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The relationship between economic growth and carbon emissions in G-7 countries: evidence from time-varying parameters with a long history Full text
2020
Destek, Mehmet Akif | Shahbaz, Muhammad | Okumus, Ilyas | Hammoudeh, Shawkat | Sinha, Avik
This paper re-investigates the time-varying impacts of economic growth on carbon emissions in the G-7 countries over a long history. In doing so, the historical data spanning the period from the 1800s to 2010 (as constructed) for each country is examined using the time-varying cointegration and bootstrap-rolling window estimation approach. Unlike the previous environmental Kuznets curve (EKC) studies, using this methodology gives us avenue to detect more than one, two, or more turning points for the economic growth-carbon emissions nexus. The empirical findings show that the nexus between economic growth and carbon emission seems over a long history to be M-shaped for Canada and the UK; N-shaped for France; inverted N-shaped for Germany; and inverted M-shaped (W-shaped) for Italy, Japan, and the USA. In addition, the possible validity of EKC hypothesis is examined for both the pre-1973 and post-1973 sub-periods. Based on this investigation, we found that an inverted U-shaped is confirmed only for the pre-1973 period in France, Italy, and the USA. These empirical evidences provide new insights to policy makers to improve environmental quality using economic growth as an economic tool for the long run by observing changes in the environmental impact of this growth from year to year.
Show more [+] Less [-]Parameters and mechanism of membrane-oriented processes for the facilitated extraction and recovery of norfloxacin active compound Full text
2020
Louafy, Rkia | Benelyamani, Abderezzak | Tarhouchi, Sanae | Kamal, Oussama | Touaj, Khalifa | Hlaibi, Miloudi
In the present work, a polymer inclusion membrane (PIM) using an amphiphilic molecule Tween 20 (TW20) as the carrier was developed and characterized to hinder environmental contamination caused by norfloxacin (NRF), an antibiotic widely used in veterinary and human medicines. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) coupled with energy X-ray dispersion spectroscopy (EDS) were used to reveal the composition, porosity, and morphology of the elaborated membrane. In order to measure the performance of the as-developed membrane, the influences of NRF initial concentration (C₀ = 0.04 mol L⁻¹, 0.02 mol L⁻¹, 0.01 mol L⁻¹, and 0.005 mol L⁻¹), pH (2.6, 4.5, and 10.5), and temperature (T = 298 K, 303 K, and 305 K) were investigated. The evolution of macroscopic (permeability (P) and initial flux (J₀)), microscopic (association constant (Kₐₛₛ) and apparent diffusion coefficient (D*)), and activation parameters (activation energy (Eₐ), enthalpy (∆H≠ₐₛₛ), and entropy (∆S≠)) was analyzed. It was found that TW20 was an effective agent for the extraction and recovery of different forms of NRF, especially the zwitterion form appeared at pH = 4.5. On the other hand, for the biologically active NRF compound, the mechanisms of the studied processes were controlled by the kinetic aspect rather than the energetic counterpart. Graphical abstract
Show more [+] Less [-]On the seasonal aerosol pollution levels and its sources in some primary schools in Vilnius, Lithuania Full text
2020
Prokopciuk, Nina | Franck, Ulrich | Dudoitis, Vadimas | Tarasiuk, Nikolaj | Juskiene, Izabele | Valiulis, Arunas | Cepuraite, Daiva | Staras, Kestutis | Ulevicius, Vidmantas
Aerosol particle number (PNC) and mass concentrations (PMC) were studied in 11 primary schools during the 2017–2018 school years (from September to May) in Vilnius, Lithuania, with the aim to evaluate the main aerosol pollution sources and its levels. Expeditious information on the total aerosol particle concentration over the full range of sizes (from 0.01 to > 1 μm) was estimated using a condensation particle counter (CPC). Particle number and mass concentrations in the size range of 0.3–10 μm were measured and estimated using an optical particle sizer (OPS). The use of aerosol particle size spectra (OPS) in school lodgements facilitated the identification of the main sources of indoor air pollution. The main sources responsible for the elevated levels of indoor PN and PM aerosol concentrations were determined: local canteens in the absence of ventilation (particle concentrations up to 97,500 part/cm³ (CPC)), the school-grader activity during the lesson breaks (275–586 μg/m³), soft furniture and carpets in the classrooms and corridors (~ 200 μg/m³), and in some cases (city center) elevated outdoor aerosol pollution levels (16800–18,170 part/cm³). Elevated aerosol pollution levels were also due to the occasional sources: construction works during lessons (200–1000 μg/m³), scraping the exterior walls of buildings near schools (up to 1600 μg/m³), and the use of petrol-powered trimmers during cutting of green plantings (22500–66,400 part/cm³ (CPC)).
