Removal of VOCs from indoor environment by ozonation over different porous materials

Ozonation of toluene over NaX, NaY and MCM-41 adsorbents was studied targeting for indoor air purification. The combined use of ozone and the various micro- or meso-porous adsorbents aimed to take advantage of the strong oxidizing capability of ozone. At the same time the residual ozone would be min...

Full description

Saved in:
Bibliographic Details
Published in:Atmospheric environment (1994) 2008-03, Vol.42 (10), p.2300-2311
Main Authors: Kwong, C.W., Chao, Christopher Y.H., Hui, K.S., Wan, M.P.
Format: Article
Language:English
Subjects:
Adsorbent
Applied sciences
Atmospheric pollution
Exact sciences and technology
Indoor pollution and occupational exposure
Ozone
Pollution
Toluene
VOC
Zeolite
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Ozonation of toluene over NaX, NaY and MCM-41 adsorbents was studied targeting for indoor air purification. The combined use of ozone and the various micro- or meso-porous adsorbents aimed to take advantage of the strong oxidizing capability of ozone. At the same time the residual ozone would be minimized due to the enhanced catalytic reaction in the porous structure. To lower the residual ozone level is a crucial issue as ozone is itself an indoor pollutant. The Lewis acid sites in the adsorbents were believed to decompose ozone into atomic oxygen, and the subsequent reactions would then convert the adsorbed toluene into CO 2 and H 2O. In the dry conditions, the MCM-41 required the smallest amount of material to achieve the 90% reduction target, followed by NaY and NaX. In the more humid environment (50% RH), extra amounts of MCM-41 and NaX adsorbents were required to reach the target as compared with the dry conditions. Desorption experiments were also conducted to study the amounts of various major species held in the adsorbents during the catalytic process. A material balance analysis of the major species in both the effluents and the adsorbents showed that within our experimental conditions, about 20–40% of the removed toluene was carried out via catalytic ozonation while adsorption covered the rest. Trace amount of intermediate species such as aldehydes and organic acids were identified in the desorbed gas indicating that they were withheld by the adsorbents during the air purification process and those in the effluent were below detection levels.
ISSN:1352-2310
1873-2844
DOI:10.1016/j.atmosenv.2007.12.030