOC-3) has excellent structural stability and the best adsorption photodegradation efficiency. The removal rate of CIP (10 mg/L) by Fe-BOC-3 (0.6 g/L) reached 81.4% within 90 min. At the same time, the effects of photocatalyst dosage, pH, persulfate, persulfate concentration, and combinations of different systems (PS, Fe-BOC-3, Vis/PS, Vis/Fe-BOC-3, Fe-BOC-3/PS, and Vis/Fe-BOC-3/PS) on the reaction were systematically discussed. In reactive species trapping experiments, electron spin resonance (ESR) signals revealed that the photogenerated holes (h+), hydroxyl radical (•OH), sulfate radical (•SO4-), and superoxide radical (•O2-) played an important role in CIP degradation; hydroxyl radicals (•OH) and sulfate radicals (•SO4-) play a major role. Various characterization methods have demonstrated that Fe-BOC-X has larger specific surface area and pore volume than original BiOCl. UV-vis DRS indicate that Fe-BOC-X has wider visible light absorption and faster photocarrier transfer and provides abundant surface oxygen absorption sites for effective molecular oxygen activation. Accordingly, a large number of active species were produced and participated in the photocatalytic process, thus effectively promoting the degradation of ciprofloxacin. Based on HPLC-MS analysis, two possible decomposition pathways of CIP were finally proposed. The main degradation pathways of CIP are mainly due to the high electron density of piperazine ring in CIP molecule, which is mainly attacked by various free radicals. The main reactions include piperazine ring opening, decarbonylation, decarboxylation, and fluorine substitution. This study can better open up a new way for the design of visible light driven photocatalyst and provide more ideas for the removal of CIP in water environment.

The acute effects of fipronil and 2,4-D, individually and in mixture: a threat to the freshwater Calanoida copepod Notodiaptomus iheringi

The magnitude of copepods' responses to pesticides, individually and in mixture, is little understood. The aims of this study were to evaluate: (i) the effects of the pesticides fipronil and 2,4-D, individually and in mixture, on the freshwater copepod Notodiaptomus iheringi; and (ii) the survival and the feeding rate of copepods after the exposure. Acute toxicity tests using the commercial formulations of fipronil and 2,4-D, individually and in mixture, were performed. The LC10-48h, LC20-48h, and LC50-48h of fipronil to N. iheringi were 2.38 ± 0.48, 3.08 ± 1.14, and 4.97 ± 3.30 μg L-1, respectively. For 2,4-D the LC10-48h, LC20-48h, and LC50-48h were 371.18 ± 29.20, 406.93 ± 53.77, and 478.24 ± 107.77 mg L-1, respectively. Morphological damages on the copepods exposed to pesticides were observed at all concentrations. Fungal filaments covering dead organisms were presented at the treatment highest concentration (R5:7.43 ± 2.78 μg L-1 fipronil). The mixture of the pesticides presented synergistic effects on the mortality of N. iheringi. Post-exposure tests showed no difference between the treatments and the control on the mortality and on the feeding rate for 4 h. However, since delayed toxicity of pesticides can occur, longer post-exposure tests using N. iheringi should be tested. N. iheringi is a key species in the aquatic Brazilian ecosystem and showed sensitivity to fipronil and 2,4-D; thus, more studies with this species assessing other responses are recommended.

Wastewater treatment plants, an "escape gate" for ESCAPE pathogens

Antibiotics are an essential tool of modern medicine, contributing to significantly decreasing mortality and morbidity rates from infectious diseases. However, persistent misuse of these drugs has accelerated the evolution of antibiotic resistance, negatively impacting clinical practice. The environment contributes to both the evolution and transmission of resistance. From all anthropically polluted aquatic environments, wastewater treatment plants (WWTPs) are probably the main reservoirs of resistant pathogens. They should be regarded as critical control points for preventing or reducing the release of antibiotics, antibiotic-resistant bacteria (ARB), and antibiotic-resistance genes (ARGs) into the natural environment. This review focuses on the fate of the pathogens Enterococcus faecium, Staphylococcus aureus, Clostridium difficile, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacteriaceae spp. (ESCAPE) in WWTPs. All ESCAPE pathogen species, including high-risk clones and resistance determinants to last-resort antibiotics such as carbapenems, colistin, and multi-drug resistance platforms, were detected in wastewater. The whole genome sequencing studies demonstrate the clonal relationships and dissemination of Gram-negative ESCAPE species into the wastewater via hospital effluents and the enrichment of virulence and resistance determinants of S. aureus and enterococci in WWTPs. Therefore, the efficiency of different wastewater treatment processes regarding the removal of clinically relevant ARB species and ARGs, as well as the influence of water quality factors on their performance, should be explored and monitored, along with the development of more effective treatments and appropriate indicators (ESCAPE bacteria and/or ARGs). This knowledge will allow the development of quality standards for point sources and effluents to consolidate the WWTP barrier role against the environmental and public health AR threats.

O2 Carrier Myoglobin Also Exhibits β-Lactamase Activity That Is Regulated by the Heme Coordination State

Heme proteins perform a variety of biological functions and also play significant roles in the field of bio-catalysis. The β-lactamase activity of heme proteins has rarely been reported. Herein, we found, for the first time, that myoglobin (Mb), an O₂ carrier, also exhibits novel β-lactamase activity by catalyzing the hydrolysis of ampicillin. The catalytic proficiency ((k_cat/K_M)/k_uncat) was determined to be 6.25 × 10¹⁰, which is much higher than the proficiency reported for designed metalloenzymes, although it is lower than that of natural β-lactamases. Moreover, we found that this activity could be regulated by an engineered disulfide bond, such as Cys46-Cys61 in F46C/L61C Mb or by the addition of imidazole to directly coordinate to the heme center. These results indicate that the heme active site is responsible for the β-lactamase activity of Mb. Therefore, the study suggests the potential of heme proteins acting as β-lactamases, which broadens the diversity of their catalytic functions.

