Determination of pesticide levels in wastewater from an agro-food industry: Target, suspect and transformation product analysis

Antifungal drugs in the aquatic environment: A review on sources, occurrence, toxicity, health effects, removal strategies and future challenges

Fungal infections pose a significant global health burden, resulting in millions of severe cases and deaths annually. The escalating demand for effective antifungal treatments has led to a rise in the wholesale distribution of antifungal drugs, which consequently has led to their release into the environment, posing a threat to ecosystems and human health. This article aims to provide a comprehensive review of the presence and distribution of antifungal drugs in the environment, evaluate their potential ecological and health risks, and assess current methods for their removal. Reviewed studies from 2010 to 2023 period have revealed the widespread occurrence of 19 various antifungals in natural waters and other matrices at alarmingly high concentrations. Due to the inefficiency of conventional water treatment in removing these compounds, advanced oxidation processes, membrane filtration, and adsorption techniques have been developed as promising decontamination methods.In conclusion, this review emphasizes the urgent need for a comprehensive understanding of the presence, fate, and removal of antifungal drugs in the environment. By addressing the current knowledge gaps and exploring future prospects, this study contributes to the development of strategies for mitigating the environmental impact of antifungal drugs and protecting ecosystems and human health.

Oxidative treatment of micropollutants present in wastewater: A special emphasis on transformation products, their toxicity, detection, and field-scale investigations

Micropollutants have become ubiquitous in aqueous environments due to the increased use of pharmaceuticals, personal care products, pesticides, and other compounds. In this review, the removal of micropollutants from aqueous matrices using various advanced oxidation processes (AOPs), such as photocatalysis, electrocatalysis, sulfate radical-based AOPs, ozonation, and Fenton-based processes has been comprehensively discussed. Most of the compounds were successfully degraded with an efficiency of more than 90%, resulting in the formation of transformation products (TPs). In this respect, degradation pathways with multiple mechanisms, including decarboxylation, hydroxylation, and halogenation, have been illustrated. Various techniques for the analysis of micropollutants and their TPs have been discussed. Additionally, the ecotoxicity posed by these TPs was determined using the toxicity estimation software tool (T.E.S.T.). Finally, the performance and cost-effectiveness of the AOPs at the pilot scale have been reviewed. The current review will help in understanding the treatment efficacy of different AOPs, degradation pathways, and ecotoxicity of TPs so formed.

Occurrence, seasonal variation and gas/particle partitioning of current used pesticides (CUPs) across 60 °C temperature and 30° latitudes in China

Gas and particle phases samples were collected at three sites in China in 2019-2020, with 60 °C temperature span and 30° latitude range. Totally, among 76 target current used pesticides (CUPs) with four types, 51 were quantified in at least one sample. The concentrations of individual CUPs ranged from 8 orders of magnitude, indicating different pollution levels. Herbicides were the dominated CUPs in Northeast China, while higher concentrations of fungicides were found in Southeast China. The highest concentrations of CUPs were observed in Southeast China in spring and winter, while in summer and autumn in Northeast China, caused by local climates and crop cultivation patterns. The gas/particle (G/P) partitioning of CUPs was mainly influenced by their physicochemical properties and ambient temperature. The G/P partitioning study indicated that the L-M-Y model was the optimum prediction model for herbicides, fungicides and pyrethroids. The L-M-Y model and the H-B model presented equal performance for organophosphate insecticides. To our knowledge, the L-M-Y model was firstly applied for the study of the G/P partitioning of CUPs, which provided new insights into the related fields of new emergency contaminates.

Identification of organic micro-pollutants in surface water using MS-based infrared ion spectroscopy

Comprehensive monitoring of organic micro-pollutants (OMPs) in drinking water sources relies on non-target screening (NTS) using liquid-chromatography and high-resolution mass spectrometry (LC-HRMS). Identification of OMPs is typically based on accurate mass and tandem mass spectrometry (MS/MS) data by matching against entries in compound databases and MS/MS spectral libraries. MS/MS spectra are, however, not always diagnostic for the full molecular structure and, moreover, emerging OMPs or OMP transformation products may not be present in libraries. Here we demonstrate how infrared ion spectroscopy (IRIS), an emerging MS-based method for structural elucidation, can aid in the identification of OMPs. IRIS measures the IR spectrum of an m/z-isolated ion in a mass spectrometer, providing an orthogonal diagnostic for molecular identification. Here, we demonstrate the workflow for identification of OMPs in river water and show how quantum-chemically predicted IR spectra can be used to screen potential candidates and suggest structural assignments. A crucial step herein is to define a set of candidate structures, presumably including the actual OMP, for which we present several strategies based on domain knowledge, the IR spectrum and MS/MS spectrum.

Advanced mass spectrometry profiling of phenolic and minerals compounds in herbal beverages

The global pandemic of COVID-19 has led to an increased interest in herbal infusions as natural remedies since 2020. This has also heightened the need for controlling the composition of these dietary supplements to ensure consumer health and prevent food fraud. In the present work, various mass spectrometry techniques were used to analyze the organic and inorganic composition of 23 herbal infusion samples. UHPLC-ESI-QTOF-MS was used to determine target, suspect, and nontarget polyphenolic compounds. Thus, 8 phenolic compounds were identified in the target analysis and additionally, 80 extra-compounds were identified through suspect and nontargeted screening. ICP-MS was used to monitor the metals released during tea leaf infusion, providing a complete mineral composition of each sample. Principal Component Analysis (PCA) and Discriminant Analysis (DA) were utilized to identify relevant compounds for differentiating and grouping the samples, thus serving as specific markers to detect potential food fraud.

