Effects of clay on the growth of cyanobacteria under laboratory conditions

Increasing pollution and eutrophication in Vietnamese freshwater bodies promote the proliferation of cyanobacteria, particularly Microcystis and Anabaena, which may produce harmful microcystins. This study investigates the effects of different clay types and concentrations on the growth of Microcystis sp. and Anabaena sp. under laboratory conditions. Clay samples were characterized by pH, organic content, mineral composition, and surface morphology, while cyanobacterial growth was monitored over 30 days at clay concentrations of 5, 20, 80, and 200 mg/L. The results indicate that differences in kaolinite, illite, and montmorillonite contents influence the capacity of clay to aggregate and remove cyanobacterial cells. The findings support the potential use of clay as an environmentally friendly approach for controlling cyanobacterial blooms in freshwater bodies used for domestic water supply.