The Tricycle Protocol is a One Health initiative that involves monitoring extended-spectrum β-lactamase-producing Escherichia coli (ESBL-Ec), an opportunistic intestinal and extraintestinal pathogen that is recognized as critically important for the development of new antimicrobial agents and as a key indicator of water, food, and environmental contamination. This study aimed to detect and characterize, phenotypically and genotypically, the presence of ESBL-Ec in coastal waters collected from three urban marine ecosystems and mussels from a mariculture area in the metropolitan region of Rio de Janeiro City, Brazil. Eighteen samples from each beach and from mussels were collected between June 2022 and December 2023. A total of 299 E. coli strains were identified over the study period, of which 33 (11
Heavy metal pollution in surface waters poses persistent threats to ecosystems and human health due to high toxicity, bioaccumulation, and environmental persistence. The Three Gorges Reservoir, a large regulated water body operating under the "storing clear water and discharging turbid water" regime, experiences periodic water level fluctuations that drive frequent source-sink shifts of sediment-associated heavy metals, complicating pollution assessment. While traditional physicochemical detection methods have limitations, metal resistance genes (MRGs)—microbial functional elements that evolve in response to metal stress—offer high sensitivity and specificity for pollution monitoring. Using metagenomic sequencing, this study investigated MRG diversity, spatial distribution, community assembly mechanisms, and their associations with heavy metal pollution in sediments from nine sampling sites across the reservoir's perennial backwater area. We tested three hypotheses: (1) MRG community composition is primarily structured by spatial distance rather than local environmental heterogeneity; (2) stochastic processes dominate MRG community assembly, with deterministic selection increasing at sites with stronger metal pollution gradients; and (3) MRG profiles can serve as sensitive biomarkers for under-monitored heavy metals such as tungsten. Results revealed no significant spatial difference in observed MRG richness (Sobs), but significantly higher MRG diversity at the Xiaojiang River estuary (XJ001). Spatial distance was the dominant driver of MRG community differentiation, with greater homogenization observed at upstream sites. Stochastic processes dominated overall MRG assembly, whereas deterministic processes contributed more at certain upstream locations. The tupC gene (encoding a tungstate transporter, functionally linked to molybdenum homeostasis) exhibited the highest abundance, indicating significant tungsten pollution, and formed a synergistic module with wtpC and modC to cope with "tungsten–molybdenum competition." Combined pollution by Ni, Cu, Zn, and Hg was evident, with corR, modC, arsT, nrsS, and nikE identified as stable biomarkers. This study addresses gaps in traditional monitoring of tungsten and provides scientific support for targeted heavy metal management and ecological restoration in the reservoir.
The detection of Cu2⁺ ions in aquatic environments is critically important due to their toxic effects on both aquatic ecosystems and human health. Excessive copper contamination can lead to severe physiological disorders, making reliable monitoring essential. In this study, sensitive and selective fluorescence sensor was successfully developed for the detection of Cu2⁺ ions. Upon interaction with Cu2⁺ ions, a distinct and selective enhancement in fluorescence intensity was clearly observed. This enhancement is attributed to the effective inhibition of intramolecular charge transfer (ICT) processes, which otherwise would quench the fluorescence signal. The proposed sensor exhibits a linear fluorescence response over a concentration range of 2–12 µM, allowing for accurate quantification. Moreover, it establishes excellent selectivity toward Cu2⁺ even in the presence of a number of potentially interfering metal ions, such as Na⁺, K⁺, Mg2⁺, Ca2⁺, Zn2⁺, and Fe3⁺. The practical applicability of the sensor was effectively studied in different water sources, including pond water, river water, and wastewater, demonstrating consistent performance. This method offers a rapid, cost-effective, and reliable approach for copper contamination in environmental water samples. Consequently, it emphasizes significant potential for environmental monitoring and public health protection.
