共查询到20条相似文献,搜索用时 31 毫秒
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Xinyi Liu Caichao Wan Xianjun Li Song Wei Luyu Zhang Wenyan Tian Ken-Tye Yong Yiqiang Wu Jian Li 《Frontiers of Environmental Science & Engineering》2021,15(4):54
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采用溶胶-凝胶法,将经过油酸铵改性的掺钒二氧化钛粉末投入到纯TiO2溶胶中,烘干、煅烧,制得带有n-n异质结半导体结构的复合型高活性掺钒二氧化钛光催化剂,并通过XRD、TEM、XPS等技术对样品进行了表征。通过对甲基橙溶液的光催化降解实验来考察TiO2/V-TiO2催化剂的光催化活性。结果表明:TiO2/V-TiO2复合催化剂拥有比纯TiO2更高的光催化活性。其中,V的掺杂摩尔分数为0.5%、TiO2:V-TiO2的质量比为10∶1的最佳复合催化剂,其光催化活性是纯TiO2的5.1倍。 相似文献
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Jinglian Zhao Liang Zhao Xinping Wang 《Frontiers of Environmental Science & Engineering》2008,2(4):415-420
The photocatalytic performance of ZnO/ZnS hybrid nanocomposite was largely higher than that of the mere ZnO or ZnS nanoparticles, but the complicated procedure and misdistribution of final products limited its large-scale productions. The exploration of a novel synthesis route of ZnO/ZnS hybrid photocatalysts with high catalytic performance is becoming a crucial step for the large-scale application of ZnO/ZnS hybrid photocatalytic technique. Preparation and characterization of nanosized ZnO/ZnS hybrid photocatalysts were studied in this paper. The photocatalysts were obtained via microwave-hydrothermal crystallization with the help of sodium citrate. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), particle size distribution (PSD), and Fourier transformed infrared spectroscopy (FT-IR). The results indicated that so-synthesized ZnO/ZnS samples consisted of the high pure cubic (sphalerite) ZnS and hexagonal ZnO nanocrystallines with a narrow particle size distribution. The possible formation mechanisms of ZnO/ZnS nanocrystallines were mainly attributed to the superficially protective effect of citrate. The photocatalytic experiments demonstrated that the ZnO/ZnS photocatalysts exhibited a higher catalytic activity for the degradation of acid fuchsine than other monocomponents. 相似文献
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大气污染控制中高梯度磁分离技术的研究与应用 总被引:3,自引:0,他引:3
本文概述了高梯度磁分离技术在燃煤脱硫除灰、烟气除尘方面的应用与研究进展以及超导磁分离技术在燃煤脱硫方面的研究,并展望了超导磁分离技术在环境保护中的应用前景。 相似文献
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Yang Yang Xiuzhen Zheng Wei Ren Jiafang Liu Xianliang Fu Sugang Meng Shifu Chen Chun Cai 《Frontiers of Environmental Science & Engineering》2022,16(11):137
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磁性介孔硅胶萃取剂的制备及萃取性能研究 总被引:1,自引:0,他引:1
合成了C18基团修饰的磁性介孔硅胶材料,并利用该材料建立了磁性固相萃取-色谱分析方法,测定了几种环境水样中酞酸酯类(PAEs)污染物的含量.结果表明,该材料具有较大的比表面积(273 m.2g-1)和饱和磁通量(29 emu.g-1),对水样中痕量的PAEs有较强的萃取能力,而且萃取剂的磁分离特性使得萃取操作更为方便、快捷.在优化条件下,30 mg萃取剂在40 min内即可从500 mL水样中萃取痕量PAEs,回收率可达80%以上.此外,该萃取剂在处理复杂环境样品时仍能保持较强的萃取能力,环境水样中4种PAEs的检测限可达15.6—32.5 ng.L-1,加标回收率为62%—109%,相对标准偏差为2%—8%. 相似文献
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Louangsouphom Bountheva Wang Xuejiang Song Jingke Wang Xin 《Environmental Chemistry Letters》2019,17(2):1061-1066
Environmental Chemistry Letters - Highly active TiO2 photocatalysts prepared at a low temperature are promising reagents to degrade organic pollutants. Moreover, the addition of... 相似文献
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Sulfoxides are versatile synthetic intermediates for the preparation of biological products. Therefore, there is a need for efficient methods to oxidize sulfides into sulfoxides. Such oxidation may be catalyzed by magnetic nanocatalysts due to their good stability, easy synthesis, high surface area, low toxicity and easy separation by magnetic forces. Here we prepared a nanocatalyst by immobilization of the chitosan–Schiff base complex on supramagnetic Fe3O4 nanoparticles. The chitosan–Schiff base complex has been previously prepared by functionalization of chitosan with 5-bromosalicylaldehyde and metalation with copper(II) acetate. The catalyst was characterized by Fourier transform infrared, powder X-ray diffraction, transmission electron microscope, scanning electron microscopy, energy-dispersive X-ray spectroscopy and thermogravimetric analysis. Results show that the Fe3O4 nanoparticles and nanocatalyst were spherical in shape with an average size of 20 nm. Upon the covalently anchoring of chitosan–Schiff base Cu complex on the magnetic Fe3O4 nanoparticles, the average size increased to 60 nm. The prepared Fe3O4–chitosan–Schiff base Cu complex catalyzed very efficiently the oxidation of sulfides to sulfoxides with 100 % selectivity in all cases under green reaction conditions and excellent yields. Additionally, ease of recovery and reusability up to four cycles without noticeable loss of catalytic activity make the present protocol beneficial from industrial and environmental viewpoint. 相似文献
10.
