Environmental and health impacts of contaminants of emerging concerns: Recent treatment challenges and approaches

Cross-sectional study on urinary metal concentrations in young adult residents of Emirate of Sharjah, United Arab Emirates

BACKGROUND

Human biomonitoring is crucial for regulatory toxicology, yet data on biomarker concentrations in the UAE are lacking. This study addresses this gap by analyzing urinary concentrations of 16 metals in UAE young adults, assessing correlations with personal characteristics, dietary patterns, and lifestyle habits.

METHODS

A cross-sectional pilot study was conducted among 144 randomly selected young adults (71 males and 73 females) from Sharjah, UAE, between January and March 2023. Participants provided urine samples, which were analyzed for 16 heavy metals using ICP-OES, and completed detailed questionnaires covering sociodemographic factors, lifestyle, and dietary habits. Descriptive statistics were used to summarize participant characteristics, and linear regression analysis was applied to explore associations between metal concentrations and factors such as gender, dietary habits, and exposure to environmental risks. Non-parametric tests, including the Mann-Whitney test, were used to assess differences by gender. Statistical significance was set at p < 0.05. Ethical approval was obtained, and informed consent was secured before participation.

RESULTS

Significant findings include dietary influences on metal exposure, with rice consumption linked to higher metal concentrations. Sex differences were significant, with females showing elevated levels of arsenic, lead, and cadmium. Lifestyle factors, such as smoking and incense use, were correlated with increased barium and boron levels.

CONCLUSION

This study highlights the significant role of dietary habits, especially the consumption of rice, in metal exposure among young adults in Sharjah. The findings highlight the urgent need for comprehensive human biomonitoring to understand environmental exposures and reform public health policies. The gender-specific differences in metal distribution suggest the necessity for targeted public health strategies. The study, however, is limited by its cross-sectional nature and the focus on a specific geographic area, warranting further research for broader generalizability. Future investigations, particularly on the impact of incense exposure on metal levels, are essential for developing comprehensive health interventions and preventive strategies in the UAE.

Wastewater treatment by algae-based membrane bioreactors: a review of the arrangement of a membrane reactor, physico-chemical properties, advantages and challenges

Reducing wastewater contaminants is an emerging area of particular concern for many industrialized and developing countries in improving the ecological quality of their water sources. In this case, the use of algae-based microbial reactors for wastewater treatment has attracted increasing attention in recent years. The advantages of both conventional microbial membrane bioreactors (MBRs) and algae-based treatment are combined in algae-based MBRs. According to the literature, previous studies did not fully discuss the techniques and performance of algae-based bioreactor systems in the treatment of wastewater. In particular, little attention has been paid to the types of waste, their consequences, and the ways in which they are treated. This makes it more difficult to develop and scale up efficient systems to treat waste discharge from industry, agriculture, and urban areas. Thus, the objective of this study is to critically evaluate algae as a valuable biological resource for wastewater treatment, with the goal of reducing emerging contaminants and increasing the chemical oxygen demand (COD) in wastewater. The most common wastewater treatment techniques employed for addressing these wastes are examined together with a brief discussion on contaminants in wastewater. Furthermore, algae-based wastewater treatment arrangements, particularly hybrid configurations, are carefully studied in relation to techniques for removing contaminants using algae. After analysing the key physicochemical characteristics that affect the ability of algal-bioremediation to remove developing contaminants, the benefits of algal-bioremediation systems are compared to those of other techniques. Lastly, an investigation is conducted into the technological difficulties associated with employing algal-bioremediation systems to eliminate emerging contaminants.

Occurrence of contaminants of emerging concern in different water samples from the lower part of the Danube River Middle Basin - A review

This study intends to assess the extent of the occurrence of CECs in different water types based on the literature data reported for the countries from a lower part of the Middle Danube Basin, including those belonging to the Western Balkan (WB) region and two upstream neighboring EU Member States, Croatia and Slovenia. These countries share main freshwater courses important for drinking water supply, agriculture, industry, navigation, tourism, etc, but in some of them there are low rate of wastewater treatment, impacting the chemical status of water resources in the region and probably beyond, if downstream countries are considered. The literature survey revealed 38 investigative studies reporting data on CECs in water matrices sampled in the region in the period 2008-2022. Surface water was the most frequently studied water type in WB countries, while wastewater was the dominant water type studied in Slovenia and Croatia. The most often analyzed compounds in the studies dealing with surface water and wastewater were the anti-epileptic drug carbamazepine, some non-steroidal anti-inflammatory drugs, and antibiotics; pharmaceutically active compounds were also the most analyzed CECs in groundwater and drinking water. Additionally, similarities/dissimilarities among the experimental approaches in these studies were discussed in relation to the state-of-the-art research directions for the CECs surveillance in the European Union, resulting in summarized strengths and gaps in capacities for the wide-range surveillance of CECs in the lower part of the Middle Danube Basin. This is the first integral overview of the studies on CECs in waters from the countries belonging to this part of the Danube Basin, representing a valuable baseline for further enhancement of the relevant monitoring efforts and chemical status of the regional water resources, especially in countries with poor wastewater management.

Ecotoxicological effects of paracetamol on the biochemical and molecular responses of spinach (Spinacia oleracea L.)

The widespread use of pharmaceuticals, including paracetamol, has raised concerns about their impact on the environment and non-target species. The aim of this study was to investigate the biochemical and molecular responses of Spinacia oleracea (spinach) to high paracetamol concentrations in order to understand the plant's stress responses and underlying mechanisms. Under controlled conditions, spinach plants were exposed to different paracetamol concentrations (0, 50, 100, and 200 mg/L). The study evaluated the impact of paracetamol exposure on biochemical parameters such as oxidative stress markers (H2O2, MDA), activities of antioxidant enzymes (APX, CAT, GPOD, SOD), levels of non-enzymatic components (phenolics and flavonoids), and phytohormones (ABA, SA, and IAA). Furthermore, the study assessed molecular impacts by analyzing stress-related genetic variation and alterations in the gene expression of the antioxidant enzymes. Results showed that paracetamol exposure significantly increased oxidative stress in spinach, which was evident through the elevated H2O2 and MDA levels. However, the antioxidant defense mechanisms were activated to counteract this effect, as evidenced by increased activity of antioxidant enzymes and higher phenolics and flavonoid levels. Moreover, induction in the phytohormone levels indicated a stress response in paracetamol-treated plants compared to control plants. RAPD analysis revealed polymorphism indicating the DNA damage, and the Real-time qRT-PCR method showed significant upregulation of stress-responsive genes, highlighting the severe impact of paracetamol at the molecular level. The study concludes that high paracetamol concentrations pose a significant threat to spinach growth by affecting both biochemical and molecular processes. These findings underscore the need for strict environmental management practices to mitigate the possible impact of continuous release, accumulation, and long-term exposure of pharmaceutical contaminants to the environment and implement policies to reduce pharmaceutical pollutants to preserve ecological health and biodiversity.

Advances and future directions of environmental risk research: A bibliometric review

Environmental risk is one of the world's most significant threats, projected to be the leading risk over the next decade. It has garnered global attention due to increasingly severe environmental issues, such as climate change and ecosystem degradation. Research and technology on environmental risks are gradually developing, and the scope of environmental risk study is also expanding. Here, we developed a tailored bibliometric method, incorporating co-occurrence network analysis, cluster analysis, trend factor analysis, patent primary path analysis, and patent map methods, to explore the status, hotspots, and trends of environment risk research over the past three decades. According to the bibliometric results, the publications and patents related to environmental risk have reached explosive growth since 2018. The primary topics in environmental risk research mainly involve (a) ecotoxicology risk of emerging contaminants (ECs), (b) environmental risk induced by climate change, (c) air pollution and health risk assessment, (d) soil contamination and risk prevention, and (e) environmental risk of heavy metal. Recently, the hotspots of this field have shifted into artificial intelligence (AI) based techniques and environmental risk of climate change and ECs. More research is needed to assess ecological and health risk of ECs, to formulize mitigation and adaptation strategies for climate change risks, and to develop AI-based environmental risk assessment and control technology. This study provides the first comprehensive overview of recent advances in environmental risk research, suggesting future research directions based on current understanding and limitations.

