Effects Of C₆₀ Nanocrystallines On Algae In Aqueous System

C₆₀ as a typical carbon-based nanomaterial,is widely used in many fields such as material science,pharmaceuticals and catalysis,and the predicted quantities of C₆₀ being released into the environment is increasing.Although C₆₀ nanoparticles are not easily dissolved in aqueous system,it can form stable suspension of C₆₀ nanocrystallines(nC₆₀),which would pose potential threats to living creatures in water bodies.This research prepared nC₆₀ by extended stirring method and posed it on three kinds of algaes（Scenedesmus obliquus,Chlorella and Microcystis aeruginosa）to investigate the effects.We also studied the environmental factors such as p H,NOM,ionic strength of their roles during the interaction process.At last,we invesgated the bioaccumulation of nC₆₀ in the Scenedesmus obliquus and the mechanism by the metabonomics method.Results have shown that: 1)nC₆₀ has two kinds of effects on the growth of Scenedesmus obliquus;it situmulate the growth of Chlorella;and it inhibite the growth of Microcystis aeruginosa.The inhibition of growth on Scenedesmus obliquus increased with the higher concentration of nC₆₀.2)We investigated the factors influencing the biological effect of nC₆₀ in aqueous system,and found that the ionic strength and NOM would facilitate the aggregation process of nC₆₀ in water environment,thus decrease the concentration of dispersed n nC₆₀ in water and facilitate the growth of Scenedesmus obliquus.But p H did not have such obvious effect.3)nC₆₀ accumulated in the algae and the concentration of it in the solution would decrease to a homeostasis.Long-term study shows that in the first few days after entering the water environment,nC₆₀ inhibited the growth of algae due to the high concentration of dispersed nC₆₀.As time goes by,nC₆₀ colloid would gradually aggregate and the concentration of dispersed nC₆₀ would decrease to a limit,under which the algae exposed in the hazardous environment reacted to the stress by the growth in the amount of cells.4)Studied the mechanism on nC₆₀ reacted on Scenedesmus obliquus by metabolomics method,we found that stress reaction of nC₆₀ will induce the concentration of L-proline to resist the effect;the low concentration of nC₆₀ will situmulate the fatty acid to be produced which will promote the growth of Scenedesmus obliquus;while the high concentration of nC₆₀ will lead to the higher concentration of L-Lysine which can give algae the programmed cell death.The research examined the effect of nC₆₀ on algaes,discussed the influence of different factors on the biological effect and studied the mechanism,whichis of significance for the evaluation of the ecological risks of nC₆₀ nanocrystallines in aqueous system.