Enhancement effect of TiO2 immobilized on activated carbon filter for the photodegradation of pollutants at typical indoor air level
Enhancement effect of TiO2 immobilized on activated carbon filter for the photodegradation of pollutants at typical indoor air level
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DOI：
10.1016/s0926-3373(03)00054-7
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发表时间：
2003-08-30
影响因子：
22.1
通讯作者：
Lee, SC
中科院分区：
文献类型：
--
作者：
Ao, CH;Lee, SC
以前曾报道过在ppb级的水蒸气和污染物之间的吸附位点的竞争效应。结果发现，在高湿度水平下，污染物的光降解速率急剧下降。为了提高污染物在ppb级和高湿度水平下的光降解，将TiO2固定在活性炭（AC）过滤器上。选择200 ppb的氮氧化物（NO）和20 ppb的苯、甲苯、甲苯和邻二甲苯（BTEX）作为目标污染物。在不同停留时间和湿度条件下，对NO和BTEX进行了敏感性分析。结果表明，在短停留时间和高湿度水平下，TiO 2和AC的组合显著增加了NO和BTEX的去除。固定在AC过滤器上的TiO2受湿度水平增加的影响较小。NO2，作为从NO的光降解产生的中间体，也相继被抑制退出系统。通过在活性炭过滤器上固定TiO2来抑制NO的光降解失活。活性炭的使用通过从空气流中吸附污染物而充当局部污染物浓缩器，从而扩散到TiO 2用于光降解。(C)2003 Elsevier Science B.V.保留所有权利。
The competition effect between water vapor and pollutants at ppb level for adsorption sites has been previously reported. It was found that at high humidity levels, the pollutant photodegradation rate reduced drastically. To improve the photodegradation of pollutants at ppb level and at high humidity levels, TiO2 is immobilized on an activated carbon (AC) filter. 200 ppb of nitrogen oxide (NO) and 20ppb of benzene, toluene, ethylbenzene and o-xylene (BTEX) were chosen as target pollutants. Sensitivity analyses were conducted for NO and BTEX under different residence times and levels of humidity. Results showed that the combination of TiO2 and AC significantly increased NO and BTEX removals at short residence time and high humidity levels. TiO2 immobilized on AC filter was less affected by the increasing humidity levels. NO2, as an intermediate generated from the photodegradation of NO, was also successively suppressed from exiting the system. Deactivation from the photodegradation of NO was suppressed by immobilizing TiO2 on an activated carbon filter. The use of activated carbon acted as a local pollutant concentrator by adsorbing pollutants from the air stream and thereby diffused to the TiO2 for photodegradation. (C) 2003 Elsevier Science B.V. All rights reserved.