超声除藻的参数优化及其在太湖除藻中的应用

Parameters optimization of ultrasound algae removal technology and bloom removal study in Taihu Lake

设计、制备了一种低频超声除藻装置,通过调节超声频率、功率和辐射时间等不同的参数,得到优化的超声参数组合,并将该技术应用于太湖除藻的现场研究.结果表明:当超声参数组合为频率20kHz,功率40W,辐射时间15s时,具有较好的实验除藻效果.在太湖现场实验中,载有超声除藻装置的实验船在400m2实验区域作用1h后,水表层的藻细胞由107个/mL降低到105个/mL,透明度由0cm上升为35cm,叶绿素a含量降低为初始浓度的3.3%,水质得到明显改善.这说明超声处理对藻类生长有显著的抑制作用,尤其适于水华发生期间的应急处理.

A kind of algae removal equipment with low frequency ultrasound was designed. The algae removal effects of ultrasound technology with different parameters combination of frequency, power and treatment time were experimentally verified. The equipment with optimal parameters was applied in Taihu Lake with an area of 400 m^2. The results show that algae are removed significantly by ultrasonic irradiation with optimal parameters at the frequency of 20 kHz, the input power of 40 W and the exposure time of 15 s. In the field study of Taihu lake, after one hour ultrasound treatment, the algae density dropped rapidly from 10^7 cells/mL to 10^5 cells/mL. Besides, the water diaphaneity was raised from 0 cm to 35 cm and the concentration of Chlorophyll a remained 3.3% of the initial value. It can be concluded that the ultrasonic technology is effective in algae removal, especially in the period of bloom outbreak.