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The role of financial development, energy demand, and technological change in environmental sustainability agenda: evidence from selected Asian countries Texte intégral
2020
Saleem, Hummera | Khan, Muhammad Bilal | Shabbir, Malik Shahzad
The study seeks to examine the policy scheme of Asian countries and their efforts to achieve sustainable environmental practices in terms of green growth, green financing, and CO2emission reduction programs. This study investigates the role of GDP growth, sources of energy consumption, and other plausible hypothetical factors in CO₂ emissions using evidence from selected Asian countries over the period of 1980–2015. The contribution of this research is unique, with the use of these plausible variables under the framework of EKC, which makes this study different from other studies and helps fill a gap in the literature. This study has used panel Fully Modified OLS (FMOLS) test, the panel Granger causality test namely the Dumitrescu-Hurlin test (2012) and the Innovative Accounting Approach. The results of FMOLS for the full panel set indicates the presence of an EKC hypothesis, where the impact of GDP growth and the square of GDP growth on CO2 emissions are positive and negative, respectively, in the context of 10 Asian economies. The findings of FMOLS for lower income economies do not support the EKC hypothesis; however, the results exhibit that high and upper middle income economies maintain the EKC hypothesis. The results of high income and upper middle income economies confirm the existence of the environment Kuznets curve, and the results of GDPᵢₜ show that both significantly positively impact logGDPᵢₜon CO2 emission.
Afficher plus [+] Moins [-]Leader-follower optimized approach for carbon-economy equilibrium in the municipal solid waste (MSW) incineration industry Texte intégral
2020
Xu, Jiuping | Zhu, Mengyuan | Zhao, Siwei
Municipal solid waste (MSW) incineration contributes significantly to carbon emissions, and has become a serious problem in China, which has seen an exponential rise in waste over the last twenty years due to rapid urbanization and the associated consumer economy growth. To tackle this issue, this paper develops a leader-follower optimized approach for economic and environmental equilibrium in incineration power plants that includes a carbon allowance allocation scheme (IPP-CAAS) under combustion and pollutant limitations. In the leader-follower (bi-level) game, the regional authority on the upper level determines the carbon allocations and environmental targets and the IPPs on the lower level develop schemes to maximize revenue under the upper-level restrictions. By employing uncertain parameters for the carbon and power conversion fluctuations, the approach is able to more accurately depict the industry characteristics of waste incineration process in this carbon-economy balance problem. The robustness and practicality of the proposed methodology was then validated through a case study. Scenario analysis under different political parameters indicates that the proposed methodology can assist the authorities to achieve carbon-economy trade-off and under serious carbon-control situations, encourage the IPPs to reduce their blended coal ratios, and invest in low-carbon incineration technology. Managerial insights on further industrial developments are also given for the authority and relevant practitioners.
Afficher plus [+] Moins [-]Radon concentration in drinking water and soil after the September 24, 2019, Mw 5.8 earthquake, Mirpur, Azad Jammu, and Kashmir: an evaluation for potential risk Texte intégral
2020
Muhammad, Said | Riz̤vānullāh, | Turab, Syed Ali | Khan, Muhammad Younis | Khattak, Nimat Ullah | Khan, Muhammad Asif
Radon (²²²Rn), a radioactive gas resulted from the natural decay of other radioactive elements, pose a threat to the exposed human population. Radon gas emits along the seismically active faults and increased the ²²²Rn contamination in sorrounding water and soil. This study investigated the concentration of ²²²Rn in drinking water and soil after the September 24, 2019, Mw 5.8 earthquake, Mirpur District, Azad Jammu, and Kashmir (AJK). For this purpose, water (n = 24) samples were collected from the bore wells of orderly located houses and soil field sampling (n = 12) along with the NE-SW directions of fracture in the Mirpur District. Determined ²²²Rn in drinking water surpassed the maximum contamination level (MCL, 11.1 kBq/m³) set by the US Environmental Protection Agency (US EPA) in 83%, 50%, and 33% of the sampling point at the site I, site II, and site III, respectively. However, that of soil ²²²Rn concentration was observed with the normal range (10–50 kBq/m³). Potential exposure of ²²²Rn consumption in drinking water was the mean effective dose through ingestion (EWᵢₙg, 0.003 ± < 0.001 mSv/a), the effective dose for inhalation (EWIₙₕ, 0.038 ± 0.002 mSv/a), and the total effective dose of human (EWT, 0.041 ± 0.002 mSv/a). Exposure values along with the rupture showed multifold higher risk values (up to 4 times) compared to background sites. These values were observed within the limits (0.1 mSv/a) set by World Health Organization (WHO); however, surpassed the thresholds of the United Nations Scientific Committee on the effects of atomic radiations (UNSCEAR) for all exposure pathways. This study concluded that groundwater in the close vicinity should be avoided or boiled before used for drinking purposes.
