Ecological and toxicological assessments of anthropogenic contaminants based on environmental metabolomics

Urbanisation-associated shifts in the avian metabolome within the annual cycle

While organisms have evolved to cope with predictable changes in the environment, the rapid rate of current global change presents numerous novel and unpredictable stressors to which organisms have had less time to adapt. To persist in the urban environment, organisms must modify their physiology, morphology and behaviour accordingly. Metabolomics offers great potential for characterising organismal responses to natural and anthropogenic stressors at the systems level and can be applied to any species, even without genomic knowledge. Using metabolomic profiling of blood, we investigated how two closely related species of passerine bird respond to the urban environment. Great tits Parus major and blue tits Cyanistes caeruleus residing in urban and forest habitats were sampled during the breeding (spring) and non-breeding (winter) seasons across replicated sites in southern Sweden. During breeding, differences in the plasma metabolome between urban and forest birds were characterised by higher levels of amino acids in urban-dwelling tits and higher levels of fatty acyls in forest-dwelling tits. The suggested higher rates of fatty acid oxidation in forest tits could be driven by habitat-associated differences in diet and could explain the higher reproductive investment and success of forest tits. High levels of amino acids in breeding urban tits could reflect the lack of lipid-rich caterpillars in the urban environment and a dietary switch to protein-rich spiders, which could be of benefit for tackling inflammation and oxidative stress associated with pollution. In winter, metabolomic profiles indicated lower overall levels of amino acids and fatty acyls in urban tits, which could reflect relaxed energetic demands in the urban environment. Our metabolomic profiling of two urban-adapted species suggests that their metabolism is modified by urban living, though whether these changes represent adaptative or non-adaptive mechanisms to cope with anthropogenic challenges remains to be determined.

Integrated transcriptomic and metabolomic approaches reveal molecular response and potential biomarkers of the deep-sea mussel Gigantidas platifrons to copper exposure

Metal pollution caused by deep-sea mining activities has potential detrimental effects on deep-sea ecosystems. However, our knowledge of how deep-sea organisms respond to this pollution is limited, given the challenges of remoteness and technology. To address this, we conducted a toxicity experiment by using deep-sea mussel Gigantidas platifrons as model animals and exposing them to different copper (Cu) concentrations (50 and 500 μg/L) for 7 days. Transcriptomics and LC-MS-based metabolomics methods were employed to characterize the profiles of transcription and metabolism in deep-sea mussels exposed to Cu. Transcriptomic results suggested that Cu toxicity significantly affected the immune response, apoptosis, and signaling processes in G. platifrons. Metabolomic results demonstrated that Cu exposure disrupted its carbohydrate metabolism, anaerobic metabolism and amino acid metabolism. By integrating both sets of results, transcriptomic and metabolomic, we find that Cu exposure significantly disrupts the metabolic pathway of protein digestion and absorption in G. platifrons. Furthermore, several key genes (e.g., heat shock protein 70 and baculoviral IAP repeat-containing protein 2/3) and metabolites (e.g., alanine and succinate) were identified as potential molecular biomarkers for deep-sea mussel's responses to Cu toxicity. This study contributes novel insight for assessing the potential effects of deep-sea mining activities on deep-sea organisms.

Tricks and tracks of prevalence, occurrences, treatment technologies, and challenges of mixtures of emerging contaminants in the environment: With special emphasis on microplastic

This paper aims to emphasize the occurrence of various emerging contaminant (EC) mixtures in natural ecosystems and highlights the primary concern arising from the unregulated release into soil and water, along with their impacts on human health. Emerging contaminant mixtures, including pharmaceuticals, personal care products, dioxins, polychlorinated biphenyls, pesticides, antibiotics, biocides, surfactants, phthalates, enteric viruses, and microplastics (MPs), are considered toxic contaminants with grave implications. MPs play a crucial role in transporting pollutants to aquatic and terrestrial ecosystems as they interact with the various components of the soil and water environments. This review summarizes that major emerging contaminants (ECs), like trimethoprim, diclofenac, sulfamethoxazole, and 17α-Ethinylestradiol, pose serious threats to public health and contribute to antimicrobial resistance. In addressing human health concerns and remediation techniques, this review critically evaluates conventional methods for removing ECs from complex matrices. The diverse physiochemical properties of surrounding environments facilitate the partitioning of ECs into sediments and other organic phases, resulting in carcinogenic, teratogenic, and estrogenic effects through active catalytic interactions and mechanisms mediated by aryl hydrocarbon receptors. The proactive toxicity of ECs mixture complexation and, in part, the yet-to-be-identified environmental mixtures of ECs represent a blind spot in current literature, necessitating conceptual frameworks for assessing the toxicity and risks with individual components and mixtures. Lastly, this review concludes with an in-depth exploration of future scopes, knowledge gaps, and challenges, emphasizing the need for a concerted effort in managing ECs and other organic pollutants.

Emerging contaminants: A One Health perspective

Environmental pollution is escalating due to rapid global development that often prioritizes human needs over planetary health. Despite global efforts to mitigate legacy pollutants, the continuous introduction of new substances remains a major threat to both people and the planet. In response, global initiatives are focusing on risk assessment and regulation of emerging contaminants, as demonstrated by the ongoing efforts to establish the UN's Intergovernmental Science-Policy Panel on Chemicals, Waste, and Pollution Prevention. This review identifies the sources and impacts of emerging contaminants on planetary health, emphasizing the importance of adopting a One Health approach. Strategies for monitoring and addressing these pollutants are discussed, underscoring the need for robust and socially equitable environmental policies at both regional and international levels. Urgent actions are needed to transition toward sustainable pollution management practices to safeguard our planet for future generations.

Utility of zebrafish-based models in understanding molecular mechanisms of neurotoxicity mediated by the gut-brain axis

The gut microbes perform several beneficial functions which impact the periphery and central nervous systems of the host. Gut microbiota dysbiosis is acknowledged as a major contributor to the development of several neuropsychiatric and neurological disorders including bipolar disorder, depression, anxiety, Parkinson's disease, Alzheimer's disease, attention deficit hyperactivity disorder, and autism spectrum disorder. Thus, elucidation of how the gut microbiota-brain axis plays a role in health and disease conditions is a potential novel approach to prevent and treat brain disorders. The zebrafish (Danio rerio) is an invaluable vertebrate model that possesses conserved brain and intestinal features with those of humans, thus making zebrafish a valued model to investigate the interplay between the gut microbiota and host health. This chapter describes current findings on the utility of zebrafish in understanding molecular mechanisms of neurotoxicity mediated via the gut microbiota-brain axis. Specifically, it highlights the utility of zebrafish as a model organism for understanding how anthropogenic chemicals, pharmaceuticals and bacteria exposure affect animals and human health via the gut-brain axis.

