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Selenite removal from wastewater using fungal pelleted airlift bioreactor Texte intégral
2020
Negi, Bharat Bhushan | Sinharoy, Arindam | Pakshirajan, Kannan
This study investigated the removal of selenite from wastewater using the fungus Asergillus niger KP isolated from a laboratory scale inverse fluidized bed bioreactor. The effect of different carbon sources and initial selenite concentration on fungal growth, pellet formation and selenite removal was first examined in a batch system. The fungal strain showed a maximum selenite removal efficiency of 86% in the batch system. Analysis of the fungal pellets by field-emission scanning electron microscopy, field-emission transmission electron microscopy and energy-dispersive X-ray spectroscopy revealed the formation of spherical-shaped elemental selenium nanoparticles of size 65–100 nm. An increase in the initial selenite concentration in the media resulted in compact pellets with smooth hyphae structure, whereas the fungal pellets contained hair like hyphae structure when grown in the absence of selenite. Besides, a high initial selenite concentration reduced biomass growth and selenite removal from solution. Using an airlift reactor with fungal pellets, operated under continuous mode, a maximum selenite removal of 94.3% was achieved at 10 mg L⁻¹ of influent selenite concentration and 72 h HRT (hydraulic retention time). Overall, this study demonstrated very good potential of the fungal-pelleted airlift bioreactor system for removal of selenite from wastewater. Graphical abstract
Afficher plus [+] Moins [-]Trends and future challenges in hydrogen production and storage research Texte intégral
2020
Liu, Wenjing | Sun, Lu | Li, Zhaoling | Fujii, Minoru | Geng, Yong | Dong, Liang | Fujita, Tsuyoshi
With the rapid industrialization, increasing of fossil fuel consumption and the environmental impact, it is an inevitable trend to develop clean energy and renewable energy. Hydrogen, for its renewable and pollution-free characteristics, has become an important potential energy carrier. Hydrogen is regarded as a promising alternative fuel for fossil fuels in the future. Therefore, it is very necessary to summarize the technological progress in the development of hydrogen energy and research the status and future challenges. Hydrogen production and storage technology are the key problems for hydrogen application. This study applied bibliometric analysis to review the research features and trends of hydrogen production and storage study. Results showed that in the 2004–2018 period, China, USA and Japan leading in these research fields, the research and development in the world have grown rapidly. However, the development of hydrogen energy still faces the challenge of high production cost and high storage requirements. Photocatalytic decomposition of water to hydrogen has attracted more and more research in hydrogen production research, and the development of new hydrogen storage materials has become a key theme in hydrogen storage research. This study provides a comprehensive review of hydrogen production and storage and identifies research progress on future research trend in these fields. It would be helpful for policy-making and technology development and provide suggestions on the development of a hydrogen economy.
Afficher plus [+] Moins [-]A review of the application of sea material shells as low cost and effective bio-adsorbent for removal of heavy metals from wastewater Texte intégral
2020
Tamjidi, Sajad | Ameri, Abolhasan
The pollution caused by heavy metal ions in industrial wastewater is of a great concern. Applying effective and low-cost methods is an urgent need for treatment of polluted water and aqueous solutions. Biosorption have received the most attention among the various methods. It has become an alternative technique to conventional technologies due to low cost, simple operation and treatment for heavy metal recovery, and high selectivity. In recent years, sea material shells have been applied as one of the most cost-effective bio-adsorbents due to their special properties. They are environmentally friendly, low cost, and easy to access and have high adsorption capacity. The purpose of this review is to present the application of oyster shell, snail shell, and shrimp shell as low-cost and effective biosorbents for removal of noxious heavy metals from aqueous solutions. In addition, heavy metals, their sources, and ways to remediate them from waste streams and various factors affecting the biosorption process with sea materials shells are also reviewed. Moreover, a brief description and literature review of the equilibrium, kinetic, and thermodynamic behaviors of the heavy metal ion adsorption process on sea material shells have been studied. Finally, further applications of sea materials shell for waste effluents treatment are specially focused.
