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Long-term trends in particulate matter from wood burning in the United Kingdom: Dependence on weather and social factors
2022
Font, A. | Ciupek, K. | Butterfield, D. | Fuller, G.W.
Particulate matter from wood burning emissions (Cwₒₒd) was quantified at five locations in the United Kingdom (UK), comprising three rural and two urban sites between 2009 and 2021. The aethalometer method was used. Mean winter Cwₒₒd concentrations ranged from 0.26 μg m⁻³ (in rural Scotland) to 1.30 μg m⁻³ (London), which represented on average 4% (in rural environments) and 5% (urban) of PM₁₀ concentrations; and 8% of PM₂.₅. Concentrations were greatest in the evenings in winter months, with larger evening concentrations in the weekends at the urban sites. Random-forest (RF) machine learning regression models were used to reconstruct Cwₒₒd concentrations using both meteorological and temporal explanatory variables at each site. The partial dependency plots indicated that temperature and wind speed were the meteorological variables explaining the greatest variability in Cwₒₒd, with larger concentrations during cold and calm conditions. Peaks of Cwₒₒd concentrations took place during and after events that are celebrated with bonfires. These were Guy Fawkes events in the urban areas and on New Year's Day at the rural sites; the later probably related to long-range transport. Time series were built using the RF. Having removed weather influences, long-term trends of Cwₒₒd were estimated using the Theil Sen method. Trends for 2015–2021 were downward at three of the locations (London, Glasgow and rural Scotland), with rates ranging from −5.5% year⁻¹ to −2.5% year⁻¹. The replacement of old fireplaces with lower emission wood stoves might explain the decrease in Cwₒₒd especially at the urban sites The two rural sites in England observed positive trends for the same period but this was not statistically significant.
Afficher plus [+] Moins [-]Metabolomics as a tool for in situ study of chronic metal exposure in estuarine invertebrates
2022
Hillyer, Katie E. | Raes, Eric | Karsh, Kristen | Holmes, Bronwyn | Bissett, Andrew | Beale, David J.
Estuaries are subject to intense human use globally, with impacts from multiple stressors, such as metal contaminants. A key challenge is extending beyond traditional monitoring approaches to understand effects to biota and system function. To explore the metabolic effects of complex metal contaminants to sediment dwelling (benthic) fauna, we apply a multiple-lines-of-evidence approach, coupling environmental monitoring, benthic sampling, total metals analysis and targeted metabolomics.We characterise metabolic signatures of metal exposure in three benthic invertebrate taxa, which differed in distribution across sites and severity of metal exposure: sipunculid (very high), amphipod (high), maldanid polychaete (moderate). We observed sediment and tissue metal loads far exceeding sediment guidelines where toxicity-related adverse effects may be expected, for metals including, As, Cd, Pb, Zn and Hg.Change in site- and taxa-specific metabolite profiles was highly correlated with natural environmental drivers (sediment total organic carbon and water temperature). At the most metal influenced sites, metabolite variation was also correlated with sediment metal loads. Using supervised multivariate regression, taxa-specific metabolic signatures of increased exposure and possibility of toxic effects were characterised against multiple reference sites. Metabolic signatures varied according to each taxon and degree of metal exposure, but primarily indicated altered cysteine and methionine metabolism, metal-binding and elimination (lysosomal) activity, coupled to change in complex biosynthesis pathways, responses to oxidative stress, and cellular damage.This novel multiple-lines-of-evidence approach combining metabolomics with traditional environmental monitoring, enabled detection and characterisation of chronic metal exposure effects in situ in multiple invertebrate taxa. With capacity for application to rapid and effective monitoring of non-model species in complex environments, these approaches are critical for improved assessment and management of systems that are increasingly subject to anthropogenic drivers of change.