Origin, types, and contribution of emerging pollutants to environmental degradation and their remediation by physical and chemical techniques

The growing presence of emerging pollutants (EPs) in aquatic environments, as well as their harmful impacts on the biosphere and humans, has become a global concern. Recent developments and advancements in pharmaceuticals, agricultural practices, industrial activities, and human personal care substances have paved the way for drastic changes in EP concentrations and impacts on the ecosystem. As a result, it is critical to mitigate EP's harmful effects before they jeopardize the ecological equilibrium of the overall ecosystem and the sustainable existence of life on Earth. This review comprehensively documented the types, origins, and remediation strategies of EPs, and underscored the significance of this study in the current context. We briefly stated the major classification of EPs based on their organic and inorganic nature. Furthermore, this review systematically evaluates the occurrence of EPs due to the fast-changing ecological scenarios and their impact on human health. Recent studies have critically discussed the emerging physical and chemical processes for EP removal, highlighting the limitations of conventional remediation technologies. We reviewed and presented the challenges associated with EP remediation and degradation using several methods, including physical and chemical methods, with the application of recent technologies. The EP types and various methods discussed in this review help the researchers understand the nature of present-day EPs and utilize an efficient method of choice for EP removal and management in the future for sustainable life and development activities on the planet.

Nanorod inside hollow-nanosphere structured magnetoelectric nanocatalyst for remotely controlled electrocatalysis assisted environmental remediation

We introduce a highly efficient method for the catalytic breakdown of organic compounds using nanorods embedded within hollow nanospheres structured magnetoelectric nanocatalyst (MENC). MENCs were fabricated through a single-step process utilizing the ultrasonic spray pyrolysis technique. The dynamic electric dipole generation capability due to synergistic interaction between nanorods at the core and the hollow nanosphere shell creates a nanoscale magnetoelectric device capable of electrocatalysis-assisted water purification through advanced oxidation processes under remotely applied magnetic field excitation. Our study examines the electrocatalytic degradation of organic pollutants by MENCs under magnetic field excitation, achieving an unprecedented 90% removal efficiency for synthetic dyes. This remarkable efficiency is a result of surface redox reactions facilitated by electron and hole transfer, resulting in the production of Reactive oxygen species (ROS) such as O2•- and •OH. Additionally, antioxidant experiments were performed to confirm the ROS generation capability of MENCs under magnetic field excitation. Furthermore, trapping experiments performed employing specific scavengers for individual reactive species reveal the mechanism responsible for the magnetic field-driven catalytic breakdown of organic contaminants by MENCs. Interestingly, the MENCs exhibit >95% reduction in Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria, respectively, within 90 min of exposure to a (20 mT& 1.9 kHz) AC magnetic field.

A review on hazards and treatment methods of released antibiotics in hospitals wastewater during the COVID-19 pandemic

Drugs and related goods are widely used in order to promote public health and the quality of life. One of the most serious environmental challenges affecting public health is the ongoing presence of antibiotics in the effluents generated by pharmaceutical industries and hospitals. Antibiotics cannot be entirely removed from wastewater using the traditional wastewater treatment methods. Unmetabolized antibiotics generated by humans can be found in urban and livestock effluent. The antibiotic present in effluent contributes to issues with resistance to antibiotics and the creation of superbugs. Over the recent 2 years, the coronavirus disease 2019 pandemic has substantially boosted hospital waste volume. In this situation, a detailed literature review was conducted to highlight the harmful effects of untreated hospital waste and outline the best approaches to manage it. Approximately 50 to 70% of the emerging contaminants prevalent in the hospital wastewater can be removed using traditional treatment strategies. This paper emphasizes the numerous treatment approaches for effectively eliminating emerging contaminants and antibiotics from hospital wastewater and provides an overview of global hospital wastewater legislation and guidelines on hospital wastewater administration. Around 90% of ECs might be eliminated by biological or physical treatment techniques when used in conjunction with modern oxidation techniques. According to this research, hybrid methods are the best approach for removing antibiotics and ECs from hospital wastewater. The document outlines the many features of effective hospital waste management and might be helpful during and after the coronavirus disease 2019 outbreak, when waste creation on all hospitals throughout the globe has considerably increased.

Comparison of surface adsorption efficacies of eco-sustainable agro/animal biomass-derived activated carbon for the removal of rhodamine B and hexavalent chromium

Effective management and remediation strategies are crucial to minimize the impacts of both organic and inorganic contaminants on environmental quality and human health. This study investigates a novel approach utilizing cotton shell activated carbon (CSAC), rice husk activated carbon (RHAC), and wasp hive activated carbon (WHAC), produced through alkali treatment and carbonization under N2 atmosphere at 600 °C. The adsorption capacities of biomass-derived mesoporous activated carbons (CSAC, RHAC, WHAC) alongside macroporous commercial activated carbons (CAC) were evaluated for removing rhodamine B (Rh B) and hexavalent chromium (Cr6+). The CSAC exhibits remarkable adsorption efficiency (255.4 mg.g-1) for Cr(VI) removal, while RHAC demonstrates superior efficacy (174.2 mg.g-1) for Rh B adsorption. Investigating various optimal parameters including initial pH (pH 3 for Cr and pH 7 for Rh B), catalyst dosage (200 mg.L-1), and initial concentration (20 mg.L-1), the Redlich-Peterson isotherm model is applied to reveal a hybrid adsorption mechanism encompassing monolayer (chemisorption) and multilayer (van der Waals adsorption) processes. Kinetic analysis highlights the pseudo-second-order and Elovich models as the most suitable, suggesting physiochemisorption mechanisms. Thermodynamic analysis indicates the endothermic nature of the adsorption process, with increased randomness at the solid-solution interface. Isosteric heat investigations using Clausius-Clapeyron, Arrhenius, and Eyring equations reveal a heterogeneous surface nature across all activated carbons. Further confirmation of Rh B and Cr(VI) adsorption onto activated carbons is provided through FTIR, FESEM, and EDAX analysis. This study highlights the innovation and promise of utilizing biomass-derived activated carbons for effective pollutant removal.

Oxidation Mechanism and Toxicity Evolution of Linalool, a Typical Indoor Volatile Chemical Product

Linalool, a high-reactivity volatile chemical product (VCP) commonly found in cleaning products and disinfectants, is increasingly recognized as an emerging contaminant, especially in indoor air. Understanding the gas-phase oxidation mechanism of linalool is crucial for assessing its impact on atmospheric chemistry and human health. Using quantum chemical calculations and computational toxicology simulations, we investigated the atmospheric transformation and toxicity evolution of linalool under low and high NO/HO2· levels, representing indoor and outdoor environments. Our findings reveal that linalool can undergo the novel mechanisms involving concerted peroxy (RO2·) and alkoxy radical (RO·) modulated autoxidation, particularly emphasizing the importance of cyclization reactions indoors. This expands the widely known RO2·-dominated H-shift-driven autoxidation and proposes a generalized autoxidation mechanism that leads to the formation of low-volatility secondary organic aerosol (SOA) precursors. Toxicological analysis shows that over half of transformation products (TPs) exhibited higher carcinogenicity and respiratory toxicity compared to linalool. We also propose time-dependent toxic effects of TPs to assess their long-term toxicity. Our results indicate that the strong indoor emission coupled with slow consumption rates lead to significant health risks under an indoor environment. The results highlight complex indoor air chemistry and health concerns regarding persistent toxic products during indoor cleaning, which involves the use of linalool or other VCPs.

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.

Comprehensive review of emerging contaminants: Detection technologies, environmental impact, and management strategies

Emerging contaminants (ECs) are a diverse group of unregulated pollutants increasingly present in the environment. These contaminants, including pharmaceuticals, personal care products, endocrine disruptors, and industrial chemicals, can enter the environment through various pathways and persist, accumulating in the food chain and posing risks to ecosystems and human health. This comprehensive review examines the chemical characteristics, sources, and varieties of ECs. It critically evaluates the current understanding of their environmental and health impacts, highlighting recent advancements and challenges in detection and analysis. The review also assesses existing regulations and policies, identifying shortcomings and proposing potential enhancements. ECs pose significant risks to wildlife and ecosystems by disrupting animal hormones, causing genetic alterations that diminish diversity and resilience, and altering soil nutrient dynamics and the physical environment. Furthermore, ECs present increasing risks to human health, including hormonal disruptions, antibiotic resistance, endocrine disruption, neurological effects, carcinogenic effects, and other long-term impacts. To address these critical issues, the review offers recommendations for future research, emphasizing areas requiring further investigation to comprehend the full implications of these contaminants. It also suggests increased funding and support for research, development of advanced detection technologies, establishment of standardized methods, adoption of precautionary regulations, enhanced public awareness and education, cross-sectoral collaboration, and integration of scientific research into policy-making. By implementing these solutions, we can improve our ability to detect, monitor, and manage ECs, reducing environmental and public health risks.

