title: Removal of high concentration dimethyl methylphosphonate in the gas phase by repeated-batch reactions using TiO2.
abstract: The aim of our study is to develop apparatuses that use TiO(2) for effective decontamination of air contaminated by Sarin gas. We performed photocatalytic decomposition of gaseous dimethyl methylphosphonate (DMMP) by TiO(2) and identified the oxidization products. The high activity of TiO(2) (0.01 g) was observed under UV-light irradiation and high concentration DMMP (33.5 microM) was removed rapidly. On the other hand, DMMP was not decreased under UV-light irradiation without TiO(2). This indicates that photocatalytic treatment is very effective for the removal of DMMP. Methanol, formaldehyde, formic acid, methyl formate, CO, CO(2) and H(2)O were detected as the primary products. In the gas phase, no highly poisonous substances were detected. In order to examine the performance of photocatalytic activity during long-term reactions, we performed photocatalytic decomposition by repeated-batch reactions using TiO(2). High photocatalytic activities decreased gradually. Meanwhile, the strong adsorption of TiO(2) against DMMP was observed as photocatalytic activities decreased. During the repeated-batch reactions with the sample scaled up (TiO(2): 0.1g), the total amount of removed DMMP reached 968.5 microM by both photocatalytic decomposition and the strong adsorption of TiO(2). These results suggest the possibility of removing large amounts of DMMP.
authors.affiliation: Research Institute for Environmental Management Technology, National Institute of Advanced Industrial Science and Technology (AIST), 16-1, Onogawa, Tsukuba, Ibaraki 305-8569, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Mera
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hirakawa
authors.forename: Taizo
authors.initials: T
authors.lastname: Sano
authors.forename: Koji
authors.initials: K
authors.lastname: Takeuchi
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Seto
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Negishi
mesh_terms: D000327:Adsorption; D000393:Air Pollutants / Q000737:chemistry* / Q000528:radiation effects; D002384:Catalysis; D000697:Central Nervous System Stimulants; D003666:Decontamination / Q000379:methods*; D005740:Gases; D009943:Organophosphorus Compounds / Q000737:chemistry* / Q000528:radiation effects; D055668:Photochemical Processes; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D000393:Air Pollutants; D000697:Central Nervous System Stimulants; D005740:Gases; D009943:Organophosphorus Compounds; C009495:titanium dioxide; C031116:dimethyl methylphosphonate; D014025:Titanium