Pistachio processing wastewater (PPW) is a high-strength agro-industrial effluent that poses a threat to receiving waters and soils, particularly in arid pistachio-producing regions. Generated at roughly 4–6 m3 per ton of processed nuts, PPW carries extreme pollutant loads—chemical oxygen demand (COD) up to 23,500 mg/L and total phenolics of 1,750 – 4,100 mg L⁻1—together with elevated turbidity, TOC, TSS, nitrogen species, chloride, and oil and grease. This systematic review synthesized 15 peer-reviewed studies (to March 2025) on PPW characterization and treatment performance. Electrochemical processes—especially electro-coagulation and electro-oxidation—consistently removed up to 99
Freshwater reservoirs in Mediterranean agricultural basins are increasingly exposed to nutrient enrichment, intensive irrigation demand, and water scarcity, particularly in semi-arid regions where integrated assessments of irrigation water quality remain limited. This study evaluated seasonal irrigation water quality and nutrient pollution in six major reservoirs (Gezende, Alaköprü, Berdan, Bağbaşı, Sarıveliler, and Ermenek) in the Eastern Mediterranean River Basin, Türkiye, which are essential water resources for agriculture and domestic use. The study assessed seasonal variability in irrigation water quality and identified the hydrochemical factors controlling irrigation suitability. Water samples collected during fall, winter, and spring were analyzed for key physicochemical parameters. Irrigation water quality was evaluated using nutrient pollution indices (NPI, NI), irrigation hazard indices (SAR, Na
The issue of soil pollution in agricultural lands is intensifying, posing a significant threat to China’s agricultural output. Cadmium (Cd) pollution is a dominant problem as it can be easily taken by humans through food chains, which has had adverse effects on human health. In this study, the effects of biochar loading with Fe and Mn were examined on Cd immobilization from contaminated farmland soil. The Fe/Mn modified biochar (Fe/Mn@BC) was characterized and the results showed that modification enhanced the adsorption capacity of Fe/Mn@BC owing to more oxygen-containing groups and metal oxides crystals. After a 30d incubation experiment, the dissolved organic matter as well as pH, electrical conductivity, and cation exchange capacity increased under 5
Microplastic contamination has become a serious global environmental issue, with synthetic polymer fragments smaller than 5 mm detected across marine, freshwater, terrestrial, and atmospheric ecosystems. Monitoring and identifying macroplastic waste becomes more difficult as it breaks down into microplastics and even nanoplastics due to mechanical, chemical, and biological deterioration. This study proposes a deep learning architecture, MSD-AttSegNet, a hybrid framework that combines multiscale dilated depthwise convolutions and channel–spatial attention with an enhanced UNet. The pipeline integrates a standardized pre-processing strategy, pixel-wise loss functions, and mathematically defined evaluation metrics. A well-known, publicly available Mendeley dataset consisting of 237 micrographs of microplastic particles (fragments or beads) in the range of 50 μ m – 1 mm and fibres with diameters around 10 μ m is used to train the proposed MSD-AttSegNet using k-fold cross-validation. The performance of the model is evaluated by calculating Accuracy (95.51
Productivity in large lakes is often heterogenous between basins, with potential effects on the fish community and contamination levels in the food web. Clean lakes and resilient food webs support biodiversity and ecological integrity, however, pressures on these ecosystems are numerous. Mercury (Hg) is a ubiquitous neurotoxic metal linked to productivity, thus highlighting its potential value for lake monitoring. However, limited knowledge exists regarding the effectiveness of Hg monitoring between basins of large lakes with different nutrient concentrations. In this study, primary producers, benthic macroinvertebrates, zooplankton, and the fish community were sampled in the less productive Kajaanselkä and more productive Enonselkä basins of Lake Vesijärvi, southern Finland. Basin differences in total Hg content [THg] (mg kg−1) and its bioaccumulation in common fish species, and biomagnification in the food web were assessed. In fish, [THg] was generally higher in the Kajaanselkä basin, although not in all species. Bioaccumulation regression slopes between [THg] and length were also not consistently different between basins. Biomagnification was detected in both basins through the regression of [THg] with nitrogen isotopes (δ15N). However, the trophic magnification slopes (TMS) and [THg] baselines (intercepts) were similar. Variation in [THg] and bioaccumulation found in some fish likely indicates differences in species-specific habitat and resource use and availability between basins. These methods revealed that basin differences in fish THg metrics did not translate to differences in food web biomagnification between basins, although the methods did highlight the potential monitoring value of pelagic fish in large boreal lakes. Similar methods may give more pronounced results given larger differences in morphology and physical and chemical characteristics between lake basins, and future work may explore basin-specific differences in biomagnification between principal habitats.
