Silicon-modified ferric hydroxide for catalytic ozonation of nitrobenzene in aqueous solution

Si–FeOOH heterogeneous catalytic ozonation has been effectively used to degrade Nitrobenzene (NB) in the wastewater treatment facilities. Based on the experimental results and theoretical analysis, the mechanism of catalytic ozonation was investigated in this study. Results show that the introduction of Si-FeOOH as a catalyst is beneficial to the enhancement of NB degradation compared with ozonation alone. The addition of Si was to improve the physical and chemical properties of FeOOH. The efficiency of NB degradation by Si-FeOOH/O3 could reach 81.2% after 20 min of reaction time at pH 7, 25°C, 1.0 mg/L of O3, 0.33 of Si/Fe molar ratio and 500 mg/L dosage of Si–FeOOH. Moreover, the assumption is that the enhanced NB degradation should be, substantially, attributed to hydroxyl radicals generated with the interaction of hydroxyl groups on the surface of catalyst and ozone, which was verified by the presence of t-BuOH.