Kinetics of ceramic honeycomb-catalyzed ozonation for the degradation of trace nitrobenzene in aqueous solution

The experiment indicated that ozonation alone and ceramic honeycomb-catalyzed ozonation of trace nitrobenzene in aqueous solution followed the first-order kinetic model at the reaction temperature of 20°C and the initial pH of 6.87. Under the conditions of this experiment, ozonation alone and ceramic honeycomb-catalyzed ozonation for degradation of nitrobenzene were primarily oxidized by highly active hydroxyl radicals. At the same time, the experimental results demonstrated that the degradations were similarly the first-order reactions depending on different temperatures (10-40°C) and different pH (3.00-10.96). The rate constants of degradation of nitrobenzene in the two different processes mentioned above were found to increase with increasing of temperature. The rate constant of ozonation alone appeared to be increased from 0.37 × 10^-3 s^-1 to 1.49 × 10^-3 s^-1, respectively, increasing from 0.56 × 10^-3 s^-1 to 2.46 × 10^-3 s^-1 in the process of ceramic honeycomb-catalyzed ozonation. The higher the temperature of system, the less extent of the enhanced degradation rate. With the increase of pH, the rate constants of ozonation alone increased from 0.15 × 10^-3 s^-1 to 2.69 × 10^-3 s^-1, and increased from 0.17 × 10^-3 s^-1 to 1.90 × 10^-3 s^-1 in the process of ceramic honeycomb-catalyzed ozonation as pH increased from 3.00 to 9.23, but it decreased to 1.64 × 10^-3 s^-1 at pH 10.96.