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Enhanced degradation of reactive brilliant red X-3B by photocatalysis integrated with micro-electrolysis Texte intégral
2021
Cheng, Gong | Zhang, Yibo | Sun, Lei | Wan, Jing | Li, Zhang | Dang, Chenyuan | Fu, Jie
The microwave electrodeless lamp UV photocatalysis (MWUV) integrated with iron carbon micro-electrolysis (ME) was applied to degrade reactive brilliant red X-3B. In the present study, the removal rate of X-3B by MWUV/ME was 95%, which was significantly higher than 56% of MWUV and 62% of ME system. The experiment results demonstrated a synergistic effect in MWUV/ME system, wherein the ME system played an important role in color removal and the formation of ·OH in photocatalysis contributed most for the mineralization of X-3B and its intermediates. The removal efficiency of TOC was 32%, 7.5%, and 59.5% under MWUV, ME, and MWUV/ME processes at the end of the reaction, respectively. The Fe³⁺ existed in the system was an enhancer of producing ·OH via self-generation of ·OH by UV irradiation or improving the separation of electron-hole in photocatalysis by capturing the electrons. Therefore, the combined treatment of MWUV and ME system has the potential of synergistic effect compared to the separate process. Lowering the initial solution pH and increasing the iron filing dosage and dissolved oxygen were beneficial for the enhancement of degradation efficiency. The inorganic anions showed a diversity influencing the degradation of X-3B. NO₃⁻, CO₃²⁻, and SO₄²⁻ (at higher concentration) promoted the degradation reaction, while Cl⁻ had non-significant effect.
Afficher plus [+] Moins [-]Performance enhancement of solar photovoltaic system for roof top garden Texte intégral
2021
Prasad, Arani Rajendra | Shankar, Ramalingam | Patil, Chandrashekhar K. | Karthick, Alagar | Kumar, Amit | Rahim, Robbi
The photovoltaic (PV) for irrigation system is an emerging technology to harness the solar energy. The performance of the PV modules depends on the incident solar radiation, geographical location, and the surface temperature of the modules. The performance of the PV system needs to be monitored by manually or embedded controllers. The commercially available technologies for monitoring the system are costlier and need to be optimized. The Arduino controller is used to monitor the performance of the photovoltaic (PV) system in Coimbatore (11.016° N, 76.9558° E), Tamilnadu, India. The PV surface temperature is monitored and controlled by flowing the water above the module by setting the mean ambient temperature as a reference temperature 34 °C when the system exceeds the reference temperature. PV surface temperature is reduced up to 16°C thus improved the electrical efficiency by 17% compare to the reference module. The Arduino controller control the relay to switch on the motor to control the mass flow rate of the water at 0.0028kg/s. The various parameters are measured such as voltage, current, and solar radiation of the location and analyzed. The estimated cost of monitoring system and various sensor is 10$ which cost comparatively 50% lower than the other PV monitoring controllers. This method can be employed in the medium and large-scale irrigation system.
Afficher plus [+] Moins [-]Composting of swine production chain wastes with addition of crude glycerin: organic matter degradation kinetics, functional groups, and carboxylic acids Texte intégral
2021
Santos, Francielly Torres Dos | Fehmberger, Cleide | Aloisio, Cleiton Margatto | Bautitz, Ivonete Rossi | Hermes, Eliane
Little is known about the effect of adding crude glycerin (CG) as a carbon source during the composting of agro-industrial residues, such as those generated in the swine production chain, especially concerning the impact on organic matter humification. Therefore, the aim of this work was to study the effect of adding crude glycerin during the composting of organic swine waste, using appropriate analyses to determine the degree of maturation of the organic material. The experiment was performed using composters constructed from pallets. The variables considered were temperature, mass, volume, organic matter, functional groups, carboxylic acids, pH, electrical conductivity, total organic carbon, total Kjeldahl nitrogen, total phosphorus, potassium, basal respiration, and germination index. For all the CG concentrations tested, thermophilic temperatures were reached, while higher amounts of CG (4.5 and 6.0%) maintained temperatures above 55 °C for longer periods (28 days). Fourier transform infrared spectroscopy analysis showed the presence of an aromatic stretching vibration signal at 1620 cm⁻¹, confirming mineralization of the organic matter, while the decrease of carboxylic acids at the end of the composting period indicated stabilization. The organic composts presented high nutrient contents and absence of toxicity, indicating that they could be safely used in agriculture.
