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排序方式: 共有96条查询结果,搜索用时 15 毫秒
1.
Nowadays, pharmaceutical antibiotics are known as a serious class of pollutants. Therefore, it is important to develop effective methods for removing these pollutants from aqueous media. Different methods were applied for this purpose, and among these methods, chemical reduction by a cheap and eco‐friendly nanocatalyst is the most efficient and simplest method. In this research, based on graphene oxide supported by zero‐valent iron in mono‐, bi‐, and tri‐metallic systems, various nanocomposites were synthesized and used to degrade tetracycline as a model antibiotic from aqueous media. An investigation was carried out on the synergic effect among graphene oxide and the nano zero‐valent iron‐based tri‐metallic system as well as removal efficiencies. It was found that higher degradation efficiency is yielded by graphene oxide supported by Fe/Cu/Ag tri‐metallic system. The maximum synergic effect occurs at an acidic medium. The Brunauer–Emmett–Teller, Fourier transform spectroscopy, scanning electron microscopy‐energy dispersive X‐ray analysis, transmission electron microscopy, and X‐ray diffraction analysis were used to characterize the synthesized nanocomposites, which has successfully proved the loading of nanoscale Fe/Cu/Ag tri‐metallic on a graphene oxide support. The central composite design was used to model and optimize all involved variables affecting antibiotic removal efficiency. The consequences illustrated the optimum condition regarding the removal of 50 ppm of tetracycline, for the nanocomposites dose of 3.0 mg ml?1, the contact time of 30 min, and pH of 2, was achieved using the simplex non‐linear optimization method. Moreover, antibiotic adsorption kinetic models were also investigated. Finally, the tetracycline removal from aqueous media at different concentrations, 25, 50, and 75 ppm, was successful by applying the proposed nanocomposite, and the results showed tetracycline removal efficiencies of above 70%. 相似文献
2.
对沉淀法合成的p区金属氧化物Ga2O3和Sb2O3紫外光光催化降解盐酸四环素的性能进行了研究,讨论了制备条件对光催化性能的影响。最佳制备条件下得到的Ga2O3-900和Sb2O3-500样品光催化性能存在巨大差异,通过X射线粉末衍射、傅里叶红外光谱、N2吸附-脱附测试、荧光光谱、拉曼光谱、电化学分析及活性物种捕获实验等对样品进行分析,研究二者光催化降解盐酸四环素的机理,揭示影响光催化性能差异的本质因素。结果表明,Ga2O3和Sb2O3光催化性能差异主要归结于二者不同的电子和晶体结构、表面所含羟基数量及光催化降解机理。 相似文献
3.
Zhe Jiao Zongning Guo Suling Zhang Hongwei Chen 《International journal of environmental analytical chemistry》2015,95(1):82-91
In this study, a novel solid-liquid-solid extraction approach, which was termed ‘microwave-assisted micro-solid-phase extraction’ (MAE-μ-SPE), was developed. Target analytes were extracted from the sample into extraction solvent enhanced by microwave field, following adsorption by the adsorbent in the micro-solid-phase extraction device. Without any clean-up steps, the extracts were analysed by high performance liquid chromatography coupled with ultra-violet detector. The MAE-μ-SPE approach was developed for the extraction of four tetracycline antibiotics residues in environmental soil, sludge and atmospheric particulate matters. Variables affecting extraction procedures were systematically investigated. Low detection limits of 0.1–6.3 ng/g and low quantification limits of 0.33–20.7 ng/g were achieved under optimised conditions. The recoveries of antibiotics ranged from 70.6% to 110.5% with relative standard deviation of less than 15.1%. The predominance was showed when compared to conventional MAE and μ-SPE method. According to the results, MAE-μ-SPE was proved to be a simple and effective sample preparation method for the analysis of trace organic contaminants in environmental samples. 相似文献
4.
