Treatment of Alexandrium Tamarense by Ultrasound Technology

Ballast water is one of the most important mechanisms for the introduction of non-indigenous organisms. The Alexandrium tamarense of representative phytoplankton in ship's ballast water, this paper studied its removal by adjusting different parameters, such as the power, irradiation time and duty cycle, so as to obtain the best optimization of ultrasound parameters. The treatment effect was verified by the observation, FDA staining, determination of chlorophyll a and re-training treatment. The results showed that Alexandrium tamarense were removed significantly by ultrasonic irradiation with optimal parameters at the input power of 500W and the exposure time of 3.5 min, the death rate of Alexandrium tamarense was 95%. The decay rate of chlorophyll is up to 98.6%. Therefore, the ultrasonic technology is an effective way to kill the Alexandrium tamarense.