خيارات البحث
النتائج 1541 - 1550 من 7,288
Synthesis of dye-sensitized TiO2/Ag doped nano-composites using UV photoreduction process for phenol degradation: A comparative study النص الكامل
2022
Behera, Amit Kumar | Shadangi, Krushna Prasad | Sarangi, Prakash Kumar
This study investigates a comparison between the photocatalytic action of two nanocomposites (TiO₂ and TiO₂(Ag) doped) on the degradation of phenol from water. The nanocomposites were synthesized by the UV photo-reduction process to get a silver metal loading of 0.25, 0.5, 0.75, and 1% (w/w). In addition to this, Eriochrome Cyanine Red (ECR) and Eosin Yellow (EY) both anionic dyes were used for sensitization of Ag-doped TiO₂ photo-catalyst such as TiO₂(Ag)ECR and TiO₂(Ag)EY. The TiO₂(Ag-1.0)EY photo-catalyst indicated higher absorbance compared to the TiO₂(Ag-1.0)ECR in the 400–700 nm range (visible range). The degradation of phenol was tested by varying the pH, silver loading and catalyst dosage. The maximum degradation of phenol was 98% in 180 min at pH 7 in presence of 1% (w/w) silver loading with 0.5 gL⁻¹ dosage of photo-catalyst TiO₂(Ag-1.0)EY. At this condition, the reduction in the phenol concentration was noticed from 20 mg/L to 0.4 mg/L.
اظهر المزيد [+] اقل [-]Occurrence and distribution of Carbapenem-resistant Enterobacterales and carbapenemase genes along a highly polluted hydrographic basin النص الكامل
2022
Teixeira, Pedro | Tacão, Marta | Henriques, Isabel
We determined the distribution and temporal variation of Carbapenem Resistant Enterobacterales (CRE), carbapenemase-encoding genes and other antibiotic resistance genes (ARGs) in a highly polluted river (Lis River; Portugal), also assessing the potential influence of water quality to this distribution. Water samples were collected in two sampling campaigns performed one year apart (2018/2019) from fifteen sites and water quality was analyzed. CRE were isolated and characterized. The abundance of four ARGs (blaNDM, blaKPC, tetA, blaCTX₋M), two Microbial Source Tracking (MST) indicators (HF183 and Pig-2-Bac) and the class 1 integrase gene (IntI1) was measured by qPCR. confirmed the poor quality of the Lis River water, particularly in sites near pig farms. A collection of 23 CRE was obtained: Klebsiella (n = 19), Enterobacter (n = 2) and Raoultella (n = 2). PFGE analysis revealed a clonal relationship between isolates obtained in different sampling years and sites. All CRE isolates exhibited multidrug resistance profiles. Klebsiella and Raoultella isolates carried blaKPC while Enterobacter harbored blaNDM. Conjugation experiments were successful for only four Klebsiella isolates. All ARGs were detected by qPCR on both sampling campaigns. An increase in ARGs and IntI1 abundances was detected in sites located downstream of wastewater treatment plants. Strong correlations were observed between blaCTX₋M, IntI1 and the human-pollution marker HF183, and also between tetA and the pig-pollution marker Pig-2-bac, suggesting that both human- and animal-derived pollution in the Lis River are a potential source of ARGs. Plus, water quality parameters related to eutrophication and land use were significantly correlated with ARGs abundances. Our findings demonstrated that the Lis River encloses high levels of antibiotic resistant bacteria and ARGs, including CRE and carbapenemase-encoding genes. Overall, this study provides a better understanding on the impacts of water pollution resulting from human and animal activities on the resistome of natural aquatic systems.
