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Impacts of microplastics on reproductive performance of male tilapia (Oreochromis niloticus) pre-fed on Amphora coffeaeformis Texto completo
2021
Ismail, Rania F. | Saleh, Norhan E. | Sayed, Alaa El-Din H.
This study examines the potential defending effects of the diatom, Amphora coffeaeformis, as a feed additive versus the deleterious effects (mainly on gonads) caused by microplastics (MPs) in Nile tilapia, Oreochromes niloticus. Groups of male tilapia were pre-fed diets with four different supplementation levels of A. coffeaeformis (0%, 2.5%, 5%, and 7.5%) for 70 days, then exposed to 10 mg/L MPs for 15 days. Thereafter, samples were taken from the four experimental groups and the control fish group, for evaluating blood picture, erythrocytes alterations, biochemical parameters, catalase (CAT), superoxide dismutase (SDO), and total antioxidant capacity (TAC). In addition, male reproductive performance was assessed by quantifying the follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone (T), also testicular sections and GSI% were also assessed. The results showed that the number of leucocytes were significantly (p < 0.05) higher, but the number of red blood cells (RBCs), the level of Hemoglobin (Hb), the percentage of Hematocrit (Ht), the number of platelets, and the eosinophil percentages were significantly decreased (p < 0.05) when fish exposed to MPs. Biochemical parameters (ALP, glucose, uric acid, albumin, and A/G ratio) were significantly increased after MP exposure compared with the control group. Furthermore, MPs induced a significant decline in both serum LH and T levels. Testicular, histological, degenerative changes and testis-ova were found in the MP-exposed fish. Thus, A. coffeaeformis supplementation displayed ameliorative properties that detoxified the negative effects of MPs. This study provides a better understanding of the reproductive injuries caused by MPs exposure and evidence for the use of A. coffeaeformis as a natural remedy in freshwater tilapia.
Mostrar más [+] Menos [-]Volatilization process of toluene from contaminated soil under consideration of co-existence of pore water Texto completo
2021
Lu, Liangliang | Liu, Zhibin | Li, Shangan | Bai, Mei | Fan, Zhanhuang
The volatilization process of contaminants has been shown to play an important role in remediation of VOC-contaminated soils. The aim of this paper is to study the volatilization characteristics of both toluene and water from soil, and to evaluate their interaction mechanism under different conditions. A test system is developed to measure mass loss of contaminants and water from soil by volatilization. It was found that basically the volatilization process could be divided into two stages in clay and one stage in sand. Two main influential mechanisms of water on the volatilization of toluene include molecules’ competitive adsorption and blocking of volatilization channels. In addition, the evaporation process of water was restricted by volatilization of toluene. Volatilization rate of toluene would increase with the increase of water content when the water content was low. But it would decrease with the increase of water content when the water content was higher than 15% in clay. In addition, there existed an optimal water content (15%) under which the maximum volatilization rate could be achieved.
Mostrar más [+] Menos [-]Ethylenediurea (EDU) protects inbred but not hybrid cultivars of rice from yield losses due to surface ozone Texto completo
2021
Zhang, Guoyou | Kobayashi, Kazuhiko | Wu, Hengchao | Shang, Bo | Wu, Rongjun | Zhang, Zujian | Feng, Zhaozhong
The rising concentration of ground-level ozone (O₃) reduces crop yield via increased oxidative stress. Application of ethylenediurea (EDU) protects plants from O₃ and could thereby serve as a means to estimate the crop yield losses due to ambient O₃ (AO₃). However, no study but a few exceptions has ever compared the yield loss estimates from EDU application with those from O₃ elevation experiments. Here, we estimated yield loss to AO₃ in rice cultivars across the 3 types, indica, japonica, and hybrid, by an EDU application in the field, and compared the yield losses with those estimated with dose-response relationships based on O₃ elevation experiments. Relative yield loss (RYL) in the EDU application was estimated at 16% across the rice types on an assumption of a 100% efficiency for protection of crop yield by EDU. This estimate of RYL was close to the 15% RYL estimated from the O₃ elevation experiments when a common sensitivity to O₃ is assumed across the cultivars. The rice yield loss due to AO₃ was thus consistent between the two approaches supporting the idea of EDU application for the yield loss estimation. When only hybrids are focused, however, the RYL from EDU application (16%) was much lower than the 34% RYL from the O₃ elevation experiments, which indicates only a 37% yield protection by EDU in the hybrid rice. The incomplete protection by EDU and its genetic variability indicates the need to quantify the efficiency of protection from AO₃-induced yield loss as estimated with O₃ manipulating experiments.
