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1.
研究了山西代县天然金红石在紫外光和日光照射条件下对苯酚的光催化降解性能,考察了光照时间、pH值、苯酚初始浓度以及H2O2添加量对降解过程的影响。在紫外光照射下,酸性条件(pH=3.5)利于光催化降解,中性和碱性条件下降解效率较低;当初始浓度为60mg/L时,降解速率可达1.922mg/(L.h);H2O2作为电子捕获剂可提高苯酚降解速率,最佳投加量为2mL/L。在日光条件下,天然金红石对苯酚表现出良好的降解性能,照射7h后,降解率达87.68%,仅略低于P25型TiO2(99.72%),可在14h内完全降解。根据电子探针和X射线衍射分析结果,认为天然金红石晶格中的V、Fe等杂质可能是提高其可见光响应效果和光催化活性的主要原因。  相似文献   

2.
Sol-gel法制备SiO2-TiO2复合薄膜,进行甲醛的光催化降解实验,研究了SiO2掺杂量、薄膜焙烧温度、甲醛溶液pH值及初始浓度对光催化性能的影响。结果表明,500℃焙烧1h,掺杂质量SiO2:TiO2=12:100时,SiO2-TiO2薄膜的光催化活性最高,150min后甲醛降解率达76%,是单纯TiO2薄膜的1.3倍,该薄膜稳定性较好,经重复8次使用,最大降解率只下降4%。  相似文献   

3.
以蒙脱土为载体制备负载型Fe/Al复合氧化物(FeAlOx/MMT)用于催化Fenton反应降解高浓度苯酚废水。实验结果表明,活性相FeAlOx中Fe/Al摩尔比为0.22时制备所得催化剂对Fenton反应具有最佳活性,且Fe/Al复合氧化物并未嵌入蒙脱土层间。在低温和高pH条件下催化体系存在诱导期,诱导期内FeAlOx/MMT缓释出Fe离子并进而由Fe离子催化溶液中的Fenton反应。通过对非均相催化降解苯酚废水的动力学研究发现,H2O2初始浓度、溶液的pH和反应温度对COD降解效率具有显著影响。调节降解过程中的温度序列和氧化剂引入程序能够缓解高温和高双氧水浓度双重因素耦合导致的HO.自消耗。在优化的降解条件下使用理论用量的H2O2可使得1 g/L的苯酚废水中苯酚降解率达到100%,而COD的降解率则达到97%。  相似文献   

4.
天然锰钾矿氧化降解水体中苯酚实验研究   总被引:11,自引:3,他引:11       下载免费PDF全文
在酸性条件下进行了锰钾矿氧化降解水体中苯酚的实验研究,结果表明:室内自然光照和氧气环境不影响苯酚降解;反应溶液酸度越大,反应进行得越快;样品用量越多、粒径越小,越有利于降解反应;反应温度升高与振荡速度增大也有利于降解反应的进行;共存电解质氯化钠、氯化钙不影响降解反应,而磷酸钠与醋酸钠则不利于降解反应。当介质pH值为2、1,160~200目锰钾矿用量为10g/L,反应温度为25℃,振荡速度为200r/min,反应8h,对50mL浓度为100mg/L苯酚的降解率基本上达到100%,达到了工业排放标准。从反应产物初步推断,苯酚降解的实质是锰钾矿氧化降解作用,为处理苯酚废水增加了一种有效的方法,并拓宽了天然锰钾矿的开发应用前景。  相似文献   

5.
采用TiCl4水解法制备钛柱化剂与钠蒙脱石离子交换后,自然风干、焙烧得到具有稳定层结构、大晶面间距(2.26 nm)和大比表面积(285.7 m2/g)的钛柱撑蒙脱石(Ti-PILM)。用制备的Ti-PILM对亚甲基蓝(MB)进行紫外光作用下的光催化降解实验,并与层结构不规则的Ti-PILM在相同条件下对MB的光催化效果进行对比,研究MB的初始浓度、Ti-PILM投放量、pH对光催化降解效果的影响。结果表明,室温条件下,降解时间120 min,当Ti-PILM投样量等于2 g/L,MB初始浓度为50 mg/L,pH为7时,Ti-PILM对MB降解速度最高。与纳米TiO2不同,Ti-PILM对MB的降解率和降解初速率与MB在其表面的吸附行为密切相关。  相似文献   

6.
天然金红石光催化降解藏红T实验研究   总被引:5,自引:0,他引:5  
以低压汞灯为光源研究了天然金红石悬浆体系中藏红T的脱色条件及其光催化反应动力学,讨论了溶液初始pH值、催化剂投入量、光强、气流量、催化剂粒径、反应气氛等实验条件对藏红T脱色速率的影响,阐述了实验过程中无机离子的生成情况。结果表明,该反应基本上符合一级反应动力学;在酸性条件下尤其是当溶液初始pH值为2.5时,藏红T的脱色速率要比在碱性和中性条件下快得多;增加光强度能较大地提高反应的降解速率;催化剂最佳投入量为1.3g/L;在氧化气氛下该反应比在非氧化气氛快得多;通入气体的流量在40L/h最合适;反应溶液中有氯离子溶出说明有机物中的含氯部分被降解。本研究为光催化作用降解有机污染物提供了新的途径。  相似文献   

