خيارات البحث
النتائج 2611 - 2620 من 7,250
Application of biowaste generated by the production chain of pitaya fruit (Hylocereus undatus) as an efficient adsorbent for removal of naproxen in water
2022
Franco, Dison S. P. | da Boit Martinello, Kátia | Georgin, Jordana | Netto, Matias S. | Foletto, Edson Luiz | Piccilli, Daniel G. A. | Silva, Luis F. O. | dos Reis, Glaydson S. | Dotto, Guilherme Luiz
Pharmaceutical compounds are a serious problem in the environment. They cause damage to the aquatic, animal, and human organisms and soon became considered emerging pollutants where their removal is extremely urgent. Among the techniques used, adsorption has been used with success, where several adsorbent materials, including those from residual biomass, have been used to remove these pollutants. In this study, the skins of the pitaya fruit (Hylocereus undatus) productive chain were carbonized with ZnCl₂ to obtain activated carbon and later used in the adsorption of the drug naproxen (NPX) in a batch system. The Freundlich model demonstrated a better adjustment for the equilibrium isotherms. A high adsorption capacity for NPX (158.81 mg g⁻¹) was obtained at 328 K, which can be attributed to the remarkable textural properties of the adsorbent, besides certain functional groups present on its surface. Thermodynamic studies confirmed the endothermic nature of the adsorption process (∆H⁰ = 0.2898 kJ mol⁻¹). The linear driving force model (LDF) presented a good statistical adjustment to the experimental kinetic data. The application of the material in the treatment of simulated wastewater composed of various pharmaceutical drugs and salts was very promising, reaching 75.7% removal. Therefore, it can be inferred that the application of activated carbon derived from pitaya bark is highly promising in removing the NPX drug and treating synthetic mixtures containing other pharmaceutical substances.
اظهر المزيد [+] اقل [-]Impacts of coal-fired power plants for energy generation on environment and future implications of energy policy for Turkey
2022
Vardar, Suat | Demirel, Burak | Onay, Turgut T.
Turkish government aimed to increase the installed capacities of coal-fired power plants (CFPPs) according to several policies and strategic plans published in recent years. Energy production from CFPPs and subsidizing the coal sector were selected for reducing the import dependency as a cheaper option. CFPPs with gaseous emissions as well as fly ash and fine dust, along with ash storage, coal storage, and coal mining operations and water use for cooling of the plants, affect the environmental quality. Hence, the health of inhabitants of the environment is affected. CFPPs to be built, according to strategic plans, will emit a significant amount of greenhouse gases (GHGs) and would severely undermine the targets for a 1.5 ℃ or 2 ℃ warmer world. Subsidies to the coal sector, along with exemptions from environmental regulations, combined with slower growth of energy production from renewable energy sources (RES), may lead to a path dependence on coal, while the rest of the world increases their energy production from RES. This study demonstrates the concrete examples of pollution caused by CFPPs in Turkey, along with health effects with the addition of policy context toward utilization of CFPPs, to point out the risks these plants constitute both for the environment and economy. Increasing the share of RES in the energy mixture is particularly important for Turkey due to being in a geographical region that is highly vulnerable to climate change effects. This study also briefly discusses how the increase of RES and de-carbonization in Turkey could be conducted in the short- and long-term, upon the literature provided.
اظهر المزيد [+] اقل [-]Performance analysis of a solar dryer integrated with thermal energy storage using PCM-Al2O3 nanofluids
2022
Subramaniam, Babu Sasi Kumar | Sugumaran, Arun Kumar | Athikesavan, Muthu Manokar
Solar energy will assist in lowering the price of fossil fuels. The current research is based on a study of a solar dryer with thermal storage that uses water and waste engine oil as the working medium at flow rates of 0.035, 0.045, and 0.065 l/s. A parabolic trough collector was used to collect heat, which was then stored in a thermal energy storage device. The system consisted of rectangular boxes containing stearic acid phase change materials with 0.3vol % Al₂O₃ nanofluids, which stored heat for the waste engine oil medium is 0.33 times that of the water medium at a rate of flow of 0.035 l/s which was also higher than the flow rates of 0.045 and 0.065 l/s. The parabolic trough reflected solar radiation to the receiver, and the heat was collected in the storage medium before being forced into circulation and transferred to the solar dryer. At a flow rate of 0.035 l/s, the energy output of the solar dryer’s waste engine oil medium and water was determined to be roughly 12.4, 14, and 15.1, and 9.8, 10.5, and 11.5 times lower than the crops output of groundnut, ginger, and turmeric, respectively. The energy output in the storage tank and the drying of groundnut, ginger, and turmeric crops with water and waste engine oil medium at varied flow rates of 0.035, 0.045, and 0.065 l/s were studied. Finally, depending on the findings of the tests, this research could be useful in agriculture, notably in the drying of vegetables.
