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纳米金修饰丝网印刷电极检测水中对苯二酚 总被引:1,自引:0,他引:1
采用丝网印刷技术及直接电化学沉积法,制备一次性使用的纳米金颗粒修饰电极,并将其用于水中对苯二酚的检测.扫描电子显微镜表征显示,纳米金粒子以聚集态沉积在电极表面;对苯二酚在纳米金修饰丝网印刷电极上的电化学行为研究表明,该电极对对苯二酚的氧化还原反应产生了明显的电催化作用;以示差脉冲伏安法测定对苯二酚,其峰电流与浓度在4.98×10-5mol.l-1—1.30×10-3mol.l-1范围内呈良好的线性关系,检出限达3.41×10-6mol.l-1;对水样进行测定,加标回收率在98%—101%之间.研究结果表明纳米金修饰的丝网印刷电极可应用于水中对苯二酚现场快速检测. 相似文献
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以去离子水为分散剂,采用连续分级法,结合使用筛分、沉降、离心及错流超滤(CFF)等技术,将60目黄棕壤提取分级为细砂粒(50~250μm)、粉粒(5~50μm)、粗黏粒(1~5μm)、细黏粒(0.1~1μm)、纳米微粒(<0.1μm)5个组分;采用激光粒度仪、透射电镜(TEM)、X射线衍射(XRD)等方法对分级结果进行了表征.激光衍射粒度分析所测得各组分实际粒径分布结果与划定的粒径分级范围均很好吻合,表明按上述方法对土壤颗粒进行分级是有效、可行的.TEM观察到的纳米粒级成分呈规则球形,绝大部分颗粒粒径在20~40nm之间,有少部分大颗粒团聚体存在. 相似文献
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Andrea Massari Marta Beggio Sandro Hreglich Riccardo Marin Stefano Zuin 《Waste management (New York, N.Y.)》2014,34(10):1897-1907
In order to assess the potential impacts posed by products containing engineered nanoparticles, it is essential to generate more data about the release of these particles from products’ life cycle. Although first studies were performed to investigate the release of nanoparticles from use phase, very few data are available on the potential release from recycling or disposal of nano-enhanced products.In this work, we investigated the behavior of TiO2 nanoparticles from incineration of solid paint waste containing these particles. Solid paint debris with and without TiO2 nanoparticles were treated in a lab scale incineration plant at 950 °C (combustion temperature) and in oxidizing atmosphere. The obtained ashes were also vitrified with additives and the release of Ti was finally evaluated by leaching test. From our incineration lab-scale experiment, we did not observe a release of TiO2 nanoparticles into the atmosphere, and Ti was attached to the surface of obtained solid residues (i.e. ashes). The characterization of ashes showed that TiO2 nanoparticles reacted during the incineration to give calcium titanate. Finally, a very low release of Ti was measured, less 1 mg/kg, during the leaching test of ashes vitrified with glass cullet and feldspathic inert. Our work suggests that TiO2 nanoparticles added in paints may undergo to physicochemical transformation during the incineration, and that Ti found in ashes may be strongly immobilized in glass matrix. Since this conclusion is based on lab-scale experiment, further research is required to identify which nanoparticles will be emitted to the environment from a real-word-incineration system of household hazardous waste. 相似文献
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以镁铁尖晶石MgFe2O4为磁核,在磁核表层包覆MgAl水滑石后经高温焙烧形成MgAl (O)复合氧化物包覆的磁性载体MgFe2O4/MgAl (O),进而负载纳米金属Pd制成磁性催化剂Pd-MgFe2O4/MgAl (O).通过X射线衍射(XRD)、X射线光电子能谱分析(XPS)、傅里叶红外光谱(FT-IR)、透射电镜(TEM)、扫描电子显微镜(SEM)、选区电子衍射(SAED)、比表面积(SBET)和振动样品磁强计(VSM)等手段对催化材料进行表征.结果表明,MgFe2O4-LDH转化为磁性MgFe2O4/MgAl (O)载体有利于催化材料比表面积的增加、结构稳定性的提升及相应催化活性位点的增加,进而有利于提升4-氯苯酚高效加氢脱氯效率.研究进一步考察了催化剂负载量、催化剂用量、底物浓度、反应温度、反应溶剂等条件对4-氯苯酚降解效率的影响.结果发现,在优化反应条件下催化反应的转换频率TOF (0.04 s-1)可媲美常温、常压、无碱性添加剂等温和条件下4-氯苯酚高效加氢脱氯反应的最佳文献报道水平.磁性催化剂Pd-MgFe2O4/MgAl (O)循环使用4次后仍保持很好的催化活性. 相似文献
