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Phytotoxicity and oxidative stress effect of 1-octyl-3-methylimidazolium chloride ionic liquid on rice seedlings
2013
Liu, Huijun | Zhang, Shuxian | Hu, Xiaona | Chen, Caidong
The effects of the ionic liquid 1-octyl-3-methylimidazolium chloride ([OMIM]Cl) was studied in hydroponically grown rice seedlings. Observed effects included increased root length and weight at concentrations of 0.1 mg/L [OMIM]Cl, however, as concentrations increased a reversed response was observed where roots and stems grew shorter and the weight decreased. The inhibitory concentration 50 (IC50,5d) values for root length and stem length were 0.59 mg/L and 0.70 mg/L, respectively. The Hill reaction activity and root system activity in [OMIM]Cl-treated rice seedlings were observed to be lower than the controls, however, root membrane permeability increased. The antioxidant enzyme activity in roots decreased, while in leaves there was an initial stimulation followed by a decrease. Malondialdehyde (MDA) content was found to be greater in seedlings subjected to [OMIM]Cl treatment. The cellular structures, such as chloroplasts, mitochondria and rough endoplasmic reticulum in rice root and leaf cells were affected at concentrations of 0.6 mg/L [OMIM]Cl.
Показать больше [+] Меньше [-]Effects of herbicides on Behr's metalmark butterfly, a surrogate species for the endangered butterfly, Lange's metalmark
2012
Stark, John D. | Chen, Xue Dong | Johnson, Catherine S.
Lange's metalmark butterfly, Apodemia mormo langei Comstock, is in danger of extinction due to loss of habitat caused by invasive exotic plants which are eliminating its food, naked stem buckwheat. Herbicides are being used to remove invasive weeds from the dunes; however, little is known about the potential effects of herbicides on butterflies. To address this concern we evaluated potential toxic effects of three herbicides on Behr's metalmark, a close relative of Lange's metalmark. First instars were exposed to recommended field rates of triclopyr, sethoxydim, and imazapyr. Life history parameters were recorded after exposure. These herbicides reduced the number of adults that emerged from pupation (24–36%). Each herbicide has a different mode of action. Therefore, we speculate that effects are due to inert ingredients or indirect effects on food plant quality. If these herbicides act the same in A. mormo langei, they may contribute to the decline of this species.
Показать больше [+] Меньше [-]Structural and functional responses of benthic invertebrates to imidacloprid in outdoor stream mesocosms
2009
Pestana, J.L.T. | Alexander, A.C. | Culp, J.M. | Baird, D.J. | Cessna, A.J. | Soares, A.M.V.M.
Structural and functional responses of a benthic macroinvertebrate assemblage to pulses of the insecticide imidacloprid were assessed in outdoor stream mesocosms. Imidacloprid pulses reduced invertebrate abundance and community diversity in imidacloprid-dosed streams compared to control streams. These results correlated well with effects of imidacloprid on leaf litter decomposition and feeding rates of Pteronarcys comstocki, a stonefly, in artificial streams. Reductions in oxygen consumption of stoneflies exposed to imidacloprid were also observed in laboratory experiments. Our findings suggest that leaf litter degradation and single species responses can be sensitive ecotoxicological endpoints that can be used as early warning indicators and biomonitoring tools for pesticide contamination. The data generated illustrates the value of mesocosm experiments in environmental assessment and how the consideration of functional and structural endpoints of natural communities together with in situ single species bioassays can improve the evaluation and prediction of pesticide effects on stream ecosystems. Combining organism-level responses with community-level processes for the evaluation and prediction of pesticide effects on stream ecosystems.
Показать больше [+] Меньше [-]Toxicity comparison of three imidazolium bromide ionic liquids to soil microorganisms
2019
Cheng, Chao | Ma, Junchao | Wang, Jinhua | Du, Zhongkun | Li, Bing | Wang, Jun | Gao, Chong | Zhu, Lusheng
Ionic liquids (ILs) are extensively used in several chemistry fields. And research about the effects of ILs on soil microbes is needed. In this study, brown soil was exposed to 1-butyl-3-methylimidazolium bromide ([C₄mim]Br), 1-hexyl-3-methylimidazolium bromide ([C₆mim]Br) and 1-decyl-3-methylimidazolium bromide ([C₁₀mim]Br). The toxicities of the three ILs are evaluated by measuring the soil culturable microbial number, enzyme activity, microbial diversity and, abundance of the ammonia monooxygenase (amoA) genes of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA). Results showed that all tested ILs caused a decrease in culturable microbial abundance. Tested ILs exposure inhibit urease activity and promote acid phosphatase and β-glucosidase activities. Tested ILs reduced soil microbial diversity and the abundances of AOB-amoA and AOA-amoA genes significantly. After a comparison of the integrated biomarker response (IBR) index, the toxicities of tested ILs to soil microorganisms were as follows: [C₁₀mim]Br > [C₆mim]Br > [C₄mim]Br. Among all collected biomarkers, the abundance of the AOA-amoA gene was the most sensitive one and was easily affected after ILs exposure.
