Study on Excess Sludge Disintegration by Ultrasonic Treatment

The influences of ultrasonic time,ultrasonic frequency,ultrasonic power,ultrasonic pulse ratio,along w ith the interaction betw een ultrasonic time and frequency,time and pow er, pow er and frequency factors on the ultrasonic disintegration effect of excess sludge w ere studied by orthogonal test of mixed-level interaction. The results show that the optimal combination parameters of the ultrasonic disintegration sludge list as the ultrasonic time of 7 minutes,the ultrasonic frequency of 20 kHz,the ultrasonic pow er of 600 W,the ultrasonic pulse ratio of 3∶ 1, and the interaction effects among the three factors of the four are not obvious. It is found that appropriately improving the sludge concentration w ould gain a better disintegration effect after studying the seven different solid concentration liquor suspended sludge disintegrated by ultrasonic. The time curves of ultrasonic disintegration sludge indicate that the disintegrating rate of each index increases slow ly w hen the sludge is disintegrated after 40 minutes,and the highest energy utilization of ultrasonic disintegration sludge appears during 15 to 20 minutes.