اظهر المزيد [+] اقل [-]Visualization and (Semi-)quantification of submicrometer plastics through scanning electron microscopy and time-of-flight secondary ion mass spectrometry النص الكامل
2022
Chou, Shih-Hsuan | Chuang, Yung-Kun | Lee, Chi-Ming | Zhang, Yushan | Jhang, Ya-Jhu | Yeh, Ching-Wen | Wu, Tai-Sing | Chuang, Chun-Yu | Hsiao, I-Lun
Increasing numbers of studies have demonstrated the existence of nanoplastics (1–999 nm) in the environment and commercial products, but the current technologies for detecting and quantifying nanoplastics are still developing. Herein, we present a combination of two techniques, e.g., scanning electron microscopy (SEM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS), to analyze submicron-sized plastics. A drop-casting of a 20-nL particle suspension on a Piranha solution-cleaned silicon wafer with dry ice incubation and subsequent freeze-drying was used to suppress the coffee-ring effect. SEM images were used to quantify particles, and this technique is applicable for 0.195–1.04-μm polystyrene (PS), 0.311-μm polyethylene terephthalate (PET), and 0.344-μm polyethylene (PE) at a minimum concentration of 2.49 × 10⁹ particles/mL. ToF-SIMS could not quantify the particle number, while it could semi-quantitatively estimate number ratios of submicron PE, PET, polyvinyl chloride (PVC), and PS particles in the mixture. Analysis of submicron plastics released from three hot water-steeped teabags (respectively made of PET/PE, polylactic acid (PLA), and PET) was revisited. The SEM-derived sizes and particle numbers were comparable to those measured by a nanoparticle tracking analysis (NTA) regardless of whether or not the hydro-soluble oligomers were removed. ToF-SIMS further confirmed the number ratios of different particles from a PET/PE composite teabag leachate. This method shows potential for application in analyzing more-complex plastic particles released from food contact materials.
اظهر المزيد [+] اقل [-]A large geographic-scale characterization of organochlorine pesticides (OCPs) in surface sediments and multiple aquatic foods of inland freshwater aquaculture ponds in China: Co-occurrence, source and risk assessment النص الكامل
2022
Chen, Lu | Qian, Yong-Zhong | Jia, Qi | Weng, Rui | Zhang, Xinglian | Li, Yun | Qiu, Jing
Inland freshwater aquaculture ponds (IFAPs) represent the key component of the global lentic freshwater environment and are increasingly important for global aquaculture production, yet the occurrence of organochlorine pesticides (OCPs) in these pond systems remains largely unknown. Here, we characterized the residual concentrations of 19 individual OCPs in sediments and in cultured fish and crustacean species (crabs, shrimp, crayfish and lobster), which were on-spot sampled from the IFAPs at a large region-scale in China. The total OCP levels in sediments varied dramatically between regions. Crabs presented the greatest OCP contamination among the studied species. Dichlorodiphenyltrichloroethanes (DDTs) was the dominating contaminant in sediments and crabs and its stable degradation products 4,4′-DDE and 4,4′-DDD were co-occurrent between these two compartments. The diagnostic ratio analysis indicated fresh inputs of DDTs, lindane and aldrin in multiple regions, which may be resulted from agricultural soil erosion, surface runoff and local anthropogenic activities. Ecological impacts of these pesticides could be expected at some sites due to their levels in sediments above the risk level. Risk assessment based on the OCP levels corrected by the cooking loss revealed that daily consumption of the IFAPs-derived aquatic foods may pose carcinogenic risks in humans.
اظهر المزيد [+] اقل [-]Valorisation of agri-food waste to fertilisers is a challenge in implementing the circular economy concept in practice النص الكامل
2022
Chojnacka, K. | Moustakas, K. | Mikulewicz, M.
