A stable emulsion was prepared by using dichloroethane as the dispersed phase and water as the continuous phase.Agglomeration and demulsification of the emulsion in ultrasonic standing wave field were studied.The factors affecting demulsification

such as ultrasound intensity

treating time

sedimentation time

ultrasonic frequency

were investigated.The results showed that the change of ultrasound directly affected the cohesion and dispersion of the particles

and ultrasound intensity should be lower than a critical value.The treating time also should be lower than a critical value.The equation for calculating the best ultrasonic frequency was proposed

and the experimental results verified the calculated best ultrasonic frequency.The orthogonal experiment was designed by considering energy consumption and demulsification efficiency.The optimum experimental conditions of the demulsification were ultrasonic frequency of 10 kHz，sound intensity of 270 W8226; m-2，irradiation time of 9 min，sedimentation temperature of 40℃ and sedimentation time of 3 h.Under the optimum experimental conditions

the demulsification efficiency could reach 91%.