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Mercury exposure in sedentary and migratory Charadrius plovers distributed widely across China Texte intégral
2020
Su, Tongping | Lin, Xin | Huang, Qin | Jiang, Demeng | Zhang, Chi | Zhang, Xuecong | Dingle, Caroline | Goodale, Eben | Que, Pinjia | Wang, Rui | Liu, Yang
Mercury pollution is a global problem and of particular concern in high emissions areas, such as China. We studied the migratory Kentish Plover, Charadrius alexandrinus, which breeds in coastal northern/central China and the inland Qinghai Lake, and the White-faced Plover C. dealbatus, a year-round resident of coastal southern China. We measured total mercury (THg) concentrations in feather and blood samples of breeding females. We expected low levels at the remote Qinghai Lake, but we found instead that feather THg concentrations were highest there (3.89 ± 1.53 [SD] μg/g DW [n = 34]; compared to 1.29 ± 0.61 μg/g of Kentish Plover elsewhere [n = 35] and 2.08 ± 1.45 μg/g for White-faced Plover [n = 56]), a result is consistent over 2 years. When including only coastal populations in the analysis, there were no differences in THg concentrations between the two species, although White-faced Plover had more variation. Feather THg concentrations for the coastal populations are similar to other studies on plovers and sandpipers globally, with most birds under the threshold of adverse effects (3 μg/g, an estimate that itself may be too low). Nevertheless, the Qinghai Kentish Plover population has mean feather concentrations above this threshold, indicating high exposure during the nonbreeding season, and some individuals have extreme values (e.g., a bird with a blood level of 7.63 μg/g DW from Zhanjiang, south China), so further research and monitoring are needed.
Afficher plus [+] Moins [-]Mobility of mercury in soil and its transport into the sea Texte intégral
2020
Gębka, Karolina | Saniewska, Dominika | Bełdowska, Magdalena
Mercury (Hg) is deposited temporarily in soil and can be remobilised into rivers and seas. Given that rivers are a significant part of the mercury budget in the southern Baltic region (inland sea located in northern Europe) and meteorological changes (e.g. intense rain, drought) are observed more frequently, it is important to recognize the factors affecting the cycling of bioavailable Hg forms. The aim of this study was to identify the processes influencing the changes of labile and stabile mercury proportion in soil and the potential impact on the outflow of labile Hg into fluvial systems. For this purpose, soil samples, river sediments, and river water were collected from the Reda River (southern Baltic Sea catchment area) during the 2015 hydrologic year. The material was analysed for total and particulate mercury content and Hg forms, by a thermo-desorption method. The analysis showed that due to changes of meteorological and hydrological conditions Hg can enter rivers and then be introduced into the marine environment in various forms. On the one hand due to high precipitation events washing out of labile (i.e. bond with halogenides, MeHg, HgSO₄), Hg forms into the river can be enhanced which affects increasing of availability of the most dangerous Hg form in the water systems. On the other hand the same event can cause the limitation of bioavailable mercury forms by a conversion of labile Hg into the most stable one (HgSO₄ ➔ HgS) under anaerobic conditions.
Afficher plus [+] Moins [-]Numerical simulation and field experiment study on onboard dust removal technology based on airflow–dust pollution dispersion characteristics Texte intégral
2020
Mo, Jinming | Yang, Junlei | Ma, Wei | Chen, Fang | Zhang, Sheji
To solve the problem of dust production by the caving coal seam on the weather side of a fully mechanized coal face with a large mining height, this study proposes coal cutter onboard dust removal technology for the first time. In this work, taking the 12511 fully mechanized coal face of the Bulianta Coal Mine with a large mining height as an example, a mathematical model was built to study the influence of the onboard dust collector on airflow–dust dispersion pollution and the key technological parameters of the dust collector, and field tests were performed for verification. The results of numerical simulation showed that the dust-carrying airflow, after being blocked by the coal cutter, dispersed in the lateral direction, leading to an increase of airflow velocity on the walkway side to 1.75 m s⁻¹, and a dust concentration as high as 2500 mg m⁻³. At the same time, an airflow vortex area with the largest diameter of 3 m was formed near the surface of the coal cutter body, which attracted dust to gather there. However, after the application of the onboard dust removal technology, the lateral dispersion of dust-carrying airflow weakened, and the dust concentration on the walkway side was reduced to below 600 mg m⁻³. In addition, this technology also obviously reduced the influence scope of the vortex and the dust concentration area. It was also found that the installation height of the suction inlet of the dust collector and the air capacity had a large impact on the dust suppression efficiency. The optimum dust suppression efficiency was reached at an installation height of 1.15 m and air capacity of 120 m³ min⁻¹. Field test verification demonstrated that the dust concentration on the walkway side could be reduced by as much as 49.3% with the application of the proposed onboard dust removal technology.
