خيارات البحث
النتائج 3451 - 3460 من 8,010
Linearized and nonlinearized modellings for comparative uptake assessment of metal-organic framework-derived nanocomposite towards sulfonamide antibiotics النص الكامل
2021
Van Tran, Thuan | Nguyen, Duyen Thi Cam | Nguyen, Thuong Thi | Pham, Quynh Trang | N. Vo, Dai-Viet | Bảo, Định Giang | Van Pham, Thinh | Nguyen, Trinh Duy
The emergent occurrence of sulfonamide species involving sulfadiazine (SDZ) and sulfamethazine (SMZ) in aquatic systems can cause a wide range of potential risks; hence, remediation strategies need to be necessary. Here, we develop the novel metal-organic framework-derived nanocomposite, and apply for the adsorption of SDZ and SMZ antibiotics. To assess the best-fitting kinetic (pseudo first-order, pseudo second-order) and isotherm (Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Redlich-Peterson, Sips, Toth, and Khan) models, a series of numerous statistical analysis was performed. Numerous error functions including squares of the errors (SSE), hybrid fractional error function (HYBRID), Marquardt’s percent standard deviation (MPSD), and mean relative error (MRE) were also analyzed to assess the linear and nonlinear models. The results indicated that both linear and nonlinear kinetic models were mostly fitted well with pseudo second-order models (Rₐdⱼ)² > 0.97. Although linear kinetics gave better (Rₐdⱼ)², error functions (MRE, SSE, HYBRID, and MPSD) were mostly higher than those of nonlinear kinetics. For adsorption isotherm, nonlinear Redlich-Peterson was the most compatible model with extremely high adjusted coefficients of determination (Rₐdⱼ)² ~ 1.0000. While nonlinear Langmuir model gave relatively high (Rₐdⱼ)² (0.9898–0.9960) and acceptable error functions, we found the considerable difference of error functions and parameters among four types of linear Langmuir (Types I, II, III, IV). The findings indicate potential errors as selecting one of linearized Langmuir types in equilibrium study. It is suggested that nonlinear models should be applied for better fitness.
اظهر المزيد [+] اقل [-]Anaerobic treatment of slaughterhouse wastewater: a review النص الكامل
2021
Shende, Akshay D. | Pophali, Girish R.
This article presents a review of anaerobic treatment technologies to treat slaughterhouse wastewater including its advantages and disadvantages. Physico-chemical characteristics and biochemical methane potential (BMP) of slaughterhouse wastewater are addressed. Various anaerobic treatment technologies are presented with the related operating parameters, viz., hydraulic retention time (HRT), organic loading rate (OLR), upflow velocity (Vᵤₚ), and biogas yield vis-a-vis treatment efficiency in terms of chemical oxygen demand (COD). In addition, various factors that affect the anaerobic treatment of slaughterhouse wastewater such as high oil & grease (O & G) concentration in influent, inhibitors, volatile fatty acids (VFAs), and the loading rate are also addressed. The literature review indicated that the slaughterhouse wastewater can be treated effectively by employing any anaerobic treatment technologies at OLRs up to 5 kg COD/m³.d with more than 80% COD removal efficiency without experiencing operational problems. Anaerobic hybrid reactors (AHRs) were found the most effective among various reviewed technologies because of their ability to operate at higher OLRs (8 to 20 kg COD/m³.d) and lower HRTs (8 to 12 hrs).
