Degradation of Diethyl Phthalate by Sono-Fenton Process and its Dependence on the Power Density

The first-order rate constants of diethyl phthalate (DEP) degradation by sonochemical, Fenton and sono-Fenton processes were compared, and the synergistic effect of the combined sono-Fenton process and the dependence of the degradation rate on the power density (80, 180, and 330 W L(-1)) were investigated. The rate constants for the individual sonochemical and Fenton processes were 10(-3) to 10(-2) and 1.02 x 10(-2) min(-1), respectively. The synergy from the combined process increased significantly as the applied power density increased, and it was 1.97 with the input of ultrasonic energy of 330 W L(-1). This increase was attributed to the higher efficiency of hydroxyl radical production from several pathways. The relationship between the degradation rate constant and power density was linear because the cavitation rate increased with increasing power level of the applied ultrasound. (C) 2011 The Japan Society of Applied Physics