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Revisiting the role of forestry, agriculture, and renewable energy in testing environment Kuznets curve in Pakistan: evidence from Quantile ARDL approach Полный текст
2020
Aziz, Noshaba | Sharif, Arshian | ʻAlī, Raz̤ā | Rong, Kong
This paper assesses the Environmental Kuznets curve based on quantile behavior of the relationship between economic growth, forest area, agriculture production, renewable energy, and environmental degradation. The current literature generally used a single indicator to address environmental issues; however single indicator neither measures overall environmental conditions nor does specify that the environment issue is generally diminishing. Our study is the first one that used ecological footprint (EF) as an indicator to test environmental Kuznets curve (EKC) hypothesis for Pakistan by employing recent approach of quantile autoregressive distributed lag (QARDL) initiated by Cho et al. (J Econ 188(1):281–300, 2015). The result of this study validates the EKC hypothesis for Pakistan and shows quantile-dependent relationship, and in that case, using the conventional methods may somewhat lead to biased results. Moreover, the rejection of the null hypothesis of parameter constancy is also confirmed by Wald test. In the long run, the findings of renewable energy consumption and forest area show significant negative effects on ecological footprints, which indicates that by increasing renewable energy usage and forest area, ecological footprints can be minimized. Interestingly, the short-term effects of agricultural production findings on EF show statistically negative results. This illustrates that EF can also be reduced in the agriculture sector by adopting environment-friendly technologies. In order to create efficient policies for environment deterioration, the empirical findings of the current analysis can be used as a guideline for policy implications.
Показать больше [+] Меньше [-]Botanical insecticide–based nanosystems for the control of Aedes (Stegomyia) aegypti larvae Полный текст
2020
Duarte, Jonatas Lobato | Maciel de Faria Motta Oliveira, Anna Eliza | Pinto, Mara Cristina | Chorilli, Marlus
Aedes (Stegomyia) aegypti is a cosmopolitan species that transmits arbovirus of medical importance as dengue, Zika, and chikungunya. The main strategy employed for the control of this mosquito is the use of larvicidal agents. However, the overuse of synthetic chemical larvicides has led to an increase in resistant insects, making management difficult. Therefore, the use of botanical insecticide–based nanosystems as an alternative to the use of synthetic agents for the control of Ae. aegypti has gained more considerable attention in the last years, mainly due to the advantages of nanostructured delivery systems, such as (a) controlled release; (b) greater surface area; (c) improvement of biological activity; (d) protection of natural bioactive agents from the environment and thus achieving stability; and (e) lipophilic drugs are easier dispersed even in aqueous vehicles. This review summarizes the current knowledge about botanical insecticide–based nanosystems as larvicidal against Ae. aegypti larvae. The majority of papers used metallic nanoparticles (NPs) as larvicidal agents, mainly silver nanoparticles (AgNPs), showing potential for their use as an alternative, followed by nanoemulsions containing vegetable oils, most essential oils, nanosystems that allow the dispersion of this high hydrophobic product in water, the environment of larval development. The final section describes scientific findings about the mode of action of these NPs, showing the gap about this subject in literature.
Показать больше [+] Меньше [-]Combined effects of cadmium and oil sludge on sorghum: growth, physiology, and contaminant removal Полный текст
2020
Lyubun, Yelena | Muratova, Anna | Dubrovskaya, Ekaterina | Sungurtseva, Irina | Turkovskaya, Olga
The physiological and biochemical responses of Sorghum bicolor (L.) Moench. to cadmium (Cd) (30 mg kg⁻¹) and oil sludge (OS) (16 g kg⁻¹) present in soil both separately and as a mixture were studied in pot experiments. The addition of oil sludge as a co-contaminant decreased Cd entry into the plant by almost 80% and simultaneously decreased the stimulation of superoxide dismutase (SOD) and peroxidase. The decrease in glutathione reductase (GR) activity and the increase in glutathione-S-transferase (GST) activity under the influence of oil sludge indicated that its components were detoxified by conjugation with glutathione. Cd additionally activated the antioxidant and detoxifying potential of the plant enzymatic response to stress. This helped to enhance the degradation rate of oil sludge in the rhizosphere, in which the participation of the root-released enzymes in the degradation could be possible. Cd increased the extent of soil clean-up from oil sludge, mainly owing to the elimination of paraffins, naphthenes, and mono- and bicyclic aromatic hydrocarbons. The mutual influence of the pollutants on the biochemical responses of sorghum and on soil clean-up was evaluated. The results are important for understanding the antistress and detoxification responses of the remediating plant to combined environmental pollution.
