Adsorption and decomposition of water-dissolved ozone on high silica zeolites.
The adsorption properties of water-dissolved ozone on high silica zeolites were investigated. Adsorbed ozone was desorbed almost reversibly. The adsorption equilibrium relations were described by a linear expression written as q=betaC, where q is the amount adsorbed, C is the equilibrium concentration and beta is the equilibrium constant. Also, the beta values were strongly dependent on the SiO(2)/Al(2)O(3) ratio (mol/mol) and on the pore structure of the high silica zeolites. The larger the SiO(2)/Al(2)O(3) ratio, the larger the value of beta. ZSM-5 (SiO(2)/Al(2)O(3) ratio: 3000), which gave the highest adsorption capacity of water-dissolved ozone, was able to highly concentrate water-dissolved ozone on the adsorbent. The decomposition behavior of adsorbed ozone was also investigated. Ozone adsorbed on high silica zeolite was observed to be a little more stable than ozone existing in bulk water. The decomposition rate was independent of SiO(2)/Al(2)O(3) ratios in the range of 30-3000 or a solution pH in the range of 4-6.
Fujita
Hirotaka
H
Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan. 830sho@iis.u-tokyo.ac.jp
Izumi
Jun
J
Sagehashi
Masaki
M
Fujii
Takao
T
Sakoda
Akiyoshi
A
D000327:Adsorption; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D012822:Silicon Dioxide / Q000032:analysis / Q000737:chemistry; D012995:Solubility; D014865:Waste Disposal, Fluid / Q000379:methods*; D014867:Water / Q000737:chemistry; D017641:Zeolites / Q000737:chemistry*
D014867:Water; D017641:Zeolites; D010126:Ozone; D012822:Silicon Dioxide