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Structure of the benthic macrofauna of an anthropogenic influenced area: Skhira Bay (Gulf of Gabès, central Mediterranean Sea) Полный текст
2019
Boudaya, Lobna | Mosbahi, Nawfel | Dauvin, Jean-Claude | Neifar, Lassad
Skhira Bay located in the Gulf of Gabès, on the southeastern coast of Tunisia, is an important area in terms of its dense vegetation coverage, wide continental shelf, and fisheries resources. However, this area with a typically micro-tidal range is subject to intensive anthropogenic pressures: soft bottom trawling, chemical pollution from phosphoric acid production, and shipping activity. The present study is the first investigation of the structure of the benthic macrofauna on this part of the Tunisian coast. In April 2010, 28 stations were sampled along four transects from the phosphogypsum outfall on an inshore-offshore gradient. A total of 239 macrobenthos taxa, belonging to nine zoological groups and 140 families, were identified with a dominance of polychaetes (33.5%), crustaceans (29.4%), and mollusks (19.6%). Results show that the stations facing the phosphogypsum discharges are the most disturbed and characterized by a poorly diversified macrofauna. The macrofauna is dominated by carnivores, suspension feeders, and selective deposit feeders, and seems to be linked more to the availability of trophic resources than to disturbance. Four benthic assemblages are identified using Cluster and MDS analyses linked to edaphic factors, such as sediment structure, organic matter content, inshore/offshore gradient, and the proximity of the phosphogypsum outfall. The biotic indices (AMBI and BO2A) calculated from macrofauna data show that the ecological status of Skhira Bay varies overall from moderate to good. This study suggests initiating a long-term monitoring program to improve our understanding of the temporal changes of this ecosystem, to recommend the necessary conservation measures in this area of high-value natural heritage.
Показать больше [+] Меньше [-]Traffic noise exposure of high-rise residential buildings in urban area Полный текст
2019
Wu, Jie | Zou, Chao | He, Shaohua | Sun, Xiaolong | Wang, Xiaoxia | Yan, Quansheng
Noise pollution is a major factor of environmental complaints in many cities, which has significant impacts on human health. As a dominating source of environmental noise, the impact of road traffic noise is increasing. Residents living in high-rise buildings along the main road are severely affected by traffic noise. In order to assess the noise level of urban area along the main road in Guangzhou, three buildings were selected to conduct traffic noise measurements, and the questionnaire about traffic noise impact on human being was completed. Through the questionnaire, around 70% of participants consider the traffic noise has negative effect, and about 60% of participants consider the noise has moderate or much higher impact on physical comfort. Around 65% of participants consider the noise had moderately or much higher impact on their psychological comfort. By analyzing the measured data, all of the measured noise levels in three buildings exceed the recommended limit of 55 dB (A) in the daytime and 45 dB (A) in the night for residence, and the exceeded value can be up to 16 dB (A). By comparing the fitting curve of noise level transfer function on each floor relative to the reference floor, the quadratic polynomial was selected to plot the transfer function rather than cubic polynomial.
Показать больше [+] Меньше [-]Biosorption technology for removal of toxic metals: a review of commercial biosorbents and patents Полный текст
2019
de Freitas, Geovani Rocha | da Silva, Meuris Gurgel Carlos | Vieira, Melissa Gurgel Adeodato
In last decades, the biosorption process has become one of the main alternative treatment technologies for the removal of pollutants from dilute aqueous solution. Among these pollutants, toxic metals have drawn attention due to their negative effects in human body and food chain. Even though biosorption is considered a cost-effective and eco-friendly technology to remove toxic metals from dilute wastewaters, there are still obstacles that restrain its commercialization. For this reason, various scientific articles and patents have been published each year to make more effective and economical this technology. This review reports an overview of past achievements, current research of biosorption studies, and future trends for the development of the biosorption as sustainable cleaner technology. Mechanisms of metal uptake, recovery and biosorbent regeneration, process design, commercial application of biosorbents, and patents registered are presented. Finally, future aspects in biosorption research and suggestions for its application will be discussed.
