Zhao Wei-rong, Liao Qiu-wen, Yang Ya-nan, Dai Jiu-song
College of Environmental & Resource Sciences, Zhejiang University, Hangzhou 310058, China.
Huan Jing Ke Xue. 2013 May;34(5):1871-6.
Photocatalytic oxidation (PCO) of toluene and benzaldehyde in indoor air by N doped TiO2 (N-TiO2) was conducted under UV irradiation of 254 nm. The intermediates were identified and monitored on real-time by proton transfer reaction-mass spectrometry. The health risks of PCO of toluene and benzaldehyde were assessed based on health risk influence index (eta). Results indicated that both the conversion rate and mineralization rate of toluene and benzaldehyde were relatively high, however, the volatile aldehyde compounds (VAs), including acetaldehyde and formaldehyde generated from ring-opening, significantly influenced the health risks of PCO of toluene and benzaldehyde. Acetaldehyde played a crucial role on health risks, which was inclined to desorb from the surface of catalysts, accumulate in gas-phase, and increase the health risks of PCO of the aromatic compounds. The concentration of formaldehyde kept stable at a relatively low level, however its impact cannot be neglected. In the PCO process of toluene and benzaldehyde, eta reached the maximum values of 8 499.68 and 21.43, with the eta(VAs), contribution of VAs to the health risk influence index of outlet, reaching 99.3% and 98.3%, respectively. The average values of eta in the PCO process of 30 min were 932.86 and 8.52, and for which eta(VAs), reached 98.5% and 98.0%, respectively. When PCO of toluene and benzaldehyde reached steady state, eta were 236.09 and 2.30, and eta(VAs) reached 97.9% and 97.8%, respectively. Hence, eta(VAs), can be taken as a characteristic parameter in assessment of health risks of PCO of aromatic compounds.
在254nm紫外光照射下，利用氮掺杂二氧化钛（N-TiO₂）对室内空气中的甲苯和苯甲醛进行光催化氧化（PCO）。通过质子转移反应质谱仪实时鉴定和监测中间产物。基于健康风险影响指数（η）评估甲苯和苯甲醛PCO的健康风险。结果表明，甲苯和苯甲醛的转化率和矿化率都相对较高，然而，包括开环产生的乙醛和甲醛在内的挥发性醛类化合物（VAs）显著影响甲苯和苯甲醛PCO的健康风险。乙醛对健康风险起关键作用，它易于从催化剂表面解吸，在气相中积累，并增加芳香族化合物PCO的健康风险。甲醛浓度在相对较低水平保持稳定，但其影响不可忽视。在甲苯和苯甲醛的PCO过程中，η分别达到最大值8499.68和21.43，其中VAs对出口健康风险影响指数的贡献η(VAs)分别达到99.3%和98.3%。30分钟PCO过程中η的平均值分别为932.86和8.52，相应的η(VAs)分别达到98.5%和98.0%。当甲苯和苯甲醛的PCO达到稳态时，η分别为236.09和2.30，η(VAs)分别达到97.9%和97.8%。因此，η(VAs)可作为评估芳香族化合物PCO健康风险的特征参数。