Afficher plus [+] Moins [-]Effect of plant hedgerows on agricultural non-point source pollution: a meta-analysis Texte intégral
2020
Zheng, Yonglin | Wang, Haiyan | Qin, Qianqian | Wang, Yige
Eutrophication has been a critical environmental issue due to soil nitrogen (N) and phosphorus (P) loss in runoff from agricultural lands. Plant hedgerow is an important measure to prevent soil erosion and reduce agricultural non-point source pollution (NPSP). In the present study, we searched 3683 research papers on plant hedgerows published from 1980 to March 2020. After screening, we used 53 effective papers on plant hedgerows for the meta-analysis by using Stata 15.1. The results showed that plant hedgerows significantly increased soil organic matter (SOM) (standardized mean difference (SMD) = 1.46; 95% confidence interval (CI) = 1.12–1.80 > 0), total N (TN) (SMD = 1.33; 95% CI 0.98–1.68 > 0), total P (SMD = 0.73; 95% CI 0.26–1.20 > 0), alkali N (SMD = 0.86; 95% CI 0.52–1.21 > 0), available P (SMD = 1.28; 95% CI 0.75–1.81 > 0) and readily available potassium (K) (SMD = 1.20; 95% CI 0.75–1.65 > 0) concentrations but exhibited no significant effects on soil total K concentration (SMD = 0.17; 95% CI − 0.13–0.47 < 0). Plant hedgerows showed a greater effect on SOM increase than soil N, P, and K, and soil TN increase than the available state, but the opposite trend was observed for P and K. This meta-analysis can clarify the influence of plant hedgerows on soil nutrients and provide ideas for the prevention and control of agricultural NPSP.
Afficher plus [+] Moins [-]Human health risk assessment of heavy metals via consumption of commercial marine fish (Thunnus albacares, Euthynnus affinis, and Katsuwonus pelamis) in Oman Sea Texte intégral
2020
Sadeghi, Parvin | Loghmani, Mehran | Frokhzad, Somayeh
This study was performed to determine the concentrations of copper (Cu), zinc (Zn), and lead (Pb) in the gill, liver, muscle, and tail fin tissues of Euthynnus affinis, Katsuwonus pelamis, and Thunnus albacares from Oman Sea. All samples were analyzed using a flame atomic absorption spectrophotometer and the results were expressed as μg g⁻¹ dry weight. Metal concentrations were significantly higher in the liver than other tissues in three species (with some exceptions) (p < 0.05). The concentrations of metal accumulation in tissues of tuna species followed the Zn > Cu > Pb. Correlation matrix and principal component analysis (PCA) revealed that Zn and Pb have anthropogenic sources. Estimated daily intake (EDI) in three tuna species for heavy metals were below the tolerable daily intake (TDI). Also, the mean target hazard quotient (THQ) based on studied metals in three tuna species was below 1, which suggests that consumption of these fish can be safe for human health in the Oman Sea. Graphical Abstract .
Afficher plus [+] Moins [-]Antioxidants and molecular damage in Nile Tilapia (Oreochromis niloticus) after exposure to microplastics Texte intégral
2020
Abū al-Saʻūd, Muḥammad Ḥāmid Muʻawwaḍ | Soliman, Hamdy A. M. | Osman, Alaa G. M. | Sayed, Alaa El-Din H.
Recently, research on the biological effects of microplastics (MPs) has grown exponentially. However, effects of MPs on freshwater fishes and the mechanisms of the biological effects of MPs were limited. So, the purpose of the current study was to clarify the effects of microplastics on oxidative stress response, DNA fragmentation, and proteinogram of the early juvenile stage of Nile Tilapia (Oreochromis niloticus). The fishes were assigned into four groups: one control, three MPs-exposed groups as 1 mg/L of MPs, 10 mg/L of MPs, and 100 mg/L of MPs respectively for 15 days and 15 days of recovery. The activities of superoxide dismutase, catalase, total peroxides, and oxidative stress index (OSI), as well as lipid peroxidation and DNA fragmentation, increased in groups exposed to MPs compared to the control group in a dose-dependent manner. In contrast, the activity of total antioxidant capacity decreased in groups exposed to MPs compared to the control group in a dose-dependent manner. The electrophoretic pattern of muscle proteins revealed alteration in the proteinogram in the MPs-exposed groups compared to control. After the recovery period, the activities of superoxide dismutase, catalase, total peroxides, total antioxidant capacity, lipid peroxidation, DNA fragmentation, and the electrophoretic pattern of muscle proteins returned to normal levels in 1 mg/L of MPs-exposed group. Combined with our previous work, these results suggest that MPs cause the overproduction of reactive oxygen species (ROS) and alters the antioxidants parameters, resulting in oxidative stress and DNA damage. The present study fosters a better understanding of the toxic effects of MPs on Tilapia as a freshwater model. Graphical Abstract
Afficher plus [+] Moins [-]Carbaryl residue concentrations, degradation, and major sinks in the Seto Inland Sea, Japan Texte intégral
2020
Derbalah, Aly | Chidya, Russel | Kaonga, Chikumbusko | Iwamoto, Yoko | Takeda, Kazuhiko | Sakugawa, Hiroshi
The fate of carbaryl in the Seto Inland Sea (west Japan) was predicted using a mass distribution model using carbaryl concentrations in river and sea water samples, degradation data, and published data. The predicted carbaryl concentrations in water in Kurose River and the Seto Inland Sea were 4.320 and 0.2134 μg/L, respectively, and the predicted concentrations in plankton, fish, and sediment were 0.4140, 2.436, and 1.851 μg/g dry weight, respectively. The carbaryl photodegradation and biodegradation rates were higher for river water (0.330 and 0.029 day⁻¹, respectively) than sea water (0.23 and 0.001 day⁻¹, respectively). The carbaryl photodegradation rates for river and sea water (0.33 and 0.23 day⁻¹, respectively) were higher than the biodegradation rates (0.029 and 0.001 day⁻¹, respectively). The hydrolysis degradation rate for carbaryl in sea water was 0.003 day⁻¹, and the half-life was 231 days. Land (via rivers) was the main source of carbaryl to the Seto Inland Sea. The model confirmed carbaryl is distributed between sediment, plankton, and fish in the Seto Inland Sea. Degradation, loss to the Open Ocean, and sedimentation are the main carbaryl sinks in the Seto Inland Sea, accounting for 43.81, 27.90, and 17.68%, respectively, of total carbaryl inputs. Carbaryl source and sink data produced by the model could help in the management of the negative impacts of carbaryl on aquatic systems and human health.