Afficher plus [+] Moins [-]A walk on the wild side: Wild ungulates as potential reservoirs of multi-drug resistant bacteria and genes, including Escherichia coli harbouring CTX-M beta-lactamases
2022
Torres, Rita Tinoco | Cunha, Monica V. | Araujo, Débora | Ferreira, Helena | Fonseca, Carlos | Palmeira, Josman Dantas
Extended-spectrum β-lactamases (ESBL)-producing Enterobacterales have been classified as critical priority pathogens by the World Health Organization (WHO). ESBL are universally distributed and, in 2006, were firstly reported on a wild animal. Understanding the relative contributions of wild animals to ESBL circulation in the environment is urgently needed. In this work, we have conducted a nationwide study in Portugal to investigate the occurrence of bacteria carrying clinically significant antimicrobial resistance genes (ARG), using widely distributed wild ungulates as model species. A total of 151 antimicrobial resistant-Enterobacterales isolates were detected from 181 wild ungulates: 50% (44/88) of isolates from wild boar (Sus scrofa), 40.3% (25/62) from red deer (Cervus elaphus), 41.4% (12/29) from fallow deer (Dama dama) and 100% (2/2) from mouflon (Ovis aries subsp. musimon). Selected isolates showed a diversified resistance profile, with particularly high values corresponding to ampicillin (71.5%) and tetracycline (63.6%). Enterobacterales strains carried blaTEM, tetA, tetB, sul2, sul1 or dfrA1 ARG genes. They also carried blaCTX₋M-type genes, which are prevalent in human infections, namely CTX-M-14, CTX-M-15 and CTX-M-98. Strikingly, this is the first report of CTX-M-98 in wildlife. Almost 40% (n = 59) of Enterobacterales were multi-drug resistant. The diversity of plasmids carried by ESBL isolates was remarkable, including IncF, K and P. This study highlights the potential role of wild ungulates as environmental reservoirs of CTX-M ESBL-producing E. coli and in the spill-over of AMR bacteria and their determinants. Our findings suggest that wild ungulates are useful as strategic sentinel species of AMR in terrestrial environments, especially in response to potential sources of anthropogenic pollution, providing early warning of potential risks to human, animal and environmental health.
Afficher plus [+] Moins [-]Robust strategies to eliminate endocrine disruptive estrogens in water resources
2022
Vēlāyutan̲, T. A. | Rizwan, Komal | Adeel, Muhammad | Barceló, Damià | Awad, Youssef Ahmed | Iqbal, Hafiz M.N.
The widespread occurrence and ubiquitous distribution of estrogens, i.e., estrone (E1), estradiol (E2), and estriol (E3) in our water matrices, is an issue of global concern. Public and regulatory authorities are concerned and placing joint efforts to eliminate estrogens and related environmentally hazardous compounds, due to their toxic influences on the environmental matrices, ecology, and human health, even at low concentrations. However, most of the available literature is focused on the occurrence of estrogens in different water environments with limited treatment options. Thus, a detailed review to fully cover the several treatment processes is needed. This review comprehensively and comparatively discusses many physical, chemical, and biological-based treatments to eliminate natural estrogens, i.e., estrone (E1), estradiol (E2), and estriol (E3) and related synthetic estrogens, e.g., 17α-ethinylestradiol (EE2) and other related hazardous compounds. The covered techniques include adsorption, nanofiltration, ultrafiltration, ultrasonication, photocatalysis of estrogenic compounds, Fenton, Fenton-like and photo-Fenton degradation of estrogenic compounds, electro-Fenton degradation of estrogenic compounds, ozonation, and biological methods for the removal of estrogenic compounds are thoroughly discussed with suitable examples. The studies revealed that treatment plants based on chemical and biological approaches are cost-friendly for removing estrogenic pollutants. Further, there is a need to properly monitor and disposal of the usage of estrogenic drugs in humans and animals. Additional studies are required to explore a robust and more advanced oxidation treatment strategy that can contribute effectively to industrial-scale applications. This review may assist future investigations, monitoring, and removing estrogenic compounds from various environmental matrices. In concluding remarks, a way forward and future perspectives focusing on bridging knowledge gaps in estrogenic compounds removal are also proposed.
