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11.
12.
Evaluation on the toxicity of ionic liquid mixture with antagonism and synergism to Vibrio qinghaiensis sp.-Q67 总被引:1,自引:0,他引:1
Ionic liquids (ILs) are a fascinating group of new chemicals with the potential to replace the classical volatile organic solvents, stimulating many applications in chemical industry. In case ILs are released to the environment, possible combined toxicity should be taken into account and it is, however, often neglected up to now. In this paper, therefore, the concentration-response curves (CRCs) of four groups of IL mixtures with various mixture ratios to Vibrio qinghaiensis sp.-Q67 were determined using the microplate toxicity analysis and were compared to the CRCs predicted by an additive reference model, the concentration addition (CA) or independent action (IA), to identify the toxicity interaction. It is showed that most of the IL mixture rays displayed the classical addition while the remaining rays exhibited antagonism or synergism. Moreover, it is found that the pEC50 values of the mixture rays exhibiting antagonism or synergism are well correlated with the mixture ratio of a certain IL therein. 相似文献
13.
Siedlecka EM Stepnowski P 《Environmental science and pollution research international》2009,16(4):453-458
Background, aim, and scope Ionic liquids are regarded as essentially “green” chemicals because of their insignificant vapor pressure and, hence, are
a good alternative to the emissions of toxic conventional volatile solvents. Not only because of their attractive industrial
applications, but also due to their very high stability, ionic liquids could soon become persistent contaminants of technological
wastewaters and, moreover, break through into natural waters following classical treatment systems. The removal of harmful
organic pollutants has forced the development of new methodologies known as advanced oxidation processes (AOPs). Among them,
the Fenton and Fenton-like reactions are usually modified by the use of a higher hydrogen peroxide concentration and through
different catalysts. The aim of this study was to assess the effect of hydrogen peroxide concentration on degradation rates
in a Fenton-like system of alkylimidazolium ionic liquids with alkyl chains of varying length and 3-methyl-N-butylpyridinium chloride.
Materials and methods The ionic liquids were oxidized in dilute aqueous solution in the presence of two different concentrations of hydrogen peroxide.
All reactions were performed in the dark to prevent photoreduction of Fe(III). The concentrations of ionic liquids during
the process were monitored with high-performance liquid chromatography. Preliminary degradation pathways were studied with
the aid of 1H NMR.
Results Degradation of ionic liquids in this system was quite effective. Increasing the H2O2 concentration from 100 to 400 mM improved ionic liquid degradation from 57–84% to 87–100% after 60 min reaction time. Resistance
to degradation was weaker, the shorter the alkyl chain.
Discussion The compound omimCl was more resistant to oxidation then other compounds, which suggests that the oxidation rates of imidazolium
ionic liquids by OH· are structure-dependent and are correlated with the n-alkyl chain length substituted at the N-1-position. The level of degradation was dependent on the type of head group. Replacing
the imidazolium head group with pyridinium increased resistance to degradation. Nonetheless, lengthening the alkyl chain from
four to eight carbons lowered the rate of ionic liquid degradation to a greater extent than changing the head group from imidazolium
to pyridinium. 1H-NMR spectra show, in the first stage of degradation, that it is likely that radical attack is nonspecific,
with any one of the carbon atoms in the ring and the n-alkyl chain being susceptible to attack.
Conclusions The proposed method has proven to be an efficient and reliable method for the degradation of imidazolium ionic liquids by
a Fenton-like reagent deteriorated with lengthening n-alkyl substituents and by replacing the imidazolium head group with pyridinium. The enhanced resistance of 1-butyl-3-methylpyridinium
chloride when the resistance of imidazolium ionic liquids decreases with increasing H2O2 concentration is probably indicative of a change in the degradation mechanism in a vigorous Fenton-like system. H-NMR spectra
showed, in the first stage of degradation, that radical attack is nonspecific, with any one of the carbon atoms in the ring
and the n-alkyl chain being susceptible to attack.
Recommendations and perspectives Since ionic liquids are now one of the most promising alternative chemicals of the future, the degradation and waste management
studies should be integrated into a general development research of these chemicals. In the case of imidazolium and pyridinium
ionic liquids that are known to be resistant to bio- or thermal degradation, studies in the field of AOPs should assist the
future structural design as well as tailor the technological process of these chemicals 相似文献
14.
This paper considers liberal and nationalist economic policy approaches to the ownership and development of Australian energy resources (oil, gas, coal and uranium). In the two decades prior to 1983, Australia pursued economic policies in relation to its energy resources which could broadly be described as ‘nationalist’. Governments of the day intervened in development decisions in an effort to enhance the ‘national interest’. From 1983, along with the deregulation of the Australian economy as a whole, policy relating to energy resources was liberalised. Development of energy reserves henceforth occurred according to the dictates of the market. This paper argues that recent Australian energy policy initiatives reflect an increase in nationalist influences and a retreat from the liberalisation agenda that dominated energy policy making in the 1980s and 1990s. Three examples are discussed where policy has been influenced by a nationalist framework: (1) the domestic gas reservation policy in Western Australia; (2) Australian government efforts to promote a ‘value adding’ nuclear processing industry and (3) Australian Labor Party policy giving preferential financial incentives for gas to liquids projects. The re-emergence of nationalism in Australia is occurring either because policy makers now favour it as a path to energy security or in some cases because they believe that appeals to nationalism will generate political support. 相似文献
15.
