Review of technologies for the control of harmful cyanobacteria and algal blooms in waterbodies, with emphasis in the use of ultrasound irradiation

Abstract

This review summarizes the advantages and disadvantages of methods of control of harmful algal and cyanobacterial blooms and/or their toxins in watercourses or in drinking water. In recent years, the blooming phenomena, or the excessive growth of cyanobacteria, have increased in extent and frequency around the world, involving increasingly higher environmental and health risks due to the potential production of toxins. In addition, the concomitant decrease in the levels of dissolved oxygen in waters cause effects on the ecosystems that could even lead to fish mortality events. The methods used to control and remediate the blooms range from chemicals to destroy the cells or they focus on reducing the concentration of phosphorus and other nutrients in the water and sediments, to biological based on predator-prey relationships, and to physical methods, aimed to attacking the cell structure, affect its buoyancy or their viability, including among them the ultrasound technology, of promising applicability, but requiring further research to evaluate its efficiency and safety. A reference is made to research plans undertaken in the framework of the LATU/Latitud Water Program, by using a commercial ultrasound irradiation equipment in a eutrophic pond.