Afficher plus [+] Moins [-]Parameter optimization of waste coal briquetting and particulate matter emissions test during combustion: A case study
2022
Guo, Zhenkun | Miao, Zekai | Guo, Fanhui | Guo, Yang | Feng, Yonghui | Wu, Jianjun | Zhang, Yixin
The abundant coal powder generated as a waste by-product during the lignite upgrading process is harmful to the environment. Lignite briquetting offers a practical solution for lignite usage. Altering the process parameters of briquetting can significantly improve briquette quality. In this paper, the characteristics of lignite briquettes, including drop strength and compressive strength were investigated. A combination of quadratic orthogonal rotation combination designs and regression equations established the best process parameters to be 40% weight of #2 upgraded coal, 20% weight of briquetting moisture, 25 MPa of briquetting pressure, and 12 h of drying time. The low error variance of the drop strength and compressive strength, at 0.01% and 1.83% respectively, verified the feasibility of the model. The analysis by scanning electron microscope (SEM) showed that the surface morphology of briquette was denser than that of raw coal. Finally, the combustion test of briquettes revealed that the particulate matter emission (PM₂.₅) of briquette was 16.7% lower than that of raw coal. In summary, these data provide a theoretical reference for realizing the reasonable utilization potential of waste products derived from industrial processes.
Afficher plus [+] Moins [-]Ultrahigh-resolution PM2.5 estimation from top-of-atmosphere reflectance with machine learning: Theories, methods, and applications
2022
Yang, Qian | Yuan, Qiangqiang | Li, Tongwen
Intra-urban pollution monitoring requires fine particulate (PM₂.₅) concentration mapping at ultrahigh-resolution (dozens to hundreds of meters). However, current PM₂.₅ concentration estimation, which is mainly based on aerosol optical depth (AOD) and meteorological data, usually had a low spatial resolution (kilometers) and severe spatial missing problem, cannot be applied to intra-urban pollution monitoring. To solve these problems, top-of-atmosphere reflectance (TOAR), which contains both the information about land and atmosphere and has high resolution and large spatial coverage, may be efficiently used for PM₂.₅ estimation. This study aims to systematically evaluate the feasibility of retrieving ultrahigh-resolution PM₂.₅ concentration at a large scale (national level) from TOAR. Firstly, we make a detailed discussion about several important but unsolved theoretic problems on TOAR-based PM₂.₅ retrieval, including the band selection, scale effect, cloud impact, and mapping quality evaluation. Secondly, four types and eight retrieval models are compared in terms of quantitative accuracy, mapping quality, model generalization, and model efficiency, with the pros and cons of each type summarized. Deep neural network (DNN) model shows the highest retrieval accuracy, and linear models were the best in efficiency and generalization. As a compromise, ensemble learning shows the best overall performance. Thirdly, using the highly accurate DNN model (cross-validated R² equals 0.93) and through combining Landsat 8 and Sentinel 2 images, a 90 m and ∼4-day resolution PM₂.₅ product was generated. The retrieved maps were used for analyzing the fine-scale interannual pollution change inner the city and the pollution variations during novel coronavirus disease 2019 (COVID-19). Results of this study proves that ultrahigh resolution can bring new findings of intra-urban pollution change, which cannot be observed at previous coarse resolution. Lastly, some suggestions for future ultrahigh-resolution PM₂.₅ mapping research were given.