Показать больше [+] Меньше [-]Chemical analysis of particulate products of aged 1,3,5-trimethylbenzene secondary organic aerosol in the presence of ammonia
2017
Huang, Mingqiang | Xu, Jun | Cai, Shunyou | Liu, Xingqiang | Hu, Changjin | Gu, Xuejun | Zhao, Weixiong | Fang, Li | Zhang, Weijun
Ammonia (NH3) gas-aging of secondary organic aerosol (SOA) results in the formation of organonitrogen compound is an important class of brown carbon. The particulate products of aged 1,3,5-trimethylbenzene (135-TMB) SOA in the presence of NH3 were measured by UV–Vis spectrophotometer, attenuated total reflectance-Fourier transform infrared (ATR-FTIR), and aerosol laser time-of-flight mass spectrometer (ALTOFMS) in present study. Experimental results indicated that NH3 has significant promotion effect on 135-TMB SOA formation. Organic ammonium salts, such as ammonium methyl glyoxylate, ammonium 3,5-dimethylbenzoate, which are formed from NH3 reactions with gaseous organic acids were detected as the principal particulate products of NH3-aged 135-TMB SOA. 4-methyl-imidazole-2-acetaldehyde, 4-methyl- 1H-imidazole and other imidazole products via the heterogeneous reactions between NH3 and dialdehydes of 135-TMB SOA were newly measured. The formation of imidazole products suggests that some ambient particles contained organonitrogen compounds may be come from this mechanism. The results of this study may provide valuable information for discussing SOA aging mechanisms and new route for NH3 deposition.
Показать больше [+] Меньше [-]New ternary water-soluble support from self-assembly of β-cyclodextrin-ionic liquid and an anionic polymer for a dialysis device
2022
Bouyahya, Asmaa | Sembo-Backonly, Berthe-Sandra | Favrelle-Huret, Audrey | Balieu, Sébastien | Guillen, Frédéric | Mesnage, Valérie | Karakasyan-Dia, Carole | Lahcini, Mohammed | Le Cerf, Didier | Gouhier, Géraldine
We developed a new hybrid material resulting from an innovative supramolecular tripartite association between an ionic liquid covalently immobilized on primary β-cyclodextrins rim and an anionic water-soluble polymer. Two hydrophilic ternary complexes based on native and permethylated β-cyclodextrins substituted with an ionic liquid and immobilized on poly(styrene sulfonate) (CD-IL⁺PSS⁻ and CD(OMe)IL⁺PSS⁻) were obtained by simple dialysis with a cyclodextrin maximal grafting rate of 25% and 20% on the polymer, respectively. These polyelectrolytes are based on electrostatic interactions between the opposite charges of the imidazolium cation of the ionic liquid and the poly(styrene sulfonate) anion. The inclusion properties of the free cavities of the cyclodextrins and the synergic effect of the polymeric matrix were studied with three reference guests such as phenolphthalein, p-nitrophenol, and 2-anilinonaphthalene-6-sulfonic acid using UV-visible, fluorescent, and NMR spectroscopies. The support has been applied successfully in dialysis device to extract and concentrated aromatic model molecule. This simple and flexible synthetic strategy opens the way to new hybrid materials useful for fast and low-cost ecofriendly extraction techniques relevant for green analytical chemistry.
Показать больше [+] Меньше [-]Activation of peroxymonosulfate by Fe-N complexes embedded within SBA-15 for removal of organic contaminants via production of singlet oxygen
2018
Yang, Qunfeng | Jia, Nanzhengfang | Shen, Chensi | Ma, Jianqing | Wen, Yuezhong
Persulfates are recognized as promising oxidants and an alternative to Fenton reaction for water treatment. However, activation methods in hand restrict the practical application. Herein, we explore the possibility of Fe-N complexes being a catalyst for persulfate activation for the first time. The catalyst denoted as Fe-Im-SBA was synthesized from ferric chloride, imidazole, and SBA-15 at high temperature. The internal pore structure of Fe-Im-SBA was maintained well; Fe, N and C elements are evenly distributed on the catalyst. This catalyst presents an extraordinarily catalytic activity for Rh B removal by PMS activation with a removal rate of Rh B that reached up to 97.0% in the first 5 min. It also performed well in a wide pH range with complete removal of Rh B in pH ranged from 0.5 to 10, suggesting the stability of this catalyst in both acidic and alkaline conditions. It also showed high adaptability to degrade different kinds of pollutants, which could give an attractive advantage of Fe-Im-SBA for environmental implications. Through X-ray absorption spectroscopies analysis, it shows that the active sites of Fe-Im-SBA are composed of Fe-N₄ sites and Fe₂–N₂ sites. ¹O₂ were proved to generate in the Fe-Im-SBA/PMS system and serve as the major ROS. Meanwhile, graphitic carbon can accelerate the transfer of electrons, which may also be the reason for its high catalytic performance.
