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Improvement of water resistance by Fe2O3/TiO2 photoelectrocatalysts for formaldehyde removal: experimental and theoretical investigation Полный текст
2022
Dong, Jing | Li, Qing | Xia, Wenjie | Lv, Bihong | Jing, Guohua | Shen, Huazhen | Yuan, Chung-shin
TiO₂-based photocatalysts are a potential technology for removing indoor formaldehyde (CHOH) owing to their strong photooxidation ability. However, their photooxidation performance is generally weakened when suffering from the competitive adsorption of H₂O. In a method inspired by the oxygen evolution reaction (OER) to generate intermediates with hydroxyl radicals on the anode electrode catalysts, an electric field was employed in this research and applied to the photooxidation of CHOH to prevent the competitive adsorption of H₂O. Additionally, 0.5–5% Fe₂O₃ decorated TiO₂ was employed to improve the photoelectrocatalytic activity. The influence of an electric field on hydroxyl-radical production was investigated by both density functional theory (DFT) with direct-imposed dipole momentum and photoelectrocatalytic experimental tests. The surface characterization of the photocatalysts, including transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR), was conducted. DFT results show that a positive electric field with a strength of 0.05 Å/V was more favorable to produce hydroxyl on Fe₂O₃/TiO₂(010) than was a negative electric field. Fe₂O₃ decoration can significantly boost hydroxyl formation, resulting from a decrease in the binding energy between the Fe of Fe₂O₃ and the oxygen and hydrogen atoms of H₂O. The dissociated hydrogen atom of the H₂O preferentially remained on the catalysts’ surface rather than being released into the gas flow. The experimental results demonstrated that applying 150 V could not directly enhance the photooxidation of CHOH by either TiO₂ or Fe₂O₃/TiO₂ but that it could relieve the H₂O inhibitory effect by more than 10% on the Fe₂O₃/TiO₂.
Показать больше [+] Меньше [-]The nexus between financial development and renewable energy consumption: a review for emerging countries Полный текст
2022
Saygin, Oguz | Iskenderoglu, Omer
The relationship between financial development and energy consumption is the most frequently research field in finance and economy. The main objective of performing this study is to answer that is there a relationship between financial development and renewable energy consumption in emerging countries? In many studies carried out in literature, the empirical findings were pointing to the existence of thiss relationship. To examine the relationship between financial development and renewable energy consumption, a total of 20 emerging countries were obtained from annual frequency data between 1990 and 2015. The system GMM estimation was used as the method of study. As a result of the analysis performed, it indicates that financial development does not impact renewable energy consumption in emerging countries when financial development is measured using both banking and stock market variables. Additionally, it can be said that the financial development increases renewable energy consumption if it is measured by only stock market capitalization.
Показать больше [+] Меньше [-]The boosting of microwave roasting technology on the desulfurization of phosphate rock Полный текст
2022
He, Di | Yao, Mei | Wang, Hongbin | Xie, Binghua | Yu, Qian | Geng, Na | Jia, Lijuan
A green and-easy to operate method, the microwave technology, was developed to promote the desulfurization process of phosphate rock, systematically investigates the strengthening effect of microwave, and uses XRD, BET, SEM, XRF, ICP, and EDS to characterize the reactants. The results show that the main reason for the desulfurization efficiency is improved by microwave heating under microwave conditions, different thermal stress phosphate rock materials lead to the destruction of each microstructure, and a specific surface area increased 40.25% phosphate rock. In addition, after microwave irradiation, the pore size of the phosphate rock at 2–5 nm is significantly increased, and the number of mesopores is significantly increased, thereby increasing the desulfurization efficiency of the phosphate rock. By investigating the effects of temperature, oxygen content, flow rate, and solid-liquid ratio on desulfurization efficiency, the paper concludes that the optimal conditions for desulfurization of phosphate rock after microwave irradiation are C(SO₂) is 2500 mg·m⁻³, temperature is 40 °C, φ(O₂) is 5%, solid-liquid ratio is 3.5 g:200 ml, and flue gas flow is 500 ml·min⁻¹.
Показать больше [+] Меньше [-]First atmospheric mercury measurements at a coastal site in the Apulia region: seasonal variability and source analysis Полный текст
2022
Martino, Maria | Tassone, Antonella | Angiuli, Lorenzo | Naccarato, Attilio | Dambruoso, Paolo Rosario | Mazzone, Fiorella | Trizio, Livia | Leonardi, Cristina | Petracchini, Francesco | Sprovieri, Francesca | Pirrone, Nicola | D’Amore, Francesco | Bencardino, Mariantonia
In the framework of the Italian Special Network for Mercury (ISNM) “Reti Speciali”, a sampling campaign to monitor atmospheric mercury (Hg) was carried out at Monte Sant’Angelo (MSA). This is a coastal monitoring station in the Apulia region, representative of the Southern Adriatic area, within the Mediterranean basin. This work presents continuous Gaseous Elemental Mercury (GEM) measurements over about three years at MSA, using the Lumex RA-915AM mercury analyzer. The aim was to obtain a dataset suitable for the analysis of Hg concentrations in terms of source and transport variation. Diurnal cycles of GEM were evaluated to observe the influence of local atmospheric temperature and wind speed on potential re-emissions from surrounding sea and soil surfaces. Data were also analyzed in terms of long-range transport, using backward trajectory cluster analysis. The spatial distribution of potential sources, contributing to higher measured GEM values, was obtained employing Potential Source Contribution Function (PSCF) statistics. The influence of major Hg anthropogenic point sources, such as mining activities and coal-fuel power plants, both regionally and continentally, from mainland Europe, was observed. The role of the vegetation GEM uptake in modulating the seasonal GEM variability was also investigated. The potential of wildfire influence over the highest detected GEM levels was further examined using active fire data and the evaluation of the vegetation dryness index during the selected episodes.