Microalgal multiomics-based approaches in bioremediation of hazardous contaminants

The enhanced industrial growth and higher living standards owing to the incessant population growth have caused heightened production of various chemicals in different manufacturing sectors globally, resulting in pollution of aquatic systems and soil with hazardous chemical contaminants. The bioremediation of such hazardous pollutants through microalgal processes is a viable and sustainable approach. Accomplishing microalgal-based bioremediation of polluted wastewater requires a comprehensive understanding of microalgal metabolic and physiological dynamics. Microalgae-bacterial consortia have emerged as a sustainable agent for synergistic bioremediation and metabolite production. Effective bioremediation involves proper consortium functioning and dynamics. The present review highlights the mechanistic processes employed through microalgae in reducing contaminants present in wastewater. It discusses the multi-omics approaches and their advantages in understanding the biological processes, monitoring, and dynamics among the partners in consortium through metagenomics. Transcriptomics, proteomics, and metabolomics enable an understanding of microalgal cell response toward the contaminants in the wastewater. Finally, the challenges and future research endeavors are summarised to provide an outlook on microalgae-based bioremediation.

LC-MS/MS-based targeted amino acid metabolic profile of Auricularia cornea grown on pinecone substrate

Pinecone substrate offers an eco-friendly and cost-effective alternative for cultivating edible fungi. This pioneering study explores the 94 amino acids metabolic profiles of Auricularia cornea grown on various pinecone substrates. To our knowledge, this is the first study of quantify A. cornea on an oleaginous substrate (pinecone) using targeted LC-MS /MS-based metabolomics approaches. Five different pinecone substrate percentages (0%, 7%, 14%, 21%, and 28% respectively) were used for A. cornea culture, and the resulting fruiting bodies were analyzed for amino acids metabolic profiles. Detected 79 amino acids metabolites, 15 undetected. High contents of succinic-acid and γ-aminobutyric acid. Thirty-three amino acid metabolites showed significant differences between groups, primarily related to protein synthesis. KEGG analysis revealed that seven major metabolic pathways were significantly enriched. The findings provide valuable insights into the metabolite composition of A. cornea grown on a pinecone substrate, potentially contribute to the understanding of its nutritional and medicinal properties.

Effects of Zinc Thiazole and Oxytetracycline on the Microbial Metabolism, Antibiotic Resistance, and Virulence Factor Genes of Soil, Earthworm Gut, and Phyllosphere

Pesticides and antibiotics are believed to increase the incidence of antibiotic resistance genes (ARGs) and virulence factor genes (VFGs), constituting a serious threat to global health. However, the impact of this combined pollution on the microbiome and that of the related ARGs and VFGs on soil-plant-animal systems remain unknown. In this study, a 60-day microcosm experiment was conducted to reveal the effects of zinc thiazole (ZT) and oxytetracycline (OTC) on microbial communities, antibiotic resistomes, and virulence factors in soil, earthworm gut, and phyllosphere samples using metagenomics. ZT exposure perturbed microbial communities and nutrient metabolism and increased the abundance of ARGs and VFGs in the gut. Combined exposure changed the profiles of ARGs and VFGs by decreasing microbial diversity in the phyllosphere. Host-tracking analysis identified some genera, such as Citrobacter and Aeromonas, as frequent hosts of ARGs and VFGs in the gut. Notably, some co-occurrence patterns of ARGs and MGEs were observed on the metagenome-assembled contigs. More importantly, ZT markedly increased the abundance of potentially drug-resistant pathogens Acinetobacter soli and Acinetobacter junii in the phyllosphere. Overall, this study expands our current understanding of the spread of ARGs and VFGs in soil-plant-animal systems under pollutant-induced stress and the associated health risks.

Untargeted Metabolomics Analyses and Contaminant Chemistry of Dreissenid Mussels at the Maumee River Area of Concern in the Great Lakes

Bivalves serve as an ideal ecological indicator; hence, their use by the NOAA Mussel Watch Program to monitor environmental health. This study aimed to expand the baseline knowledge of using metabolic end points in environmental monitoring by investigating the dreissenid mussel metabolome in the field. Dreissenids were caged at four locations along the Maumee River for 30 days. The mussel metabolome was measured using nuclear magnetic resonance spectroscopy, and mussel tissue chemical contaminants were analyzed using gas or liquid chromatography coupled with mass spectrometry. All Maumee River sites had a distinct mussel metabolome compared to the reference site and revealed changes in the energy metabolism and amino acids. Data also highlighted the importance of considering seasonality or handling effects on the metabolome at the time of sampling. The furthest upstream site presented a specific mussel tissue chemical signature of pesticides (atrazine and metolachlor), while a downstream site, located at Toledo's wastewater treatment plant, was characterized by polycyclic aromatic hydrocarbons and other organic contaminants. Further research into the dreissenid mussel's natural metabolic cycle and metabolic response to specific anthropogenic stressors is necessary before successful implementation of metabolomics in a biomonitoring program.

Deeper insights into the effects of low dietary levels of polychlorinated biphenyls on pig metabolism using gas chromatography-high resolution mass spectrometry metabolomics

Polychlorinated biphenyls (PCBs) are a class of contaminants of great concern, linked to the development of many chronic diseases. Adverse effects of PCBs have been documented in humans after accidental and massive exposure. However, little is known about the effect of chronic exposure to low-dose PCB mixtures, and studies regarding scattered lifetime exposures to non-dioxin-like (NDL)-PCBs are especially missing. In this work, serum samples from pigs chronically exposed through their diet during 22 days to Aroclor 1260 (i.e. a commercially available mixture of NDL-PCBs) underwent a metabolomics analysis using gas chromatography-high resolution mass spectrometry (GC-HRMS), with the objective to investigate the effect of exposure to low doses of NDL-PCBs (few ng/kg body weight (b.w.) per day). The study showed that the serum profiles of 84 metabolites are significantly altered by the administration of Aroclor 1260, of which 40 could be identified at level 1. The aggregate interpretation of the results of this study, together with the outcome of a previous one involving LC-HRMS profiling, provided a substantial and concise overview of the effect of low dose exposure to NDL-PCBs, reflecting the hepatotoxic and neurotoxic effects already reported in literature at higher and longer exposures. These results are intended to contribute to the debate on the current toxicological reference values for these substances.

