The application of low-frequency and low-power ultrasound algae removal technology in Pengxi River in Three Gorges Area

摘要

Three ultrasonic transmitters of single power of 50W, frequency of 20～50 kHz, 60～100 kHz and 100～150 kHz were used to remove bloom algae of Pengxi River in Three Gorges Area. The results show that algae are removed in some certain degree by 5 min's irradiation of low-frequency and low-power ultrasound, the process follows the first order reaction, and the rate constant is 0.0384 min~(-1). In this study, the optimal ultrasonic time is 5 min, the removal of algae density and Chlorophyll-a are about 15% and 7%, the optimal frequency are 20～50 kHz and 100～150 kHz respectively.