Toxicity of Zinc Oxide Nanoparticles to Chlorella vulgaris and Scenedesmus dimorphus Algae Species

Abstract

Taking into consideration the increasing application of nanoparticles resulting to their entry into industrial and non-industrial wastes makes necessary to investigate on potential effects of these materials on aqueous environments. One of these common compounds is zinc oxide nanoparticle which as a ceramic absorbent material has different applications. In this research the effect of this nanoparticle is investigated on two algae species Chlorella vulgaris and Scenedesmus dimorphus. The appropriate experimental concentrations were determined by performing range-finding tests and the effect of each concentration (5 treatments and three replicates for each) of ZnO nanoparticle was studied during three time periods of 24, 48 and 72 hours against the control. The experiment was performed based on Organization for Economic Co- operation and Development (OECD) method. The number of algae cells was daily counted. Data analysis was performed using Probit analysis. The amounts of EC , EC , EC , No Observed Effect Concentration (NOEC), 10 50 90 specific growth rate, doubling time and percentage of growth inhibition were calculated. The amounts of cell density and growth inhibition in control were significantly different (p<0.05) from those intreatments of nanoparticle. 72h EC value is 0.01 mg/l for Chlorella and 0.09 mg/l for Scenedesmus. The sensitivity of 50 Chlorella species to ZnO nanoparticle is much more than Scenedesmus species.