Afficher plus [+] Moins [-]Assessing the environmental impact of China’s tourism activities: a tourism heat footprint method Texte intégral
2021
Wang, Shuxin | Cao, Weihong | Du, Jiankuo | Tang, Pingping | Fu, Hengyang | Tang, Zi | Li, Jiamei
Numerous research studies have examined carbon emissions generated from tourism activities. However, the environmental impact of anthropogenic heat release has not attracted researchers’ attention. We apply the tourism heat footprint method to assess the environmental impact of China’s tourism activities. The results indicate that (1) China’s tourism heat footprint increased from 0.99 × 10³ w/km² in 1994 to 7.53 × 10³ w/km² in 2018, with an average annual growth rate of 8.82%. (2) Particularly during high seasons, the tourism heat footprint increases sharply; tourism transportation accounts for the highest proportion of the tourism heat footprint, ranging from 36.50 to 69.07% from 1994 to 2018. (3) The rapid growth in arrivals and transportation-related changes have contributed to the rapid growth of the tourism heat footprint. Advances in science and technology, laws and regulations, environmental pollution constraints, and national macroeconomic policy have helped reduce the tourism heat footprint. Generally, tourism activities caused by a significant increase in income are the root cause of tourism heat footprint growth. (4) Finally, some suggestions, including cultivating a low-energy tourism culture, improving energy efficiency, implementing low-energy policies, and performing spatial-temporal monitoring, are proposed. This paper expands sustainable tourism’s analytical research and enriches the tourism footprint family evaluation process.
Afficher plus [+] Moins [-]Linking financial development, economic growth, and ecological footprint: what is the role of technological innovation? Texte intégral
2021
Kihombo, Shauku | Ahmed, Zahoor | Chen, Songsheng | Adebayo, Tomiwa Sunday | Kirikkaleli, Dervis
The literature analyzing the ecological impacts of financial development (FD) documents mixed results. In addition, very limited researches consider the role of technological innovation in ecological sustainability even though technological innovation is indispensable to achieve technological advancement, which may help in sustainable development and ecological sustainability. Therefore, this work probes the effects of technological innovation, financial development, and economic growth (GDP) on the ecological footprint (EF) controlling urbanization and employing a STIRPAT framework. The analysis of data from West Asia and Middle East nations from 1990 to 2017 revealed cointegration in the model. The long-run coefficients produced by the continuously updated fully modified technique revealed that a 1% upsurge in technological innovation decreases EF by 0.010%. Interestingly, technological innovation is helpful to decrease EF and enhance economic growth in the West Asia and Middle East (WAME) countries. However, a 1% rise in FD boosts the level of EF by 0.0016% inferring that FD stimulates ecological degradation. Likewise, urbanization in the WAME countries raises EF levels and contributes adversely to ecological quality. In addition to this, the study revealed the environmental Kuznets curve hypothesis in the selected countries accounting for technological innovation, FD, and urbanization in the model. The causal analysis provided evidence of unidirectional causality from FD to EF and bidirectional causality between technological innovation and EF. The study recommends more investment in research and development and strong collaboration between the universities and industries to promote the level of technological innovation for both sustainable development and ecological sustainability. In addition, urban sustainability policies are necessary without decreasing the urbanization level.
