The Application of Low-Frequency and Low-Power Ultrasound Algae Removal Technology in Pengxi River in Three Gorges Area

Abstract

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.