Distribution, ecological fate, and risks of steroid estrogens in environmental matrices

Over the past two decades, steroidal estrogens (SEs) such as 17α-ethylestradiol (EE2), 17β-estradiol (E2),17α-estradiol (17α-E2), estriol (E3) and estrone (E1) have elicited worldwide attention due to their potentially harmful effects on human health and aquatic organisms even at low concentration ng/L. Natural steroidal estrogens exhibit greater endocrine disruption potency due to their high binding effect on nuclear estrogen receptors (ER). However, less has been explored regarding their associated environmental risks and fate. A comprehensive bibliometric study of the current research status of SEs was conducted using the Web of Science to assess the development trends and current knowledge of SEs in the last two decades, from 2001 to 2021 October. The number of publications has tremendously increased from 2003 to 2021. We summarized the contamination status and the associated ecological risks of SEs in different environmental compartments. The results revealed that SEs are ubiquitous in surface waters and natural SEs are most studied. We further carried out an in-depth evaluation and synthesis of major research hotspots and the dominant SEs in the matrices were E1, 17β-E2, 17α-E2, E3 and EE2. Nonetheless, investigations of SEs in soils, groundwater, and sediments remain scarce. This study elucidates SEs distribution, toxicological risks, ecological fate and mitigation measures, which will be beneficial for future monitoring, management, and risk assessment. Further studies are recommended to assess the toxicological risks of different SEs in complex environmental matrices to pursue a more precise and holistic quantitative estimation of estrogenic risk.

Assessment of contaminants of emerging concern in European apex predators and their prey by LC-QToF MS wide-scope target analysis

Apex predators are good indicators of environmental pollution since they are relatively long-lived and their high trophic position and spatiotemporal exposure to chemicals provides insights into the persistent, bioaccumulative and toxic (PBT) properties of chemicals. Although monitoring data from apex predators can considerably support chemicals' management, there is a lack of pan-European studies, and longer-term monitoring of chemicals in organisms from higher trophic levels. The present study investigated the occurrence of contaminants of emerging concern (CECs) in 67 freshwater, marine and terrestrial apex predators and in freshwater and marine prey, gathered from four European countries. Generic sample preparation protocols for the extraction of CECs with a broad range of physicochemical properties and the purification of the extracts were used. The analysis was performed utilizing liquid (LC) chromatography coupled to high resolution mass spectrometry (HRMS), while the acquired chromatograms were screened for the presence of more than 2,200 CECs through wide-scope target analysis. In total, 145 CECs were determined in the apex predator and their prey samples belonging in different categories, such as pharmaceuticals, plant protection products, per- and polyfluoroalkyl substances, their metabolites and transformation products. Higher concentration levels were measured in predators compared to prey, suggesting that biomagnification of chemicals through the food chain occurs. The compounds were prioritized for further regulatory risk assessment based on their frequency of detection and their concentration levels. The majority of the prioritized CECs were lipophilic, although the presence of more polar contaminants should not be neglected. This indicates that holistic analytical approaches are required to fully characterize the chemical universe of biota samples. Therefore, the present survey is an attempt to systematically investigate the presence of thousands of chemicals at a European level, aiming to use these data for better chemicals management and contribute to EU Zero Pollution Ambition.

Legacy and emerging pollutants in Latin America: A critical review of occurrence and levels in environmental and food samples

The increase and indiscriminate use of personal care products, food products, fertilizers, pesticides, and health products, among others, have resulted/are resulting in extensive environmental contamination. Most of these products contain traces of widespread chemicals, usually known as emerging pollutants (EPs) or pollutants of emerging concern (PEC). The Latin American (LA) region comprises 20 countries with different social and cultural aspects, with 81 % of the population living in urban areas. The LA region has some countries on the top list of users/consumers of EPs, from pesticides and fertilizers to personal care products. However, there is a gap in information related to the distribution of EPs in the environment of this region, with very few existing review texts exploring this issue. Therefore, this present paper advances this approach. An exhaustive literature review, with the selection of 176 documents, provided unique up-to-date information on the presence/distribution of 17 classes of legacy or emerging pollutants in different food and environmental matrices (soil, sediment, water, and air). The study shows that the wide distribution and recorded levels of these pollutants in the continental environment are potential risks to human health, mainly through food and drinking water ingestion. Polycyclic aromatic hydrocarbons are pollutants of deep public concern since they show carcinogenic properties. Several classes of pollutants, like endocrine disruptors, have caused harmful effects on humans and the environment. Besides that, pharmaceutical products and pesticides are compounds of high consumption worldwide, being environmental contamination a real and ongoing possibility. Finally, gaps and future research needs are deeply pointed out.

