A hydrothermal sonochemical reactor has been developed as a new approach to the hydrothermal treatment of aqueous wastes. At 2.8 MPa and 220 degreesC, acetic acid degradation reached 83% for a space time in the reactor of 10 min. The ultrasonic activation increased the yield of the acetic acid oxidation reaction by 40%. Furthermore, tests with an industrial waste containing salts and halogens showed the performance of the titanium liner of the sonochemical reactor for overcoming salt precipitation and corrosion. The hydrodynamic study of the reactor from the residence time distribution (Rtd) determination gave access to sonochemical reactor modeling from a battery of three continuously stirred tank reactors.