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Результаты 3091-3100 из 3,208
Consumer purchase intention towards environmentally friendly vehicles: an empirical investigation in Kuala Lumpur, Malaysia Полный текст
2015
Afroz, Rafia | Masud, Muhammad Mehedi | Akhtar, Rulia | Islam, Md Ashraful | Duasa, Jarita Bt
This paper examines whether attitudes towards electric vehicles (ATEVs), subjective norms (SNs) and perceived behavioural control (PBC) have significant associations with consumer purchase intention (PI) and the purchase behaviour of environmentally friendly vehicles (EFVs). The results from the survey questionnaires are analysed using confirmatory factor analysis (CFA) and structural equation modelling (SEM). The findings of this paper indicate that ATEV, SN and PBC significantly influence PI. This finding also indicates that environmental consequence and individual preferences do not influence the PI of the respondents. We found that Malaysian car owners are largely unaware of the greenhouse effects on the environment or attach to it little importance, which is reflected in their PI towards EFVs. The outcomes of this study could help policymakers design programmes to influence attitudes, subjective norms, perceived behavioural control and purchase behaviour to prevent further air pollution and reduce CO₂ emissions from the transportation sector.
Показать больше [+] Меньше [-]Evaluation of variations and affecting factors of eco-environmental quality during urbanization Полный текст
2015
Cui, Erqian | Ren, Lijun | Sun, Haoyu
Regional eco-environmental quality is the foundation of economic sustainable development and rational utilization of resources. It is necessary to understand and evaluate the regional eco-environmental quality correctly. Based on national remote sensing land use data, normalized difference vegetation index (NDVI) data and some other statistical data, this paper established an eco-environmental quality index (EQI) model to evaluate the ecological status of Jinan from 2000 to 2011. The results of eco-environmental quality showed little variation, with EQI values ranged from 62.00 to 69.01. EQI of each region in Jinan firstly decreased sharply and then increased slowly with the development of local economy. Besides the spatial and temporal variations analysis, affecting factors of eco-environmental quality was also discussed in this article. According to the results of correlation and regression analysis, meteorological conditions (rainfall and sunshine duration) and industrial structure (the proportion of primary industry) had relatively high correlations with eco-environmental quality. To summarize, a better eco-environmental status is associated with increasing rainfall, shorter sunshine duration, and lower proportion of primary industry. This article aims to giving supporting data and decision-making bases to restore the ecological environment and promote the sustainable development of Jinan.
Показать больше [+] Меньше [-]Dechlorination of pentachlorophenol (PCP) in aqueous solution on novel Pd-loaded electrode modified with PPy–SDBS composite film Полный текст
2015
Sun, Zhirong | Wei, Xuefeng | Zhang, Huan | Hu, Xiang
Pentachlorophenol (PCP) is a persistent pollutant and a suspected human carcinogen. It can be found in the air, water, and soil and enters the environment through evaporation from treated wood surfaces, industrial spills, and disposal at uncontrolled hazardous waste sites. Ecotoxicity of PCP necessitates the development of rapid and reliable remediation techniques. Electrocatalytic hydrogenolysis (ECH) has been proven as a promising method for detoxification of halogenated wastes, due to its rapid reaction rate, low apparatus cost, mild reaction conditions, and absence of secondary contaminants. Challenge for the application of ECH is to prepare a Pd-coated cathode with high stability, high catalytic activity, and low Pd loading level. In this work, Pd/polypyrrole–sodium dodecyl benzene sulfonate/meshed Ti (Pd/PPy–SDBS/Ti) electrode was prepared and was characterized by cyclic voltammetry, scanning electron microscopy, X-ray diffraction, and inductively coupled plasma-atomic emission spectrometry. Electrochemically reductive dechlorination of PCP on the Pd/PPy–SDBS/Ti electrode in aqueous solution was investigated. Pd microparticles were uniformly dispersed on PPy–SDBS film which was previously electrodeposited on the meshed Ti supporting electrode. The loading of Pd on the electrode was 0.72 mg cm⁻². Electrocatalytic dechlorination of PCP was performed in a two-compartment cell separated by cation-exchange membrane. The PCP removal on the Pd/PPy–SDBS/Ti electrode could reach 100 % within 70 min with dechlorination current 3 mA when PCP initial concentration was 10 mg L⁻¹and initial pH was 2.4. Conversion of PCP on the Pd/PPy–SDBS/Ti electrode followed pseudo-first-order kinetics, and the apparent activation energy was 13.0 kJ mol⁻¹. The removal of PCP still kept 100 % after 70 min dechlorination when the Pd/PPy–SDBS/Ti cathode was reused ten times. The electrode exhibited promising dechlorination potential with high electrocatalytic activity, good stability, and low cost.