A bioanalytical approach for assessing the effects of soil extracts from solid waste dumpsite in Calabar (Nigeria) on lipid and estrogenic signaling of fish Poeciliopsis lucida hepatocellular carcinoma-1 cells in vitro and in vivo African catfish (Clarias gariepinus)

In applying bioanalytical approaches, the aim of this study was to determine the toxicity of contaminants derived from a solid waste dumpsite in Calabar (Nigeria), by investigating the alterations of lipid and estrogen signaling pathways in Poeciliopsis lucida hepatocellular carcinoma-1 (PLHC-1) cells and compared to in vivo African catfish (Clarias gariepinus), using polar, nonpolar and elutriate extraction methods. Cells were exposed for 48 hr period to different concentrations of the contaminant extracts. The PLHC-1 cells were evaluated for lipid responses as follows adipoRed assay, retinoid x receptor (rxr), peroxisome proliferator-activated receptor isoforms (ppar-α and γ), estrogen receptor (er-α) and vitellogenin (vtg) transcripts. The lipid signaling activation was also assessed in vivo using C. gariepinus, where hepatic levels of ppar-α were determined at both transcript and functional proteins levels. Data showed variable-, extract type and concentration-specific elevations in mRNA and protein levels for lipidomic and estrogenic effects. These effects were either biphasic at low and high concentrations, depending upon extract type, or concentration-dependent elevations. In general, these toxicological responses may be attributed to soil organic and inorganic contaminants burden previously derived from the dumpsite. Thus, our data demonstrate a unique lipid and endocrine-disruptive chemical (EDC) effects of each soil extract, suggesting multiple and complex contaminant interactions in the environment and biota. Analysis of numerous soil- or sediment-bound contaminants have numerous limitations and cost implications for developing countries. Our approach provides a bioanalytical protocol and endpoints for measuring the metabolic and EDC effects of complex environmental matrices for ecotoxicological assessment and monitoring.

Immobilized microalgal system: An achievable idea for upgrading current microalgal wastewater treatment

Efficient wastewater treatment accompanied by sustainable "nutrients/pollutants waste-wastewater-resources/energy nexus" management is acting as a prominent and urgent global issue since severe pollution has occurred increasingly. Diverting wastes from wastewater into the value-added microalgal-biomass stream is a promising goal using biological wastewater treatment technologies. This review proposed an idea of upgrading the current microalgal wastewater treatment by using immobilized microalgal system. Firstly, a systematic analysis of microalgal immobilization technology is displayed through an in-depth discussion on why using immobilized microalgae for wastewater treatment. Subsequently, the main technical approaches employed for microalgal immobilization and pollutant removal mechanisms by immobilized microalgae are summarized. Furthermore, from high-tech technologies to promote large-scale production and application potentials in diverse wastewater and bioreactors to downstream applications lead upgradation closer, the feasibility of upgrading existing microalgal wastewater treatment into immobilized microalgal systems is thoroughly discussed. Eventually, several research directions are proposed toward the future immobilized microalgal system for microalgal wastewater treatment upgrading. Together, it appears that using immobilization for further upgrading the microalgae-based wastewater treatment can be recognized as an achievable alternative to make microalgal wastewater treatment more realistic. The information and perspectives provided in this review also offer a feasible reference for upgrading conventional microalgae-based wastewater treatment.

Cross-Platform Comparison of Amino Acid Metabolic Profiling in Three Model Organisms Used in Environmental Metabolomics

Environmental metabolomics is a promising approach to study pollutant impacts to target organisms in both terrestrial and aquatic environments. To this end, both nuclear magnetic resonance (NMR)- and mass spectrometry (MS)-based methods are used to profile amino acids in different environmental metabolomic studies. However, these two methods have not been compared directly which is an important consideration for broader comparisons in the environmental metabolomics field. We compared the quantification of 18 amino acids in the tissue extracts of Daphnia magna, a common model organism used in both ecotoxicology and ecology, using both 1H NMR spectroscopy and liquid chromatography with tandem MS (LC-MS/MS). 1H NMR quantification of amino acids agreed with the LC-MS/MS quantification for 17 of 18 amino acids measured. We also tested both quantitative methods in a D. magna sub-lethal exposure study to copper and lithium. Again, both NMR and LC-MS/MS measurements showed agreement. We extended our analyses with extracts from the earthworm Eisenia fetida and the plant model Nicotiana tabacum. The concentrations of amino acids by both 1H NMR and LC-MS/MS, agreed and demonstrated the robustness of both techniques for quantitative metabolomics. These findings demonstrate the compatibility of these two analytical platforms for amino acid profiling in environmentally relevant model organisms and emphasizes that data from either method is robust for comparisons across studies to further build the knowledge base related to pollutant exposure impacts and toxic responses of diverse environmental organisms.

Is substrate choice an overlooked variable in ecotoxicology experiments?

It is crucial to understand the effects caused by experimental parameters such as temperature, light, and food type on lab and field-based ecotoxicology experiments, as these variables, and combinations thereof, can affect results. The type of substrate used in exposure experiments, however, is generally assumed to have no effect. This may not always be correct. The metabolic changes in the freshwater crustacean, Austrochiltonia subtenuis exposed to copper, using three common substrates, gauze; toilet paper; and cellulose were investigated. Substrate alone did not affect survival, but each substrate elicited a different metabolic response and adult and juvenile amphipods had different substrate preferences. Several classes of metabolites were shown to change in response to different substrates and toxicant. These included disaccharides, monosaccharides, fatty acids, and tricarboxylic acid cycle intermediates. The results illustrate that metabolomic responses can differ in response to experimental factors that were previously thought not to be significant. In fact, our data indicate that substrate should be viewed as an experimental factor as important to control for as more well-known confounders such as temperature or food, thus challenging the current paradigm. Assuming substrate type has no effect on the experiment could potentially lead to errors in contaminant toxicity assessments. We propose that ideal good practise would be that all experimental factors should be evaluated for their potential influence on metabolomic profiles prior to contaminant response experiments being undertaken.

Transcriptomic and metabolomic integration to assess the response of gilthead sea bream (Sparus aurata) exposed to the most used insect repellent: DEET

DEET is one of the most frequently detected insect repellents in the environment reaching concentrations of several μg L^-1 in surface water. There is scarce information available regarding its mode of action in non-target organisms. Here, we have used an integrated metabolomic and transcriptomic approach to elucidate the possible adverse effects of DEET exposure in the marine fish gilthead sea bream (Sparus aurata). Individuals were exposed at an environmentally relevant concentration of DEET (10 μg L^-1) for 22 days in a continuous flow-through system. Transcriptomic analysis revealed 250 differentially expressed genes in liver, while metabolomic analysis identified 190 differentially modulated features in liver and 98 in plasma. Multi-omic data integration and visualization allowed elucidation of the modes of action of DEET exposure, including: energy depletion through the disruption of carbohydrate and amino acids metabolisms, oxidative stress leading to DNA damage, lipid peroxidation, and damage to cell membrane and apoptosis. Activation of xenobiotic pathway as well as the inmune-inflammatory reaction was evidenced in the present work.