Efficient Validation Strategies in Environmental Analytical Chemistry: A Focus on Organic Micropollutants in Water Samples

This article critically reviews analytical method validation and quality control applied to the environmental chemistry field. The review focuses on the determination of organic micropollutants (OMPs), specifically emerging contaminants and pesticides, in the aquatic environment. The analytical technique considered is (gas and liquid) chromatography coupled to mass spectrometry (MS), including high-resolution MS for wide-scope screening purposes. An analysis of current research practices outlined in the literature has been performed, and key issues and analytical challenges are identified and critically discussed. It is worth emphasizing the lack of specific guidelines applied to environmental analytical chemistry and the minimal regulation of OMPs in waters, which greatly affect method development and performance, requirements for method validation, and the subsequent application to samples. Finally, a proposal is made for method validation and data reporting, which can be understood as starting points for further discussion with specialists in environmental analytical chemistry.

Target and non-target analysis of organochlorine pesticides and their transformation products in an agrochemical-contaminated area

Organochlorine pesticides show biological toxicity and their degradation typically takes many years. Previous studies of agrochemical-contaminated areas have mainly focused on limited target compounds, and emerging pollutants in soil have been overlooked. In this study, we collected soil samples from an abandoned agrochemical-contaminated area. Target analysis and non-target suspect screening by gas chromatography coupled with time-of-flight mass spectrometry were combined for qualitative and quantitative analysis of organochlorine pollutants. Target analysis showed that dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyldichloroethane (DDD) were the main pollutants. With concentrations between 3.96 × 10⁶ and 1.38 × 10⁷ ng/g, these compounds posed significant health risks at the contaminated site. Non-target suspect screening identified 126 organochlorine compounds, most of which were chlorinated hydrocarbons and 90% of the compounds contained a benzene ring structure. The possible transformation pathways of DDT were inferred from proven pathways and the compounds identified by non-target suspect screening that had similar structures to DDT. This study will be useful for studies of the degradation mechanism of DDT. Semi-quantitative and hierarchical cluster analysis of compounds in soil showed that the distribution of contaminants in soil was influenced by the types of pollution sources and distance to them. Twenty-two contaminants were found in the soil at relatively high concentrations. The toxicities of 17 of these compounds are currently not known. These results improve our understanding of the environmental behavior of organochlorine contaminants in soil and are useful for further risk assessments of agrochemical-contaminated areas.

Pesticides and Parabens Contaminating Aquatic Environment: Acute and Sub-Chronic Toxicity towards Early-Life Stages of Freshwater Fish and Amphibians

Pesticides and personal care products are two very important groups of contaminants posing a threat to the aquatic environment and the organisms living in it.. Therefore, this study aimed to describe the effects of widely used pesticides and parabens on aquatic non-target biota such as fish (using model organisms Danio rerio and Cyprinus carpio) and amphibians (using model organism Xenopus laevis) using a wide range of endpoints. The first part of the experiment was focused on the embryonal toxicity of three widely used pesticides (metazachlor, prochloraz, and 4-chloro-2-methyl phenoxy acetic acid) and three parabens (methylparaben, propylparaben, and butylparaben) with D. rerio, C. carpio, and X. laevis embryos. An emphasis was placed on using mostly sub-lethal concentrations that are partially relevant to the environmental concentrations of the substances studied. In the second part of the study, an embryo-larval toxicity test with C. carpio was carried out with prochloraz using concentrations 0.1, 1, 10, 100, and 1000 µg/L. The results of both parts of the study show that even the low, environmentally relevant concentrations of the chemicals tested are often able to affect the expression of genes that play either a prominent role in detoxification and sex hormone production or indicate cell stress or, in case of prochloraz, to induce genotoxicity.

Spatial-temporal occurrence of contaminants of emerging concern in urban rivers in southern Brazil

The widespread use and misuse of antibiotics and pesticides has been linked with several risks to the environment and human health. In the present report, the results of the monitoring of 64 pharmaceuticals and 134 pesticides occurrence in an urban river in Southern Brazil are presented and discussed. Sampling campaigns have covered the period 2016-2018. The identification and determination of the analytes were achieved by high-resolution mass spectrometry. The data were analyzed using chemometric tools to obtain spatial-temporal models. Toxicological evaluation was achieved using acute toxicity (zebrafish standardized protocol), and determination of risk quotient. Within the 198 analytes included in the targeted analysis method for surface water, 33 were identified in an urban river during 2 years of monitoring, being 20 pharmaceuticals and 13 pesticides. Using high-resolution mass spectrometry, a suspect screening approach was established in an un-target analysis. The evaluation was carried out using a data bank built from consumption data of drugs and pesticides, in the metropolitan region of Porto Alegre - RS and their respective metabolites. The suspect screening analysis done with a data bank with more than 1450 compounds results in 27 suspect findings. The target analysis results showed a continuous prevalence of non-steroidal anti-inflammatories, analgesics, antipyretics, beta-blockers, corticoids, and antibiotics. Regarding the pesticides, the main classes were fungicides, especially those from triazol and strobilurin classes.

