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Synthesis, characterization, and application of 1-butyl-3-methylimidazolium thiocyanate for extractive desulfurization of liquid fuel
2016
1-Butyl-3-methylimidazolium thiocyanate [BMIM]SCN has been presented on extractive desulfurization of liquid fuel. The FTIR, ¹H-NMR, and C-NMR have been discussed for the molecular confirmation of synthesized [BMIM]SCN. Further, thermal, conductivity, moisture content, viscosity, and solubility analyses of [BMIM]SCN were carried out. The effects of time, temperature, sulfur compounds, ultrasonication, and recycling of [BMIM]SCN on removal of dibenzothiophene from liquid fuel were also investigated. In extractive desulfurization, removal of dibenzothiophene in n-dodecane was 86.5 % for mass ratio of 1:1 in 30 min at 30 °C under the mild process conditions. [BMIM]SCN could be reused five times without a significant decrease in activity. Also, in the desulfurization of real fuels, multistage extraction was examined. The data and results provided in the present paper explore the significant insights of imidazolium-based ionic liquids as novel extractant for extractive desulfurization of liquid fuels.
显示更多 [+] 显示较少 [-]Soil pH effects on the interactions between dissolved zinc, non-nano- and nano-ZnO with soil bacterial communities
2016
Zinc oxide nanoparticles (ZnO NPs) are used in an array of products and processes, ranging from personal care products to antifouling paints, textiles, food additives, antibacterial agents and environmental remediation processes. Soils are an environment likely to be exposed to manmade nanoparticles due to the practice of applying sewage sludge as a fertiliser or as an organic soil improver. However, understanding on the interactions between soil properties, nanoparticles and the organisms that live within soil is lacking, especially with regards to soil bacterial communities. We studied the effects of nanoparticulate, non-nanoparticulate and ionic zinc (in the form of zinc chloride) on the composition of bacterial communities in soil with a modified pH range (from pH 4.5 to pH 7.2). We observed strong pH-dependent effects on the interaction between bacterial communities and all forms of zinc, with the largest changes in bacterial community composition occurring in soils with low and medium pH levels (pH 4.8 and 5.9). The high pH soil (pH 7.2) was less susceptible to the effects of zinc exposure. At the highest doses of zinc (2500 mg/kg dw soil), both nano and non-nano particulate zinc applications elicited a similar response in the soil bacterial community, and this differed significantly to the ionic zinc salt treatment. The results highlight the importance of considering soil pH in nanotoxicology studies, although further work is needed to determine the exact mechanisms controlling the toxicity and fate and interactions of nanoparticles with soil microbial communities.
显示更多 [+] 显示较少 [-]Microglial cells (BV-2) internalize titanium dioxide (TiO2) nanoparticles: toxicity and cellular responses
2016
Because of their whitening and photocatalytic effects, titanium dioxide nanoparticles (TiO₂-NPs) are widely used in daily life. These NPs can be found in paints, plastics, papers, sunscreens, foods, medicines (pills), toothpastes, and cosmetics. However, the biological effect of TiO₂-NPs on the human body, especially on the central nervous system, is still unclear. Many studies have demonstrated that the brain is one of the target organs in acute or chronic TiO₂-NPs toxicity. The present study aimed to investigate the effect of TiO₂-NPs at different concentrations (0.1 to 200 μg/mL) on murine microglial cells (BV-2) to assess their activity on cell growth and viability, as well as their neurotoxicity. Different parameters were measured: cell viability, cell proliferation and DNA content (SubG1 peak), mitochondrial depolarization, overproduction of reactive oxygen species (especially superoxide anions), and ultrastructural changes. Results showed that TiO₂-NPs induced some cytotoxic effects with a slight inhibition of cell growth. Thus, at high concentrations, TiO₂-NPs were not only able to inhibit cell adhesion but also enhanced cytoplasmic membrane permeability to propidium iodide associated with a loss of mitochondrial transmembrane potential and an overproduction of superoxide anions. No induction of apoptosis based on the presence of a SubG1 peak was detected. The microscopic observations also indicated that small groups of nanosized particles and micron-sized aggregates were engulfed by the BV-2 cells and sequestered as intracytoplasmic aggregates after 24-h exposure to TiO₂-NPs. Altogether, our data show that the accumulation TiO₂-NPs in microglial BV-2 cells favors mitochondrial dysfunctions and oxidative stress.