The bioconcentration factor (BCF) is central to ecological-risk assessment, but experimental BCF measurement is too slow for large-scale chemical screening. Polyhalogenated organophosphate esters are widely used flame retardants and remain of concern because of their persistence and potential bioaccumulation. Here, we developed a quantitative structure–property relationship (QSPR) framework to predict BCF and support environmental risk prioritization for structurally related compounds. A dataset of 160 compounds was divided into training (n = 130) and test (n = 30) sets. Ten descriptors were selected from 766 candidates using a genetic algorithm. Multiple linear regression (MLR), support vector machine (SVM), and backpropagation artificial neural network (BP-ANN) models were constructed and evaluated. Dataset partitioning was examined using Tanimoto similarity analysis and uniform manifold approximation and projection (UMAP) visualization. Model performance was assessed using 11 validation metrics, bootstrap confidence intervals, and Williams-plot applicability-domain analysis. Among the three models, BP-ANN gave the lowest external prediction errors in the present test set (MAEtest = 0.33 and RMSEtest = 0.41) and Q2F2 = 0.79. This ranking should be interpreted cautiously because the test set contained 30 compounds. Descriptor interpretation suggests that BCF variation is associated with lipophilicity, molecular topology, electronic distribution, and phosphorus-containing functional groups. The framework may support early-tier screening of structurally related flame retardants within the defined applicability domain, but experimental confirmation remains necessary for regulatory decisions.
The continued occurrence of antibiotics in the aquatic medium requires new adsorbent materials with low cost but high efficiency. This study developed N,S-RHBC material based on rice husk biochar, co-doped with nitrogen and sulfur combined with KOH activation, creating a porous framework and high density of functionalities suitable for the elimination of oxytetracycline hydrochloride. The optimal material was obtained at the ratio of RHBC:KOH:thiourea 1:3:1, temperature 700 °C, achieving an adsorption efficiency of 96.27
This study examines the spatial and temporal variations of BTEX (Benzene, Toluene, Ethylbenzene, Xylene) compounds in ambient air across West Bengal from 2019 to 2021, with a focus on source apportionment, health risks, and ozone formation potential (OFP). The findings revealed that a declining trend in BTEX concentrations, from 23.25 µg/m3 in 2019 to 17.90 µg/m3 in 2021, attributed to COVID-19 lockdown-induced reductions in vehicular and industrial emissions. The Toluene/Benzene (T/B) and Ethylbenzene/Xylene (E/X) ratios indicated that traffic emissions dominated most locations, whereas industrial emissions were more pronounced during the lockdown. Health risk assessments show elevated cancer risks (LCR > 1 × 10–4) at Padmapukur (7.24 × 10–3), Ballygunge (7.13 × 10–3), and Fort William (1.39 × 10–3), highlighting long-term public health concerns. The Ozone Formation Potential (OFP) remained high post-lockdown, emphasizing the need for stricter VOC emission controls, the adoption of cleaner industrial technologies, and traffic management policies. The correlation analysis suggested that VOC emissions in a few monitoring stations like AS and GS (r = .855) and BN and PP (r = .997) were closely linked, likely due to shared pollution sources. Continuous VOC monitoring, improved air quality regulations, and public awareness initiatives are crucial for mitigating pollution-related health risks.
Benthic sediments from an anthropogenically less-influenced transboundary river (Padma, Bangladesh) have been studied in terms of elemental abundances to understand the geochemical processes and evaluate the potentiallytoxic elemental abundances. Composite sediment samples from 20 sampling locations were measured using neutron activation analysis to determine the concentrations of 15 geo-environmentally significant major and trace elements (Na, K, Al, Ti, Cr, Co, Mn, Zn, Rb, Sb, As, Ba, Cs, Th, and U). Average abundances (μg.g−1) of Rb (108.4), Sb (0.79), Cs (7.42), Th (19.99), and U (4.29) were higher than the corresponding crustal abundances. Results show that geo-accumulation index (Igeo) ranged from uncontaminated to moderately contaminated (0 ≤ Igeo < 1), whereas enrichment factor (EF) suggested minor to significant enrichment (1.5 ≤ EF < 5), particularly for Th, Sb, and U. Positive-matrix-factorization model and other statistical analyses expressed that most of the elements principally possess geogenic origins, which were associated with rock weathering, elemental mobilization, and biogeochemical processes with mineralogical fractionation. In contrast, some elements (Cr, Co, Mn, Sb, As, and Ba) were accumulated from various anthropogenic sources, such as industrial construction sites, building construction materials, municipal waste, etc. Furthermore, sediment behavior according to the sediment quality guideline (SQG) threshold values, Cr and Mn have massive biological impacts on the aquatic ecosystem and ecological balance. Ecological risk assessment showed that individual ecological risk factor (Eri) and overall risk index (RI: 36.9–90.9, mean: 59.2) fall within the low risk category. This study reveals that the Padma River is mostly impacted by geogenic origins, where elemental concentrations are associated with complex fluvial characteristics.