Recent advances in assessment methods and mechanism of microbe-mediated chlorpyrifos remediation

Chlorpyrifos (CP) is one of the Organophosphorus pesticides (OPs) primarily used in agriculture to safeguard crops from pests and diseases. The pervasive use of chlorpyrifos is hazardous to humans and the environment as it inhibits the receptor for acetylcholinesterase activity, leading to abnormalities linked to the central nervous system. Hence, there is an ardent need to develop an effective and sustainable approach to the on-site degradation of chlorpyrifos. The role of microbes in the remediation of pesticides is considered the most effective and eco-friendly approach, as they have strong degradative potential due to their gene and enzymes naturally adapted to these sites. Several reports have previously been published on exploring the role of microbes in the degradation of CP. However, detection of CP as an environmental contaminant is an essential prerequisite for developing an efficient microbial-mediated biodegradation method with less harmful intermediates. Most of the articles published to date discuss the fate and impact of CP in the environment along with its degradation mechanism but still fail to discuss the analytical portion. This review is focused on the latest developments in the field of bioremediation of CP along with its physicochemical properties, toxicity, fate, and conventional (UV-Visible spectrophotometer, FTIR, NMR, GC-MS, etc) and advanced detection methods (Biosensors and immunochromatography-based methods) from different environmental samples. Apart from it, this review explores the role of metagenomics, system biology, in-silico tools, and genetic engineering in facilitating the bioremediation of CP. One of the objectives of this review is to educate policymakers with scientific data that will enable the development of appropriate strategies to reduce pesticide exposure and the harmful health impacts on both Human and other environmental components. Moreover, this review provides up-to-date developments related to the sustainable remediation of CP.

Metformin Contamination in Global Waters: Biotic and Abiotic Transformation, Byproduct Generation and Toxicity, and Evaluation as a Pharmaceutical Indicator

Metformin is the first-line antidiabetic drug and one of the most prescribed medications worldwide. Because of its ubiquitous occurrence in global waters and demonstrated ecotoxicity, metformin, as with other pharmaceuticals, has become a concerning emerging contaminant. Metformin is subject to transformation, producing numerous problematic transformation byproducts (TPs). The occurrence, removal, and toxicity of metformin have been continually reviewed; yet, a comprehensive analysis of its transformation pathways, byproduct generation, and the associated change in adverse effects is lacking. In this review, we provide a critical overview of the transformation fate of metformin during water treatments and natural processes and compile the 32 organic TPs generated from biotic and abiotic pathways. These TPs occur in aquatic systems worldwide along with metformin. Enhanced toxicity of several TPs compared to metformin has been demonstrated through organism tests and necessitates the development of complete mineralization techniques for metformin and more attention on TP monitoring. We also assess the potential of metformin to indicate overall contamination of pharmaceuticals in aquatic environments, and compared to the previously acknowledged ones, metformin is found to be a more robust or comparable indicator of such overall pharmaceutical contamination. In addition, we provide insightful avenues for future research on metformin.

Comparison of sub-lethal metabolic perturbations of select legacy and novel perfluorinated alkyl substances (PFAS) in Daphnia magna

Per- and polyfluoroalkyl substances (PFAS) are a class of pollutants of concern due to their ubiquitous presence, persistence, and toxicity in aquatic environments. Legacy PFAS pollutants such as perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) have been more widely studied in aquatic environments. However, replacement PFAS, such as ammonium perfluoro (2-methyl-3-oxahexanoate; GenX) are increasingly being detected with little known information surrounding their toxicity. Here, Daphnia magna, a model organism for freshwater ecotoxicology was used to compare the acute sub-lethal toxicity of PFOS, PFOA, GenX, and PFAS mixtures. Using liquid chromatography with tandem mass spectrometry (LC-MS/MS), the targeted polar metabolic profile extracted from single Daphnia was quantified to investigate perturbations in the exposure groups versus the unexposed organisms. Multivariate statistical analyses demonstrated significant non-monotonic separation in PFOA, GenX, and PFAS mixture exposures. Sub-lethal exposure to concentrations of PFOS did not lead to significant separation in multivariate analyses. Univariate statistics and pathway analyses were used to elucidate the mode of action of PFAS exposure. Exposure to all individual PFAS led to significant perturbations in many amino acids including cysteine, histidine, tryptophan, glycine, and serine. These perturbations are consistent with biochemical pathway disruptions in the pantothenate and Coenzyme A (CoA) biosynthesis, thiamine metabolism, histidine metabolism, and aminoacyl-tRNA biosynthesis pathways. Overall, the collected metabolomic data is consistent with disruptions in energy metabolism and protein synthesis as the primary mode of action of sub-lethal PFAS exposure. Secondary modes of action among individual pollutant exposures demonstrated that the structural properties (carboxylic acid vs. sulfonic acid group) may play a role in the metabolic perturbations observed. Sub-lethal exposure to PFAS mixtures highlighted a mixed response when compared to the individual pollutants (PFOS, PFOA, and GenX). Overall, this study emphasizes the niche capability of environmental metabolomics to differentiate secondary modes of action from metabolic perturbations in both single pollutant and pollutant mixtures within the same chemical class.

A review of spatiotemporal patterns of neonicotinoid insecticides in water, sediment, and soil across China

Neonicotinoid insecticides (NNIs) have been widely used to control insect pests, while their environmental residues and associated hazardous impacts on human and ecosystem health have attracted increasing attention worldwide. In this study, we examined the current levels and associated spatial and temporal patterns of NNIs in multiple environmental media across China. Concentrations of NNIs in surface water, sediment, and soil were in the range of 9.94-755 ng·L^-1, 0.07-8.30 ng·g^-1 DW, and 0.009-356 ng·g^-1 DW, respectively. The high levels of NNIs in surface water, such as in Yangtze River (755 ng·L^-1), North River (539 ng·L^-1), Nandu River (519 ng·L^-1), and Minjiang River (514 ng·L^-1), were dominated by imidacloprid, thiamethoxam, and acetamiprid due to their extensive use. The levels of NNIs in sediments were relatively low, and the highest concentration (8.30 ng·g^-1 DW) was observed in Dongguan ditch. Sediment-water exchange calculated from fugacity fraction indicated that NNIs in sediment can be released back into the water due to their high solubility and low K_OW. Soils from agricultural zones contained the largest residual NNIs, with imidacloprid concentrations in cultivated soil reaching 119 ng·g^-1 DW. The calculated leaching potential showed that clothianidin has the highest migration potential to deep soil or groundwater. The monitored data of NNIs presented a decreasing trend from 2016 to 2018, which might be caused by the implementation of relevant control policies for NNI applications. The high levels of NNIs mainly occurred in southern China due to frequent agricultural activities and warm and humid meteorological conditions. The results from this study improve our understanding of the pollution levels and environmental behavior of NNIs in different environmental media across China and provide new knowledge that is needed for making future control policies for NNIs production and application.