Afficher plus [+] Moins [-]Source and distribution characteristics of 239, 240, 241Pu, 237Np and 134, 137Cs in sediments in the Northwest and Central Equatorial Pacific after the Fukushima nuclear accident
2022
Wang, Fenfen | Zheng, Jian | Aono, Tatsuo | Pan, Shaoming | Men, Wu
To understand the possible influence of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident on the deep sea, as well as the geochemical behavior and transport of radionuclides, ¹³⁴Cs, ¹³⁷Cs, ²³⁹, ²⁴⁰Pu, ²⁴¹Pu, and ²³⁷Np were measured in the abyssal sediments of the Northwest Pacific (NWP) and Central Equatorial Pacific (CEP) Ocean. Data on the characteristics of these sediments obtained after the FDNPP accident are extremely rare, especially in the NWP subtropical gyre (NPSG) region. FDNPP-derived radio-Cs (¹³⁴Cs, ¹³⁷Cs) arrived at the open sea floor of the NWP before 2018 but was only found in the Kuroshio-Oyashio Extension (KOE) region. No FDNPP-derived Pu was detected in the abyssal sediments of the NWP or CEP. Pu in the NWP mainly originated from global fallout and the Pacific Proving Ground (PPG) close-in fallout, except for at station WP1 (39°N in the KOE region), where an abnormal but non-FDNPP-derived Pu signal was detected. Pu in the eastern CEP sediment was less affected by the PPG close-in fallout from the Marshall Islands and was mainly derived from global fallout, with some close-in fallout from the Johnston Atoll test. The KOE region was the area most affected by PPG close-in fallout Pu via Kuroshio transport, while the lowest inventories of ²³⁹⁺²⁴⁰Pu and ²³⁷Np were found in the NPSG region due to its oligotrophic environment. The ²³⁷Np originated from the same source as Pu, and the latitudinal pattern of ²³⁷Np was consistent with that of Pu. Station SS (in the marginal sea of the NWP) contained high ²³⁷Np/²³⁹Pu atom ratios in the deeper layers of sediment and had a ²³⁷Np depth profile opposite that of the ²³⁹⁺²⁴⁰Pu profile, compared to other stations; these differences are mainly attributed to differences in the behaviors of ²³⁷Np and ²³⁹Pu.
Afficher plus [+] Moins [-]Reconstructing atmospheric Hg levels near the oldest chemical factory in central Europe using a tree ring archive
2022
Nováková, Tereza | Navratil, Tomas | Schütze, Martin | Rohovec, Jan | Matoušková, Šárka | Hošek, Michal | Matys Grygar, Tomáš
The Chemical Factory in Marktredwitz (CFM) is known as the oldest chemical factory in Germany (1778–1985), and from the beginning of the 20ᵗʰ century focused primarily on the production of mercury (Hg) compounds. Due to extensive pollution, together with employee health issues, the CFM was shut in 1985 by a government order and remediation works proceeded from 1986 to 1993. In this study, tree ring archives of European Larch (Larix decidua Mill.) were used to reconstruct changes of air Hg levels near the CFM. Mercury concentrations in larch boles decreased from 80.6 μg kg⁻¹ at a distance of 0.34 km–3.4 μg kg⁻¹ at a distance of 16 km. The temporal trend of atmospheric Hg emissions from the CFM reconstructed from the tree ring archives showed two main peaks. The first was in the 1920s, with a maximum tree ring Hg concentration 249.1 ± 43.9 μg kg⁻¹ coinciding with when the factory had a worldwide monopoly on the production of Hg-based seed dressing fungicide. The second peak in the 1970s, with a maximum tree ring Hg concentration of 116.4 ± 6.3 μg kg⁻¹, was associated with a peak in the general usage and production of Hg chemicals and goods. We used the tree ring record to reconstruct past atmospheric Hg levels using a simple model of Hg distribution between the larch tree rings and atmosphere. The precision of the tree ring model was checked against the results of air Hg measurements during the CFM remediation 30 years ago. According to the tree ring archives, the highest air Hg concentrations in the 1920s in Marktredwitz were over 70 ng m⁻³. Current air Hg levels of 1.18 ng m⁻³, assessed in the city of Marktredwitz, indicate the lowest air Hg in the past 150 years, underscoring the effective remediation of the CFM premises 30 years ago.
