真空紫外光协同臭氧催化氧化降解甲苯的研究

Study on the degradation of gaseous toluene by VUV-OZCO

对比了单独O3、单独VUV、单独臭氧催化氧化和VUV-臭氧催化氧化联合工艺体系对甲苯进行降解,分别考察了在VUV-臭氧催化氧化体系下初始甲苯浓度、停留时间、相对湿度等因素对甲苯降解效率的影响,并对其降解甲苯的路径及协同作用机理进行了初步探讨。研究表明,VUV-臭氧催化氧化工艺对甲苯的降解效果最佳。在VUV-臭氧催化氧化工艺条件下,甲苯降解率随着初始甲苯浓度的增加而降低,随着停留时间的延长而升高,随着相对湿度的增加则呈现先升高后降低的现象。此外,VUV-臭氧催化氧化可提高臭氧的利用率,从而提高甲苯降解的矿化率,同时消耗剩余臭氧,避免二次污染。在后续臭氧催化氧化体系中,苯甲醛、乙醛、丙酮、乙醇等中间副产物更易被矿化降解。

In order to get the best oxidation process for toluene, the degradation experiments by different oxidationprocesses including O3, VUV and VUV -OZCO are carried out for comparison. The effects of initial concentration oftoluene, retention time and relative humidity on the degradation efficiency of toluene are investigated under VUV-OZCOprocess. Meanwhile, the path of the degradation of toluene and its synergistic mechanism are discussed preliminarily.The results indicate that VUV-OZCO process owns the best degradation efficiency for toluene among these processes.When using the VUV -OZCO process, the degradation rate will decrease with the increase of initial tolueneconcentration, increase with prolonging the retention time, and increase firstly and then decrease with the increase ofrelative humidity. In addition, it can enhance the mineralization of toluene and eliminate remaining ozone by VUV-OZCO,which avoid secondary pollution problems. Compared with the intact toluene, the intermediates such as benzaldehyde,acetaldehyde, acetone, ethanol and so on are more easily completely mineralized in the ozone catalytic system.