Afficher plus [+] Moins [-]Role of cotton sticks biochar in immobilization of nickel under induced toxicity condition and growth indices of Trigonella corniculata L Texte intégral
2020
Younis, Uzma | Danish, Subhan | Malik, Saeed Ahmad | Ahmed, Niaz | Munir, Tariq Muhammad | Rasheed, Muhammad Khalid
Among various heavy metals, nickel (Ni) is a potential pollutant that accumulates in broad-leaf vegetables and is reported to be carcinogenic. Biochar (BC) is a nutrient-rich and effective organic amendment for immobilization of Ni in soil. Fenugreek (Trigonella corniculata L.), a broad-leaf vegetable, is commonly cultivated due to its all-inclusive composition of nutrients such as calcium and iron and β-carotene and vitamins. Therefore, a field-pot study was conducted to examine the effectiveness of cotton-sticks-waste biochar (BC) for soil immobilization of Ni in fenugreek crop cultivated between early-October to end-November 2015. Fenugreek was grown in a sandy-loam soil experimentally contaminated with various Ni levels (0, 25, 50, and 100 mg Ni kg⁻¹ soil) under three BC levels (0, 3, and 5%; w/w). Overall, results showed increasing plant lipid peroxidation (assessed via malondialdehyde) and ascorbic-acid concentration with increasing Ni toxicity level without BC application (p ≤ 0.05). Application of 3% BC increased the chlorophyll a (20.0%), chlorophyll b (49.1%), total chlorophyll (27.6%), carotenoids (21.6%), anthocyanin (27.2%), photosynthetic rate (112%), transpiration rate (45.0%), and sub-stomatal CO₂ concentration (19.9%) in fenugreek as compared to control (0% BC) under 50 mg Ni kg⁻¹ soil. Higher BC application rate (5%) was more effective in increasing the chlorophyll a (33.6%), chlorophyll b (81.1%), total chlorophyll (43.9%), carotenoids (71.7%), anthocyanin (77.8%), photosynthetic rate (127%), transpiration rate (42.2%), and sub-stomatal CO₂ concentration (23.5) over control under 100 mg Ni kg⁻¹ soil. We suggest that the consistent increases in dry mass, carbon flux rate and, protein, amino acids, and sugar contents of fenugreek (cultivated in a soil toxified with Ni and amended with 5% BC) seems to be caused by the reduction in the mobility of Ni in the presence of BC in a sandy-loam soil.
Afficher plus [+] Moins [-]Trade openness, environmental regulation, and human capital in China: based on ARDL cointegration and Granger causality analysis Texte intégral
2020
Wen, Huaide | Dai, Jun
This research aims to examine the empirical cointegration, long-run and short-run dynamics, and causal relationships between trade openness, environmental regulation, and human capital level in China throughout 1990–2016. Based on the ARDL Bounds Testing method, the empirical results confirmed long-run cointegration between trade openness, environmental regulation, and human capital level. Environmental regulation and trade openness have a significant positive impact on the human capital level, and environmental regulation has a U-shaped effect on human capital accumulation. The Granger causality test results indicate that environmental regulation Granger causes human capital level, the human capital level Granger causes trade openness, and trade openness and environmental regulation have a bidirectional relationship. This research brings new contributions to sustainable development theory.