Mostrar más [+] Menos [-]Quantifying construction waste reduction through the application of prefabrication: a case study in Anhui, China Texto completo
2021
Hao, Jianli | Chen, Zhikun | Zhang, Zihan | Loehlein, Gisela
Due to the rapid pace of urbanization in China, there has been a significant increase in construction work, which has resulted in the generation of more waste. Reducing the waste at source is the most efficient way to reduce its negative impacts, and prefabrication is a construction method that does exactly that. Since prefabricated construction generates less waste compared to conventional cast-in-situ construction, it is being promoted by the Chinese government. This study investigates the benefits of prefabrication and quantifies the percentage of construction waste reduction through its application in China. It does so by using a 26-storey concrete-brick residential building as a case study, and by conducting uncertainty analysis with Oracle Crystal Ball simulation software to assess the reduction of waste when using prefabricated components in place of cast-in-situ elements. Simulation results demonstrated that the waste generation rate for in-situ timber formwork and masonry work was 10.52 and 4.77 kg/m² respectively, and that the use of prefabricated components reduced those figures by 36.04% and 25.53% respectively. This study quantifies the benefits of prefabrication as a method for reducing the generation of construction waste in China. Not only would extensive use of prefabrication decrease the cost related to construction waste management in China, but it could also mitigate the environmental and social impacts of construction waste globally.
Mostrar más [+] Menos [-]Evaluation of pasture allowance of manganese for ruminants Texto completo
2021
Ge, Xiaoping | Chen, Fu | Saqlain, Laraib | Ma, Jing | K̲h̲ān̲, Ẓafar Iqbāl | Kafīl, Aḥmad | Malik, Ifra Saleem | Ashfaq, Asma | Sultana, Razia | Munir, Mudasra | Nadeem, Muhammad | Awan, Muhammad Umer Farooq | Sohail, Muhammad
The aim of this study was to access the Mn contamination in soil, forages, and animals. Heavy metal pollution is a matter of prime significance in natural environment. Through food chain, toxicity of heavy metals and their bioaccumulation potential are transferred into humans. Higher concentrations of metallic compounds are toxic to living organisms but these are essential to maintain body metabolism. Intake of food crops polluted with heavy metals is chief food chain channel for human exposure. Animals are exposed to heavy metal stress by the intake of richly contaminated food crops; those are chief part of food chain. Samples of soil, plant, animal blood, hair, and feces were collected to find contamination through wet digestion process in lab and metal analysis. Different forages were collected to study Mn content that was our major concern in this study. The present findings also emphasized on the assessment of bio-concentration factor (BCF). Other significant indices of mobility and pollution of metal were also calculated, i.e. pollution load index (PLI), daily intake of metal (DIM), health risk index (HRI), and enrichment factor (EF). The experimentation result showed different concentrations of metal in different seasons. The Mn concentration in forages was 20.01–28.29 mg/kg and in soil was 5.27–8.90 mg/kg. Soil samples showed higher level of (PLI) Pollution load index. Bio-concentration of MN was 2.59–4.21 mg/kg. It can be concluded that regular monitoring of the metal is essential to evaluate the contamination status. Mn contents were in the safe limits in soil and plants; however, its toxic level was observed in animals.
Mostrar más [+] Menos [-]Organic load removal and microbial disinfection of raw domestic sewage using SrSnO3/g-C3N4 with sunlight Texto completo
2021
de Sousa Filho, Idio Alves | Freire, Daniel Oliveria | Weber, Ingrid Távora
Sewage treatment and water reuse are, undoubtedly, one of the main points on scientific agenda of the 21ˢᵗ century. Many technologies for sewage treatment are available; however, it is still as an open issue that deserves much attention in order to facilitate their application, develop more effective methods and propose alternative treatment for unusual situations. Developing high performance materials for sewage treatment fits the idea of the development of efficient and alternative methods for microorganism removal and the high organic load of wastewater and is of fundamental importance. In this paper, a heterojunction with perovskite-type strontium stannate (SrSnO₃) and graphitic carbon nitride (g-C₃N₄) — SrSnO₃/g-C₃N₄ — was synthesized and used for photocatalytic treatment of domestic sewage using only sunlight. Results were accompanied by assessing the total organic carbon decrease and removal of pathogenic microorganisms. X-ray diffraction and X-ray excited photoelectron spectroscopy demonstrated that a heterostructure was successfully formed and photocatalytic tests showed an important activity in the visible range, i.e., under sunlight. Exposing raw sewage to 240 min (from 11 a.m. until 3 p.m.) in the presence of SrSnO₃/g-C₃N₄, led to a 56.1% mineralization. This process was 2.5 more efficient than photolysis under sunlight. Moreover, the treated sewage showed no coliform growth (either fecal or total) or heterotrophic bacteria. This simple treatment makes sewage suitable and safe for reuse, for example, for agriculture purposes according to Brazilian regulations criteria and could be an alternative for isolated areas in which sewage treatment plants are not available.
Mostrar más [+] Menos [-]The impact of the COVID-19 pandemic on socio-economic and sustainability Texto completo
2021
Wei, Xueli | Li, Lijing | Zhang, Fan
PUMPING ELEPHANT: The COVID-19 pandemic has adversely affected the lives of people around the world in millions of ways . Due to this severe epidemic, all countries in the world have been affected by all aspects, mainly economic. It is widely discussed that the COVID-19 outbreak has affected the world economy. When considering this dimension, this study aims to examine the impact of the COVID-19 pandemic on the world economy, socio-economics, and sustainability. In addition, the research focuses on multiple aspects of social well-being during the pandemic, such as employment, poverty, the status of women, food security, and global trade. To this end, the study used time series and cross-sectional analysis of the data. The second-hand data used in this study comes from the websites of major international organizations. From the analysis of secondary data, the conclusion of this article is that the impact of the pandemic is huge. The main finding of the thesis is that the social economy is affected by the pandemic, causing huge losses in terms of economic well-being and social capital.
