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How does “the Belt and Road” and the Sino-US trade conflict affect global and Chinese CO2 emissions?
2020
Fan, Jing-Li | Dong, Yangyang | Zhang, Xian
In the context of the rapid development of the Belt and Road (B&R) Initiative, the continuous transfer of Sino-US trade to the B&R countries is an important means to mitigate the threat of Sino-US trade, and the environmental impact of this transfer should be considered, so as to provide a scientific basis for China’s policy formulation about achieving this possible trade transfer with minimized environmental impacts. This study proposes a multiregional input-output model and analyzes the impact on carbon dioxide (CO₂) emissions of transferring the Sino-US trade to the B&R countries for two types of scenarios. The results show the following: (1) A transfer of either the import trade or the export trade increases global and Chinese CO₂ emissions by 81.76 Mt and 24.84 Mt, respectively. When both the import trade and export trade are transferred, the increases in CO₂ emissions are only 0.22% and 0.26%, respectively. (2) Globally, the changes in international trade-embodied CO₂ emissions are responsible for most of the global emission changes, especially the CO₂ emissions exported from Russia, India, and many Southeast Asian countries to China. (3) Different from the impact on global emissions, the increases in Chinese domestic production-based CO₂ emissions influence China’s total CO₂ emissions. Due to the imported CO₂ emissions, the consumption-based CO₂ emissions are affected to a greater degree and increase by 70.30 Mt, accounting for only 0.86% of the CO₂ emissions in 2015. Finally, some policy implications are proposed.
显示更多 [+] 显示较少 [-]Effects of H2O2 on growth, metabolic activity and membrane integrity in three strains of Microcystis aeruginosa
2020
Foo, Su Chern | Chapman, Ian J. | Hartnell, David M. | Turner, Andrew D. | Franklin, Daniel J.
The application of hydrogen peroxide (H₂O₂) as a management tool to control Microcystis blooms has become increasingly popular due to its short lifetime and targeted action. H₂O₂ increases intracellular reactive oxygen species resulting in oxidative stress and subsequently cell death. H₂O₂ is naturally produced in freshwater bodies as a result of photocatalytic reactions between dissolved organic carbon and sunlight. Previously, some studies have suggested that this environmental source of H₂O₂ selectively targets for toxigenic cyanobacteria strains in the genus Microcystis. Also, past studies only focused on the morphological and biochemical changes of H₂O₂-induced cell death in Microcystis with little information available on the effects of different H₂O₂ concentrations on growth, esterase activity and membrane integrity. Therefore, this study investigated the effects of non-lethal (40–4000 nM) concentrations on percentage cell death; with a focus on sub-lethal (50 μM) and lethal (275 μM; 500 μM) doses of H₂O₂ on growth, cells showing esterase activity and membrane integrity. The non-lethal dose experiment was part of a preliminary study. Results showed a dose- and time-dependent relationship in all three Microcystis strains post H₂O₂ treatment. H₂O₂ resulted in a significant increase in intracellular reactive oxygen species, decreased chlorophyll a content, decreased growth rate and esterase activity. Interestingly, at sub-lethal (50 μM H₂O₂ treatment), percentage of dead cells in microcystin-producing strains was significantly higher (p < 0.05) than that in non-microcystin-producing strains at 72 h. These findings further cement our understanding of the influence of H₂O₂ on different strains of Microcystis and its impact on membrane integrity and metabolic physiology: important to future toxic bloom control programmes.
显示更多 [+] 显示较少 [-]Modelling the interaction between tourism, energy consumption, pollutant emissions and urbanization: renewed evidence from panel VAR
2020
Adedoyin, Festus Fatai | Bekun, Festus Victor
In less than two decades, the global tourism industry has overtaken the construction industry as one of the biggest polluters, accounting for up to 8% of global greenhouse gas emissions as reported by the United National World Trade Organization (UNWTO 2018). This position resonates the consensus of the United Nations Framework Convention on Climate Change (UNFCCC). Consequently, research into the causal link between emissions and the tourism industry has increased significantly focusing extensively on top earners from the industry. However, few studies have thoroughly assessed this relationship for small island economies that are highly dependent on tourism. Hence, this study assessed the causal relationship between CO₂ emissions, real GDP per capita (RGDP) and the tourism industry. The analysis is conducted for seven tourism-dependent countries for the period 1995 to 2014 using panel VAR approach, with support from fully modified ordinary least square and pooled mean group–autoregressive distributed lag models. Unit root tests confirm that all variables are stationary at first difference. Our VAR Granger causality/block exogeneity Wald test results show a unidirectional causality flowing from tourism to CO₂ emission, RGDP and energy consumption, but a bi-directional causality exists between tourism and urbanization. This implies that in countries that depend on tourism, the behaviour of CO₂ emission, RGDP and energy consumption can be predicted by the volume of tourist arrivals, but not the other way around. The impulse response analysis also shows that the responses of tourism to shocks in CO₂ appear negative within the 1st year, positive within the 2nd and 3rd years but revert to equilibrium in the fourth year. Finally, the reaction of tourism to shocks in energy consumption is similar to its reaction to shocks in RGDP. Tourism responds positively to shocks in urbanization throughout the periods. These outcomes were resonated by the Dumitrescu and Hurlin causality analysis where the growth-induced tourism hypothesis is validated as well as feedback causality observed between tourism and pollutant emission and urbanization and pollutant emission in the blocks over the sampled period. Consequently, this study draws pertinent energy and tourism policy implications for sustainable tourism on the panel over their growth trajectory without compromise for green environment.
