Potential use of a combined ozone and zeolite system for gaseous toluene elimination
Potential use of a combined ozone and zeolite system for gaseous toluene elimination
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DOI：
10.1016/j.jhazmat.2006.08.077
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发表时间：
2007-05-08
影响因子：
13.6
通讯作者：
Hui, K. S.
中科院分区：
文献类型：
--
作者：
Chao, C. Y. H.;Kwong, C. W.;Hui, K. S.
本研究探讨臭氧与沸石组合系统在去除工业及室内环境中主要污染物甲苯的效能。通过臭氧去除甲苯的假设，可以大大影响限制在沸石结构中的氧化反应进行了评估。臭氧在13 X分子筛的刘易斯酸位上分解产生的活性氧原子对甲苯的降解有一定的贡献。将含有1.5、2和3 ppm甲苯水平的空气与0- 6ppm范围内的臭氧一起注入，然后排放到固定量的3600 g沸石13 X中，床长为90 mm。实验结果表明，与单独使用沸石或臭氧相比，甲苯的去除率显著提高。特别地，当在40%相对湿度水平下使用6ppm臭氧时，超过90%的1.5ppm甲苯被去除。在当前实验条件下反应几个小时后，13 X沸石的失活可能是由于吸附的水、二氧化碳和反应副产物。采用FT-IR、GC-MS和HP-LC等方法对沸石中残留物和废气中的中间产物进行了表征。在红外光谱中，在1380 cm（-1）处发现了一个明显的O原子吸附在刘易斯酸中心上的峰，并发现了微量的醛类化合物。(C)2006 Elsevier B. V.保留所有权利。
This study investigated the performance of a combined ozone and zeolite system in eliminating gaseous toluene which is a major contaminant in many industrial and indoor environments. The hypothesis that the removal of toluene by ozone can be substantially affected by confining the oxidation reaction in a zeolite structure was evaluated. The degradation of toluene seemed to be contributed by the active oxygen atom generated from the decomposition of ozone at the Lewis acid sites in the zeolite 13X. Air containing toluene levels at 1.5, 2 and 3 ppm was injected with ozone in the range of 0-6 ppm before being vented into a fixed amount of 3600 g zeolite 13X with 90 mm bed-length. The experimental results showed that the elimination rate of toluene was significantly enhanced when compared to using zeolite or ozone alone. In particular, over 90% of the 1.5 ppm toluene was removed when 6 ppm ozone was used at 40% relative humidity level. Deactivation of the zeolite 13X after a few hours of reactions under the current experimental conditions was probably due to the adsorbed water, carbon dioxide and the reaction by-products. The residue species left in the zeolite and the intermediate species in the exhaust gas stream were characterized by FT-IR, GC-MS and HP-LC methods, respectively. A distinctive peak of O atom attached to the Lewis acid site at 1380cm(-1) was found in the FT-IR spectrum and trace amount of aldehydes was found to be the reaction by-products. (C) 2006 Elsevier B.V. All rights reserved.