Mostrar más [+] Menos [-]131I and 99mTc in Effluents from a Nuclear Medicine Facility and Associated Sewage Treatment Unit Texto completo
2021
do Carmo, Alessander Sá | Vianello, Elizabeth Aparecida | Pereira, Wagner | de Macêdo, Evangelina Marcia Lima | Filho, Lucas Gomes Padilha | de Souza, Sérgio Augusto Lopes | da Silva, Ademir Xavier
The release of liquid effluents containing radionuclides from radioactive plants in urban areas has been the subject of discussions related to the environmental issue. This study presents the analysis of the activity concentrations (AC) of ¹³¹I and ⁹⁹ᵐTc in sewage samples collected in a nuclear medicine facility (NMF), associated with an university hospital situated in Rio de Janeiro, Brazil. The analyzes and measurements by gamma spectrometry of the collected sewage samples were performed, whose the estimated values (EV) for AC obtained for ¹³¹I in July (8.78 × 10³ Bq m⁻³) and September 2016 (9.80 × 10³ Bq m⁻³) and in February 2017 (1.14 × 10⁴ Bq m⁻³) were lower than the exemption level (EL = 1.90 × 10⁴ Bq m⁻³). For ⁹⁹ᵐTc, the EV for AC obtained from August (4.77 × 10² Bq m⁻³ and 2.96 × 10⁴ Bq m⁻³) to September 2017 (2.18 × 10³ Bq m⁻³) were lower than the EL (1.90 × 10⁹ Bq m⁻³). From an environmental point of view, the presence of ¹³¹I in the sewage treatment unit (STU), even if below the legal release limit, points out the greater importance of this radionuclide, as it requires special precautions in its adequate storage for the radioactive decay in the NMF and the dilution effect to reduce its AC minimizing the environmental impact after the effluent release to the environment. The presence of ¹³¹I in the STU was not expected pointing to the need and evaluation of the waste management system (WMS) of the NMF.
Mostrar más [+] Menos [-]Examining the asymmetric effects of Pakistan’s fiscal decentralization on economic growth and environmental quality Texto completo
2021
Li, Xiaolong | Younas, Muhammad Zeeshan | Andlib, Zubaria | Ullah, Sana | Sohail, Sidra | Hafeez, Muhammad
This study aims to investigate the asymmetric fiscal decentralization effect on economic growth and environmental quality by using Pakistan data from 1984 to 2018. Our findings demonstrate that expenditure decentralization has asymmetric effects on economic growth and CO2 emissions in short- and long-run in Pakistan. Therefore, positive and negative fluctuations in expenditure decentralization affect economic growth and CO2 emissions differently in Pakistan. The results of asymmetric ARDL suggested that negative shock of revenue decentralization is reduced the economic growth and CO2 emissions in the short and long-run, while positive shock of revenue decentralization is reduced the economic growth and CO2 emissions. Our asymmetric results are country-specific and more effective in policy analysis in Pakistan. The outcomes of this study may also help Pakistan’s local governments and the central government in addressing the problem of economic growth and environmental pollution.
Mostrar más [+] Menos [-]Role of ROS generation in acute genotoxicity of azoxystrobin fungicide on freshwater snail Lymnaea luteola L Texto completo
2021
Ali, Daoud | Ibrahim, Khalid E. | Hussain, Seik Altaf | Abdel-Daim, Mohamed M.
Azoxystrobin (AZ) is an aryloxy pyrimidine fungicide extensively applied in the agriculture field all over the world. There is a little information about the ecotoxicity of AZ fungicide on the freshwater snail Lymnaea luteola (L. luteola). The present study investigated the toxic effect of AZ fungicide on L. luteola by using various measures. We determined the mean LC₅₀ value―96 h of AZ fungicide (0.79 mg/L) for L. luteola, in a static system. Based on this value, three sublethal concentrations, viz., I (0.079 mg/L), II (~ 0.40 mg/L), and III (~ 0.53 mg/L), were determined. The snails were exposed to these three concentrations of AZ fungicide for 96 h, and hemolymph and digestive glands were collected after 24 and 96 h for assessment of oxidative stress, apoptosis, and histological and genotoxic changes. The induction of intracellular reactive oxygen species (ROS) and apoptosis in hemocyte cells was increased in a dose- and time-dependent manner. It was observed that lipid peroxide (LPO) and glutathione S transferase (GST) were increased, and glutathione and superoxide dismutase decreased in digestive glands. A similar trend was observed for the DNA damage as measured in terms of the percentage of tail DNA and olive tail moment in digestive gland cells. This study showed the collective use of oxidative stress, histological, and genotoxicity parameters in in vivo laboratory studies using snails that are useful for screening the toxic potential of environmental contaminants such as AZ fungicide.Graphical abstract
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