Sonochemistry of organic compounds in homogeneous aqueous oxidising systems

The influence of ultrasound on the degradation of trichloroethylene, o-chlorophenol and 1,3-dichloro-2-propanol in some Fenton type aqueous systems was investigated. Kinetic analysis of the results revealed that the ultrasonic waves do not really enhance the reactivity of the system, but rather add their own degradation mechanism to the chemical degradation. This effect is comparable to the well known sonochemical switching effect. As a consequence, the degradation rate of the combined systems is the sum of the pure sonochemical degradation rate and the silent chemical degradation rate. The only exception to this rule is the degradation of o-chlorophenol in the presence of hydrogen peroxide, in the absence of catalysts. Care had to be taken in order to avoid artifacts that may arise, e.g., when neglecting temperature effects.