Photocatalytic oxidation of indoor toluene: process risk analysis and influence of relative humidity, photocatalysts, and VUV irradiation.
Photocatalytic oxidation of indoor toluene: process risk analysis and influence of relative humidity, photocatalysts, and VUV irradiation.
复制标题
DOI：
10.1016/j.scitotenv.2012.08.081
复制
发表时间：
2012-11
期刊：
影响因子：
--
通讯作者：
Weirong Zhao;Jiusong Dai;Feifei Liu;Jiaze Bao;Y. Wang;Yong Yang;Yanan Yang;Dongye Zhao
中科院分区：
文献类型：
--
作者：
Weirong Zhao;Jiusong Dai;Feifei Liu;Jiaze Bao;Y. Wang;Yong Yang;Yanan Yang;Dongye Zhao
采用质子转移反应质谱法实时测定室内空气中甲苯光催化氧化（PCO）中13种气态中间体的浓度，并采用程序升温解吸质谱法检测光催化剂表面吸附的7种中间体的解吸强度。考察了相对湿度（RH）、光催化剂和真空紫外线（VUV）照射对中间体分布和类别以及健康风险影响指数（η）的影响。 RH 提高了氢氧自由基的形成速率，导致气相中产生更多具有更高氧化态的中间体。 N掺杂促进光生电子和空穴的分离，从而增强PCO活性。 VUV 照射导致更高的矿化率和更多具有更高氧化态和更低毒性的中间体，例如羧酸。健康风险分析表明，较高的 RH、TiO2 氮掺杂和 VUV 会导致“更环保”的中间体和更小的 η。最后，提出了一个概念图来展示 η 随入口污染物的各种毒性的矿化程度而变化的情况。
Concentrations of 13 gaseous intermediates in photocatalytic oxidation (PCO) of toluene in indoor air were determined in real-time by proton transfer reaction mass spectrometry and desorption intensities of 7 adsorbed intermediates on the surface of photocatalysts were detected by temperature‐programmed desorption‐mass spectrometry. Effects of relative humidity (RH), photocatalysts, and vacuum ultraviolet (VUV) irradiation on the distribution and category of the intermediates and health risk influence index (η) were investigated. RH enhances the formation rate of hydroxide radicals, leading to more intermediates with higher oxidation states in gas phase. N doping promotes the separation of photo-generated electrons and holes and enhances PCO activity accordingly. VUV irradiation results in higher mineralization rate and more intermediates with higher oxidation states and lower toxicity e.g. carboxylic acids. Health risk analysis indicates that higher RH, N doping of TiO2, and VUV lead to “greener” intermediates and smaller η. Finally, a conceptual diagram was proposed to exhibit the scenario of η varied with extent of mineralization for various toxicities of inlet pollutants.