导　　师： 马军

学科专业： 081403

授予学位： 博士

作　　者： ;

机构地区： 哈尔滨工业大学

摘　　要： 随着工业的迅速发展,人类面临的水资源危机越来越严重,传统的水处理工艺难以去除水中有毒有害有机物。高级氧化工艺具有反应迅速、适用范围广、高稳定难降解有机物去除效率高等优点,得到研究者的广泛研究。TiO2除了作为光催化剂外,在臭氧催化氧化领域也表现出良好的催化活性。本论文中利用溶胶凝胶法制备了纳米级的金红石型TiO2并对TiO2进行了金属掺杂改性研究。分别以硝基苯和草酸作为目标物,筛选出掺杂效果最好的催化剂并优化了制备条件。本研究对催化剂的表面性质进行了表征,推测了臭氧催化氧化机理。 本文采用溶胶凝胶法制备了纳米级的TiO2,以硝基苯为目标物进行臭氧催化氧化试验。结果表明,不同晶型的TiO2具有不同的催化性能,锐钛矿型的TiO2几乎没有催化臭氧的能力,金红石型TiO2具有良好的催化性能。在金红石型TiO2催化臭氧的反应中,随着催化剂投量、臭氧浓度、反应温度提高,硝基苯去除率也随之增加;随着溶液pH升高,硝基苯的去除率也随之升高,在溶液pH值为10时具有最高的去除率,随后降低;不同的水质本底对硝基苯去除率的基本没有影响。金红石型TiO2催化臭氧工艺中羟基自由基的形成是主导的反应机理,该工艺过程中有机物降解生成的中间产物与单独臭氧工艺也基本相同:羧酸类、醛酮类、酚类。 选择了钴、铁、镍、锰及锌五种过渡态的金属离子对TiO2进行掺杂改性研究。制备的Mn//TiO2、Ni//TiO2、Co//TiO2、Fe//TiO2、Zn//TiO2这五种催化剂相对单独臭氧氧化工艺均大幅地提高了硝基苯的去除率,但与金红石型的纯TiO2催化效果相差并不大,掺杂并没有能提高臭氧催化分解硝基苯的效果。监测结果表明,在臭氧催化氧化过程中有微量金属离子溶出,但均远远低于国家标准。 Mn//TiO2和Co//TiO2这两种掺杂催化剂能够大幅度� With the rapid development of industry, the human being are facing ever increasing problem of water crisis. The traditional water treatment process is difficult to remove toxic organic compounds from water. Having many advantages, such as: quick response, high efficiency for the degardation of stabel organic pollutants, advanced oxidation processes are widely investigated. In addition to being used as a photocatalyst, TiO2 also showed good catalytic activity in the field of catalytic ozonation. In this paper, nanosized rutile TiO2 and metal doped TiO2 were prepared by sol-gel method, and investigated for their effectiveness in degrading organic pollutants in catalytic ozonation. The best way of catalyst doping were selected and the preparation conditions were optimized, using nitrobenzene and oxalic acid as the target respectively. The surface properties of the catalysts were characterized. The mechanism of catalytic ozonation was speculated. In this paper, nano-sized TiO2 was propared by sol-gel method, and nitrobenzene was used as the target for catalytic ozonation experiment. Different crystal structure of TiO2 have different catalytic properties. Anatase TiO2 almost has no ability for catalytic ozonation, while rutile TiO2 has good catalytic properties. In the rutile-type TiO2 catalytic ozonation reaction, the nitrobenzene removal rate increases respectively with the increase in the amount of catalyst, ozone concentration, reaction temperature. The removal rate of nitrobenzene increases with the increase of solution pH. When the solution pH value is 10, the degradation rate of nitobenzene is highest. In different water background, the removal rate of nitrobenzene were almost the same. Rutile TiO2 catalyzed ozonation is the dominant reaction mechanism of hydroxyl radical. Degradation intermediates of nitrobenenze generated during catalytic ozonation is basically the same with those generated in ozonation alone: That is: carboxylic acids, aldehydes and ketones, phenols. Cobalt, iron, nickel, mang

关 键 词： 臭氧 二氧化钛 硝基苯 草酸 掺杂改性 羟基自由基

领　　域： [环境科学与工程]