Afficher plus [+] Moins [-]Drought evolution indicated by meteorological and remote-sensing drought indices under different land cover types in China Texte intégral
2020
Javed, Tehseen | Yao, Ning | Chen, Xinguo | Suon, Sovannaka | Li, Yi
Remote sensing freely provides many processed image products such as moderate resolution imaging spectroradiometer (MODIS), and long-term data record (LTDR), for the investigation of drought evolution. Our objectives are to investigate drought evolution and spatiotemporal variations from 1982 to 2017 based on two remote-sensing indices, namely, the normalized difference vegetation index (NDVI) and the vegetation condition index (VCI), and a popular meteorological index—standardized precipitation index (SPI)—under four different land cover types, cropland, forestland, grassland, and desertland in China. The modified Mann–Kendall test was used to detect the significance of a trend. The Pearson correlation method was used to find the relationship between NDVI anomaly, VCI, precipitation, and SPI. The results revealed that (a) both mean monthly and yearly precipitation had a general land cover type rank of forestland > grassland ≈ cropland > desertland. (b) A positive correlation was found between drought indices (NDVI anomaly, VCI, SPI) and precipitation for different land cover types. The NDVI anomaly and VCI were well correlated with 3-month SPI for cropland and were well correlated with 6-month SPI for forestland. VCI performed better than NDVI anomaly when correlating with SPI. (c) The coefficient of determination (R²) was obtained for precipitation and VCI in the driest (2011) and wettest (2016) years. The R² values for desert and grassland ranged from 0.70 to 0.90 and for cropland and forestland were lower (0.54–0.69). (d) Only precipitation, SPI, and VCI of cropland had significant increasing trends. The spatial distribution patterns of precipitation, NDVI, and VCI increased with the decreased elevation. The study revealed that desert and grassland had been regularly exposed to moderate or extreme droughts conditions and confirmed that desert and grassland are more sensitive to short-term drought.
Afficher plus [+] Moins [-]Establishment of geochemical baseline and multiple assessment of vanadium pollution in sediment cores from the two cascade reservoirs, North China Texte intégral
2020
Wang, Jiankang | Peng, Wenqi | Wang, Shaoming | Gao, Bo | Qu, Xiaodong | Zhang, Min | Xu, Dongyu
Vanadium (V) is a potential toxic pollutant, and thus, V pollution in reservoir sediment should be scientifically evaluated because reservoirs are the main source of drinking water in China. However, the pollution assessment of V in reservoir sediment is often overestimated or underestimated due to the limitation for selecting local background values. In this study, the selection of the V background value in sediments was based on regional geochemical baseline (RGB) model. Multiple methods including geo-accumulation index (Igₑₒ), potential ecological risk index (EI), and health risk assessment were applied to evaluate V pollution in sediment cores collected from the Panjiakou–Daheiting Reservoirs (PDR). The results show that the mean value of V concentrations in the PDR sediment cores was 92.86 mg/kg (57.69–141.19 mg/kg), which is higher than the soil background in Hebei Province and stream sediment values in China. V concentrations in the Panjiakou Reservoir were higher than those in the Daheiting Reservoir. The RGB value of V was 96.33 mg/kg in the PDR sediments. A comparison of the V concentrations and RGB values in the sampling sites indicated that half of these sites are impacted by anthropogenic inputs. Among the sites influenced by human activity, the average anthropogenic contribution was 9.9%, suggesting that majority of V in the PDR sediments originated from natural source. The pollution assessments of V were evaluated using Igₑₒ and EI with RGB as the background value, and results indicated that the sediments in the PDR were not polluted with V. The environmental impact assessment model was also established for calculating V accumulation in fish due to sediment resuspension. Then, health risk assessment model was applied to further calculate the health risk to residents due to fish consumption. The evaluated target hazard quotient demonstrated that local fish consumption produced no adverse effect on human health during sediment disruption.
