Pumice-supported ZnOOH catalyst, taking zinc nitrate salt as precursor substance, was prepared by incipient wetness impregnation to enhance the catalytic ozonation capacity of pumice. Catalytic ozonation of p-chloronitrobenzene (p-CNB) in aqueous solution was conducted, wherein pumice and ZnOOH-pumice were used as the catalysts. The catalyst showed significant catalytic activity in the decomposition of p-CNB in aqueous solution. It was found that the processes of ozonation/ZnOOH-pumice and ozonation/pumice could increase the removal efficiency of p-CNB by 93.4 % and 72.1 %, respectively, compared with that achieved by sole ozonation. tert-Butyl alcohol remarkably increases the removal efficiency of catalytic p-CNB ozonation, which suggests that p-CNB degradation follows the mechanism of hydroxyl radical (·OH) oxidation. Catalytic ozone decomposition and ·OH captured show that ZnOOH-pumice catalyzed ozone generates the highest ·OH concentrations under the present experimental conditions compared with that obtained from the ozone/pumice and ozone-alone systems. Different water qualities show a very strong influence on the catalytic ozonation of p-CNB. From a practical point of view, ZnOOH-pumice shows promise for use in water treatment because it retains its catalytic activity for up to ten successive cycles and the residual ion content was minimal after catalytic ozonation.