Afficher plus [+] Moins [-]Levels and distribution of polybrominated diphenyl ethers in humans and environmental compartments: a comprehensive review of the last five years of research Texte intégral
2020
Klinčić, Darija | Dvoršćak, Marija | Jagić, Karla | Mendaš, Gordana | Herceg Romanić, Snježana
Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants (BFRs), present in the environment, animals, and humans. Their levels, distribution, and human exposure have been studied extensively, and over the last decade, various legal measures have been taken to prohibit or minimize their production and use due to the increasing amount of evidence of their harmful effects on human and animal health.Our aim here was to make a comprehensive and up-to-date review of the levels and distribution of PBDEs in the aquatic environment, air, and soil, in indoor dust, and in humans. To fulfill this, we searched through Web of Science for literature data reported in the last five years (2015–2019) on levels of at least six key PBDE congeners in abovementioned matrices. According to our summarized data, significant PBDE mass concentrations/fractions are still being detected in various sample types across the world, which implies that PBDE contamination is an ongoing problem. Secondary sources of PBDEs like contaminated soils and landfills, especially those with electronic and electrical waste (e-waste), represent a particular risk to the future and therefore require a special attention of scientists.
Afficher plus [+] Moins [-]Copper oxychloride–induced testicular damage of adult albino rats and the possible role of curcumin in healing the damage Texte intégral
2020
Gad El-Hak, Heba Nageh | Mobarak, Yomn Mohammed
The current research study investigated the effect of 80 mg/kg b.wt./day curcumin (cur) against 50, 100, and 200 mg/kg copper oxychloride (COC) for 90 days induced testicular damage using histological, ultrastructural, and biochemical techniques. Histological and cellular abnormalities have been noted in seminiferous tubules of COC-treated group and treated group with Cur- and COC-treated group. The biochemical result showed that serum testosterone was significantly decreased in COC-treated rats and Cur COC-treated rats compared with the control groups. Testes copper content and malondialdehyde was increased, whereas the testes total antioxidant, manganese, ferrous, and zinc levels were decreased (p ≥ 0.05) compared to the control groups. In conclusion, the present work reported that the treatment of rats with 80 mg/kg body weight curcumin prior to treatment with COC did not mitigate the deleterious effects of COC and manifested no signs of protection.