A quick test method for predicting the adsorption of organic micropollutants on activated carbon

Controlling the contamination of water cycles with organic micropollutants (OMPs) has been targeted in many regions. Adsorption with activated carbon is an effective technology to remove OMPs from different water matrices. To efficiently design or operate the adsorption process, the adsorption of OMPs should be properly assessed, usually with time-consuming batch adsorption tests and sophisticated analyses. In this study, a quick adsorption test method has been developed by loading powdered activated carbon (PAC) into a syringe filter which can be used subsequently to filtrate the water sample in short time (<60 s). Treated wastewater was applied to compare the quick test method and conventional batch test regarding the adsorption of 14 frequently detected OMPs, the abatement of UV₂₅₄, and changes in fractions of dissolved organic matter (DOM). Similar adsorption patterns of individual OMPs, total OMPs, and DOM fractions was found with two methods. UV₂₅₄ can predict the removal of total OMPs and most individual OMPs in both methods. Both the abatement of UV₂₅₄ or the removal of OMPs determined in the quick test led to a highly accurate prediction of OMP adsorption in the conventional adsorption tests. The novel quick test method thus could help operators and researchers quickly monitor the adsorption capacity of PAC products.

A review toward contaminants of emerging concern in Brazil: Occurrence, impact and their degradation by advanced oxidation process in aquatic matrices

This work presents data regarding the occurrence and treatment of Contaminants of Emerging Concern (CECs) in Brazil in the past decade. The literature review (2011-2021) revealed the detection of 87 pharmaceutical drugs and personal care products, 58 pesticides, 8 hormones, 2 illicit drugs, caffeine and bisphenol A in distinct matrices (i.e.: wastewater, groundwater, sea water, rainwater, surface water, drinking water and hospital effluent). Concentrations of CECs varied from ng-μg L^-1 depending on the location, compound and matrix. The inefficiency of conventional wastewater treatment methods on the removal of CECs and lack of basic sanitation in some regions in the country aggravates contamination of Brazilian aquatic environments and poses potential environmental and health risks. Advanced oxidation processes (AOPs) are pointed out as viable and efficient alternatives to degrade CECs and prevent environmental contamination. A total of 375 studies involving the use of AOPs in Brazilian aqueous matrices were published in the last decade. Fenton and photo-Fenton processes, photo-peroxidation, ozonation, electrochemical advanced oxidation and heterogeneous photocatalysis are some of the AOPs applied by Brazilian research groups. Although many works discuss the importance of applying these technologies for CECs removal in real treatment plants, most of these studies assess the treatment of distilled water or simulated effluent. Therefore, the conduction of studies applying AOPs in real matrices are critical to drive the implementation of these processes coupled to conventional water and wastewater treatment in real plants in order to prevent the contamination of environmental matrices by CECs in Brazil.

Occurrence, Comparison and Priority Identification of Antibiotics in Surface Water and Sediment in Urbanized River: A Case Study of Suzhou Creek in Shanghai

Antibiotics in water have attracted increasing attention due to their potential threat to aquatic ecosystems and public health. Most previous studies have focused on heavily polluted environments, while ignoring urbanized rivers with high population density. Taking Suzhou Creek in Shanghai as an example, this study attempted to explore the antibiotic pollution characteristics of typical urbanized rivers. Further, it screened out priority antibiotics so as to provide reference for the regular monitoring of antibiotics in urban surface water in the study’s later stage. Four classes of 27 antibiotics in surface water samples and sediment samples were detected and analyzed by SPE-UPLC-MS/MS under both wet season and dry season. Results demonstrate that the total amount of antibiotics detected reached 1936.9 ng/L and 337.3 ng/g in water samples and sediment samples, respectively. Through Pearson correlation analysis, it can be shown that there is a very significant correlation between a variety of antibiotics in water and sediment. The results of ecological risk assessment based on risk quotient (RQ) show that certain antibiotics presented high and medium risk to the surrounding ecosystem. Finally, the priority antibiotics selected by optimized priority screening method were EM, SPD, CLR and RTM. Therefore, we have proven that the antibiotics being discharged in urbanized rivers show different types of antibiotics, while presenting a toxicological risk to certain species.

Facile Synthesis of ZnO-CeO2 Heterojunction by Mixture Design and Its Application in Triclosan Degradation: Effect of Urea

In this study, simplex centroid mixture design was employed to determine the effect of urea on ZnO-CeO. The heterojunction materials were synthesized using a solid-state combustion method, and the physicochemical properties were evaluated using X-ray diffraction, nitrogen adsorption/desorption, and UV–Vis spectroscopy. Photocatalytic activity was determined by a triclosan degradation reaction under UV irradiation. According to the results, the crystal size of zinc oxide decreases in the presence of urea, whereas a reverse effect was observed for cerium oxide. A similar trend was observed for ternary samples, i.e., the higher the proportion of urea, the larger the crystallite cerium size. In brief, urea facilitated the co-existence of crystallites of CeO and ZnO. On the other hand, UV spectra indicate that urea shifts the absorption edge to a longer wavelength. Studies of the photocatalytic activity of TCS degradation show that the increase in the proportion of urea favorably influenced the percentage of mineralization.

