OZONATION OF ORTHO-CRESOL IN AQUEOUS-SOLUTIONS

The o-cresol aqueous solution ozonation of concentrations similar to those encountered in some wastewaters has been studied. The degradation rate of o-cresol is increased with temperature, pH, gas flow rate, agitation speed and ozone partial pressure. For a 10-3 M initial concentration of o-cresol a mass rate of 11.7 mg of ozone per minute leads to o-cresol conversions of about 70% in less than 20 min of ozonation, the kL a of the reactor being between 2.8 and 13.0 h-1. From the variation observed in the o-cresol ozonation yield with time a competitive effect of secondary reactions has been shown. The ozone absorption rate was always higher than 3 times the maximum ozone absorption in organic-free water (value defined as reaction factor). This fact indicates that the reactions involved develop in the proximity of the gas-liquid interface and the kinetic regime is fast. © 1990.