Показать больше [+] Меньше [-]Phase ratio variation approach for the study of partitioning behavior of volatile organic compounds in polymer sample bags: Nalophan case study Полный текст
2015
Van Durme, Jim | Werbrouck, Bas
Sorption of volatile organic compounds on the inner surface of polymer sampling bags leads to important underestimations of the real headspace concentration. Introducing a wide range of volatiles in a two-phase system containing Nalophan revealed that recoveries decreased down to 57 % in a period of 22 h. In this work, a phase ratio variation approach is investigated to quantify the degree of scalping, and thus enabling to compensate for sorption phenomena. This method requires limited measurements, without the need for time-consuming calibrations. By spiking identical amounts of volatiles in three two-phase systems, each having unique polymer volume/mass ratios β (β ₁ = 0, β ₂ = 80.9, β ₃ = 161.9), individual partitioning coefficients could be experimentally determined for a wide range of compounds. Additionally, a correlation was found between these partitioning coefficients and the liquid molar volume for a number of aliphatic, aromatic, and oxygenated compounds.
Показать больше [+] Меньше [-]In situ remediation technologies for mercury-contaminated soil Полный текст
2015
He, Feng | Gao, Jie | Pierce, Eric | Strong, P. J. | Wang, Hailong | Liang, Liyuan
Mercury from anthropogenic activities is a pollutant that poses significant risks to humans and the environment. In soils, mercury remediation can be technically challenging and costly, depending on the subsurface mercury distribution, the types of mercury species, and the regulatory requirements. This paper introduces the chemistry of mercury and its implications for in situ mercury remediation, which is followed by a detailed discussion of several in situ Hg remediation technologies in terms of applicability, cost, advantages, and disadvantages. The effect of Hg speciation on remediation performance, as well as Hg transformation during different remediation processes, was detailed. Thermal desorption, electrokinetic, and soil flushing/washing treatments are removal technologies that mobilize and capture insoluble Hg species, while containment, solidification/stabilization, and vitrification immobilize Hg by converting it to less soluble forms. Two emerging technologies, phytoremediation and nanotechnology, are also discussed in this review.
Показать больше [+] Меньше [-]The bioavailability and adverse impacts of lead and decabromodiphenyl ether on soil microbial activities Полный текст
2015
Chen, Lei | Zhang, Wei | Zhang, Rong | Lin, Kuangfei | He, Lei | Wu, Liqun
Lead (Pb) and decabromodiphenyl ether (BDE209) are the main pollutants at electronic waste (e-waste) recycling sites (EWRSs), and their potential toxic effects on soil organisms have received extensive attention. However, the impact on soil microorganisms of joint exposure to the two chemicals remains almost unknown. Therefore, indoor incubation tests were performed to explore the adverse impacts of Pb and BDE209 on soil microbial activities and chemical transformation for the first time. The results have demonstrated that BDE209 was barely degraded in all treated groups, indicating that the presence of Pb hardly affected BDE209 dissipation. The fractions analysis according to Tessier suggested that Pb gradually transformed towards more stable fractions in the slightly alkaline soil, thus reducing the bioavailability of Pb. Additionally, increased Pb doses caused significantly higher bioavailability (p < 0.05), and the same trend was clearly observed after simultaneous exposure to BDE209. Generally, single Pb or BDE209 exposure markedly inhibited (p < 0.05 or 0.01) soil microbial biomass C (C ₘᵢc), while soil basal respiration (SBR) indicated the opposite response trend (inhibition or stimulation for BDE209 or Pb alone, respectively). Compared to the controls, Pb dramatically (p < 0.01) facilitated soil metabolic quotient (qCO₂) during the incubation period. After joint exposure to Pb and BDE209, C ₘᵢc generally declined with increasing exposure concentration, following certain dose-response relationships. However, SBR and qCO₂ were highly significantly stimulated (p < 0.01), and more doses of Pb and BDE209 resulted in higher values. The results of these observations have provided a basic understanding of the potential ecological risk of Pb and BDE209 in soil at EWRSs.
Показать больше [+] Меньше [-]The dendroanalysis of oak trees as a method of biomonitoring past and recent contamination in an area influenced by uranium mining Полный текст
2015
Märten, Arno | Berger, Dietrich | Köhler, Mirko | Merten, Dirk
We reconstructed the contamination history of an area influenced by 40 years of uranium mining and subsequent remediation actions using dendroanalysis (i.e., the determination of the elemental content of tree rings). The uranium content in the tree rings of four individual oak trees (Quercus sp.) was determined by laser ablation with inductively coupled plasma mass spectrometry (LA-ICP-MS). This technique allows the investigation of trace metals in solid samples with a spatial resolution of 250 μm and a detection limit below 0.01 μg/g for uranium. The investigations show that in three of the four oaks sampled, there were temporally similar uranium concentrations. These were approximately 2 orders of magnitude higher (0.15 to 0.4 μg/g) than those from before the period of active mining (concentrations below 0.01 μg/g). After the mining was terminated and the area was restored, the uranium contents in the wood decreased by approximately 1 order of magnitude. The similar radial uranium distribution patterns of the three trees were confirmed by correlation analysis. In combination with the results of soil analyses, it was determined that there was a heterogeneous contamination in the forest investigated. This could be confirmed by pre-remediation soil uranium contents from literature. The uranium contents in the tree rings of the oaks investigated reflect the contamination history of the study area. This study demonstrates that the dendrochemical analysis of oak tree rings is a suitable technique for investigating past and recent uranium contamination in mining areas.