Strategies for enhancing the efficacy of anaerobic digestion of food industry wastewater: An insight into bioreactor types, challenges, and future scope

Food waste have become a growing concern worldwide with raising population and economic growth. Wastewater discharged from food industries contains many valuable and toxic components that have a negative impact on the ecological system. Large amounts of wastewater are discharged from the food industry, which necessitates the creation of effective technologies. Wastewater from the food industry can be seen as a rich source of energy and a primary source for generating valuable products. Waste disposal and resource recovery are sustainably valued by anaerobic digestion of wastewater from the food sector. The characteristics, composition, and nature of wastewater produced from various food sectors are elaborated upon in this review. An overview of the anaerobic digestion process for wastewater treatment in the food industry is included. Enhancement strategies for the anaerobic digestion process have been discussed in detail. In addition, various types of reactors utilized for performing anaerobic digestion is illustrated. Though anaerobic digestion process possesses advantages, the challenges and future scope are examined for improving the outcome.

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.

Nutritional inter-dependencies and a carbazole-dioxygenase are key elements of a bacterial consortium relying on a Sphingomonas for the degradation of the fungicide thiabendazole

Thiabendazole (TBZ), is a persistent fungicide/anthelminthic and a serious environmental threat. We previously enriched a TBZ-degrading bacterial consortium and provided first evidence for a Sphingomonas involvement in TBZ transformation. Here, using a multi-omic approach combined with DNA-stable isotope probing (SIP) we verified the key degrading role of Sphingomonas and identify potential microbial interactions governing consortium functioning. SIP and amplicon sequencing analysis of the heavy and light DNA fraction of cultures grown on ¹³ C-labelled versus ¹² C-TBZ showed that 66% of the ¹³ C-labelled TBZ was assimilated by Sphingomonas. Metagenomic analysis retrieved 18 metagenome-assembled genomes with the dominant belonging to Sphingomonas, Sinobacteriaceae, Bradyrhizobium, Filimonas and Hydrogenophaga. Meta-transcriptomics/-proteomics and non-target mass spectrometry suggested TBZ transformation by Sphingomonas via initial cleavage by a carbazole dioxygenase (car) to thiazole-4-carboxamidine (terminal compound) and catechol or a cleaved benzyl ring derivative, further transformed through an ortho-cleavage (cat) pathway. Microbial co-occurrence and gene expression networks suggested strong interactions between Sphingomonas and a Hydrogenophaga. The latter activated its cobalamin biosynthetic pathway and Sphingomonas its cobalamin salvage pathway to satisfy its B12 auxotrophy. Our findings indicate microbial interactions aligning with the 'black queen hypothesis' where Sphingomonas (detoxifier, B12 recipient) and Hydrogenophaga (B12 producer, enjoying detoxification) act as both helpers and beneficiaries.

Overarching issues on relevant pesticide transformation products in the aquatic environment: A review

The intensification of agricultural production during the last decades has forced the rapid increase in the use of pesticides that finally end up in the aquatic environment. Albeit well-documented, pesticides continue to raise researchers' attention, because of their potential adverse impacts on the environment and, inevitably, humans. Once entering the aquatic bodies, pesticides undergo biotic and abiotic processes, resulting in transformation products (TPs) that sometimes are even more toxic than the parent compounds. A substantial shift of the scientific interest in the TPs of pesticides has been observed since their environmental fate, occurrence and toxicity is still in its formative stage. In an ongoing effort to expand the existing knowledge on the topic, several interesting works have been performed mostly in European countries, such as France, Germany, Italy, Switzerland, Greece, and Spain that counts the highest number of relevant publications. Pesticide TPs have been also studied to a lesser extent in Asia, North and South America. To this end, the main objective of this review is to delineate the global occurrence, fate, toxicity as well as the analytical challenges related to pesticide TPs in surface, ground, and wastewaters, with the view to contribute to a better understanding of the environmental problems related with TPs formation. The concentration levels of the TPs, ranging from the low ng/L to high μg/L scale and distributed worldwide. Ultimately, an attempt to predict the acute and chronic toxicity of TPs has been carried out with the aid of an in-silico approach based on ECOSAR, revealing increased chronic toxicity for the majority of the identified TPs, despite the change they underwent, while a small portion of them presented serious acute toxicity values.

Suspecting screening "known unknown" pesticides and transformation products in soil at pesticide manufacturing sites

The occurrence and risks of pesticides and their transformation products in soil at the manufacturing sites are "known unknowns." In this study, pesticides and their transformation products were screened in soil at 6 pesticide manufacturing sites across China using liquid and gas chromatography coupled with quadrupole time-of-flight mass spectrometry. The screening strategy can correctly identify 75% of 209 pesticides spiked at 50 ng g^-1. A total of 212 pesticides were identified; 23.1% of pesticides detected were above 200 ng g^-1, and the maximum concentration was 1.5 × 10⁵ ng g^-1. The risk quotients of 20% pesticides were greater than 1, and the maximum risk quotient of imidacloprid reached 6.3 × 10⁴. The most recent site showed a larger number of pesticides with higher diversity, whereas older sites were dominated by organochlorine insecticides. The extended screen identified 163 transformation products with concentrations up to 6.6 × 10⁴ ng g^-1. Half of the transformation products had higher concentrations than their parent compounds, and metabolic ratios up to 371 were observed. The results of this study validate the prevalence of pesticides and their transformation products in soil at pesticide manufacturing sites. The results also highlight the importance of comprehensive screening at industrial sites and call for improved management and regulation of pesticide manufacturing, particularly for in-service facilities.