The area of agricultural wastes valorisation to fertilizers is attracting growing attention because of the increasing fertilizer prices of fertilizers and the higher costs of waste utilization. Despite the scientific and political interest in the concept of circular economy, few studies have considered the practical approach towards the implementation of elaborated technologies. This article outlines innovative strategies for the valorisation of different biobased wastes into fertilizers. The present work makes a significant contribution to the field of new ideas for waste biomass management to recover significant fertilizer nutrients. These results emphasize the importance of the biomass use as a base of renewable resources, which has recently gained special importance, especially in relation to the outbreak of pandemia and war. Broken supply chains and limited access to deposits of raw materials used in fertilizer production (natural gas, potassium salts) meant that now, as never before, it has become more important and feasible to implement the idea of a circular economy and a green deal. We have obtained satisfactory results that demonstrate that appropriate management of biological waste (originating from agriculture, food processing, aquaculture, forest, pharmaceutical industry, and other branches of industry, sewage sludge) will not only reduce environmental nuisance (reducing waste heaps), but will also allow recovery of valuable materials, such as nitrogen (especially valuable amino acids), phosphorus, potassium, microelements, and biologically active substances with properties that stimulate plant growth. The results reported here provide information on production of biobased plant protection products (bioagrochemicals) from agri-food waste. This work reports an overview of biopesticides and biofertilisers production technologies and summarizes their properties and the mechanisms of action.
اظهر المزيد [+] اقل [-]Bioremediation of petroleum-contaminated saline soil by Acinetobacter baumannii and Talaromyces sp. and functional potential analysis using metagenomic sequencing النص الكامل
2022
Liu, Xiaoyan | He, Lihong | Zhang, Xinying | Kong, Dewen | Chen, Zongze | Lin, Jia | Wang, Chuanhua
Microbial remediation is a potential remediation method for petroleum-contaminated soil. In order to explore the petroleum degradation mechanism by microorganisms, the oilfield soil was remedied by Acinetobacter baumannii combined with Talaromyces sp. The degradation mechanism was studied by analyzing soil microbial community and functional genes through metagenomics during the degradation process. The result showed the degradation rate of petroleum was 65.6% after 28 days. The concentration of petroleum decreased from 1220 mg/kg to 420 mg/kg. In the co-culture group, Acinetobacter baumannii became the dominant species, the annotated genes of it at the species level accounted for 7.34% while that of Talaromyces sp. accounted for only 0.34%. Meanwhile, the annotated genes of Bacillus, Halomonas, and Nitriliruptor at the genus level were up-regulated by 1.83%, 0.90%, and 0.71%, respectively. In addition, large functional genes were significantly up-regulated, including the peroxisome, P450 enzyme (CYP53, CYP116, CYP102, CYP645), and biofilm formulation, promoting the oxidation and hydroxylation, and catalyzing the epoxidation of aromatic and aliphatic hydrocarbons. Meanwhile, the degrading genes of alkanes and aromatic hydrocarbons were expressed promotionally, and degradation pathways were deduced. In conclusion, the inoculation of Acinetobacter baumannii combined with Talaromyces sp. accelerated the degradation of petroleum in oilfield soil and improved the growth of indigenous petroleum-degrading bacteria. Many functional genes related to petroleum degradation were promoted significantly. These results proved the co-culture of bacteria-fungi consortium contributes to the bioremediation of petroleum-contaminated soil.
اظهر المزيد [+] اقل [-]Association between urinary propylene oxide metabolite and the risk of dyslexia النص الكامل
2022
Liu, Qi | Wan, Yanjian | Zhu, Bing | Xie, Xinyan | Zhu, Kaiheng | Jiang, Qi | Feng, Yanan | Xiao, Pei | Xiang, Zhen | Wu, Xiaoqian | Zhang, Jiajia | Meng, Heng | Song, Ranran
Although it is a probable human carcinogen, propylene oxide is widely applied in industry and daily life. However, data on neurodevelopmental effects of propylene oxide exposure among children are extremely limited. We aimed to determine the urinary concentrations of propylene oxide metabolite among school-aged children and evaluate the potential association of propylene oxide exposure with risk of dyslexia. A total of 355 dyslexic children and 390 controls were recruited from three cities (Jining, Wuhan, and Hangzhou) in China, between 2017 and 2020. Urinary N-acetyl-S-(2-hydroxypropyl)-L-cysteine (i.e., 2-hydroxypropyl mercapturic acid; 2-HPMA) was measured as the biomarker of propylene oxide exposure. The detection frequency of 2-HPMA was 100%. After adjusting for potential confounders, the odds ratio (OR) for dyslexia per 2-fold increase in urinary 2-HPMA was 1.19 [95% confidence interval (95% CI): 1.01, 1.40, P = 0.042]. Compared with the lowest quartile of urinary 2-HPMA concentrations, children with the highest quartile of 2-HPMA had a 1.63-fold (95% CI: 1.03, 2.56, P = 0.036) significantly increased risk of dyslexia, with a dose-response relationship (P-trend = 0.047). This study provides epidemiological data on the potential association between propylene oxide exposure and the risk of dyslexia in children. Further studies are warranted to confirm the findings and reveal the underlying biological mechanisms.