7.
纳米TiO2光催化降解亚甲基蓝   总被引:2,自引:0,他引:2  
在以钛酸丁酯为钛源,采用溶胶-凝胶法合成制备纳米TiO2催化剂样品的基础上,将其用于在紫外光照射和无光照射条件下进行亚甲基蓝降解的实验研究,并与P-25纳米TiO2进行光催化降解对比研究。对在不同条件下合成制备样品的光催化降解率的差异,通过X射线粉晶衍射、扫描电镜等从物相组成、微观结构等因素上进行了分析和探讨。结果表明,采用溶胶-凝胶法在450℃焙烧2 h所得到的纳米TiO2具有很好的光催化降解亚甲基蓝的能力,当催化剂样品质量浓度为2.5 g/L,亚甲基蓝初始浓度为5.0 mg/L时,室温下光催化反应3 h,其降解率达98%以上,其光催化降解率比P-25纳米TiO2高;光催化降解率与催化剂样品的制备条件、物相组成、颗粒尺寸等因素有关。  相似文献   

8.
掺铁二氧化钛薄膜的自组装制备、表征与光催化性能研究   总被引:3,自引:0,他引:3  
李青霞  孙振亚  王婷 《矿物学报》2011,31(1):102-107
采用自组装方法于低温液相反应体系中成功制备出大尺寸二维纳米二氧化钛薄膜和掺铁二氧化钛薄膜。样品通过荧光发射光谱、拉曼光谱、高分辨透射电镜等方法进行表征,并研究了紫外光和可见光下Fe3+/TiO2纳米薄膜对甲基橙溶液(MO)的光催化降解过程,探讨了Fe3+对TiO2的光催化活性的影响。结果表明,此方法不需要高温煅烧即可得到高催化活性的金红石和锐钛矿混合型二氧化钛薄膜,以金红石为主。Fe3+掺杂明显提高了TiO2对甲基橙溶液的光催化降解效率:掺杂Fe3+浓度为0.5 mmol/L时光催化效果最优,且更利于较低浓度甲基橙溶液的降解,在紫外光和可见光下对初始浓度5 mg/L甲基橙溶液的降解率分别达到98.62%和89.24%。  相似文献   

9.
铁(氢)氧化物矿物对有机污染物的光催化氧化作用   总被引:22,自引:3,他引:19  
对水溶液中(氢)氧化铁的光催化氧化反应的发展与机理研究进行了总结,着重对近十年来应用针铁矿/过氧化氢进行光催化氧化环境中有机物的研究进展及其环境矿物学意义作了概述和探讨。采用天然生物矿化的纳米针铁矿/过氧化氢以偶氮染料甲基橙为光解模型物进行了光催化氧化的初步研究,结果表明铁细菌形成的针铁矿具有降解生物难降解的有机污染物的能力。在甲基橙溶液初始浓度为30mg/L,铁细菌矿化的针铁矿用量2.5g/L,反应体系H2O2的初始浓度97mmol/L,pH值为6.92,15W紫外灯照射2h后,甲基橙浓度可降低33%。  相似文献   

10.
地下水中三氯乙烯-苯酚的好氧共代谢的实验研究   总被引:4,自引:1,他引:3  
以苯酚作为三氯乙烯(TCE)降解的共代谢基质,用瓦勃氏微量呼吸测压仪(简称瓦呼仪)作为测试手段,分析了经苯酚驯化后的混合微生物对苯酚、TCE的降解特性;并讨论了以苯酚作为共代谢基质时TCE降解的可能性。实验结果表明:未驯化的活性污泥不能降解TCE; 经苯酚驯化后的活性污泥,当TCE的质量浓度为50 μg/L时其降解效果较好,TCE的氧化率达3369%;TCE的质量浓度为100 μg/L时其降解效果较差,其氧化率仅为3.2%;苯酚和TCE共代谢降解时,苯酚的存在促进了TCE的降解,当苯酚质量浓度为40 mg/L、TCE质量浓度为50 μg/L时共代谢降解效果最好,TCE的氧化率为79.11%。  相似文献   

11.
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.  相似文献   

12.
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.  相似文献   

13.
Robert L. Linnen   《Lithos》2005,80(1-4):267-280
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.  相似文献   

14.
15.
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).  相似文献   

16.
正20141520 Bo Ying(Key Laboratory of Metallogeny and Mineral Assessment,MLR,Beijing 100037,China);Liu Chenglin Saline Spring Hydrochemical Characteristics and Indicators for Potassium Exploration in Southwestern and Northern Tarim Basin,Xinjiang(Acta Geoscientica Sinica,ISSN1006-3021,CN11-3474/P,34(5),2013,p.594-602,5 illus.,3 tables,28 refs.)  相似文献   

17.
正20141243Chen Ge(Hangzhou Research Institute of Petroleum Geology,PetroChina,Hangzhou 310023,China);Si Chunsong Study on Sedimentary Numerical Simulation Method of Fan Delta Sand Body(Journal of Geology,  相似文献   

18.
正20142599Chen Sanming(Guangxi Key Laboratory of Concealed Deposits Exploration,Guilin University of Technology,Guilin541004,China);He Yuzhou Block Model and Reserves Estimation of Panzhihua Iron Deposit Based on 3D Geological Modeling(Journal of Guilin University of Technology,ISSN1674-9057,CN45-1375/N,33(4),2013,p.610-615,9illus.,1table,15refs.)  相似文献   

19.
正20140594 Bai Daoyuan(Hunan Institute of Geology Survey,Changsha 410016,China);Zhong Xiang Faults in the Jingzhou Basin and Their Tectonic Settings(Geotectonica et Metallogenia,ISSN1001-1552,CN44-1595/P,37(2),2013,p.173-183,6illus.,59refs.)Key words:basin evolution,tectonic setting,South China In the Upper Paleozoic and Jurassic se-  相似文献   

20.
正20141912Cao Hui(State Key Laboratory for Continental Tectonics and Dynamics,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)Gravitational Collapse and Folding during Orogenesis:A Comparative Study of FIA Trends and Fold Axial Plane Traces(Geology in China,ISSN1000-3657,CN11-1167/P,40(6),2013,p.1818-1828,9illus.,35refs.,with  相似文献   

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