A mathematical model of the ozonization of aqueous solutions of organic compounds in bubble columns is formulated in the paper. The model reflects both the effect of mass transfer resistance in the gas phase on the resultant process rate and the diffusion of ozone and organic compound with a simultaneous complex chemical reaction in the liquid phase. A numerical simulation of the model for various operating conditions for ozonization of aqueous phenol solution in the absorber with concurrent and cross flow of gas and liquid phases was carried out. Results of calculations for plug flow model of gas and ideal mixing and plug flow of liquid in the absorbers of equal length and heights were compared.