显示更多 [+] 显示较少 [-]Sustainable remediation of mercury contaminated soils by thermal desorption
2016
Mercury soil contamination is an important environmental problem that needs the development of sustainable and efficient decontamination strategies. This work is focused on the application of a remediation technique that maintains soil ecological and environmental services to the extent possible as well as search for alternative sustainable land uses. Controlled thermal desorption using a solar furnace at pilot scale was applied to different types of soils, stablishing the temperature necessary to assure the functionality of these soils and avoid the Hg exchange to the other environmental compartments. Soil mercury content evolution (total, soluble, and exchangeable) as temperature increases and induced changes in selected soil quality indicators are studied and assessed. On total Hg, the temperature at which it is reduced until acceptable levels depends on the intended soil use and on how restrictive are the regulations. For commercial, residential, or industrial uses, soil samples should be heated to temperatures higher than 280 °C, at which more than 80 % of the total Hg is released, reaching the established legal total Hg level and avoiding eventual risks derived from high available Hg concentrations. For agricultural use or soil natural preservation, conversely, maintenance of acceptable levels of soil quality limit heating temperatures, and additional treatments must be considered to reduce available Hg. Besides total Hg concentration in soils, available Hg should be considered to make final decisions on remediation treatments and potential future uses. Graphical Abstract Solar energy use for remediation of soils affected by mercury.
显示更多 [+] 显示较少 [-]Levels and distributions of polybrominated diphenyl ethers, hexabromocyclododecane, and tetrabromobisphenol A in sediments from Taihu Lake, China
2016
The concentrations and distribution of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), and tetrabromobisphenol A (TBBPA) were investigated in 28 sediment samples collected from Taihu Lake, Eastern China. The results showed that all three classes of compounds were detected in 28 sediment samples but that PBDEs were the main contaminants in the study area. The total PBDE concentrations ranged from 3.77 to 347 ng/g dry weight (dw) with a mean value of 72.8 ng/g dw, whereas the concentrations ranged from 0.168 to 2.66 and from 0.012 to 1.30 ng/g dw for HBCD and TBBPA, respectively. In all of the sediment samples, BDE-209 was the predominant congener, accounting for 95.9 to 98.6 % of the total PBDEs, which indicated that commercial mixtures of deca-BDEs were the main sources of PBDE contamination. Higher concentrations of PBDEs were found in samples collected from Meiliang Bay and Gonghu Bay near the inflow river, which suggested that inflow runoff might play an important role in the PBDE levels in Taihu Lake sediments.
显示更多 [+] 显示较少 [-]The role of supplemental ultraviolet-B radiation in altering the metabolite profile, essential oil content and composition, and free radical scavenging activities of Coleus forskohlii, an indigenous medicinal plant
2016
The effects of supplemental ultraviolet-B (s-UV-B; 3.6 kJ m⁻² day⁻¹ above ambient) radiation were investigated on plant metabolite profile, essential oil content and composition, and free radical scavenging capacities of methanolic extracts of Coleus forskohlii (an indigenous medicinal plant) grown under field conditions. Essential oil was isolated using hydrodistillation technique while alterations in metabolite profile and oil composition were determined via gas chromatography-mass spectroscopy (GC-MS). Leaf and root methanolic extracts were investigated via various in vitro assays for their DPPH radical-, superoxide radical-, hydrogen peroxide-, hydroxyl radical-, and nitric oxide radical scavenging activities, ferrous ion chelating activity, and reducing power. Phytochemical analysis revealed the presence of alkaloids, anthocyanins, coumarins, flavonoids, glycosides, phenols, saponins, steroids, tannins, and terpenoids. Oil content was found to be reduced (by ∼7 %) in supplemental UV-B (s-UV-B) treated plants; the composition of the plant extracts as well as essential oil was also considerably altered. Methanolic extracts from treated plant organs showed more potency as free radical scavengers (their EC₅₀ values being lower than their respective controls). Anomalies were observed in Fe²⁺ chelating activity for both leaves and roots. The present study concludes that s-UV-B adversely affects oil content in C. forskohlii and also alters the composition and contents of metabolites in both plant extracts and oil. The results also denote that s-UV-B treated plant organs might be more effective in safeguarding against oxidative stress, though further studies are required to authenticate these findings.
显示更多 [+] 显示较少 [-]The influence of biomass energy consumption on CO2 emissions: a wavelet coherence approach
2016
Bilgili, Faik | Ozturk, Ilhan | Koçak, Emrah | Bulut, Ümit | Pamuk, Yalçın | Muğaloğlu, Erhan | Bağlıtaş, Hayriye H.