Показать больше [+] Меньше [-]Phytotoxicity and genotoxicity assessment of imazethapyr herbicide using a battery of bioassays Полный текст
2015
Magdaleno, Anahí | Peralta Gavensky, Marina | Fassiano, Anabella V. | Ríos de Molina, María C. | Santos, Marina | March, Hugo | Moretton, Juan | Juárez, Ángela B.
The imazethapyr herbicide (formulation Verosil®) was evaluated for phytotoxicity and genotoxicity using a battery of bioassays: (1) the growth inhibition of the green alga Pseudokirchneriella subcapitata, (2) the root growth and germination of the higher plant Lactuca sativa, (3) the genetic damage using the Salmonella/microsome test, and (4) the aneugenic and clastogenic effects on Allium cepa. The Verosil® formulation was highly toxic to the non-target green alga (median effective concentration (EC50) = 1.05 ± 0.05 mg active ingredient (a.i.) L⁻¹), and concentrations above 10 mg a.i. L⁻¹ inhibited root elongation in lettuce: relative growth index (RGI) between 0.28 ± 0.01 and 0.66 ± 0.10. No genotoxic effect was observed in S almonella typhimurium at 100 mg a.i. L⁻¹, either with or without the microsomal fraction. However, significant differences in the frequency of chromosomal aberrations in anaphases and telophases (bridges, chromosome fragments, and vagrants) were observed in A. cepa at concentrations between 0.01 and 1 mg a.i. L⁻¹ with respect to the control. The frequencies of micronuclei showed significant differences with respect to the control at concentrations between 0.001 and 0.1 mg a.i. L⁻¹. A very high mitotic index (MI = 93.8 ± 5.8) was observed associated with a high number of cells in the prophase stage at 100 mg a.i. L⁻¹, indicating cytotoxicity. These results showed that imazethapyr is toxic to the non-target populations in both aquatic and terrestrial ecosystems. This herbicide might also exert clastogenic and aneugenic mitotic damage in higher plants. Therefore, the imazethapyr formulation may constitute an environmental risk to plants.
Показать больше [+] Меньше [-]Uptake, effects, and regeneration of barley plants exposed to gold nanoparticles Полный текст
2015
Feichtmeier, Nadine S. | Walther, Paul | Leopold, Kerstin
Within the last years, nanogold has become more and more important in nanotechnology, for example, as catalyst or in medical applications. Its rising production, application, and disposal inevitably lead to an increased emission of gold nanoparticles (Au-NPs) in the environment. However, only little is known about the uptake and effects of Au-NPs on biota. The objective of this study was to investigate the reversibility and effects of citrate-coated Au-NP uptake into the model organism barley (Hordeum vulgare L.). For this purpose, barley seeds were cultivated in Au-NP-containing nutrient solution for 2 weeks before the seedlings were transferred into Au-NP-free media and grown for another 3 weeks. Stability of Au-NPs in the cultivation media was investigated over the 2-week exposure time. Gold content in the leaves and roots of the plants was measured after 2 weeks of exposure and after 7, 14, and 21 days of regeneration by means of total reflection X-ray fluorescence (TXRF) analysis after microwave-assisted digestion. Moreover, Au-NPs within plant material were localized by transmission electron microscopy (TEM) of ultrathin cross sections. The obtained results reveal that Au-NPs accumulate in the plant roots. Concentration-dependent effects on the uptake of macronutrients and micronutrients, as well as on biomass production of exposed plants, in particular, on root growth were observed. Even though exposed barley plants were able to regenerate to a certain extent, their root growth was permanently decreased.
Показать больше [+] Меньше [-]Residues and potential ecological risks of veterinary antibiotics in manures and composts associated with protected vegetable farming Полный текст
2015
Zhang, Haibo | Luo, Yongming | Wu, Longhua | Huang, Yujuan | Christie, Peter
Veterinary antibiotics (VAs) are emerging contaminants and enter into soil principally by agricultural application of organic fertilizer. A total of 33 solid animal manures and 17 compost samples from protected vegetable farms in nine areas of China were analyzed for the antibiotic classes of tetracyclines, fluoroquinolones, sulfonamides, and macrolides (17 substances in total). Oxytetracycline was found as a dominant compound in the samples, and its highest concentration reached 416.8 mg kg⁻¹in a chicken manure sample from Shouguang, Shandong Province. Among the samples, animal manures (especially pig manure) contained higher VA residues than composts. However, fluoroquinolones exhibited higher persistence in the compost samples than other antibiotic classes. This is particularly the case in the rice husk compost, which contained the highest level of ofloxacin and ciprofloxacin (1334.5 and 1717.4 μg kg⁻¹on average, respectively). The veterinary antibiotic profile in the risk husk compost had a good relationship with that in the corresponding manures. The refined commercial compost had the lowest VA residues among the compost samples in general. This implied that composting process might be important to reduce the antibiotic residue. High residue of antibiotics in soil was assumed to be a hazard to ecosystem. This is especially noticeable under current application rates (150 t ha⁻¹ a⁻¹) in protected vegetable farming because over half of the samples exhibited a risk quotient (RQ) >1 for one or more antibiotics.
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