Показать больше [+] Меньше [-]Acetylcholinesterase in honey bees (Apis mellifera) exposed to neonicotinoids, atrazine and glyphosate: laboratory and field experiments
2013
Boily, Monique | Sarrasin, Benoit | DeBlois, Christian | Aras, Philippe | Chagnon, Madeleine
In Québec, as observed globally, abnormally high honey bee mortality rates have been reported recently. Several potential contributing factors have been identified, and exposure to pesticides is of increasing concern. In maize fields, foraging bees are exposed to residual concentrations of insecticides such as neonicotinoids used for seed coating. Highly toxic to bees, neonicotinoids are also reported to increase AChE activity in other invertebrates exposed to sub-lethal doses. The purpose of this study was therefore to test if the honey bee’s AChE activity could be altered by neonicotinoid compounds and to explore possible effects of other common products used in maize fields: atrazine and glyphosate. One week prior to pollen shedding, beehives were placed near three different field types: certified organically grown maize, conventionally grown maize or non-cultivated. At the same time, caged bees were exposed to increasing sub-lethal doses of neonicotinoid insecticides (imidacloprid and clothianidin) and herbicides (atrazine and glyphosate) under controlled conditions. While increased AChE activity was found in all fields after 2 weeks of exposure, bees close to conventional maize crops showed values higher than those in both organic maize fields and non-cultivated areas. In caged bees, AChE activity increased in response to neonicotinoids, and a slight decrease was observed by glyphosate. These results are discussed with regard to AChE activity as a potential biomarker of exposure for neonicotinoids.
Показать больше [+] Меньше [-]Improved photocatalytic efficiency of TiO2 by doping with tungsten and synthesizing in ionic liquid: precise kinetics-mechanism and effect of oxidizing agents
2021
Raut, Sandesh S. | Kamble, Sanjay P. | Kulkarni, Prashant S.
The degradation of nitroaromatics/toxic energetic compounds contaminated water is a major cause of concern. W-doped TiO₂ nanoparticles (NPs) were synthesized in ionic liquid, ethyl methyl imidazolium dicyanamide (EMIM-DCA) by a solvothermal method. The developed NPs were sintered at 500 °C and characterized by UV-Vis-DRS, FT-IR, FE-SEM, XRD, XPS, and BET techniques. The 30–40-nm-sized NPs were subjected to photocatalytic degradation of the toxic energetic compound, tetryl (2,4,6-trinitrophenylmethylnitramine) under UV-Vis light. Various operating parameters such as the effect of concentration of catalyst, pH of feed phase, oxidizing agents, and recycling of catalyst were studied in detail. For the first time, the degradation-mechanism pathway and kinetics of tetryl were evaluated. The degradation products were precisely analyzed by using HPLC, GC-MS, and TOC techniques. The USEPA has prescribed a drinking water limit of 0.02 mg L⁻¹, and it was found that 0.5 g of 4% W-TiO₂ could totally degrade tetryl (50 mg L⁻¹) within 8 h. The kinetic rate constant of 4% W-TiO₂ was 0.356 h⁻¹, whereas pure TiO₂ showed 0.207 h⁻¹.
Показать больше [+] Меньше [-]Effects of the ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate on the growth of wheat seedlings
2014
Liu, Tong | Zhu, Lusheng | Xie, Hui | Wang, Jinhua | Wang, Jun | Sun, Fengxia | Wang, Fenghua
Ionic liquids (ILs) are called "green" solvents, which are due to their unique physicochemical properties and potential applications in various areas. However, the toxicity of ILs has attracted increasing attention from scientific researchers. The present paper studied the toxic effects of 1-octyl-3-methylimidazolium hexafluorophosphate ([C₈mim]PF₆) on wheat seedlings at 0, 1, 2, 4, 6, and 8 mg l⁻¹on days 7, 10 and 13. The present results showed that the growth of wheat seedlings was seriously inhibited when the concentration was higher than 2 mg l⁻¹and the inhibitory effect enhanced with increasing concentration and time. The EC₅₀values for germination, shoot length, root length and dry weight were 11.104, 5.187, 4.380 and 6.292 mg l⁻¹, respectively. [C₈mim]PF₆could cause an increase in the production of ROS, which led to the oxidative damage and lipid peroxidation. Furthermore, these toxic effects on wheat seedlings were irreversible.
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