A novel and sustainable composite of L@PSAC for superior removal of pharmaceuticals from different water matrices: Production, characterization, and application

This study endeavors to develop cost-effective environmentally friendly technology for removing harmful residual pharmaceuticals from water and wastewater by utilizing the effective adsorption of pistachio shell (PS) biochar and the degradation potency of laccase immobilized on the biochar (L@PSAC). The carbonatization and activation of the shells were optimized regarding temperature, time, and NH4NO3/PS ratio. This step yielded an optimum PS biochar (PSAC) with the highest porosity and surface area treated at 700 °C for 3 h using an NH4NO3/PS ratio of 3% wt. The immobilization of laccase onto PSAC (L@PSAC) was at its best level at pH 5, 60 U/g, and 30 °C. The optimum L@PSAC maintained a high level of enzyme activity over two months. Almost a complete removal (>99%) of diclofenac, carbamazepine, and ciprofloxacin in Milli-Q (MQ) water and wastewater was achieved. Adsorption was responsible for >80% of the removal and the rest was facilitated by laccase degradation. L@PSAC maintained effective removal of pharmaceuticals of ≥60% for up to six treatment cycles underscoring the promising application of this material for wastewater treatment. These results indicate that activated carbon derived from the pistachio shell could potentially be utilized as a carrier and adsorbent to efficiently remove pharmaceutical compounds. This enzymatic physical elimination approach has the potential to be used on a large-scale.

PFOA accumulation in the leaves of basil (Ocimum basilicum L.) and its effects on plant growth, oxidative status, and photosynthetic performance

BACKGROUND

Perfluoroalkyl substances (PFASs) are emerging contaminants of increasing concern due to their presence in the environment, with potential impacts on ecosystems and human health. These substances are considered "forever chemicals" due to their recalcitrance to degradation, and their accumulation in living organisms can lead to varying levels of toxicity based on the compound and species analysed. Furthermore, concerns have been raised about the possible transfer of PFASs to humans through the consumption of edible parts of food plants. In this regard, to evaluate the potential toxic effects and the accumulation of perfluorooctanoic acid (PFOA) in edible plants, a pot experiment in greenhouse using three-week-old basil (Ocimum basilicum L.) plants was performed adding PFOA to growth substrate to reach 0.1, 1, and 10 mg Kg- 1 dw.

RESULTS

After three weeks of cultivation, plants grown in PFOA-added substrate accumulated PFOA at different levels, but did not display significant differences from the control group in terms of biomass production, lipid peroxidation levels (TBARS), content of α-tocopherol and activity of ascorbate peroxidase (APX), catalase (CAT) and guaiacol peroxidase (POX) in the leaves. A reduction of total phenolic content (TPC) was instead observed in relation to the increase of PFOA content in the substrate. Furthermore, chlorophyll content and photochemical reflectance index (PRI) did not change in plants exposed to PFAS in comparison to control ones. Chlorophyll fluorescence analysis revealed an initial, rapid photoprotective mechanism triggered by PFOA exposure, with no impact on other parameters (Fv/Fm, ΦPSII and qP). Higher activity of glutathione S-transferase (GST) in plants treated with 1 and 10 mg Kg- 1 PFOA dw (30 and 50% to control, respectively) paralleled the accumulation of PFOA in the leaves of plants exposed to different PFOA concentration in the substrate (51.8 and 413.9 ng g- 1 dw, respectively).

CONCLUSION

Despite of the absorption and accumulation of discrete amount of PFOA in the basil plants, the analysed parameters at biometric, physiological and biochemical level in the leaves did not reveal any damage effect, possibly due to the activation of a detoxification pathway likely involving GST.

Bio-electrochemical degradation of carbamazepine (CBZ): A comprehensive study on effectiveness, degradation pathway, and toxicological assessment

Recent attention on the detrimental effects of pharmaceutically active compounds (PhACs) in natural water has spurred researchers to develop advanced wastewater treatment methods. Carbamazepine (CBZ), a widely recognized anticonvulsant, has often been a primary focus in numerous studies due to its prevalence and resistance to breaking down. This study aims to explore the effectiveness of a bio-electrochemical system in breaking down CBZ in polluted water and to assess the potential harmful effects of the treated wastewater. The results revealed bio-electro degradation process demonstrated a collaborative effect, achieving the highest CBZ degradation compared to electrodegradation and biodegradation techniques. Notably, a maximum CBZ degradation efficiency of 92.01% was attained using the bio-electrochemical system under specific conditions: Initial CBZ concentration of 60 mg/L, pH level at 7, 0.5% (v/v) inoculum dose, and an applied potential of 10 mV. The degradation pathway established by identifying intermediate products via High-Performance Liquid Chromatography-Mass Spectrometry, revealed the complete breakdown of CBZ without any toxic intermediates or end products. This finding was further validated through in vitro and in vivo toxicity assays, confirming the absence of harmful remnants after the degradation process.

Functionalization of porous silica with graphene oxide and polyethyleneimine, containing zinc copper ferrite nanoparticles for water treatment and antibacterial application

The article discusses the removal of methylene blue (MB) dye, a common cationic dye used in the textile industry, from aqueous solutions through an adsorption process. The use of porous components as adsorbents are shown to facilitate complete separation after the process is completed. The substrate was synthesized by connecting zinc copper ferrite (ZnCuFe2O4), polyethyleneimine (PEI), and Graphene Oxide (GO) sheets to MCM-48, which is a mesoporous material. The surface of MCM-48 was modified using CPTMS, which created an O-Si-Cl bridge, thereby improving the adsorption rate. The substrate was shown to have suitable sites for electrostatic interactions and creating hydrogen bonds with MB. The adsorption process from the Freundlich isotherm (R2 = 0.9224) and the pseudo-second-order diagram (R2 = 0.9927) demonstrates the adsorption of several layers of dye on the heterogeneous surface of the substrate. The synthesized substrate was also shown to have good bactericidal activity against E. coli and S. aureus bacterial strain. Furthermore, the substrate maintained its initial ability to adsorb MB dye for four consecutive cycles. The research resulted that ZnCuFe2O4@MCM-48/PEI-GO substrate has the potential for efficient and economical removal of MB dye from aqueous solutions (R = 88.82%) (qmax = 294.1176 mg. g-1), making it a promising solution for the disposal of harmful industrial waste.

Taguchi optimisation of the synthesis of vine-pruning-waste hydrochar as potential adsorbent for pesticides in water

This research aimed to synthesise an effective hydrochar adsorbent from vineyard pruning wastes to remove emerging contaminants as a potential valorisation product. The adsorption capacity of the hydrochar was optimised using the Taguchi method. Four synthesis variables were evaluated: hydrothermal reaction temperature, use of H3PO4 as a catalyst, number of acetone washes, and type of chemical cold activation. The simultaneous adsorption of five model pesticides (clothianidin (CTD), acetamiprid (ACE), 2,4-D, metalaxyl (MET), and atrazine (ATZ)) at an initial pH of 7 was studied. At optimum conditions, the hydrochar presented a total adsorption capacity of 22.7 μmol/g, representing a 2.7-fold improvement with respect to pristine hydrochar performance. High percentage removals were achieved for all pollutants (85 % CTD, 94 % ACE, 86 % MET, and 95 % ATZ) except for 2,4-D (4 %). This research provides a valuable reference for developing hydrochar adsorbents for pollution control and the valorisation of biomass wastes.

Assessment of new hydrogen peroxide activators in water and comparison of their active species toward contaminants of emerging concern

Advanced oxidation processes are the most efficient tool to thwart the overaccumulation of harmful organic compounds in the environment. In this direction bioinspired metal complexes may be a viable solution for oxidative degradations in water. However, their synthesis is often elaborated and their scalability consequently low. This study presents alternative easy-to-synthesize bioinspired metal complexes to promote degradations in water. The metals employed were iron and manganese ions, hence cheap and highly accessible ions. The complexes were tested toward Phenol, Estrone, Triclosan, Oxybenzone, Diclofenac, Carbamazepine, Erythromycin, Aspartame, Acesulfame K, Anisole and 2,4-Dinitrotoluene. The reaction favoured electron-rich compounds reaching a removal efficiency of over 90%. The central ion plays a crucial role. Specifically, Mn(II) induces a non-radical pathway while iron ions a predominant radical one (⋅OH is predominant). The iron systems resulted more versatile toward contaminants, while the manganese ones showed a higher turn-over number, hence higher catalytic behaviour.