Show more [+] Less [-]Using pXRF to assess the accumulation, sources, and potential ecological risk of potentially toxic elements in soil under two greenhouse vegetable production systems in North China Full text
2020
Liu, Guoming | Liu, Benle | Yang, Lanqin | Hu, Wenyou | Qu, Mingkai | Lu, Fangyi | Huang, Biao
Intensive greenhouse vegetable production (GVP) has increased the pollution risk of potentially toxic elements (PTEs) in soils. This study examined the accumulation, sources, and potential ecological risk of six PTEs (Cu, Zn, As, Ni, Pb, and Cr) in soil under two GVP (solar greenhouse (SG) and round-arched plastic greenhouse (RAPG)) systems by portable X-ray fluorescence spectroscopy (pXRF) and conventional laboratory analysis. The results indicated that all PTE concentrations were lower than their corresponding thresholds in GVP soils, presenting a low potential ecological risk in both GVP soils according to risk indices (RI ≤ 40.67). As, Ni, Pb, and Cr were not significantly accumulated in both GVP soils. Although Cu and Zn accumulated in both GVP soils, their accumulation extents in SG soil were both greater than that in RAPG soil. Cu and Zn were mainly originated from anthropogenic activities based on multivariate statistical analysis, which were greatly associated with excessive manure application. Overall, pXRF can identify the accumulation difference of PTEs between the two GVP soils, which is generally consistent with conventional laboratory analysis. Hence, pXRF can be a promising alternative to conventional laboratory analysis for rapid assessment of PTEs accumulation, sources, and the potential ecological risk in the two GVP soils. Although PTEs had a low ecological risk, Cu and Zn accumulation in SG soil was increased with the planting years. Therefore, rational application of livestock manure containing high levels of Cu and Zn should inspire strategies to mitigate the environmental risk in GVP soils, especially in SG soil.
Show more [+] Less [-]Smoke-free workplaces are associated with smoke-free homes in India: evidence for action Full text
2020
Tripathy, Jaya Prasad
India enacted a smoke-free law in 2003. It is believed that smoke-free workplaces will lead to more smoking in private places such as homes. The national Global Adult Tobacco Survey (GATS 2) India 2016–2017 collects information on the self-reported prevalence of SHS exposure in homes and workplaces. The present study utilised the GATS 2 dataset to establish the association between working in a smoke-free workplace and living in a smoke-free home. 70.1% of respondents who worked indoors reported smoke-free workplace; 64.5% of respondents reported that they live in a smoke-free home. Respondents who reported that their workplace was smoke-free were significantly more likely to live in smoke-free homes compared with those who are exposed to SHS at the workplace (69.5% vs 45.5%, AOR = 1.8, 95% CI 1.5–2.1). Males, urban residents, family with fewer members, non-smokers and non-smokeless tobacco users were significantly more likely to live in a smoke-free home. Significant differences were also observed with respect to religion, caste, region and education levels. Our results provide conclusive evidence to support that smoke-free workplaces influence smoke-free homes in India. Thus, it highlights the importance of accelerating the implementation of existing national tobacco control legislation on smoke-free public places.
Show more [+] Less [-]The effects of maternal exposure to BPA during pregnancy on the male reproductive system and the testicular microRNA expression profile Full text
2020
Ma, Lin | Yu, Haiyang | Wang, Xu | Li, Dan | Zhang, Yumin | Pei, Xiucong | Duan, Zhiwen | Ma, Mingyue
The effect of prenatal bisphenol A (BPA) exposure is increasingly concerned. We investigated the effect of maternal BPA exposure during pregnancy on male offspring and its potential mechanism. Thirty pregnant Sprague Dawley (SD) rats were randomly divided into exposed and control groups. At PND56, the number of sperm, luteinizing hormone, and testosterone in the BPA-exposed group decreased, and testicular tissue structure was damaged in offsprings. At GD20, the miRNA profile in the testis of male offspring was examined and the expression levels of 28 deregulated miRNAs were validated by qRT-PCR. We found that miR-361-5p, miR-203a-3p, and miR-19b-2-5p had significantly different expression levels in the testis. These results suggest that maternal exposure to BPA can lead to differential changes in progeny miRNAs, which will provide direction for future in-depth mechanisms of reproductive injury.