Gut microbiota dysbiosis involves in host non-alcoholic fatty liver disease upon pyrethroid pesticide exposure

A growing body of evidence has demonstrated the significance of the gut microbiota in host health, while the association between gut microbiota dysbiosis and multiple diseases is yet elusive in the scenario of exposure to widely used pesticides. Here, we show that gut microbiota dysbiosis involves in host's abnormal lipid metabolism and consequently the non-alcoholic fatty liver disease in Xenopus laevis upon exposure to cis-bifenthrin, one of the most prevalent pyrethroid insecticides in the world. With the guidance of gut microbiota analysis, we found that cis-bifenthrin exposure significantly perturbed the gut microbial community, and the specific taxa that served as biomarkers were identified. Metabolomics profiling and association analysis further showed that a significant change of intestinal metabolites involved in lipid metabolic pathways were induced along with the microbiota dysbiosis upon exposure to cis-bifenthrin. Detailed investigation showed an altered functional regulation of lipids in the liver after cis-bifenthrin exposure and the accumulation of lipid droplets in hepatocytes. Specifically, a change in deoxycholic acid alters bile acid hepatoenteral circulation, which affects lipid metabolism in the liver and ultimately causes the development of fatty liver disease. Collectively, these findings provide novel insight into the gut microbiota dysbiosis upon pesticide exposure and their potential implication in the development of chronic host diseases related to liver metabolic syndrome.

The assessment of environmental risk related to the occurrence of pharmaceuticals in bottom sediments of the Odra River estuary (SW Baltic Sea)

The occurrence of 130 pharmaceutically active compounds (PhACs) in sediments collected from 70 sampling sites in the Odra River estuary (SW Baltic Sea) was investigated. The highest concentration levels of the compounds were found in the vicinity of effluent discharge from two main Szczecin wastewater treatment plants: "Pomorzany" and "Zdroje", and nearby the seaport and shipyard. The highest environmental risks (RQ > 1) were observed for pseudoephedrine (RQ = 14.0), clindamycin (RQ = 7.3), nalidixic acid (RQ = 3.8), carbamazepine (RQ = 1.8), fexofenadine (RQ = 1.4), propranolol (RQ = 1.1), and thiabendazole (RQ = 1.1). RQ for each compound varied depending on the sampling sites. High environmental risk was observed in 30 sampling sites for clindamycin, 22 sampling sites for pseudoephedrine, 19 sampling sites for nalidixic acid, 4 sampling sites for carbamazepine, and 3 sampling sites for fexofenadine. The medium environmental risk (0.1 < RQ < 1) was observed for 16 compounds: amisulpride, amitriptyline, amlodipine, atropine, bisoprolol, chlorpromazine, lincomycin, metoprolol, mirtazapine, moclobemide, ofloxacin, oxazepam, tiapride, tolperisone, verapamil, and xylometazoline. Due to the scarcity of toxicological data related to benthic organisms, only an approximate assessment of the environmental risk of PhACs is possible. Nevertheless, the compounds with medium and high risk should be considered as pollutants of high environmental concern whose occurrence in the environment should remain under close scrutiny.

Exploring the Applications of Carbon-Detected NMR in Living and Dead Organisms Using a 13C-Optimized Comprehensive Multiphase NMR Probe

Comprehensive multiphase-nuclear magnetic resonance (CMP-NMR) is a non-invasive approach designed to observe all phases (solutions, gels, and solids) in intact samples using a single NMR probe. Studies of dead and living organisms are important to understand processes ranging from biological growth to environmental stress. Historically, such studies have utilized ¹H-based phase editing for the detection of soluble/swollen components and ¹H-detected 2D NMR for metabolite assignments/screening. However, living organisms require slow spinning rates (∼500 Hz) to increase survivability, but at such low speeds, complications from water sidebands and spectral overlap from the modest chemical shift window (∼0-10 ppm) make ¹H NMR challenging. Here, a novel ¹³C-optimized E-Free magic angle spinning CMP probe is applied to study all phases in ex vivo and in vivo samples. This probe consists of a two-coil design, with an inner single-tuned ¹³C coil providing a 113% increase in ¹³C sensitivity relative to a traditional multichannel single-CMP coil design. For organisms with a large biomass (∼0.1 g) like the Ganges River sprat (ex vivo), ¹³C-detected full spectral editing and ¹³C-detected heteronuclear correlation (HETCOR) can be performed at natural abundance. Unfortunately, for a single living shrimp (∼2 mg), ¹³C enrichment was still required, but ¹³C-detected HETCOR shows superior data relative to heteronuclear single-quantum coherence at low spinning speeds (due to complications from water sidebands in the latter). The probe is equipped with automatic-tuning-matching and is compatible with automated gradient shimming─a key step toward conducting multiphase screening of dead and living organisms under automation in the near future.

Effects of Light and Temperature on the Metabolic Profiling of Two Habitat-Dependent Bloom-Forming Cyanobacteria

Rapid proliferation of cyanobacteria in both benthic and suspended (planktonic) habitats is a major threat to environmental safety, as they produce nuisance compounds such as cytotoxins and off-flavors, which degrade the safety and quality of water supplies. Temperature and light irradiance are two of the key factors in regulating the occurrence of algal blooms and production of major off-flavors. However, the role of these factors in regulating the growth and metabolism is poorly explored for both benthic and planktonic cyanobacteria. To fill this gap, we studied the effects of light and temperature on the growth and metabolic profiling of both benthic (Hapalosiphon sp. MRB220) and planktonic (Planktothricoides sp. SR001) environmental species collected from a freshwater reservoir in Singapore. Moreover, this study is the first report on the metabolic profiling of cyanobacteria belonging to two different habitats in response to altered environmental conditions. The highest growth rate of both species was observed at the highest light intensity (100 μmol photons/m²/s) and at a temperature of 33 °C. Systematic metabolite profiling analysis suggested that temperature had a more profound effect on metabolome of the Hapalosiphon, whereas light had a greater effect in the case of Planktothricoides. Interestingly, Planktothricoides sp. SR001 showed a specialized adaptation mechanism via biosynthesis of arginine, and metabolism of cysteine and methionine to survive and withstand higher temperatures of 38 °C and higher. Hence, the mode of strategies for coping with different light and temperature conditions was correlated with the growth and alteration in metabolic activities for physiological and ecological adaptations in both species. In addition, we putatively identified a number of unique metabolites with a broad range of antimicrobial activities in both species in response to both light and temperature. These metabolites could play a role in the dominant behavior of these species in suppressing competition during bloom formation. Overall, this study elucidated novel insights into the effects of environmental factors on the growth, metabolism, and adaptation strategies of cyanobacteria from two different habitats, and could be useful in controlling their harmful effects on human health and environmental concerns.