Enhancing compound confidence in suspect and non-target screening through machine learning-based retention time prediction

The retention time (RT) of contaminants of emerging concern (CECs) in liquid chromatography-high-resolution mass spectrometry (LC-HRMS) is crucial for database matching in non-targeted screening (NTS) analysis. In this study, we developed a machine learning (ML) model to predict RTs of CECs in NTS analysis. Using 1051 CEC standards, we evaluated Random Forest (RF), XGBoost, Support Vector Regression (SVR), and Artificial Neural Network (ANN) with molecular fingerprints and chemical descriptors to establish an optimal model. The SVR model utilizing chemical descriptors resulted in good predictive capacity with R2ext = 0.850 and r2 = 0.925. The model was further validated through laboratory NTS compound characterization. When applied to examine CEC occurrence in a large wastewater treatment plant, we identified 40 level S1 CECs (confirmed structure by reference standard) and 234 level S2 compounds (probable structure by library spectrum match). The model predicted RTs for level S2 compounds, leading to the classification of 153 level S2 compounds with high confidence (ΔRT <2 min). The model served as a robust filtering mechanism within the analytical framework. This study emphasizes the importance of predicted RTs in NTS analysis and highlights the potential of prediction models. Our research introduces a workflow that enhances NTS analysis by utilizing RT prediction models to determine compound confidence levels.

Promoting the circular economy: Valorization of a residue from industrial char to activated carbon with potential environmental applications as adsorbents

Pyrolysis of residues enriched with carbon, such as in agroforestry or industrial activities, has been postulated as an emerging technology to promote the production of biofuels, contributing to the circular economy and minimizing waste. However, during the pyrolysis processes a solid fraction residue is generated. This work aims to study the viability of these chars to develop porous carbonaceous materials that can be used for environmental applications. Diverse chars discharged by an industrial pyrolysis factory have been activated with KOH. Concretely, the char residues came from the pyrolysis of olive stone, pine, and acacia splinters, spent residues fuel, and cellulose artificial casings. The changes in the textural, structural, and composition characteristics after the activation process were studied by N2 adsorption-desorption isotherms, scanning electron microscopy, FTIR, elemental analysis, and XPS. A great porosity was developed, SBET within 776-1186 m2 g-1 and pore volume of 0.37-0.59 cm3 g-1 with 70-90% of micropores contribution. The activated chars were used for the adsorption of CO2, leading to CO2 maximum uptakes of 90-130 mg g-1. There was a good correlation between the CO2 uptake with microporosity and oxygenated surface groups of the activated chars. Moreover, their ability to adsorption of contaminants in aqueous solution was also evaluated. Concretely, there was studied the adsorption of aqueous heavy metals, i.e., Cd, Cu, Ni, Pb, and Zn, and organic pollutants of emerging concern such as caffeine, diclofenac, and acetaminophen.

Into the toxicity potential of an array of parabens by biomimetic liquid chromatography, cell viability assessments and in silico predictions

Five parabens (PBs) i.e., Methylparaben (MP), Ethylparaben (EP), Isopropylparaben (iPrP), Isobutylparaben (iBuP), Benzylparaben (BzP), and their parent compound i.e., para-hydroxy Benzoic Acid (pHBA), were studied both in vitro and in silico. Specifically, we determined their retention on several both protein- (Human Serum Albumin and α1-acidic glycoprotein) and (phospho) lipid- (immobilized artificial membrane (IAM)) based biomimetic stationary phases to evaluate their penetration potential through the biomembranes and their possible distribution in the body. The IAM phases were based either on phosphatidylcholine (PC) analogues i.e., PC.MG and PC.DD2 or on sphingomyelin (SPH). We also assessed their viability effect on breast cancer cells (MCF-7) via MTT assay subjecting the cells to five different PB concentrations i.e., 100 μM, 10 μM, 1 μM, 0.1 μM and 0.01 μM. Finally, their pharmacokinetics and toxicity were assessed by the ADMET Predictor™ software. Isopropylparaben was found to be more active than 17β estradiol (E2) employed as positive control, on the screened cell line inducing cell proliferation up to 150 % more of untreated cells. Other analogues showed only a slight/moderate cell proliferation activity, with parabens having longer/branched side chain showing, on average, a higher proliferation rate. Significant linear direct relationships (for PC.DD2 r2 = 0.89, q2 = 0.86, for SPH r2 = 0.89, q2 = 0.85, for both P value < 0.05) were observed between the difference in proliferative effect between the readout and the control at 0.01 μM concentration and the retention on the IAM phases measured at pH 5.0 for all compounds but pHBA, which is the only analyte of the dataset supporting a carboxylic acid moiety. IAM affinity data measured at pH 7.0 were found to be related to the effective human jejunal permeability as predicted by the software ADMET® Predictor, which is relevant when PBs are added to pharmaceutical and food commodities.

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

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

Efficient removal of toxicity associated to wastewater treatment plant effluents by enhanced Soil Aquifer Treatment

The regeneration of wastewater has been recognized as an effective strategy to counter water scarcity. Nonetheless, Wastewater Treatment Plant (WWTP) effluents still contain a wide range of contaminants of emerging concern (CECs) even after water depuration. Filtration through Soil Aquifer Treatment (SAT) systems has proven efficient for CECs removal although the attenuation of their associated biological effects still remains poorly understood. To evaluate this, three pilot SAT systems were monitored, two of them enhanced with different reactive barriers. SATs were fed with secondary effluents during two consecutive campaigns. Fifteen water samples were collected from the WWTP effluent, below the barriers and 15 m into the aquifer. The potential attenuation of effluent-associated biological effects by SATs was evaluated through toxicogenomic bioassays using zebrafish eleutheroembryos and human hepatic cells. Transcriptomic analyses revealed a wide range of toxic activities exerted by the WWTP effluents that were reduced by more than 70% by SAT. Similar results were observed when HepG2 hepatic cells were tested for cytotoxic and dioxin-like responses. Toxicity reduction appeared partially determined by the barrier composition and/or SAT managing and correlated with CECs removal. SAT appears as a promising approach to efficiently reduce effluent-associated toxicity contributing to environmental and human health preservation.

Synthesis, characterization, and application of Cu-substituted LaNiO3 perovskites as photocatalysts and/or catalysts for persulfate activation towards pollutant removal

The presence of emerging contaminants in environmental aqueous matrices is an ever-growing problem, since conventional wastewater treatment methods fail to adequately remove them. Therefore, the application of non-conventional methodologies such as advanced oxidation processes is of great importance to tackle this modern problem. Photocatalysis as well as catalytic activation of persulfates are promising techniques in this field as they are capable of eliminating various emerging contaminants, and current research aims to develop new materials that can be utilized for both processes. In this light, the present study focused on the use of a simple sol-gel-combustion methodology to synthesize Cu-substituted LaNiO3 perovskite materials in an attempt to improve the photocatalytic and catalytic performance of pure LaNiO3, using molar ratios of Cu:Ni that have not been previously reported in the literature. The morphological, structural, and optical features of the synthesized materials were characterized by a series of analytical techniques (e.g., X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, diffuse reflectance spectroscopy, etc.). Also, their performance as photocatalysts, persulfate anion activators and simultaneously as photocatalysts/persulfate anion activators (hybrid) was evaluated by conducting laboratory-scale experiments using phenol (phenolics) as a model emerging contaminant. Interestingly, the results revealed that LaCu0.25Ni0.75O3 exhibited the best efficiency in all the applied processes, which was mainly attributed to the introduction of oxygen vacancies in the structure of the substituted material. The contribution of selected reactive species in the hybrid photocatalytic/catalytic experiments utilizing LaCu0.25Ni0.75O3 as a (photo)catalyst was investigated using appropriate scavengers, and the results suggested that singlet oxygen is the most dominant. Additionally, the stability of all synthesized perovskites was assessed by monitoring the concentration of the leached Cu and/or Ni cations at the end of every applied process. Finally, the reusability of LaCu0.25Ni0.75O3 was evaluated in three consecutive catalytic cycles using the hybrid experiment methodology, as this process demonstrated the best efficiency in terms of phenolics removal, and the results were rather promising.