Multi-criteria decision-making techniques associated with (Q)SAR risk assessment for ranking surface water microcontaminants identified using LC-QTOF MS

Contaminants of emerging concern (CECs) have been a focus of study for years, with investigations revealing the contamination of different environmental matrices (surface water, soil, air, and sediment) by diverse classes of microcontaminants. Understanding the contamination profiles requires identification and risk assessment of the microcontaminants. In the present work, analysis was made of the presence of 3250 compounds in 27 samples from the Conceição River (Rio Grande do Sul State, Brazil), using an SPE-LC-QTOF MS method. In total, 150 microcontaminants (confirmed and suspected) of different classes, especially pesticides and pharmaceuticals, were identified by an initial qualitative analysis. Subsequently, in silico predictions of eight endpoints, using quantitative structure-activity relationship ((Q)SAR) models, were employed to determine the risk of each previously screened microcontaminant. This large amount of (Q)SAR data, frequently with conflicting information in relation to the responses of the different endpoints, makes it difficult to define which microcontaminants should be prioritized for analysis. Therefore, in order to rank the identified microcontaminants by risk assessment, two multi-criteria decision-making (MCDM) ranking techniques (ToxPi and TOPSIS), associated with a weighting method, were performed to establish the order of priority for further quantitative analysis of the most hazardous microcontaminants. The two rankings were statistically similar, especially for the 20 highest priority microcontaminants. Nonetheless, sensitivity tests carried out for the ToxPi and TOPSIS outputs showed higher performance robustness of TOPSIS, compared to ToxPi. This is the first time that such an approach (screening/(Q)SAR/MCDM methods) has been performed in the context of microcontaminant environmental risk evaluation and demonstrated to be an available strategy to help rank the most concern microcontaminants identified in aqueous environment samples.

Combined effects of maternal exposure to fungicides on behavioral development in F1 -generation mice: 3. Fixed-dose study of imazalil

BACKGROUND

Few published studies are reported for the neurobehavioral toxicity of combined exposure to fungicides in mammals. This study was aimed to re-evaluate the reproductive and neurobehavioral effects of maternal exposure to combined imazalil (IMZ) and thiabendazole (TBZ) with fixed-dose of IMZ in mice.

METHODS

IMZ/TBZ was given in the diet to provide levels of 0%/0% (control), 0.006%/0.006% (IMZ/TBZ), 0.006%/0.018%, and 0.006%/0.054% during the gestation and lactation periods. Selected reproductive and neurobehavioral parameters were measured in the F₁ generation.

RESULTS

No adverse effect of IMZ/TBZ was observed in litter size, litter weight, or sex ratio at birth. Concerning behavioral developmental parameters, the time required of olfactory orientation was accelerated significantly in higher-dose groups in female offspring on postnatal day 14 in a dose-related manner. Exploratory behavior examination indicated that the frequency of mice with urination increased in a significantly dose-related manner in male offspring. After weaning, any variables of exploratory behavior indicated no significant effects in both sexes of adult mice in the F₁ generation. In spontaneous behavior, the longitudinal pattern of total distance was not parallel (different pattern) among the control and IMZ/TBZ treatment groups in adult males.

CONCLUSIONS

The results from these series of combined exposure studies of IMZ/TBZ suggest that the main effects on exploratory and spontaneous behavior of adult mice in the F₁ generation after finishing chemical administration have been caused by the IMZ concentration of maternal exposure, with TBZ's effects being complementary.

Pharmaceuticals, pesticides and metals/metalloids in Lake Guaíba in Southern Brazil: Spatial and temporal evaluation and a chemometrics approach

Compiling and reporting data related to the presence of pharmaceuticals and pesticides are crucial means of assessing the risk those chemicals pose to human health and environment. Data sets from different sources were combined using a data fusion approach to produce a spatial and temporal variation of contaminants presents in water from Lake Guaíba (29°55'-30°24' S; 51°01'-51°20' W). Lake Guaíba is a 496 km² water body situated in the geological depression of Rio Grande do Sul State, Brazil; that is fed by several rivers from the metropolitan area, the 5th largest metro area in Brazil, with approximately 5 million inhabitants. Analytical methodology to quantify pharmaceuticals and pesticides by LC-QTOF-MS and GC-MS/MS was validated for 41 pharmaceutical and 62 pesticides. Furthermore, 27 chemical elements were analyzed by ICP-MS, and physical chemical parameters were determined using established methodologies. All validation parameters were in accordance with the National Institute of Metrology, Standardization, and Industrial Quality. Thirty-five water samples were analyzed from January to August 2019, and 15 pharmaceuticals and 25 pesticides were present in concentrations ranging from 6.00 ng L^-1 to 580.00 ng L^-1. Twenty-seven elements were analyzed during the same period, and 18 were present in concentrations ranging from 0.2 μg L^-1 to 7060 μg L^-1. Samples were tagged according to the points and months of collection to identify temporal and spatial patterns. The main findings show that the compounds are distributed throughout the studied area without an apparent regular pattern, suggesting that events in a specific point affect the entire ecosystem. Conversely, temporal variations were well defined, as samples were grouped according to the climatic conditions of the months of collection. Considering the calculated quotient risks, atrazine, cyproconazole, diuron, and simazine showed the highest risk levels for algae; acetaminophen, diclofenac, and ibuprofen showed the highest risk levels for aquatics invertebrates.