اظهر المزيد [+] اقل [-]Comparative study of the sensitivity of two freshwater gastropods, Lymnaea stagnalis and Planorbarius corneus, to silver nanoparticles: bioaccumulation and toxicity النص الكامل
2022
Wang, Ting | Marle, Pierre | Slaveykova, Vera I. | Schirmer, Kristin | Liu, Wei
Metal-based nanoparticles (NPs) are considered detrimental to aquatic organisms due to their potential accumulation. However, little is known about the mechanisms underlying these effects and their species-specificity. Here we used stable silver (Ag) NPs (20 nm, from 10 to 500 μg/L) with a low dissolution rate (≤2.4%) to study the bioaccumulation and biological impacts in two freshwater gastropods: Lymnaea stagnalis and Planorbarius corneus. No mortality was detected during the experiments. Ag bioaccumulation showed a dose-related increase with an enhanced concentration in both species after 7d exposure. L. stagnalis displayed a higher accumulation for AgNPs than P. corneus (e.g., up to 18- and 15-fold in hepatopancreas and hemolymph, respectively) which could be due to the more active L. stagnalis having greater contact with suspended AgNPs. Furthermore, the hepatopancreas and stomach were preferred organs for bioaccumulation compared to the kidney, mantle and foot. Regarding biological responses, the hemolymph rather than hepatopancreas appeared more susceptible to oxidative stress elicited by AgNPs, as shown by significantly increasing lipid peroxidation (i.e., formation of malondialdehyde). Neurotoxicity was detected in L. stagnalis when exposed to high concentrations (500 μg/L). Comparison with impacts elicited by dissolved Ag revealed that the effects observed on AgNPs exposure were mainly attributable to NPs. These results highlighted the relationship between the physiological traits, bioaccumulation, and toxicity responses of these two species to AgNPs and demonstrated the necessity of species-specificity considerations when assessing the toxicity of NPs.
اظهر المزيد [+] اقل [-]Pollutant specific optimal deep learning and statistical model building for air quality forecasting النص الكامل
2022
Middya, Asif Iqbal | Roy, Sarbani
Poor air quality is becoming a critical environmental concern in different countries over the last several years. Most of the air pollutants have serious consequences on human health and wellbeing. In this context, efficient forecasting of air pollutants is currently crucial to predict future events with a view to taking corrective actions and framing effective environmental policies. Although deep learning (DL) as well as statistical forecasting models are investigated in the literature, they have rarely used in air pollutant-specific optimal model building for long-term forecasting. In this paper, our aim is to develop the pollutant-specific optimal forecasting models for the phases spanning from preprocessing to model building by investigating a set of predictive techniques. In this regard, this paper presents a methodology for long-term forecasting of some important air pollutants. More specifically, a total of eight best performing models such as stacked LSTM, LSTM auto-encoder, Bi-LSTM, convLSTM, Holt-Winters, auto-regressive (AR), SARIMA, and Prophet are investigated for developing pollutant-specific optimal forecasting models. The study is carried out based on the real-world data obtained from government-run air quality monitoring units in Kolkata over a period of 4 years. The models such as Holt-Winters, Bi-LSTM, and ConvLSTM achieve high forecasting accuracy with respect to MAE and RMSE values for majority of the pollutants.