Показать больше [+] Меньше [-]Risk of contamination of infiltrated water and underground soil by heavy metals within a ceramic permeable brick paving system Полный текст
2020
Lin, Zizeng | Chen, Huiming | Yang, Hai
The risk of heavy metal contamination of infiltrated water and underground soil on a permeable brick paving system was investigated. The paving system was constructed as a frame structure base on top of a 1.0-m-thick clay layer with permeable ceramic brick at the surface. The concentrations of heavy metals (Zn, Cu, and Pb) in infiltrated water and soil at different underground depths under the paving system were measured. Speciation rates of Zn, Cu, and Pb at different clay depths were further determined to ascertain the probability of downward migration of the unstable forms. The results showed reduced risk of infiltrated water pollution by heavy metals due to underground soil acting as an effective trap. However, topsoil was more susceptible to heavy metal pollution, with the different pollution soil depths of Cu, Zn, and Pb mainly attributed to the different binding abilities between the heavy metals and soil. Soil Cu and Zn remained relatively stable, whereas there was a potentially high risk of Pb migration. The study found that topsoil could accumulate non-degradable heavy metals to unacceptable levels over a period of 30 years and that topsoil should therefore be replaced after 30 years to reduce the risk of soil pollution. This study fills a knowledge gap by both determining the risks of heavy metal pollution to underground soil and infiltrated water and exploring effective ways to reduce heavy metal pollution.
Показать больше [+] Меньше [-]The efficacy of sustainability reporting towards cost of debt and equity reduction Полный текст
2020
Shad, Muhammad Kashif | Lai, Fong-Woon | Shamim, Amjad | McShane, Michael
This paper empirically investigates the impact of overall sustainability reporting as well as its components (economic, environmental, and social sustainability reporting) on the cost of debt and equity capital for Malaysian oil and gas companies. The data was collected from 41 publicly listed oil and gas companies in Malaysia for the period from 2008 to 2017. Qualitative information was gathered for sustainability reporting and then converted into quantitative form by assigning weights according to the extent of reporting. The cost of capital information was sourced through Thomson Reuters Datastream. Panel data analysis was employed using generalized least square (GLS) random effects regression to examine the relationship between sustainability reporting and cost of capital. Firm reputation, size, and profitability were included as control variables. The findings indicate that overall sustainability reporting and one component, economic sustainability reporting, reduce both cost of debt and cost of equity. However, environmental sustainability reporting reduces only the cost of debt but does not reduce the cost of equity. Social sustainability reporting shows no effect on the cost of debt or equity. The findings of this paper should be useful for regulators, legislators, shareholders, creditors, and practitioners in pursuing sustainability practices that not only improve economic and environmental performance but also enhance overall performance by reducing the cost of capital. The results of the paper highlight that companies investing in sustainability can generate positive value through the enhancement of reputational capital. This study is the first to empirically investigate the relationship between overall sustainability reporting, including its three components, and the cost of both debt and equity capital.
Показать больше [+] Меньше [-]Research on recognition and protection of ecological security patterns based on circuit theory: a case study of Jinan City Полный текст
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.
Показать больше [+] Меньше [-]Discarded biodiesel waste–derived lignocellulosic biomass as effective biosorbent for removal of sulfamethoxazole drug Полный текст
2020
Ganesan, Sivarasan | Karthick, Kumaravel | Namasivayam, Chinnaya | Arul Pragasan, Lingassamy | Kirankumar, V. S. | Devaraj, Sabarinathan | Ponnusamy, Vinoth Kumar
This work aims to evaluate the removal of pharmaceutical drug using discarded biodiesel waste–derived lignocellulosic-based activated carbon biomaterial. Lignocellulosic-based activated carbon (LAC) biomaterial was prepared from Jatropha shell (biodiesel processing waste) by a zinc chloride activation method. The LAC biomaterial was characterized using various techniques including powder XRD, FT-IR, SEM-EDAX, and BET analysis. LAC biomaterial was applied to examine the adsorption of sulfamethoxazole (SMZ) drug in aqueous solution under ambient temperature. Various experimental parameters such as the effect of pH, treatment time, adsorbate concentration, and LAC dose of adsorption experiments were thoroughly examined and optimized. Under the optimal conditions, LAC biomaterial showed the maximum adsorption removal efficiency of SMZ drug. The kinetic models of Lagergren first-order, pseudo-second-order, intraparticle diffusion, and Bhangam’s equation for SMZ removal onto LAC were used to recognize the probable mechanism of adsorption manner. From the experimental results, the Freundlich isotherm model (Kf = 83.56 mg g⁻¹ (L mg⁻¹)¹/ⁿ) shows similar fit than the Langmuir (Q₀ = 206.2 mg g⁻¹) and Dubinin-Radushkevich (Qₘ = 150.69 mg g⁻¹) condition models of adsorption isotherms. The rate constants of adsorption were found to confirm the pseudo-first-order kinetic and Bhangam’s models with a significant correlation. The separation factor (RL) showed the favorable condition of the adsorption isotherm for the experimental system. The desorption results indicate that the ionic molecular exchange of SMZ from the hydroxyl group of LAC surface plays an important role in the recycling processes. Therefore, these results proved that the prepared low-cost LAC biomaterial could be used as an efficient adsorption material for the effective removal of pharmaceutical drugs in aqueous samples.