显示更多 [+] 显示较少 [-]Plastics and microplastics, effects on marine coastal areas: a review
2020
Díaz-Mendoza, Claudia | Mouthon-Bello, Javier | Pérez-Herrera, Natalia Lucia | Escobar-Díaz, Stephanie María
Plastics have become strong environmental stressors of coastal marine ecosystems. Their introduction into the marine ecosystem is subjected to different mechanisms, including the inadequate disposal of solid waste and dumping of wastewater. In addition, their chemical composition makes them resistant to variables such as temperature and salinity of water. These polymers are degraded and fragmented mainly due to the action of the waves, which results in the formation of smaller particles called microplastics. Microplastics are characterized by being persistent in the environment due to their low biodegradation, and although they have a maximum size of 5 mm, there is a wide range of sizes suggested by different authors. According to their use, microplastics can be classified as primary when they are recognized at first sight, and as secondary, when they are gradually divided. Microplastics have become a potential risk to the health of marine species due to their small size, and the risk to human health due to their persistence through trophic chains is alarming. Given the potential impact these materials would have in the biota, and the need to assist the different regulatory agencies to develop political acts on the proper management and disposal of microplastics, the aim of this work was to identify different research carried out at international level on established methodologies for studies of identification and quantification of microplastics, bacterial communities, and contaminants adhered to microparticles. Given the above, some methodologies have been identified and used in various studies for the identification and quantification of these materials on beaches. It should be noted that in different countries, there has been an increase in research related to contamination by microplastics on beaches, in which bacterial communities attached to these plastic particles have been also identified. Likewise, not only the risks and threats have been determined for marine species but also for the health of people who frequent tourist places such as beaches.
显示更多 [+] 显示较少 [-]Bioaccumulation of Vanadium in Selected Organs of the Freshwater Fish Heteropneustes fossilis (Bloch)
2020
Ambili Ravindran and M. V. Radhakrishnan
Extensive industrialization and urbanization have introduced domestic as well as industrial wastes into aquatic ecosystems.Dueto lack of proper treatment and improper mode of disposal, the water bodies have become more polluted with toxic substancesand their adverse effects including mortality to aquatic organisms, are becoming more prominent.In recent years, much attention has been paid to the possible danger of metal poisoning in humans as a result of consumption of contaminated fishes.Vanadium is a rare elementfound combined with certain minerals and mainly from the production of certain alloys used in jet engines. Humans may be exposed to excessive vanadium and may develop adverse vascular effects.In the present investigation, efforts have been made to investigate the effect of sublethal concentration of vanadium (6.5 ppm; 10% of 96h LC50) on the bioaccumulation in gill, liver and skin of the catfish Heteropneustes fossilis for 60 days. The pattern of bioaccumulation was in the order liver > gill > skin. Theresults suggest that the organ-specific variation is directly related to the structural and functional change, proximity to the toxicant and presence of ligands having high affinity to vanadium.
显示更多 [+] 显示较少 [-]Estimation of Environmental Damages of Cement Building and Environmental Benefits of Prefabricated Building: A Case Study Based on a Residential Project in Henan Province, China
2020
Chen Nan , Zhang Jie
Traditional cement building generates abundant construction wastes during construction and waste transportation. Thus, it incurs high building resource consumption, low building efficiency, and frequent occurrence of safety accidents, which result in relatively low utilization ratio of building resources and relatively serious environmental pollution pressure. A prefabricated building can save building materials and energies and decrease construction waste emission; it is also an essential choice when the construction industry develops to a high level in a country. A case study based on a residential project in Henan Province, China was carried out. Firstly, studies concerning the environmental benefits of prefabricated building in foreign developed countries were reviewed. Second, the types of environmental damage from cement building were summarized. Third, an evaluation index system of environmental benefits of the prefabricated building was established. Finally, environmental benefit scores in the case study were calculated using the fuzzy comprehensive evaluation method based on the analytic hierarchy process. Results demonstrated that prefabricated building is extensively applied in Europe. Traditional cement buildings bring various types of environmental pollution, including water, solid waste, and dust pollutions and vegetation damage. In a case study, the environmental benefits of the prefabricated building are assessed at a good level close to excellent. Environmental benefits of the prefabricated building can be improved by encouraging real estate developers to adopt prefabricated building. In this manner, the installation efficiency of mechanical devices and construction efficiency can be increased, and the construction safety of projects can be improved. Research conclusions can provide references not only for the government to formulate policies in favour of prefabricated building development and measures for reducing environmental pollutions but also for the construction industry to enrich benefit evaluation systems for prefabricated building projects. This study is highly important in the realization of green sustainable development in the construction industry.