H2O2 activation over Co substitution in Fe1-xS for tetracycline degradation: Effect of Co substitution

In this work, the effect of Co substitution in the Fe_1-xS (CSP) on the activation of H₂O₂ to degrade tetracycline (TC) is investigated. A series of CSP samples with different Co content are synthesized via a high-temperature sulfidation method and characterized by XRD, XPS, SEM, and electrochemical analysis. The result showed that low Co content (≤1%) promotes the catalytic activity of Fe_1-xS, while excessive Co (1%﹤x ≤ 3%) inhibits its catalytic activity. The investigation of Behnajady-Modirshahla-Ghanbery kinetic model (BMG) showed that the maximum initial degradation rate of TC over 1.0% CSP/H₂O₂ was 1.6 times than that of in CSP/H₂O₂ system. The Box-Behnken with Response Surface Methodology was employed to verify optimum condition for TC degradation. The quenching experiments and ESR determined that ·OH, ·O₂^- and ¹O₂ were involved in TC degradation with the treatment of 1.0% CSP/H₂O₂ system. Electrochemical analysis, ·OH quantification, and metal ion concentrations measure reveal that Co substitution accelerates electron transfer efficiency and Fe²⁺ regeneration. Furthermore, nine intermediates are identified and the possible degradation pathway of TC is proposed. The unique effect of Co provides novel insight and efficient strategies for improving the reactivity of iron sulfide.

Persistence, environmental hazards, and mitigation of pharmaceutically active residual contaminants from water matrices

Pharmaceutical compounds are designed to elicit a biological reaction in specific organisms. However, they may also elicit a biological response in non-specific organisms when exposed to ambient quantities. Therefore, the potential human health hazards and environmental effects associated with pharmaceutically active compounds presented in aquatic environments are being studied by researchers all over the world. Owing to their broad-spectrum occurrence in various environmental matrices, direct or indirect environmental hazardous impacts, and human-health related consequences, several pharmaceutically active compounds have been categorized as emerging contaminants (ECs) of top concern. ECs are often recalcitrant and resistant to abate from water matrices. In this review, we have examined the classification, occurrence, and environmental hazards of pharmaceutically active compounds. Moreover, because of their toxicity and the inefficiency of wastewater treatment plants to remove pharmaceutical pollutants, novel wastewater remediation technologies are urgently required. Thus, we have also analyzed the recent advances in microbes-assisted bioremediation as a suitable, cost-effective, and eco-friendly alternative for the decontamination of pharmaceutical pollutants. Finally, the most important factors to reach optimal bioremediation are discussed.

Major contaminants of emerging concern in soils: a perspective on potential health risks

Soil pollution by the contaminants of emerging concern (CECs) or emerging contaminants deserves attention worldwide because of their toxic health effects and the need for developing regulatory guidelines. Though the global soil burden by certain CECs is in several metric tons, the source-tracking of these contaminants in soil environments is difficult due to heterogeneity of the medium and complexities associated with the interactive mechanisms. Most CECs have higher affinities towards solid matrices for adsorption. The CECs alter not only soil functionalities but also those of plants and animals. Their toxicities are at nmol to μmol levels in cell cultures and test animals. These contaminants have a higher propensity in accumulating mostly in root-based food crops, threatening human health. Poor understanding on the fate of certain CECs in anaerobic environments and their transfer pathways in the food web limits the development of effective bioremediation strategies and restoration of the contaminated soils and endorsement of global regulatory efforts. Despite their proven toxicities to the biotic components, there are no environmental laws or guidelines for certain CECs. Moreover, the information available on the impact of soil pollution with CECs on human health is fragmentary. Therefore, we provide here a comprehensive account on five significantly important CECs, viz., (i) PFAS, (ii) micro/nanoplastics, (iii) additives (biphenyls, phthalates), (iv) novel flame retardants, and (v) nanoparticles. The emphasis is on (a) degree of soil burden of CECs and the consequences, (b) endocrine disruption and immunotoxicity, (c) genotoxicity and carcinogenicity, and (d) soil health guidelines.

An Overview of Antibiotic Resistance and Abiotic Stresses Affecting Antimicrobial Resistance in Agricultural Soils

Excessive use of antibiotics in the healthcare sector and livestock farming has amplified antimicrobial resistance (AMR) as a major environmental threat in recent years. Abiotic stresses, including soil salinity and water pollutants, can affect AMR in soils, which in turn reduces the yield and quality of agricultural products. The objective of this study was to investigate the effects of antibiotic resistance and abiotic stresses on antimicrobial resistance in agricultural soils. A systematic review of the peer-reviewed published literature showed that soil contaminants derived from organic and chemical fertilizers, heavy metals, hydrocarbons, and untreated sewage sludge can significantly develop AMR through increasing the abundance of antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARBs) in agricultural soils. Among effective technologies developed to minimize AMR's negative effects, salinity and heat were found to be more influential in lowering ARGs and subsequently AMR. Several strategies to mitigate AMR in agricultural soils and future directions for research on AMR have been discussed, including integrated control of antibiotic usage and primary sources of ARGs. Knowledge of the factors affecting AMR has the potential to develop effective policies and technologies to minimize its adverse impacts.

Adsorption of Sodium Diclofenac in Functionalized Palygoskite Clays

The effects of acid and organo-functionalizations on the surface of Brazilian palygorskite clay was investigated, evaluating its potential in the adsorptive capacity of the drug sodium diclofenac present in wastewaters. The modifications on the clay structure were investigated by X-ray diffraction, X-ray fluorescence, thermogravimetric, differential thermal analysis, Fourier transform infrared spectroscopy, surface area by N₂ adsorption (77.5 K) and Zeta potential. The experimental design was carried out to find the best conditions for the adsorption tests, in which concentration, mass and pH were significant. In the kinetic study, the pseudo-second-order model better described the adsorption process for acid and organo-functionalized samples. Such results indicate that the adsorption behavior probably occurs due to the phenomenon of chemisorption. Regarding the adsorption isotherms, the Langmuir model was the one that best adjusted both the experimental data of acid and the organo-functionalized samples, whose maximum adsorption capacity were 179.88 and 253.34 mg/g, respectively. This model also indicates that the sodium diclofenac is adsorbed to monolayers homogeneously through chemisorption. In general, the studied clays proved to be suitable adsorbents for the removal of sodium diclofenac.