Co-contamination by microplastics (MPs) and heavy metals (HMs) in aquatic sediment has become an increasing environmental concern, yet their coupled distribution patterns and interaction mechanisms in urban–rural river sediment remain insufficiently understood. In this study, sediment samples were collected from typical urban–rural rivers upstream of Hongze Lake during the dry and wet seasons. MPs were identified using μ-FTIR and Raman spectroscopy according to particle size, HMs were quantified by ICP-MS, and the driving factors of HM adsorption onto MPs were explored using structural equation modeling (SEM). The abundance of MPs exhibited significant seasonal variation, with overall higher levels in the dry season. In addition, particles, polyvinyl chloride (PVC) and the transparent color were the predominant form and composition of MPs in both seasons. HMs showed clear selective partitioning between sediment and MPs. Cr was preferentially enriched on MPs (Ksed-MP = 0.0248), whereas Cd was mainly retained in sediment (Ksed-MP = 172) during both seasons. From the dry season to the wet season, HMs generally exhibited an enhanced tendency to loading on MPs. SEM revealed that hydrological seasonality (β = 0.731) and polymer type (β = 0.436) were the key drivers of HM adsorption onto MPs by direct and indirect pathways. Within the study-specific relative screening framework, the calculated index values were generally higher during the dry season and were primarily influenced by Cd and polymers assigned high hazard scores. These findings provide new insight into the co-contamination mechanisms of MPs and HMs and support targeted management of sediment pollution in other typical urban–rural river networks in the world.
Urban drainage systems are increasingly recognized as significant routes for the transport of MPs from land sources to water ecosystems. Hudiara drain is one of the most contaminated drainage systems and its tributary in Lahore (Pakistan), the Rohi drain takes in municipal, industrial, urban run off and solid waste before it flows into River Ravi and other downstream freshwater bodies. Despite numerous studies on contaminants in the Hudiara drain, data regarding microplastic pollution is scare. The current study thus examined the presence, quantity, and characteristics of MPs at eight sites along the Rohi drain to assess its function as a microplastic transport pathway. After chemical digestion and filtration, water samples were examined through brightfield microscopy, fluorescence microscopy, and Fourier Transform Infrared Spectroscopy (FTIR). Our results demonstrate that MPs were found at every sampling location, with average concentrations surpassing 2,500 MPs L⁻1. The predominant microplastic type was transparent polyethylene fiber and thread-like particles, with the majority falling within the 0.1–5 mm size range. A comparison with earlier documented data from freshwater ecosystems in Pakistan, such as rivers, lakes, and coastal areas, alongside global research on urban drainage and wastewater systems, showed that Hudiara drain has significantly greater microplastic pollution than numerous aquatic environments globally. The high level of microplastic pollution demonstrates an alignment with the drain's severely contaminated status and its exposure to ongoing human activities throughout its path. This research recognizes the Hudiara drainage network as a microplastic transport pathway in the Ravi River watershed and offers foundational data to aid in the future monitoring and pollution reduction efforts in urban areas.
Antimicrobial resistance (AMR) represents one of the global threats challenging the dissemination and emergence of resistant microorganisms and resistance genes across humans, veterinary, agriculture, and environmental sectors. These sectors are interconnected and form the basis of the “One Health” approach, in which surface water systems are now considered key players in the persistence and dissemination of AMR. The reservoirs act as potential sources for the dissemination of antibiotic resistant bacteria (ARB) harbouring resistant genes, posing a significant risk to the environment and public health. Therefore, a study entailing the prevalence of antibiotic-resistant coliforms in the Sabarmati River and its polluted sites was conducted. The microbiome of water samples from six different sampling sites harboured 35 different antibiotic resistance genes (ARGs), among which sul1, sul2, sul4, aadA1, and qacE can be potential biomarkers, as these were found in the merging site and the downstream site. The antibiotic resistance frequency (ARF) of the coliforms was higher against ampicillin, cefixime, cefotaxime, chloramphenicol, amoxicillin/clavulanic acid, ampicillin/sulbactam, and ertapenem, and its co-occurrence with ARGs and heavy metals detected through Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) may be associated with the development of AMR in the riverine environment. The findings emphasize critical hotspots for AMR development and underscore the need for improved measures to limit the spread of environmental AMR.
