Degradation of aqueous phenol by simultaneous use of ozone with silica-gel and zeolite

Phenol in water was degraded by simultaneous use of ozone and silica-gel or zeolite. When Al2O3-supported silica-gel or TiO2-supported silica-gel was conjugated with ozonation, the phenol degradation was significantly enhanced, although raw silica-gel did not show such effect. When zeolite was conjugated with ozonation, phenol degradation was significantly enhanced as well. The ion-exchange of Na+ in zeolite by Ni2+ or Co2+ and supporting metallic Ni or Co thereon did not show significant influence on this effect.