Afficher plus [+] Moins [-]Research on recognition and protection of ecological security patterns based on circuit theory: a case study of Jinan City Texte intégral
2020
Huang, Jiuming | Hu, Yecui | Zheng, Fangyu
Accelerated urbanization and population growth have resulted in the loss of ecological land and biodiversity, accompanied by the degradation of ecosystem services. Identifying and improving existing ecological security patterns are of great significance for maintaining the sustainable development of cities. In this study, Jinan, the capital of China’s Shandong Province, was used as a case study area. Based on three ecosystem services, namely, soil conservation, water conservation and carbon fixation, ecological sources were determined. Furthermore, a resistance surface was constructed based on biodiversity. On these bases, the circuit theory concept of random walks was applied to simulate ecosystem processes in a heterogeneous landscape and identify ecological corridors, pinch points and barriers. A total of 25 ecological sources, 48 ecological corridors and 19 pinch points were identified, and restoration areas were delimited to three levels. These elements together constituted the ecological security patterns. Specifically, the ecological sources were mainly distributed in southern Jinan and were covered mostly with forest land. The ecological corridors were located mainly in the eastern and southwestern plains below the southern mountainous areas and were covered mostly with cropland. Furthermore, the eastern corridors were much longer than the southwestern corridors. Pinch points were distributed mostly along rivers or around large-scale construction land. Barriers were distributed mainly in Zhangqiu District and northern Licheng District. Based on these findings, hierarchical restoration areas were delimited. Differentiated development contradictions in restoration areas were discussed, and corresponding ecological protection measures were proposed. An ecological security optimization pattern of “one center, two wings, and two belts” was finally proposed to provide planning strategies for decision-makers.
Afficher plus [+] Moins [-]Comprehensive reutilization of iron in iron ore tailings: preparation and characterization of magnetic flocculants Texte intégral
2020
Li, Yunyi | Tian, Xiaoyu | He, Xiao | Liu, Yangsheng | Ye, Jiangyu | Wei, Yunmei
A large number of iron ore tailings (IOTs) are produced in steel industry, posing threat to the environment during its storage and disposal. To effectively reutilize Fe in IOTs, we propose a comprehensive utilization scheme: (1) most Fe in IOTs is extracted by concentrated hydrochloric acid to form FeCl₃ flocculants; (2) after separation from the FeCl₃ flocculants, a small amount of Fe is absorbed on the residue solids, which is further washed out to synthesize micron Fe₃O₄ as magnetic seeds. Results show that the as-synthetic FeCl₃ flocculants meet the product standard for FeCl₃ flocculants in China (GB/T 4482-2018) after a series of treatments including rotary evaporation, neutralization, and dilution and have comparable performance with commercial polyaluminum chloride (PAC) and polyaluminum ferric chloride (PAFC). Moreover, the addition of synthetic superparamagnetic Fe₃O₄ (as magnetic seeds) doubled the flocculation rate compared with as-synthetic FeCl₃ flocculants alone. Finally, the reutilization of Fe in IOTs can create a direct economic value of ¥ 1.27/kg IOTs, and produce 745 g high-silicon residues for further reutilization, which indicates that our comprehensive utilization scheme is of great application potential.
Afficher plus [+] Moins [-]Mitigating arsenic accumulation in rice (Oryza sativa L.) using Fe-Mn-La-impregnated biochar composites in arsenic-contaminated paddy soil Texte intégral
2020
Lin, Lina | Gao, Minling | Song, Zhengguo | Mu, Haiyan
Arsenic (As) is a prominent metal contaminant of the soil in China. Pot experiments were conducted to examine the effects of corn stem powder biochar (BC) and Fe-Mn-La-impregnated biochar composites (FMLBC₁, FMLBC₂, and FMLBC₃; BC:Fe:Mn:La at different weight ratios) on As accumulation in an indica cultivar of rice (Oryza sativa L.). The application of FMLBCs and BC improved the dry weight of the grains, leaves, stems, and roots of rice. The As uptake in different rice organs was significantly reduced in the FMLBC-amended soils (FMLBC₃ > FMLBC₂ > FMLBC₁) compared with the BC treatment. Compared to the concentration of As in the control, the concentration of As in rice grains decreased by 56.0–89.4% with the addition of 2% FMLBC₃. The application of FMLBCs significantly increased the ratio of essential amino acids in grains and the contents of Fe and Mn plaques on root surfaces. The reduction in As accumulation can be ascribed to the Fe, Mn, and La oxides that enhance the adsorption and retention of As, as well as the FMLBCs that provide nutrients and create a rhizosphere environment, promoting rice growth. This study demonstrated that applications of 2% FMLBC₂ and FMLBC₃ have the potential to remediate As-contaminated soils, reduce As accumulation in rice plants, and improve rice grain quality.