Soil microbiomes divergently respond to heavy metals and polycyclic aromatic hydrocarbons in contaminated industrial sites

Contaminated sites from electronic waste (e-waste) dismantling and coking plants feature high concentrations of heavy metals (HMs) and/or polycyclic aromatic hydrocarbons (PAHs) in soil. Mixed contamination (HMs + PAHs) hinders land reclamation and affects the microbial diversity and function of soil microbiomes. In this study, we analyzed HM and PAH contamination from an e-waste dismantling plant and a coking plant and evaluated the influences of HM and PAH contamination on soil microbiomes. It was noticed that HMs and PAHs were found in all sites, although the major contaminants of the e-waste dismantling plant site were HMs (such as Cu at 5,947.58 ± 433.44 mg kg^-1, Zn at 4,961.38 ± 436.51 mg kg^-1, and Mn at 2,379.07 ± 227.46 mg kg^-1), and the major contaminants of the coking plant site were PAHs (such as fluorene at 11,740.06 ± 620.1 mg kg^-1, acenaphthylene at 211.69 ± 7.04 mg kg^-1, and pyrene at 183.14 ± 18.89 mg kg^-1). The microbiomes (diversity and abundance) of all sites were determined via high-throughput sequencing of 16S rRNA genes, and redundancy analysis was conducted to investigate the relations between soil microbiomes and contaminants. The results showed that the microbiomes of the contaminated sites divergently responded to HMs and PAHs. The abundances of the bacterial genera Sulfuritalea, Pseudomonas, and Sphingobium were positively related to PAHs, while the abundances of the bacterial genera Bryobacter, Nitrospira, and Steroidobacter were positively related to HMs. This study promotes an understanding of how soil microbiomes respond to single and mixed contamination with HMs and PAHs.

Insights into the microalgae-bacteria consortia treating swine wastewater: Symbiotic mechanism and resistance genes analysis

This study investigated the effects of microalgae-bacteria consortia (MBC) (Chlorella pyrenoidosa-activated sludge (AS)) treating swine wastewater with low C/N ratios. After co-culture, the removal rates of NH₄⁺-N and PO₄^3--P increased by 53.84% and 43.52%. Furthermore, the sulfamethoxazole (SMX) degradation rates in MBC were slightly higher than in the activated sludge process. Interestingly, the absolute abundance of antibiotic resistance genes (ARGs) in effluent from MBC is relatively less than in the AS process. C. pyrenoidosa has a negative zeta potential that allows bacteria to adhere to its surface. The concentrations of carbohydrates and proteins in extracellular polymeric substance (EPS) of MBC dramatically increased compared with the AS process. At the phylum level, Proteobacteria, Bacteroidota, and Cyanobacteria were the main bacteria, while Ascomycota and Basidiomycota were the primary fungi in MBC. Overall, those findings lead to a better understanding of the swine wastewater containing antibiotic treatment by MBC.

Environmental Metabolomics Promises and Achievements in the Field of Aquatic Ecotoxicology: Viewed through the Pharmaceutical Lens

Scientists often set ambitious targets using environmental metabolomics to address challenging ecotoxicological issues. This promising approach has a high potential to elucidate the mechanisms of action (MeOAs) of contaminants (in hazard assessments) and to develop biomarkers (in environmental biomonitoring). However, metabolomics fingerprints often involve a complex mixture of molecular effects that are hard to link to a specific MeOA (if detected in the analytical conditions used). Given these promises and limitations, here we propose an updated review on the achievements of this approach. Metabolomics-based studies conducted on the effects of pharmaceutical active compounds in aquatic organisms provide a relevant means to review the achievements of this approach, as prior knowledge about the MeOA of these molecules could help overcome some shortcomings. This review highlighted that current metabolomics advances have enabled more accurate MeOA assessment, especially when combined with other omics approaches. The combination of metabolomics with other measured biological endpoints has also turned out to be an efficient way to link molecular effects to (sub)-individual adverse outcomes, thereby paving the way to the construction of adverse outcome pathways (AOPs). Here, we also discuss the importance of determining MeOA as a key strategy in the identification of MeOA-specific biomarkers for biomonitoring. We have put forward some recommendations to take full advantage of environmental metabolomics and thus help fulfil these promises.

Pharmaceuticals and personal care products in aquatic environments and their removal by algae-based systems

The consumption of pharmaceuticals and personal care products (PPCPs) has been widely increasing, yet up to 90-95% of PPCPs consumed by human are excreted unmetabolized. Moreover, the most of PPCPs cannot be fully removed by wastewater treatment plants (WWTPs), which release PPCPs to natural water bodies, affecting aquatic ecosystems and potentially humans. This study sought to review the occurrence of PPCPs in natural water bodies globally, and assess the effects of important factors on the fluxes of pollutants into receiving waterways. The highest ibuprofen concentration (3738 ng/L) in tap water was reported in Nigeria, and the highest naproxen concentration (37,700 ng/L) was reported in groundwater wells in Penn State, USA. Moreover, the PPCPs have affected aquatic organisms such as fish. For instance, up to 24.4 × 10³ ng/g of atenolol was detected in P. lineatus. Amongst different technologies to eliminate PPCPs, algae-based systems are environmentally friendly and effective because of the photosynthetic ability of algae to absorb CO₂ and their flexibility to grow in different wastewater. Up to 99% of triclosan and less than 10% of trimethoprim were removed by Nannochloris sp., green algae. Moreover, variable concentrations of PPCPs might adversely affect the growth and production of algae. The exposure of algae to high concentrations of PPCPs can reduce the content of chlorophyll and protein due to producing reactive oxygen species (ROS), and affecting expression of some genes in chlorophyll (rbcL, psbA, psaB and psbc).

Energy information flow-based ecological risk transmission among communities within the heavy metals contaminated soil system

An energy information flow-based ecological risk assessment framework (EIF-ERA) is developed for identifying ecological risk transmission rules among communities (i.e., vegetation E1, herbivorous animals E2, soil microorganisms E3, and carnivorous animals E4) within the heavy metals contaminated soil system. This framework is integrated with numerous techniques of carcinogenic risk evaluation, ecological risk assessment (ERA), and Monte Carlo simulation. Stepwise quadratic response surface analysis (SQRSA) is employed for reflecting the relation between contaminants' concentration and comprehensive risk. Two scenarios with respect to the environmental quality standards (scenarios 1) and carcinogenic risk reversion (scenarios 2) are merged into the EIF-ERA. A real-world mining area in Xinglong County in Chengde is selected to verify the developed framework's effectiveness. Results reveal that E3 is considered as the most sensitive community when contaminant interference occurs, and its 62.3% and 37.7% of comprehensive risk are contributed by initial and direct risks, respectively. Other communities can receive direct risk through control allocation (CA). Monte Carlo anlysis shows that there are 7.68% and 20.25% increase in the initial risk of Cd and Pb when their quantile statistics increase from 70% to 90%. Determination of an appropriate screening value is vital for contaminated mining soil remediation due to its inefficiency of remediation funds, especially when considering the trict standards of contaminants' concentration within scenarios 1. The surrogates obtained from the SQRSA display the relation of contaminant concentration and comprehensive risks with the adjusted R² greater than 0.77. These findings can be in support of system design, risk assessment, and site remediation.