اظهر المزيد [+] اقل [-]The potency of eco-innovation, natural resource and financial development on ecological footprint: a quantile-ARDL-based evidence from China
2022
Afshan, Sahar | Yaqoob, Tanzeela
Given the alarming deterioration of the environment, the present analysis investigates the role of eco-innovation, natural resources and financial development in influencing the environmental degradation of China. Applying the novel method of quantile ARDL, the current research is beneficial in portraying the dependence patterns of the variables with special emphasis on the nexus of eco-innovation and ecological footprint across numerous quantiles of the distribution which has not been examined so far in the literature. The empirical findings reveal that in the long run, eco-innovation reduces the level of ecological deterioration in China across all quantiles. On the other hand, the results suggest that the increase in credit to the private sector and natural resource rents augments environmental degradation. The outcomes imply that the over-dependence on natural resources and financial development can worsen the goals of sustainable development in China if the strategies of conservation and management are ignored. Moreover, witnessing the favorable role of eco-innovation, competent policies and regulations can be made toward sustainable efficient technologies and eco-friendly energy sources to halt global warming.
اظهر المزيد [+] اقل [-]Highly effective adsorption of caffeine by a novel activated carbon prepared from coconut leaf
2022
Oliveira, Elvio N. | Meneses, Alex T. | de Melo, Samara F. | Dias, Franciele M. R. | Perazzini, Maisa T. B. | Perazzini, Hugo | Meili, Lucas | Soletti, João I. | Carvalho, Sandra H. V. | Bispo, Mozart D.
The disposal of coconut wastes is costly and damaging to the environment, but its uses are advantageous activated carbons production. Coconut leaves waste were used for activated carbon production by pyrolysis at 500° C and activation with potassium carbonate. The activated carbon was used for caffeine removal from aqueous solution. The coconut leaves activated carbon showed a predominantly amorphous structure from X-ray diffraction analysis and a pH at the zero charge point of 7.9. From the N₂ adsorption/desorption method, the adsorbent showed a predominance of mesopores, with average pore size of 45.48 ηm and a surface area of 678.03 m²/g. From kinetic studies the data followed the pseudo-second order, where the intraparticle diffusion can be neglected. The adsorption isotherms were satisfactorily adjusted for the Redlich-Peterson model and a type curve L was identified. The thermodynamic parameters showed that adsorption occurred spontaneously, was exothermic and governed by physical adsorption. The artificial neural networks developed were capable of predicting both kinetics and equilibrium adsorption data under different operating conditions and was comparable to the traditional models available in literature in the training experiments, encouraging its use for data generalization when an efficient dataset is used. In conclusion, coconut leaves waste showed to be a promising feedstock to produce activated carbon aiming caffeine removal from water and wastewater.
اظهر المزيد [+] اقل [-]Heavy metal domestication enhances beneficial effects of arbuscular mycorrhizal fungi on lead (Pb) phytoremediation efficiency of Bidens parviflora through improving plant growth and root Pb accumulation
2022
Atwill, Yurong Y. | Huang, Beitong | Xu, Jiazheng | Li, Zhenxin | Tang, Zhanhui | Wu, Xuefeng
Native arbuscular mycorrhizal fungi (AMF) generally provide more effective assistance for phytoremediation to remove heavy metal (HM) from polluted soils than non-native AMF. Nevertheless, it is a time-consuming work to isolate, identify, and propagate AMF inoculum for practical application. This study aims to explore an alternative method to improve the phytoremediation efficiency of Bidens parviflora using domesticated AMF under HM stress condition for a certain period of time. Our results showed that Funneliformis mosseae inoculation alleviated oxidative damage to plant membranes by enhancing activities of superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase. Furthermore, mycorrhizal plants had higher chlorophyll concentration, photosynthesis efficiency, and root Pb content to protect the aerial parts from damage. These protective mechanisms were found to be more efficient in domesticated AMF inoculation compared with non-domesticated AMF inoculation. Overall, this study suggests that F. mosseae domesticated for 12 months could greatly enhance plant root Pb accumulation and plant growth mainly through strengthening antioxidant defenses as well as the photosynthesis efficiency under Pb stress conditions. Plants inoculated with pre-domesticated AMF provided a promising new strategy to enhance phytoremediation of Pb-contaminated soils.