Pesticide residues in (treated) wastewater and products of Belgian vegetable- and potato processing companies

Pesticides are broadly utilized in crop cultivation and could end up in wastewater of vegetable- and potato companies during water-consuming processing steps. To gain insight into the presence of pesticide residues in (waste)water of these industries, water was analysed and monitored from three vegetable- and two potato processing companies in Belgium. During one year samples were collected of water before and after primary/secondary treatment (i.e. influent and effluent) and after tertiary treatment. Next to water, also (processed) carrot and potato products were analysed. Results show that boscalid (maximum: 18.32 μg/L) and terbuthylazine (maximum: 87.99 μg/L) are predominantly present in the vegetable industry and chlorpropham (maximum: 8.80×10⁶ μg/L) and terbuthylazine (maximum: 3.37×10⁵ μg/L) in the potato industry. The conventional treatment techniques seem to be insufficient for the removal of pesticides. Concentrations were even higher in the effluent than in the influent. Also, tertiary treatment techniques as ultra-filtration and reverse osmosis fail to reduce all pesticides below the European potable water limit of 0.1 μg/L. To meet this standard, the development and validation of new removal techniques are essential. Regarding product samples, almost no pesticide residues exceeded the MRL. Chlorpropham concentrations were statistically confirmed to be higher in potatoes and wastewater sampled when stored potatoes are processed.

Application of a fast and sensitive method for the determination of contaminants of emerging concern in wastewater using a quick, easy, cheap, effective, rugged and safe-based extraction and liquid chromatography coupled to mass spectrometry

The inefficiency of wastewater treatment plants (WWTPs) to remove contaminants of emerging concern (CECs) leads to their continuous release to the environment. Consequently, CECs are present at low concentrations in the treated wastewater (TWW), producing unpredicted and unwanted effects on living organisms as they are discharged into water receiving bodies. This work presents a fast and reliable method for the determination of CECs in TWW based on the innovative application of a QuEChERS (quick, easy, cheap, effective, rugged and safe) method for water extraction and determination by sensitive liquid chromatography coupled to quadrupole-linear ion trap tandem mass spectrometry (LC-QqLIT-MS/MS). The scope of the proposed QuEChERS-based method allows the monitoring of 107 CECs, including pharmaceuticals (58), antibiotics (16) and pesticides (33). The proposed method was successfully validated in urban TWW at two concentration levels (50 and 500 ng L^-1) and it is a feasible alternative to conventional and time-consuming solid-phase extraction (SPE) methodologies. 89% of the CECs presented mean recovery values in the 70-120% range with relative standard deviations (RSDs) always < 20% (intra and inter-day precision), and limits of quantification (LOQs) in the range 5-500 ng L^-1 (89% of the compounds showed a LOQ ≤ 50 ng L^-1). The applicability of the method was demonstrated by the analysis of urban TWW samples (7 sampling events). In total, 35 CECs (23 pharmaceuticals, 2 antibiotics and 10 pesticides) were detected in the monitored samples with concentrations ranging from 5 to 677 ng L^-1.

Removal of Imidacloprid from Water by Microalgae Nannochloropsis sp. and Its Determination by a Validated RP-HPLC Method

The large-scale use of pesticides is one of the main causes of the dramatic degradation of our environment. Pesticides such as imidacloprid (IMID) have been linked to declines in bee health and toxicity to other beneficial insects. They pose a threat to human health due to their persistence in the environment and accumulation in the food chain. Therefore, it is essential to test possible environmentally-friendly solutions for their elimination. The present study evaluates the efficiency of microalgae Nannochloropsis sp. for the removal of IMID from synthetic wastewater. The influence of aeration, light, and the presence of UV radiation on the degradation of IMID were factors considered in the study. A rapid RP-HPLC method was developed and validated for the analysis and quantification of IMID in the context of bioremediation with microalgae. Nannochloropsis sp. removed 4.39 µg mL^-1 from an initial content of 9.59 µg mL^-1 (reaching approximately 50%) of IMID in the first 20 h. This study demonstrated that the removal of IMID by the marine microalgae Nannochloropsis sp. is both effective and light-dependent.