Afficher plus [+] Moins [-]Comparative analysis of EMF monitoring campaigns in the campus area of the University of Novi Sad Texte intégral
2020
Kljajic, Dragan | Djuric, Nikola
Following an increasing number of artificial electromagnetic field (EMF) sources in human surrounding, a number of research studies have been devoted to the issue of environmental EMF pollution. A particular attention has been attributed to the highly sensitive EMF zones, where people can stay for a longer period of time, which, among others, includes university campuses. Thus, the modern approach of long-term EMF monitoring has been established, carrying out cumulative field strength measurements at locations that are most visited by student population and university staff. The goal was to establish periodic and systematic EMF investigation over such highly sensitive areas, through a standardized procedure for EMF monitoring. In this paper, details about two EMF monitoring campaigns over the University of Novi Sad campus were presented, performing comparative analysis of their results. The obtained results revealed the increase (up to four times) of the cumulative field strength values, as well as the general population exposure, at specific locations. Between these two campaigns, the emergence of the new base station, as well as numerous Wi-Fi networks, was noticed in the campus. Consequently, the highest field strength values were acquired at two locations, most directly exposed to the main beams of base station’s antennas, although all obtained values were at least five times lower than the minimal reference levels prescribed by the Serbian legislation. Even though such results are acceptable, the future monitoring campaigns should be planned, particularly since the installation of new EMF sources are expected in the campus of the University of Novi Sad.
Afficher plus [+] Moins [-]Construction of electric vehicle driving cycle for studying electric vehicle energy consumption and equivalent emissions Texte intégral
2020
Zhao, Xuan | Ye, Yiming | Ma, Jian | Shi, Peilong | Chen, Hao
This paper proposes an effective and scientific method for the construction of a representative driving cycle for electric vehicles (EV) and takes it as a foundation for studying the energy consumption and equivalent emissions for EV. First, a test route is developed through the analysis of the topology of the Xi’an road structure and traffic flow. Second, the vehicle driving pattern data is gathered through an integrated method of chase car method and on-board method. The velocity-acceleration (V-A) grid method is used to divide speed and acceleration data into micro-states. Third, the proposed driving cycle construction method incorporates the Markov chain and Monte Carlo (MCMC) simulation method. Then, a filter process is designed to screen out the most representative driving cycle. Finally, the comparison of the simulation result and test results shows the constructed EV driving cycle is in line with reality, and estimating the EV’s energy consumption per kilometer, driving range, and equivalent emissions under official driving cycles results in large relative errors. Therefore, the construction of a real-world driving cycle for specific cities or areas is necessary to evaluate energy consumption, driving range, and equivalent emissions of EV.
Afficher plus [+] Moins [-]Assessing the impacts of globalization and gender parity on economic growth: empirical evidence from OIC countries Texte intégral
2020
Farooq, Fatima | Yusop, Zulkornain | Chaudhry, Imran Sharif | Iram, Robina
The contemporary debate on globalization and gender equality has a strong impact on economic growth. The present study analyzes the impacts of globalization and gender parity on economic growth in the Organization of Islamic Cooperation (OIC) 47 member countries for the period (1991–2017), using System GMM panel data technique. The results of system GMM have also been empirically estimated by making two groups (viz., low-income and high-income OIC member countries from the World Bank data classification, 2019) to examine the robustness of globalization and gender parity on economic growth. The results reveal that there is a negative impact of globalization on economic growth in the overall sample of OIC countries. When estimated by decomposing low-income countries and high-income countries, globalization has a significantly positive impact on economic growth in the case of high-income OIC countries, whereas globalization slashes GDP in the case of low-income OIC countries. The study finds that there is a positive impact of gender parity (ratio of female to male labor force work participation) on economic growth. Moreover, foreign remittances, government expenditures, capital formation, and human capital are also becoming the causes of a significant increase in economic growth in OIC member countries.
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