Afficher plus [+] Moins [-]Responses of microbial community composition and function to biochar and irrigation management and the linkage to Cr transformation in paddy soil
2022
Xiao, Wendan | Ye, Xuezhu | Ye, Zhengqian | Zhang, Qi | Zhao, Shouping | Chen, De | Gao, Na | Huang, Miaojie
Combining biochar with irrigation management to alter the microbial community is a sustainable method for remediating soils contaminated by heavy metals. However, studies on how these treatments promote Cr(VI) reduction are limited, and the corresponding microbial mechanisms are unclear. Therefore, we conducted a pot experiment to explore the responses of soil microbial communities to combined biochar amendment and irrigation management strategies and their involvement in Cr transformation in paddy soils. Six treatments were established using varying concentrations of biochar (0, 1, and 2% [w/w]) combined with two irrigation management strategies (continuous flooding [CF] and dry–wet alternation [DWA]). The results showed that the combined biochar addition and irrigation management strategy significantly altered soil pH, redox potential, organic matter content, and Fe(II) and sulfide concentrations. In addition, the Cr(VI) concentration under CF irrigation management was conspicuously lower (48.2–54.4%) than that under DWA irrigation management. Biochar amendment also resulted in a substantial reduction (8.8–27.4%) in Cr(VI) concentration. Moreover, the changes in soil physicochemical properties remarkably affected the soil microbial community. The microbial diversity and abundance significantly increased with biochar amendment. Furthermore, the combined biochar amendment and CF strategy stimulated the growth of Geobacter- and Anaeromyxobacter-related Fe(III)-reducing bacteria, Gallionella-related Fe(II)-oxidizing bacteria, and Desulfovibro- and Clostridium-related sulfate-reducing bacteria, which simultaneously facilitated the generation of Fe(II) and sulfide, thereby enhancing Cr(VI) reduction. Consequently, our results suggest that the effectively increased abundance of Fe-reducing/oxidizing bacteria and sulfate-reducing bacteria via combined CF irrigation management and biochar addition may be a key factor in reducing Cr(VI) in paddy soil. The keystone genera responsible for Cr(VI) reduction were Geobacter, Anaeromyxobacter, Gallionella, Desulfovibro, and Clostridium. This study provides novel insights into the coupling mechanism of the Fe/S/Cr transformation mediated by Fe-reducing/oxidizing bacteria and sulfate-reducing bacteria.
Afficher plus [+] Moins [-]Synergetic removal of thallium and antimony from wastewater with jacobsite-biochar-persulfate system
2022
Liu, Juan | Wei, Xudong | Ren, Shixing | Qi, Jianying | Cao, Jielong | Wang, Jin | Wan, Yuebing | Liu, Yanyi | Zhao, Min | Wang, Liang | Xiao, Tangfu
Both of thallium (Tl) and antimony (Sb) are toxic elements in the natural environment. Emerging Tl and Sb pollution in water has gradually gained public concerns globally. However, limited technologies are available for co-removal of Tl and Sb from wastewater. Herein, an novel system was successfully fabricated to enhance the synergetic removal of both Tl and Sb in wastewater. In this study, MnFe₂O₄-biochar composite (MFBC) facilely synthesized by a one-pot hydrothermal method was used as adsorbent and persulfate (PS) activator for simultaneously removing Tl and Sb from wastewater. The optimal reaction conditions for best removal efficiency of Tl and Sb simultaneously were obtained by using the response surface design combined with Box-Behnken Design (BBD) model. Results unveiled that the average removal rates of Tl and Sb can achieve 98.33% and 89.14%, respectively under the optimal reaction conditions. Electron Spin Resonance (ESR), and radical quenching experiments showed that OH• and SO₄•– play a critical role in the removal of Tl–Sb compound pollution. Via using different characterization, it is revealed that the mechanism of removing Tl–Sb containing wastewater by MFBC-1.4/PS system is oxidation, adsorption, complexation and ion exchange. All these results indicate that MFBC-1.4/PS technology is prospective in highly effective removal of Tl and Sb from wastewater simultaneously.
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