【作者】 史文晶；

【导师】 上官文峰；

【作者基本信息】 上海交通大学 ， 化学工程与技术， 2010， 硕士

【摘要】 室内环境与人体健康一直都是公众瞩目的焦点,世界卫生组织研究调查表明,目前室内污染问题在世界各地比较普遍,在发展中国家尤为突出。甲醛和苯系物是室内空气中的主要挥发性有机污染物,严重危害人类的健康,研究甲醛和苯系物的去除对提升室内空气品质及保障人类健康显得尤为重要。本文采用臭氧与光催化相结合的手段,以“吸附/富集—光催化/臭氧耦合”的方法达到对目标污染物的高效降解,对具有独特择形吸附的分子筛H-ZSM-5进行改性,将Mn离子通过浸渍法和离子交换方式引入到分子筛中以改善催化耦合效果。本文研究了催化剂对有机物降解性能,并对所制备的催化剂结构、表面性质和催化活性进行了表征和评价。并且用不同的方式将H-ZSM-5和TiO₂（P25）催化剂负载在活性炭板上,在模拟室内环境的密封测试舱内考察了耦合条件下降解甲醛、甲苯的效果。研究结果表明:1.利用浸渍法制备出的TiO₂/MnOx-ZSM-5系列催化剂在降解乙醛实验中证明UV/O₃耦合作用大于单独UV作用与单独O3作用之和。催化剂中MnOx的存在有利于提高臭氧的利用率,为乙醛的深度降解提供了更多的O₂^-和·OH。2.通过离子交换法制备出的TiO₂/Mn-ZSM-5系列催化剂,光催化臭氧耦合降解乙醛的效率较高,这是由于Mn离子起了关键作用,臭氧和乙醛除了可以在分子筛上进行反应,还可以在分子筛孔道中和笼中的Mn离子上进行反应,使得有效反应面积增加,从而提高对臭氧的利用率。TiO₂/Mn-ZSM-5较高的催化活性表现出“吸附/浓缩—臭氧/光催化耦合”的协同效应。3.将催化剂负载于活性炭板,并在测试舱测试降解甲醛和甲苯混合气体的效果。结果表明:利用光催化臭氧耦合作用,密闭仓中高于环境标准5-10倍的甲醛、甲苯能持续快速降解,并在短时间内达到国家相关环境标准。更多还原

【Abstract】 The relationship between the indoor environment and human health is paid great attention in the world. The research report from World Health Organization （WHO） suggested that indoor pollution had become a worldwide problem especially in developing countries. As we know, formaldehyde and benzene are two major indoor air volatile organic pollutants, which are seriously harmful to human health.The hybrid system of ozonization and photodegradation was studied in the present work. The synergism of‘adsorption/enrichment-photodegradation/ozonization’was used to efficiently degrade the target pollutants. H-ZSM-5 has a shape-selective adsorption structure. It was modified with Mn-ion by impregnation and ion-exchange in order to improve acetaldehyde degradation in UV-ozone atmosphere. The influence of catalyst structure and surface properties on catalytic activity were investigated. Meanwhile, various ways for loading TiO₂ （P25） to H-ZSM-5 and active carbon support have been employed. The degradation of formaldehyde and toluene was simulated in a sealed test chamber. Following conclusions have been drawn:TiO₂/MnO₂-ZSM-5 prepared by impregnation showed higher activities of acetaldehyde degradation in UV-ozone than the sum of UV and ozone used separately. MnOx introduced in catalysts increased the utilization rate of ozone because more O₂^- and·OH were produced for the acetaldehyde degradation.TiO₂/Mn-ZSM-5 prepared by ion-exchange showed higher activities of acetaldehyde degradation than TiO₂/ZSM-5 in UV-ozone. Mn as a promoter at the surface of the zeolite has a beneficial effect on the reaction rate of ozone and acetaldehyde. Mn mainly enhanced and stabilizes the BET surface area of zeolite. The high activity of TiO₂/Mn-ZSM-5 is due to the synergistic effect of‘adsorption/enrichment-photodegradation/ ozone’.All catalysts supported on the activated carbon were detected for the decomposition of formaldehyde and toluene in a test chamber. The results indicated that the degradation activity by ozone- photodegradation coupling was five to ten times higher than that by general method, and the pollutants could be quickly derogated and reached the relevant national environmental standards.更多还原