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掺杂纳米TiO2光催化氧化处理硝基苯废水研究 总被引:1,自引:0,他引:1
针对硝基苯难降解性,以及其在环境中长期存在和积累的问题,采用溶胶-凝胶法制备的系列金属离子掺杂纳米TiO2为催化剂,在紫外光照射下对硝基苯废水进行光催化降解.实验结果表明,光催化氧化处理硝基苯废水的效果依次为,铜掺杂纳米TiO2、铁掺杂纳米TiO2、铬掺杂纳米TiO2、商品纳米TiO2.铜掺杂纳米TiO2光催化氧化处理硝基苯废水的最佳条件为:合成废水pH为3.0,铜掺杂纳米TiO2用量为7.5g/L废水,用30W紫外灯在搅拌条件下光照4 h,废水的硝基苯含量由100 mg/L降至2.59 mg/L,去除率达到97.41%. 相似文献
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针对新型光催化剂Bi2WO6在可见光条件下光生电子-空穴分离效率低的问题,本文采用液固相水热反应的方法制备了F/Ce掺杂改性的Bi2WO6光催化剂。通过X射线粉末衍射(XRD)、扫描电镜(SEM)和紫外-可见漫反射(UV-vis DRS)等分析表明,F/Ce掺杂Bi2WO6光催化剂具有明显的层状结构,可有效降低电子-空穴的复合率,且改性后的Bi2WO6吸收波长发生红移。光催化氧化处理甲基橙降解实验结果表明:F和Ce共掺杂下Bi2WO6在可见光下具有最高的光催化活性,主要活性物质为羟基自由基(·OH),甲基橙的降解率在50 min后可以达到97%,催化活性比纯Bi2WO6提高了近2倍。本研究为研发水环境中高浓度有机废水,特别是难降解有机污染物的高效治理技术提供了基础数据。 相似文献
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针对硝基苯难降解性,以及其在环境中长期存在和积累的问题,采用溶胶-凝胶法制备的系列金属离子掺杂纳米TiO2为催化剂,在紫外光照射下对硝基苯废水进行光催化降解。实验结果表明,光催化氧化处理硝基苯废水的效果依次为,铜掺杂纳米TiO2、铁掺杂纳米TiO2、铬掺杂纳米TiO2、商品纳米TiO2。铜掺杂纳米TiO2光催化氧化处理硝基苯废水的最佳条件为:合成废水pH为3.0,铜掺杂纳米TiO2用量为7.5g/L废水,用30W紫外灯在搅拌条件下光照4h,废水的硝基苯含量由100mg/L降至2.59mg/L,去除率达到97.41%。 相似文献
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采用仲丁醇铝和商用TiO2(P25)一锅法合成了两种二氧化钛纳米复合材料TiO2-勃姆石(TiO2-AlOOH)及TiO2-氧化铝(TiO2-Al2O3).制备的样品主要采用傅立叶变换红外光谱(FT-IR),X-射线衍射(XRD),氮吸附和扫描电子显微镜(SEM)等方式进行表征.分析证明TiO2颗粒成功地分散到铝载体内形成纳米复合材料并采用亚甲基蓝作为模拟降解物对其光催化性能进行了测定.研究发现具有勃姆石结构的复合材料TiO2-AlOOH比TiO2-Al2O3有更好的脱色效果,这可能是由于其具有更大的比表面积以及表面富含羟基.同时这两种材料在碱性条件下可以达到最好的脱色率. 相似文献
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采用Fenton试剂降解含甲基橙染料的模拟废水,通过对甲基橙染料处理过程中UV-Vis吸收光谱的分析,证明了Fenton氧化法对甲基橙染料的处理效果。进一步研究了Fenton氧化降解甲基橙废水的反应动力学,并建立了反应动力学模型。结果表明,Fenton氧化过程中,影响甲基橙降解速率的主要因素为H2O2和甲基橙的初始浓度。H2O2和甲基橙初始浓度与反应速率常数之间的关系可分别归纳为:kRH=0.05c(H2O2)1.4和kRH=0.023c(RH)-1.3。 相似文献
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负载型纳米TiO2光催化降解罗丹明B动力学与机理研究 总被引:6,自引:0,他引:6
采用负载型纳米TiO2/AC在流化床反应器中降解罗丹明B染料废水。研究了罗丹明B的光催化降解反应动力学与降解机理。结果表明,负载型纳米TiO2光催化降解罗丹明B过程符合一级动力学方程,降解机理首先是罗丹明B分子发色基团苯氨基、羰基键被破坏,然后是无色中间产物的逐渐降解。 相似文献
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在超临界二氧化碳(SC-CO2)溶媒中,以钛酸四丁酯为前驱体,利用超临界溶媒的高传质性能将钛的前驱体运送到硅基分子筛MCM-41的内壁,合成了TiO2MCM-41介孔分子筛催化剂。X-射线粉末衍射和傅立叶变换红外谱图等结果表明:二氧化钛可以很好地负载在介孔结构中并保持了原来的孔道结构。以甲基橙为模拟污染分子,紫外灯为光源,研究了催化剂用量、初始溶液pH值等条件对甲基橙脱色率的影响。该合成步骤简单,材料性能优异,具有推动光催化材料污染控制和环境修复工业化的潜力。 相似文献
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This work focuses on the photocatalytic oxidation of gaseous methyl ethyl ketone chosen as a typical indoor air pollutant. Two types of TiO coatings were prepared and deposited on glass plates: one using the commercial Degussa P25 TiO2 and the other one by sol-gel method. The first objective of this study was to compare different ways of preparing thin films of sol-gel TiO2 coated on glass plates, taking into account their general aspect and their photocatalytic efficiency. Several parameters were tested, such as the stabilising agent, the glass type of the support, the number of coatings and the calcination temperature. One of the synthesised materials was then kept to carry out the following study. The study aimed to assess the influence of TiO2 coating types on the effect of water vapour. This was achieved by performing MEK photocatalytic degradation kinetics under two levels of humidity at a fixed temperature. Experimental results were then modelled by the Langmuir-Hinshelwood equation. The obtained parameters gave specific trends in function of the considered catalyst. The second part of this work was to identify MEK degradation byproducts during its photocatalytic oxidation. The main detected intermediate was acetaldehyde, followed by methyl formate. A MEK degradation pathway was then proposed. 相似文献
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就热滚塑钢管在密闭式工业循环水系统(纯水循环水和软化水循环水)中的应用和管路设计方法进行了分析和探讨,并将其与碳钢不锈钢复合管做了简单比较,提出了热滚塑钢管与碳钢不锈钢复合管相结合的管路设计方法. 相似文献
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针对仪化热电厂离子交换器树脂泄漏问题,分析了树脂泄漏原因,采取了更换进水十字头和不锈钢缠绕丝管、采用不锈钢槽钢和中排不锈钢绕焊过滤筛管以及增设不锈钢滤网等一系列措施.经过改造后,离子交换器树脂泄漏得到了有效控制,其经验对同类水处理系统解决此类问题具有一定的指导意义. 相似文献