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Due to the unique antibacterial activities, silver nanoparticles (AgNPs) have been extensively used in commercial products. Anthropogenic activities have released considerable AgNPs as well as highly toxic silver ion (Ag+) into the aquatic environment. Our recent study revealed that ubiquitous natural organic matter (NOM) could reduce Ag+ to AgNP under natural sunlight. However, the toxic effect of this process is not well understood. In this work, we prepared mixture solution of Ag+ and AgNPs with varied Ag+% through the sunlight-driven reduction of Ag+ by NOM and investigated the acute toxicity of the solutions on Daphnia magna. Formation of AgNPs was demonstrated and characterized by comprehensive techniques and the fraction of unconverted Ag+ was determined by ultrafiltration-inductively coupled plasma mass spectrometry determination. The formation of AgNPs enhanced significantly with the increasing of solution pH and cumulative photosynthetically active radiation of sunlight. The toxicity of the resulting solution was further investigated by using freshwater crustacean D. magna as a model and an 8 hr-median lethal concentration (LC50) demonstrated that the reduction of Ag+ by NOM to AgNPs significantly mitigated the acute toxicity of silver. These results highlight the importance of sunlight and NOM in the fate, transformation and toxicity of Ag+ and AgNPs, and further indicate that the acute toxicity of AgNPs should be mainly ascribed to the dissolved Ag+ from AgNPs. 相似文献
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聚苯乙烯磺酸钠对零价纳米铁表面结构和去除水中As(Ⅲ)的影响 总被引:1,自引:1,他引:0
零价纳米铁由于其高反应活性及应用中的灵活性,在地下水原位治理中备受关注.但在应用中,常需要加入分散剂以提高纳米铁悬浮液的稳定性因此,本文以低浓度的聚苯乙烯磺酸钠(PSS)作为分散剂,制备了能长时间稳定的复合零价纳米铁(nZVI/PSS)悬浮液,并探讨PSS对nZVI表面结构和去除As(Ⅲ)过程中的影响,结果表明,nZVI和nZVI/PSS颗粒平均粒径均为50 ~ 60 nm;X射线光电子能谱(XPS)结果表明,相比于nZVI,nZVI/PSS表面上C、OH-和O2-的百分含量增高,而吸附的H2O减少;X-射线衍射(XRD)结果显示,nZVI/PSS在44.8°出现α-Fe0的X射线衍射峰,结晶度比nZVI显著提高.批实验结果表明,As(Ⅲ)的去除率随nZVI(nZVI/PSS)投加量的增大而提高,随溶液初始pH的增大而降低,且nZVI/PSS对As(Ⅲ)的去除率略低于nZVI.动力学拟合结果显示,nZVI和nZVI/PSS对As(Ⅲ)的去除符合准一级反应动力学方程. 相似文献
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We characterized fluorescent silica nanoparticles (FNPs), which had been applied in many biological systems, in fish embryo rearing media (ERM) solution and evaluated the potential toxicity to the early development of Oryzias latipes embryos. Distribution of FNPs in embryos and larvae of O. latipes was studied by fluorescent and confocal laser scanning microscopic studies. Embryos exposed to three different concentrations of FNPs in stirred or sonicated ERM solutions were observed up to 2 d after hatching. FNPs had a negligible effect on the hatchability of O. latipes embryos; however, compared to controls, more than 30% of eggs were abnormal in 10 and 50 mg FNP L−1 solutions. We found that the toxic effect was increased in sonicated FNP solution, which seems to be related with the dissolution of FNPs in ERM solutions that could be accelerated by sonication. Further study found that the CaCl2 included in ERM solution might enhance the dissolution of the FNPs and the silicate ion released from FNPs partially contributed to larval toxicity. This study showed that some nanoparticles may not be stable in biological fluids even if they are stable in water. Dissolution factors such as sonication and cellular components should be considered in biological application of nanoparticles. 相似文献