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 High Flux Electrochemical Filtration System Based on Electrospun Carbon Nanofiber Membrane for Efficient Tetracycline Degradation

In this work, an electrochemical filter using an electrospun carbon nanofiber membrane (ECNFM) anode fabricated by electrospinning, stabilization and carbonization was developed for the removal of antibiotic tetracycline (TC). ECNFM with 2.5 wt% terephthalic acid (PTA) carbonized at 1000 °C (ECNFM-2.5%-1000) exhibited higher tensile stress (0.75 MPa) and porosity (92.8%), more graphitic structures and lower electron transfer resistance (23.52 Ω). Under the optimal condition of applied voltage 2.0 V, pH 6.1, 0.1 mol L−1 Na2SO4, initial TC concentration 10 ppm and membrane flux 425 LMH, the TC removal efficiency of the electrochemical filter of ECNFM-2.5%-1000 reached 99.8%, and no obvious performance loss was observed after 8 h of continuous operation. The pseudo-first-order reaction rate constant in flow-through mode was 2.28 min−1, which was 10.53 times higher than that in batch mode. Meanwhile, the energy demand for 90% TC removal was only 0.017 kWh m−3. TC could be converted to intermediates with lower developmental toxicity and mutagenicity via the loss of functional groups (-CONH2, -CH3, -OH, -N(CH3)2) and ring opening reaction, which was mainly achieved by direct anodic oxidation. This study highlights the potential of ECNFM-based electrochemical filtration for efficient and economical drinking water purification.

Caffeine and Paraxanthine as Tracers of Anthropogenic Wastewater in Coastal Lagoons in Yucatan, Mexico

Due to karstic bedrock geology and poor wastewater management practices, anthropogenic activities are impacting water quality in Yucatan's aquatic systems. Specifically, raw wastewater inputs to the aquifer subsequently flow to coastal lagoons through groundwater fluxes. This study establishes the presence of anthropogenic wastewater by measuring caffeine and its metabolite, paraxanthine, in four of Yucatan's major coastal lagoons: Celestun, Chelem, Dzilam de Bravo, and Ria Lagartos. Concentrations of caffeine ranged from non-detected (ND) to 2390 ng L^-1 and paraxanthine from ND to 212 ng L^-1, which correspond with pollution threats from anthropogenic wastewater inputs. The potential sources are: (1) direct in situ discharges from nearby urban settlements; and (2) contribution from submerged groundwater discharges. Overall, results indicate the potential of caffeine as an environmental tracer of anthropogenic wastewater contamination for the region.

Application Progress of O3/UV Advanced Oxidation Technology in the Treatment of Organic Pollutants in Water

Organic pollution is a significant challenge in environmental protection, especially the discharge of refractory organic pollutants in chemical production and domestic use. The biological treatment method of traditional sewage treatment plants cannot degrade such pollutants, which leads to the continuous transfer of these pollutants into the water environment. Therefore, it is necessary to study clean and efficient advanced treatment technologies to degrade organic pollutants. The ozone/UV advanced oxidation process (O3/UV) has attracted extensive attention. This paper summarizes the reaction mechanism of O3/UV and analyzes its application progress in industrial wastewater, trace polluted organic matter and drinking water. The existing research results show that this technology has an excellent performance in the degradation of organic pollutants and has the characteristics of clean and environmental protection. In addition, the control of bromate formation and its economy is evaluated, and its operating characteristics and current application scope are summarized, which has a practical reference value for the follow-up in-depth study of the O3/UV process.

Ecological and human health risks of manure-borne steroid estrogens: A 20-year global synthesis study

Estrone (E1), 17α-estradiol (17α-E2), 17β-estradiol (17β-E2), and estriol (E3) are persistent in livestock manure and present serious pollution concerns because they can trigger endocrine disruption at part-per-trillion levels. This study conducted a global analysis of estrogen occurrence in manure using all literature data over the past 20 years. Besides, predicted environmental concentration (PEC) in soil and water was estimated using fate models, and risk/harm quotient (RQ/HQ) methods were applied to screen risks on children as well as on sensitive aquatic and soil species. The estradiol equivalent values ranged from 6.6 to 4.78 × 10⁴ ng/g and 12.4 to 9.46 × 10⁴ ng/L in the solid and liquid fraction. The estrogenic potency ranking in both fractions were 17β-E2> E1>17α-E2>E3. RQs of measured environmental concentration in the liquid fraction pose medium (E3) to high risk (E1, 17α-E2 & 17β-E2) to fish but are lower than risks posed by xenoestrogens. However, the RQ of PECs on both soil organisms and aquatic species were insignificant (RQ < 0.01), and HQs of contaminated water and soil ingestion were within acceptable limits. Nevertheless, meticulous toxicity studies are still required to confirm (or deny) the findings because endocrine disruption potency from mixtures of these classes of compounds cannot be ignored.

Different antibiotic profiles in wild and farmed Chilean salmonids. Which is the main source for antibiotic in fish?