Biodegradation and detoxification study of triphenylmethane dye (Brilliant green) in a recirculating packed-bed bioreactor by bacterial consortium

In the last few decades, Brilliant green (BG) dye is widely employed to colour the fabric materials in various industries (e.g. textile, pulp and paper, etc.). The wastewater containing BG dye emerges as a major challenge among the researchers due to its toxic, mutagenic, and carcinogenic effects on human beings and marine life. In this context, the present study is mainly focused on the biodegradation of BG dye present in wastewater. The biodegradation of BG dye was performed in an indigenously designed recirculating packed bed bioreactor (RPBBR). Modified Polypropylene-Polyurethane foam (PP-PUF), a support packing material, was immobilised with a newly isolated bacterial consortium of Enterobacter asburiae strain SG43 (BGT1) and Alcaligenes sp. SY1 (BGT2). The bioreactor was operated under various organic loading rates (OLRs) of 2.7, 1.27, 0.93, 0.71, and 0.53 kg COD/m3.d-1 with a hydraulic retention time (HRT) of 4 days. The bioreactor exhibited the maximum BG dye removal efficiency of 91%. Proton Nuclear Magnetic Resonance (1H NMR), UV-Vis spectroscopy, Gas chromatography-mass spectrometry (GC-MS), and Fourier Transform Infrared Spectroscopy (FTIR) depicted the biodegradation of BG dye. Phaseolus mungo seeds germinated in BG dye biodegraded wastewater was significantly high (83.56%) than the untreated wastewater (32.4%), which was reasonably subjected to the detoxification of treated wastewater.

4-Methylbenzylidene camphor induced neurobehavioral toxicity in zebrafish (Danio rerio) embryos

4-Methylbenzylidene camphor (4-MBC) is a widely used organic UV filter in personal care products. Extensive use of 4-MBC and its frequent detection in aquatic ecosystems defile the biota with muscular and neuronal impairments. This study investigates the neurobehavioral toxicity of 4-MBC using Danio rerio as a model organism. Embryos were exposed semi-statically to 4-MBC at 5, 50, and 500 μg/L concentrations for 10-day post fertilization (dpf). Embryos exhibited a significant thigmotaxis and decreased startle touch response with altered expression of nervous system mRNA transcripts on 5 & 10 dpf. Compared to the sham-exposed group, 4-MBC treated larvae exhibited changes in the expression of shha, ngn1, mbp, elavl3, α1-tubulin, syn2a, and gap43 genes. Since ngn1 induction is mediated by shh signaling during sensory neuron specification, the elevated protein expression of NGN1 indicates 4-MBC interference in the sonic hedgehog signaling pathway. This leads to sensory neuron impairment and function such as 'sense' as evident from reduced touch response. In addition, larval brain histology with a reduced number of cells in the Purkinje layer emblazing the defunct motor coordination. Predictive toxicity study also showed a higher affinity of 4-MBC to modeled Shh protein. Thus, the findings of the present work highlighted that 4-MBC is potential to induce developmental neurotoxicity at both behavioral and molecular functional perspectives, and developing D. rerio larvae could be considered as a suitable alternate animal model to assess the neurological dysfunction of organic UV filters.

Photodegradation kinetics and halogens release of the emerging concern pollutants dexamethasone and S-metolachlor on TiO2/rGO composites

This work studies the photocatalytic degradation of solutions containing 0.11 mM of a glucocorticoid (dexamethasone, DEX) and 0.11 mM of an herbicide (S-metolachlor, MTLC), organohalogenated compounds containing fluorine and chlorine atoms in their molecules, respectively. To treat 1 L volume, a mass of 0.5 g of TiO2/rGO composite in suspension has been used as photocatalyst, irradiated with UV-A LEDs with 200 W m-2 of irradiance. MTLC is partially adsorbed on the surface of the catalyst, while DEX is not adsorbed, showing different degradation kinetics. The halogen ions released into the solution from the breakage of the parent molecules, F- and Cl- respectively, were analysed. In the case of MTLC, the released Cl- followed two different kinetic trends, being faster, and with a rate that matched the rate of MTLC disappearance, the part corresponding to non-adsorbed MTLC. In the experiments with DEX solutions a different behaviour was observed; the released F- in the photocatalytic degradation was partially adsorbed on the catalyst surface, but the adsorption capacity decreased with the use of the photocatalyst in consecutive cycles until the solubilised F- matched the degraded concentration of DEX. Furthermore, the mass balance between the degraded contaminant and the solubilised halogen anion, for both contaminants, allowed to conclude the absence of halogenated intermediates under the final operating conditions, that is a remarkable outcome in water remediation processes.

Stereoselective analysis of chiral pesticides: a review

Chiral organic pollutants, including pesticides, herbicides, medicines, flame retardants, and polycyclic musk, represent a significant threat to both the environment and human health. The presence of asymmetric centers in the structure of chiral pesticides introduces stereoisomers with distinct distributions, fates, biomagnification capacities, and cytotoxicities. In aquatic environments, pesticides, as persistent/pseudo-persistent compounds, have been detected in substantial quantities, posing severe risks to non-target species and, ultimately, public health through water supply and food exposures. In response to this environmental challenge, stereoselective analytical methods have gained prominence for the identification of pesticide/drug enantiomers in recent years. This review examines the environmental impact of chiral pesticides, emphasizing the distinct biological activities and distribution patterns of their stereoisomers. By highlighting the advancements in liquid chromatography for enantiomeric analysis, the review aims to underscore the urgent need for a comprehensive understanding of these pollutants to facilitate informed remediation strategies and ensure the safer dispersal of chiral organic pollutants in the environment, thereby addressing the potential risks they pose to ecosystems and human health. Future research should focus on developing sustainable and efficient methodologies for the precise analysis of stereoisomers in complex matrices, particularly in sewage water, emphasizing the importance of sewage processing plants in ensuring water quality.

Unraveling kinetic and synergistic effects during ultrasound-enhanced carbocatalysis for water remediation as a function of ultrasonic frequency

The ability of the ultrasound (US) combined with peroxymonosulfate (PMS), and a carbonaceous material (BC) was evaluated in the degradation of a model pollutant (acetaminophen, ACE). The US/BC/PMS system was compared with other possible systems (US, oxidation by PMS, BC adsorption, BC/PMS, US/PMS, and US/BC. The effect of the ultrasonic frequency (40, 375, and 1135 kHz) on the kinetics and synergy of the ACE removal was evaluated. In the US system, kinetics was favored at 375 kHz due to the increased production of hydroxyl radicals (HO•), but this did not improve in the US/PMS and US/BC systems. However, synergistic and antagonistic effects were observed at the low and high frequencies where the production of radicals is less efficient but there is an activation of PMS through mechanical effects. US/BC/PMS at 40 kHz was the most efficient system obtaining ∼95% ACE removal (40 μM) in the first 10 min of treatment, and high synergy (S = 10.30). This was promoted by disaggregation of the carbonaceous material, increasing the availability of catalytic sites where PMS is activated. The coexistence of free-radical and non-radical pathways was analyzed. Singlet oxygen (1O2) played the dominant role in degradation, while HO• and sulfate radicals (SO4•-), scarcely generated at low frequency, play a minimum role. Performance in hospital wastewater (HWW), urine, and seawater (SW) evidenced the competition of organic matter by BC active sites and reactive species and the removal enhancement when Cl- is present. Besides, toxicity decreased by ∼20% after treatment, being the system effective after three cycles of reuse.

Recent progress in mineralization of emerging contaminants by advanced oxidation process: A review

Emerging contaminants are chemicals generated due to the usage of pesticide, endocrine disrupting compounds, pharmaceuticals, and personal care products and are liberated into the environment in trace quantities. The emerging contaminants eventually become a greater menace to living beings owing to their wide range and inhibitory action. To diminish these emerging contaminants from the environment, an Advanced Oxidation Process was considered as an efficient option. The Advanced Oxidation Process is an efficient method for mineralizing fractional or generous contaminants due to the generation of reactive species. The primary aim of this review paper is to provide a thorough knowledge on different Advanced Oxidation Process methods and to assess their mineralization efficacy of emerging contaminants. This study indicates the need for an integrated process for enhancing the treatment efficiency and overcoming the drawbacks of the individual Advanced Oxidation Process. Further, its application concerning technical and economic aspects is reviewed. Until now, most of the studies have been based on lab or pilot scale and do not represent the actual scenario of the emerging contaminant mineralization. Thus, the scaling up of the process was discussed, and the major challenges in large scale implementation were pointed out.