اظهر المزيد [+] اقل [-]Global trends and characteristics of vermicompost research over the past 24 years النص الكامل
2021
Ghorbani, Mona | Sabour, Mohammad Reza
This study aims to investigate a practical bibliometric analysis and discuss its trends to evaluate the global scientific production of vermicompost research from 1993 to 2017 and explain its several advantages to our environment and waste management. The data were from the database of the Science Citation Index (SCI) published by the ISI Web of Science and illustrated by Excel and VOS viewer. According to the 2174 publications, this article was conducted based on four significant aspects, including publications growth trends, countries/territories, categories and journals, and keywords co-occurrence network analysis. This study revealed remarkable positive growth trends of the research and the number of articles related to vermicompost over the last 24 years with more countries participating in this field. Although the USA has the most collaboration with other countries, developing countries such as India, which was the most productive one, made significant progress in sharing articles within the study period. Based on analyses of dominant categories, the most common subject category was Environmental Science, and the most productive journal was Bioresource Technology. Finally, we analyzed author keywords to the extracted research article emphasis. The results showed that mainstream research claim vermicomposting with the help of Eisenia fetida earthworms which converts several wastes such as sewage sludge to a soil improvement fertilizer. It is an essential approach to eliminate heavy metals from the wastes and provide essential nutrients to improve the growth and yield of plants.
اظهر المزيد [+] اقل [-]A review on fabricating functional materials by heavy metal–containing sludges النص الكامل
2021
Hou, Hao | Liu, Zixing | Zhang, Jia | Zhou, Jizhi | Qian, Guangren
With the development of industry, sustainable use of natural resources has become a worldwide hot topic. Heavy metal–containing sludge (HMS) is a hazardous waste after wastewater treatment. At present, HMS is still treated by landfill or landfill after incineration. Considering the components, HMS usually contains various heavy metals and organic compounds, which is potentially used as a raw resource for catalyst production. This review thus concludes recent reports and developments in this field. First, basic technologies are summarized as component regulation, precursor formation, and structure transformations. Second, prepared materials are applied in various catalytic fields, such as gas purification, photocatalysis, electrocatalysis, and Fenton catalysis. During these processes, key factors are multi-metallic components, metal doping, temperature, and pH. They not only influence the formation of HMS-derived catalyst but also the catalytic activity. Furthermore, catalytic activities of HMS-derived catalysts are compared with those synthesized by pure reagents. An assessment and accounting are also supplied if raw resources are substituted by HMS. Finally, in order to apply HMS in a real application, more works must be devoted to the influence of trace metal doping on catalytic activities and stabilities. Besides, more pilot experiments are urgently necessary.
اظهر المزيد [+] اقل [-]Relationship between tourism number and air quality by carbon footprint measurement: a case study of Jiuzhaigou Scenic Area النص الكامل
2021
Yuan, Hong | Nie, Kun-xi | Xu, Xiao-ya
Both the environmental and the ecological protection are key issues in the sustainable development of tourism. As a well-known world natural and cultural heritage, intensive study about the environment of Jiuzhaigou scenic spot has been launched since China’s natural landscape protection. The field of low-carbon tourism is starting to be explored in China, and this article uses the life cycle assessment theory to evaluate the footprint of Jiuzhaigou. We find that the air quality is closely related to the number of tourists. Therefore, to maintain the environment of Jiuzhaigou, the number of tourists is proposed to restrict. The contribution of this paper is to provide pricing theory for attracting potential tourists and to give a theoretical basis for controlling the number of tourists in Jiuzhaigou Scenic Area.
اظهر المزيد [+] اقل [-]Copper-promoted heterogeneous Fenton-like oxidation of Rhodamine B over Fe3O4 magnetic nanocatalysts at mild conditions النص الكامل
2021
Du, Wei | Huang, Ran | Huang, Xuanlin | Chen, Rong | Chen, Fengxi
Rhodamine B (RhB) is used in various industries and its effluent must be effectively treated because of its harmful and carcinogenic nature. In this work, ionothermally synthesized Cu-doped Fe₃O₄ magnetic nanoparticles (Cu–Fe₃O₄ MNPs) were found to be a highly efficient heterogeneous Fenton-like catalyst for complete decolorization of the RhB solution with H₂O₂ at pH ~ 7 and 25 °C. The effects of the catalyst loading, initial concentrations of RhB and H₂O₂, co-existing natural organic matter and inorganic salts, reaction temperature, and radical scavengers on the catalytic performance of Cu–Fe₃O₄ were investigated. Monte-Carlo simulations revealed that copper dopants facilitated the activation of H₂O₂ via adopting a terminal end-on adsorption mode and increased collision frequency by bringing the RhB molecules closer to H₂O₂ and the magnetite surface. These theoretical calculations provide new insight into the promotional effect of copper dopants in magnetite at molecular level.