Jinjuan Xue Chengjuan Huang Yuqing Zong Jiandong Gu Mingxin Wang Shuaishuai Ma 《应用有机金属化学》2019,33(11)
Fe (III)‐grafted Bi2MoO6 nanoplates (Fe (III)/BMO) with varying small quantity of Fe (III) clusters modification were fabricated through a simple hydrothermal and impregnation process. The characterization results indicate that the modification of Fe (III) clusters on the surface of Bi2MoO6 nanoplates with intimate interfacial contact is beneficial to the expansion of visible light absorption range and the separation of photoinduced carriers during the interface charge transfer process. The photocatalytic properties of the samples were studied by degradation of tetracycline (TC) and selective aerobic oxidation of biomass‐derived chemical 5‐hydroxymethylfuraldehyde (HMF) under visible light. The 1.5 wt% Fe (III) clusters‐grafted Bi2MoO6 nanoplates exhibited optimum photocatalytic activity, which is the TC degradation kinetic rate constant is 5.3 times higher than that of bare BMO, and the highest HMF conversion of 32.62% can be obtained with a selectivity of 95.30%. Furthermore, a possible visible light photocatalysis mechanism over Fe (III)/BMO sample has been proposed. This study may supply some insight for the development of visible‐light‐driven Bi2MoO6‐based photocatalysts applicable to both environmental remediation and biomass‐derived chemical transformation. 相似文献
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该文以四环素为模板分子,4-氨基苯硫酚(4-ATP)为功能单体,采用循环伏安法在金纳米粒子和石墨烯量子点复合材料修饰的玻碳电极表面电聚合分子印迹膜,制备四环素(TC)分子印迹传感器(MIPs/GQDs-AuNPs/GCE),并通过循环伏安法(CV)、电化学交流阻抗法(EIS)和线性扫描伏安法(LSV)等研究了其电化学响应性能。结果表明,该传感器对四环素具有良好的电流响应。在最佳实验条件下,TC氧化峰电流值与其浓度在2.0×10~(-8)~3.0×10~(-5) mol/L范围内呈良好的线性关系,相关系数为0.999 4,检出限为1.5×10~(-9) mol/L,加标回收率为97.9%~106%。该传感器稳定性好、响应灵敏、选择性高,具有良好的应用前景。 相似文献
8.
Meng Li Hong‐Ye Bai Zu‐Lin Da Xu Yan Chao Chen Jin‐Hui Jiang Wei‐Qiang Fan Wei‐Dong Shi 《Crystal Research and Technology》2015,50(3):244-249
CaFe2O4/MgFe2O4 nanowires with heterostructure had been successfully synthesized by electrospinning method. The obtained samples were systematically characterized by scanning electron microscopy (SEM), X‐Ray diffraction (XRD), UV–Vis diffuse reflectance spectra (UV‐Vis DR) and Environment scanning electron microscopy (ESEM). The novel CaFe2O4/MgFe2O4 nanowires exhibit an enhanced photocatalytic activity for degrading of tetracycline (TC) under visible light. Compared with bare CaFe2O4 or MgFe2O4 samples, the prepared CaFe2O4/MgFe2O4 (Ca:Mg:Fe = 3:2:10) composited nanowires show the best photocatalytic performance with a degradation efficiency of 40% after 150 min reaction time. This enhancement is attributed to the heterostructure of CaFe2O4/MgFe2O4 nanowires, which effectively repress the recombination of photo‐generated electrons and holes. Based on heterostructure and energy band positions, the enhancement of mechanism under visible‐light enhances the photocatalytic activity. 相似文献
9.
An overview of analytical methodologies for the determination of antibiotics in environmental waters 总被引:3,自引:0,他引:3
The widespread occurrence of antibiotics as contaminants in the aquatic environment has increased attention in the last years. The concern over the release of antibiotics into the environment is related primarily to the potential for the development of antimicrobial resistance among microorganisms. This article presents an overview of analytical methodologies for the determination of quinolone (Qs) and fluoroquinolone (FQs), macrolide (MLs), tetracycline (TCs), sulfonamide (SAs) antibiotics and trimethoprim (TMP) in different environmental waters. The analysis of these antibiotics has usually been carried out by high-performance liquid chromatography (HPLC) coupled to mass spectrometry (MS) or tandem mass spectrometry (MS/MS) and to a lesser extent by ultraviolet (UV) or fluorescence detection (FD). A very important step before LC analysis is sample preparation and extraction leading to elimination of interferences and prevention of matrix effect and preconcentration of target analytes. 相似文献
10.
高效液相色谱同时测定饲料中三种抗生素 总被引:3,自引:0,他引:3
建立了反相高效液相色谱法同时检测饲料中土霉素、四环素、金霉素的方法.色谱柱为AichromBond-AQ C18柱,150×4.6mm,粒度5μm;流动相:0.01mol/L磷酸二氢钠溶液(pH2.5)+乙氰,采用梯度洗脱,乙氰浓度在0~13min内由13%上升到40%;柱温35℃;流速为1.0mL/min;进样量101μL;检测波长375nm.方法检出限:土霉素和四环素0.25μg/mL、金霉素0.50μg/mL,回收率91.70%~101.19%,RSD<1.39%(n=7). 相似文献