Recent developments in layer-by-layer assembled systems application in water purification

Electrostatically-based layer-by-layer (LbL) assembly is a versatile surface functionalization technique allowing the construction of complex three-dimensional architectures on virtually any type of material using various combinations of nano-bricks. One of the most promising applications of LbL assembled systems is in water purification. The main two strategies developed in this purpose consist in either enhancing the barrier properties of separation membranes and in the construction of core-shell organic/inorganic sorbents. In this review, the recent achievements in this topic are discussed with respect to the use of LbL-based composites in desalination and removal of heavy metal ions or organic pollutants. Finally, some works dealing with economic aspects of using LbL assemblies for water purification are presented, thus highlighting forthcoming strategies to develop economically-viable materials for such applications.

Suspect and non-target screening: the last frontier in environmental analysis

Suspect and non-target screening (SNTS) techniques are arising as new analytical strategies useful to disentangle the environmental occurrence of the thousands of exogenous chemicals present in our ecosystems. The unbiased discovery of the wide number of substances present over environmental analysis needs to find a consensus with powerful technical and computational requirements, as well as with the time-consuming unequivocal identification of discovered analytes. Within these boundaries, the potential applications of SNTS include the studies of environmental pollution in aquatic, atmospheric, solid and biological samples, the assessment of new compounds, transformation products and metabolites, contaminant prioritization, bioremediation or soil/water treatment evaluation, and retrospective data analysis, among many others. In this review, we evaluate the state of the art of SNTS techniques going over the normalized workflow from sampling and sample treatment to instrumental analysis, data processing and a brief review of the more recent applications of SNTS in environmental occurrence and exposure to xenobiotics. The main issues related to harmonization and knowledge gaps are critically evaluated and the challenges of their implementation are assessed in order to ensure a proper use of these promising techniques in the near future.

Extended suspect screening to identify contaminants of emerging concern in riverine and coastal ecosystems and assessment of environmental risks

A suspect screening methodology was developed for the fast and reliable identification of 360 contaminants of emerging concern (CECs) of anthropogenic origin in the vulnerable area of the Ebro Delta (Catalonia, Spain) and to track for potential contamination sources. The suspect screening methodology was combined with a risk assessment approach to prioritize the most ecologically relevant CECs. Out of the 360 suspects, 37 compounds were tentatively identified, 22 of which were fully confirmed using isotopically labelled standards. The detected suspect compounds included pesticides, pharmaceuticals, personal care products, stimulants and their metabolites. Pesticides were more ubiquitous in irrigation and drainage channels, while pharmaceuticals, stimulants, and personal care products were the most common in effluent wastewaters, in the receiving freshwater systems as well as in the marine environment. Ten compounds were found to be of high ecological concern, including the pharmaceuticals telmisartan, venlafaxine, and carbamazepine, the herbicides terbuthylazine, desethylterbuthylazine, and terbutryn, the fungicides azoxystrobin, tebuconazole and prochloraz and the insecticide tebufenozide. These compounds could be used as markers of anthropogenic contamination in riverine and coastal ecosystems.

Screening of potential oestrogen receptor α agonists in pesticides via in silico, in vitro and in vivo methods

In modern agricultural management, the use of pesticides is indispensable. Due to their massive use worldwide, pesticides represent a latent risk to both humans and the environment. In the present study, 1056 frequently used pesticides were screened for oestrogen receptor (ER) agonistic activity by using in silico methods. We found that 72 and 47 pesticides potentially have ER agonistic activity by the machine learning methods random forest (RF) and deep neural network (DNN), respectively. Among endocrine-disrupting chemicals (EDCs), 14 have been reported as EDCs or ER agonists by previous studies. We selected 3 reported and 7 previously unreported pesticides from 76 potential ER agonists to further assess ERα agonistic activity. All 10 selected pesticides exhibited ERα agonistic activity in human cells or zebrafish. In the dual-luciferase reporter gene assays, six pesticides exhibited ERα agonistic activity. Additionally, nine pesticides could induce mRNA expression of the pS2 and NRF1 genes in MCF-7 cells, and seven pesticides could induce mRNA expression of the vtg1 and vtg2 genes in zebrafish. Importantly, the remaining 48 out of 76 potential ER agonists, none of which have previously been reported to have endocrine-disrupting effects or oestrogenic activity, should be of great concern. Our screening results can inform environmental protection goals and play an important role in environmental protection and early warnings to human health.

Structure and QSAR analysis of photoinduced transformation products of neonicotinoids from EU watchlist for ecotoxicological assessment

Current research is increasingly focusing on the ecotoxicity of anthropogenic micro-pollutants and their degradation and transformation products resulting from biological and chemical treatment processes. These products enter the aquatic environment through various routes and may endanger aquatic organisms and plants. In this study, five neonicotinoids from the EU watchlist and their degradation products induced by UVC irradiation were examined. All identified photoinduced degradation or transformation products were subsequently submitted to Quantitative Structure Activity (QSAR) analysis. Among the investigated structures, 15 substances already identified in previous studies and eleven new transformation products were analyzed. By using QSAR analysis, it became possible to predict ecotoxicity of individual substances with mere computational effort. Starting from the chemical structure, lower toxicity against green algae and invertebrates was predicted for the transformation products in general. For other aquatic target organisms, such as branchiopoda, actinopterygii and fathead minnow, the residual hazardous effect as compared to the initial compound depends on the presence of specific structural elements. For the neonicotinoids investigated, the cleavage or elimination of the nitrile or nitro group through the degradation process, was predicted to increase toxicity.