Показать больше [+] Меньше [-]Formation and evolution of secondary particulate matter during heavy haze pollution episodes in winter in a severe cold climate region of Northeast China Полный текст
2022
Hong, Ye | Sun, Junying | Ma, Yanjun | Wang, Yangfeng | Li, Xiaolan | Zhang, Yunhai | Liu, Ningwei | Zhou, Deping
The formation and evolution of sulfate (SO₄²⁻) and nitrate (NO₃⁻) secondary contaminants under different stages of pollution episodes and different meteorological and emission conditions were compared, based on the simultaneous observation of fine particulate matter (PM₂.₅) and its chemical components in four heavy haze pollution episodes at 14 sampling sites in a severe cold climate region of Northeast China in winter from 2017 to 2019. The results yielded two main findings. (1) Nitrate formation during the day was mainly due to the combination of high emissions and high relative humidity (RH, 50–90%), high temperature (T, 0 to 5 °C), high atmospheric oxidizability (ozone (O₃) and nitrous acid (HONO) concentrations), and high ammonia (NH₃) concentrations. Nitrate was formed by a gas-phase homogeneous reaction of the hydroxyl radical (OH·) with nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and ammonia (NH₃). (2) The main differences in SO₄²⁻ formation between Northeast China and other regions were that the gas-phase oxidation process played an important role. This was mainly a result of the promotion of the gas-phase oxidation of SO₄²⁻ due to the high oxidizing ability and the suppression of the aqueous reaction due to the low Ts in winter and low-sulfur coal emissions. Sulfate formation mostly occurred through an aqueous phase reaction in winter, but the highest yield and the fastest production capacity were produced by the gas-phase reaction.
Показать больше [+] Меньше [-]Research on the spatiotemporal evolution and influencing factors of green economic efficiency in the Yangtze River Economic Belt Полный текст
2022
Song, Yaqing | Sun, Xin | Xia, Pingfan | Cui, Zhikun | Zhao, Xin
In the Yangtze River Economic Belt (YREB), the green economy is an essential to sustainable economic development. In this study, we calculated a comprehensive index of environmental pollution based on the global entropy weight method and used the super slacks-based measure (SBM) model to estimate the green economic efficiency (GEE) of provinces and cities in the YREB from 2005 to 2018. Subsequently, we explored temporal and spatial evolution characteristics combined with the Theil and Moran indexes, and adopted the spatial Dubin model to analyze its influencing factors. We divided the YREB into three watersheds to facilitate the analysis. The results show that the GEE in the YREB initially decreased and then increased, and the difference among the three major watersheds was higher than that within the watershed. We found a positive spatial autocorrelation in the development level of the green economy in the YREB. While industrial structure had a negative effect, economic development, scientific and technological level, and environmental regulation all had a positive effect on GEE. Finally, we offered policy recommendations to improve the level of green development in the YREB.
Показать больше [+] Меньше [-]Environmentally relevant concentrations of triclosan exposure promote the horizontal transfer of antibiotic resistance genes mediated by Edwardsiella piscicida Полный текст
2022
Lu, Jinfang | Zhang, He | Pan, Liangliang | Guan, Wanchun | Lou, Yongliang
Aquaculture pathogen and antibiotic resistance genes (ARGs) co-occur in the aquatic environment. Accumulated evidence suggests that aquaculture pathogens can facilitate the horizontal transfer of plasmid-mediated ARGs. However, the role of Edwardsiella piscicida (E. piscicida) in ARG dissemination is still not fully understood. In addition, the potential impact of triclosan (TCS) on the spread of ARGs mediated by E. piscicida is still unknown, so a mating model system was established to investigate the transfer process of ARGs. The results showed that E. piscicida disseminated ARGs on RP4 by horizontal gene transfer (HGT). Furthermore, TCS exposure promoted this process. The conjugative transfer frequencies were enhanced approximately 1.2–1.4-fold by TCS at concentrations from 2 to 20 μg/L, when compared with the control. TCS promoted the HGT of ARGs by stimulating reactive oxygen species (ROS) production, increasing cell membrane permeability, and altering expressions of conjugative transfer–associated genes. Together, the results suggested that aquaculture pathogens spread ARGs and that the emerging contaminant TCS enhanced the transfer of ARGs between bacteria.