Afficher plus [+] Moins [-]Phosphorus species in bottom sediments of the Three Gorges Reservoir during low and high water level periods Texte intégral
2020
Wang, Shuai | Rao, Wenbo | Qian, Jin | Mao, Changping | Li, Kun
Eutrophication and algal blooms have recently been found in the backwater areas of some tributaries in the Three Gorges Reservoir (TGR), for which phosphorus (P) is an important driving factor. However, P species in the TGR sediments at different water levels were little known. In this study, five P species of the TGR sediments during the high and low water level periods were analyzed with a sequential extraction method. The total P (TP) concentrations were 714.88 ± 37.86 μg/g and 697.57 ± 111.49 μg/g at the low and high water levels, respectively. The concentrations of P species decreased in the orders detrital P > authigenic P > organic P > iron-bound P > exchangeable P at the low water level and detrital P > organic P > authigenic P > iron-bound P > exchangeable P at the high water level. P in the TGR sediment sourced mainly from the upstream input at the low water level but from the inputs of tributaries and hillslope soils at the high water level. The bioavailable P (BAP) possessed > 29.5% of total P in the two periods. The total storages of total P and BAP were estimated to be about 1.34 × 10⁶ t and 1.77 × 10⁵ t, respectively during 2003–2017. It was further found that the BAP concentration significantly increased from periods I (2003–2009), II (2010–2014), to III (2015–2017), while the deposition flux and storage of BAP were the highest in period II. Our findings provide new insight into the P cycle and benefit eutrophication treatment in the TGR.
Afficher plus [+] Moins [-]Spatial distribution of endemic fluorosis caused by drinking water in a high-fluorine area in Ningxia, China Texte intégral
2020
Li, Mingji | Qu, Xiangning | Miao, Hong | Wen, Shengjin | Hua, Zhaoyang | Ma, Zhenghu | He, Zhirun
Endemic fluorosis is widespread in China, especially in the arid and semi-arid areas of northwest China, where endemic fluorosis caused by consumption of drinking water high in fluorine content is very common. We analyzed data on endemic fluorosis collected in Ningxia, a typical high-fluorine area in the north of China. Fluorosis cases were identified in 539 villages in 1981, in 4449 villages in 2010, and in 3269 villages in 2017. These were located in 19 administrative counties. In 2017, a total of 1.07 million individuals suffered from fluorosis in Ningxia, with more children suffering from dental fluorosis and skeletal fluorosis. Among Qingshuihe River basin disease areas, the high incidence of endemic fluorosis is in Yuanzhou District and Xiji County of Guyuan City. The paper holds that the genesis of the high incidence of endemic fluorosis in Qingshui River basin is mainly caused by chemical weathering, evaporation and concentration, and dissolution of fluorine-containing rocks around the basin, which is also closely related to the semi-arid geographical region background, basin structure, groundwater chemical characteristics, and climatic conditions of the basin. The process of mutual recharge and transformation between Qingshui River and shallow groundwater in the basin is intense. There is a close coupling relationship between the power of central and southern Ningxia disease areas and Qingshui River watershed of excess fluorine water. Because the traditional drinking water source of the residents in the basin is shallow groundwater, the underground water is the main cause of the high incidence of endemic fluorosis. The results show that Xiji County and Yuanzhou District were the areas of high incidence of endemic fluorosis which gradually decreased to the middle and lower reaches of Qingshui River. In space, distribution characteristics are Qingshui River source area > Qingshui River valley basin area, tributary area > trunk stream area, upstream area > middle reaches area> downstream area of Qingshui River. This is relatively consistent with the spatial distribution of fluoride ion content in Qingshui River groundwater.
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