Biotreatment and bacterial succession in an upflow immobilized cell bioreactor fed with fludioxonil wastewater

The large quantities and the persistent nature of fungicide wastewaters have increased the efforts towards a sustainable technological solution. In this context, fludioxonil-contaminated wastewater was treated in an upflow immobilized cell bioreactor, resulting in chemical oxygen demand (COD) removal efficiency even higher than 80%, whereas the electrical conductivity (EC) of the effluent was gradually increased. Organic-F was mineralized by 94.0 ± 5.2%, which was in accordance with the high fludioxonil removal efficiency (95.4 ± 4.0%). In addition, effluent total Kjeldahl nitrogen (TKN) concentration reduced significantly during bioprocessing. A strong relationship among COD removal, TKN/total nitrogen removal, and effluent EC increase (p < 0.01) was identified. Despite the adequate aeration provided, effluent nitrite and nitrate concentrations were negligible. Illumina sequencing revealed a reduction in the relative abundances of Betaproteobacteria, Chloroflexi, Planctomycetes, and Firmicutes and an increase in the proportion of Alphaproteobacteria and Actinobacteria. A shift in bacterial communities occurred during fludioxonil treatment, resulting in the significant increase of the relative abundances of Empedobacter, Sphingopyxis, and Rhodopseudomonas (from 0.67 ± 0.13% at the start-up to 34.34 ± 1.60% at the end of biotreatment). In conclusion, the immobilized cell bioreactor permitted the proliferation of specialized activated sludge microbiota with an active role in the depuration of postharvest fungicides.

Proposal of a new, fast, cheap, and easy method using DLLME for extraction and preconcentration of diazepam and its transformation products generated by a solar photo-Fenton process

This work evaluated the formation of transformation products (TPs) during the degradation of diazepam (DZP) by a solar photo-Fenton process. Six TPs were identified, three of them for the first time. After elucidation of the TPs, a new, cheap, fast, and easy method was employed to extract and preconcentrate DZP and its TPs, using dispersive liquid-liquid microextraction (DLLME). The method was optimized using factorial and Doehlert designs, with the best results obtained using acetonitrile as disperser solvent and chloroform as extraction solvent, with volumes of 1000 and 650 µL, respectively. When DZP degradation was performed in ultrapure water, the extraction/preconcentration of DZP and its TPs by DLLME was very similar to the results obtained using a traditional SPE method. However, when hospital wastewater was used as the matrix, more limited extraction efficiency was obtained using DLLME, compared to SPE. Meanwhile, all the TPs extracted by SPE were also extracted by the DLLME technique. Furthermore, DLLME was much less expensive than SPE, besides being faster, easier, and requiring only small amounts of organic solvents. This work reports a new and very important tool for the extraction and preconcentration of TPs formed during degradation using techniques such as advanced oxidation processes (AOPs), since without this step it would not be possible to identify all the TPs formed in some complex wastewater matrices.

Combined effects of maternal exposure to fungicides on behavioral development in F1 -generation mice: 2. Fixed-dose study of thiabendazole

BACKGROUND

Few published studies are reported for the neurobehavioral toxicity of combined exposure to fungicides in mammals. This study was aimed to re-evaluate the reproductive and neurobehavioral effects of maternal exposure to combined imazalil (IMZ) and thiabendazole (TBZ) with fixed-dose of TBZ in mice.

METHODS

IMZ/TBZ were given in the diet to provide levels of 0%/0% (control), 0.0015%/0.018% (IMZ/TBZ), 0.006%/0.018% and 0.024%/0.018% during the gestation and lactation periods. Selected reproductive and neurobehavioral parameters were measured in the F₁ generation.

RESULTS

No adverse effect of IMZ/TBZ was observed in litter size, litter weight, or sex ratio at birth. Concerning behavioral developmental parameters, the cliff avoidance on PND 7 of male offspring was restrained significantly in the treatment groups in a dose-related manner. Exploratory behavior examination indicated that the average time of rearing significantly lengthened in the high-dose group of male offspring. After weaning, the average time of rearing in exploratory behavior lengthened in a significant dose-related trend in adult females of the F₁ generation. Spontaneous behavior examination indicated that the average speed decreased significantly through 120 min in the high-dose group of the F₁ -generation males. In females, the average time of rearing lengthened significantly through 120 min in the high-dose group. In the longitudinal patterns, the parallel lines of the control and treatment groups indicated a significant distance in the average time of rearing in the F₁ -generation females.

CONCLUSIONS

The results from two combined exposure studies of IMZ/TBZ suggest that TBZ concentrations have caused major effects on exploratory and spontaneous behavior.