Показать больше [+] Меньше [-]Mapping Potential Toxic Elements in Agricultural and Natural Soils of the Piedemonte Llanero in Colombia Полный текст
2022
Trujillo-González, Juan Manuel | Torres-Mora, Marco Aurelio | Serrano-Gómez, Marlon | Castillo Monroy, Edgar Fernando | Jiménez Ballesta, R. (Raimundo) | Rodrigo-Comino, Jesús
The accumulation of potential toxic elements (PTEs) in soils is usually conditioned by parental material or anthropogenic sources. To achieve correct land management and land degradation neutrality, it is necessary to spatially detect them. However, there are several areas over the world with high concentrations of PTE but without efficient maps and tools to correctly find solutions and apply control measures. The current study attempts to identify the concentrations, sources, and spatial distributions of the main PTEs such as As, Cd, Cr, Cu, Ni, Pb, and Zn in a non-explored area combining fieldwork and geostatistical analysis. In order to accomplish this goal, a total of 90 soil samples were collected in agricultural and natural areas in the Piedemonte Llanero, Colombia. The chemical analysis was conducted by acid digestion and determined through ICP-OES. Then, ordinary kriging was applied to spatially analyze the most vulnerable areas. Our results demonstrated the effectiveness of these techniques and it is noted that the agricultural areas presented the highest concentrations and represented the potential source of PTEs. On the other hand, the natural areas presented the following concentrations of PTEs Cr (17.10 mg/kg), As (2.92 mg/kg), Cu (7.57 mg/kg), Ni (8.63 mg/kg), Cd (0.17 mg/kg), Pb (8.80 mg/kg), and Zn (27.57 mg/kg) lower than agricultural soils. This information was a key first step to be presented to the policymakers and stakeholders to organize soil sustainable management plans for the Piedemonte Llanero in Colombia.
Показать больше [+] Меньше [-]Risk of exposure to Hg and pesticides residues in a traditional fishing community in the Amazon: a probabilistic approach based on dietary pattern Полный текст
2022
Azevedo, Lucas Silva | Pestana, Inácio Abreu | Nascimento, Luiza | Oliveira, Ronaldo Cavalcante | Bastos, Wanderley Rodrigues | Di Beneditto, Ana Paula Madeira
Exposure to mercury (Hg) and pesticides (o.p’DDT, p.p’DDT, o.p’DDE, and p.p’DDE) in the Amazon through eating fish is of concern due to the large participation of this food in the diet of traditional fishing communities. The aim of this study was to evaluate the estimated daily intake (EDI) and the incremental lifetime cancer risk associated with Hg and o.p’DDT, p.p’DDT, o.p’DDE, and p.p’DDE in an Amazonian community. The results showed that for Hg, the EDI from carnivorous and detritivorous fish had the highest values, while for pesticides, the EDI from detritivorous fish intake had the highest value. The incremental lifetime cancer risk was below the permitted limit. A recommendation for controlling the high risk of exposure includes the reduction of detritivorous fish ingestion and/or replacement with herbivorous fish, which had lower EDI. We highlight the importance of investigating the human dietary patterns when estimating risk of exposure to Hg and pesticides.
Показать больше [+] Меньше [-]Compact glyoxal tanning system: a chrome-free sustainable and green approach towards tanning-cum-upgradation of low-grade raw materials in leather processing Полный текст
2022
Ramesh, Renganath Rao | Ponnuvel, Muthukumaran | Ramalingam, Sathya | Rathinam, Aravindhan
Increased concern over the use of metal salts such as chromium, zirconium, and aluminum for tanning of hides and skins has made the leather production industry to be constantly on the lookout for organic tanning agents in place of the inorganic system. Though glutaraldehyde has been looked at as a viable option, it still lags in imparting superior strength properties to the leather and also it has been reported to have inherent toxicity. With that concept in view, this research work focuses on the usage of glyoxal along with synthetic tanning agents as a replacement for glutaraldehyde and other inorganic tanning systems. The offer level and starting pH for the glyoxal tanning process was optimized as 6% (w/w) and 5.0, respectively, and the shrinkage temperature of the collagen was found to be around 80 °C. Additionally, the controlled shrunken grain effect of the aldehyde tanning system was explored by changing the pH of the process, which helped to improve the thickness of low-grade thinner raw materials by up to 40%. The mechanism for the shrunken grain effect has also been proposed in this work by studying the dimensional changes occurring in the leather matrix upon treating skin/hide with glyoxal at different pH levels. The mechanical and strength properties of the leather were found to be better than the glutaraldehyde tanning system. The BOD/COD ratio of wastewater generated from the glyoxal process was found to be greater than 0.3 making them easily treatable. Considering all these factors, compact glyoxal-based tanning along with synthetic tanning agents can be a game-changing technology for the leather processing industry.
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