A bibliometric analysis of emerging contaminants (ECs) (2001-2021): Evolution of hotspots and research trends

Emerging contaminants (ECs) have attracted increasing attention in the past two decades because of their ubiquitous existence and high environmental risk. Understanding the progress of research and the evolution of hot topics is critical. This study provides a bibliometric review, along with a quantitative trend analysis of approximately 8000 publication records dated from 2001 to 2021. Wider distribution in various subjects was discovered in terms of publication numbers, indicating a strong tendency for EC research to become an interdisciplinary topic. Visualization of term co-occurrence analysis revealed that the ECs study went through three stages over time: identification and detection, traceability and risk, and process and control. Quantitative trend analysis revealed that antibiotics, microplastics, endocrine disrupting chemicals (EDCs), per/poly-fluoroalkyl substances (PFAS), pesticides, heavy metals, and nanoparticles are attracting increasing attention, whereas conventional pharmaceuticals, persistent organic pollutants, and materials such as benzotriazole, diclofenac, bisphenol A, carbamazepine, triclosan, and titanium dioxide exhibit a downward trend. PFAS and EDCs are considered potential future core hotspots for the hysteretic rise in research attention compared with conventional ECs. Furthermore, analysis of research linkage and the developing stages of ECs could be possible approach to determine the evolution of hotspots in ECs study. This study provides objective and comprehensive insights into the research landscape of ECs, which may shed light on future developmental directions for researchers interested in this field.

Electrogeneration of H2O2 through carbon-based ink on Al foam for electro-Fenton treatment of micropollutants in water

In the present work, the catalytic efficiency of inks based on different carbon materials, namely activated carbon (AC), carbon graphite (CG), and carbon black (CB) was investigated for the oxygen reduction reaction (ORR). Additionally, we explored the feasibility of using this ink as a coating for an Aluminum foam (Alfoam) cathode in an electrochemical cell. The goal was to utilize this setup to produce hydrogen peroxide (H2O2) in the electro-Fenton (EF) process, targeting for treating water contaminated with contaminants of emerging concern (CECs). Among the materials investigated, all of them exhibited the ability to facilitate the ORR. However, AC proved to be the most suitable material due to its optimal balance between physical and electrocatalytic properties, thus enabling the formation of H2O2. When the different inks were applied to the surface of aluminum foam, it was observed that only the ink based on carbon black CB achieved a homogeneous distribution with the same ink quantity. As a result, it was observed that the Alfoam/CB electrode exhibited the highest H2O2 generation capacity, producing 45.6 mg L-1, followed by electro-generation of 5.1 mg L-1 using Alfoam/AC and 11 mg L-1 using Alfoam/CG. Furthermore, the application of Alfoam/CB in EF processes allowed for the almost complete degradation of 15 emerging contaminants of concern (CECs) present in secondary effluent. The innovative outcome of this study positions the developed technology as a promising and effective alternative for the treatment of water contaminated with CECs, demonstrating significant potential for industrial-scale application.

Screening for drinking water contaminants of concern using an automated exposure-focused workflow

BACKGROUND

The number of chemicals present in the environment exceeds the capacity of government bodies to characterize risk. Therefore, data-informed and reproducible processes are needed for identifying chemicals for further assessment. The Minnesota Department of Health (MDH), under its Contaminants of Emerging Concern (CEC) initiative, uses a standardized process to screen potential drinking water contaminants based on toxicity and exposure potential.

OBJECTIVE

Recently, MDH partnered with the U.S. Environmental Protection Agency (EPA) Office of Research and Development (ORD) to accelerate the screening process via development of an automated workflow accessing relevant exposure data, including exposure new approach methodologies (NAMs) from ORD's ExpoCast project.

METHODS

The workflow incorporated information from 27 data sources related to persistence and fate, release potential, water occurrence, and exposure potential, making use of ORD tools for harmonization of chemical names and identifiers. The workflow also incorporated data and criteria specific to Minnesota and MDH's regulatory authority. The collected data were used to score chemicals using quantitative algorithms developed by MDH. The workflow was applied to 1867 case study chemicals, including 82 chemicals that were previously manually evaluated by MDH.

RESULTS

Evaluation of the automated and manual results for these 82 chemicals indicated reasonable agreement between the scores although agreement depended on data availability; automated scores were lower than manual scores for chemicals with fewer available data. Case study chemicals with high exposure scores included disinfection by-products, pharmaceuticals, consumer product chemicals, per- and polyfluoroalkyl substances, pesticides, and metals. Scores were integrated with in vitro bioactivity data to assess the feasibility of using NAMs for further risk prioritization.

SIGNIFICANCE

This workflow will allow MDH to accelerate exposure screening and expand the number of chemicals examined, freeing resources for in-depth assessments. The workflow will be useful in screening large libraries of chemicals for candidates for the CEC program.

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

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

Recommendations to reduce the streetlight effect and gray areas limiting the knowledge of the effects of plant protection products on biodiversity

Preserving biodiversity against the adverse effects of plant protection products (PPPs) is a major environmental and societal issue. However, despite intensive investigation into the ecotoxicological effects of PPPs, the knowledge produced remains fragmented given the sheer diversity of PPPs. This is due, at least in part, to a strong streetlight effect in the field of ecotoxicology. Indeed, while some PPPs have been investigated in numerous ecotoxicological studies, there are many for which the scientific literature still has little or no information on their ecotoxicological risks and effects. The PPPs under the streetlight include a large variety of legacy substances and a more limited number of more recent or currently-in-use substances, such as the herbicide glyphosate and the neonicotinoid insecticides. Furthermore, many of the most recent PPPs (including those used in biocontrol) and PPP transformation products (TPs) resulting from abiotic and/or biotic degradation are rarely addressed in the international literature in the field of ecotoxicology. Here, based on a recent collective scientific assessment of the effects of PPPs on biodiversity and ecosystem services in the French and European contexts, this article sets out to illustrate the limitations and biases caused by the streetlight effect and numbers of gray areas, and issue recommendations on how to overcome them.

Recent Advances on Electrochemical Sensors for Detection of Contaminants of Emerging Concern (CECs)

Contaminants of Emerging Concern (CECs), a new category of contaminants currently in the limelight, are a major issue of global concern. The pervasive nature of CECs and their harmful effects, such as cancer, reproductive disorders, neurotoxicity, etc., make the situation alarming. The perilous nature of CECs lies in the fact that even very small concentrations of CECs can cause great impacts on living beings. They also have a nature of bioaccumulation. Thus, there is a great need to have efficient sensors for the detection of CECs to ensure a safe living environment. Electrochemical sensors are an efficient platform for CEC detection as they are highly selective, sensitive, stable, reproducible, and prompt, and can detect very low concentrations of the analyte. Major classes of CECs are pharmaceuticals, illicit drugs, personal care products, endocrine disruptors, newly registered pesticides, and disinfection by-products. This review focusses on CECs, including their sources and pathways, health effects caused by them, and electrochemical sensors as reported in the literature under each category for the detection of major CECs.

Recent advances in microbial engineering approaches for wastewater treatment: a review

In the present era of global climate change, the scarcity of potable water is increasing both due to natural and anthropogenic causes. Water is the elixir of life, and its usage has risen significantly due to escalating economic activities, widespread urbanization, and industrialization. The increasing water scarcity and rising contamination have compelled, scientists and researchers, to adopt feasible and sustainable wastewater treatment methods in meeting the growing demand for freshwater. Presently, various waste treatment technologies are adopted across the globe, such as physical, chemical, and biological treatment processes. There is a need to replace these technologies with sustainable and green technology that encourages the use of microorganisms since they have proven to be more effective in water treatment processes. The present review article is focused on demonstrating how effectively various microbes can be used in wastewater treatment to achieve environmental sustainability and economic feasibility. The microbial consortium used for water treatment offers many advantages over pure culture. There is an urgent need to develop hybrid treatment technology for the effective remediation of various organic and inorganic pollutants from wastewater.

Occurrence, removal, and risk assessment of emerging contaminants in aquatic products processing sewage treatment plants

Emerging contaminants (ECs) in aquatic environments have attracted attention due to their wide distribution and potential ecotoxicities. Sewage treatment plants (STPs) are proven to be the major source of ECs in the aquatic environment, while there remains insufficient understanding of the removal and risk assessment of ECs in STPs. Here, we clarified the degradation and risk impact of 13 ECs in two aquatic product processing sewage treatment plants (APPSTPs) along the southeast coast of China. The concentrations of ECs followed the order: endocrine-disrupting chemicals (1877.85-15,398.02 ng/L in influent, 3.37-44.47 ng/L in effluent) >  > sulfonamide antibiotics (SAs, 75.14-906.19 ng/L in influent, 1.14-15.33 ng/L in effluent) > pharmaceutical and personal care products (PPCPs, 44.47-589.93 ng/L in influent, 2.54-34.16 ng/L in effluent) ≈ fluoroquinolone antibiotic (54.76-434.83 ng/L in influent, 10.75-32.82 ng/L in effluent) > other antibiotics (16.21-51.96 ng/L in influent, 0.68-6.17 ng/L in effluent). Moreover, the concentrations of PPCPs (decreased by 55.33-87.65% in peak fishing season) and antibiotics (increased by 44.99% in peak fishing season) were affected by fishing activities. In particular, the sequencing batch reactor (SBR) process had a better removal effect than the anaerobic-anoxic-oxic (A2/O) process on the treatment of some contaminants (e.g., norfloxacin and nonylphenol). Risk evaluations of ECs demonstrated that nonylphenol and SAs were at high- and low-risk states, respectively. Overall, our results provide important information for the degradation treatment of ECs, which is essential for pollutant management policy formulation.

