Ozonation of aqueous phenol using high‐silica zeolite in an aerated mixing vessel

We examined the degradation of aqueous phenol by ozonation in an aerated mixing vessel, which was combined with a fixed‐bed reactor packed with high‐silica zeolite (HSZ) pellets. Ozone‐containing oxygen gas was introduced as fine bubbles through a sparger placed in the aerated mixing vessel, whereas the aqueous phenol solution was circulated between the vessel and the reactor. Measurements of transient changes in the concentration of both phenol and total organic carbon in the treated solution revealed that the degradation of phenol or total organic carbon by ozonation was enhanced by the presence of HSZ because both phenol and ozone could adsorb on the hydrophobic micropores. As a result of quantitative analysis of the treated solution, it was found that catechol, hydroquinone, humic acid, and maleic acid were the possible reaction intermediates during ozonation of aqueous phenol employing HSZ.