Water management is a crucial factor that influences the remediation efficiency of pesticide-contaminated soils. This study systematically investigated the mechanisms of thiacloprid (THI) removal by biochar-supported zero-valent iron composite (ZVI/PBC) under different water regimes (field capacity at 40
Biosorption represents a sustainable and cost-effective strategy for mitigating heavy metal contamination in aquatic systems. This study investigated the biosorptive potential of the marine cyanobacteria Oscillatoria acutissima and Oscillatoria simplicissima for the removal of copper ions Cu2+ from aqueous solutions and examined the key physicochemical parameters influencing their performance. Batch biosorption experiments were systematically conducted to evaluate the effects of contact time (0–24 h), temperature (20–40°C), pH (4–8), and initial Cu2⁺ concentration (5–50 mg/L) on copper uptake and algal physiological responses. Copper removal efficiency was quantified using atomic absorption spectrometry, while chlorophyll a concentration served as a proxy for algal growth and stress response. Batch experiments demonstrated that optimal Cu(II) removal ( 80
Excessive phosphate discharge into aquatic environments causes severe eutrophication, posing significant threats to ecological balance and human health. Adsorption is a promising technology for phosphate removal, and fly ash (FA), an industrial solid waste, has attracted attention as a low-cost adsorbent. However, raw FA suffers from low adsorption capacity and pH-dependent performance, limiting its practical application. In this study, a dual-alkali (NaOH and Ca(OH)2) modified FA adsorbent (FA-NC) was developed to address these limitations. The synthesis parameters, including the alkali composition, total alkali dosage, and calcination temperature, were systematically optimized. The optimal FA-NC was prepared by mixing 5.0 g of fly ash with 7.0 g of NaOH and Ca(OH)2 at a mass ratio of 1:1, followed by calcination at 600 °C for 2 h. An adsorbent dosage of 1.0 g L−1 was selected for the subsequent phosphate adsorption experiments. The physicochemical properties of FA-NC were characterized by XRD, SEM, EDS, XPS, and nitrogen adsorption–desorption techniques, and its phosphate adsorption performance was evaluated through batch and dynamic experiments. The results showed that under the standard batch condition (1.0 g L−1 FA-NC, 20.0 mg P L⁻1, 240 min), phosphate removal exceeded 97
The upstream Citarum River is one of the volcanic and tropical rivers used by local inhabitants for their daily needs and potentially influences the magnetic mineral traits of the sediments, including in meanders as part of the river system. This study aims to investigate the impact of meanders in the upstream Citarum River on the physicochemical properties of the sediments. The magnetic properties of the sediments in the river were characterized through measurements of magnetic susceptibility, hysteresis parameters, magnetic morphology and mineralogy. These results were then cross-referenced with physical and chemical attributes, as well as other pollution indices. In addition to direct comparison, Principal Component Analysis (PCA) was performed to identify strong and significant correlations that reflect the environmental conditions recorded in the sediment samples. The results indicate that although the point bar exhibited relatively higher magnetic susceptibility values, the straight flow samples showed greater concentrations of Potentially Toxic Elements (PTEs) and higher values of the associated indices (e.g., Pollution Load Index = 1.95 – 4.04) compared to those from the point bar and cut bank. The elevated magnetic susceptibility and pollution indices suggest a dominant influence of anthropogenic activities on the sediment composition. The spatial heterogeneity of sediment physicochemical parameters is driven by differences in hydrodynamic conditions, geomorphological settings, and topographic gradients along the river continuum, from upstream to downstream. Furthermore, sediment transport dynamics, contaminant redistribution, and adsorption–desorption interactions of PTEs with magnetic particles play significant roles in governing the observed spatial variations in physicochemical characteristics of sediments.
Persistent herbicide contamination of soils represents a challenge for sustainable agricultural systems, necessitating efficient remediation strategies. This study evaluated the effectiveness of Canavalia ensiformis associated with macaúba (Acrocomia aculeata) biochar and microbial inoculation for the phytoremediation of the herbicide sulfentrazone. The experiment was conducted under field conditions using a randomized complete block design (RCBD) with a 3 × 3 × 2 factorial arrangement, consisting of three sulfentrazone doses (0, 375, and 625 g a.i. ha⁻1), three remediation strategies (control, biochar, and biochar combined with microbial inoculation), and the presence or absence of C. ensiformis, with four replicates. Gas exchange, chlorophyll fluorescence, photosynthetic pigments, biomass production, and sulfentrazone residues in the soil were evaluated. Herbicide exposure reduced anthocyanin content by up to 44.6