Enhanced degradation of ibuprofen in an integrated constructed wetland-microbial fuel cell: treatment efficiency, electrochemical characterization, and microbial community dynamics

Over the past few decades, there has been a growing concern regarding the fate and transport of pharmaceuticals, particularly antibiotics, as emerging contaminants in the environment. It has been proposed that the presence of antibiotics at concentrations typically found in wastewater can impact the dynamics of bacterial populations and facilitate the spread of antibiotic resistance. The efficiency of currently-used wastewater treatment technologies in eliminating pharmaceuticals is often insufficient, resulting in the release of low concentrations of these compounds into the environment. In this study, we addressed these challenges by evaluating how different influent ibuprofen (IBU) concentrations influenced the efficiency of a laboratory-scale, integrated constructed wetland-microbial fuel cell (CW-MFC) system seeded with Eichhornia crassipes, in terms of organic matter removal, electricity generation, and change of bacterial community structure compared to unplanted, sediment MFC (S-MFC) and abiotic S-MFC (AS-MFC). We observed that the addition of IBU (5 mg L-1) resulted in a notable decrease in chemical oxygen demand (COD) and electricity generation, suggesting that high influent IBU concentrations caused partial inhibition for the electroactive microbial community due to its complexity and aromaticity. However, CW-MFC could recover from IBU inhibition after an acclimation period compared to unplanted S-MFC, even though the influent IBU level was increased up to 20 mg L-1, suggesting that plants in CW-MFCs have a beneficial role in relieving the inhibition of anode respiration due to the presence of high levels of IBU; thus, promoting the metabolic activity of the electroactive microbial community. Similarly, IBU removal efficiency for CW-MFC (i.e., 49-62%) was much higher compared to SMFC (i.e., 29-42%), and AS-MFC (i.e., 20-22%) during all experimental phases. In addition, our high throughput sequencing revealed that the high performance of CW-MFCs compared to S-MFC was associated with increasing the relative abundances of several microbial groups that are closely affiliated with anode respiration and organic matter fermentation. In summary, our results show that the CW-MFC system demonstrates suitability for high removal efficiency of IBU and effective electricity generation.

Evaluation of the photodegradation activity of bismuth oxoiodide/bismuth sub-carbonate nanocatalyst: Experimental design and the mechanism study

In this study, a binary BiOI/(BiO)2CO3 catalyst was prepared and used for sulfasalazine (SSZ) photodegradation in an aqueous phase. The semiconductors were identified by XRD, SEM-EDX, and UV-Vis diffuse reflectance spectroscopy (DRS) methods. Applying the Kubelka-Munk model on DRS results, the band gap energies of 2.09, 3.5, and 2.07 eV were obtained for BiOI, (BiO)2CO3, and BiOI/(BiO)2CO3 samples. pHpzc values of 6.3, 10.1, and 8.1 were estimated for BiOI, (BiO)2CO3, and BiOI/(BiO)2CO3, respectively. After observing the boosted photocatalytic activity by the coupled system, the interaction effects of the influencing variables in SSZ photodegradation were evaluated via the response surface methodology (RSM) approach. The optimal RSM-run conditions were 8.5 ppm SSZ at pH 8, which contained 0.28 g/L of the BiOI/(BiO)2CO3 catalyst and 29 min illumination time, resulting in 87% SSZ photodegradation. The effects of some scavenging agents were also studied to elucidate the relative roles of the reactive species in the SSZ photodegradation by the proposed catalyst, that is, hydroxyl radicals ∼ photoinduced electrons > superoxide radicals ∼ photoinduced holes. The proposed catalyst retained good activity after 5 successive reusing runs.

Contaminants of emerging concern in urine: a review of analytical methods for determining diisocyanates, benzotriazoles, benzothiazoles, 4-methylbenzylidene camphor, isothiazolinones, fragrances, and non-phthalate plasticizers

Human biomonitoring (HBM) frameworks assess human exposure to hazardous chemicals. In this review, we discuss and summarize sample preparation procedures and analytical methodology for six groups of chemicals of emerging concern (CECs), namely diisocyanates, benzotriazoles, benzothiazoles, 4-methylbenzylidene camphor, isothiazolinones, fragrances, and non-phthalate plasticizers, which are increasingly detected in urine, however, are not yet widely included in HBM schemes, despite posing a risk to human health. The sample preparation procedures depend largely on the chemical group; however, solid-phase extraction (SPE) is most often used due to the minimized sample handling, lower sample volume, and generally achieving lower limits of quantification (LOQs) compared to other extraction techniques. In terms of sample analysis, LC-based methods generally achieve lower limits of quantification (LOQs) compared to GC-based methods for the selected six groups of chemicals owing to their broader chemical coverage. In conclusion, since these chemicals are expected to be more frequently included in future HBM studies, it becomes evident that there is a pressing need for rigorous quality assurance programs to ensure better comparability of data. These programs should include the reporting of measurement uncertainty and facilitate inter-laboratory comparisons among the reporting laboratories. In addition, high-resolution mass spectrometry should be more commonly employed to enhance the specificity and selectivity of the applied analytical methodology since it is underrepresented in HBM. Furthermore, due to the scarcity of data on the levels of these CECs in urine, large population HBM studies are necessary to gain a deeper understanding of the associated risks.

Prenatal harmful substances: Thai pregnant women's experiences

Background

The exposure of unborn babies to harmful substances during prenatal stages can lead to fetal anomalies, emphasizing the significance of pregnant women's practices in ensuring optimal fetal outcomes. However, there is a lack of understanding regarding this issue from the perspective of pregnant women.

Objective

This study aimed to describe the experiences of pregnant women in avoiding harmful substances to their unborn babies.

Methods

This study used a qualitative descriptive approach. Data were collected between September 2020 and April 2021 through in-depth interviews with 17 pregnant women purposively selected from two hospitals in southern Thailand. Data were transcribed verbatim and analyzed using thematic analysis.

Results

Four themes emerged from the participants' experiences: 1) understanding of harms, which included substance characteristics, exposure characteristics, body's protective mechanism, personal experiences, and obtained information; 2) practices for safety, which consisted of food safety, work safety, ambient air safety, and safety in personal/household products; 3) challenges in avoiding harmful substances, which were unrecognition, unavailability of safe substances, discomfort and inconvenience, inevitability, and family traditions; and 4) overcoming the challenges through personal changes, obtaining support, and ensuring a peaceful mind.

Conclusion

The findings provide valuable insights into prenatal exposure to harmful substances, which can serve as a basis for developing comprehensive guidelines for best practices. It is crucial for nurses to receive training that enables them to educate pregnant women, enhancing their awareness of important harmful substances and promoting effective methods for maintaining safety in their daily activities. Additionally, nurses can develop interventions to empower pregnant women to overcome challenges by involving significant individuals, particularly family members, in providing support and creating an optimal prenatal environment.

Global trends in the research and development of medical/pharmaceutical wastewater treatment over the half-century

The COVID-19 pandemic has severely impacted public health and the worldwide economy. The overstretched operation of health systems around the world is accompanied by potential and ongoing environmental threats. At present, comprehensive scientific assessments of research on temporal changes in medical/pharmaceutical wastewater (MPWW), as well as estimations of researcher networks and scientific productivity are lacking. Therefore, we conducted a thorough literature study, using bibliometrics to reproduce research on medical wastewater over nearly half a century. Our primary goal is systematically to map the evolution of keyword clusters over time, and to obtain the structure and credibility of clusters. Our secondary objective was to measure research network performance (country, institution, and author) using CiteSpace and VOSviewer. We extracted 2306 papers published between 1981 and 2022. The co-cited reference network identified 16 clusters with well-structured networks (Q = 0.7716, S = 0.896). The main trends were as follows: 1) Early MPWW research prioritized sources of wastewater, and this cluster was considered to be the mainstream research frontier and direction, representing an important source and priority research area. 2) Mid-term research focused on characteristic contaminants and detection technologies. Particularly during 2000-2010, a period of rapid developments in global medical systems, pharmaceutical compounds (PhCs) in MPWW were recognized as a major threat to human health and the environment. 3) Recent research has focused on novel degradation technologies for PhC-containing MPWW, with high scores for research on biological methods. Wastewater-based epidemiology has emerged as being consistent with or predictive of the number of confirmed COVID-19 cases. Therefore, the application of MPWW in COVID-19 tracing will be of great interest to environmentalists. These results could guide the future direction of funding agencies and research groups.