Fish from both aquaculture and wild capture are exposed to veterinary and medicinal antibiotics (ABs). This study explored the occurrence and probable source of 46 antibiotic residues in muscle of farmed salmon and wild trout from Chile. Results showed that at least one AB was detected in all studied samples. Diverse patterns were observed between farmed and wild specimens, with higher ABs concentrations in wild fish. Considering antimicrobial resistance, detected ABs corresponded to the categories B (Restrict), C (Caution) and D (Prudence) established by Antimicrobial Advice Ad Hoc Expert Group (European Medicines Agency). Multivariate statistic was used to verify differences between farmed and wild populations, looking for the probable source of ABs as well. Principal components analysis (PCA) revealed that ciprofloxacin, moxifloxacin, enrofloxacin, amoxicillin, penicillin G, oxolinic acid, sulfamethoxazole, trimethoprim and clarithromycin were associated with wild samples, collected during the cold season. Conversely, norfloxacin, sulfaquinoxaline, sulfadimethoxine, nitrofurantoin, nalidixic acid, penicillin V, doxycycline, flumequine, oxacillin, pipemidic acid and sulfamethizole were associated with wild samples collected during the warm season. All farmed salmon samples were associated with ofloxacin, tetracycline, cephalexin, erythromycin, azithromycin, roxithromycin, sulfabenzamide, sulfamethazine, sulfapyridine, sulfisomidin, and sulfaguanidine. In addition, linear discriminant analysis showed that the AB profile in wild fish differ from farmed ones. Most samples showed ABs levels below the EU regulatory limit for edible fish, except for sulfaquinoxaline in one sample. Additionally, nitrofurantoin (banned in EU) was detected in one aquaculture sample. The differences observed between farmed and wild fish raise questions on the probable source of ABs, either aquaculture or urban anthropic activities. Further research is necessary for linking the ABs profile in wild fish with the anthropic source. However, to our knowledge, this is the first report showing differences in the ABs profile between wild and aquaculture salmonids, which could have both environmental and health consequences.

Ferrate (VI)-mediated transformation of diethyl phthalate (DEP) in soil: Kinetics, degradation mechanisms and theoretical calculation

Diethyl phthalate (DEP), as a kind of universally used plasticizer, has aroused considerable public concern owing to its wide detection, environmental stability, and potential health risks. In this work, the highly efficient removal of DEP by ferrate (VI) (Fe(VI)) was systematically explored in soil environment. The effects of the oxidant dosages, soil types, as well as the presence of coexisting cations and anions in tested soil on DEP removal were evaluated. When the dosage of Fe(VI) was 20 mM, complete removal of DEP (50 μg/g) was achieved in the tested soil after 2 min of reaction. Furthermore, the removal rate of DEP was closely related to the soil types, and the degradation rates were decreased obviously in red soil (RS), black soil (BS) and paddy soil (PS), probably due to the acidic condition and high content of organic matters. Moreover, the presence of Ca²⁺, Mg²⁺ and Al³⁺ in soil can inhibit the removal of DEP by Fe(VI), while SO₄^2- has an slightly promotion effect. Six oxidation intermediates were detected in the reaction process of DEP, product analysis revealed that the transformation of DEP was mainly through two pathways, including hydrolysis and hydroxylation reactions, which were probably mediated by oxygen atom transfer process of Fe(VI). Based on the frontier electron density theory calculation, two ester groups of DEP were prone to be attacked by Fe(VI), and the hydroxyl addition tended to occur at the para-position of one of the ester groups on the benzene ring. This study provides a novel approach for phthalate esters removal from soil using Fe(VI) oxidation and shows new insights into the oxidation mechanisms.

An Overview of Antibiotics as Emerging Contaminants: Occurrence in Bivalves as Biomonitoring Organisms

Simple Summary

In recent years, the use of antibiotics has increased worldwide in both human and veterinary fields. This led to them accumulating in the environment to such an extent that they are actually included in the category of contaminants of emerging concern. For this reason, many of them have been included in monitoring lists of potential pollutants by competent authorities in order to limit their concentration in surface waters and to determine the risk to the aquatic environments. From this perspective, the aim of this review is to update and discuss the available data on antibiotic residues, using bivalves as biomonitoring organisms. Bivalves are good candidate for this purpose, being globally present in large and accessible populations, sedentary and able to accumulate several xenobiotics thanks to their large filtration capacity. The current research indicates that antibiotics’ presence in bivalves has been investigated along European, American and Asian coasts. Except for tetracycline, determined at high concentration in the North Adriatic Sea, all antibiotics residues in bivalves were under the maximum residual limit established by the competent authorities. Nevertheless, further investigations are necessary in order to prevent antimicrobial resistance, preserve the environment from antibiotic pollution and monitor the associated risk for animals and humans.

Abstract

Antibiotics are used for therapeutic and prophylactic purposes in both human and veterinary medicine and as growth promoting agents in farms and aquaculture. They can accumulate in environmental matrices and in the food chain, causing adverse effects in humans and animals including the development of antibiotic resistance. This review aims to update and discuss the available data on antibiotic residues, using bivalves as biomonitoring organisms. The current research indicates that antibiotics’ presence in bivalves has been investigated along European, American and Asian coasts, with the majority of studies reported for the last. Several classes of antibiotics have been detected, with a higher frequency of detection reported for macrolides, sulfonamides and quinolones. The highest concentration was instead reported for tetracyclines in bivalves collected in the North Adriatic Sea. Only oxytetracycline levels detected in this latter site exceeded the maximum residual limit established by the competent authorities. Moreover, the risk that can be derived from bivalve consumption, calculated considering the highest concentrations of antibiotics residues reported in the analyzed studies, is actually negligible. Nevertheless, further supervisions are needed in order to preserve the environment from antibiotic pollution, prevent the development of antimicrobial resistance and reduce the health risk derived from seafood consumption.