Показать больше [+] Меньше [-]Effects of extreme temperatures on hospital emergency room visits for respiratory diseases in Beijing, China Полный текст
2019
Ma, Yuxia | Zhou, Jianding | Yang, Sixu | Yu, Zhiang | Wang, Fei | Zhou, Ji
Extreme temperature is closely associated with human health, but limited evidence is available for the effects of extreme temperatures on respiratory diseases in China. The goal of this study is to evaluate the effects of extreme temperatures on hospital emergency room (ER) visits for respiratory diseases in Beijing, China. We used a distributed lag non-linear model (DLNM) coupled with a generalized additive model (GAM) to estimate the association between extreme temperatures and hospital ER visits for different age and gender subgroups in Beijing from 2009 to 2012. The results showed that the exposure-response curve between temperature and hospital ER visits was almost W-shaped, with increasing relative risks (RRs) at extremely low temperature. In the whole year period, strong acute hot effects were observed, especially for the elders (age > 65 years). The highest RR associated with the extremely high temperature was 1.36 (95% CI, 0.96–1.92) at lag 0–27. The longer-lasting cold effects were found the strongest at lag 0–27 for children (age ≤ 15 years) and the relative risk was 1.96 (95% CI, 1.70–2.26). We also found that females were more susceptible to extreme temperatures than males.
Показать больше [+] Меньше [-]Changes in mineral forms of nitrogen and sulfur and enzymatic activities during composting of lignocellulosic waste and chicken feathers Полный текст
2019
Bohacz, Justyna
The aim of this study was to show the dynamics of changes in the activity of enzymes responsible for C, N, and S metabolism, i.e., cellulase, protease, urease, and arylsulfatase in two lignocellulosic composts as well as changes in the concentration of mineral forms important in plant nutrition (N-NH₄⁺, N-NO₃⁻, S-SO₄²⁻). Most of the enzyme activity was higher during 10 weeks of composting in compost I, containing higher amounts of easily available organic matter than in compost II. Enzymatic activities in compost II remained at a higher level for a longer time, but they increased at a slower rate. Mineral content changes in the compost mass consisted primarily of an increase in N-NO₃⁻ concentration and a decrease in N-NH₄⁺ and S-SO₄²⁻ levels, especially in compost I. The concentration of mineral nitrogen and sulfur forms in compost water extracts was about 10–100 times lower than in the compost mass. At the end of composting, the amount of sulfates in the compost mass was 30 and 150 mg kg⁻¹ dw in compost II and I, respectively. In this context, the composts obtained should be considered valuable for fertilizing soils poor in this component and for cultivating plants with high sulfate S demand.
Показать больше [+] Меньше [-]Influence of phytase enzyme on ruminal biogas production and fermentative digestion towards reducing environmental contamination Полный текст
2019
Vallejo-Hernández, Laura Haydée | Rodríguez, German Buendia | Elghandour, Mona Mohamed Mohamed Yasseen | Greiner, Ralf | Salem, Abdelfattah Zeidan Mohamed | Adegbeye, Moyosore Joseph
Influence of phytase enzyme on ruminal biogas production and fermentative digestion towards reducing environmental contamination Полный текст
2019
Vallejo-Hernández, Laura Haydée | Rodríguez, German Buendia | Elghandour, Mona Mohamed Mohamed Yasseen | Greiner, Ralf | Salem, Abdelfattah Zeidan Mohamed | Adegbeye, Moyosore Joseph
Environmental impact of livestock production has received a considerable public scrutiny because of the adverse effects of nutrient run-offs, primarily N and P, from agricultural land harboring intensive energy livestock operations. Hence, this study was designed to determine the efficacy of dietary phytase supplementation on fermentation of a sorghum grain–based total mixed ration (TMR) using a ruminal in vitro digestion approach. Phytase was supplemented at three doses: 0 (control), 540 (P540), and 720 (P720) g/t dry matter, equivalent to 0, 2.7 × 10⁶, and 3.6 × 10⁶ CFU/t DM, respectively. Compared to P720 and the control, gas production was higher for P540 after 12 h (P = 0.02) and 24 h (P = 0.03) of fermentation suggesting a higher microbial activity in response to phytase supplementation at lower phytase levels. Correspondingly, dry matter degradability was found to have improved in P540 and P720 compared to the control by 13 and 11% after 24 h of incubation (P = 0.05). For ammonia nitrogen (NH₃-N), a tendency towards lower values was only observed for P540 at 24 h of fermentation (P = 0.07), while minimal treatment effects were observed at other fermentation times. The concentrations of total volatile fatty acids (VFA) were higher (P < 0.05) after 48 h of fermentation for P540 and P720 compared to the control (P = 0.03) by 10% and 14%, respectively. Ruminal acetate tended towards higher values in the presence of phytase after 12 h of fermentation (P = 0.10), but towards lower values after 24 h of fermentation (P = 0.02), irrespective of the phytase dose applied. A trend towards lower ruminal propionate levels was observed in the presence of phytase after 6 h (P = 0.10) and 12 h (P = 0.06) of fermentation, while no effects were found at other fermentation times. In conclusion, phytase supplementation has the potential to improve metabolic energy activity of rumen microorganisms and the use of feed constituents. Thus, phytase supplementation could help to reduce environmental contamination in areas of ruminant production.