اظهر المزيد [+] اقل [-]Proposed city-specific interim targets for India based on WHO air quality guidelines 2021
2022
Kesavachandran, Chandrasekharan Nair | Prathish, Krishna Pillai | Sakhre, Saurabh | Ajay, Sundaresan Vasanthi | Rahul, Chirackal Muraleedharan
The World Health Organization has proposed the ambient air quality guidelines 2021. The uniqueness of the guidelines of the World Health Organization — air quality guidelines 2021 — is the inclusion of interim targets. Higher levels of air pollutants including PM₂.₅ for ambient air in India were recorded in recent times, and its association with respiratory and cardiovascular health risks was evidenced in the recent literature. To achieve the ambient air quality standards in India as per the World Health Organization — air quality guidelines, there is a need for interim targets in the future National Ambient Air Quality Standards to be proposed in India. These interim targets may be proposed for non-attainment/attainment cities based on the PM₂.₅ concentration levels to achieve a realistic target of recommended levels in a graded manner and thereby minimize air pollution in the specific location.
اظهر المزيد [+] اقل [-]Preventable mortality attributable to exposure to air pollution at the rural district of Punjab, India
2022
Ravindra, Khaiwal | Singh, Tanbir | Mor, Suman
Air pollution has emerged as a leading global health risk in recent decades, where its health impacts are primarily focused on urban areas. In India, semi-urban and rural areas are also emerging as air pollution hotspots. As these regions are out of focus, the current study monitored air pollution (PM₂.₅) at a rural district of Punjab in North India and attempted to study the associated health impacts. Hospital data of outpatient department (OPD), inpatient department (IPD) and all-cause mortality was correlated with change in PM₂.₅ concentrations. PM₂.₅ concentrations showed seasonal variations having relatively higher concentrations during post-monsoon and winter seasons. This rise in air pollution (annual average 92 µg/m³) was found to be mainly due to crop residue burning, including local meteorology. In comparison, hospital data shows that hospital visits and admissions were higher during monsoon. This shows that hospital admissions could not be directly linked to air pollution in rural areas as other factors such as short days during winters and self-medication, socio-economic factors and dependency on local unauthorised traditional healers may influence. The application of the AirQ + model for short-term health effects reveals that out of 2582 total deaths, preventable deaths ranging from 246 (WHO guidelines value – 10 µg/m³) to 159 (Indian NAAQS – 40 µg/m³) could be ascribed to air pollution exposure and specifically PM₂.₅. However, these deaths are avoidable by developing strategies to minimise air pollution in rural areas. Hence, a comprehensive approach is needed to plan air pollution reduction strategies, including urban, semi-urban and rural areas.
اظهر المزيد [+] اقل [-]Short-term dynamics and long-term relationship between natural gas consumption and economic growth in Nigeria: an ARDL approach with breaks
2022
Galadima, Mukhtar Danladi | Aminu, Abubakar Wambai | Adam, Ibrahim Muhammad | Adamu, Ibrahim Mohammed | Suleiman, Hassan Hassan
This paper investigates the short-term dynamics as well as the long-term relationship between natural gas consumption and economic growth in Nigeria, taking breaks into account. The techniques employed include Shahbaz-Omay-Roubaud unit root test with sharp and smooth breaks and autoregressive distributed lag (ARDL) model with breaks. The results revealed that natural gas consumption is positively related to growth both in the short-term and long-term but only significant in the latter. However, there is evidence of bidirectional causality in the long-term and unidirectional causality in the short-term, from growth to natural gas consumption. The implication of the findings is that natural gas is a contributing factor to the growth of the Nigerian economy, and any energy policy aimed at increasing the consumption of natural gas could lead to the increase in economic growth and that Nigerian authorities could adopt energy conservation policies in the short-term so as to take the issue of global warming into consideration. Therefore, the paper recommends stepping up efforts to increase natural gas consumption by building more gas storage facilities, pipeline installations, exploring alternative energy sources, raising awareness/enlightenment about the uses of natural gas, suitability in its use, economic and environmental benefits of its use, ensuring its affordable availability, and beeping up security against pipelines vandalization. Moreover, in the short-term, the country could enact energy conservation policies to combat global warming.
اظهر المزيد [+] اقل [-]Assessing the dynamic linkage between energy efficiency, renewable energy consumption, and CO2 emissions in China
2022
Lei, Wang | Xie, Yuantao | Hafeez, Muhammad | Ullah, Sana
Efficient energy is crucial in reducing CO2 emissions. The researchers are digging for a new efficient source of energy in the modern era. Therefore, this study explores the dynamic impacts of energy efficiency and renewable energy consumption on CO2 emissions from 1991 to 2019 for China. By using the non-linear ARDL approach, we found that a negative shock in energy efficiency has a positive impact on CO2 emissions in long run. Furthermore, renewable energy consumption with positive shock has a negative significant impact on CO2 emissions, but negative shock in renewable energy consumption leads to increase pollution emissions in long run. Besides, positive shocks to energy efficiency and renewable energy consumption have also a favorable negative effect on CO2 emissions in the short run. While a negative shock in energy efficiency has only unobservable negative impacts on CO2 emissions in the short run. Based on findings, some policy measures are suggested to attain environmental sustainability in China.
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