Algae-mediated antibiotic wastewater treatment: A critical review

The existence of continually increasing concentrations of antibiotics in the environment is a serious potential hazard due to their toxicity and persistence. Unfortunately, conventional treatment techniques, such as those utilized in wastewater treatment plants, are not efficient for the treatment of wastewater containing antibiotic. Recently, algae-based technologies have been found to be a sustainable and promising technique for antibiotic removal. Therefore, this review aims to provide a critical summary of algae-based technologies and their important role in antibiotic wastewater treatment. Algal removal mechanisms including bioadsorption, bioaccumulation, and biodegradation are discussed in detail, with using algae-bacteria consortia for antibiotic treatment, integration of algae with other microorganisms (fungi and multiple algal species), hybrid algae-based treatment and constructed wetlands, and the factors affecting algal antibiotic degradation comprehensively described and assessed. In addition, the use of algae as a precursor for the production of biochar is highlighted, along with the modification of biochar with other materials to improve its antibiotic removal capacity and hybrid algae-based treatment with advanced oxidation processes. Furthermore, recent novel approaches for enhancing antibiotic removal, such as the use of genetic engineering to enhance the antibiotic degradation capacity of algae and the integration of algal antibiotic removal with bioelectrochemical systems are discussed. Finally, some based on the critical review, key future research perspectives are proposed. Overall, this review systematically presents the current progress in algae-mediated antibiotic removal technologies, providing some novel insights for improved alleviation of antibiotic pollution in aquatic environments.

Perturbation of clopyralid on bio-denitrification and nitrite accumulation: Long-term performance and biological mechanism

The contaminant of herbicide clopyralid (3,6-dichloro-2- pyridine-carboxylic acid, CLP) poses a potential threat to the ecological system. However, there is a general lack of research devoted to the perturbation of CLP to the bio-denitrification process, and its biological response mechanism remains unclear. Herein, long-term exposure to CLP was systematically investigated to explore its influences on denitrification performance and dynamic microbial responses. Results showed that low-concentration of CLP (<15 mg/L) caused severe nitrite accumulation initially, while higher concentrations (35-60 mg/L) of CLP had no further effect after long-term acclimation. The mechanistic study demonstrated that CLP reduced nitrite reductase (NIR) activity and inhibited metabolic activity (carbon metabolism and nitrogen metabolism) by causing oxidative stress and membrane damage, resulting in nitrite accumulation. However, after more than 80 days of acclimation, almost no nitrite accumulation was found at 60 mg/L CLP. It was proposed that the secretion of extracellular polymeric substances (EPS) increased from 75.03 mg/g VSS at 15 mg/L CLP to 109.97 mg/g VSS at 60 mg/L CLP, which strengthened the protection of microbial cells and improved NIR activity and metabolic activities. Additionally, the biodiversity and richness of the microbial community experienced a U-shaped process. The relative abundance of denitrification- and carbon metabolism-associated microorganisms decreased initially and then recovered with the enrichment of microorganisms related to the secretion of EPS and N-acyl-homoserine lactones (AHLs). These microorganisms protected microbe from toxic substances and regulated their interactions among inter- and intra-species. This study revealed the biological response mechanism of denitrification after successive exposure to CLP and provided proper guidance for analyzing and treating herbicide-containing wastewater.

Carbamazepine degradation by visible-light-driven photocatalyst Ag3PO4/GO: Mechanism and pathway

Carbamazepine (CBZ), as one of the most frequently detected pharmaceuticals, is of great concern due to its potential impact on the ecosystem and human health. This study provides an effective approach to remove CBZ by using photocatalyst silver phosphate combined with graphene oxide (Ag₃PO₄/GO) under visible irradiation. The morphology, composition, and optical properties of Ag₃PO₄/GO were characterized employing SEM, XRD, and DRS. Graphene oxide could improve the visible-light utilization and promote electron's charge to enhance the photocatalytic performance of Ag₃PO₄/GO. With the optimal reaction condition of 5.86 mW/cm² light intensity, 15-25 °C temperature, 5-7 pH, and 0.5 mg/L catalytic dosages, 5 mg/L CBZ could be completely degraded in 30 min, and the apparent rate constant could reach 0.12 min^-1. Additionally, the radical trapping experiments indicated •OH and O₂-• were the main reactive oxygen species employed to eliminate CBZ. The decay pathways of CBZ had been proposed accordingly, and the main product was the low-molecular products.

Prediction of adverse effects of effluents containing phenolic compounds in the Ba River on the ovary of fish (Hemiculter leucisculus) using transcriptomic and metabolomic analyses

The aim of this work was to evaluate the endocrine disrupting effects on the ovarian development of sharpbelly (Hemiculter leucisculus) caused by effluents containing phenolic compounds. This was achieved using integrated transcriptomic and metabolomic analyses, along with histopathological examinations. Sharpbelly, an indigenous freshwater fish widely distributed in East Asia, were collected by pole fishing from three sampling sites in the Ba River. These sampling sites include a mid-stream site near a wastewater outfall and a reference site located upstream and a far field comparison site located downstream. In sharpbelly collected near the wastewater discharge, the oocyte development was activated, compared to the other two sites. Histopathological alterations in the fish ovaries were likely due to the upregulated steroid hormone biosynthesis process, as suggested by the differentially expressed genes (e.g., hsd3b, hsd17b1) and differentially accumulated metabolites (e.g., pregnenolone). Additionally, under the stress of effluents containing phenolic compounds, genes related to the signaling pathways for oxidative phosphorylation and leukocyte transendothelial migration were dysregulated, suggesting the potential induction of inflammation and several ovarian diseases. Overall, these findings suggest that effluents containing phenolic compounds influence ovary development and reproductive function of female sharpbelly. Whether there is any resulting dysfunction of folliculogenesis, abnormality of ovulation, production of premature eggs and/or potential induction of ovarian cancers remains to be determined by further studies, for a better evaluation on effluents containing phenolic compounds to the fish fertility and the health of their offspring, and even the stability of the wild fish population. Notably, the integration of transcriptomics and metabolomics can complement the routine chemical analysis to comprehensively monitor the effects of wastewater treatment plant effluents on the health of wild fish.

The roles of cadmium on growth of seedlings by analysing the composition of metabolites in pumpkin tissues

Changes in the types and contents of metabolites in plants can occur in response to environmental stress. In this study, pumpkin seeds were cultivated in a cadmium ion solution (cadmium sulfate) for 7 days, and growth parameters, antioxidant enzyme activities, and metabolites in the root, stem, and leaf were analyzed. The results showed that cadmium accumulation characteristics were in the order of root > stem > leaf. Cadmium restrained root growth and promoted superoxide dismutase, peroxidase, catalase activities in the root, but inhibited their activities in the leaf. Cadmium did not change the total biomass of pumpkin seedlings. Orthogonal partial least squares (OPLS) analyses were conducted to detect the relationships between fresh weight and metabolites. These analyses revealed that maltose had significantly positive relationships with the fresh weight of the root, stem, and leaf. Cadmium influenced glyoxylate and dicarboxylate metabolism, aminoacyl-tRNA biosynthesis, sulfur metabolism, butanoate metabolism, alanine, aspartate and glutamate metabolism, glutathione metabolism, glycine, serine and threonine metabolism in the root; glycolysis/gluconeogenesis in the stem; and biosynthesis of unsaturated fatty acids, galactose metabolism, cutin, suberine and wax biosynthesis in the leaf. It is important that cadmium inhibited root growth by inhibiting carbohydrate transport from the leaf to the root and promoted leaf growth by the accumulation of carbohydrates in the leaf. Furthermore, cadmium also restrained amino acid metabolism in the root of pumpkin seedlings. These results provide new information about how pumpkin seedlings respond to cadmium stress.