Показать больше [+] Меньше [-]Influence of phytase enzyme on ruminal biogas production and fermentative digestion towards reducing environmental contamination Полный текст
2019
Vallejo-Hernández, Laura H.H. | Buendia Rodríguez, German | Elghandour, Mona M. M. Y. | Greiner, Ralf | Salem, Abdelfattah Z. M. | Adegbeye, Moyosore J.
Ameliorative effect of zinc oxide nanoparticles against potassium bromate-mediated toxicity in Swiss albino rats Полный текст
2019
Hassan, Iftekhar | Husain, Fohad Mabood | Khan, Rais Ahmad | Ebaid, Hossam | Al-Tamimi, Jameel | Alhazza, Ibrahim M. | Aman, Shazia | Ibrahim, Khalid Elfaki
Potassium bromate (PB) is a commonly used food additive, a prominent water disinfection by-product, and a class IIB carcinogen. It exerts a various degree of toxicity depending on its dose and exposure duration consumed with food and water in the living organisms. The present investigation aims to demonstrate the protective efficacy of zinc oxide nanoparticles (ZnO NPs) derived from Ochradenus arabicus (OA) leaf extract by green technology in PB-challenged Swiss albino rats. The rodents were randomly distributed, under the lab-standardized treatment strategy, into the following six treatment groups: control (group I), PB alone (group II), ZnO alone (group III), ZnO NP alone (group IV), PB + ZnO (group V), and PB + ZnO NPs (group VI). The rats were sacrificed after completion of the treatment, and their blood and liver samples were collected for further analysis. Group II showed extensive toxic effects with altered liver function markers (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, gamma-glutamyl transferase, glutathione-S-transferase, and thioredoxin reductase) and compromised redox status (SOD, CAT, GR, GPx, GSH, MDA, and total carbonyl content). The histopathological analysis and comet assay further supported the biochemical results of the same group. Besides, group III also showed moderate toxicity evidenced by an alteration in most of the studied parameters while group IV demonstrated mild toxicity after biochemical analysis indicating the excellent biocompatibility of the NPs. However, group VI exhibited attenuation of the PB-induced toxic insults to a significant level as compared to group II, whereas group V failed to show similar improvement in the studied parameters. All these findings entail that the ZnO NPs prepared by green synthesis have significant ameliorative property against PB-induced toxicity in vivo. Moreover, administration of the NPs improved the overall health of the treated animals profoundly. Hence, these NPs have significant therapeutic potential against the toxic effects of PB and similar compounds in vivo, and they are suitable to be used at the clinical and industrial levels.
Показать больше [+] Меньше [-]Generation of biodiesel from industrial wastewater using oleaginous yeast: performance and emission characteristics of microbial biodiesel and its blends on a compression injection diesel engine Полный текст
2019
Tamilalagan, Anbarasan | Singaram, Jayanthi | Sakthivel, R. (Rajamohan)
Microbial-derived biodiesel was tested on a lab scale CI diesel engine for carrying out exhaust emission and performance characteristics. The performance, emission, and combustion characteristics of a single cylinder four stroke fixed compression ratio engine when fueled with microbial bio-diesel and its 10–30% blends with diesel (on a volume basis) were investigated and compared with conventional diesel. The bio-diesel was obtained from microbes which were grown by combining distillery spent wash with lignocellulosic hydrolysate at nutrient deprived conditions. The microbes consumed the wastes and converted the high strength waste water into lipids, which were trans-esterified to form bio-diesel. Testing of microbial bio-diesel blends with ordinary diesel at different loading pressures and the emission characteristics were compared. Results indicate that with increasing of the blends, reduction of HC and CO emissions were observed, whilst brake thermal efficiency maxed out at 20% blending. Further increase of blends showed a tendency of increasing of both emissions in the exhaust stream. The Brake Specific Fuel consumption was observed to decline with blending until 20% and then increased. The nitrogen oxide emissions, however, were found to increase with increasing blend ratios and reached a maximum at 20% blend. The escalation of HC, CO, CO₂, and NOx emissions was also observed at higher blending ratios and higher engine loads. The performance studies were able to show that out of the three blends of biodiesel, 20% biodiesel blend was able to deliver the best of reduced hydrocarbon and carbon monoxide emissions, whilst also delivering the highest Brake thermal efficiency and the lowest Brake Specific Fuel consumption.