اظهر المزيد [+] اقل [-]Commercial cuttlefish exposed to noise from offshore windmill construction show short-range acoustic trauma النص الكامل
2022
Solé, Marta | De Vreese, Steffen | Fortuño, José-Manuel | van der Schaar, Mike | Sánchez, Antonio M. | André, Michel
Commercial cuttlefish exposed to noise from offshore windmill construction show short-range acoustic trauma النص الكامل
2022
Solé, Marta | De Vreese, Steffen | Fortuño, José-Manuel | van der Schaar, Mike | Sánchez, Antonio M. | André, Michel
The installation of marine renewable energy devices (MREDs, wind turbines and converters of wave, tidal and ocean thermal energy) has increased quickly in the last decade. There is a lack of knowledge concerning the effects of MREDs on benthic invertebrates that live in contact with the seabed. The European common cuttlefish (Sepia officinalis) is the most abundant cephalopod in the Northeast Atlantic and one of the three most valuable resources for English Channel fisheries. A project to build an offshore wind farm in the French bay of Saint-Brieuc, near the English Channel, raised concern about the possible acoustic impact on local cuttlefish communities. In this study, consisting of six exposure experiments, three types of noise were considered: 3 levels of pile-driving and 3 levels of drilling. The objectives were to assess possible associated changes in hatching and larva survival, and behavioural and ultrastructural effects on sensory organs of all life stages of S. officinalis populations. After exposure, damage was observed in the statocyst sensory epithelia (hair cell extrusion) in adults compared to controls, and no anti-predator reaction was observed. The exposed larvae showed a decreased survival rate with an increasing received sound level when they were exposed to maximum pile-driving and drilling sound levels (170 dB re 1 μPa² and 167 dB re 1 μPa², respectively). However, sound pressure levels's lower than 163 dB re 1 μPa² were not found to elicit severe damage. Simulating a scenario of immobile organisms, eggs were exposed to a combination of both pile driving and drilling as they would be exposed to all operations without a chance to escape. In this scenario a decrease of hatching success was observed with increasing received sound levels.
اظهر المزيد [+] اقل [-]Commercial cuttlefish exposed to noise from offshore windmill construction show short-range acoustic trauma النص الكامل
2022
Solé, Marta | De Vreese, Steffen | Fortuño Alós, José Manuel | Van der Schaar, Mike | Sánchez, Antonio M. | André, Michel | Agencia Estatal de Investigación (España) | Iberdrola
13 pages, 9 figures, supplementary data https://doi.org/10.1016/j.envpol.2022.119853.-- Data availability: Data will be made available on request | The installation of marine renewable energy devices (MREDs, wind turbines and converters of wave, tidal and ocean thermal energy) has increased quickly in the last decade. There is a lack of knowledge concerning the effects of MREDs on benthic invertebrates that live in contact with the seabed. The European common cuttlefish (Sepia officinalis) is the most abundant cephalopod in the Northeast Atlantic and one of the three most valuable resources for English Channel fisheries. A project to build an offshore wind farm in the French bay of Saint-Brieuc, near the English Channel, raised concern about the possible acoustic impact on local cuttlefish communities. In this study, consisting of six exposure experiments, three types of noise were considered: 3 levels of pile-driving and 3 levels of drilling. The objectives were to assess possible associated changes in hatching and larva survival, and behavioural and ultrastructural effects on sensory organs of all life stages of S. officinalis populations. After exposure, damage was observed in the statocyst sensory epithelia (hair cell extrusion) in adults compared to controls, and no anti-predator reaction was observed. The exposed larvae showed a decreased survival rate with an increasing received sound level when they were exposed to maximum pile-driving and drilling sound levels (170 dB re 1 μPa2 and 167 dB re 1 μPa2, respectively). However, sound pressure levels's lower than 163 dB re 1 μPa2 were not found to elicit severe damage. Simulating a scenario of immobile organisms, eggs were exposed to a combination of both pile driving and drilling as they would be exposed to all operations without a chance to escape. In this scenario a decrease of hatching success was observed with increasing received sound levels | We acknowledges the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX 2019-000928-S). Funding for this project was provided by Ailes Marines SAS (Iberdrola Group). Project: Noise influence for cuttlefish invertebrate - St Brieuc Wind Farm Site (Ref. CPCS – 771596). France | Peer reviewed
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