【作者】 张鹏；

【导师】 马广大；

【作者基本信息】 西安建筑科技大学 ， 环境工程， 2004， 硕士

【摘要】 气体放电法和光催化氧化法是近年来发展起来的处理挥发性有机化合物的新兴方法，目前还都处于试验研究阶段。与传统的处理方法相比，这两种方法具有工艺简单、成本低、无二次污染等特点。阻挡放电—光催化法是在以上两种方法的基础上探索出的一种新的发展方向，目的是将两种方法相结合，发挥各自的优势，从而达到更好的去除效果。本文以苯为处理对象，对阻挡放电—光催化法处理VOCs作了机理性的分析，总结了对反应产生影响的各种因素。 阻挡放电作为气体放电的一种形式，其本身就具有处理VOCs废气的能力，也是目前许多研究人员的主要研究方向。它主要是通过高能电子的轰击作用破坏VOCs分子的化学键，利用氧化性很强的·OH、·HO₂、·O自由基及O₃等对VOCs分子进行氧化，从而使VOCs最终降解为CO、CO₂、H₂O。试验结果表明，电场强度高，气体在反应器中停留时间长，有利于自由基的产生和苯的去除。 在试验过程中，通过改变反应器填料的材质和尺寸，对填料进行了优选，并总结出介质填料在反应过程中所起到的作用，分析了阻挡放电的原理。通过测定臭氧浓度来反映放电强度与氧等离子体浓度的关系。 文章还介绍了不同种类光催化剂的用途，重点介绍了纳米半导体的概念和纳米TiO₂的光催化原理，以及在它纳米尺度下所具有的各种效应。试验通过采用溶胶—凝胶法将纳米TiO₂均匀的涂在介质填料的表面，形成一层光催化剂薄膜，利用气体放电时产生的紫外光将光催化剂激发，对苯进行催化氧化。更多还原

【Abstract】 The study of dielectric barrier discharge(DBD) and photocatalysis process is a new idea in volatile organic compounds(VOCs) controlling. These two methods have many advantages, such as simple technology and low costs etc. The purpose of this paper is to develop the advantages of two processes. We chose the benzene as the target, analysed the mechanism of DBD and photocatalysis process, summarized the factors which can influence the reactions of this process.As a kind of gas discharge, DBD has ability to deal with the benzene itself. This process is also the main research direction of a lot of researchers at present. It can destroy the chemical bonds of benzene. The benzene will be transformed into pieces, then O3 and free radical such as OH,HO2 O can oxidize the pieces, finally the molecules of benzene are turned into CO CO2 and H2O. The result of the test shows, high electrostatic field strength, low velocity in reactor are suitable to remove benzene.In the test of degradation of benzene, we optimised the dielectric stuffing by changing the size and material of stuffing, summarized the function of stuffing performed in the course of reacting, described the relation between intensity of discharge and density of plasma through determining the density of ozone.The article introduces the use of different kinds of photocatalyst, and describes the concept of nanometer semiconductor and the catalysis principle of nanometer TiO2 especially. We enclosed TiO2 on the stuffing surface, then TiO2 formed a layer of membrane. When the photocatalyst was excited by the ultraviolet ray which was produced by gas discharge, it would catalyse and oxidize the pieces of benzene.更多还原