[Effect of organic compounds on the degradation of nitrobenzene in aqueous solution by catalytic ozonation].

We investigated the effects of organic compounds on the processes of ozonation alone and ceramic honeycomb-catalyzed ozonation for the degradation of nitrobenzene in aqueous solution, including formaldehyde, methanol, formic acid and dibutyl phthalate. The results indicated that degradation rate of ozonation alone and ceramic honeycomb-catalyzed ozonation decreased by 11.6% and 9.6% with the increase of the concentration of formaldehyde (0-12 mg x L(-1)). The degradation rates of the two processes both increased firstly and decreased subsequently with the increase of the concentration of methanol (0-16 mg x L(-1)). The degradation rate of ozonation alone reached the climax at the concentration of methanol 2 mg x L(-1), and that of ceramic honeycomb-catalyzed ozonation reached the culmination at the concentration of methanol 4 mg x L(-1) under the same experimental condition. With the increase of the concentration of formic acid (0-8 mg x L(-1)), the degradation rates also increased firstly and decreased subsequently, and those of ozonation alone and ceramic honeycomb-catalyzed ozonation reached the vertex, respectively, at the concentration of methanol 0.5 mg x L(-1) and 2 mg x L(-1). At the lower concentration, methanol and formic acid could accelerate the degradation of nitrobenzene, however, the reaction was retarded at higher concentrations of methanol and formic acid. The degradation rates of ozonation alone and ozonation/ceramic honeycomb both declined by 19.7% and 18.6% with the increase of the concentration of dibutyl phthalate (0-10 mg x L(-1)).