Afficher plus [+] Moins [-]Experimental energy improvement of a special design heat exchanger-based hybrid solar collector for a photovoltaic module square surface Texte intégral
2021
Boumaaraf, Billel | Boumaaraf, Houria | Ait-cheikh, Mohamed Salah | Khelifa, Abdelkrim
Solar cells convert a part of the solar irradiance into electrical energy, and the remaining produces heat, which can be converted as a thermal energy accumulated in the module. This conversion depends on the solar cells temperature. Since conversion efficiency is very low, 5–20%, this investigation proposes an optimal combination of a photovoltaic module with a specially designed heat exchanger in order to improve the conversion energy efficiency. So, an experimental prototype of a photovoltaic thermal collector, with a special heat exchanger design for a PV module square surface is built and tested outdoor. The system is constituted of a PV module with square surface and a heat exchanger with a copper tube, in a spiral form. In order to assess the effect of the exchanger design on hybrid system performance, a comparison with a traditional photovoltaic module is done. During the experimental tests, various parameters were measured, such as solar irradiance, ambient temperature, coolant inlet/outlet temperature and surface temperature of the device. Based on the obtained results, it has been found that the use of the new PVT decreases the PV cells temperature in the order of 20°C. A consequence of that shows that the electrical power increases, by 6 W; moreover, the electrical energy efficiency goes from 7.93 to 9.65%, while the thermal energy efficiency of the PVT reaches 74.3%. The overall energy efficiency for the same system achieved was 84 %. Therefore, the energy loss is minimized, reaching 16%.
Afficher plus [+] Moins [-]Analysis and health risk assessment of phthalate esters (PAEs) in indoor dust of preschool and elementary school centers in city of Tehran, Iran Texte intégral
2021
Abdi, Somayeh | Sobhanardakani, Soheil | Lorestani, Bahareh | Cheraghi, Mehrdad | Panahi, Homayon Ahmad
Individuals spend a lot of time indoors; thus they are generally exposed to phthalates used in consumer products. Therefore, those exposed to phthalates as indoor contaminants are at high risks. The present study was conducted to evaluate the carcinogenic and non-carcinogenic hazard of phthalate esters (PAEs), like dimethyl phthalate, diethyl phthalate, di(nbutyl) phthalate, butyl benzyl phthalate, dioctyl phthalate, and di(2-ethylhexyl) phthalate in the dust obtained from 21 schools in Tehran, in 2019. A total of 63 indoor dust specimens were obtained by a vacuum cleaner. After transferring dust samples to the laboratory, 100 mg of each sample was centrifuged and mixed with 20 ml acetone and kept through a night and ultrasonicated within 30 min. Eventually, PAEs’ contents were measured via gas chromatography-mass spectrometry. Based on the findings, median concentrations of DMP, DEP, DnBP, BBP, DEHP, and DnOP were 0.90, 0.10, 6.0, 0.20, 118.30, and 4.10 mg kg⁻¹ respectively. Moreover, the overall average daily exposure doses (ADD) of phthalate esters via dust ingestion, skin contact, and inhalation were 1.56E-03, 1.70E-06, and 1.56E-07 mg kg⁻¹ day⁻¹, respectively, and the lifetime average daily exposure doses (LADD) were 1.83E-04, 2.34E-08, and 2.46E-08 mg kg⁻¹ day⁻¹, respectively; thus ingestion of dust particles was found to be the main pathway of exposure to phthalate for non-carcinogenic and carcinogenic risks. Although based on the results, the studied samples were below the US Environmental Protection Agency threshold of 1.00E-06, due to the disadvantages of phthalates in human safety, these kinds of investigations are helpful in understanding the main ways of exposure to PAEs and providing a science-based framework for the future attempts for mitigating the PAEs indoor emissions.
Afficher plus [+] Moins [-]A convolutional neural network approach for detection of E. coli bacteria in water Texte intégral
2021
Khan, Farhan Mohammad | Gupta, Rajiv | Sekhri, Sheetal
The detection of Escherichia coli bacteria is essential to prevent health diseases. According to the laboratory-based methods, 12–48 h is required to detect bacteria in water. The drawback of depending on laboratory-based methods for the detection of E. coli bacteria can be prone to human errors. Hence, the bacterial detection process must be automated to reduce error. We implement an automated E. coli bacteria detection process using convolutional neural network (CNN) to address this issue. We have also proposed a mobile application for the rapid detection of E. coli bacteria in water that uses CNN. The developed CNN model achieved an accuracy of 96% and an error (loss) of 0.10, predicting each sample in only 458ms. The performance of the model was validated using the F-score, precision, sensitivity, and accuracy statistical measures, which shows that the model is reliable and effective in detecting E. coli. The study generates a methodology for predicting E. coli bacteria in water, which can be used to predict hotspots in terms of continuous exposure to water contamination.