佛山农业表层土壤磁化率特征及其与重金属含量的关系 总被引:1,自引:0,他引:1
环境磁学方法针对城市、矿区、工业区等特定区域土壤的研究现已比较普遍,但在农业土壤重金属研究中的应用还比较少。本文对采自佛山市的532件农业表层土壤样品进行低频(976 Hz)和高频(15616 Hz)磁化率测试,在分析其空间分布特征的基础上选取175件(其中,旱地土样149件,水田土样26件)代表性样品进行重金属(Cd、Pb、Cr、Cu、Ni、Zn、Hg、As)含量的分析测试。在分析不同土壤样品磁化率与重金属含量之间相关关系的基础上,从旱地和水田土壤中分别挑选出6种与低频磁化率高度相关的重金属元素(旱地Ni、Cu、Cr、Zn、Cd、Pb,相关系数分别为0.599、0.492、0.279、0.510、0.445、0.225;水田Ni、Cu、Cr、Zn、Cd、Hg,相关系数分别为0.728、0.699、0.606、0.602、0.764、0.450)进行回归分析,列出回归方程,并得到一些初步认识。主要有(1)低频磁化率与频率磁化率在空间分布上总体呈现相反趋势;(2)重金属含量与低频磁化率总体呈正相关,但正相关的元素种类在旱地和水田土壤中有所差异;(3)所研究的旱地土壤重金属含量与频率磁化率呈负相关关系,但这种相关关系在水田土壤中没有明显表现;(4)Pb 元素在旱地土壤中与低频磁化率表现出显著正相关(P〈0.01),在水田土壤中却与低频磁化率和频率磁化率表现出一定的负相关性。(5)通过测定农业土壤的磁化率即可初步推算出相应的重金属含量,为磁学方法在农业表层土壤重金属快速监测领域的进一步应用提供了数据支持和科学依据。 相似文献
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Liping LIANG Jing ZHANG Pian FENG Cong LI Yuying HUANG Bingzhi DONG Lina LI Xiaohong GUAN 《Frontiers of Environmental Science & Engineering》2015,9(1):16
Bisphenol A (BPA), an endocrine disrupting compound, has caused wide public concerns due to its wide occurrence in environment and harmful effects. BPA has been detected in many surface waters and drinking water with the maximum concentrations up to tens of μg·L-1. The physicochemical technology options in eliminating BPA can be divided into four categories: oxidation, advanced oxidation, adsorption and membrane filtration. Each removal option has its own limitation and merits in removing BPA. Oxidation and advanced oxidation generally can remove BPA efficiently while they also have some drawbacks, such as high cost, the generation of a variety of transformation products that are even more toxic than the parent compound and difficult to be mineralized. Only few advanced oxidation methods have been reported to be able to mineralize BPA completely. Therefore, it is important not only to identify the major initial transformation products but also to assess their estrogenic activity relative to the parent compounds when oxidation methods are employed to remove BPA. Without formation of harmful by-products, physical separation methods such as activated carbon adsorption and membrane processes are able to remove BPA in water effluents and thus have potential as BPA removal technologies. However, the necessary regeneration of activated carbon and the low BPA removal efficiency when the membrane became saturated may limit the application of activated carbon adsorption and membrane processes for BPA removal. Hybrid processes, e.g. combining adsorption and biologic process or combining membrane and oxidation process, which can achieve simultaneous physical separation and degradation of BPA, will be highly preferred in future. 相似文献
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Nagappagari Lakshmana Reddy Vempuluru Navakoteswara Rao Murkinati Mamatha Kumari Raghava Reddy Kakarla Parnapalle Ravi Marappan Sathish Mani Karthik Shankar Muthukonda Venkatakrishnan Inamuddin 《Environmental Chemistry Letters》2018,16(3):765-796
Massive production of hydrogen by water decomposition triggered by a solar light active photocatalyst is a major objective in chemistry and a promising avenue to overcome the global energy crisis. The development of efficient, stable, economically viable and eco-friendly photocatalysts for hydrogen production is a challenging task. This article reviews the use of nanocomposite in three combinations: metal oxide–metal oxide semiconductor, metal–metal oxide semiconductor and metal chalcogenide–metal oxide core–shell nanostructures. These core–shell structures occur in two forms: a simple form where the photocatalyst is either in the core or the shell or in a more complex system where the core–shell structure comprises a co-catalyst deposited on a semiconducting material. We discuss the design, synthesis and development of semiconductor-based nanocomposite photocatalysts for hydrogen production. The major points are the role of catalytic active sites, the chemical nature of sacrificial agents, the effect of light sources, the variable light intensity and the energy efficiency calculation. For TiO2-based nanocomposites, the metal oxide or metal co-catalyst loading of 1.0–3.0 wt% was optimal. TiO2 nanotube–CuO hybrid nanocomposites produce 1,14,000 µmol h?1 \({\text{g}}^{ - 1}_{\text{cat}}\), whereas TiO2/Au nanocomposites display 1,60,000 µmol h?1 \({\text{g}}^{ - 1}_{\text{cat}}\). For core–shell catalysts, a shell thickness of 2–20 nm was found for the best activity, and its performance is as follows: (a) CdS–NiO system produces around 19,949 µmol h?1 \({\text{g}}^{ - 1}_{\text{cat}}\) and (b) CuO–Cr2O3 as co-catalyst immobilized on TiO2 system produces around 82,390 µmol h?1 \({\text{g}}^{ - 1}_{\text{cat}}\). 相似文献