Afficher plus [+] Moins [-]Exploring the linkage between the supply and demand of cultural ecosystem services in Loess Plateau, China: a case study from Shigou Township Texte intégral
2020
Shi, Qinqin | Chen, Hai | Liu, Di | Zhang, Hang | Geng, Tianwei | Zhang, Hongjuan
Including cultural ecosystem services (ES) in the management of an ecosystem can improve the social acceptance and legitimacy of management decisions. In order to adapt to the inherently fragile ecological environment, the Loess Plateau has formed a unique land-use mode and rural cultural landscape, yet the research on the cultural ES in this area is limited. The study of cultural ES from the supply and demand perspective will contribute to realize the sustainable cultural ES supply and meet people’s growing demand for a better life. This study conducted a questionnaire survey with 381 people in 42 villages of Shigou Township in the Loess Plateau to explore local residents’ demand (perceived importance) of 8 types of cultural ES. The 5-point Likert scale was used to quantify the relative level of residents’ demand of cultural ES. Spearman’s rank correlation analysis was used to evaluate the correlations between pairs of cultural ES. In addition, this study constructed the indicator system of cultural ES supply from two dimensions of cultural ES supply capacity and accessibility and used a redundancy analysis to explore the linkage between the cultural ES supply and demand. The results showed that residents had a higher demand for esthetics and sense of place, but lower demand for spiritual and religious in Shigou Township. There were significant and positive correlations between different types of cultural ES, and most of them were enjoyed in “bundles.” Each type of cultural ES was related to different types of percentage land cover, and geographical distance played an important role in cultural ES supply. Last, we proposed that local residents’ perceived importance of cultural ES should be included in decision-making to improve public support for ecosystem management, and managers should simultaneously pay attention to the supply capacity and accessibility of cultural ES to realize the sustainable cultural ES supply.
Afficher plus [+] Moins [-]Acute oral toxicity study on Wistar rats fed microalgal protein hydrolysates from Bellerochea malleus Texte intégral
2020
Barkia, Ines | Ketata Bouaziz, Hanen | Sellami Boudawara, Tahiya | Aleya, Lotfi | Gargouri, Ali Faouzi | Saari, Nazamid
Protein hydrolysates and bioactive peptides from various protein sources have demonstrated their effectiveness for the prevention of illness and the improvement of symptoms from several diseases. In particular, the use of microalgae to generate bioactive peptides has received a growing interest because of their potential to be cultivated on non-arable land and high nutritional value. However, scant research is available on the toxicity of peptide-based preparations. The present study aims to evaluate the toxicity of microalgal protein hydrolysates (MPH) from one marine species of microalgae (Bellerochea malleus) to determine the feasibility of their use for functional food applications. Results showed that the oral administration of MPH at three doses (D1, 100 mg kg⁻¹ BW; D2, 400 mg kg⁻¹ BW; and D3, 2000 mg kg⁻¹ BW) to male Wistar rats did not induce any adverse effects or mortality up to13 days of treatment. Data analysis of relative organ weights and biochemical and hematological parameters did not show any significant differences between control and treated groups at the three doses investigated. Data from histopathological observations did not reveal any signs of major toxicity at the doses D1 and D2. However, mild signs of inflammation and necrosis were observed in the kidney of rats fed MPH at D3. All together, these results reveal the overall safety of MPH and provide new evidence for advocating their use for functional food or nutraceutical applications.
Afficher plus [+] Moins [-]Sustainability and CDM potential analysis of a novel vs conventional bioenergy projects in South Asia by multi-criteria decision-making method Texte intégral
2020
Rasheed, Rizwan | Javed, Hajra | Rizwan, Asfra | Yasar, Abdullah | Tabinda, Amtul Bari | Mahfooz, Yusra | Wang, Yubo | Su, Yuehong
In this study, the multi-attribute utility theory model, one of the most widely utilized multi-criteria decision-making methods, is employed to analyze the relative sustainability and cleaner development mechanism (CDM) potential of a novel bioenergy project in Pakistan and four registered CDM bioenergy installations in China, India, Sri Lanka, and Thailand. Four major sustainability evaluation criteria selected for the study are technology, economy, environment, and social aspects, whereas “simple multi-attribute rating technique” (SMART) and “additive synthesis method” were utilized for the calculation of weighting factors. The most significant indicator was emission reduction, and least significant indicator was job creation with 24% and 15% respective weightages, in the sustainability scoring. Moreover, for three considered evaluation scenarios, (I) base case, (II) per kilowatt, and (III) per kilowatt hour, the bioenergy project in Pakistan has the highest comparative sustainability values of 0.735, 0.592, and 0.492 respectively. This analysis will provide an insight assistance to developing countries for establishing sustainable energy installations under CDM.
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