Laboratory testing to control algae blooms by ultrasound

Abstract

An increased development of Cyanophyceae produced by eutrophication of the aquatic environments yields algae blooms and compounds with unpleasant odors and flavors as well as liberation of toxic metabolites. Excessive algae growth is also a problem for water that can be used for human consumption or industrial processes, but treatment for their removal leads to increases in operating costs. In this paper, the use of ultrasound to control algal blooms, in particular Cyanophyceae, at laboratory level is assayed. The results obtained (using a frequency of 20 kHz and a power of 9 W) show that organisms belonging to classes Chrysophyceae, Euglenophyceae and  Chlorophyceae were removed after 5 minutes of exposure, and Raphidiopsis mediterranean within the first 10 minutes, while reduction was 98% for M. aeruginosa and 99% for Dolichospermum spiroides after 60 minutes.