显示更多 [+] 显示较少 [-]Analysis of the Spatial Patterns of Particulate Pollution in the Persistent Haze in Northeast China: A Case Study in Harbin City
2020
Lei Wang, Jiarong Deng, Lijin Yang, Yunlong Yao , Dawei Xu
With the help of PM2.5, PM10, and the Air Quality Index (AQI) and other air quality data, the posterior trajectory model of the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT-4) model, having researched fire points of the straw in Harbin City, spatial pattern characteristics and genesis of the persistent haze in Harbin City from 20th October 2016 to 11th November 2016 were analysed. During the study period, the highest value of PM2.5 reached 1880?g/m3, the PM10 reached 1411?g/m3, the daily average concentration was high, and the AQI concentration reached a maximum value on 28th October and 4th November, and the persistent haze phenomenon was the most significant. Besides, the study found that the haze incident and a large quantity of pollutants due to the concentration of burning straw around Harbin had a strong connection. The burning of particulate matter had a significant impact on the region’s pollution level. The results of this study contribute to the control of particulate pollution in winter cities of developing countries.
显示更多 [+] 显示较少 [-]Synthesis of Molecularly Imprinting Polymers for the Removal of Xylenol Orange from Water
2020
Showkat Ahmad Bhawani, Nur Anati Bazilah Daud, Salma Bakhtiar, Rachel Marcela Roland , Mohamad Nasir Mohamad Ibrahim
The molecularly imprinted polymers (MIPs) were prepared by using the non-covalent approach. In the polymerization process, xylenol orange was used as a template (T), acrylic acid as a functional monomer (M), divinylbenzene as a cross-linker (CL) and 2,2’-azobisisobutyronitrile (AIBN) as an initiator and microemulsion as a solvent. The synthesized polymers were characterized by using FTIR and SEM micrograph. The batch binding analysis was used to evaluate the rebinding efficiency of imprinted polymers. The highest rebinding efficiency was obtained from the MIP-R2 (0.1:0.6:2, T:M:CL). The selected MIP-R2 was used for the removal of xylenol orange from the water sample and have shown removal efficiency of about 80%.
显示更多 [+] 显示较少 [-]A Novel Approach to Utilize Used Disposable Paper Cups for the Development of Adsorbent and its Application for the Malachite Green and Rhodamine-B Dyes Removal from Aqueous Solutions
2020
Kshipra Shukla, Alka Verma, Lata Verma, Shalu Rawat and Jiwan Singh
This study focuses on the removal of organic dyes, such as Malachite Green (MG) and Rhodamine-B (Rh-B) from an aqueous solution with the help of a novel adsorbent (activated carbon) with magnetic property prepared by used disposal paper cups (AC@PC) at 500°C. The synthesized AC@PC adsorbent was characterized by using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS) and point of zero charge (pHZPC). Adsorption of MG and Rh-B onto the AC@PC adsorbent from aqueous solution was investigated systematically. Langmuir, Freundlich and Temkin isotherms were also studied, however, it has been observed that Langmuir isotherm model was best fitted for both the dyes, which describe the adsorption behaviour at equilibrium. Pseudo-first and pseudo-second order kinetic model describe the rate of adsorption. Kinetic study explained that the process of adsorption followed the pseudo-second order model. Thermodynamic parameters such as enthalpy (?H°), entropy (?S°) and Gibb’s free energy (?G°) were also studied and revealed that the adsorption of MG was endothermic, whereas adsorption of Rh-B was exothermic onto the AC@PC. The prepared adsorbent shows potentially high adsorption properties for both the dyes.
显示更多 [+] 显示较少 [-]Influence of Tannery Effluents on Morphological Characters of Ipomoea pes-caprae (L.) Sweet and Clerodendron inerme (L.) Gaertn.
2020
A. Venkatesan
Tannery industry is common in many parts of the world, which is polluting groundwater ecosystems and producing major heavy metals and sodium chloride. The present study is aimed at some morphological characters in phytoremediation of heavy metals and ions from tannery effluents by using halophytic species such as Ipomoea pes-caprae and Clerodendron inerme. The morphological characters were analysed at an interval of 30, 60, 90 and 120 days. The results indicated that all the morphological characters were increased with an increasing concentration of tannery effluents and no injury symptoms in growth condition. It may be concluded that these halophytic species are potentially suitable for phytoremediation of heavy metals from the tannery effluent contaminated soils, which will reclaim the soil for further use as crop cultivation or crop improvement.
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