Показать больше [+] Меньше [-]The effect of Cu-resistant plant growth-promoting rhizobacteria and EDTA on phytoremediation efficiency of plants in a Cu-contaminated soil Полный текст
2019
Abbaszadeh-Dahaji, Payman | Baniasad-Asgari, Ayda | Hamidpour, Mohsen
Remediation of heavy metal–contaminated soils is essential for safe agricultural or urban land use, and phytoremediation is among the most effective methods. The success of phytoremediation relies on the size of the plant biomass and bioavailability of the metal for plant uptake. This research was carried out to determine the effect of Ethylenediaminetetraacetic acid (EDTA) ligand and Cu-resistant plant growth-promoting rhizobacteria (PGPR) on phytoremediation efficiency of selected plants as well as fractionation and bioavailability of copper (Cu) in a contaminated soil. The test conditions included three plant species (maize: Zea mays L., sunflower: Helianthus annuus L., and pumpkin: Cucurbita pepo L.) and six treatments, comprising two PGPR strains (Pseudomonas cedrina K4 and Stenotrophomonas sp. A22), two PGPR strains with EDTA, EDTA, and control (without PGPR and EDTA). The combination of EDTA and PGPR enhanced the Cu concentration in both shoot and root tissues and increased the plant biomass. The Cu specific uptake was at a maximum level in the shoots of pumpkin plants when treated with the PGPR strain K4 + EDTA (202 μg pot⁻¹), and the minimum amount of Cu was recorded for sunflower with no PGPR or EDTA addition (29.6 μg pot⁻¹). The result of the PGPR-EDTA treatments showed that the combined application of EDTA and PGPR increased the shoot Cu-specific uptake approximately fourfold in pumpkin. Pumpkin with the highest shoot Cu specific uptake and maize with the highest root Cu specific uptake were the most effective plants in phytoextraction and phytostabilization, respectively. The effectiveness of different PGPR-EDTA treatments in increasing Cu specific uptake by crop plants was assessed by measuring the amount of Cu extracted from the rhizosphere soil adhering to the roots of crop species, by the use of the single extractants Diethylenetriamine pentaacetic acid (DTPA), H₂O, NH₄NO₃, and NH₄OAc. PGPR-EDTA treatments increased the amount of water-extractable Cu from rhizosphere soils more than ten times that of the control. The combined application of the EDTA and PGPR reduced the carbonated Fe and Mn oxide–bound Cu in the contaminated soil, and increased the soluble and exchangeable concentration of Cu. Pumpkin, with high shoot biomass and the highest shoot Cu specific uptake was found to be the most effective field crop in phytoextraction of Cu from the contaminated soil. The results of this pot study demonstrated that the EDTA+PGPR treatment could play an important role in increasing the Cu bioavailability and specific uptake by plants, and thus increasing the phytoremediation efficiency of plants in Cu-contaminated areas.
Показать больше [+] Меньше [-]Duration analysis on the adoption behavior of green control techniques Полный текст
2019
Gao, Yang | Zhao, Duanyang | Yu, Lili | Yang, Haoran
Based on field survey data of 366 traditional households (THs) and 364 family farms (FFs) from Huang-Huai-Hai Plain, a discrete-time cloglog model for parameter estimation was constructed to reveal factors that affect the two types of farms’ duration from the awareness to the adoption of green control techniques (GCTs). Differences in the influencing factors affecting the duration of the two types of farmers were also discussed. The research results are as follows. First, the duration from awareness to adoption of GCTs is significantly shorter in FFs than that in THs. Second, a higher degree of education, risk preference, family financial status, perceived ease of use and usefulness of the technique, and extension of media and supervision of agricultural technique extension departments of local governments significantly reduce the duration from awareness to adoption of GCTs by THs and FFs, whereas a male head of household prolongs the duration. Third, the age, farm size, and number of laborers exert different impacts on the duration from awareness to adoption of GCTs by THs and FFs.
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