اظهر المزيد [+] اقل [-]Characterization of microbial response to petroleum hydrocarbon contamination in a lacustrine ecosystem النص الكامل
2021
D’Ugo, Emilio | Bruno, Milena | Mukherjee, Arghya | Chattopadhyay, Dhrubajyoti | Giuseppetti, Roberto | De Pace, Rita | Magurano, Fabio
Microbiomes of freshwater basins intended for human use remain poorly studied, with very little known about the microbial response to in situ oil spills. Lake Pertusillo is an artificial freshwater reservoir in Basilicata, Italy, and serves as the primary source of drinking water for more than one and a half million people in the region. Notably, it is located in close proximity to one of the largest oil extraction plants in Europe. The lake suffered a major oil spill in 2017, where approximately 400 tons of crude oil spilled into the lake; importantly, the pollution event provided a rare opportunity to study how the lacustrine microbiome responds to petroleum hydrocarbon contamination. Water samples were collected from Lake Pertusillo 10 months prior to and 3 months after the accident. The presence of hydrocarbons was verified and the taxonomic and functional aspects of the lake microbiome were assessed. The analysis revealed specialized successional patterns of lake microbial communities that were potentially capable of degrading complex, recalcitrant hydrocarbons, including aromatic, chloroaromatic, nitroaromatic, and sulfur containing aromatic hydrocarbons. Our findings indicated that changes in the freshwater microbial community were associated with the oil pollution event, where microbial patterns identified in the lacustrine microbiome 3 months after the oil spill were representative of its hydrocarbonoclastic potential and may serve as effective proxies for lacustrine oil pollution.
اظهر المزيد [+] اقل [-]An asymmetrical analysis to explore the dynamic impacts of CO2 emission to renewable energy, expenditures, foreign direct investment, and trade in Pakistan النص الكامل
2021
Rehman, Abdul | Ma, Hengyun | Ahmad, Munir | Ozturk, Ilhan | Işık, Cem
Carbon dioxide emission and GHGs are associated with fossil fuels which have adverse effects on the environment. The key intention of this paper was to determine the asymmetric effect of CO₂ emission on expenditures, trade, FDI, and renewable energy consumption in Pakistan. An asymmetrical technique (nonlinear autoregressive distributed lag) was employed to validate the constructive and adverse relation among variables. Furthermore, the Granger causality test was also used to verify the unidirectional association amid variables. Study outcomes revealed that the adverse shocks of renewable energy consumption exposed expressively to upsurge CO₂ emission in the short-run dynamics. Conversely, constructive shocks of renewable energy consumption display an adversative association with CO₂ emission. Furthermore, the decreasing trend in foreign direct investment tends to impede the detrimental effects of CO₂ emission. Additionally, the variable expenditures also create the non-eco-friendly impacts and manifest the positive linkage through CO₂ emission. Trade possesses statistically insignificant linkage with environmental degradation. The results also disclose that positive as well as negative variations in the foreign direct investment expose to degrade the environmental eminence. Long-run results suggest the direct association between downward trend in renewable energy consumption and CO₂ emission signifying that the pollution level decreases, and the upward trend in renewable energy consumption, however, demonstrates insignificantly positive effects. The results also disclose that positive as well as negative variations in the FDI lead to degrade the CO₂ emission. Moreover, it is found that the expenditures soar the issue of pollution again in the long run. Finally, the consequence of trade on CO₂ emission is adverse, as the outcome suggests. In order to improve the environmental policies for sustainable growth, the study provides direction toward a sustainable environment by reducing carbon dioxide emission.