Occurrence of Pharmaceuticals and Endocrine Disrupting Compounds in Brazilian Water and the Risks They May Represent to Human Health

The risks of pharmaceuticals and endocrine disrupting compounds (P&EDC) to the environment and human health are a current topic of interest. Hundreds of P&EDC may reach the environment, hence, there is a need to rank the level of concern of human exposure to these compounds. Thus, this work aimed at setting a priority list of P&EDC in Brazil, by studying their occurrence in raw and drinking water, calculating health guideline values (GV), and estimating the risks of population exposure to water intake. Data on the Brazilian pharmaceutical market as well as published data of the monitoring of Brazilian natural and drinking water have been collected by means of an exhaustive literature review. Furthermore, many foreign data were also collected to enable a comparison of the values found in Brazilian studies. A list of 55 P&EDC that have the potential to be found in Brazilian water is proposed, and for 41 of these a risk assessment was performed by estimating their margin of exposure (ME), by considering their occurrence in drinking water, and guideline values estimated from reported acceptable daily intake (ADI) data. For seven compounds the risk was deemed high (three estrogens and four anti-inflammatories), whereas for another seven compounds, it was regarded as an 'alert' situation. Although such risk analysis is conservative, since it has been calculated based on the highest reported P&EDC concentration in drinking water, it highlights the need to enhance their monitoring in Brazil to strengthen the database and support decision makers. An analysis of the occurrence of antimicrobial resistance agents (antibiotics, resistant bacteria, and resistance genes) in surface waters was also carried out and confirmed that such agents are present in water sources throughout Brazil, which deserves the attention of policy makers and health agents to prevent dissemination of antimicrobial resistance through water use.

Polyvinylpyrrolidone-assisted synthesis of highly water-stable cadmium-based metal-organic framework nanosheets for the detection of metronidazole

Recently, much effort has been dedicated to ultra-thin two-dimensional metal–organic framework (2D MOF) nanosheets due to their outstanding properties, such as ultra-thin morphology, large specific surface area, abundant modifiable active sites, etc. However, the preparation of high-quality 2D MOF nanosheets in good yields still remains a huge challenge. Herein, we report 2D cadmium-based metal–organic framework (Cd-MOF) nanosheets prepared in a one-pot polyvinylpyrrolidone (PVP)-assisted synthesis method with high yield. The Cd-MOF nanosheets were characterized with good stability and dispersion in aqueous systems, and were highly selective and sensitive to the antibiotic metronidazole (MNZ) with low limit of detection (LOD: 0.10 μM), thus providing a new and promising fluorescent sensor for rapid detection of MNZ in aqueous solution.

Except PVP was added for Cd-MOF nanosheets, the preparation process of bulk and Cd-MOF nanosheets was similar.

Impact of phthalates and bisphenols plasticizers on haemocyte immune function of aquatic invertebrates: A review on physiological, biochemical, and genomic aspects

The invertebrate innate immunity is a crucial characteristic that represents a valuable basis for studying common biological responses to environmental pollutants. Cell defence mechanisms are key players in protecting the organism from infections and foreign materials. Many haemocyte-associated immunological parameters have been reported to be immunologically sensitive to aquatic toxins (natural or artificial). Environmental plastic pollution poses a global threat to ecosystems and human health due to plastic vast and extensive use as additives in various consumer products. In recent years, studies have been done to evaluate the effects of plasticizers on humans and the environment, and their transmission and presence in water, air, and indoor dust, and so forth. Hence, the development of biomarkers that evaluate biological responses to different pollutants are essential to obtain important information on plasticizers' sublethal effects. This review analyses the current advances in the adverse effects of plasticizers (as emerging contaminants), such as immunological response disruption. The review also shows a critical analysis of the effects of the most widely used plasticizers on haemocytes. The advantages of an integrative approach that uses chemical, genetic, and immunomarker assays to monitor toxicity are highlighted. All these factors are imperative to ponder when designing toxicity studies to recognize the potential effects of plasticizers like bisphenol A and phthalates.

Determination of contaminants of emerging concern and their transformation products in treated-wastewater irrigated soil and corn

In many parts of the world, clean water has become increasingly scarce. Irrigation of agricultural land with treated wastewater is commonly used in response to water shortages but there is concern about the environmental fate and transport of contaminants present in the irrigation wastewater. This study aimed to examine the presence of wastewater sourced contaminants in soil and field grown corn (Zea mays) crops spray irrigated with treated wastewater. Soil, corn grain, leaves, and roots were sampled and tested from a long-term wastewater irrigation site as well as a non-irrigated control site in close geographic proximity. Samples were analyzed using comprehensive two-dimensional gas chromatography coupled to time of flight mass spectrometry (GC × GC-TOFMS) and both targeted and non-targeted analyses were conducted to determine chemical differences between the wastewater irrigated and control samples. Target compounds detected and quantified in the samples include herbicides, phthalates, and polycyclic aromatic hydrocarbons. Non-targeted analysis showed chemical differences between each the wastewater irrigated and control samples. Furthermore, new chloro-dimethyl-benzotriazole compounds, which are suspected to be transformation products created by the chlorine disinfection process of the wastewater treatment plant, were tentatively identified in the wastewater effluent. Twenty of these new benzotriazoles were detected and semi-quantified in the wastewater irrigated soil samples at a maximum concentration of 472 ng/g. Eight of the most abundant benzotriazoles were also detected in the corn roots at concentrations up to 56 ng/g.

