title: Catalytic activities of zeolite compounds for decomposing aqueous ozone.
abstract: The advanced oxidation process (AOP), chemical oxidation using aqueous ozone in the presence of appropriate catalysts to generate highly reactive oxygen species, offers an attractive option for removing poorly biodegradable pollutants. Using the commercial zeolite powders with various Si/Al ratios and crystal structures, their catalytic activities for decomposing aqueous ozone were evaluated by continuously flowing ozone to water containing the zeolite powders. The hydrophilic zeolites (low Si/Al ratio) with alkali cations in the crystal structures were found to possess high catalytic activity for decomposing aqueous ozone. The hydrophobic zeolite compounds (high Si/Al ratio) were found to absorb ozone very well, but to have no catalytic activity for decomposing aqueous ozone. Their catalytic activities were also evaluated by using the fixed bed column method. When alkali cations were removed by acid rinsing or substituted by alkali-earth cations, the catalytic activities was significantly deteriorated. These results suggest that the metal cations on the crystal surface of the hydrophilic zeolite would play a key role for catalytic activity for decomposing aqueous ozone.
authors: Department of Life, Environment and Materials Science, Fukuoka Institute of Technology 3-30-1, Wajirohigashi, Higashi-ku, Fukuoka 811-0295, Japan.
authors: Ai
authors: A
authors: Kusuda
authors: Department of Life, Environment and Materials Science, Fukuoka Institute of Technology 3-30-1, Wajirohigashi, Higashi-ku, Fukuoka 811-0295, Japan. Electronic address: kitayama@fit.ac.jp.
authors: Mikito
authors: M
authors: Kitayama
authors: Department of Life, Environment and Materials Science, Fukuoka Institute of Technology 3-30-1, Wajirohigashi, Higashi-ku, Fukuoka 811-0295, Japan.
authors: Yoshio
authors: Y
authors: Ohta
mesh_terms: D002384:Catalysis; D018360:Crystallography, X-Ray; D057927:Hydrophobic and Hydrophilic Interactions; D007474:Ion Exchange; D010126:Ozone / Q000737:chemistry*; D011208:Powders; D013997:Time Factors; D014867:Water / Q000737:chemistry*; D017641:Zeolites / Q000737:chemistry*
chemical_list: D011208:Powders; D014867:Water; D017641:Zeolites; D010126:Ozone
keywords: advanced oxidation process; catalyst; hydroxyl radical; ozone; zeolite