CEST2025

The intensifying climate crisis strengthens freshwater scarcity and water pollution, heightening the urgency for innovative water management solutions. Cyanobacteria, commonly known as blue-green algae, contribute to this challenge by causing eutrophication events and producing harmful cyanotoxins in surface waters, driven by nutrient enrichment from agricultural and urban activities. The globally increasing cyanobacteria blooms threaten drinking water safety, aquatic ecosystems, and recreational water use. Cyanotoxins, such as microcystins and anatoxins, pose severe risks to human health, including liver damage, gastrointestinal issues, and neurological symptoms. Ozonation has emerged as a promising approach in water treatment, effectively disrupting cyanobacterial cells and degrading cyanotoxins simultaneously. This study investigates the sensitivity of different cyanobacteria species (Microcystis sp., Aphanizomenon sp., and Cylindrospermopsis sp.) and a green alga (Scenedesmus obliquus) to ozone exposure, determining optimal dosages for biomass disruption and assessing the influence of cell age on treatment outcomes. Experimental results reveal that cyanobacteria exhibit greater sensitivity to ozone than green algae, with a 4 mg/L dose effectively destroying cyanobacterial biomass and preventing recovery. Lower ozone doses impact cell vitality but allow recovery within three days. The age of the cultures also significantly affects their response to treatment, emphasizing the need for tailored ozonation strategies. These findings highlight ozonation's potential as a sustainable and efficient water treatment solution to mitigate cyanobacterial blooms, safeguarding water resources and public health.