In terms of today, one may argue, throughout observations from energy literature papers, that (i) one of the main contributors of the global warming is carbon dioxide emissions, (ii) the fossil fuel energy usage greatly contributes to the carbon dioxide emissions, and (iii) the simulations from energy models attract the attention of policy makers to renewable energy as alternative energy source to mitigate the carbon dioxide emissions. Although there appears to be intensive renewable energy works in the related literature regarding renewables’ efficiency/impact on environmental quality, a researcher might still need to follow further studies to review the significance of renewables in the environment since (i) the existing seminal papers employ time series models and/or panel data models or some other statistical observation to detect the role of renewables in the environment and (ii) existing papers consider mostly aggregated renewable energy source rather than examining the major component(s) of aggregated renewables. This paper attempted to examine clearly the impact of biomass on carbon dioxide emissions in detail through time series and frequency analyses. Hence, the paper follows wavelet coherence analyses. The data covers the US monthly observations ranging from 1984:1 to 2015 for the variables of total energy carbon dioxide emissions, biomass energy consumption, coal consumption, petroleum consumption, and natural gas consumption. The paper thus, throughout wavelet coherence and wavelet partial coherence analyses, observes frequency properties as well as time series properties of relevant variables to reveal the possible significant influence of biomass usage on the emissions in the USA in both the short-term and the long-term cycles. The paper also reveals, finally, that the biomass consumption mitigates CO₂ emissions in the long run cycles after the year 2005 in the USA.
显示更多 [+] 显示较少 [-]Sustainable waste management through end-of-waste criteria development
2016
Zorpas, Antonis A.
The Waste Framework Directive 2000/98 (WFD) contains specific requirements to define end-of-waste criteria (EWC). The main goal of EWC is to remove and eliminate the administrative loads of waste legislation for safe and high-quality waste materials, thereby facilitating and assisting recycling. The target is to produce effective with high quality of recyclables materials, promoting product standardization and quality and safety assurance, and improving harmonization and legal certainty in the recyclable material markets. At the same time, those objectives aim to develop a plan in order to improve the development and wider use of environmental technologies, which reduce pressure on environment and at the same time address the three dimensions of the Lisbon strategy: growth, jobs and environment. This paper presents the importance of EWC, and the approach of setting EWC as EWC affect several management systems as well as sustainable and clean technologies.
显示更多 [+] 显示较少 [-]Mercury bio-extraction by fungus Coprinus comatus: a possible bioindicator and mycoremediator of polluted soils?
2016
Falandysz, Jerzy
The Shaggy Ink Cap (Coprinus comatus), which is a common in wild in northern hemisphere was examined in field for potential to be used as possible bio-extractor of Hg from polluted grounds but also as possible bioindicator of urban soils (roadside, barren lands, lawns) pollution with Hg. The contents of Hg in caps and stipes of C. comatus from the grounds examined in this study correlated positively with the levels of soil contamination. Analysis of sets of data available worldwide on Hg in C. comatus and soils beneath-fruiting bodies showed on a positive correlation between degree of soil and mushroom contamination. Hence, C. comatus could be considered as a sensitive species and with bioindication and bioremediation potency for soils polluted with Hg in further studies. Young-fruiting bodies of C. comatus are edible and considered excellent if consumed soon after pick-up. Eating them when foraged from the urban places can provide to a consumer Hg at relatively high dose, while unresolved question is absorption rate of Hg compounds contained in ingested mushroom meal.
显示更多 [+] 显示较少 [-]Burrowing mayfly Ephemera orientalis (Ephemeroptera: Ephemeridae) as a new test species for pesticide toxicity
2016
Mo, Hyoung-ho | Kim, Yongeun | Lee, Yun-Sik | Bae, Yeon Jae | Khim, Jong Seong | Cho, Kijong
The potential of mayfly Ephemera orientalis McLachlan eggs and first-instar larvae in ecotoxicological testing was investigated. Both stages of E. orientalis showed high tolerance to various environmental variables, such as water temperature, pH, water hardness, and dissolved organic carbon. Toxicological assays were conducted with three insecticides (emamectin benzoate, endosulfan, and cypermethrin), one fungicide (mancozeb), and one herbicide (paraquat dichloride). The two toxicity endpoints for the assay were the 14-day egg median hatching rate (EHC₅₀) in static and renewal exposure systems and 24-h median larval mortality (LC₅₀). Cypermethrin was the most toxic to both eggs (EHC₅₀ in static system = 36.9 μg/L; EHC₅₀ in renewal system < 0.15 μg/L) and larvae (LC₅₀ = 4.5 μg/L), and paraquat dichloride was the least toxic to eggs (EHC₅₀ in static system = 54,359.8 μg/L; EHC₅₀ in renewal system = 49541.3 μg/L) and larvae (LC₅₀ = 9259.5 μg/L). The results were compared to literature data of Daphnia magna Straus and Cloeon dipterum Linnaeus to determine its relative sensitivity to pesticides. These three species had different toxicities to the tested pesticides, especially according to the exposure system. E. orientalis eggs in the static system were found to be less sensitive were D. magna and C. dipterum, but eggs in the renewal system and larvae had similar or higher sensitivities to the tested pesticides. The results revealed that this species has potential for use in ecotoxicological testing of pesticides. Because of its geographic distribution, E. orientalis may be used as an alternative or complementary test species for ecotoxicological studies in Northeast Asian countries, where natural populations of the international standard species, D. magna, are rarely found.
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