Toxic Effects of Gemcitabine and Paclitaxel Combination: Chemotherapy Drugs Exposure in Zebrafish

Pharmaceuticals are widely recognized as potentially hazardous to aquatic ecosystems. In the last two decades, the constant intake of biologically active chemicals used in human healthcare has been related to the growing release of these agents into natural environments. As reported by several studies, various pharmaceuticals have been detected, mainly in surface water (seas, lakes, and rivers), but also in groundwater and drinking water. Moreover, these contaminants and their metabolites can show biological activity even at very low concentrations. This study aimed to evaluate the developmental toxicity of exposure to the chemotherapy drugs gemcitabine and paclitaxel in aquatic environments. Zebrafish (Danio rerio) embryos were exposed to doses of gemcitabine 15 μM in combination with paclitaxel 1 μM from 0 to 96 h post-fertilization (hpf) using a fish embryo toxicity test (FET). This study highlights that both gemcitabine and paclitaxel exposure at single non-toxic concentrations affected survival and hatching rate, morphology score, and body length after exposure in combination. Additionally, exposure significantly disturbed the antioxidant defense system and increased ROS in zebrafish larvae. Gemcitabine and paclitaxel exposure caused changes in the expression of inflammation-related, endoplasmic reticulum stress-related (ERS), and autophagy-related genes. Taken together, our findings underline that gemcitabine and paclitaxel increase developmental toxicity in zebrafish embryos in a time-dependent manner.

Environmental behaviors of emerging contaminants in freshwater ecosystem dominated by submerged plants: A review

Persistent exposure of emerging contaminants (ECs) in freshwater ecosystem has initiated intense global concerns. Freshwater ecosystem dominated by submerged plants (SP-FES) has been widely constructed to control eutrophic water. However, the environmental behaviors (e.g. migration, transformation, and degradation) of ECs in SP-FES have rarely been concerned and summarized. This review briefly introduced the sources of ECs, the pathways of ECs entering into SP-FES, and the constituent elements of SP-FES. And then the environmental behaviors of dissolved ECs and refractory solid ECs in SP-FES were comprehensively summarized, and the feasibility of removing ECs from SP-FES was critically evaluated. Finally, the challenges and perspectives on the future development for ECs removal from SP-FES were prospected, giving possible research gaps and key directions. This review will provide theoretical and technical support for the effective removal of ECs in freshwater ecosystem, especially in SP-FES.

Evaluation of heavy metals contamination in cereals, vegetables and fruits with probabilistic health hazard in a highly polluted megacity

Heavy metals (HMs) contamination in foodstuffs could pose serious health issues for public health and humans are continually exposed to HMs through the consumption of cereals, fruits, and vegetables. The present study was conducted to assess 11 HMs in foodstuffs to investigate pollution levels and health risks to children and adults. The mean contents of Cd, Cr, Cu, Ni, Zn, Fe, Pb, Co, As, Mn and Ba in foodstuffs were 0.69, 2.73, 10.56, 6.60, 14.50, 9.63, 2.75, 0.50, 0.94, 15.39 and 0.43 mg/kg, respectively and the concentration of Cd, Cr, Cu, Ni and Pb were higher than maximum permissible concentrations (MPCs) showing that these foods may be contaminated with metals and constitute a danger to consumers. Vegetables had relatively higher metal contents followed by cereals and fruits. The average value of the Nemerrow composite pollution index (NCPI) for cereals, fruits, and vegetables were 3.99, 6.53, and 11.34, respectively indicating cereal and fruits were moderately contaminated whereas vegetables were heavily contaminated by the studied metals. The total estimated daily and weekly intakes for all studied metals were higher than the maximum tolerable daily intake (MTDI) and provisional tolerance weekly intake (PTWI) recommended by FAO/WHO. The target hazard quotients and hazard index of all studied metals exceeded the standard limit for adults and children suggesting significant non-carcinogenic health hazards. The total cancer risk value of Cd, Cr, Ni, Pb, and As from food intake exceeded the threshold range (1.0E-04), suggesting potential carcinogenic risks. Based on practical and sensible evaluation techniques, the current work will assist policymakers in controlling metal contamination in foodstuffs.

Carbon-based single-atom catalysts in advanced oxidation reactions for water remediation: From materials to reaction pathways

Single-atom catalysts (SACs) have been widely recognized as state-of-the-art catalysts in environment remediation because of their exceptional performance, 100% metal atomic utilization, almost no secondary pollution, and robust structures. Most recently, the activation of persulfate with carbon-based SACs in advanced oxidation processes (AOPs) raises tremendous interest in the degradation of emerging contaminants in wastewater, owning to its efficient and versatile reactive oxidant species (ROS) generation. However, the comprehensive and critical review unraveling the underlying relationship between structures of carbon-based SACs and the corresponding generated ROS is still rare. Herein, we systematically summarize the fundamental understandings and intrinsic mechanisms between single metal atom active sites and produced ROS during AOPs. The types of emerging contaminants are firstly elaborated, presenting the prior pollutants that need to be degraded. Then, the preparation and characterization methods of carbon-based SACs are overviewed. The underlying material structure-ROS type relationship in persulfate-based AOPs is discussed in depth to expound the catalytic mechanisms. Finally, we briefly conclude the current development of carbon-based SACs in AOPs and propose the prospects for rational design and synthesis of carbon-based SACs with on-demand catalytic performances in AOPs in future research.

Recent Advances in the Biocatalytic Mitigation of Emerging Pollutants: A Comprehensive Review

The issue of environmental pollution has been worsened by the emergence of new contaminants whose morphology is yet to be fully understood. Several techniques have been adopted to mitigate the pollution effects of these emerging contaminants, and bioremediation involving plants, microbes, or enzymes has stood out as a cost-effective and eco-friendly approach. Enzyme-mediated bioremediation is a very promising technology as it exhibits better pollutant degradation activity and generates less waste. However, this technology is subject to challenges like temperature, pH, and storage stability, in addition to recycling difficulty as it is arduous to isolate them from the reaction media. To address these challenges, the immobilization of enzymes has been successfully applied to ameliorate the activity, stability, and reusability of enzymes. Although this has significantly increased the uses of enzymes over a wide range of environmental conditions and facilitated the use of smaller bioreactors thereby saving cost, it still comes with additional costs for carriers and immobilization. Additionally, the existing immobilization methods have their individual limitations. This review provides state-of-the-art information to readers focusing on bioremediation using enzymes. Different parameters such as: the sustainability of biocatalysts, the ecotoxicological evaluation of transformation contaminants, and enzyme groups used were reviewed. The efficacy of free and immobilized enzymes, materials and methods for immobilization, bioreactors used, challenges to large-scale implementation, and future research needs were thoroughly discussed.

Sequential photo electro oxidation and biodegradation of textile effluent: Elucidation of degradation mechanism and bacterial diversity

Textile effluent contains a highly toxic and refractory azo dyes. Eco-friendly method for efficient decolorization and degradation of textile effluent is essential. In the present study, treatment of textile effluent was carried through sequential electro oxidation (EO) and photo electro oxidation (PEO) using RuO₂-IrO₂ coated titanium electrode as an anode and cathode followed by biodegradation. The pre-treatment of textile effluent by photo electro oxidation for 14 h exhibited 92% of decolorization. Subsequent biodegradation of the pre-treated textile effluent enhanced the reduction of chemical oxygen demand to 90%. Metagenomics results exhibited that Flavobacterium, Dietzia, Curtobacterium, Mesorhizobium, Sphingobium, Streptococcus, Enterococcus, Prevotellaand Stenotrophomonas bacterial communities majorly involved in the biodegradation of textile effluent. Hence, integrating sequential photo electro oxidation and biodegradation proposed an efficient and eco-friendly approach for treating textile effluent.