اظهر المزيد [+] اقل [-]Influence of environmental drivers on allergy to pollen grains in a case study in Spain (Madrid): meteorological factors, pollutants, and airborne concentration of aeroallergens النص الكامل
2021
Cabrera Romero, Martha | Subiza, Javier | Fernández Caldas, Enrique | Garzón García, Belén | Moreno-Grau, Stella | Subiza, José Luis
The aim of this study was to compare airborne levels of Phl p 1 and Phl p 5, with Poaceae pollen concentrations inside and outside of the pollen season, and to evaluate their association with symptoms in grass allergic patients and the influence of climate and pollution. The Hirst and the Burkard Cyclone samplers were used for pollen and allergen quantification, respectively. The sampling period ran from 23 March 2009 to 27 July 2010. Twenty-three patients with seasonal allergic asthma and rhinitis used an electronic symptom card. The aerosol was extracted and quantified for Phl p 1 and Phl p 5 content. Descriptive statistics, non-parametric paired contrast of Wilcoxon, Spearman’s correlations, and a categorical principal component analysis (CatPCA) were carried out. Significant variations in pollen, aeroallergen levels, pollen allergen potency, and symptoms score were observed in this study. Phl p 5 pollen allergen potency was higher at the beginning of the 2010 grass pollen season. Presence of Phl p 1 outside the pollen season with positive O₃ correlation was clinically relevant. 45.5% of the variance was explained by two dimensions in the CatPCA analysis, showing the symptom relationships dissociated in two dimensions. In the first one, the more important relationship was with grass pollen grains concentration and Phl p 5 and to a lesser extent with Phl p 1 and levels of NO₂ and O₃, and in the second dimension, symptoms were associated with humidity and SO₂. Clinically relevant out-season Phl p 1 was found with a positive O₃ correlation. The effect of climate and pollution may have contributed to the higher seasonal allergic rhinitis symptom score recorded in 2009.
اظهر المزيد [+] اقل [-]Seasonal association between ambient fine particulate matter and venous thromboembolism in Beijing, China: a time-series study النص الكامل
2021
Wu, Junhui | Tian, Yaohua | Wu, Yao | Wang, Zijing | Wu, Yiqun | Wu, Tao | Qin, Xueying | Wang, Mengying | Wang, Xiaowen | Wang, Jiating | Hu, Yonghua
Little is known about the influence of ambient fine particulate matter (PM₂.₅) on the incidence of venous thromboembolism in areas with heavy air pollution. We examined seasonal associations between airborne concentrations of fine particulate matter and outpatient visits for venous thromboembolism in Beijing using a city-wide time-series design that covered a period of 30 months (January 1, 2010 to June 30, 2012). Generalized additive models were used to investigate the associations with adjustment of temperature for various time lags (lag 0 for the warm season and lag 0–10 for the cold season). Overall, 92,435 outpatient visits were recorded by the Beijing Medical Claim Data for Employees database during the study period. We found a significant association between PM₂.₅ levels and outpatient visits for venous thromboembolism. A 10-μg/m³ increase in PM₂.₅ concentrations on lag days 0–2 corresponded to a 0.64% (95% confidence interval: 0.55–0.73%; P < 0.001) increase in outpatient visits for venous thromboembolism during the cold season, and a 10-μg/m³ increase in PM₂.₅ concentrations on lag days 0–3 corresponded to a 0.82% (95% confidence interval: 0.67–0.96%; P < 0.001) increase in outpatient visits for venous thromboembolism during the warm season. Our findings suggest that PM₂.₅ exposure is associated with outpatient visits for venous thromboembolism in Beijing, and a more pronounced association was observed during the warm season. We propose that various temperature-adjustment strategies should be used when investigating seasonal associations.
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