Algal bloom inhibition through cobalt nano particles to control Oscillatoria growth in fresh water lakes

Cobalt nano particles (CoNPs) were synthesized and tested against microalgae isolated from fresh water cyanobacterial blooms by assessing the effects on growth rate, biomass concentration and biochemical parameters. Oscillatoria was identified as the predominant isolate from algal blooms and treated with varying concentrations (1, 2, 3, 4 and 5 mg L-1) of CoNPs. Steady decline in the growth rate of microalgae was observed at the end of 5 days indicating the toxicity of CoNPs on microalgal growth. At the end of cultivation period, 88% of reduction in biomass concentration of Microcystis and Oscillatoria were observed at 5 mg L-1 of CoNPs. Both protein and carbohydrate contents of the microalgae were reduced with increasing concentration of nano particles. Based on the findings, this study demonstrates the efficiency of cobalt nano particles (CoNPs) on inhibition of fresh water algal blooms thereby reducing the eutrophication problem.