Toxicity Study of Multiwalled Carbon Nanotubes on Freshwater Aquatic Algae

Nanotechnology based applications had been extended to almost all aspects of daily life, however, the ecotoxicity of nanomaterials especially multiwalled carbon nanotubes is not well studied. The present study, therefore, dealt with the evaluation of ecotoxicity of multiwalled carbon nanotubes (MWCNTs) against fresh water algae i.e., Chlorella which was collected from the authorised collection centre and maintained in the laboratory giving appropriate growth conditions. MWCNTs suspensions were prepared in various concentrations from 0.06 mg/ml to 0.24 mg/ml using algal test medium and further quantified by UV/Vis spectroscopy. It has been observed that with the increase of the concentrations of MWCNTs, the growth of algae and the lipid production decreases simultaneously. It shows 24.13% less growth and 5.06% less lipid production compare to control at maximum concentration of MWCNTs i.e., 0.24 mg/ml. Toxicity of MWCNTs was further confirmed through transmission and scanning electron microscopic images of algae.