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For the sake of efficient utilization of sunlight, Ag nanoparticles loaded N-doped TiO? photocatalysts (Ag/N-TiO?) were successfully fabricated via a two-step method to make the best use of the respective advantages of noble metal loading and nonmetal doping. Ag/N-TiO? was characterized using XRD, XPS and UV-Vis DRS. Compared to TiO?, the dramatic enhancement of the visible-light-induced photocatalytic degradation ef?ciency of Ag/N-TiO? obtained for the degradation of methyl orange should be attributed to the synergistic effect of N-doping and Ag-loading, including the good visible light absorption and the effective electron-hole separations. This demonstrates Ag/N-TiO? is a promising photocatalytic material for organic pollutant degradation under visible light irradiation. 相似文献
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A new bifunctionalized TiO(2) film containing a dye-sensitized region and a degradation region was described. A similar structure of dye-sensitized solar cell (DSSC) was fabricated in the dye-sensitized region to accomplish separation of electrons from positive charges, and separation of dye from pollutants to avoid dye decomposition. The bifunctionalized TiO(2) film electrode and anode electrode can degrade methyl orange (MO) in reactors A and B, respectively. The degradation efficiency was enhanced remarkably by an external electrical potential. The decolorization of MO reaches as high as 95% after 2 h visible light irradiation at an external potential of 0.5 V along with a loss of 41% total organic carbon (TOC). The possible reason for the improvement of degradation by external DC potential was discussed. Effects of pH and inorganic salts on the decolorization are present. 相似文献
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Four selected azo dyes (acid orange 6, acid orange 7, methyl orange and methyl red) were completely decolourised in the presence of anaerobic granular sludge, while only methyl red was degraded in aerobic conditions using a conventional activated sludge. Additional experiments with culture broth devoid of cells showed that anaerobic decolourisation of azo dyes was performed by extracellular reducing agents produced by anaerobic bacteria. This was further confirmed by abiotic experiments with sulphide and NADH. The presence of redox mediators such as riboflavin led to dramatic acceleration of the anaerobic biodecolourisation process. The azo dye reduction products were found to be sulphanilic acid and 4-aminoresorcinol for acid orange 6; sulphanilic acid and 1-amino-2-naphthol for acid orange 7; N,N-dimethyl-1,4-phenylenediamine and sulphanilic acid for methyl orange; and N,N-dimethyl-1,4-phenylenediamine and anthranilic acid for methyl red. Anaerobic toxicity assays showed that the azo dyes were more toxic than their breakdown products (aromatic amines), except 1-amino-2-naphthol. In the presence of activated sludge, only anthranilic acid was completely mineralised while sulphanilic acid was persistent. 4-aminoresorcinol, 1-amino-2-naphthol and N,N-dimethyl-1,4-phenylenediamine underwent autooxidation in aerobic conditions yielding coloured polymeric products. On the contrary, in the presence of granular methanogenic sludge, 4-aminoresorcinol, 1-amino-2-naphthol and anthranilic acid were quantitatively methanised, sulphanilic acid was partially (70%) mineralised while N,N-dimethyl-1,4-phenylenediamine was only demethylated producing 1,4-phenylenediamine as an end product. 相似文献
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为探讨微压过滤冲洗池采用不锈钢和腈纶滤网作为过滤元件的过滤性能,以过滤时间、拦截泥沙质量及泥沙去除率为评价指标,在水流含沙量为0.66 kg/m3和流量为5.0 m3/h条件下分别开展了物理模型试验。试验结果表明:在水箱水深变化方面,腈纶滤网存在水深恒定、水深快速增加及水深急速增加3个过滤阶段,而不锈钢滤网没有水深急速增加阶段;两种滤网的水深恒定时间相差不大,但不锈钢滤网的过滤时间略大于腈纶滤网;腈纶滤网拦截泥沙质量大于不锈钢滤网,且腈纶滤网能拦截到更小粒径的泥沙;腈纶和不锈钢滤网的泥沙去除率分别为61.10%~83.50%和44.00%~62.05%,前者是后者的1.35~1.42倍。综合考虑各项指标认为腈纶滤网更适用于微压过滤冲洗池,试验成果可为微压过滤冲洗池的深入研究提供理论依据和技术支撑。 相似文献