饮用水TiO_2光催化消毒机理及应用研究进展

Research progress on mechanism and application of TiO_2 photocatalysis drinking water sterilization

TiO2光催化氧化技术具有无毒、广谱性杀菌的特点,将其应用于饮用水消毒的研究受到重视.笔者综述了TiO2光催化氧化的消毒机理及其在微生物灭活方面的研究进展.研究表明:TiO2光催化氧化产生的HO.及其它活性氧类物质对水中细菌、病毒、细菌孢子等具有很强的灭活能力,其代表性的微生物灭活机理主要有代谢破坏、遗传物质破坏和细胞壁(膜)结构破坏等机理.在对几种机理分析后认为,其机理应是强氧化性自由基,首先破坏微生物细胞壁,造成细胞膜及胞内代谢物质及遗传物质的氧化破坏,最终导致细胞死亡.TiO2光催化对兰伯氏贾第虫,隐孢子虫等杀灭能力有限,且缺乏持续消毒能力,未来应针对TiO2饮用水光催化消毒的影响因素、过程控制因子及其与化学消毒剂优化组合等问题进行深入研究.

TiO2 photocatalysis has the characteristics of non-toxic and broad-spectrum sterilizing ability; its application in drinking water disinfection has drawn a great attention. A summary on the mechanism of TiOz photocatalysis disinfection and its application in microorganism inactivation are made in this article. The radicals such as HO ^· , O2^- , ·OOH and H2O2 generated by TiO2 photocatalysis have the ability of inactivating bacteria, virus and spores in water. At present, metabolization destroying, germ plas- ma destroying and cell wall structure destroying are several typical photocatalysis sterilization mechanisms, namely, the strong oxidizing radicals can destroy cell wall, subsequently, cell membrane and metabolization substance as well as germ plasma are destroyed, as a result, the cells die. TiO2 photocatalysis can not effectively kill giardia lamblia and cryptosporidiosis, besides, it has no sustaining sterilizing ability. The influencing factors and technical controlling factors need a further study.