Ionic liquids as lubricants or lubrication additives: An ecotoxicity and biodegradability assessment
Stolte S Steudte S Areitioaurtena O Pagano F Thöming J Stepnowski P Igartua A 《Chemosphere》2012,89(9):1135-1141
This paper reports on the (eco)toxicity and biodegradability of ionic liquids considered for application as lubricants or lubrication additives. Ammonium- and pyrrolidinium-based cations combined with methylsulphate, methylsulphonate and/or (CF3SO2)2N− anions were investigated in tests to determine their aquatic toxicity using water fleas Daphnia magna, green algae Selenastrum capricornutum and marine bacteria (Vibrio fischeri). Additional test systems with an isolated enzyme (acetylcholinesterase) and isolated leukaemia cells from rats (IPC-81) were used to assess the biological activity of the ionic liquids. These compounds generally exhibit low acute toxicity and biological activity. Their biodegradability was screened according to OECD test procedures 301 B and 301 F. For choline and methoxy-choline ionic liquids ready biodegradability was observed within 5 or 10 d, respectively. Some of the compounds selected have a considerable potential to contribute to the development of more sustainable products and processes. 相似文献
16.
17.
The adsorption behaviour of Basic Red 12, Acid Orange 7 and Acid Blue 1 on zinc oxide nanoparticles (ZNP) has been investigated to understand the physicochemical process involved and to explore the possible use of nanoparticles in the treatment and management of textile waste matter. The dye removal capacity of ZNP towards Basic Red 12, Acid Orange 7 and Acid Blue 1 was found to be 15.64, 6.78 and 6.38 mg g?1, respectively. The adsorption process was pH dependent and optimum pH values of 9.0, 2.0 and 4.0 were obtained for Basic Red 12, Acid Orange 7 and Acid Blue 1, respectively. Equilibrium was established after 1.0 h for all dyes. Langmuir, Freundlich and Temkin isotherm models were applied to the system. The adsorbent ZNP was characterised using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) and Fourier transform infrared (FTIR) techniques. SEM analysis revealed the noticeable nanoporous morphology of the material. The results of FTIR spectroscopy showed that the process is driven by an electrostatic complexation mechanism. XRD studies revealed the nanocrystalline structure of ZNP. BET surface area measurement suggested a high pore volume and large surface area for the adsorbent. The kinetic measurements suggested pseudo-second-order kinetic processes with high regression coefficients and smaller standard error of estimate values and lower residual sum of squares. The thermodynamic measurements suggested that all processes were exothermic and accompanied by negative values for Δ G0, Δ S0 and Δ H0. 相似文献
18.
CO2引起的气候变暖已成为全球最关注的环境问题之一,利用离子液体固定CO2引起了众多学者的关注。介绍了近年来离子液体吸收CO2的研究进展,包括常规离子液体和含氨基离子液体、氨基酸离子液体、聚离子液体及其他离子液体等4种功能化离子液体,并简要分析了吸收机理。综合分析了每种离子液体的吸收性能,离子液体对CO2的吸收能力均随温度上升而减小,随压力升高而增加。烷基链的增长以及含氟基团的增加有利于对CO2的吸收。功能化离子液体由于引入了功能化基团,相同条件下,其对CO2的吸收力几乎是常规离子液体的两倍。此外,将离子液体与有机溶液(特别是醇胺溶液)混合能提高离子液体对CO2的吸收能力,且能降低生产费用。最后指出了高吸收性能、低黏度、低毒以及低成本是未来离子液体的研究方向。 相似文献
19.
Bulk precipitation samples at Mumbai (India) were collectedduring the monsoon seasons of 1991 to 1996 and analysed forionic concentrations using an Ion Chromatograph DIONEX model100. The variability of sulphate to nitrate ratio in rainwaterfluctuates in a wide range from 1.5 to 20 and governed by thesulphate concentrations in the sample. The regression analysisof the data reveals that in the bulk precipitation at Mumbai, SO4
2- is becoming increasingly important relative toNO3
-. The role of meteorological influences onscavenging of air pollutants by rain water has been tried toexplain the phenomena. The computed wet deposition rates for Sand N during 1991–1996 show that the S deposition is higherthan N in all the years. There is a wide fluctuation indeposition rates of S ranging from 2 to 55 kg km2 per annum. 相似文献
20.
R. P. Cleaver P. S. Cumber A. Halford 《Journal of Loss Prevention in the Process Industries》2003,16(6):533-543
The paper presents a mathematical model for predicting outflow rates from a ruptured pipeline transporting compressed volatile liquids. The main focus of the paper is the methodology used to predict thermodynamic properties of interest. The model is validated using experimental data in the open literature. As the field scale outflow data does not include typical operating conditions the model is further validated at higher pressures and longer pipelines by comparing outflow rates calculated using a commercial pipeline simulation package, PROFES. The mathematical model predictions of mass flow rate and pipeline inventory agree well with the measured data and the more sophisticated pipeline model.
The simple pipeline rupture model is a useful tool for consequence analysis as it has a fast runtime on a standard PC. A further advantage is it is more easily, without having to address all of the numerical issues that arise when using a more sophisticated pipeline model. This allows a safety engineer to focus on the potential hazard rather than driving the model. 相似文献