Показать больше [+] Меньше [-]Accounting for environmental sustainability from coal-led growth in South Africa: the role of employment and FDI Полный текст
2020
Joshua, Udi | Alola, Andrew Adewale
As much as energy supply remains a major challenge in most of the African countries, the compounding environmental effect of energy consumption has continued to be a serious concern to policymakers and environmental stakeholders. On this note, this study seeks to investigate the coal-led growth hypothesis for South Africa by incorporating employment as a control variable for the first time. The incorporation of the employment in investigating the coal-led growth hypothesis especially for the case of South Africa is novel given that the World Coal Association (2016) reported that the country is the sixth largest exporter and seventh largest producer of coal globally. The study implemented an Autoregressive Distributed Lag (ARDL) bound testing to cointegration for the data spanning from 1970 to 2017. As such, the empirical result revealed that coal usage is the highest emitter of carbon, suggesting that a 1% increase in coal consumption account for about 68% emission in the short run, and 56% in the long run, respectively. On the other hand, foreign direct investment (FDI) inflow discourages carbon emission in the short-run and long run so that a 1% increase in FDI inflow causes a reduction in CO2 by about 0.003% and 001%. The novelty of this study is proven in the estimation of the interaction between employment and coal consumption. However, employment induced by economic growth and coal consumption both have significant tendencies of inflicting adverse environmental impacts in the short-run and long run. Thus, this study put forward relevant policy and for onward recommendation for the government to woo new foreign investors and to switch to renewable energy as an alternative sources as a possible approach of energy efficiency and environmental sustainability with a view to achieving sustainable development goals.
Показать больше [+] Меньше [-]Adsorptive removal of lanthanum based on hydrothermally synthesized iron oxide-titanium oxide nanoparticles Полный текст
2020
Danish, Ekram Y. | Marwani, Hadi M. | Almoslehi, Kholoud F. | Bakhsh, Esraa M.
Iron oxide-titanium oxide (Fe₂O₃-TiO₂) nanoparticles were developed as an effective adsorbent in order to extract and remove lanthanum ions selectively from aqueous media. Fe₂O₃-TiO₂ nanoparticles were prepared by simple hydrothermal method and structurally characterized using FESEM, EDS, XRD, FTIR, and BET techniques. The analytical potential of Fe₂O₃-TiO₂ nanoparticles was interpreted by applying the kinetic and isotherm models. The maximum static uptake capacity was 89.63 mgg⁻ ¹ at pH 7. Adsorption isotherm data evinced that a monolayer adsorption occurred on a homogeneous adsorbent surface which is compatible with Langmuir isotherm model. Data acquired from kinetic models study proved that La (III) adsorption onto Fe₂O₃-TiO₂ nanoparticles followed a pseudo-second-order kinetic equation. Thermodynamic study exhibited that a spontaneous process is favorable for adsorption mechanism of La (III) on Fe₂O₃-TiO₂ nanoparticles. Moreover, the existence of different coexisting ions did not influence the extraction of La (III). Finally, the recommended methodology was applied on several environmental samples.
Показать больше [+] Меньше [-]A bi-level multiobjective optimization model for waste load allocation in rivers Полный текст
2020
Zhang, Xuan | Luo, Jungang | Xie, Jiancang
It is often difficult to apply existing waste load allocation (WLA) models to management institutions at all levels of the river basin because the existing WLA models do not consider the principles of fairness and efficiency at each management level of the basin. The implementation of environmental protection tax law has also greatly impacted WLA. This paper proposes the bi-level multiobjective allocation model under an environmental protection tax law to solve the WLA problem for different management levels. The upper allocation targets the minimal environmental Gini coefficient and the minimal unit pollutant emission cost. The impact of the environmental protection tax is also considered. The targets of the lower-level allocation are the maximal industrial output value and the minimal unevenness of reduction rates. The proposed model was applied to the case of the Wei River basin, and the results demonstrated that the bi-level multiobjective allocation model could solve the problem of WLA under an environmental protection tax law. Each level of the bi-level multiobjective allocation model considers the principles of fairness and efficiency to distribute the load in the basin, thereby offering a better reference for decision-makers at both levels.
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