Exposure to pyrimethanil induces developmental toxicity and cardiotoxicity in zebrafish

Pyrimethanil is a broad-spectrum fungicide commonly used in the prevention and treatment of Botrytis cinerea. However, little information is available in the literature to show the toxicity of Pyrimethanil to cardiac development. In this study, we used an experimental animal model to explore the developmental and cardiac toxicity of Pyrimethanil in aquatic vertebrates; we exposed zebrafish embryos to Pyrimethanil at concentrations of 2, 4, and 6 mg/L from 5.5 to 72 h post fertilisation. We found that Pyrimethanil caused a decrease in the hatching rate, heart rate, and survival rate of zebrafish embryos. Pyrimethanil exposure also resulted in pericardial and yolk sac edema, spinal deformity, and heart loop failure. Moreover, Pyrimethanil increased reactive oxygen stress levels and heightened the activity of superoxide dismutase and catalase. Alterations were induced in the transcription of apoptosis-related genes (p53, Bax, Bcl2, Casp 9, and Casp6l1) and heart development-related genes (Tbx2b, Gata4, Myh6, Vmhc, Nppa, Bmp2b, Bpm 4, and Bpm 10). Our data showed that the activation of Wnt signalling by BML-284 could partially rescue the malformed phenotype caused by Pyrimethanil. Our results provide new evidence for Pyrimethanil's toxicity and the danger of its residues in the environment and agricultural products.

Photocatalytic degradation of an agro-industrial wastewater model compound using a UV LEDs system: kinetic study

An ultraviolet light emitting diode (UV-A LED) system was built to test the capability of performing heterogeneous photocatalysis using TiO₂ P25. The LEDs maximum wavelength is 365 nm with an irradiance power of 85 W m^-2. The device was tested in batch and continuous (CSTR) mode in a laboratorial scale reactor. The degradation of an agro-industrial wastewater model compound (p-hydroxybenzoic acid, pHBA) was investigated, assessing the effect of different experimental conditions such as pH, pHBA and TiO₂ concentration keeping constant the UV-A LEDs power and temperature. The photodegradation of different concentrations of pHBA with [TiO₂] = 500 mg L^-1, I_UV = 85 W m^-2 and a T = 21 °C were analysed by pseudo-first order kinetics. The results were applied to the Langmuir-Hinshelwood model yielding k_c = 0.885 mg L^-1 min^-1 and k_LH = 0.217 L mg^-1. In a comparative experiment the UV-A LEDs system showed faster kinetics (k = 0.0134 min^-1) than solar radiation (I_UV = 23 W m^-2; k = 0.0077 min^-1), with [pHBA] = 75 mg L^-1 and [TiO₂] = 500 mg L^-1. The values of the Electric Energy per Order (E_EO) = 115 kWh m^-3 order^-1 and the Specific Applied Energy (E_SAE) = 318 kWh mol^-1 order^-1 were obtained with [TiO₂] = 1000 mg L^-1 and [pHBA] = 50 mg L^-1. Analogous results were obtained ([TiO₂] = 500 mg L^-1) in a CSTR with a slight decrease in the first order kinetic constant due to the "non-ideal" reactor: from 0.0284 to 0.0158 min^-1 and from 0.0143 to 0.00825 min^-1 with [pHBA] = 50 mg L^-1 and 75 mg L^-1, respectively. This work shows that photocatalytic reactors with UV-A LEDs can advantageously replace conventional UV mercury lamps based reactors in the photodegradation of phenolic compounds.

Paradigm shifts and current challenges in wastewater management

Wastewater is a significant environmental and public health concern which management is a constant challenge since antiquity. Wastewater research has increased exponentially over the last decades. This paper provides a global overview of the exponentially increasing wastewater research in order to identify current challenges and paradigm shifts. Besides households, hospitals and typical industries, other sources of wastewater appear due to emerging activities like hydraulic fracturing. While the composition of wastewater needs constant reassessment to identify contaminants of interest, the comprehensive chemical and toxicological analysis remains one of the main challenges in wastewater research. Moreover, recent changes in the public perception of wastewater has led to several paradigm shifts: i) water reuse considering wastewater as a water resource rather than a hazardous waste, ii) wastewater-based epidemiology considering wastewater as a source of information regarding the overall health of a population through the analysis of specific biomarkers, iii) circular economy through the implementation of treatment processes aiming at harvesting valuable components such as precious metals or producing valuable goods such as biofuel. However, wastewater research should also address social challenges such as the public acceptance of water reuse or the access to basic sanitation that is not available for nearly a third of the world population.

Development of an integral strategy for non-target and target analysis of site-specific potential contaminants in surface water: A case study of Dianshan Lake, China

Surface water contains a large number of potential pollutants and their transformation products, which cannot be discovered by normal target analysis alone. To detect site-specific and unknown contaminants in the environment, we established an integral analytical strategy based on liquid chromatography-high resolution mass spectrometry (LC-HRMS) combined with data processing using specific software (Compound Discoverer 3.0). In this case study of Dianshan Lake, 95 potential contaminants were tentatively identified and ranked by the scoring system. Then, the 95 compounds were categorized into 4 subgroups: pesticides, drugs, plastic additives and surfactants. To determine the sources and distribution of those pollutants, 4 heat maps were developed based on the sum of peak areas of respective categories. In addition, 19 substances with high exposure risk among the 95 compounds tentatively identified were confirmed and quantified. In the present study, the analytical strategy with non-target screening followed by target analysis demonstrated that pesticides and plastic additives are the two dominant types of contaminants in Dianshan Lake. High accuracy and high-resolution data combined with integrated software provided abundant information for the identification of a wide range of potential contaminants in the environment. This approach can be a useful tool for the simple and rapid screening and tentative detection of site-specific contaminants.