Targeted Metabolomics to Assess Exposure to Environmental Chemicals of Concern in Japanese Quail at Two Life Stages

This proof-of-concept study characterizes the Japanese quail (Coturnix japonica) hepatic metabolome following exposure to benzo[a]pyrene, chlorpyrifos, ethinylestradiol, fluoxetine hydrochloride, hexabromocyclododecane, lead(II)nitrate, seleno-L-methionine, and trenbolone in embryos and adults. The analysis revealed effects on lipid metabolism following exposure to several chemicals at both life stages. The most pronounced effects were observed in embryos exposed to 41.1 μg/g chlorpyrifos. This work highlighted challenges and the need for further avian metabolomics studies.

Nanobiotechnological advancements in agriculture and food industry: Applications, nanotoxicity, and future perspectives

The high demand for sufficient and safe food, and continuous damage of environment by conventional agriculture are major challenges facing the globe. The necessity of smart alternatives and more sustainable practices in food production is crucial to confront the steady increase in human population and careless depletion of global resources. Nanotechnology implementation in agriculture offers smart delivery systems of nutrients, pesticides, and genetic materials for enhanced soil fertility and protection, along with improved traits for better stress tolerance. Additionally, nano-based sensors are the ideal approach towards precision farming for monitoring all factors that impact on agricultural productivity. Furthermore, nanotechnology can play a significant role in post-harvest food processing and packaging to reduce food contamination and wastage. In this review, nanotechnology applications in the agriculture and food sector are reviewed. Implementations of nanotechnology in agriculture have included nano- remediation of wastewater for land irrigation, nanofertilizers, nanopesticides, and nanosensors, while the beneficial effects of nanomaterials (NMs) in promoting genetic traits, germination, and stress tolerance of plants are discussed. Furthermore, the article highlights the efficiency of nanoparticles (NPs) and nanozymes in food processing and packaging. To this end, the potential risks and impacts of NMs on soil, plants, and human tissues and organs are emphasized in order to unravel the complex bio-nano interactions. Finally, the strengths, weaknesses, opportunities, and threats of nanotechnology are evaluated and discussed to provide a broad and clear view of the nanotechnology potentials, as well as future directions for nano-based agri-food applications towards sustainability.

Lead (Pb) sorption to hydrophobic and hydrophilic zeolites in the presence and absence of MTBE

The co-contamination of the environment by metals and organic pollutants is a significant concern, and one such example is lead (Pb) and methyl tert-butyl ether (MTBE) due to their historic use as fuel additives. Clinoptilolite is an abundant and efficient zeolite for metal removal, but the potential interference of co-existing organic pollutants on metal removal, such as MTBE, have rarely been discussed. In this study, a combination of batch sorption tests and synchrotron-based X-ray absorption spectroscopic analyses were employed to investigate Pb sorption mechanism(s) onto clinoptilolite in the presence and absence of MTBE. A comparison was made to synthetic ZSM-5 zeolite to gain insights into differences in Pb binding mechanisms between hydrophilic (clinoptilolite) and hydrophobic (ZSM-5) zeolites. Site occupancy and surface precipitation contributed equally to Pb removal by clinoptilolite, while surface precipitation was the main Pb removal mechanism for ZSM-5 followed by site occupancy. Despite the negligible effect of 100 mg/L MTBE on observed Pb removal from solution by both zeolites, a surface-embedded Pb removal mechanism, through the Mg site on clinoptilolite surface, arises when MTBE is present. This study provides an understanding of atomic-level Pb uptake mechanisms on zeolites, with and without co-contaminating MTBE, which aids in their application in water treatment at co-contaminated sites.

Occurrence, variations, and risk assessment of neonicotinoid insecticides in Harbin section of the Songhua River, northeast China

Neonicotinoid insecticides (NNIs) have been intensively used and exploited, resulting in their presence and accumulation in multiple environmental media. We herein investigated the current levels of eight major NNIs in the Harbin section of the Songhua River in northeast China, providing the first systematic report on NNIs in this region. At least four NNIs in water and three in sediment were detected, with total concentrations ranging from 30.8 to 135 ng L^-1 and from 0.61 to 14.7 ng g^-1 dw, respectively. Larger spatial variations in surface water NNIs concentrations were observed in tributary than mainstream (p < 0.05) due to the intensive human activities (e.g., horticulture, urban landscaping, and household pet flea control) and the discharge of wastewater from many treatment plants. There was a significant positive correlation (p < 0.05) between the concentrations of residual imidacloprid (IMI), clothianidin (CLO), and Σ₄NNIs in the sediment and total organic carbon (TOC). Due to its high solubility and low octanol-water partition coefficient (K _ow), the sediment-water exchange behavior shows that NNIs in sediments can re-enter into the water body. Human exposure risk was assessed using the relative potency factor (RPF), which showed that infants have the highest exposure risk (estimated daily intake (ΣIMI_eq EDI): 31.9 ng kg^-1 bw·d^-1). The concentration thresholds of NNIs for aquatic organisms in the Harbin section of the Songhua River were determined using the species sensitivity distribution (SSD) approach, resulting in a value of 355 ng L^-1 for acute hazardous concentration for 5% of species (HC₅) and 165 ng L^-1 for chronic HC₅. Aquatic organisms at low trophic levels were more vulnerable to potential harm from NNIs.

Tire pyrolysis wastewater treatment by a combined process of coagulation detoxification and biodegradation

Recycling waste tires through pyrolysis technology generates refractory wastewater, which is harmful to the environment if not disposed properly. In this study, a combined process of coagulation detoxification and biodegradation was used to treat tire pyrolysis wastewater. Organics removal characteristics at the molecular level were investigated using electrospray ionization (ESI) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The results showed that nearly 90% of the organic matter from the wastewater was removed through the process. Preference of the two coagulants for different classes of organics in tire pyrolysis wastewater was observed. The covalently bound inorganic-organic hybrid coagulant (CBHyC) used in this work had a complementary relationship with biodegradation for the organics removal: this coagulant reduced toxicity and enhanced the biodegradation by preferentially removing refractory substances such as lignin with a high degree of oxidation (O/C > 0.3). This study provides molecular insight into the organics of tire pyrolysis wastewater removed by a combined treatment process, supporting the advancement and application of waste rubber recycling technology. It also contributes to the possible development of an effective treatment process for refractory wastewater.