Pharmaceuticals and environmental risk assessment in municipal wastewater treatment plants and rivers from Peru

This is the first study dealing with removal of the pharmaceutical substances in municipal wastewater treatment plants (MWWTPs) from Peru and the impact of these compounds in surface waters receiving treated wastewater. To this aim, samples from MWWTP of Lima (Peruvian Coast), MWWTP of Cusco, Puno and Juliaca (Peruvian Highlands), as well surface water (confluence of Torococha and Coata rivers in Juliaca) were analyzed. A total of 38 target pharmaceuticals were included in this study and were determined by Liquid Chromatography coupled to tandem Mass Spectrometry (LC-MS/MS). Around 60% and 75% of the target pharmaceuticals could be quantified in surface water and MWWTPs, respectively. Acetaminophen was the drug found at the highest concentration, and it was present in all the treated wastewater samples reaching average values above 100 μg/L in the department of Puno. The gabapentin anti-epileptic drug (up to 11.85 μg/L in MWWTP Lima) and the antibiotics clarithromycin, trimethoprim, ciprofloxacin, sulfamethoxazole and azithromycin (1.86 to 4.47 μg/L in MWWTP Lima) were also found at moderate concentrations in the treated wastewater. In surface water, the highest concentration corresponded also to acetaminophen (28.70 μg/L) followed by sulfamethoxazole (4.36 μg/L). As regards the pharmaceuticals removal, data of this work showed that the MWWTP Cusco (aerobic biologic process by synthetic trickling filters as secondary treatment) was more efficient than the MWWTP Lima (a preliminary treatment that combines grilles, sand trap, degreaser-aerated and sieved of 1.0 mm). However, many pharmaceuticals (around 50% of the compounds investigated) presented concentrations in treated wastewater similar or even higher than in influent wastewater. The environmental ecological risk of pharmaceuticals was assessed based on calculated Risk Quotient (RQ) in the treated wastewater and surface water from the concentration data found in the samples. According to our data, three antibiotics (clarithromycin, ciprofloxacin, clindamycin) and the analgesic acetaminophen posed high environmental risk (RQ ≥ 1) on the aquatic environment. In the river, all antibiotics (except norfloxacin) as well as the analgesic-anti-inflammatory compounds acetaminophen, diclofenac posed a high environmental risk (RQ ≥ 1). Based on data reported in this work for the first time in water samples from Peru, it can be deduced that the treatment processes applied in important cities from Peru are not enough efficient to remove pharmaceuticals in wastewater. As a consequence, severe environmental risks associated to the presence of pharmaceuticals in treated wastewater and surface water are expected; so complementary treatment processes should be implemented in the MWWTPs for a more efficient elimination of these compounds.

A chemical prioritization process: Applications to contaminants of emerging concern in freshwater ecosystems (Phase I)

Contaminants of emerging concern (CECs), such as pharmaceuticals, personal care products, and hormones, are frequently found in aquatic ecosystems around the world. Information on sublethal effects from exposure to commonly detected concentrations of CECs is lacking and the limited availability of toxicity data makes it difficult to interpret the biological significance of occurrence data. However, the ability to evaluate the effects of CECs on aquatic ecosystems is growing in importance, as detection frequency increases. The goal of this study was to prioritize the chemical hazards of 117 CECs detected in subsistence species and freshwater ecosystems on the Grand Portage Indian Reservation and adjacent 1854 Ceded Territory in Minnesota, USA. To prioritize CECs for management actions, we adapted Minnesota Pollution Control Agency's Aquatic Toxicity Profiles framework, a tool for the rapid assessment of contaminants to cause adverse effects on aquatic life by incorporating chemical-specific information. This study aimed to 1) perform a rapid-screening assessment and prioritization of detected CECs based on their potential environmental hazard; 2) identify waterbodies in the study region that contain high priority CECs; and 3) inform future monitoring, assessment, and potential remediation in the study region. In water samples alone, 50 CECs were deemed high priority. Twenty-one CECs were high priority among sediment samples and seven CECs were high priority in fish samples. Azithromycin, DEET, diphenhydramine, fluoxetine, miconazole, and verapamil were high priority in all three media. Due to the presence of high priority CECs throughout the study region, we recommend future monitoring of particular CECs based on the prioritization method used here. We present an application of a chemical hazard prioritization process and identify areas where the framework may be adapted to meet the objectives of other management-related assessments.

Targeting the right parameters in PAH remediation studies

Contaminated land burdens the economy of many countries and must be dealt with. Researchers have published thousands of documents studying and developing soil and sediment remediation treatments. Amongst the targeted pollutants are the polycyclic aromatic hydrocarbons (PAHs), described as a class of persistent organic compounds, potentially harmful to ecosystems and living organisms. The present paper reviews and discusses three scientific trends that are leading current PAH-contaminated soil/sediment remediation studies and management. First, the choice of compounds that are being studied and targeted in the scientific literature is discussed, and we suggest that the classical 16 US-EPA PAH compounds might no longer be sufficient to meet current environmental challenges. Second, we discuss the choice of experimental material in remediation studies. Using bibliometric measures, we show the lack of PAH remediation trials based on co-contaminated or aged-contaminated material. Finally, the systematic use of the recently validated bioavailability measurement protocol (ISO/TS 16751) in remediation trials is discussed, and we suggest it should be implemented as a tool to improve remediation processes and management strategies.