Toxicity Effects of SiO2 Nanoparticles on Green Micro-Algae Dunaliella Salina

New extension of nanoparticles used in the last two decades and hence, entrance of them to industrialand non-industrial sewage necessitate study of probable effects of these materials in aquatic ecosystems.This research was performed in order to determine the toxicity effect of silica dioxide (SiO2) nanoparticles on Dunaliella salina green algae in laboratory conditions. SiO2 nanoparticle is one of the bestfull-used nano particles which have application in industries like production of ceramics, plastics, glass,cosmetics, medicine and paper. Dunaliella algae because of having economic value and differentbiochemical composition is used as complements with natural origin in food and pharmacologyindustries. For toxicity determination of this material, the experiment was performed according toO.E.C.D standard method. Experiments on Dunaliella were performed for 72 hours with 7 treatments,two controls and three replicates in each treatment and daily counting of cells in each tube. Countingcell algae population was done by microscope on a Thoma counting slide. For data analysis, probitanalysis, Excel software and SPSS21 were used. The 72 hours NOEC, EC90, EC50 and EC10 werecalculated. The amounts of 72 hours are EC10 =5.37.10-5 , EC50 = 0.169 , EC90 = 512.86, NOEC =1.6×10-2 mg/l. Cell compression noticeably decreased (P < 0.05) by increasing nanoparticleconcentration and silica oxide nanoparticle caused to inhibit growth in Dunaliella species.