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An experimental research into the aqueous photocatalytic oxidation (PCO) of organic groundwater pollutants, methyl-tert-butyl ether (MTBE), tert-butyl alcohol, phenol, humic substances, 2-ethoxy ethanol and ethylene glycol was undertaken using visible light-sensitive
nitrogen-doped titanium dioxide photocatalysts. Nitrogen-doped titania proved to be an effective photocatalyst for MTBE with
its action comparable to and even surpassing that of Degussa P25. In contrast, with the other substances the photocatalysts
showed negligible activity. This difference was explained by the poor adsorption properties of N-doped catalysts. The predominance
of different PCO mechanisms dependent of the surface properties of N-TiO2 catalysts was elucidated. 相似文献
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Shuang Zhang Shuai Liang Yifan Gao Yang Wu Xia Huang 《Frontiers of Environmental Science & Engineering》2023,17(3):30
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Xiaona CHU Jiangyong HU Say Leong ONG 《Frontiers of Environmental Science & Engineering》2009,3(4):393-403
Proteomics involves the separation of proteins, identification of the amino acid sequence of the interested or target proteins, study of the function of the proteins, modification, structure and ultimate assignments to functional pathways in the cell. The proteomic investigations have contributed greatly to human diseases studies, new drugs discovery researches, and environmental science in recent years. This article provides a review on the development of the main proteomic technologies, including both the gel based and non-gel based technologies, and their applications in environmental science. Proteomic technologies have been utilized in the environmental stresses studies to analyze the induction or reduction of proteins at expression level and identify the target proteins to investigate their function in response to environmental stresses, such as high or low pH, oxidation stress, and toxic chemicals. Such protein responses are also helpful to understand the mechanisms of some cellular activities and the functions of some proteins. 相似文献
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Reza Katal Mohammad Tanhaei Jiangyong Hu 《Frontiers of Environmental Science & Engineering》2021,15(2):27
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The polymorphism of the human serum paraoxonase1 was analyzed by two distinguished methods in six different ethnic groups (Caucasians, Mongoloids, Negroids), using (1) the Computer Method2 and (2) the Carro‐Ciampi Method3‘4. Analysis of the response of the enzyme activities to salts resulting in low and high activity ratios. Comparison of the results: In Caucasians we distinguished three phenotypes by the Computer method. The polymorphism was governed by two alleles. The Hardy‐Weinberg rule for a two‐allele model was valid. Individuals belonging to the homozygotic group with low activity had a low activity ratio (Carro‐Ciampi method). With both methods a frequency between 57% and 61% was observed for this group. Individuals with medium and high activity had a high activity ratio. In Negroids and Mongoloids samples we found (by the Computer method) a low activity group (Ghanaians 9.6%, Jamaicans 13.6%, Indonesians 6.7%, Koreans 19.6%). The Hardy‐Weinberg rule for a two‐ or three‐allele model was not valid. Individuals belonging to the low activity group had a low activity ratio, all individuals with higher activity a high activity ratio (Carro‐Ciampi method). Our results suggest that the members of the low activity group in the three races are homozygote for an identical allele. 相似文献
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Zeshen Tian Bo Wang Yuyang Li Bo Shen Fengjuan Li Xianghua Wen 《Frontiers of Environmental Science & Engineering》2021,15(5):81
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