Afficher plus [+] Moins [-]Predictors of poor outcomes among patients of acute methanol intoxication with particular reference to Sequential Organ Failure Assessment (SOFA) score Texte intégral
2021
Sharif, Asmaa Fady | AlAmeer, Mahdi Riyadh | AlSubaie, Duhaim Saad | Alarfaj, Naser Husam | AlDawsari, Mubarak Khalifah | AlAslai, Khalid Mansour | BuSaleh, Mahmoud Jawad | AlSabr, Abdulaziz Ibrahim | Al-Mulhim, Khalid Abdulmohsen
Methanol intoxication is a global problem with serious morbidities and mortalities. Apart from the lifelong disabilities experienced by methanol intoxication survivors, mortality rates of up to 44% of exposed patients have been reported. The aim of the current study was to outline the early findings that could be utilized as effective in-hospital outcome predictors among cases of methanol exposure. Furthermore, the role of the Sequential Organ Failure Assessment (SOFA) score was evaluated as an early in-hospital outcome indicator among patients presented with acute methanol intoxication. A multicenter study including 37 patients diagnosed with acute methanol intoxication and referred to three major poison control centers in Saudi Arabia during the past 3 years (January 1, 2018–January 1, 2021) was conducted. Data including demographics, exposure history, presenting complaints, clinical findings, and laboratory investigation were collected. The patients were scored on Glasgow Coma Scale (GCS), Poison Severity Score (PSS), and SOFA score on admission. Out of the presented patients, 83.8% were alcoholic men. No deaths have been reported, and 51.4% were discharged with unfavorable outcomes, including 29.7% suffered optic neuropathy and blindness, 18.9% showed acute renal impairment, and 10.8% were complicated with respiratory failure. The diastolic blood pressure, anion gap, visual acuity, number of hemodialysis sessions, PSS, duration of Intensive Care Unit (ICU) stay, and SOFA score were all significant organ failure predictors (P < 0.05). However, only the SOFA score showed the best significant prediction on multivariate analysis, with an odds ratio (95% confidence interval) of 0.10 (0.04–0.17) and P = 0.003. At a cutoff of greater than 4.5, the SOFA score could significantly predict unfavorable outcomes with area under curve (AUC) = 0.955, accuracy 89.2%, specificity 94.4%, and sensitivity 84.2%. Early identification of methanol exposed patients at risk is critical and lifesaving. The SOFA score is a substantially useful and early inclusive unfavorable outcome predictor.
Afficher plus [+] Moins [-]Transformation of bisphenol AF by chlorination: kinetic study and product identification Texte intégral
2021
Chang, Jingyi | Xiang, Wenrui | Qu, Ruijuan | Sun, Cheng | Wang, Zunyao | Zhu, Feng | Huo, Zongli
Bisphenol AF (BPAF), commonly used as a substitute for bisphenol A (BPA), is also an endocrine disruptor with cytotoxicity, neurotoxicity, genotoxicity, and biotoxicity. In this study, we found that BPAF could be effectively degraded by free chlorine. The second order rate constant of the reaction ranged from 1.67 to 126.67 M⁻¹·s⁻¹ in the pH range of 5.0–11.0. Nineteen products were detected by LC-Q-TOF-MS analysis, including chlorinated BPAF (i.e., mono/di/tri/tetrachloro-BPAF), 8 dimers, and 6 trimers. According to the identified products, two transformation pathways of electrophilic substitution and electron transfer are proposed. Humic acid (HA) could inhibit the degradation rate of BPAF due to its ability to reduce the reactive BPAF radical intermediates to the parent compound. The addition of low concentrations of Br⁻ and I⁻ accelerates the reaction rate of BPAF, due to the formation of HOBr and HOI with a higher oxidizing capacity. In seawater, BPAF degraded rapidly, and 16 new halogenated products were formed. Theoretical calculation shows that electrophilic substitution is more prone to occur at the ortho position of the hydroxyl group to form chlorinated products, while electron transfer tends to occur at the hydroxyl oxygen, resulting in the formation of BPAF radical and its subsequent coupling products.
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