Sonochemical degradation which combines destruction of the target compounds by free radical reaction and thermal cleavage is one of the recent advanced oxidation processes (AOP) and proven to be effective for removing low concentration organic pollutants from aqueous streams. This work describes the degradation of several organic compounds of varying volatility in aqueous solution in two types of ultrasonic reactors. The process variables studied include initial concentration of the organics, temperature, and type of saturated gas. The effects of additional oxidant and electrolyte were also examined. A kinetic model was tested to determine its ability to predict the degradation rate constant of different volatile organic compounds at different initial conditions. A figure of merit for the electrical energy consumption for the two types of ultrasonic reactors is also presented.