Abstract
Recently, technique for the degradation of hazardous organic compounds has been investigated, and ultrasound has been investigated as one of the techniques for degradation of hazardous organic compounds. In this study, indirect ultrasonic irradiation method was applied to degradation process of phenol, the model hazardous organic compound. We focused on the effects of the relationship between ultrasonic transducer and reactor on degradation of phenol, radical generation and ultrasonic power inside the reactor. The degradation rate of phenol was influenced by reactor's position. And, the effect of reactor's position on the degradation rate overlapped with its effects on chemical efficiency estimated by KI oxidation dosimetry and ultrasonic power measured by calorimetry. The degradation rate of phenol was improved by TiO_2 particle addition, because the particle's surface area was considered to be working for OH radical formation by ultrasonic irradiation. On the other hand, the reactor's position influenced the degree of the improvement of the decomposition conversion by particle addition. When the particles are dispersed well, the surface area of particle is considered to be large. However, when a part of particles are agglomerated, the surface area of particle is considered to be small. Therefore, it is supposed that the dispersion condition of TiO_2 particles in the sample solution is influenced bv reactor's position.