Show more [+] Less [-]Phlebia gigantea cells immobilized on renewable biomass matrix as potential ecofriendly scavenger for lead contamination Full text
2020
Akar, Tamer | Aydın, Pınar | Celik, Sema | Tunali Akar, Sibel
A novel biomaterial was prepared by the immobilization of Phlebia gigantea cells in the medium containing lignocellulosic waste and used for the first time in the bioremediation purpose. The developed new biocomposite possesses higher Pb(II) retention potential when compared with the free microbial cells. It could remove Pb(II) up to 74.11% at a biosorbent dosage of 4.0 g L⁻¹. Surface characterization was carried out through zeta potential, EDX, SEM, and IR studies to understand the metal-biocomposite interactions. The biosorption amount at equilibrium slightly decreased with the increase of the solution temperature. Kinetic data indicated Pb(II) biosorption onto suggested biocomposite fits well with the pseudo-first-order model. Biosorption equilibrium data suited Langmuir model with the highest coefficient of determination values. The immobilized material reached to maximum monolayer Pb(II) retention capacity (1.449 × 10⁻⁴ mol g⁻¹) within the short equilibrium time (10 min). The designed biocomposite was also adapted to continuous flow mode sorption process. Regeneration tests by dynamic flow mode confirmed reutilization potential of biocomposite.
Show more [+] Less [-]The key factors and removal mechanisms of sulfadimethoxazole and oxytetracycline by coagulation Full text
2020
Zhang, Weichao | Wei, Qunshan | Xiao, Jiuhua | Liu, Yanbiao | Yan, Changzhou | Liu, Jianshe | Sand, Wolfgang | Chow, Christopher W. K.
The effects of coagulant dosage, alkalinity, turbidity, ionic strength, and dissolved organic matter (DOM) on the removal of sulfadimethoxazole (SMZ) and oxytetracycline (OTC) by coagulation were studied and the reaction mechanisms of the coagulation process were revealed in this research. From our results, alkalinity, turbidity, ionic strength, and DOM had different effects on the removal of antibiotics. The SMZ and OTC removals were improved with increase in poly-aluminum chloride (PACl) dosage, whereas the turbidity had less influence on the removal of SMZ and OTC because the adsorption of SMZ and OTC to kaolin was low, confirmed by a control when no PACl added. The hydrolysate of PACl played a more important role than turbidity in SMZ and OTC removals. The SMZ and OTC removals were significantly increased with the increase in alkalinity, which provided a suitable condition in situ for coagulant to form more optimal species of hydrolysate. The ionic strength, which was adjusted by NaNO₃, also had a positive effect on the removal of SMZ but no obvious effect on the OTC removal. Furthermore, DOM had a higher effect on the removal of SMZ than that of OTC. In another word, if a water plant wants to improve the removal of SMZ and OTC by coagulation unit, PACl hydrolysate, alkalinity, and DOM are the three key factors to be considered primarily. Moreover, an experiment for the recovery of antibiotics from the flocs was done and the results showed that OTC and SMZ were removed by different mechanisms. The OTC was removed via complexation formed through the reaction between OTC and coagulant while the SMZ was removed through the pathway of adsorption and inter-particle bridging to the surface of coagulant hydrolysate.
Show more [+] Less [-]Paving ways for a sustainable future: a literature review Full text
2020
Shao, Qinglong
Sustainable development, while simultaneously sustaining the ability of natural systems to provide ecosystem services on which the economy and society depend, is one of the most important development goals. In this review, the theories of five sustainable development pathways are presented, followed by a discussion on the influences of involuntary and voluntary practices. Specifically, this paper reviews the literature on limits to growth and on planetary boundaries, examines the critique of green growth, and outlines the debate between degrowth and a-growth. Then, the importance of economic recession as an involuntary instrument and working time reduction policies as a voluntary instrument in mitigating environmental pressure is examined. Policy implications are highlighted in the final section.
Show more [+] Less [-]Examining the impact factors of the water environment using the extended STIRPAT model: A Case Study in Sichuan Full text
2020
Liang, Xuedong | Gong, Qunxi | Zheng, Haotian | Xu, Jing
China’s rapid social and economic development has led to a significant deterioration in the water environment, which has limited sustainable regional development. Therefore, understanding the specific factors that affect the water environment is vital for future water conservation efforts. From a social economy perspective, this paper used population, the economy, urbanization, technological level, water consumption, and other factors to expand the STIRPAT model, after which partial least squares was applied to solve the model parameters and comprehensively analyze the impact of regional development on the water environment in Sichuan Province from 2007 to 2017. It was found that the main factors affecting the water environment were resident population, urbanization, service industry development, and industrialization, with the industrialization factor being found to have a reverse waste-sewage water discharge inhibition. In addition, it was found that during the study period, there was no environmental Kuznets curve between water resource environmental pollution and economic growth in Sichuan Province. Finally, some policy recommendations for improving the water environment were given based on the results.
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